| 摘要 |
PURPOSE:To contrive to improve the critical temperature and critical electric current density of an oxide superconductor by calcining a molded product comprising the oxides of Bi, Sr, Pb, Ca, Cu and K in an oxygen-containing atmosphere under an increased pressure. CONSTITUTION:Bi2O3, SrCO3, CaCO3, CuO, PbO and K2CO3 are mixed in a molar ratio of Bi:Sr:Ca:Cu:Pb:K of 1.8-2.2:2:2.0-3.5:3.0-4.5:0.1-0.6:0.1-0.5, respectively, and subsequently press-molded into a molded product. The molded product is calcined at 820-850 deg.C in an oxygen-containing atmosphere, cooled and calcined at 820-850 deg.C under an increased pressure of >=100kg/cm<2> for >=100hr to provide an oxide superconductor having a critical temperature of >=100 deg.C, a critical electric current density of >=500A/cm<2> at 77K in a magnetic field of 100Oe and a composition oriented in the direction of C axis. |
