Radiation Resistance and Hydrolytic Stability of Y0.95Gd0.05PO4-Based Ceramics with the Xenotime Structure

The Y0.95Gd0.05PO4 phosphate with the xenotime structure has been synthesized in powder form and as ceramics. Ceramics with a relative density of ~99% have been produced by spark plasma sintering. The sintering temperature was 1140°C and the sintering time was ~18 min, without isothermal holding. We have assessed the radiation resistance of the ceramics under irradiation with 132Xe26+ ions and investigated the restoration of the obtained metamict phase to a crystalline one via high-temperature heat treatment. No complete amorphization of the samples has been reached at the fluences used in this study. The calculated critical fluence is (9.2 ± 0.1) × 1014 cm–2, and the calculated latent track radius is ~2.8 nm. Hydrolytic tests have shown that the phosphate under study is stable in water under dynamic conditions. The observed Y and Gd leaching rates were Ri = 1.68 × 10–6 and 1.5 × 10–7 g/(cm2 day), respectively.