Oxide ceramics are the candidate materials for encapsulating minor actinides. Since the decay of radioactive elements generates a large amount of heat and radiation, knowledge on structural changes and stability under radiation environments is required. Oxygen−deficient fluorite structural derivatives have attracted attention for their radiation effects, because oxide ceramics with a fluorite type structure are known to exhibit excellent radiation resistance. We have recently performed swift heavy ion irradiation into δ−Sc4Hf3O12 and found the formation of a metastable phase with a bixbyite (C−rare earth) structure . However, the stability of this structure is not well understood. In the present study, we examined the effects of heat treatment and electron beam irradiation on the bixbyite phase.
 M. Iwasaki, Y. Kanazawa, D. Manago, M. K. Patel, G. Baldinozzi, K. E. Sickafus, and M. Ishimaru, J. Appl. Phys. 132, 075901 (2022).