Electron gas model for the lattice dynamics of transition metals

Abstract

Calculations of the phonon dispersion relations and specific heats for two transition metals are made using Krebs approach, in which the dynamical matrix is split into a closed-shell part and an ionic part. The ionic contribution to the elements of the dynamical matrix is calculated from a screened Coulomb interaction of the metal ions embedded in the sea of Bloch electrons. Computed vibration frequencies from this approach are periodic in the reciprocal space. The phonon dispersion relations along the [0001], [01–10] and [11–20] symmetry directions for yttrium and hafnium are computed. These and the calculated specific heats compare well with the experimental results.