october 8–13, 2017, sofia, bulgaria program and...international autumn school on fundamental and...

October 8–13, 2017, Sofia, BulgariaBulgarian Academy of Sciences

International Autumn School on Fundamental and Electron Crystallography (IASFEC)

PROGRAM and ABSTRACTS

INVITED LECTURERS

• Prof.JokeHadermann,UniversityofAntwerp,Belgium• Prof.MassimoNespolo,UniversityofLorraine,France• Prof.MoisAroyo,UniversityoftheBasqueCountry,Spain

ORGANIZING COMMITTEE

• Associateprof.DanielaKarashanova,PhD–InstituteofOpticalMaterialsandTechnologies,BAS–chair

• Associateprof.BogdanRanguelov,PhD–InstituteofPhysicalChemistry,BAS• Associateprof.MihailTarassov,PhD–InstituteofMineralogyandCrystallo

graphy,BAS• Assoc.prof.DianaNihtianova,PhD–InstituteofMineralogyandCrystallography,

BAS• Prof.RosicaNicolova,PhD–InstituteofMineralogyandCrystallography,BAS• Prof.BorisShivachev,PhD–InstituteofMineralogyandCrystallography,BAS• Prof.DanielaKovacheva,PhD–InstituteofGeneralandInorganicChemistry,

BAS• Assoc.prof.VladislavKostovKytin,PhD–InstituteofMineralogyandCrystallo

graphy,BAS• Assoc.prof.ZaraCherkezova–Zheleva,PhD–InstituteofCatalysis,BAS• BilianaGeorgieva,PhD–InstituteofOpticalMaterialsandTechnologies,BAS• MayaVelichkova,PhD–InstituteofGeneralandInorganicChemistry,BAS• PavelMarkov,PhD–InstituteofGeneralandInorganicChemistry,BAS• LubenMihaylov,PhD–FacultyofChemistryandPharmacy,SofiaUniversity

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International Autumn School on Fundamental and Electron Crystallography, 8–13 October 2017, Sofia, Bulgaria

SCIENTIFIC PROGRAM

Day 1: 08 October 2017, Sunday

morning Arrival,registrationandaccommodationLecturer:prof.MoisAroyo

13:30–18:00 • Basicmatrixalgebra(matrixmultiplication,calculationofdeterminantandtrace)

Day 2: 09 October 2017, Monday

8:45–9:00 OpeningoftheSchool(Dr.DanielaKarashanova)Lecturers:prof.MoisAroyo,prof.MassimoNespolo

9:00–11:00 • Introductiontogrouptheory:thenotionofsymmetryandsymmetrygroups.

• Latticesandunitcells.Crystallographicsymmetryintwodimensions11:00–11:30 Coffeebreak

11:30–13:30 • Crystallographicsymmetryinthreedimensions:Bravaislattices,pointgroups,holohedriesandmerohedries,pointgroups;HermannMauguinsymbolsforpointgroups.

13:30–15:00 Lunch

15:00–16:30 • Latticeplanes,MillerindicesandBravaisMillerindices.Forms,zonesandzoneaxes.

• ChoiceofthezonestolookatinEDforthedifferentcrystalsystems.• Introductiontothestereographicprojectionandexercisesonthestereographicprojectiontobuildcrystallographicpointgroups.

16:30–17:00 Coffeebreak17:00–18:45 • Subgroupsofpointgroups19:00–20:00 Dinner

Day 3: 10 October 2017, Tuesday

Lecturers:prof.MassimoNespolo,prof.MoisAroyo

9:00–11:00 • Metrictensorandcrystallographiccalculations:normofavector,anglebetweenvectors,changeofbasis.

11:00–11:30 Coffeebreak

11:30–13:30 • Symmetryoperationswithascreworglidecomponent.• Frompointtospacegroups.

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13:30–15:00 Lunch

15:00–16:30 • Examplesandexercisesonspacegroupdiagrams.• Projectionsofspacegroupsandtheirtwodimensionalsymmetry.


17:00–18:45 • Groupsubgrouprelations.Klassengleiche,translationengleiche,isomorphicsubgroups.Changeofbasisfromgrouptosubgroup.Definitionandbasicfeaturesofparentanddaughterphases.

• Integral,zonalandserialdiffractionconditions.• Diffractionsymbolandpossiblespacegroupscorrespondingtoit.

19:00–20:00 Dinner

Day 4: 11 October 2017, Wednesday

Lecturers and guidance:Dr.DanielaKarashanova,Dr.DianaNihtianova,Dr.BogdanRanguelov,Dr.MihailTarassov

09:30 Workinggroupsatrotationalprinciple1/2day TransmissionElectronMicroscopy(TEM)laboratoryvisit

• basicsofTEM• samplepreparationforTEM• experimentalSAEDandCBEDpatternscaption

1/2day Scanningelectronmicroscopy(SEM)–laboratoryvisit• basicsofSEM• samplepreparationforSEM• ElectronBackScatteredDiffraction(EBSD)

11:00–11:3016:00–16:30

CoffeebreakandexchangeofgroupsCoffeebreakandPostersession

13:30–14:45 Lunch14:45–15:00 School’sphotoinfrontofthemainentrance15:00–17:00 Postersession19:00–20:00 Dinner

Day 5: 12 October 2017, Thursday

Lecturer:prof.JokeHadermann

9:30–11:00 • IndexingofanEDpattern.• Calculation/simulationofaSAEDpatternforagivencompound(fromcellparametersandzoneaxis).

• ReconstructionoftheunitcellfromSAEDalongdifferentzoneaxes.


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11:30–13:30 • ConnectionofthesymmetryinrealspacetothatoftheEDpattern.• AnalysisoftheinformationonecanobtainfromCBED.

13:30–15:00 Lunch

15:00–16:30 • DifferencesbetweenthesymmetryinformationfromSAED(additionofinversioncentre,can‘tdistinguishmor2)andCBED(candistinguishallpointsymmetryelements).

• ExercisesonexperimentalSAEDandCBEDpatterns


17:00–18:30 • Fromsuperlattices(subcells)inEDtosublattices(supercells)inrealspace.

• DeterminationofpointgroupsandspacegroupsfromEDpatterns.

19:30–22:30 OfficialDinner

Day 6: 13 October 2017, Friday

Lecturer:prof.MassimoNespolo

9:30–11:00 • Domains(twins,antiphasedomains);effectoftwinningonthediffractionpattern.

• Calculationoftwinindex,obliquity,unitcellofthetwinlattice.• Splittingofreflectionsfollowingaphasetransitiontoalowerlatticesystem.

11:00–11:30 CoffeebreakLecturer:prof.JokeHadermann

11:30–13:30 • EffectofthepresenceofsymmetryoperationswithaglidecomponentonEDpatterns,effectofscrewaxes,GjonnesMoodielines

• DeterminationofspacegroupsfromEDpatterns

13:30–15:00 Lunch15:00–16:30 • Dynamicaleffectsofthemultiplediffractionsandtheireffectonthe

reflectionconditionsandexpectedequivalenceofreflections.• Partialreconstructionofthespacegroupsymmetryfromatomicresolutionimages(projectionofspacegroups,effectsofmisorientation).


17:00–18:30 • ShortintroductiononthepossibilitiesofextractingandusingthereflectionsonEDpatternsinaquantitativemannertosolvestructuresabinitioandtorefinestructures.

• Exercisesonthedeterminationofspacegroupfromelectrondiffractionpatterns.

18:30–18:45 Concludingremarks(Dr.DanielaKarashanova)19:00–21:00 Farewelldinner

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Necessary background (assumed achieved by all participants):• Interactionofradiationwithmatter.• Elementaryphysicsofscatteringanddiffraction.Fouriertransform,atomic

scatteringfactorandstructurefactor.• Reciprocallattice.• Bragg‘slawandEwald‘ssphere.

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CONTENTS

XRaydiffraction,hightemperatureMössbauerandRamanspectroscopystudiesofSr3–xCaxFe2TeO9(0≤x≤1)doubleperovskite...................................... 11Abdelhadi El Hachmi, B. Manoun, Y. Tamraoui and P. Lazor

EffectofRuonthemagneticpropertiesofNi50Mn38Sb12....................................... 12Akhilesh K. Patel, K. G. Suresh

Valorizationofwastefromthewoodindustry(sawdust)andtheiruseasadsorbentmaterial:physicochemicalcharacterization,modelingandoptimizationadsorptionusingResponseSurfaceMethodology(RSM)................. 15Asmaa Salamat, Adib Merieme, Abdelkbir Kenz, Mohammed Talbi, M’hamed Elkouali, Tarik Ainane

Effectofannealingtemperatureonthecrystallinestructure,growthbehaviourandpropertiesofAlnicotypethinfilms................................................ 16Delia Patroi, Yuri Nikitenko, Vladimir Zhaketov, Eugen Manta, Eros Alexandru Patroi, Mirela Maria Codescu

SurfaceelectromigrationofAuonGe(111)byLowEnergyElectronMicroscopy............................................................................................... 17Ali El Barraj, Stefano Curiotto, Fabien Cheynis, Pierre Müller, Frédéric Leroy

Detectionandselectivityofexhaustgasestunedbyhydrophobiczeolites............ 19J. Grand, F. Dubray, S. N. Talapaneni and S. Mintova

StructureoftwonewK2SnX(PO4)3(X=Cr,In)Langbeinitetypephases............ 21H. Bellefqih, A. Marchoud, R. Fakhreddine, N. Boudar, R. Tigha and A. Aatiq

StructuralanalysisofFe/Vsuperlatticeusingtransmissionelectronmicroscope(TEM).................................................................................................. 22Hasan Ali

ChloritefromElatsitePCD,asamineralvector..................................................... 26H. Georgieva, R. Nedialkov

StudiesaboutM400andM800steelsampleseriesusingneutrondiffractionmeasurements........................................................................................ 27Alexandru Iorga, Delia Patroi, Gizo Bokuchava, I.V. Papushkin, Eros-Alexandru Patroi, Eugen Manta, Florina Radulescu

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Scanningelectronmicroscopy:adirectmethodofidentifyingpollengrains........ 29I. Piroeva, S. Atanasova-Vladimirova

