Phonon dispersion and phonon densities of states for ZnS and ZnTe

Abstract

Neutron scattering data are reported for II–VI zincblende crystals, which are believed to be of sufficient precision to refine earlier ZnS ambiguities and to provide a basis for model fitting comparable to existing III‐V results. Valence shell models, including 9–12 parameters (VSM) and a variable shell charge extension (VCM), were fit to the data and used to generate phonon density of states and Debye temperatures. Very good fits to the neutron data were obtained, but no model was found that also predicts an accurate set of electric and mechanical constants. It is concluded that an unambiguous ionic charge Z cannot be assigned from the neutron results in either case