An Intoduction to Carbon Nanotubes
By: Shaun ArdPhysics 672
Fullerenes 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 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
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.
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
Nanotubes are fully described by their chiral vector
Ch = n â1 + m â2
Important parameters dt = (3/)ac-c(m
2 + mn + n2)1/2
=tan-1(3n/(2m + n)) Grouped according to
Armchair: n=m, =30° Zigzag: n or m=0, =0° Chiral: 0°<30°
A. Maiti, Caron Nanotubes: Band gap engineering with strain, Nature Materials 2 (2003) 440
V. Popov, Carbon nanotubes: properties and applications, Materials Science and Engineering R 43 (2004) 61-102
Properties: Electronic
(5,5) (9,0) (10,0)
V. Popov, Carbon nanotubes: properties and applications, Materials Science and Engineering R 43 (2004) 61-102
1-D band structure calculated from 2-D graphene band structure using “zone folding” scheme
Ekμ= E2D(k*K2/|K2|+μK1)
K1=(-t2b1+ t1b2)/ N
K2=(mb1- nb2)/ N
Properties: Electronic cont. Theory predicts
nanotubes exhibit both metallic and semi-conducting behavior
|n-m| evenly divisible by 3- metallic
All others semi-conducting 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 Young’s Modulus
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
Tans et al, Room-temperature transistor based on a single carbon nanotube, Nature 393 (1998)
Nano Transistors
Applications
From IPN CNT group
Field Emitters
Applications
MIT/Riccardo Signorelli J. Fischer, Matt Ray/EHP
Charge Storage
Lithium Ion Batteries
Ultra Capacitors
Conclusion
Nano =