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Experimental and Molecular Dynamics Studies Related with Carbon Nanotubes
Experimental and Molecular Dynamics Studies Related with Carbon Nanotubes
Shigeo Maruyama
Dept. of Mech. Eng., The University of Tokyohttp://www.photon.t.u-tokyo.ac.jp/~maruyama/
E-mail: [email protected]
Colloquium Micro/Nano Thermal Engineering @ Seoul, 2002/2/18
(a) C60 (c) La@C82(b) C70
(e) SWNT (f) MWNT
C60
PVWin
(d) Sc2@C84
Typical Structures of Fullerene & NanotubesTypical Structures of Fullerene & Nanotubes
What is Carbon Nanotube?What is Carbon Nanotube?
Chirality and Radius of SWNTChirality and Radius of SWNT
(10,10)Armchair
(10,0) Zigzag (10,5) Chiral
a1
a2
http://vortex.tn.tudelft.nl/~dekker/nanotubes.html
STM Image of Individual AtomsSTM Image of Individual Atoms TEM Pictures of SWNT RopesTEM Pictures of SWNT Ropes
Individual tube diameter: 1.3 nmSpacing: 0.34 nmMisalignments and Terminations
TEM from Smalley et al. at Rice University
About 100 SWNTs
2
R. E. Smalley at Rice University
Bucky Paper (A Tangle of Ropes)Bucky Paper (A Tangle of Ropes)
Discovery of MWNT: Iijima (1991)
Discovery of SWNT (Co-Fe): Iijima(1993)
MWNT by CVD
Macroscopic Prod. SWNTs (Ni-Co): Smalley (1996)
Arc Production (Ni-Y): Journet et al. (1997)
SWNT by CVD catalytic growth from metal particle
Field Emission, AFM Tip, Hydrogen Adsorption
Discovery of Carbon NanotubesDiscovery of Carbon Nanotubes
Tips of AFM
Field Emission
Applications of NanotubesApplications of Nanotubes
Fuel Cell Electrode
FET BiosensorNanowires
H2 StorageMechanical
Generation of SWNTsGeneration of SWNTs
Laser-Oven SWNT GeneratorLaser-Oven SWNT Generator
Electric Furnace
Nd:YAG Laser
Manometer
Quarz Lens (f=1200mm)
Quartz Tube
LeakAr Flow
StopperQuartzWindow
Mo Rod
Target Rod
Holder
Vacuum pump
Pirani Meter
RotaionFeed-through
Laser-Oven Nanotube GeneratorLaser-Oven Nanotube Generator
TEM from Smalley et al. at Rice University100 200Ramam Shift (cm–1)
Inte
nsity
1.20nm
1.47nm
1.32nm
532 nm 53 %
532 nm 26 %
532 nm 1 %
3
He gas
Power(+) Power(-)
Window
Graphite Electrodes
CCDCamera
Reflector
Stepping motor
Vacuum pump
Arc-Discharge Generator
SEM Image of PurificationSEM Image of Purification
600nm600nm
Original Purified
Amorphous Carbon Bundle of Tubes
Catalytic CVD Generation of SWNTsCatalytic CVD Generation of SWNTs
Self-Oriented Arrays of MWCNTs by CCVD(H. Dai’s Group at Stanford)
Self-Oriented Arrays of MWCNTs by CCVD(H. Dai’s Group at Stanford)
CCVD (Catalytic Chemical Vapor Deposition)CCVD (Catalytic Chemical Vapor Deposition)
MgO supported Metal
1000 °C, methane
TEM Raman
J.-F. Colomer, C. Stephan, S. Lefrant, G. V. Tendeloo, I.Willems, Z. Konya, A. Fonseca, Ch. Laurent, J. B. Nagy
CPL (2000)
J.-F. Colomer, C. Stephan, S. Lefrant, G. V. Tendeloo, I.Willems, Z. Konya, A. Fonseca, Ch. Laurent, J. B. Nagy
CPL (2000)
Single walled carbon nanotubes (swnt)from Hi pressure CO ( Pco)
R. E. SmalleyCNLRice University
1 step
Gas phase
$500/gram
The HiPco ProcessThe HiPco Process
4
New Catalytic CVD Generation of SWNTsNew Catalytic CVD
Generation of SWNTs
Experimental TechniqueExperimental Technique
2.5/2.5 : Fe:Co (wt%) on Zeolite 30mg
C source vacuum
Electric Furnace
(CH3CO2)2Fe(CH3CO2)2Co-4H2O
Catalysts Supports
Zeolite USYHSZ-390HUA
SiO2 99.6 wt%Al2O3 0.4wt%SiO2/Al2O3: 390.0
300nm
SEM Image SEM Image
50nm
TEM Image TEM Image
10nm
TEM ImageTEM Image
0 500 1000 1500
100 200 300 400
2 1 0.9 0.8 0.7
Raman Shift (cm–1)
Inte
nsity
(arb
. uni
ts)
Raman Shift (cm–1)
Diameter (nm)Raman Spectra
(488nm)Raman Spectra
(488nm)
)(248)( 1−=cm
nmdω
Laser vaporization conditionRod Ni/Co 0.6 at.% Ar gas 50sccmTemperature 1130℃
laser
CCVD 800
5
Temperature DependenceTemperature Dependence
1200 1400 1600
Inte
nsity
(arb
.uni
ts)
Raman Shift (cm–1)100 200 300 400
2 1 0.9 0.8 0.7
Inte
nsity
(arb
.uni
ts)
Raman Shift (cm–1)
Diameter (nm)
600
650
700
800
Laser 1130
1.22nm 1.02nm 0.96nm 0.83nm
BWFD band G band
Generation mechanism of SWNTsGeneration mechanism of SWNTs
Model by Yudasaka et al., JPC B (1999)Model by Yudasaka et al., JPC B (1999)
Model by Kataura et al., Carbon (2000)Model by Kataura et al., Carbon (2000)
