Molecular-dynamics simulation of lattice thermal conductivity in Pb1-xSnxTe and Pb1-xGexTe at high temperature

Molecular-dynamics studies on lattice thermal conductivity (kappa(L)) of Pb1-xSnxTe and Pb1-xGexTe 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 placed on the alloying effects of kappa(L) calculated by changing the alloy content x in PbTe-based alloys. It has been shown that a remarkable reduction of kappa(L) at finite x is demonstrated in Pb1-xSnxTe and Pb1-xGexTe without 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.