| 摘要 |
PURPOSE:To obtain a superconductor of high critical current density with the C-plane of the crystal oriented in a given direction, by forming oxide superconductor powder which has been subjected to magnetic orientation at temperatures below the critical temperature followed by heating and sintering. CONSTITUTION:Oxide superconductor powder having oxygen-defect type perovskite type structure of formula (Ln is at least one kind of element selected from Y, La, Sc, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu; delta is oxygen defect) with a particle size of 1-5mum, aspect ratio of 3-5, lattice constants are such that a=0.382nm and b=0.389nm, and thermal expansion coefficient of 10<-5>-10<-6>/ deg.C is subjected to 1-15 tesla of magnetic field at temperatures below the critical temperature to effect orientation in the C-axis direction followed by compression forming while keeping this state, and them carrying out calcination in an oxygen atmosphere at 500-1,000 deg.C for 1-3hr followed by annealing to ca. 350 deg.C at a rate of ca. 1 deg.C/min in an oxygen atmosphere for 1-10hr. |
