COMPOSITION DEPENDENT AC ELECTRICAL-PROPERTIES OF LEAD VANADATE GLASS

The frequency and temperature dependence of the complex ac electrical properties are reported in the frequency range 0.1-100 kHz and in the temperature range 80-300 K for the lead vanadate glass in a wide compo sition range (50-90 mol% of V2O5). The experimental results are analys ed with reference to the theoretical models based on quantum tunneling through a barrier and classical hopping over a barrier. It is observe d that the large polaron tunneling is the dominant charge transfer mec hanism for the glass compositions with 80 and 90 mol% of V2O5, while c lassical hopping plays significant role in the charge transfer mechani sm for other glass compositions. Possible reasons for the change of lo ss mechanism with compositions are suggested.