Mesoporousnanostructuredceriatitaniamixedoxidedopedwithcopperascatalystsforsustainableenvironmentalprotection:Effectofpreparationprocedure......................................................................................... 30I. Genova, G. Issa, R. Ivanova, J. Henych, M. Dimitrov, D. Kovacheva, V. Štengl, T. Tsoncheva

DifferencesinthecrystallizationbehavioroftheBa0.6Sr0.4Zn2Si2O7phaseinthepresenceofoxidesandnoblemetals................................................... 32L. Vladislavova, Ch. Thieme, Ch. Rüssel

NewinsightsintotheeffectofawashinwateronthepropertiesofNa3V2(PO4)2F3–yOy(0≤y≤2)materialsaspositiveelectrodesforNaionbatteries................................................................................................................... 33L. H. B. Nguyen, T. Broux, P. Sanz Camacho, T. Bamine, A. Iadecola, L. Bourgeois, E. Suard, D. Carlier, Ch. Masquelier and L. Croguennec

TridymitefromAlšarundertheSEMEDSandXRDinvestigations–evidenceforsilicicvolcanism................................................................................. 38M. Lazarova, T. Sijakova-Ivanova, I. Boev and B. Boev

Investigationofthechemisorptionof3aminopropylsilylgroupsonsilicagelusingspectroscopytechniques.......................................................................... 39Miha Bukleski

Pt(Cu)catalystformethanoloxidationpreparedbygalvanicreplacementonTiO2powdersupport.......................................................................................... 41N. Dimitrova, J. Georgieva, S. Sotiropoulos, Tz. Boiadjieva-Scherzer, E. Valova, S. Armyanov

Morphologicalcharacterizationoforganicinorganichybridmaterials................. 43N. Velikova, Y. Ivanova, I. Spassova

StructureandmagneticpropertiesofSr3Co2Fe24O41............................................... 44P. Peneva, T. Koutzarova, S. Kolev, Ch. Ghelev, B. Vertruyen, R. Closset, R. Cloots and A. Zaleski

Microstructuralcharacterizationofblacktourmaline............................................. 45R. Angelov, B. Georgieva, L. Angelova and D. Karashanova

Goniometryin21stcentury.Whynot?................................................................. 47S. Dencheva

Surfacemorphologyofwinecrystals..................................................................... 48S. Atanasova-Vladimirova, I. Piroeva

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In vitro bioactivegelatin/silvercontainingsolgelglassescomposites:FTIRandSEManalysis.......................................................................................... 49L. Radev, O. Kersten, I. Michailova, T. Dimova, Diana Zaimova

ChemicalbondingandnonlinearopticalpropertiesofTeO2–Bi2O3–B2O3glasses................................................................................... 50T. Tasheva, V. Dimitrov

Canineseminalplasma–functionsandinteractionwithcapacitation................... 51D. Daskalova, T. Tsvetkov, K. Lazov, D. Gradinarska, M. Hristova, M. Ivanova

CrystallochemistryofM2+hydroxysaltminerals.................................................... 52Z. Delcheva

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X-Ray diffraction, high temperature Mössbauer and Raman spectroscopy studies of Sr3–xCaxFe2TeO9 (0 ≤ x ≤ 1) double

perovskite

AbdelhadiElHachmi1,*,B.Manoun1,Y.Tamraoui1andP.Lazor2

1 Laboratoire des Sciences des Matériaux, des Milieux et de la modélisation (LS3M), FP Khouribga, Hay Ezzaitoune BP 145, Khouribga 25000, Université Hassan 1er, Morocco

2 Department of Earth Sciences, Uppsala University, SE-752 36, Uppsala, Sweden

*[email protected]

Keywords:Doubleperovskite,Sr3–xCaxFe2TeO9,Xraydiffraction,Ramanspectroscopy.

DoubleperovskiteswithgeneralstoichiometryA2BB′O6(A=alkalineearths;B,B′=transitionmetals)havebeenthetopicofalargenumberofstudiesin the lastfewyears,since thediscoveryofcolossalmagnetoresistanceinSr2FeMoO6 [1] and Sr2FeReO6 [2] because this effect is of technologicalinterestforthedetectionofmagneticfieldsandinmagneticmemorydevices[3].ThesematerialsarehalfmetallicferromagnetswithTC’ssignificantlyaboveroomtemperature.

XraydiffractionandRamanspectroscopystudiesofCasubstituteddoubleperovskitecompoundSr3–xCaxFe2TeO9with (0≤x≤1)were investigated.BothRietveldrefinementsandRamanstudiesatroomtemperatureshowedthatserieshaveatetragonalsymmetrywiths.g.I4/m.PhasetransitionsareobservedbyRaman spectroscopy from tetragonal to cubic structures as afunctionof temperature.For this series, the transitions showconsiderablechangesinthetemperaturedependenceofthemodes:AlltheRamanmodesshowalinearbehaviorwhentemperatureisincreased,thentheslopechangedramaticallyindicatingthesymmetrychangebetweenthetwosystemsencounteredintheseries.Mössbauerstudiesrevealthepresenceofironinthe3+oxidationstate.Aparamagnetictoferromagnetictransitionisobservedwhenstrontiumissubstitutedbycalcium(forx=0andx=0.5thematerialsareparamagneticandwhenx=1,thecompositionbecamemagnetic).References[1] Kobayashi,K.I.etal.(1998)Nature395,677.[2] Kim,T.H.etal.(1999)Appl.Phys.Lett.74,1737.[3] Ramirez,A.P.(1997)J.Phys.:Condens.Matter.9,8171.

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Effect of Ru on the magnetic properties of Ni50Mn38Sb12

AkhileshK.Patel,K.G.Suresh*

Department of Physics, Indian Institute of Technology Bombay, Mumbai-400076, India

*[email protected]

Abstract.We report on the structural,magnetic and transport propertiesofRudopedNi50Mn38Sb12Heusleralloy.Thechangesinthecriticaltemperatureswiththemagneticfieldareexamined.Apartfromsecondordermagneticphasetransitionat326K,afirstorderstructuraltransitionfromcubicaustenitetoorthorhombicmartensiteoccursat265K.Magnetocaloriceffectiscalculatedandthemagneticentropychangein70kOeisfoundtobe12.3Jkg–1K–1.

1. IntroductionThemultifunctionalityofHeusleralloyslikemagnetocaloriceffect(MCE),shape memory effect, exchange bias, magnetoresistance, has paramountsignificance in condensedmatter physics. In particular,MCE in these alloys is promising [1]. In recent years, numerousmagneticmaterials havebeeninvestigatedinsearchofpotentialmagneticrefrigerantmaterials[2].Though, the first ordermagnetic phase transitionmaterials are associatedwithlatentheatandthermalhysteresis,thesematerialsarefoundtoexhibitlarge change inmagnetic entropy (ΔSM) at the transition temperature [2].Recently,NiMnbasedHeusleralloysbecameverypromisingduetotheirfirstordertransitionnearroomtemperature,largeMCEandshapememoryeffect[3,4].InNiMnbasedcompoundsNiMnSn,NiMnInandNiMnSbarepromising[5–8].Inthiswork,westudiedtheeffectofRusubstitutionforNiinNi50Mn38Sb12.

2. Experimetnal TechniquesPolycrystallineNi46Ru4Mn38Sb12 ispreparedbyarcmeltingtheconstituentelements of highpurity.The ingot ismelted several times to ensured thehomogeneity.MagnetizationismeasuredusingSQUIDVSM(QD,USA).XraydiffractioniscarriedoutusingPANalytical.ImaginganddiffractionpatternwerecarriedoutbyFEGTEM.

3. Results and discussionFig. 1(a) shows the temperature dependentmagnetization in 500Oe collectedusingzerofieldcooling(ZFC),fieldcooledcooling(FCC)andfield–

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cooledwarming(FCW)modes.Therespectivetemperaturesofmartensitic,austeniteandferromagneticphasesarelabeled.Magnetizationisothermsatatemperatureintervalof3KaroundthemartensitictransitiontemperatureTM~265K,arerecorded(notshownhere).

Usingtheseisotherms,themagnetocaloriceffectofNi46Ru4Mn38Sb12isestimatedusingtheformulagivenbelow.

(1)

Fig.1showstheroomtemperatureXraydiffraction(XRD),whichcrystalizeincubicwithFm–3mspacegroup.Fig.2(a)showstheHRTEMimage,

Fig. 1. RoomtemperatureXraydiffractionofNi46Ru4Mn38Sb12

1

0

),(),(H

H HM dH

THTMHTS

Fig. 2.(a)HRTEMimageofNi46Ru4Mn38Sb12(b)TEMdiffractionpatternofNi46Ru4Mn38Sb12

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whichshowscrystallinenature.Fig.2(b)showstheTEMimageofthesampleandcorrespondingplanesindexedbytheir(hkl)values,whichisshowedcubicstructureandconfirmedtheXraydiffraction

4. ConclusionsInconclusion,adetailedstructuralandmagneticstudyofRudopedNiMnSbbasedHeusleralloyiscarriedoutusingXRD,TEMandmagnetization.Apart fromsecondordermagneticphase transitionat326K,a firstorderstructuraltransitionfromcubicaustenitetoorthorhombicmartensiteoccursat 265K. Inparticular,MCEaroundmartensitic transition temperature isfoundtobeabout12.3Jkg–1K–1.

AcknowledgementAKPacknowledgesUGCforthefinancialsupportthroughJRF.

References[1] A.K.Nayaketal.,2009J.Phys.D:Appl.Phys.42 035009[2] Pecharskyetal.,1997Phys. Rev. Lett. 78 4494[3] UllakkoKetal.,1996Appl. Phys. Lett. 69 1966[4] PasqualeMetal.,2005Phys. Rev. B72 094435[5] KrenkeTetal.,2005Nature 4 450[6] BhobePAetal.,2007Appl. Phys. Lett. 91 242503[7] KhanMetal.,2007J. Appl. Phys. 101 053919[8] DuJetal.,2007J. Phys. D: Appl. Phys. 40 5523

Fig. 3.(a)TemperaturedependentmagnetizationofNi46Ru4Mn38Sb12intherageof5–400K.Therespectivetransitiontemperaturesarelabeled.(b)Thechangeinmagneticentropyasafunctionoftemperature

inafewrepresentativemagneticfields.

