Molecular-Dynamics Simulation of Lattice Thermal Conductivity in Pb_<1-x>Sn_xTe and Pb_<1-x>Ge_xTe at High Temperature

The molecular-dynamics studies on lattice thermal conductivity (κ_L) of Pb_Sn_xTe and Pb_Ge_xTe are carried out by employing ion model potential for mutual ion-ion interactions at the average temperatures 300 and 500 K under non-equilibrium condition. Special emphasis of investigation is on the alloying effects on κ_L by changing the alloying content x of Sn and Ge in PbTe. It has been shown that a remarkable reduction of κ_L at finite x is demonstrated in Pb_Sn_xTe and Pb_Ge_xTe without a relying on a phonon scattering description. We have compared our results with ones evaluated by the Abeles' formula of lattice thermal conductivity due to phonon scattering from alloy fluctuations