H. Kataura , Y. Kumazawa , Y. Maniwa , Y. Ohtsuka , R. Sen , S. Suzuki ,Y. Achiba, Carbon 38 (2000) 1691-1697.
D S Ra c d
R R
e e= = = == = = == =
−6 325 129 15 13150 80469 0 011304 19 2 517 2 0
1
0 0 0
1 2
. eV . . & . &
. . .. & . &
βδ
A A
A A
Potential parameters
From D. W. Brenner: Phys. Rev. B, 42, 9458(1990)
1f
r0
R1 R2
Cut-off function
k
i j
qijk
C-C Potential FunctionC-C Potential Function
{ }∑∑<
−=i ij
ijAijijRb rVBrVE)(
* )()(
{ })(2exp1
)()( ee
R RrSSDrfrV −−−
= β
−−−
= )(2exp1
)()( ee
A RrSS
SDrfrV β
{ }δ
θ−
≠
+=
+= ∑
),(
* )()(1,2 jik
ikijkcijjiij
ij rfGBBB
B
++−+=
220
20
20
20
0 )cos1(1)(
θθ
dc
dcaGc
Total Energy Eb:
M-C and M-M Potential Function ExpressionM-C and M-M Potential Function Expression
CARij VVVE ++=VR: Repulsive term VA: Attractive term
VC: Coulomb term
N C: carbon coordinate number
B*: normalized bond order
cM, cC : charge of M (+) and C(-)
f(rij) : cut-off function
{ })(2exp1
)( eije
ijR RrSSDrfV −−−
= β { })(/2exp1
)( *eij
eijA RrS
SSDBrfV −−−
⋅−= β
ijijC r
ccerfV MC
0
2
4)(πε
−=
∑≠
+=)(carbon
C )(1jk
ikrfN
{ }δ)1(1 C* −+= NbB
)exp(3 2C
1M kNkc +−−= CMC / Ncc =
∑≠
+=)( metal
M )(1jk
iki rfN2
MMji
ijNNN +
=
{ })1(exp)( 21 −−+= ijDeeije NCDDND
{ })1(exp)( 21 −−−= ijReeije NCRRNR
M-C M-M
N Mi: metal coordinate number
ij
jiijC r
ccerfV MM
0
2
4)(πε
=
6
Snapshots of Clustering Process at 6000 psSnapshots of Clustering Process at 6000 ps2500 carbon atoms & 25 Ni atoms
Control temperature Tc = 3000 K, 585Å Cubic Box
Snapshots of Annealing Processfor NiC60
Snapshots of Annealing Processfor NiC60
Cluster Source Nozzle for FT-ICR
Pulsed Valve
Target Disk
Waiting Room
Focused Laser Beam
He 10 atm
Expansion Cone
Cluster Beam
FT-ICR (Fourier Transform Ion Cyclotron Resonance)Mass Spectrometer
Turbopump
Gate Valve
Cluster Source
6 Tesla Superconducting Magnet
100 cm
DecelerationTube
Front Door
Screen Door
Rear Door
Excite & DetectionCylinder
ElectricalFeedthroughGas Addition
Ionization Laser
Probe Laser
Negative ClustersNegative Clusters
70 80Number of Carbon Atoms
Inte
nsity
(arb
itrar
y)
716 718 720 722 724
Mass (amu)
Inte
nsity
C60– + C60H
–
NiC50– + CoC50
– + NiCoC45–
FT–ICR Signal
Isotope Analysis
Isotope DistributionIsotope Distribution
35%C50NiCo
40%C55Ni
40%C55Co
50%C60H
100%C60
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The Way to Nanotube? The Way to Nanotube?