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Valorization of waste from the wood industry (sawdust) and their use as adsorbent material: physicochemical

characterization, modeling and optimization adsorption using Response Surface Methodology (RSM)

AsmaaSalamat1,AdibMerieme1,AbdelkbirKenz1,MohammedTalbi1,M’hamedElkouali1,TarikAinane1,2*

1 Laboratory of Analytical Chemistry and Physical Chemistry of Materials, Faculty of Sciences Ben Msik, University of Hassan II, BP 7955 Casablanca 20660, Morocco

2 Superior School of Technology – Khenifra (EST-Khenifra), University of Moulay Ismail, PB 170, Khenifra 54000 Morocco

Keywords:waste,woodindustry,sawdust,physicochemicalcharacterization,modeling, optimization,RSM.

Thepresentworkreportsonsimpleandeffectiveecofriendlyapproachforthevalorizationofsawdust(wastefromthewoodindustry)intheenvironmentalapplicationasadsorbentbiomaterials.

Afterdetermination thephysicochemicalpropertiesof the tested sawdust:pH, conductivity, the biomaterial was characterized using various instrumental techniques including scanningelectronmicroscope (SEM), energydispersive spectroscopy (EDS) and Fourier transformed infrared spectroscopy(FTIR).

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Effect of annealing temperature on the crystalline structure, growth behaviour and properties

of Alnico-type thin films

DeliaPatroi1,YuriNikitenko2,VladimirZhaketov2,EugenManta1,ErosAlexandruPatroi1*,MirelaMariaCodescu1

1 National Institute for R&D in Electrical Engineering INCDIE ICPE-CA, 313 Splaiul Unirii, 030138, Bucharest, Romania

2 Joint Institute for Nuclear Research, Frank Laboratory of Neutron Physics, Dubna, Russia

*eros.patroi@icpeca.ro,[email protected]

Keywords:Alnico,Thinfilms,Sputtering,RareEarthfree.

Thin films of nominal composition Fe44.7Al17.2Co22.3Ni12.7Cu3.1 (at%) havebeen prepared by DC magnetron sputtering from the same compositiontargetalloy,closetoAlnico5permanentmagnets.TheirstructurehasbeenstudiedbymeansofscanningelectronmicroscopyandXraydiffractionandrevealsapartlyamorphousstateintheaspreparedsamples.

TheirmagneticpropertiesareweakerthanthoseofaclassicAlnicopermanentmagnetorthosepreviouslyreported.Thefilmswererapidannealedat1000°C, following twodifferentwaysof rapidcooling,similar toclassicAlnicopermanentmagnetsannealingprocedure,thenstructuralandmagneticpropertieschangeswereinvestigated.Perpendicularmagneticanisotropywasrevealedwhilethemorphologyisdevelopingfromthincontinuousfilmtoacrystallinenanoparticulatefilm.

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Surface electromigration of Au on Ge(111) by Low Energy Electron Microscopy

AliElBarraj,StefanoCuriotto,FabienCheynis,PierreMüller,FrédéricLeroy

CINaM-CNRS UMR 7325, Campus de Luminy Case 913 13288 Marseille Cedex 9, France

Theprojectconsistsinstudyingelectromigrationprocesses[1]atsurfacesinmetalsemiconductorsystems[2,3].Inpresenceofanelectriccurrentpassingthroughasample,anelectromigrationforcemayapplyonsurfaceatomsresultinginaglobalmasstransfer.ThisforcecanbedescribedasF=Z*eE,whereZ* isaneffectivevalence,e istheelectronchargeandE istheappliedelectricfield.TheeffectivevalenceZ* takesintoaccountboththeelectrostatic interactionbetweentheelectricfieldE andthesurfaceatomcharge(chargetransferwiththesubstrate)calledthedirectforceandthefrictionalforceresultingfromthetransferofmomentumfromthechargecarrierstosurfaceatoms(windforce)[4].

WehavefirststudiedtheelectromigrationofAuatomiclayersonGe(111)substrate.Theexperimentswereperformedin situ inaUltraHighVaccum(UHV) setupequippedwithaLowEnergyElectronMicroscope (ElmitecLEEM III microscope) [5]. The Ge(111) single crystals were cleaned inUHVandpreparedbyionbombardment(Ar)andhightemperatureannealing(900°C).Thenapproximately0.5MLofAuisdepositedattheGe(111)surface.Upon640°CtheAulayerformsadilute1×1reconstructionwhereasitrearrangesintodense√3×√3R30°reconstructeddomainsbelow.Wehavecharacterizedthedriftmotionof√3×√3domainsonatomicallyflatterracesinducedbyadirectelectriccurrent(~106A.m–2).Thedomainsvelocitydependsonthetemperature(Jouleseffect)andelectriccurrent.Increasingthetemperaturebetween500–640°C,theAudomainsvelocityvariesapproximatelyfrom30to800nm.s–1.

In the following figurewe can see anArrhenius plot of theAu domainsvelocity.Theslopeshows tworegimesathighand lowtemperature.Thisresultindicatesthattwomaindifferentprocessesofelectromigrationoccur.However,thedriftvelocityisindependentonthedomainsizeshowingthattheelementaryprocessofmotion isdominated inbothcasesbya terracediffusionprocessratherthanperipherydiffusionorattachmentdetachment.

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References[1] P.S.HoandT.kwok,Rep.Prog.Phys.52,301–348(1989).[2] H.YasunagaandA.Natori,Surf.Sci.Rep.15,205–280(1992).[3] T.Ichinokawaetal.Phys.Rev.B47(15)9654(1993).[4] C.Taoetal.,Science328,736–740(2010).[5] F.Cheynisetal.Rev.Sci.Instru.B85043705(2014).

Fig. 1.(a)LEEMsequenceof2imagesshowingAudomainsdrift.(b)Arrheniusplotofthedomainvelocity.

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Detection and selectivity of exhaust gases tuned by hydrophobic zeolites

J.Grand1*,F.Dubray,S.N.Talapaneni2andS.Mintova1

1 Laboratoire Catalyse et Spectrochimie, Normandie Université, ENSICAEN, CNRS, 6 boulevard Maréchal Juin, 14050 Caen, France

2 University of South Australia (UniSA) Mawson Lakes Campus, South Australia, SA 5095, Australia

*[email protected]

NanosizedMFItypezeolitenanocrystalscontainingdifferentmetalatoms,either incorporated in theframework(W–MFI)orextraframework(Sn–MFI)havebeenpreparedandassembledashomogeneousandstablefilms.Inaddition,puresilicaMFI(Si–MFI)zeolitefilmswerepreparedandusedas reference samples. All zeolite nanocrystals were spincoated on siliconwafersviaamultistepdepositionusingapolymerbinderinordertoincreasethemechanicalstabilityof thefilms.TheobtainedzeolitefilmswereexposedtodifferentconcentrationsofCO,CO2,NOandNO2gases(1–100 ppm) in the presence ofwater (100 ppm). The influence of thelocalizationofthemetalsandthehydrophobicityontheirselectivityandsorptioncapacitytowardsexhaustgaseswasinvestigatedbyfollowingthesorptionbehaviorbyoperandoIRspectroscopy.The high sensitivity of bothSnMFI andWMFI films towards very lowconcentrationsofexhaustedgases,especiallyCO2andNO2,inthepresence

Fig. 1. Detection ofCO2with (a)W–MFIand(c)Sn–MFIfilmsandCOwith (b)W–MFI and (d) Sn–MFIfilms.

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ofwaterwasdemonstrated(1–3ppm). Interestingly, ithasbeenobservedthattheincorporationofmetalatomsinthezeoliteframework,W–MFIfilm,leadstoanincreasedsensibilityandsorptioncapacitytowardsCOandCO2,whencomparedwiththeextraframeworkSn–MFIfilm(Fig.1).ThiscouldbeexplainedbythehigherhydrophobicityoftheWMFImaterial.

AcknowledgementWeacknowledgethefinancialsupportfromTARGED.

References[1] S.N.Talapaneni,J.Grand,S.Thomas,H.A.Ahmed,S.Mintova,Materials and Design

2016,99,574.[2] J.Grand,S.N.Talapaneni,J.P.Gilson,S.Mintova,PatentWO2017068387A12017;J.

Grand,S.N.Talapaneni,A.Vicente,C.Fernandez,E.Dib,H.A.Aleksandrov,G.N.Vayssilov,R.Retoux,P.Boullay,J.P.Gilson,V.Valtchev,S.Mintova,Nature Mater.,accepted.

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Structure of two new K2SnX(PO4)3 (X = Cr, In) Langbeinite-type phases

H.Bellefqih*,A.Marchoud,R.Fakhreddine,N.Boudar,R.TighaandA.Aatiq

Département de Chimie, Laboratoire de Physico-Chimie des Matériaux Appliqués, Université Hassan II de Casablanca, Faculté des Sciences Ben M’Sik, Avenue Idriss

El harti, B.P. 7955, Casablanca, Morocco

*[email protected]

Keywords:langbeinitestructure;Rietveldrefinement;Xraydiffraction.

Structures of twoK2SnX(PO4)3 (X=Cr, In) phosphates, obtainedby conventionalsolidstatereactiontechniquesat950°C,weredeterminedatroomtemperaturefromXraypowderdiffraction(XRD)usingtheRietveldanalysis. The twomaterials exhibit the Langbeinitetype structure (P213 spacegroup,Z=4).Cubicunit cellparametervaluesare:a=9.8741(1)Åanda = 10.0460(1)Å forK2SnCr(PO4)3 andK2SnIn(PO4)3 respectively. FinalRietveldrefinementsleadtoacceptablereliabilityfactors(e.g.,Rwp=9.1%;RB=5.2%forK2SnCr(PO4)3andRwp=8.1%;RB=5.1%forK2SnIn(PO4)3.LangbeiniteframeworksareprincipallybuiltofSn(X)O6octahedrasharingcornerswithPO4tetrahedra.Structuralrefinementsshowthatthetwocrystallographicallyindependentoctahedralsites(ofsymmetry3)haveamixedSn/X (B=Cr, In) population. The two potassium cations occupied largeisolatedcageswithintheframework.

