High-Pressure Phase Transitions of PbTe Using the First-Principles Calculations

High-pressure structural phase transitions in PbTe are investigated by means of the first principles total energy calculations within the generalized gradient approximation (GGA) and local density approximation (LDA) by using the density functional theory. First principle calculation shows that PbTe is stable with the NaCl-type (B1) structure under ambient conditions and transforms to the CsCl-type (B2) structure under high pressure via an intermediate phase. Two candidate structures of the intermediate phase, namely Pnma and Cmcm, are chosen for total energy calculations and discussed. It indicates that the intermediate phase adopts the Pnma structure rather than the Cmcm structure, and lattice parameters of the Pnma phase calculated by using GGA and LDA are in consistent with experimental results.