Structural role of In2O3 in PbO-P2O5-As2O3 glass system by means of spectroscopic and dielectric studies

PbO-P2O5-As2O3 glasses containing different concentrations of In2O3 (ranging from 0 to 5 mol%) were prepared. A number of studies, viz., chemical durability, differential thermal analysis, spectroscopic (infrared, optical absorption and Raman spectra) and dielectric properties (constant ɛ′, loss tan δ, ac conductivity σac over a range of frequency and temperature) of these glasses have been carried out. The studies on chemical durability indicate that there is a significant increase in the corrosion resistance of the glasses; where as the results of differential thermal analysis suggests that there is a substantial improvement in the glass forming ability, with increase in the concentration of In2O3 in the glass matrix. The spectroscopic investigations point out that the indium ions mostly take part network forming positions with InO6 structural units and increase the rigidity of the glass network. The studies of dielectric properties reveal that the presence of indium oxide in the glass network causes a considerable improvement in the insulating strength of the lead phosphate glasses.