Effect of annealing and replacement of vanadium by Cr(III) and Mn(IV) ions in (V2O5)0.8–(P2O5)0.2 glass on its magnetic susceptibility, electrical conductivity, and dielectric constant

Abstract

The effect of heat treatment and substitution of vanadium by other transition metal ions, such as Cr3+ or Mn4+ in (V2O5)0.8–(P2O5)0.2 glass on the electrical conductivity, dielectric constant, dielectric loss, and magnetic susceptibility has been studied over a temperature range of 80–400 K and frequencies of 102–106 Hz. The ac conductivity, σac, was found to be increased by annealing and decreased by the replacement of vanadium with Mn4+ or Cr3+ ions. The σac value increased with the measuring frequency ω according to σac(ω)=A(ω)s, where s has a value in the range of 0.33–0.48. Dielectric loss ε showed maxima at temperatures depending on the sample composition and the measuring frequency. The magnetic susceptibility χ was found to increase by annealing and by introducing Cr3+ or Mn4+ into glass materials. The results obtained were explained on the basis of a mutual interaction, which is exclusively occurring between double redox pairs during the sample preparation or during the annealing process, to produce a shift in redox ratios. The experimental results were correlated together and discussed.