| 摘要 |
PURPOSE:To improve critical current density by specifying calcination temperature, calcination time and calcination atmosphere and synthesizing only a single phase of superconductor in production of a Bi-based oxide superconductor using the calcination method. CONSTITUTION:A raw material is prepared so that the composition may be (Bi:Sr:Ca:Cu) = 2:2:2:3. The resultant raw material is calcined, subsequently pulverized and mixed and the obtained mixture is press molded. The molded material is then subjected to primary calcination at 840-844 deg.C for >=40hr in a condition where an inert gas containing 5-15% oxygen is flown. The resultant calcined material is pulverized, mixed, press molded and subsequently subjected to secondary calcination at 842-846 deg.C for >=20 hr at a condition where the inert gas containing 5-15% oxygen is flown. This calcined material is then calcined at 800-845 deg.C and <=300 kg/cm<2> uniaxial pressure for >=30min in air using the uniaxial hot pressing method and the uniaxial pressure is released during lowering of the temperature. |
