Temperature dependence of the thermal conductivity of single-wall carbon nanotubes

The thermal conductivity of several single-wall carbon nanotubes has been calculated over a temperature range of 100-500 K using molecular dynamics simulations with the Tersoff-Brenner potential for C-C interactions. In all cases, starting from similar values at 100 K, the thermal conductivities show a peaking behaviour before falling off at higher temperatures. The peak position shifts to higher temperatures for nanotubes with larger diameters and no significant dependence on the tube chirality is observed. It is shown that this phenomenon is due to the onset of Umklapp scattering, which shifts to higher temperatures for nanotubes with larger diameters.