| 摘要 |
PURPOSE:To produce a bulky oxide superconducting material capable of attaining high critical current density. CONSTITUTION:Ba oxide powder is mixed (a) with Cu oxide powder and this powdery mixture is melted (b) at >=1,100 deg.C, rapidly cooled (c) at >=10 deg.C/sec cooling rate and crushed (d) to <=0.2mm to form Ba-Cu compd. oxide powder. RE2O3 powder (RE is one or more kinds of elements selected among Y, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu) or a powdery RE2O3-RE2BaCuO5 mixture is added (e) to the Ba-Cu compd. oxide powder and they are kneaded, molded (f) and successively subjected to heat treatment (g) for partial melting by heating to 1,000-1,350 deg.C, heat treatment (h) for crystal growth by slow cooling at <=200 deg.C/hr cooling rate and heat treatment (i) for regulating the amt. of oxygen by cooling in an oxygen atmosphere. RE2BaCuO5 phase is finely and uniformly dispersed in REBa2Cu3O7-x phase and high critical current density can be attained. |
