Dielectric behavior of glasses and glass-ceramics

This paper attempts to summarize the basic molecular mechanisms which control the dielectric properties of glasses and glass-ceramic materials. An analysis of these polarizations reveals that alkali ions are the principal constituents which determine the dielectric loss properties. In glassy materials containing alkali ions in rather large quantities, these ions control the losses over most of the frequency spectrum. The mean of the relaxation frequency is somewhere in the vicinity of 1CT³ cycles/second depending upon temperature, glass structure, and the amount of alkali present. The polarization over most of the spectrum at room temperature is of the orientational type. At elevated temperatures, interfacial polarization losses predominate. The losses are, however, still identifiable with the alkali ions.