| 摘要 |
PURPOSE:To obtain an oxide superconductor which is high in the critical temp. and has high critical current density by grinding tetragonal type rare earth element-Ba-Cu-O-based powder and continuously pressuremolding the ground material and roasting the molded body in the oxidative atmosphere. CONSTITUTION:The raw materials such as Y2O3, BaCO3 and CuO are mixed at a prescribed molar ratio and this mixture is calcined in the oxidative atmosphere so that the powder shown in a formula (RE shows Y and rare earth elements) is obtained. Then the obtained rhombic type calcined powder is heat- treated at about 600-800 deg.C in the inert atmosphere. Thereby the tetragonal type powder is obtained which has the composition shown in a formula. Then this powder is ground and the ground material is continuously pressure-molded and the molded body is roasted in the oxidative atmosphere to obtain an oxide superconductor. Thereby, since the tetragonal type powder is utilized as a powdery raw material, the degree of orientation of the molded body is enhanced and the degree of orientation of the sintered body is enhanced. Further, the critical current density of the sintered body is enhanced. |
