A novel (La0.2Ce0.2Gd0.2Er0.2Tm0.2)2(WO4)3 high-entropy ceramic material for thermal neutron and gamma-ray shielding

In this study, a new type of (La 0.2 Ce 0.2 Gd 0.2 Er 0.2 Tm 0.2 ) 2 (WO 4 ) 3 single-phase high-entropy ceramic (HEC) powder was designed, prepared by solid-phase synthesis, and evenly mixed into an epoxy resin (EP) matrix to test the thermal neutron and γ-ray shielding performance. In terms of γ-ray shielding, (La 0.2 Ce 0.2 Gd 0.2 Er 0.2 Tm 0.2 ) 2 (WO 4 ) 3 showed a higher lead equivalent value than EP at 65 keV, indicating a clear shielding effect in the feeble absorbing area of lead-based and bismuth-based materials; moreover, (La 0.2 Ce 0.2 Gd 0.2 Er 0.2 Tm 0.2 ) 2 (WO 4 ) 3 showed good γ-ray shielding performance in both low-energy and medium-energy regions. In terms of thermal neutron shielding, the composite with the highest HEC content (EP/W3) had a nearly 100% shielding efficiency, while that of EP was approximately 50%, indicating that this material has favorable thermal neutron and γ-ray shielding performance. Moreover, the thermal conductivity of the resulting composite material was lower than 0.3 W·m −1 ·K −1 , the tensile strength was higher than 10 MPa, and the density was lower than 1.5 g·cm −3 . All these results suggest that (La 0.2 Ce 0.2 Gd 0.2 Er 0.2 Tm 0.2 ) 2 (WO 4 ) 3 is a candidate radiation shielding material.