Abstract: Spinels have been proposed for a multitude of nuclear-energy-related applications, including as nuclear waste forms, inert matrix fuels and structure materials for nuclear reactor, due to its excellent mechanical properties, chemical durability and radiation resistance. The study of radiation behavior and radiation tolerance have important significance in materials selection, assessment and modification. The 500 keV He ions irradiation were performed on Mg_1-xZn_xAl₂O₄ (x = 0-1) spinels at room temperature with different ion fluence. There were a phase transition from order spinel to disorder spinel (O-D) but no amorphization in all of the samples even if the highest ion fluence1×10¹⁷ ions/cm² according to the results of grazing incidence X-ray diffraction and Raman scattering spectrum (Raman). The swelling ratio of MgAl₂O₄, Mg_0.4Zn_0.6Al₂O₄ and ZnAl₂O₄ caused by irradiation is 0.43％, 0.12％and 0.67％, respectively. We think Mg_0.4Zn_0.6Al₂O₄ spinel have the best radiation swelling tolerance, closely followed by MgAl₂O₄ and ZnAl₂O₄ is the worst when the ion fluenceis below 1×10¹⁷ ions/cm². But, maybe the swelling ratio of Mg_0.4Zn_0.6Al₂O₄ will outstrip MgAl₂O₄ at the higher ion fluence than 1×10¹⁷ ions/cm².

Key words: spinel, ion irradiation, O-D transition, swelling