Faculty Publications
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Item Influence of BaO Addition on Density and Refractive Index of 50P2O5- xB2O3-(50-X) BaO Glasses(Springer, 2024) Rashmi, I.; Shashikala, H.D.The borophosphate glasses of composition 50P2O5- xB2O3- (50-x)BaO (x = 5,10,15,20, 25 mol %) were prepared using the melt-quenching technique. The Archimedes principle was used to measure the density of glasses. The density has been observed to increase with the rise in BaO concentration. Molar volume (Vm) and oxygen packing density (OPD) were computed as a function of BaO using measured density to analyze the structural changes in the glass matrix. The amorphous phase of the glass was confirmed using XRD. The refractive index and UV–visible spectroscopy of prepared glasses were measured. The dielectric constant (ɛ), molar refraction (Rm), electronic polarizability (αm), anion polarizability (αO2-), reflection loss (R), metallization factor (M), and indirect bandgap which are useful in the explanation of physical and optical properties of these glasses were evaluated. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.Item Influence of low concentrations of vanadium and titanium ions on the structural and optical properties of borophosphate glasses(Elsevier B.V., 2025) Rashmi, I.; Raghuvanshi, V.; Ingle, A.; Shashikala, H.D.; Nagaraja, H.S.A series of P2O5–B2O3–BaO glass system containing various V2O5 and TiO2 content (from 0.25 to 0.75 mol%) were synthesized using the melt-quenching method to examine their structural, EPR, and optical characteristics. EPR analysis confirmed VO2+ hyperfine splitting and the presence of Ti3+ ions in a tetragonally compressed octahedral structure. The local structures of VO2+ and Ti3+ centers were explored through spin Hamiltonian parameters (g??e) and optical transition energies. UV–visible spectroscopy revealed multiple oxidation states of vanadium (V3+, VO2+ and V5+) and titanium (Ti3+, Ti4+), which significantly influenced the optical characteristics. Photoluminescence (PL) studies indicated the presence of oxygen vacancies and intrinsic defects in the glass matrix, with [VO4]3- groups and Ti3+ ions significantly enhancing emission properties. The enhanced luminescence was observed for glasses with 0.75 mol% TiO2 and 0.75 mol% V2O5. Notably, the 0.75 mol% V2O5-doped glass, exhibited CIE chromaticity coordinates (x = 0.26, y = 0.31), closely aligning with standard white light. The tunability of optical properties through transition metal oxide doping highlights the potential of these glasses for advanced photonic applications, including optical filters and display technologies. © 2025 Elsevier B.V.