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Structural analysis of Fe/V superlattice using transmission electron microscope (TEM)

HasanAli

Angström Laboratory, Upsala, Sweden

[email protected]

Fe/Vmultilayershavebeenusedasamodel system to studyandexplorevariousfundamentalproblemsincondensedmatterphysics,forexamplethinfilmmagnetism[1].Insuchthinmetallicmultilayers,thephysicalpropertiesofthesystemstronglydependoncrystalqualityofthestructure.Thecrystalqualityinturnisinfluencedbylayerthicknessandstraininthesystem.Tostudytheeffectofthicknessandstrainoncrystalquality,Fe/Vmultilayerswere grownwith different layer thicknesses and subsequently the crystalstructureandstrainwasdeterminedbyusingdifferenttechniques.

Transmissionelectronmicroscope(TEM)wasappliedasastructuralcharacterizationtooltodeterminethelayerstructureandstraininoneofthegrownsamples.ThesamplechosenforTEMcharacterizationwasaFe/Vsuperlattice(SL)withFe=4andV=28monolayers(ML)depositedonasinglecrystallineMgO(001)substrate.TheSLstartsandendswithVlayerandwascappedwithapalladium(Pd)layertoreducetheeffectsofoxidation.

Thesamplewaspreparedbyusingquadmagnetronsputteringsystem.Thesamplestagewasrotatedtoobtainahomogeneousdepositionacrossthesurface.Thetemperatureofthesubstratewascontrolledwithin~1K.Thebasepressureofthegrowthchamberwas2.7×10–7Paandwasachievedusingthecombination of a turbomolecular pump and aTi sublimation pump.Thetargetswere99.99%pureandtheArgaswasof99.9997%purity.

TEM sample was prepared in a crosssectional geometry by mechanicalpolishing, dimple grinding and finally grazing incidence Ar ion milling.Scanningtransmissionelectronmicroscope(STEM),highresolutionTEM(HRTEM)andselectedareadiffraction(SAD)techniqueswereappliedtodeterminethestructureandmeasurethestraininthesystem.Fig.1showsahighangleannulardarkfield(HAAD)imageofthesample.Itcanbeseenthatthelayersareflatandnowavinessispresent.Fig.2showsaHRTEMimageof thesample.Due tocloseatomicnumbersofFeandV,noclearcontrastisseenbetweenthelayers.AlsoduetoatomicstepsattheMgOsub

23


strate,itisveryhardtoexactlymarktheinterfacesbetweenFeandV.ThelatticespacingsofFeandV,bothinplaneandoutofplane,weremeasuredusinglineprofiles.Thestraininthesystemwasthendeterminedusingtheformula

Fig. 1. HAADFimageofFe/V(4/28)SL

Fig. 2. HRTEMimageofFe/V(4/28)SL

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ThemeasuredvaluesofstrainaregiveninTable.1.Thesevaluescloselymatch to thevaluesmeasuredbyour collaboratorsusing an analysispresentedbyBirchetal.[2].

Fig.3showstheSADpatternofthesample.TheSLreflectionscanbeseenveryclearly.TheSLperiodwasmeasuredtobeabout4.54nmwhichagreesverywellwiththepreviouslymeasuredvaluesbyXraytechniques.

Inconclusion,weuseTEMasastructuralcharacterizationtool tocloselyviewthelayeringandcrystalstructureofFe/V(4/28)SLdepositedonMgO(001)substrate.Wemeasurethevaluesoflatticeparameters,strainandsuperlatticeperiodwhichcloselymatchtothepreviouslymeasuredvaluesbyXraytechniquesandhenceverifyandstrengthenthoseresults.

Table. 1. Measured values of strain from Fig. 1

Fig. 3.SADpatternofFe/V(4/28)SLattheregionofMgOfilminterface

25


References[1] B.Hjorvarsson, J.A.Dura,P. Isberg,T.Watanabe,T. J.Udovic,G.Andersson,C.

F.Majkrzak, Reversible Tuning of theMagnetic Exchange Coupling in Fe/V (001)SuperlatticesUsingHydrogen,Phys.Rev.Lett.79(5)(1997)901–904.

[2] J.Birch,J.E.Sundgren,P.Fewster,Measurementofthelatticeparametersintheindividuallayersofsinglecrystalsuperlattices,JApplPhys78(11)(1995)6562.

26


Geochemical characteristics and composition of chlorites from Elatsite PCD, Bulgaria

H.Georgieva*,R.Nedialkov

Sofia University “St. Kliment Ohridski”, Faculty of Geology and Geography

*[email protected]

The Elatsite porphyry copper deposit (PCD), part of the ApuseniBanatTimokSrednogoriecopperbelt,isoneofthebiggestandwellstudiedPCDsinEurope.ItsoremineralizationisrelatedtotheUpperCretaceousmagmatism.Asmallporphyriticintrusion(QmonzodioritetoGranodiorite)elongatedinEWdirectionandmanyporphyriticdikesareintrudedintherocksof the basement (theVezhenVariscan granodiorite pluton and the variegatedPaleozoicgreenschistdegreeschists).Studiesontheoremineralizationreveal5oremineralparageneses–thehydrothermalrockalterationsaredeterminedaspropylitic,hightemperatureKsilicatealteration,Ksilicatesericitic,Qsericiticandquartzadulariacarbonaticalteration.

Chlorites in Elatsite have been established through: a) propylitic alterationwithchlorite(Chl1)replacingmagmaticbiotiteandamphiboles;b)Ksilicatesericitic alterationwithChl2 replacing the hydrothermal blackmica(phlogopite);c)QsericiticandquartzadulariacarbonaticalterationswhereChl3participatesintheformationofnests(simultaneous)andveinlets(subsequenttothealterations).

Studyingtheprocessofchloritizationisanimportantstepforthebetterunderstandingand interpretationof thedistributionoforecomponentof thedeposit.After the electronmicroprobe andLAIMSMSanalysisof chloritefromthedifferenttypesofalterationsisestablishedanunequaldistributionoforeelementsinalteredminerals.Thereforethenextstepinthestudywillbetheapplicationofelectronmicroscopyasamethodtodeterminethemechanismofsubstitutionofminerals[1,2].

References[1] Eggleton, R. and Banfield, J.(1985) The alteration of granitic biotite to chlorite –

AmericanMineralogist,Vol.70,pp.902–910.[2] Yuguchi, T., Sasao, E., Ishibashi, M., Nishiyama, T. (2015) Hydrothermal chloriti

zationprocesses frombiotite in theTokigranite,Central Japan:Temporalvariationsof thecompositionsofhydrothermalfluidsassociatedwithchloritization–AmericanMineralogist,Vol.100,pp.1134–1152.

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Studies about M400 and M800 steel sample series using neutron diffraction measurements

AlexandruIorga1*,DeliaPatroi1,GizoBokuchava2,I.V.Papushkin2,ErosAlexandruPatroi1,

EugenManta1,FlorinaRadulescu1

1 INCDIE ICPE-CA, Bucharest, Romania 2 FLNP JINR, Dubna, Russia

*alexandru.iorga@icpeca.ro

Keywords:Neutrondiffraction,electricalsheets,magneticlosse.

The have been investigated structural changes in specimen seriesM400andM800byneutronTOFdiffractionmethod.TheexperimentswereperformedonFourierstressdiffractometerFSDattheIBR2fastpulsedreactorinFLNPJINR(Dubna,Russia)[1,2].TheFSDdiffractometerwasspeciallydesignedforresidualstressstudiesinbulkindustrialcomponentsandnewadvancedmaterials.OnFSDaspecialpurposecorrelationtechnique is used to achieve high resolution level of the diffractometer – acombinationofthefastFourierchopperfortheprimaryneutronbeamintensitymodulationandthereversetimeofflight(RTOF)methodfordataacquisition[3,4].

DuringtheexperimentontheFSDdiffractometerinvestigatedsampleswereinstalledonHUBERgoniometerwithflatsideperpendiculartotheincidentneutron beam limited by diaphragmof 10×24mm. In thisway it is possibletoobtainhighresolutionneutrondiffractionspectraΔd/d≈2·10–3forbackscatteringdetector(2θ=140°)andΔd/d≈4·10–3for±90°detectorsatd=2Åwiththefairlyshortflightdistance(~6.6m)betweenFourierchopperandneutrondetectors[5].

CharacterizationofmagneticmaterialwasperformedbymeasuringthemagneticpropertieswithSingleSheetTester–SST,foramagneticpolarizationJ=50,…1500mT,sinusoidal,atfrequencyf=3,...50.200HzaccordingtorulesDIN50462.Theenergylossesseparationwasperformedinordertoidentifyandreduceeachcomponentoftheselosses:eddycurrentloss(Wcl);hysteresisenergyloss(Wh);excessloss(Wexc)duetoeddymicrocurrentthatoccursatthemovementofthedomainwalls.

28


References[1] G.D.Bokuchava,V.L.Aksenov,A.M.Balagurov,V.V.Zhuravlev,E.S.Kuzmin,A.P.

Bulkin,V.A.Kudryashev,V.A.Trounov,“Neutron Fourier diffractometer FSD for in-ternal stress analysis: first results”,AppliedPhysicsA:MaterialsScience&Processing,v.74[Suppl1],2002,pps86–s88.

[2] A.M. Balagurov, G.D. Bokuchava, E.S. Kuzmin, A.V. Tamonov, V.V. Zhuk,“Neutron RTOF diffractometer FSD for residual stress investigation”,ZeitschriftfürKristallographie,SupplementIssueNo.23,2006,pp.217–222.

[3] P.Hiismäki,H.Pöyry,A.Tiitta,“Exploitation of the Fourier chopper in neutron dif-fractometry at pulsed sources”,JournalofAppliedCrystallography,Vol.21,1988,pp.349–354.

[4] A.M. Balagurov, I.A. Bobrikov, G.D. Bokuchava, V.V. Zhuravlev, V.G. Simkin,“Correlation Fourier Diffractometry: 20 Years of Experience at the IBR-2 Reactor”,PhysicsofParticlesandNuclei,2015,Vol.46,No.3,pp.249–276.

[5] G.D.Bokuchava,A.M.Balagurov,V.V.Sumin,I.V.Papushkin,“Neutron Fourier dif-fractometer FSD for residual stress studies in materials and industrial components”,JournalofSurface Investigation.Xray,SynchrotronandNeutronTechniques,2010,Vol.4,No.6,pp.879–890.

