Patents Assigned to International Superconductivity Technology Center
  • Patent number: 5407907
    Abstract: A method of pulling a crystal of a metal oxide is disclosed, in which the growth of the crystal is performed in a liquid phase having a composition which is different from the metal oxide and which contains components constituting the metal oxide. The liquid phase is in contact with a solid phase located at a position separated from the position at which the crystal of the metal oxide grows. The solid phase has a composition different from that of the metal oxide and supplies components constituting the metal oxide to the liquid phase.
    Type: Grant
    Filed: May 21, 1993
    Date of Patent: April 18, 1995
    Assignees: International Superconductivity Technology Center, Asahi Glass Co., Ltd., Ishikawajimaharima Jukogyo Kabushiki Kaisha, Sumitomo Metal Industries, Ltd., Kyushu Electric Power Co., Railway Technical Research Institute
    Inventors: Yasuji Yamada, Teruo Izumi, Kanshi Ohtsu, Yuichi Nakamura, Kengo Ishige, Yuh Shiohara, Minoru Tagami, Shoji Tanaka
  • Patent number: 5407908
    Abstract: 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),Pb.sub.a (M.sub.1-x-y Ce.sub.x Sr.sub.y).sub.4 Cu.sub.3-a O.sub.z(I)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 a, x, y, and z denote the numbers which satisfy 0.3.ltoreq.a.ltoreq.0.7, 0<x.ltoreq.0.25, 0.3.ltoreq.y<0.5, 8.5.ltoreq.z.ltoreq.9.5, respectively, forming the mixed powder into a shaped body, and firing the shaped body at a temperature of 900.degree. to 1150.degree. C. in an oxidizing atmosphere.
    Type: Grant
    Filed: July 13, 1993
    Date of Patent: April 18, 1995
    Assignees: International Superconductivity Technology Center, Tohoku Electric Power Company, Incorporated, Central Research Institute of Electric Power Industry, The Furukawa Electric Co., Ltd.
    Inventors: Toshihiko Maeda, Kazuhiro Sakuyama, Shin-ichi Koriyama, Ataru Ichinose, Hisao Yamauchi, Shoji Tanaka
  • Patent number: 5395820
    Abstract: An oxide superconductor comprising a crystal of LnBa.sub.2 Cu.sub.3 O.sub.y (wherein Ln is at least one of rare earth elements including Y) and, finely dispersed therein, Ln.sub.2 BaCuO.sub.5 and a composite oxide of PtBaCuO having an average particle diameter of 0.1 to 10 .mu.m is disclosed. The oxide superconductor is produced by melting a raw material powder comprising a composite oxide of Ln, Ba and Cu, rapidly solidifying the melt, pulverizing the resultant solid, mixing a Pt powder with the pulverized mixture, forming a resultant mixture, heating a resultant formed body to bring the formed body to a partially-molten state and cooling the partially-molten material.
    Type: Grant
    Filed: December 1, 1992
    Date of Patent: March 7, 1995
    Assignees: International Superconductivity Technology Center, Hokuriku Electric Power Company, Sumitomo Electric Industries, Ltd., Kawasaki Jukogyo Kabushiki Kaisha, Nippon Steel Corporation
    Inventors: Masato Murakami, Tsutomu Takata, Koji Yamaguchi, Akihiro Kondoh, Naoki Koshizuka
  • Patent number: 5389604
    Abstract: 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.
    Type: Grant
    Filed: June 17, 1993
    Date of Patent: February 14, 1995
    Assignees: Nippon Steel Corporation, Tosoh Corporation, Kawasaki Jukogyo Kabushiki Kaisha, Hokuriku Electric Power Company, Kawasaki Steel Corporation, Railway Technical Research Institute, International Superconductivity Technology Center
    Inventors: Masato Murakami, Naomichi Sakai, Hiroshi Takaichi, Akihiro Kondoh, Shoichi Kagiya, Naomichi Nakamura, Hiroyuki Fujimoto, Naoki Koshizuka, Shoji Tanaka
  • Patent number: 5376309
    Abstract: Disclosed is a boride material for electronic elements, which is represented by a chemical formula of A.sub.1-x E.sub.x B.sub.12 (where A is Zr of Hf, E is Sc or Y, and 0.1.ltoreq.x.ltoreq.0.9) and the crystal system of which is a cubic one at a temperature not lower than its phase transition temperature and is a hexagonal one at a temperature not higher than its phase transition temperature. The boride material is prepared by mixing oxide powders or sulfate powders of the constitutive elements A and E and a boron powder followed by shaping the powder mixture and then sintering the shaped body.
