Dynamics of Ag⁺ ions in Ag₂S-doped superionic AgPO₃ glasses

Abstract

Dynamics of Ag⁺ ions in Ag₂S-doped AgPO₃ glasses have been studied in the frequency range 10 Hz to 2 MHz and in the temperature range 93-323 K. The composition dependence of the dc conductivity and the activation energy of these glasses has been compared with that of the AgI-doped AgPO₃ glasses. An attempt has been made to explain the comparatively lower conductivity for the present Ag₂S doped glasses than that for the AgI-doped glasses by analyzing the Fourier transform infrared data. The frequency-dependent electrical data have been analyzed in the framework of conductivity formalism. We have obtained the mobile ion concentration and the power-law exponent from the analysis of the conductivity spectra. We have observed that the concentration of Ag⁺ ions is independent of temperature and the conductivity is primarily determined by the mobility. It has also been observed that a fraction of the Ag⁺ ions in the glass is involved in the dynamic process. Scaling of the conductivity spectra is observed to be independent of temperature and Ag₂S content in the compositions.