Magnetic and spectroscopic properties of PbO–La2O3–P2O5:Cr2O3 glass system

PbO–La2O3–P2O5 glasses containing different concentrations of Cr2O3 ranging from 0 to 0.5 mol% were prepared. A number of studies viz., differential thermal analysis, infrared, optical absorption, ESR spectra and magnetic properties of these glasses have been carried out as a function of chromium ion concentration. The analysis of the results of these studies indicated that chromium ions mostly exist in Cr3 + state in these glasses when the concentration of Cr2O3 ≤ 0.3 mol% occupy octahedral positions and above this concentration chromium ions seem to subsist in Cr6 + state and occupy tetrahedral positions with CrO2 −4 structural units.