BaF2-doped borosilicate glasses for next-generation radiation shielding and optical applications: A hybrid experimental and computational study

BaF2-doped borosilicate glasses were produced using the melt-quenching method with compositions of (56-x)B2O3 + 12SiO2 + 20CaO + 12Li2O + xBaF2 (x = 0, 2.5, 5, 7.5, and 10 mol%). The impact of BaF2 on the structural, optical, and radiation shielding characteristics was examined through experimental techniques and computational modelling. Density measurements indicated an increase from 2.2138 g/cm3 (BSCLB0) to 2.6549 g/cm3 (BSCLB10), attributed to the higher density of BaF2. Optical analysis revealed that the incorporation of BaF2 significantly altered the glass properties. The UV absorption edge shifted toward shorter wavelengths, decreasing the cut-off wavelength from 362.59 nm (BSCLB0) to 338.82 nm (BSCLB10), which suggests enhanced transparency in the UV region. The optical band gap energy for direct transitions increased from 3.835 eV to 4.145 eV, indicating a more compact glass structure. Meanwhile, the refractive index (n) declined from 1.769 (BSCLB0) to 1.558 (BSCLB10), demonstrating that BaF2 enhances optical clarity but may not be ideal for applications requiring a high refractive index. Additionally, the extinction coefficient (k) decreased, signifying reduced optical losses. The Urbach energy (EU), which reflects structural disorder, rose from 0.883 eV to 1.004 eV, implying slight modifications in the glass network due to BaF2 doping. The radiation shielding potential of BaF2-enriched borosilicate glasses was assessed using Monte Carlo simulations, EpiXS software, and Artificial Neural Networks (ANNs). The mass attenuation coefficient (MAC) exhibited a rise from 5.700 cm2/g (BSCLB0) to 17.093 cm2/g (BSCLB10) at 15 keV, indicating superior photon attenuation. Furthermore, the half-value layer (HVL) declined from 2.95 cm to 2.65 cm at 50 keV, confirming improved shielding performance. Glasses with higher BaF2 content displayed elevated effective atomic numbers (Zeff), reaching approximately 50 at 40 keV, which helps in minimizing secondary radiation generation. In terms of neutron shielding, the removal cross-section (ΣR) showed a modest increase, reaching 0.0956 cm−1 for BSCLB10, making these glasses comparable to boron carbide and graphite in neutron attenuation. These findings suggest that BaF2-doped borosilicate glasses are promising candidates for dual-purpose shielding applications, effectively attenuating both gamma rays and neutrons in nuclear and medical environments.