| 摘要 |
PURPOSE:To form a pin stopping center within the grain boundary of a superconductor in which the grain boundary exists in the form of bulk or thin film and to improve the critical current density thereof by adding a compd. contg. magnetic ions to said superconductor. CONSTITUTION:A small amt. of the compd. (e.g.: the oxide of Nd and Eu having the larger ion radius than Y among lanthanoid groups in case of the system of the base material in the undermentioned example) contg. the magnetic ions which have sufficiently low reactivity with the superconductor, i.e., the base material and do not extremely deteriorate the superconducting characteristic of the base material is added to the raw materials (e.g.: Y2O3, BaCO3, CuO) at the time of producing the base material of the oxide superconductor (e.g.: Y, Ba, Cu, O system) in which the grain boundary exists in the form of bulk or thin film. The raw materials are calcined, ground and molded and the molding is calcined again and is slowly cooled, by which the superconducting material intentionally added with the compd. contg. the magnetic ions is obtd. |