3000K
Collisions 2000K Slower Rate of Shrinking
2000K
Enlarged View
Generation Model of SWNTsGeneration Model of SWNTs
Electric Furnace
Ni/Co LoadedGraphite
Evaporation~ 1.7 µg/pluse
Ar flow0.8 cm/s, 500 Torr
YAG Pulse
Block
Block
200~500µs2cm
3ms~1s
Molecular Dynamics Simulations Related to SWNTsMolecular Dynamics Simulations Related to SWNTs Fuel Cell and Hydrogen StorageFuel Cell and Hydrogen Storage
FUEL CELLS(PEFC) Distributed power supply
AutomobilesMobile machines
Supply of hydrogenStorage problems for small light-weighted fuel cells
Liquid hydrogenHigh pressure gasMetal hydrideCarbon materials
Methanol Regenerator is heavy
Low temperature, Energy loss
Weight of case
Heavy
A. C. Dillon et al., Nature, 386, (1997)
Energy Density of HydrogenEnergy Density of Hydrogen Initial Configuration for (10,10) SWNTsInitial Configuration for (10,10) SWNTs
10 x 3.45 x 20 nm box
9504 Hydrogen Molecules
7 SWNTs Bundle (440 C atoms each)
3080 C atoms
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Snapshots of Absorption for (10,10) SWNTsSnapshots of Absorption for (10,10) SWNTs
Initial 12 MPa
Transformα = 0.05 α = 1
Phase TransformationPhase Transformation
(a) 12 MPa (b) Transformed
(c) 6 MPa (d) Transformed
0 102
4
6
8
Gra
vim
etry
Ene
rgy
Den
sity
[wt%
]
Pressure [MPa]
(a)
(b)
(c)
(d)
Snapshots for Various SWNTsSnapshots for Various SWNTs
(10,10) (16,16)
ClosePacked
InterstitiallyFilled
6.1 wt %
7.5 wt %
7.2 wt %
8.6 wt %
Heat ConductionHeat Conduction
Measurement of an Isolated MWNTMeasurement of an Isolated MWNT
P. Kim, L. Shi, A. Majumdar, P. L. McEuen, Thermal Transport Measurements of Individual Multiwalled Nanotubes, Los Alamos Natl. Lab.,
Prepr. Arch., Condens. Matter (2001), 1. PRL 87, 215502-1 (2001)
100 µm 1 µm
Simulation TechniqueSimulation Technique
y290K 310K
202nm0.7nm
290K 310Ky
(Diamond)2230K
/,6
,/2
)(
D =
==∆=
−+=
θ
θωωπ
αα
ασ
h
&&&
DBDDSCB
RandPot
kmtTkσ
m xffx
Temperature Control by Phantom Technique
Without the Periodic Boundary Condition!!
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Temperature Distribution along a NanotubeTemperature Distribution along a Nanotube
–1000 0 1000290
300
310
Position (Å)
Tem
pera
ture
(K)
64.5 K/µm
phantom (290K)
phantom (310K)
q = 25.0 GW/m2
Thermal ConductivityBetter than Diamond?
Effect of nanotube lengthEffect of nanotube length
300K
Ring Area of 3.4 Å102 103100
200
300
400
500
600700
Length of nanotube L (Å)
Ther
mal
con
duct
ivity
λ (W
/mK)
(5,5)
(10,10)
λ=a L0.32
(8,8)
λ=a L0.21
λ=a L0.06
Phonon Dispersion Relations (5,5)-101nmPhonon Dispersion Relations (5,5)-101nm
0 0.5 1.0
10
20
30
40
50
60
Wave vector k (1/Å )
Fre
quency
(TH
z)
0 0.5 1.0 0 0.5 1.0
cca −3π
r θ z
0
1000
2000
ν/c
(cm
–1)
vz
aa
Phonon Dispersion Relations (5,5)-101nmPhonon Dispersion Relations (5,5)-101nm
0 0.5 1.0
10
20
30
40
50
60
Wave vector k (1/Å )
Fre
quency
(TH
z)
0 0.5 1.0 0 0.5 1.0
cca −3π
r θ z
0
1000
2000
ν/c
(cm
–1)
vz
km/s10=v
Twisting Acoustic
Mode km/s17=ω
=dkdv
Longitudinal Acoustic
Mode
km/s7=v
Transverse Acoustic(Doubly
Degenerated)
0 0.5 1.0
cca −3π0 0.5 1.0
Wave vector k (1/Å )
r z
0
1000
2000
ν/c
(cm
–1)
vz
vx
R. Saito et al., Phys. Rev. B, 57 (1998), 4145.
Phonon Dispersion Relations (10,10)-101nm
Phonon Dispersion Relations (10,10)-101nm
Peapod (Fullerene@Nanotube)Peapod (Fullerene@Nanotube)
B. W. Smith, M. Monthioux and D. E. Luzzi, Nature (1998).
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Snapshots of Peapod to Double-walled Carbon Nanotube
at 3000K