National Research Institute for Metals

Other

Mitsubishi Chemical Corporation

Sumitomo Heavy Industries, Ltd.

Japan Science and Technology Agency

Mituba Electric Mfg. Co., Ltd.

Hiroshi Maeda

Toshihisa Asano

Yoshiaki Tanaka

Masao Fukutomi

Kazunori Komori

Fumiaki Matsumoto

Tomoyuki Yanagiya

Kiyoshi Inoue

Yutaka Fukuyama

Yoshio Katsuro

Yoshihiro Omae

Nobutake Mise

Masaru Shimoyama

Tsutomu Yamashita

Mamoru Nakayama

Masayuki Hijikata

Shoji Oishi

Masanobu Ishida

Takaharu Yamamoto

Tsuyoshi Yamaguchi

Susumu Nakajima

Yuuichi Sekine

Hiroaki Takehara

Masanori Nagao

Sangjae Kim

Mitsunori Sato

Yoshikazu Sakai

Yoshikazu Sakal

Shigeki Aoki

Mitsunori Satoh

Ichiro Morimoto

The present invention provides a high-temperature oxide superconductors, which comprises an oxide expressed as (BiA)&#x2014;B&#x2014;C&#x2014;Cu oxide (where, A is Sb and/or AS; B and C are elements different from each other, each being one or more elements selected from the group consisting of Be, Mg, Ca, Sr and Ba; and x is characterized by 0&#x2266;x&#x2266;1). According to the present invention, it is possible to manufacture a high-temperature oxide superconductor having a transition temperature of over 100 K and not containg a rare-earth element at all, and to manufacture an excellent superconductor in reliability and stability easilier than doing conventional superconductors such as Y&#x2014;Ba type ones.

High-temperature oxide superconductor

The present invention relates to a defect-free oxide high-critical temperature superconductor acicular crystal, that is, an oxide high-critical temperature superconductor acicular crystal that is substantially a perfect crystal and also relates to a method for producing the same, wherein such a crystal is essential for achieving superconducting electronic devices. The oxide high-critical temperature superconductor acicular crystal of the present invention includes an acicular crystal having a BiSrCaCuO(Bi-2223) crystal structure and is grown from a powder compact by heat-treating the powder compact in an oxygen atmosphere, wherein the powder compact contains an oxide having the Bi-2223 crystal structure and TeO, CaO, or (SrCa)TeO. The achievement of the acicular crystal having the Bi-2223 crystal structure contributes to the development of superconducting electronic devices that have been theoretically proposed but have not been achieved.

Oxide high-critical temperature superconductor acicular crystal and its production method

A carbon black having an average particle size of at most 13 nm, D of at most 80 nm, a D /D ratio of at most 0.6 and at least pH 5.

Carbon black and process for producing the same

A clad superconductive wire or tape of an oxide superconductive material and a silver-copper alloy base containing 0.05-90 atomic % a copper or a silver alloy. The silver-copper alloy base contains one or more elements selected from the group of Zr, Hf, Al, V, Nb and Ta in amounts of from 0.01-3 atomic %, or contains Au in amount of 0.01-10 atomic %. The silver alloy contains one or more elements selected from the group of Ti, Zr, Hf, V, Nb, Ta, Mg, Ca, Sr and Ba in amounts of from 0.01 to 3 atomic %, or one or more elements selected from the group of Au, Al, Ga, In and Sn in amounts of 0.05 to atomic %. The base material is filled with a Bi-containing oxide of Bi,Pb,Sr,Ca,Cu,O,wherein u&equals;0-0.3, X&equals;0.8-1.2, y&equals;0.2-1.2, and z&equals;0.8-2.0, and processed to obtain a superconductive wire or tape having enhanced mechanical strength, superconductivity and plastic workability.

Oxide superconductive wire and process for manufacturing the same

A clad superconductive wire or tape of an oxide superconductive material and a silver-copper alloy base containing 0.05-90 atomic % copper or a silver alloy. The silver-copper alloy base contains one or more elements selected from the group of Zr, Hf, Al, V, Nb and Ta in amounts of from 0.01-3 atomic %, or contains Au in amount of 0.01-10 atomic %. The silver alloy contains one or more elements selected from the group of Ti, Zr, Hf, V, Nb, Ta, Mg, Ca, Sr and Ba in amounts of from 0.01 to 3 atomic %, or one or more elements selected from the group of Au, Al, Ga, In and Sn in amounts of 0.05 to atomic %. The base material is filled with a Bi-containing oxide of Bi,Pb,Sr,Ca,Cu,O,wherein u&equals;0-0.3, X&equals;0.8-1.2, y&equals;0.2-1.2, and z&equals;0.8-2.0, and processed to obtain a superconductive wire or tape having enhanced mechanical strength, superconductivity and plastic workability.

