| 摘要 |
PURPOSE:To obtain a superconductor having high critical current density and causing no abnormal phenomenon at the grain boundary by sintering dehydrated powdery starting materials in a dry atmosphere and heat treating the sintered body in a dry oxygen atmosphere. CONSTITUTION:Powder starting materials such as carbonates or oxides of Ln (Ln is Y, Sc, La, lanthanide or a mixture of such elements), Ba and Cu are wet-mixed, dehydrated by heating at several hundred deg.C for several hr in vacuum, calcined at 800-900 deg.C in a dry atmosphere having <=2mg/dm<3> water content and pulverized to form calcined powder of <=100mum particle size. This powder is molded and sintered at 850-950 deg.C in a dry atmosphere having <=2mg/dm<3> water content and the sintered body is heat treated in a dry oxygen atmosphere having <=2mg/dm<3> water content to obtain an Ln1Ba2Cu3Ox (x=6.5-7.0) type superconductor having <=2,000ppm water content. |
