Computation of phonon dispersion curves and thermodynamic properties of Pd80P20 metallic glass

Abstract

In this paper, the theoretical computation of phonon frequencies for Pd80P20 metallic glass is presented both for the longitudinal and transverse modes. For computing the phonon frequencies, we follow Bhatia and Singh approach. The elastic constants of the Pd80P20 metallic glass are used for determining the force constants for computing the phonon frequencies. The theoretically obtained phonon frequencies of Pd80P20 show relevant behaviour in the low momentum region for both the modes (longitudinal and transverse). Further, we have estimated transverse sound velocity from the computed phonon frequencies in the low momentum region. Similarly, in the low momentum region of the phonon frequency curves, we have computed longitudinal sound velocity and Debye temperature employing different types of dielectric screenings. The theoretical results obtained from the dispersion curves are in good agreement with the available data on Pd80P20 metallic glass.