| 摘要 |
PURPOSE:To facilitate production of molded articles of superconductor such as wire or sheet, by previously melting a mixture comprising specific amounts of starting raw materials at the melting point, molding, heat-treating and then cooling. CONSTITUTION:Starting raw materials comprising (A) an oxide or carbonate of one or more elements selected from Y, Sm, Eu, Dy, Er, Gd, Ho, Tm and Yb, (B) a carbonate of Ba and/or Sr and (C) a Cu oxide such as CuO are weighed and blended in the atomic ratio of A/B/C of 0.17-0.28/0.17-0.34/0.43-0.66. Then the blend is heated and melted by using a plasma arc furnace under 0.01-760Torr Ar pressure at a temperature at which the molten oxide can flow - 3,000 deg.C molded into a desired shape such as wire, or rod material or thin sheet, then heat-treated in an oxygen-containing atmosphere at 900-1,100 deg.C for >=1hr and successively annealed in an oxygen- containing atmosphere at <=2 deg.C cooling rate up to 500 deg.C. |
