Design and characterization of BaO-enriched borophosphate glasses for advanced gamma and neutron radiation shielding applications

Abstract

Magnesium borophosphate glass composites with compositions xBaO–30MgO–10P₂O₅–(50–x)B₂O₃–10Na₂O (x = 0, 1, 3, 10, 15, 20, 35 mol%) were synthesized via the melt-quenching method and evaluated for gamma and neutron radiation shielding. X-ray diffraction confirmed their amorphous nature, while density increased from 2.797 g cm⁻³ (x = 0) to 3.938 g cm⁻³ (x = 35) with BaO addition, accompanied by a reduction in molar volume. Gamma-ray attenuation studies over 0.015–15 MeV revealed that increasing BaO content enhanced the mass attenuation coefficient (μ_m) and effective atomic number (Z_eff), with the 35 mol% BaO sample achieving the highest Z_eff (15.34) and lowest half-value layer (HVL) at all energies. At 0.662 MeV, μ_m reached 0.0769 cm² g⁻¹ for x = 35, comparable to or exceeding values for barite concrete and similar glass systems. Exposure build-up factor (EBF) values decreased consistently with BaO enrichment, indicating improved photon shielding. For neutron interactions, the slow neutron cross-section (Σ_s) decreased from 0.0646 cm⁻¹ (x = 0) to 0.0248 cm⁻¹ (x = 20) due to reduced boron content, while the fast neutron removal cross-section (Σᵣ) varied slightly from 0.1144 cm⁻¹ to 0.1012 cm⁻¹. The trade-off in slow neutron attenuation is offset by the significant improvement in gamma-ray and fast neutron shielding. These results indicate that BaO-doped magnesium borophosphate glasses combine high gamma attenuation efficiency, structural compactness, and stable fast neutron performance, making them promising candidates for advanced medical, nuclear, and industrial radiation shielding applications.