Influence of aluminium ions on physical properties of PbO-P2O5-As2O3 glasses

PbO-P2O5-As2O3 glasses containing different concentrations of Al2O3 ranging from 0 to 5 mol% were prepared. Dielectric properties (viz., dielectric constant $\varepsilon{'}$, loss tan $\delta $ and a.c. conductivity $\sigma_{ac}$ over a moderately wide range of frequency and temperature and dielectric breakdown strength in air medium), optical properties (optical absorption, IR spectra and thermoluminescence) and differential thermal analysis have been studied. The interesting changes observed in these studies have been explained in the light of different structural groups of aluminium ions.