Glasses with the general formula, (1-y)[(1+x)Ag2O•xP2O5]yAgI (where y was between 0.55 and 0.70, and x was between 0 and 0.4), were prepared. The experimental data confirmed that, as reported in the literature, an increase in the AgI content caused the electrical conductivity to increase and the glass transformation temperature to decrease. The increase in conductivity was attributed mainly to a decrease in the activation energy for conduction. The results were explained in terms of a model that involved de-mixing of the glass into AgI micro-domains and a phosphate matrix. It was suggested that the Ag+ migration paths also involved sites other than those near to I- ions, and that the activation energy for conduction in AgI-doped glasses could be considered to be an average of the values for the various phases that were present. As in the case of glasses with lower AgI contents, a linear relationship was obtained when the ratio of the activation energies for AgI-doped and undoped glasses was plotted versus the fraction of Ag+ ions which was introduced as Ag2O.

A.Costantini, F.Branda, R.Fresa, A.Buri: Physics and Chemistry of Glasses, 1996, 37[5], 193-5