    Type: Grant
    Filed: September 3, 1993
    Date of Patent: December 27, 1994
    Assignees: International Superconductivity Technology Center, Hokkaido Electric Power Co.
    Inventors: Kazuyuki Hamada, Nobuyuki Sugii, Mitsunobu Wakata, Kohichi Kubo, Kiyotaka Matsuura, Hisao Yamauchi
  • Patent number: 5369275
    Abstract: An apparatus for solid surface analysis capable of carrying out the X-ray fluorescence analysis of the sample surface according to the characteristic X-rays detected by the energy dispersive X-ray detector. The apparatus can also obtain an enlarged image of the sample surface according to the secondary electrons emitted from the excited sample surface detected by the electron detector. The apparatus can also carry out an X-ray diffraction analysis of the sample surface according to diffracted X-rays detected by the diffracted X-ray detector. The apparatus is also capable of attaching or detaching the energy dispersive X-ray detector easily by incorporating a connection room which can be put in a vacuum state independent of the vacuum chamber.
    Type: Grant
    Filed: July 10, 1992
    Date of Patent: November 29, 1994
    Assignees: International Superconductivity Technology Center, Fujikura Ltd., Showa Electric Wire & Cable Co., Ltd.
    Inventors: Toshio Usui, Yuji Aoki, Masayuki Kamei, Tadataka Morishita
  • Patent number: 5369090
    Abstract: 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:Bi.sub.p Sr.sub.q Ca.sub.r Cu.sub.2 O.sub.ywherein2.00< p< 2.18, 1.87< q< 2.00, 0.9.ltoreq. r.ltoreq. 1.0,and y is a positive number, in a moving rate of said rod of from 0.1 to 0.35 mm per hour in the side where crystals are accumulated, in which preferably, in the initial stage of the formation of crystals, the diameters of the rod-like crystals to be accumulated are changed in the wavelike state, and more preferably, in the middle stage of the subsequent formation of crystals, the amount of change thereof is gradually decreased.
    Type: Grant
    Filed: April 15, 1993
    Date of Patent: November 29, 1994
    Assignee: International Superconductivity Technology Center
    Inventors: Kenshi Takamuku, Genda Gu, Naoki Koshizuka
  • Patent number: 5350738
    Abstract: The present invention provides a method of manufacturing a high quality oxide superconductor film capable of controlling the film-forming rate and the film composition easily and forming the superconductor film safely and economically, over a wide region and homogeneously, wherein each of elements of R in which R represents one or more of elements selected from the group consisting of Y and lanthanide series rare earth elements, Ba and Cu is vapor deposited in the state of metal on a substrate under a high vacuum of lower than 10.sup.-8 Torr by a vacuum vapor deposition process to form a precursor comprising an amorphous metal and the precursor is oxidized and crystallized by applying a heat treatment without taking out the same into the atmospheric air.
    Type: Grant
    Filed: November 27, 1992
    Date of Patent: September 27, 1994
    Assignees: International Superconductivity Technology Center, Kabushiki Kaisha Kobe Seiko Sho, Sharp Kabushiki Kaisha
    Inventors: Takashi Hase, Ryusuke Kita, Masato Sasaki, Tadataka Morishita
  • Patent number: 5342826
    Abstract: A Bi-Sr-Ca-Cu-O system superconducting thin film formed on a substrate comprising [110] single crystals of an ABO.sub.3 type oxide having a perovskite structure, in which a (119) face is selectively grown relative to a substrate surface. The film is formed on the substrate by chemical vapor deposition process. A method of manufacturing a BiSrCaCuO system superconducting film in which an a-axis is oriented preferentially relative to the surface of a substrate comprising MgO (100) single crystals, wherein the chemical composition ratio (Sr+Ca+Cu)/Bi of the BiSrCaCuO system superconducting film is made not less than 3.5. A Bi-Sr-Ca-Cu-O system superconducting thin film formed on a substrate comprising MgO [110] single crystals, in which a (110) face is selectively grown to the substrate surface. The film is formed on the substrate by a chemical vapor deposition process.
