| abstract |
An oxide superconductor includes a main component represented by the following formula: LnBa 2 Cu 3 O 7-x , where Ln comprises two or more types of elements selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, and Y, and a content of each element is 10 to 90 mol %, and fluorine at a molar ratio of 10 −2 to 10 −6 with respect to copper. |