tnt2012 abstract book

© 2011 FEI Company. We are constantly improving the performance of our products, so all specifications are subject to change without notice.

Learn more at FEI.com

For over 60 years, FEI has been a global leader in focused

electron and ion beam microscopy technologies. From the

most powerful, commercially-available microscope, the

Titan™ G2 60-300 S/TEM, to the Magellan™, the first extreme

high resolution (XHR) SEM, FEI produces innovative imaging

solutions for the material science, life science, electronics and

natural resource markets, revolutionizing your exploration and

discovery at the nanoscale.

Your Journey to

the Nanoscale

Begins Here

TNT2012 i

nd

ex

Foreword 02

Committees 04

Poster awards 05

Sponsors 06

Exhibitors 07

Speakers 13

Abstracts 27

Posters list 203

Image credit: Atomic motion tracks newly presented by merging the STM images before and after X-ray irradiation.

Akira Saito (Osaka University and RIKEN SPring-8 Center, Japan)

2 | s e p t e m b e r 1 0 - 1 4 , 2 0 1 2 T N T 2 0 1 2 m a d r i d ( s p a i n )

On behalf of the International, Local and Technical Committees, we take great pleasure in welcoming you to Madrid (Spain) for the 13th “Trends in NanoTechnology” International Conference (TNT2012). TNT2012 is being held in large part due to the overwhelming success of earlier TNT Nanotechnology Conferences and will be organised in a similar way to the prior events. This high-level scientific meeting series aims to present a broad range of current research in Nanoscience and Nanotechnology worldwide, as well as initiatives such as EU/ICT/FET, MANA, CIC nanoGUNE Consolider, etc. TNT events have demonstrated that they are particularly effective in transmitting information and promoting interaction and new contacts among workers in this field. Furthermore, this event offers visitors, exhibitors and sponsors an ideal opportunity to interact with each other. One of the main objectives of the Trends in Nanotechnology conference is to provide a platform where young researchers can present their latest work and also interact with high-level scientists. For this purpose, the Organising Committee provides every year around 60 travel grants for students. In addition, this year, 9 awards (2400 Euros in total) will be given to young PhD students for their contributions presented at TNT. More than 40 senior scientists are involved in the selection process. Grants and awards are funded by the TNT Organisation in collaboration with several governmental and research institutions.

TNT is now one of the premier European conferences devoted to nanoscale science and technology. We are indebted to the following Scientific Institutions, Companies and Government Agencies for their financial support: Phantoms Foundation, Escuela Técnica Superior de Ingenieros Industriales (ETSII Madrid), Universidad Politécnica de Madrid (UPM) / Campus de Excelencia Internacional, Instituto de Fusión Nuclear (IFN), Fundación para el Fomento de la Innovación Industrial (F2I2), Donostia International Physics Center (DIPC), CIC nanoGUNE, Universidad Autónoma de Madrid (UAM), Instituto Español de Comercio Exterior (ICEX) & “españa-technology for life” program, NIMS (Nanomaterials Laboratory) and MANA (International Center for Materials and Nanoarchitectonics), Institute for Bioengineering of Catalonia (IBEC), FEI, nanotec Red, Tecnan, Carl Zeiss Microscopy, European Physical Society (EPS), AtMol Integrated Project (EU/ICT/FET) and Viajes El Corte Inglés. We would also like to thank the following companies and institutions for their participation: nanotec Electronica, nanotec Red, Raith, nanoimmunotech, IOP Publishing, Schaefer Techniques, Omicron Nanotechnology, NanoInnova Technologies, MONCLOA Campus of International Excellence, ICEX, Irida, Renishaw, Techno Fusión and UAM+CSIC Campus of International Excellence. In addition, thanks must be given to the staff of all the organising institutions whose hard work has helped planning this conference.

F

or

ew

or

d

T N T 2 0 1 2 m a d r i d ( s p a i n ) s e p t e m b e r 1 0 - 1 4 , 2 0 1 2 | 3

Image credit: SEM image of PVDF nanostructures prepared by solution template wetting. Mari Cruz García-Gutiérrez (IEM-CSIC, Spain)

O

rg

an

isin

g C

om

mit

te

e


TNT2012 Committees

Organising Committee

Jose-Maria Alameda (Universidad de Oviedo, Spain)

Masakazu Aono (MANA, NIMS, Japan)

Robert Baptist (CEA / DRT / LETI, France)

Xavier Cartoixa (UAB, Spain)

Antonio Correia (Phantoms Foundation, Spain) –

Conference Chairman

Pedro Echenique (DICP / UPV, Spain)

Jose Maria Gonzalez Calbet (UCM, Spain)

Uzi Landman (Georgia Tech, USA)

Alfonso Lopez (Grupo Atenea, Spain)

Jose Manuel Perlado Martin (IFN-ETSII / UPM, Spain)

Jose Maria Pitarke (CIC nanoGUNE Consolider, Spain)

Ron Reifenberger (Purdue University, USA)

Jose Rivas (INL, Portugal)

Juan Jose Saenz (UAM, Spain)

Josep Samitier (IBEC - Universitat de Barcelona, Spain)

Frank Scheffold (University of Fribourg, Switzerland)

Didier Tonneau (CNRS-CINaM, France)

International Scientific

Committee

Masakazu Aono (MANA / NIMS, Japan)

Emilio Artacho (CIC nanoGUNE Consolider, Spain)

Andreas Berger (CIC nanoGUNE Consolider, Spain)

Fernando Briones (IMM / CSIC, Spain)

Remi Carminati (Ecole Centrale Paris, France)

Jose-Luis Costa Kramer (IMM / CSIC, Spain)

Antonio Garcia Martin (IMM / CSIC, Spain)

Raquel Gonzalez Arrabal (IFN-ETSII / UPM, Spain)

Pierre Legagneux (Thales, France)

Annick Loiseau (ONERA - CNRS, France)

Stefan Roche (ICN and CIN2, Spain)

Josep Samitier (IBEC - Universitat de Barcelona, Spain)

Technical Committee

Carmen Chacón Tomé (Phantoms Foundation, Spain)

Viviana Estêvão (Phantoms Foundation, Spain)

Maite Fernández Jiménez (Phantoms Foundation, Spain)

Paloma Garcia Escorial (Phantoms Foundation, Spain)

Pedro Garcia Mochales (UAM, Spain)

Adriana Gil (Nanotec, Spain)

Carlo Guerrero (IFN-ETSII / UPM, Spain)

Conchi Narros Hernández (Phantoms Foundation, Spain)

Joaquin Ramon-Laca (Phantoms Foundation, Spain)

Jose-Luis Roldan (Phantoms Foundation, Spain)

Local Organising

Committee

Carlos Conde Lázaro (UPM, Spain) –

Conference Honorary Chairman

Jesus Felez (ETSII / UPM, Spain)

Gonzalo Leon (UPM, Spain)

Jose María Martínez Val (F2I2, Spain)

Emilio Minguez (UPM, Spain)


TNT2012 Poster awards

Funded by Award

NIMS / MANA 300 Euros300 Euros300 Euros300 Euros

IBEC 300 Euros300 Euros300 Euros300 Euros

European Physical Society 250 Euros250 Euros250 Euros250 Euros

Phantoms Foundation Digital Video CameraDigital Video CameraDigital Video CameraDigital Video Camera



David Prize Private donation 300 US Dollars300 US Dollars300 US Dollars300 US Dollars

Keren Prize Private donation 300 US 300 US 300 US 300 US DollarsDollarsDollarsDollars

TNT 2012 Organisation Free registration to the Free registration to the Free registration to the Free registration to the

2013 2013 2013 2013 ConferenceConferenceConferenceConference


TNT2012 Sponsors

Platinum Sponsor

Sponsors


TNT2012 Exhibitors

page page page page 8888

page 8page 8page 8page 8









ppppageageageage 11111111





TNT2012

E

xh

ibit

or

s

Nanotec Electronica is one of the leading companies in the Nanotechnology Industry. In only ten years Nanotec Electronica has established itself as one of the strongest companies that design, manufacture and supply Scanning Probe Microscopes (SPM). Our highly qualified team uses cutting-edge technology in order to provide a cost-effective tool to gain access to the nanometer scale for both scientific and industrial communities. With its headquarters based in Spain and distributors located around the world, Nanotec ensures global presence and guarantees total customer satisfaction. Nanotec´s Cervantes FullMode Atomic Force Microscope (AFM) in its several configurations allows not only imaging samples with atomic precision but also the study of magnetic, electronic and mechanical properties at the nanoscale, making it a powerful tool for physicists, chemists, biologists and engineers willing to characterize their samples at the nanometer scale. Its robust design provides strong mechanical stability to ensure high imaging resolution, and its semi-automated and open design allows scientists to exploit the capability of SPM to its maximum for both research and academic purposes. Nanotec Electronica also provides Dulcinea Control Systems, with an open and modular design that facilitates interfacing with any other standard AFM/SNOM/STM system available in the market. Highly versatile, it allows different modes of operation from Contact Mode to Frequency Modulation Mode and lithography ensuring a reliable and accurate performance of all SPM systems. Nanotec has also developed and freely distributes SPM software WSxM. Its user-friendly interface ensures easy operation of SPM microscopes and data processing. WSxM is available for its free download at www.nanotec.es. If you have any questions, or want any information about Nanotec Electronica, please contact us at: Nanotec Electronica

Centro Empresarial Euronova 3 Ronda de Poniente 12, 2º C 28760 Tres Cantos (Madrid) SPAIN Tel: +34-918043347 www.nanotec.es

Nanotec Red with offices in Spain, Argentina, Brazil, and the USA is dedicated to the transfer of Nanotechnology solutions to the retail sector, industrial companies, big and SME companies, and government entities in Spanish speaking countries.

Our team of experts is in constant contact with companies and government entities interested in embracing advanced technology to achieve their objectives and they rely on Nanotec Red to find the best solutions.

Talk to Nanotec Red if you want representation in these countries representing over 500MM people and thousands of companies that will adopt Nanotechnology over the coming 10 years. Rely on us, this is a great opportunity, don't let it pass.

Nanotec Red

Via Augusta 252 , planta 4, puerta A 08017 Barcelona España Tel: (+34) 902 009 469 Email: [email protected] Web: www.nanotecred.com

Raith manufactures high performance electron and ion beam lithography tools for nanotechnology applications in research and development. Raith tools are designed to meet the needs of researchers, designers, and engineers in both university and industry settings. Raith nanolithography products range from stand alone electron or ion beam lithography and nanoengineering tools (RAITH150TWO, e_LiNEplus, PIONEER, ionLiNE) to retrofit lithography attachments for SEM or SEM/FIB systems (ELPHY MultiBeam, ELPHY Plus, ELPHY Quantum). Raith electron beam lithography tools are in use throughout the world. Customers such as ST Microelectronics, The Massachusetts Institute of Technology in Boston or the IBM Research Centre are among the Raith clientele. The Raith ELPHY pattern generator family has become a standard for SEM and FIB based nanolithography during past 30 years. Raith GmbH

Exhibit Contact: Andreas REMSCHEID Konrad-Adenauer-Allee 8 - PHOENIX West 44263 Dortmund- Germany Phone: +49 (0)231 / 95004 - 0 Fax: +49 (0)231 / 95004 - 460 E-mail: [email protected] / [email protected] Web: www.raith.com


TNT2012

E

xh

ibit

or

s

nanoimmunotech is the first European company specialized in the functionalization, biological and physico-chemical characterization of nanoparticles. Our main area of activity is focused on biomedical, pharmaceutical and biotechnology companies, cosmetic, veterinary and agro-food market and research groups interested in the use of nanostructures with potential biotechnological applications. nanoimmunotech main objective is to become a world leader in Functionalization and Characterization of nanometric systems, offering products and services within the Biotechnology and Health sectors. The company has highly qualified and internationally recognized human resources, state-of-the-art laboratory capabilities, standardized protocols and finally, the know how to perform proper supervision, advice and validation of different nanosystems, as a first step to the previous use of nanoparticles in biotechnological applications. nanoimmunotech

Anaïs Normand Marketing Department Edificio Cero Emisiones Avenida de la Autonomía 7 50003 Zaragoza, Spain Mobile: (+34) 610 182 755 Phone: (+34) 876 440 071 Fax: (+34) 876 440 200 Email: [email protected] Website: www.nanoimmunotech.es

IOP Publishing provides publications through which leading-edge scientific research is distributed worldwide. Since launch we have expanded rapidly to become one of the leading international STM publishers. We have a global reach, with offices in Philadelphia, Washington DC, Mexico City, Munich, Moscow, St. Petersburg, Wroclaw, Beijing and Tokyo as well as Bristol and London in the UK Web: http://publishing.iop.org/

Schaefer Techniques has a long history as a supplier of high performance and reliable scientific instruments. We provide a wide range of products in the fields of vacuum technology, scanning probe microscopy, surface and materials analysis. During the TNT conference, we will present mainly four different products:

1. TT-AFM from AFM Workshop: the TT-AFM is a complete and affordable AFM for nanotechnology researchers, instruments innovators and teachers. Right out of the box, the TT-AFM includes all standard modes such as contact, dynamic, phase and lateral forces. All I/O electronic signals are accessible from rear panel connectors. With an open design, the LabView-based software is ready for custom applications.

2. GBS smartWLI product family, white light interferometers: Two economical microscopes called smartWLI-Basic and smartWLI-Extended as well as an upgrade to existing microscopes called smartWLI-microscope are available. The strength of these instruments is the economical price as well as an extremely fast calculation algorithm which makes them the fastest WLI on the market! smartWLI allows non-contact measurement with nanometer accuracy.

3. RHK Technology: RHK manufactures and supports customized, integrated UHV AFM/STM Systems and Controls used by University and Government Labs worldwide for advanced surface science research. RHK products include the new all-digital, ultra-fast, ultra low-noise R9 Universal SPM Controller; multi-purpose Beetle VT (25-1500 K) AFM/STM; rugged PanScan LT AFM/STM for mK and high-Tesla applications; sophisticated QuadraProbe LT AFM/STM 4-Probe (<6 K) for electrical measurements and transport studies; and specialized Prep/Analysis chambers and instruments.

4. Alemnis: In-situ SEM Indenter. Alemnis is specialized in developing, manufacturing and integrating customized instruments and tools for mechanical characterization and manipulation in all kinds of micro- and nanotechnology applications. The in-situ indenter is a compact test platform for in-situ materials characterization. It has been developed to work inside scanning electron microscopes as well as other types of microscopes. It includes long-range stick-slip piezoelectric actuators to position and test the samples with nanometer resolution.

Schaefer Techniques

1, rue du Ruisseau Blanc F-91620 NOZAY Tel : +33(0)1 64 49 63 50 e-mail : [email protected] Web : www.schaefer-tec.com


TNT2012

E

xh

ibit

or

s

Nanotechnology has been our everyday business since long before the term ever existed.

Founded in 1984 by Norbert Nold, Omicron started business by introducing the SPECTALEED and the legendary Ultra High Vacuum STM 1 as their first and highly successful products. The STM 1, which still delivers state-of-the-art performance even by today's standards in nearly 200 laboratories worldwide, firmly established Omicron's present position as the world market leader in UHV scanning probe microscopy.

Today, our products like, for example, the new NanoESCA or the UHV Gemini Column are right at the forefront of research. We are used to redefining the limits of the technically feasible again and again. More than 500 articles demonstrate this to the full. Many of them were published in leading journals such as Nature, Science, Physical Review Letters or Chemical Review Letters.

Omicron NanoTechnology GmbH

Limburger Str. 75 65232 Taunusstein Germany Tel: 06128/987-0 / Fax: 06128/987-185 email: [email protected] web: www.omicron.de

NanoInnova Technologies SL (www.nanoinnova.com) is a spin-off company of the Universidad Autónoma de Madrid. NanoInnova Technologies designs, develops and commercializes Chemical Vapor Deposition (CVD) instruments for bottom up graphene synthesis and chemically modified graphene.

A range of raw materials such as graphene oxide, reduced graphene oxide, Palladium (0) nanoparticles supported in reduced graphene oxide, etc, are part of the Nanoinnova Technologies SL portfolio. Nanoinnova Technologies SL is involved in the development and commercialization of new catalyst for fine chemical transformations such as cross coupling reactions, nanostructured modification of electrodes, new stationary phases in purification and new supports and functionalities of biomolecules.

Nanoinnova Technologies SL

Science Park of Madrid C/Faraday 7 28049-Madrid Tel: +34 918317366 Web: www.nanoinnova.com Email: [email protected]

This ambitious project is presented jointly by the Complutense and the Technical Universities of Madrid, together with other partner institutions located in the Campus such as the CIEMAT, the CSIC and the INIA. Its main purpose is to transform the Campus of Moncloa into an international reference regarding research, education and innovation. The project is structured as a collaborative agreement between the integrating institutions to achieve scientific excellence and internationalization; to guarantee connectivity and integration; to make the Campus a sustainable system that will boost student employment and contribute to innovation and development. Our aim is to create a plural and participatory campus, fuelled by the transforming power of diversity, exchanges and dialogue; an efficient and transparently-governed university campus, open to all its members and to all its partner institutions, as well as to the interaction with the social, economic and cultural fabric. The Campus commits itself to a specialization into six thematic clusters to achieve scientific and teaching excellence:

• Global Change and New Energies • Materials for the Future • Agriculture, Food Industry and Health • Innovative Medicine • Heritage • Sustainable mobility

The distinctive strengths in each of them converge to create unique configurations marked by their innovative and interdisciplinary character, being not only highly competitive at the European level, but also capable of producing a significant progress in the transfer of knowledge. Campus de Excelencia Internacional: Campus Moncloa

CEI Campus Moncloa Office Royal Botanic Gardens Building, Alfonso XIII Ciudad Universitaria 28040 Madrid, Spain www.campusmoncloa.es


TNT2012

E

xh

ibit

or

s

Irida Iberica is one of the youngest but most dynamic nanotechnology instruments providers in Spain. We introduce novel techniques and the best technological solutions for most of the nanotechnology applications challenges. Irida offers a unique value to price combination for a wide variety of surface analysis products like Optical Profilers or Atomic Force Microscopes, as well as the most versatile configurations for material science and biological samples analysis. Our products, manufactured by world leading companies, are some of the most sophisticated instruments in the market because of their cutting edge technology. But it is our service department that makes the difference because is what gives our clients the security of a nonstop research or production work.

Irida Iberica S.L.

Diligencia 9 28108 Madrid, Spain Tel. +34911130824 Email: [email protected] Web: www.irida.es

Renishaw is a global company with core skills in measurement, motion control, spectroscopy and precision machining. We develop innovative products that significantly advance our customers' operational performance - from improving manufacturing efficiencies and raising product quality, to maximising research capabilities and improving the efficacy of research procedures.

Renishaw manufactures a wide range of optical spectroscopy products, including: Raman microscopes, Raman analyzers for scanning electron microscopes, combined systems for Raman/SPM measurements etc...Recent developments in ultra-fast imaging enables you to produce Raman chemical images far faster than has been possible before. Raman images that used to take hours to produce can now be created in minutes. This technology is perfectly suited to carbon measurements for Nanotechnology (Graphene, Carbon Nanotubes etc...)

Renishaw Ibérica, S.A.U.

Gavà Park C. Imaginació, 3 08850 GAVÀ Barcelona Email: [email protected] Web: www.renishaw.es

The TechnoFusión project, currently in a preparatory study phase, involves the construction of a Singular Scientific-Technical Facility (National Centre for Fusion Technologies - TechnoFusión) in the Region of Madrid, Spain, creating the required infrastructure for the development of the technologies required for future commercial fusion reactors, and assuring participation by Spanish research groups and companies. The performance of materials and components under the extreme conditions of a fusion reactor is largely unknown. For this purpose, facilities are required for the manufacture, testing and analysis of critical materials. Additional resources will be needed to develop and exploit numerical codes for the simulation of materials in special environments, to develop remote handling technologies and other areas related to the management of liquid metals used in several components of the reactor. TechnoFusión Scientific-Technical Facility will consist of a complex of seven large research areas related to fusion technologies: material production and processing, material irradiation, plasma-wall interaction studies, liquid metal technologies, material characterization techniques, remote handling technologies and computer simulation. Many of these technological areas will be unique in the world. The goal of TechnoFusión is to bring together sufficient human and material resources to contribute significantly to the development of a safe, clean, and inexhaustible source of energy for future generations. Web: www.technofusion.es


TNT2012

E

xh

ibit

or

s

UAM (Universidad Autónoma de Madrid, with 2500 teaching staff and 34000 students) and CSIC (Spanish National Research Council, that has in UAM's campus four institutes and five mixed UAM+CSIC institutes, with a research staff of more than 2000) joined forces to host a large number of top scientists from both institutions that carry out highly competitive research in several areas. The aggregation of the UAM and CSIC in the International Campus of Excellence (CEI), along with other research and transfer centres, companies, business organisations, local authorities and Madrid regional authorities, will give significant impetus to improve the Campus teaching, research and knowledge transfer capacities. The project’s main goals are two: to increase the international relevance of this particular Campus of Excellence, seeking that the CEI UAM+CSIC be the leading Spanish campus by 2015 and among the 100 top universities in the world and top 50 in Europe and to integrate it very closely with its surroundings, in order to lead the social, cultural and economic development of Madrid North. Web: http://campusexcelencia.uam-csic.es

The Spanish Institute for Foreign Trade (ICEX) ("Instituto Español de Comercio Exterior") is the Spanish Government agency serving Spanish companies to promote their exports and facilitate their international expansion, assisted by the network of Spanish Embassy’s Economic and Commercial Offices and, within Spain, by the Regional and Territorial Offices. It is part of the Spanish Ministry of Economy and Competitiveness (“Ministerio de Economía y Competitividad”). España, Technology for life: www.spainbusiness.com Web: www.icex.es


TNT2012 Speakers

pagepagepagepage

Pablo Alonso González (CIC nanoGUNE Consolider, Spain) "Optical nano-imaging of gate-tuneable graphene plasmons"

Oral Senior Plenary Session 29292929

Masakazu Aono (MANA / NIMS, Japan) "Synaptic characteristics of the atomic switch"

Keynote Plenary Session 30303030

Takao Aoyagi (MANA / NIMS, Japan) "Molecular design of Smart Biomaterials for Nano Life"


Carlos Arroyo Rodríguez (Delft University of Technology , Netherlands) "Quantum interference effects on charge transport through a single benzene ring"


Joël Azevedo (CEA Saclay / SPEC, France) "Graphene and carbon nanotubes film organization with a new solution-based method: a substrate

independent transfer for transparent electrode applications”

Oral PhD Parallel Session

35353535

Myriam Barrejón (Universidad de Castilla-La Mancha, Spain) "Synthesis of a new GO-C60 hybrid by “click” chemistry"

Oral PhD Parallel Session 37373737

Tiziana Bond (Lawrence Livermore National Lab, USA) "Plasmonic to enhance sense and sensitivity at the nanoscale"

Keynote Plenary Session ----

Paolo Bondavalli (Thales Research and Technology, France) "Electrodes based on mixture of Graphene/Graphite/Carbon nanotubes obtained by a new dynamic

spray-gun technique for supercapacitor related applications"

Oral Senior Plenary Session

38383838

Eduardo M. Bringa (Universidad Nacional de Cuyo, Argentina) "Multiscale simulations of irradiated nanofoams"


Andreu Cabot (IREC, Spain) "I2–II–IV–VI4 Nanocrystals: Synthesis and Thermoelectric Properties"


Fernando Calle Gómez (ISOM and ETSI Telecomunicación / UPM, Spain) "Nanotechnology for high frequency communications: nitrides and graphene"


Mercedes Carrascosa (Universidad Autónoma de Madrid, Spain) "Applications of photovoltaic fields of iron doped LiNbO3 in nanotechnology"

Oral Senior Parallel Session 44444444

Jean-Christophe Charlier (Université Catholique de Louvain, Belgium) "Electronic properties and quantum transport in doped and defective graphene"


Eugene Choulkov (DIPC - UPV/EHU, Spain) "Electronic Stucture of Topological Insulators"


Fabiano Corsetti (Asociacion CIC nanoGUNE, Spain) "New implementations of the orbital minimization method in the SIESTA code"


Aron W. Cummings (Sandia National Laboratories, United States) "Enhanced Performance of Carbon Nanotube Field-Effect Transistors Due to Gate-Modulated Electrical

Contact Resistance"


51515151

Silvano de Franceschi (CEA, France) "Silicon-based quantum electronics"


Carmen Del Hoyo Martínez (University of Salamanca, Spain) "Nanoclays as adsorbents of organic contaminants for a sustainable application"


Francisco Del Pozo (CTB-UPM, Spain)

Oral Senior Parallel Session ----

Alexandr Dobrovolsky (Linkoping University, Sweden) "Optical studies and defect properties of GaP/GaNP core/shell nanowires"


Index alphabetical order


TNT2012

S

pe

ak

er

s

pagepagepagepage

Maysoun Douas (Inst. Ciencia Materiales de Madrid (ICMM),Spain) "Identification of nanocavities water content"


Alberto Eljarrat Ascunce (Universitat de Barcelona, Spain) "EELS-HAADF spectrum imaging for characterization of (AlGa)N multilayer heterostructures."


Toshiaki Enoki (Tokyo Institute of Technology, Japan) "Electronic properties of graphene edges"


Roch Espiau de Lamaestre (CEA-Leti, France) "Integration of plasmonics within a CMOS environment"


Virginia Estévez (Universidad del Pais Vasco, Spain) "Angular dependence of the tunneling magnetoresistance in nanoparticle arrays"


Maël Dehlinger (CNRS-CINaM, France) "Towards sub-100nm resolution chemical mapping by XRF combined to simultaneous topography"


Michael Fluss (Lawrence Livermore National Laboratory, USA) "Nano-dispersed particles in Fe(Crx) and their performance under dual (He+Fe) and triple (H+He+Fe) ion

beam irradiation"

Keynote Plenary Session

66666666

Katerina Foteinopoulou (Institute of Optoelectronics and Microsystems (ISOM) and ETSII, UPM, Spain) "Entropy-driven phase transition in dense packings of athermal chain molecules"

Oral Senior Parallel Session

68686868

Alberto Fraile García (Institute of Nuclear Fusion, Spain) "Molecular Dynamics simulation of liquid metals for nuclear fusion technology"


Luis S. Froufe-Pérez (Inst. de Estructura de la Materia, CSIC, Spain) "Light emission statistics as a local probe for structural phase switching"


Javier García de Abajo (IQFR-CSIC, Spain) "Graphene plasmonics"


Sandra García-Gil (CEMES-CNRS, France) "Progress towards a single swap molecule with Ruthenium complexes: DFT study on a gold surface"


Mari Cruz García Gutiérrez (Instituto de Estructura de la Materia, IEM-CSIC, Spain) "Tuning physical properties of polymers by nanoconfinement"


Francisco José García Vidal (UAM, Spain) "Light-matter coupling mediated by surface plasmons"


David Garoz (Institute of Nuclear Fusion, Spain) "Crack mechanical failure in ceramic materials under ion irradiation: case of lithium niobate crystal"


Philippe Ghosez (Université de Liège, Belgium) “Coupling of lattice modes in oxides superlattices: Wedding of three"


María José Gómez-Escalonilla (U. Castilla-La Mancha, Spain) "Photochemical Evidence of Electronic Interwall Communication in Double-Wall Carbon Nanotubes"


Raquel Gómez-Medina (Universidad Autónoma de Madrid, Spain) "Negative scattering asymmetry parameter for dipolar particles: Unusual reduction of the transport

mean free path and radiation pressure"


83838383

Nuria Gordillo García (Instituto de Fusión Nuclear/ ETSI de Industriales-UPM, Spain) "Nanostructured tungsten as a first wall material for the future nuclear fusion reactors"


Kurt Gothelf (Aarhus University, Denmark) "DNA programmed assembly of molecules"


Stephan Götzinger (Max Planck Institute for the Science of Light, Germany) "Optical antennas: nanoscience meets quantum optics"


Peter Gruetter (McGill University, Canada) "What can AFM tell us about organic photovoltaic systems?"


Francisco Guinea (ICMM-CSIC, Spain) "Interaction effects in graphene heterostructures"


Kelli Hanschmidt (Institute of Physics, University of Tartu, Estonia) "Properties optimisation of titania microfibers by direct drawing"



TNT2012

S

pe

ak

er

s

pagepagepagepage

Kikuo Harigaya (Nanosystem Research Institute, AIST, Japan) "Theoretical Study of Edge States in BC2N Nanoribbons with Zigzag Edges"


Anwar Hasmy (Universidad Simón Bolívar, Venezuela) "Nanotechnology in Latin America and the Caribbean: Current Situation and perspective"


Antonio Hernando (Universidad Complutense, Spain) "Metallic microwires as non-reflective microwave systems"


Tibor Hianik (Comenius University, Slovakia) "Application of nanostructures in aptamer based biosensors"


Kevin Inderbitzin (U. Zurich - Physics-Institute, Switzerland) "Ultrafast X-Ray Nanowire Single-Photon Detectors and Their Energy-Dependent Response"


Masashi Ishii (National Instit. for Materials Science (NIMS), Japan) "Nano-probing of the surface excited by keV photon: What should we detect for high spatial

resolution?"


99999999

José Ignacio Izpura (GMME-CEMDATIC. UPM, Spain) "On the origin of RTS noise in nanoFETs "


Christian Joachim (CEMES/CNRS - GNS, France) "Design of Atom and Single Molecule Boolean Logic gates"


Gerald Kada (Agilent Technologies, Austria) "Calibrated Nanoscale Capacitance and Dopant Profile Measurements using a novel Nearfield Scanning

Microwave Microscope"


104104104104

W. Joshua Kennedy (NASA Johnson Space Center, United States) "Optical limiting by absorption bleaching in carbon nanotube devices: comparison of field-induced and

electrochemically-induced charge injection “


106106106106

Vladimir Labunov (Belarusian State University of Informatics and Radioelectronics, Belarus) "Novel “Carbon Nanotube/Graphene Layer” Nanostructures Obtained by Injection CVD Method for

Electronic Applications "


107107107107

Uzi Landman (Georgia Tech, USA) "Emergent non-scalable behavior in the nanoscale"


Yael Liebes (Ben Gurion University of the Negev, Israel) "Fabrication and characterization of nanopores in Si based materials"


Cheng-An Lin (Chung Yuan Christian University, Taiwan) "Rapid Conversion from Protein-Caged Nanomaterials to Microbubbles: A Sonochemical Route toward

Bimodal Imaging Agents"


111111111111

Dan Lis (University of Namur - FUNDP, Belgium) "Nanopillars as Plasmonic Platform to Enhance Nonlinear Vibrational Sum-Frequency Generation Spectroscopy"


Fco. Javier Llorca (IMDEA Materiales, Spain) "Nanoscale Metallic and Metal-Ceramic Multilayers for Radiation-Resistant Applications"


Maria Jesús López Bosque (Parc Cientific de Barcelona/Plataforma de Nanotecnologia, Spain) "Hierarchical micro-nano-structures for cell adhesion studies"


115115115115

Fernando López-Tejeira (Instituto de Estructura de la Materia (IEM-CSIC), Spain) "Refractive Index Sensing based on Plasmonic Fano-like Interference"


Raquel Lucena García (I. de Catálisis y Petroleoquímica-CSIC,Spain) "New Intermediate band sulphide nanoparticles acting in the full visible light range spectra as an active

photocatalyst"


118118118118

Antonio Luque (Universidad Politécnica de Madrid, Spain) "Quantum Dot Intermediate Band Solar Cells: Issues for an Attractive Concept"


Maria Ada Malvindi (Italian Institute of Technology, Center for Bio-Molecular Nanotechnologies@Unile, Italy) "Silica nanostructures toxicity assessment and their potential for biomedical applications"


122122122122

José María Riola (Ministry of Defense, Spain) "Nanotechnologies for security and defense - Sectors of interest"

Oral Senior Plenary Session ----


TNT2012

S

pe

ak

er

s

pagepagepagepage

Manuel Marqués (Universidad Autónoma de Madrid, Spain) "Plasmonic nanoparticle chain in a light field: a resonant optical sail"


Richard Martel (Université de Montreal, Canada) "Environmental Effects in Carbon Nanotube and graphene-based Transistors"


Gema Martínez-Criado (European Synchrotron Radiation Facility, France) "Imaging the carrier confinement within a single nanowire"


Remo Masut (École Polytechnique de Montréal, Canada) "Reciprocal space and transmission electron microscopy study of heterogeneous GaP:MnP magnetic

epilayers containing MnP nanoclusters"


126126126126

Diogo Mata (University of Aveiro, Portugal) "Spatial and temporal control of osteoblastic cells proliferation on electroconductive carbon nanotube-

based bone grafts"


128128128128

Sébastien Maussang (Renishaw Ibérica, Spain) "Recent advances in fast imaging Raman technology for nano materials characterisation"


Jean-Louis Mergny (INSERM U869 – U.Bordeaux Segalen, France) "Unusual nucleic acid structures for DNA-based nanotechnologies"


Rodolfo Miranda (UAM/IMDEA Nanociencia, Spain) "Evidence for magnetic order in a purely organic 2D layer adsorbed on epitaxial graphene"


Laurens W. Molenkamp (Wurzburg University, Germany) "Dirac fermions in HgTe quantum wells"


Juan Ramon Morante (IREC, Spain) "Three dimensional electrodes base on core/shell nanowires for photoelectrochemical cells"


Edgar Muñoz (Instituto de Carboquímica (ICB-CSIC), Spain) "Metal-Carbon Nanohybrid Foams: from Laser Chemistry to Nanochemistry"


Jeffrey B. Neaton (Lawrence Berkeley National Laboratory, USA) "Understanding Electronic Structure and Charge Transport in Single-Molecule Junctions"


Bernat Olivera (University of Alicante, Spain) "Measurement of the capacitance across a tunnel barrier"


Cornelia G. Palivan (University of Basel, Switzerland) "Protein-polymer nanoreactors and processors act as artificial organelles"


Ovidio Y. Peña Rodríguez (IFN - ETSII Madrid /UPM, Spain) "Plasmonic nanoparticles for the protection of the final optics in inertial confinement fusion facilities:

Capabilities and limitations"


141141141141

Daniel Pérez-Estévez (University of Vigo, Spain) "Functionalizated magnetic nanoparticles for biodetection, imaging and separation of Mytilus

galloprovincialis larvae using NIT-zipper® technology”


142142142142

Laetitia Philippe (EMPA Materials Science & Technology, Switzerland) "Urchin-inspired zinc oxide as building blocks for nanostructured solar cells"


Marcos Pita (Inst. of Catalysis and Petroleumquemistry-CSIC,Spain) "Improving the Direct Electron Transfer Efficiency in Laccase Electrodes for Biofuel Cell Cathodic Reactions"


Julio Plaza (Technological Institute "La Marañosa" (Ministry of Defense), Spain) "Strategies and activities in nano"


Dieter Pohlenz (Omicron NanoTechnology GmbH, Germany) "High Precision local electrical Probing: A New Low Temperature 4-Tip STM with Gemini UHV-SEM Navigation"


Dietmar Pum (BOKU - University of Natural Resources and Life Sciences, Austria) "S-layer proteins as patterning elements in the life and non-life sciences"


Juris Purans (University of Latvia, Latvia) "Near field X-ray spectromicroscopies: new tools for nanoscience"


Akhilesh Rai (University of Coimbra, Portugal) "One pot synthesis of potent antimicrobial gold nanoparticles"

Oral Senior Parallel Session ----

Rebeca Ribeiro (Laboratoire National des ChamO Magnetiques Inteses, France) "Unveiling the Landau Levels Structure of Graphene Nanoribbons"



TNT2012

S

pe

ak

er

s

pagepagepagepage

Carlos Rivera (Technological Institute "La Marañosa" (Ministry of Defense), Spain) "Graphene potentialities for space and defense applications: focus on mechanical properties"


Juan Rodríguez (Universidad Nacional de Ingenieria, Peru) "Supported Nanomaterials for Photocatalytic Water disinfection at rural areas: From Lab. Scale to on site

experiments"


156156156156

Miguel Romera (Universidad Politécnica de Madrid, Spain) "Substantial increase of the critical current on a Spin Transfer Nanopillar by adding

an Fe/Gd/Fe trilayer"


157157157157

Volker Rose (Argonne National Laboratory, USA) "New Capabilities at the Interface of X-rays and Scanning Tunneling Microscopy"


Gabino Rubio-Bollinger (Universidad Autónoma de Madrid, Spain) "Mechanical properties of freely suspended atomically thin dielectric layers of mica"


Amalia Ruíz (ICMM-CSIC, Spain) "An Efficient MRI Contrast Agent Based on PEGylated Iron Oxide Nanoparticles"


Carlos Sabater (Universidad de Alicante, Spain) "Creating nanowires with atomic precision"


Akira Saito (Osaka University, Japan) "Nanoscale elemental analysis and applications using STM combined with brilliant hard X-rays"


Beatriz Salinas (Centro Nacional de Investigaciones Cardiovasculares, Spain) "Biorthogonal chemistry for the functionalization of superparamagnetic nanoparticles: cross olefin metathesis"


Pablo San José (Instituto de Estructura de la Materia (CSIC), Spain) "AC Josephson effect in finite-length nanowire junctions with Majorana modes"


Cristina Sánchez (CTB-UPM, Spain) "Thermal and mechanical effects of different excitation modes based on low frequency laser modulation

in optical hyperthermia"


170170170170

Rafael Sánchez (ICMM-CSIC, Spain) "Maximal entanglement out of transport through double quantum dots"


Daniel Sánchez Portal (CFM/EHU-CSIC, Spain) “TDDFT simulations of the energy loss of moving projectiles in solids and nanostructures"


Marcus Semones (WaveGuide Corp., USA) “WaveGuide's u-NMR and Magnetic Nanoswitches for Security and Defense Applications"


Paz Sevilla (Universidad Complutense de Madrid, Spain) "Fluorescence and Raman characterization of a transport system formed by the anti tumoral drug

emodin, silver nanoparticles and porous silicon”


176176176176

We-Hyo Soe (IMRE / A*STAR, Singapore) "Manipulation of molecular quantum states in an STM tunneling junction using classical metal atom inputs"


David Soriano (Institut Català de Nanotecnologia (ICN), Spain) "Disorder-induced Randomization of Spin Polarization and Interfacially Protected Surface States in Three-

dimensional Models of Topological Insulators"


179179179179

Marek Szymonski (Jagiellonian University/NANOSAM, Poland) "Atomically precise construction and electronic properties of dangling-bond nanostructures on hydrogen

passivated Ge(001) surface"


181181181181

Philippe Tamarat (LP2N, Université de Bordeaux, Institut d'Optique Graduate School & CNRS, France) "Efficient biexciton emission in single CdSe nanocrystals"


182182182182

Concha Tojo (University of Vigo, Spain) "Microemulsions as reaction media for the synthesis of bimetallic nanoparticles"


Jessica Topple (McGill University, Canada) "Small Molecule Organic Photovoltaics at the Nanoscale"


Alessandro Troisi (University of Warwick, UK) "Atomistic Models of Charge Separation and Recombination in Organic Photovoltaics Interfaces"



TNT2012

S

pe

ak

er

s

pagepagepagepage

Joaquin Tutor (ETSI-ICAI Universidad Pontificia Comillas, Spain) "Present and Perspectives on Dissemination and Training in Nanotechnology in IberoAmerica: Red

NANODYF – CYTED"


189189189189

Takashi Uchihashi (NIMS, Japan) "Superconductivity at adatom/molecule-induced silicon surfaces and interfaces"


Yoshio Ukyo (Toyota R&D Labs, Japan) “Microstructural change of li(NiCo)O2 based materials of li ion battery during charge and discharg"


Helena Varela (Universidad de Alicante, Spain) "Monitoring the oxygen content in graphene oxide"


Hiroshi Yao (University of Hyogo, Japan) "Postsynthetic Asymmetric Transformation of Boronic-Acid-Protected Gold Nanoclusters Studied by

Magnetic Circular Dichroism (MCD) and Electronic Circular Dichroism (ECD)"


195195195195

Mariusz Zdrojek (Warsaw University of Technology, Poland) "Laser heating control with polarized light in isolated multi-walled carbon nanotubes"



TNT2012 Speakers

pagepagepagepage

Masakazu Aono (MANA / NIMS, Japan) "Synaptic characteristics of the atomic switch"

30303030

Takao Aoyagi (MANA / NIMS, Japan) "Molecular design of Smart Biomaterials for Nano Life"

32323232

Tiziana Bond (Lawrence Livermore National Lab, USA) "Plasmonic to enhance sense and sensitivity at the nanoscale"

----

Eduardo M. Bringa (Universidad Nacional de Cuyo, Argentina) "Multiscale simulations of irradiated nanofoams"

40404040

Fernando Calle Gómez (ISOM and ETSI Telecomunicación / UPM, Spain) "Nanotechnology for high frequency communications: nitrides and graphene"

42424242

Jean-Christophe Charlier (Université Catholique de Louvain, Belgium) "Electronic properties and quantum transport in doped and defective graphene"

46464646

Eugene Choulkov (DIPC - UPV/EHU, Spain) "Electronic Stucture of Topological Insulators"

48484848

Silvano de Franceschi (CEA, France) "Silicon-based quantum electronics"

53535353

Toshiaki Enoki (Tokyo Institute of Technology, Japan) "Electronic properties of graphene edges"

61616161

Roch Espiau de Lamaestre (CEA-Leti, France) "Integration of plasmonics within a CMOS environment"

63636363

Michael Fluss (Lawrence Livermore National Laboratory, USA) "Nano-dispersed particles in Fe(Crx) and their performance under dual (He+Fe) and triple (H+He+Fe) ion beam

irradiation"

66666666

Javier García de Abajo (IQFR-CSIC, Spain) "Graphene plasmonics"

74747474

Francisco José García Vidal (UAM, Spain) "Light-matter coupling mediated by surface plasmons"

78787878

Philippe Ghosez (Université de Liège, Belgium) “Coupling of lattice modes in oxides superlattices: Wedding of three"

80808080

Kurt Gothelf (Aarhus University, Denmark) "DNA programmed assembly of molecules"

86868686

Stephan Götzinger (Max Planck Institute for the Science of Light, Germany)

"Optical antennas: nanoscience meets quantum optics"

199199199199

Peter Gruetter (McGill University, Canada) "What can AFM tell us about organic photovoltaic systems?"

87878787

Francisco Guinea (ICMM-CSIC, Spain) "Interaction effects in graphene heterostructures"

88888888

Anwar Hasmy (Universidad Simón Bolívar, Venezuela) "Nanotechnology in Latin America and the Caribbean: Current Situation and perspective"

93939393

Antonio Hernando (Universidad Complutense, Spain) "Metallic microwires as non-reflective microwave systems"

94949494

Keynotes


TNT2012

Sp

ea

ke

rs

pagepagepagepage

Tibor Hianik (Comenius University, Slovakia) "Application of nanostructures in aptamer based biosensors"

95959595

Masashi Ishii (National Instit. for Materials Science (NIMS), Japan) "Nano-probing of the surface excited by keV photon: What should we detect for high spatial resolution?"

99999999

Christian Joachim (CEMES/CNRS - GNS, France) "Design of Atom and Single Molecule Boolean Logic gates"

103103103103

Uzi Landman (Georgia Tech, USA) "Emergent non-scalable behavior in the nanoscale"

109109109109

Fco. Javier Llorca (IMDEA Materiales, Spain) "Nanoscale Metallic and Metal-Ceramic Multilayers for Radiation-Resistant Applications"

114114114114

Antonio Luque (Universidad Politécnica de Madrid, Spain) "Quantum Dot Intermediate Band Solar Cells: Issues for an Attractive Concept"

120120120120

Richard Martel (Université de Montreal, Canada) "Environmental Effects in Carbon Nanotube and graphene-based Transistors"

200200200200

Jean-Louis Mergny (INSERM U869 – U.Bordeaux Segalen, France) "Unusual nucleic acid structures for DNA-based nanotechnologies"

131131131131

Rodolfo Miranda (UAM/IMDEA Nanociencia, Spain) "Evidence for magnetic order in a purely organic 2D layer adsorbed on epitaxial graphene"

132132132132

Laurens W. Molenkamp (Wurzburg University, Germany) "Dirac fermions in HgTe quantum wells"

133133133133

Jeffrey B. Neaton (Lawrence Berkeley National Laboratory, USA)

"Understanding Electronic Structure and Charge Transport in Single-Molecule Junctions"

137137137137

Ovidio Y. Peña Rodríguez (IFN - ETSII Madrid /UPM, Spain) "Plasmonic nanoparticles for the protection of the final optics in inertial confinement fusion facilities: Capabilities

and limitations"

141141141141

Dietmar Pum (BOKU - University of Natural Resources and Life Sciences, Austria) "S-layer proteins as patterning elements in the life and non-life sciences"

149149149149

Juris Purans (University of Latvia, Latvia) "Near field X-ray spectromicroscopies: new tools for nanoscience"

150150150150

Juan Rodríguez (Universidad Nacional de Ingenieria, Peru) "Supported Nanomaterials for Photocatalytic Water disinfection at rural areas: From Lab. Scale to on site

experiments"

156156156156

Volker Rose (Argonne National Laboratory, USA) "New Capabilities at the Interface of X-rays and Scanning Tunneling Microscopy"

159159159159

Akira Saito (Osaka University, Japan) "Nanoscale elemental analysis and applications using STM combined with brilliant hard X-rays"

165165165165

Daniel Sánchez Portal (CFM/EHU-CSIC, Spain) “TDDFT simulations of the energy loss of moving projectiles in solids and nanostructures"

173173173173

Marcus Semones (WaveGuide Corp., USA) “WaveGuide's u-NMR and Magnetic Nanoswitches for Security and Defense Applications"

175175175175

We-Hyo Soe (IMRE / A*STAR, Singapore) "Manipulation of molecular quantum states in an STM tunneling junction using classical metal atom inputs"

178178178178

Marek Szymonski (Jagiellonian University/NANOSAM, Poland) "Atomically precise construction and electronic properties of dangling-bond nanostructures on hydrogen

passivated Ge(001) surface"

181181181181

Alessandro Troisi (University of Warwick, UK) "Atomistic Models of Charge Separation and Recombination in Organic Photovoltaics Interfaces"

188188188188

Takashi Uchihashi (NIMS, Japan) "Superconductivity at adatom/molecule-induced silicon surfaces and interfaces"

190190190190

Yoshio Ukyo (Toyota R&D Labs, Japan) “Microstructural change of li(NiCo)O2 based materials of li ion battery during charge and discharg"

192192192192


TNT2012 Speakers

pagepagepagepage

Pablo Alonso González (CIC nanoGUNE Consolider, Spain) "Optical nano-imaging of gate-tuneable graphene plasmons"

29292929

Carlos Arroyo Rodríguez (Delft University of Technology , Netherlands) "Quantum interference effects on charge transport through a single benzene ring"

34343434

Paolo Bondavalli (Thales Research and Technology, France) "Electrodes based on mixture of Graphene/Graphite/Carbon nanotubes obtained by a new dynamic spray-gun

technique for supercapacitor related applications"

38383838

Andreu Cabot (IREC, Spain) "I2–II–IV–VI4 Nanocrystals: Synthesis and Thermoelectric Properties"

41414141

Aron W. Cummings (Sandia National Laboratories, United States) "Enhanced Performance of Carbon Nanotube Field-Effect Transistors Due to Gate-Modulated Electrical Contact

Resistance"

51515151

Virginia Estévez (Universidad del Pais Vasco, Spain) "Angular dependence of the tunneling magnetoresistance in nanoparticle arrays"

64646464

Maël Dehlinger (CNRS-CINaM, France) "Towards sub-100nm resolution chemical mapping by XRF combined to simultaneous topography"

65656565

Luis S. Froufe-Pérez (Inst. de Estructura de la Materia, CSIC, Spain)

"Light emission statistics as a local probe for structural phase switching"

72727272

Mari Cruz García Gutiérrez (Instituto de Estructura de la Materia, IEM-CSIC, Spain) "Tuning physical properties of polymers by nanoconfinement"

76767676

Nuria Gordillo García (Instituto de Fusión Nuclear/ ETSI de Industriales-UPM, Spain) "Nanostructured tungsten as a first wall material for the future nuclear fusion reactors"

85858585

Cheng-An Lin (Chung Yuan Christian University, Taiwan) "Rapid Conversion from Protein-Caged Nanomaterials to Microbubbles: A Sonochemical Route toward Bimodal

Imaging Agents"

111111111111

Dan Lis (University of Namur - FUNDP, Belgium) "Nanopillars as Plasmonic Platform to Enhance Nonlinear Vibrational Sum-Frequency Generation Spectroscopy"

112112112112

José María Riola (Ministry of Defense, Spain) "Nanotechnologies for security and defense - Sectors of interest"

----

Manuel Marqués (Universidad Autónoma de Madrid, Spain) "Plasmonic nanoparticle chain in a light field: a resonant optical sail"

124124124124

Laetitia Philippe (EMPA Materials Science & Technology, Switzerland) "Urchin-inspired zinc oxide as building blocks for nanostructured solar cells"

143143143143

Julio Plaza (Technological Institute "La Marañosa" (Ministry of Defense), Spain) "Strategies and activities in nano"

147147147147

Carlos Rivera (Technological Institute "La Marañosa" (Ministry of Defense), Spain) "Graphene potentialities for space and defense applications: focus on mechanical properties"

154154154154

Gabino Rubio-Bollinger (Universidad Autónoma de Madrid, Spain) "Mechanical properties of freely suspended atomically thin dielectric layers of mica"

160160160160

Pablo San José (Instituto de Estructura de la Materia (CSIC), Spain) "AC Josephson effect in finite-length nanowire junctions with Majorana modes"

169169169169

Orals - senior

(plenary session)


TNT2012

Sp

ea

ke

rs

pagepagepagepage

David Soriano (Institut Català de Nanotecnologia (ICN), Spain) "Disorder-induced Randomization of Spin Polarization and Interfacially Protected Surface States in Three-

dimensional Models of Topological Insulators"

179179179179

Philippe Tamarat (LP2N, Université de Bordeaux, Institut d'Optique Graduate School & CNRS,

France) "Efficient biexciton emission in single CdSe nanocrystals"

182182182182

Joaquin Tutor (ETSI-ICAI Universidad Pontificia Comillas, Spain) "Present and Perspectives on Dissemination and Training in Nanotechnology in IberoAmerica: Red NANODYF –

CYTED"

189189189189

Helena Varela (Universidad de Alicante, Spain) "Monitoring the oxygen content in graphene oxide"

194194194194

Hiroshi Yao (University of Hyogo, Japan) "Postsynthetic Asymmetric Transformation of Boronic-Acid-Protected Gold Nanoclusters Studied by Magnetic

Circular Dichroism (MCD) and Electronic Circular Dichroism (ECD)"

195195195195

Mariusz Zdrojek (Warsaw University of Technology, Poland) "Laser heating control with polarized light in isolated multi-walled carbon nanotubes"

197197197197


TNT2012 Speakers

pagepagepagepage

Mercedes Carrascosa (Universidad Autónoma de Madrid, Spain) "Applications of photovoltaic fields of iron doped LiNbO3 in nanotechnology"

44444444

Fabiano Corsetti (Asociacion CIC nanoGUNE, Spain) "New implementations of the orbital minimization method in the SIESTA code"

49494949

Carmen Del Hoyo Martínez (University of Salamanca, Spain) "Nanoclays as adsorbents of organic contaminants for a sustainable application"

54545454

Francisco Del Pozo (CTB-UPM, Spain)

----

Alexandr Dobrovolsky (Linkoping University, Sweden) "Optical studies and defect properties of GaP/GaNP core/shell nanowires"

56565656

Katerina Foteinopoulou (Institute of Optoelectronics and Microsystems (ISOM) and ETSII, UPM, Spain) "Entropy-driven phase transition in dense packings of athermal chain molecules"

68686868

Sandra García-Gil (CEMES-CNRS, France) "Progress towards a single swap molecule with Ruthenium complexes: DFT study on a gold surface"

75757575

David Garoz (Institute of Nuclear Fusion, Spain) "Crack mechanical failure in ceramic materials under ion irradiation: case of lithium niobate crystal"

79797979

María José Gómez-Escalonilla (U. Castilla-La Mancha, Spain) "Photochemical Evidence of Electronic Interwall Communication in Double-Wall Carbon Nanotubes"

81818181

Raquel Gómez-Medina (Universidad Autónoma de Madrid, Spain) "Negative scattering asymmetry parameter for dipolar particles: Unusual reduction of the transport mean free

path and radiation pressure"

83838383

Kikuo Harigaya (Nanosystem Research Institute, AIST, Japan) "Theoretical Study of Edge States in BC2N Nanoribbons with Zigzag Edges"

91919191

José Ignacio Izpura (GMME-CEMDATIC. UPM, Spain) "On the origin of RTS noise in nanoFETs "

101101101101

Gerald Kada (Agilent Technologies, Austria) "Calibrated Nanoscale Capacitance and Dopant Profile Measurements using a novel Nearfield Scanning

Microwave Microscope"

104104104104

W. Joshua Kennedy (NASA Johnson Space Center, United States) "Optical limiting by absorption bleaching in carbon nanotube devices: comparison of field-induced and

electrochemically-induced charge injection “

106106106106

Vladimir Labunov (Belarusian State University of Informatics and Radioelectronics, Belarus) "Novel “Carbon Nanotube/Graphene Layer” Nanostructures Obtained by Injection CVD Method for Electronic

Applications "

107107107107

Maria Jesús López Bosque (Parc Cientific de Barcelona/Plataforma de Nanotecnologia, Spain) "Hierarchical micro-nano-structures for cell adhesion studies"

115115115115

Fernando López-Tejeira (Instituto de Estructura de la Materia (IEM-CSIC), Spain) "Refractive Index Sensing based on Plasmonic Fano-like Interference"

117117117117

Maria Ada Malvindi (Italian Institute of Technology, Center for Bio-Molecular Nanotechnologies@Unile, Italy) "Silica nanostructures toxicity assessment and their potential for biomedical applications"

122122122122

Orals - senior

(parallel session)


TNT2012

S

pe

ak

er

s

pagepagepagepage

Gema Martínez-Criado (European Synchrotron Radiation Facility, France) "Imaging the carrier confinement within a single nanowire"

125125125125

Remo Masut (École Polytechnique de Montréal, Canada) "Reciprocal space and transmission electron microscopy study of heterogeneous GaP:MnP magnetic epilayers

containing MnP nanoclusters"

126126126126

Sébastien Maussang (Renishaw Ibérica, Spain) "Recent advances in fast imaging Raman technology for nano materials characterisation"

130130130130

Juan Ramon Morante (IREC, Spain) "Three dimensional electrodes base on core/shell nanowires for photoelectrochemical cells"

134134134134

Edgar Muñoz (Instituto de Carboquímica (ICB-CSIC), Spain) "Metal-Carbon Nanohybrid Foams: from Laser Chemistry to Nanochemistry"

135135135135

Cornelia G. Palivan (University of Basel, Switzerland) "Protein-polymer nanoreactors and processors act as artificial organelles"

139139139139

Daniel Pérez-Estévez (University of Vigo, Spain) "Functionalizated magnetic nanoparticles for biodetection, imaging and separation of Mytilus galloprovincialis

larvae using NIT-zipper® technology”

142142142142

Marcos Pita (Inst. of Catalysis and Petroleumquemistry-CSIC,Spain) "Improving the Direct Electron Transfer Efficiency in Laccase Electrodes for Biofuel Cell Cathodic Reactions"

145145145145

Dieter Pohlenz (Omicron NanoTechnology GmbH, Germany) "High Precision local electrical Probing: A New Low Temperature 4-Tip STM with Gemini UHV-SEM Navigation"

148148148148

Akhilesh Rai (University of Coimbra, Portugal) "One pot synthesis of potent antimicrobial gold nanoparticles"

----

Miguel Romera (Universidad Politécnica de Madrid, Spain) "Substantial increase of the critical current on a Spin Transfer Nanopillar by adding

an Fe/Gd/Fe trilayer"

157157157157

Rafael Sánchez (ICMM-CSIC, Spain) "Maximal entanglement out of transport through double quantum dots"

172172172172

Paz Sevilla (Universidad Complutense de Madrid, Spain) "Fluorescence and Raman characterization of a transport system formed by the anti tumoral drug emodin,

silver nanoparticles and porous silicon”

176176176176

Concha Tojo (University of Vigo, Spain) "Microemulsions as reaction media for the synthesis of bimetallic nanoparticles"

184184184184

Jessica Topple (McGill University, Canada) "Small Molecule Organic Photovoltaics at the Nanoscale"

186186186186


TNT2012 Speakers

pagepagepagepage

Joël Azevedo (CEA Saclay / SPEC, France) "Graphene and carbon nanotubes film organization with a new solution-based method: a substrate

independent transfer for transparent electrode applications”

33335555

Myriam Barrejón (Universidad de Castilla-La Mancha, Spain) "Synthesis of a new GO-C60 hybrid by “click” chemistry"

37373737

Maysoun Douas (Inst. Ciencia Materiales de Madrid (ICMM),Spain) "Identification of nanocavities water content"

57575757

Alberto Eljarrat Ascunce (Universitat de Barcelona, Spain) "EELS-HAADF spectrum imaging for characterization of (AlGa)N multilayer heterostructures."

59595959

Alberto Fraile García (Institute of Nuclear Fusion, Spain) "Molecular Dynamics simulation of liquid metals for nuclear fusion technology"

70707070

Kelli Hanschmidt (Institute of Physics, University of Tartu, Estonia) "Properties optimisation of titania microfibers by direct drawing"

89898989

Kevin Inderbitzin (U. Zurich - Physics-Institute, Switzerland) "Ultrafast X-Ray Nanowire Single-Photon Detectors and Their Energy-Dependent Response"

97979797

Yael Liebes (Ben Gurion University of the Negev, Israel) "Fabrication and characterization of nanopores in Si based materials"

110110110110

Raquel Lucena García (I. de Catálisis y Petroleoquímica-CSIC,Spain) "New Intermediate band sulphide nanoparticles acting in the full visible light range spectra as an active

photocatalyst"

118118118118

Diogo Mata (University of Aveiro, Portugal) "Spatial and temporal control of osteoblastic cells proliferation on electroconductive carbon nanotube-based

bone grafts"

128128128128

Bernat Olivera (University of Alicante, Spain) "Measurement of the capacitance across a tunnel barrier"

138138138138

Rebeca Ribeiro (Laboratoire National des ChamO Magnetiques Inteses, France) "Unveiling the Landau Levels Structure of Graphene Nanoribbons"

152152152152

Amalia Ruíz (ICMM-CSIC, Spain) "An Efficient MRI Contrast Agent Based on PEGylated Iron Oxide Nanoparticles"

161161161161

Carlos Sabater (Universidad de Alicante, Spain) "Creating nanowires with atomic precision"

163163163163

Beatriz Salinas (Centro Nacional de Investigaciones Cardiovasculares, Spain) "Biorthogonal chemistry for the functionalization of superparamagnetic nanoparticles: cross olefin metathesis"

167167167167

Cristina Sánchez (CTB-UPM, Spain) "Thermal and mechanical effects of different excitation modes based on low frequency laser modulation in

optical hyperthermia"

170170170170

Orals - PhD

(parallel session)

TNT2012 Abstracts


Optical nano-imaging of

gate-tuneable graphene plasmons 1 CICnanoGUNE, 20018, Donostia–SanSebastián, Spain

2 ICFO-Institut de Ciéncies Fotoniques, Mediterranean Technology Park,

08860 Castelldefels (Barcelona), Spain 3 IQFR-CSIC, Serrano119, 28006, Madrid, Spain

4 IKERBASQUE, BasqueFoundationforScience, 48011, Bilbao, Spain

5 Centro de Fisica de Materiales (CSIC-UPV/EHU) and Donostia International

Physics Center (DIPC), 20018, Donostia-San Sebastián, Spain 6 NeaspecGmbH, 82152, Martinsried, Munich, Germany

7 Graphenea S.A., 20018, Donostia-SanSebastián, Spain

8 CNM-IMB-CSIC–Campus UAB, 08193, Bellaterra, Barcelona, Spain

9 GREMAN, UMR7347, UniversitédeTours/CNRS, France

Graphene holds great promise for ultra-compact

and electronically controlled plasmonics [1,2].

Recently, resonant coupling of propagating THz

waves to plasmons in micro-ribbons has been

demonstrated [3], while IR near-field microscopy

has been applied to observe the coupling of

graphene plasmons to phonons [4]. In our work [5]

we use (similar to ref. [6]) scattering-type scanning

near-field optical microscopy (s-SNOM) to visualize

propagating and localized infrared plasmon modes

in graphene nanostructures in real space (Fig. 1). By

spectroscopic imaging we measure the graphene

plasmon wavelength λp as a function of excitation

wavelength, which confirms the theoretically

predicted plasmon dispersion. We observe that the

plasmon wavelength λp=λ0/40 is remarkably

reduced compared to the illumination wavelength

λ0, which can directly be attributed to the two-

dimensionality and unique conductance properties

of graphene. Furthermore, we demonstrate

tunability of the plasmon wavelength by gating

graphene nanoribbons on a SiO2 substrate. The

possibility to tune plasmons of extreme

subwavelength electronically opens up a new

paradigm in optical and opto-electronic

telecommunications and information processing.

References

[1] A. Vakil, N. Engheta, Science 332, 1291–1294

(2011)

[2] F.H.L. Koppens, D.E. Chang, J. Garcia de Abajo,

Nano lett. 11, 3370 (2011)

[3] L. JU, et al., Nat. Nanotech. 6, 630 (2011)

[4] Z. Fei, et al., Nano Lett. 11, 4701 (2011)

[5] J. Chen, et al., arXiv:1202.4996

[6] Z. Fei, et al., arXiv:1202.4993

Figure 1. Imaging propagating and localized

graphene plasmons by s-SNOM. a) Schematic

of the experimental configuration used to

launch and detect propagating surface waves

in graphene. The near fields generated at the

apex of an illuminated metal tip launch

plasmons on graphene. Back reflection of the

plasmons at the graphene edge yields plasmon

interference. b) Near-field amplitude image

acquired for a tapered graphene ribbon on top

of 6H-SiC, revealing interference of graphene

plasmons. The imaging wavelength is λ0=9.7

μm. The tapered ribbon is 12 μm long and up

to 1 μm wide.

P. Alonso-González1,

J. Chen5,1

, M. Badioli2,

S. Thongrattanasiri3,

F. Huth1,6

, J. Osmond2,

M. Spasenović2,

A. Centeno7, A. Pesquera

7,

P. Godignon8, A. Zurutuza

7,

N. Camara9, J. Garcia de

Abajo3, R. Hillenbrand

1,4 and

F. Koppens2

[email protected]


Synaptic characteristics of

the atomic switch 1 WPI Center for Materials Nanoarchitectonics (MANA),

National Institute for Materials Science (NIMS), Tsukuba, Japan 2 Low-power Electronics Association and Project (LEAP), Tsukuba, Japan

More than ten years ago, some of the present

authors (Aono, Hasegawa and Terabe) and co-

workers developed the atomic switch [1, 2]. The

atomic switch is generally known as such nanoscale

switching devices that make ON/OFF switching by

the growth and shrinkage of a conduction path

composed of metal atoms (in contrast with other

nanoscale switching devices collectively called the

resistive switch in which a conduction path is

formed by anion [e.g. oxygen ion] vacancies, etc.).

Actually, the atomic switch has more interesting

functionalities depending on its structure and

constituent materials (see Fig. 1). In this paper,

after reviewing the general characteristics of the

atomic switch briefly, we would like to concentrate

on the discussion of the synaptic characteristics of

the atomic switch.

Figure 1. Various types of the atomic switch, which have

different structures and constituent materials.

The atomic switch was first developed as a

nanoscale, two-terminal, nonvolatile switch with a

nanoscale vacuum gap between a solid-electrolyte

(Ag2S) electrode and a simple-metal counter

electrode, i.e. a gap-type atomic switch [1, 2]; if

necessary, a volatile atomic switch can be made [3].

It has been found later that the vacuum gap can be

filled with soft organic molecules [4] and if the

molecules are photoconductive, a photosensitive

atomic switch can be made, where ON/OFF

switching is controlled by photons [4]. The

switching mechanism of the gap-type atomic switch

has been studied in detail [5-7].

Soon after the development of the gap-type atomic

switch, we developed a gapless- type atomic switch

without a gap between a solid-electrolyte electrode

(Cu2S was used) and a simple-metal counter

electrode [8-11]; this gapless-type atomic switch is

advantageous for practical application. We have

also found that the solid electrolyte in the gapless-

type atomic switch can be a polymer-based

electrolyte (e.g. poly-ethylene + AgClO4) [12],

suggesting that a flexible two-dimensional atomic

switch array can be fabricated. Moreover, it has

been found that the electrolyte in the gapless-type

atomic switch can be replaced by a metal oxide

(e.g. Ta2O5) [13-17]; the metal oxide is not a solid

electrolyte but works as an ion transport layer. The

switching mechanism of this ion-transport-layer

atomic switch has been studied in detail [18-21].

We have succeeded to develop three-terminal

atomic switches (transistors) using a solid

electrolyte (Cu2S) [22, 23] or an ion-transport layer

(Ta2O5) [24, 25]. Interest-ingly, an atomic transistor

using Ta2O5 can be operated in either volatile or

non-volatile modes by simply controlling applied

voltage [24].

