Hunting for advanced low-energy gamma-rays shielding materials based on PbWO₄ through crystal defect engineering

Increasing exposure chances of humans to low-energy gamma-rays occur with the rapid application expansion of nuclear technology, which tend to induce carcinogenic and mutagenic effects on living bodies, and then need to be protected from. PbWO4 has excellent gamma-rays attenuating ability while Pb displays a weak shielding property of low-energy gamma-rays from 40 keV to 88 keV. Here, crystal defect engineering with Ce doping is applied to fabricate the crystal structure of PbWO4 for tailoring its low-energy gamma-rays shielding property. Characterization with XRD, Raman, XPS, XRF, SEM and TEM techniques indicates cerium ions have been introduced into the lattice of PbWO4 crystals during the doping process. In addition, Ce doping amount plays key roles in tuning the crystal defects in PbWO4 including ion substitution, charge compensation and structural deformation. Importantly, PbWO4 doped with 10 mol% Ce displays an optimal mass attenuation coefficient (2.61 cm(2)/g) to 59.5 keV gamma-rays and shows a 39% increase ratio to the PbWO4 without doping. In addition, typically anisotropic PbWO4 crystals are found at 40 mol% Ce doping amount, which give its potential versatility. This work provides a solution to make up for PbWO4 to shield low-energy gamma-rays that could further promote its application in personal protection, such as clothing. (C) 2020 Elsevier B.V. All rights reserved.