29


Scanning electron microscopy: a direct method of identifying pollen grains

I.Piroeva*,S.AtanasovaVladimirova

Rostislaw Kaischew Institute of Physical Chemistry, Bulgarian Academy of Sciences

*[email protected]

AsimplemethodofusingscanningelectronmicroscopytoobservepollengrainsThismethoddoesnotrequirefreezedrying,criticalpointdrying,orany chemical fixation procedures to prepare the specimens for scanning.Pollengrainscanbe identifieddirectly from thescanningelectronmicrographs,thusexpeditingthestudy.Thepollenhasbeentakenfromherbariummaterials.IthasbeenobservedandshotwithScanningElectronMicroscope(SEM)JEOLJSM6390withoutanypreliminarytreatment.Pollensampleshasbeencoveredbygoldpowder.

Shotingshasbeenmade inmagnifications900and15000.While thesecondaryelectronimagingmode,themostcommoninuse,hasgreatvalueincharacterizingtheexinesurfaceitispossibletoobtainamorecomprehensiverepresentationofpollengrainwallsbyexpandingthecapabilityofthesecondarymodeimagingdetectors.

30


Mesoporous nanostructured ceria-titania mixed oxide doped with copper as catalysts for sustainable environmental

protection: Effect of preparation procedure

I.Genova1*,G.Issa1,R.Ivanova1,J.Henych2,M.Dimitrov1,D.Kovacheva3,V.Štengl2,T.Tsoncheva1

1 Institute of Organic Chemistry with Centre of Phytochemistry, BAS, Sofia, 1113, Bulgaria 2 Materials Chemistry Department, Institute of Inorganic Chemistry AS CR

3 Institute of Inorganic Chemistry, BAS, Sofia, 111, Bulgaria

*[email protected]

Keywords:nanostructuredmetaloxides,totaloxidationofethylacetate,methanoldecomposition.

Recently,thesynthesisofnanostructuredmetaloxideshasbecomeahighlydevelopedfieldandattractedtheattentionofthescientistsintheirpursuitofstructuralpeculiaritiesandvariousunusualphysical,chemicalandcatalyticproperties.Aspecialinterestandeffortshavebeenfocusedonthepreparationofmetaloxideswithhighspecificsurfaceareaand/orcrystallineparticlesinthenanosizedrangeusingvarioussyntheticroutes.Itwasreportedthatdopingoftitaniawithtransitionmetalscanincreaseitscatalyticactivityandthermalstabilityasaresultofspecificinteractionand/orsynergismbetweenvariousmetaloxideparticles.Theaimofcurrent investigation istofollowtheeffectofcoppermodificationprocedureofmesoporousceriatitaniaoxidesontheircatalyticbehaviourinmethanoldecompositiontoCOandhydrogenasapotentialalternativefuelandethylacetateoxidationasarepresentativeVOCs.

Forthepurposeofinvestigationthemesoporousceriaand/ortitaniaoxidesweresynthesizedbytemplateassistedhydrothermaltechniqueusingCTABasstructuredirectedagent.Forthefirsttimea“chemisorptionhydrolysis”(CH)techniquewasappliedforthecopperloadingontheceriaand/ortitaniaoxidesandcomparedwiththeconventionalincipientwetnessimpregnation(WI)procedure.Thecoppercontentinallmaterialswasabout9wt.%.TheobtainedmaterialswerestudiedbyacomplexofphysicochemicaltechniquessuchasXRD,N2physisorption,XRD,TEM,SEM,UVVis,Ramanand FTIR spectroscopies and TPR of H2. The catalytic properties of theobtainedmaterialswerestudiedinoxidationofethylacetateandmethanol

31


decomposition.High surface areamesoporous ceriatitania binarymaterials can be successfully synthesized using template assisted hydrothermaltechnique.Binaryoxidesupportsexhibitimproveddispersion,highsurfaceareaandporevolumecombinedwithexcellentoxygenmobility.Smalladditivesofcoppertoceriaand/ortitaniaoxidespromotedtheircatalyticactivityin totaloxidationof ethyl acetate andmethanoldecomposition to syngas,butthiseffectisstronglyinfluencedbypreparationprocedure.Theapplied“chemisorptionhydrolysis” technique provided formation ofmore homogeneously and finely dispersed copper specieswhich also possess highercatalyticactivityascomparedtotheconventionalincipientwetnessimpregnationtechnique.

AcknowledgementsFinancialsupportfromprojectDM09/4/2016isacknowledged.

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Differences in the crystallization behavior of the Ba0.6Sr0.4Zn2Si2O7 phase in the presence

of oxides and noble metals

L.Vladislavova1*,Ch.Thieme1,2,Ch.Rüssel1

1 Otto-Schott-Institut, Chair of Glass Chemistry I, Jena University, Fraunhoferstr. 6, 07743 Jena, Germany

2 Fraunhofer Institute for Microstructure of Materials and Systems IMWS, Walter-Hülse-Str. 1, 06120 Halle, Germany

*liliya.vladislavova@unijena.de

Keywords:Nucleation,Crystallization,Platinum,ZrO2,Lowthermalexpansion.

TheeffectofdifferentnucleationagentstotheglasssystemBaOSrOZnOSiO2wasstudied.Glassesweremeltedwithdifferentconcentrationsofadditives such asZrO2,TiO2, andPt.The obtained glass ceramicswere investigatedbydifferentmethodsalsowithrespecttotheircrystallizationbehavior.ThecrystallizationkineticsofglassesfromwhichBa1–xSrxZn2Si2O7(0.1≤x≤0.9)solidsolutioncanbeprecipitatedisofincreasinginterest.ThisphasehasasimilarstructuretotheHTphaseofBaZn2Si2O7andpossessesvaluesofthermalexpansionclosetozeroorevennegative.Materialswhichdonotchangetheirdimensionduringheatingfindapplicatione.g.incookpanels,telescopemirrors,andothers.

For thecharacterizationof theglassceramics,Xraydiffractionwasusedtodeterminetheobtainedcrystallinephase.Thecombinationoflightscanningmicroscopyandscanningelectronmicroscopywasusedtocharacterizethemicrostructureandtodeterminethecrystallitesize.Applyingdifferentheatingratesinadifferentialscanningcalorimeter,enabledtocalculatetheactivationenergyusingtheequationsofOzawaandKissingeraswellastheAvramiparameters,whichprovidefurtherinformationonthecrystallizationprocess.

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New insights into the effect of a wash in water on the properties of Na3V2(PO4)2F3–yOy (0 ≤ y ≤2) materials

as positive electrodes for Na-ion batteries

L.H.B.Nguyena,b,f,T.Brouxa,b,f,P.SanzCamachoa,f,T.Baminea,f,A.Iadecolac,f,L.Bourgeoisd,E.Suarde,D.Carliera,f,

Ch.Masquelierb,f,gandL.Croguenneca,f,g

a ICMCB-CNRS, Université de Bordeaux, Bordeaux INP, 87 avenue Schweitzer, 33608 Pessac Cedex (France)

b Laboratoire de Réactivité et de Chimie des Solides, CNRS-UMR#7314, Université de Picardie Jules Verne, 33 Rue Saint Leu, 80039 Amiens Cedex (France) c Soleil Synchrotron, L’Orme des Merisiers, 91190 Saint-Aubin (France) d ISM, Université de Bordeaux, Bordeaux INP, 33405 Talence (France)

e ILL – Institut Laue-Langevin, 38000 Grenoble (France) f RS2E, Réseau Français sur le Stockage Electrochimique de l’Energie,

FR CNRS 3459, Amiens Cedex (France) g ALISTORE-ERI European Research Institute, FR CNRS 3104, Amiens Cedex (France)

Sodiumionbatteries (SIBs) have recentlybeendeveloped as an alternatefor future sustainable energy storage system in place of the conventionallithiumionbatteries(LIBs).AmongstthosewhichhavelatelybeenstudiedaspositiveelectrodematerialsforSIBs,Na3V2(PO4)2F3isthemostpromisingoneduetoitshighlystablepolyanionicframework,anditshightheoreticalenergydensityof507Wh.kg–1(128Ah.kg–1atanaveragepotentialof3.95Vvs. Na+/Na)whichiscompetitivewithLiFePO4thathaslongbeenusedinLIBs[1–5].However,mostofthematerialsreportedintheliteraturetobeNa3V2(PO4)2F3 are in factoxygensubstitutedones (Fig.1). Inorder

Fig. 1. 3Drepresentationofthestructurewith a partial oxygen substitution for

fluorineinNa3V2(PO4)2F3–yOy(0<y≤2)[6].

34


todetermine theeffectofoxygensubstitutionon thecrystalstructureandelectrochemicalpropertiesofNa3V2(PO4)2F3,Brouxet al. synthesisedasolidsolutionNa3V2(PO4)2F3–yOywithyrangingbetween0and0.5andrevealedthat thericher inoxygencontent, the lower theaveragedischargevoltageis,andthesodiumdeintercalationmechanismevolvedfromaseriesofbiphasicreactionsfory=0toasolidsolutionalloverthecompositionrangeuptoy=0.5[6].Thepresenceofoxygendefectsinthesecompoundscanbeeasilydetectedbytheuseof23Naand31PMASsolidstatenuclearmagneticresonance(ssNMR).

Inthiswork,thestudyontheformationofasolidsolutionNa3V2(PO4)2F3–yOywasextendedtohigheroxygencontent(0.75≤y≤2).Furthermore,theeffectsofawashinginwateronthecrystalstructureandelectrochemicalperformanceofthesematerialswerealsostudiedindetailsas:(i) thephaseswerealwaysobtainedwithasmallamountofimpurities(Na3VF6andNa5P3O10)whichcanbeeasilyremovedbyawashinginwater,(ii) asurginginterestintheelectrodeformulationinaqueoussolution,and(iii) thestabilityofthematerialwhenstoredinhumidconditionshastobedetermined.Withy<1,

thewashingsimplywashedawayalltheundesirable impurities. When the oxygencontentexceededy=1,thewashingledtoasignificantchangeinthecolouroftheobtainedpowdersandtoanunexpectedmassivemassloss,especiallyforthemostoxidisedphase.Thesignificantmass loss in the oxidised phases wasdue to thedissolutionofanamorphousphaseandofthecrystallinedecompositionproducts.Thedisappearanceoftheamorphous phasewas clearly observedbySEM(Fig.2).

Theresultsofourstudyrevealedthatthesolid solution Na3V2(PO4)2F3–yOy couldbeextendeduptoy=1(Fig.3).

