| 摘要 |
PURPOSE:To improve the stability of the quality of the superconductor at a low cost by mixing the powder of a specified calcined material and the mixed powder of materials selected from an Sr compd., etc., calcining the mixture at a temp. not lower than the sintering temp. of a calcined product, press- forming the mixture, and then sintering the formed product. CONSTITUTION:The powder of a Bi compd. such as Bi2O3 having <=10mum particle diameter, the powder of PbO, and the powder of one kind of material selected from an Sr compd., a Ca compd., and a Cu oxide are mixed. The mixture is calcined at about 800 deg.C for about 2 hr, and crushed to obtain processed powder (A). The powders of the remaining two kinds of materials among the Sr compd., Ca compd., and Cu oxide are mixed, and the mixed powder is calcined at 800-1000 deg.C for about 2 hr and crushed to obtain processed powder (B). The A powder and the B powder are press-formed, and the formed product is sintered at 830-880 deg.C in an oxidizing atmosphere. Consequently, the sintered superconductor consisting of Bi, Pb, Sr, Ca, Cu, and O and in which the atomic ratio of the constituents shown by formula I is controlled by formulas II, III, IV, and V is produced. |