Interestingly, we have revealed that the two-

terminal gap-type atomic switch exhibits learning

ability [26, 27]; namely, the conductivity of the

Masakazu Aono1,

Tsuyoshi Hasegawa1,

Kazuya Terabe1,

Tohru Tsuruoka1,

Takeo Ohno1,

Alpana Nayak1 and

Toshitsugu Sakamoto2


TNT2012

Ab

st

ra

ct

s

switch can have inter-mediate values between the

OFF and ON conductivities, depending on the

history of input signals. More interestingly, the

atomic switch show interesting characteristics

similar to a synapse in neural network [28-30]; such

characteristics are also observed in a certain

gapless-type atomic switch [31]. On the basis of

these results, we have been developing

neuromorphic circuits made of atomic switches [28,

31, 32]. These studies have been partially reviewed

in Refs. 33-37.

Remarkable results related to the neuromorhpic

circuits constructed by atomic switches are

discussed in detail in this paper.

References

[1] K. Terabe et al., Riken Review No. 37 (July,

2001) 7.

[2] K. Terabe et al., Nature 433 (2005) 47.

[3] T. Hasegawa et al., to be published.

[4] T. Hino et al., Small 6 (2010) 1745.

[5] A. Nayak et al., J. Phys. Chem. Lett. 1 (2010)

604.

[6] A. Nayak et al., Appl. Phys. Lett. 98 (2011)

233501.

[7] I. Valov et al., Nature Mater., in press.

[8] T. Sakamoto et al., Appl. Phys. Lett. 82 (2003)

3032.

[9] S. Kaeriyama et al., IEEE J. Solid-State Circuits

40 (2005) 168.

[10] N. Banno et al., IEICE Trans. Electron. E89-C

(2006) 1492.

[11] N. Banno et al., IEEE Trans. Electron Devices

55 (2008) 3283.

[12] S. Wu et al., Adv. Funct. Mater. 21 (2011) 93.


092110.

[14] N. Banno et al., Appl. Phys. Lett. 97 (2010)

113507.

[15] M. Tada et al., IEEE Trans. Electron Devices

57 (2010) 1987.

[16] Y. Tsuji et al., Appl. Phys. Lett. 96 (2010)

023504.

[17] N. Banno et al., Jpn. J. Appl. Phys. 50 (2011)

074201.

[18] T. Tsuruoka et al., Nanotechnology 21 (2010)

425205.

[19] T. Tsuruoka et al., Nanotechnology 22 (2011)

379502.

[20] T. Tsuruoka et al., Adv. Funct. Mater. 22

(2012) 70.

[21] A. Nayak et al., Nanotechnology 22 (2011)

235201.

[22] T. Sakamoto et al., IEDM Technical Digest

(2005) 475.


252104.

[24] T. Hasegawa et al., Appl. Phys. Express 4

(2011) 015204.

[25] H. Kawaura et al., Electronics and

Communications in Japan 94 (2011) 55.

[26] T. Hasegawa et al., Adv. Mater. 22 (2010)

1831.

[27] T. Hasegawa et al., Appl. Phys. A 102 (2011)

811.

[28] T. Ohno et al., Nature Mater. 10 (2011) 591.

[29] T. Ohno et al., Appl. Phys. Lett. 99 (2011)

203108.

[30] A. Nayak et al., submitted.

[31] R. Yang et al., submitted.

[32] A. Stieg et al., Adv. Mater. 24 (2012) 286.

[33] R. Waser, M. Aono, Nature Mater. 6 (2007)

833.

[34] T. Hasegawa et al., MRS Bulletin 34 (2009)

929.

[35] M. Aono, T. Hasegawa, Proc. IEEE 12 (2010)

2228.

[36] T. Hino et al., Sci. Technol. Adv. Mater. 12

(2011) 013003.

[37] T. Hasegawa et al., Adv. Mater. 24 (2012)

252.


Molecular design of smart

biomaterials for nano life

International Center for Materials Nanoarchitectonics (WPI-MANA),

National Institute for Materials Science, 1-1, Namiki, Tsukuba, Ibaraki, 305-0044, Japan

Recent progress in biological field enables development

of new biological drugs for human health.

Nanostructured materials also contribute to fabricate

new diagnosis or medical devices and so on. That is,

interdisciplinary research including biology, materials

science and nanotechnology give us new system or

materials to open new area more and more. We are

interested in developing ‘smart’ biotechnologies using

nanostructured stimuli-responsive polymers that

respond to small changes in external stimuli with large

discontinuous changes in their physical properties. These

‘smart’ biomaterials are designed to act as an “on-off”

switch for drug delivery technologies, gene therapy,

affinity separations, chromatography, diagnostics etc.

Design of nanostructure of smart polymers and

application for smart nanofiber

Poly(N-isopropylacrylamide) (abbreviated as PIPAAm) is

one of the typical thermo-responsive materials and

much attention is attracting in nanobio-field. So far, we

newly designed series of functional IPAAm-based

functional monomers as shown in Figure 1. Such

monomers have the same polymerizable group

(acrylamide) and corresponding copolymer shows

completely random sequences and as a result, can show

very sensitive responses. For example, the copolymers

with carboxyl group are useful stimuli-responsive thin

hydrogel coating with nano-level thickness (Figure 2).

The modified magnetite nano particles were attracted to

magnet and speed was accelerated by heating over it

transition temperature. Moreover, the particles can

response to the external alternating magnetic field

based on inductive heating. Hydorphilicity and

hydrophobicity of nanoparticles surface can be

modulated by on–off of only current switch [1]. Such

materials would be applied to diagnosis after

conjugation with biomolecules such as antibody using

functional groups effectively.

Such functional group enables the design of highly

functional stimuli-responsive materials. Photo-, pH- and

temperature-responsive polymers were designed as

shown in Figure 3 [2]. Photo-reactive benzophenone is

very effective to C-C bond formation by radical reaction.

Namely, photo irradiation leads cross-linking reaction in

the materials. Then, we prepared here a new type of

“smart” nanofibers (NFs) with dynamically and reversibly

tunable properties using thermally crosslinkable IPAAm

copolymers via electrospinning. PIPAAm is soluble in

aqueous milieu below LCST. Cross-linking reaction

prevent the nanofibers from solubilization. Actually, the

cross-linked NFs web was used for cell capture and

release aiming at cell container [3]. First, temperature-

responsive dynamic behavior of the NF web was

investigated. When soaked in PBS and heated to 37C,

the web underwent drastic shrinking due to a

conformational change of the copolymer. As the cross-

linked NFs had an LCST of approximately 18C, the web

surface size decreased to almost one-third of the original

size after this first heating. The temperature was then

alternated below and above the LCST and,

correspondingly, the web first swelled, and then shrank.

Takao Aoyagi, Yong-Jin Kim,

Yohei Kotsuchibashi and

Mitsuhiro Ebara

[email protected]

Figure 1. Molecular structures of developed monomers.

Figure 2. Magnetite nanoparticle coated with stimuli-

responsive polymers.

Figure 3. Photo, pH and temperature-responsive polymer.


TNT2012

Ab

st

ra

ct

s

Figure 4. SEM image of cross-linked nanofiber composed

of PIPAAm.

Interestingly, the web did not return to the original size

when the temperature was lowered below the LCST. It is

plausible that the porosity of the NF web gradually

decreased during heating and cooling cycles, thereby

reducing the ability of water to hydrate the entire

surface area of the web.

Next, the cell wrapping, encapsulation, and releasing

capability of NF webs were evaluated by incubating cells

on the webs. Normal human dermal fibroblasts (NHDFs)

were dropped on cross-linked NF webs at 37C. We found

that the web immediately started to fold upperward and

wrapped the droplet. The releasing capability of cells

from the NF webs was evaluated by collecting released

medium from the web during the heating process from 4

to 37C. Approximately 70%, 19%, and 6% of cells were

released from the web at 1st, 2nd, and 3rd cycle of

temperature alternation, respectively. In other words,

almost all cells seeded on the web were released after 3

temperature cycles, whereas only negligible amounts of

cells were released during the swelling process from 37

to 4C.

Block copolymer design for nano-assembly

We designed the double thermo-responsive block

copolymer aiming at effective targeting drug delivery. To

achieve this purpose, we synthesized the block

copolymers applying an atom transfer radical

polymerization (abbreviated as ATRP). The block

copolymer, Poly(PIAAm-b-poly(IPAAm-co-BMAAm),

comprises two segments (blocks), which have two

different lower critical solution temperatures

(abbreviated as LCST) as shown in Figure 5 [4].

As seen in Figure 6, in cold condition that is below first

LCST, the block copolymer is completely soluble in

aqueous milieu. Increasing the solution temperature,

between first and second LCST, they form the micelle-

like associates and are very useful to reserve drug

molecules in the core phase. In hot condition that is

above second LCST, the outer polymer chains that form

shell structure also shrink and eventually they form the

aggregates. The unstable structure would improve the

drug release form the core phase.

Recently, we developed highly functional nano-assembly

as shown in Figure 7 [5]. This system comprises the

mixing of three kinds of well-designed block copolymer.

These copolymers contain common segment structure

with lower specific LCST. Heating above the specific

LCST, all copolymer participate and form micelle-like

structure. Sugar moieties are pilot to interact to

hepatocyte. Actually, we confirmed the affinity in vitro.

Figure 5. Synthesis of double thermo-responsive block

copolymer by ATRP.

Figure 6. Nano-assembly by double thermo-responsive

block copolymer.

Figure 7. Highly functional nano-assembly for target drug

delivery.

References

[1] H. Wakamatsu, K. Yamamoto, A. Nakao, T.

Aoyagi, J. Mag. Mag. Mater., 302, (2006) 327.

[2] D. Matsukuma, K. Yamamoto, T. Aoyagi ,

Langmuir, 22, (2006) 5911.

[3] Y-J Kim, M. Ebara, T. Aoyagi, Angew. Chem.,

submitted.

[4] Y. Kotsuchibashi, M. Ebara, K. Yamamoto, T.

Aoyagi, J. Polym. Sci.: Polym. Chem., 48,(2010)

4393.

[5] Y. Kotsuchibashi, M Ebara, N. Idota, R. Narain,

Takao Aoyagi, Polym. Chem., in press.

O

OO

O

OHO

nOHN OHN

O

b

OHN OHN OHN OHN

O

b

O

NH

OOO

OH

OH

OH

OH

HO


Quantum interference effects on

charge transport through a single

benzene ring 1 Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1,

2628 CJ Delft, The Netherlands 2 Department of Chemical Engineering, Delft University of Technology,

Julianalaan 136, 2628 BL Delft, The Netherlands

We explore charge transport through a single benzene ring, which is a prototypical molecular system where

quantum interference effects are expected. Using the mechanically controllable break junction technique,

we measured the low-bias conductance of molecular junctions where the benzene ring is wired between

gold electrodes through thienyl anchoring groups and ethynyl spacers. We show that the conductance for a

meta-coupled benzene ring is more than an order of magnitude smaller than that of a para-coupled

benzene. The dramatic reduction of the conductance is consistent with destructive quantum interference

effects in the meta-coupled benzene. This is supported by non-equilibrium Green’s function calculations that

confirm the occurrence of quantum interference in these systems.

Figure 1. (a) Layout of a mechanically controlled break-junction (MCBJ) setup. Two-dimensional trace

histograms constructed from 500 consecutive breaking traces taken at ambient conditions and 0.1 V

bias for junctions exposed to molecules coupled in (b) para and (c) meta configuration. Calculated

transmission of para (blue line) and meta (red line) in the gas phase.

Carlos R. Arroyo1, Simge

Tarkuc2, Riccardo Frisenda

1,

Johannes S. Seldenthuis1,

Charlotte H.M. Woerde2,

Rienk Eelkema2, Ferdinand

C. Grozema2 and Herre S. J.

van der Zant1

[email protected]


Graphene and carbon nanotubes film

organization with a new solution-

based method: a substrate

independent transfer for transparent

electrode applications 1 CEA Saclay, IRAMIS, SPEC (URA CNRS 2464), LEM, 91191 Gif sur Yvette, France

2 CEA Saclay, IRAMIS, SPEC (URA CNRS 2464), MOB, 91191 Gif sur Yvette, France

3 Université Paris-Sud 11, LCP, 91405 Orsay Cedex, France

Graphene and carbon nanotubes (CNT) have

exceptional properties that make them fascinating

objects for both academic and application-oriented

studies. In particular, with the combination of their

electronic, mechanical and optical properties, they

are considered as potential candidates for new

generations of transparent electrodes in o-PV cells,

touch screens and flexible displays. However, such

technologies rely on the capacity to form high-

quality thin-films with a controlled morphology.

In order to address the related issues a low-cost

and original method based on the transfer of

surfactant-stabilized water films has been

developed in our group. This bubble deposition

method (BDM) proved very efficient to organize

and transfer, under ambient conditions, dense and

homogeneous monolayers of nano-objects such as

nanowires and nanoparticles, over large areas. The

BDM does not require sophisticated transfer

processes and is compatible with a large panel of

substrates (silicon, glass, polymers…), both

hydrophilic or hydrophobic.

Recently we proved the usefulness of this approach

to self-assemble carbon materials such as single-

wall carbon nanotubes (SWNTs)[1] and graphene

oxide sheets (GO)[2] into close-packed monolayers.

Of particular interest is the compatibility of this

technique with: (i) a pre-structuration of the

substrate in micro-channels, such structuration

leading to the specific increase of the deposition

density within the channels (see figure 1)[3]; (ii)

homogeneous transfers at the wafer scale using

vertical water films in place of bubbles; (iii) a simple

layer-by-layer approach, enabling the formation of

thickness-adjusted films through multiple

depositions. This layer-by-layer approach was

extended notably to realize hybrid materials and, as

a proof of concept, a stacked structure was formed

by alternating SWNTs and GO layers[2].

Figure 1. SEM images of a carbon nanotube film

transferred on a lithographically patterned glass

substrate.

Our results provide insight into important problems

that impeded the development of SWNT and

Graphene based devices. Indeed, in contrast with

most methods (such a spin coating), BDM leads to

the transfer of the full amount of engaged material.

It is thus compatible with high added-value

materials, such as SWNTs selected by chirality. We

also present how this method can be used to

aligned carbon nanotubes at various scales using

the drainage of the water confined in the double

surfactant wall of the bubble[1].

Joël Azévédo1, S.

Campidelli1, Claire Costa-

Coquelard2, Jean-Jacques

Benattar2, Sébastien

Sorgues3, Christophe

Colbeau-Justin3 and V.

Derycke1

[email protected]


TNT2012

Ab

st

ra

ct

s

Despite the variety of existing methods there is still

a lack of a simple, efficient and substrate-

independent technique enabling the deposition of

graphene sheets free of wrinkles. The Langmuir

Blodgett approach is highly efficient to self-

assemble a monolayer but the roughness of the

films deteriorates rapidly when several layers are

tentatively stacked. In contrast, we show that this

drawback can be almost completely suppressed

using our approach with both small (1-10 µm2) and

large (10-500 µm2) GO sheets (see figure 2). As well

as the precise control of the nano-objects

assembly, the efficient chemical reduction of GO

into graphene is still a pressing issue that limits the

development of GO-based electrodes. We are

currently investigating this point and will report our

last results combining the BDM with a post-

deposition reduction step.

Figure 2. AFM images of a close-packed arrangement of

small (left) and large (right) graphene oxide sheets in a

dense and homogeneous monolayer film.

Figure 3. Amplitude of the TRMC signal of Si, {SDBS-

CNT}-Si and CNT-Si surfaces.

The BDM is both versatile and scalable, and is

adapted to a wide variety of applications. Of

particular interest are conductive films that are

optically transparent and yield adequate and

uniform electronic properties. They could be used

as replacement for ITO in both light emitting

devices and photovoltaic ones. Concerning PV, one

particularly interesting system is the carbon/silicon

heterostructure that was shown to display very

high efficiency of light-to-current conversion

despite its simplicity. Using the BDM, ultra-thin and

uniform films of both SWNTs and GO were

deposited on silicon substrates and the mechanism

of charge separation at the carbon/silicon

interfaces is studied by the non-invasive Time

Resolved Microwave Conductivity (TRMC)

method.[3] This technique is based on the analysis

of the evolution of the microwave absorption of the

studied samples containing mobile charges

generated by a nanosecond laser excitation. The

measured signal is proportional to the conductance

change and consequently to the number of charge

carrier and to their mobility. It allows studying the

evolution of the lifetime of the photo-generated

carriers as a function of the heterostructure

properties. As an example, the charge carrier

lifetime in the case of a modified silicon-nanotube

junction (see figure 3) is 100 times longer than for

the bare silicon. Such signature of an efficient

charge separation at the carbon/silicon interface

measured by TRMC is very helpful to understand

and optimize nanotube-silicon solar cells.

References

[1] Guolei Tang, Xinfeng Zhang, Shihe Yang,

Vincent Derycke, Jean-Jacques Benattar, Small,

6 (2010), 1488

[2] J. Azevedo, C. Costa-Coquelard, P. Jegou, T. Yu

and J.-J. Benattar, Journal of Physical

Chemistry C, 115 (2011), 14678

[3] Claire Costa-Coquelard, Joël Azevedo, Florence

Ardiaca and Jean-Jacques Benattar, submitted

to Applied Surface Science

[4] C. Swiatkowski, A. Sanders, K.-D. Buhre and M.

Kunst, Journal of Applied Physics, 78(3) (1995),

1763


Synthesis of a new GO-C60 hybrid

by “click” chemistry 1 Instituto de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL),

Universidad de Castilla-La Mancha, 45071 Toledo, Spain 2 Instituto de Catálisis y Petroleoquímica, CSIC, Cantoblanco, 28049, Madrid, Spain

3 Université de Strasbourg,France

Graphene (GS) and graphene oxide (GO) have

attracted great interest for its superior physical,

chemical, mechanical, and electrical properties that

enable a wide range of applications from

electronics to nanoelectromechanical systems [1].

Functionalization of these materials can allow to

modulate their electronic, optical and electrical

properties, and due to the insolubility and the

relatively inert surface of the GS and GO, new

methods for functionalization are being

explored [2].

As precedent, hybrid materials of Carbon

Nanotubes (CNTs) and fullerenes have generated

intense attention, driven by the possibility of

combining some of the outstanding properties of

the CNTs with those of fullerenes rising new

properties of the hybrid. The presence of fullerenes

in the SWCNTs environment could improve the

mechanical properties of the SWCNTs and tune the

electronic and optical properties of both, the CNT

and the fullerene cage, a subject of great interest

for optoelectronic applications [3].

"Click” chemistry is a well-known, versatile and

clean reaction and it is extremely efficient to

connect discrete molecules, polymers or

nanoparticles onto the nanotube sidewalls, through

the formation of a triazole ring linker.

In this sense, the preparation of hybrids involving

graphene and fullerenes will permit to explore the

potentials applications of these materials. Based on

this consideration, we present the synthesis and

the characterization of a soluble hybrid material,

GO-C60 that combines fullerene and graphene oxide

(GO) into a single structure. The GO was firstly

modified by the Tour procedure, affording the

alkyne group followed by click chemistry between

the modified GO and an azide fullerene derivative

yielding the fullerene-triazole-GO (GO-C60) hybrid.

This hybrid material has been fully characterized by

using a number of complementary techniques,

including Raman, X-ray photoelectron spectroscopy

(XPS), thermogravimetric analysis (TGA), high

resolution transmission electron microscopy (HR-

TEM); finally the photophysical properties of the

resulting multicomponent system have been

investigated in detail.

References

[1] M.J. Allen, V. C. Tung and R. B. Kaner, Chem.

Rev,110, (2010),132.

[2] L. Yan, Y. B. Zheng, F. Zhao, S. Li, X. Gao, B. Xu,

P. S. Weiss and Y. Zhao, Chem. Soc. Rev., 41,

(2012), 97.

[3] (a) M. Vizuete, M. J. Gómez-Escalonilla, J. L.

G. Fierro, M. Yudasaka, S. Iijima, M. Vartanian,

J. Iehl, J.-F Nierengarten and F. Langa, Chem.

Commun., 47, (2011), 12771 (b) M. Vizuete, M.

Barrejón, María J. Gómez-Escalonilla and F.

Langa, Nanoscale, (2012), DOI:

10.1039/c2nr30376.

Myriam Barrejón1,

María Vizuete1, María José

Gómez-Escalonilla1,

Jose Luis G. Fierro2,

Jean François Nierengarten3

and Fernando Langa1

[email protected]


Electrodes based on mixture of

Graphene/Graphite/Carbon

nanotubes obtained by a new

dynamic spray-gun technique for

supercapacitor related applications

Thales Research and technology, 128 Rt Dpt, Palaiseau, France

The emergency of a new generation of

supercapacitors based on new kind of

nanomaterials has been pointed out by several

important papers recently issued [1-3]. In this

context the graphene/graphite and carbon

nanotubes present extremely interesting

properties. This contribution deals with the

fabrication of supercapacitors using an original

dynamic air-brush deposition technique [4]. The

advantages of this technique are the compatibility

with different kind of surfaces, the completely

automatic process (Figure 1a and 1b), the

uniformity of the material deposited and the

versatility. Using this technique we have fabricated

graphite/carbon nanotubes based electrodes (Fig.2

and 3) using different percentages of the two

materials sprayed on the surface in order to study

the influence of the different concentrations [5].

We are able to achieve flexible electrodes using

graphite as collectors with capacitances from 20 to

50F/g with energy density of around 5 Wh/kg and

power density around 10 kW/kg. Thickness can be

modulated from some nms to tenths of µms. Our

aim is to exploit the mixing of the two

nanomaterials in order to enhance the potential

electrode surface allowing to the ions to access all

the potential surface achieving a sort of hierarchical

assembly of the nanomaterials [3]. All the materials

are put into solution using a very simple process

(Figure 2). This technique can constitute a real

breakthrough for the fabrication of new kind of

electrodes using fine mixing of nanomaterials to

improve supercapacitor performances using an

industrially suitable process, moreover compatible

with flexible surfaces. Our process is able to impact

very quickly product for everyday life and can be

considered relatively low-cost considering that it

can be easily employed in a extremely reproducible

way.

a) b)

Figure 1. a) and b) Spray-gun deposition machine

Figure 2. Carbon

Nanotubes/Graphite

solution

Figure 3. Electrode achieved

using spray-gun deposition

method

Paolo Bondavalli and

Colin Delfaure

[email protected]


TNT2012

Ab

st

ra

ct

s

References

[1] Simon, P. Gogotsi Y, Materials for electrochemical capacitors, Nature Materials, 7, 845-854, 2008.

[2] A. Izadi-Najafabadi, T.Yamada,D.N.Futaba, M. Yudasaka, H. Takagi, H. Hatori, Sumio Iijima, and K.

Hata, High-Power Supercapacitor Electrodes from Single-Walled Carbon Nanohorn/ Nanotube

Composite, , 5, 2, pp 811–819, ACNANO, 2011.

[3] Q.Cheng, J.Tang, J.Ma, H.Zhang, N. Shinyaa and L-C.Qin, Graphene and carbon nanotube composite

electrodes for supercapacitors with ultra-high energy density, Phys. Chem. Chem. Phys., 13, 17615–

17624, 2011.

[4] Nouvelle méthode pour la réalisation de dépôts modulables et reproductibles de nanomatériaux sur

des grandes surfaces et potentielles applications, P.Bondavalli, L. Gorintin, P. Legagneux, 2010 Patent

FR1004031.

[5] Procédée de fabrication d’ un assemblage collecteur-électrode pour cellule de stockage d 'énergie

électrique, assemblage collecteur-électrode cellule de stockage d'énergie, P.Bondavalli, P.Legagneux

2011 FR 11 01690.


Multiscale simulations of

irradiated nanofoams

CONICET & Instituto de Ciencias Básicas, Universidad Nacional de Cuyo,

5500 Mendoza, Argentina

Materials with nanoscale porosity appear in several

different scenarios, from radiation damage in

nuclear reactors to evolution of astrophysical dust.

Nanoscale porosity can affect mechanical

properties and evolution of radiation damage,

leading to possible tailoring of desirable properties

like enhanced ductility and radiation endurance.

We use molecular dynamics (MD) and Monte Carlo

simulations to analyze the radiation damage and

surface modification of nanofoams, i.e. solids with

large porosity at the nanoscale. Atomistic

simulations can provide valuable insights when

experimental techniques can be difficult to use and

interpret. We consider two different irradiation

regimes: (a) irradiation with ions with keV energies,

where nuclear stopping dominates radiation

damage, of interest for fusion and fission energy

applications; (b) swift heavy ion irradiation, with

energies up to few GeV, relevant for track

formation and interstellar grain evolution.

We find that irradiation effects have larger spatial

extent than for full-density solids and include the

production of point-defects and twins which

change the mechanical properties of the samples.

For swift ions, porosity does not always decrease

surface ejection [J. Rodriguez-Nieva et al.,

Astrophys. J. Letters 743, L5 (2011)]. We use our

MD results as input for a Monte Carlo (MC) code to

calculate sputtering yields from nanofoams of

different geometries under different irradiation

conditions. For keV ions, we find that nanofoams

can act as efficient sinks for radiation-induced

defects and, therefore, that they can be radiation

resistant [E.M. Bringa et al., Nano Letters 12, 3351

(2012)]. We then use our MD results to build

models which predict possible radiation endurance

under intense irradiation.

This work was carried out in collaboration with J.

Rodriguez-Nieva, J. Monk, J.A. Caro, M.J. Loeffler, T.

Cassidy, R. E. Johnson, R. Baragiola, and D. Farkas.

E. M. Bringa

[email protected]


I2–II–IV–VI4 Nanocrystals: synthesis

and thermoelectric properties

Departament Electronica, Universitat de Barcelona, Barcelona, 08028, Spain &

Catalonia Institute for Energy Research, IREC, Sant Adria del Besos, Barcelona,

08930, Spain

Today’s main strategy to produce materials with

high thermoelectric figures of merit is to trigger

phonon scattering at multiple length scales without

disturbing the charge carrier transport. The goal is

to minimize the lattice thermal conductivity in

highly electrically conductive materials; the so-

called electron-crystal phonon-glass paradigm. This

strategy is implemented by two main approaches: i)

the scattering of phonons at the atomic length

scale by the synthesis of complex crystal phases

that include 1D phonon scattering centers, such as

vacancies or rattling atoms, and/or 2D layered

crystallographic structures; ii) the scattering of

phonons at the 1-100 nm scale by reducing the

crystal domain dimensions to the nanoscale.

In this scenario, colloidal synthesis routes are

particularly well suited for the production of

thermoelectric materials. Solution-processing

methods have a high potential for the production

of low-cost, high-yield, large-scale, high-output and

shape-adaptable devices. Moreover, bottom-up

approaches allow to directly obtain

nanocomposites with reduced crystal domain size

and controlled geometry.

At the same time, some quaternary chalcogenides

have the required attributes to be potentially

excellent thermoelectric materials. Not only the

complex structures of these quaternary compounds

are associated with intrinsically low thermal

conductivities, but also their different cationic

valences provide a means of controlling their Fermi

level by adjusting their cation ratios. Besides, some

I2-II-IV-VI4 materials crystallizing in the stannite

phase are characterized by a convenient structure

layering, which allows decoupling the electrical

conductivity from both the thermal conductivity

and the Seebeck coefficient.

We will present a novel colloidal synthetic route to

prepare I2–II–IV–VI4 quaternary nanocrystals with

controlled size, shape and composition. We put

special effort in designing a cost-effective and

scalable process susceptible of being implemented

in real applications. The synthetic route is applied

to the preparation of grams of the quaternary

chalcogenide Cu2+xCd1-xSnSe4 (0 ≤ x ≤ 0.5) with

accurately controlled composition and narrow size

distributions. The electrical and thermoelectric

properties of these materials were characterized

over a wide temperature range. We will show how

these materials have high Seebeck coefficients

(150-300 μV/K), electrical conductivities up to

14000 S/m, and thermal conductivities down to

0.3 W/mK, leading to ZT values up to 0.4 at 700 K.

Besides, the advantages and disadvantages of this

bottom-up approach to produce thermoelectric

nanomaterials will be discussed.

Maria Ibáñez,

Doris Cadavid,

Joan Ramon Morante and

Andreu Cabot

[email protected]


Nanotechnology for high

frequency communications:

nitrides and graphene 1 ISOM and Dept. Ingeniería Electrónica, ETSI Telecomunicación, UPM, Campus de

Excelencia Internacional Moncloa. Avda. Complutense 30, 28040 Madrid, Spain 2 Dept. Electrical Engineering and Computer Science, Massachusetts Institute of

Technology, 77 Massachusetts Ave., Bldg. 39-567B, Cambridge, MA 02139

The achievement of higher frequencies (HF) and

the reduction of energy consumption, to improve

sensing, communication and computation, involve

the continued scaling down to the nanometer level.

This scaling is enabled by of innovative device

designs, improved processing technologies and

assessment tools, and new material structures. In

this work, we have used all these factors to

demonstrate state-of-the-art HF devices in two

materials with quite different electronic properties:

wide semiconductor bandgap III-nitrides for

resonators and power amplifiers; and graphene, a

zero bandgap material expected to revolutionize

low noise and HF flexible electronics. Some issues

faced during their development will be discussed

during the talk.

Surface acoustic wave (SAW) devices are required

for radar systems and wireless communications, as

well as for high performance sensors. These SAW

devices consist of an interdigitated transducer (IDT)

on a piezoelectric substrate with a large sound

velocity. To enhance their frequency, we exploit the

combination of a compact IDT fabricated with e-

beam lithography, the highest sound velocity

provided by a diamond substrate, and the confined

Sezawa modes in a thin AlN piezoelectric layer

deposited on top. Both the IDT period and the film

thickness are key parameters in the design and

fabrication of the devices. The sputtering

deposition of the piezoelectric layer on micro and

nanocrystalline diamond and the lithography of the

transducers are optimized. HF SAW resonators

operating in the 10-20 GHz range (Fig. 1), showing

up to 40 dB out-of-band rejection and Q factors

larger than 10,000 are demonstrated [1]. Pressure

sensors have also been developed on free standing

AlN/diamond membranes.

Figure 1. Measured and simulated reflection coefficient

(S11) (top) and susceptance (bottom) for λ=800 nm one-

port SAW resonators on a 600 nm thick AlN film on

diamond. Several resonances corresponding to Sezawa

modes are observed.

The huge power density of AlGaN/GaN high

electron mobility transistors (HEMTs) has brought

during the last decade new possibilities and

advantages for the design of wide and multiband

amplifiers. High power-gain cutoff frequency (fmax)

has been achieved by combining low-damage gate-

recess technology, scaled device geometry, and

recessed source/drain ohmic contacts to enable

minimum short-channel effects (i.e., high output

resistance Rds) and very low parasitic resistances

[2]. SiC substrates are required to minimize self-

heating, as shown in Fig. 2(a). Some challenges for

long-term reliability and device scaling, due to the

strain induced by the large lattice mismatch

between the AlGaN barrier and the GaN buffer,

Fernando Calle1 and

Tomás A. Palacios2

[email protected]


TNT2012

Ab

st

ra

ct

s

may be solved using the lattice-matched InAlN/GaN

heterostructure. LG=30 nm InAlN/GaN HEMTs on a

SiC substrate with a record fT in excess of 300 GHz

were obtained by applying an oxygen plasma

treatment [3]. The thin oxide layer on the InAlN

surface suppressed the gate leakage current,

passivated the surface, and significantly improved

the RF performance. Further efforts are dedicated

to identify the limiting factors and dominant failure

mechanisms to improve GaN-based HEMT

reliability, in particular heat spreading, by means of

diamond layers and other C-based materials such

as graphene and nanotubes.

Figure 2. Left: Tchannel vs output power for different Tamb

in devices grown on sapphire (a) and SiC (b). Right: RF

performance of the 30-nm-gate-length InAlN/GaN HEMT

with fT = 300 GHz. (From [3]).

Graphene is a carbon, one-atom-thick layer, the

thinnest but strongest material in the world. It is a

zero bandgap semiconductor with a room-

temperature electron and hole mobility above

100,000 cm2/V.s. A multidisciplinary effort among

physicists, chemists, material scientists and device

engineers has led to new electronic devices and

circuits taking advantage of its unique properties.

Some examples include RF multipliers, mixers,

modulators and demodulators [4] (see fig. 3).

Several technological issues during graphene

devices processing (including growth technique,

substrates, electrical isolation, contamination and

passivation, etc. [5]) will be discussed.

(a)

(b)

Figure 3. Top: First BN/Graphene/BN field effect

transistor with LG=400 nm. Bottom: Output power of a

HF doubler for an input signal of 8 GHz (a), and gain

frequency response (b).

The authors thank their students and colleagues at

ISOM-UPM and MIT for their contribution to this

work. That at ISOM-UPM has been funded by the

Spanish Government projects ReADi (TEC2010-19511),

AEGAN (TEC2009-14307) and RUE (CSD-2009-00046).

References

[1] J.G. Rodríguez, G.F. Iriarte, J. Pedrós, O.A. Williams,

F. Calle, IEEE Electron Dev. Lett. 33 (2012) 495.

[2] J. Chung, W. Hoke, E. Chumbes, T. Palacios, IEEE

Electron Dev. Lett. 31 (2010) 195.

[3] D.S. Lee, X. Gao, S. Guo, D. Kopp, P. Fay, T. Palacios,

IEEE Electron Dev. Lett. 32 (2011) 1525.

[4] T. Palacios, A. Hsu, H. Wang, IEEE Commun. Mag.

48 (2010) 122.

[5] F. Calle, A. Boscá, D. López-Romero, T. Palacios,

Graphene Sectorial Meeting, Castelldefels (2011).

0 50 100 150 200 2500

50

100

150

200

250

300

350

400

Gate Length Lg (nm)

Current Gain Cutoff Frequency f T (GHz)

0 100 2000

5

10

15

20

L (nm)

f T x Lg (GHz µµ µµm)

100 200

Lg (nm)

250 1 10 100 3000

10

20

30

40

50

60

Frequency (GHz)

Gain (dB)

lh21l2

fT = 300 GHz

U

Lg = 30-nm

Vds = 4 V

Vgs = -2.9 V

300

400

500

600

700

800

RTH=56 Kmm/W

RTH=45 Kmm/W

RTH=36 Kmm/W

Tchannel (K)

Sim:300 K

400 K

500 K

300 K

400 K

500 K

Sapphire substrate Exp:(a)

0 1 2 3 4 5 6 7300

400

500

600

700

800

RTH=21 Kmm/W

RTH=11 Kmm/W

Sim:

300 K

400 K

500 K

300 K

400 K

500 K

Tchannel (K)

P (W/mm)

SiC substrate Exp:

RTH=16 Kmm/W

(b)


Applications of photovoltaic fields of

iron doped LiNbO3 in

nanotechnology 1 Dpto. de Física de Materiales, Universidad Autónoma de Madrid, 28049 Madrid, Spain

2 CMAM, Universidad Autónoma de Madrid, 28049 Madrid, Spain

3 Instituto de Ciencias Biomédicas, CSIC, C/ Arturo Duperier 4 28029 Madrid, Spain

4 Dpto. de Biología, Universidad Autónoma de Madrid, 28049 Madrid, Spain

As it is well known, the bulk photovoltaic effect

(PVE) [1] appears in certain crystalline materials

(usually ferroelectrics), that show an asymmetric

crystal cell unit arrangement. It produces a

directional electronic drift when electrons are

excited to the conduction band through visible light

illumination. The drift induces a charge separation

and generates an electric field between the

illuminated edges of crystal. Reported

measurements of this electric field reach values as

high as 105 V/cm in the material employed in our

experiments, i.e. iron doped LiNbO3 [2].

In this communication we will summarize our

results in two applications of the PV fields in

nanotechnology i) micro/nanoparticle trapping and

structuring on the surface of LiNbO3 crystals, and ii)

Effects of PV fields of LiNbO3 micro- and

nanoparticles in tumour cells.

As photovoltaic material we have used congruent

LiNbO3 with a 0.1% wt Fe doping

([Fe] = 4.25×1019

cm3). In these crystals,

photovoltaic fields in the range 50-70 kV/cm have

been measured using optical techniques.

Particle trapping and structuring

Recently, a method based on the evanescent fields

generated by the bulk photovoltaic effect in iron

doped LiNbO3 has been proposed and first

experiments reported [3-5]. The main advantage of

this procedure for particle trapping is that the

involved electrophoretic and/or dielectrophoretic

forces do not require any electrodes and massive

manipulation of nanoparticles can be achieved

using the patterning capabilities of light. Then, we

have developed a set of experiments with different

kind of particles, either dielectric (CO3Ca,

polystyrene) or conducting (graphite, aluminium

and silver). Holographic patterns as well as single

beam illumination have been used. The data are

analyzed within a theoretical scheme we have

recently proposed [6]. The results allow for a more

meaningful assessment of the possible applications

of the PV effect for trapping and patterning of

nanoparticles. As an illustration, Fig. 1 shows the

particle arrangements obtained using dielectric

(CO3Ca, diameter ~1 μm) particles (a), and metallic

(silver, diameter ~100 nm) particles, (b), under

periodic light pattern with spatial periodicity Λ = 20

and 10 μm respectively. In all cases the periodicity

of the obtained pattern was the same to that of the

exciting light.

Figure 1. Particle pattern obtained on the surface of

LiNbO3 plates after sinusoidal illumination with period Λ:

(a) CaCO3 particles (Λ=20 μm) (b) silver particles

(Λ=10 μm).

Biomedical applications

We have recently demonstrated the effect of PV

fields on biological media by culturing tumour cells

on Fe:LiNbO3 plates. A massive necrotic cell death

was induced in human tumour cell cultures after

H. Burgos1, M. Jubera,

A. García-Cabañes1,

Blázquez-Castro1,

J. Espada3, J. C. Stockert

4,

F. Agulló-López1,2

and

M. Carrascosa1

[email protected]


TNT2012

Ab

st

ra

ct

s

irradiation with low intensity visible light [7]. In

order to explore the potential of PVE for future

biomedical applications we are now investigating

the effect of LiNbO3:Fe micro-nanoparticles on

tumour (HeLa) cell cultures. In a first experiment

cells were incubated with microparticles (1-3 μm

diameter). Cells did not show any morphology

change in dark whereas after 60 min irradiation

(546 nm, 133.2 J/cm2 light dose), about half of the

cells had a round and refringent aspect, i.e. they

show a certain damage. Two hours after ending

illumination most cells were necrotic as

represented in Figure 2. Control cultures (without

microparticles) exposed to 546 nm light for 60 min

showed no damage.

Figure 2. Time evolution of the number of viable (circles)

and necrotic (squares) cells evaluated through

morphological criteria for HeLa cell cultures with LNB

micro-particles. Representative viable and necrotic cells

are shown in the microphotographs at the top of both

figures. The gray bars indicate the period of green light

exposure.

The next step is to reduce particle size to a

diameter of tenths of nm to induce their

incorporation by cells. Experiments to evaluate the

effect of nanoparticles in cells for different light

doses are now in progress.

This work was supported by MICIN under grant

MAT2008-06794-C03 and MAT2011-28379-C03-01.

References

[1] B. Sturman and V. M. Fridkin, The Photovoltaic

and Photorefractive Effects in Non-

centrosymetric Materials, Gordon & Breach

Science Publishers, Amsterdam 1992.

[2] E. M. de Miguel.,J. Limeres, M. Carrascosa and

L.Arizmendi, J. Opt. Soc. Am. B 17, (2000)

1140.

[3] X. Zhang, J. Wang, B. Tang, X. Tan, R.A. Rupp, L.

Pan, Y. Kong, Q. Sun, J. Xu, Opt. Express 17,

(2009) 9981.

[4] H.A. Eggert, F.Y. Kuhnert, K. Buse, J.R.

Adleman, D. Psaltis, Appl. Phys. Lett. 90, (2007)

241909.

[5] M. Esseling, F. Holtmann, M. Woerdemann, C.

Denz, Opt. Express 18, (2010) 17404.

[6] J. Villarroel, H. Burgos, A. García-Cabañes, M.

Carrascosa, A. Blázquez-Castro, F. Agulló-

López; Opt. Express 19, (2011) 24320.

[7] A. Blázquez-Castro, J.C. Stockert, B. López-

Arias, A. Juarranz, F. Agulló-López, A. García-

Cabañes, M. Carrascosa, Photochem.

Photobiol. Sci. 10, (2011) 956.


Electronic properties and

quantum transport in doped and

defective graphene 1 Université catholique de Louvain (UCL), Institute of Condensed Matter and Nanoscience

(IMCN), Nanoscopic Physics (NAPS), Chemin des étoiles 8, 1348 Louvain-la-Neuve, Belgium 2 CIN2 (ICN-CSIC) and Universitat Autonoma de Barcelona (UAB),

Catalan Institute of Nanotechnology, Campus UAB, 08193 Bellatera (Barcelona), Spain

Graphene, a one atom-thick membrane, has

sparked out intense research activities from both

experimental and theoretical sides since almost a

decade now. The striking properties of graphene in

various fields, such as mechanical, thermal, or

electronic transport properties, are intrinsically

related to its two-dimensional aspect and to its

honeycomb lattice structure yielding both to the

peculiar electronics of Dirac Fermions. From the

electronic transport point of view, clean graphene

samples exhibit particularly long coherence length

and high electronic mobility both interesting for

devices applications in nanoelecronics. Graphene

provide simultaneously is genuine playground for

fundamental researches such as exploration of

Anderson (anti-)localization phenomena in real

two-dimensional systems.

In this presentation, simulations of electronic

transport in defective graphene membranes are

exposed. Employing tight-binding models validated

by ab initio calculations, and using a real-space

order-N Kubo-Greenwood transport method [1-2],

the effect of structural defects disrupting the ideal

honeycomb lattice is investigated theoretically. The

effect of various concentrations of “point defects”

such as vacancies and Stone-Wales defects on both

the electronic and transport properties of graphene

is examined. Using molecular dynamics simulations,

highly defective graphene membranes presenting

domains of amorphous graphene structure [3] are

created, and their transport properties are carefully

inspected. Structural defects are found to induce

strong resonant scattering states at different

energies depending on the nature and the

concentration of defects. These induced resonant

scattering states can yield to extremely short mean

free paths and low mobilities. At low temperatures,

they also lead to an enhanced contribution of

quantum interferences driving to localization

phenomena in the quantum transport regime. In

case of highly defective graphene membrane, the

amorphization of the structure changes the system

into a strong two-dimensional Anderson insulator

material [3], which could be experimentally

confirmed by the observation of a variable range

hopping transport behavior at low temperatures.

The modification of the electronic properties of sp2

carbon nanostructures by the controlled addition of

foreign atoms into the carbon lattice has been

widely proposed and investigated, in close analogy

to the doping of silicon in the semiconductors

industry. However, in contrast with conventional

materials, the effect of foreign atoms in

nanostructures is expected to depend significantly

on the position and surrounding of each atom due

to the quantum confinement of the electrons. In

principle, the fact that nitrogen atoms contain one

additional electron than carbon, suggests that

nitrogen doped carbon nanostructures will exhibit

the characteristics of an n-type material [4].

Furthermore, recent experiments on graphene

reveal through scanning tunneling microscopy

(STM) images, that N doping can occur in different

kinds of geometries [4]. This presentation explores

different configurations for nitrogen atoms

incorporated onto graphene, and investigates their

effects and properties using ab initio electronic

structure calculations. The computed total and

local density of states reveal specific signatures for

each type of defect, which could be correlated with

experimental scanning tunneling spectroscopy (STS)

measurements. In addition, STM images are

Jean-Christophe Charlier1,

Aurelien Lherbier1,

Andrés R. Botello-Méndez1

and Stephan Roche2

jean-

[email protected]


TNT2012

Ab

st

ra

ct

s

presented in order to aid the eventual large scale identification of these defects. Our calculations, and recent

experimental observations suggest that the classically assumed nitrogen incorporations into graphitic

structures (i.e., single substitution and pyridinic), are not necessarily the most common [4]. It is generally

true, however, that substitution defects (single, double substitution) dopes graphene with electrons, and

vacancy-nitrogen complexes (e.g. pyridinic, or single nitrogen + vacancy) add holes to the system.

References

[1] A. Lherbier, S.M.-M. Dubois, X. Declerck, S. Roche, Y.M. Niquet, and J.-C. Charlier, Phys. Rev. Lett. 106, 046803

(2011). [2] A. Lherbier, S.M.-M. Dubois, X. Declerck, Y.M. Niquet, S. Roche, and J.-C. Charlier, Phys. Rev. B 86, 075402 (2012).

[3] A. Lherbier, S. Roche, O.A. Restrepo, Y.M. Niquet, A. Delcorte, J.-C. Charlier, submitted for publication (2012).

[4] R. Lv, Q. Li, A.R. Botello-Méndez, et al., NATURE Scientific Reports, in press (2012).


Electronic stucture of

topological insulators a Departamento de Física de Materiales, Facultad de Ciencias Químicas, UPV/EHU,

Apdo. 1072, 20080 San Sebastián, Basque Country, Spain b Donostia International Physics Center (DIPC), Paseo de Manuel Lardizabal, 4,

20018 San Sebastián/Donostia, Basque Country, Spain c Centro de Física de Materiales, CFM-MPC, Centro Mixto CSIC-UPV/EHU,

Apdo.1072, 20080 San Sebastián/Donostia, Basque Country, Spain d Tomsk State University, pr. Lenina 36, 634050, Tomsk, Russian Federation

e Institute of Strength Physics and Materials Science,

pr. Academicheskiy 2/4, 634021, Tomsk, Russian Federation f Max-Planck-Institut für Mikrostrukturphysik Weinberg 2, D-06120, Halle, Germany

g Graduate School of Science, Hiroshima University,

1-3-1 Kagamiyama, Higashi Hiroshima 739-8526, Japan h Physik-Institut, Universität Zürich,

Winterthurerstrasse 190, CH-8057 Zürich, Switzerland

The recently discovered three-dimensional

topological insulators (TIs) belong to a class of

insulators in which the bulk gap is inverted due to

the strong spin-orbit interaction [1]. A direct

consequence of such bulk band structure arises at

the surface: the spin-polarized topologically

protected massless metallic states, forming a Dirac

cone [2-5]. These surface states (SS) exhibit many

interesting properties resulting from the fact that

the spin of electron is locked perpendicular to its

momentum, thus forming a SS spin structure that

protects electrons from backscattering. This makes

topological insulators potentially promising

materials for creation of new quantum devices.

Here recent theoretical and experimental results on

electronic structure obtained for new families of TIs

are presented. Comparison of topological surface

states with classical and Rashba split surface states

as well as Dirac cone state in graphene is given. The

origin of buried topological surface states is

discussed. Materials science problems and

perspectives in the field of TIs are discussed.

References

[1] M. Z. Hasan and C. L. Kane, Rev. Mod. Phys. 82,

3045 (2010).

[2] K. Kuroda et al., Phys. Rev. Lett., 105, 076802

(2010).

[3] S. V. Eremeev, Yu. M. Koroteev, and E. V.

Chulkov, JETP Lett. 92, 161 (2010).

[4] K. Kuroda et al., Phys. Rev. Lett., 108, 206803

(2012).

[5] S.V. Eremeev et al., Nature Communications,

3, 635 (2012).

Evgueni V. Chulkova,b,c

,

Sergey V. Eremeevb,d,e

,

Tatiana V. Menshchikovad,

Maia Vergnioryb,

Yury M.Koroteevb,d,e

,

Arthur Ernstf,

Jürgen Henkf, A. Kimura

g

and J. Hugo Dilh


New implementations of the orbital

minimization method in the SIESTA

code

a CIC nanoGUNE Consolider, E-20018 Donostia-San Sebastián, Spain

b Department of Earth Sciences, University of Cambridge, Downing Street,

Cambridge CB2 3EQ, United Kingdom

The orbital minimization method (OMM) is the

general name given to a class of iterative

minimization algorithms devised for solving the

generalized eigenvalue problem in the context of

linear-scaling DFT [1]. The central idea of the

method is to find the Wannier functions of the

electronic system that describe the occupied

subspace by direct unconstrained minimization of

an appropriately constructed functional [2,3]. The

method is made to scale linearly with system size

by imposing a localization radius on the Wannier

functions, which in turn determines the truncation

range of the density matrix.

Unfortunately, the OMM suffers from a serious

problem of multiple local minima, requiring in

practice that the initial guess reflect the correct

bonding properties of the system. Alternatively,

Kim et al. [4] have proposed to work with more

orbitals than those needed to span the occupied

subspace, leading to a linearly dependent basis.

This eliminates the local minima problem, but

introduces the electronic chemical potential as an

unknown parameter.

We report on several new implementations of the

OMM in the SIESTA [5] DFT code, that aim to

exploit the efficiency and stability of the method

while circumventing the limitations described

above.

Firstly, we show the potential of the original OMM

method as a conventional DFT solver (without the

linearscaling approximation), as the local minima

are no longer present when the Wannier functions

are allowed to extend over the whole system. The

algorithm is therefore both accurate and efficient,

due to the fact that no explicit orthogonalization

operation is required between orbitals, and that

the solution from each minimization can be reused

iteratively for multiple self-consistent field steps

and ab initio MD steps. We also show that the

sparsity pattern of the Hamiltonian matrix in SIESTA

can be used in this context to significantly reduce

the computational cost; in conclusion, the method

has proven to be competitive with explicit

diagonalization even in small systems despite the

large ratio of occupied states to total basis size that

is used in SIESTA and other atomic orbital codes.

Secondly, we discuss a number of approaches for

imposing the correct electron number in the

augmented OMM of Kim et al. that can be used

with Wannier localization for linear-scaling DFT

calculations; we report on an automated

adjustment of the chemical potential to preserve

electron number, a projected gradient method and

a normalization transformation of the Wannier

function coefficients. We discuss the connection

between our approaches and those used in density

matrix methods; in particular, the OMM presents

further challenges in this respect due to the fact

that we do not have direct access to the density

matrix in the Wannier basis. Finally, we present

initial results for a modified OMM functional that

allows for smeared Fermi level calculations (pseudo

finite temperature), opening up the possibility of

performing linear-scaling DFT for metallic systems

in SIESTA.

Fabiano Corsettia and

Emilio Artachoa,b

[email protected]


TNT2012

Ab

st

ra

ct

s

References

[1] D. R. Bowler and T. Miyazaki, Rep. Prog. Phys., 75 (2012) 036503.

[2] P. Ordejón, D. A. Drabold, R. M. Martin, and M. P. Grumbach, Phys. Rev. B, 51 (1995) 1456.

[3] F. Mauri, G. Galli, and R. Car, Phys. Rev. B, 47 (1993) 9973.

[4] J. Kim, F. Mauri, and G. Galli, Phys. Rev. B, 52 (1995) 1640.

[5] J. M. Soler et al., J. Phys.: Condens. Matter, 14 (2002) 2745.


Enhanced performance of carbon

nanotube field-effect transistors due

to gate-modulated electrical contact

resistance

Sandia National Laboratories, MS9161, Livermore, CA, USA

Due to their unique electrical properties, carbon

nanotubes (CNTs) have attracted a great deal of

interest for their potential in next-generation

nanoelectronics [1,2]. While individual CNTs can

exhibit favorable electronic properties, it is often

the CNT/metal contacts that govern the behavior

and performance of CNT devices [3,4]. Thus, it is

important to develop a fundamental understanding

of contacts to CNTs in order to fully realize the

potential of CNT devices. Recent experimental work

[5,6] has provided new insight by demonstrating

that the nanotube/palladium (Pd) contact

resistance depends on the contact length, and that

appropriate control of the contacts allows for the

realization of high-performance short-channel CNT

field-effect transistors (FETs) with subthreshold

swings that surpass those expected from

conventional scaling theory. This last result is

particularly important not only for technology, but

also because it suggests that new paradigms govern

the properties of these nanoscale transistors. For

example, it has been suggested that modulation of

the contacts by the gate, a phenomenon not

usually observed in conventional transistors, could

lead to such behavior [6].

In this work [7], we use numerical simulations to

study these recent experimental measurements

and explicitly demonstrate that the superior scaling

behavior is due to a strong modulation of the

contacts by the gate. This results not only in

modulation of the band alignment at the contact,

but also leads to a novel phenomenon where the

subthreshold swing is dominated by gate control of

the near-contact region in the channel. This gives

rise to subthreshold swings for short-channel

devices that are below what is predicted by

standard theory, allowing for improved

performance.

The simulated CNT FET is shown in Figure 1. For

this work, we consider a (16,0) nanotube with a

diameter (dCNT) of 1.2 nm, which matches the

average size of the CNTs in Ref. 5. We also consider

two different contact geometries. In Figure 1a,

there is metal both above and below the nanotube,

as a model for a CNT completely embedded in

metal. In Figure 1b, we consider a contact where

the metal only sits on top of the CNT. To determine

the transport properties of the FET, we use a self-

consistent non-equilibrium Green’s function (NEGF)

approach [8] that allows us to calculate the low-

bias current through the device.

Figure 1. Schematic of a carbon nanotube field-effect

transistor. In part (a) the source and drain metals are

above and below the nanotube (embedded contact),

while in part (b) the metal only sits on top of the

nanotube (top contact).

Using the NEGF approach, we calculated the

transfer characteristics of the CNT FETs for channel

and contact lengths that match the experimental

devices. The results are shown in Figure 2, where

the experimental data is given by the symbols and

the theoretical data is given by the solid lines. The

top row of Figure 2 shows the results for Lch = 40

nm, the middle row is for Lch = 20 nm, and the

Aron W. Cummings and

François Léonard

[email protected]


TNT2012

Ab

st

ra

ct

s

bottom row is for Lch = 15 nm. The left column

shows the simulation results for embedded

contacts (see Figure 1a), while the right column is

for top contacts (see Figure 1b). The experimental

data is the same for both columns. An important

feature of the experimental data is the extremely

good scaling of the transistor characteristics as the

channel length is reduced. Indeed, comparing the

experimental data for the channel lengths of 40, 20,

and 15 nm in Figure 2, one can see that the

subthreshold swing is essentially unchanged as the

channel length is scaled down. While the thin HfO2

dielectric provides good control over the FET

channel, our simulations indicate that this by itself

is not sufficient to explain the good subthreshold

behavior. This can be seen by comparing the left

and right columns of Figure 2. The left column

shows the simulation results for the embedded

contacts. In this case, the theoretical subthreshold

swing is much larger than the experimental value

for small channel lengths, and we see a poor fit to

the experimental results. However, when we

remove the metal below the CNT, the subthreshold

swing is significantly reduced for the short-channel

devices and we obtain excellent agreement with

the experimental data, as shown in the right

column of Figure 2. Thus, the geometry of the

contact plays a crucial role in determining device

performance and scaling, and the improved

behavior upon removing the bottom metal

indicates a strong influence of the gate on the

contact properties.

In summary, we presented simulations of short-

channel ballistic CNT FETs that explain recent

experimental results using Pd contacts. We have

reached the important conclusion that the contacts

are strongly modulated by the gate when no

bottom metal contact is present, allowing for lower

subthreshold swings for short channels and

improved scaling behavior. This result introduces

important design considerations for CNT electronic

devices, and should also apply to devices made of

other nanomaterials such as nanowires and

graphene.

Figure 2. Current vs. gate voltage for short-channel CNT

FETs. The top, middle, and bottom rows are for Lch = 40,

20, and 15 nm, respectively. The left (right) column is the

case for embedded (top) contacts. The symbols

represent experimental results from Ref. 5, and the solid

lines represent the results from numerical simulations.

References

[1] J.-C. Charlier, X. Blase, and S. Roche, Rev. Mod.

Phys. 79 (2007), 677-732.

[2] P. Avouris, Z. Chen, and V. Perebeinos, Nat.

Nanotechnol. 2 (2007), 605-615.

[3] Z. Chen, J. Appenzeller, J. Knoch, Y. Lin, and P.

Avouris, Nano. Lett. 5 (2005), 1497-1502.

[4] F. Léonard and A. A. Talin, Nat. Nanotechnol. 6

(2011), 773-783.

[5] A. D. Franklin and Z. Chen, Nat. Nanotechnol. 5

(2010), 858-862.

[6] A. D. Franklin, M. Luisier, S.-J Han, G. Tulevski,

C. M. Breslin, L. Gignac, M. S. Lundstrom, and

W. Haensch, Nano Lett. 12 (2012), 758-762.

[7] A. W. Cummings and F. Léonard, ACS Nano, in

press, DOI: 10.1021/nn301302n.

[8] S. Datta, Electronic Transport in Mesoscopic

Systems (Cambridge University Press,

Cambridge, 1995).


Silicon-based

quantum electronics

CEA, Grenoble, France

Low-dimensional silicon-based nanostructures

constitute a versatile and convenient platform for

novel electronic devices with quantum

functionalities. After a brief overview of the most

promising development routes, I shall report on a

recent experiment in which we have been able to

observe a gate-tunable tunneling current through a

series of two donor atoms embedded in the

channel of a multi-gate silicon transistor. The

lowest energy states, corresponding to a single

electron on either of the two donors, form a two-

level system well separated from all other

electronic levels. Gigahertz driving results in a

quantum interference pattern associated with the

absorption or the stimulated emission of up to ten

microwave photons, from which we estimate a

charge dephasing time of 0.3 nanoseconds. This

experimental achievement is an essential step

towards either charge- or spin- based quantum

computing devices in silicon.

Related publications:

[1] Katsaros et al., “Hybrid superconductor-

semiconductor devices made from self-

assembled SiGe nanocrystals on silicon”,

Nature Nanotechnology 5, 458 (2010).

[2] Katsaros et al., “Observation of spin-selective

tunneling in SiGe nanocrystals”, Phys. Rev.

Lett. 107, 246601 (2011).

[3] Dupont-Ferrier et al., “Coupling and coherent

electrical control of two dopants in a silicon

nanowire”, arXiv:1207.1884v1.

Silvano De Franceschi


Nanoclays as adsorbents of organic

contaminants for a sustainable

application

Facultad de Ciencias Químicas

Plaza de la Merced s/n- 37008 Salamanca

University of Salamanca - Spain

Thanks to the development of the science and the

technology of the nourishment in the last 50 years,

there have revealed itself several new substances

that can fulfill beneficial functions in the food, and

these substances, named food additives, are today

within reach of all. The food additives recover a

very important role in the complex nourishing

supply. The additives fulfill several useful functions

in the food, which often we give for sat.

Nevertheless the widespread use of food additives

in the food production also influences the public

health. The food industries, which are very

important for the economy, spill residues proved

from its activity that they have to be controlled to

evaluate the environmental impact and to offer the

necessary information about the quantitative

evaluation of the chemical risk of the use of food

additives for the public health.

The clay materials have led to numerous

applications in the field of public health (del Hoyo,

2007; Volzone, 2007) having been demonstrated its

effectiveness as adsorbents of all contaminants.

Some biodegradable materials are used for for

adsorption of chemical contaminants: lignins

(Valderrabano et al., 2008) and also clays and clay

minerals, whose colloidal properties, ease of

generating structural changes, abundance in

nature, and low cost make them very suitable for

this kind of applications.

Among the strategies used at present to preserve

the quality of the water and this way to diminish

the environmental risk that supposes the chemical

pollution, stands out the use of adsorbents of

under cost, already they are natural or modified, to

immobilize these compounds and to avoid the

pollution of the water with the consequent

reduction of environmental and economic costs.

Regarding innocuous and low cost materials, it is

necessary to mention clays and clay minerals,

which colloidal properties, facility of generating

structural modifications, abundance in the nature

and low cost make them very adapted for the

adsorption of chemical pollutants. The clayey

materials have given place to numerous

applications to preserve the water contamination

and its efficiency having being demonstrated as

natural or modified adsorbents of all kinds of

pollutants (Yariv, 2002). We have studied the

adsorption of several food additives by natural or

thermally modified clays, searching their

interaction mechanisms and the possible recycling

of these materials for environmental purposes and

prevention of the public health.

There are different materials used in the adsorption

and immobilization of chemical contaminants, most

of whom remain under patent, so they do not know

the procedures and products used, but in all cases

the safety and / or biodegradability of materials

used is an important issue in their choice for

environmental applications. The most used are

based on the use of organo-montmorillonites and

hydrotalcite (del Hoyo et al., 2008; Undabeytia et

al. 2008).

Likewise, by means of mechanical and chemical

treatments clays can be transformed in materials

with a high surface (> 300m2) and high reactivity.

The acid treatment causes the partial dissolution of

the octahedric layer giving place to an increase of

Carmen del Hoyo Martínez,

Jorge Cuéllar Antequera,

Vicente Sánchez Escribano,

Marina Solange Lozano

García and Raul Cutillas Díez

[email protected]


TNT2012

Ab

st

ra

ct

s

the acid sites type Brönsted (Torrers Sánchez et al., 1999). Other treatments of the clays that might

optimize the adsorption of organic compounds, are the utilization of the grinding by attrition and the

thermal treatment of clays (del Hoyo et al., 1999). The grinding by attrition provokes a modification in the

crystalline structure of the clays, which produces a change in the properties of superficial load, modification

of the coordination of the octahedric Al and irreversible collapse of the interlayer.

We have studied the adsorption of several contaminants by natural or modified clays, searching their

interaction mechanisms and the possible recycling of these materials for environmental purposes and

prevention of the health.

References

[1] del Hoyo, C., Rives, V., Vicente, M.A. (1999). PhD Thesis. Drug-clay systems. University of Salamanca.

[2] del Hoyo, C.; Dorado, C.; Rodríguez-Cruz, S.; Sánchez-Martín, M.J. (2008). Journal of Thermal Analysis

and Calorimetry. 1, 1-8. Physico-chemical study of selected surfactant-clay mineral systems.

[3] del Hoyo, C. (2007b). Applied Clay Science. 36, 103-121.Layered Double Hydroxides and human health:

An overview.

[4] Torres-Sánchez L, Lopez-Carrillo L, Ríos C. (1999). Salud Pública de México. 41, 106-108. Lead

elimination by traditional acidic curing.

[5] Undabeytia T., Nir S, Sanchez-Verdejo T, Morillo, E. Water Research. 42. 1211-1219. (2008). A

clayvesicle system for water purification from organic pollutants.

[6] Valderrábano, M., Rodríguez-Cruz, S., del Hoyo, C., Sánchez-Martín, M.J. (2006). 4th International

Workshop "Bioavalailability of pollutants and soil remediation". 1, 5-6. Physicochemical study of the

adsorption of pesticides by lignins.

[7] Volzone, C. (2007). Applied Clay Science. 36, 191-196. Retention of pollutant gases: Comparison

between clay minerals and their modified products.

[8] Yariv S., Cross H. (2002). Marcel Dekker, New York, U.S.A. 225 pp. Organo-clays complexes and

interactions


Optical studies and defect properties

of GaP/GaNP core/shell nanowires 1 Department of Physics, Chemistry and Biology, Linköping Univ, 581 83 Linköping, Sweden

2 Department of Physics, University of California, San Diego, La Jolla, California 92093, USA

3 Graduate Program of Material Science and Engineering, University of California, San

Diego, La Jolla, California 92093, USA 4 Department of Electrical and Computer Engineering, University of California, San Diego,

La Jolla, California 92093, USA

III-V core/shell nanowires (NWs) have recently

attracted much attention due to their potential

applications in optoelectronic and photonic

devices, in particular solar cells and LEDs. Among all

III-V compounds, GaP-based materials have the

smallest lattice mismatch to Si and are, therefore,

the best candidate for epitaxial growth of III-V

materials on Si substrates. Adding a small amount

of N to GaP allows one to tune the band gap energy

and also to change the band gap character from an

indirect one in GaP to a direct-like one in the GaNP

alloys, leading to improvements in light emission

efficiency. Unfortunately, the above described

properties desired for optoelectronic applications

have not been fully utilized, largely due to

degradation of optical and electrical properties

caused by defects present in GaNP. The growth of

these materials in the form of NWs offers the

possibility to overcome the limitations. In this work,

we investigate optical properties and influence of

defects on optical quality of the GaP/GaNxP1-x

core/shell NWs grown on Si (111) substrates

employing temperature-dependent

photoluminescence (PL), time-resolved PL and

optically detected magnetic resonance (ODMR)

measurements.

The GaP/GaNxP1-x core/shell NW samples with

x = 0.9% studied in this work were grown by gas-

source molecular beam epitaxy (MBE). For a

comparison, a 250 nm-thick GaN0.009P0.991 epilayer

grown by gas-source MBE on a (001)-oriented GaP

substrate was also investigated. Scanning electron

microscopy (SEM) showed that the GaP/GaNP NWs

are uniform in sizes and have an axial length of

about 2.5 μm, a total diameter of about 220 nm,

and a typical diameter of the GaP core of ~110 nm.

By using a variety of optical characterization

techniques we demonstrate the NWs grown on Si

substrates have an excellent optical quality that is

comparable to that of the GaNP epilayer grown on

GaP substrates. In all structures, the PL spectra

have the same line shape and originate from

radiative transitions within N-related localized

states. However, the core/shell NW samples have

weaker PL intensity and faster PL decay at room

temperature, indicative for a higher defect density

leading to efficient nonradiative recombination.

From the performed ODMR measurements, the

responsible defects most likely involve a P atom at

their core and are located either at the GaP/GaNP

interface or at the GaNP surface. The high defect

density in the NWs is tentatively attributed to a

high surface-to-volume and interface-to-volume

ratios in these structures.

A. Dobrovolsky1, S. Chen

1,

J. Stehr1, Y. J. Kuang

2,

S. Sukrittanon3, H. Li

4,

C. W. Tu3,4

, W. M. Chen1,

and I. A. Buyanova1

[email protected]


Identification of

nanocavities water content 1 Departamento de Física de Materiales, Facultad de Ciencias, Universidad Autónoma de

Madrid, Cantoblanco 28049 Madrid, Spain. 2 Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones

Científicas, Cantoblanco, 28049 Madrid, Spain.

