| 摘要 |
PURPOSE:To improve the superconductive transition point and the critical current by annealing the starting composition for oxide superconductor in an Ar atmosphere and in an oxygen atmosphere. CONSTITUTION:One element selected from Nd, Sm, Eu and Y (Ln), a Ba oxide, a Cu oxide are mixed so that Ln:Ba:Cu becomes 1:2:3, the mixture is calcined in an oxygen atmosphere, compression-molded and annealed at 850 to 1,000 deg.C in case of Nd, at 850 to 980 deg.C in case of Sm, at 850 to 975 deg.C in case of Eu, and at 810 to 940 deg.C in case of Y in an Ar atmosphere, then annealed at a temperature lower than 500 deg.C in an oxygen atmosphere to give the oxide superconductor of formula I through formula IV (6.7<y<7.2). |
