Patent number: 5252544
Abstract: An oxide superconductor which has a composition expressed by the following general formula and whose crystal structure is 1222-phase structure.Pb.sub.a (M.sub.1-x-y Ce.sub.x Sr.sub.y).sub.4 Cu.sub.3-a O.sub.z (I)(where M represents at least one element selected from the group consisting of Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and Lu, and a, x, y, and z denote the numbers which satisfy 0.3.ltoreq.a.ltoreq.0.7, 0<x.ltoreq.0.25, 0.3.ltoreq.y<0.5, 8.5.ltoreq.z.ltoreq.9.5, respectively). A Pb-based Cu oxide superconductor manufacturing method comprising the steps of mixing powders of raw materials containing at least Pb, Sr, Ce, M (where M represents at least one element selected from the group consisting of Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and Lu groups) and Cu in the proportion to have the composition shown in the general formula (I) above, optionally forming the mixed powder into a shape body, and firing the obtained powder mixture or the shape body in the temperature range of 900.degree.
Type:
Grant
Filed:
June 7, 1991
Date of Patent:
October 12, 1993
Assignees:
International Superconductivity Technology Center, Tohoku Electric Power Company, Incorporated, Kyocera Corporation, Central Research Institute of Electric Power Industry, The Furukawa Electric Co., Ltd.
Inventors:
Toshihiko Maeda, Kazuhiro Sakuyama, Shin-ichi Koriyama, Ataru Ichinose, Hisao Yamauchi, Shoji Tanaka
Patent number: 5190914
Abstract: A superconducting material is disclosed which includes oxides of metals having the following composition:(Pb.sub.1-z Cu.sub.z) ((Sr.sub.1-y Ba.sub.y).sub.1-v Ca.sub.v).sub.2 (A.sub.1-x Ca.sub.x)Cu.sub.2wherein A is at least one element selected from the group consisting of Y, La, Nd, Sm, Eu, Gd, Ho, Er, Yb and mixtures of at least one of Y, La, Nd, Sm, Eu, Gd, Ho, Er and Yb with at least one of Tb, Tm and Lu, x, y, v and z are numbers satisfying the following conditions:0.ltoreq.x.ltoreq.0.4,0.1.ltoreq.y<0.7,0.ltoreq.v.ltoreq.0.2x, and2y-0.4.ltoreq.z.ltoreq.2y+0.2with the proviso that 0.6-x.ltoreq.z<1.0 when 0.ltoreq.x.ltoreq.0.2 and that 0.4.ltoreq.z<1.0 when 0.2.ltoreq.x.ltoreq.0.4. The superconducting material is produced by providing a blend of compounds of the metals in the metal oxides, and heating the blend at an oxygen partial pressure P of at least 0.001 atm and temperature of (860+40logP) .degree.C. to (1060+40logP) .degree.C.
Type:
Grant
Filed:
February 28, 1991
Date of Patent:
March 2, 1993
Assignees:
International Superconductivity Technology Center, Kyocera Corporation, Tohoku Electric Power Company, Inc., Furukawa Electric Co., Ltd.
Inventors:
Shin-ichi Koriyama, Kazuhiro Sakuyama, Toshihiko Maeda, Hisao Yamauchi, Shoji Tanaka