    Type: Grant
    Filed: September 24, 1992
    Date of Patent: August 30, 1994
    Assignees: International Superconductivity Technology center, Ishikawajima-Harima Heavy Industries Co., Ltd., Sharp Corporation
    Inventors: Nobuhiko Kubota, Tsunemi Sugimoto, Kazushi Sugawara, Yuh Shiohara
  • Patent number: 5341059
    Abstract: 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.
    Type: Grant
    Filed: September 30, 1992
    Date of Patent: August 23, 1994
    Assignees: International Superconductivity Technology Center, Nippon Steel Corporation, Railway Technical Research Institute, Kawasaki Jukogyo Kabushiki Kaisha, Shikoku Electric Power Co., Inc.
    Inventors: Hiromasa Fukuyama, Satoru Aihara, Masato Murakami, Hiroyuki Fujimoto, Akihiro Kondoh, Hiroshi Takaichi, Naoki Koshizuka
  • Patent number: 5318745
    Abstract: A method of manufacturing an oxide superconductor having a composition expressed by formula La.sub.2-X Sr.sub.X CaCu.sub.2 O.sub.6 (0<X.ltoreq.0.6), comprising the steps of: preliminarily burning a raw powder having a predetermined composition, and sintering the powder to obtain a sintered body; and subjecting the sintered body to hot isostatic pressing at a temperature falling within a range of from 940.degree.-1600.degree. C. under total pressure of 10 MPa or more and oxygen partial pressure of 2 MPa or more. By virtue of the step of subjecting the sintered body to hot isostatic pressing, a superconductor can be manufactured at a temperature and under a pressure within respective wide ranges. Further, the composition of the superconductor can be selected within a wide range of 0<X.ltoreq.0.6. Moreover, the superconductor can be manufactured by performing quenching after the hot isostatic pressing.
    Type: Grant
    Filed: July 8, 1992
    Date of Patent: June 7, 1994
    Assignees: International Superconductivity Technology Center, Mitsubishi Materials Corporation, Hitachi, Ltd.
    Inventors: Takeshi Sakurai, Toru Yamashita, Hisao Yamauchi, Shoji Tanaka
  • Patent number: 5306696
    Abstract: A method of producing a superconductor of metal oxides having the following composition:(M.sub.1-x Ca.sub.x)(Ba.sub.1-y Sr.sub.y).sub.2 Cu.sub.4 O.sub.8wherein M stands for a rare earth element, x is 0 or a positive number of less than 1 and y is 0 or a positive number of less than 1, is disclosed, which includes hydrdolyzing an organic solvent solution or dispersion containing (a) alkoxide or fine particulate of a hydroxide of the rare earth element M, (b) alkoxides orfine particulate of hydroxides of Ca, Ba and Sr and (c) alkoxide, nitrate or fine particulate of hydroxide of copper in presence of water and nitrate ions. The alkoxides or hydroxides of Ca and Sr are present only when x and y are not zero, respectively. The hydrolyzed product is then dried, shaped and pyrolyzed to obtain the superconductor.
    Type: Grant
    Filed: December 10, 1990
    Date of Patent: April 26, 1994
    Assignees: Kabushiki-Gaisha Arubakku Kohporehiosentah, Nippon Mining Co., Ltd., Ishikawajima-Harima Jukogyo Kabushiki Kaisha, International Superconductivity Technology Center
    Inventors: Hirohiko Murakami, Junya Nishino, Seiji Yaegashi, Yu Shiohara, Shoji Tanaka
  • Patent number: 5284822
    Abstract: Disclosed are an oxide superconductor, and an optimum process for producing the same. The oxide superconductor comprises a base material phase including an oxide superconducting material, the oxide superconducting material including barium (Ba) at least and being free from grain boundaries, and precipitation phases contained in an amount of 1 to 50% by volume in the base material phase and dotted therein in a manner like islands, the precipitation phases being oxides of a metal selected from the group consisting of silicon (Si), aluminum (Al), zirconium (Zr), magnesium (Mg), titanium (Ti), strontium (Sr), tungsten (W), cobalt (Co) and vanadium (V), and being products of decomposition reaction of the base material phase. In the production process, the constituent materials are treated thermally at a partially melting temperature in order to give the above-described novel structure to the oxide superconductor.
