Diameter and Temperature Dependence of Thermal Conductivity of Single-Walled Carbon Nanotubes

Temperature and diameter dependence of the thermal conductivity of several armchair single-walled carbon nanotubes (SWNTs) are studied by nonequilibrium molecular dynamics method with Brenner II potential. The thermal conductivities are calculated at temperatures from 100 K to 600 K. It is found that the thermal conductivity decreases as the temperature increases and increases as the diameter of SWNT increases. The results demonstrate that these two phenomena are due to the onset of the Umklapp process.