Dielectric and AC conductivity studies in Li_2O doped vanado-zinc-boro-phosphate glass nano composites

摘要

A set of Li2O doped vanado-zinc-borophosphate glass nano composites in the composition, (B_2O_3)_(0.2)-(P_2O_5)_(0.5-x)-(ZnO)_(0.1)-(V_2O_5)_(0.2)-(Li_2O)_x; x=0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3 and 0.4 have been synthesized by quickly quenching the melt at 1300K. Phase formation has been confirmed by observing powder XRD patterns. Dielectric constant and dielectric loss factors have been measured in a Precession Impedance Analyzer over wide range of frequency and temperature. Within input variable ranges, the dielectric constant varied from 600 to 1500 and dielectric loss fact ors varied from 10 to 22×10~3. Both the dielectric parameters decreased with increase of frequency and increased with increase of temperature. These changes have been interpreted in terms of different contributions to the total polarization of the samples. AC conductivity has been derived from dielectric data and it has been analyzed in the light of Mott's Small Polaron Hopping model. Conductivity increased with increase of frequency and temperature. Activation energy for conduction obtained from the analysis has been found to decrease with increase of frequency. For the first time the present type of glass nanocomposites have been subjected to dielectric investigations and data analyzed thoroughly.