Molecular Dynamics Study on Thermal Conductivity of Carbon Nanotubes

The thermal conductivity of a (5, 5) carbon nanotube at room temperature is studied by non-equilibrium molecular dynamics simulations. The thermal conductivity increases from 30 W/(m.K) to 1000 W/(m.K) as the tube length increases from 6 nm to 4 mu m. It is proportional to the tube length when the tube length is less than 40 nm, which indicates that the heat conduction is in the ballistic transport regime. The thermal conductivity relates to the tube length by an exponential function as the tube length increases, and the length dependence exponent decreases and approaches zero, which indicates that the phonon transport changes from the ballistic regime to the diffusive regime. (C) 2010 Wiley Periodicals, Inc.