dc conductivity and dielectric properties of V2O5-Bi2O3-ZnO glass

Semiconducting oxide glass with composition 40V(2)O(5)-40Bi(2)O(3)-20ZnO is prepared by rapid quenching method. The glassy phase is confirmed from X-ray diffraction (XRD) pattern which shows a broad hump around 20 = 30 degrees. The dc conductivity of the glass has been measured in the temperature range 300-600 K and compared with that of other vanadium and copper based zinc oxide containing glasses. The dc conductivity is due to non-adiabatic small polaron hopping conduction which is confirmed from the fitting of the conductivity data with different polaronic hopping models. The frequency (75 kHz - 30 MHz) dependent dielectric constant of the glass decreases first and then increases with the increase of frequency at room temperature. The anomaly in frequency dependent dielectric constant at similar to 5 MHz may be due to the displacement and/or orientational motion of BiO3 and BiO6 structural units present in the glass.