Faculty Publications

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Author: search.filters.author.Ingle, A.Subject: search.filters.subject.Titanium dioxide

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    A comprehensive study uncovering physical, structural, and optical properties of Cu2O and TiO2-reinforced borosilicate glasses as optical filters
    (Elsevier B.V., 2024) Raghuvanshi, V.; Rashmi, I.; Ingle, A.; Shashikala, H.D.; Nagaraja, H.S.
    In this study, the integration of transition metal oxides (TMOs), specifically Cu2O and TiO2, into a borosilicate glass matrix (30SiO2–35B2O3–35Na2O–5CaF2-X (TMO)) was investigated for enhanced glass functionality. Glass samples with varying TMO concentrations (X = 0, 1, 2, 3, 4 mol%) were prepared using the melt-quenching technique. X-ray diffraction confirmed the amorphous nature of the synthesized samples, while FTIR analysis showed structural changes, transitioning from trigonal BO3 to BO4 tetrahedra, alongside the formation of non-bridging oxygen species due to TMO integration. UV–Vis spectroscopy demonstrated a red shift in optical absorption profiles, correlating with a reduction in the indirect band gap as TMO content increased. Photoluminescence studies showed distinct behaviors, with Cu2O suppressing emission peaks and TiO2 exhibiting intriguing blue and green emissions, diminishing at higher concentrations. It was attributed that Cu2O had a larger impact on altering the glass network than TiO2. These findings contribute to understanding the properties of Cu2O and TiO2-containing borosilicate glasses, suggesting tailored optical properties for potential applications as bandpass filter and UV blocker. © 2024 Elsevier B.V.
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    Influence of titanium redox states on luminescence and conductivity in TiO2 -doped borophosphate glass system
    (Elsevier B.V., 2025) Rashmi, R.; Ingle, A.; Raghuvanshi, V.; Shashikala, H.D.; Nagaraja, H.S.
    Borophosphate glasses have garnered significant interest due to their potential for optical and electronic applications. This research delves into the luminescent and conductive properties of 40P2O5–25B2O3-(35-x) BaO-xTiO2 (x = 0–5 mol%) glasses synthesized via the melt-quench method. The glass doped with 4 mol% TiO2 exhibited intense luminescence within the 400–600 nm spectrum, manifesting as a vivid blue emission and the highest Ti3+ ion concentration. Beyond this threshold, the luminescence intensity waned, highlighting the significance of Ti4+/Ti3+ ratios. Absorption spectra and X-ray photoelectron spectroscopy were utilized to study these multivalent ions. Temperature-dependent AC conductivity, exhibited a linear increase, consistent with the Correlated Barrier Hopping (CBH) model. Enhanced polaron hopping between Ti3+ and Ti4+ with increasing TiO2 content improved the dielectric constant and conductivity, peaking at 4.145×10?5 Scm?1 at 5 mol% TiO2 within the 450–530 °C range. These findings underscore the tunability of TiO2-doped glasses for optoelectronic applications. © 2024 Elsevier B.V.
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    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.