Size, Morphology and Temperature Dependence of the Thermal Conductivity of Single-Walled Silicon Carbide Nanotubes

Abstract

The thermal conductivity of single-walled silicon carbide nanotubes (SW-SiCNTs) has been investigated by molecular dynamics (MD) simulation using the many-body Tersoff potential. To validate the reliability of the simulations code, the following measures have been taken: The calculated potential energies of SW-SiCNTs and the calculated thermal conductivities of single-walled carbon nanotubes (SWCNTs) are, respectively, compared with available data, and both comparisons are in good agreement. To investigate the size (tube length and diameter), morphology (chirality and the atom arrangement) and temperature dependence of the thermal conductivity of SW-SiCNTs, the thermal conductivities of SW-SiCNTs with different sizes, morphologies and temperatures, are calculated and compared with each other. It is found that (1) as the temperature increases, the thermal conductivity decreases at different rate, which depends on the tube morphology; (2) as long as the length increases, the thermal conductivity increases correspondingly; (3) the thermal conductivity depends on the tube diameter and exhibits a peaking behavior as a function of diameter; (4) atom arrangement strongly affects the thermal conductivity not only in quantity but also in the extent of dependence on chirality; and (5) the thermal conductivity is dependent on the chirality of nanotube with different extent.

Keywords:

• Thermal conductivity
• single-walled nanotubes
• silicon carbide
• molecular dynamics