Investigation of the Effect of Manganese in Bismuth–Borate Glass System for Gamma-Ray Shielding: A Theoretical and Experimental Correlation

This study investigates the structural and gamma-ray shielding properties of MnO2-doped bismuth–borate glasses by analyzing their mass attenuation coefficient (MAC), half-value layer (HVL), density, optical properties, and elastic parameters. The experimental MAC values, obtained using a 137Cs source (4.5 µCi, 662 keV) were compared with theoretical values from XCOM software, showing close agreement. Results indicate that the sample with the highest Bi2O3 content, exhibited the highest MAC and the lowest HVL (1.477 cm at 662 keV), making it the most effective radiation shield. Density decreased with increasing MnO2, while molar volume and non-bridging oxygen content increased, influencing band gap reduction from 3.49 to 3.27 eV. The refractive index and cationic polarizability increased with MnO2 concentration, affecting structural rigidity. Poisson’s ratio analysis indicated higher cross-link density in MnO2-rich samples (S4–S6), leading to a more rigid network. Compared to barite concrete, prepared samples demonstrated superior radiation shielding, making them promising candidates for gamma-ray attenuation applications.