High-entropy rare-earth tungstate (PrEuYLaSm)2(WO4)3: Synthesis, physical, structural evolution and shielding properties

In this study, a novel high-entropy rare-earth tungstate, (PrEuYLaSm)₂(WO₄)₃, was synthesized by high-energy ball milling followed by calcination, and its structural, microstructural, thermal, gamma-ray, and neutron shielding properties were systematically investigated. X-ray diffraction results revealed that ball milling induced partial amorphization of the initial oxide mixture, while calcination at 1100 °C promoted the formation of a single-phase monoclinic A₂W₃O₁₂-type structure without detectable secondary phases. SEM-EDS mapping showed the homogeneous distribution of Pr, Eu, Y, La, Sm, W, and O throughout the synthesized material. Differential thermal analysis showed sequential desorption, crystallization, and structural ordering processes, together with the absence of sharp decomposition up to 1100 °C, indicating good thermal stability. Radiation shielding evaluation demonstrated that the synthesized high-entropy tungstate exhibited strong gamma-ray attenuation performance, with high mass attenuation coefficient values, low half-value layer values, and stable effective atomic number behaviour over a wide photon energy range. Although some individual oxides showed superior performance at specific energies, the high-entropy composition provided a more balanced shielding response overall. In neutron shielding, the material showed competitive fast neutron removal capability among oxide systems. It can be concluded that the multifunctional potential of (PrEuYLaSm)₂(WO₄)₃ for competitive high-temperature and radiation shielding applications.