Thermal conductivity from approach-to-equilibrium molecular dynamics

We use molecular dynamics simulations to study the thermal transport properties of a range of poor to good thermal conductors by a method in which two portions are delimited and heated at two different temperatures before the approach-to-equilibrium in the whole structure is monitored. The numerical results are compared to the corresponding solution of the heat equation. Based on this comparison, the observed exponential decay of the temperature difference is interpreted and used to extract the thermal conductivity of homogeneous materials. The method is first applied to bulk silicon and an excellent agreement with previous calculations is obtained. Finally, we predict the thermal conductivity of germanium and a-quartz. (C) 2013 AIP Publishing LLC.