Influence of molybdenum ions on the structure of ZnO-As2O3-Sb2O3 glass system by means of spectroscopic and dielectric studies

Glasses of the composition 5 ZnO-(50 − x) As2O3-45 Sb2O3:x MoO3, with six values of x ranging from 0 to 10 mol% are prepared. The samples are characterized by X-ray diffraction, scanning electron microscopy and differential thermal analysis (DTA) techniques. A number of studies, viz., spectroscopic properties (optical absorption, IR, Raman, and ESR spectra), magnetic susceptibility and dielectric properties (dielectric constant ε′, loss tan δ, ac conductivity σac over a wide range of frequency and temperature as well as dielectric break down strength at room temperature), are carried out as a function of molybdenum ion concentration and analyzed in the light of different oxidation states of molybdenum. The analyses of the results indicate that molybdenum ions mostly exist in Mo5+ state rather than in Mo6+ state.