Optical and TL Studies of Oxy fluoroborate Glasses

Glass system of (80-x)B2O3-10Al2O3-10SiO2-xCaF2 (where x=5, 10, 20, 30 and 40 mol.%) were prepared by melt-quenching method and checked using XRD technique which reveals the amorphous state of these systems. Density and molar volume were measured. Increases in density from 2.156 to 2.809 (g/cm3) were observed with an increase in CaF2 content. Fourier transform infrared spectroscopy (FTIR) spectral study was investigated using deconvolution quantitative analysis. Ultraviolet-Visible (UV-VIS) absorption spectra were also measured using polished parallel surfaces glass samples. These glasses showed a decrease in the optical band gap (Eopt) from 3.40 to 2.91 eV and an increase in the localized states tails ( E) from 0.21 to 0.35 eV with increasing in the CaF2 content. The overall results suggested that CaF2 content in glass samples played a role as a network modifier in the system. In addition, a correlation between the results from density, UV-VIS and FTIR measurements ensured the conclusion that changing in the atomic structure were due to the formation of BO4 units.