Thermal Conductivity of Carbon Nanotubes
Jianwei Che*, Tahir Cagin, and William A. Goddard III
California Institute of Technology, Materials and Process Simulation Center, and Division of Chemistry and Chemical Engineering
Pasadena, CA 91125 USA
This is an abstract
for a presentation given at the
Foresight Conference on Molecular Nanotechnology.
The full article is available at http://www.foresight.org/Conferences/MNT7/Papers/Che/index.html.
Electronic structure and transport properties of carbon nanotubes are of particular interest due to their potential use as components in nano electronics applications [1-5].
Emerging need for decrease in device size, the use of molecular level theories in device design and modeling becomes more and more important. One particular issue needs to be addressed in nanoelectronics device modeling is the thermal transport properties of the components. Hence, the study of the thermal conductivity of nanotubes and its dependence on structure, defects, and strain is of critical importance. The anisotropic character of the thermal conductivity of the graphite crystal is naturally reflected in the carbon nanotubes. For the large diameter carbon nanotubes, it resembles to the behavior of planar graphite sheet. However, when the tube diameter decreases, the change from 2 dimensional planar structure to a quasi 1-dimensional tube plays a crucial role in the thermal conductivity. At the same time, the smaller diameter nanotubes have large strains due to increased curvature in contrast to the large diameter nanotubes. This particular strain effect can also explain the differences in thermal conductivity of small diamter nanotube and planar graphite.
We employed a newly modified empirical potential to carry out the calculation of the thermal transport properties for carbon nanotubes . The effects of the structural defects, the tube size, the tube chirality, and chemical impurities on these quasi 1-dimensional systems are also studied. As a comparison, we also present how the impurities and defects affect the thermal properties in 3 dimensional crystal structures.
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