International Superconductivity Technology Center

Kyocera Corporation

The Furukawa Electric Co., Ltd.

Tohoku Electric Power Company, Inc.

Central Research Institute of Electric Power Industry

Matsushita Electric Industrial Co., Ltd.

Sanyo Electric Co., Ltd.

Kabushiki Kaisha Kobe Seiko Sho

Tokyo Gas Company Limited

The Tokyo Electric Power Company, Incorporated

Mitsubishi Metal Corporation

Shin-ichi Koriyama

Shoji Tanaka

Toshihiko Maeda

Hisao Yamauchi

Kazuhiro Sakuyama

Ataru Ichinose

Nobuo Suzuki

Takashi Kawano

Takahiro Wada

Takeshi Sakurai

Naoki Koshizuka

Takaaki Ikemachi

Takayuki Miyatake

Disclosed herein are high-temperature oxide superconductors of RBa.sub.2 Cu.sub.4 O.sub.8 type, with Ba partly replaced by Sr or Ca, or with R and Ba partly replaced by Ca and Sr, respectively, as represented by the chemical composition formula of R(Ba.sub.1-y Sr.sub.y).sub.2 Cu.sub.4 O.sub.8 or R(Ba.sub.1-z Ca.sub.z).sub.2 Cu.sub.4 O.sub.8 or (R.sub.1-x Ca.sub.x) (Ba.sub.1-y Sr.sub.y).sub.2 Cu.sub.4 O.sub.8. They exhibit superconductivity at high temperatures. Especially, the last one exhibits superconductivity at a higher temperature than the former two. All of them can be made with a less amount of Ba as a deleterious substance, and the first two have improved sinterability. The best results are obtained when they are produced by the process involving the hot hydrostatic pressure treatment of the mixture of raw materials at 850.degree.-1100.degree. C. in an atmosphere composed of an inert gas and oxygen. The process permits a wider selection of Ba raw materials.

High temperature oxide superconductor

A method for manufacturing a Pb-based Cu oxide superconductor. The method includes the steps of mixing powders of a raw material containing at least Pb, Sr, Ce, M, where M is at least one element selected from the group consisting of Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and Lu, and Cu in a proportion to have the composition of the formula (I),

Method of manufacturing an oxide superconductor

An oxide superconductor which has a composition expressed by the following general formula and whose crystal structure is 1222-phase structure.

Oxide superconductor having the formula Pb.sub.a (M.sub.1-x-y Ce.sub.x

An oxide superconductor having the following formula:

Method of preparing Pb-Sr-Ca-Ln-Ca-O metal oxide superconductor

A superconducting material is disclosed which includes oxides of metals having the following composition:

Superconducting material of metal oxides

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Urayasu, Japan

Shin-ichi Koriyama