TeO2-induced modifications in BaO-PbO2-B2O3-TeO2 glasses: A study of structural, optical properties and radiation attenuation efficiency

This study examines the optical and radiation protection effectiveness of BaO-PbO 2 -B 2 O 3 -TeO 2 glasses with varying TeO 2 contents (5, 10, 15, and 20 mol %), whereby the developed glasses' density increases with higher TeO 2 content. Fourier Transform Infrared (FTIR) spectroscopy was employed to identify and analyze the functional groups associated with TeO 2 and B 2 O 3 within the glass matrix. Optical analysis revealed that the absorption edge shifted to shorter wavelengths with a 5–15 mol% increase in the TeO 2 content, indicating greater glass rigidity. There was a 2.802–3.006 eV (direct transitions) and 2.145–2.520 eV (indirect transitions) increase in the optical band gaps (E g ), attributed to a reduction in non-bridging oxygens. However, the Ba20Te20 (20 mol% of TeO 2 ) glass showed a decline in E g due to electron localization. Additionally, the refractive index, dielectric constant, Urbach energy and metallization exhibited trends that revealed structural changes linked to TeO 2 content, with increased metallic characteristics observed at 20 mol% TeO 2 . Regarding radiation attenuation, the mass attenuation coefficients (MAC) demonstrated a clear trend, with Ba20Te20achieving the highest MAC, confirming its potential as an effective attenuating material. The effective atomic number (Z eff ) and linear attenuation coefficient (LAC) analyses further corroborated these findings, revealing that low-energy photons predominantly interact with the glass matrix. Comparisons with some PbO-doped glasses indicated that Ba20Te20 glass had the lowest half-value layer (HVL), making it more effective as a shielding material. These findings contribute important new knowledge regarding developing borate-based glasses doped with TeO 2 , highlighting their enhanced radiation protection features.