Mixed mobile ion effect in fluoride glasses

Abstract

Certain ionic materials containing dissimilar mobile cations exhibit the nonlinear behavior of diffusion-related properties, called the mixed mobile ion effect. In these materials only cations participate in the diffusion process. In this paper we report on the mixed mobile ion effect in fluoride glasses, where anions also participate in the diffusion processes in addition to cations, unlike mixed alkali oxide glasses and crystals. We have provided several pieces of evidence in favor of this effect in fluoride glasses. This phenomenon was associated with the low dimensionality of the diffusion pathways in the mixed alkali fluoride glasses compared to single alkali glasses.