Potential He–ion irradiation damage resistance in Sr0.5Zr2(PO4)3–Ce0.5Sm0.5PO4 composite ceramics used for nuclear waste form

In this study, the 500 keV He–ion irradiation effects were systematically analyzed in Sr 0.5 Zr 2 (PO 4 ) 3 –Ce 0.5 Sm 0.5 PO 4 composite ceramics used for nuclear waste form. The phase evolution was investigated at various ion doses of 1 × 10 16 , 1 × 10 17 , and 5 × 10 17 ions/cm² using GIXRD, Raman. Meanwhile, the irradiation effects at various depths of 100 nm, 1500 nm and 3000 nm in the typical sample with an ions dose of 5 × 10 17 ions/cm 2 were further observed through FIB–TEM and SEM. The results indicated that Sr 0.5 Zr 2 (PO 4 ) 3 phase transitioned from crystalline to amorphous state, while Ce 0.5 Sm 0.5 PO 4 phase exhibited crystalline–disorder transition. Furthermore, the microscopic strain changes of both post–irradiated phases were assessed by a geometric phase analysis (GPA) method, which revealed that Sr 0.5 Zr 2 (PO 4 ) 3 phase accumulated more lattice stress than Ce 0.5 Sm 0.5 PO 4 phase. Ultimately, this study confirmed that the irradiation resistance of Sr 0.5 Zr 2 (PO 4 ) 3 phase under He–ion irradiation was inferior to that of Ce 0.5 Sm 0.5 PO 4 phase.