| abstract |
An oxygen excess type metal oxide expressed with the following formula (1) and exhibiting high speed reversible oxygen diffusibility whereby a large amount of excess oxygen is diffused at a high speed and reversibly in a low temperature region: n A j B k C m D n O 7+δ (1) where A: one or more trivalent rare earth ions and Ca B: one or more alkaline earth metals C, D: one or more oxygen tetra-coordinated cations among which at least one is a transition metal, where j>0, k>0, and, independently, m≧0, n≧0, and j+k+m+n=6, and 0<δ≦1.5. |