Thermal conductivity of B-C-N and BN nanotubes

We have measured the temperature-dependent thermal conductivity kappa(T) of boron-carbon-nitride (B-C-N) and boron nitride (BN) nanotube mats between room temperature and 20 K. For both materials, kappa(T) increases with increasing temperature, with no sign of saturation. We employ an analysis method to estimate the intrinsic kappa(T) of BN nanotubes converted from B-C-N nanotubes, and find that at room temperature kappa(T) of a multiwalled BN nanotube can be comparable to that of a multiwalled carbon nanotube and may exceed it if made isotopically pure. At low temperature, the functional form of kappa(T) reflects dimensional confinement. (c) 2005 American Institute of Physics.