Transcript An Intoduction to Carbon Nanotubes

An Intoduction to Carbon
Nanotubes
By: Shaun Ard
Physics 672
Fullerenes
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Nobel Prize in Chemistry
1996 (Smalley, Kroto, Curl)
Cage-like structures of
Carbon
Composed of
honeycomb type lattices
of hexagons and
pentagons
Important types include
“Buckeyball” and
Nanotubes
Sussex Fullerene Gallery
Kohlenstoffnanoroehre Animation
Nanotube Discovery
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Carbon filaments had
long been known, but
nanotube discovery
credited to S. Iijima in
1991
Discovered by chance
during investigation of
fullerene production
Y. Ando et al, Growing Carbon Nanotubes,
Materials Today, Oct (2004) 22
Nanotube Discovery (MWNT)
S. Iijima, Helical microtubules of graphitic
carbon, Nature (London) 354 (1991) 56
Copyright Alain Rochefort Assistant Professor
Engineering Physics Department,
Nanostructure Group, Center for Research on
Computation and its Applications (CERCA).
Nanotube Discovery (SWNT)
S. Iijima et al, Single-shell carbon nanotubes
of 1-nm diameter, Nature (London) 363
(1993) 603
D.S. Bethune et al, Cobalt-catalysed growth
of carbon nanotubes with single-atomic-layer
walls, Nature (London) 363 (1993) 605
Synthesis Enhancement
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Laser-Furnace method
 High quality SWNTs
 Diameter control
 New materials“peapods”
 Allows for study of
formation dynamics
Reprinted from Mater. Today, 7,Y.Ando, X. Zhao,T.
Sugai, and M. Kumar,“Growing Carbon Nanotubes,” 22–
29, Copyright 2004, with permission from Elsevier.
Synthesis Enhancement cont.
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Catalytic Chemical
Vapor Deposition
 Allows for growth of
aligned nanotubes
 Use of a variety of
substrates or
surfaces
 Easily scaled up for
increased production
Firstnano “EasyTube 3000”
Properties: Foundation
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Nanotubes are fully
described by their chiral
vector
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Important parameters
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Ch = n â1 + m â2
dt = (3/p)ac-c(m2 + mn
+ n2)1/2
Q=tan-1(3n/(2m + n))
A. Maiti, Caron Nanotubes: Band gap engineering
with strain, Nature Materials 2 (2003) 440
Grouped according to q
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Armchair: n=m, q=30°
Zigzag: n or m=0, q=0°
Chiral: 0°<q < 30°
V. Popov, Carbon nanotubes: properties and applications,
Properties: Electronic
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1-D band structure
calculated from 2-D
graphene band
structure using “zone
folding” scheme
Ekμ= E2D(k*K2/|K2|+μK1)
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K1=(-t2b1+ t1b2)/ N
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K2=(mb1- nb2)/ N
(5,5)
(9,0)
(10,0)
V. Popov, Carbon nanotubes: properties and applications,
Properties: Electronic cont.
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Theory predicts
nanotubes exhibit
both metallic and
semi-conducting
behavior
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|n-m| evenly divisible
by 3- metallic
All others semiconducting with a
band gap inversely
proportional to the
tube diameter
T.W. Odomet al, Atomic Structure and
Electronic Properties of Single-Walled
Nanotubes, Nature (London) 391 (1998) 62
Properties: Mechanical
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Young’s Modulus
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On the order of 1
Tpa (steel ~200
GPa)
No dependence on
diameter for MWNTs
but strong
dependence for
SWNTs
J. Salvetat, Elastic Modulus of Ordered and
Disordered Multiwalled Carbon Nanotubes,
Adv. Mater. 11 (1999) 161
Applications
Nano-Wires
Applications
Nano Transistors
Tans et al, Room-temperature transistor based on
a single carbon nanotube, Nature 393 (1998)
Applications
Field Emitters
From IPN CNT group
Applications
J. Fischer, Matt Ray/EHP
Lithium Ion Batteries
MIT/Riccardo Signorelli
Ultra Capacitors
Charge Storage
Conclusion
Nano =