DC Electrical Characteristics Research Articles

Structural State and Diffusion in a Silicate Glass

Compositional changes in a glass alter both the number of ions that contribute to a diffusion process and their mobilities. The present work comprises an investigation of the diffusional properties of a glass in which composition was maintained but the mobilities of the contributing ions were altered by previous heat treatment of the glass and by the application of hydrostatic pressure. Changes in the self-diffusion of alkali ions, as evidenced by changes in the ac and dc electrical characteristics of the glass, indicated that the activation energy of diffusion depends on the structural state. The entropy and frequency factors, which also play a role in alkali ion self-diffusion, appear, however, to be insensitive to the structural state.