Computation of Elastic Moduli and Dispersion in (s–d) Interactive Atomic Liquids. The Example of Liquid Pt and Pd Metals

Abstract

AbstractA form of Wills‐Harrison's potential is used to derive the longitudinal and transverse phonon frequencies of Pt and Pd through the use of Takeno and Goda's equations. The low k‐values of phonon frequencies are found to be linear with k and from the slopes of these linear plots the elastic constants are calculated for both metals. The potential functions are also used to calculate the elastic constants of these liquid metals through the use of Schofield's equations. Structure factors in excellent agreement with experiment are generated treating the liquids as square‐well fluids. The paramenters are used to calculate S(0), the structure factor in the long‐wave limit. From the computed S(O) the compressibility and hence C11 are calculated. Because of the well‐known caging effect that occurs due to back scattering, effective masses are used in the calcultion of phonon frequencies. It is gratifying to note that the elastic constants calculated by different methods are in satisfactory agreement with each other.