The mutual effect of heavy element ions (Pb2+/W6+) on the structural, optical and shielding properties of alkali borate glass doped with Ni2+/ Ni3+ions

shielding properties of Ni2+/Ni3+-doped alkali borate glasses. Although both modifiers reduced the metallization
criterion (≈0.390), indicating improved semiconducting behavior, their qualitative effects varied significantly.
Incorporation of W6+ions led to a reduction in sample density from 2.93 to 2.4 g/cm3, a decrease in the band gap
energy from 3.69 to 2.92 eV, and increased the non-bridging oxygen (NBO) content. In contrast, Pb2+ ions
improved the transparency, reduced the structural disorder, as inferred from the Urbach energy parameter, and
enhanced ionic bonding around Ni2+ions, as inferred from the ligand field effect parameters. The influence of
Pb²⁺ and W⁶⁺ ions also diverged in modulating the electronic transitions of Ni²⁺/Ni³ ⁺ ions within the visible and
NIR regions. Depending on the composition and energy level, the impact of PbO and WO3 content on the ra
diation attenuation characteristics varied. While samples with higher PbO concentrations outperformed in some
aspects, a significant convergence was observed in the values of the mass attenuation coefficient (MAC) and
effective atomic number (Zeff) between samples containing 10% WO3 and those containing 10% PbO at high
energy levels, reaching 92.3% and 91.2%, respectively, at 15MeV. In contrast, the half-value layer (HVL)
values of these samples were close at low energy levels, recording a convergence of 88.9% at 0.015MeV. In
addition, the average convergence of the measured radiation shielding parameters between the WO3-free sample
and the sample with a 50PbO/50WO3 hybrid concentration was approximately 91%.