Sanyo Electric Co., Ltd.

Ryohkan Yuasa

Masao Nakao

Atsuo Mizukami

Masaaki Nemoto

Hideki Kuwahara

Masaru Yamano

Shuji Fujiwara

Hiroaki Furukawa

Shingo Terakado

Hiromi Mukaida

Kazuaki Shikiti

A desired pattern is formed on a non-superconducting oxide film after the non-superconducting oxide film has been formed on a magnesia substrate. A superconducting oxide film is formed over the exposed parts of the substrate and the non-superconducting oxide film. The epitaxial orientation of the superconducting oxide film section on the non-superconducting oxide film is different from that of the superconducting oxide film section on the substrate. A tilt-boundary junction is produced at a boundary between the superconducting film sections which are different in epitaxial orientation from each other. Thus, a Josephson junction having a desired pattern can be obtained.

Process of making high T.sub.c Josephson junction device

The superconducting device according to the present invention is provided with a superconducting thin film of the Tl-Ba-Ca-Cu oxide deposited on a substrate thereof. Consequently, the device can be produced at a low cost because no rare earth elements are required. The superconducting thin film according to the present invention is formed by sputtering on substrate from a Tl-Ba-Ca-Cu oxide target by means of the sputtering method, followed by annealing in an oxidizing atmosphere. In this way, according to the present invention, it is possible to produce a superconducting thin film of the Tl-Ba-Ca-Cu oxide in a simple way by using an ordinary sputtering apparatus.

Superconducting device and method of producing superconducting thin film

The superconducting device according to the present invention is provided with a superconducting thin film of the Bi-Sr-Ca-Cu oxide deposited on a substrate thereof. Consequently, the device can be produced at a low cost because no rare earth elements are required. The superconducting thin film according to the present invention is formed by sputtering onto a substrate from a Bi-Sr-Ca-Cu oxide target, followed by annealing in an oxidizing atmosphere. In this way, it is possible to produce a superconducting thin film of the Bi-Sr-Ca-Cu oxide in a simple way by using an ordinary sputtering apparatus. In this method, it is preferable that a MgO substrate be used and the optimum annealing temperature is about 880.degree. C.

The present invention relates to a superconducting material that is, substances having compositions expressed by empirical formulae Y.sub.1-x Ba.sub.x CuO.sub.3, YBa.sub.2 Cu.sub.3 O.sub.7 and LnBa.sub.2 Cu.sub.3 O.sub.7 and critical temperatures of 90 K. or more, and to a method of producing the same in which for example Y.sub.2 O.sub.3, BaCO.sub.3 and CuO are blended at a mixture molar ratio of 1:2:6 and the resulting mixture is molded under pressure followed by slowly cooling in an oxidizing atmosphere.

Growing community of inventors

Tsukuba, Japan

Ryohkan Yuasa