Disorder processes in A³⁺B³⁺O₃compounds: implications for radiation tolerance

Intrinsic defect processes were compared for an extensive range of A3+B3+O3 compounds with A cation radii from Sc3+ to La3+ and B cation radii from Al3+ to In3+. Crossovers between cation antisite, Schottky and oxygen Frenkel disorder are predicted as a function of cation radius. The radiation tolerance of these compounds was discussed in the light of their relative defect process energies. On this basis there should be a wide variation in radiation tolerance. In particular, only a limited compositional range, coincident with the bixbyite structure, will exhibit the high tolerance previously observed in materials with fluorite and fluorite-related structures. Materials with the rhombohedral or orthorhombic perovskite structures will be significantly less tolerant.