Despiteofbeingreportedinliterature,anyofoureffortstostabilisethephaseswithy> 1 always led to the formation of anamorphousphaseinthepresenceofacrystallineonewhoseunitcellparametersare

Fig. 2. SEMimageofNa3V2(PO4)2FO2(y=2)powderbeforewashing(a),and

afterwashing(b).

35


similar to those of Na3V2(PO4)2F2O(y = 1), or to the decomposition ofNa3V2(PO4)2F3–yOyintoseveralproducts, includingNaVOPO4,Na4P2O7,andNaP1/3V2/3O3.

The discovery of a solid solutionformationinthecompositionrangefromy=0uptoy=1wasalsosupportedbyacontinuousevolutioninthechemicalshiftsonthe31PMASNMR.InNa3V2(PO4)2F3,onemainresonant signal was recorded at δ= 6000 ppm corresponding to thedominantpresenceof theP(OVIII)4environment, the minor signal atδ = 4500 ppm was assigned totheP(OVIII)3(OVIV)environment,whichwascreatedby theexistenceofasmallamountofoxygendefectinthestructure.Uponoxygensubstitution,the intensityof thesignalatδ=6000ppmdiminishedwhilenewsignalsstartedtogrowatδ=3000,1500and0ppm,whichare thesignaturesofP(OVIII)2(OVIV)2,P(OVIII)1(OVIV)3,andP(OVIV)4,respectively.Theintensityofthelatestsignalreachedamaximumvaluewithatotaldisappearanceofothersignalsaty=1.5,suggestingthesolepresenceofP(OVIV)4environment,whichisincontradictionwiththetheoreticalcompositionofthematerial(25%VIIIand75%VIV)(Fig.4).

Fig. 3. TheevolutionoftheunitcellparametersofNa3V2(PO4)2F3–yOy(0≤y≤2)(Space

groupAmam).

Fig. 4. 31P MAS NMR spectra ofNa3V2(PO4)2F3–yOy (0 ≤ y ≤ 2) recordedwitha30kHzspinning rateandunder2.35Tmagneticfield.

36


Fig. 5.Ahigherzoominthediamagneticregimeof31PMASNMRspectraofNa3V2(PO4)2F3–yOy(0.75≤y≤2)recordedwitha30kHzspinningrateandunder

2.35Tmagneticfield.

Althoughtherewasonlyonesignal tobefoundonthe 31PMASNMRofNa3V2(PO4)2F3–yOywithy=1.5to2,ahigherzoomintothisregimerevealedthepresenceofadoubletwithdifferentrelativeintensity(Fig.5).Thisfindingsuggestedthattheremightbeasubtledifferenceinthelocalenvironmentinthosematerials.

ElectrochemicaltestswhichwereperformedinsimilarconditionsforeachcompositionofNa3V2(PO4)2F3–yOy–noCarboncoatingandanappliedcurrentofC/20–revealedthatonly1.5Na+ionscouldbeextractedfromthepristinematerialNa3V2(PO4)2F3–δOδ(δ~0)whiletwoNa+ionscouldbedeintercalatedreversiblyforallthemixedvalencecompositionsNa3V2(PO4)2F3–yOy(0<y≤2)showinganimprovedelectronicconductivity(Fig.6).

AcknowledgmentsTheauthorsthankSOLEIL(GifsurYvette,France)forSynchrotronXrayspectroscopyexperimentsonROCKbeamline(proposalnumber20160282).TheauthorsalsoacknowledgetheRS2ENetworkforthefundingofLHBN’sPhDthesis,aswellasthefinancialsupportofRégionNouvelleAquitaine,of

37


theFrenchNationalResearchAgency(STOREEXLabexProjectANR10LABX7601 and SODIUM Descartes project ANR13 DESC000102)andoftheH2020EuropeanProgram(ProjectNAIADES).

References[1] LeMeinset al.,J. Solid State Chem. 1999, 148 (2),260–277.[2] Tsirlinet al.,Phys. Rev. B 2011,84,014429116.[3] Parket al.,Adv. Funct. Mater. 2014, 24 (29),4603–4614.[4] Serraset al.,Chem. Mater. 2013, 25 (24),4917–4925.[5] Bianchiniet al.,Chem. Mater. 2014, 26 (14),4238–4247.[6] Brouxet al.,Chem. Mater. 2016,28,7683–7692.

Fig. 6.TheelectrochemicalperformanceoftheNa3V2(PO4)2F3–yOy(0≤y≤2)materialsinsodiumcellsatC/20andwiththesameelectrodecomposition

(Activematerial:Cblack:PVdF=80:10:10bywt.%).

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Tridymite from Alšar under the SEM-EDS and XRD investigations – evidence for silicic volcanism

M.Lazarova,T.SijakovaIvanova,I.BoevandB.Boev

Faculty of Natural and Technical Sciences, “Goce Delcev” University, Stip, Macedonia

Keywords:volcanism,silicic,tridymite,perlite.

This paper presents the mineralogical and geochemical investigations oftridymiteandperliteusingXRD,SEMEDSmethods.ThevolcaniccalderaAlšar is located in thewesternareaof thevolcaniccomplex in theKozufMountainatthefrontieroftheVardarzoneandthemetamorphiccomplexElenSupe, a relic of the oldPrecambrian continental crust.ThevolcanicactivityinthisareaofthevolcaniccomplexintheKozufMountainisrepresentedbyigneousrockswithdaciticrhyoliticcomposition.Therearemanysedimentpyroclasticrocksinthecompositionofthecaldera,representedbyvolcanoclastictuffswithlayersoftridymiteandlayersofperlite.

Tridymite appears in layers, few meters thick and its color is white.Transparenttotranslucentwithvitreousluster.Thestreakiswhite.Hardnessis6½–7,whiledensityis2.28–2.33g/cm3.Cleavageisindistincton{0001}andimperfecton{1010}.Tridymiteandperliteareusuallyassociatedwithsilicicvolcanism.Thereisalsocrystobaliteandsmalleramountofopalintridymite’s composition. The appearance of opal is due to the diageneticchangesofthehightemperatureSiO2glass.Normalizedvaluesoftherareelementearthshow thedistribution in thesamemanneras in the igneousrocksatthevolcaniccalderaofAlšar.

39


Investigation of the chemisorption of 3-aminopropylsilyl groups on silica gel using spectroscopy techniques

MihaBukleski*

Ss. Cyril and Methodius University in Skopje, Faculty of Natural Sciences and Mathematics, Institute of Chemistry, Arhimedova 5, 1000 Skopje,

Republic of Macedonia

*[email protected]

Keywords:3aminopropyltrimethoxysilane(APTMS),Silicagel,chemisorption,DRIFTspectra,IRstudies.

Themainpurposeofusing3Aminopropyltrimethoxysilane(APTMS)wastofunctionalizesilicagel’ssurfaceforitsfurtheruseinobtainingferrocenylderivativethatcanexhibitcatalyticactivity.APTMShastwodifferentfunctionalgroups(aminoandmethoxymoieties)andcanthusbeusedasacouplingagent(spacer),especiallyonsilicagelasshowninFig.1.

Thepresentinvestigationisconcernedwithseveralquestions,oneofwhichis the spectroscopicdetectionof chemisorbedmoleculesofAPSon silicagel,assignmentofthebandsandderivingconclusionsonthepossibleconformationandformedbondsofthechemisorbedgroups.TheotherquestionconcernsspectroscopicinvestigationofpossiblechemicalreactionbetweentheferrocenylphosphinederivativeandtheAPSmolecules.Theanswertothesequestionsisimportantsinceitgivesdirectproveofabuiltheterogene

Fig. 1. ChemicalreactionbetweenthefreeOHgroupsfromtheactivatedsilicagelandAPTMSinanhydrousconditions

40


ous catalyst, because the so obtainedmodified silica gelwith ferrocenylphosphinemoleculesalreadyshowscatalyticproperties.

As a first step, a method for quantitative determination of the attachedAPTMSmoleculesasaminopropylsilil(APS)fragmentsonthesilicagel’ssurfaceisproposed.ThequantificationwasdonebymeansoftheDiffuseReflectance Infrared Fourier Transform (DRIFT) spectroscopy technique.TheappearanceandvanishingoftheIRbandsarisingfromtheOH,CH2andNH2vibrationswerefollowed.ThemaximumamountoftheAPSwasdeterminedbyintegratingthespectrainthefrequencyrangeoftheν(CH2)/ν(CH3)vibrationsbetween3014and2808cm–1.Theresultswerefurtherconfirmedbycarbonelementalanalysis,AASandBETsurfacemeasurements.

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Pt(Cu) catalyst for methanol oxidation prepared by galvanic replacement on TiO2 powder support

N.Dimitrova1*,J.Georgieva1,S.Sotiropoulos2,Tz.BoiadjievaScherzer3,E.Valova1,S.Armyanov1

1 Rostislaw Kaischew Institute of Physical Chemistry, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria

2 Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece

3 CEST Kompetenzzentrum für elektrochemische Oberflächentechnologie GmbH, Wiener Neustadt, Austria

*[email protected]

Pt(Cu)catalystwaspreparedbyphotodepositionofCuonTiO2powdersupport,followedbypartialgalvanicreplacementofCubyPtinachloroplatinatesolution.Pt/TiO2catalystwaspreparedbyadirectphotodepositionofPtonTiO2supportforcomparison.Thesurfacemorphologyandcompositionofthesampleswerecharacterizedbytransmissionelectronmicroscopy(TEM), energydispersive spectrometry (EDS) and Xray photoelectronspectroscopy (XPS).The crystal structureof thePt(Cu)/TiO2 andPt/TiO2catalystswas examined byXray diffraction (XRD).The electrochemicaland photoelectrochemical behavior of both platinized TiO2 catalysts was

TEMmicrographandSAEDimageofPt(Cu)/TiO2catalyst

42


evaluated by cyclic voltammetry, linear sweep voltammetry and chronoamperometryexperimentsinthedarkandunderUVlightillumination.TheelectrocatalyticactivityofthePt(Cu)/TiO2catalysttowardsmethanoloxidationwasevaluatedandcomparedtoPt/TiO2catalyst.ThePt(Cu)/TiO2catalyst showed5 timeshighermasscatalyticactivity formethanoloxidationthanaPt/TiO2catalyst,furtherenhancedunderUVlightillumination.TheincreasedcatalyticactivityisassociatedwithmoreeffectivedispersionandbetterutilizationofPt,depositedbygalvanicreplacementofCu,aswellaswithenhancedelectronholeseparationefficiency.

