Anionic Conduction in Lead Halosilicate Glasses

Abstract

Electrical conductivity due to halide ions has been measured for the glasses in the system 30SiO 2 · (70 − x )PbO · x PbX 2 (0 < x < 17.2 mol%; X = F, Cl). The conductivity increases with x by several orders of magnitude for both series of glasses. The contribution of principal factors to the conductivity has been examined. The analysis of the activation energy on the basis of the Anderson‐Stuart model shows that the strain energy is a predominant term in the Cl glasses, while both the strain energy and the electrostatic energy have a comparable contribution in the F glasses. The decrease in the activation energy with increasing PbX 2 content is related to the decrease in the shear modulus for the Cl glasses and to the increase in the permittivity for the F glasses.