Superconductivity and carbon nanotubes

25 July 2007

Carbon nanotubes have been examined for a number of properties including semi-conducting properties, when these carbon nanotubes are placed between metallic nonsuper contacts. Several studies have opened the door for using carbon nanotube as testing ground to study conductivity in molecular wires. Various observations indicate that many interesting features arise due to nanoscale size of these carbon nanotubes.

A study carried out by M. Kociak and his team found that the main factor is good quality of contacts produced for the ropes. The carbon nanotube ropes were suspended between Platinum/ gold bilayers and precaution was taken that the bilayer used for the experimental study do not become superconducting at very low temperature. The authors have made a rope of around 350 nanotubes of length of 1 micrometer.

The study has allowed producing devices having a room temperature resistance of few kilo ohms down to a few ohms. Actually the resistance does not completely become zero, however it reaches a minimum value of 74 ohms in the above experimental study. If we carry out the calculation for a metallic nanotube it comes out 6.5-kilo ohm and the value of resistance (74 ohm) as observed in the experiment indicates that the metallic nanotubes in rope contribute to the conduction in super conducting state.

Related Posts: