Scheelite-type BaWO4 doped with Ho2O3 oxide as a promising lead-free shield for gamma rays: Structural, optical properties, and radiation attenuation efficiency

Humans are constantly exposed to ionizing radiation and radioactive substances that exist naturally within the earth, their bodies, and their homes. Therefore, people and their surroundings must be protected from high levels of ionizing radiation. In general, different materials for radiation protection are used in diverse fields and for specific cases. In this work, a new ceramic-based material containing barium tungstate-doped with different amounts (x= 0-75%) of holmium oxide Ho2O3 was proposed as a & gamma;-radiation shield. The structural and optical studies were performed based on X-ray diffraction technique, Fourier transform infrared spectrum, and diffuse reflectance spectroscopies. Radiation attenuation coefficients were determined using the Monte Carlo simulation. The structural analyses indicated that the BaWO4 crystal belongs to the scheelite structure and a lattice distortion was shown due to the effect of Ho2O3 doping. The band gap energy of the material increased progressively with increasing the content of the dopant in the host material. The radiation shielding coefficients reduced with increasing the concentration of Ho2O3 into BaWO4, where the linear attenuation coefficient reduced by 13% from 0.386 cm-1 to 0.338 cm-1 at 0.662 MeV when the concentration of Ho2O3 increased from 0% to 75%, respectively. Simultaneously, the lead equivalent thickness increased from 3.22 cm to 3.67 cm with raising the Ho2O3 concentration.

Automated summary

A new ceramic-based material containing barium tungstate-doped with different amounts of holmium oxide (Ho2O3) was proposed as a γ-radiation shield. Structural and optical studies were performed, and radiation attenuation coefficients were determined using the Monte Carlo simulation. The results showed that the material had a scheelite structure, and the radiation shielding coefficients decreased with increasing Ho2O3 concentration.