HEAT-TRANSPORT IN DIELECTRIC SOLIDS WITH DIAMOND STRUCTURE

Through an iteration procedure the phonon transport equation is solved for solids with diamond structure. The interaction between nearest an d next-nearest neighbours is expressed in terms of a pair potential by which an accurate description of the phonon spectrum and of the anhar monic properties of the crystal is obtained. In this way the role of t he various scattering mechanisms contributing to thermal resistance ca n be investigated without the use of the continuum approximation or of the relaxation time approximation for phonon-phonon interaction. The theory is applied to Ge and Si, for which the predicted temperature be haviour of thermal conductivity is found in excellent agreement with e xperiment.