This model combined key features of earlier dynamic structure and jump relaxation models, and provided a coherent model for ionic transport processes in such materials. The basic concept was that mobile ions hopped backwards and forwards many times before the Coulomb field was relaxed and before the so-called target site adjusted itself to the requirements of the new occupant. Other mobile ions, and the glass network, were involved in this unified relaxation process. The effects of site relaxation were reflected by the frequency dependence of the conductivity, by mechanical loss spectra and by direct-current anomalies such as the mixed cation effect.

A.Bunde, K.Funke, M.D.Ingram: Solid State Ionics, 1996, 86-88[2], 1311-7