International Superconductivity Technology Center

Nippon Steel Corporation

Kawasaki Jukogyo Kabushiki Kaisha

Kyocera Corporation

The Tokyo Electric Power Company, Incorporated

Railway Technical Research Institute

Other

Nec Corporation

Matsushita Electric Industrial Co., Ltd.

Sumitomo Electric Industries, Limited

Kawasaki Steel Corporation

Kabushiki Kaisha Kobe Seiko Sho

Tosoh Corporation

Mitsubishi Metal Corporation

International Superconductivity Technology Center, the Juridical Foundation

Naoki Koshizuka

Shoji Tanaka

Masato Murakami

Akihiro Kondoh

Hiroyuki Fujimoto

Hiroshi Takaichi

Jian-Guo Wen

Nobuo Suzuki

Takahiro Wada

Youichi Enomoto

Takeshi Sakurai

Takayuki Miyatake

Shoichi Kagiya

Terutsugu Oyama

Koji Yamaguchi

Shinichi Koriyama

Hisao Yamauchi

Yasuzo Tanaka

Naomichi Sakai

Hiromasa Fukuyama

Yoshihiro Ishimaru

Hiroyoshi Yamada

Tetsuro Sato

Kunihiko Hayashi

Shin-ichi Koriyama

Takato Machi

Kaname Matsumoto

Satoshi Shimura

Yu Shiohara

Kazunari Mochizuki

Gustavo Adolfo Alvarez

Furen Wang

Kenshi Takamuku

Yuan Wu

Genda Gu

Yasunori Fudamoto

Satoru Aihara

Tsutomu Takata

Naomichi Nakamura

Tadashi Utagawa

Yong Zhao

Yong Feng

An MgB-based superconducting wire for a liquid hydrogen fluid level sensor which can maintain an unimmersed portion of the MgB-based superconducting wire for a liquid hydrogen fluid level sensor in a non-superconducting state even without heating the unimmersed portion is provided. A wire for a liquid hydrogen fluid level sensor comprises an MgB-based superconductor which contains Mg, B, and Al. The critical temperature at which the electrical resistance becomes essentially zero is 20-25 K, and the transition width, which is the difference between the temperature at which the electrical resistance begins to decrease toward zero and the critical temperature, is at most 5 K.

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The present invention relates to an MgB-based superconductor that is easy to manufacture and well suited to mass production, and that exhibits excellent superconducting characteristics (such as a high critical current density) while still retaining the high critical temperature characteristics of MgB. A powder mixture of magnesium, boron, and titanium is pressed into a pellet, and this product is sintered under an atmospheric pressure and other conditions (preferably at 600&#xb0; C. or higher) to manufacture an MgB-based superconductor in which titanium and/or a titanium compound are dispersed in polycrystalline MgB. The composition of the MgB-based superconductor is preferably adjusted to have an atomic ratio of Mg:B:Ti=x:2:y, 0.7&#x3c;x&#x3c;1.2 and 0.05&#x3c;y&#x3c;0.3, and more preferably 0.07&#x3c;y&#x3c;0.2, by adjusting the amounts in which the raw materials are added.

MgB2&#x2014;based superconductor with high critical current density, and method for manufacturing the same

In a method of manufacturing a Josephson junction, a first superconductive layer is formed on a substrate. An insulating film is formed on the first superconductive layer. The insulating film is etched to have an inclination portion. The first superconductive layer is etched using the etched insulating film as a mask, to have an inclination portion. A barrier layer is formed on a surface of the inclination portion of the first superconductive layer. A second superconductive layer is formed on the barrier layer and the inclination portion of the insulating layer.

High temperature superconductor Josephson junction element and manufacturing method for the same

A method of manufacturing a superconductor wire which comprises: rolling a polycrystalline metallic substrate; heating the rolled polycrystalline metallic substrate at a temperature of 900&deg; C. or more in a non-oxidizing atmosphere, whereby obtaining a rolled textured structure which is oriented such that the &lsqb;100&rsqb; plane thereof is parallel with a rolled plane and the <001> axis thereof is parallel with a rolled direction; heating the polycrystalline metallic substrate of the rolled textured structure at a temperature of 1,000&deg; C. or more in an oxidizing atmosphere, whereby forming an oxide crystal layer consisting essentially of an oxide of the polycrystalline metal; and forming an oxide superconductor layer on the oxide crystal layer.