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Morphological characterization of organic-inorganic hybrid materials

N.Velikova1*,Y.Ivanova2,I.Spassova1

1 Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria

2 Department of Silicate Technologies, University of Chemical Technology and Metallurgy, Sofia, Bulgaria

*[email protected]

Keywords:Solgel,silsesquioxane,hybridmaterials,mesoporousmaterials,surfactant.

Theobjectiveofthisworkisthesynthesisofmesoporousorganicinorganicsilicabasedmaterialsbysolgelmethod,aswellastoinvestigatetheinfluenceofthereactionconditionsonthematerialsmorphology.

ThematerialsweresynthesizedbysolgelmethodbyusingofPluronicP123(nonionic triblock copolymer) as a structure directing agent, silsesquioxane (Bis[3(trimethoxysilyl)propyl]amine ([(CH3O)3Si(CH2)3]2NH)) andtetraethyl orthosilicate (Si(OC2H5)4) under acidic condition.Thematerialsmorphologywas investigated by byXray diffraction, Scanning ElectronMicroscopy, Transmission Electron Microscopy and nitrogen adsorptionmeasurements after removing of P123 by extraction in acidic solution.Obtainedsampleshaveparticlelikemorphology,highvaluesofporesize,porevolumeandsurfaceareaafterextractionoftheusedtemplate.

44


Structure and magnetic properties of Sr3Co2Fe24O41

P.Peneva1*,T.Koutzarova1,S.Kolev1,Ch.Ghelev1,B.Vertruyen2,R.Closset2,R.Cloots2andA.Zaleski3

1 Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee, 1784 Sofia, Bulgaria, е-mail: [email protected]

2 LSIC, Chemistry Department B6, University of Liege, Sart Tilman, B-4000 Liege, Belgium

3 Institute of Low Temperature and Structure Research, PAS, 50422 Wroclaw, Poland

*[email protected]

Themultiferroics aremultifunctionalmaterialswhere twoormoreof theprimaryferroicproperties(ferromagnetism, ferroelectricity, ferroelasticity, ferrotoroidicity)coexist.Theinterestinmagnetoelectricmultiferroicmaterialsinwhichferroelectricityandferromagnetismarebothpresentisduetothemagnetoelectriceffect.Themainrequirementtotheapplicationsofthemagnetoelectricmultiferroicmaterialsisthatthemagnetoelectriccouplingbebothlargeandactiveatroomtemperatureandthemagneticorderingtemperaturebehigh.TheZtypehexaferriteSr3Co2Fe24O41exhibitsamagnetoelectriceffectatroomtemperature.

WereportstudiesofstructuralandmagneticpropertiesofSr3Co2Fe24O41inpowdersandinbulkform.Theprecursorpowderswerepreparedfollowingthesolgelautocombustionmethodandsynthesizedat1200°CtoproduceSr3Co2Fe24O41.Toprepare thebulksample, theSr3Co2Fe24O41powderwaspressed,heattreatedat1200°Cfor5hoursandrapidlyquenchedtoroomtemperature.

TheXRDspectraofthepowdershowedthecharacteristicpeakscorrespondingtotheZtypehexaferritestructureasamainphaseandsecondphasesofCoFe2O4.TheSEMimagesofthepowdersampleshowsthattheparticlesarewellagglomeratedtoformclustersofdifferentsizesandshapes.Inthebulksample,weclearlyobservedlargeregionsofthehexagonalparticleswithastructureorderedalongthecaxis.Magneticphasetransitionsinthetemperaturerangeof4.2-300Kwerealsoobservedconnectedtothedifferentspinstructure.

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Microstructural characterization of black tourmaline

R.Angelov,B.Georgieva,L.AngelovaandD.Karashanova*

Institute of Optical Materials and Technologies, Bulgarian Academy of Sciences, Acad. Georgy Bonchev str., bl. 109, 1113 Sofia, Bulgaria

*[email protected]

“Tourmaline” is the unifying name of a group of boron silicatemineralswithcommoncrystalstructureandalargevarietyofelementsintheircomposition.Togetherwithmuscovite,tourmalineisthemineralwiththemost

Schorl,RhombohedralSGR3m(160)a=15.97c=7.16

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applications in the industry,due to theexceptionalphysicalandchemicalpropertiesashighpiezoandthermoelectricity,radiationinthefarinfraredregion,significantcatalyticactivityetc.

Themicrostructureandthephasecompositionofblacktourmaline–schorl,from Vladaya vein in Vitosha Mountain are studied by means of HighResolutionTransmissionElectronMicroscopy(HRTEM)andXRDanalysis(PhaseidentificationaccordingtoPDF851811[PDF2,ICDD]).

BrightfieldandHRTEMmicrographsandselectedareaelectrondiffraction(SAED)patterns–polyandsinglecrystalline,receivedalongdifferentzoneaxesarepresented.

47


Goniometry in 21-st century. Why not?

S.Dencheva

Sofia University “St. Kl. Ohridski”

[email protected]

In the ages of nanotechnologies,modern scientists seem to have lost thetastefortheclassicalgoniometricresearch.ButasfarasIknow,thisistheonlywaytoanswerthequestion:“Whatsimpleformsactuallygrowinthecrystal?”Andthisissuehasnotlostitsrelevanceduetotheanisotropyofthepropertiesofsubstanceswithsymmetrylowerthanthecubic.Andif,thankstoGoldschmidt,thesimpleformsof“grandfathered”mineralsareknown,itisnotsofortherecentlydiscoveredandthemicroscopicones.

Thisworkaimstobrieflyintroduceyoutotheauthor’seffortstodeterminetheMiller’sindicesofsimpleformsofselectedminerals,bothatmacroormicrolevels.

AcknowledgementsIwouldliketoexpressmyacknowledgementstoProf.GeorgiKirov,whointroducedmetotheworldofcrystallographyandhasbeensupportingmeinanumberofstudies.

48


Surface morphology of wine crystals

S.AtanasovaVladimirova*,I.Piroeva

Rostislaw Kaischew Institute of Physical Chemistry, Bulgarian Academy of Sciences

*[email protected]

Tartrates, affectionately known by industry professionals as “wine diamonds”,are tiny,crystallinedeposits thatoccur inwineswhenpotassiumandtartaricacid,bothnaturallyoccurringproductsofgrapes,bindtogethertoformacrystal.Itlookslikesugargranulesandisfoundatthebottomofthebottleorstucktothestopper.Inbottledwine,thepresenceoftartaricacidanditssalts,potassiumbitartrateandcalciumtartrate,canresultinformationofcrystallineprecipitates.Unpurifiedpotassiumbitartratecan takeon thecolorofthegrapejuicefromwhichitwasseparated.

Thescanningelectronmicroscope(SEM)viewssurfacesofwinecrystals.Theyhavingdifferentsurfacemorphologiesandhabitswereobtained:thinplates,prismfaces,pyramidgrainetc.

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In vitro bioactive gelatin/silver containing sol-gel glasses composites: FTIR and SEM analysis

L.Radev1*,O.Kersten2,I.Michailova3,T.Dimova4*,DianaZaimova1

1 University of Chemical Technology and Metallurgy, Department of Fundamental Chemical Technology, Sofia, 1756, Bulgaria

2 Anhalt University of Applied Science, Department of Engineer Science, Koethen, 06366, Germany

3 University of Chemical Technology and Metallurgy, Department of Silicate Technology, Sofia, 1756, Bulgaria

4 Department of Pharmaceutical Science, Medical University, Varna, 9000, Bulgaria

*[email protected]

Themainobjectivesofthepresentedstudyisthepreparationof80BG/20G(inwt.%)compositesbetweensolgelglasses(BG)intheSiO2–CaO–P2O5–xAg2O (x=0, 1, 2 and4wt.%) systemandgelatin (G), after soaking in1.5SBFsolutionsfor12daysinstaticconditions.ThestructureandinvitrobioactivityofthepreparedcompositeswereexaminedbyXRDandFTIR.

XRDforthecomposites,beforesoakingin1.5SBFsolutions,revealedthepresenceofdifferentCaCO3crystallinephases,suchasaragonite,calciteandvaterite.Inthepreparedsamples,XRDalsodetectedthepresenceofinsituformedhydroxyapatite,accompaniedwithwollastonitephase.FTIRofthestudied80BG/20Gcomposites,aftersoakingin1.5SBFsolutions,provedtheformationofBtypecarbonatecontactinghydroxyapatite(bioapatite)on their surface.SEMEDXresultsof the soaked samples showthepresenceofHAaggregatesonthesoakedsurceases.Onthebasesofresultsobtainedwecanconclude that the synthesizedBG/Gcompositesareinvitrobioactive.

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Chemical bonding and nonlinear optical properties of TeO2–Bi2O3–B2O3 glasses

T.Tasheva*,V.Dimitrov

Department of Silicate Technology, University of Chemical Technology and Metallurgy, 8 Kl. Ohridski Blvd, 1756 Sofia, Bulgaria

*[email protected]

OxideglassesinthesystemTeO2–Bi2O3–B2O3arepreparedusingaconventionalmelt quenching method. The polarizability approach based on theLorentzLorenzequationisapplied.Theopticalbasicityandtheoxideionpolarizabilityareestimated.Thetheoreticalrefractiveindexandtheenergygapoftheglassesarealsoestimated.Thechemicalbondingoftheglassesiselucidatedonthebasisoftheinteractionparameterandthesinglebondstrengthofanaveragecationoxideion(M–O)bond.

Itisfoundthattheglassespossessrelativelyhighvaluesoftheopticalbasicityand theelectronicoxide ionpolarizability, relatively lowvalues fortheaveragesinglebondstrengthand lowvaluesof the interactionparameter.TherefractiveindexbasedthirdordernonlinearopticalsusceptibilityoftheglassesisestablishedusinggeneralizedMiller’sruleandthreephotonmodel.Theglassespossesscomparativelyhighthirdordernonlinearopticalsusceptibility(~10–13esu).Theseresults indicatefor thepresenceofweakchemicalbondswhichareformedbetweenTeO4,BiO6,BO4andBO3groupsconfirmedbyIRspectralanalysis.Structuralmodelofthestudiedglassesisproposed.

