On the minimum limit to thermal conductivity of multi-atom component crystalline solid solutions based on impurity mass scattering

We investigate the effect of mass disorder on the thermal conductivity of Lennard-Jones based multi component solid solutions via classical molecular dynamics simulations. In agreement with Klemens' perturbation theory, the thermal conductivity reduction due to mass scattering alone is found to reach a critical point, whereby adding more impurity atoms in the solid solution does not reduce the thermal conductivity. A further decrease in thermal conductivity requires a change in local strain-field, which together with mass defect scattering can lead to ultralow thermal conductivities in solid solutions, surpassing the theoretical minimum limits of the corresponding amorphous phases. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.