Study on solid solubility of Gd in UO2 using X-ray diffraction

Abstract The change in solid solubility of Gd after sintering of UO 2 with Gd additions has been explained based on the X-ray diffraction study. It was observed that Gd has large solid solubility in UO 2 due to the same ionic radii of U 4+ and Gd 3+ in the lattice. On sintering, the observed reduction in the lattice parameter of UO 2 with Gd addition is due to formation of oxygen ion vacancies. Two different methods were used for the preparation of specimen materials: co-precipitation and mechanical mixing. The co-precipitation route, unlike mechanical mixing route, gives atomistic mixtures where lattice parameter changes before sintering with addition of Gd.