Processes for producing synthetic quartz powder and producing shaped

A clad superconductive wire or tape of an oxide superconductive material and a silver-copper alloy base containing 0.05-90 atomic % copper or a silver alloy. The silver-copper alloy base contains one or more elements selected from the group of Zr, Hf, Al, V, Nb and Ta in amounts of from 0.01-3 atomic %, or contains Au in amount of 0.01-10 atomic %. The silver alloy contains one or more elements selected from the group of Ti, Zr, Hf, V, Nb, Ta, Mg, Ca, Sr and Ba in amounts of from 0.01 to 3 atomic %, or one or more elements selected from the group of Au, Al, Ga, In and Sn in amounts of 0.05 to atomic %. The base material is filled with a Bi-containing oxide of Bi.sub.1 Pb.sub.u Sr.sub.x Ca.sub.y Cu.sub.z O.sub.w wherein u=0-0.3, x=0.8-1.2, y=0.2-1.2, and z=0.8-2.0, and processed to obtain a superconductive wire or tape having enhanced mechanical strength, superconductivity and plastic workability.

Oxide superconductive wire and process for manufacutring the same

A clad superconductive wire or tape of an oxide superconductive material and a silver-copper alloy base containing 0.05-90 atomic % copper or a silver alloy. The silver-copper alloy base contains one or more elements selected from the group of Zr, Hf, Al, V, Nb and Ta in amounts of from 0.01-3 atomic %, or contains Au in amounts of 0.01-10 atomic %. The silver alloy contains one or more elements selected from the group of Ti, Zr, Hf, V, Nb, Ta, Mg, Ca, Sr and Ba in amounts of from 0.01 to 3 atomic %, or one or more elements selected from the group of Au, Al, Ga, In and Sn in amounts of 0.05 to 5 atomic %. The base material is filled with a Bi-containing oxide of Bi.sub.1 Pb.sub.u Sr.sub.x Ca.sub.y Cu.sub.z O.sub.w wherein u=0-0.3, X=0.8-1.2, y=0.2-1.2, and z=0.8-2.0, and processed to obtain a superconductive wire or tape having enhanced mechanical strength, superconductivity and plastic workability.

A substrate electrode having a plurality of substrate holders capable of causing a substrate to tilt by an arbitrary angle .theta. relative to the horizontal plane is provided. A plurality of auxiliary electrodes are arranged substantially vertically below the substrate electrode and between the substrate electrode and a target. The substrate electrode and the auxiliary electrodes are electrically insulated from the target. Bias voltage applied to the substrate electrode and the auxiliary electrodes causes the plasma boundary between the cathode dark space and the negative glow to form a cathodic plasma space having a parabolic section, thus forming a crystal-oriented thin film on the substrate surface.

Crystal-oriented thin film manufacturing apparatus

A high-strength and high-conductivity copper alloy sheet is provided, which consists of a composition of from 6 to 24 wt. % Ag, and Cu and impurities as the balance, and has a sheet structure in which Cu solid solution and Ag solid solution are streched into a fiber shape.

High-strength and high-conductivity copper alloy sheet

The present invention provides a new copper alloy containing silver from 4 to 32 at. %, which is useful for a magnet conductor, an IC lead frame, etc., having simultaneously a high strength and a high conductivity, manufactured by blending from 4 to 32 at. % silver into copper, casting, rapidly cooling and cold-working wherein the cold-working step includes a hot working treatment at a reduction rate of 40% to 70% at temperatures of from 300.degree. to 500.degree. C.

Method of manufacturing a high strength, high conductivity copper-silver

A compacted and highly oriented microstructure of the bulk-shaped Bi-Sr-Ca-Cu-O system oxide superconductor is obtained by the intermediate pressing method of the present invention. The growth rate of the high critical temperature phase in the bulk of Pb-doped Bi-Sr-Ca-Cu-O system oxide superconductor is also much improved and the sintering duration for obtaining a single phase having a high critical temperature is shorteneed by this method. Additionally, a higher critcal current density of Bi-Sr-Ca-Cu-O system oxide superconductor is obtained by the working under pressure process after cooling between a first and a second sintering step. Furthermore, the magnetic field dependence of the critical current density of Bi-Sr-Ca-Cu-O system oxide superconductor is also improved by the method of the present invention. The thus intermediate pressing process between the first and second sintering step of the present invention may be applied so easily as to facilitate the manufacture of tapes, wires, discs or the like of the Bi-Sr-Ca-Cu-O system oxide superconductor.

Method for manufacturing oxide high-temperature superconductor

An electrical contact material consisting essentially of silver and a small amount of zinc oxide, tellurium oxide, and optionally indium oxide and tin oxide, these oxides being uniformly dispersed in the silver matrix.

Electrical contact material of silver base alloy

Growing community of inventors

Tsukuba, Japan

Hiroshi Maeda