| 摘要 |
PURPOSE:To obtain a superconductor having high critical current density by heat-treating superconductive powder separated selectively from powder obtd. by providing calcined oxide superconductor. CONSTITUTION:A calcined oxide superconductor, for example, a superconductor obtd. by calcining provisionally a mixture consisting of 3:6:8 proportion of Y2O3, BaCO3, CuO and consisting of a superconducting phase YBa2Cu3O7 and an insulating phase Y2BaCuO5, is cooled at, for example, 91K, held in a magnetic field, and superconductive powder is separated selectively utilizing the diamagnetism of the superconductive powder against the magnetic field. An oxide superconductor is obtd. by heat-treating the separated powder in O2 atmosphere at such as 800-1200 deg.C. By this method, an oxide superconductor having a critical temp. and critical current density improved to 92K Tc and 3450A/cm<2> from 91K and 315A/cm<2>, respectively, is obtd. |