Water condensation at the nanoscale is known to

play an important role in the collapse of virial

capsids during desiccation [1]. The meniscus

formation along with the geometry of the

nanocavity allows capillary force to modify the

mechanical stability towards collapse [2]. The

changes on the near field optics, during the

desiccation process, may be a good tool showing

how this process takes place. Indeed, scan near

field optical microscope (SNOM) can characterize

sample composition by the changes in the optical

near field. Since the virial capsides are almost

transparent at optical wavelengths [3], different

water contents in these nanocavities will produce

different output signals distinct enough to

characterize the desiccation sequence by SNOM

experiments. Here we present a theoretical study in

which we combine the lattice gas model to

simulate water meniscus formation and a finite

difference time domain (FDTD) algorithm for light

propagation through the media involved. We

simulate a tapered dielectric waveguide that scans,

at constant height, a sample containing a virial

capsides (Fig. 1). Our results show different

contrasts related to different water contents (Fig.

2) and different meniscus orientations. We propose

this method as a way to study water content and

evaporation process in nanocavities being either

biological, like virial capsides, or nonbiological like

photonic crystals.

References

[1] C. Carrasco, M. Douas, R. Miranda, M.

Castellanos, P.A. Serena, J.L. Carrascosa, M.G.

Mateu, M.I. Marqués, and P.J.d. Pablo,

Proceedings of the National Academi of

Science, 106 (2009) 5475-5480.

[2] P.A. Serena, M. Douas, M.I. Marqués, C.

Carrasco, P.J.d. Pablo, R. Miranda, J.L.

Carrascosa, M. Castellanos, and M.G. Mateu,

Physica Status Solidi C, 6 (2009) 2128-2132.

[3] W. M. Balch, J. Vaughn, J. Novotny, D. T.

Drapeau, R. Vaillancourt, J. Lapierre, and A.

Ashe, Limnol. Oceanogr., 45 (2000) 492-498

Figure 1. Schematic representation of the region of

interest for the simulated tapered coated optical fiber

tip. The tip is used for illuminating the region under the

aperture, while transmitted signal is detected at a

distance of 100 nm form the sample (Integration plane).

Maysoun Douas1,2

,

Manuel. I. Marqués1 and

Pedro. A. Serena2

[email protected]


TNT2012

Ab

st

ra

ct

s

Figure 2. Optical signal intensity maps coming from the contribution of both, water content and nanocavity during the

desiccation process, we have removed the signal due to the absence of virial capside, therefore both positive and

negative values are present. Water occupation is100 % (A), 75% (B) and 50% (C).


EELS-HAADF spectrum imaging for

characterization of (AlGa)N

multilayer heterostructures 1 Lab. of Electron NanoScopies, LENS-MIND-IN2UB, Dept. Electrònica,

Universitat de Barcelona, Spain 2 Inst. de Sistemas Optoelectrónicos y Microtecnología, ISOM, Univ. UPM, Spain

3 Also at Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5–7,

D-10117 Berlin, Germany 4 Laboratorio de Microscopías Avanzadas (LMA) - INA and Departamento de Física de la

Materia Condensada, Universidad de Zaragoza, 50018 Zaragoza, Spain 5 Fundación ARAID, 50004 Zaragoza, Spain.

6 TEM-MAT, (CCiT), Universitat de Barcelona, Solís i Sabarís 1, Barcelona, Spain

Group III nitride materials promise production of optoelectronic devices that cover the entire visible range thanks to their widely–tunable room–temperature band gap energy. Nevertheless, in–plane lattice mismatch between the binary components is an issue affecting their design and growth. This causes proneness of the structures to present defects at the interfaces between compounds, finally decreasing the overall performance of the devices. In the present case we deal with a heterostructure of the binaries AlN/GaN for the configuration of distributed Bragg reflectors (DBR) [1-3]. Reflectivity and X-ray diffraction reciprocal space mapping (XRD–RSM) measurements have been performed in high reflectivity, crack–free, 6, 10 and 20 period AlN/GaN multilayer structures grown by Molecular Beam Epitaxy. These methods are useful for testing optical and structural properties of the samples, viewed as a whole. Furthermore, the sample is thoroughly probed at a local scale through combined high angle annular dark field (HAADF) and low-loss electron energy loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM) equipped with an aberration corrected and a monochromator. Our own-made computer routines are presented as they are useful in the automatization of the analysis of this kind of spectra [4-5]. The combination of these techniques and the great quality of the measured data allows us to recover information of the sample at the nanoscale, with sub-eV energy resolution (for the

EEL spectra [6]). Besides the complete structural characterization of the AlN and GaN layers, the formation of AlGaN transient layers is demonstrated (thick and thin, see Fig.1). The origin of these layers is investigated and its impact in the DBRs optical properties is discussed. Z contrast HAADF imaging shows that structural quality is preserved through the formation of transient AlGaN layers with exceptionally high reproducibility of the segregation phenomenon (See Fig.1). Peak reflectivity and stopband width results are presented for all the samples and compared to theoretically expected values. The analysis points out that to further improve the optical performance of the DBRs, the thicker transient AlGaN interlayer has to be significantly reduced. This would increase interface abruptness and decrease the “thickness disorder” bringing thus direct benefits to the peak reflectivity and stopband width. The mechanisms to control interlayer thickness remain unclear at the moment, constraining thus further advance. Reflectivity in our samples is high (> 90%), and XRD-RSM has shown a good structural quality, assessed by HAADF-STEM micrographs showing a crack–free, highly periodic structure, up to 20 periods. The widths of four layers that compose the periodic heterostructure are measured through the combined HAADF-EELS techniques: ~ 10, 15, 50 and 15 nm for AlGaN1 (AlN–on–GaN), GaN, AlGaN2 (GaN–on–AlN) and AlN layers.

A. Eljarrat1, L. López-

Conesa1, Ž. Gačević2, S. Fernández-Garrido2,3, E. Calleja2, C. Magén4,5, S. Estradé1,6 and F. Peiró1

[email protected]


TNT2012

A

bs

tr

ac

ts

Finally, hyper-spectral images at the nanoscale are analyzed with some new designed specialized computer routines. These retrieve important information for the chemical and structural characterization of some anomalous segregations in the multilayer heterostructure (See Fig.1). 2D maps are produced measuring and filtering properties present in the spatially localized spectra. Among these properties are the plasmon excitation, relative thickness or zero-loss-peak (elastic scattering). The combination of EELS and HAADF in STEM has proved to be a valuable tool in the characterization of structural properties from local measurements with great spatial resolution and chemical sensibility.

References

[1] T. Ive, O. Brandt, H. Kostial, T. Hesjedal, M. Ramsteiner, and K. H. Ploog, Appl. Phys. Lett. 85 (2004).

[2] G. Koblmueller, F. Wu, T. Mates, J. Speck, S. Fernandez-Garrido, and E. Calleja, Appl. Phys. Lett. 91 (2007).

[3] G. Koblmueller, R. Averbeck, L. Geelhaar, H. Riechert, W. Hosler, and P. Pongratz, J. Appl. Phys. 93 (2003).

[4] A. Eljarrat, Z. Gacevic, S. Fernández-Garrido, E. Calleja, C. Magén, S. Estradé, and F. Peiró, Journal of Physics: Conference Series 326 (2011).

[5] Z. Gacevic, S. Fernández-Garrido, D. Hosseini, S. Estradé, F. Peiró, and E. Calleja, J. Appl. Phys. 108, 113117 (2010).

[6] R. F. Egerton, Rep. Mod. Phys. 72, 016502 (2009).

Figure 1. (a) STEM-HAADF image of a 20-period AlN/GaN DBR showing the full structure, from the GaN buried layer at right hand side to the top of the DBR. The high periodicity of the structure is appreciated in this image, while lower panel (c) shows a detail of two successive periods. Top graph, (b), shows the aluminum ratio profiles (circles) calculated through Vegard Law analysis of the plasmon excitation energy position along with the HAADF intensity profile (blue). Below, (d) shows the result of determining the plasmon excitation energy (chemically sensitive) in a whole hyperspectral image datacube, corresponding to a nanoscale anomalous segregation.


Electronic properties of

graphene edges

Department of Chemistry, Tokyo Institute of Technology,

2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551, Japan

The presence of edges significantly modifies the

electronic properties of graphene where low

energy electrons behave like massless Dirac

fermions. When graphene is cut into pieces and

edges are introduced into the infinite π-electron

system, the electronic properties near the edges

are changed from the intrinsic one. The resultant

modulation of the electronic states depends on the

distinct type of graphene edge termination called

zigzag- and armchair- directions (Fig. 1), which

correspond to the two fundamental crystal

directions of bipartite lattice. Graphene bipartite

lattice consists of inequivalent A and B hexagonal

sublattices, in which zigzag direction is defined as a

line across A-A (B-B) atoms, while armchair

direction is a line along A-B atoms.

In this presentation, we report the results of

scanning probe characterization of the two finite

effects on the electronic properties near the

graphene edges. The standing wave state is

identified as superperiodic patterns in observed π

states of armchair-terminated graphene edges [1]

and nanographene [2]. The standing wave state is

highly correlated with geometry-dependent

electronic properties of polycyclic aromatic

hydrocarbon molecules in terms of Clar theory. The

observed π state with √3a×√3a periodicity (a = 0.25

nm) in armchair-terminated nanographene

fragments that is prepared by chemical oxidation of

graphene [2] (Fig. 2) is in good agreement with

expected π-electron distributions based on the Clar

theory. In Clar theory armchair-terminated

nanographene is characterized by localization of

aromatic sextets, which is analogous to the

localized standing wave due to the interference.

The edge state is characterized as enhanced

amplitude of local density of state (LDOS) at the

zigzag edges, in which energy dispersion of the π

state reveals a sharp distribution at the Fermi level

[3]. The observed high-resolution LDOS image of

the zigzag edge that is prepared by expansion of

atomic vacancies of graphite by exposure of atomic

hydrogen [4] shows good matching with simulated

Toshiaki Enoki and

Shintaro Fujii

[email protected]

Figure 1. Schematic illustration of zigzag- and armchair-

edges.

Figure 2. Observed π state with √3a×√3a periodicity in

armchair-terminated nanographene fragments.


TNT2012

Ab

st

ra

ct

s

image based on density functional theory (Fig. 3).

The key point in achieving well-defined zigzag

edges is to perform all preparation and

measurement procedures strictly under the ultra-

high vacuum conditions, avoiding contact with

ambient environment. As predicted from π-

electron distributions based on the Clar theory,

zigzag-terminated nanographene has π radical

character at the edge sites, indicating that the

zigzag edge site is chemically reactive and can be

oxidized in ambient conditions. In general,

electronic properties of graphene edges can be

altered by edge terminations and therefore it is

essential to gain better understanding of the

influence of edge chemistry on the edge state. We

will thus focus on the experimental characterization

of modified edge states musty due to variation in

edge terminations such as di-hydrogenated- and/or

klein- sites. Depending on the edge terminations

the edge state i.e. the enhanced LDOS at the edge

sites is vanished. Detail will be discussed in

combination with DFT simulations.

Figure 3. Experimental LDOS image of hydrogenated

zigzag edge (left) and simulated DFT image (right).

References

[1] Sakai, K., Takai, K., Fukui, K., Nakanishi, T.

and Enoki, Phys. Rev. B 81 (2010) 235417-1-7.

[2] Fujii, S.; Enoki, T. Angew. Chem. Int. Ed. (2012),

10.1002/anie.201202560 and 10.1002

/ange.201202560.

[3] Kobayashi, Y., Fukui, K., Enoki, T. and Kusakabe,

K., Phys. Rev. B 73 (2006), 125415-1-8.

[4] M. Ziatdinov, S. Fujii, K. Kusakabe, M. Kiguchi,

T. Mori, and T. Enoki, to be submitted.


Integration of plasmonics

within a CMOS environment

CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex, France

We are interested in assessing the potential of

plasmonics for improved optical performances in

various fields of applications such as imaging,

sensing and integrated Si-photonics. Indeed the use

of nanostructured metals can help achieve, for

example, compact color filters or low loss, low

energy consumption optical components. We have

taken up the corresponding challenges of the

development of large scale fabrication of plasmonic

components, in a microelectronic environment

such as the one provided by the CMOS platforms at

CEA-LETI.

I will highlight some noticeable realizations of past

years, and emphasize the peculiarities of CMOS

plasmonics. For example, elementary CMOS

processes can be used to fabricate metallic optical

filters in the IR range whose rejection properties

are interesting for imaging and sensing applications

[1]. We also demonstrated that Cu interconnect

technology can be very valuable to achieve low

optical loss plasmonic functionalities, thanks to

very high quality materials. Impact of grain

boundaries on the plasmon propagation at a Cu

surface will be illustrated [2], as well as use of Cu in

some Si-photonics integrated devices such as

couplers [3] or electro-optical modulators [4].

Throughout those examples, I will discuss the

CMOS compatibility of plasmonics in terms of

technological process and devices’ reliability.

References

[1] J. Le Perchec, et al., Optics Express 19 (2011)

15720.

[2] H.S. Lee, et al, Optics Express 20 (2012) 8974.

[3] C. Delacour, et al, NanoLetters 10 (2010) 2922.

[4] A. Emboras, et al., Optics Express 20 (2012)

13612.

Roch Espiau de Lamaestre


Angular dependence of the

tunneling magnetoresistance in

nanoparticle arrays

Dpto. Física de Materiales, Universidad del Pais Vasco, 20018 San Sebatian, Spain

Due to the small size of the nanoparticles, the

transport through metallic nanoparticle arrays is

governed by the Coulomb blockade physics. To add

one charge to a nanoparticle costs a finite energy,

the charging energy Ec. The transport is suppressed

for energies smaller than the charging energy. Once

there is current through the system, it is a strongly

non-linear function of the voltage because of the

charging effects [1]. When the nanoparticle arrays

are placed between two ferromagnetic electrodes,

the interplay between the ferromagnetism and the

charging effects controls the transport through the

system. In the case of a single nanoparticle if the

spin relaxation time is long, spin accumulation

appears when the magnetic moments of the

electrodes have anti-parallel orientation, but not

for parallel one. In a recent paper [2], it has been

showed that the interplay between ferromagnetism

and charging effect has a dramatic influence on the

nanoparticle arrays, leading to unexpected results.

For arrays with N≥ 3 nanoparticles, there is a

regime with large negative differential conductance

and a huge enhancement of the tunneling

magnetoresistance with respect to the cases of one

or two nanoparticles, see Fig. 1. How these effects

are affected by different factors as asymmetry,

dimensionality, disorder or range of interaction

have been also analyzed [3]. The works [2,3] have

been done for parallel and antiparallel magnetic

orientations of the electrodes. Now we want to

study the case in which the magnetization

directions of the electrodes are noncollinear. This

means that the magnetization directions of the

electrodes form an angle θ, that is different to 0 or

π. For noncollinear magnetization, the spin

accumulation at the nanoparticles, the flow of

current and the tunneling magnetoresistance will

depend on θ [4], as occurs in the case of a single

nanoparticle, see Fig 2.

Figure 1. Tunneling magnetoresistance as a function of

the bias voltage for different arrays sizes at KBT=10-4

Ec ,

and spin polarization p=0.7. Main figure: arrays of

N=3,10 and 20 nanoparticles. Inset: values for one and

two nanoparticles.

Figure 2. Tunneling magnetoresistance as a function of θ

for a single nanoparticle at KBT=10-4

Ec, and p=0.7.

References

[1] E. Bascones, V. Estévez, J.A. Trinidad, and A.H.

MacDonald, Phys. Rev. B, 77 (2008) 245422.

[2] V. Estévez and E. Bascones, Phys. Rev. B, 83

(2011) 020408 (R).

[3] V. Estévez and E. Bascones, Phys. Rev. B, 84

(2011) 075441.

[4] V. Estévez and K.Y. Guslienko, in preparation.

V. Estévez and

K.Y. Guslienko

[email protected]


Towards sub-100nm resolution

chemical mapping by XRF combined

to simultaneous topography

Aix Marseille Université, CNRS, CINaM UMR 7325, 13288, Marseille, France

The aim of our work is to develop new

instrumentation providing physical and chemical

characterization of individual nanoobjects. For that

purpose, we have designed and fabricated a new

characterization tool combining X-Ray Spectroscopy

and Shear Force Microscopy, working at ambient

conditions, allowing surface topography

measurement simultaneously to chemical mapping

[1,2]. This apparatus is based on the visible

luminescence collection of a sample through the

microscope probe. However, this apparatus only

allows the study of luminescent materials, limited

mainly to semiconductors. To extend the use of the

technique to a wider range of materials, we want

now to collect the X-ray Fluorescence instead of the

visible luminescence during SFM scan, in a similar

concept, as shown in Fig. 1.

Figure 1. Scheme of the instrument principle designed to

simultaneous collect XRF and topography, based on a

Shear-Force Microscope

An incident X-ray beam laterally irradiates a sample

which emits XRF collected through an X-ray

monocapillary and analyzed by an EDX detector.

Approached in near-field mechanical interaction

with the surface and vibrating thanks to a quartz

tuning fork, its apex can be used as a probe of a

shear-force microscope head. This equipment is

thus able to combine simultaneous chemical

mapping and topography of a sample.

For that purpose, we have designed a test-bed to

show the feasibility of this project. Experiments

achieved with a 10 µm diameter X-ray capillary

used for detection carried out with an in-lab

microfocused source show high signal to noise

ratio. Extrapolation of signal intensity that can be

expected if the capillary used is shrunk to 1 µm and

indicate that the concept is realistic in lab, and that

sub 100 nm lateral resolution is achievable in

synchrotron environment.

References

[1] C. Fauquet, M. Dehlinger, F. Jandard, S.

Ferrero, D. Pailharey, S. Larcheri, R. Graziola, J.

Purans, A. Bjeoumikhov, A. Erko, I. Zizak, B.

Dahmani and D. Tonneau, Nanoscale Research

Letters, 6 (2011) 308.

[2] M. Dehlinger, C. Dorczynski, C. Fauquet, , F.

Jandard, A. Bjeoumikhov, S. Bjeoumikhova, R.

Gubzhokov, A. Erko, I. Zizak, D. Pailharey, S.

Ferrero, B. Dahmani, D. Tonneau, Int. J.

Nanotechnol., 9 No 3-7 (2012) 460.

X-ray fluorescence

Xray

monocapillary

Sample

Excitation X-ray beam

EDX detector

pinhole

Quartz

tuning fork

X-ray fluorescence

Xray

monocapillary

Sample

Excitation X-ray beam

EDX detector

pinhole

Quartz

tuning fork

C. Fauquet, M. Dehlinger,

S. Lavandier and

D. Tonneau

[email protected]


Nano-dispersed particles in Fe(Crx)

and their performance under dual

(He+Fe) and triple (H+He+Fe) ion

beam irradiation 1 Lawrence Livermore National Laboratory, Livermore, CA

2 Department of Nuclear Engineering, University of California, Berkeley, CA

Considerable research has been performed on

irradiated nano-dispersed ferritic-martensitic steels

to deduce their radiation hardening and

embrittlement behavior. At low doses (1-5 dpa) the

radiation hardening and DBTT shift saturates [1].

Higher dose studies are necessary to confirm this

behavior and to also investigate the effects of

helium and hydrogen production at relevant doses

for fusion conditions. These studies can be

accomplished with triple beam irradiation where

displacement damage is produced by heavy-ions

and hydrogen and helium are injected

“simultaneously”. A particularly interesting

candidate material class is the nano scale oxide

dispersed strengthened (ODS) steels.

Figure 1. The triple ion beam chamber at CEA Saclay

where heavy ions, H, and He can simultaneously

irradiate one or more specimens (p’vt communication).

Several radiation mechanisms are likely to

determine the upper temperature limit for these

steels: thermal creep and loss of strength, high

temperature helium (and hydrogen) embrittlement,

void swelling (accelerated by helium and

hydrogen), and corrosion [1]. The objective for

accelerated ion-beam testing of materials is to

define more accurately the operational

temperature limits for specific materials and to

identify any unknown mechanisms for materials

degradation that would put these material(s) out of

specification for nuclear energy design purposes.

Dual and triple multiple simultaneous ion-beam

(MSIB) irradiations were conducted at JANNUS-

Saclay (see Figure 1) followed by TEM and

micromechanical post irradiation examination. Fe-

14Cr alloy and K3-ODS steel coupons that were

irradiated with 24 MeV Fe+8

ions to produce

displacement damage and energy-modulated He

and H ions were implanted simultaneously to

emulate the production of transmutation products

from nuclear reactions. The displacement damage,

in dpa (displacements per atom), from Fe8+

, as a

function of depth into the specimen, and the He

and H implantation profiles were deduced using the

SRIM code. A typical calculated profile of the dual

(Fe+He) and triple (Fe+He+H) beam implant is

shown in Figure 2. As shown, the overlap region for

the dpa, He, and H was chosen to be at a shallower

depth than the implanted Fe to avoid the “added

ion effect”.

The scientific challenge is to understand the

relationship between materials processing of the

nano-dispersed steel and its radiation performance.

Our experiments are thus focusing on helium

management, cavity growth, and mechanical

property changes as they relate to structure of the

nano-particles.

M. J. Fluss1, L. Hsiung

1,

S. Tumey1, B. William Choi

1

and P. Hosemann2


TNT2012

Ab

st

ra

ct

s

Figure 2. SRIM Calculation of the implantation profile in

Fe of 24 MeV Fe and energy degraded He and H. The dpa

produced by the Fe is shown and the He and H implants

are given in terms of appm/dpa.

We will report some preliminary measurements of

the mechanical properties as a function of the

depth from the surface into the irradiated volume

of the irradiated materials utilizing FIB extracted

and FIB shaped specimens followed by micro-

mechanical testing; indentation and pillar

compression. These measurements reveal the

robustness of the ODS steel to radiation induced

changes in mechanical properties.

Figure 3. A HRTEM image of helium bubbles in

association with “cluster domains” of various shape.

Here each helium bubble appears as white contrast

surrounded by a dark Fresnel fringe in each

underfocused image. The image shows the trapping of

several individual bubbles at a disordered cluster

domain, which suggests that the appearance of cluster

core/bubble shell is a result of the coalescence of small

bubbles as conceptualized in the illustration on the right.

In earlier work [2] we have characterized the

nature of helium sequestration at the nano-

particle/matrix interface. In these TEM

examinations of the irradiated ODS steel we have

discovered that the nano-particle size distribution

can be heavily biased to sub nano-meter scale

particles. This discovery (see Figure 3) has led us to

explore, in more depth, the processing origin of the

structure of the nano-particles. From this work we

have deduced that a complex chemistry during the

consolidation of the precursor powders influences

crystallization, stoichiometry, and leads to the well-

known core-shell structure observed for the nano-

dispersoids in ODS steels. Controlling these

complex chemical and kinetic processes may well

be a key to optimizing the material microstructure

so as to achieve the best radiation tolerance and

long-term performance.

This work was performed under the auspices of the

U.S. Department of Energy by Lawrence Livermore

National Laboratory under Contract DE-AC52-

07NA27344. This work was funded by the

Laboratory Directed Research and Development

Program at LLNL under project tracking code 12-SI-

002.

References

[1] S.J. Zinkle, and N.M. Ghoniem, Fusion

Engineering and Design 51–52 (2000) 55–71,

and N. Baluc et al, Nucl. Fusion 47 (2007)

S696–S717, and E.E. Bloom, S.J. Zinkle , F.W.

Wiffen, Journal of Nuclear Materials 329–333

(2004), pp. 12–19.

[2] L. L. Hsiung, M. J. Fluss, S. J. Tumey, B. W. Choi,

Y. Serruys, F. Willaime, and A. Kimura, Phys.

Rev. B 82, 184103 2010.


Entropy-driven phase transition in

dense packings of athermal chain

molecules

Institute of Optoelectronics and Microsystems (ISOM) and

ETSII, Universidad Politecnica de Madrid (UPM),

Jose Gutierrez Abascal 2, 28006, Madrid, Spain

The random or ordered packing of objects has been

in the spotlight of research since early times. How

spheres, cubes, disks, whether oranges, candies or

molecules, stack up when poured into a vessel is an

intriguing problem with a wide range of practical

applications in colloids, engineering, biology,

materials and polymer science. Hard spheres

constitute the simplest, nontrivial model which

captures interactions based exclusively on the

concept of excluded volume; as such it is amenable

to analytic approaches. Simulations on

crystallization in monomeric hard-sphere packings

were first presented back in 1950s in the works of

Wood and Jacobson [1] and Alder and Wainwright

[2]. Given that athermal systems do not incur into

energetic gains or penalties upon configurational

transitions, entropy is the driving force for phase

transition (crystallization) [3,4]. It is now well

established that given sufficient time, crystal

nucleation and growth can be naturally observed in

monomeric hard-sphere assemblies at all packing

densities above the melting point [5].

While the disorder-order transition and the

corresponding crystal nucleation and growth are

readily observable in simulations of monoatomic

hard spheres the modeling of the corresponding

process in dense packings of hard-sphere chains

(macromolecules) remained, until recently, elusive.

Whether the chain connectivity and the related

holonomic constraints completely halt, partially

frustrate or even do not affect at all, athermal

crystallization remained a controversial topic.

In the present contribution we employ extensive

Monte Carlo (MC) simulations, based on chain-

connectivity-altering algorithms, to generate and

successively equilibrate random (disordered)

packings of freely-jointed chains of tangent hard

spheres of uniform size [6]. Through this modeling

approach thousands of statistically uncorrelated

configurations of the simulated chain systems are

generated at concentrations ranging from very

dilute up to the close vicinity of the maximally

random jammed (MRJ) state [7] within modest

computational time [8].

The degree of ordering (crystallization) is

monitored by means of the characteristic

crystallographic element (CCE) norm [9], a strictly

monotonic and structure-discriminating measure of

order based on the point symmetry group of the

local environment of a site. The CCE norm has been

shown to sensitively and quantitatively detect

changes in local ordering, while identifying the

emerging ordered structure with high specificity

[9]. Once applied to the athermal polymer packings

the CCE norm revealed that in the absence of any

external influence the hard-sphere chains were

observed to systematically and spontaneously

crystallize at all packing densities above 0.56 [10].

Furthermore, the observed phase transition

appears to be insensitive to variations in chain

length and polydispersity, and the crystallinity of

the established stable phase increases with

increasing concentration [11].

By far the most salient feature of the crystal

polymer structures is the presence of a randomly

stack-faulted, layered morphology with a single

stacking direction (Fig. 1). Thus, incipient nucleus

consists of parallel, two-dimensional layers of

either hexagonal close packed (hcp) or face center

cubic (fcc) character in random alternation.

Katerina Foteinopoulou,

Nikos Ch. Karayiannis,

Manuel Laso

[email protected]


TNT2012

Ab

st

ra

ct

s

To understand better the driving mechanism and

the entropic origins of the phase transition we

study the rearrangement of local free volume

around each site. Here, local density is determined

as the reciprocal of the volume of the

corresponding Voronoi polyhedron. It is shown that

local free volume becomes more spherical and

more symmetric through the phase transition. In

turn, ordered sites are able to explore their local

vicinity more efficiently increasing their mobility.

Thus, there is a significant increase in translational

entropy which drives the nucleation and growth of

crystals.

Finally, we discuss some recent simulation findings

on the effect of the intensity of the holonomic

constraints (here in the form of bond lengths) on

the ability of chains to crystallize at packing

densities near the melting transition.

Current insights from athermal polymer

crystallization can shed light on the role of entropy

in chemically more complicated phenomena like

protein folding and crystallization in the bulk and

under confinement.

References

[1] W. W. Wood and J. D. Jacobson, J. Chem. Phys.

27 (1957) 1208.

[2] B. Alder and T. Wainwright, J. Chem. Phys. 27

(1957) 1208.

[3] L. Onsager, Ann. N. Y. Acad Sci. 51 (1949) 627.

[4] D. Frenkel, H. N. W. Lekkerkerker and A.

Stroobants, Nature 332 (1988) 822.

[5] M. D. Rintoul and S. Torquato, Phys. Rev. Lett.

77 (1996) 4198.

[6] N. C. Karayiannis and M. Laso, Macromolecules

41 (2008) 1537.

[7] S. Torquato, T. M. Truskett and P. G.

Debenedetti, Phys. Rev. Lett. 84 (2000) 2064.

[8] N. C. Karayiannis and M. Laso, Phys. Rev. Lett.

100 (2008) 050602.

[9] N. C. Karayiannis, K. Foteinopoulou and M.

Laso, J. Chem. Phys. 130 (2009) 074704.

[10] N. C. Karayiannis, K. Foteinopoulou and M.

Laso, Phys. Rev. Lett. 103 (2009) 045703.

[11] N. C. Karayiannis, K Foteinopoulou, C. F.

Abrams and M. Laso, Soft Matter 6 (2010)

2160.

Figure 1. System configurations at (a) early stage of simulation (amorphous packing), and (b) late stage where the

majority of sites possess a highly ordered local environment. Blue and red colored spheres correspond to sites with fcc-

like and hcp-like local order, respectively (c) and (d) same as in (a) and (b) but all sites are colored according to the

parent chain [10].


Molecular Dynamics simulation of

liquid metals for nuclear fusion

technology

Instituto de Fusión Nuclear, ETSII, Madrid Spain

Liquid metals and alloys could be present in future

nuclear reactors as breeder blankets (coolant and

tritium production system) and/or plasma facing

materials in wet walls, divertors in magnetic

confinement reactors etc [1, 2]. In breeding

blankets tritium and helium will be produced by Li

splitting but tritium extraction and tritium

interaction with helium bubbles is still far from

being well understood. Lithium-Lead eutectic alloy

is one of the most promising candidates because of

its low chemical activity compared to pure lithium

and good breeding ratio [3]. Here we present some

atomistic simulations in hydrogen liquid metal

systems. We have studied H (and its isotopes)

diffusion in two different liquid metals making use

of two different interatomic potentials, namely an

Embedded Atom Method (EAM) potential for Pd-H

system [4] and one more advanced EAM/angular

dependent potential for Al-H system [5]. A full

theory of H behavior in liquid metals is, to date,

lacking and experimental results are scarce. Also we

have developed a Li-Pb EAM interatomic potential

capable to predict LiPb eutectic properties [6] after

careful validation of Li and Pb EAM potentials [7-9].

Capabilities to reproduce database are shown. We

address several features dealing to H diffusion in

liquid metals as well as self diffusion of Li in LiPb

systems.

Figure 1. Diffusivity values for H in Al and Pd (see inset)

compared with host metal self-diffusivity (black

squares). H diffusivity (blue line) is close to the

calculated (red = Theory) just as DH= DM√mM where mM

stands for the mass of the host metal.

Alberto Fraile,

Santiago Cuesta-López,

J. Manuel Perlado,

Roberto Iglesias and

Alfredo Caro

[email protected]


TNT2012

Ab

st

ra

ct

s

References

[1] V A Evtikhin1 et al. Lithium divertor concept and results of supporting experiments. 2002 Plasma Phys.

Control. Fusion 44 955

[2] Norajitra P. The EU advanced dual coolant blanket concept, Fusion Eng. Des. 61–62 (2002) 449–453.

[3] Wong C. P. C. An overview of dual coolant Pb–17Li breeder first wall and blanket concept development

for the US ITER-TBM design. Fusion Engineering and Design 81 (2006) 461–467.

[4] X. W. Zhou and J. A. Zimmerman, B. M. Wong and J. J. Hoyt. An embedded-atom method interatomic

potential for Pd–H alloys. J. Mater. Res., Vol. 23, No. 3, Mar 2008

[5] F. Apostol and Y. Mishin. Angular-dependent interatomic potential for the aluminum-hydrogen system.

Phys. Rev. B 82, 144115 (2010).

[6] A. Fraile, S. Cuesta-López, A. Caro, J. M. Perlado. To be published.

[7] Zhou X. W. Atomic scale structure of sputtered metal multylayers. Acta Mater. 49, 4005 (2001).

[8] Belashchenko D. Application of the Embedded Atom Model to Liquid Metals: Liquid Lithium. High

Temperature vol 47 No 2 211-218.(2009).

[9] A. Fraile, S. Cuesta-López, R. Iglesias, A. Caro and J. M. Perlado. Submitted to Journal of Nuclear

Materials.

[10] E. M. Sacris and N. A. D. Parlee. The diffusion of hydrogen in liquid Ni, Cu, Ag, and Sn. Metallurgical and

Materials Transactions B. Vol. 1, No 12 (1970), 3377-3382.

[11] E. Ahmed, J. I. Akhter, M. Ahmad. Molecular dynamics study of thermal properties of noble metals.

Computational Materials Science 31 (2004) 309–316

[12] A. Meyer. Self-diffusion in liquid copper as seen by quasielastic neutron scattering. Phys. Rev. B 81,

012102 (2010)

[13] A. Meyer. Determination of self-diffusion coefficients by quasielastic neutron scattering measurements

of levitated Ni droplets. Phys. Rev. B 77, 092201 (2008).


Light emission statistics as a local

probe for structural phase switching 1Instituto de Estructura de la Materia, CSIC, Serrano 121, 28006 Madrid, Spain

2Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid,

28049 Madrid, Spain 3Instituto de Microelectrónica de Madrid, CSIC, Isaac Newton 8, Tres Cantos, 28760

Madrid, Spain

The statistical properties of light transport and

emission in disordered media has been a matter of

intense research during the last century. Being the

basis of coherent multiple scattering of waves well

known, the phenomenon itself is not yet fully

explored and understood. These multiple wave

scattering effects are at the heart of emerging

behaviors like Anderson localization of light and

electrons, band structure in crystalline solids or

photonic crystals (PhC), among many others.

Although the limits of perfectly ordered systems on

the one hand, and uncorrelated and relatively

weakly scattering systems on the other hand, are

quite well understood. There is a gap between both

limits which is largely unexplored. In particular, it

has been shown in many different situations that

disordered systems exhibiting certain structural

correlations can share properties of both crystalline

and fully disordered systems. For instance, the

conductivity of liquid metals [1] or the cornea

transparency [2] can be understood in the same

footing: a disordered but correlated system can

present spectral regions of high transparency for

electron or light transport.

The effects of disorder in an initially ordered

structure, such as a PhC, might lead to strong

Anderson localization, as the scattering mean free

path can be severely reduced in the band edges [3].

Also, strongly correlated charged colloids can

scatter light in such a way that the transport mean

free path presents a strong chromatic dispersion

[4]. Even in the absence of practically any long

range correlations, the structure of the scatterers

itself can be used to modify the light emission and

transport properties of a disordered system in such

a way that transport parameters [5], or even the

threshold of a random laser [6], can present

resonances which can be tuned in advance.

The effect of correlations in a disordered structure

regarding light emission properties of single

fluorescent emitter has been a matter of much less

intense research efforts. It is clear that the

structure surrounding a single emitter can largely

alter its emission dynamics [7]. In the last years,

several groups considered such effects in a

statistical way suitable for the description of

disordered systems [7,8,9]. In particular, in ref.[9] it

was shown that several structural properties near a

phase transition can be accessed via fluorescence

intensity fluctuations.

It has been theoretically proven that near field

scattering in random systems alters fluorescence

dynamics in such a way that microscopic

information about the surroundings of a single

emitter can be obtained from lifetime fluctuations

or from the shape of the statistical distribution tails

[10,11].

In this presentation, we theoretically show how, in

the previous context, fluorescence emission rate

statistics are largely altered due to the appearance

of structural correlations in a disordered system.

We have developed a model of point resonant

interacting scatterers which are placed at random.

Emission dynamics of a single emitter is calculated

for each sample of an ensemble of structural

realizations of the system.

While keeping constant the scattering properties of

single scatterers, the global geometry, and

scatterers density, the structural correlations are

Luis S. Froufe-Pérez1,

N. de Sousa2, J.J. Sáenz

2 and

A. García Martín3

[email protected]


TNT2012

Ab

st

ra

ct

s

controlled changing the temperature of the

interacting set of scatterers.

It is shown that fluorescence decay rate statistics of

a the single emitter correlates with the structural

phase transitions of the system. In the low

temperature limit, the structure freezes in an face

center cubic lattice. This structure presents a gap

(frequency range of low photonic density of states)

corresponding to a small fluorescence decay rate.

As usual, it also presents narrow frequency

windows of high density of states, corresponding to

band edges of the perfect infinite crystalline

structure, leading to high decay rates.

At frequencies corresponding to both a band gap

and a band edge, we perform decay rate statistics

varying the temperature of the system. It is shown

that, at low temperature, decay rates hardly

fluctuates and its average value corresponds to the

crystalline one. On temperature raising,

fluctuations of decay rate grow, and the averaged

values undergoes a relatively sharp transition to a

different value. This transition can be identified

with a structural phase transition in the system.

Interestingly, there is a narrow range of

temperatures in which a strongly confined system

can switch between two metastable structures

which can be identified with liquid and gas. In this

phase switching region, the statistical properties of

the emission dynamics of a single emitter

immersed in the system is strongly coupled to the

structural phase switching. Hence, performing

lifetime statistics can serve as a tool for monitoring

phase switching and nucleation dynamics in

volumes comparable with the emission wavelength

or smaller.

References

[1] N. W. Aschcroft and J. Lekner, Phys. Rev. 145

(1966) 84.

[2] [2] R. W. Hart and R. A. Farrell, J. Opt. Soc. Am.

59 (1969) 766.

[3] Sajeev John, Phys. Rev. Lett. 58 (1987) 2486.

[4] L. F. Rojas-Ochoa, J. M. Mendez-Alcaraz, J. J.

Sáenz, P. Schurtenberger, and F. Scheffold,

Phys. Rev. Lett. 93 (2004) 073903.

[5] P. D. García, R. Sapienza, A. Blanco, and C.

López, Adv. Mater. 19, 2597 (2007); R.

Sapienza, P.D. García, J. Bertolotti, M.D.

Martín, A. Blanco, L. Viña and C. López, D.S.

Wiersma, Phys. Rev. Lett. 99, (2007) 233902.

[6] S. Gottardo, R. Sapienza, P.D. Garcia, A. Blanco,

D. S. Wiersma and C. Lopez, Nat. Phot. 2

(2008) 429.

[7] Jordi Hernando, Erik M. H. P. van Dijk, Jacob P.

Hoogenboom, Juan-José García-López, David

N. Reinhoudt, Mercedes Crego-Calama, María

F. García-Parajó, and Niek F. van Hulst, Phys.

Rev. Lett. 97 (2006) 216403.

[8] H. Gersen, M. F. García-Parajó, L. Novotny, J. A.

Veerman, L. Kuipers, and N. F. van Hulst, Phys.

Rev. Lett. 85 (2000) 5312.

[9] R. A. L. Vallee, M. Van der Auweraer W. Paul

and K. Binder, Phys. Rev. Lett. 97 (2006)

217801.

[10] L. S. Froufe-Pérez, R. Carminati and J. J. Sáenz,

Phys. Rev. A 76 (2007) 013835.

[11] L. S. Froufe-Pérez and R. Carminati, Phys. Stat.

Sol. (a) 205 (2008) 1258.


Graphene plasmonics

1 IQFR – CSIC, Serrano 119, 28006 Madrid, Spain

2 ICFO, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain

We will discuss the extraordinary optical properties

of highly doped graphene, along with new classical

and quantum phenomena involving plasmons in

this material. Doped graphene can host low-energy

collective plasmon oscillations with unprecedented

levels of spatial confinement, large near-field

enhancement, and long lifetimes, which facilitate

their application to enhanced light-matter

interaction, optical detection, sensing, and

nonlinear optics. Graphene plasmons only exist

when the carbon sheet is electrically charged, as

they involve collective motion of the doping charge

carriers, and their frequencies, which scale up with

the doping density, can be readily controlled

through electrostatic gates, thus opening a realistic

avenue towards electrical modulation of plasmon-

related phenemona. We will start with a tutorial

description of graphene plasmons and a critical

comparison with conventional noble-metal

plasmons. A summary of recent experimental

observations will be presented, including spatial

mapping of confined graphene plasmons and

spectroscopic evidence of plasmon-mediated

resonant absorption [1]. Theoretical descriptions of

graphene plasmons will be examined, ranging from

classical electromagnetic theory to first-principles

quantum-mechanical approaches. We will elucidate

the conditions under which quantum nonlocality

shows up in the optical response of this material.

The interaction with quantum emitters (e.g.,

quantum dots) placed in the vicinity of the carbon

sheet will be shown to reach the strong-coupling

regime and potentially serve as a robust platform

for quantum-optics devices that can achieve

temporal control of plasmon blockade, Rabi

splitting, super-radiance, and other quantum

phenomena via electrostatic doping [2]. Classical

devices for infrared spectroscopy, sensing, and light

modulation will be also discussed [3]. Prospects to

extend these phenomena to the visible and near-

infrared regimes will be examined. These advances

in graphene constitute a viable realization of strong

light-matter interaction, temporal control of

quantum phenomena, and ultrafast electro-optical

tunability in solid-state environments, thus bringing

the expectations raised within the field of

plasmonics closer to reality.

Figure 1. Complete optical absorption (top) and

quantum plasmon blockade (bottom) in graphene.

References

[1] Chen et al., Nature 487, 77 (2012); Fei et al.,

Nature 487, 82 (2012).

[2] Manjavacas, Nordlander, and García de Abajo,

ACS Nano 6, 1724 (2012).

[3] Thongrattanasiri, Koppens, and García de

Abajo, Phys. Phys. Lett. 108, 047401 (2012).

Sukosin Thongrattanasiri1,

Alejandro Manjavacas1,

Frank Koppens2 and

Javier García de Abajo1

[email protected]


Progress towards a single SWAP

molecule with Ruthenium complexes:

DFT study on a gold surface

CEMES-CNRS

29 rue Jeanne-Marvig

F-31055 Toulouse, France

The idea of embedding molecules in between

electrodes to make an electronic device that could

perform the basic functions of digital electronics

begin in the 70's . Due to the intrinsic difficulties of

connecting one molecule to another to make

complete circuits, it was proposed [1] to use just a

single molecule: “mono-molecular electronics”

which could integrate the hole circuit.

One possibility to arrive to these “mono molecular

circuits” is to divide the molecule in “qubits” in

order to exploit the quantum engineering

developed for several years around quantum

computers [2].

The project to be developped consists in

synthetising a molecule which could be able to

realize a logical function such an inversor (SWAP).

This molecular logic gate would be made of

Ruthenium (III) and (II) metal centers [3,4,5], which

magnetic interaction could be turned on/off by

changing the oxidation state of the central

molecule using an appropiate light radiation.

It is very important to have a good understanding

of the behaviour of the building blocks of the target

molecule. In particular we present a DFT study of

the building blocks (Ru (II) and Ru (III) complexes)

on Au(111) in order to understand the magnetic,

electronic and geometrical properties of this

complexes. Especially how the ligands can affect

the magnetism and transport properties of these

metal complexes when adsorbed on surfaces. Some

recent experimental STM images on these

complexes will also be presented.

This work is part of a collaboration between Univ.

Zaragoza-INA and CEMES-CNRS within the TRAIN2

project (Trans-Pyrenees Action on Advanced

Infrastructures for Nanosciences and Nanotechnology).

References

[1] C. Joachim, J.K. Gimzewski, A. Aviram, Nature, 2000,

408, J41.

[2] M.A. Nielsen, I.L. Chiang, Quantum computation &

quantum information, Cambridge University Press

2000.

[3] Synthesis and characterization of

bis(bipyridine)ruthenium(II) complexes with bromo

and protected ethynyl ß-diketonato ligands. S.

Munery, J. Jaud & J. Bonvoisin. Inorg. Chem.

Commun.(2008)11,975-977.

[4] Synthesis and characterization of ß-diketonato

ruthenium(II) complexes with two 4-bromo or

protected 4-ethynyl-2,2’-bipyridine ligands. C. Viala &

J. Bonvoisin. Inorg. chim. Acta (2010) 363, 1409-1414.

[5] Synthesis and characterization of a series of

ruthenium tris(ß-diketonato) complexes with UHV-

STM investigation and numerical calculations. S.

Munery, N. Ratel-Ramond, Y. Benjalal, L. Vernisse, O.

Guillermet, X. Bouju, R. Coratger & J. Bonvoisin. Eur. J.

Inorg. Chem. (2011), 2698–2705.

[6] UHV-STM Investigations and Numerical Calculations

of a Ruthenium β-Diketonato Complex with Protected

Ethynyl Ligand: [Ru(dbm)2(acac-TIPSA)]Loranne

Vernisse, Sabrina Munery, Nicolas Ratel-Ramond,

Youness Benjalal, Olivier Guillermet, Xavier Bouju,

Roland Coratger, and Jacques Jean BonvoisinJ. Phys.

Chem. C, Just Accepted ManuscriptDOI:

10.1021/jp304523f.

S. García-Gil,

J. Bonvoisin and

X. Bouju

sandra.garcia-gi l @ cemes.fr


Tuning physical properties of

polymers by nanoconfinement

Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid, Spain

Arrays of polymer nanostructures exhibit an

interesting behavior that makes them promising

candidates for use in photonics, electronics,

mechanical, and sensor devices [1-3]. High aspect

ratio (length/diameter) one-dimensional (1D)

nanostructures are also appropriate for studying

size-dependent processes with length scales

comparable to the nanostructures’ size.

Figure 1. SEM image of PVDF nanostructures prepared

by solution template wetting. Side view and top view

(inset) showing the nanorod morphology when the

alumina template has been removed.

Material properties strongly depend upon

molecular order and orientation. Crystallization is

one of the simplest molecular-scale self-

organization processes capable to control spatially

the ordering of molecules and hence to tune the

properties of partially crystalline polymer

nanostructures, as they will largely depend upon

the properties of their crystalline domains. Recent

studies of polymer crystallization in restricted

geometries shed some light on the possibility of

controlling crystallization at the nanoscale. Some of

the methods used allow well-defined

nanostructures to be generated, such as via

nanoimprint lithography (NIL) [2], and template

wetting [1, 3].

Wetting of porous anodic aluminum oxide (AAO)

templates has been used in this work for the

preparation of 1D polymer nanostructures. This

technique is based on the fact that both polymer

melts and solutions tend to wet the walls of

nanoporous templates avidly if the walls exhibit a

high surface energy [4] (see Figure 1).

This contribution will cover recent research on

these phenomena, demonstrating the use of

wetting nanoporous alumina (AAO) template with

polymer solution to produce arrays of

poly(vinylidene fluoride) (PVDF) ferroelectric γ-type

nanorods supported onto a nonpolar α-structure

film (Figure 2). The method is based upon a crystal

phase transition due to PVDF confinement within

alumina nanoporous [5]. Based on the previous

experience, we extended our research to

poly(vinylidene-co-trifluoroethylene) (PVDF-TrFE)

random copolymer nanoarrays. X-ray

microdiffraction using synchrotron radiation has

been performed at ID13 beamline (European

Synchrotron Radiation Facility). Scanning the

sample with 1 µm diameter X-ray beam, from the

residual polymer film (bulk) to the nanorod array,

we have investigated the effects of confinement on

5 µµµµm

200 nm

5 µµµµm

200 nm200 nm

Mari Cruz García-Gutiérrez,

Amelia Linares,

Jaime J. Hernández,

Ignacio Martín-Fabiani,

Daniel R. Rueda and

Tiberio A. Ezquerra

[email protected]


TNT2012

Ab

st

ra

ct

s

crystal phase transition, degree of crystallinity and

crystal orientation with the aim of optimizing the

ferroelectric properties of polymer nanostructures

for their application in organic electronics [6].

Acknowledgements: The authors thank the financial

support from the MICINN (grant MAT2011-23455).

Figure 2. Two-dimensional X-ray diffraction patterns

recorded in transmission geometry. (top) Diffraction

pattern of the residual PVDF film and (bottom)

diffraction pattern of PVDF nanorods inside porous

alumina. The SAXS region of the patterns has been

enlarged and presented as insets.

References

[1] C. R. Martin, Science, 266 (1994) 1961.

[2] Z. Hu, M. Tian, B. Nysten, A.M. Jonas, Nat.

Mater., 8 (2009) 62.

[3] M. Steinhart, R.B. Wehrspohn, U. Gösele, J.H.

Wendorff, Angew. Chem. Int. Ed. 43 (2004)

1334.

[4] M. Zhang, P. Dobriyal, J.T. Chen, T.P. Russell, J.

Olmo, A. Merry, Nano Lett., 6 (2006) 1075.

[5] M.C. García-Gutiérrez, A. Linares, J.J.

Hernández, D.R. Rueda, T.A. Ezquerra, P. Poza,

R. Davies, Nano Lett., 10 (2010) 1472.

[6] S.J. Kang, I. Bae, Y.J. Shin, Y.J. Park, J. Huh, S-M.

Park, H-C. Kim, C. Park, Nano Lett., 11 (2011)

138.

α α α α form


Light-matter coupling

mediated by surface plasmons

Departamento de Física Teórica de la Materia Condensada and IFIMAC,

Universidad Autónoma de Madrid, Madrid 28049, Spain

In this talk I will analyze two phenomena associated with light-matter coupling and in which surface plasmon

polaritons (SPPs) play a key role. First I will present a fundamental study on how SPPs in a quasi one-

dimensional plasmonic waveguide can be used to engineer the entanglement between two distant qubits.

This two-qubit entanglement is due to the dissipative part of the effective qubit-qubit coupling provided by

the SPPs. The second part of my talk will be devoted to present the theoretical foundation of the

phenomenon of strong coupling between quantum emitters and propagating SPPs observed in two-

dimensional metal surfaces. The case of a single emitter will be analyzed first, exploring the range of

parameters in which the strong coupling regime could emerge. Then we study an ensemble of N quantum

emitters and incorporate the presence of dephasing mechanisms and external pumping into the theoretical

framework. In the final part of the talk the capabilities of graphene surface plasmons to act as mediators in

different light-matter coupling scenarios will be discussed

.

Francisco J. García-Vidal

[email protected]


Crack mechanical failure in ceramic

materials under ion irradiation:

case of lithium niobate crystal.

Institute of Nuclear Fusion (UPM)

José Gutiérrez Abascal 2

Madrid, Spain

Swift heavy ion irradiation (ions with mass heavier than 15 and energy exceeding MeV/amu) transfer their

energy mainly to the electronic system with small momentum transfer per collision. Therefore, they produce

linear regions (columnar nano-tracks) around the straight ion trajectory, with marked modifications with

respect to the virgin material, e.g., phase transition, amorphization, compaction, changes in physical or

chemical properties. In the case of crystalline materials the most distinctive feature of swift heavy ion

irradiation is the production of amorphous tracks embedded in the crystal. Lithium niobate is a relevant

optical material that presents birefringence due to its anysotropic trigonal structure. The amorphous phase

is certainly isotropic. In addition, its refractive index exhibits high contrast with those of the crystalline

phase. This allows one to fabricate waveguides by swift ion irradiation with important technological

relevance. From the mechanical point of view, the inclusion of an amorphous nano-track (with a density 15%

lower than that of the crystal) leads to the generation of important stress/strain fields around the track.

Eventually these fields are the origin of crack formation with fatal consequences for the integrity of the

samples and the viability of the method for nano-track formation. For certain crystal cuts (X and Y), these

fields are clearly anisotropic due to the crystal anisotropy.

We have used finite element methods to calculate the stress/strain fields that appear around the

iongenerated amorphous nano-tracks for a variety of ion energies and doses. A very remarkable feature for

X cut-samples is that the maximum shear stress appears on preferential planes that form +/-45º with respect

to the crystallographic planes. This leads to the generation of oriented surface cracks when the dose

increases. The growth of the cracks along the anisotropic crystal has been studied by means of novel

extended finite element methods, which include cracks as discontinuities. In this way we can study how the

length and depth of a crack evolves as function of the ion dose. In this work we will show how the

simulations compare with experiments and their application in materials modification by ion irradiation.

David Garoz,

Antonio Rivera, J. Olivares,

F. Agullo-Lopez and

J. M. Perlado

[email protected]


Coupling of lattice modes in oxides

superlattices: wedding of three

Theoretical Physics of Materials, University of Liège,

Allée du 6 août 17 (B5a), 4000 Liège, Belgium

Complex transition metal oxides form an important

class of compounds, exhibiting a wide variety of

functional properties exploited in various devices.

Thanks to advances in deposition techniques, these

oxides can nowadays be combined in

heterostructures, with a structural quality

comparable to what is achieved for conventional

semiconductors. Creating such heterostructures

gives not only the possibility to combine the

intrinsic properties of different compounds but also

to induce totally new phenomena at their

interfaces. Recent examples include the metallic

and superconducting interface found at the

boundary between the two band insulators LaAlO3

and SrTiO3 or the emergence of so-called improper

ferroelectricity in ultrashort period PbTiO3/SrTiO3

superlattices. In the latter system, the ferroelectric

polarization is no more the primary driver of the

phase transition but arises from an unexpected

trilinear coupling of one polar and two non-polar

lattice modes, producing a complex structural

ground state and unusual dielectric properties.

Recently, a similar type of coupling was shown by

Benedek and Fennie to be a way to achieve an

unprecedented control of the magnetization by an

electric field in single-phase Ca3Mn2O7, a naturally

occurring layered perovskite of the Ruddlesden-

Popper series. The wedding of lattice modes in

layered perovskites looks like a promizing approach

to achieve enhanced magneto-electric coupling but

the identification of compounds realizing that at

room temperature remains a challenge.

After a brief introduction regarding the emergence

of exotic phenomena at oxide interfaces, I will

explain the concepts of improper and hybrid

improper ferroelectricity. I will discuss the

conditions for the appearance of a trilinear

coupling of polar and non-polar lattice modes in

different types of artificial and naturally-occuring

layered perovskites and emphasize the interest of

such a coupling to generate new and/or enhanced

functional properties. Relying on first-principes

simulations, I will then discuss the specific example

of a 1/1 BiFeO3/LaFeO3 superlattice, showing that

this system appears as a promizing candidate to

realize electric switching of the magnetization at

room temperature.

Works done in collaboration with Z. Zanolli, E.

Bousquet, J. Zhao, H. Djani, A.Safari, A. Prikockyté

and D. Fontaine at ULG, J. Iñiguez and J. C. Wojdel

at ICMAB, P. Hermet at University of Montpellier

and the experimental groups of J.-M. Triscone and

P. Paruch at the University of Geneva. Supported by

the European project OxIDes (EC-FP7), the ARC

project TheMoTher and the Francqui Foundation

(Belgium).

Philippe Ghosez

[email protected]


Photochemical evidence of electronic

interwall communication in double-

wall carbon nanotubes

a Instituto de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL),

Universidad de Castilla-La Mancha, 45071-Toledo, Spain. b Instituto de Catálisis y Petroleoquímica, CSIC, Cantoblanco, 28049, Madrid, Spain.

c Instituto Universitario de Tecnología Química CSIC-UPV, Universidad Politécnica de

Valencia, 46022-Valencia, Spain

Double-wall carbon nanotubes (DWCNTs) [1] have

attracted considerable attention when compared

to single-wall CNT (SWCNTs), because show some

advantages like higher thermal and chemical

stability and are mechanically more robust [2]. In

addition, DWCNTs, being the simplest example of

multi-wall carbon nanotubes (MWCNTs), are ideal

structures for studying how the interwall

interactions influence the properties of the CNTs

with two or more walls for chemical [3] and

physical [4,5] applications. The electronic

communication between outer and inner tubes is

observed by in situ Raman spectroelectrochemistry

of unmodified DWCNTs; charge transfer from the

outer tube to the inner tube occurs only if the

electronic states of the outer tube are filled with

electrons or holes and if these filled states are

higher in energy than those of the inner tube [6].

Donor-acceptor nanohybrids prepared by covalent

functionalization of SWCNTs with electron donors

are very actively studied as donor–acceptor

nanohybrid models and as building blocks for

optoelectronic devices [7]. Nevertheless, there are

not examples in the literature where a valid

comparison of the photochemical properties of

DWCNT and SWCNT with identical degree of

functionalization has been provided. Despite the

interest in understand the role of the inner, intact

graphenic wall in the properties of CNTs, there are

scarce examples of functionalization of this kind of

CNTs, but, from the avalible data, it is well

established that the functional moiety is selectively

attached to the sidewall of the outer shell of

DWCNTs without disrupting the properties of inner

tubes.

In the current work, we compare the behaviour of

functionalized SWCNT and DWCNT in photoinduced

electron transfer. Single and double wall carbon

nanotubes (CNTs) having dimethylanilino (DMA)

units covalently attached to the external graphene

wall have been prepared by the reaction of

dimethylaminophenylnitronium ion with the

corresponding CNT. The samples have been

characterized by Raman and XPS spectroscopies,

thermogravimetry and high-resolution transmission

electron microscopy where the integrity of the

single or double wall of the CNT and the percentage

of substitution (one dimethylanilino group every 45

carbons of the wall for the single and double walled

samples) has been determined. Nanosecond laser

flash photolysis has shown the generation of

transients that has been derived from the charge

transfer between the dimethylanilino as electron

donor to the CNT graphene wall as electron

acceptor. Time resolved spectroscopy data indicate

María J. Gómez-

Escalonillaa, María

Vizuetea, Sergio García-

Rodriguezb, José Luis G.

Fierrob, Pedro Atienzar

c,

Hermenegildo Garcíac *

and Fernando Langa a

[email protected]


TNT2012

Ab

st

ra

ct

s

that the charge mobility in DWCNT is much higher than in the case of SWCNT, suggesting that DWCNT

should be more appropriate to develop fast response devices for nanoelectronics.

References

[1] R. Pfeeiffer, T. Pichler, Y. A. Kim and H. Kuzmany, Double-Wall Carbon Nanotubes, Carbon Nanotubes:

Advanced Topics in the Synthesis, Structure, Properties and Applications, Ed. A. Jorio, M. S. Dresselhaus

and G. Dresselhaus, Springer, New York, (2008), pp 495-530.

[2] Y. A. Kim, H. Muramatsu, T. Hayashi, M. Endo, M. Terrones and M. S. Dresselhaus, Chem. Phys.

Lett.,398, (2004), 87.

[3] A. H. Brozena, J. Moskowitz, B. Y. Shao, S. L. Deng, H. W. Liao, K. J. Gaskell and Y. H. Wang, J. Am. Chem.

Soc.,132, (2010), 3932.

[4] A. A. Green and M. C. Hersam, Nat. Nanotechnol.,4,(2009),64.

[5] A. A. Green and M. C. Hersam, ACS Nano,5,(2011),1459.

[6] M. Kalbac, A. A. Green, M. C. Hersam and L. Kavan, Chem. Eur. J., 17,(2011),9806.

[7] V. Sgobba and D. M. Guldi, Chem. Soc. Rev.,38,(2009),165.


Negative scattering asymmetry

parameter for dipolar particles:

unusual reduction of the transport

mean free path and radiation

pressure 1 Dpto. Física de la Materia Condensada and Instituto Nicolás Cabrera, Universidad

Autónoma de Madrid, Campus de Cantoblanco, Madrid 28049, Spain 2 Department of Physics, University of Fribourg, Chemin du Muse 3, 1700 Fribourg,

Switzerland 3 Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones

Científicas (CSIC), Campus de Cantoblanco, Madrid 28049, Spain

Propagation of light and image formation in turbid

media has long been a subject of great interest [1]

and constitutes the core of powerful techniques

with countless applications including biomedical

imaging [2, 3] and dynamic spectroscopy

techniques [4-6], characterization of composite

materials and complex fluids [7], remote sensing or

telecommunications [8] to mention a few.

Lossless dielectric nanospheres (made of

nonmagnetic materials) with relatively low

refraction index may present strong electric and

magnetic dipolar resonances [9-11].

We establish a relationship between the optical

force [12,13] from a plane wave on small electric

and magnetic dipolar particles, the transport cross

section, and the scattering asymmetry parameter g

[14].

In this way we predict negative g (that minimize the

transport mean free path below values of the

scattering mean free path) for a dilute suspension

of both perfectly reflecting spheres as well as of

lossless dielectric nanospheres made of moderate

permittivity materials, e.g., silicon or germanium

nanospheres in the infrared region. Lossless

dielectric Mie spheres of relatively low refraction

index (as low as 2.2) are shown to present negative

g in specific spectral ranges [14].

Figure 1. (a) Color map of the g factor for spherical

absorptionless particles as a function of their refractive

index m and size parameter y = mka. As seen in the

attached scale, green areas correspond to negative

values of g. (b) Color map of the sphere scattering cross

section. Red corresponds to dominant electric dipole

contributions to the scattering cross section. Green

corresponds to dominant magnetic dipole contributions,

while blue sums up all higher-order multipole terms.

Vertical dashed lines coincide with y parameter for

maximum electric dipole contribution (right vertical line)

and maximum magnetic dipole contribution (left vertical

line). The white horizontal line at m ≈ 3.5 which

corresponds to a silicon sphere. (After Ref.[14]).

R. Gómez-Medina1,

L. S. Froufe-Pérez1,

M. Yépez1, F. Scheffold

2,

M. Nieto-Vesperinas3 and

J. J. Sáenz1

[email protected]


TNT2012

Ab

st

ra

ct

s

References

[1] Waves and Imaging through Complex Media, edited by P. Sebbah (Kluwer Academic, Dordrecht,

2001); in Wave Scattering in Complex Media: From Theory to Applications, edited by B. A. van

Tiggelen and S. E. Skipetrov, NATO Science Series II: Mathematics, Physics and Chemistry,Vol. 107

(Kluwer Academic, Dordrecht, 2003).

[2] A. Yodh and B. Chance, Phys. Today 48(3), 34 (1995); S. K. Gayen and R. R. Alfano, Opt. Photon.

News 7 (1996) 17.

[3] J. Ripoll, V. Ntziachristos, J. P. Culver, D. N. Pattanayak, A. G. Yodh, and M. Nieto-Vesperinas, J. Opt.

Soc. Am. A 18 (2001) 821.

[4] D. A. Weitz and D. J. Pine, in Dynamic Light Scattering, edited by W. Brown (Oxford University

Press, New York, 1993).

[5] G. Maret and P. E. Wolf, Z. Phys. B 65 (1987) 409; D. J. Pine, D. A. Weitz, P. M. Chaikin, and E.

Herbolzheimer, Phys. Rev. Lett. 60 (1988) 1134.

[6] R. Lenke and G. Maret, in Multiple Scattering of Light: Coherent Backscattering and Transmission,

edited by W. Brown (Gordon & Breach, Reading, UK, 2000).

[7] F. Scheffold and P. Schurtenberger, Soft Mater. 1 (2003) 139.

[8] A. Derode, A. Tourin, J. de Rosny, M. Tanter, S. Yon, and M. Fink, Phys. Rev. Lett. 90 (2003) 14301;

G. Lerosey, J. de Rosny, A. Tourin, and M. Fink, Science 315 (2007) 1120.

[9] A. García-Etxarri, R. Gómez-Medina, L. S. Froufe-Pérez, C. López, L. Chantada, F. Scheffold, J.

Aizpurua, M. Nieto-Vesperinas and J. J. Sáenz, Opt. Express, 19 (2011) 4815-4826.

[10] R. Gómez-Medina, B. García-Cámara, I. Suárez-Lacalle, F. González, F. Moreno, M. Nieto-Vesperinas

and J. J. Sáenz, J. Nanophoton. 5 (2011) 053512.

[11] M. Nieto-Vesperinas, R. Gómez-Medina, and J. J. Sáenz, J. Opt. Soc. Am. A, 28 (2011) 54-60.

[12] M. Nieto-Vesperinas, J. J. Sáenz, R. Gómez-Medina, and L. Chantada, Opt. Express, 18 (2010)

11428-11443.

[13] R. Gómez-Medina, M. Nieto-Vesperinas and J. J. Sáenz, Phys. Rev. A, 83 (2011) 033825.

[14] R. Gómez-Medina, L. S. Froufe- Pérez, M. Yépez, F. Scheffold, M. Nieto-Vesperinas and J. J. Sáenz,

Phys. Rev. A, 85 (2012) 035802.


Nanostructured tungsten as a first

wall material for the future

nuclear fusion reactors 1Instituto de Fusión Nuclear, ETSI de Industriales, UPM, C/ José Gutierrez Abascal, 2,

E-28006 Madrid, Spain. 2CEI Campus Moncloa, UCM-UPM

3Instituto de Energía Solar (IES), UPM, Avenida Complutense s/n, E-28040 Madrid, Spain

4Instituto de Microelectrónica de Madrid, IMM-CNM-CSIC, Isaac Newton 8 PTM,

E-28760 Tres Cantos, Madrid, Spain. 5Dpto. de Física de Materiales, Facultad de CC. Físicas, UCM, Ciudad Universitaria s/n, E-

28040 Madrid, Spain. 6Dpto. de Física de Materiales, Facultad de CC. Químicas, UCM, Ciudad Universitaria s/n,

E-28040 Madrid, Spain. 7Dpto. de Ciencia de Materiales CISDEM, ETSI de Caminos, UPM, E-28040 Madrid, Spain.

The lack of materials able to withstand the severe

radiation conditions (high thermal loads and

atomistic damage) expected in fusion reactors is the

actual bottle neck for fusion to become a reality.

The main requisite for plasma facing materials

(PFM) is to have excellent structural stability since

severe cracking or mass loss would hamper their

protection role which turns out to be unacceptable.

Additional practical requirements for plasma facing

materials are among others: (i) high thermal shock

resistance, (ii) high thermal conductivity (iii) high

melting point (iv) low physical and chemical

sputtering, and (v) low tritium retention.

W has been proposed to be one of the best

candidates for PFM for both laser (IC) and magnetic

(MC) confinement fusion approaches. However,

works carried out up to know have identified some

limitations for W which have to be defeated in order

to fulfill specifications [1, 2, 3]. Nowadays engineered

3D surfaces are being fabricated to reduce the

thermal loads arriving to the PFM by increasing the

surface area and thus, minimize the energy density

deposited into the material [4]. On the other hand,

ultrafine grain and nanostructured materials are being

developed to facilitate the light species release and to

improve the W mechanical properties [5].

