Quantum theory of dielectric relaxation in polar solids

Abstract

A novel approach to the impurity dipole relaxation in polar solids is described in which the dipole reorientational sites are formed by an appropriate electron—phonon coupling interaction. The electronic states used for a two‐site formulation are defined as ones pertaining to the impurity and/or the associated intrinsic point defect. The theory takes into account the adiabaticity of the electron transfer in addition to the barrier‐controlled ionic tunneling. It compares favorably with available experimental relaxation‐time data on alkali halides.