31-01-2012, 04:48 PM
CARBON NANOTUBES FOR VLSI: INTERCONNECT AND TRANSISTOR APPLICATIONS
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Definition: Carbon Nanotubes
1.Single-wall carbon nanotubes (CNTS)are a new form of carbon made by rolling up a single graphite sheet to a narrow but long tube closed at both sides by fullerene-like end caps.
2.However, their attraction lies not only in the beauty of their molecular structures: through intentional alteration of their physical and chemical properties fullerenes exhibit an extremely wide range of interesting and potentially useful properties.
INTRODUCTION
Carbon Nanotubes: Tiny tubes about 10,000 times thinner than a human hair consist of rolled up sheets of carbon hexagons.
Discovered in 1991 by researchers at NEC, they have the potential for use as minuscule wires or in ultra small electronic devices.
To build those devices, scientists must be able to manipulate the Nanotubes in a controlled way. IBM researchers using an atomic force microscope (AFM), an instrument whose tip can apply accurately measured forces to atoms and molecules, have recently devised a means of changing a nanotube's position, shape and orientation, as well as cutting it
BASIC STRUCTURE OF NANOTUBES
Nanotubes are members
of the fullerene structural
family, which also includes
the spherical bucky balls.
Their name is derived from
their size, since the diameter
of a Nanotube is of the order
of a few nanometers, while
they can be up to 18 cm in
length.
Advantages
.SINGLE WALLED NANOTUBES
Less defective
Experimental studies are easy to perform
.MULTI WALLED NANOTUBES
Their resistance to chemicals have improved.
Do not need a catalyst for growth.
Do not contain magnetic impurities.