    Type: Grant
    Filed: May 7, 1991
    Date of Patent: February 8, 1994
    Assignees: International Superconductivity Technology Center, Toyota Jidosha Kabushiki Kaisha, Kawasaki Jukogyo Kabushiki Kaisha, NGK Insulators, Ltd.
    Inventors: Takenobu Sakai, Kozi Nishio, Naoyuki Ogawa, Izumi Hirabayashi, Shoji Tanaka
  • Patent number: 5281575
    Abstract: In manufacturing a high-temperature superconductive oxide thin film by irradiating a laser beam onto an oxide target in an atmosphere of oxygen to form the high-temperature superconductive oxide thin film on an oxide substrate, the laser beam is irradiated from a back surface of the substrate and is transmitted through the substrate, and thereafter the laser beam is irradiated onto the oxide target.
    Type: Grant
    Filed: April 21, 1992
    Date of Patent: January 25, 1994
    Assignees: International Superconductivity Technology Center, Kabushiki Kaisha Kobe Seiko Sho, Hitachi Densen Kabushiki Kaisha
    Inventors: Takashi Hase, Tadataka Morishita, Katsumi Ohata, Hirohiko Izumi
  • Patent number: 5276012
    Abstract: A method is disclosed of forming an oxide superconducting film comprising the steps of (1) mixing (a) the vapors of organic metal materials in such proportions as to provide a predetermined metal composition, or (b) said organic metal materials in such proportions as to provide a predetermined metal composition vaporizing and mixture, and (2) bringing the mixture into contact with a heated substrate so that an oxide superconducting film is formed on said substrate by a chemical vapor deposition process, wherein laser light is applied onto said substrate during formation of said oxide superconducting film on said substrate, whereby the crystallographic orientation of said oxide superconducting film being formed in the irradiated area of said substrate is such that the c-axis is parallel to the substrate.
    Type: Grant
    Filed: February 11, 1992
    Date of Patent: January 4, 1994
    Assignees: NGK Spark Plug Co., Ltd., International Superconductivity Technology Center, Hitachi Ltd.
    Inventors: Takahisa Ushida, Kazutoshi Higashiyama, Izumi Hirabayashi, Shoji Tanaka
  • Patent number: 5262393
    Abstract: The present invention provides a layered copper oxide as an insulator for superconductor or as a superconductor, which has a chemical composition represented by the formula of (R,Ce).sub.3 Sr.sub.2 Cu.sub.2 (M,Cu)O.sub.11, wherein R is a rare earth element other than Ce and M is one or both of Pb and T1, and has a crystal structure comprising a (M,Cu)Sr.sub.2 (R,Ce)Cu.sub.2 O.sub.7 ; unit of a TlBa.sub.2 CaCu.sub.2 O.sub.7 (1-2-1-2)-type structure and a [(R,Ce)O.sub.2 ].sub.2 unit of a fluorite-type structure alternately put on each other, or a chemical composition represented by the formula of (R,Ce).sub.3 Sr.sub.2 Cu.sub.2 (M,Cu)O.sub.10+z, wherein R is a rare earth element other than Ce, M is one or both of Pb or Tl, and has a crystal structure comprising a (R,Ce)Sr.sub.2 Cu.sub.2 (Cu,M)O.sub.6+z unit of a YBa.sub.2 Cu.sub.3 O.sub.3 O.sub.6+.delta. -type structure and a [(R,Ce)O.sub.2 ].sub.2 unit of a fluorite-type structure alternately put on each other, wherein z is in the range of 0.ltoreq.z.ltoreq.
    Type: Grant
    Filed: October 25, 1991
    Date of Patent: November 16, 1993
    Assignees: Matsushita Electric Industrial Co., Ltd., International Superconductivity Technology Center, Central Research Institute of Electric Power Industry, Ube Industries, Ltd.
    Inventors: Takahiro Wada, Ataru Ichinose, Kazuyuki Hamada, Hisao Yamauchi, Shoji Tanaka
  • Patent number: 5254530
    Abstract: A Bi-Sr-Ca-Cu-O-type superconductive film is formed on an MgO (100) single crystal substrate by the chemical vapor deposition method at a film formation speed of 780.degree. C. or less and a film formation speed of 1.0 nm/min or more, and exhibits an a-axis or b-axis preferential growth with respect to the substrate surface.
    Type: Grant
    Filed: June 18, 1992
    Date of Patent: October 19, 1993
    Assignees: International Superconductivity Technology Center, Ube Industries, Ltd., Sharp Corporatoin, Fujikura Ltd.
