National Research Institute for Metals

National Institute for Materials Science

Japan As Represented by Director General of National Research Institute for Metals

Kabushiki Kaisha Toshiba

Kazumasa Togano

Kyoji Tachikawa

Hiroaki Kumakura

Takeshi Hatano

Hitoshi Kitaguchi

Yoshihiko Takano

Akira Ishii

Syunichi Arisawa

Hanping Miao

Kiyoshi Inoue

Yutaka Yamada

Mitsuo Sasaki

Satoru Murase

Takao Takeuchi

Susumu Tsukamoto

Ei Nakamura

Hirosada Irie

Shunichi Arisawa

Hirohaki Kumakura

Tsutomu Yamashita

Sangjae Kim

Masashi Tachiki

A method of forming a novel high temperature superconducting Josephson junction which is capable of achieving a formation of a Josephson junction having high characteristics conveniently and quickly without necessitating costly micromachining facilities. Two high temperature superconducting whisker crystals are crossed with each other on a substrate and subjected to thermal treatment to form a Josephson junction between the two high temperature superconducting whisker crystals.

Method of forming high temperature superconducting Josephson junction

A method of forming a novel high temperature superconducting Josephson junction which is capable of achieving a formation of a Josephson junction having high characteristic conveniently and quickly without necessitating costly micromachining facilities. Two high temperature superconducting whisker crystals are crossed with each other on a substrate and subjected to thermal treatment to form a Josephson junction between the two high temperature superconducting whisker crystals.

Method of forming high temperature superconducting josephson junction

A method of producing a composite material of a bismuth 2212 phase and a metallic substrate, wherein the first and second baking are conducted as an isothermal heat treatment. According to this process, temperature control is easy, high productivity is obtained, and the critical current density is improved.

Method of producing oxide superconductive composite material

A simple and low-cost method for producing a thin film of ribbon-like oxide high-temperature (high-Tc) superconductor, which comprises placing a solid starting material for the oxide high-temperature superconductor on a substrate and heating it at a temperature in the vicinity of the melting point of the solid starting material under ambient pressure in an oxygen atmosphere.

Method for producing thin films of ribbon-like oxide high-temperature superconductor

In a process in which a composite consisting of a metallic base and a superconductor mainly containing a Bi,Sr,CaCu,O,superconducting phase is formed into a composite wire or wire, the composite is subjected to calcination and cold working before heat treatment for crystallization from a partial molten state.

Making of bismuth 2212 superconducting wire or tape

A powder having a predetermined composition is filled in a tube. The tube is drawn to obtain a wire and the wire is rolled to obtain a tape-like starting body. Then, a laser beam is irradiated on the part of the tape to heat and melt the part of the tape. The starting body is rapidly heated and then cooled, thereby the part of the starting body is melted and solidified to form a compound superconductor layer.

Method of manufacturing compound superconductors

A process for producing a superconducting compound tape or wire material, which comprises irradiating electron beams at an acceleration voltage of 5 to 150 KV on a starting tape or wire material consisting essentially of constituent elements of a superconducting compound, a compound between the constituent elements, and/or an alloy between the constituent elements at a power density, determined on the starting tape or wire material, of 1.times.10.sup.3 to 1.times.10.sup.7 W/cm.sup.2 while the starting tape or wire material is moved at a rate of 1 cm to 10 m/sec relative to the electron beams.

Process for producing superconducting compound tape or wire material by

An A-15 type superconductor compound having the composition A.sub.3 B composed of niobium (element A) and at least one element (B) selected from gallium, aluminum and germanium is produced by coating at least one element B on a substrate of niobium, heat-treating the coated niobium substrate at a temperature of 500.degree. to 2,000.degree. C. for 1 second to 300 hours to form intermetallic compounds of niobium and the coated element which are richer in element B than A-15 A.sub.3 B compound, and thereafter subjecting the substrate to the irradiation of high density energy beams such as electron beams or laser beams to form the A-15 type superconductor compound having the composition A.sub.3 B.

Process for production of A-15 type superconductor compound

In a method for producing a Nb.sub.3 Sn superconductor which comprises drawing a composite having a core of a Nb-Hf alloy containing 0.1 to 30 atomic % of Hf and a sheath containing Cu and Sn, and heat-treating the composite to form a Nb.sub.3 Sn layer between the core and the sheath; the improvement wherein the sheath is formed of pure Cu, a Cu-Sn alloy containing not more than 6 atomic % of Sn, a Cu-Ga alloy containing not more than 20 atomic % of Ga, a Cu-Al alloy containing not more than 20 atomic % of Al, a Cu-Ga-Sn alloy containing not more than 6 atomic % of Sn and not more than 20 atomic % of Ga, or a Cu-Al-Sn alloy containing not more than 6 atomic % of Sn and not more than 20 atomic % of Al; and after the drawing, a Sn film is coated on the surface of the sheath, and then the product having a Sn film coated thereon is heat-treated.

Method for producing Nb.sub.3 Sn superconductors

A method for producing a V.sub.3 Al superconductor which comprises making a composite composed of a sheath portion of a copper alloy containing 1 to 15 atomic percent of germanium, 1 to 15 atomic percent of silicon or 2 to 25 atomic percent of gallium and surrounded by the sheath portion, at least one core portion of a vanadium-aluminum alloy containing 0.5 to 20 atomic percent of aluminum; elongating the composite; and then heat-treating the elongated composite thereby to form a V.sub.3 (Al, Ge), V.sub.3 (Al, Si) or V.sub.3 (Al, Ga) layer between the sheath portion and the core portion.

Growing community of inventors

Ibaraki, Japan

Kazumasa Togano