Oxide superconductor and method of preparing the same

摘要

An oxide superconductor includes a main component represented by the following formula: LnBa₂Cu₃O_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.