Noncentral forces in the study of lattice dynamics of metals

Abstract

A comparative study of angular force models proposed by Clark et al (1964) and deLauney (1956) including the electron-ion interaction on the lines of Behari and Tripathi (1970) as applied to the cubic metals has been made. The forces are considered up to second neighbours only. Analytically it is found that the two models are equivalent for bcc structures but they give different results for fcc metals. The phonon dispersion curves for three transition metals (V,Nb,Ta) have been computed and the numerical results from both the models are found to be exactly coincident and also in good agreement with the experimental data.