Carbon Nanotubes: The End of the Silicon Era?
19 May 2008, 13:39
Categories: nanotubes-wires-fullerenes
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A pair of Russian physicists, Radushkevich and Lukyanovich, first discovered carbon nanotubes (CNTs) in 1952; they published clear images of 50 nanometer diameter tubes made of carbon in the Soviet Journal of Physical Chemistry. However, little attention was given to their discovery, and it was not until 1991 that these unique structures first gained widespread attention among the world’s scientists, when Sumio Iijima of the NEC Lab imaged them with a high-resolution transmission electron microscope.
CNTs offer us a very unique set of electrical and physical properties. Physically, they range in diameter from about one nanometer to 70 nanometers, and are known as the strongest material on the planet (under tension). The carbon atom bonds that hold CNTs together are stronger than those in diamond, effectively making the nanotube a stronger material than diamond.
Electrically, the physical shape of nanotubes significantly influences their theoretical ability to carry an electric current. If the carbon atoms were simply kept in their two-dimensional array (i.e, as a graphene sheet), electrons would be able to move in all directions. But once this sheet is wrapped into a tubular shape, quantum confinement will only allow electrons to move down the length of the tube and not around it. Because of this, some types of nanotubes – depending on their diameter – can theoretically carry charges some 1,000 times greater than common conductive materials, such as copper or silver.
Posted by: The Editors
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