| 摘要 |
PURPOSE:To readily obtain the titled superconductor having a stable crystal structure, the high critical temperature and great critical current density, by substituting part of the first and second atoms. in the site (A) of an oxide superconductor, such as specific perovskite type, with the third atoms., such as alkaline earth metal. CONSTITUTION:A starting raw material (e.g. a mixture of Y2O3 with BaCO3, K2CO3 and CuO in respective specific amounts) prepared by mixing compounds of atoms. (A) in the site (A) consisting of (a) at least one first atom. selected from Mg, Ca, Sr, Ba, Zn and Cd, (b) at least one second atom. selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu and (c) the third atom. selected from alkali metals, halogens and S, Se, etc., in an amount so as to substitute part of the first and second atoms. at a given ratio and (B) Cu is fired in, e.g. O2 atmosphere, pulverized and refired. The above-mentioned operation is repeated to afford the titled perovskite type superconductor of the type expressed by formulas I-VI having at least one of CuO6 octahedron and CuO5 pentahedron. |