We report on the growth of nanostructured W by

using DC magnetron sputtering and high impulse

power magnetron sputtering (HIPIMS) on different

kind of substrates under different deposition

conditions. X-ray diffraction (XRD) patterns

illustrate that films are polycrystalline and

preferentially oriented along the (110) axes.

Transmission electron microscopy (TEM) and field

emission gun-scanning electron microscopy (FEG-

SEM) evidence that films consists of nanocolumns

perpendicular to the substrate with a diameter in

between 50 and 250 nm depending on the

deposition conditions.

Some of the samples were annealed in an Ar

atmosphere at temperatures in the range from RT

to 1000ºC in order to study their thermal stability.

Cross-sectional FEG-SEM images show no

significant change in the nanocolumn shape but

they point up the poor adhesion between film and

substrate for those samples deposited on steels

and heated at temperatures higher than 800ºC.

References

[1] Takeshi Hirai, Koichiro Ezato and Patrick Majerus,

Materials Transactions, 46, (2005) 412-424.

[2] Kajita S., Sakaguchi W., Ohno N., Yoshida N.,

Saeki T. 2009. Nucl. Fus. 49, 095005.

[3] Sharafat S., Takahashi A., Hu Q., Ghoniem N.M.

2009. J. Nucl. Mat. 386-388, 900.

[4] T. J. Renk, P. P. Provencio, T. J. Tanaka, J. P.

Blanchard, C. Martin , and T. R. Knowles, Fusion

Science and technology 61 (2012) 1-24.

[5] M. Rieth et al. private communication.

N. Gordillo1,2

, R. Gonzalez-

Arrabal1, A. Rivera

1,

I. Fernandez-Martinez3,4

,

F. Briones4, J. Del Río

5,

C. Gomez6, J. Y Pastor

7,

E. Tejado7, M. Panizo-Laiz

1

and J. M. Perlado1


DNA programmed

assembly of molecules Centre for DNA Nanotechnology (CDNA), iNANO and Department of Chemistry, Aarhus University, 8000 Århus C, Denmark

The idea behind our research is to use DNA as a programmable tool for directing the self-assembly of molecules and materials. The unique specificity of DNA interactions, our ability to code specific DNA sequences and to chemically functionalize DNA, makes it the ideal material for controlling self-assembly of components attached to DNA sequences. We have developed some new approaches in this area such as the use of DNA for self-assembly of organic molecules[1] and position dendrimers. We have used DNA origami to assemble organic molecules, study chemical reactions with single molecule resolution [4]. We have also formed 3D DNA origami structures [5] and dynamic DNA structures [6]. Our recent progress on surface modification of DNA origami structures will also be presented.

References

[1] Ravnsbæk; J. B et al. Angew. Chem. Int. Ed. 2011, 50, 10851–10854.

[3] Liu, H. et al. J. Am. Chem. Soc. 2010, 132, 18054-18056.

[4] Voigt, N. V. et al. Nature Nanotech. 2010, 5, 200-205.

[5] Andersen, E. S. et al. Nature 2009, 459, 73-76. [6] Zhang, Z. et al. Angew. Chem. Int. Ed. 2011, 50,

3983–3987.

Kurt V. Gothelf


What can AFM tell us about

organic photovoltaic systems?

Physics Dept., McGill University, Montreal (Quebec), Canada

The major challenge in Photovoltaic (PV) is the cost

per kWh. It is also clear that continuous growth of

PV will not be achievable by concentrating on just

one material system (such as Si), due to materials

limitations (Ag, In etc. necessary for electrodes).

Hybrid organic-inorganic systems are low cost, but

also have a low efficiency and lifetimes, so the cost

per kWh of energy is currently not very attractive.

The reason for this is fundamentally not well

understood, as the conversion of photons to

electrical power is a complicated many-step

process.

Organic Photovoltaic (OPV) diodes based on

distributed heterojunctions of organic

semiconductors currently produce solar power

conversion efficiencies approaching 10%.

Photocurrent generation in these devices requires

interfacial charge separation of singlet excitons at

donor-acceptor heterojunctions to produce charge

carriers, and it is now clear that this is a multi-step

process involving dissociation of intermediate

electron and hole pairs that are bound by Coulomb

interactions. This last process competes with

relaxation into charge-transfer-exciton states

localized at the heterojunction. Such interfacial

excitons are central to electronic processes at

organic heterojunctions in two important ways.

Firstly, charge-transfer excitons act as intrinsic traps

that limit photocarrier generation, due to their

large binding energy (~300 meV). Secondly, there is

now phenomenological information establishing

the importance of charge-transfer excitons in

defining the open-circuit voltage and short-circuit

photocurrent in organic solar cells, but

fundamental understanding on molecular length

scales lacks.

Building upon previous morphological studies of

tailoring molecular island size and nucleation site

distribution, I will present preliminary results of our

experimental observation of excitons in a model

OPV system. Thin films of PTDCI (an electron donor)

and copper (II) phthalocyanine (an electron

acceptor) molecular islands were grown under ultra

high vacuum conditions on insulators. Structure

and surface contact potential were simultaneously

mapped using nc-AFM and Kelvin probe force

microscopy on a nm scale. We could clearly detect

changes of surface potentials at molecular

heterojunctions under illumination. This open the

possibility of directly correlating exciton diffusion

length, diffusion anisotropy and trapping sites with

atomic scale structure, allowing us to gain deep

fundamental insights.

Figure 1. 3D rendered NC-AFM topography and

corresponding simultaneous KPFM images, overlayed to

illustrate the correlation between film morphology and

surface work function distribution under on/off

illumination conditions. The change in KPFM signal on

the island indicated by the green arrow suggests that

enhanced charge-carrier separation takes place across

the organic heterojunction under illumination.

J. Topple, Z. Schumacher,

A. Tekiel, and P. Grutter


Interaction effects in graphene

heterostructures

Instituto de Ciencia de Materiales de Madrid. Consejo Superior de

Investigaciones Científicas Sor Juana Inés de la Cruz 3. 28049 Madrid. Spain

New graphene heterostructures built up of

graphene and boron nitride layers have a high

tunability, and they can be the basis of new

devices[1-3]. They show intriguing new

phenomena, such as electron localization induced

by screening, and large Coulomb drag between

carriers in different graphene layers.

The tunability of these devices allow for sizable

modifications of the interactions between

electrons. We discuss here possible new phases

induced by the electron-electron interaction,

including superconductivity at sufficiently high

carrier density.

References

[1] L. A. Ponomarenko, A. K. Geim, A. A. Zhukov,

R. Jalil, S. V. Morozov, K. S. Novoselov, V. V.

Cheianov, V. I. Fal'ko, K. Watanabe, T.

Taniguchi, et al., Nature Phys.7, 958 (2011).

[2] L. Britnell, R. V. Gorbachev, R. Jalil, B. D. Belle,

F. Schedin, M. I. Katsnelson, L. Eaves, S. V.

Morozov, N. Peres, J. Leist, et al., Science 335,

947 (2012).

[3] R. V. Gorbachev, A. K. Geim, M. I. Katsnelson, K.

S. Novoselov, T. Tudorovskiy, I. V. Grigorieva, A.

H. MacDonald, K. Watanabe, T. Taniguchi, L. A.

Ponomarenko, arXiv:1206.6626 (2012).

Francisco Guinea

[email protected]


Properties optimisation of

titania microfibers

by direct drawing 1 Institute of Physics, University of Tartu, Riia 142, 51014 Tartu, Estonia

2 Department of Materials Engineering, Tallinn University of Technology,

Ehitajate 5, 19086 Tallinn, Estonia 3 Department of Aerospace Engineering, University of Illinois at Urbana-Champaign,

306 Talbot Lab, 104 South Wright Street, Urbana, Illinois 61801, USA

Ceramic microfibers are interests both in scientific

and technological means. One of the main factors

that is supporting the use of fibres is their edgeless

cylindrical geometry, which for externally applied

mechanical stresses can not localize into specific

spots to easily cause cracks. Nanostructured

polycrystalline titania (TiO2) microfibres, studied in

this work were produced by direct drawing from

visco-elastic alkoxide precursors [1,2]. The fibre

crystallinity and grain size were shown to depend

on applied post-treatment (calcination

temperature) conditions. Single fibre tensile tests

showed a strong sensitivity of the elastic modulus

and the tensile strength to the microstructural

features of the fibres. The elastic modulus of as-

fabricated fibres increased about 10 times after

calcination at 700 °C, while the strain at failure

remained almost of the same percentage of ~1.4%

[3]. The highest tensile strength of more than 800

MPa was exhibited by nanoscale grained fibres with

a bi-modal grain size distribution consisting of rutile

grains embedded into anatase matrix [4]. This

structure is believed to have reduced the critical

defect size and thus increased the tensile strength.

The resultant materials showed properties that

were appropriate for reinforcement of different

matrixes.

(a)

(b)

Figure 1. Changes in modulus of elasticity (a) and tensile

strength (b) with temperature of heat treatment.

Kelli Hanschmidt1,3

,

Tanel Tätte1,

Irina Hussainova2,

Marko Part1,

Hugo Mändar1,

Kaspar Roosalu1 and

Ioannis Chasiotis3

[email protected]


TNT2012

Ab

st

ra

ct

s

References

[1] T. Tätte, M. Hussainov, J. Gurauskis, H. Mändar, G. Kelp, K. Hanschmidt, I. Hussainova, Nanotechnology

(2010) 245-248.

[2] T. Tätte, M. Hussainov, M. Paalo, M. Part, R. Talviste, V. Kiisk , H. Mändar, K. Põhako, T. Pehk, K. Reivelt,

M. Natali, J. Gurauskis, A. Lõhmus, U. Mäeorg, Sci Tech Adv Mater. 12 (2011) 1-12.

[3] S. Sakka, K. Kamiya, Mater Sci Res. 17 (1984) 83–94.

[4] H. Gleiter, Prog Mater Sci. 33 (1989) 223-315.


Theoretical study of edge states in

BC2N nanoribbons with zigzag edges 1 Nano-scale Theory Group, NRI, AIST

Higashi 1-1-1, Tsukuba, Ibaraki 305-8565, Japan 2 First-Principles Simulation Group, CMSU, NIMS,

Sengen 1-2-1, Tsukuba, Ibaraki 305-0047, Japan

Graphene is an atomically thin carbon sheet in

which carbon atoms are arranged in a honeycomb

lattice. Due to their outstanding electronic

structure and electron transport properties,

graphene attracts much interest for future

electronic devices. Graphene nanoribbons are finite

width graphene sheets. The electronic properties of

graphene nanoribbons strongly depend on the

edge structures [1]. Graphene nanoribbons with

zigzag edges have the so-called flat bands at the

Fermi level [1]. The states corresponding to the flat

bands are localized at the zigzag edges [1]. For the

so-called edge states, the A- (B-) sublattice

structure plays decisive role, i.e., the distribution of

electronic charge of the edge states becomes finite

only one sublattice sites including the outermost

sublattice. Recently, graphene nanoribbons were

fabricated by e-beam lithography [2] and unzipping

of carbon nanotubes [3], and were synthesized

using bottom-up processes [4]. Furthermore, quite

recently, the edge states in graphene nanoribbons

were confirmed by STM/STS measurement [5].

On the other hand, boron and nitrogen atoms

behave as acceptors and donors, respectively.

Therefore, boron-carbon-nitride, i.e., graphene

sheet doped with B and N, should show interesting

electronic properties with controllability by doping.

BC2N sheet is organic analogous of graphene, which

can be regarded as one of example of boron-

carbon-nitride. Graphite-like BC2N was synthesized

using chemical vapor depositions of boron

trichloride, BCl3, and acetronitrile, CH3CN [6]. The

electronic properties of BC2N sheets depend on the

atomic arrangement [7]. The electronic properties

of nanoribbons made with BC2N were investigated

by several authors [8]. However, there are no

reports on the presence of the flat bands and edge

states in BC2N nanoribbons.

In this paper, we investigate the electronic

properties of BC2N nanoribbons with zigzag edges

using a tight binding model. In the tight-binding

model, B and N atoms are described by higher and

lower site energy, EB and EN, compared with that of

C atom, EC, respectively [9]. Let N be a number of

the zigzag lines. We shall consider three different

structures of BC2N nanoribbons with zigzag edges

as shown in the left part of Fig. 1 (a). In this figure,

B and N atoms are indicated by the black and white

circles, and C atoms are located the empty vertices.

It should be noted that atoms are arranged as B-C-

N-C along the zigzag line in these BC2N

nanoribbons.

Figure 1 (b) shows calculated results of the band

structures of BC2N nanoribbons for N = 10. We

observed the flat bands at E = 0. However, we

confirm that the flat bands are absent if atoms are

not arranged as B-C-N-C along the zigzag lines.

Therefore, we can conclude that B-C-N-C

arrangement along the zigzag line is necessary to

obtain the flat bands. In the right part of Fig. 1 (a),

the local density of states (LDOS) at E = 0 for several

structures are shown by the circles. In this figure,

the radii of the circles are proportional to the

magnitude of the LDOS at each site. The electronic

charge is localized at the BC2N nanoribbons edges,

showing the presence of the edge states. As

discussed below, the edge states in BC2N

nanoribbons is different from those in conventional

graphene nanoribbons.

In the model-1, the charge distributions at the both

edges are different each other, i.e., the charge

Kikuo Harigaya1 and

Tomoaki Kaneko2

[email protected]


TNT2012

Ab

st

ra

ct

s

distribution at the edge, where the outermost sites

are occupied with C atoms, is similar to that at the

conventional zigzag edge, while the charge of the

edge states at the edge, where the outermost sites

are occupied with B and N atoms, distributes the

both sublattice sites. Recently, Kaneko et al.

showed that the edge states in zigzag graphene

nanoribbons are robust on the substitution of

outermost C atoms with B and N atoms alternately

[10]. However, such substitution causes change in

charge distribution, i.e., the sublattice structure is

broken [10]. The edge states at the edge, where the

outermost sites are occupied with B and N atoms

alternately, are similar to those discovered by

Kaneko et al. [10]. In the model-2 nanoribbon, the

charge distribution of the edge states is similar to

that of graphene nanoribbons, but the sublattice

structure is broken inside the nanoribbons. In the

model-3 nanoribbon, the charge distributes over

both sublattice sites, showing the similarity of

those discovered by Kaneko et al. [10].

In this paper, we also performed the first-principles

calculations based on the density functional

theories within projector-augmented wave method

and the local density approximation implemented

in VASP code. We shall discuss the comparison of

the results within the tight-binding model with

those within the density functional theories.

References

[1] M. Fujita, et al., J. Phys. Soc. Jpn., 65 (1996)

1920, K. Nakada et al., Phys. Rev. B, 54 (1996)

17954.

[2] M. Y. Han et al., Phys. Rev. Lett., 98 (2007)

206805.

[3] D. V. Kosynkin et al., Nature, 458 (2009) 872; L.

Y. Jiao et al., Nature Nanotech., 5 (2010) 321.

[4] J. M. Cai et al., Nature, 466 (2010) 470.

[5] C. Tao, et al., Nature Nanotech., 7 (2011) 616.

[6] M. Kawaguchi, Adv. Matter., 9 (1997) 615.

[7] A. Y. Liu, R. M. Wentzcovitch, and M. L. Cohen,

Phys. Rev. B, 39 (1989) 1760; H. Nozaki and S.

Itoh, J. Phys. Chem. Solids, 57 (1996) 41.

[8] P. Lu, et al., J. Phys. Chem. C, 115 (2011) 3572;

Appl. Phys. Lett., 96 (2010) 133103; B. Xu, et

al., Phys. Rev. B, 81 (2010) 205419; L. Lai and J.

Lu, Nanoscale, 3 (2011) 2583.

[9] T. Yoshioka, H. Suzuura, and T. Ando, J. Phys.

Soc. Jpn., 72 (2003) 2656.

[10] T. Kaneko, K. Harigaya, and H. Imamura, (in

preparation).

Figure 1. (a) Schematic illustration of BC2N nanoribbons (left side) and corresponding LDOS at E=0 for N=10 (right side).

In this schematic illustration, the black and white circles represent B and N atoms, respectively. (b) The band structures

of BC2N nanoribbons with N=10.


Nanotechnology in Latin America

and the Caribbean:

current situation and perspective

Universidad Simón Bolívar / Red Venezolana de Nanotecnología

Caracas, Venezuela

Through the manipulation of nanosized materials to

create new products and processes,

nanotechnology is being a leading driver for socio-

economic development in emerging countries, in

particular in those technology based business. In

Latin America many countries begin to consider and

implement national strategies in order to lever up

the industrialization and competitiveness of the

manufacturing sectors (1-4). The talk will

summarizes and highlights the behavior of

bibliometric indexes as well the activities organized

in the last decades on Nanoscience and

Nanotechnology in Latin America and the

Caribbean region. The current state and

perspectives of nanotechnology, as well the intra

and inter-regional cooperation, will be discussed.

References

[1] Kay L & Shapira P (2009) “Developing

nanotechnology in Latin America” J. Nanopart.

Res. 11: 259-278.

[2] López MS, Hasmy A & Vessuri H (2011)

“Nanoscience and Nanotechnology in

Venezuela” J. Nanopart. Res. 13: 3101-3106.

[3] Delgado GC & Takeuchi N (Eds.) (2011)

“Divulgación y Formación de la nanotecnología

en Iberoamérica: Informe de la Red ‘José

Roberto Leite’-NanoDyF/Cyted”, Mundo Nano.

4, No. 2.

[4] Foladori G, Invernizzi N & Záyago E (Coords.)

Perspectivas sobre el desarrollo de las

nanotecnologías en América Latina ISBN: 978-

607-401-538-6, ReLANS-UAZ-Porrúa Eds.,

México, 2012.

(a)

(b)

Figure 1. (a) The total Nanotechnology publications in

the three more populated Latin American countries

(Argentina, Brazil and Mexico) are compared with the

total number of publications of the region (CELAC) and

Spain in the last two decades. (b) Distribution of the

international cooperation of nanotechnology

publications in Latin America and the Caribbean region.

Anwar Hasmy

[email protected]


Metallic microwires as

non-reflective microwave systems

Universidad Complutense, Spain

It has been shown that either magnetic or non magnetic metallic microwires, forming composites, attenuate

microwave reflection of metallic surfaces. The frequency of maximum antireflective effect (30dB) can be

tuned through the control of volume fraction and aspect ratio of the microwires. It has been found that the

high conductivity of the microwires enable an outstanding enhancement of the electrical permittivity of the

composite. This increase gives rise to the possibility of achieving the destructive interference condition for

composite thickness much shorter than the vacuum wavelength. Experiments carried out on radar

reflections for a Spanish Navy ship previously painted with a composite of microwires and paint are shown

and discussed.

Antonio Hernando


Application of nanostructures in

aptamer based biosensors 1 Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynská dolina

F1, 842 48 Bratislava, Slovakia 2 Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, 900 28

Ivanka pri Dunaji, Slovakia 3 Analytical Chemistry Department, Kazan Federal University, 18 Kremlevskaya Street,

Kazan, 42008, Russian Federation 4 Institut de Chimie Moléculaire et de Matériaux d’Orsay, Université Paris-Sud, Bâtiment

420, 91405 Orsay, France 5 Biophysics Institute, Johannes Kepler Univ. Linz, Altenbergertrasse 69, 4040 Linz, Austria

DNA and RNA aptamers are single stranded oligonucleotides with high affinity to proteins or other ligands that are similar to those of antibodies. The aptamers are selected in vitro by the SELEX method [1]. In solution, aptamers maintain an unique 3D configuration that contains specific binding site to the ligand. Aptamers can be easily modified by biotin, SH or amino- groups, leading to a variety of immobilization strategies on solid supports. Using simple molecular engineering based on DNA hybridization it is possible to develop aptamer dimers containing two binding sites like antibodies [2,3]. These aptamer dimers (aptabodies) are characterized by enhancing sensitivity to the analyte, for example to thrombin or cellular prions. We have shown that typical guanine quadruplexes that form binding site for thrombin are stable in aptamer dimers [4]. Currently there is increased interest in development of aptamer based biosensors (aptasensors) for detection of proteins and other molecules using various sensing methods, such us optical, acoustical and electrochemical [5,6]. Aptasensors could be used for fast and low cost medical diagnostics. The sensitivity of detection depends not only on the selectivity of binding site, but also on the supporting part added to the aptamer that serves for better immobilisation onto a solid support. Nanostructures such as carbon and ZnO nanotubes, graphenes, molecularly imprinted polymers, and that modified by calixarenes and dendrimers are of great advantage in aptamer immobilisation and also improve detection of ligands especially in combination with electrochemical methods.

In this contribution we report various immobilisation and detection strategies of proteins using nanostructured aptasensors. By means of multiwalled carbon nanotubes (MWCNTs) as an immobilization matrix we developed high sensitive biosensor for detection of human thrombin [2] and cellular prions (PrPC) [7] in biological liquids. We have shown that immobilisation of aptamers and aptamer dimers at MWCNTs improved the sensitivity of the sensor for thrombin and allowed detection in a complex matrix such as blood plasma. By means of electrochemical quartz crystal microbalance method (EQCM) we performed comparative analysis of the sensitivity of DNA aptamers and antibodies specific to PrPC immobilised on a surface of MWCNTs. We found that the limit of detection (LOD) for both aptamers (50 pM) and antibodies (20 pM) was comparable. Most recently we substantially improved the LOD using immobilisation of aptamers onto multilayer surface composed of MWCNTs with covalently attached polyamidoamine dendrimers (PAMAM) of fourth generation (G4) conjugated with ferrocene-1'-(N(3-butylpyrrole)butanamide) (Fe-NHP). Streptavidin-biotin conjugation served as linker with biotin-modified aptamer designed for specific prion recognition (Fig. 1a). Using cyclic voltammetry (CV) it has been possible to record reversible redox currents of the ferrocene with oxidation and reduction peaks corresponding to the potentials 0.24 mV and 0.17 mV (vs. Ag/AgCl reference electrode), respectively. The current decreased with increasing PrPC concentrations form 1 pM to 10 µM and reaches saturation after 1 µM (Fig. 1b). The current decay was due to limitation of the electron exchange in the sensing layer. LOD was

Tibor Hianik1, Gabriela

Castillo1, Maja Šnejdarková2, Alexandra Poturnayová2, Anna Porfireva3, Gennady Evtugyn3, Anna Miodek4, Helene Dorizon4, Hafsa Korri-Youssoufi4 and Andreas Ebner5

[email protected]


TNT2012

A

bs

tr

ac

ts

found to be 1.3 pM which is acceptable for practical applications. The sensor was tested also in a human blood serum with satisfactory recovery in average of 74%. The interferences with BSA up to concentrations 10 µM were negligible.

Figure 1. a) The scheme of the biosensor based on MWCNTs-dendrimer- ferrocene-streptavidin layer with immobilised aptamers sensitive to PrP

C (1-MWCNT, 2-

Dendrimer, 3-Fe-NHP, 4-Biotinylated aptamer connected to streptavidin, 5-PrP

C). b) Relative changes of the

current peak corresponding to the ferrocene oxidation vs. concentration of PrP

C or bovine serum albumin (BSA),

respectively (ΔI=I-I0, where I0 and I are amplitudes of the current prior and after addition of the analyte, respectively).

Recently we developed new approach for aptamer immobilisation using electropolymerized layer of Neutral Red (NR) at glassy carbon electrode (GCE) onto which polycarboxylated thiacalix[4]arene has been adsorbed by electrostatic accumulation. NR and aminoterminated thrombin-specific aptamer were then covalently linked to the thiacalixarenes by EDC-NHS chemistry (Fig. 2) [8]. The NR reduction

current recorded after 10 min incubation decayed with increased thrombin concentration due to limitation of the electron exchange in the surface layer. The aptasensor makes it possible to determine thrombin in concentration range 0.1–50 nM (LOD 0.05 nM) in blood serum without any alteration of the response in the presence of 100 fold excess of serum proteins.

Acknowledgements: Financial support of Agency for

Promotion Research and Development under the

project No. APVV-0410-10 and SK-FR-0025-09, Slovak

Academy of Sciences under the project mnt-era.net

(proposal No. 2009-50), VEGA 1/0785/12 by Centre of

Excellence SAS for Functionalized Multiphase

Materials (FUN-MAT) and by the Grant of Education

and research ministry of French government are

gratefully acknowledged. We are grateful to Dr.

Human Rezaei and Dr. Jasmina Vidic from VIM group

of INRA France for generous gift of PrPC proteins.

References

[1] A.D. Ellington, J.W. Szostak, Nature, 346 (1990) 818.

[2] T. Hianik, A. Porfireva, I. Grman, G. Evtugyn, Protein and Peptide Letters, 15 (2008) 799.

[3] T. Hianik, I. Grman, I. Karpišová, Chem. Commun., 41 (2009) 6303.

[4] S. Ponikova, K. Tlučková, M. Antalík, V. Víglaský, T. Hianik, Biophys. Chem., 155 (2011) 29.

[5] T. Hianik, J. Wang, Electroanalysis, 21 (2009) 1223.

[6] M. Mascini (Ed.) Aptamers in Bioanalysis, Wiley, New Jersey, 2009.

[7] T. Hianik, A. Porfireva, I. Grman, G. Evtugyn, Protein and Peptide Letters, 16 (2009) 363.

[8] G. Evtugyn, V. Kostyleva, c R. Sitdikov, A. Porfireva, M. Savelieva, I. Stoikov, I. Antipin, T. Hianik Electroanalysis, 24 (2012) 91.

Figure 2. General scheme of the aptasensor assembling for detection thrombin at glassy carbon electrode. Neutral Red (NR) is the electroactive probe [8].


Ultrafast X-ray nanowire

single-photon detectors and their

energy-dependent response 1 Physics Institute, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland

2 Institute for Micro- and Nanoelectronic Systems, Karlsruhe Institute of Technology,

Hertzstr. 16, 76187 Karlsruhe, Germany

More than a decade before the successful

development of superconducting nanowire single-

photon detectors (SNSPD) for the optical and near-

IR wavelength range [1], serious efforts were

undertaken to use this detection principle for the

detection of X-ray photons with keV-energies [2].

However, these preliminary X-ray detectors

struggled with problems regarding the relaxation

back into the superconducting state after photon

detection, called latching, making it difficult to

operate the devices in a continuous detection

mode. Recently, SNSPDs were used in time-of-flight

spectrometry of molecules [3, 4]. For this purpose,

a SNSPD from 5 nm thin NbN was successfully

tested for X-ray detection in a feasibility study [5].

However, the absorptivity of thin NbN films for X-

ray photons and therefore the quantum efficiency

of the detectors were low.

In order to enhance the absorptivity of the

superconducting detector, we fabricated an X-ray

superconducting nanowire single-photon detector

(X-SNSPD) from 100 nm thick niobium (Fig. 1(a)).

The detector geometry was designed for a kinetic

inductance large enough to significantly reduce the

above mentioned problem with continuous photon

detection, and small enough for ultrafast pulse

recovery times.

We report on the detection of X-ray photons [6]

with keV-energies in continuous mode with an

ultrafast pulse recovery time TP of less than 4 ns

(Figs. 1(b) and (c)) and an average pulse rise time of

about 190 ps (Fig.1(d)), the latter being limited by

our electronics setup. In contrast to optical photon-

detection in thin-film SNSPDs, X-ray photon

detection was possible even at bias currents

smaller than 0.4 percent of the critical current (Fig.

2 inset (a)).

Figure 1. (a) Optical image of examined X-SNSPD from

100 nm thick niobium. (b) Typical voltage pulses after

X ray photon absorption, with definition of the pulse

length TP shown schematically. (c) Pulse length TP

histogram. (d) Pulse rise time histogram (time spans

between 15 and 85 percent of pulse amplitude). For (b)

(d) the X SNSPD was irradiated by the X-ray tube with an

acceleration voltage of 49.9 kV.

Most remarkably, we observed that the X-SNSPD

signal amplitude distribution depends significantly

on the acceleration voltage of the photon emitting

X-ray tube. Figure 2 shows the corresponding

normalized pulse amplitude histograms at different

acceleration voltages between 7 kV and 50 kV.

Since the detector operates in a single-photon

detection mode (Fig. 2 inset (b)) the variation of the

signal amplitude distribution can be attributed to

the variation of the photon energy spectrum at

different X ray tube settings. This phenomenon,

which is new for SNSPDs, is explained by the

orders-of-magnitude smaller resistance of the

normal conducting domains as compared to the

Kevin Inderbitzin1,

A. Engel1, A. Schilling

1,

K. Il’in2 and M. Siegel

2

[email protected]


TNT2012

Ab

st

ra

ct

s

situation in thin-film SNSPDs. For acceleration

voltages of the X-ray tube larger than 12.5 kV, we

observe distinct preferred signal amplitudes (see

arrows in Fig. 2) which we may tentatively ascribe

to the main characteristic emission lines of the

tungsten target at 8.4 kV and 9.7 kV, for which a

minimum excitation energy equal to 10.2 keV or

11.5 keV resp. is necessary. These observations

may hint to a certain energy-resolving capability of

our niobium X-SNSPD.

Figure 2. Histograms of signal amplitudes from photons

emitted by the X-ray tube at different tube acceleration

voltages (indicated in the legend) and from photons

emitted by a radioactive Fe-55 source, which mainly

emits at 5.9 keV. The tube acceleration voltage

determines the maximum energy of the emitted

photons. The histograms use a bin size of 4 mV (5.2 mV

for the Fe-55 data respectively) and are normalized at

79 mV, which lies below the noise level. The two arrows

indicate preferred signal amplitudes which may

tentatively be ascribed to the main characteristic

emission lines of the tungsten target at 8.4 kV and

9.7 kV. Inset (a) shows a plot of the count rate as a

function of the reduced bias current at an acceleration

voltage of 49.9 kV. Inset (b) shows that the X-SNSPD

photon count rate is proportional to the photon flux,

which is varied by the X-ray tube anode current.

Moreover, no dark count events were triggered in

over five hours of measurement, even with bias

currents very close to the critical current. Our

results show that ultrafast dark-count-free X-

SNSPDs can be fabricated which can operate in a

large spectral range. They could find applications

where very high count rates, precise timing, a good

signal-to-noise ratio and response in a wide

spectral range for photon counting are required,

such as experiments with synchrotron X ray

sources, free-electron lasers and hot plasmas (as in

nuclear fusion experiments).

In addition, X-SNSPDs from 100 nm thick TaN have

been fabricated and characterized, which show an

increased X ray absorptivity and reduced sensitivity

for latching compared to the X-SNSPD from Nb.

References

[1] G. N. Gol’tsman, O. Okunev, G. Chulkova, A.

Lipatov, A. Semenov, K. Smirnov, B. Voronov,

A. Dzardanov, C. Williams, and R. Sobolewski,

Appl. Phys. Lett., 79 (2001) 705

[2] A. Gabutti, R. G. Wagner, K. E. Gray, R. T.

Kampwirth, and R. H. Ono, Nucl. Instrum.

Methods A, 278 (1989) 425.

[3] K. Suzuki, K. Suzuki, S. Miki, Z. Wang, Y.

Kobayashi, S. Shiki, and M. Ohkubo, J. Low

Temp. Phys., 151 (2008) 766.

[4] N. Zen, A. Casaburi, S. Shiki, K. Suzuki, M.

Ejrnaes, R. Cristiano, and M. Ohkubo, Appl.

Phys. Letters, 95 (2009) 172508.

[5] D. Perez de Lara, M. Ejrnaes, A. Casaburi, M.

Lisitskiy, R. Cristiano, S. Pagano, A. Gaggero, R.

Leoni, G. Golt’sman, and B. Voronov, J. Low

Temp. Phys., 151 (2008) 771.

[6] K. Inderbitzin, A. Engel, A. Schilling, K. Il’in,

and M. Siegel, to be published


Nano-probing of the surface

excited by keV photon:

what should we detect for high

spatial resolution?

National Institute for Materials Science (NIMS)

1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan

X rays, keV photons with high transmittance and

low refraction indices, are not easy to focus on

nano-scale area. Meanwhile, scanning probe

microscopy (SPM) detecting physical properties is

not favorable for chemical state mapping. SPM of x

ray excited surface (X-SPM) is expected to

compensate these disadvantages and be profitable

for both of x-ray analyses and surface science: X-

SPM limits its detection area on nano-meter-scale

under the tip and probes x-ray absorption sensitive

to chemical states. Various SPM’s detecting

photoelectrons, tunneling current, chemical

bonding force, optical emission, etc., have been

examined to detect the x-ray absorption for this

technique. Now we confront a problem: What

should we detect in X-SPM?

In spite of considerable efforts by a lot of

researchers on this field, we still have difficulties

with this technique. These are mainly caused by a

little x-ray absorption effect on surface and high

background level owing to x-ray excitation of

deeper and wider region than the probing area

with SPM. In order to solve these difficulties, we

developed X-SPM’s based on two original ideas, (1)

lifetime conversion and (2) AC detection [1-3].

(1) Lifetime conversion

It is well known that the lifetime of inner-shell

excitation by x rays is about femtoseconds, fs. It is

obviously undetectable time for SPM. Therefore,

we focused on specific objects which have meta-

stable excitation states with a long lifetime of

milliseconds, ms. As show in Fig. 1, if a sample has

localized electrons in valence states, a sequential

relaxation after the x-ray excitation finally ionizes

the valence states. The valence states excitation

normally has long lifetime of ~ms detectable with

SPM. The conversion from ~fs to ~ms realizes high

efficient detection equivalently. Generally speaking,

the localized electrons can be found in defects,

surface, interface, etc. These localized electrons

have a great potential to induce functionality and

significant change in material properties. This fact

indicates that we can discuss the scientific interests

with X-SPM using the lifetime conversion

technique.

Figure 1. Lifetime conversion from fs to ms.

(2) AC detection

Basically, DC current (including photocurrent and

tunneling current) detections with SPM receive

significant background of photoelectrons from the

outside of the probing area. Therefore, we

detected AC current or force instead of the DC

current. Since the AC current can be represented

with impedance, capacitance probe, i.e., scanning

capacitance microscope (SCM) is available for the

Masashi Ishii

[email protected]


TNT2012

Ab

st

ra

ct

s

X-SPM. Figure 2 shows the first report of x-ray

absorption spectra obtained with SCM [1]. The

successful application of SCM suggests that other

related techniques such as EFM (Electrostatic Force

Microscopy) and KFM (Kelvin Force Microscopy)

can be used for X-SPM. The force detection is more

effective to avoid the photoelectrons. By using

EFM, we achieved chemical mapping with a spatial

resolution of a few nm [2].

Figure 2. X-SCM for the AC detection technique.

Figure 3. Charge confinement using AC frequency tuning.

In spite of these particular successes, application to

general samples is not established. In these

methods, the lifetime of the localized electrons in

the valence states determines the detection

efficiency. Unfortunately, the lifetime strongly

depends on samples and is unknown factor

normally. We recently developed another

technique, (3) charge confinement for the lifetime

control. As shown in the inset of Fig. 3, when AC

electric field is applied to samples, the charges are

confined in trapping levels above some frequency

corresponding to an escape time of the charges.

Figure 3 shows an experimental evidence of the

charge confinement in TiO2. The charges are

confined above 1 kHz with an impedance peak,

resulting in enhancement of luminescence from Sm

dopants as a marker [4]. We conclude that AC

frequency is a key parameter for the lifetime

control for technique (2). EFM with a wider

bandwidth AC oscillator is expected to realize X-

SPM for more general samples.

References

[1] M. Ishii, Jpn. J. Appl. Phys. 41, 4415 (2002).

[2] M. Ishii, B. Hamilton, N. R. J. Poolton, N.

Rigopoulos, Stefan De Gendt, and K. Sakurai,

Appl. Phys. Lett. 90, 063101 (2007).

[3] M. Ishii, B. Hamilton, and N. R. J. Poolton, J.

Appl. Phys. 104, 103535 (2008).

[4] M. Ishii, S. Harako, X. Zhao, S. Komuro, and B.

Hamilton, Appl. Phys. Lett., 99, 101909 (2011).

Surface defects


On the origin of RTS

noise in nanoFETs

Group of Microsystems and Electronic Materials.

GMME-CEMDATIC

ETSIT. Universidad Politécnica de Madrid.

28040-Madrid. Spain.

Electronic nano-devices are giving rise to new

phenomenological effects, since the high surface to

volume ratio associated to their nano-scale volume

makes superficial effects to predominate over bulk

effects. With the reduction of the size of the

devices to the nano-scale, the modeling of some

phenomena traditionally treated as statistical

effects should be carefully revised. A clear example

of these phenomena is the noise in nano-devices

whose dimensions have been reduced looking for

“zero trap” (or “zero dopant”), and thus “zero

noise” devices.

In this communication we analyze the Random

Telegraph Signal (RTS) noise in a nano-scaled

cylindrical transistor specifically designed to

eliminate the presence of traps that commonly

account for RTS noise in micro-sized devices [1],

such as metal oxide semiconductor field effect

transistors [2] or AsGa heterostructures [3]. We

apply a new Admittance-based noise model [4], in

which the electrical noise arises from Fluctuations

of electrical energy in the susceptance of the device

under test followed by their subsequent

Dissipations by the accompanying conductance.

This model, which complies with the

thermodynamic laws and the principles of the

quantum physics, has interesting repercussions in

many systems, allowing to explain some of the

effects [5,6] that are not well managed by the

common theory in use today. In the field of

electrical noise in field effect transistors, which is

considered in this communication, it explains in a

simple way the RTS instability observed in nano-

scaled cylindrical transistors which are designed

looking for a “zero-trap-device”. Contrary to

common theory where the low–frequency noise in

FETs has been attributed to modulation in mobility

and/or carrier density owing to the trapping and

de-trapping processes taking place at bulk and

interface states, the Admittancebased model shows

that any phenomenon that modulates the space

charge region in the vicinity of the semiconductor

surface causes a modulation of the channel trough

the familiar Field-Effect used in transistors and not

by an unlike (though possible) modulation of the

channel conductivity. In particular, this explains

why trapping effects appear in the “zero-trap”

transistor presented in [1]. In this case, the ungated

(thus uncontrolled) channel portion outside the

controlling gate is the responsible of the excess of

noise. Not only the Admittance-based model

accounts for this excess of noise but also explains

the tunability of this RTS noise with a surface

voltage, which is disregarded in the traditional

model.

In conclusion, the fluctuation-dissipation

phenomena (noise) that take place by individual

particles (electrons, phonons, polarons, etc) in

nano-scaled electronic devices can be totally

explained with the new Admittance-based model of

noise. A correct evaluation of this noise based in

thermodynamics and quantum mechanics

principles is of major interest for designing new

devices.

Jose Ignacio Izpura,

Enrique Iborra and

Marta Clement

[email protected]


TNT2012

Ab

st

ra

ct

s

References

[1] T. A. Kramer, R. F. W. Pease, “Low frequency noise in sub-100 nm MOSFETs”, Physica E, 19, (2003),

pp. 13-17.

[2] K.K. Hung, P.K. Ko, Chenming Hu, Yiu Chung Cheng. “Random Telegraph Noise in Deep-

Submicrometer MOSFETSs”, IEEE Electron. Dev. Let., 11 (1990), pp. 90-92.

[3] C. Surya, Sze-Him Ng, E.R. Brown, and P.A. Maki. “Spectral and random telegraph noise

characterizations of low-frequency fluctuations in GaAs/Al0.4Ga0.6As resonant tunneling diodes”

Electron Devices, IEEE Trans. 41 (1994), pp. 2016-2022.

[4] J. I. Izpura, J. Malo, “A Fluctuation-Dissipation model for electrical noise,” Circuits and Systems, Vol.

2, No. 3, 2011, pp. 112-120.

[5] J. I. Izpura, “On the electrical origin of flicker noise in vacuum devices,” IEEE Trans. Instrum. Meas.,

Vol. 58, 2009, pp. 3592-3601.

[6] J. I. Izpura, J. Malo, and E. Iborra, “On the effects of Electronic Feedback in the noise of MEMS and

two-Terminal Devices”. Sensors and Actuators A, To be published.


Design of atom and single molecule

boolean logic gates

Nanoscience Group & MANA Satellite

CEMES-CNRS Toulouse

AtMol (www.atmol.eu)

A*STAR VIP Atom Tech, IMRE Singapore

An atomic scale Boolean logic gate is a single quantum system (a molecule or a surface dangling bond circuit)

electronically interacting with atomic scale metallic electrodes supposed to perform alone an “M inputs - P

outputs” digital logic function. All the known designs of atomic scale logic gates: semi-classical circuits,

quantum Hamiltonian circuits and qubit circuits are different versions of a quantum control. Semi-classical

and quantum circuit design rules will be recalled. They differ in the way the classical input data are encoded

on the quantum system and how the quantum to classical conversion proceeds at the outputs. A quantum

design also can benefit from decoherence coming from the interconnections in a way to be planar implanted

at the surface of a passivated semiconductor as explored in the AtMol Integrated European Project.

C. Joachim


Calibrated nanoscale capacitance

and dopant profile measurements

using a novel nearfield scanning

microwave microscope 1Agilent Technologies Austria, Mooslackengasse 17, 1190 Vienna, Austria

2JKU University of Linz, Institute for Biophysics, Altenbergerstr. 69, 4040 Linz, Austria

3Agilent Technologies Inc., NanoDivision, 4330 W. Chandler Blvd., Chandler, AZ 85226, USA

4National Institute for Standards and Technology (NIST), Electromagnetic Division,

Boulder, CO, USA 5Technical University of Vienna, Institute for Solid State Electronics, Floragasse 7,

1040 Vienna, Austria

A scanning microwave microscope (SMM) for

spatially resolved capacitance measurements in the

attoFarad-to-femtoFarad regime is presented. The

system is based on the combination of an atomic

force microscope (AFM) and a performance

network analyzer (PNA).

Figure 1. SiO2 staircase in 3D-topography view (left) and

corresponding PNA amplitude signal (right) used for

calibrated capacitance measurements.

For the determination of absolute capacitance

values from PNA reflection amplitudes, a calibration

sample of conductive gold pads of various sizes on a

SiO2 staircase structure was used (figure 1). The

thickness of the dielectric SiO2 staircase ranged from

10 nm to 200 nm. The quantitative capacitance

values determined from the PNA reflection

amplitude were compared to control measurements

using an external capacitance bridge [1]. Depending

on the area of the gold top electrode and the SiO2

step height, the corresponding capacitance values,

as measured with the SMM, ranged from 0.1 fF to

22 fF at a noise level of ~2 aF and a relative accuracy

of 20% [2].

For dopant profiling, n- and p-doped reference

samples with densities between 1014

and 1019

atoms/cm3 in 1.5 micron-wide regions were imaged

in dC/dV modulation mode (figure 2). A calibration

curve relating signal levels and dopant densities

was established [3].

Possible applications of an SMM range from quality

control of integrated circuits (ICs), solar cells, and

other semiconductor devices to materials science,

(e.g. measurements of quantum dot dielectric

constants), and to bioscience (e.g. the detection of

viruses, and thickness measurements of protein

layers). Examples shown will include capacitance

and dielectric measurements on organic thin films

(SAMs), graphene, nanotubes and nanowires as

well as magnetic bacteria.

Figure 2. Si Dopant density calibration test sample with

densities ranging from 1014

(left side, yellow) to 1019

Atoms/cm3 (right side, blue.)

Gerald Kada1, Matthias A.

Fenner1, Hans-Peter

Huber2, Hassan

Tanbakuchi3, Manuel

Moertelmaier1, Pavel

Kabos4,5Juergen

Smoliner5, Peter

Hinterdorfer2 and Ferry

Kienberger1

[email protected]


TNT2012

Ab

st

ra

ct

s

References

[1] H.P. Huber, M. Moertelmaier, T.M. Wallis, C.J. Chiang, M. Hochleitner, A. Imtiaz, Y.J. Oh, K. Schilcher,

M. Dieudonne, J. Smoliner, P. Hinterdorfer, S.J. Rosner, H. Tanbakuchi, P.Kabos, F. Kienberger, Rev

Sci Instrum, 81 (2010) 113701.

[2] J. Smoliner, H.-P. Huber, M. Hochleitner, M. Moertelmaier, F. Kienberger, J Appl Phys, 108 (2010)

064315.

[3] H. P. Huber, I. Humer, M. Hochleitner, M. Fenner, M. Moertelmaier, C. Rankl,A. Imtiaz, T. M. Wallis,

H. Tanbakuchi, P. Hinterdorfer, P. Kabos, J. Smoliner, J. J. Kopanski, and F. Kienberger. J Applied Phys

111(2012), 014301.


Optical limiting by absorption

bleaching in carbon nanotube

devices: comparison of field-induced

and electrochemically-induced

charge injection

NASA Johnson Space Center

2101 NASA Parkway B13 ES4, Houston, USA

We studied direct charge injection in a heterogeneous film of single-wall carbon nanotubes using the

technique of charge-induced absorption. We found that the injected charges screen the excitons in the

semiconducting tubes, reducing their binding energy and transferring oscillator strength from the exciton

transitions to free carriers. These effects parallel those of the electrochemical doping in the same samples.

Furthermore, we interpret the bleaching bias in the electroabsorption (a chi-3 process) in isolated SWNT as

being due to injected charges, which has implications for a variety of SWNT-based optoelectronic devices. I

will discuss the experiments and some potential methods for using this effect in optoelectronic switches.

References

[1] W. Joshua Kennedy and Z. Valy Vardeny, Applied Physics Letters, 98 (2011) 263110.

[2] Christoph Gadermaier, Enzo Menna, Moreno Meneghetti, W. Joshua Kennedy, Z. Valy Vardeny, and

Guglielmo Lanzani, Nano Letters, 6 (2006) 301-305

W. Joshua Kennedy

[email protected]


Novel “Carbon Nanotube/Graphene

Layer” nanostructures obtained by

injection CVD method for electronic

applications 1 Belarusian State University of Informatics and Radioelectronics, Brovka Str. 6,

Minsk 220027, Belarus 2 Technological Center, Moscow State Institute of Electronic Technology, K-498,

Moscow 103498, Russia

As it was predicted theoretically, a 3D network

nanostructure, composed of parallel graphene layers

stabilized by vertically aligned CNTs, when doped

with lithium cations can be efficient structure for

hydrogen storage [1], and, moreover, this

nanostructure is considered as a novel material with

tailored multidimensional thermal transport

characteristics [2].

First practical realization of CNT/graphene

nanostructures with vertically aligned CNTs grown in

between the graphene layers by CVD method was

reported in ref. [3]. The exfoliated graphene oxide

was selected as the substrate to grow CNTs. These

nanostructures have been successfully used as the

electrodes in supercapacitors. The existence of CNTs

in these nanostructures significantly enhanced the

graphene property by, as believed, bridging the

defects for electron transfer and increasing the basal

spacing between graphene sheets.

However, the proposed method of CNT/graphene

nanostructures realization is extremely complicated.

The experimental fabrication of such nanostructures

with the low cost processes is challenging.

Present investigation is devoted to the creation of

composite nanostructures of the arrays of vertically

aligned CNTs and the planar graphene (graphite)

layers (PGL) located at the top of the CNT arrays

(CNT-PGL nanostructures) by using the only one-step

process - the most simple and low cost CVD process

with the injected catalyst realized at ambient

conditions. One-layer [4], as well as multi-layer

nanostructures [5] were created. The last

nanostructures we designated as CNT-PGL

nanostacks.

Composite carbon structures were synthesized by

the injection CVD method using xylene/ferrocene

solution, as described in refs [4, 5]. Rate of injection

was varied in the range 0,01-0,2 cm3/min. The

constant flow of Ar (100 cm3/min) through a reactor

was provided during the processes of reactor

heating and cooling and CNTs synthesis. The content

of ferrocene in the feeding solution was 1,0 (wt %).

The process was carried out at the atmospheric

pressure at the working temperatures of 850˚C.

Wafers of n-type Si with 600 nm thermal oxide layer

were used as substrates.

The elemental composition were investigated by

Auger and EDX spectroscopy, structural

characterization was performed using scanning and

transmission electron microscopy, Raman

Spectroscopy.

Figure 1. SEM images of the fragments of the one-layer

CNT-PGL nanostructure: (a) nanostructure formed on

Si/SiO2 substrate, (b) graphene strips detached from the

surface of CNT array at different magnifications, (c) back

side of a strip with the attached CNTs.

Si SiO2

а b

c d

V. Labunov1,

A. Prudnikava1,

I. Komissarov1, B. Shulitski

1,

Y. Shaman2, V. Galperin

2

and A. Basaev2

[email protected]


TNT2012

Ab

st

ra

ct

s

The growth mechanism of one- and multi-layer CNT-

PGL nanostructures was proposed.

In Fig. 1 the SEM images of the fragments of one-

layer CNT-PGL nanostructure are presented.

It was proved that the structure consists of carbon,

i.e. represents CNT-PGL structure indeed. What is

particular, PGL can be easily detached from the CNT

array (Fig. 1a-d). The strips of graphene may be used

for the production of different devices or for the

physical experiments.

In Fig. 2 it is shown that by the developed technology

one can produce any number of layers of CNT-PGL

nanostructures. For example, three-layer (Fig. 2a) and

four-layer (Fig. 2b) nanostructures are presented.

Figure 2. SEM images of multi-layer CNT-PGL

nanostructures: (a) three-layer (indicated with arrows)

and (b) four-layer nanostructures.

The CNT-PGL nanostructures presented in Figs. 1,2 are

“ordered” nanostructures, because they demonstrate

strongly organized configuration of CNT-PGL layers.

Another type of CNT/graphene nanostructures,

“disordered”, obtained by the same method, but in

different regimes are presented in Fig. 3.

Figure 3. (a, b). “Disordered” CNT/graphene

nanostructures shown at different magnifications (SEM).

In our approach the high-quality CNT/graphene

nanostructures are produced by a very low cost

process. We expect to observe extraordinary

electrical properties of these structures and

compatible commercialization conditions with any

other approach. Moreover, the used CVD technique

is versatile and scalable. The obtained

nanostructures can enable many applications

including high-performance elastic and flexible

conductors, electrode materials for lithium ion

batteries and supercapacitors, thermal

management, catalyst and biomedical supports,

electrical energy storage devices based on this new

class of carbon material, and so on.

References

[1] Dimitrakakis, G.; Tylianakis, E.; Froudakis, G.,

Nano Letters, 10 (2008) 3166-3170.

[2] Varshney, V.; Patnaik, S.; Roy, A.; Froudakis, G.;

Farmer, B., ACS nano, 2 (2010) 1153-1161.

[3] Fan, Z.; Yan, J.; Zhi, L.; Zhang, Q.; Wei, T.; Feng,

J.; Zhang, M.; Qian, W.; Wei, F., Advanced

Materials, 33 (2010) 3723-3728.

[4] Labunov, V. A.; Shulitski, B. G.; A.L. Prudnikava;

Y.P. Shaman; Basaev, A. S., Semiconductor

Physics, Quantum Electronics &

Optoelectronics, 2 (2010) 137-141.

[5] Labunov, V.; Shulitski, B.; Prudnikava, A.;

Basaev, A., physica status solidi (a) (2010) 1-6.

b

3 μm

a

b

a

0.5 μm

0.4 μm


Emergent non-scalable behavior in

the nanoscale

School of Physics, Georgia Institute of Technology

Atlanta, GA 30332-0430 USA

Finite materials systems of reduced sizes exhibit

discrete quantized energy level spectra and specific

structures and morphologies, which are manifested

in unique, non-scalable, size-dependent physical

and chemical properties. Indeed, when the scale of

materials structures is reduced to the nanoscale,

emergent behavior often occurs, that is not

commonly expected, or deduced, from knowledge

learned at larger sizes. Characterization and

understanding of the size-dependent evolution of

the properties of materials aggregates, and their

propensities for size (“magic numbers”) and shape

self-selection and for self-assembly, are among the

major challenges of modern materials science.

Using computer-based first-principles quantum

computations and simulations [1], often in

conjunction with laboratory experiments, we

highlight and illustrate such behavior in diverse

nano-scale systems. In particular, we focus on the

following topics: (i) Charging effects in

Nanocatalysis [2], (ii) Pathways of post-ionization

proton-coupled-electron-transfer (PCET) DNA

reactions underlying mutagenesis and malignancy,

and involving a segmented water-wire transport

mechanism [3]; (iii) Coexistence of correlated

electron liquids and weakly-pinned Wigner crystals

under high magnetic fields in the fractional

quantum Hall effect regime, observed recently in

the neighborhood of 1/3 fractional filling in 2D

semiconductor quantum dots, and explained by a

unified microscopic theory [4].

* Supported by the US Department of Energy and

the Air Force Office of Scientific Research.

References

[1] U. Landman, “Materials by Numbers:

Computations as Tools of Discovery”, Proc.

Nat. Acad. Sci. (USA) 102, 6671 (2005).

[2] A. Sanchez, et al., J. Phys. Chem. A 103, 9573

(1999); B. Yoon, et al., Science, 307, 403

(2005); U. Landman, et al., Topics in Catalysis

44, 145 (2007); S. M. Lang, et al., JPC C 115,

6788 (2011); B. Yoon, et al., JPC C 116, 9594

(2012);

[3] R.N. Barnett, et al., Science 294, 567 (2001); J.

Am. Chem. Soc. 128, 10798 (2006); Acct.

Chem. Res., 43, 280 (2010); J.J Joseph et. al.,

Am. Chem. Soc. (2012).

[4] C. Yannouleas and U. Landman, Phys. Rev. B

84, 165327 (2011).

Uzi Landman


Fabrication and characterization

of nanopores in

Si based materials Ben-Gurion University of the Negev, P. O. Box 653, Beer-Sheva, Israel

The use of single nanopores (NPs) as biomolecule

sensing elements has gained a lot of interest in

recent years. In such biosensors the change in ionic

current when the analyte molecule translocates

through the NP is monitored, providing both

quantitative and qualitative analytical information.

The membrane’s material is important factor for

determining the resulting shape and surface properties that are extremely important for the

sensing process, and also affects fabrication

conditions. Thus, there is a constant quest for novel

techniques allowing the fabrication of NPs tunable,

in both size and materials properties. Herein, we

present fabrication, electrical and shape

characterization methodologies of NPs drilled in

silicon based membranes, including Si3N4,

crystalline Si and multilayered SiO2/Si/SiO2

membranes.

A novel method for the fabrication of NPs using

focused electron beam induced etching (FEBIE) will

be presented [1-3]. In this technique, pores are

etched by a cyclic process of reducing either nitride

or oxide membrane to elementary oxide followed

by spontaneous etching of the Si by XeF2. NPs can

be drilled with high precision with diameter in the

range of 10–200 nm, depending on electron

exposure time and acceleration voltage, and XeF2 pressure. The 3D shape of the NP is shown to

depend on the type of membrane used. Forming

NPs in both Si3N4 and SiO2/Si/SiO2 multilayers

membranes results in a funnel-like shape NPs [2, 3].

However, in the latter case cylindrical shape can be

obtained, depending on the post exposure time to

XeF2. This method facilitates the formation of high

aspect-ratio structures in rather thick membranes,

for which other the traditional NP drilling by

transmission electron microscope (TEM) fails. Additionally, due to the chemical nature of the

method, the chemical structure of the NP rims is

identical to that of the bulk material. This single

step process opens the way to fast integration with

silicon technology, making the suggested devices

especially suited for lab-on-chip applications.

I will further present a model we developed to

extract the 3D shape of the NPs from the

dependence of the ionic conductance of NPs on the

ionic strength of the electrolyte used in the

experiments [4], eliminating the need for

elaborated and expensive electron microscope analysis. The suggested methodology can be used

to monitor changes in the NP shape after

manufacture and during electrical characterizations

with high precision.

References

[1] Yemini M, Hadad B, Liebes Y, Goldner A and

Ashkenasy Nanotechnology, 20 (2009) 245302.

[2] Liebes Y, Hadad B and Ashkenasy N,

Nanotechnology 22 (2011) 285303.

[3] Liebes Y., Bandalo V., Sökmen Ü., Tornow Marc

and Ashkenasy N., (submitted).

[4] Liebes Y, Drozdov M, Avital Y Y, Kauffmann Y,

Rapaport H, Kaplan W D and Ashkenasy N,

Appl. Phys. Lett. 97 (2010) 223105.

Liebes Yael,

Rapaport Hanna and

Ashkenasy Nurit

[email protected]


Rapid conversion from protein-caged

nanomaterials to microbubbles:

a sonochemical route toward

bimodal imaging agents † Departments of Biomedical Engineering,

‡ Physics,

¶Bioscience Technology,

§ Center for

Nano Bioengineering, and Center for Nano-Technology, Chung Yuan Christian University,

Chung-Li 32023, Taiwan; + Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua

University, Hsinchu 30013, Taiwan; ┴ Departments of Medical Research and Internal Medicine, Mackay Memorial Hospital, and

Department of Medicine, Mackay Medical College, Taipei 10449, Taiwan; #Department of Health Developing and Health Marketing, Kainan University, Taoyuan 33857,

Taiwan; ║Graduate Institute of Clinical Medicine, Graduate Institute of Medical Sciences, and

Graduate Institute of Biomaterials, Taipei Medical University, Taipei 110, Taiwan

We report a facile method for nanoparticle (NP)-

coated microbubbles (MBs), which can be used for

bimodal ultrasound contrast agent. Based on our

previous reported amphiphilic polymer [1],

hydrophobic NPs not only can be transferred to

aqueous solution, but can offer a universal surface

for proteins assembly as core-shell complex of

NP/protein corona. The polycarboxylate polymer was

used successfully for linking inorganic colloidal NPs of

different materials (Au, CdSe/ZnS, Fe3O4) to BSA

protein corona. A second type of protein-caged

nanomaterials, protein-caged gold nanoclusters

(AuNCs) can be synthesized by intra-protein

“biomineralization” or self-assembly of AuNCs with

proteins, thus resulting in high photoluminescence in

red to near-infrared emission. Both types of protein-

caged nanomaterials can be rapidly converted into

MBs by introducing sonochemical route, which

promote disulfide crosslinking of cysteine residues

between protein-caged nanomaterials and free

albumin during acoustic cavitation. Further, the

functionalization of MBs can be easily achieved by

adjusting the original NP/protein mixture. We also

demonstrated different imaging modalities with

biocompatible AuNC-coated MBs, used in

conjunction with both in vitro/ in vivo ultrasound and

fluorescent imaging, which can held many potential

applications in medical diagnostics and therapy [2].

Figure 1. Scheme of synthesis of protein-caged

nanomaterials toward dual-functional MBs.

References

[1] Lin, C.-A. J.; Sperling, R. A.; Li, J. K.; Yang, T. Y.; Li,

P. Y.; Zanella, M.; Chang, W. H.; Parak, W. G. J.,

Design of an amphiphilic polymer for

nanoparticle coating and functionalization.

SMALL 2008, 4, (3), 334-341.

[2] Lin C. A. J., Chuang W.K., Huang Z.Y., Kang S.T.,

Chang C.Y., Chen C.T., Li J.L., Li J.K., Wang H.H.,

Kung F.C., Shen J.L., Chan W.H., Yeh C.K., Yeh H.I.,

Lai W.F.T., and Chang W.H., Rapid

Transformation of Protein-Caged Nanomaterials

into Microbubbles As Bimodal Imaging Agents,

ACS Nano, ASAP, 2012. DOI:

10.1021/nn300768d.

Cheng-An J. Lin†§

, Wen-Kai

Chuang†, Zih-Yun Huang

†,

Shih-Tsung Kang+, Ching-Yi

Chang†, Ching-Ta Chen

†,

Jhih-Liang Li†, Jimmy K. Li

†,

Hsueh-Hsiao Wang┴, Fu-

Chen Kung#, Ji-Lin Shen

‡§,

Wen-Hsiung Chan¶§

, Chih-

Kuang Yeh+, Hung-I Yeh

┴,

Wen-Fu T. Lai║ and Walter

H. Chang†§

[email protected]


Nanopillars as plasmonic platform to

enhance nonlinear vibrational sum-

frequency generation spectroscopy 1Lasers and Spectroscopies Laboratory (LLS), Research Centre in Physics of Matter and

Radiation (PMR), University of Namur (FUNDP), Belgium 2Institute of Condensed Matter and Nanosciences - Bio & Soft Matter (IMCN/BSMA),

Université catholique de Louvain (UCL), Belgium 3it4ip, Seneffe, Belgium

Metallic nanostructures such as nanopillars and

nanoantennas are able to confine the energy of an

incident radiation into volumes much smaller than

the wavelength of incoming waves through

localized surface plasmon resonance (LSPR) [1]. This

electromagnetic-field enhancement, attributed to

the collective motion of free electrons, has been

extensively used for surface-enhanced Raman

scattering (SERS) and other surface-enhanced

spectroscopic processes. This has driven metal

nanostructures to become a powerful tool for

chemical and biological optical sensing

experiments[2].

In this work, we coupled such localized

electromagnetic-field enhancement effect to a

nonlinear second-order optical spectroscopy to

obtain high molecular signal intensity and

sensitivity. The technique is based on a three waves

mixing process in which one infrared (ω1) and one

visible (ω2) photon interact together with matter to

generate a new coherent photon at the sum

frequency (ωsfg = ω1 +ω2). The whole process relying

on the second order nonlinear susceptibility χ(2)

,

the sum frequency generation (SFG) signal can be

emitted only where the centrosymmetry is broken,

that is at surfaces and interfaces separating two

bulk media[3,4]. In fine, SFG spectroscopy is a

background free vibrational surface-sensitive

spectroscopy able to retrieve accurate information

on molecular thin films properties, such as

conformation, orientation, dynamics, bio-

recognition processes, phase transitions.

Here, we report a strong enhancement of the

vibrational SFG signal from molecules adsorbed on

metallic nanopillars when those latter are excited

at their localized plasmon resonance frequencies.

In detail, gold nanopillars, sizing around 100 nm in

height and 60 nm in diameter, stand vertically on a

substrate of gold or platinum. The nanopillars

exhibit two plasmon modes that can be selectively

excited by the incident visible laser beam or by the

generated SFG beam itself. Until now, for a density

of 109 nanopillars/cm

2, the molecular SFG signal

obtained on such nanostructured surfaces is more

than 100 times larger that what can be achieved on

unstructured flat surfaces. Besides, because of the

directional profile of the two plasmon modes, an

adequate choice of the beams polarizations and

frequencies leads to a spatial selectivity of the SFG

emission. It is indeed likely possible to selectively

probe the molecules adsorbed onto the nanopillar

side wall, the nanopillar top part (as shown on

Figure 1), or the flat region of the substrate in-

between the pillars. This gives promising issues to

set up label free vibrational bio-recognition

platforms with “multi-zone” enhanced sensitivity.

References

[1] L. Novotny and N. van Hulst, Nat. Photon. 5

(2011) 83

[2] Willets, K. A.; Van Duyne, R. P., Annu. Rev. Phys.

Chem., 58 (2007) 267-297.

[3] Shen, Y. R., Nature, 337 (1989) 519-525.

[4] Vidal, F.; Tadjeddine, A., Rep. Prog. Phys. 68

(2005) 1095-1127.

Dan Lis1, Yves Caudano

1,

Marie Henry2,

Sophie Demoustier-

Champagne2,

Etienne Ferain3 and

Francesca Cecchet1

[email protected]


TNT2012

Ab

st

ra

ct

s

Figure 1. The left figure shows SFG spectra in ppp polarization (in the order SFG, Vis and IR beam) of a dodecanethiol

(DDT) molecular film adsorbed over the sample surfaces. The red curve corresponds to the spectra of the DDT layer

adsorbed over a flat platinum surface, while the blue curve is the spectra recorded on the gold nanopillar region when

those latter have their longitudinal LSPR mode excited at 650 nm by the visible laser beam. A schematic representation

of the the experimental conditions is shown in the right figure. An important SFG intensity increase (blue curve) is

observed thanks to the excitation of the LSPR mode of the nanopillar.


Nanoscale metallic and

metal-ceramic multilayers for

radiation-resistant applications

IMDEA Materials Institute, C/Erik Kandel 2, Tecnogetafe, 28906 Getafe (Madrid), Spain

Depart. of Materials Science, Polytechnic University of Madrid, 28040 Madrid, Spain

High energy neutron and proton radiation can

induce serious damage in structural metals,

including void swelling and embrittlement. Hence

the design of advanced metallic materials with

significantly enhanced radiation tolerance is critical

for the application of advanced nuclear energy

systems. Nanoscale metallic and metal-ceramic

multilayers are currently under consideration as

potential candidates to overcome this problem as a

result of their unique mechanical properties and of

their ability to withstand radiation without

degradation of the mechanical performance. Both

behaviors come about as a result of the large area

fraction of interfaces which control the multilayer

mechanical properties and radiation resistance

when the layer thickness is below 100 nm.

In this presentation, the mechanical behavior of

two nanoscale multilayer systems (Cu/Nb and

Al/SiC) is analyzed as a function of processing route

(magnetron sputtering or accumulated roll

bonding), layer thickness (in the range 5 nm to 50

nm) and temperature (from room temperature up

to 400ºC). Results form novel nanoindentation and

micropillar compression tests at different

temperatures, combined with transmission

electron microscopy and numerical modeling,

together with current theoretical models are used

to understand the dominant deformation and

fracture micromechanisms of this novel

nanostructured materials.

