RELAXATION PROCESSES IN IONIC CONDUCTIVE CHALCOGENIDE GLASSES STUDIED BY ELECTRICAL AND NMR SPECTROSCOPIES

The frequency dependence of conductivity has been studied over a large temperature range in Ag+ and Li+ ionic conductive glasses. The activation energies E(ac)' deduced from the Arrhenius plot of sigma-ac are independent of the frequency. They are comparable with the activation energies deduced from the low-temperature branch of NMR curves log 1/T1 = f(1/T). The empirical factor beta = E(ac)'/E(dc) has been deduced from these results. Fitting the curves to log sigma-ac = f(log-omega) leaded to values of S that are dependent on the temperature.