| 摘要 |
PURPOSE:To obtain an oxide superconducting molded article having high density and excellent superconducting characteristics and composed of alkaline-earth metal, rare-earth metal, copper and oxygen, by sintering a raw material mixture in air and then in oxygen atmosphere. CONSTITUTION:Powdery raw materials comprising oxide, halide, carbonate, nitrate, sulfate, etc., of alkaline-earth metal, rare-earth element and copper are mixed at specific ratios. The raw material powder is preliminarily calcined at 500-1,200 deg.C in oxygen atmosphere and molded. The molded article is sintered at 600-1,100 deg.C in air and then calcined at 500-1,100 deg.C in oxygen atmosphere to obtain the objective oxide superconducting molded article composed of an alkaline earth metal, a rare-earth element, copper and oxygen. The sintering time in air can be shortened and the oxygen decreased by the sintering in air can be replenished by the following calcination in oxygen atmosphere. According ly, the change in the composition and structure can be suppressed to low levels. |