Javier LLorca

[email protected]


Hierarchical micro-nano-structures

for cell adhesion studies a Nanotechnology Platform, Parc Científic Barcelona, 08028 Barcelona, Spain

b Advanced Digital Microscopy Core Facility, Inst. for Research in Biomedicine,

08028 Barcelona, Spain c Institut de Bioenginyeria de Catalunya, 08028 Barcelona, Spain

Introduction

The capacity to fabricate materials exhibiting well-

defined features able to selectively interact with

biology at cellular and subcellular levels has had

tremendous implications in the field of tissue

engineering. It is now well established that cell

behaviors can be controlled, enhanced, or

diminished by interacting with surface

topographies of different size scales (1-3).

However, the reasons behind these effects are not

well understood and motivate the development of

materials that facilitate the systematic study of cell-

topography interactions. With this in mind, we

report two different fabrication processes to build

hierarchical structures in a variety of different

materials in order to investigate the competitive

effects of micro and nanotopographies on cell

adhesion, spreading, and morphology.

Materials and Methods

Micro and nanofabrication techniques such as ion

beam lithography (FIB), electron beam lithography

(EBL), photolithography, and reactive ion etching

(RIE) were combined to create micro/nano

hierarchical structures on silicon. Two distinct

strategies were developed in order to create high

resolution surface topographies with the chance to

build versatile designs. Then, these structures were

transferred to a number of biocompatible polymers

including polydimethylsiloxane (PDMS),

polymethylmethacrylate (PMMA), low density

polyethylene (LDPE), and recombinant elastin-like

polypeptides (ELP). PMMA samples consisted on

four different patterned areas with microchannels,

nanochannels and perpendicular and parallel

micro/nanochannels were fabricated in order to

determine the competitive and synergetic effect of

the micro- and nano-scale topographies in rat

mesenchymal stem cells adhesion and morphology.

Results and Discussion

Scanning electron microscopy (SEM) and atomic

force microscopy (AFM) observations revealed that

hierarchical topographical patterns consisting of

perpendicular and parallel micro/nanochannels

were fabricated in silicon and then these structures

were successfully transferred to the different

polymeric materials. Optical, widefield

epifluorescence, confocal, and SEM observations

revealed that the cells changed their morphology,

alignment and elongation, depending on the

different surface topographies (Fig. 1). Cell

alignment and elongation significantly increased on

parallel nano/microchannels (Figs. 1, 2). However,

cells did not have a significant preference for micro

or nanochannels in perpendicular region (Fig. 2).

Conclusions

We have developed two distinct methods to

fabricate hierarchical structures with high

resolution and accurate topography control in

silicon and biocompatible polymers. Due to the

opportunity to interact with biology at both the

nano and microscale, these types of hierarchical

structures could be used for a variety of

applications in tissue engineering and regenerative

medicine. Surface topographies with hierarchical

features expanding from the nano to the

macroscale offer the possibility to synergistically

improve the bioactivity of materials and control

biological processes.

María Jesús López-Bosquea,

Marina Cazorlaa, Judith

Linaceroa, Esther Tejeda-

Montesa, Yolanda Atienza

a,

Anna Lladob, Julien

Colombellib, Elizabeth

Engelc, Alvaro Mata

a

[email protected]


TNT2012

Ab

st

ra

ct

s

Figure 1. Representative fluorescence images of cells on (a) micro- (b) perpendicular (c) parallel and (d) nano-channels.

(e-f) SEM and (g) fluorescence images (red=vinculin, green=actin cytoskeleton) of cells growing on perpendicular

channels. Direction of nanochannels is schematically shown by white lines (b-d, g).

Figure 2. (a) Quantification of cell alignment revealing that cells are aligned preferentially along the micro-, nano- and

parallel channels. However, cells sense the competitive effect of the micro- and nanoscale topographies, interacting

with both micro- and nano-channels when perpendicular to each other. (b) Quantification of cell elongation revealing

that cells sense the synergistic effect of the micro- and nano-topographies on parallel channels. The cells are

significantly more elongated on parallel channels compared to the micro- and nano-channels individually.

References

[1] M.J. Dalby, N. Gadegaard, R. Tare, A. Andar, M.O. Riehle, P. Herzyk, C. D. W. Wilkinson, R. O. C. Oreffo,

Nature Materials 6 (2007) 997–1003

[2] R. J. McMurray, N. Gadegaard, P. M. Tsimbouri, K. V. Burgess, L. E. McNamara, R.Tare, K. Murawski,

E.Kingham, R. O. C. Oreffo, M. J. Dalby, Nature Materials 10 (2011) 637–644

[3] A. Mata, L. Hsu, R. Capito, C. Aparicio, K. Henrikson, S. I. Stupp, Soft Matter 5(6) (2009) 1228–1236


Refractive index sensing based on

plasmonic fano-like interference

Instituto de Estructura de la Materia (IEM-CSIC)

Serrano 121

E-28006 Madrid, Spain

As Unlike those propagating at metal/dielectric

interfaces, localized collective oscillations of charges

confined to the surface of metal nanoparticles can

be directly excited by external illumination without

the need of any additional coupling-in technique,

provided that particles are much smaller than the

incident wavelength. These oscillations, which can

be pictured as a “wave” of electrons moving across

the surface of the particle, are referred to as

localized surface plasmon resonances (LSPRs) and

they are responsible of nanoparticles' bright colors

when in colloidal suspension, as a result of their

intense absorbing and scattering of light in the

visible range.

One of the most appealing properties of LSPRs is

that their resonant frequency strongly depends on

nanoparticles's size, shape and composition, as well

as on the refractive index of the surrounding

medium. Given that present technological advances

allows one to control particle geometry down to

nanometer scale, spectral shift of LSPRs can then be

used to detect extremely small changes of the

immediate dielectric environment. For instance,

such as those produced by the binding of some

biological molecules with a higher refractive index

than that of their aqueous solvent.

When assessing the actual performance of a

refractive index sensing scheme based on the

spectral shift of a given plasmon resonance, we have

to first consider its refractive index sensitivity, which

is defined as the linear regression slope within a

given range for the position of the resonance (either

a peak or a dip) as a function of refractive index. This

magnitude is usually expressed in terms of

wavelength or energy shifts per refractive index unit

and it provides a preliminary measure of the sensor

quality. However, sensitivity alone cannot

characterize the sensor performance but in an ideal

scenario of infinitely high spectral resolution and no

system noise. Sherry et al. [1] therefore proposed

the so-called figure of merit (FoM), which is defined

as the plasmon resonance sensitivity divided by its

“Full Width at Half Maximum” (FWHM), as the most

meaningful indicator for evaluating the performance

of LSPR-based sensors. Such dimensionless quantity

allows one to directly compare the sensing

properties of different systems irrespective of their

shape, size and operating wavelength.

According to its very definition, the optimal FoM

would then be obtained from those resonances

exhibiting both high sensitivity to environment and

narrow FWHM, which are precisely the main

features of spectral line profiles arising from Fano

interference [2]. Such an interaction of discrete- and

continuum-like states (often labeled as “dark” and

“bright” modes) has already been employed for

refractive index sensing by means of either

propagating or localized plasmon resonances. In this

work [3], we propose that the Fano-like interference

of longitudinal plasmon resonances occurring at a

single nanorod [4] can be employed for refractive

index sensing in two different configurations that are

reasonably attainable. We also discuss their

expected performance in terms of their FoMs, which

are calculated under realistic conditions by means of

the separation of variables (SVM) and the finite

element (FEM) methods [5, 6].

References

[1] L. J. Sherry et al., Nano Lett., 5 (2005) 2034.

[2] B. Luk’yanchuk et al., Nat. Mater., 9 (2010) 707.

[3] F. López-Tejeira, R. Paniagua-Domínguez and J.

A. Sánchez-Gil, submitted.

[4] F. López-Tejeira et al., New J. Phys., 14 (2012)

023035.

[5] N. V. Voshchinnikov and V.G. Farafonov,

Astrophys. Space Sci., 204 (1993) 19.

[6] COMSOL Multiphysics version 4.2.

F. López-Tejeira,

R. Paniagua-Domínguez and

J. A. Sánchez-Gil

[email protected]


New intermediate band sulphide

nanoparticles acting in the full

visible light range spectra as an

active photocatalyst 1 Instituto de Catálisis y Petroleoquímica, CSIC, Marie Curie 2, 28049 Madrid, Spain.

2 Instituto de Energía Solar, Universidad Politécnica de Madrid,

Ciudad Universitaria s/n, 28040 Madrid, Spain.

Nowadays one of the challenges of materials

science is to find new technologies that will be able

to make the most of renewable energies. An

example of new proposals in this field are the

intermediate-band (IB) materials, which promise

higher efficiencies in photovoltaic applications

(through the intermediate band solar cells), or in

heterogeneous photocatalysis (using nanoparticles

of them, for the light-induced degradation of

pollutants or for the efficient photoevolution of

hydrogen from water).

Figure 1. IB working principle: (a) photons of different

energies excite electrons from the VB directly to the CB

and also from the VB to the IB and from the IB to the CB.

(b) A wider photon energy range is thus used.

Figure 2. Density of states (computed with DFT) of In2S3

with octahedral In partially substituted by V.

An IB material consists in a semiconductor in which

gap a new level is introduced [1], the intermediate

band (IB), which should be partially filled by

electrons and completely separated of the valence

band (VB) and of the conduction band (CB). This

scheme (figure 1) allows an electron from the VB to

be promoted to the IB, and from the latter to the

CB, upon absorption of photons with energy below

the band gap Eg, so that energy can be absorbed in

a wider range of the solar spectrum and a higher

current can be obtained without sacrificing the

photovoltage (or the chemical driving force)

corresponding to the full bandgap Eg, thus

increasing the overall efficiency.

This concept, applied to photocatalysis, would

allow using photons of a wider visible range while

keeping the same redox capacity. It is important to

note that this concept differs from the classic

photocatalyst doping principle, which essentially

tries just to decrease the bandgap. This new type of

materials would keep the full bandgap potential but

would use also lower energy photons.

In our group several IB materials have been

proposed, mainly for the photovoltaic application,

based on extensively doping known

semiconductors with transition metals [2],

examining with DFT calculations their electronic

structures. Here we refer to In2S3 and SnS2, which

contain octahedral cations; when doped with Ti or

V an IB is formed according to quantum

calculations (see e.g. figure 2).

We have used a solvotermal synthesis method to

prepare in nanocrystalline form the In2S3 thiospinel

and the layered compound SnS2 (which when

undoped have bandgaps of 2.0 and 2.2 eV

Raquel Lucena1, José Carlos

Conesa1, Fernando Fresno

1,

Perla Wahnón2, Pablo

Palacios2 and Yohanna

Seminovski2

[email protected]


TNT2012

Ab

st

ra

ct

s

respectively) where the cation is substituted by

vanadium at a ≈10% level. This substitution has

been studied, characterizing the materials by

different physical and chemical techniques (TXRF,

XRD, HR-TEM/EDS) (see e.g. figure 3) and verifying

with UV spectrometry that this substitution

introduces in the spectrum the sub-bandgap

features predicted by the calculations (figure 4).

Figure 3. a) XRD diagram of SnS2 and V:SnS2 synthesized

materials, indicating the nanocrystal size deduced from

linewidths. b) V:In2S3 HR-TEM image of In2S3 with EDS

measurement of the composition at the In2S3

nanocrystals.

Figure 4. Experimental diffuse reflectance spectrum of

pure and V-doped nanocrystalline In2S3.

For both sulphide type nanoparticles (doped and

undoped) the photocatalytic activity was studied by

following at room temperature the oxidation of

formic acid in aqueous suspension, a simple

reaction which is easily monitored by UV-Vis

spectroscopy. The spectral response of the process

is measured using a collection of band pass filters

that allow only some wavelengths into the reaction

system. Thanks to this method the spectral range in

which the materials are active in the

photodecomposition (which coincides with the

band gap for the undoped samples) can be

checked, proving that for the vanadium substituted

samples this range is increased, making possible to

cover all the visible light range. Furthermore it is

checked that these new materials are more

photocorrosion resistant than the toxic CdS witch is

a well know compound frequently used in tests of

visible light photocatalysis.

Figure 5. Rate constant k measured for aqueous HCOOH

photooxidation under light of different wavelengths on

In2S3 with and without ≈10% V doping, compared with

the respective DR Vis-NIR spectra.

These materials are thus promising not only for

degradation of pollutants (or for photovoltaic cells)

but also for efficient photoevolution of hydrogen

from water; work in this direction is now being

pursued.

References

[1] A. Luque, A. Martí, Phys. Rev. Lett. 78, 1977,

5014.

[2] a) P.Palacios et al. Phys. Rev. B 73 (2006)

085206; ibid. J. Chem. Phys. 124 (2006)

014711.

b) P. Palacios et al. Thin Solid Films 515 (2007)

6280; ibid. J. Phys. Chem. C 112 (2008) 9525.

c) P. Palacios et al. Phys. Rev. Lett. 101 (2008)

046403.

[3] a) R. Lucena et al. Chem. Maters. 20 (2008) 5125.

b) P. Wahnón et al. Phys. Chem. Chem. Phys.13

(2011) 20401.

0 10 20 30 40 50 60 70 80 90 100

V:SnS2 30nm

SnS2 23nm

2 θθθθ / º

a)

0.5 1.0 1.5 2.0 2.5 3.0 3.5

0

2

4

6

8

10

12

k/s

(K

M function)

E (eV)

V:In2S

3

In2S

3

Kubelka-Munk transform:KM=(1-R)2/2R

0.5 1.0 1.5 2.0 2.5 3.0 3.5

0

2

4

6

8

10

12

k/s

(K

M function)

E (eV)

V:In2S

3

In2S

3

Kubelka-Munk transform:KM=(1-R)2/2R

400 500 600 700 800 9000.000

0.002

0.004

0.006

0.008

0.010

0.012

0.014

0.016

0.018

0.020

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

K / M

in-1

λλλλ / nm

Absorption

spectra of In2S3

Absorption

spectra of In1,8V0,2S3

In2S

3

In1,8

V0,2

S3

absorp

tion (αα αα)


Quantum dot intermediate band

solar cells:

issues for an attractive concept

Instituto de Energía Solar, Universidad Politécnica de Madrid, Spain

The Intermediate Band Solar Cell [1] is formed by

sandwiching and Intermediate Band (IB) material

between two ordinary semiconductors p- and n-

doped. The IB material has an energy band or set of

levels (the IB) situated within the bandgap of a

semiconductor. In this way, besides the

photocurrent generation by photons with enough

energy as to pump electrons form the valence band

(VB) to the conduction band (CB) a second path of

current appears with two photons of less energy

that completes the pumping using the IB as

stepping stone. The concept is very attractive

because this cell is potentially able to increase the

photocurrent without decreasing the photovoltage.

In this way the detailed balance [1] top efficiency is

63% to compare to the 41% of a single bandgap

solar cell.

IBSCs can be made with alloys presenting an IB [2]

and with IB materials containing Quantum Dot (QD)

arrays [3, 4]. In the first case we have to deal with

relatively exotic materials in which the device

technology is incipient and therefore the cell

efficiency measured so far is very small. In the

second case, which is the one to present in this talk

the device technology is rather developed. Most of

the work so far has been done with Stranski-

Krastanov InAs QDs in GaAs, grown by MBE [4].

IBSCs of 18% efficiency [5] have been presented,

reasonable but below the expectations.

The reason for this is that the voltage is usually

strongly reduced and the current is increased only

slightly. In IBSC the voltage is believed to be

controlled [6, 7], like in most devices, by SRH

recombination through the ordinary impurities of

the solar cell (not the IB levels) but the presence of

the IB increases the minority carriers and the cell

behaves as with a reduced bandgap. More

perfection in the material quality may prevent this

reduction and this has actually been attained [8] in

InAs/GaAs QD IBSCs made by MOCVD.

The reduced current is an intrinsic property of the

QDs. VB→IB absorption requires that the initial and

final eigenfunctions have strong projection in both

the CB and the VB [7, 9]; unfortunately the IB

eigenfunctions are almost fully projected on the CB

and all the VB eigenfunctions have no or negligible

projection on the CB. Controlling the shape and

density of the QDs might be a way to overcoming

this issue.

In summary, the IBSC has become a hot subject in

photovoltaics. The concept is very attractive but

bringing it into practice will still require efforts.

Antonio Luque


TNT2012

Ab

st

ra

ct

s

References

[1] A. Luque, A. Martí, Physical Review Letters 1997, 78, 5014.

[2] N. Lopez, L. A. Reichertz, K. M. Yu, K. Campman, W. Walukiewic, Physical Review Letters 2011, 106,

028701.

[3] A. Martí, L. Cuadra, A. Luque, in Proc. 28th IEEE Photovoltaics Specialists Conference, IEEE, New York

2000, 940.

[4] A. Luque, A. Martí, C. Stanley, N. López, L. Cuadra, D. Zhou, A. Mc-Kee, Journal of Applied Physics 2004,

96, 903.

[5] S. A. Blokhin, A. V. Sakharov, A. M. Nadtochy, A. S. Pauysov, M. V. Maximov, N. N. Ledentsov, A. R.

Kovsh, S. S. Mikhrin, V. M. Lantratov, S. A. Mintairov, N. A. Kaluzhniy, M. Z. Shvarts, Semiconductors

2009, 43, 514.

[6] A. Luque, P. G. Linares, E. Antolín, I. Ramiro, C. D. Farmer, E. Hernández, I. Tobías, C. R. Stanley, A. Martí,

Journal of Applied Physics 2012, 111, 044502.

[7] A. Luque, A. Marti, C. Stanley, Nature Photonics 2012, 6, 142.

[8] C. G. Bailey, D. V. Forbes, S. J. Polly, Z. S. B. IEEE, Y. Dai, Chelsea Mackos, R. P. Raffaelle, S. M. Hubbard,

IEEE Journal on Photovoltaics 2012, DOI 10.1109/JPHOTOV.2012.2189047.

[9] A. Luque, A. Mellor, E. Antolin, P. G. Linares, I. Ramiro, I. Tobias, A. Marti, Solar Energy Materials and

Solar Cells 2012, 103, 171.


Silica nanostructures toxicity

assessment and their potential for

biomedical applications

Italian Institute of Technology

Center for Bio-Molecular Nanotechnologies@Unile

Via Barsanti, 73010 Arnesano, Lecce, Italy

Silica nanoparticles are widely used in various

industrial fields and recently, they have been

exploited also for biomedical research. The impact

of SiO2NPs on human health and the environment

is thus of great interest. Nowadays, the overall

evaluation of the toxicity/biocompatibility of

SiO2NPs is extremely difficult, owing to

controversial results in the literature and to the lack

of standard procedures and/or insufficient

characterization of the nanomaterials in biological

systems. Therefore the biocompatibility needs to

be documented in greater detail. In this study we

evaluated the toxicity of different silica

nanostructures, both pure and quantum dots

(QDs)- or iron oxide-doped, and studied their

potential applications in gene delivery. We

performed a systematic in vitro study to assess the

biological impact of pure SiO2NPs, by investigating 3

different sizes (Fig.1) and 2 surface charges in 5 cell

lines. We analyzed the cellular uptake and

distribution of the NPs along with their possible

effects on cell viability, membrane integrity and

generation of reactive oxygen species (ROS). We

observed that all the investigated SiO2NPs do not

induce detectable cytotoxic effects (up to 2.5 nM

concentration) in all cell lines (Fig.2a). Once having

assessed the biocompatibility of SiO2NPs we

evaluated their potential in gene delivery, showing

their ability to bind, transport and release DNA,

allowing the silencing of a specific protein

expression (Fig.2b) [1]. The biocompatibility of

SiO2NPs and their gene carrier performance were

also evaluated and confirmed in primary neuronal

cells [2]. Finally, we investigated the toxicity of

silica nanoparticles doped with iron oxide

nanocrystals. We tested nanoparticles with two

surface charges in two cell lines by evaluating their

effect on cell viability, cell membrane integrity and

induction of ROS. We found that SiO2NPs doped with

iron oxide nanoparticles do not induce detectable

cytotoxic effects up to 1 nM concentration (Fig.3b)

with negatively charged NPs exerting the higher

toxicity. This is likely associated to the nanoparticles

degradation in lysosomal environment.

Overall, we demonstrate that SiO2 nanostructures

are quite safe in vitro and have promising potential

in biomedical applications.

References

[1] M.A. Malvindi et al., Nanoscale, 2012, 4; 4(2),

486-495.

[2] G. Bardi et al., Biomaterials, 2010, 31, 6555-

6566.

Maria Ada Malvindi,

Virgilio Brunetti,

Giuseppe Vecchio,

Antonio Galeone,

Valeria De Matteis,

Roberto Cingolani and

Pier Paolo Pompa

[email protected]

Figure 1.

Representative

TEM images of

three sizes of

SiO2NPs: 25, 60 and

115 nm.


TNT2012

Ab

st

ra

ct

s

a) b)

Figure 2. a) Viability of A549 cells 48 and 96 h after the exposure to increasing doses evaluated of 25 nm SiO2NPs by the

WST-8 assay; b) In vitro silencing of tGFP expression.

Figure 3. a) SiO2NPs doped with iron oxide NPs; b) Viability of A549 cells 48 and 96 h after the exposure to increasing

doses of SiO2NP doped with iron oxide NPs evaluated by the WST-8 assay; c) Iron release in lysosomal environment.


Plasmonic nanoparticle chain in a

light field: a resonant optical sail 1Departamento de Física de la Materia Condensada and Instituto “Nicolás Cabrera”,

Universidad Autónoma de Madrid, 28049 Madrid, Spain. 2Departamento de Física de Materiales and Instituto “Nicolás Cabrera”, Universidad

Autónoma de Madrid, 28049 Madrid, Spain.

Metallic Optical trapping and driving of small

objects has become a topic of increasing interest in

multidisciplinary sciences. We propose [1] to use a

chain made of metallic nanoparticles as a resonant

light sail, attached by one end point to a

transparent object and propelling it by the use of

electromagnetic radiation. Driving forces exerted

on the chain are theoretically studied as a function

of radiation’s wavelength and chain’s alignments

with respect to the direction of radiation.

Interestingly, there is a window in the frequency

spectrum in which null torque equilibrium

configuration, with minimum geometric cross

section, corresponds to a maximum in the driving

force.

References

[1] S. Albaladejo, J. J. Sáenz and M. I. Marqués,

Nanoletters 11, 4597 (2011)

Silvia Albaladejo1,

Juan José Sáenz1 and

Manuel I. Marqués2

[email protected]


Imaging the carrier confinement

within a single nanowire

1European Synchrotron Radiation Facility, 38043-Grenoble, France

2IMM, Instituto de Microelectrónica de Madrid (CNM, CSIC), 28760-Tres Cantos, Spain

3Department of Applied Physics, Valencia University, 46100-Burjasot, Spain

4Institute for Electronics, Microelectronics, and Nanotechnology, CNRS-UMR 8520,

Department ISEN, F-59652 Villeneuve d’Ascq, France 5National CRI Center for Semiconductor Nanorods, Department of Physics and

Astronomy, Seoul National University, Seoul 151747, Republic of Korea

The assembly of group-III nitride nanowires into optoelectronics offers a promising approach to improve the

performance of light-emitting devices. Two dimensional quantum confinement effects, created by coaxial

band structure engineering, lead large spectral tunability and high luminescence quantum yields.

Sophisticated core/multishell nanowires have already been designed to produce a large variety of size-

dependent phenomena for advanced light-emitting diodes. Although theory suggests that the carrier

distributions in nanowires exhibit two dimensional confinement under a cross-section of hexagonal

geometry, its direct observation has never been addressed. By combining synchrotron excited optical

luminescence with simultaneous energy-disperse X-ray spectroscopy using a nanometre-sized hard X-ray

beam, here we show experimental evidence for these carrier localization effects. Applied to single coaxial n-

GaN/InGaN multiquantum-well/p-GaN nanowires, our hyperspectral imaging method reveals a stronger

transition at the hexagon corners, matching theoretical predictions. Based on core-level excitation

processes, our experiment opens new avenues for further local structure, and time-resolved studies with

both nanometre resolution and optical sensitivity. We anticipate that this methodology will contribute to a

greater understanding of the underlying design concepts of photonic nanodevices.

Gema Martínez-Criado1 ,

A. Homs1, B. Alén

2,

J. A. Sans3, J. Segura-Ruiz

1,

A. Molina-Sánchez4,

J. Susini1, J. Yoo

5 and

G.-C. Yi5

[email protected]


Reciprocal space and transmission

electron microscopy study of

heterogeneous GaP: MnP magnetic

epilayers containing MnP

nanoclusters Regroupement québécois sur les matériaux de pointe (RQMP) and Département de génie physique, École Polytechnique de Montréal P.O. Box 6079, Station Centre-Ville, Montréal, Québec H3C 3A7, Canada Work done in collaboration with: C. Lavoie, IBM T.J. Watson Research Center, Yorktown Heights, NY 10598, USA; C. Lacroix and D. Ménard, Département de génie physique, École Polytechnique de Montréal; M. Garcia-Hernandez, and A. de Andres, Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain.

The integration of magnetic nanoclusters in thin III-V semiconductor films can enhance magneto-resistance and magneto-optic effects with the potential to be integrated in novel devices for room temperature applications [1-3]. The magnetic properties of heterogeneous films strongly depend on the structural properties of the clusters and film matrix, which are in turn determined by the growth conditions. We show how a three dimensional mapping of reciprocal space by X-ray diffraction combined with transmission electron microscopy measurements can determine the texture of GaP epilayers containing embedded MnxP nanoclusters grown on GaP substrates by metal organic vapor phase epitaxy [4-5]. This systematic approach allows identification of all phases present in the heterogeneous films, in particular showing traces of hexagonal Mn2P precipitates, whose formation can be avoided by lowering the film growth temperature. Growth at 650 oC produces mostly orthorhombic MnP nanoclusters, responsible for the magnetic properties, which are oriented along specific GaP crystallographic directions, forming six well defined families. The population of these families can be quantified and is influenced by the growth temperature and the film thickness. The MnP clusters principally grow on GaP(001) and GaP{111} facets with a small fraction of clusters nucleating on higher-index GaP{hhl} facets. Most epitaxial alignments share a similar component: the

MnP(001) plane (c-axis plane) is parallel to the GaP{110} plane family. Axiotaxial ordering between the MnP clusters and the GaP matrix has also been observed [5].

Figure 1. The TEM image on the left shows a plan view of a heterogeneous GaP:MnP epilayer containing MnP nanoclusters grown at a substrate temperature of 650

oC

[ref. 4]. The heterogeneous films are grown on semi-insulating GaP(001) substrates in a low-pressure cold-wall MOVPE reactor, using trimethylgallium, tertiary-butylphosphine, and methyl cyclopentadienyl manganese tricarbonyl as precursors for Ga, P and Mn respectively, and Pd-purified hydrogen as the carrier gas. The reactor pressure was set at 40 Torr with a total flow rate maintained at 4000 sccm. Growth rate is 1.2 μm/ h for GaP(001) at a growth temperature of 650 oC C

S. Lambert-Milot, S. Gaudet, P. Desjardins, and R.A.

Masut

[email protected]


TNT2012

A

bs

tr

ac

ts

Acknowledgements The authors acknowledge J. Bouchard for technical support, J.-P. Massé for assistance with TEM measurements, and J. Jordan-Sweet and E. Dimasi for technical assistance at the NSLS X20 and X6B beamlines. This research was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Canada Research Chair Program, and the Fonds Québécois de la Recherche sur la Nature et les Technologies (FQRNT). The research was carried in part at the NSLS, Brookhaven National Laboratory, supported by the U.S. D.O.E., Division of Materials Sciences and Division of Chemical Sciences, under Contract No. DE-AC02-98CH10886.

References

[1] G. Monette, C. Lacroix, S. Lambert-Milot, V. Boucher, D. Ménard and S. Francoeur, J. Appl. Phys. 107 (2010) 09A949.

[2] C. Lacroix, S. Lambert-Milot, P. Desjardins, R.A. Masut and D. Ménard J. Appl. Phys. 103 (2008) 07D531.

[3] C. Lacroix, S. Lambert-Milot, P. Desjardins, R.A. Masut and D. Ménard, J. Appl. Phys. 105 (2009) 07C119.

[4] S. Lambert-Milot, C. Lacroix, D. Ménard, R. A. Masut, P. Desjardins, M. Garcia-Hernandez and A. de Andres, J. Appl. Phys. 104 (2008) 083501.

[5] S. Lambert-Milot, S. Gaudet, C. Lacroix, D. Ménard, R.A. Masut, P. Desjardins, and C. Lavoie, J.Vac. Sci. & Tech., submitted.

Figure 2. Reciprocal space measurements: were carried out at the National Synchrotron Light Source (NSLS) (Brookhaven National Laboratory) X20A and X6B beam lines. The figure below illustrates the large photon flux provided by the synchrotron source, a key feature to obtain a full 3D reciprocal space map which will allow texture determination.

Figure 3. Texture and phase quantification: is obtained from X-ray diffraction (a set of more than 600 pole figures, as the example illustrated below) combined with transmission electron microscopy (TEM) analysis


Spatial and temporal control of

osteoblastic cells proliferation on

electroconductive carbon

nanotube-based bone grafts 1 CICECO, Dept. of Materials and Ceramic Eng., Univ. of Aveiro, 3810-193 Aveiro, Portugal

2 I3N, Physics Dept., Univ. of Aveiro, 3810-193 Aveiro, Portugal

3 CEMUC, Dept. of Metallurgical and Materials Eng., Univ. of Porto,

4200-465 Porto, Portugal 4 Faculty of Dental Medicine, Univ. of Porto, 4200-393 Porto, Portugal

Biomaterials can still be reinvented to become

simple and universal bone regeneration solutions.

Following this roadmap, "smart" bone grafts have

been designed with new functionalities able to

stimulate specific bone cells responses. Regarding

the beneficial effects of endogenous electrical

signals in natural bone, electron conductivity

emerge as an exciting functionality. As opposed to

natural piezoelectric bone, electroconductive bone

grafts have key advantages: external control over

the level and duration of stimulation; confinement

of exogenous electrical fields on their surface

leading to spatial and temporal control of bone

tissue regeneration. Following this, the present

work aims to: (1) process MWCNTs-based bone

grafts; (2) assess the α-MEM-conductive bone

grafts interactions under (or not) electrical fields;

(3) evaluate in vitro the efficiency of conductive

bone grafts in delivering electrical stimulus to

osteoblastic cells.

Biologically safer carbon nanotubes (CNT) [1-3]

presenting outstanding characteristics - non-

metallic phases, bioactive, high aspect-ratio and

ultimate electrical conductivity - were used here as

fillers to obtain highly conductive biomaterials.

Calcium phosphate (CaP)/CNT powders show high

interaction being the CNTs decorated with CaP

particles (Fig. 1a). Microstructures of fracture (Fig.

1b) and polished surfaces (Fig. 1c) show that CNT

are well dispersed combining individual CNT (Fig.

1d) and controlled sized agglomerates (<10 Dm)

(Fig. 1c). This CNT 3D network gives an electrical

percolation threshold (Pc) in the range of 0.9-1.8

vol.% (Fig. 1e). Pursuing the main goal of this work,

the selection of the CNT loading should be: low to

preserve the biological profile of the matrix; high to

give composites with higher conductivity than the

biological milieus. The 2.5 wt.% loading is the one

that matches this two requisites (Figs. 1e,f).

Figure 1. Microstructure and electrical conductivity of

CNT-based composites.

In an in vivo scenario, it is expected that this

composite formulation induces the locally increase

of the conductivity and confines the exogenous

electrical fields on its surface. To evaluate this, two

set of experiments were performed in α-MEM

(12 ml). The presence of six CaP samples show an

increase of 0.15 % of the impedance of the medium

(Figs. 2a,c). Conversely, six CaP/CNT (2.5 wt.%)

samples decrease the impedance in 1.26 % (Figs.

2b,c). Scanning vibrating electrode (SVET)

measurements were accomplished under a

constant electrical field Exx of 3 mV.cm-1

/100 DA,

accordingly to the configuration of Fig. 2d. At the

D. Mata1, M. Amaral

1,2,

A.C. Bastos1, M.A. Neto

1,

F.J. Oliveira1, M.A. Lopes

3,

M.H. Fernandes4 and

R.F. Silva1

[email protected]


TNT2012

Ab

st

ra

ct

s

borders, it can be seen that the conductive sample

induces less distortion of the E lines than the

dielectric one (Figs. 2e,f). Also, the Eyy component,

perpendicular to the sample surface, is maximized

for the conductive sample (Figs. 2 g-j).

The current-voltage response of ion channels in

osteoblastic cells is shown in Fig. 3a. An action

potential of +10 mV for 5 ms is enough to induce a

maximum peak of current in the cell. This is

followed by a depolarization to the resting state

during 20 ms (red line in Fig. 3a). This biological

data was used as reference to select the AC

electrical signal parameters for the stimulation

experiments (Fig. 3b). In vitro stimulation of MG63

osteoblastic cells was accomplished in a home-

made apparatus (Fig. 3c, current circuit highlighted

by blue arrows) using 12 ml of α-MEM solution and

six samples per culture plate (same conditions seen

in Fig. 2). The frequency was kept constant at 40Hz

and the electrical field (5.6 and 15.3 mV.cm-

1)/current density (91 and 167 DA.cm

-2)/current

(100 DA and 200 DA) and time (15 and 30 min)

were varied. Potential and density current

distributions of the stimulation area of the culture

plate (Figs. 3c,d) are presented for the 200 DA

stimulus condition in Figs. 3e,f. It can be seen that

the samples (black dotted line in Figs. 3e,f) were

uniformly stimulated. MTT assay in Fig. 4g shows

that electroconductive CaP/CNTs templates under

electrical stimulus accelerate the proliferation of

osteoblastic cells. For all the stimulation conditions

the cell population is higher than the control

(nonstimulated material) (Fig. 3g). Conversely, for

the dielectric materials the stimulus delivering is

less efficient, showing responses equal or lower

than the control (Figs. 3h,i). Interestingly, these

observations corroborate the results of Fig. 2. SEM

and CLSM microscopy images (Figs. 3j,k) show no

evident differences in cells morphology between

the two conditions and for the three materials.

In conclusion, osteoblastic cells were efficiently

stimulated on CNT-based bone grafts. MTT assays

showed almost 300% increase in cell proliferation,

relatively to the non-stimulated condition, after

only 3 days of daily stimulation time of 15 min.

These exciting observations are intimately related

with the locally increase of the conductivity and the

confinement of electrical fields on the surface of

the conductive material.

References

[1] Mata D, Ferro M, Fernandes AJS, Amaral M,

Oliveira FJ, Costa PMFJ, Silva RF. Carbon 48

(2010) 2839-54.

[2] Mata D, Amaral M, Fernandes AJS, Oliveira FJ,

Costa PMFJ, Silva RF. Carbon 49 (2011) 2181-

96.

[3] Mata D, Silva RM, Fernandes AJS, Oliveira FJ,

Costa PMFJ, Silva RF. Carbon 50 (2012) 3585-

06.

Figure 2. α-MEM-

MWCNTs-based bone

grafts interactions under

(or not) electrical fields.

Figure 3. In vitro

evaluation of the

efficiency of CNT-based

bone grafts in delivering

electrical stimulus to

osteoblastic cells.


Recent advances in fast imaging

Raman technology for nano

materials characterisation

Renishaw Ibérica S.A.U,

Gavà Park, C. Imaginació, 3, 08850 Gavà,

Barcelona, Spain

Raman spectroscopy continues to provide

analytical solutions in a variety of material science

applications offering chemical specificity on a

micrometer scale.

The ability to create chemical and stress images by

acquiring Raman spectra from an array of positions

and then processing them to reveal the parameter

of interest is a powerful technique. Traditionally,

these spatially-related data have been collected by

raster scanning the sample beneath the incident

laser spot, typically in micrometer intervals. New

approaches to Raman imaging have been

developed that enhance the capabilities of modern

Raman instruments that now have the ability to

produce images on the nano scale.

The use of either high precision motorised stages or

piezoelectric-controlled sample stages permits

accurate and repeatable sample movements in

intervals significantly smaller than the diffraction

limited laser spot size. When used in conjunction

with an atomic force microscope tip, feedback can

be applied to ensure the sample’s surface remains

in the plane of the laser focus, optimising

efficiency. Topographic images of the surface can

be correlated with Raman images as the data are

acquired simultaneously. This approach is proving

to be most useful in materials research and the

study of semiconductor materials, particularly in

assessing carbon nanotube structures, graphene

film properties and in stress in silicon devices.

Other application areas include biological

intracellular structure and tissue imaging.

Additionally, a new method of acquiring both 2D

and 3D confocal Raman images has been developed

– ‘Streamline’. Spectra are collected in parallel,

rather than in series using the traditional methods.

Shorter total acquisition times result, with high

quality individual spectra recorded in the order of

fifty milliseconds. The method also benefits from

‘on the fly’ data analysis resulting in real time

image creation. This innovative approach allows the

technique to succeed where others have failed:

producing uncompromised data and images for

small or large areas at speeds much greater than

possible with competing methods. A number of

materials examples will be shown to illustrate the

benefits of this method and will demonstrate how

information can be achieved on the nanometre

scale.

Sébastien Maussang


Unusual nucleic acid structures for

DNA-based nanotechnologies

Univ. Bordeaux, IECB, INSERM U869, France

Nucleic acids are prone to structural polymorphism:

in addition to the classical DNA double-helix, a

number of alternative structures may be formed.

Important biological processes require melting of

the DNA double-helix and several genetic diseases

are mediated by the formation of non B-DNA

structures. Among these, G-quadruplexes (G4)

represent an exceptional polymorphic class of

higher-order nucleic acid structures in which the

structural unit is formed by a planar arrangement

of four Hoogsteen-bonded guanines known as

Gquartets (Fig.1). A vertical π-stacking arrangement

of several G-quartets and the presence of

monovalent cations provide these structures with

remarkable stabilities.

Nucleic acids are gaining in popularity and utility for

creating new nanomaterials due to their ability to

self-assemble. Pairing of double-stranded DNA is

being explored by a growing number of researchers

to construct extremely sophisticated

nanostructures and nanodevices. We believe that

G4 offer interesting possibilities for

nanotechnology and biotechnology and we are

currently seeking new properties for DNA-based

logic gates and nanomaterials.

Figure 1. Presentation of a G-quartet with four coplanar

guanines

This work is supported by INSERM, Fondation pour

la Recherche Médicale (FRM), University of

Bordeaux, Agence Nationale de la Recherche (ANR

grants F-DNA, G4-Toolbox & QuantADN), and

Région Aquitaine grants. I thank all members of

ARNA laboratory as well as L. Yatsunyk

(Swarthmore College), P. Alberti (MNHN, Paris) D.

Monchaud (Dijon) M.P. Teulade-Fichou (Curie,

Orsay) R. Eritja (Barcelona), A. Galeone (Naples)

and L. Lacroix (Toulouse) for helpful discussions.

Jean-Louis Mergny


Evidence for magnetic order in a

purely organic 2D layer adsorbed on

epitaxial graphene 1 Dep. Física de la Materia Condensada, Universidad Autónoma de Madrid,

Cantoblanco 28049, Madrid, Spain 2 Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia),

Cantoblanco 28049, Madrid, Spain

Collective magnetic properties are usually

associated to d or f electrons which carry the

individual magnetic moments. Band magnetism in

organic materials based on π electrons has

remained an experimental challenge, in spite of

rigorous predictions of a fully spin polarized ground

state in half-filled flat band organic systems [1].

Figure 1. Above: STM image of TCNQ/graphene/Ru(0001)

at 4.6 K; Belowleft: spin polarized PDOS on different

molecules and right: local spin polarized tunnelling

spectroscopy on the two molecular domains.

Cryogenic Scanning Tunneling Microscopy (STM)

and Spectroscopy in UHV and accurate Density

Functional Theory (DFT) simulations show [2] that

isolated TCNQ molecules deposited on a monolayer

of graphene epitaxially grown on Ru(0001) acquire

charge from the substrate and develop a sizeable

magnetic moment, which is revealed by a

prominent Kondo resonance. The magnetic

moment is preserved upon dimer and monolayer

formation.

The self-assembled 2D monolayer of magnetic

molecules develops spatially extended spin-split

electronic bands visualized in the real space by

STM, where only the majority band is filled, thus

becoming a 2D, purely-organic magnet whose

predicted spin alignment in the ground state is

visualized by spin-polarized STM at 4.6 K.

References

[1] Y. Nagaoka, “Ferromagnetism in a narrow,

half-filled band”, Phys. Rev. 147, 392 (1966).

[2] Manuela Garnica, Daniele Stradi, Sara Barja,

Cristina Díaz, Fabian Calleja, Manuel Alcamí,

Nazario Martín, Amadeo L. Vázquez de Parga,

Fernando Martín, and Rodolfo Miranda (to be

published).

Rodolfo Miranda1,2


Dirac fermions in HgTe

quantum wells

Physics Institute, EP3, Wuerzburg University,

Am Hubland, 97074 Wuerzburg, Germany

HgTe quantum wells have a linear band dispersion at low energies and thus mimic the Dirac Hamiltonian.

Changing the well width tunes the band gap (i.e., the Dirac mass) from positive, through zero, to negative.

Wells with a negative Dirac mass are 2-dimensional topological insulators and exhibit the quantum spin Hall

effect, where a pair of spin polarized helical edge channels develops when the bulk of the material is

insulating.

Our transport data provide very direct evidence for the existence of this third quantum Hall effect.

Wells with a thickness of 6.3 nm are zero gap Dirac systems, similar to grapheme. However, zero gap HgTe

wells possess only a single Dirac valley, which avoids inter-valley scattering.

L. W. Molenkamp

laurens.molenkamp@

physik.uni-wuerzburg.de


Three dimensional electrodes base

on core/shell nanowires for

photoelectrochemical cells

Departament Electronica, Universitat de Barcelona,

Barcelona, 08028, Spain

Catalonia Institute for Energy Research, IREC,

Sant Adria del Besos, 08930, Spain.

Three dimensional array’s offer an increased active

surface area for all type of electrodes, in general,

and, in particularly, for higher efficiency in photo

electrochemistry devices. In this scenario, core-

shell nano hetero or homo structures are the

essential brick for built-in these electrodes and they

become essential to define advanced photo

electrochemistry elements or, even, for a more

complex and promising artificial photosynthesis

systems that require frontal or back illumination

according to the photo reactor design related to

the production of sun fuels.

However, all their outstanding properties depend

on the adequate capability for photon capture and

the consequent control of the charge separation.

Under these conditions, doping of the inner part of

the structure becomes basic for the charge

extraction associated with a high transport facility,

low internal resistance, as well as the surface

conditions are determining for the charge transfer

of the other type of carriers. As a consequence,

doping management becomes an essential point

for energy band engineering and, so, a fundamental

key for controlling the overall nanostructure

performances.

In this contribution, we report on the growth on

electrodes of nanowires with controlled doping and

how they can be coated for selected shell material

with controlled thickness for having homo and

hetero structures with modified surface properties

and varied electrical field values at the surface. It

contributes to enhance the charge carrier transfer

as well as it presents also excellent transport

properties. As demonstration, examples of

vertically aligned homostructures ZnO:ZnO and

heterostructures ZnO/ZnS or ZnO/TiO2,… among

others core /shell nanowires will be presented like

for discussing the functional matching in these

coaxial heterojunction including electrical, optical

crystallographic and thermo chemical

performances related to their degradation and

stability.

In general, these core/shell nanowires have been

grown by a facile and low cost electrodeposition

two-step process. In this way, due to the controlled

surface electrical field, photoelectrochemical

properties of these nanowires have been found to

be highly enhanced with the presence of these shell

layers and an experimental study as function of

their thicknesses will be presented and modelized

to explain the promotion the surface-related

radiative recombination processes. The

enhancement factor is proved to depend on the

shell thickness. These performances are associated

with the improvement of the photogenerated

charge carrier separation and surface to neutral

inner part transfer capability achieved when

increasing the space charge area within the

nanowires with a built-in electric field introduced

by the doping profile. These features allow the

deduction of practical rules for the design and

optimization of these three dimensional

photoelectrodes for the production of sun fuels.

Jiandong Fan, C. Fábrega,

T. Andreu, Andreu Cabot

and Joan Ramon Morante

[email protected]


Metal-Carbon Nanohybrid Foams:

from Laser Chemistry to

Nanochemistry 1 Instituto de Carboquímica ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain

2 Instituto de Síntesis Química y Catálisis Homogénea, Universidad de Zaragoza-CSIC,

Zaragoza, Spain 3 Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, Zaragoza,

Spain 4 Departamento de Química Física, Universidad de Zaragoza, 50009 Zaragoza, Spain

Metal-carbon nanohybrid foams have been

produced by laser irradiation of organometallic

precursors [1]. The laser irradiation of aromatic

organometallic precursors resulted in milligram

quantities of soot exhibiting a fibrous appearance.

Scanning electron microscopy (SEM)

characterization showed that the microstructure of

this material exhibited the porous, foam-like

texture which results from the aggregation of

‘‘necklace’’-like ensembles of nanobeads, similar to

that observed in other ‘‘spongy’’ carbon materials,

such as carbon aerogels [2,3] and carbon nanofoam

[4]. Transmission electron microscopy (TEM)

studies reveals that these metal-carbon

nanohybrids are multi-component materials that

consist of metal nanoparticles embedded in

amorphous carbon aggregates, amorphous carbon

nanoparticles, and graphitic nanostructures, which

can be eventually observed as independent,

separate components in the produced soots (Fig. 1)

[5].

The present work also reports on important

experimental parameters toward the controlled

synthesis of these carbon foams. Thus,

characterization studies indicate that the

composition, metal nanoparticle dilution and

crystallite size, and structure of the metal-carbon

foams can be tailored by suitably tuning the laser

parameters used and by choosing the metals and

ligands of the irradiated targets [5,6]. It is also

demonstrated here that, contrary to carbon

aerogels, the employed metals are not required for

the growth of the observed graphitic

nanostructures [2,3,5] .

Figure 1. SEM-(left, scale bar: 100 nm) and TEM (right,

scale bar: 10 nm) micrographs of laser-ablation

produced Au-carbon foams [1].

This “laser chemistry”, based on the use of

molecular precursors, would enable the facile

production of multifunctional nanostructured

carbon materials with a range of tunable

properties. Alternatively to this “laser chemistry”

approach, wet chemistry strategies have been

designed for the synthesis of metal-carbon

nanohybrids based on the in-situ reduction of

noble-metal salts in presence of carbon foams

produced by laser ablation of metal-free organic

compounds. Further physical-chemical

characterization studies, chemical processing, and

potential technological applications of these metal-

carbon nanohybrid foams will be also discussed [6].

Andrés Seral-Ascaso1,

Asunción Luquin2, María

Luisa Sanjuán3, Rosa

Garriga4, Mariano Laguna

2,

Germán F. de la Fuente3,

and Edgar Muñoz1


TNT2012

Ab

st

ra

ct

s

References

[1] E. Muñoz, M. de Val, M. L. Ruiz-González, C. López-Gascón, M. L. Sanjuán, M. T. Martínez, J. M.

González-Calbet, G. F. de la Fuente, M. Laguna, Chem. Phys. Letters 420 (2006) 86.

[2] R.W. Fu, G. Dresselhaus, M.S. Dresselhaus et al., Langmuir 21 (2005) 2647.

[3] F.J. Maldonado-Hódar, C. Moreno-Castilla et al., Langmuir 16 (2000) 4367.

[4] A.V. Rode et al., Appl. Phys. A 69 (1999) S755.

[5] E. Muñoz, M. L. Ruiz-González, A. Seral-Ascaso, M. L. Sanjuán, J. M. González-Calbet, M. Laguna, G. F.

de la Fuente Carbon 48 (2010) 1807.

[6] A. Seral-Ascaso et al., submitted.


Understanding Electronic Structure

and Charge Transport in

Single-Molecule Junctions

Molecular Foundry

Lawrence Berkeley National Laboratory, USA

Interfaces are pervasive in nanostructured

materials, and the details of their atomic-scale

morphology, electronic structure, and environment

dictate the flow of matter, charge, and energy,

ultimately determining function. Single-molecule

junctions represent the molecular limit of a hybrid

interface, and recent transport measurements of

well-defined junctions have provided new

opportunities to quantitatively understand how

interfacial composition and structure is connected

to conductance, thermopower, current-voltage (IV)

characteristics, and rectifying behavior. In this talk,

I will summarize predictive fundamental studies [1-

4], using density functional theory and many-body

perturbation theory, of the electronic structure and

transport properties of single-molecule junctions.

Advantages and limitations of our approaches will

be discussed in the context of recent calculations

and experiments.

References

[1] H. J. Choi et al, Phys. Rev. B 76, 155420 (2007)

[2] S. Y. Quek et al, Nano. Lett. 9, 3949 (2009)

[3] J. B. Neaton et al, Phys. Rev. Lett. 97, 216405

(2006); M. DellAngela et al, Nano Lett. 10,

2470 (2010); I. Tamblyn et al, Phys. Rev. B 84,

201402 (2011); S. Sharifzadeh et al,

arXiv:1204.0509

[4] S. Y. Quek et al, ACS Nano 5, 551 (2011); V.

Fatemi et al, Nano Lett 11, 1988 (2011); J.

Widawsky et al, Nano Lett. 12, 354 (2012); P.

Darancet et al, in preparation (2012)

Jeffrey B. Neaton


Measurement of the capacitance

across a tunnel barrier 1 LT-NanoLab, Department of Applied Physics, University of Alicante, Alicante, Spain

2 Institut für experimentalphysik, Freie Universität Berlin, Berlin, Germany

Electronic transport in the process of the formation

of nanocontacts between two metallic electrodes

can be measured by bringing together two metallic

wires made of the same material using different

techniques such the Scanning Tunneling

Microscope (STM) [1]. Most of the experiments

have been focused to measure the conductance of

the junctions, however until now very little

attention has been paid to other electronic

characteristics of this system such as the

capacitance[2].

Here we report the measurement of the whole

impedance characteristics of a controlled vacuum

gap in between two metallic electrodes using a

homemade STM. High vacuum and cryogenic

conditions are necessary to achieve the desired low

mechanic (below 10pm) and thermal noise.

Electronics is carefully implemented taking care to

reach low electronic noise too. In order to measure

the impedance of the atomic junctions, a lock-in

amplifier technique has been used.

In our experiments we have observed a decrease of

capacitance when the tunnel current is increasing,

as predicted by theory[2-4]. On an other hand, we

also observe such a decrease in the field emission

regime when increasing the applied bias voltage in

between electrodes (shown at the figure), and

when each field emission resonance state

(Gundlach oscillations) takes place. This effect has

also been independently observed by the

measurement of the forces at the junction by the

Tuning Fork technique.

Figure 1. Au>Au measurements taken at 4.2K and

cryogenic vacuum using STM where distance between

tip and sample is held constant.

References

[1] N. Agraït, A. Levy-Yeyati, J.M. Van Ruitenbeek.

Phys. Rep. 377, 81 (2003).

[2] J. G. Hou et al., Phys. Rev. Lett. 86, 5321

(2001).

[3] M. Büttiker, J.Phys.:Condens. Matter 5, 9361

(1993).

[4] J. Wang et al. , Phys. Rev. Lett. 80, 4277 (1998).

Bernat Olivera1,

Giovanni Sáenz-Arce1,

Martina Corso2,

Carlos Sabater1,

Juan Ignacio Pascual2 and

Carlos Untiedt1

[email protected]


Protein-polymer nanoreactors and

processors act as artificial organelles

Department of Chemistry,

University of Basel,

Klingelbergstrasse 80, Basel 4056, Switzerland

The combination of biological molecules and

synthetic polymer carriers/templates represents a

very promising approach for development of

efficacious therapies with minimum side effects,

diagnostic methods featuring significantly higher

sensitivity and selectivity, and personalized

diagnostics and therapeutics via theragnostic

approaches. In this respect, suitable amphiphilic

block copolymers self-assemble into in aqueous

media into vesicles with membranes mimicking

biological membranes. The properties of such

vesicles can be extensively controlled via chemical

composition, molecular weight and the hydrophilic-

to-hydrophobic block length ratio of the polymers,

and have the advantage of superior stability and

robustness. The combination with suitable

biological molecules (proteins, enzymes, DNA,

peptides) introduces other well-defined functions,

such as molecular recognition, cooperation, and

catalytic activity.

We exploited the concept of bio-synthetic

combination to develop antioxidant nanoreactors

that encapsulated superoxide dismutase/mimics in

the aqueous cavities of vesicles generated by the

self-assembly of poly(2-methyloxazoline)-b-

poly(dimethylsiloxane)-poly(2-methyloxazoline),

PMOXA-PDMS-PMOXA copolymers [1,2]. By

synthesizing appropriately functionalized polymers

(e.g. biotin, antibody) we successfully immobilized

the nanoreactors on solid support to follow the

folding/unfolding of single proteins, and to monitor

enzymatic reactions down to the scale of a few

molecules [3]. A step further in obtaining

multifunctionaliy, is to co-encapsulate enzymes that

act in tandem inside the polymer cavity: cascade

reactions can therefore take place in situ [4].

Here we present antioxidant processors designed

by simultaneous co-encapsulation of enzymes and

channel proteins (Figure 1) [5]. Cascade reaction of

co-encapsulated superoxide dismutase and

lactoperoxidase allowed for a complete

detoxification of superoxide radicals and related

H2O2. The polymer membrane was selectively

controlled by insertion of channel proteins, which

allowed the exchange of substrates and products

with the environment, supporting the in situ

activity of the enzymes. In addition, the detection

of superoxide radicals and related H2O2 was based

on a fluorescent product of the second enzyme that

strongly favored a dual application of the

processor: in biosensing and detoxification of

reactive oxygen species. By changing the

enzyme/combination of enzymes either to

hemoglobin, or to superoxide dismutase - catalase,

we enlarged the detoxification approach to other

free radicals species, such as nitrogen reactive

species, or combination of oxygen and nitrogen

reactive species.

Figure 1. Schematic representation of an antioxidant

processor based on the co-encapsulation of a

combination of enzymes inside polymer nanovesicles.

Cornelia G. Palivan

[email protected]


TNT2012

Ab

st

ra

ct

s

Inside cells nanoreactors and processors preserved their integrity over more than 48hours, and did not

present toxicity in that interval. After cellular uptake, the nanoreactors/processors retained their function

over extended periods of time, thus acting as artificial organelles that continuously exchange molecular

information with the host cell. This opens new avenues in protein therapy as well as intracellular sensing

approaches.

References

[1] F. Axthelm, O. Casse, W. Koppenol, T. Nauser, W. Meier, C. Palivan, J. Phys. Chem. B, 112(28), (2008),

8211.

[2] O. Onaca, D.W. Hughes, V. Balasubramanian, M. Grzelakowski, W. Meier, C. G. Palivan, Macromol.

Biosci, 10(5), (2010), 531.

[3] S. Egli, M. G. Nussbaumer, V. Balasubramanian, M. Chami, N. Bruns, C. G. Palivan, W. Meier,

J.Am.Chem.Soc., 133 (12), (2011), 4476.

[4] a. D. M. Vriezema, J. Hoogboom, K. Velonia, K. Takazawa, P. C. M. Christianen, J. C.Maan, A. E.

Rowan and R. J. M. Nolte, Angewandte Chemie, 115, (2003), 796. b. S. F. M. van Dongen, M. Nallani,

J. L. L. M. Cornelissen, R. J. M. Nolte and J. C. M. van Hest, Chem.Eur. J., 15, (2009), 1107.

[5] P. Tanner, O. Onaca, V. Balasubramanian, W. Meier, C. G. Palivan. Chem. Eur. J, 17, (2011), 4552.


Plasmonic nanoparticles for the

protection of the final optics in

inertial confinement fusion facilities:

capabilities and limitations

Instituto de Fusión Nuclear, Universidad Politécnica de Madrid,

C/ José Gutiérrez Abascal 2, E-28006 Madrid, Spain

HiPER (High Power Laser Energy Research Facility)

is an ESFRI project of the EU for the production of

energy using laser-driven Inertial Confinement

Fusion (ICF). In this kind of facilities the final optics

assemblies are the last element of the main laser

system and the first one of the target area systems.

The materials of this system are subject to bursts of

direct targets of more than 100 MJ injected at 10-

20 Hz. Currently there are no materials capable of

withstanding these conditions for a reasonable

camera size (R ∼ 5 m). The use of a certain

concentration of gas (typically a few μg/cm3 Xe) or

deflecting incident ions by means of electric fields

are some of the solutions that have been proposed

to mitigate this effect. However, the optimal

solution is the development of new materials able

to protect the lenses and maintain its transparency

in these aggressive conditions. Plasmonic

nanostructures embedded in thin films look like an

ideal candidate for this task because they are able

to stop an important part of the radiation and,

simultaneously, they offer unprecedented abilities

to manipulate electromagnetic waves. For instance,

simple spherical silver nanoparticles present a quite

low optical density at 350 nm (i.e., the wavelength

of HiPER’s lasers). Another possibility worth

exploring is the usage of plasmonic Fano

resonances to produce a high transparency in some

selected spectral regions. Finally, another attractive

feature of plasmonic nanostructures is that they

can potentially behave as self-healing materials

because the mean free path of the vacancies is

greater than the material grains, which leads to

effective annihilation of vacancies at grain

boundaries.

Ovidio Y. Peña Rodríguez


Functionalizated magnetic

nanoparticles for biodetection,

imaging and separation of Mytilus galloprovincialis larvae using NIT-zipper

® technology.

*University of Vigo, Spain Novel nanomaterials are envisaged to have a major impact on a number of relevant areas. It is anticipated that within the next few years the application of nanomaterials and nanotechnology-based manufacturing will have a crucial role in biomedical, pharmaceutical, cosmetic, veterinary, environmental and agro-food technologies. In this work, several sizes of high-quality monodisperse Fe3O4 Nanoparticles (NPs) were synthesized and functionalizated (or bioconjugated)using NIT-zipper® disruptive technology, following the manufacturer's instructions (Nanoimmunotech), with monoclonal antibodies (mAbs) directed against mussel (Mytilus galloprovincialis) larvae, such as M22.8 and M36.5 (Pérez et al., 2009), and with different labels (fluorescent dyes), that may allow an easier and more specific identification. Functionalizated Nps were incubated with mussel larvae and magnetic separation was perform. The

larvae collected in the magnet were analyzed by fluorescent and optical microscopy (pictures: A; 20X mussel larvae with Texas Red dye, B; magnetic nanoparticles aggregates inside mussel larvae, and C; 20X mussel larvae with FITC dye) and flow citometry. The obtained results clearly indicate that our successful nanosystem recognise the mussel larvae in field plankton samples from different geographical regions, but not the larvae of any other bivalve species. Thus, it could be used for routine monitoring and purification of mussel larvae in plankton samples from different sources, offering an innovative solution to agro-food markets that could give rise to new processes and solve current problems, like the lack of suitable methods for an unequivocal recognition and a rapid sorting of the bivalve larvae species in plankton samples, in these industries.

Daniel Pérez-Estévez*, Christian Sánchez-Espinel, Gonçalo Doria, Sara Puertas, Silvia Lorenzo-Abalde, África González-Fernández, Rubén Santos.


Urchin-inspired zinc oxide as

building blocks for nanostructured

solar cells 1 Laboratory for Mechanics of Materials and Nanostructures, EMPA Materials Science &

Technology, Feuerwerkstrasse 39, 3602 Thun, Switzerland 2 Institut Européen des Membranes (UMR CNRS 5635), Université Montpellier 2, Place

Eugène Bataillon, 34095 Montpellier, France. 3 Electron Microscopy Center, EMPA Materials Science & Technology, Ueberlandstrasse

129, 8600 Duebendorf, Switzerland 4 Laboratory for Thin Films and Photovoltaics, EMPA, Materials Science & Technology,

Ueberlandstr. 129, CHD-8600 Dübendorf, Switzerland

According to recent studies on the global power plant

market, the installed capacity of solar power grew

faster than that of any other power technology. Last

generation nanostructured photovoltaic devices

include dye sensitized (photoelectrochemical, quasi-

solid, and solidstate) solar-cells and their hybrid and

fully inorganic variants as extremely thin absorber

(ETA) solar-cells. They appear to have a big light

harvesting potential compared to planar thin film

photovoltaic devices due to their “built-in” large

surface area architecture involving an n-type

semiconductor material covered by a light absorber

(dye, organic or inorganic films) for collecting

photons. After charge separation, electrons are

collected by a photoanode for electricity generation.

TiO2 and ZnO were agreed to be the most promising

materials as wide band gap n-type semiconductors

with a preference for ZnO due to its better electronic

transport properties and its comparatively easy

controllable growth as single-crystal nanowire arrays

Better control of light-scattering and electronic

transport through this n-type semiconductor is

essential for improving the solar efficiency.Among

numerous studied architectures, nanoparticles and

nanowires are the most employed building-blocks

because they either provide high surface areas

(nanoparticles) or direct electron transport

(nanowires). In direct comparison, single-crystal

nanowire arrays offer shorter electron collection

paths, thus avoiding charge recombination; but solar

cells based on nanoparticles still have a higher solar

efficiency due to their larger surface area. Hence,

increasing the surface area of planar nanowire

carpets by increasing the diameter and length of the

individual nanowire has been proposed in many

research reports to enhance the solar light harvesting.

As a commonly acquired result, such an increase of

the surface area in nanowire carpets leads to an

augmentation of charge recombination being

detrimental for solar cell efficiency. Therefore, future

nanostructured solar-cell architectures need to

improve multiple light-scattering while keeping

reasonable surface areas with a short electron

collection path; in other words, improving the solar

light absorption and reducing the electron-hole

recombination. To tackle this challenge we have

recently developed urchin-like nanostructures by

electrodeposition of ZnO nanowires onto surface

activated polymer spheres. This structure showed a

twofold improvement of light scattering compared to

nanowire arrays. However, these nanostructures had

a limited mechanical stability and their interspacing

could not be varied which prohibited further

optimized use in applications. In the present paper,

we report on a novel architecture – based on a self-

stabilized hollow urchin-like ZnO nanowire building-

blocks using a novel low-costand scalable synthesis

route which allows for controlled building-block

interspace and tunable nanowire dimensions. We

show that the light diffusion and absorption as well as

solar cell efficiency can be elegantly controlled and

enhanced by engineering the dimensions of such

building-blocks.

References

[1] J. Elias, C. Levy-Clement, M. Bechelany, J.

Michler, G. Y. Wang, Z. Wang, L. Philippe Adv.

Mater. 2010, 22, 1607.

Laetitia Philippe1,

Jamil Elias1, Mikhael

Bechelany2, Ivo Utke

1,

Rolf Erni3, Davood Hosseini

4

and Johann Michler1

laetitia [email protected]


TNT2012

Ab

st

ra

ct

s

Figure 1. Schematic view of synthesis route for (I) self-stabilized hollow urchin-like ZnO nanowire building blocks and (II)

successive fabrication steps for the ETA solar-cell: a) Dip coating for the deposition of an ordered monolayer of

polystyrene microspheres onto an FTO covered glass substrate; b) Size reduction of spheres using plasma etching with

oxygen plasma; c) Deposition of a uniform conformal thin layer of about 20 nm of ZnO by ALD; d) Electrodeposition of

n-type ZnO NWs with controlled length and diameter; e) Formation of hollow u-ZnO by dissolving the polystyrene

spheres in toluene; f) Coating of NWs with an absorber film of CdSe by electrodeposition; g) Covering with p-type

CuSCN by chemical impregnation, and h) Deposition of a gold thin film electrode by physical vapor deposition.

Figure 2. SEM images of ZnO urchin-like structures after dissolution of the polystyrene sphere monolayers a) without PE

and b) with 20 min PE treatment. The insets of a) and b) are the SEM images of the ordered PS before electrodepostion

coated with 20 nm of ZnO by ALD. c) Side view of individual u-ZnO structures. Note: the planar NW-carpet between the

u-ZnO. d) and e) are views of individual hollow u-ZnO structures from a scratched part of the sample where the

structures were reversed upside down. All the scale bars in the figure (except (e)) are 2 μm.


Improving the Direct Electron

Transfer Efficiency in Laccase

Electrodes for Biofuel Cell Cathodic

Reactions 1 Instituto de Catalisis y Petroleoquimica, Consejo Superior de Investigaciones Cientificas.

C/Marie Curie 2 L10, 28049 Madrid, Spain 2 Biomedical Laboratory Science and Technology, Faculty of Health and Society,

Malmö University SE-205 06 Malmö, Sweden

Fungal laccases are one of the best candidates for

enzymatic biofuel cell cathodes due to its ability to

reduce O2 directly to H2O at high potentials;

laccases are also suitable for direct electron

transfer when appropriately wired toward different

electroactive surfaces such as gold or graphite.

However, laccase faces several hindering conditions

when taking to many in vivo-like environments,

being the most relevant chloride inhibition and the

functional pH. Chloride anions are a reversible

inhibitor of laccase and are present in most

biological fluids. Additionally, the typically acidic

pH-optima for laccase performance take any

laccase-modified electrode out of range for many

natural fluids.

This presentation will show strategies to improve

laccase performance under these nonfavoured

environments. It has been shown that specific

orientation of laccase for DET can reduce this

inhibition source when immobilized on a low-

density graphite (LDG) electrode [1] and how to

extend this immobilization method to gold planar

electrodes [2]. We will show the improvement

brought to current density and chloride resistance

by combining a LDG electrode with gold

nanoparticles. The limitations brought by the use of

neutral pH can be addressed by generation of a

local acidic pH environment. This has been

achieved by inserting the laccase electrode in a

magnetic ring that allows the deposition of

magnetic nanoparticles carrying another enzyme

able to acidify the environment [3]. For conceptual

purposes we have used glucose oxidase (GOx) to

produce a gluconic-acid environment, managing to

lower pH 2 units while keeping the bulk pH neutral

and therefore allowing laccase to work. Catalase

was present for oxygen-regeneration purposes.

