Pressure Dependence of Phonon Dispersion in Bcc Tungsten

Abstract

Combining the modified analytic embedded atom method with the theory of lattice dynamics, we reproduce the experimental results of the phonon dispersion in bcc metal tungsten at zero pressure along the major symmetry directions [00ζ], [0ζζ], and [ζζζ] and then predict the phonon dispersion relations of tungsten under the high pressures of 40, 50, 80, 100, and 120 GPa based on the equation of state of Rose and Vinet. Our simulated results at high pressure are in agreement with the finding of other bcc metals when the differences in masses, interatomic spacings, and melting temperatures of these metals are taken into account. This implies that the predicted phonon dispersion relations at different pressures are reasonable, showing that the modified analytic embedded atom method can describe the phonon dispersion relation of solids at zero pressure or at high pressure.