abstract |
Provided is an oxide superconductor having a composition represented by REaBabCu3O7-x, where RE represents one rare earth element or a combination of at least two rare earth elements, 1.05<=a<=1.35, 1.80<=b<=2.05, and x represents the oxygen deficiency amount. In the oxide superconductor, a superconducting phase contains a non-superconducting phase having an outer diameter of 30 nm or less. |