| 摘要 |
PURPOSE:To easily obtain a bismuth-based superconductor having high critical current temp. by partially melting a molded body and thereafter slowly cooling the molded body to the crystallization temp. and then crystallizing it in the production of the bismuth-based superconductor via partial melting. CONSTITUTION:The raw materials (e.g. Bi2O3, SrCO3, CaCO3 and CuO) necessary to produce a bismuth-based superconductor are mixed at the prescribed ratio. The mixture is calcined, ground and molded. Then the obtained molded body is heated and partially melted. Thereafter it is slowly cooled to the crystallization temp. and particle growth of a superconductive phase is sufficiently caused by the reaction of both a solid phase component and a liquid phase component. The cooling velocity at the time of slow cooling is ordinarily and properly regulated to about 0.1-2 deg.C/minute. Then the bismuth-based superconductor (e.g. Bi-Sr-Oa-Cu-Obased superconductor) having extremely high critical current temp. is obtained by holding the molded body at the crystallization temp. to crystallize it. |