References

[1] Cristina Vaz-Dominguez, Susana Campuzano,

Olaf Rüdiger, Marcos Pita, Marina Gorbacheva,

Sergey Shleev, Victor M. Fernandez, Antonio L.

De Lacey. Biosensors and Bioelectronics, 24,

(2008), 531–537.

[2] Marcos Pita, Cristina Gutierrez-Sanchez, David

Olea, Marisela Velez, Cristina Garcia-Diego,

Sergey Shleev, Victor M. Fernandez, Antonio L.

De Lacey. Journal of Physical Chemistry C, 27,

(2011), 13420-13428.

[3] Sylvain Clot, Cristina Gutierrez-Sanchez, Sergey

Shleev, Antonio L. De Lacey, Marcos Pita.

Electrochemistry Communications, 18, (2012),

37-40.

Marcos Pita1,

Cristina Gutierrez-Sanchez1,

Sergey Shleev2 and

Antonio L. De Lacey1

[email protected]


TNT2012

Ab

st

ra

ct

s


Strategies and activities in nano Photonics Unit - Instituto Tecnológico la Marañosa, Ctra M301 Km 10.500, 28330 San Martín de la Vega, Spain In recent years, emerging technologies are becoming of great interest due to the possibility of developing applications which can improve the features of the existing ones, and even, there is the possibility of developing novel applications that cannot be achieved without these. Usually, there are two different ways of developing applications: a bottom-up approach, starting from the development of science and technology to assess its properties and create an application from them. A top-down approach, on the other hands, starts with a real problem that needs a specific application, and then seeks for the most optimal technology that can create an application to solve that problem. With this end-user point of view, Ministry of Defense has defined several sectors of interest [1], in which different kind of technologies can provide the means to develop the required applications, and among them, nanotechnology, and more specifically photonics and new emerging fields like metamaterials and plasmonics are expected to play an important role. Applications related to light guiding, multispectral sensing, lensing, and reduction of scattered light can be achieved using metamaterials. These are artificial materials [2] whose optical properties are solely determined by the fabricated microstructure, making it possible to the control the dielectric permittivity (ε) and magnetic permeability (μ) to achieve unsual properties such as negative refraction at certain wavelengths. Combined with Transformation Optics [3], these new materials allow an accurate control of the flow of light. This

unique properties of metamaterials make them also attractive to be used in security features like of bank notes, passports or ID cards. Fast and accurate detection of biological or chemical agents is a topic of great interest in the field of security. IR spectroscopy is one of the most promising technologies for this application, since it allows the detection of IR signatures to be compared with databases to identify the threat. Also, the interaction of agents with sensing surfaces can change the optical properties, making it suitable for the use of plasmons in this kind of detection.

References

[1] Ministerio de Defensa. Estrategia de Tecnología e Innovación para la Defensa – ETID (2010)

[2] V.G. Veselago, The electrodynamics of substances with simultaneously negative values of ε and μ. Soviet Physics Uspekhi (1968) Vol 10 N4, 509

[3] D. Schurig, J.J. Mock, B.J. Justice, S.A. Cummer, J.B. Pendry, A.F. Starr, D.R. Smith, Metamaterial Electromagnetic Cloak at Microwave Frequencies. Science(2006) 977

J. Plaza, R. Almazán, L. Gómez, D. Fernández, M.T. Rodrigo, M.C. Torquemada, V. Villamayor, I. Catalán, C. Sierra, I Génova, F. Rangel, A. Vicioso, C. Gutiérrez, M. Álvarez and M. Magaz

[email protected]


High Precision local electrical

Probing: A New Low Temperature

4-Tip STM with Gemini UHV-SEM

Navigation

Instituto Omicron NanoTechnology GmbH,

Limburger Str. 75, 65232 Taunusstein, Germany

Developments in commercial surface science

instrumentation regularly follow the major trends

in science. The variety of instrumental approaches

is as wide-ranged as science itself. Therefore, the

identification of relevant analysis techniques and

their advancement towards ease-of-use and a

routinely accessible performance level represent a

major challenge for enterprises. Beside OMICRON´s

major activities in conventional SPM, electron

spectroscopy and thin film techniques, the class of

“multitechnique” instruments represents another

important R&D line that is in the focus of this

presentation.

One prominent example in nanotechnology is the

development of individual nano-scale devices. A

tremendous variety of approaches exist and

fundamental questions arise. Comprehensive

concepts towards electrically integrated and

therefore functional devices are however rare.

Individual (metallic) nano-scale contacts represent

one of the main challenges. High precision local

electrical probing has the potential to increase

efficiency in evaluating different approaches.

The OMICRON UHV NANOPROBE already meets the

involved requirements: (1) Rapid and simultaneous

SEM navigation of four local STM probes; (2)

Localization of nanostructures by sub-4nm UHV

Gemini SEM resolution; (3) Individual probe fine

positioning by atomic scale STM imaging; (4) STM

based probe approach for “soft-landing” of sharp

and fragile probes and controlled electrical contact;

(5) suitable low noise signal re-routing for transport

measurements; (6) chemical/magnetic analysis by

complementary analysis techniques such as SAM,

SEMPA, CL and others.

And although the UHV NANOPROBE represents a

flexible solution, especially in combination with

complementary techniques, it´s concept is

fundamentally limited in terms of lowest

temperature and SPM resolution. Together with

the Forschungszentrum Jülich, we thus have been

developing a completely new design, the Low

Temperature UHV NANOPROBE. It represents the

evolution from a high performance probing system

towards 4 simultaneously operating and high

performing low temperature SPMs, navigated by

SEM. The major R&D targets have been (1)

equilibrium temperature of sample and probes at

temperatures T<5K; (2) simultaneous SEM for

probe navigation close to base temperatures; and

(3) high STM performance of all four probes, truly

suitable for manipulation and spectroscopy. First

evaluation measurements will be presented: STM

on Au(111) with pm stability, STS revealing the

supeconducting gab of a Nb tip with approx. 3meV

gap size, and first transport measurement at T<5K.

Figure 1. Left: Image of the LT NANOPROBE stage. Right:

STM on Au(111) at a temperature of below 5 K. The

atomic structure and the herringbone reconstruction are

clearly visible.

A. Bettac, B. Guenther,

J. Koeble, M. Maier and

A. Feltz

[email protected]


S-layer proteins as patterning

elements in the life and

non-life sciences

Department of Nanobiotechnology,

University of Natural Resources and Life Sciences,

Vienna, Austria

Crystalline S(urface)-layers are the most commonly

observed cell surface structures in prokaryotic

organisms (bacteria and archaea) [1]. S-layers are

highly porous protein meshworks with unit cell

sizes in the range of 3 to 30 nm, and thicknesses of

∼10 nm. S-layers exhibit either oblique (p1, p2),

square (p4) or hexagonal (p3, p6) lattice symmetry.

One of the key features of S-layer proteins is their

intrinsic capability to form self-assembled

monolayers in solution, at solid supports such as

silicon or gold, at the air-water interface, at planar

lipid films and at liposomes and nanocapsules.

Basic research on S layer proteins enabled us to

make use of the unique self-assembly properties of

native and, in particular, genetically functionalized

S-layer fusion protein lattices as matrices for the

binding of molecules and the templated synthesis

of nanomaterials [2]. S-layer proteins were already

used as scaffolds for making hybrid organic-

inorganic nanostructures such as highly ordered

nanoparticle arrays or silicified nanoporous

biomembranes. In another approach the genetic

engineering of fluorescent S-layer proteins allowed

to develop novel pH indicators as used in drug-

targeting and delivery systems. Further on,

advances in elucidating the atomistic structure of S-

layer proteins and simulating the self-assembly

process opened the door to the design of new bio-

functional materials for a diverse range of

applications.

The overall goal of our research is dedicated

towards the development of an S-layer-based

biomolecular construction kit. This presentation

summarizes the key properties of S-layer proteins,

with a focus on the self-assembly process, and

describes different applications in the life and non-

life sciences.

Figure 1. Confocal micrographs showing the pH

dependence of four different fluorescent S-layer fusion

proteins.

Acknowledgements: Part of this work was funded

by the Air Force Office of Scientific Research

(AFOSR) Agreement Awards FA9550-09-0342 and

FA9550-10-0223, the Austrian Nano-Initiative

(Project Slaysens), and the Erwin Schödinger Society

for Nanobiosciences, Vienna, Austria.

References

[1] Sleytr, U.B., Schuster, B., Egelseer, E.M., Pum,

D., Horejs, C.M., Tscheliessnig, R., Ilk, N., In

Progress in Molecular Biology and

Translational Science, Horworka, S. (Ed.),

Academic Press, Burlington, MA (USA), Vol.

103 (2011) 277.

[2] Pum, D., Sleytr, U.B., In Nanobioelectronics –

for electronics, biology, and medicine,

Offenhäuser, A., Rinaldi, R. (Eds.), Springer,

New York, NY (USA), (2009) 167.

Dietmar Pum and

Uwe B. Sleytr

[email protected]


Near field X-ray

spectromicroscopies:

new tools for nanoscience

Institute of Solid State Physics,

8 Kengaraga Riga, Latvia

In the last years, the X-ray absorption (XAS)

techniques have undergo remarkable development:

(i) experiments with unprecedented femtometer

accuracy, under extreme conditions of high

pressure and temperature [1], (ii) experiments with

nanoscale lateral resolution [2]. Nevertheless,

investigations of complex nanostructured materials

used in modern technologies require special X-ray

experimental techniques able to imaging

simultaneously topography and chemical mapping

(X-ray analysis of matter) on the nanometer scale.

Near Field (NF) X-ray Spectromicroscopy (FF

illumination and NF detection) is a fully new

approach for the detailed investigation of

nanostructures down to the nanometer level. The

extremely high lateral resolution of Local Probe

Microscopies (LPM, AFM,STM) makes them among

the most largely used in nanoscience. However,

these tools suffer of a lack in chemical sensitivity.

On the other hand, far field X-ray spectroscopy

probes the chemical and structural properties of

materials. A combination of X-ray spectroscopies

and LPM is the ideal answer to many problems in

nanosciences. This report highlights the most

important contributions which were held in the

combination of X-ray spectroscopies and LPM

techniques.

The basics of such approach are circulating since

years. The first observations of core-level

photoelectrons generated by X-ray irradiation of the

tip-surface region of STM have been published by

Tsuji [4]. Ishii [5] has measured the capacitance XAS

signal with a metal tiny electrode. The combination

of XAS and scanning near-field optical microscopy

(SNOM) as a local detector was proposed by Purans

[6], while a combination of XRF technique and LPM

with a cantilever, having a hole of 100 nm, as a

collimator of X-ray beam was proposed by Nagamura

[7]. First STM and SNOM experiments under focused

synchrotron-radiation (SR) were performed at ESRF

on the microbeam line ID-3 [8]. Detailed STM study

using soft SR X-rays was performed by Matsushima et

al. [9]. A STM dedicated to in situ experiments under

the irradiation of highly brilliant hard-X-rays of

synchrotron radiation has been developed by Saito et

al. [10] and a current modification was detected at

the absorption edge with a spatial resolution of the

order of 10 nm. Finally, Ishii and Hamilton et al. [11]

has combined electrostatic force microscopy (EFM)

with tunable synchrotron x-ray source excitation.

Further progress we have achieved in the framework

of the European X-TIP project by the focusing SR

beam to increase the density of the incident

photons. X-ray optics at third generation

Synchrotron Radiation facilities have lead to the

stable production of X-ray microbeams with

extremely high photon densities making this

approach feasible. We have started with three types

of experiments: (i) XAS-AFM: X-ray excited

secondary electrons detection by conductive tip in

AFM mode; (ii) XAS-SNOM: X-ray excited optical

luminescence (XEOL) detection by SNOM in AFM

mode; (iii) XAS-SCM/AFM: X-ray excited capacitance

or/and photoconductivity of sample detection by

conductive tip in SCM, KFM or AFM mode.

The new instrumentation developed within this

project offers the possibility to carry out a selective

structural analysis of the sample surface with the

subwavelength spatial resolution determined by

the SNOM probe aperture. In addition, the apex of

the optical fibre plays the role of a topographic

probe, and chemical and topographic mappings can

be simultaneously recorded.

Juris Purans

[email protected]


TNT2012

Ab

st

ra

ct

s

References

[1] J. Purans et al., Phys. Rev. Lett. 100 (2008) 055901 ; R.F. Pettifer et al., Nature 435 (2005) 78.

[2] W. Chao et al., Nature 435 (2005) 1210; DT. Attwood, Nature 442 (2006) 642.

[3] S. Larcheri and J. Purans, Rev. Sci. Instrum. 79 (2008) 013702.

[4] K.Tsuji et al., Surf. and Interface Anal. 27 (1999) 132.

[5] M.Ishii, Physica B. 308-310 (2001) 1153 ; M. Ishii et al., Appl. Phys. Lett. 90 (2007) 063101.

[6] J.Purans, Proc. TXRF2003 Sat. meeting on micro X-ray beam analysis, 13.09.2003, Osaka, Japan.

[7] T. Nagamura, Proceedings TXRF2003 Sat. meeting on micro X-ray beam analysis, 13.09.2003, Osaka,

Japan.

[8] F.Comin, D. Pailharey, R. Felici, J. Chevrier, J.Purans, ESRF user report on the project SI-956, 2004,

Grenoble.

[9] T.Matsushima et al., , Rev. Sci. Instr. 75 (2004) 2149.

[10] A. Saito et al., J. Synchrotron Rad. 13 (2006) 216.

[11] M. Ishii et al., Appl. Phys. Lett. 90 (2007) 063101.


Unveiling the Landau levels structure

of graphene nanoribbons 1 Laboratoire National des Champs Magnétiques Intenses, INSA UPS CNRS,

UPR 3228, Université de Toulouse, 143 av. de Rangueil, 31400 Toulouse, France 2 IMEP-LAHC, Grenoble-INP, Minatec 3 Parvis Louis Néel, BP 257 38016 Grenoble, France

3 CIN2 (ICN-CSIC) and Universitat Autonoma de Barcelona, Catalan Institute of

Nanotechnology, Campus de la UAB, 08193 Bellaterra (Barcelona), Spain 4 ICREA, Institucio Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain

In the present work we show the first experimental

evidence of Hall quantization in graphene

nanoribbons along with the impact of the 1-D

confinement of Dirac fermions.

Carbon-based nanoelectronics is, in the actuality,

one of the most promising subjects of

nanotechnology. The challenging task for

technologists is the achievement of clean devices

with an engineered energy gap. The lateral

confinement in graphene nanoribbons leads to a

series of 1-D electronic sub-bands with a

confinement gap. In presence of a large enough

magnetic field, the band structure evolves to

magneto-electric sub-bands and graphene-like

Landau levels are expected to develop. The

presence of these Landau levels makes itself

evident with the appearance of ShubnikovdeHaas

(SdH) oscillations and conductance quantization

plateaus.

Up to now, Hall quantization in graphene

nanoribbons (GNRs) remains puzzling since no

experimental evidence has been found for widths

smaller than 200 nm [1-4]. The absence of Hall

quantization in GNRs has been attributed to

disorder, which is suspected to crosslink the chiral

edge currents and impede the conductance

quantization.

Lithographically patterned GNRs of 100 and 70 nm

widths are made using oxygen plasma etching and

a PMMA etching mask. These GNR present a high

conductance, a high field effect mobility and a

weakly diffusive transport regime with presence of

Fabry-Perot oscillations at low temperature.

Magneto-resistance (MR) measurements show the

first experimental evidence of Hall quantization in

GNRs (Fig. 1) for filling factors ʋ= 2 and 6. On the

other hand, anomalies in the magneto-transport

measurements are evidenced:

(i) At high electrostatic doping level SdH

oscillations show a clear departure from the

regular linear behaviour of the Landau index as

a function of 1/B (Fig. 1(a) inset). This is a

direct signature of the electronic confinement

that starts to overcome the magnetic

confinement.

(ii) The maxima of MR for all the ribbons,

fingerprint of the Landau levels depopulation

[5], present an up-shift of several Tesla

compared to the theoretical value [6].

(iii) The narrower ribbons exhibit the expected 6G0

conductance maxima for a two-terminal

measurement [5] but the 2G0 plateau is absent

and the depopulation of the N=2 Landau level

goes along with an unusual double peak of the

resistance (Fig. 1(b)).

To unveil the origin of the singular Landau

spectrum we performed numerical simulations of

the GNR band structure as a function of the

perpendicular magnetic field and self-consistent

calculations of the carrier distribution under

magnetic field. We directly compared the

oscillatory behaviour of the magnetoresistance and

the onset of the magneto-electric sub-bands (Fig.

2). The simulations give evidence of magneto-

oscillations of the Fermi energy (blue line in Fig. 2)

which consistently explains the broadening of the

magneto-resistance peaks and their up-shift lo

larger magnetic field. The presence of a second

peak in the MR spectrum (Fig. 2 (b)) also finds a

natural explanation: this is the clear signature of

the orbital degeneracy lifting enhanced by the

magnetic field and the pinning of the Fermi energy.

R.L. Ribeiro1,

J.M. Poumirol1, A. Cresti

2,

W. Escoffier1, J.M. Broto

1,

S. Roche3,4

and B. Raquet1

[email protected]


TNT2012

Ab

st

ra

ct

s

Figure 1. Two terminal magneto-resistance measurements in a) GNR of 100nm width exhibiting the h/2e2 and h/6e

2

quantization Hall resistance. Inset: Landau level index as a function of 1/B from: experimental magneto-resistance

(circles) at high electrostatic doping, band structure calculations (crosses) and calculations of occupied sub-bands in a

hard-wall confinement. b) Magneto-resistance of a GNR of 70nm width with the presence of a double resistance peak

in the crossing of N=2 Landau level.

Figure 2. Numerical simulation of the band structure (black lines) in 814-aGNR (100 nm, Sample A) and 571-aGNR (70

nm, Sample B), self-consistent calculations of the Fermi energy under magnetic field (blue curve) and direct comparison

with magneto-resistance measurements (red curve).

References

[1] C. Berger et al. Science, 312 (2006) 1191.

[2] F. Molitor et al. PRB 79 (2009) 075426.

[3] J. B. Oostinga et al. PRB, 81 (2010) 193408.

[4] J. M. Poumirol, et al. PRB, 82 (2010) 041413.

[5] J. R. Williams et al. PRB, 80 (2009) 045408.

[6] N. M. R. Peres et al. PRB, 73 (2006) 241403

[7] R. L. Ribeiro et al. PRL 107 086601 (2011).


Graphene potentialities for space and

defense applications: focus on

mechanical properties 1 Ingeniería y Servicios Aeroespaciales, S.A., Paseo del Pintor Rosales 34, 28008, Madrid,

Spain 2 Unidad de Fotónica, Instituto Tecnológico “La Marañosa”, Crta. San Martín de la Vega,

km. 10.5, 28330, Madrid, Spain

The promising properties of graphene have

motivated considerable research effort in recent

years [1]. Surprisingly, the potential advantages

offered by the technology based on graphene

structures extend to a great variety of physical

phenomena, including those affecting to electrical,

optical, magnetic, thermal, chemical and

mechanical properties. In some cases, the

parameters predicted and measured have reached

even the highest values reported for any known

material (e.g., the highest carrier mobility at room

temperature or the greater strength). However,

much work must still be carried out to bring the

inherent advantages of graphene to practical

applications. Such work comprises the

development of an efficient method to synthesize

graphene in the proper form for each desired

application without degrading its intrinsic

properties. Further steps should also ensure the

suitability of other technological aspects such as

the compatibility with device-oriented fabrication

processes, the scalability or the affordability.

Here we provide a comprehensive overview of the

potential uses of graphene-based devices and

components for space and defense sectors.

Basically, funded programmes have promoted next

generation electronics and fundamental research

topics. The development of future radio-frequency

(RF) electronics is of paramount importance to

improve the ever more demanding systems,

especially taking into account the difficulty to

maintain the historical trend predicted by Moore's

law with traditional Si-based electronics. In addition

to the more conventional approach of improving

performance parameters of active devices, new

functionalities or uses, such as those derived from

the ambipolar nature of graphene or the possibility

to achieve low-resistivity interconnects,

respectively, have also been proposed [2].

Nevertheless, the benefits explored have not only

been restricted to the utilization of graphene's

superb electrical properties. Graphene has also

been studied as building block of metamaterials

and plasmonic components, as well as for

transparent conductors, and high-speed electro-

optical modulators and photodetectors [3].

Another remarkable areas which deserve attention

in the present work are sensors and coatings (e.g.,

for inflatable structures or impermeable

membranes) [4],[5]. In all cases, the success of

graphene-based devices will depend on whether

this material can lead to substantial improvement

over competing technologies.

The case of mechanical properties and the

corresponding applications will be discussed in

further detail. Three topics, namely, piezoelectricity

(both engineered by chemical modification of the

surface or introducing stressor structures),

graphene papers and graphene composite

materials, will be addressed [6],[7]. The analysis

performed for the later structures will be focused

on determining their effective Young's modulus,

intrinsic strains and failure strains, as well as the

proper parameters to account for the interlayer

and intralayer bond strengths. It is worth noting

that graphene composites could be exploited to

enhance the macroscopic properties of the matrix

material. Therefore, other macroscopic behaviours

such as those due to the impact resistance will be

assessed for suitable structures. The applications

considered regarding mechanical properties will

include the use of graphene as filler material, the

control of mechanical motion, energy harvesting

and sensors (e.g., resonator-based mass sensors).

Carlos Rivera1,2

[email protected]


TNT2012

Ab

st

ra

ct

s

References

[1] A. K. Geim and K. S. Novoselov, Nature Materials, 6 (2007) 183–191.

[2] J.-S. Moon and D. K. Gaskill, IEEE Trans. Microw. Theory Tech., 59 (2011) 2702–2708.

[3] T. Mueller, F. Xia, and P. Avouris, Nature Photonics, 4 (2010) 297–301.

[4] J. S. Bunch, S. S. Verbridge, J. S. Alden, A. M. van der Zande, J. M. Parpia, H. G. Craighead, and P. L.

McEuen, Nano Lett., 8 (2008) 2458–2462.

[5] E. W. Hill, A. Vijayaragahvan, and K. Novoselov, IEEE Sensors J., 11 (2011) 3161–3170.

[6] S. Stankovich, D. A. Dikin, G. H. B. Dommett, K. M. Kohlhaas, E. J. Zimney, E. A. Stach, R. D. Piner, S. T.

Nguyen, and R. S. Ruoff, Nature, 442 (2006) 282–286.

[7] M. T. Ong and E. J. Reed, ACS Nano, 6 (2012) 1387–1394.


Supported nanomaterials for

photocatalytic water disinfection at

rural areas: from lab. scale to on-site

experiments

Facultad de Ciencias, Universidad Nacional de Ingeniería,

P.O. Box 31-139, Av. Túpac Amaru 210, Lima, Perú

In this work, It will be reviewed our experience in the fabrication and characterization of photocatalytic

nanomaterials for water purification. The growth of TiO2 nanoparticles fixed onto rigid and flexible

substrates will be shown as well as ZnO nanorods supported onto a flat substrate. All of these materials will

be discussed as a function of the main parameters used in their preparation and their ability to

photocatalytically eliminate bacteria in water. Studies were performed in the laboratory as well as at a

greenfield site. For long term on-site experiments, for example, bacteria decontamination under real

conditions has been successfully tested at rural places using solar irradiated photocatalytic prototypes of up

to 120 L. With these studies, it was demonstrated the feasibility to obtain water disinfection by using

supported photocatalytic nanomaterials illuminating it with solar radiation and makes us optimistic for the

development of robust technologies for water treatment at rural areas.

Juan Rodríguez

[email protected]


Substantial increase of the critical

current on a Spin Transfer Nanopillar

by adding an Fe/Gd/Fe trilayer 1 Instituto de Sistemas Optoelectrónicos y Microtecnología, Universidad Politénica de

Madrid. Avenida Complutense 30, Madrid, Madrid, Spain. 2 Unité Mixte de Physique CNRS/Thales and Université Paris Sud 11, 1 ave. A. Fresnel,

91767 Palaiseau, France. 3 Intitut d’Électronique Fondamentale, Université Paris Sud 11-CNRS, rue André Ampère -

F 91405 Orsay, France. 4 Instituto de Microelectrónica de Madrid (CNM, CSIC), Isaac Newton 8, Tres Cantos,

Madrid 28760, Spain. Spin Transfer Torque (STT) excitations have created an increasing interest on the last few years due to the technological possibilities of current induced domain wall movement [1], switching nanomagnets [2] or generating radiofrequency signals [3]. However, they can also be detrimental in other applications like magnetic read heads, where stability and signal-to-noise ratio are very important issues in which STT has a negative effect [4]. In consequence, while for many applications the goal is to reduce the critical current density (jC) at which STT is induced, others require just the opposite.

The inclusion of Rare Earths (RE) contaminants on a magnetic layer has been one of the main approaches used to affect important magnetic properties like polarization, precessional frequency or damping [5,6,7]. Within RE, Gadolinium (Gd) is of special interest because it is ferromagnetic up to Room Temperature (TC(Gd)=293 K) and it has a very large magnetic moment at low temperatures. As a dopant it has already shown great potential for tuning the resonance frequency of a magnetic domain wall [8] or its velocity in magnetic nanostripes [9], or even controlling the spin polarization of the material [5,9].

In this work we have studied the influence of Gadolinium on the STT in Permalloy based nanopillars. We report a remarkable increase of the jC required to destabilize the Permalloy layer when a Fe/Gd/Fe ferrimagnetic trilayer is added onto the structure. Indeed, other ferrimagnetic structures have been already successfully applied in spin valves in order to increase the critical current for STT [10]. The use of a thin layer of Gd could potentially add

stability to this kind of structures without detriment of performance.

Figure 1. Stability phase diagram at 10 K corresponding to a reference Py device (a) and to a device with Fe/Gd/Fe (c). Color diagrams have been obtained from the positive branch (i.e. from –Imax to +Imax) of the R-I loops for different fields, and normalized so ΔR=0 corresponds to P state (dark blue in the diagrams). The colored lines on top of the contour plots highlight hysteretic transitions. Brown lines indicate a transition from high to low resistance in the positive branch (–Imax to +Imax), either from AP-state to lower resistance (solid brown line) or from some other intermediate resistance value (I-state) to a lower resistance (dashed brown line). Black lines represent transitions from the P state to a higher resistance state on the negative branch of the R-I loops, either from P to AP state (solid black line) or from P to a I-state (dashed black line). Selected R-I loops at 10 K and different fields for the reference device are represented in (b) and for the device with Fe/Gd/Fe in (d). The current sequence was I=0→ -Imax → +Imax → 0. Arrows in (c) and (d) emphasize minor transitions or instabilities.

M. Romera1, J. Grollier2,

V. Cros2, S. Collin2, T. Devolver3, M. Muñoz4 and J. L. Prieto1

[email protected]


TNT2012

A

bs

tr

ac

ts

The basic structure used in this study is SiO2// Cu(60)/ CoFe(12)/ Cu(10)/ Py(4)/ AFL/ Cu(8) where Py stands for Permalloy (Ni80Fe20) and AFL is an Artificial Ferrimagnetic Layer of Fe(1)/ Gd(1)/ Fe(1). Numbers between brackets represent thickness in nanometers. In order to understand the effect of the AFL, we have measured also a reference sample with only Py in the free layer (i.e. SiO2// Cu(60)/ CoFe(12)/ Cu(10)/ Py(4)/ Cu(8)). Figure 1 shows the phase diagram and some selected R-I loops measured at 10 K on elliptical pillars (with axis of 50 and 150 nm) patterned on the reference sample (Fig. 1a and 1b) and on the sample with AFL (Fig. 1c and 1d) respectively.

In the hysteretic region of the diagrams (at low fields) the jC is observed to increase almost an order of magnitude with the insertion of the AFL (from 2.3·107 A/cm2 to 1.6·108 A/cm2). In the reference device, reversible transitions (usually associated to unstable precession-like motion of the free layer) are predominant out of the hysteretic region and can be observed even for very high fields (~500 Oe). On the other hand, in the device with AFL these reversible transitions are almost no existent in all the range of field applied. In fact, in this device there are not transitions at all for applied fields higher than ~200 Oe.

The effect of the Fe/Gd/Fe trilayer on the magnetic properties of the Py layer has been studied through Ferromagnetic Resonance, SQUID and P-Moke measurements (Fig. 2). We observed that the AFL modify the damping, saturation magnetization and thickness on the free layer, but these variations only explain an increase of the critical current by a factor 1.6. On the other hand, Gd has small polarization (~13% [5]), and most of the magnetic moment in the Gd layer comes from strongly localized 4f electrons. Therefore, all the angular momentum carried by the spin polarized current in the Py/Fe free layer must be transferred to the antiparallel Gd layer at the interface between the 3d Py/Fe and the 4f Gd. The effect of this sudden transfer of angular momentum can be observed experimentally in any standard Spin Valve just by inserting a very thin Gd layer between the non-magnetic layer and the free layer. By doing this the magnetoresistance value drops to zero [11]. The large jC enhancement observed in our nanopillars seems to be caused by a reduction of the effective torque on the free layer associated to the sudden transfer of angular momentum at the interface of the antiparallel Gd layer.

Figure 2. Measurements at RT in a Py(4nm)-film (black symbols) and a Py(4nm)/Fe(1nm)/Gd(1nm)/Fe(1nm)-film (red symbols). (a) Imaginary part of the permeability measured at high fields. (b) FMR data (symbols) adjusted to the Kittel equation (line). (c) P-Moke hysteresis loops with the field applied perpendicular to the sample plane. It is also important to highlight the fact that the total ΔR of the device does not change much by adding Fe/Gd/Fe, as the thickness of the Py layer underneath is of the order of its spin diffusion length. Therefore our results with this type of trilayers might constitute a potential solution to the problems of STT instability in some nanometer-size devices.

References [1] S. S. P. Parkin, M. Hayashi, L. Thomas, Science,

320 (2008) 190. [2] B. O¨ zyilmaz, A. D. Kent, D. Monsma, J. Z. Sun,

M. J. Rooks, and R. H. Koch, Phys. Rev. Lett., 91 (2003) 067203.

[3] D. Houssameddine, U. Ebels, B. Delaët, B. Rodmacq, I. Firastrau, F. Ponthenier, M. Brunet, C. Thirion, J.P. Michel, L. Prejbeanu-Buda, M.C. Cyrille, O. Redon and B. Dieny, Nat. Mat., 6 (2007) 447.

[4] J.G. Zhu and X. Zhu, IEEE Trans. Magn., 40 (2004) 182.

[5] C. Kaiser, A.F. Panchula and S.S.P. Parkin, Phys. Rev. Lett., 95 (2005) 047202.

[6] S.G. Reidy, L. Cheng and W.E. Bailey, Appl. Phys. Lett., 82 (2003) 1254.

[7] G. Woltersdorf, M. Kiessling, G. Meyer, J.U. Thiele, and C. H. Back, Phys. Rev. Lett., 102 (2009) 257602.

[8] S. Lepadatu, J.S. Claydon, D. Ciudad, C.J. Kinane, S. Langridge, S.S. Dhesi and C.H. Marrows, Appl. Phys. Lett., 97 (2010) 072507.

[9] R. L. Thomas, M. Zhu, C. L. Dennis, V. Misra and R. D. McMichael, J. Appl. Phys., 110 (2011) 033902.

[10] N. Smith, S. Maat, M. J. Carey and J. R. Childress, Phys. Rev. Lett., 101 (2008) 247205.

[11] M. Romera, M. Muñoz, P. Sánchez, C. Aroca and J. L. Prieto, J. Appl. Phys., 106, 0239922 (2009).


New capabilities at the interface of

X-rays and scanning tunneling

microscopy

Advanced Photon Source and Center for Nanoscale Materials

Argonne National Laboratory, USA

In this talk we will discuss the development of a

novel high-resolution microscopy technique for

imaging of nanoscale materials with chemical,

electronic, and magnetic contrast. It will combine

the sub-nanometer spatial resolution of scanning

tunneling microscopy (STM) with the chemical,

electronic, and magnetic sensitivity of synchrotron

radiation. [1,2] Drawing upon experience from a

prototype that has been developed to demonstrate

general feasibility, current work has the goal to

drastically increase the spatial resolution of existing

state-of-the-art x-ray microscopy from only tens of

nanometers down to atomic resolution. Key

enablers for high resolution are insulator-coated

“smart tips” with small conducting apex (cf. Fig. 1).

[3] The technique will enable fundamentally new

methods of characterization, which will be applied

to the study of energy materials and nanoscale

magnetic systems. A better understanding of these

phenomena at the nanoscale has great potential to

improve the conversion efficiency of quantum

energy devices and lead to advances in future data

storage applications. The combination of the high

spatial resolution of STM with the energy selectivity

afforded by x-ray absorption spectroscopy provides

a powerful analytical tool.

Scan me

Figure 1. X-ray nanotomography surface rendering of a

smart scanning tunneling microscope tip. The platinum-

iridium tip (red) has been coated with a SiO2 insulating

layer (green).

References

[1] V. Rose, J.W. Freeland, S.K. Streiffer, “New

Capabilities at the Interface of X-rays and

Scanning Tunneling Microscopy”, in Scanning

Probe Microscopy of Functional Materials:

Nanoscale Imaging and Spectroscopy, S.V.

Kalinin, A. Gruverman, (Eds.), Springer, New

York (2011), pg 405-432.

[2] M.L. Cummings, T.Y. Chien, C. Preissner, V.

Madhavan, D. Diesing, M. Bode, J.W. Freeland,

V. Rose, Ultramicroscopy 112, 22 (2012).

[3] V. Rose, T.Y. Chien, J. Hiller, D. Rosenmann,

R.P. Winarski, Appl. Phys. Lett. 99, 173102

(2011).

Volker Rose


Mechanical properties of freely

suspended atomically thin

dielectric layers of mica 1 Dpto de Física de la Materia Condensada. Universidad Autónoma de Madrid,

Campus de Cantoblanco. E-28049 Madrid, Spain. 2 Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1,

2628 CJ Delft, The Netherlands. 3 Yale University. Department of Engineering Science. Becton 215, 15 Prospect St. New

Haven, CT 06520, USA. 4 Instituto Madrileño de Estudios Avanzados en Nanociencia IMDEA-Nanociencia,

E-28049 Madrid , Spain.

We study the elastic deformation of freely

suspended atomically thin sheets of muscovite

mica [1][3] (see Figure 1), a widely used electrical

insulator in its bulk form. Using an atomic force

microscope, we carried out bending test

experiments [1,2] (see Figure 2) to determine the

Young’s modulus and the initial pre-tension of mica

nanosheets with thicknesses ranging from 14 layers

down to just one bilayer. We find that their Young’s

modulus is high (190 GPa), in agreement with the

bulk value which indicates that the exfoliation

procedure employed to fabricate these nanolayers

does not introduce a noticeable amount of defects.

Additionally, ultrathin mica presents low pre-strain

and it can stand reversible deformations up to tens

of nanometers without breaking. The low pre-

tension and high Young's modulus and breaking

force found in these ultrathin mica layers

demonstrates their prospective use as complement

for graphene in applications requiring flexible

insulating materials or as reinforcement in

nanocomposites.

References

[1] A. Castellanos-Gomez et al., Nano Research

(accepted) 2012.

[2] A. Castellanos-Gomez et al., Advanced

Materials, 24 (2012) 772-775.

[3] A. Castellanos-Gomez et al., Small, 7 (2011)

2491-2497.

Figure 1. Optical micrograph of ultrathin two

dimensional mica layers deposited on a silicon subtrate

patterned with holes, where the mica sheet is

suspended. Different colors correspond to different mica

sheet thicknesses. The graph shows the optical contrast

dependence on the mica sheet thickness.

Figure 2. Force vs. deformation traces measured at the

center of the suspended part of mica nanosheets with 2,

6 and 12 layers in thickness. The slope of the traces

around zero deflection is marked by a dotted line. (Inset)

schematic diagram of the bending test experiment

carried out on a freely suspended mica nanosheet.

G. Rubio-Bollinger1,

A. Castellanos-Gomez1,2

,

M. Poot3,2

, G. A. Steele2,

H.S.J. van der Zant2 and

N. Agraït1,4

[email protected]


An efficient MRI contrast agent

based on PEGylated iron oxide

nanoparticles

Instituto de Ciencia de Materiales de Madrid/CSIC, Cantoblanco, 28049 Madrid, Spain

Estudios Avanzados de Cuba, San Antonio de Los Baños km 3½, La Habana, Cuba

Superparamagnetic nanoparticles are of special

interest for various applications in nanomedicine.

Nowadays, one of the most important and rapidly

growing fields is the use of iron oxide particles as

contrast agents for magnetic resonance imaging

(MRI). Also, the immobilization of poly(ethylene

glycol) (PEG) onto the nanoparticles's surface is the

most used strategy to avoid opsonisation and

cellular recognition, improving biocompatibility and

pharmacokinetic. In this study, we developed a MRI

contrast agent based on PEGylated iron oxide

nanoparticles. Magnetite nanoparticles (12 nm in

diameter) were obtained via thermal

decomposition of a iron coordination complex to

assure nanoparticle homogeneity in size and shape

(Fig. 1). Particles were coated with DMSA by a

ligand exchange process to remove oleic acid, after

which three distinct short-chain PEG polymers were

covalently bound to the nanoparticle surface via

EDC activation of the carboxylic groups. In all cases,

colloidal suspensions had hydrodynamic sizes

below 100 nm and low surface charge,

demonstrating the effect of PEG coating on the

colloidal properties and stability of the magnetic

nanoparticles. We tested in vitro the internalization

and biocompatibility of these materials in the HeLa

human cervical carcinoma cell line. Cells

preincubated with PEG-coated iron nanoparticles

were visualized outside the cells and their

biocompatibility at high Fe concentrations was

demonstrated using a standard MTT assay. Finally,

we used relaxivity parameters (r1 and r2) to

evaluate the efficiency of suspensions as MRI

contrast agents; r2 values were four times higher

than that for commercial products, probably due to

the larger nanoparticle size. The time of residence

in blood after coating increased up to hours in New

Zealand rabbits and Wistar rats (Fig. 2). Our results

suggest that this PEGylation strategy for large

magnetic nanoparticles (>10 nm) holds promise for

biomedical applications. T2 MRI images of rat liver

before and after injecting the synthesized contrast

agent showed a significant increase in the contrast

with time from 10 min up to 50 minutes (Fig. 3).

References

[1] D. Peer, J.M. Karp, S. Hong, O.C. Farokhzad, R.

Margalit, R. Langer, Nat. Nanotechnol. 2007, 2,

751

[2] M. Colombo, S. Carregal-Romero, M. F. Casula,

L. Gutiérrez, M.P. Morales, I.B. Böhm, J.T.

Heverhagen, D. Prosperi, W. J. Parak, Chem.

Soc Rev. 2012, DOI:10.1039/c2cs15337h.

[3] J. Gao in Biofunctionalization of Nanomaterials

(Eds: Ch. Kumar), Wiley-VCH Verlag GmbH &

Co. KGaA, Weinheim, Germany 2005, Ch. 3.

[4] S. Perrault, C. Walkey, T. Jennings, H. Fischer,

W. Chan, Nano Lett. 2009, 9, 1909.

[5] C. Fang, N. Bhattarai, C. Sun, M. Zhang, Small

2009, 5, (14) 1637.

[6] A. G. Roca, S. Veintemillas-Verdaguer, M. Port,

C. Robic, C. J. Serna, M. P. Morales, J. Phys.

Chem. B 2009, 113, 7033.

Amalia Ruiz, Gorka Salas,

Macarena Calero, Yenisel

Hernández, Angeles

Villanueva, Fernando

Herranz, Sabino

Veintemillas-Verdaguer,

Eduardo Martínez,

Domingo F. Barber and

María del Puerto Morales

[email protected]


TNT2012

Ab

st

ra

ct

s

Figure 1. (a) TEM images of magnetite nanoparticles (b) Size-distribution graph. The red line is the log-normal fitting

function of the particle size data.

Figure 2. (e, f) ICP quantification of iron concentration in

blood after injection into e) rabbits and f) rats. NP-

DMSA-PEG-NH2 [○], NP-DMSA-PEG-(NH2)2 [■] and NP-

DMSA-PEG-Prop-(NH2)2) [∆].

Figure 3. T2 MR images of rat liver before and after

injecting the synthesized contrast agent. In the left

animal injected with NP-DMSA-PEG-(NH2)2 and in the

right control animal (a)T2 image after 10 minutes of

injection.(b)T2 image after 50 minutes of injection.


Creating nanowires with

atomic precision

University of Alicante, Departamento Física Aplicada, Carretera San Vicente del Raspeig

s/n, San Vicente del Raspeig, Spain

Measuring the conductance between gold

electrodes and limiting the indentation depth

between the two electrodes up to a conductance

value of approximately 5G0 in the case of gold we

can obtain the same conductance behavior for

hundreds of cycles of formation and rupture of the

nanocontact. Furthermore, when two metals

approach, the first contact between them occurs

abruptly in most cases. This phenomenon is called

“jump-to-contact”. It is well known that the

conductance in a nanocontact is related to the

smallest area of the contact between the two

electrodes. Therefore, variations of the

conductance should be related to changes in the

atomic structure at the contact. Similarly, a jump in

the conductance is observed when the two

electrodes are pulled apart and the contact is

broken, in what is called "jump-out-of-contact".

Both experiments are rationalized using molecular

dynamics simulations together with density

functional theory transport calculations which show

how:

a) after repeated indentations (mechanical

annealing), the two metallic electrodes are

shaped into tips of reproducible structure.

b) certain atomic contact structures are most

likely to occur.

These results provide a crucial insight into

fundamental aspects relevant to nano-tribology or

scanning probe microscopies.

References

[1] C.Sabater, C. Untiedt, J.J.P, Phys. Rev. Lett.

108, 205502 (2012).

[2] C. Untiedt, M. J. Caturla, M. R. Calvo, J. J.

Palacios, R. C. Segers, and J. M. van

Ruitenbeek, Phys. Rev. Lett. 98, 206801 (2007)

Figure 1. Experimental traces obtained for Au

nanocontacts during formation and rupture when

limiting the conductance to (a) 5G0 and (b) 8G0. The inset

shows a 3D figure of the rupture where the third axis is

each individual trace.

Figure 2. Snapshots of the MD simulations of rupture

and formation of a nanocontact in gold for the initial

configuration and before cycles 2, 5, 10, 15 and 20 (top).

Number of atoms in the top nanoelectrode (in %) that

were initially on the second one, and viceversa, as a

function of the number of cycles(bottom). Temperature

was not fixed in this calculation.

C. Sabater, J.J. Palacios,

M.J. Caturla, C. Untiedt

[email protected]


TNT2012

Ab

st

ra

ct

s

Figure 3. Traces of conductance from DFT (open circles

are calculations with 1 electron and diamonds are

calculations with 11 electrons) and estimates from MD

minimum cross section (lines) for calculations with 525

atoms. (a) Rupture trace during first cycle and (b)

rupture trace for cycle number 10 for a maximum

indentation of 5 atoms in cross section.

Figure 4. (color online) Analysis of the steepest jump of

conductance before the formation of a metallic contact

for the case of gold, made from more than 300 000

conductance traces. The left panel shows a density plot,

where the horizontal axes represents the conductance at

which the jump takes place and the vertical axes shows

the conductance of the contact formed. We have

artificially changed the colors of the peak above (gray

scale) to make it visible. The right panel shows the

corresponding histogram of the conductance of the

contact formed after the jump.


Nanoscale elemental analysis and

applications using STM combined

with brilliant hard X-rays 1 Department of Precision Science & Technology, Osaka University, 2-1 Yamada-oka,

Suita, Osaka 565-0871, Japan 2 RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148, Japan

3 Institute for Molecular Science, Myodaiji-cho, Okazaki 444-8585, Japan

4 WPI center, National Institute for Materials Science,Tsukuba 305-0003, Japan

Analyses by scanning tunneling microscopy (STM)

combined with brilliant X-rays from synchrotron

radiation (SR) can provide various possibilities of original

and important applications. The STM observation under

inner-shell excitation at a specific core-level enables us

to analyze the elements or control the local reaction

with the high spatial resolution of STM [1].

We have recently demonstrated the elemental analyses

with a spatial resolution lower than 2 nm on

semiconductor surfaces [2]. The principle of our

analyses is not to collect the secondary electrons by

STM tip (that may damage the spatial resolution), but to

extract the element-specific modulation of the

”tunneling current” succeeding the core-excitation

process, which contains truly local information. A key to

accomplish successful results is to effectively increase

the signal to noise (S/N) ratio. On this purpose, we

developed a special SR-STM system.

The experimental setup is shown in Fig.1. To surmount

a tiny core-excitation efficiency by hard X-rays, we

focused two-dimensionally an incident beam having the

highest photon density at the SPring-8. Many problems

derived from the high brilliance (thermal and electrical

noise, damage of STM scanner, instability such as

thermal drift, etc.) were solved by the special apparatus

and system [1]. Furthermore, we developed a special tip

[3] (that can eliminate the noisy electrons coming from

a wide area) and signal acquisition system that realizes a

high signal to noise ratio to obtain a small modification

of the tunneling current originating from the core

excitation.

After first results on a semiconductor hetero-interface

(Si(111)7x7-Ge) [1], second results on the nanoscale

elemental analysis were acquired for metal-

semiconductor interface (Ge(111)-Cu nano-domains)

[2]. For both cases, the spatial resolution of the analysis

was estimated to be 1~4 nm, and it is worth noting that

the measured domains had a thickness of less than one

atomic layer (Fig.2).

Figure 1. Schematic view of experimental setup.

Figure 2. (a) Line profile of beam-induced tip current

image along the line shown in the bottom image. (b)

Topographic image and (c) beam-induced tip current

image of Ge (111)-Cu (-2V, 0.2 nA).

After progresses of the measurement system and

techniques, we succeeded in obtaining a series of

successive STM images at an atomically same area

Akira Saito1,2

, T. Tanaka1, H.

Matsuno1, H. Miki

1, Y.

Furudate1, Y. Takagi

3, M.

Akai-Kasaya1, Y. Tanaka

2, Y.

Kohmura2, T. Ishikawa

2, Y.

Kuwahara1,2

and M. Aono4

[email protected]


TNT2012

Ab

st

ra

ct

s

without serious drift or sample damages. Accordingly,

we could acquire a linear dependence of the element

contrast on the incident photon density. The photon

density dependence of the elemental contrast will give

an important clue to know the origin of the element

contrast. Actually, our result on the linear dependence

of the element contrast on the photon density suggests

that we can deny a possibility of the local potential

change derived from the core excitation, because the

potential should give an exponential dependence of the

contrast on the incident photon density.

Also we could recently measured scanning tunneling

spectroscopy (STS), which have long been impossible

because of instability due to brilliant X-ray irradiation.

STS information gives us more direct hint to approach

the mechanism of contrast to obtain a higher

resolution. It is notable that the image in Fig. 2(c) shows

the contrast originating from the chemical difference

(that is not based on the surface step height),

presenting the structures different from the

conventional topographic (Fig. 2(b)) image.

Next, we have recently achieved a direct observation of

the “X-ray induced atomic motion” with the track of the

atomic motion at an atomic scale using the SR-STM

system under the incident photon density of ~2x1015

photon/sec/mm2 [4]. This observation was enabled only

by use of the in situ SR-STM system, because the STM

images in the atomically same area should be compared

before and after X-ray irradiation. In our STM images,

the low-magnification images showed that the X-ray

induced atomic motion rate is so low that structural

changes are hardly detectable by other surface analysis

techniques such as diffraction analysis. However, the

magnified STM images revealed a clear change in the

atomic structures after X-ray irradiation. Then, we

developed a technique to recognize atomic motions

directly to comprehend their behavior. By merging the

STM images obtained before and after X-ray irradiation,

the atomic motion track could be newly presented as

several continuous lines (Fig. 3), whereas other stable

atoms are shown as spheres. The appeared atomic track

is the direct evidence and visualized information of the

atomic diffusion at an atomic scale. It is worth

comparing our results with past conventional thermal

STM observations on the same surface [5], where the

atomic motion was found to occur in the form of 2-

dimensional domain and begin at ~220°C. However, our

results show the atomic track having a local chain

distribution. This locality in diffusion can be attributed

to the anisotropy of the surface structure, and probably

the origin of atomic motion, to core excitation. In fact,

considering the temperature increase of 92 K from the

room temperature estimated from the X-rays

irradiation, our atomic motion occurs at very low

temperature in comparison with the past report.

Apart from the result on the elemental analysis, this

finding on the atomic motion will serve to study the

initial radiation effect on the optical devices such as

mirror or grating at the X-ray sources of new generation

such as X-ray free electron laser (XFEL). Also our

observation of the damage barrier has potential

importance as an indicator for a damage threshold in

the near future for analyzing tiny materials using strong

X-rays.

On the other hand, the above mentioned results will

allow us to study the element-specific atomic control of

local reaction with the spatial resolution of STM, giving

hope of wide application. For example, the dense X-rays

are suggested to have new applications, such as direct

X-ray lithography. In other viewpoint, our results show a

new application of the in situ SR-STM system. Our

method for observing the atomic track will serve to

provide new information not only for the radiation

effects on various optical devices in new X-ray

generators, but also for basic science by observing

photon-matter interactions.

Figure 3. Atomic motion tracks newly presented by

merging the STM images before and after X-ray

irradiation.

References

[1] A.Saito, et al.: J.Synchrotron Rad.13 (2006)

216. ;Jpn.J.Appl.Phys.45 (2006) 1913.; Curr.

Appl.Phys. (2012) in press.

[2] A.Saito et al.: Surf. Interface Anal. 40 (2008)

1033.; "Nano-imaging" (NTS publisher, 2008)

p.278.

[3] A.Saito et al.: Surf. Sci. 601 (2007) 5294.

[4] A.Saito et al.: J. Nanosci. Nanotechnol. 11

(2011) 1873.

[5] R.M. Feenstra et al.: Phys. Rev. Lett. 66 (1991)

3257.


Biorthogonal chemistry for the

functionalization of

superparamagnetic nanoparticles:

cross olefin metathesis 1 Unidad de Imagen Avanzada. Centro Nacional de Investigaciones Cardiovasculares

(CNIC).Madrid, Spain 2 Dpto.Química-Física II, Facultad de Farmacia Universidad Complutense, CIBERES,

Madrid, Spain 3 Biomaterials and Bioinspired Materials Instituto de Ciencia de Materiales de

Madrid,Madrid, Spain

The use of magnetic nanoparticles in biomedical

applications has witnessed an exponential growth

last years. Iron oxide nanoparticles (NP),

particularly, have gained a dominant role because

of their physicochemical properties and low

toxicity. Due to their superparamagnetic behavior

these particles are of paramount importance in

imaging techniques like Magnetic Resonance

Imaging (MRI) and Magnetic Particle Imaging (MPI).

In order to provide stability and targeting these NPs

require specific coating. The association of one or

more biologically relevant molecules at the

interface of a NP defines a NP-bioconjugate, which

combines the unique physicochemical properties of

NP materials with biological activity such as

selective binding. To date, researchers have largely

relied upon the traditional chemistries associated

with protein labeling for the preparation of NP-

bioconjugates. However, the range of

bioconjugation techniques used with NPs has

lagged behind the multitude of biological

applications proposed. Although traditional

bioconjugate chemistries have been adequate for

proof-of-concept studies, the optimization of NP-

bioconjugates for real applications (e.g., clinical)

will require much greater control than these

chemistries can offer. Rather, clean, efficient, and

bioorthogonal conjugation reactions are required

to eliminate undesirable side reactions, minimize

nonspecific NP-bioconjugate activity, improve

reproducibility in production, and maximize efficacy

[1-3]. Within this group of bioorthogonal chemistry,

olefin metathesis offers many of these features

thanks to the new family of catalysts, especially

Hoveyda-Grubbs 2nd generation. The metathesis

mechanism reorganizes the carbon atoms of two

C=C bonds, generating two new ones in the

presence of a catalyst. This kind of reaction allows

access from the easily prepared olefins to those

that are cumbersome to obtain, being an efficient

and stereoselective synthesis of the more

substitute olefins in mild conditions. All of these

advantages make the metathesis of alkenes one of

the most powerful tools in synthetic chemistry, but

as far as we know, it has not been applied for the

functionalization of iron oxide superparamagnetic.

Here we present our results in the functionalization

of superparamagnetic iron oxide nanoparticles with

four different terminal olefins through metathesis

reaction [4]. First, we synthesized iron oxide

nanoparticles by the decomposition of organic

precursor obtaining hydrophobic Fe3O4 NPs, with

oleic acid as surfactant. The olefin metathesis was

made between the double bond in oleic acid

structure and four different molecules with a

terminal double bond; methyl acrylate, 6-

hexenetirile, allyltrifluoroacetate and 3-allyloxi-1,2-

propandiol, in presence of catalytic amounts

(4%mol) of Hoveyda-Grubbs second generation

catalyst. These new NPs were fully characterized by

TEM, VSM, MS and FTIR, showing the success of the

reaction and quite good values for the

hydrodynamic size and PDI as can be seen in

figure 1.

B. Salinas1,2

,

J. Ruiz-Cabello1,2

,

M.P. Morales3 and

F. Herranz2

[email protected]


TNT2012

Ab

st

ra

ct

s

Figure 1. General metathesis synthesis and summary of

the averaged sizes.

Figure 2. Hydrolysis of NPs (2) with methyl acrylate,

generating hydrophilic NPs.

After the metathesis the ester bond in 2 was

hydrolyzed rendering water stable sample 6 due to

the presence of the terminal carboxylic acid, with a

Z average of 28 ± 10 nm (PDI 0.30 ± 0.07, N=3).

These NPs were fully characterized. The

physicochemical properties of the inorganic core

were studied by TEM and VSM, which

demonstrated the superparamagnetic behavior of

the sample [4].

The presence of the acid was probed through the

FTIR spectrum and the ζ potential profile, which

exhibit their stability in physiological conditions,

with a value of -37 ± 5 mV at pH 7, and the typical

profile for NPs stabilized by a carboxylic acid.

For biomedical applications the nanoparticles must

show high stability in solutions with high ionic

strength. To this end metathesis is especially well

suited as it allows such modifications in one single

step from the hydrophobic particles if the right

olefins are used. For this reason once

demonstrated the possibility of using the

metathesis in USPIO the second stage was the

direct bioconjugation with hydrophilic polymers

bearing a terminal olefin. On this regard we will

focus in the results obtained with Polyethylene

glycol (PEG) and different proteins from the

extracellular matrix. First, the biopolymers were

modified to show a terminal olefin through a

substitution reaction. The metathesis was applied

as shown before over the sample 1, rendering

hydrophilic NPs. These NPs were fully characterized

by FTIR, MS, VSM and TEM, showing the success of

the reaction keeping the superparamagnetic

behavior of the NPs, which allow their possible use

as MRI contrast agent.

In this work we demonstrate, for the first time, the

use of the cross olefin metathesis reaction for

bioorthogonal functionalization of iron oxide

nanoparticles with different ligands, allowing the

incorporation of different functional groups and

biomolecules. Using appropriate catalyst and

reaction conditions it is possible to modify the

structure of the surfactant without self-metathesis,

as demonstrated with the hydrodynamic size, TEM

images and FT-IR spectra reported here. This

simplifies the synthesis of hydrophobic and

hydrophilic nanoparticles with applications in

different fields.

References

[1] Russ Algar W., Prasuhn D. E., Stewart M. H.,

Jennings T. L., Blanco-Canosa J. B., Dawson P.

E., Medintz I. L. 2011 Bioconjugate Chem., 22,

825–858.

[2] Herranz F., Morales M.P., Roca A.G., Desco M.,

Ruiz-Cabello J. 2008 Chemistry- A European

Journal, 14(30), 9126-9130.

[3] Herranz F., Almarza E., Rodríguez I., Salinas B.,

Rosell Y., Desco M., Bulte J.W.M., Ruiz-Cabello

J. 2011 Microsp. Res. Tech. 74 (4), 577-591.

[4] B. Salinas, J. Ruiz-Cabello, M.P. Morales, F.

Herranz. 2012 Bioinspired, Biomimetic and

Nanomaterials. 1, 166-172.


AC Josephson effect in finite-length

nanowire junctions with Majorana

modes

Instituto de Estructura de la Materia (CSIC)

Serrano 123, 28006 Madrid (SPAIN)

It has been predicted that superconducting junctions made with topological nanowires hosting Majorana

bound states (MBS) exhibit an anomalous 4π-periodic Josephson effect. Finding an experimental setup with

these unconventional properties poses, however, a serious challenge: for finite-length wires, the equilibrium

supercurrents are always 2π periodic as anticrossings of states with the same fermionic parity are possible.

We show, however, that the anomaly survives in the transient regime of the ac Josephson effect. Transients

are, moreover, protected against decay by quasiparticle poisoning as a consequence of the quantum Zeno

effect, which fixes the parity of Majorana qubits. The resulting long-lived ac Josephson transients may be

effectively used to detect MBS.

References

[1] Phys. Rev. Lett. 108, 257001 (2012)

Pablo San Jose


Thermal and mechanical effects of

different excitation modes based on

low frequency laser modulation in

optical hyperthermia

Centre for Biomedical Technology (CTB), Technical University of Madrid (UPM),

Campus Montegancedo, Pozuelo de Alarcón (Madrid), Spain

Recently, gold nanoparticles, in combination with

laser light, have been used successfully to achieve

controlled thermal damage in tumor tissue [1] [2].

Gold nanostructures show a unique optical

property, ie, they efficiently absorb light due to the

surface plasmon resonance phenomenon and then

convert the absorbed light into localized heat [3].

Our first work was aimed at obtaining a proof of

concept of an optical hyperthermia system [4]. The

instrument was similar to others currently being

used [5] [6], but with the possibility of using

different excitation methods by changing the light

exposure pattern from continuous wave light to

pulsed light. The system was developed to evaluate

the effectiveness of gold nanorods designed to

work in the optimal tissue window for light

absorbance (808 nm) used to produce cellular

death in glioblastoma cell lines (1321N1). The

obtained results showed that the use of gold

nanorods in hyperthermia therapy is very effective

(Figure 1) but in order to develop an optimal

treatment, many parameters still need to be

optimized, concerning both laser irradiation and

gold nanorods characteristics.

After these first results, our work is focused on the

development of new excitation methods with the

aim of increasing the effectiveness of the

hyperthermic treatment thanks to the well known

thermal effects and to other mechanical effects

that are being studied and could influence the cell

death process.

The low frequency modulation of the laser source

(<30KHz) allows the generation of a pulsed signal

that intermittently excites the gold nanorods. The

temperature curves obtained for different

frequencies and duty cycles of modulation but with

equal average power and identical laser

parameters, show that the thermal behavior in

continuous wave and modulation modes are the

same (Figure 2). However, the cell death

experiments suggest that the percentage of death

is higher in the cases of modulation (Figure 3). This

observation allows us to conclude that there are

other effects in addition to temperature that

contribute to the cellular death.

Figure 1. Photothermal treatment of 1321N1. The cells

were stained with propidium iodide and then fixed and

analyzed on a flow cytometer. The graph shows the

percentages of dead cells (IP+-cells) over total cells,

calculated for each condition. Control: 1321N1 basal cell

death rate. AuNRs: 1321N1 cells incubated with gold

nanorods. Laser: 1321N1 cells subjected to laser

irradiation. Laser + AuNRs: 1321N1 cells subjected to

laser irradiation in the presence of gold nanorods.

The mechanical effects like sound or pressure

waves are expected to be generated from thermal

expansion of gold nanorods. In order to study the

behavior and magnitude of these processes we

have developed a measure device based on

ultrasound piezoelectric receivers (25KHz) and a

lock-in amplifier that is able to detect the sound

Cristina Sánchez,

Julio Alberto Ramos,

Tamara Fernández,

Milagros Ramos,

Alberto Martínez,

Francisco del Pozo,

José Javier Serrano

[email protected]


TNT2012

Ab

st

ra

ct

s

waves generated in samples of gold nanorods

during laser irradiation providing us a voltage level

proportional to the pressure signal.

The first results (Figure 4) show that the pressure

measurements are directly proportional to the

concentration of gold nanorods and the laser

power, therefore, our present work is focused on

determine the real influence of these effects in the

cell death process.

References

[1] Huff TB, Tong L, Zhao Y, Hansen MN, Cheng JX,

Wei A. Hyperthermic, Nanomedicine (Lond), 2

(2007) 125-132.

[2] Kuo WS, Chang CN, Chang YT, et al., Angew

Chem Int Ed Engl., 49 (2010) 2711-2715.

[3] Jain PK, El-Sayed IH, El-Sayed MA, Nano Today,

2 (2007) 16-27.

[4] Fernández T, Sánchez C, Martínez A, del Pozo

F, Serrano JJ, Rarmos M, Int. J. Nanomed, 7

(2012) 1511-1523.

[5] Fourkal E, Vlechev I, Taffo A, Ma C, Khazak V,

Skobeleva N., IFMBE Proc., 25 (2009) 761-763.

[6] Rozanova N, Zhang JZ, Science in China Series

B: Chemistry, 52 (2009) 1559–1575.

Figure 2. Temperature curves of gold

nanorods suspension for different duty

cycles of modulation in comparison to the

continuous wave mode (CW). The

parameters of the laser are fixed in an

average power of 381 mW and a frequency

of modulation of 5KHz.

Figure 3. IP/calcein essay 24h after irradiation: Comparison between different times and excitation modes (modulation

and CW).

Figure 4. Voltage levels for different laser

intensitiy values (linearly proportional to

the power source) in a duty cycle sweep.


Maximal entanglement out of

transport through double

quantum dots

Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC),

Sor Juana Inés de la Cruz 3, Madrid, Spain

Double quantum dots connected in series to source and drain electronic reservoirs can be tuned to contain

up to two electrons. In such configuration, current suppression due to Pauli exclusion principle has been

detected [1]. This effect is known as spin blockade. Driving the system with time dependent magnetic fields

allows the coherent manipulation of the two electron states. Single spin rotations remove Pauli correlations

and restore the flow of current [2,3]. Analyzing the current spectrum as a function of the driving frequency,

we find dark resonances where spin blockade is restored due to collective rotations of the two spins. Then,

the two electrons are spatially separated, each one kept in a different quantum dot. Furthermore, for such

frequencies the system evolves towards a maximally entangled stationary state [4]. We find robust Rabi

oscillations of two positive parity Bell states for weak coupling to the reservoirs. We investigate the influence

of the magnetic field polarization.

References

[1] K. Ono, D.G. Austing, Y. Tokura, S. Tarucha, Science 297 (2002) 1313.

[2] F.H.L. Koppens, C. Buizert, K. J. Tielrooij, I. T. Vink, K. C. Nowack, T. Meunier, L. P. Kouwenhoven, L. M. K.

Vandersypen, Nature 442 (2006) 766.

[3] R. Sánchez, C. López-Monís, G. Platero, Phys. Rev. B 77 (2008) 165312.

[4] R. Sánchez, G. Platero, in preparation.

Rafael Sánchez and

Gloria Platero

[email protected]


TDDFT simulations of the energy

loss of moving projectiles in solids

and nanostructures

Centro de Física de Materiales UPV/EHU-CSIC,

Paseo Manuel de Lardizabal 5, 2018 San Sebastián, Spain

We have recently developed a code to perform real

time time-dependent density-functional theory

simulations [1,2,3]. Our method is based on the

SIESTA code [4] and uses a linear combination of

atomic orbitals as a basis set. Previous versions of

our code had been used to study the optical

response of finite systems [1], i.e., electron

dynamics was followed after the system was

initially perturbed while nuclei were kept fixed in

their initial positions. Our most recent version,

however, allows performing coupled electron-

nuclear dynamics within the Ehrenfest

approximation and has been applied to study the

problem of radiation damage in solids and

nanostructures.

Figure 1. Electronic stopping power of H and He

projectiles in gold as a function of projectile velocity.

Results of our simulations are compared with the

experimental data from on single and polycrystalline thin

gold films.

Although radiation damage processes are of

extraordinary fundamental and technological

importance, ab initio simulations of these effects in

solids are still very scarce to date. Most simulations

for solids and condensed systems are based on

semi-empirical approaches, like SRIM [5]. The

energy transferred to the solid goes both onto

displacements of the target ions (nuclear stopping)

and electronic excitations (electronic stopping).

While at very low velocities nuclear stopping can

we dominant, at moderate, intermediate and high

energies the most efficient energy loss mechanism

is the electronic stopping. The effect of electronic

stopping is frequently incorporated in simulations

through an ion and target dependent friction

coefficient. Thus, the electronic stopping is

assumed to depend linearly on velocity. This is

generally true for simple metals, for which the

friction coefficient can be estimated very efficiently

using a jellium model plus scattering theory [6].

However, it has been recently observed that there

are significant deviations from linearity at low

velocities in insulators and noble metals, both

showing different kinds of threshold effects.

Understanding of such effects demands an explicit

treatment of the electronic stopping in the

presence of the actual atoms and actual electronic

structure of the host system. Our simulations using

time-evolving TD-DFT could reproduces the

anomalies in the stopping power observed

experimentally for projectile velocities below 0.3

a.u., for insulators and noble metals [2,3]. In

addition, we could analyze the Barkas effect

(difference in stopping between protons and

antiprotons) in LiF [2], and the He/H anomaly in Au

[3] (the stopping is larger for He at all velocities,

contrary to expectations based on free electron

models). Our approach has quite general

applicability and we plan to apply it to other

radiation damage problems. As an example, we

have recently studied the influence of the electrons

being excited on the effective internuclear forces

when an Al target is bombarded with protons [7].

