Correlation of ion dynamics and structure of superionic tellurite glasses.

Ion dynamics and structure of a series of superionic AgI-doped silver tellurite glasses have been investigated in this paper. The composition dependence of the dc conductivity and the activation energy of these glasses has been compared with those of AgI-doped silver phosphate and borate glasses. We have observed that the conductivity increases and the activation energy decreases with increase of AgI content and that the tellurite glasses have higher conductivity than those for phosphate or borate glasses. We have analyzed the ac electrical data in the framework of the power law and the electric modulus formalisms. We have established a correlation between the crossover rate of the mobile silver ions and the rearrangement of the structural units in tellurite glasses. The scaling of the conductivity spectra has been used to interpret the temperature and composition dependence of the relaxation dynamics. Analysis of the dielectric relaxation in the framework of modulus formalism indicates an increase in the ion-ion cooperation in the glass compositions with increasing AgI content.