Optical and Radiation Shielding Studies on Borobismuth Iron Oxide-Samarium Bismuth Titanate Glass-Matrix Samples

Abstract

Glass matrix with the chosen composition (100-x) [0.7Bi₂O₃-0.2B₂O₃-0.1Fe₂O₃] + x (Bi_3.75Sm_0.75Ti₃O₁₂) (with x=30, 40, 50, 60 wt.%), were prepared by conventional melt –quench method. The XRD pattern shows the dominant phase of crystalline nature, over the amorphous nature.  UV-visible spectra for all the glass-matrix samples were taken in the range of 200-900 nm. Optical parameters like energy gaps (E_gap), refractive index, molar polarizability, metallization criterion etc were calculated. Oxygen packing density was found to decrease with increasing the Bi_3.75Sm_0.75Ti₃O₁₂ (BST) content, and hence BST acts like a glass network modifier.  Raman spectra results conformed the layered-perovskite structure with distorted TiO₆ octahedral, which is considered to be the characteristic feature for layered-structure glass ceramics. Polaron radius of the samples increased from 9.74 to 14.1 Å, with increasing the BST composition in the glass-matrix. FTIR Spectroscopic results have shown the presence of tri, tetra, penta borate units with distorted BiO₆ units. Optical spectroscopic measurements were carried out on samples and the insights prove that the optical band gap got narrowed down from (1.73eV-1.48 eV). From this one can presume to create a room for photovoltaic applications. Gamma radiation shielding properties were studied using PhyX/PSD software. MAC (Mass Attenuation Coefficient) values were found to be high in the energy range of 0.01MeV- 0.04MeV.  The effective atomic number (Z_eff), electron density (N_e), mean free path (MFP) and half-value layer (HVL) values were evaluated for all the compositions. The gamma radiation studies on glass-matrix exhibit excellent gamma ray shielding features and therefore these materials are considered to be future environment-friendly nuclear shielding materials.