AB INITIO STUDY OF STRUCTURAL PROPERTIES OF INTERMETALLIC COMPOUNDS PtX (X = Si, Ge, Sn AND Pb) UNDER HIGH PRESSURE

High pressure effect on the structural evolution properties of intermetallic compounds PtX (X = Si, Ge, Sn AND Pb) was studied based on the first principle density functional theory. The compressibility of PtSi and PtGe under high pressure presents anisotropic behavior. The crystal stacking characteristic of the PtX (X = Si and Ge) along the three axes may be responsible for their anisotropic axial compressibility under high pressure. The sequence of axial compressibility for PtSi is c < a < b, whereas PtGe exhibits the sequence of a < c < b. The pressure derivative of c/a was qualified to be 8.92×10-4GPa-1 and 1.38×10-3GPa-1 for PtSn and PtPb, respectively. The applied pressure stabilized the crystal structures of PtSn and PtPb.