A model was presented for the ac conduction, in ionically conducting solids, that took account, in a simple way, of the interaction between carriers. The Coulomb force formed a so-called ionic atmosphere that exerted a restoring force upon a central ion, whose motion corresponded to an overdamped oscillator. the effect of the relaxation of the ionic atmosphere was considered by introducing an additional equation for the displacement of the potential towards the particle position. The general behavior of the ac conductivity could be understood in terms of 2 types of motion: motion of the bound ion at high frequencies, determined by microscopic friction, and a much slower motion which was coupled to the surrounding carrier relaxation at low frequencies.

Simple Model for AC Ionic Conduction in Solids. J.Bisquert, V.Halpern, F.Henn: Journal of Chemical Physics, 2005, 122[15], 151101