Dielectric dispersion in Li2O–MoO3–B2O3 glass system doped with V2O5

Li2O–MoO3–B2O3 glasses containing different amounts of V2O5, ranging from 0 to 1.5 mol%, were prepared. The dielectric properties (viz., constant ɛ′, loss tan δ, AC conductivity σac over a wide range of frequency and temperature) have been studied as a function of the concentration of vanadium ions. The variation of AC conductivity with the concentration of V2O5 passes through a maximum at 0.8 mol% V2O5. In the high-temperature region, the AC conduction seems to be connected with the mixed conduction, viz., electronic and ionic conduction. The dielectric relaxation effects exhibited by these glasses have been analyzed quantitatively by pseudo Cole–Cole plot method and the spreading of relaxation times has been established. Further analysis of these results has been carried out with the aid of the data on ESR, IR and optical absorption spectra.