Transport properties and relaxation studies in BaO substituted Ag2O–V2O5–TeO2 glass system

The dc and ac conductivities of the glasses have been studied over wide ranges of compositions and frequency. The conductivity arises mainly from polaron hopping between V4+ and V5+ ions. The dc conductivity increases with TMO content while activation energy decreases. High temperature conductivity data satisfy the Mott's small polaron hopping model. The dc activation energies calculated from the complex impedance plots matches quite well with activation energy calculated from the relaxation phenomenon. The ac conductivities have been fitted to the Almond–West type power law expression. The scaling of the conductivity spectra with respect to temperature is attempted for these glasses at high temperature. The modulus data are analyzed using the KWW stretched exponential function. The mobile ion concentration factor K′ is found to be independent of temperature. We have further shown that the motion of Ag+ ions is coupled more and more from the viscous motion of the glassy matrix with the increase of modifier content.