An electron gas model for the lattice dynamics of thallium and zirconium

Abstract

Metallic lattice is visualized as a series of point ions immersed in an electron gas. The total interaction with the metal is supposed to consist of ion-ion central interaction and ion-electron interaction. The former has been incorporated along the lines of Born-Karman and the latter has been accounted for by considering the ionic charge as smeared over the metal. The force corresponding to the strain developed within the Wigner-Seitz sphere is averaged over the whole sphere. The phonon dispersion relations along the symmetry direction and the (θ-T)-curve have been plotted for zirconium (Zr) and thallium (Tl) with force constants effective up to fourth neighbour only. The theoretical values are found to be closer to the experimental data. © 1975 Società Italiana di Fisica.