Ion hopping processes and structural relaxation in glassy materials

Ion mobility is discussed in the context of a unified site relaxation model which combines key features of the earlier dynamic structure and jump relaxation models. Other mobile cations and the network of the glass are both involved in the site relaxation process. The effect is partially to recouple the movements of ions to structural relaxation processes and this recoupling is observed in mechanical loss spectra and in the behaviour of ion-exchanged and melt-quenched glasses.