Isra University

The replacement of lead (Pb) in radiation shielding materials is a critical priority for advancing safe medical diagnostics and environmental protection. However, viable alternatives that match Pb's attenuation performance remain limited. In this study, we present a new class of lead-free, high-density glasses: (30-x-y) B₂O₃-9ZnO-31BaO-(30+x) TeO₂-ySm₂O₃, where x = 0, 2, 4, 6 mol% and y = 0, 0.5, 1, 1.5 mol%. These glasses were synthesised via the melt-quenching method. The shielding capabilities of the synthesised glasses were systematically investigated through experimental and Phy-X/PSD theoretical analysis. The experimental arrangement employed a narrow-beam transmission geometry with a NaI(Tl) scintillation detector and radioactive sources including ¹³³Ba, ²²Na, ¹³⁷Cs, and ⁶⁰Co. Gamma-ray attenuation capabilities were evaluated using linear and mass attenuation coefficients (LAC and MAC), half- and tenth value layers (HVL and TVL), mean free path (MFP), and effective atomic number (Z_eff). The results showed that the combined inclusion of TeO₂ and Sm₂O₃ led to a measurable increase in density and gamma attenuation properties across all gamma energies, with strong agreement between experimental and theoretical results, showing a maximum deviation of 8.37 %. The Z_eff ranged from 22.2 at 356 keV to 18.014 at 1332 keV for TeSm-0.5, showing the expected energy-dependent variation due to dominant gamma interaction processes. The HVL and TVL increased with energy but decreased with increasing TeO₂ and Sm₂O₃ contents, with TeSm-1.5 showing the lowest HVL (1.575 cm at 511 keV) and TVL (6.311 cm at 662 keV). These results demonstrate that prepared lead-free glasses achieve substantial shielding efficiency, with potential applications in transparent protective barriers and healthcare infrastructure.

The zinc-tellurium-bismuth-borate glass system has been synthesized, and its physical, optical, dielectric, and radiation attenuation properties have been investigated. Experimental outcomes reveal that density and bandgap energy express an increasing trend with increasing ZnO content in these glasses. DC conductivity discloses space-charge-limited conduction behavior, which changes to Ohmic conduction with increasing ZnO concentration. AC conductivity also depicts changing behavior from ionic to hopping conduction of charge carriers with rising ZnO content in these glasses. The MAC values demonstrate a rising trend from 46.38 cm²/g to 56.73 cm²/g, while HVL and mean free path reveal a reduction from 3.477 cm to 2.885 cm and from 5.016 cm to 4.162 cm, respectively, as the ZnO content in these glasses increases. The BZBT6 glass exhibits radiation shielding characteristics comparable to those of commercially available lead-containing glass (RS-520) and appears to be suitable as a gamma-radiation shield at intermediate energies.