Structure, optical properties, and ionizing radiation shielding performance using Monte Carlo simulation for lead-free BTO perovskite ceramics doped with ZnO, SiO2, and WO3 oxides

Abstract

This study reports the influence of different oxides doping on the structure, optical characteristics, and radiation protecting performances of perovskite BaTiO3 (BT used thereafter) ceramic synthesized by solid-state reaction process. The crystal structure and phase identification are examined through X-ray diffraction technique (XRD) and Rietveld refinement analyses that confirm a monophasic tetragonal structure with a P4mm space group in BT ceramic. The tetragonality is maintained with ZnO doping, however, for ceramics doped with WO3 and SiO2, a cubic structure is detected with the presence of some impurities. The variation in the structural parameters is indicative of the distortion in the unit cell under the influence of different oxides doping. The optical properties reveal a variation in optical bandgap under the effect doping. The values of Eg follow the order of BT: Zn < BT < BT: W < BT: Si. BT doped with SiO2 exhibits a wider bandgap energy (3.41 eV) compared to all prepared ceramics. The radiation shielding studies were examined using Monte Carlo simulation. The linear attenuation coefficient (μ) values for BaTiO3 are 1.238, 0.453, and 0.297 cm−1 for photons with energies 0.244, 0.662, and 1.332 MeV, respectively, and these values were increased gradually with the addition of ZnO or WO3 metal oxides. In contrast, the addition of SiO2 compounds to the basic composition BT causes a reduction in both the density and shielding capacity of the fabricated BT. The half-value thickness (Δ0.5) was evaluated and the results demonstrated that the Δ0.5 increases between 0.560 and 2.399 cm (for BT ceramics), 0.555–2.370 cm (for BT: Zn), 0.528–2.293 cm (BT: W), and 0.609–2.619 cm (for BT: Si ceramics) when the γ-ray energy raised between 0.244 and 1.408 MeV, respectively. Also, the addition of ZnO and WO3 slightly enhance the Δ0.5 values by a factor of 1.142% and 4.532%. On the other hand, the addition of the SiO2 compound to BaTiO3 increases the Δ0.5 value by a factor of 9.16%.