| 摘要 |
PURPOSE:To obtain the title superconductor of enhanced critical current density without deterioration of critical temperature, by calcining a mixed powder comprising specific calcined powder and Si3N4, SiC or SiO2 followed by cooling. CONSTITUTION:First, mixed powder comprising RE2O3 (RE is rare earth element), BaCO3 and CuO, so as to represent the formula I (0.05<=x<=0.80; 3<=y<=3.3) is calcined at 850-950 deg.C to produce calcined powder. Secondly, this powder is mixed with Si3N4, SiC or SiO2 so that the ratio: RE/Ba/Cu/Si become 1/2(x+1)/y/x followed by forming to produce a form. Third, this form is calcined in an oxygen stream at 920-980 deg.C for 1-5hr followed by cooling, thus obtaining the title oxide superconductor. This superconductor has the following characteristics: 1. crystal structure in which BaSiO4 is segregated in the polycrystals in an oxide superconductor of the formula II, 2. critical current density is >=1.1X10<3>A/cm<2> in a magnetic field of 0.15T. |
