Investigating Structure and Physical Properties of Chromium Oxide Doped Bismuth Borate Glasses

The glasses, composed of multiple components, contain chromium oxide x.Cr₂O₃.(70-x)B₂O₃.18Bi₂O₃.12Na₂O, where x varies (x=0, x=0.15, x=0.25, x=0.35, x=0.50 mol %), synthesized using the melt-quench method. The amorphous nature of the synthesized samples was confirmed using X-ray diffraction (XRD). We observed that an increase in Cr₂O₃ content resulted in a rise in the density (ρ) of the glasses, ranging from 3.88 g/cm³ to 4.009 g/cm³. Notably, the molar volume displays behaviour opposite to the density trends. The oxygen packing density (OPD) exhibited augmentation with elevated chromium oxide concentrations, implying a more compact and tightly packed glass structure. Fourier transform infrared (FTIR) spectroscopic data show distinct features of the synthesized glass samples corresponding to chromium oxide content. The FTIR spectra display vibrations of metal cations and Cr3+ at around 530 cm−1, and a band at approximately 1150 cm⁻¹, attributed to the B-O bonds with non-uniform stretching vibrations in [BO₃] units. The analytical findings indicate the predominant presence of [BiO₆], [BiO₃], and [BiO₄] vibrations in the glasses. The Raman spectroscopy affirms the presence of distinct structural units, including BiO₃, BiO₆, BO₃, and BO₄. These findings provide a foundational basis for customizing glass compositions to meet specific technological requirements, encompassing applications in optics and radiation shielding.