Influence of CaF2 on spectroscopic studies of lead fluoro bismuth borate glasses doped with Cr3+ ions

An extensive study has been carried out to predict the physical and structural properties of CPBBCR: CaF2-PbF2-Bi2O3-B2O3Cr2O3 glasses. The changes in the density & molar volume due to the substitution of PbF2 by CaF2 have been discussed in terms of relative crystal densities of PbF2 & CaF2. The detailed UV–visible spectra for the CPBBCR samples have been done to study the variation of optical band, Urbach energy and Rachah parameters. The EPR spectrum of Cr3+ doped glass sample exhibited broad resonance signal with effective g = 4.12 and g = 1.97. Deconvoluted Raman spectra are used to attain hidden peaks in the Raman spectra. With the increase in CaF2, Raman spectra suggested that the there is a transfer of [BO4] to [BO3]. FTIR analysis of these samples confirmed the presence of metal cation vibrations, BiO3, BO3 & BO4 units. FTIR spectra also confirmed that the Bi2O3 will act as network modifier.