| 摘要 |
PURPOSE:To obtain an oxide superconductor composition having variable Tc, low sensitivity to magnetic field and high Jc, by substituting a part of Cu of an oxide superconductor composition having a specific component composition with a transition metal Al at a specific atomic ratio. CONSTITUTION:The objective oxide superconductor composition is expressed by formula wherein 0<=x<=0.15 and -0.1<=y<=0.1. The composition can be produced e.g. by the following process. BaCO3, Y2O3, CuO and Al2O3 each having a purity of >=99.9% are separately weighed, mixed with a ball mill in wet state and calcined at 800-850 deg.C. The calcined product is crushed with a mortar, added with an organic binder, granulated and pressed to form a disk. The disk is sintered in O2 at 850-900 deg.C, subjected to high-pressure oxygen treatment in O2 atmosphere of 100-150atm at 300-400 deg.C and then sintered. The value of y of the sintered product is -0.1<=y<=0.1. |
