| 摘要 |
PURPOSE:To increase the critical current density of an oxide superconductor having a desired compsn. by pulverizing the crystal powder of the superconductor and confining the content of the impurities in the raw material powder to specific wt.%, then sintering the powder. CONSTITUTION:The superconductive oxide crystal having the desired compsn. is previously prepd. and is ground to a prescribed grain size by a grinding device such as ball mill. The grinding is executed by coating the contact part of the grinding device and the powder with the same raw material as the material of the powder or nylon, etc. The intrusion of the impurities into the raw material powder is thereby prevented even during the grinding. This superconductor is obtd. by adding a molding assistant to this powder and extruding the powder, then sintering the molding in an oxidizing atmosphere kept at about 900-1,000 deg.C. Since the impurity materials in the raw material powder can be confined to <=0.5wt.%, the continuity of the crystals of the superconductive with each other is improved and the critical current density is increased. |
