Optical and structural attributes of magnesium oxide borate glass doped with TiO2 for photonic applications

This study examines the impact of dopant TiO₂, co-dopant MgO, and the physical properties of magnesium borate glasses. The fabrication of glass compositions was accomplished through the melt quenching technique, yielding formulations of xTiO₂-(50−x)MgO-50B₂O₃, where x = 0, 1, 3, 5, 7, and 9 in mol%. The structural, optical, and dielectric properties of these glasses were systematically analyzed to elucidate the impact of varying magnesium ion concentrations. X-ray diffraction (XRD) analysis confirmed the amorphous nature of the glass system. Density measurements, conducted via the Archimedes method, revealed an increase with increasing TiO₂ mol%, while the molar volume decreased, following theoretical expectations. Absorption spectra spanning 200 to 1000 nm were obtained using a UV–visible spectrometer. Tauc’s plot facilitated the determination of direct and indirect energy band gaps, revealing fluctuations in band gap energy with varying TiO₂ mol%. The refractive index was derived from the energy band gap values. Additionally, Fourier-transform infrared (FTIR) spectroscopy, covering wave numbers from 400 to 4000 cm⁻¹, was employed to characterize the functional groups present in the glasses.