The bond fluctuation model of superionic conductors predicts that the polarizability of solids that exhibited high ionic conduction was large. Based upon this background, a study of the non-linear optical constants in superionic glasses was begun. As a first step, the relationship between the third-order susceptibility χ(3) and the linear susceptibility χ(1) of various kinds of glasses was studied. It was found that the values of χ(3) of superionic conducting glasses exceed considerably the values predicted by the usual Miller rule. The deviation arose from the increase of the ionic coordinate dependent electronic polarizability, which played also an important role in the ion transport processes.

A Study on the Relationship between Nonlinear Optical Constants and the Ionic Conductivity in Glasses. S.Ikeda, M.Aniya: IOP Conference Series - Materials Science and Engineering, 2011, 18[8], 112017