51


Canine seminal plasma – functions and interaction with capacitation

D.Daskalova,T.Tsvetkov*,K.Lazov,D.Gradinarska,M.Hristova,M.Ivanova

Institute of Biology and Immunology of Reproduction – BAS

*[email protected]

Keywords:chromatography,seminalplasmaproteins,hyperactivation,capacitation,spermatozoa.

Semenisaheterogeneousandcomplexcellsuspensioninaproteinrichfluidwithvariousfunctions,someofthemwellknown,otherstillunexplained.Theaimofthecurrentresearchisfocusedoncanineseminalplasmaproteinsandtheirfunctionalrelationshipwithcapacitationofspermatozoa.Attemptsweremadetoidentifycanineseminalplasmaproteinswitheffectonspermcapacitation andmotility.HighPerformanceLiquidChromatographywasdoneand4seminalplasmaproteinfractionswereobtainedandfurthercharacterizedbyelectrophoresis(7.6–200kDa).ComputerassistedspermanalysisafterincubationofspermatozoawithseparatedseminalplasmaproteinsrevealedthatFraction1,consistingofhighmolecularweightproteins(70–200kDa), could increase thepercentageof spermatozoawithprogressiveandrapidmotility.IncubationwithseminalplasmaproteinsfromFraction1leadstoasignificantincreaseofVCL(Curvilinearvelocity)anddecreaseofLIN(Linearity)ofspermatozoa,whencomparedtotheothertestsamplesandthecontrolsample.Proteinswithhighmolecularweightprobablyhavethemostsignificantinfluenceontheprocessofhyperactivationandcapacitationofcaninespermatozoa.

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Crystallochemistry of M2+-hydroxysalt minerals

Z.Delcheva

Institute of Mineralogy and Crystallography – Bulgarian Academy of Sciences, “Acad. Georgi Bonchev” block 107, 1113 Sofia

[email protected]

Thehydroxysaltmineralsformasubstantialpartofthemineralogicalnomenclature.Theyarenormallystableoverasmallrangeofexternalconditions (such as Eh, pH, T, P, concentration of solutions, component ratio,impurities,etc)aswellas theyarecommonlyassociatedwithmanyothermineralsofsimilarcompositionsinsameparageneses.Incontrasttothestablerockformingmineralsthehydroxylsaltmineralsreacttoslightenvironmentalchangesthroughchangesinthecrystalstructure.Therefore,theyareconvertedeasily(andveryoftenreversibly)intoeachotherunderenvironmentalchanges.

Theexcellent resistanceofzincandzincplatedsteelundernaturalconditionsisduetotheformationofaprotectivecorrosionlayerofzinchydroxysalts(zincrust).Themineralcompositionofthislayerdependsstronglyontheexposureenvironment,anditsprotectiveeffectisdeterminedbythemorphologyandarrangementofthecrystals[1].Thezinchydroxysaltsarealsothesubjectofstudybecauseofsomeotherusefulproperties:ionexchangeand sorption properties, photocatalytic properties, hydrogengas sensingproperties,flameretardantproperties[2,3]aswellastheirapplicabilityasprecursorsofnanostructuredZnOforvariousapplications[4,5].

Themutual transformations of the Zn2+ hydroxylsalt minerals with general formulaZn2+(OH)2–xAx/n

n– .±H2O,where inAareSO42–(osakaite,na

muwite, lahsteinite, gordaite), Cl– (simoncolleite), NO3– (synthetic NO3

simoncolleite)andCO32–(hydrozincite)wereinvestigated.Thebipolarchar

acterofthedominantanion(OH–)predetermineslayeredcharacterofstructuresoftheinvestigatedminerals[6],whiletheabilityofZn2+iontosettlebothintetrahedralandoctahedraloxygencoordinationexplainsthespecificoctahedraltetrahedral construction of the layers inZn hydroxysalts. Themainbuildingunitisthebrucitelikelayerinwhichoneseventh(osakaite,namuwite,lahsteinite,gordaite)oronefourth(simoncolleite,hydrozincite)oftheoctahedralsitesarevacant.Thezinccationsarelocatedoneithersideofthevacantoctahedralpositions.These(tetZn2+)aretetrhedrallycoordinated

53


bythreeOHgroupsofbrucitelikelayersandawatermolecule(inosakaite,NO3simoncolleite),aCl–anion(ingordaiteandsimoncolleite),OatomofCO3

2– anion inhydrozincite.Thus, theoctahedraltetrahedral layer canbecharacterizedas“interrupteddecoratedsheet”[7].

Theinteractionofmineralswithchloride,nitrate,sulfateandcarbonatesolutionswithaparticularattentiontothereactionmechanismswasstudied.TheinitialandnewlyformedphasesweremainlycharacterizedbyXraypowderdiffraction,becausethepowderXraydiffractiondataadequatelyreflectthechanges in thecompositionof the systems.TheSEM investigationswereusedtorevealreaction(transformation)mechanisms.

Theinterpretationofthemutualtransformationmechanismisbasedonthecrystalchemical and morphological similarities between parent and newformedphase.

Twotypeoftransformationmechanismswerefoundtoproceed:adissolutionprecipitationprocess(DSP)andasolidstatetransformation(SST).

The results reveal the crucial role ofweakly bonded components for thestructurestability.Suchcomponentsarenonhydroxylanions(Cl,CO3,SO4,NO3), watermolecules and interlayer cations. Thus, the ratio octahedral/tetrahedral positionof the layer dependsonnonhydroxyl anion– sulfateanionrequiresformationof layerwith6:1ratioandmonodentatebondingof theanion. In thecompositionswith3:1anionsdictate theformationofthestructureswithdifferentsymmetry:Cl–anionscausethecrystallizationofthemineralswithrhombohedralcell,whiletheCO3

2–,NO3––orthorhom

biccell.Thechangeoftheenvironmentalcompositionleadstoreactionbetweennonhydroxylanionsof the interlayerandthesolutioncomponents.Asaresult,newtypeofinterlayerisformed.Ifitiscompatible(i.e.satisfiesthebondvalencerequirementsoftheoctahedraltetrahedrallayer),thesolidstatetransformationisoccurred.Ifduringtheexchangereaction,thecomponentsofthenewinterlayercannotformastablesystemofhydrogenbonds,the crystal is destroyed and the transformation becomes trough theDSPmechanism.Insomecases,anewsystemofHbonds,preservingthelayeriscreatedandtransformationproceedsthroughSSTmechanism.

References

[1] Volovitch,P.,Allely,C.,Ogle,K.2009.Understandingcorrosionviacorrosionproductcharacterization:I.Casestudyof theroleofMgalloying inZnMgcoatingonsteel.Corrosionscience.51,1251–1262.

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[2] Hongo,T.,Lemur,T.S.,Satokawa,S.,Yamazaki,A.2010.ChromateadsorptionandpHbufferingcapacityofzinchydroxysalts.Appl.ClaySci.48,455–459.

[3] He,P.,Gao,H.D.,Wu,L.B.,Jiang,Z.W.,Wang,G.L,Li,X.M.2013.PorousZnOsheets transformed fromzinc sulfatehydroxidehydrate and their photoluminescenceperformance.ActaPhys.Chem.Shin.29,874–880.

[4] Moezzi,A.,Cortie,M.B.,McDonagh,A.M.2013.Zinchydroxidesulfateanditstransformationtocrystallinezincoxide.DaltonTrans.42,14432–7.

[5] Liang, W., Li, W., Chen, H., Liu, H., Zhu, L. 2015. Exploring electrodepositedflowerlike Zn4(OH)6SO4.4H2O nanosheets as precursor for porous ZnO nanosheets.ElectrochimicaActa.156,171–178.

[6] Hawthorne, F. C. 1992. The role of OH and H2O in oxide and oxysalt minerals.ZeitschriftfurKristallographie.201,183–206.

[7] Hawthorne,F.C.,Schindler,M.2000.Topologicalenumerationofdecorated[Cu2+ϕ2]Nsheetsinhydroxyhydratedcopperoxysaltminerals.Can.Mineral.38,751–761.

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Characterization of cuprite (Cu2O) particles from waste copper cake

GyunverHodjaoglu

Institute of Physical Chemistry – Bulgarian Academy of Sciences (IPC-BAS) Acad. G. Bonchev Str., block 11, 1113 Sofia, Bulgaria

email:[email protected]

Coppercakeisanindustrialvaluablesecondarywasteproductproducedinthehydrometallurgicalzincplantaftercementationstageofcopperionswithzincpowder.Thewasteisdepositedaswetsedimentforexportorstorage.Dependingon thereactionconditions thecakecontainsahugeamountofcupriteparticles formedbycementationprocess and restparticles formedfromthesolutionimpurities.WiththeleachingandecologicalaspectscoppercakefromKCMPlovdivhasbeentreatedwithdilutedsulphuricacidforutilizationofthecupritecontent.InthisstudythedrysamplesbeforeandafterleachingprocedurewerecharacterizedbyScanningElectronMicroscopy(SEM)forobservationoftheparticlesmorphology(Cu2O)andappearanceofnewreactionproducts(CuSO4).EnergyDispersiveSpectroscopy(EDS)wasalsoappliedforthechemicalcharacterizationoftheobservedparticles.TheresultsshowthatSEMEDXisapowerfultechniqueforinitialfastdeterminationof leachingefficiencyanddetectionofcopper sulphatemicrocrystals.ItwasfoundthatthestartingwastecontainslargeamountofzincsulphatewhereasthefinalleachedcakeisZnfree.TheSEManalysisisveryperspectiveforfurthercharacterizationsofothertypesofcopperMecakes,theirchemicalcharacterizationandstudyingunidentifiedsolidparticlesduringdepositionandtestleaching.

AcknowledgementsThe author gratefully acknowledge the financial support of ProjectBG05M2OP0012.0090023,“Establishmentanddevelopmentofscientificpotentialforthespecializationsofphysicalchemistryandelectrochemistry”,fundedbytheOperationalProgram“ScienceandEducationSmartGrowth”,cofunded by the European Union through the European Structural andInvestmentFunds.

october 8–13, 2017, sofia, bulgaria program and...international autumn school on fundamental and...

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