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Author: search.filters.author.Ingle, A.Subject: search.filters.subject.Transition metal oxides

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    Influence of V2O5 addition as a dopant and dispersed content in barium borophosphate glass on structural and optical properties
    (Elsevier Ltd, 2024) Rashmi, I.; Ingle, A.; Raghuvanshi, V.; Shashikala, H.D.; Nagaraja, H.S.
    The Barium Borophosphate glass system with molar compositions 40P2O5– 25B2O3-(35-x) BaO-xV2O5 and 40P2O5–25B2O3–35BaO-xV2O5 (x = 0,1,3,5 mol%) was synthesized using melt-quenching method. A comprehensive investigation of the structural and optical properties was conducted to compare the effects of V2O5 as a dopant and as an addition to the glass matrix. The physical parameters were assessed through the measurement of density. The influence of V2O5 introduction on vibrational modes was studied through Fourier-transform infrared (FTIR) and Raman spectroscopy. The UV–visible absorbance analysis unveiled the existence of multiple valence states of vanadium (V3+, V4+ and V5+). The reduction in bandgap was determined through the utilization of a Tauc plot, while the measurement of the refractive index allowed for the assessment of its variation with the composition of V2O5. Photoluminescence spectroscopy (PL) was employed to explore the presence of intrinsic defects within the glass matrix and the impact of V2O5 on the emission spectra. Furthermore, CIE chromaticity coordinates of synthesized samples were observed in both the white and blue regions, suggesting their potential application in display devices. Significantly, V2O5 glass doped with 1 mol% displayed chromaticity, characterized by CIE coordinates x = 0.288 and y = 0.386, closely matching the white region as well as the bandpass filter. The introduction of transition metal oxide dopants into borophosphate glass yielded exceptional emission properties. The ability to modify optical properties makes it more promising for these glass materials, particularly for applications like optical filters and displays. © 2024 Elsevier Ltd and Techna Group S.r.l.
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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 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.