Method of manufacturing an oxide superconductor wire

An oxide superconducting multilayered thin film structure having a laminated layer structure of oxide superconductor thin film layers and non-superconductor thin film layers constituted by a combination of material groups for making strain free interfaces among both thin film layers. For example, an oxide superconductor multilayered film constituted by a laminated layer structure where thin films of an oxide superconductor represented by the chemical formula of M'Ba.sub.2 Cu.sub.3 O.sub.7-.delta. (M'; a rare earth element of Nd, Sm, Eu or the like or an alloy of these, .delta.; oxygen depletion amount) and thin films of an oxide represented by the chemical formula of M*Ba.sub.2 Cu.sub.3 O.sub.7-.delta. (M*; an element of Pr, Sc or the like or an alloy of these, .delta.; oxygen depletion amount) are alternately stacked. The oxide thin films are thin films fabricated by a pulsed laser deposition process or a sputtering process. A Josephson device can be provided by using the multilayered film.

Oxide superconductor multilayered film and oxide superconductor

A superconducting Josephson junction element including a first, a-axis oriented, superconductive metal oxide crystal grain having a first area of a {001} plane, and a second, c-axis oriented, superconductive metal oxide crystal grain having a second area of a {110} plane, wherein the first and second crystal grains are in contact with each other at the first and second areas to form a grain boundary therebetween.

High Tc superconducting Josephson junction element

A method for producing an REBaCuO oxide superconductor having large magnetic levitation force, where RE is a rare earth element selected from the group consisting of Y, Sm, Eu, Gd, Dy, Ho, Er, and Yb, involves the steps of using a raw material mixture as the starting feed, heating the raw material mixture for partial melting, followed by cooling and solidification, pulverizing and mixing the resulting solid, shaping the resulting mixture into a given shape, placing or embedding nucleates on or in the resulting shape, followed by heating for partial melting, and cooling the resulting partial melt to a substantial temperature at which a superconducting phase starts to form, followed by slow cooling, whereby the superconducting phase is preferentially formed and grown from a nucleation site.

Production of oxide superconductors having large magnetic levitation

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 process for producing an oxide superconductor, comprising putting a formed body of raw material powders for forming an oxide superconductor on silver or silver oxide within a pan which does not melt at the melting point of silver, heating the pan to a temperature higher than the melting point of silver to bring the formed body to a semi-molten state with the formed body being floated on molten silver, cooling the pan and taking the formed body out of the re-solidified silver. This process enables a large bulk material having a diameter of 10 cm or more to be produced without occurrence of cracking.

Process for producing oxide superconductor

The present invention relates to a process for preparing an oxide superconductor having a high critical current density, a uniform structure and an excellent mechanical property and thermal stability, which comprises heating raw material powders of a REBaCuO system at 1050.degree. C. or higher, cooling the material for solidification, pulverizing and mixing the solidified material to homogeneously disperse the structure of the solidified material, molding the material, optionally mixed with silver oxide or silver, into a predetermined shape, and reheating the molding to 1050.degree. C. or higher to grow a superconducting phase.

Process for preparing oxide superconductor

Oxide superconductor and process for producing the same

To ensure a well-oriented crystal structure, there is provided a process of producing an oxide superconductor of a Y--Ba--Cu--O system with a composition having an atomic ratio Y:Ba:Cu of 1.0-2.0:2.0-2.5:3.0-3.5, the process comprising the steps of: preparing a semimelt including solid and liquid phases and consisting of Y, Ba, Cu and O in the atomic ratio; and solidifying the semimelt to form the oxide superconductor by so controlling a moving speed of a solidification front to have two components of different values in two perpendicularly intersecting directions.

Process of producing oxide superconductor

A process for producing Bi-based oxide superconductor single crystals by the floating zone method is disclosed, which comprises using a feed rod of an oxide comprising a formulation of metallic elements represented by the following general formula:

Process for producing bi-based oxide superconductor single crystals

A superconducting bearing unit compring a permanent magnet mounted to a rotating shaft and a superconducting body mounted on the inner periphery of a housing surrounding the shaft, the superconducting member being adapted to be cooled with the rotating shaft moved upwards until it attains a superconducting condition, so that the rotating shaft is supported in use in a balanced condition between the weight of the rotating shaft, etc. and a pinning force caused by the permanent magnet and the superconducting member.

Superconducting bearing unit and operating method thereof

A superconductive material is disclosed which has the following composition:

Superconducting material

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Tokyo, Japan

Naoki Koshizuka