Comparative Study of Phonon Density of State for Platinum under High Pressure: Grüneisen Approximation Approach

Abstract

The phonon density of state (PDOS) for platinum was studied under high pressures and different volume compression by using Grünesien approach and different equations of state (EOSs), Birch-Murnaghan EOS and Bardeen (EOS),Birch-Murnaghan EOS which is based on the solid mechanics definition of finite strain and Bardeen (EOS) which basedon inters atomic potentials. The obtained results are compared with the results of Abinitio calculations. This work reveals the importance of considering Grünesien parameter variation under high pressure to shows how to get rid of difficulties in evaluating (PDOS) using EOS for solids