The thermodynamic and optical properties of germanium, silicon, diamond and gallium arsenide

Abstract

Measurements of the dispersion curves of the normal modes of vibration, by inelastic neutron scattering techniques, have been used to find the parameters of dipole approximation models to describe the lattice dynamics of germanium, silicon, diamond and gallium arsenide. The model for diamond, which has not previously been published, shows marked differences in the dispersion curves between this material and the other three and these give rise to characteristic differences in the physical properties. The models for all four materials give good agreement with the experimental results and enable other physical properties to be calculated with reasonable confidence in the frequencies of the normal modes computed from the models.