Since its first discovery in 1991, the existence of a new form of carbon as nanotubes, has
excited scientists the world over. Carbon in the form of nanotubes has the potential to form a material of
great mechanical strength (hundred times stronger than steel) as well as displaying remarkable electrical
properties. Depending on the arrangement of the atoms within the nanotubes, they can either be conducting,
insulating or act as semiconductors: and as the tubes are so small, with diameters of the order of 1nm (ten
thousand times less than a human hair) whilst still being extremely good conductors of electricity the
implications for miniaturisation and speeding up of electronic components are immense.
The stumbling block to date has been how to fabricate the tubes in such a way as to produce the required
properties. All the known methods of fabrication produced a disordered mass of tubes with correspondingly
random structures and properties. That is all about to change, with a major breakthrough made in the
Department's Nanoscale Science Laboratory (NSL) headed by Professor Mark Welland, in conjunction with
Professor Jim Gimzewski at UCLA and Dr. Maria Seo at IBM, Zurich.
The work has been described by other workers in the field as the most stunning result in 'buckytube' research
in a year. "It was so unexpected to fabricate perfect crystalline arrays of nanotubes in this way, when all
previous attempts have shown nanotubes wrapped together looking like plates of spaghetti" says Professor Mark
Welland. "We couldn't believe it at first, and it has taken six months before we were convinced that what we
were seeing was real. I am still amazed at the beautiful images of these crystals."
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| Four nano-tube crystals growing from a molybdenum substrate. Each
one is 50nm in diameter. |
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