AC CONDUCTIVITY OF TELLURITE GLASSES

Measurements of the a.c. conductivities have been made on the [TeO2](1 00-x)[MoO3](x) glassy system, where x=20, 30 and 45 mol%, in the tempe rature range 300-573 K and in the frequency range 100 Hz to 10 kHz. Th e a.c. conductivity sigma(omega) was found to increase with frequency according to the universal empirical relation sigma(omega)alpha omega( 5). The frequency exponent a was found to decrease with increasing tem perature. The conductivity data showed a strong dependence on the tran sition metal ions (TMI) in the glass. The experimental data obtained h ave been analysed according to the quantum mechanical tunneling (QMT) model. The density of localized states has been calculated using the a bove model and found to be in the range corresponding to semiconductin g glasses containing TMIs.