Phonons in mixed crystals: a self-consistent theory including mass and force-constant changes

Abstract

A self-consistent theory has been proposed for phonons in mixed crystals, taking into account both mass and force-constant changes. The force-constant changes are included approximately and treated within a separable kernel approximation. In the limiting cases the theory reproduced the well known results of the low-concentration theories and the mass-disordered coherent potential approximation theory.