Noncentral force model for the lattice dynamics of cubic metals
Abstract
A noncentral force model for the lattice dynamics of cubic metals is propounded by taking into account the volume forces (electronion interaction) and the angular forces of the type suggested by de Launay and Clark et al. in addition to the usual central forces. The electronion interaction is formulated through the Krebs theory. The secular equation contains five constants which are determined from the three elastic constants and two zoneboundary frequencies. The model is applied to calculate the phonon dispersion curves, frequency distribution functions, and heat capacities of alkali metals. The results show satisfactory agreement with the neutron scattering and calorimetric data. It is shown that the two angular forces are equivalent for calculating the lattice frequencies of bodycenteredcubic metals.
 Publication:

Physical Review B
 Pub Date:
 February 1979
 DOI:
 10.1103/PhysRevB.19.1963
 Bibcode:
 1979PhRvB..19.1963S