Daniel Sánchez-Portal

[email protected]


TNT2012

Ab

st

ra

ct

s

Figure 2. Screening of a localized hole during

photoemission from a metal (jellium) clusters. The

induced electronic density is shown close to the

symmetry z-axis (r = 0.02 a.u., the electron is emitted

along the z-axis and r is the perpendicular coordinate).

The time evolves along the vertical axis. The color map

shows the change in density in units of the background

density. The color scale is limited to a maximum value of

in order to reveal the effects in the regions where the

induced density is small. The induced density above this

value is shown in green. The actual maximum value of

the induced density is about 50 in units of background

density. It corresponds to the small region around the

position of the hole. (a) Shows the results of the TDDFT

calculation of the complete system. In (b) the induced

density is calculated as a sum of two separate

contributions, screening of the hole and screening of the

moving electron. The cluster contains 106 electrons and

has radius of 18.93 a.u., with density corresponding to

rs = 4.The velocity of the electron is constant and is

equal to 1 a.u. Insets: profile of the plot along the time

axis at (r= 0.02 a.u., z= 0.2 a.u.)

Finally, the dependence of the electron dynamics

on the size and dimensionality is an important issue

in many fields. For example, it determines the

efficiency and time scale of the screening of

interactions, the rate of many chemical reactions at

surfaces and the optical response of nanoobjects.

We plan to use our methods to investigation some

of these issues. In particular, I will present some of

our recent semi-classical results on the influence of

the localized-hole screening on the energy losses

during photoemission from metal clusters [10].

References

[1] A. Tsolakidis, D. Sánchez-Portal, and R. M.

Martin Phys. Rev. B 66 (2002) 235416.

[2] J. M. Pruneda, D. Sánchez-Portal, A. Arnau, J.

I. Juaristi, and Emilio Artacho Phys. Rev. Lett.

99 (2007) 235501.

[3] M. A. Zeb, J. Kohanoff, D. Sánchez-Portal, A.

Arnau, I. Juaristi and E. Artacho, Phys. Rev.

Lett. 108 (2012) 225504.

[4] J. M Soler, E. Artacho, J. D. Gale, A. García, J.

Junquera, P. Ordejón and D. Sánchez-Portal,

J. Phys.: Condens. Matter 14 (2002) 2745.

[5] J. F. Ziegler, J. P. Biersack, and U. Littmark,

“The Stopping and Range of Ions in Matter”,

New York, 1985. Pergamon. ISBN 0-08-

022053-3.

[6] P. M. Echenique, R. M. Nieminen, J. C. Ashley

and R. H. Ritchie, Phys. Rev. A 33 (1986) 897.

[7] A. A. Correa, J. Kohanoff, E. Artacho, D.

Sánchez-Portal and A. Caro, Phys. Rev. Lett.

108 (2012) 213201.

[8] E. V. Chulkov, A. G. Borisov, J. P. Gauyacq, D.

Sánchez-Portal, V. M. Silkin, V. P. Zhukov and

P. M. Echenique Chemical Reviews 106

(2006) 4160.

[9] R. D. Muiño, D. Sanchez-Portal, V. M. Silkin,

E. V. Chulkov and P. M. Echenique, PNAS 108

(2011) 971.

[10] N. Koval, D. Sánchez-Portal, A. G. Borisov, R.

D. Muiño, to appear on Nanoscale Research

Letters.


WaveGuide's u-NMR and magnetic

nanoswitches for security and

defense applications

WaveGuide Corporation

One Broadway, 14th floor

Cambridge, MA 02142, USA

The uNMR, innovative technology combined with proprietary Magnetic Nanoswitches enables low cost

rapid, on-site screening for Security and Defense Applications.

Product applications include point of testing of suspicious samples to determine if a biothreat agent is

present, anti-counterfeiting, adulteration and product diversion in industries as diverse as petroleum,

pharmaceuticals and beverages.

WaveGuide Corporation is a Harvard University spin out that is commercializing a handheld nuclear

magnetic resonance spectrometer (uNMR) and proprietary Magnetic Nanoswitches.

Marcus Semones

[email protected]


Fluorescence and Raman

characterization of a transport

system formed by the anti tumoral

drug emodin, silver nanoparticles

and porous silicon 1 Dep. Química Física II, Facultad de Farmacia, UCM, 28040 Madrid, Spain

2 Instituto de Estructura de la Materia, CSIC, Serrano 121, 28006 Madrid, Spain

3 Departamento de Física Aplicada, Facultad de Ciencias, UAM, 28049 Madrid, Spain

Emodin is an orange crystalline solid that belongs

to the anthraquinone family (fig. 1). It has shown

anticancer effect in breast and prostate tumors. It

presents high solubility in organic solvents but it is

insoluble in water. To overcome this limitation

design of advanced drug delivery systems are

necessary in order to deliver the drug at the target

site with the adequate rate and concentration.

Between the new materials that have recently

revealed a lot of promise in drug delivery, porous

silicon (PSi) is an interesting one (fig. 2). It is

biocompatible and biodegradable and is able to

form micro devices to carry the drugs until the site

of interaction [1-3]. If the molecules do not remain

inside the pores it is necessary to functionalize the

silicon surface. As this is the case of emodin, we

have solved the problem by using silver

nanoparticles. These metal nanostructures present

additional advantages derived from the Localized

Surface Plasmon Resonances (LSPR) they support.

The principal benefit is related with the obtaining

of surface enhanced spectroscopy such as SERS

(surface enhanced Raman scattering) and SEF

(surface enhanced fluorescence) that can be used

as potent and high sensitive techniques for

molecular detection.

Figure 1. Structure and acid-base equilibrium of emodin.

Figure 2. Cross section of a porous silicon layer.

Understanding and knowledge of the

physicochemical properties of the systems used to

transport and release the drugs constitute a

prerequisite in designing advanced drug delivery

systems. Interaction of emodin with silver

nanoparticles has been previously studied in our

group [4-5]. In the present work we have used

Raman and SEF spectroscopy to perform a

characterization of emodin adsorbed on silver

nanoparticles and loaded on PSi.

Besides optimization of pore size and impregnation

conditions of PSi, enhancement factor of

fluorescence signal of emodin has been obtained

(fig. 3). It varies between 5 and 24 for diverse

conditions used. Preliminary Raman and

fluorescence studies of other non steroidal anti

inflammatory drugs (NSAIDS), in particular

ketorolac and indomethacin, in solution and

adsorbed on silver nanoparticles will also be

presented. Conclusion collected in this study

Paz Sevilla1,2

, Margarita

Hernandez2, Gonzalo

Recio3, E. Corda

2,

Raúl J. Martín-Palma3,

José V. García-Ramos2 and

Concepción Domingo2

[email protected]


TNT2012

Ab

st

ra

ct

s

constitutes a first step in the design of a new drug delivery system to be used with emodin or with other

drugs like ketorolac or indomethacin.

600 700 800 9000

5000

10000

15000

20000b)

Intensity

Wavelength (nm)

a)

Figure 3. Fluorescence spectra of nanostructured porous silicon: a) loaded with the

antitumoral drug emodin, b) loaded with the antitumoral drug emodin adsorbed on silver

nanoparticles. Excitation laser wavelength used was 532 nm. All spectra were normalized to

the Raman signal from the Si at 547 nm.

References

[1] N. J. Halas, Nanomedicine, 4 (2009) 369.

[2] R. J. Martín-Palma, M. Manso-Silván, and V. Torres-Costa, J. Nanophotonics, 4 (2010) 042502.

[3] A. Muñoz-Noval, V. Sánchez-Vaquero, V. Torres-Costa, D. Gallach, V. Ferro-Llanos, J. J. Serrano, M.

Manso-Silván, J.P. García-Ruiz, F. del Pozo, and R.J. Martín-Palma, J. Biomedical Optics, 16 (2011)

025002.

[4] P. Sevilla, F. García-Blanco, J.V. García-Ramos and S. Sánchez-Cortes, Phys. Chem. Chem. Phys., 11

(2009) 8342.

[5] R. De-Llanos, S. Sánchez-Cortés, C. Domingo, J. V. García-Ramos and P. Sevilla, J. Phys. Chem. C, 115

(2011) 12419.


Manipulation of molecular quantum

states in an STM tunneling junction

using classical metal atom inputs

IMRE, A*STAR, 3 Research Link, 117602, Singapore

Digital logic gates are basic functional units in any

digital electronic circuit performing arithmetic logic

operations. The most straightforward approach for

improving the performance of digital logic gates is

the further miniaturization of solid state transistors

as their primordial building blocks. However those

downsizing encounters several fundamental

problems at the atomic scale, i.e. leakage currents,

heat dissipation, fabrication limitations, etc. AtMol

is a project pioneering a new proposed paradigm to

implement molecular electronics and quantum

computing. The final goal of this project is to

fabricate a fully functional molecular chip, whose

chip core will be made of atom wires

interconnecting a single logic processing molecule.

A low-temperature scanning tunneling microscope

(STM) is a very suitable tool not only for surface

science but also to investigate single molecule

electronics. STM differential conductance (dI/dV)

measurement is a very effective technique to gain

access to the low lying electronic states of single

molecules. To have access to those states, a

molecule has to be electronically decoupled or

weakly coupled, i.e. physisorbed, to the metal

surface. We present here how the electron

probability distributions of molecular states are

imaged in real space using a pentacene molecule

directly adsorbed on a gold surface. [1] STM dI/dV

conductance images taken at voltages

corresponding to the resonances near the substrate

Fermi level were found to be very close to the

mono-electronic molecular orbitals (MO), in

contrast high-order resonance states images were

composed also with MO components from low-

order resonance states. dI/dV conductance maps of

other molecules will be also presented. [2,3]

Quantum states of a molecule can be modified by

light irradiation, external fields, structural

transformation, etc. Here, we show that is possible

to manipulate the quantum states of a

trinaphthylene molecule by using classical metal

atom contacts. [4] Herein two naphthylene

branches of the trinaphthylene molecule are used

to set atom input terminals and the remaining one

functions as the signal output terminal. One Au

atom in contact with an input branch carries 1-bit

of classical information input that is converted into

quantum information throughout the molecule.

The Au-trinaphthylene electronic interactions give

rise to measurable energy shifts of the molecular

electronic states demonstrating a NOR logic gate

functionality. The NOR truth table of the single

molecule logic gate was characterized by STM dI/dV

measurements. How far the quantum information

is transferred through will also be discussed. [5]

References

[1] W –H Soe, C Manzano, A De Sarkar, N

Chandrasekhar and C Joachim, Phys. Rev. Lett. 102

(2009) 176102.

[2] W –H Soe, C Manzano, H S Wong and C Joachim, J.

Phys.: Condens. Matter (2012) in press.

[3] W –H Soe, H S Wong, C Manzano, M Grisolia, M

Hliwa, X Feng, K Müllen and C Joachim, ACS Nano 6

(2012) 3230.

[4] W –H Soe, C Manzano, N Renaud, P de Mendoza, A

De Sarkar, F Ample, M Hliwa, A M Echavarren, N

Chandrasekhar and C Joachim, ACS Nano 5 (2011)

1436.

[5] C Manzano, W –H Soe, P de Mendoza, A M

Echavarren C Joachim, to be submitted.

We–Hyo Soe

[email protected]


Disorder-induced randomization of

spin polarization and interfacially

protected surface states in

three-dimensional models of

topological insulators 1 CIN2 (ICN-CSIC), Campus UAB, 08193, Bellaterra (Barcelona), Spain

2 Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010, Barcelona, Spain

The growing interest on topological insulators (TI)

relies on their fascinating electronic properties,

namely, a non-trivial insulating bulk which

guarantees the formation of highly robust Dirac-like

states at the surface holding a chiral spin

texture.[1-3] This new topological phase of

condensed matter is governed by strong spin-orbit

coupling and their surface states are protected

against disorder preserving time-reversal symmetry

(non-magnetic).

Here we use a three-dimensional model of TI on a

diamond lattice, described by the Fu-Kane-Mele

(FKM) Hamiltonian,[4] and show how Dirac cone

characteristics can be tuned on opposite surfaces

upon differentiation of atomic-scale surface

terminations. In particular, when the outermost

surface layers are removed, the number of Dirac

cones in the surface Brillouin zone (SBZ) changes

from three at the three equivalent M-points to a

single one at Gamma. This result extends the

applicability of the FKM model to real TI such as the

frequently studied Bi2Se3, Bi2Te3 or Sb2Te3.

More interestingly, when opposite surfaces are

geometrically differentiated by removing the

outermost layer from only one surface, Dirac cones

develop at the M-points in one surface and at the

Gammapoint in the other and remain uncoupled

and gapless down to few bulk layers (see Fig.1(b,e)

for 11 and 3 layers thickness respectively).[5,6] Our

findings are consistent with recent experimental

observations by Bian et al.[7] and open the way to

controlled engineering of thin 3D-TI with highly

robust chiral states.

Figure 1. Band structure of slabs of various thicknesses

(layers L) and surface terminations (T1 is the default

termination and T2 is the one obtained by removing the

outermost layer as explained in the text). When opposite

surfaces are geometrically differentiated (b,e) the

surface states remain gapless down to few bulk layers.

Additionally, by introducing Anderson bulk

disorder,[8-11] we investigate the changes in the

spin texture with increasing disorder in the slab in

order to determine the extent to which the

topological protection of surface states is reduced.

As disorder strength is increased, spin polarization

becomes smaller and spread over a wider range of

vector length, evidencing randomization of the spin

texture fingerprint (see Fig. 2; blue and red arrows

correspond to the clean and disordered cases

respectively). Our findings suggest ways to analyze

the bulk crystalline quality of TI by inspecting the

spin texture features through spin-resolved ARPES

experiments.

David Soriano1,

Frank Ortmann1 and

Stephan Roche1,2

[email protected]


TNT2012

Ab

st

ra

ct

s

Figure 2. Spin texture of a T2-T2 slab (12 layers) in

presence (red) and in absence (blue) of bulk Anderson

disorder. The randomization of the spin texture in

presence of bulk disorder is evident.

Acknowledgements. This work is supported by the

TRAIN2 project of the SUDOE Territorial

Cooperation Programme.

References

[1] J. E. Moore, Nature, 464 (2010) 194.

[2] [2] M. Z. Hasan and C. L. Kane, Rev. Mod.

Phys., 82 (2010) 3045.

[3] X.-L. Qi and S.-C- Zhang, Rev. Mod. Phys., 83

(2011) 1057.

[4] L. Fu, C. L. Kane and E. J. Mele, Phys. Rev. Lett.,

98 (2007) 106803.

[5] Y. Zhang, C.-Z. Chang, C.-L. Song, L.-L. Wang, X.

Chen, J.-F. Jia, Z. Fang, X. Dai, W.-Y. Shan, S.-Q.

Shen, Q. Niu, X.-L. Qi, S.-C. Zhang, X.-C. Ma and

Q.-K. Xue, Nature, 464 (2010) 194.

[6] A. A. Taskin, S. Sasaki, K. Segawa and Y. Ando,

arXiv:1204.1829.

[7] G. Bian, X. Wang, Y. Liu, T. Miller and T. C.

Chiang, Phys. Rev. Lett., 108 (2012) 176401.

[8] A. M. Black-Schaffer and A. V. Balatsky, Phys.

Rev. B, 85 (2012) 121103(R).

[9] G. Schubert, H. Fehske, L. Fritz and M. Vojta,

Phys. Rev. B, 85 (2012) 201105(R).

[10] J. Henk, A. Ernst, S. V. Eremeev, E. V. Chulkov,

I. V. Maznichenko and I. Mertig, Phys. Rev.

Lett., 108 (2012) 206801.

[11] H. Beidenkopf, P. Roushan, J. Seo, L. Gorman, I.

Drozdov, Y. S. Hor, R. J. Cava and A. Yazdani,

Nature Phys., 7 (2011) 939.

[12] D. Soriano, F. Ortmann and S. Roche

(submitted)


Atomically precise construction and

electronic properties of dangling-

bond nanostructures on hydrogen

passivated Ge(001) surface 1 Centre for Nanometer-Scale Science and Advanced Materials (NANOSAM),

Department of Physics, Astronomy, and Applied Computer Science, Jagiellonian

University, Reymonta 4, PL 30-059, Krakow, Poland 2 Institute of Materials Research and Engineering, 3 Research Link,

Singapore 117602, Singapore 3 Department of Chemical and Biomolecular Engineering, National University of

Singapore, 4 Engineering Drive 4, Singapore 117576, Singapore 4 Nanosciences Group & MANA Satellite, CEMES-CNRS

29 rue Jeanne Marvig, F-31055 Toulouse, France

We report on studies concerning preparation of

well organized atomic wires and 2D nanopads by

tip-induced hydrogen desorption from hydrogen

passivated Ge(001) surface. Dangling-bond (DB)

nanostructures on the passivated surface are

fabricated using atomically precise STM tip-induced

dimer-by-dimer hydrogen desorption. We have

developed new, very efficient protocol allowing for

at will fabrication of pre-designed DB structures.

Their geometrical structure is characterized with

atomic resolution by means of LT-STM. High

resolution STM images of wires of different

orientation and lengths are in good agreement with

ESQC/SGFM calculations. Furthermore, the

electronic properties of the fabricated

nanostructures are examined by scanning tunneling

spectroscopy (STS) measurements allowing for

acquisition of the density of states spatial

distribution, which can be measured successfully

with a lateral resolution reaching an individual

dangling-bond. Deeper understanding of

experimental observations is provided by

calculations of surface electronic structure and

electron transport properties performed with semi-

empirical method fitted to first principles density

functional theory (DFT). Based on the example of

short DB wires we discuss the effect of through

surface and through space electronic coupling

between the created DBs, which results in

narrowing of the surface band gap with increasing

DB wire length.

Marek Kolmer1,

Szymon Godlewski1,

Bartosz Such1,

Hiroyo Kawai2,

Mark Saeys2,3

,

Christian Joachim2,4

and

Marek Szymonski1


Efficient biexciton emission

in single CdSe nanocrystals

LP2N, Université de Bordeaux, Institut d’Optique Graduate School & CNRS,

351 cours de la libération, 33405 Talence, France

Quantum-confined nanoparticles have been

increasingly investigated over the past decade due

to the superior efficiency and tunability of their

emission wavelength from the ultraviolet to the

near infra red. Among those nanoparticles, colloidal

CdSe nanocrystals (NC) are particularly attractive

for many applications such as nanoscale

electronics, laser technology, quantum

cryptography, and biological fluorescent labeling.

A detailed understanding of the NCs band-edge

exciton fine structure is crucial for these

applications. While intensive experimental and

theoretical work has been performed to describe

the size dependence of the exciton fine structure in

nearly spherical NCs, the shape dependence has

received much less attention despite recent

advances in NC growth methods which lead to a

greater control over shape distribution. Pioneering

theoretical and experimental investigations [1, 2]

have indicated that the shape dependence of NCs

can be as important as the size dependence in

terms of tuning their electronic and optical

properties. The elucidation of these shape effects

remains an experimental challenge which can be

addressed by the optical study of individual NCs,

where ensemble averaging over shape and size

distributions is suppressed.

Shape and size effects also govern the optical

response of NCs in the multiexcitonic regime,

where potential applications such as optical gain

are envisaged [3]. Despite the important role that

biexcitons play in the optics of NCs, it has been

practically impossible to observe the biexciton

recombination line in the PL of CdSe NCs under

continuous wave excitation, because of efficient

nonradiative Auger recombination [4].

This presentation will be focused on our recent

magneto-optical and time-resolved spectroscopic

investigations of single commercial qdot655

streptavidin conjugates NCs (comprising a core of

CdSe capped by a ZnS layer) as a function of

temperature. The remarkable photostability of

these NCs at low temperature led us to unveil the

spectral and temporal signatures of the emission

from the lowest exciton-fine-structure states [5,6],

trion emission [7] and biexciton emission [8].

Because of the NCs shape distribution, we find

various band-edge exciton fine structures that are

consistent with theoretical predictions for

elongated NCs. Furthermore, contrarily to what

was anticipated for “standard” CdSe-based core

shell NCs, we show evidence for spectral and

temporal signatures of highly efficient radiative

biexcitonic recombinations in this type of NCs.

Special attention will also be paid to the attractive

trion (charged exciton) emission properties for

potential applications in quantum information

processing.

References

[1] A. L. Efros et al., Physical Review B 54, 4843

(1996).

[2] J. T. Hu et al., Science 292, 2060 (2001).

[3] V. I. Klimov et al., Science 290, 314 (2000).

[4] V. I. Klimov et al., Science 287, 1011 (2000).

[5] L. Biadala et al., Physical Review Letters 103,

037404 (2009).

[6] L. Biadala et al., Physical Review Letters 105,

157402 (2010).

[7] Y. Louyer et al., Applied Physics Letters 96,

203111 (2010).

[8] Y. Louyer et al., Nano Letters 11, 4370 (2011).

Philippe Tamarat,

Yann Louyer, Mark Fernée,

Louis Biadala and

Brahim Lounis

[email protected]


TNT2012

Ab

st

ra

ct

s

Figure 1. Emission spectrum of a single CdSe/ZnS nanocrystal at 2 K, showing evidence for strong radiative biexciton

recombination.


Microemulsions as reaction media

for the synthesis of bimetallic

nanoparticles

Physical Chemistry Department, University of Vigo, E-36200 Vigo, Spain

Bimetallic nanoparticles are particularly attractive

due to their properties often differ markedly from

either of the constituent metals. Nowadays it is well-

known that the design and control of spatial

arrangement of both metals in bimetallic

nanoparticles are critical for exploiting their

potential applications. The properties of bimetal

nanoparticles strongly depend on their size,

structure and morphology, so it is of the utmost

importance to fully elucidate the mechanism

underlying the nucleation and growth of

nanoparticles. The fact that the nucleus evolves to a

particle by accumulating new layers implies that the

differences in nucleation rates of both metals would

strongly affect the metals segregation and final

nanoparticle sizes.

Because the synthetic route seems to be crucial to

determine final sizes and structures of bimetallic

nanoparticles, our study is focused on a concrete

method: the reverse microemulsion route. This

method is one of the most important methods to

control the particle size, because the surfactant-

stabilized droplets provide a microenvironment for

the preparation of nanoparticles by exchanging their

contents and preventing the excess aggregation of

particles. But microemulsion itself is a very

complicated system, and the dynamics of

intermicellar exchange plays an important role in the

kinetics [1, 2]. In line with our ongoing effort to study

the formation of simple and bimetallic nanoparticles

in microemulsions, we have aimed here to

investigate the nucleation and growth of bimetallic

nanoparticles and to provide a detailed insight into

the factors affecting nanoparticle structure and size.

The main concept used to describe nucleation is

related to the critical radius. Above this size, it is

favorable for the new phase to form; below this size,

the clusters will tend to dissolve rather than grow.

Monte Carlo simulations were carried out to

investigate the influence of critical nucleus sizes on

the structure and sizes of final bimetallic

nanoparticles. Because bimetallic particles are

composed by two different metals (A and B), which

can need a different minimum number of atoms to

form a stable nucleus, the algorithm distinguish two

critical nucleation numbers (nA* and nB*). In addition,

the possibility of heterogeneous nucleation (nucleus

composed by different metals) has also been

considered by including a new parameter (nAB*),

defined as the minimum number of metal atoms (A

or B) inside the same droplet needed to form a

heterogeneous nucleus capable of further growth.

In relation to the nanoparticle structure, core-shell

structures are expected when one metal reduces

faster than the other [3]. The study reveals that,

keeping equal the reduction rates of the two metals,

the final structure is also sensitive to changes in the

critical nucleus numbers, because these parameters

determine the rate of nucleation. Figure 1A shows

simulation results using equal reduction rates, a low

value of concentration (⟨cA⟩=⟨cB⟩=4 molecules of

reactant per droplet), a rigid film (f=5, kex=1) and

different critical nucleus sizes (nA* =1, nB* =9, nAB*

=4). In this figure the number of particles containing

different percentages of one of the metals (A: faster

nucleation metal) is monitored from the

nanoparticle core to the outside (layer by layer). One

can observe that the inner layers are composed by

the metal which nucleates faster, and composition

shows a progressive improvement towards a mix of

both metals as the process advances (from the inner

to the outer layers). Finally, the outer layers show an

enrichment in the slower nucleation metal.

Therefore this kind of structure can be considered a

core-shell, although it was obtained simulating two

metals with the same reduction rate. An increase in

the difference between nucleation rates of both

C. Tojo and F. Barroso

[email protected]


TNT2012

Ab

st

ra

ct

s

metals gives rise to a better segregation of metals in

the final nanoparticle. Likewise, as long as the

formation of heterogeneous seeds is faster, the

degree of alloying is greater. In addition, it is

observed that the difference in nucletion rates of

both metals is not the only parameter to determine

the metals segregation, playing the interdroplet

channel size a relevant role. In agreement with

experimental observations, the results also suggest

that the metal segregation can be avoid by using a

more flexible surfactant (see figure 1). These results

allow us to tune the experimental conditions for

designing specific bimetallic structures.

In relation to the nanoparticle sizes, three different

experimental behaviours have been found:

bimetallic nanoparticles can be significatively smaller

(negative deviation [4-7]), larger (positive deviation

[8]) or equal than individual monometallic

nanoparticles (no deviation [9, 10]). Because these

results were ascribed to a difference in the

nucleation process, we have carried out computer

simulations to study how nanoparticle sizes change

by using different combinations of the three critical

nucleus numbers. Our results show that a negative

deviation is obtained when heterogeneous critical

size nAB*, is smaller than the two homogeneous ones

(nA* and nB*), i.e., heterogeneous nucleation rate is

the fastest nucleation. On the contrary, to obtain

positive deviations the heterogeneous nucleation

must be slower than the homogeneous ones. Both

kind of deviations were obtained only if a rigid

surfactant film was used. Also relevant to the

discussion is the observation that no kind of

deviation could be obtained when different

reduction rates ratios were simulated. Therefore,

the only factor affecting nucleation which can

explain the sizes deviations is the different rate in

heterogenous and homogeneous nucleation. Direct

comparison between experimental and simulation

results is not possible, because to the best of our

knowledge, no experiment has ever directly

measured the size of the critical nucleus.

The simulation results are expected to contribute to

developing advanced strategies for the design

nanostructured particles.

References

[1] R.P. Bagwe, K.C. Khilar, Langmuir, 16 (2000) 905.

[2] M.A. López-Quintela, C. Tojo, M.C. Blanco, L.

García-Río, J.R. Leis, Curr. Opin. Colloid Interface.

Sci., 9 (2004) 264.

[3] C. Tojo, M. de Dios, M.A. López-Quintela, J. Phys.

Chem. C, 113 (2009) 19145.

[4] M. Wu, D. Chen, T. Huang, Langmuir, 17 (2001)

3877.

[5] A. Habrioux, W. Vogel, M. Guinel, L. Guetaz, K.

Servat, B. Kokoh, N. Alonso-Vante, Phys. Chem.

Chem. Phys., 11 (2009) 3573.

[6] M. Wu, D. Chen, T. Huang, Chem. Mater., 13

(2001) 599.

[7] M. Wu, L. Lai, Coll. Surf.A, 244 (2004) 149.

[8] J. Santhanalakshmi, P. Venkatesan, J. Nanopart.

Res., 13 (2011) 479.

[9] L.M. Magno, W. Sigle, P.A.v. Aken, D.G.

Angelescu, C. Stubenrauch, Chem. Mater., 22

(2010) 6263.

[10] F.J. Vidal-Iglesias, J. Solla-Gullón, V. Montiel, J.M.

Feliu, A. Aldaz, J. Power Sources, 171 (2007) 448.

Figure 1. Number of particles versus the percentage of one of the products (A), from the nanoparticle

core to the outside (layer by layer) using different surfactant flexibilities, and remaining constant

critical sizes (nA* =1, nB* =9, nAB*=4), concentration ⟨cA⟩=⟨cB⟩=4, ⟨cR⟩=8, and reduction rates vA=vB.

0

50

100

150

200

0

1

234567891011

01

23

45

67

8910

number of particles

layers

% metal A

A

f=5

B

f=30 C

f=90

0

10

20

30

40

50

60

70

0

1

2

3

4567891011

01

23

45

67

89

10

layers

% metal A

0

5

10

15

20

25

0

1

2

3

4567891011

01

23

45

67

89

10

layers

% metal A

B

f=30C

f=90

very flexible filmflexible film

rigid film


Small molecule organic

photovoltaics at the nanoscale

McGill University, Montreal, Canada

Organic photovoltaics (OPVs) are a sustainable

method of solar energy harvesting with possible

fabrication advantages over more developed

inorganic semiconductor solar cells. However, the

power conversion efficiency of OPV devices is

currently about 8.6%, compared to over 20% for

crystalline silicon and up to 43.5% for triple junction

inorganic solar cells [1-4]. The structure of solar

harvesting device active layers is crucial to

performance [5-7], but little is currently known

about the specific loss mechanisms responsible. We

present a preliminary study of structure-function

relationships in thin films of organic photovoltaic

materials by simultaneous non-contact atomic

force microscopy (NC-AFM) and Kelvin probe force

microscopy (KPFM).

Thin films of small electron donor and electron

accepter molecules were thermally evaporated on

KBr (001) surfaces under ultra-high vacuum. Local

contact potential difference and topography were

mapped with simultaneous KPFM and NC-AFM to

investigate corresponding optoelectronic and

structural properties at the nanometre scale. Light

may be coupled into the UHV AFM system to

illuminate samples during imaging, thus allowing

characterization of active OPV materials during the

generation of excitons and charge carriers. Our

early results demonstrate that combined NC-AFM

and KPFM is a powerful approach to studying

fundamental physical processes in photovoltaic

power generation. Understanding structure-

function relationships in OPVs will contribute to the

advancement of renewable energy light harvesting

devices that are clean, efficient and affordable.

Figure 1. Illustration depicting possible structure-

dependent OPV efficiency loss mechanisms under

investigation. (a) Charge flow dependent on molecular

anisotropy and bottleneck structure, (b) recombination

loss structure and the influence of defects.

References

[1] L. Kazmerski, Best Research-Cell Efficiencies Report, National Renewable Energy Laboratory (2011).

[2] S. H. Park, A. Roy, S. Beaupre, S. Cho, N. Coates, J.S. Moon, D. Moses, M. Leclerc, K. Lee, A.J. Heeger,

Nature Photonics 3 (2009) 297.

[3] Y. Liang, Z. Xu, J. Xia, S.T. Tsai, Y. Wu, G. Li, C. Ray, L. Yu, Adv. Mater. 22 (2010) E135.

[4] Martin A. Green, Keith Emery, Yoshihiro Hishikawa and Wilhelm Warta, Prog. Photovolt: Res. Appl. 18

(2010) 346.

[5] P.G. Nicholson and F.A. Castro, Topical Review, Nanotechnology 21 (2010) 492001.

[6] A. Liscio, V. Palermo and P. Samori, Accounts of Chemical Research 43 (2010) 541.

[7] D.C. Coffey and D.S. Ginger, Nature Materials 5 (2006) 735.

J.M. Topple,

Z. Schumacher,

A. Tekiel and P. Grutter

[email protected]


TNT2012

Ab

st

ra

ct

s

Figure 2. Volmer-Weber growth of islands of CuPc (electron donor) and PTCDI (electron

accepter) molecules on KBr (001). (a,c) 3D-rendered topography imaged by NC-AFM,

(b,d) local contact potential difference imaged by KPFM.


Atomistic models of charge

separation and recombination in

organic photovoltaics interfaces

Department of Chemistry,

University of Warwick, U.K.

The key process in organic photovoltaics cells is the

separation of an exciton, close to the

donor/acceptor interface into a free hole (in the

donor) and a free electron (in the acceptor). In an

efficient solar cell, the majority of absorbed

photons generate such hole-electron pairs but it is

not clear why such a charge separation process is

so efficient in some blends (for example in the

blend formed by poly(3-hexylthiophene) (P3HT)

and a C60 derivative (PCBM)) and how can one

design better OPV materials. The electronic and

geometric structure of the prototypical

polymer:fullerene interface (P3HT:PCBM) is

investigated theoretically using a combination of

classical and quantum simulation methods. It is

shown that the electronic structure of P3HT in

contact with PCBM is significantly altered

compared to bulk P3HT. Due to the additional free

volume of the interface, P3HT chains close to PCBM

are more disordered and, consequently, they are

characterized by an increased band gap. Excitons

and holes are therefore repelled by the interface.

This provides a possible explanation of the low

recombination efficiency and supports the direct

formation of “quasi-free” charge separated species

at the interface. This idea is further explored by

using a more general system-independent model

Hamiltonian. This talk will discuss how and when a

combination of computational and theoretical

models can truly contribute to organic electronics

and will provide few examples of genuine material

properties predictions based on computational

models.

References

[1] T. Liu, D.L. Cheung and A. Troisi A, Phys. Chem.

Chem. Phys. 2011, 13, 21461.

[2] D.P. McMahon, D.L. Cheung, Troisi A, J. Phys.

Chem. Lett. 2011, 2, 2737.

[3] A. Troisi, Chem. Soc. Rev. 2011, 40, 2347.

[4] A. Troisi, Organic Electronics 2011, 12, 1988.

Alessandro Troisi, Tao Liu,

Domenico Caruso,

David L. Cheung and

David P. McMahon

[email protected]


Present and perspectives on

dissemination and training in

nanotechnology in IberoAmerica:

Red NANODYF – CYTED

Mechanical Engineering Department, ETSI-ICAI Universidad Pontificia Comillas

Coordinator of NANODYF Network, Area 6 Science and Society, CYTED Program

Promoting the assimilation of contents of Nanotechnology involves action in dissemination, and formal

education in schools and universities. Iberoamerican countries have not specific plans in this important line

of action, which will result in a delay of their citizens compared to other regions. IberoAmerica cannot be

excluded from this process of dissemination and training in Nanotechnology because the future economy

trends will be structured around advances in nanotechnology, and because there is already a significant

Iberoamerican presence in research and development in Nanotechnology. So, that is the purpose and

mission of the "Jose Roberto Leite" Network of Dissemination and Education in Nanotechnology (NANODYF)

from the CYTED Program, which in its first year of work (2011) has detected what the current state of the

Outreach and Training nanotechnology in a group of countries representing the Iberoamerican region is; and

it aims to draw a future strategy to improve and enhance areas that are weak or even absent in the region.

Joaquín Tutor Sánchez


Superconductivity at

adatom/molecule-induced silicon

surfaces and interfaces National Institute for Materials Science,

1-1, Namiki, Tsukuba, Ibaraki 305-0044, Japan

The state-of-the-art nanotechnology has enabled

fabrication of ultrathin superconductors of high

crystallinity and with atomically controlled

thicknesses and interfaces. This has opened ways to

tune superconductivity [1,2] and to investigate the

thinnest crystalline layers for its emergence [3,4]. Notably, superconductivity was found to exist for

silicon surface reconstructions with metal adatoms

[5], which are the ultimate forms of thin epitaxial

films. This finding is, however, based on

spectroscopic evidence of superconducting energy

gaps observed by scanning tunneling microscopy

(STM). The very existence of supercurrent through

these surfaces has not been clarified yet and

important information such as critical current

density has been missing.

We have performed direct and macroscopic

electron transport measurements on a silicon

surface reconstruction with In adatoms (Si(111)-

(√7×√3)-In) in UHV at low temperatures [6]. The

superconducting transition is evidenced by

observations of the zero resistance state and of I −

V characteristics exhibiting sharp and hysteretic switching below 2.8 K ( ≡ Tc) (see Fig.1 and Fig.2).

This macroscopic supercurrent also shows a

significant robustness; the two-dimensional (2D)

critical current density J2D,c is estimated to be as

high as 1.8 A/m at 1.8 K. If the thickness of Si(111)-

(√7×√3)-In is assumed to be double the covalent

radius of In (= 0.30 nm), this corresponds to a 3D

critical current density of 6.1×109 A/m2, comparable to those of practical bulk

superconductors. The precise values of Tc and J2D,c

are dependent on sample preparation, suggesting

the importance of crystallinity of the surface

reconstruction layer. The observed temperature

dependence of critical current density J2D,c indicates

that the surface atomic steps serve as strongly

coupled Josephson junctions. The analysis based on

the Josephson junction model using the standard

Ambegaokar-Baratoff equation [7] allows us to

obtain the resistance of the atomic step. The value

is found to be consistent with that deduced from normal sample resistance.

Figure 1. Temperature dependence of zero bias

dependence of the Si(111)-(√7×√3)-In reconstruction.

The insets show the configurations of the four-terminal

measurements and an STM image of the sample surface.

The present study demonstrates that various

surface reconstructions of silicon and related

semiconductors could be used as practical

superconducting materials. To achieve this aim,

however, the surface metal-adatom layer should be

passivated and buried under a capping layer while the superconductivity remains intact, which poses a

new technical challenge. We present a trial for

passivation of surface superconducting layer with

molecular assembly [8]. We find that Co-

phthalocyanine molecules can be assembled in a

Takashi Uchihashi

[email protected]


TNT2012

Ab

st

ra

ct

s

highly ordered fashion on the Si(111)-( √7×√3)-In

surface by a simple sublimation method, while the

resulting layer still exhibits a signature of

superconducting transition. The fabrication of a molecular interface could also be used to tune the

properties of superconductivity by modifying the

phonon spectrum and by introducing magnetic

moments into molecules [9].

Figure 2. Temperature dependence of I-V characteristics

of the same sample, from which critical current Ic can be

determined. The inset shows that temperature

dependence of Ic.

References

[1] Y. Guo et al., Science 306 (2004) 1915.

[2] M. M. Özer et al., Nature Phys. 2 (2006) 173.

[3] S. Qin et al., Science 324 (2009) 1314. [4] C. Brun et al., Phys. Rev. Lett. 102 (2009)

207002.

[5] T. Zhang et al., Nature Phys. 6 (2010) 104.

[6] T. Uchihashi et al., Phys. Rev. Lett. 107, 207001

(2011); also see Viewpoint in Physics 4, 92

(2011).

[7] V. Ambegaokar and A. Baratoff, Phys. Rev.

Lett. 10 (1963) 486.

[8] B. N. Cotier et al., Appl. Phys. Lett. 78 (2001)

126. [9] T. Gang et al., Nature Nanotech. 7 (2012) 232.


Microstructural change of li(NiCo)O2

based materials of Li ion battery

during charge and discharg

TOYOTA Central Research & Development Laboratories Inc.,

480-1192 Yokomichi, Nagakute, Aichi Japan

1. Introduction

During charge and discharge of lithium-ion

batteries with Li(NiCo)O2 based positive active

materials, electrochemical reaction with lithium

intercalation /deintercalation proceeds reversibly.

The performance of Li(Ni,Co)O2 materials has been

studied by many authors. For example, we have

reported the fading mechanism of lithium ion

batteries with on LiNi0.8Co0.15Al0.05O2 as the positive

material and pointed out that the reaction and

diffusion resistances of positive electrode

drastically increased during durability test at high

temperatures. It was revealed that the

microstructural change of positive material played

a important role for resistance increase. In this

presentation, the microstructural change of

LiNi0.8Co0.15Al0.05O2 material investigated by various

methods, such as electrochemical techniques,

STEM, EELS, and XAFS. The cylindrical cells (18650-

type) of LiNi0.8Co0.15Al0.05O2 and artificial graphite

with carbonate electrolyte were used for durability

tests at high temperatures. The electrodes taken

out of the cells before and after durability tests

were evaluated by using various methods. The

LiNi0.8Co0.15Al0.05O2 materials before and after 1

cycle were also evaluated by STEM-EELS to

compare with the materials after long durability

test.

2. STEM analysis

The microstructural change near grain boundaries

before and after 1 cycle observed by using low

magnification STEM is shown in Fig.1. The grain

boundaries have thin grain boundary layers which

produce bright contrast indicate by arrows in Fig.1

(a). As shown in this figure, the thickness of some

grain boundary layers (indicated by arrows in b)

increased drastically and some microcracks are

found at triple points and grain boundaries.

According to the observation by high resolution

STEM, EELS and ED, it was revealed that the crystal

structure changes from ordered layer structure

(bulk) to disordered rock-salt structure (surface)

through partially ordered structure. The thickness

of grain boundary layer changed from about 5 nm

before first cycle to about 25 nm after first cycle.

This means that phase transition occurred

especially near at grain boundary (surface) during

intercalation / deintercation of lithium.

Figure 1. Low magnification STEM images fresh (a) and

after first cycle. The thickness of the grain boundary

layer (white contrast indicate by arrows) increased

drastically after first cycle [8].

3. XAFS analysis

The determination of the Ni valence before and

after durability test was conducted by using XAFS

method. The Ni K-edge spectra (XANES) after

durability test are shifted to lower energy. Fig.2

shows Ni valence determined by the energies from

the half-step heights of the Ni K-edge spectra as a

function of x in Li1-xNi0.8Co0.15Al0.05O2. As shown in

this figure, the Ni valence after durability test

Yoshio Ukyo, Yoji Takeuchi

and Yoshinari Makimura


TNT2012

Ab

st

ra

ct

s

decreased, especially near surface (CEY).In my

presentation, the fading mechanism of Li-ion

battery with Li1-xNi0.8Co0.15Al0.05O2 will be discussed

in detail based on the results obtained.

Figure 2. The dependence of Ni valence before and after

cycle test at high temperature on SOC (x in

Li1-xNi0.8Co0.15Al0.05O2) [2].

References

[1] Y. Itou et al, J. Power sources, 146 (2005) 39.

[2] T. Nonaka et al, J. Electrochem. Soc., 154

(2007) A353.

[3] T. Sasaki et al, J. Electrochem. Soc., 154 (2007)

A289.

[4] S. Muto et al, J. Electrochem. Soc., 154 (2007)

A371.

[5] T. Sasaki et al, J. Electrochem. Soc., 158 (2011)

A1214.

[6] T. Nonaka et al, J. Power sources, 162 (2006)

1329.

[7] H. Kondo et al, J. Power sources, 174 (2007)

1131.

[8] S. Zheng et al, J. Electrochem. Soc., 158 (2011)

A357.


Monitoring the oxygen content in

graphene oxide

Universidad de Alicante, 1Chemical Engineering Department,

University of Alicante, 03080 Alicante, Spain

The chemical derivation of graphene oxide

emerged as an easy route to obtain atomically thin

carbon sheets with the aim to obtain graphene in a

large scale. This graphene oxide (G-O) is decorated

with different oxygen groups that disrupt the

electronical properties of pristine graphene. The

real structure of graphene oxide has not yet been

fully understood, same as its predecessor, the

graphite oxide, which has been studied over

hundred years. Most of the studies, based in bulk

analysis of the graphene oxide such as TGA or XPS,

stated C/O ratios of 2:1 and variable oxygen

contents that range from 20 to 33% [1].

We have developed a particular synthesis method

to produce graphene oxide from helical ribbon

carbon nanofibers (HR-CNF). Our studies of the

quantification of the oxygen content comprised XPS

and TGA of the bulk powder and EDS and EELS of

single G-O sheets. XPS results were consistent with

the literature providing C/O ratios up to 2, while

the analysis of the sheets showed much less oxygen

content and, therefore, a higher C/O ratio. This

difference between the bulk and the sheet analysis

agrees with some recent studies that state that

most of the oxidation of the graphene oxide is due

to some debris attached to the sheets and not to

the oxygen covalently bonded [2].

This revelation indicates that the existing models of

graphene oxide, based on the results of bulk

analysis, should be submitted to debate. The

knowledge of the structure could lead to a better

enhancement of the properties of the graphene

oxide.

Here, we monitor by different techniques the

oxygen content in powder and exfoliated samples

of graphene oxide. We tried to find the

composition if a single graphene oxide sheet and

compared it with the content in the all bulk.

References

[1] Bagri, A., C. Mattevi, M. Acik, Y.J. Chabal, M.

Chhowalla, and V.B. Shenoy, Structural

evolution during the reduction of chemically

derived graphene oxide. Nat Chem, 2010. 2(7):

p. 581-587.

[2] Rourke, J.P., P.A. Pandey, J.J. Moore, M. Bates,

I.A. Kinloch, R.J. Young, and N.R. Wilson, The

Real Graphene Oxide Revealed: Stripping the

Oxidative Debris from the Graphene-like

Sheets. Angewandte Chemie International

Edition, 2011. 50(14): p. 3173-3177.

Helena Varela-Rizo,

Iluminada Rodriguez-

Pastor, Gloria Ramos-

Fernández

Ignacio Martín-Gullón

[email protected]


Postsynthetic asymmetric transformation

of boronic-acid-protected gold

nanoclusters studied by magnetic

circular dichroism (MCD) and electronic

circular dichroism (ECD)

Graduate School of Material Science, University of Hyogo, Hyogo 678-1297, Japan

Investigations of monolayer-protected metal

nanoclusters, possessing typically less than 100 atoms, are

largely motivated in the past decade due to their

intriguing size-dependent physicochemical properties.

Much attention is recently paid on inducing chirality in

metal nanoclusters owing to their widespread catalytic

use of chirally-modified metal surfaces. Postsynthetic

asymmetric transformation is one of the notable

techniques for facile control of symmetry-breaking [1].

Our approach here is to use gold nanoclusters bearing an

achiral boronic acid group that can bind to chiral cis-diols

such as fructose [2]. In addition, we also apply magnetic

circular dichroism (MCD) spectroscopy to gain a better

understanding of the nanoclusters’ electronic structures

as well as their chiroptical signals induced by their surface

fructose complexation. A relationship between the MCD

and normal (induced) CD responses is also examined, both

of which distinctly stem from the cluster’s electronic

transitions. We also find that this asymmetric induction is

pH-sensitive, suggesting that the gold cluster-fructose

complex formation has a great advantage for some

biological applications.

We synthesized 3-mercaptophenylboronic acid (3-MPB)-

protected gold clusters with a mean core diameter of 1.1

nm (gel fractioned), and examined their electronic

absorption, MCD and chiroptical responses induced by the

reaction of boronic acid-chiral fructose binding (Figure 1).

Note that the mean core size of the cluster was

determined by a solution-phase SAXS measurement.

Figures 2a and 2b show absorption and MCD spectra (at a

magnetic field of –1.6 T) of the gold nanocluster

compound in methanol/aqueous buffer (pH = 10.0)

mixture, respectively. It is well known that small gold

nanoparticles (< ~2 nm) no longer support the plasmon

excitation characteristic, so the structured absorption

comes from molecule-like electronic transitions. On the

other hand, the MCD spectrum shows overall positive

features in the metal-based electronic transition region at

–1.6 T. The MCD signals were very weak at > ~500 nm,

probably arising from transitions out of the HOMO into

LUMO (essentially intraband transitions), whereas

relatively strong MCD signals were detected at higher

energy transitions (< ~500 nm) that involve more or less

character of thiolate ligands. Hence it is expected that the

MCD responses of the thiolate-protected gold clusters

would primarily arise from the electronic state mixing of

the ligands and gold atoms. Note that the sign of the MCD

signal was completely reversed when the field is switched

(+1.6 T), confirming that signatures are not from an

experimental artifact but originate from real MCD signals.

Based on the MCD features, we deem that magnetic field-

induced mixing of electronic states of the ligands and

surface gold atoms would bring about the Faraday B-term,

because (i) a ground-state Zeeman splitting (at H = 1.6 T)

is in the order of 0.2 meV (if present), smaller than the

energy of room temperature (~26 meV), so the C-term

contribution should be trivial; (ii) the MCD response does

not contain any derivative line shape with respect to the

absorption peak, so the A-term contribution would be also

negligible [3].

Figure 1. Reaction scheme for the postsynthetic binding

between surface 3-MPB and chiral fructose bearing diols in

basic solution.

Figure 2. Absorption and MCD spectra (at -1.6 T) of the gold

nanocluster compound. Deconvoluted Gaussian band fits of

the electronic absorption and MCD spectra are also shown.

Hiroshi Yao and

Masanori Saeki

[email protected]


TNT2012

Ab

st

ra

ct

s

We next performed spectral deconvolution analysis of

both the absorption and MCD data to quantitatively

estimate accurate transition energies and their spectral

linewidths in the nanocluster since the MCD features

must correspond to electronic transitions (even

unresolved) in the electronic absorption. The Gaussian

fits of MCD as well as electronic absorption spectra are

also shown in Figure 2. For deconvoluting the

experimental data, we assumed that the analysis is

constrained by the requirement that a “single set” of

Gaussian components be used for the fitting of both

the absorption and the MCD spectra. For the excellent

(satisfactory) agreement between the measure and

calculated spectra, eight Gaussian components were

necessary. Importantly, the two different spectral

patterns have made the spectral deconvolution

analysis successful.

The pristine gold nanocluster had no optical activity.

However, D-/L-fructose addition to the nanocluster

solution altered CD responses. Figure 3a shows the CD

spectra of the gold nanocluster compound in the

presence of D-/L-fructose at pH=10.0. Note that

fructose did not induce significant absorption changes

of the gold nanocluster, strongly indicating that

complexation between the surface 3-MPB ligand and

chiral fructose hardly influenced the electronic states of

the clusters, and consequently, the gold core

rearrangement or size growth was unlikely to take

place upon complexation. On the other hand, the

nanocluster showed an appreciable Cotton effect with

complicated coupling patterns when complexed with

D- or L-fructose (that is, asymmetric induction).

Additionally, an almost perfect mirror-image

relationship was obtained in the region of metal-based

electronic transitions, implying enantiomeric

complexation.

To gain a better understanding of the structure (shape)

of CD spectra, we compare them with the peak-

separated bands obtained by the deconvolution

analysis. Figure 3b shows the induced CD and the

deconvoluted absorption spectra of the gold

nanocluster with D-fructose (10–3

M) plotted against

energy in wavenumber. For the guide of eyes, vertical

dash lines are drawn at the same energy positions. The

induced CD response is distinctly related to the peak-

separated bands; for example, the deconvoluted

spectra of 2, 3, 5, 6, and 7 exhibited negative, positive,

negative, positive, and negative peaks in the CD

response, respectively (see Figure 3b). The band 4

showed (+/–) split-type CD signal, implying an

interaction between the inclusive electronic transitions.

The spectrum 1 (the lowest energy component) seems

to be CD silent. In conclusion, the induced CD

signatures can be successfully correlated with the

isolated (separated) electronic transitions obtained by

deconvolution analysis based on the absorption and

MCD spectra. This spectral analysis is expected to

benefit better understanding of the electronic states

and the origin of the optical activity in chiral metal

nanoclusters.

Figure 3. (a) Effects of D-L- fructose on the CD spectrum of

the 3-MPB-protrctrd gold nanocluster in the methanolic

base solution. Green and red curves indicate the spectra

obtained upon addition of D- and L-fructose, respectively.

Mirror imagen relationship can be seen between them. (b)

Electronic absorption and CD spectra of the gold cluster in

the presence of chiral D-fructose (10-3

M). The data were

plotted against wavenumber. The deconvoluted spectra

with Gaussian function are also shown for ease of

comparison. (c) CD spectra of the nanocluster in the

presence of D-/L-fructose (10-3

M) in the methanolic acid

solution (pH = 1.68). Green and red curves indicate the

spectra obtained upon addition of D- and L-fructose,

respectively.

At the end, to confirm that the induced CD responses

are controllable by external parameters, we examined

pH-dependent optical activity of the 3-MPB-protected

gold cluster in the presence of chiral fructose. The

binding constant of the anionic boronate-diol is very

much larger than that of the neutral boronic acid-diol

[2], so that significant decomposition of the complexes

is highly expected in acidic conditions. Figure 3c shows

(induced) CD spectra of the gold nanocluster

compound in the presence of D-/L-fructose (10–3

M) in

methanol/aqueous oxalate buffer (pH=1.68). In

contrast to Figure 3a, no CD signals were detected,

suggesting no complexation of surface 3-MPB moieties

with chiral fructose. Interestingly, optical activity of the

gold nanoclusters can be simply controlled by external

parameters such as the pH value. This method will be a

powerful strategy to quantitatively induce optical

activity in a controlled manner.

References

[1] Yao, H. Kitaoka, M.; Sasaki, A. Nanoscale, 4

(2012) 955.

[2] Yao, H.; Saeki, M.; Kimura, K. J. Phys. Chem. C,

114 (2010) 15909.

[3] Stephens, P. J. Ann. Rev. Phys. Chem., 25 (1974)

201.


Laser heating control with polarized

light in isolated multi-walled carbon

nanotubes

Faculty of Physics, Warsaw University of Technology,

Koszykowa 75, 00-662 Warsaw, Poland

We are proposing a novel method of laser heating

control only through change in polarization of the

incident light, keeping its power density constant

[1]. The idea combines antenna effect found in

isolated multi-walled carbon nanotubes and the

possibility of their heating by light illumination. To

observe this we used Raman spectroscopy

technique (see fig. 1), where the heating manifests

itself in a pronounced downshift of the Raman G

and 2D lines as a function of the polarization angle

(see fig. 2). To our knowledge, this is the first

experimental demonstration of polarization

dependent heating effect in carbon nanotubes

probed by Raman spectroscopy or by any other

technique. Interpretation of the observed

phenomena will be discussed.

Figure 1. (a) Schematic of the experimental setup used

for exploring the dependence of the inelastic scattering

amplitude and phonon energy on the angle φ between

the carbon nanotube axis and the direction of the

electric field vector of the incident and scattered light.

(b) Raman spectrum from an isolated multiwalled

nanotube. (c) Atomic force microscopy image of isolated

MWCNT (d~ 30 nm) on the SiO2/Si substrate.

Our method can be useful in field electron emission

devices or in selective nanotubes heating and

destruction. It can also be extended to other one

dimensional nanoobjects, if only certain conditions

are fulfilled. We expect that the effect presented

here can be found in other high aspect ratio nano-

objects, if only localization of the electronic states

is high enough and/or they stay within the

electrostatic limit.

Figure 2. Angular evolution of G and 2D band positions

for two polarization configurations (VV and VH). Four

data series in a plot (a) acquired for the different laser

power densities (p1 >p2 >p3 >p4) prove the thermal origin

of the Raman shift change. Experimental data (open

symbols) were fitted with the cos2(φ) function (lines).

References

[1] M. Zdrojek, J. Judek, M. Wąsik, Phys. Rev. Let.

108, 225501 (2012)

Mariusz Zdrojek,

Jarosław Judek and

Michał Wąsik

[email protected]

Late Abstracts


Optical antennas: nanoscience

meets quantum optics

Department of Physics, Friedrich-Alexander University Erlangen-Nürnberg

& Max Planck Institute for the Science of Light,

Günther-Scharowsky-Str. 1 /Bldg. 24,

91058 Erlangen, Germany

The ultimate control of light-matter interaction is

achieved when a single emitter strongly interacts

with a single photon. A manipulation at the level of

single quanta is not only of fundamental interest

but is of special importance for emerging quantum

technologies, such as quantum information

processing. In this talk I will first briefly review our

experimental progress on the interaction of

strongly focused photons with a single molecule [1,

2]. Then I will discuss how optical antennas can be

used to enhance light-emitter interaction and how

the emission properties of a single emitter can be

dramatically altered. Two types of antennas are

presented. With a metallic nanoantenna [3], we

experimentally achieved a two orders of magnitude

reduction in the fluorescence lifetime of a single

molecule [4]. In another experiment we embedded

a single organic molecule in a planar dielectric

antenna, which directs the emission towards the

collection optics. We realized a single-photon

source with near-unity collection efficiency and a

record count rate of 50x106 photons per second

[5]. With the current design we collect 96% of the

photons emitted by a single molecule. Metallo-

dilectric antennas promise photon collection rates

exceeding 99% [6].

References

[1] J. Huang et al., Nature 460, 76 (2009).

[2] Y. Rezus et al., Phys. Rev. Lett. 108, 093601

(2012).

[3] H. Eghlidi et al., Nano Lett. 9, 4007 (2009).

[4] K.G. Lee et al., arXiv:1208.1113v1 (2012).

[5] K.G. Lee et al., Nat. Phot. 5, 166 (2011).

[6] X.-W. Chen et al., Opt. Lett. 36, 3545 (2011).

Stephan Götzinger

[email protected]


Environmental Effects

in Carbon Nanotube and

graphene-based Transistors

Département de Chimie, Université de Montréal, Montréal, Canada

Charge transfer doping by atmospheric gas is

ubiquitous in carbon-based field-effect transistors

(FETs), but this important phenomenon is yet

poorly understood. This talk will mainly discuss our

recent investigation on the origin of air doping and

on its signatures in the electrical, optical and

thermoelectric properties of carbon nanotube and

graphene devices.

Figure 1. Transfer characteristics for a 1 μm long

individual SWNT FETs in air. (a) A device on SiO2 and (b)

on parylene. In black is the forward gate voltage scan

and in red the reverse scan. The source-drain bias

voltage was Vsd = -1 V.

By using both carbon nanotube (Figure 1) and

graphene layers (Figure 2) as testbeds, we first

measured the influence of the chemical nature of

the substrate and the impact of different gas

exposure on the switching behaviour of both

nanoscale and thin-film FETs. Our studies revealed

that electrochemical charge transfer doping by the

water/oxygen redox couple is the underlying

mechanism behind the environmental effects in

most nanodevices (Figure 3). A solution to control

the air doping using plastic substrates was provided

and the kinetics of the charge transfer process was

monitored using graphene FETs [1,2]. The results

are quantitatively described using the Marcus-

Gerischer theory on charge transfer. Here we will

present the results and conclusions of our studies

and provide hint for controling the air-doping effect

in nanotube [1] and graphene devices [2,3].

Figure 2. Air effect on graphene FET with different

substrates. (A) Graphene on SiO2 and (B) graphene on

parylene. — (Red) Transfer characteristics of graphene

FETs measured in vacuum at room temperature after a 4

hour anneal at 400K. — (Cyan) Characteristics measured

after 30 minutes in air.

In a second study, we report the observation of the

optical signatures of doping and disorder in the

mid-infrared (MIR) absorption spectra of single-

walled carbon nanotubes (SWNTs) [4]. An

asymmetric line shape of the SWNT phonon modes

at ~870 and ~1600 cm-1

is characteristic of a Fano

resonance (Figure 4). This kind of resonance is

indicative of the presence of a strong e-ph

interaction and stems from the scattering of an

electronic continuum onto a phonon discrete

mode. The π phase shift of the wavefunction in the

neighborhood of the resonance creates destructive

interferences, which are seen as a dip in the

spectrum. According to theoretical calculations, the

bands at ~870 and ~1600 cm-1

are ascribed to oTO

and iTO infrared active phonon modes, respectively

Richard Martel

[email protected]


TNT2012

Ab

st

ra

ct

s

[5]. A supplementary mode is observed at

~1260 cm-1

, which corresponds to a defect mode,

the so-called "D-band" in Raman spectroscopy. Our

results are in agreement with previous studies of

SWNTs in the MIR, though prior works failed to

recognize the role of e-ph interactions on these

infrared bands [6]. We also found that the e-ph

coupling broadens the phonon modes, which also

shifts to higher energy compared to the uncoupled

state. Finally, the influence of defects on the MIR

cross-section of Fano resonances was explored by

functionalization of SWNTs with bromophenyl

moieties. We measured that the absorption cross-

section increases when defects are induced in the

wall in comparison to undamaged SWNTs in the

same doping state. We therefore propose that the

Fano resonances are activated in two ways: First,

increasing the number of charge carriers leads to

an increase in the number of scattering events and

in intraband continuum absorption; second, the

creation of defects lowers the symmetry and

relaxes the selection rules. Similar Fano resonances

in single layer graphene will also be discussed.

Figure 3. Electron-transfer mechanism within the

Marcus-Gerischer theory. Schematic of the

water/oxygen redox couple density of states (DOS) for

an equivalent concentration of oxidizing and reducing

species and a comparison with the SWNT DOS (left) and

graphene DOS (right). The arrow indicates the direction

of the charge transfer reaction.

In a third study, P-doping by air exposure and N-

doping by local potassium (K) deposition was used

to prepare a suspended carbon nanotube film

having a PN doping profile between two metal

contacts. The electrical response of this PN device

was studied using laser excitation and temperature

gradients. The device response is best described in

terms of a thermal mechanism that is independent

of the nanotube-metal barrier. Moreover, we show

using estimates of the local Seebeck coefficients

that a PN junction in a suspended nanotube film

behaves as a thermopile. The performances of the

novel nanotube thermopile will be presented and

compared to state-of-the-art SWNT bolometers [7].

Figure 4. MIR spectra of an intrinsic and doped SWNT

film. Arrows indicate the phonon modes and the

presence of the Fano resonance. Inset: NIR-vis spectra of

the SWNT film.

This work was done in collaboration with Pierre

Lévesque, François Lapointe, Carla M. Aguirre,

Benoit Cardin-St-Antoine, Patrick Desjardins, David

Ménard and T. Szkopek.

References

[1] C. M. Aguirre, P. Levesque, M. Paillet, F.

Lapointe, B. C. St-Antoine, P. Desjardins and R.

Martel, Adv. Mat.. 21, 3087-3091 (2009).

[2] S. S. Sari, P. Lévesque, C. M. Aguirre, J.

Guillemette, R. Martel and T. Szkopek, Appl.

Phys. Lett. 95, 242104 (2009).

[3] P. L. Lévesque, S. S. Sabri, C. M. Aguirre, J.

Guillemette, M. Siaj, P. Desjardins, T. Szkopek,

R. Martel, Nano Letters, 11, 132-135 (2011).

[4] F. Lapointe, E. Gaufrès, I. Tremblay, N. Y-Wa

Tang, P. Desjardins and R. Martel, Phys. Rev.

Lett. 109, 097402 (2012).

[5] Jeon, G. S. & Mahan, G. D. Phys. Rev. B 72

155415 (2005).

[6] Bantignies, J.-L. et al. Phys. Rev. B 74 195425

(2006).

[7] B. C. St-Antoine and D. Ménard, Nano Letters,

11, 609-613 (2011); B. C. St-Antoine, David

Ménard and R. Martel, Nano Research, 5, 73-

81 (2012).

Posters list:

alphabetical ord

er

authors

authors

authors

authors

country

country

country

country

topic

topic

topic

topic

poster title

poster title

poster title

poster title

student

student

student

student

senior

senior

senior

senior

Ab

uin

, M

an

ue

l

Spai

n

Nan

om

agn

eti

sm a

nd

Spin

tro

nic

s "M

agn

eti

c d

om

ain

str

uct

ure

of

Co

ult

ra-t

hin

isla

nd

s o

n R

u”

stu

de

nt

B. S

anto

s, A

. Mas

cara

qu

e, M

. Mai

cas,

L.

Pé

rez,

E. M

iral

les,

A. Q

ue

sad

a, A

. T

.

N´D

iaye

, A. K

. Sch

imd

an

d J

. de

la F

igu

era

Alb

en

iz,

Sa

ioa

Sp

ain

N

ano

fab

rica

tio

n t

oo

ls &

n

ano

scal

e in

tegr

atio

n

"Syn

the

sis

and

ch

arac

teri

zati

on

of

nan

ofi

llers

bas

ed

on

mo

dif

ied

cl

ay m

ate

rial

s"

stu

de

nt

M.A

. Vic

ente

, R. T

rujil

lan

o, S

.A. K

ori

li, A

. Gil

Alb

uq

ue

rqu

e,

Eu

de

nil

son

Bra

zil

Low

dim

en

sio

nal

mat

eri

als

(nan

ow

ire

s, c

lust

ers

,

qu

antu

m d

ots

, etc

.)

"Ele

ctro

nic

Sp

ect

ra o

f C

alci

um

Car

bo

nat

e P

oro

us

Nan

ost

ruct

ure

d

Mat

eri

al"

sen

ior

U.L

. Fu

lco

, C.A

. Bar

bo

za, a

nd

E. M

ore

ira

Ba

rutc

a,

Ba

nu

Tu

rke

y R

isks

-to

xici

ty-r

egu

lati

on

s "E

valu

atio

n o

f th

e C

yto

toxi

c an

d G

en

oto

xic

Po

ten

tial

of

TiO

2

Nan

op

arti

cle

s"

stu

de

nt

Gu

ne

s A

lp Y

akab

oyl

u, H

atic

e G

en

c, K

en

an

Isik

, A. T

ansu

Ko

par

al, E

nd

er

Suva

ci

Ba

sto

s, J

uli

o

Spai

n

Nan

oC

he

mis

try

"Mo

rph

olo

gica

l ch

ange

s o

f ge

l–ty

pe

fu

nct

ion

al p

oly

me

rs a

fte

r

inte

rmat

rix

syn

the

sis

of

po

lym

er

stab

ilize

d s

ilve

r n

ano

par

ticl

es"

st

ud

en

t M

aría

Muñ

oz

, Dm

itri N

Mur

avie

v, P

atri

cia

Rui

z

Ba

tes,

Je

ffre

y R

C

anad

a N

ano

fab

rica

tio

n t

oo

ls &

n

ano

scal

e in

tegr

atio

n

"Un

inte

nd

ed

Co

nse

qu

en

ces

of

Focu

sed

Ion

Be

am M

illin

g o

n

Nan

ost

en

cil L

ith

ogr

aph

y"

stu

de

nt

Y. M

iyah

ara

, J. A

. J. B

urg

ess

, O. I

gle

sia

s-Fr

iere

an

d P

. Gru

tte

r

Be

lan

dri

a,

Ed

ga

r

Ve

ne

zue

la

Low

dim

en

sio

nal

mat

eri

als

(nan

ow

ire

s, c

lust

ers

,

qu

antu

m d

ots

, etc

.)

