Comprehensive investigation of La2O3-modified borate glasses for optical and radiation shielding applications

In this study, a series of borate-based glasses with the composition (70–x) B₂O₃ + 5ZnO + 5SrO + 5Na₂O + 5CaO+ 10BaO+xLa₂O₃ (x = 0, 2.5, 5 mol%) were synthesized using the conventional melt-quenching technique. Structural analyses confirmed the amorphous nature of all samples, while optical investigations revealed a reduction in the band gap with increasing La₂O₃ content. Machine learning-assisted density prediction provided an effective pre-synthesis optimization strategy for the borate glass system. Characterizations of the mechanical and physical properties showed that the amount of La was necessary. Gamma-ray attenuation was experimentally evaluated for the glass samples in the energy range of 81–383 keV. At 383 keV, AY52 maintained its advantage with a MAC of 0.1343 cm²/g and a LAC of 0.3794 cm⁻¹, compared to 0.1058 cm²/g and 0.3402 cm⁻¹ for AY50. Moreover, AY52 also exhibited the highest effective atomic number (Zeff) and the lowest buildup factors (EABF and EBF) across the energy range, confirming its enhanced shielding performance compared to AY50 Neutron shielding evaluations revealed modest improvements, with the effective removal cross-section (ΣR) slightly decreasing from 0.11184 cm⁻¹ (AY50) to 0.10821 cm⁻¹ (AY52), and absorbed neutron dose rates of 0.8344 µSv/h (AY52) compared to 0.8352 µSv/h (AY50). Overall, the incorporation of La₂O₃ enhanced the structural stability, photon attenuation capacity, and mechanical strength of the borate glass system, making it a promising lead-free candidate for radiation shielding applications.