Investigation of structural and optical properties of lithium lead bismuth silicate glasses

Heavy metal-based oxide glasses with composition 30Li 2 O·20PbO· x Bi 2 O 3 ·(50 − x )SiO 2 (where, x = 0 to 50 mol%) were prepared by standard melt-quench procedure at temperature 1150 °C for 30 min. The amorphous nature of the prepared samples was confirmed by the low-intensity broad hump in XRD analysis. Fourier transform infrared spectroscopy predicts the role of Bi 2 O 3 as network former as well as modifier due to the existence of BiO 3 and BiO 6 structural units. The Archimedes principle was used to compute the density of samples, which was found to increase with the bismuth concentration. The optical properties of synthesized samples were measured using UV–VIS–NIR spectroscopy. With increasing bismuth content, optical parameters such as cut-off wavelength, theoretical optical basicity, oxide ion polarizability, and molar refractivity increase, whereas the optical energy bandgap decreases. The large values of refractive index and smaller metallization criterion for all the samples (ranges from 0.310 to 0.395) suggest that studied glasses can be explored for non-linear optical applications.