Dc Conductivity of Ge-S-Ag and As-S-Ag Glasses

The dc conductivity in GeS₂-GeS-Ag₂S and As₂S₃-Ag₂S glasses was measured over the range – 20° to 80°C using an electrode of 1 at.% Ag amalgam to avoid polarization. The room-temperature conductivity varies with increasing Ag₂S content from 10^?15 to 10^?4Ω^?1 cm^?1 for GeS₂-GeS-Ag₂S glasses and from 10^?16 to 10^?5Ω^?1 for As₂S₃-Ag₂S glasses. Also, the transport numbers of Ag ions in the glasses were measured by the Hittorf and emf methods. The results show that all glasses in both systems, except for compositions with low Ag₂S contents, are purely ionic conductors because of the presence of Ag ions, so that they may be regarded as solid electrolytes.