Pressure and temperature dependence of EXAFS Debye-Waller factor of platinum

The anharmonic contributions and pressure effects on extended X-ray absorption fine structure (EXAFS) Debye-Waller factor of platinum metal have been investigated up to 900 K and 14 GPa within the anharmonic correlated Debye model. Parameters of interatomic potential have been derived under the second-moment approximation of tight binding scheme. Our calculations of the EXAFS Debye-Waller factor and anharmonic effective potential are compared with those of experiments showing the good and reasonable agreements. We have shown in detail that the anharmonicity of the thermal vibration of atoms give an important contribution to EXAFS Debye-Waller factor at high temperature. And the increasing of pressure will depress the EXAFS amplitude through the reduction of atomic mean-square relative displacement characterizing the Debye-Waller factor.