    Inventors: Tsunemi Sugimoto, Kazushi Sugawara, Mikio Nakagawa, Yuh Shiohara
  • Patent number: 5252544
    Abstract: An oxide superconductor which has a composition expressed by the following general formula and whose crystal structure is 1222-phase structure.Pb.sub.a (M.sub.1-x-y Ce.sub.x Sr.sub.y).sub.4 Cu.sub.3-a O.sub.z (I)(where M represents at least one element selected from the group consisting of Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and Lu, and a, x, y, and z denote the numbers which satisfy 0.3.ltoreq.a.ltoreq.0.7, 0<x.ltoreq.0.25, 0.3.ltoreq.y<0.5, 8.5.ltoreq.z.ltoreq.9.5, respectively). A Pb-based Cu oxide superconductor manufacturing method comprising the steps of mixing powders of raw materials containing at least Pb, Sr, Ce, M (where M represents at least one element selected from the group consisting of Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and Lu groups) and Cu in the proportion to have the composition shown in the general formula (I) above, optionally forming the mixed powder into a shape body, and firing the obtained powder mixture or the shape body in the temperature range of 900.degree.
    Type: Grant
    Filed: June 7, 1991
    Date of Patent: October 12, 1993
    Assignees: International Superconductivity Technology Center, Tohoku Electric Power Company, Incorporated, Kyocera Corporation, Central Research Institute of Electric Power Industry, The Furukawa Electric Co., Ltd.
    Inventors: Toshihiko Maeda, Kazuhiro Sakuyama, Shin-ichi Koriyama, Ataru Ichinose, Hisao Yamauchi, Shoji Tanaka
  • Patent number: 5244872
    Abstract: An oxide superconductor having the following formula:Pb.sub.2 Sr.sub.2 Ca.sub.1-p Ln.sub.p Cu.sub.3 O.sub.q orPb.sub.1-x Cu.sub.x Sr.sub.2 Ca.sub.1-y Ln.sub.y Cu.sub.2 O.sub.zwherein Ln represents a rare earth element, p is 0.3-0.7, q is 7.8-8.2, x is 0.2-0.5, y is 0.3-0.7 and z is 6.8-7.2 is prepared using a coprecipitation method. An acetic acid solution of carbonates, acetates or nitrates of Pb, Sr, Ca, Cu and Ln is mixed with an aqueous solution of oxalic or tartaric acid, or a lower alkyl ester thereof. The mixture is reacted to precipitate the Pb, Sr, Ca, Cu and Ln as oxalates or tartarates and the precipitates are dried and sintered to obtain the oxide superconductor.
    Type: Grant
    Filed: November 1, 1991
    Date of Patent: September 14, 1993
    Assignees: International Superconductivity Technology Center, Sanyo Electric Co., Ltd., Kyocera Corporation, Tokyo Gas Co., Ltd.
    Inventors: Takaaki Ikemachi, Takashi Kawano, Shin-ichi Koriyama, Hisao Yamauchi
  • Patent number: 5244871
    Abstract: An oxide superconductor comprises a composition represented by the composition formula: (Nd.sub.x --Ce.sub.y --L.sub.z).sub.2 CuO.sub.4-d (wherein L is an element selected from Ca and Mg, and x+y+z=1). The compositions of Nd, Ce and L of the oxide superconductor corresponds to a point falling inside an area of Nd--Ce--L ternary diagram surrounded by straight lines (A-B), (B-C), (C-D) and (D-A) connecting point (A) with point (B), point (B) with point (C), point (C) with point (D) and point (D) with point (A), respectively, the points (A), (B), (C) and (D) being points (x=1, y=0, z=0), (x=0.4, y=0.6, z=0), (x=0.4, y=0.3, z=0.3) and (x=0.1, y=0, z=0.9), respectively, in the Nd--Ce--L ternary diagram. Above-described Nd--Ce--L--Cu--O oxides can exhibit superconductivity within a wide range of composition when heat-treated in an atmosphere of nitrogen.
    Type: Grant
    Filed: October 9, 1991
    Date of Patent: September 14, 1993
    Assignees: Mitsubishi Metal Corporation, Hitachi, Ltd., International Superconductivity Technology Center
    Inventors: Takeshi Sakurai, Toru Yamashita, Hisao Yamauchi, Shoji Tanaka