Heavy-ion irradiation effects on U₃O₈ incorporated Gd₂Zr₂O₇ waste forms

In this research, the heavy-ion irradiation effects of U-bearing Gd₂Zr₂O₇ ceramics were explored for nuclear waste immobilization. U₃O₈ was designed to be incorporated into Gd₂Zr₂O₇ from two different routes in the form of (Gd_1-4xU_2x)₂(Zr_1-xU_x)₂O₇ (x = 0.1, 0.14). The self-irradiation of actinide nuclides was simulated by Xe²⁰⁺ heavy-ion radiation under different fluences. Grazing incidence X-ray diffraction (GIXRD) analysis reveals the relationship between radiation dose, damage and depth. The radiation tolerance is promoted with the increment of U₃O₈ content in the discussed range. Raman spectroscopy testifies the enhancement of radiation tolerance and microscopically existed phase evolution from the chemical bond vibrations. In addition, the microstructure and elemental distribution of the irradiated samples were analyzed as well. The amorphization degree of the sample surface declines as the U content was elevated from x = 0.1 to x = 0.14.