microplasmas and nanostructures - jsps.go.jp · sturmtruppen satira of the 2nd world war. 5...
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Microplasmas and Nanostructures
from Italy via Belfast to Japan
by Davide MariottiJSPS Research Fellow
at the Nanoarchicectonics Research Center(AIST)
Today Menu
• Something about Italy• Something about Me
• Plasmas• Plasmas and Nanostrctures• MicroPlasma and Nanostructures
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Something about Italy
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Italy is a Constitutional RepublicPopulation: 58 462 375
• 9 000 people over 100 years old• 4% foreigners
Surface: 80% of Japan (46% of population)21 regions2 countries within our borders(San Marino and Vatican City)1 Italian territory (Campione) within Swiss bordersOfficial language: Italian(12 other languages officially
recognized)
Some numbers
Italy & Japan
Etna
Vesuvio
Stromboli
Vulcano
Active Volcanoesand Earthquakes
Campi Flegrei
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Definitely a good team is Valentino Rossi and Yamaha!!
Italy & Japan
Sport
Comics
DIABOLIKthief for the poor people
PAPERINIKWalt Disney character created by an Italian
STURMTRUPPENsatira of the 2nd World War
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Japanese mangasSince 1978 Japanese mangas and cartoons became very popular in
Italy, especially in TV
Italian survival kit
Intesi?!(understood?!)
Te lo giuro!(I promise)
Sono pappa e ciccia(they are one thing)
Me ne infischio!(I don’t care!)
E’ tocco!(He’s crazy!)
C’ha i paraocchi!(lit. he wears blinders)(He’s narrow minded!)
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Something about …
… meI was born here
My University
Electronic Engineering
I like snowboarding here
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… then …Hyvinkaain Finland
Dublinin Ireland
Loughboroughin England
Belfastin Northern
Ireland
PhD at University of
Ulster
…Today Menu
Something about ItalySomething about Me
• Plasmas• Plasmas and Nanostrctures• MicroPlasma and Nanostructures
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Plasma?Everything You Always Wanted to Know
About Plasmas * But Were Afraid to Ask
Molecules, electrons etc.Molecules or atoms• Not positively charged• Not negatively charged• Neutral
Excited molecules/ atoms
• Neutral• Energetic• Emit light
Ions• Molecules or atoms that
have lost one or more electrons
• Positively/Negatively charged
Electrons• Have escaped from
molecules or atoms• Negatively charged
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Solid, liquid, gas … and plasmas
LIQUID• Molecule bonds are flexible• Electrons close to
molecules
SOLID• Molecules fixed in lattice• Electrons bound to
molecules or lattice
GAS• Molecules free to move• Few electrons and ions that
are free to move• Some excited molecules
are present
PLASMA• Molecules free to move
• Many electrons, ions and excited molecules, all free
to move• … and light coming out
MoleculesExcited moleculesIonsElectrons
ENERGY
ENERGY
ENER
GY
Why plasma is different from a gas?
Collisions are to blame!Gas
Plasma
Therefore more and stronger collisions leading to more
ionization,excitation,
dissociation andradiation
MoleculesExcited moleculesIonsElectrons
Ionization
Excitation
Dissociation
Differenttypes ofMolecules &RADICALS
Radiation
ENERGY
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Where can we find plasmas?
• What do they look like?
• How big are they?
• What do they eat?
Luminous like a coloured light
Inconsistent like a burning flame
Big as the universe … or small as a spark or a pixel in a screen
Consume ENERGY
QUIZwhere can we find plasmas?
• Display
• Most of the Universe
• Lights,signs
• IC Industry
• FusionEnergy And many other places
• Material processing industry• Welding, cutting etc.• Gaseous pollutants abatement• Chemical analysis• … & many more in the future,
e.g nanotechnology
• Lightning
• Flames
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How do we make a plasma?
• Provide energy! How?• Heat transfer, radiation …• … in many cases… simply by Electric Field
and we call it Plasma or Discharge
+
-
∆V
MoleculesExcited moleculesIonsElectrons
plasmagas
In nature … Lightning
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Plasma Display applications,A simple view
Front Glass
Transparent Electrodes
Spacer
Back cover of the Display
Electrodes
TOP VIEW
+
-
Plasma
Plasma Display, the real one
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Plasmas in Material processing
WHY DO WE WANT TO MODIFY SURFACES?
- To obtain different properties- To form NANOSTRUCTURES with even more different
properties
plasma
Energy & reactive speciescan change the surface
GAS
Small changes atthe surface
Sputtering and etching
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deposition
Many things can be done with plasmas … but How to control
plasmas?
• Gas content (e.g. mixture of argon, nitrogen, hydrogen, methane etc.)
• Pressure, from low-pressure to atmospheric
• Plasma system configuration
• Energy given to the plasma
• …etc.
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PSU Circuit,Transformer etc.
GasElectrons/Ions
Joule’s Effect
EM FieldWork
Ionisation
Elasticcollisions
HeatTransfer
MaterialSurface
Material
ChemicalProcesses
Dissociation
ReactiveSpeciesKinetic
bombardment
Excitation
ElectronEmission
Energy flux
Particle flux
Plasmas … not that simple
Plasmas and Nanostructures
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What does a nanostructure look like?
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Gold thin layer
Molybdenum-oxide rods on Molybdenum wire
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Carbon flakes on Molybdenum wire
Which plasma should we use for nanostructures?
A lightning would destroy everything
… what about lightning? Would a small lightning work?
… BUT … (next video)
VIDEO
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Glow-like plasmas
VIDEO
microPlasmasand
Nanostructures
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• Glow-like at atmospheric pressure
• Reduced power
• Portable equipment
• Different plasma properties all together
Why MICROplasma?
Why MICROplasma?A = Surface = 6 x r2
V = Volume = r3
AV
= 6r2
r3
6r
=
r = 10 r = 1
AV
= 6r
0.6= AV
= 6r
6=
In the smaller cube, whatever you do at the surface is 10 times more important!!!!!
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Metallic Support
Gas in
Gas out
Capillary(contains flowing gas)
Metallicwire/tubing
Substrate
Our MICROplasma
Ground/Floating
Power Supply (High/Low Freq.)
studying MICROplasmasoptical emission diagnostic
Plasma Light Emission
Spectrometer
Optical Fibre
Plasma properties
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Plasma properties
Change & improve plasma
BetterNANOSTRUCTURES
… hopefully
有難うございました
Davide Mariotti
d.mariotti at aist.go.jp
Thanks to my host
Dr. Naoto Koshizaki
and all my colleagues, in particular:
Dr. Yoshiki Shimizu
Dr. A. Chandra Bose
Thanks to JSPS
for the opportunity to come to Japan and to come here in Takasaki
Thanks to You
for your attention
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