"Ram

an e

ffe

ct in

car

bo

n n

ano

tub

es

fille

d w

ith

nan

ow

ire

s"

sen

ior

E. F

lah

aut

and

J. G

on

zále

z

Blá

zqu

ez

Ca

stro

, A

lfo

nso

Sp

ain

N

ano

bio

tech

no

logi

es

&

Nan

om

ed

icin

e

"Ph

oto

toxi

city

ind

uce

d b

y Ir

on

-do

pe

d L

iNb

O3 n

ano

par

ticl

es

in

hu

man

tu

mo

r ce

lls"

sen

ior

J. E

spad

a, J

.C. S

tock

ert

, F. A

gulló

-Ló

pe

z, A

.

Gar

cía-

Cab

añe

s an

d M

. Car

rasc

osa

Bo

rha

ni,

Ba

ha

reh

Ir

an

Nan

oC

he

mis

try

"Pre

par

atio

n a

nd

ch

arac

teri

zati

on

of

po

lyp

rop

yle

ne

/

MgA

l 2O

4.M

gO n

ano

com

po

site

s"

stu

de

nt

Mo

hse

n M

oh

sen

-Nia

On

ly P

ost

ers

sub

mit

ted

by

regi

ster

ed p

arti

cip

ants

an

d

pay

men

t p

roce

ssed

are

lis

ted

bel

low

.

authors

authors

authors

authors

country

country

country

country

topic

topic

topic

topic

poster title

poster title

poster title

poster title

student

student

student

student

senior

senior

senior

senior

Ca

gia

o,

Mª

Esp

era

nza

Sp

ain

N

ano

stru

ctu

red

an

d

nan

op

arti

cle

bas

ed

mat

eri

als

"Stu

dy

of

wea

ther

eff

ect

on

pvd

f/p

mm

a b

ased

ble

nd

co

atin

gs a

gein

g:

infl

uen

ce o

f ar

tifi

cial

age

ing

(xen

ote

st)

and

ne

utr

al s

alin

e f

og"

se

nio

r F.

Z.B

en

abid

, F.Z

ou

ai, S

.Bo

uh

ela

l an

d D

.

Be

nac

ho

ur

Ca

na

leja

s T

eje

ro,

Víc

tor

Spai

n

Oth

er

"Ult

rase

nsi

tive

No

n-C

he

mic

ally

Am

plif

ied

Ne

gati

ve-T

on

e E

lect

ron

Be

am L

ith

ogr

aph

y R

esi

st"

stu

de

nt

S. C

arra

sco

,F. N

avar

ro-V

illo

slad

a, M

.C.

Cap

el-

Sán

che

z, J

.L. G

arcí

a Fi

err

o, M

.C.

Mo

ren

o-B

on

di,

C.A

. Bar

rio

s

Ca

rto

ixa

, X

av

ier

Spai

n

Oth

er

"Co

nd

uct

ance

Qu

anti

zati

on

in R

esi

stiv

e S

wit

chin

g"

sen

ior

Shib

ing

Lon

g, C

arlo

Gag

li, R

icca

rdo

Ru

rali,

En

riq

ue

Mir

and

a, D

avid

Jim

én

ez,

Ju

lien

Bu

ckle

y, M

ing

Liu

an

d J

ord

i Su

ñé

Ce

rpa

, A

risb

el

Spai

n

Nan

om

agn

eti

sm a

nd

Spin

tro

nic

s

"Hys

tere

sis

loo

ps

and

mag

ne

tic

susc

ep

tib

ility

fo

r d

iffe

ren

t

ori

en

tati

on

an

gle

of

ori

en

ted

car

bo

n n

ano

tub

es

usi

ng

VSM

an

d

SQU

ID"

sen

ior

Dan

iel C

alle

,Eliz

abe

tta

Ago

stin

elly

,

Gas

par

e V

arva

ro, V

ivia

na

Ne

gri,

Seb

asti

án

Ce

rdán

, Pal

om

a B

alle

ste

ros

Ch

an

dra

vil

as,

Pra

sha

nt

Ind

ia

Nan

ob

iote

chn

olo

gie

s &

Nan

om

ed

icin

e

"Siz

e D

ep

en

de

nt

Dif

fere

nti

al Im

mu

ne

Re

spo

nse

wit

h P

oly

-ε-

cap

rola

cto

ne

Nan

op

arti

cle

s-A

n in

vit

ro s

tud

y"

stu

de

nt

Pra

shan

t, C

.K.,

Mad

hu

sud

an B

ha

tt, M

ano

j

Gau

tam

, A.K

.Din

da

Ch

oi,

Do

o-S

un

Ko

rea

Nan

oO

pti

cs

Nan

oP

ho

ton

ics

Pla

smo

nic

s

"Co

lori

ng

of

inje

ctio

n m

old

ed

pla

stic

pla

te b

y su

rfac

e

nan

ost

ruct

ure

s w

ith

ou

t p

igm

en

t"

sen

ior

Ye

on

g-E

un

Yo

o, J

ae-S

un

g Y

oo

n

De

la

Pri

da

, V

icto

r M

an

ue

l

Spai

n

Nan

om

agn

eti

sm a

nd

Spin

tro

nic

s

"Ele

ctro

pla

tin

g an

d m

agn

eto

-str

uct

ura

l ch

arac

teri

zati

on

of

mu

ltila

yere

d C

o5

0N

i 50/C

o8

0N

i 20 n

ano

wir

es

fro

m s

ingl

e

ele

ctro

che

mic

al b

ath

in a

no

dic

alu

min

a te

mp

late

s"

sen

ior

V. V

ega

, L. I

gle

sias

, J. G

arcí

a, D

. Gö

rlit

z, K

.

Nie

lsch

, E. D

íaz

Bar

riga

-Cas

tro

, R.

Me

nd

oza

-Ré

sen

de

z, A

. Po

nce

, C. L

un

a

De

hli

ng

er,

Ma

ël

Fran

ce

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Op

tica

l an

d s

tru

ctu

ral p

rop

ert

ies

of

Al d

op

ed

Zn

O n

ano

-

stru

ctu

red

film

s fo

rme

d b

y So

l-G

el p

roce

ssin

g"

sen

ior

Car

ole

Fau

qu

et,

An

na

Re

yme

rs, V

lad

imir

Ge

vorg

yan

, Ala

in R

angu

is, D

amie

n

Ch

aud

anso

n, A

rtak

Kar

ape

tyan

an

d

Wla

dim

ir M

arin

e

De

ng

, C

he

nx

ing

Fran

ce

Gra

ph

en

e /

Car

bo

n

nan

otu

be

s b

ase

d

Nan

oe

lect

ron

ics

and

fie

ld

em

issi

on

"Ob

serv

atio

n o

f lo

w-f

ield

mag

ne

tore

sist

ance

in g

rap

he

ne

at

roo

m

tem

pe

ratu

re"

stu

de

nt

Lin

Xia

oya

ng,

Li W

eiw

ei,

Kai

li Ji

ang,

Daf

iné

Rav

elo

son

a, C

lau

de

Ch

app

ert

, We

ish

en

g

Zhao

authors

authors

authors

authors

country

country

country

country

topic

topic

topic

topic

poster title

poster title

poster title

poster title

student

student

student

student

senior

senior

senior

senior

Día

z G

arc

ía,

Ele

na

Spai

n

Nan

om

agn

eti

sm a

nd

Spin

tro

nic

s "S

pin

se

lect

ive

tra

nsp

ort

th

rou

gh h

elic

al m

ole

cula

r sy

ste

ms"

se

nio

r R

. Gu

tie

rre

z, R

. Raa

man

an

d G

. Cu

nib

ert

i

Do

mè

ne

ch G

arc

ía,

Be

rta

Spai

n

Nan

oC

he

mis

try

"De

velo

pm

en

t o

f n

ew

Po

lym

er-

Me

tal-

Nan

oco

mp

osi

tes

bas

ed

on

ac

tiva

ted

fo

ams

and

te

xtile

fib

ers

an

d t

he

ir c

atal

ytic

eva

luat

ion

."

stu

de

nt

K. Z

iegl

er,

J. M

acan

ás, F

. Car

rillo

, M.

Mu

ño

z, D

.N. M

ura

vie

v

Do

shi,

Nil

ay

U

nit

ed

Ara

b

Em

irat

es

Nan

ofa

bri

cati

on

to

ols

&

nan

osc

ale

inte

grat

ion

"N

ano

fab

rica

tio

n o

f n

ano

scal

ed

inte

grat

ed

cir

cuit

ch

ips"

st

ud

en

t

Eb

rah

imiN

eja

d,

Sa

lma

n

Iran

N

ano

mat

eri

als

for

En

erg

y "C

om

pre

ssiv

e B

uck

ling

of

Bo

ron

Nit

rid

e N

ano

tub

es

wit

h H

ydro

gen

Sto

rage

" st

ud

en

t A

li Sh

oku

hfa

r, A

min

Ho

sse

ini-

Sad

egh

,

Ab

olf

azl Z

are

-Sh

ahab

ad

i

En

cule

scu

, Io

nu

t

Ro

man

ia

Low

dim

en

sio

nal

mat

eri

als

(nan

ow

ire

s, c

lust

ers

,

qu

antu

m d

ots

, etc

.)

"In

flu

en

ce o

f m

eta

llic

nan

ost

ruct

ure

s o

n t

he

op

tica

l pro

pe

rtie

s o

f

dye

-do

pe

d p

oly

me

r th

in f

ilms"

se

nio

r E

. Mat

ei,

I. E

ncu

lesc

u, C

. Tra

utm

ann

Ev

an

ge

lou

, S

ofi

a

Gre

ece

Nan

oO

pti

cs

Nan

oP

ho

ton

ics

Pla

smo

nic

s

"Eff

ect

s o

f a

Pla

smo

nic

Nan

ost

ruct

ure

on

Ke

rr N

on

line

arit

y in

a

Fou

r-Le

vel Q

uan

tum

Sys

tem

" st

ud

en

t V

assi

lios

Yan

no

pap

as, E

mm

anu

el P

asp

alak

is

Fa

teix

a,

Sa

ra

Po

rtu

gal

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Eff

ect

of

no

ble

me

tal n

ano

par

ticl

es

on

th

e g

lass

tra

nsi

tio

n

tem

pe

ratu

re o

f p

oly

(t-b

uty

lacr

ylat

e)

com

po

site

s"

stu

de

nt

An

a L.

Dan

iel-

da-

Silv

a, N

oé

mi J

ord

ão, A

na

Bar

ros-

Tim

mo

ns,

Tit

o T

rin

dad

e

Fig

ue

rola

, A

lbe

rt

Spai

n

Low

dim

en

sio

nal

mat

eri

als

(nan

ow

ire

s, c

lust

ers

,

qu

antu

m d

ots

, etc

.)

"Go

ld-C

atal

yze

d G

row

th o

f C

ollo

idal

Cad

miu

m C

hal

coge

nid

e

Wo

rm-l

ike

Nan

ost

ruct

ure

s"

sen

ior

Víc

tor

Fern

ànd

ez-A

ltab

le a

nd

An

dre

a Fa

lqu

i

Fil

ik,

Ha

ya

ti

Tu

rke

y N

ano

Ch

em

istr

y "P

rep

arat

ion

of

Pla

tin

um

Nan

op

arti

cle

s-G

rap

he

ne

Mo

dif

ied

Ele

ctro

de

an

d S

en

siti

ve D

ete

rmin

atio

n o

f P

arac

eta

mo

l"

sen

ior

Gam

ze Ç

eti

nta

ş, A

siye

Asl

ıhan

Ava

n,

Serk

an N

aci K

oç,

İsm

ail B

oz

Flo

rica

, C

am

eli

a

Ro

man

ia

Low

dim

en

sio

nal

mat

eri

als

(nan

ow

ire

s, c

lust

ers

,

qu

antu

m d

ots

, etc

.)

"Ele

ctri

cal p

rop

ert

ies

of

ZnO

sin

gle

nan

ow

ire

s co

nta

cte

d b

y FI

BID

and

EB

L"

stu

de

nt

Ge

org

ia Ib

ane

scu

, Ele

na

Mat

ei,

Nic

ole

ta

Pre

da,

Mo

nic

a E

ncu

lesc

u, M

aria

Eu

gen

ia

To

imil

Mo

lare

s, Io

nu

t E

ncu

lesc

u

Fra

nk

ov

a,

Jan

a

Cze

ch

Re

pu

blic

Nan

ob

iote

chn

olo

gie

s &

Nan

om

ed

icin

e

"In

flu

en

ce o

f si

lve

r n

ano

par

ticl

es

on

in v

itro

wo

un

d h

eal

ing

mo

de

l"

sen

ior

Ad

éla

Gal

and

áko

vá, H

ana

Vág

ne

rová

,

Bo

hu

mil

Zále

šák

an

d J

itka

Ulr

ich

ova

authors

authors

authors

authors

country

country

country

country

topic

topic

topic

topic

poster title

poster title

poster title

poster title

student

student

student

student

senior

senior

senior

senior

Fu

lco

, U

mb

ert

o

Bra

zil

Gra

ph

en

e /

Car

bo

n

nan

otu

be

s b

ase

d

nan

oe

lect

ron

ics

and

fie

ld

em

issi

on

"Ele

ctro

nic

Tra

nsp

ort

in Q

uas

ipe

rio

dic

Gra

ph

en

e p

–n

–p

Ju

nct

ion

s"

stu

de

nt

E.L

. Alb

uq

ue

rqu

e a

nd

M.S

. Vas

con

celo

s

Ga

lan

dá

ko

vá

, A

dé

la

Cze

ch

Re

pu

blic

Nan

ob

iote

chn

olo

gie

s &

Nan

om

ed

icin

e

"Bio

logi

cal e

ffe

cts

ind

uce

d b

y si

lve

r an

d g

old

nan

op

arti

cle

s: in

vitr

o s

tud

y."

sen

ior

Jan

a Fr

anko

vá, K

lára

Hab

arto

vá, B

oh

um

il

Zále

šák,

Jit

ka U

lric

ho

vá

Ga

ldik

as,

Arv

aid

as

Lith

uan

ia

Nan

oC

he

mis

try

"Mo

de

ling

of

Dif

fusi

on

Pro

cess

in N

ano

size

d P

ero

vski

te L

aCo

O3

Po

wd

er

Cat

alys

ts"

sen

ior

N. B

ion

, S. R

oye

r, D

. Du

pre

z, D

. Sid

abra

Ga

rcía

-Ga

rcía

, E

nri

qu

e

Spai

n

Hig

h s

pat

ial r

eso

luti

on

spe

ctro

sco

pie

s u

nd

er

SPM

pro

be

"Te

rah

ert

z T

ime

Do

mai

n S

pe

ctro

sco

py

for

mo

lecu

les

insp

ect

ion

:

wat

er

vap

or

and

dru

gs"

stu

de

nt

Yah

ya M

ou

bar

ak M

ezi

ani,

Jesú

s E

nri

qu

e

Ve

lázq

ue

z-P

ére

z an

d J

aim

e C

alv

o-G

alle

go

Ga

rrig

a,

Ro

sa

Spai

n

Nan

oC

he

mis

try

"Go

ld N

ano

par

ticl

e D

eco

rati

on

of

Car

bo

n N

ano

tub

es

and

Gra

ph

en

e:

Syn

the

sis,

Ph

ysic

al-C

he

mic

al C

har

acte

riza

tio

n, a

nd

Ap

plic

atio

ns"

sen

ior

An

dré

s Se

ral-

Asc

aso

, Asu

nci

ón

Lu

qu

in,

Mar

ian

o L

agu

na,

Ge

rmán

F. d

e la

Fu

en

te

and

Ed

gar

Mu

ño

z

Ga

spa

r, V

ito

r P

ort

uga

l N

ano

bio

tech

no

logi

es

&

Nan

om

ed

icin

e

"Ce

ll In

tern

aliz

ing

and

pH

-re

spo

nsi

ve C

hit

osa

n N

ano

par

ticl

es

for

Imp

rove

d D

eliv

ery

of

DN

A B

iop

har

mac

eu

tica

ls"

stu

de

nt

F. S

ou

sa, R

O L

ou

ro, J

A Q

ue

iro

z, IJ

Co

rre

ia

Ga

va

Ma

rin

i, V

an

de

rle

ia

Bra

zil

Nan

oC

he

mis

try

"Ze

in n

ano

par

ticl

es

as a

car

rie

r sy

ste

m f

or

terp

ine

n-4

-ol"

se

nio

r Si

lvia

Mar

ia M

arte

lli, C

lari

ce F

ed

oss

e

Zorn

io,T

hia

go C

aon

, Clá

ud

ia M

aria

O

live

ira

Sim

õe

s a

nd

Val

dir

So

ldi

Gic

qu

el-

Gu

ézo

, M

au

d

Fran

ce

Nan

oO

pti

cs

Nan

oP

ho

ton

ics

Pla

smo

nic

s

"Ph

oto

nic

s b

ase

d o

n c

arb

on

nan

otu

be

s"

sen

ior

Q.

Gu,

F.

Gri

llot,

S. L

oua

lich

e, J

. Le

Pou

liqu

en,

T. B

atte

, O

.Deh

aese

, A

. Le

Co

rre,

L. B

ram

erie

, D

. B

osc

,L.

Bo

dio

u, J

.-C

. Si

mo

n, Y

. B

atti

e, A

.

Lois

eau,

B. L

. Lia

ng,

D.L

. Huf

fake

r

Go

me

z, A

ran

cha

Spai

n

Low

dim

en

sio

nal

mat

eri

als

(nan

ow

ire

s, c

lust

ers

,

qu

antu

m d

ots

, etc

.)

"Co

ntr

olle

d s

ynth

esi

s o

f si

nan

ow

ire

s o

n s

i su

bst

rate

s"

stu

de

nt

T. C

amp

o, F

. Már

qu

ez, E

. Eliz

ald

e, C

. Mo

ran

t

Gó

me

z-M

ed

ina

, R

aq

ue

l

Spai

n

Nan

oO

pti

cs

Nan

oP

ho

ton

ics

Pla

smo

nic

s

"No

n-c

on

serv

ativ

e e

lect

ric

and

mag

ne

tic

op

tica

l fo

rce

s o

n

sem

ico

nd

uct

or

par

ticl

es"

se

nio

r M

. Nie

to-V

esp

eri

na

s an

d J

. J. S

áe

nz

authors

authors

authors

authors

country

country

country

country

topic

topic

topic

topic

poster title

poster title

poster title

poster title

student

student

student

student

senior

senior

senior

senior

Go

nzá

lez,

Im

an

ol

Spai

n

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Nan

oco

mp

osi

tes

bas

ed

on

po

ly(e

the

r im

ide

) b

y th

e a

dd

itio

n o

f a

po

ly(b

uty

len

e t

ere

ph

thal

ate

)/ca

rbo

n n

ano

tub

e m

aste

rbat

ch:

Ele

ctri

cal c

on

du

ctiv

ity

and

me

chan

ical

pe

rfo

rman

ce"

sen

ior

José

Ign

acio

Egu

iazá

bal

Go

nzá

lez-

Arr

ab

al,

Ra

qu

el

Spai

n

Nan

om

ate

rial

s fo

r E

ne

rgy

"H d

iffu

sio

n in

nan

oe

stru

ctu

red

as

com

par

ed

to

mas

sive

W"

sen

ior

N. G

ord

illo

, M. P

aniz

o-L

aiz,

A. R

ive

ra, F

.

Mu

nn

ik, K

. Sar

avan

an a

nd

J. M

. Pe

rlad

o

Go

nzá

lez-

Sa

nta

nd

er,

Cla

ra

Spai

n

Th

eo

ry a

nd

mo

de

llin

g at

the

nan

osc

ale

"L

oca

lizat

ion

of

stat

es

on

gra

ph

en

e-t

ype

latt

ice

s "

stu

de

nt

F. D

om

íngu

ez-

Ad

ame

, R. A

. Rö

me

r

Gro

ult

, H

ug

o

Spai

n

Nan

oC

he

mis

try

"Mic

ella

r ap

pro

ach

fo

r th

e d

esi

gn o

f n

ew

up

-co

nve

rtin

g

nan

op

ho

sph

ors

an

d s

up

erp

aram

agn

eti

c n

ano

par

ticl

es

for

op

tica

l im

agin

g an

d in

viv

o M

RI"

st

ud

en

t J.

Ru

iz-C

abe

llo a

nd

F. H

err

anz

Gry

m,

Jan

C

zech

R

ep

ub

lic

Nan

ost

ruct

ure

d a

nd

n

ano

par

ticl

e b

ase

d

mat

eri

als

"Liq

uid

-ph

ase

ep

itax

ial g

row

th o

n n

ano

po

rou

s su

bst

rate

s"

sen

ior

Du

šan

No

hav

ica,

Pe

tar

Gla

dko

v

Gu

err

ero

Co

ntr

era

s, C

arl

os

Luis

Spai

n

Nan

om

ate

rial

s fo

r E

ne

rgy

"Nan

ocr

ysta

ls in

th

e M

anu

fact

ure

of

Targ

et

for

Ine

rtia

l C

on

fin

em

en

t Fu

sio

n."

se

nio

r M

ano

lo P

erl

ado

an

d S

an

tiag

o C

ue

sta-

Lóp

ez

Ha

she

m N

ia,

Aza

de

h

Iran

N

ano

bio

tech

no

logi

es

&

Nan

om

ed

icin

e

"Eff

icie

nt

Ge

ne

Del

iver

y N

ano

vect

ors

Bas

ed o

n F

un

ctio

nal

izat

ion

Of

Sin

gle

wal

l Car

bo

n N

ano

tub

es (

SWN

T) w

ith

Po

lyet

hyl

en

imin

e (P

EI)"

st

ud

en

t M

.Ram

eza

ni,

M. R

ahim

izad

eh

, H. E

shgh

i, K

h. A

bn

oo

s

He

rmo

sa,

Cri

stin

a

Spai

n

Nan

oC

he

mis

try

"So

lve

nt-

ind

uce

d D

ela

min

atio

n o

f a

Mu

ltif

un

ctio

nal

Tw

o

Dim

en

sio

nal

Co

ord

inat

ion

Po

lym

er"

st

ud

en

t

A. G

alle

go, O

. Cas

tillo

, I. B

erl

anga

, C.

Gó

me

z, E

. Mat

eo

, J. I

. Mar

tín

ez

, F. F

lore

s,

A. H

ou

lto

n, B

. R. H

orr

ock

s, C

. Gó

me

z N

avar

ro, J

. Gó

me

z-H

err

ero

, S. D

elg

ado

and

F. Z

amo

ra

Hü

tte

l, A

nd

rea

s K

.

Ge

rman

y

Gra

ph

en

e /

Car

bo

n

nan

otu

be

s b

ase

d

nan

oe

lect

ron

ics

and

fie

ld

em

issi

on

"Sin

gle

wal

l car

bo

n n

ano

tub

es

as h

igh

ly s

en

siti

ve n

ano

-

ele

ctro

me

chan

ical

hyb

rid

sys

tem

s: d

rivi

ng,

bra

kin

g, d

ete

ctio

n"

sen

ior

D. S

chm

id, P

. Sti

ller

and

C. S

tru

nk

Ibra

him

, Im

ad

Ge

rman

y

Gra

ph

en

e /

Car

bo

n

nan

otu

be

s b

ase

d

nan

oe

lect

ron

ics

and

fie

ld

em

issi

on

"Gro

wth

of

hig

h y

ield

me

talli

c-fr

ee

ho

rizo

nta

lly a

lign

ed

sin

gle

wal

l

carb

on

nan

otu

be

s n

ucl

eat

ed

fro

m f

ulle

ren

e"

stu

de

nt

Alic

ja B

ach

mat

iuk,

Be

rnd

Bü

chn

er,

Mar

k H

. R

üm

me

li, G

ian

au

relio

Cu

nib

ert

i

authors

authors

authors

authors

country

country

country

country

topic

topic

topic

topic

poster title

poster title

poster title

poster title

student

student

student

student

senior

senior

senior

senior

Ilie

, A

de

lin

a

Un

ite

d

Kin

gdo

m

Nan

ob

iote

chn

olo

gie

s &

Nan

om

ed

icin

e

"No

n-C

ova

len

t B

iofu

nct

ion

aliz

atio

n o

f G

rap

he

ne

wit

h C

age

-lik

e

Mu

lti-

En

zym

e C

om

ple

xes

for

Sen

sin

g"

sen

ior

Ab

ee

r A

lsh

amm

ari,

Mar

eik

e

G.

Po

sne

r,

Ab

his

he

k U

pad

hya

y,

Fran

k M

arke

n, S

tefa

n B

agb

y

Ima

mo

glu

, G

am

ze

Tu

rke

y

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Th

e E

ffe

ct o

f E

lect

roch

em

ical

Me

tho

ds

on

Th

e S

hap

e o

f Zi

nc

Oxi

de

Nan

ost

ruct

ure

s"

stu

de

nt

Y.S

ahin

, E. S

uva

ci

Ing

ua

nta

, R

osa

lin

da

Ital

y N

ano

mat

eri

als

for

En

erg

y "H

igh

eff

icie

ncy

ele

ctro

de

s b

ase

d o

n n

ano

stru

ctu

red

mat

eri

als

for

en

erg

y d

evi

ces"

se

nio

r Se

ren

a R

and

azzo

, M

aria

Ch

iara

Mis

tre

tta,

Sa

lvat

ore

Pia

zza,

Car

me

lo S

un

seri

Iña

rre

a,

Jesú

s Sp

ain

Low

dim

en

sio

nal

mat

eri

als

(nan

ow

ire

s, c

lust

ers

,

qu

antu

m d

ots

, etc

.)

"Off

-re

son

ance

mag

ne

tore

sist

ance

sp

ike

in ir

rad

iate

d u

ltra

cle

an

2D

ES"

se

nio

r

Iña

rre

a,

Jesú

s Sp

ain

T

he

ory

an

d m

od

elli

ng

at

the

nan

osc

ale

"Mic

row

ave

-in

du

ced

re

sist

ance

osc

illat

ion

s an

d z

ero

-re

sist

ance

stat

es

in 2

D b

ilaye

r sy

ste

ms"

se

nio

r G

lori

a P

late

ro

Jon

es,

Sa

rah

Ire

lan

d

Th

eo

ry a

nd

mo

de

llin

g at

the

nan

osc

ale

"Th

e E

ffe

ct o

f V

acan

cy D

efe

cts

on

Ele

ctro

n S

catt

eri

ng

in C

arb

on

Nan

otu

be

s"

stu

de

nt

G. G

ree

ne-

Din

iz, G

. Fag

as, M

.G. H

aver

ty, S

.

Shan

kar,

C. M

arti

nez

-Lac

amb

ra, J

.C. G

reer

Ko

sak

ov

skii

, G

erm

an

Ru

ssia

Gra

ph

en

e /

Car

bo

n

nan

otu

be

s b

ase

d

nan

oe

lect

ron

ics

and

fie

ld

em

issi

on

"Qu

antu

m E

ffe

cts

At

Fie

ld E

mis

sio

n F

rom

Car

bo

n Q

uas

i-1

D

Cat

ho

de

s"

stu

de

nt

Gu

lyae

v Y

u.V

., K

osa

kovs

kaya

Z.Y

a., B

lago

v

E.V

.,La

tysh

ev

Yu

.I.,

Orl

ov

A.P

., S

mo

lovi

ch

A.M

.

Kra

sod

om

ski,

Wo

jcie

ch

Po

lan

d

Nan

oC

he

mis

try

"Mo

dif

ied

gra

ph

en

e a

nd

gra

ph

ite

oxi

de

dis

pe

rsio

ns

in p

etr

ole

um

frac

tio

ns"

se

nio

r M

ich

ał K

raso

do

msk

i, M

ich

ał W

ojt

asik

, K

amil

Po

myk

ała

Ku

dri

n,

Ale

xe

y

Ru

ssia

N

ano

mag

ne

tism

an

d

Spin

tro

nic

s

"Th

e f

eat

ure

s o

f ca

rrie

r tr

ansp

ort

in t

he

fe

rro

mag

ne

tic

sem

ico

nd

uct

or

qu

antu

m w

ell

stru

ctu

res"

se

nio

r O

. Vik

hro

va, Y

u. D

anilo

v, I.

Kal

en

tie

va, B

.

Zvo

nko

v

Lad

o T

ou

riñ

o,

Isa

be

l

Spai

n

Th

eo

ry a

nd

mo

de

llin

g at

the

nan

osc

ale

"Mo

lecu

lar

mo

de

ling

of

aro

mat

ic in

tera

ctio

ns

be

twe

en

pyr

en

e

de

riva

tive

s an

d c

arb

on

nan

otu

be

s"

sen

ior

Viv

ian

a N

egr

i, Se

ba

stiá

n C

erd

án a

nd

Pal

om

a B

alle

ste

ros

authors

authors

authors

authors

country

country

country

country

topic

topic

topic

topic

poster title

poster title

poster title

poster title

student

student

student

student

senior

senior

senior

senior

Lap

rise

-Pe

lle

tie

r, M

yri

am

C

anad

a N

ano

bio

tech

no

logi

es

&

Nan

om

ed

icin

e

"Me

sop

oro

us

Silic

a N

ano

par

ticl

es

(MSN

s) a

s M

RI/

PET

Du

al-

Mo

dal

ity

Imag

ing

Pro

be

s"

stu

de

nt

Jean

-Lu

c B

rid

ot,

Ré

my

Gu

ille

t-N

ico

las,

Fre

dd

y K

leit

z ,M

arcA

nd

ré F

ort

in

Leiv

a,

An

ge

l

Ch

ile

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Th

in F

ilms

of

Po

lye

lect

roly

tes

wit

h A

dso

rbe

d G

old

Nan

op

arti

cle

s"

sen

ior

Mar

cela

Urz

úa,

Max

imili

ano

Pin

o a

nd

D

eo

dat

o R

adic

´

Leó

n,

Na

tali

a

Ve

ne

zue

la

Low

dim

en

sio

nal

mat

eri

als

(nan

ow

ire

s, c

lust

ers

,

qu

antu

m d

ots

, etc

.)

"Sh

ell

stru

ctu

res

in a

lum

iniu

m n

ano

con

tact

s at

ele

vate

d

tem

pe

ratu

res"

se

nio

r Jo

sé

Luis

C

ost

a-K

räm

er,

C

arlo

G

ue

rre

ro

and

Mar

ise

l Día

z

Léto

urn

ea

u,

Ma

thie

u

Can

ada

Nan

ob

iote

chn

olo

gie

s &

Nan

om

ed

icin

e

"Pla

sma-

liqu

id E

lect

roch

em

istr

y :

a Fa

st M

eth

od

fo

r Sy

nth

esi

zin

g

Mag

ne

tic

Nan

op

arti

cle

s"

stu

de

nt

Ch

rist

ian

Sar

ra-B

ou

rne

t, M

yria

m L

apri

se-

Pe

lleti

er,

Mar

c-A

nd

ré F

ort

in

Lig

he

zan

, Li

lia

na

R

om

ania

N

ano

bio

tech

no

logi

es

&

Nan

om

ed

icin

e

"Th

erm

al p

rop

ert

ies

of

the

S-l

aye

r p

rote

in f

rom

Lac

tob

acill

us

saliv

ariu

s"

stu

de

nt

Ral

itsa

Ge

org

ieva

an

d A

dri

an

Ne

agu

Lim

, Jo

ng

So

o

Spai

n

Nan

om

agn

eti

sm a

nd

Spin

tro

nic

s "F

luct

uat

ion

re

lati

on

s fo

r sp

intr

on

ics"

se

nio

r R

osa

Lo

pe

z an

d D

avid

San

che

z

Lóp

ez,

Ke

nia

A.

Spai

n

Nan

ob

iote

chn

olo

gie

s &

Nan

om

ed

icin

e

"An

tifo

late

s-M

od

ifie

d Ir

on

Oxi

de

Nan

op

arti

cle

s fo

r T

arge

tin

g

Can

cer

Ce

lls"

stu

de

nt

M. N

. Piñ

a, J

. Mo

rey,

R. A

lem

any,

B. O

.

Vö

gle

r, F

. M. L

. Bar

celó

Lori

te,

Isra

el

Ge

rman

y

Gra

ph

en

e /

Car

bo

n

nan

otu

be

s b

ase

d

nan

oe

lect

ron

ics

and

fie

ld

em

issi

on

"Stu

dy

of

the

tra

nsp

ort

pro

pe

rtie

s fr

eq

ue

ncy

de

pe

nd

en

ce o

f

mu

ltila

yer

grap

he

ne

by

Imp

ed

ance

Sp

ect

rosc

op

y"

sen

ior

A. B

alle

star

, J. B

aryo

la-Q

uiq

uia

, P.

Esq

uin

azi

Luci

o,

Ma

ria

Isa

be

l

Spai

n

Nan

ob

iote

chn

olo

gie

s &

Nan

om

ed

icin

e

"Ne

w s

ele

ctiv

e d

rugs

bas

ed

on

car

bo

n n

ano

ho

rns"

st

ud

en

t G

iulio

Fra

cass

o,

Mar

co C

olo

mb

atti

, M

aría

An

ton

ia H

erre

ro,

Mau

rizi

o P

rato

an

d E

ster

V

ázq

uez

Lun

a,

Ca

rlo

s

Me

xico

N

ano

mag

ne

tism

an

d

Spin

tro

nic

s "M

icro

stru

ctu

ral a

nd

Mag

ne

tic

Pro

pe

rtie

s o

f H

em

atit

e S

ub

mic

ron

P

seu

do

-Cu

be

s O

bta

ine

d b

y N

ano

crys

tal O

rie

nte

d A

ttac

hm

en

t"

sen

ior

R. M

en

do

za-R

esé

nd

ez

Lam

iaa

, M

.A.A

li

Spai

n

Nan

ob

iote

chn

olo

gie

s &

Nan

om

ed

icin

e

"To

xici

ty s

tud

ies

of

po

lym

er

bas

ed

su

pe

rpar

amag

ne

tic

iro

n o

xid

e

nan

op

arti

cle

s "

stu

de

nt

Vic

tor

Sorr

ibas

, Mar

tin

Gu

tie

rre

z, R

osa

C

orn

ud

ella

, Jo

sé A

nto

nio

Mo

ren

o, R

afae

l

Piñ

ol,

Lie

rni G

abilo

nd

o, A

nge

l Mill

án,

Fern

an

do

Pal

acio

authors

authors

authors

authors

country

country

country

country

topic

topic

topic

topic

poster title

poster title

poster title

poster title

student

student

student

student

senior

senior

senior

senior

Ma

kh

sud

a,

Ab

du

saly

am

ov

a

Taj

ikis

tan

N

ano

Ch

em

istr

y "T

he

pre

par

atio

n a

nd

inve

stig

atio

n o

f p

rop

ert

ies

of

Er 2

O3"

sen

ior

Kh

.Kab

gov,

F.S

har

ipo

v, J

u.M

. Yu

, M.S

hu

lga

Ma

lla

via

, R

ica

rdo

Spai

n

Nan

ofa

bri

cati

on

to

ols

&

nan

osc

ale

inte

grat

ion

"Pro

po

sal o

f a

low

-co

st, m

ask-

less

pro

ced

ure

fo

r p

atte

rnin

g

ele

ctro

de

s o

f o

rgan

ic d

evi

ces

at n

ano

scal

e u

sin

g e

lect

ro-

dis

char

ges"

sen

ior

A. L

. Alv

are

z, C

. Co

ya, J

. Jim

en

ez-

Tri

llo ,

M.

Gar

cía-

Ve

lez,

G. A

lvar

ado

Ma

ne

ed

ae

ng

, A

tth

ap

ho

n

Th

aila

nd

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Siz

e-C

on

tro

llab

le C

alci

um

Car

bo

nat

e C

ryst

als

by

Ho

mo

logo

us

Seri

es

of

An

ion

ic S

urf

acta

nts

" se

nio

r A

dri

an

E. F

loo

d, S

uch

itra

Ph

ith

akso

em

sak

Ma

rco

s E

ste

ba

n,

Ra

qu

el

Ge

rman

y N

ano

Ch

em

istr

y "“

Liga

nd

-Fre

e”

Me

tal-

Nan

op

arti

cle

s in

Ion

ic L

iqu

ids"

st

ud

en

t F.

M. A

lbe

rti,

D. M

arq

uar

dt,

H. M

eye

r, C

.

Ru

tz, K

. Sch

ütt

e, C

. Vo

llme

r, C

. Jan

iak

Ma

sut,

Re

mo

Can

ada

Nan

om

ate

rial

s fo

r E

ne

rgy

"Nan

ost

ruct

ure

d t

he

rmo

ele

ctri

c al

loys

ob

tain

ed

by

me

chan

ical

allo

yin

g fo

llow

ed

by

ho

t e

xtru

sio

n o

r b

y m

icro

wav

e s

inte

rin

g "

sen

ior

M.K

. Ke

shav

artz

, J. A

rre

guin

-Zav

ala,

D.

Vas

ilevs

kiy

and

S. T

ure

nn

e

Ma

tei,

Ele

na

Ro

man

ia

Low

dim

en

sio

nal

mat

eri

als

(nan

ow

ire

s, c

lust

ers

,

qu

antu

m d

ots

, etc

.)

"Eff

ect

of

the

de

po

siti

on

co

nd

itio

ns

on

th

e p

rop

ert

ies

of

mag

ne

tic

nan

ow

ire

s"

sen

ior

Ion

ut

En

cule

scu

,Cam

elia

Flo

rica

, M

on

ica

En

cule

scu

, Vic

tor

Ku

ncs

er,

Mar

ia E

uge

nia

To

imil

Mo

lare

s

Ma

uri

z, P

au

lo

Bra

zil

Nan

oO

pti

cs

Nan

oP

ho

ton

ics

Pla

smo

nic

s

"Op

tica

l tra

nsm

issi

on

sp

ect

ra in

Fib

on

acci

ph

oto

nic

mu

ltila

yers

wit

h m

irro

r sy

mm

etr

y"

stu

de

nt

M.L

. Vas

con

celo

s an

d E

.L. A

lbu

qu

erq

ue

Ma

zela

, W

ojc

iech

Po

lan

d

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Eva

luat

ion

of

carb

on

nan

otu

be

s -

oil

dis

pe

rsio

n s

tab

ility

" se

nio

r W

ojc

iech

Kra

sod

om

ski,

Mic

hał

Paj

da,

Kam

il P

om

ykał

a, L

esz

ek

Zie

mia

ńsk

i

Me

le,

Da

vid

Fran

ce

Gra

ph

en

e /

Car

bo

n

nan

otu

be

s b

ase

d

nan

oe

lect

ron

ics

and

fie

ld

em

issi

on

"Hig

h F

req

ue

ncy

Ep

itax

ial G

rap

he

ne

Fie

lds

Eff

ect

Tra

nsi

sto

rs

(GFE

T)

on

SiC

" st

ud

en

t E

. Pic

ho

nat

, S. F

régo

nè

se, A

. Ou

erg

hi a

nd

H

. Hap

py

Me

nd

oza

-Re

sén

de

z, R

aq

ue

l

Me

xico

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Gre

en

Syn

the

sis

of

Silv

er

Nan

op

arti

cle

s M

ed

iate

d b

y B

ee

Pro

du

cts"

se

nio

r N

.O. N

uñ

ez,

C. L

un

a

authors

authors

authors

authors

country

country

country

country

topic

topic

topic

topic

poster title

poster title

poster title

poster title

student

student

student

student

senior

senior

senior

senior

Mir

asm

ou

ri,

Mo

sle

m

Iran

Nan

oO

pti

cs

Nan

oP

ho

ton

ics

Pla

smo

nic

s

"Th

e s

urf

ace

Pla

smo

n\'

s fr

eq

ue

nci

es

of

two

Me

talli

c N

ano

sph

ere

s

by

Blo

ch-J

en

sen

Hyd

rod

ynam

ical

Mo

de

l"

sen

ior

F.E

bra

him

i,V.E

bra

him

i

Mo

ha

jeri

, S

oh

a

Iran

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Ele

ctro

de

po

siti

on

of

Po

lyan

ilin

e n

ano

wir

es"

se

nio

r A

. Do

lati

, E.J

abb

ari

Mo

rey

, Je

ron

i

Spai

n

Nan

oC

he

mis

try

"Ch

em

ical

re

me

dia

tio

n:

Squ

aram

ide

Mag

ne

tic

Iro

n N

ano

par

ticl

es

for

Re

mo

val o

f To

xic

Me

tals

ion

s in

Wat

er"

se

nio

r M

aría

de

las

Nie

ves

Piñ

a an

d K

en

ia A

.

Lóp

ez

Mu

ná

rriz

, Ja

vie

r

Spai

n

Gra

ph

en

e /

Car

bo

n

nan

otu

be

s b

ase

d

nan

oe

lect

ron

ics

and

fie

ld

em

issi

on

"Sp

in-d

ep

en

de

nt

tran

spo

rt in

gra

ph

en

e n

ano

rib

bo

ns

wit

h a

pe

rio

dic

arr

ay o

f fe

rro

mag

ne

tic

stri

ps"

st

ud

en

t C

. G

aul,

A.

V.

Mal

ysh

ev,

P.

A.

Ore

llan

a, C

.

A. M

ülle

r an

d F

. Do

mín

gue

z-A

da

me

Mu

sta

fa,

Gh

ula

m

Au

stri

a

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Nan

op

arti

cle

s an

d n

ano

com

po

site

s as

VO

C r

eco

gnit

ion

mat

eri

als"

se

nio

r M

un

awar

Hu

ssai

n, P

ete

r A

Lie

be

rze

it

Na

eim

i, A

ten

a

Spai

n

Nan

om

agn

eti

sm a

nd

Spin

tro

nic

s

"Co

pp

er

(II)

Te

tras

ulf

on

ate

d P

hth

alo

cyan

ine

Imm

ob

ilize

d o

n

Sup

erp

aram

agn

eti

c N

ano

par

ticl

es"

se

nio

r A

bd

olr

eza

Re

zae

ifar

d, M

aaso

um

eh

Ja

farp

ou

r

Ore

lla

na

, P

ed

ro

Ch

ile

Low

dim

en

sio

nal

mat

eri

als

(nan

ow

ire

s, c

lust

ers

,

qu

antu

m d

ots

, etc

.)

"Fan

o a

nd

An

dre

ev

Re

fle

ctio

n in

Qu

antu

m d

ots

" se

nio

r A

na

Mar

ía C

alle

, Mó

nic

a P

ach

eco

Ozo

gu

t, U

gu

r C

an

Tu

rke

y

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Sh

ape

an

d S

ize

Co

ntr

olle

d Z

nO

Par

ticl

es

and

Th

eir

Cyt

oto

xic

Be

hav

iou

r"

sen

ior

Ban

u B

aru

tca,

Ke

nan

Isik

, En

de

r Su

vaci

, A.

Tan

su K

op

aral

, Yu

cel S

ahin

Pa

laci

os,

Pa

blo

Sp

ain

N

ano

mat

eri

als

for

En

erg

y "T

he

ore

tica

l stu

dy

of

ban

d a

lign

me

nt

in n

ano

-po

rou

s Zn

O

inte

ract

ing

wit

h s

ub

stit

ute

d P

hth

alo

cyan

ine

s"

sen

ior

P. W

ahn

ón

, B

. Mar

i

Pa

rk,

Ky

ou

ng

-Ge

un

Ko

rea

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Sy

nth

esi

s o

f n

ano

-siz

ed

SiC

an

d S

i/Si

C f

rom

sili

con

an

d c

arb

on

po

wd

ers

by

no

n-t

ran

sfe

rre

d a

rc t

he

rmal

pla

sma"

st

ud

en

t Ji

n-W

o K

im, J

ae-K

ang

Kim

, San

g-K

i Kan

g,

Ye

on

-Tae

Yu

Pa

rt,

Ma

rko

Est

on

ia

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"No

vel m

eth

od

in s

ynth

esi

s o

f Y

SZ m

icro

tub

es

and

th

eir

app

licat

ion

as

ALD

su

bst

rate

s"

stu

de

nt

Ke

ijo R

iikjä

rv, K

elli

Han

sch

mid

t, A

ile

Tam

m, H

ugo

Män

dar

,Gu

nn

ar N

urk

,Kau

po

Ku

kli,

Tan

el T

ätte

authors

authors

authors

authors

country

country

country

country

topic

topic

topic

topic

poster title

poster title

poster title

poster title

student

student

student

student

senior

senior

senior

senior

Pe

llic

o S

áe

z, J

ua

n

Spai

n

Nan

oC

he

mis

try

"Syn

the

sis

& F

un

ctio

nal

izat

ion

of

Fe3O

4 N

ano

par

ticl

es

for

Mag

ne

tic

Par

ticl

e Im

agin

g”

stu

de

nt

J. R

uiz

-Cab

ello

, S. V

ein

tem

illas

-Ve

rdag

ue

r,

M. P

ue

rto

Mo

rale

s, I.

Ro

drí

gue

z, F

. H

err

anz

Pe

ralt

a,

Ma

yra

V

en

ezu

ela

N

ano

fab

rica

tio

n t

oo

ls &

nan

osc

ale

inte

grat

ion

"A T

hre

e d

ime

nsi

on

al e

-be

am li

tho

grap

hy

tech

niq

ue

fo

r th

e

con

stru

ctio

n o

f h

igh

de

nsi

ty m

icro

an

d n

ano

coils

" st

ud

en

t J.

L. C

ost

a-K

ram

er

, E. M

ed

ina,

A. D

on

oso

Pé

rez-

Ga

rrid

o,

An

ton

io

Spai

n

Gra

ph

en

e /

Car

bo

n

nan

otu

be

s b

ase

d

nan

oe

lect

ron

ics

and

fie

ld

em

issi

on

"Gra

ph

en

e s

tru

ctu

res

wit

h c

ircu

lar

shap

e:

a st

ud

y o

f th

e in

flu

en

ce

of

top

olo

gica

l de

fect

s in

tra

nsp

ort

pro

pe

rtie

s"

sen

ior

Est

he

r Jó

dar

an

d F

ern

and

o R

oja

s

Ph

ila

nd

er,

Gh

ou

wa

a

Sou

th A

fric

a N

ano

Ch

em

istr

y "P

rop

ert

ies

of

Van

adiu

m D

ioxi

de

Co

atin

gs f

or

Smar

t W

ind

ow

Ap

plic

atio

ns"

st

ud

en

t M

. Maa

za a

nd

E. I

wu

oh

ag

Po

nz,

Fe

rna

nd

o

Spai

n

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

m

ate

rial

s

"A n

ano

pla

tfo

rm b

ase

d o

n s

elf

-ass

em

ble

d p

lan

t-m

ade

n

ano

par

ticl

es

wit

h m

ult

iple

ap

plic

atio

ns"

se

nio

r Fl

ora

Sán

che

z, C

arm

en

Man

silla

, P

ablo

Ibo

rt, S

ol C

ue

nca

, Mar

ta A

guad

o, C

ésa

r F.

Cru

z, Iv

on

ne

Go

nzá

lez

Pro

en

ca,

Ma

ria

na

P

ort

uga

l N

ano

mag

ne

tism

an

d

Spin

tro

nic

s

"Cro

sso

ver

be

twe

en

mag

ne

tic

reve

rsal

mo

de

s in

ord

ere

d a

rray

s o

f

ele

ctro

de

po

site

d n

ano

tub

es"

st

ud

en

t C

. T

. So

usa

, J.

E

scri

g,

J.

Ve

ntu

ra,

M.

Váz

qu

ez,

J. P

. Ara

újo

Ra

hm

an

, M

oh

am

ma

d M

ah

bu

bu

r

Spai

n

Nan

oO

pti

cs

Nan

oP

ho

ton

ics

Pla

smo

nic

s

"3D

nan

ost

ruct

uri

ng

of

nan

op

oro

us

ano

dic

alu

min

a fo

r p

ho

ton

ic

app

licat

ion

s"

stu

de

nt

Ger

ard

Mac

ias

Sotu

ela,

Mar

ia A

lba,

Llu

ís F

.

Mar

sal,

Jose

p P

alla

rès

and

Jo

sep

Fer

ré-

Bo

rru

ll

Re

zan

ka

, P

av

el

Cze

ch

Re

pu

blic

N

ano

Ch

em

istr

y "S

yste

mat

ic c

ircu

lar

dic

hro

ism

stu

dy

of

syst

em

s co

nta

inin

g

cyst

ein

e a

nd

silv

er

nan

op

arti

cle

s"

sen

ior

Jaku

b K

okt

an, a

nd

Vla

dim

ír K

rál

Ric

cia

rdi,

Ro

be

rto

N

eth

erl

and

s N

ano

Ch

em

istr

y "H

ete

roge

ne

ou

s ca

taly

sis

insi

de

a m

icro

reac

tor

con

tain

ing

acid

-

fun

ctio

nal

ize

d p

oly

me

r b

rush

es"

st

ud

en

t Ju

rria

an H

usk

en

s, W

ille

m V

erb

oo

m

Ric

o-G

arc

ía,

José

Ma

ría

Spai

n

Nan

oO

pti

cs

Nan

oP

ho

ton

ics

Pla

smo

nic

s

"Eff

ect

of

sho

rt-r

ange

ord

er v

s. lo

ng-

ran

ge d

iso

rder

on

th

e ef

fect

ive

pro

per

ties

of

a 1

D "

met

amat

eria

l" c

hai

n o

f re

son

ant

par

ticl

es "

se

nio

r Jo

sé M

anu

el L

óp

ez-

Alo

nso

, A

sho

d

Ara

dia

n

Riv

era

Gil

, P

ila

r

Ge

rman

y N

ano

bio

tech

no

logi

es

&

Nan

om

ed

icin

e

"Po

lym

eri

c C

apsu

les

as m

ult

ifu

nct

ion

al t

oo

l fo

r in

trac

ellu

lar

ion

co

nce

ntr

atio

n"

sen

ior

Mo

ritz

Naz

are

nu

s, S

um

aira

Ash

raf,

Wo

lfga

ng

J. P

arak

authors

authors

authors

authors

country

country

country

country

topic

topic

topic

topic

poster title

poster title

poster title

poster title

student

student

student

student

senior

senior

senior

senior

Ro

dri

go

, C

eci

lia

Spai

n

Nan

om

agn

eti

sm a

nd

Spin

tro

nic

s

"Dis

en

tan

glin

g th

e m

agn

eto

resi

stan

ce r

esp

on

se t

hro

ugh

th

e

mag

ne

tiza

tio

n r

eve

rsal

in m

agn

eti

c m

ult

ilaye

rs"

stu

de

nt

P. P

ern

a, M

. Mu

ño

z, J

. L. P

rie

to, A

.

Bo

llero

, J. L

. F. C

uñ

ado

, M. R

om

era,

J.

Ake

rman

n, E

. Jim

én

ez,

N. M

iku

sze

it, V

.

Cro

s, J

. Cam

are

ro a

nd

R. M

iran

da

Ro

drí

gu

ez

Ro

drí

gu

ez,

Pe

dro

Spai

n

Nan

oO

pti

cs

Nan

oP

ho

ton

ics

Pla

smo

nic

s

"Ph

on

on

s C

on

trib

uti

on

to

th

e In

frar

ed

an

d V

isib

le S

pe

ctra

of

II-V

I

Sem

ico

nd

uct

or

Nan

osh

ells

" st

ud

en

t C

. Kan

yin

da-

Mal

u a

nd

R.M

. de

la C

ruz

Ro

drí

gu

ez-

Ca

bo

, B

orj

a

Spai

n

Nan

oC

he

mis

try

"Ph

osp

ho

niu

m-b

ase

d io

nic

liq

uid

s fo

r th

e f

orm

atio

n o

f

nan

op

arti

cle

s"

stu

de

nt

Iago

Ro

drí

gue

z-P

alm

eir

o,

Ad

riá

n S

ánch

ez,

Eva

Ro

dil,

An

a So

to, A

lbe

rto

Arc

e

Ro

jas,

Fe

rna

nd

o

Spai

n

Gra

ph

en

e /

Car

bo

n

nan

otu

be

s b

ase

d

nan

oe

lect

ron

ics

and

fie

ld

em

issi

on

"Ge

ne

tic

Alg

ori

thm

s in

th

e c

on

tro

l an

d d

esi

gn o

f ch

arge

on

e q

ub

it

qu

antu

m g

ate

s in

cir

cula

r gr

aph

en

e q

uan

tum

do

ts"

sen

ior

Gib

rán

A

mp

arán

an

d

An

ton

io

Pé

rez-

Gar

rid

o

Ru

ng

nim

, C

ho

mp

oo

nu

t

Th

aila

nd

N

ano

bio

tech

no

logi

es

&

Nan

om

ed

icin

e

"In

sigh

t in

to m

ole

cula

r d

ynam

ics

pro

pe

rtie

s o

f ge

mci

tab

ine

anti

can

cer

dru

gs lo

ade

d in

sid

e a

n o

pe

n-e

nd

ed

sin

gle

-wal

led

carb

on

nan

otu

be

"

stu

de

nt

Uth

um

po

rn A

rsaw

ang,

Th

anya

da

Ru

ngr

otm

on

gko

l an

d S

up

ot

Han

no

ngb

ua

Sa

ba

ter,

Ca

rlo

s

Spai

n

Low

dim

en

sio

nal

mat

eri

als

(nan

ow

ire

s, c

lust

ers

,

qu

antu

m d

ots

, etc

.)

"In

vest

igat

ion

of

Pla

stic

an

d E

last

ic D

efo

rmat

ion

s o

f G

old

Nan

ow

ire

s u

nd

er

Un

iaxi

al S

trai

n w

ith

Po

int-

Co

nta

ct S

pe

ctro

sco

py"

st

ud

en

t T

aman

aco

Fra

nci

squ

ez

and

Car

los

Un

tie

dt

Sa

inz,

Ra

qu

el

Spai

n

Nan

oC

he

mis

try

"Co

lloid

al s

tab

ility

of

Gra

ph

en

e O

xid

e a

nd

de

riva

tive

s in

wat

er"

se

nio

r R

od

rigu

ez-

Tap

iad

or

M.I

., A

lcáz

ar C

.,

Mo

ren

o R

. an

d F

err

ito

R.

Sa

lun

di,

Aig

i

Est

on

ia

Oth

er

"De

velo

pm

en

t o

f h

igh

pe

rfo

rman

ce e

lect

ro-o

pti

cal f

ilms

by

sol-

gel

me

tho

d"

stu

de

nt

M. T

imu

sk, M

. Jär

vekü

lg, R

. Lõ

hm

us,

I.

Kin

k an

d K

. Sa

al

Sa

nta

ma

ría

, P

ab

lo

Spai

n

Nan

ost

ruct

ure

d a

nd

n

ano

par

ticl

e b

ase

d

mat

eri

als

"Im

pro

ved

me

chan

ical

an

d b

arri

er

pro

pe

rtie

s o

f am

orp

ho

us

po

lyam

ide

film

s b

y th

e a

dd

itio

n o

f a

hig

hly

exf

olia

ted

nan

ocl

ay"

stu

de

nt

Jose

Ign

acio

Egu

iazá

bal

Se

min

ov

ski,

Yo

ha

nn

a

Spai

n

Th

eo

ry a

nd

mo

de

llin

g at

the

nan

osc

ale

"Fir

st P

rin

cip

les

calc

ula

tio

ns

of

SnS 2

laye

red

se

mic

on

du

cto

r, t

akin

g

into

acc

ou

nt

the

Van

de

r W

aals

inte

ract

ion

s."

stu

de

nt

Pab

lo P

alac

ios,

Pe

rla

Wah

nó

n, a

nd

R

icar

do

Gra

u-C

resp

o

Se

ren

a,

Pe

dro

A.

Spai

n

Th

eo

ry a

nd

mo

de

llin

g at

the

nan

osc

ale

"To

war

ds

a m

ole

cula

r d

ynam

ics

de

scri

pti

on

of

the

me

chan

ical

pro

pe

rtie

s o

f an

tib

od

ies

as m

eas

ure

d w

ith

a f

orc

e m

icro

sco

pe

" se

nio

r J.

G. V

ilhe

na,

Ric

ard

o G

arcí

a, R

ub

én

Pé

rez

authors

authors

authors

authors

country

country

country

country

topic

topic

topic

topic

poster title

poster title

poster title

poster title

student

student

student

student

senior

senior

senior

senior

Sh

am

ma

, R

eh

ab

Egy

pt

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"A n

ove

l nan

ove

sicu

lar

carr

ier

syst

em

fo

r o

cula

r d

eliv

ery

of

clo

trim

azo

le"

stu

de

nt

Mo

na

Bas

ha

Ah

me

d a

nd

Sam

eh

Ho

ssan

Eld

il

Sh

ay

an

i R

ad

, M

ary

am

Iran

N

ano

bio

tech

no

logi

es

&

Nan

om

ed

icin

e

"Ch

arac

teri

zati

on

an

d in

vit

ro e

valu

atio

n o

f m

icro

leak

age

an

d

anti

bac

teri

al p

rop

ert

ies

of

pre

par

ed

Zn

O a

nd

Zn

O:A

g n

ano

seal

ers

"

stu

de

nt

Ah

amd

Ko

mp

anya

, Ali

Kh

ors

and

Zak

a,

Maj

id A

bri

sham

ia, M

arya

m J

avid

ib, M

aje

d

Mo

rtaz

avib

Slo

va

k,

Pe

tr

Cze

ch

Re

pu

blic

Nan

ob

iote

chn

olo

gie

s &

Nan

om

ed

icin

e

"Nan

oco

mp

osi

te c

arb

on

mat

eri

al –

silv

er

nan

op

arti

cle

s:

Pre

par

atio

n a

nd

an

tib

acte

rial

act

ivit

y"

stu

de

nt

Dr.

Kvi

tek

Lib

or

So

corr

o,

Ab

ian

Spai

n

Nan

ob

iote

chn

olo

gie

s &

N

ano

me

dic

ine

"Im

mu

no

glo

bu

lin G

se

nso

r b

y m

ean

s o

f lo

ssy

mo

de

re

son

ance

s in

du

ced

by

a n

ano

stru

ctu

red

po

lym

eri

c th

in-f

ilm d

ep

osi

ted

on

a

tap

ere

d o

pti

cal f

ibe

r"

stu

de

nt

Jesu

s M

. Co

rre

s, Ig

nac

io D

el V

illar

, Fr

anci

sco

J. A

rre

gui,

Ign

acio

R. M

atia

s

So

ne

, B

ert

ran

d

Sou

th A

fric

a N

ano

stru

ctu

red

an

d

nan

op

arti

cle

bas

ed

mat

eri

als

"Nan

ost

ruct

ure

d t

un

gste

n t

rio

xid

e t

hin

film

s b

y aq

ue

ou

s ch

em

ical

gro

wth

fo

r ap

plic

atio

ns

in g

as s

en

sin

g an

d e

lect

roch

rom

ism

" st

ud

en

t T

. Mal

we

la, L

. Vay

ssie

res,

E. I

wu

oh

a an

d

M. M

aaza

Sp

aso

jev

ic,

Vo

jisl

av

Yu

gosl

avia

N

ano

mag

ne

tism

an

d

Spin

tro

nic

s

"Mag

ne

tic

pro

pe

rtie

s o

f n

ano

stru

ctu

red

Ca 1

-xG

dxM

nO

3 o

bta

ine

d

by

glyc

ine

-nit

rate

pro

ced

ure

" se

nio

r V

. Ku

sige

rski

, M. R

osi

c, J

. Bla

nu

sa, M

. Per

ovi

c,

A. M

rako

vic,

B. A

nti

c, a

nd

B. M

ato

vic

Sze

pie

nie

c, M

ark

Ir

ela

nd

T

he

ory

an

d m

od

elli

ng

at

the

nan

osc

ale

"In

flu

en

ce o

f E

lect

ron

Co

rre

lati

on

s o

n Q

uas

ipar

ticl

e E

ne

rgie

s an

d

Life

tim

es"

st

ud

en

t Ir

en

e Y

eri

skin

, Jim

Gre

er

Su

ny

ol,

Jo

an

Jo

sep

Spai

n

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Nan

ocr

ysta

llin

e m

agn

eti

c sh

ape

me

mo

ry a

lloys

: N

i-M

n-(

In,S

n)"

se

nio

r L.

Esc

od

a, J

. Sau

rin

a, A

. Car

rillo

, E. B

osc

h,

B. H

ern

and

o

Th

ue

som

ba

t, P

ak

vir

un

T

hai

lan

d

Ris

ks-t

oxi

city

-re

gula

tio

ns

"Eff

ect

of

Silv

er

Nan

op

arti

cle

s o

n R

ice

Ory

za S

ativ

a L.

KD

ML

10

5

see

dlin

gs"

stu

de

nt

Ch

adch

awan

Su

pac

hit

ra, H

ann

on

gbu

a

Sup

ot

and

Aka

sit

San

on

g

Um

ala

s, M

ad

is

Est

on

ia

Nan

ost

ruct

ure

d a

nd

n

ano

par

ticl

e b

ase

d

mat

eri

als

"Syn

the

sis

of

ZrC

-TiC

nan

ost

ruct

ure

s"

stu

de

nt

Val

ter

Re

ed

o, A

nts

Lõ

hm

us

and

Irin

a H

uss

ain

ova

Vil

ão

Ra

mo

s, G

ina

Po

rtu

gal

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Ele

ctri

cal c

on

du

ctiv

ity

and

re

lati

ve p

erm

itti

vity

of

15

nm

Al 2

O3-

wat

er

nan

ofl

uid

s"

stu

de

nt

R. I

gle

sias

, M.A

. Riv

as, F

. Co

elh

o a

nd

T.P

.

Igle

sia

s

authors

authors

authors

authors

country

country

country

country

topic

topic

topic

topic

poster title

poster title

poster title

poster title

student

student

student

student

senior

senior

senior

senior

Vä

lbe

, R

au

l

Est

on

ia

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"Pre

par

atio

n o

f R

-me

thyl

Imid

azo

lium

-So

diu

m H

exa

flo

rosi

licat

e

Co

mp

lex

Cry

stal

s"

stu

de

nt

Val

ter

Re

ed

o, U

no

Mäe

org

, An

dre

s H

oo

p,

An

ts L

õh

mu

s

We

bst

er,

Me

liss

a

Au

stra

lia

Nan

ost

ruct

ure

d a

nd

nan

op

arti

cle

bas

ed

mat

eri

als

"De

tect

ing

oil

see

ps

in s

eaw

ate

r, s

en

sin

g b

acte

ria

in m

ilk, a

nd

ide

nti

fyin

g d

ise

ase

sta

tes

fro

m a

pat

ien

t’s

uri

ne

: N

ew

ap

plic

atio

ns

for

gold

nan

op

arti

cle

ch

em

ire

sist

ors

"

sen

ior

Bu

rkh

ard

Rag

use

, Le

ch W

iecz

ore

k, E

dit

h

Ch

ow

, Jam

es

S. C

oo

pe

r, L

ee

J. H

ub

ble

Ya

ma

mo

to,

Ko

he

i

Jap

an

Low

dim

en

sio

nal

mat

eri

als

(nan

ow

ire

s, c

lust

ers

,

qu

antu

m d

ots

, etc

.)

"Th

erm

al C

on

du

ctan

ce C

alcu

lati

on

s o

f Si

lico

n N

ano

wir

es"

st

ud

en

t H

iro

yuki

Is

hii,

N

ob

uh

iko

K

ob

ayas

hi

an

d

Ke

nji

Hir

ose

Ya

tsk

iv,

Ro

ma

n

Cze

ch

Re

pu

blic

Nan

ost

ruct

ure

d a

nd

n

ano

par

ticl

e b

ase

d

mat

eri

als

"In

flu

en

ce o

f Zn

O s

urf

ace

po

lari

ty o

n t

he

ele

ctro

ph

ore

tic

de

po

siti

on

of

me

tal n

ano

par

ticl

es.

" se

nio

r Ja

n G

rym

Ye

risk

in,

Ire

ne

Ire

lan

d

Th

eo

ry a

nd

mo

de

llin

g at

the

nan

osc

ale

"Ele

ctro

ne

gati

vity

an

d E

lect

ron

Cu

rre

nts

in M

ole

cula

r T

un

ne

l

Jun

ctio

ns"

st

ud

en

t S.

McD

erm

ott

, R. J

. Bar

tle

tt, G

. Fa

gas

and

J.C

. Gre

er

Yu

, Y

eo

nta

e

Ko

rea

Nan

om

ate

rial

s fo

r E

ne

rgy

"Lig

ht

scat

teri

ng

eff

ect

of

nan

o-s

ize

d h

ollo

w T

iO2 la

yer

on

con

vers

ion

eff

icie

ncy

of

DSS

C"

sen

ior

Kye

on

gju

n K

o, K

yeo

ngg

eu

n P

ark

Yo

use

fi,

Ela

he

Ir

an

Nan

ofa

bri

cati

on

to

ols

&

nan

osc

ale

inte

grat

ion

"M

orp

ho

logy

stu

dy

of

the

ele

ctro

de

po

site

d p

lati

nu

m n

ano

tub

e"

stu

de

nt

A. D

ola

ti, I

. Im

anie

h

Zv

ato

ra,

Pa

ve

l

Cze

ch

Re

pu

blic

N

ano

Ch

em

istr

y "S

tru

ctu

ral a

nd

mag

ne

tic

pro

pe

rtie

s o

f n

ano

crys

talli

ne

La1

-xSr

xMn

O3

+d"

stu

de

nt

Mir

osl

av V

eve

rka,

Pav

el V

eve

rka,

Kar

el

Kn

íže

k, K

are

l Záv

ěta

, On

dře

j

Kam

an,V

lad

imír

Krá

l, E

tie

nn

e D

ugu

et,

G

razi

ella

Go

glio

an

d E

mil

Po

llert

Edited by

Alfonso Gómez 17

28037 Madrid – Spain

[email protected]

www.phantomsnet.net

Depósito legal / Spanish Legal Deposit: BI-1480/2012

tnt2012 abstract book

Documents