Thermal conductivity of carbon nanotube cable type composite

Abstract

For single-wall carbon nanotubes filled with gold nanowires, a kind of carbon nanotube cable type composite material, its thermal conductivity is simulated by non-equilibrium molecular dynamics method. The Tersoff potential is employed for C-C bonding interactions, the Lennard-Jones potential for C-Au interactions and the embedded atom method potential for Au-Au interactions. It turns out that the electronic thermal conductivity (ETC) of gold nanowire is much lower than that of the composite with the same size, so the ETC of metal nanowire could be ignored. The carbon atoms tend to vibrate along the axial direction of the tube because of the interaction between gold and carbon atoms. Furthermore, the umklapp scatterings among phonons are reduced and the phonon mean free path is increased. Therefore, the thermal conductivity of the composite is 20%45% higher than the bare carbon nanotubes in a temperature range of 100500 K, but the growth rate decreases with the rise of temperature. The thermal conductivity of the composite rises with the increasing of length but in a sharper rate, and decreases with the increasing of diameter in the same rate, which is similar to the bare carbon nanotubes.