Patents Assigned to International Superconductivity Technology
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Patent number: 6365553Abstract: The invention provides an oxide superconductor capable of sufficiently withstanding external forces such as a large electromagnetic force and thermal stresses accompanying rapid heating and cooling while in service, and internal stresses so as to be able to exhibit a high trapped magnetic field stably over a long period of time. The oxide superconductor such as, for example, “a copper oxide superconductor containing rare earth elements”, is composed of an oxide superconductive bulk body impregnated with a low melting metal or an oxide superconductive bulk body impregnated with a low melting metal and having a thin film of the low melting metal formed on the external surface thereof. Such oxide superconductors as described above can be produced by a process whereby the oxide superconductive bulk body kept in an atmosphere of reduced pressure is brought into contact with the low melting metal.Type: GrantFiled: August 25, 2000Date of Patent: April 2, 2002Assignees: International Superconductivity Technology Center, Railway Technical Research InstituteInventors: Masaru Tomita, Masato Murakami
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Patent number: 6313725Abstract: The invention is to establish means of producing easily and at low cost “a coupled body of superconducting magnets”, comprised of multi-pole bulk superconducting magnets lined up such that the polarities thereof alternately vary so as to cause a magnetic field gradient to occur. The magnetizing method for producing a coupled body comprised of multi-pole bulk superconducting magnets with respective polarities varying comprises the steps of coupling adjacent members for bulk superconducting magnets of a plurality of members for bulk superconducting magnets with each other in such a way as to be freely superposable, foldable, and unfoldable, superposing all the members for the bulk superconducting magnets on top of one after another, and applying a magnetizing process thereto in as superposed state, and unfolding alternately and juxtaposing the respective bulk superconducting magnets as superposed after the magnetizing process as shown in FIG. 1(A) to FIG. 1(D).Type: GrantFiled: September 22, 2000Date of Patent: November 6, 2001Assignees: Railway Technical Research Institute, International Superconductivity Technology CenterInventors: Ken Nagashima, Masato Murakami, Takeshi Miyamoto, Atsuyuki Kobayashi, Osami Tsukamoto
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Patent number: 6242939Abstract: A superconducting circuit device of a voltage-type logic device is large in current driving capability and, accordingly, electric power consumption; however, the switching speed is not so fast, and a superconducting circuit device of a fluxoid-type logic device is small in current driving capability and, accordingly, the electric power consumption; however the switching speed is faster than that of the superconducting circuit device of the voltage-type logic device, wherein the superconducting circuit device of the voltage-type logic device and the superconducting circuit device of the fluxoid-type logic device are selectively used in a superconducting circuit such as a superconducting random access memory, a superconducting NOR circuit and a superconducting signal converting circuit so as to realize small electric power consumption and high-speed switching action.Type: GrantFiled: March 2, 2000Date of Patent: June 5, 2001Assignees: NEC Corporation, International Superconductivity Technology CenterInventors: Shuichi Nagasawa, Kazunori Miyahara, Youichi Enomoto
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Patent number: 6235685Abstract: A rod 1 made of superconducting oxide is soaked in a molten normal conductor 2 to join the rod 1 and the normal conductor 2, whereby a superconducting oxide current lead is prepared. As a result, a contact resistance at the interface between the superconducting oxide and the normal conductor can be reduced. Consequently, Joule's heat at a current lead having a small cross sectional area can be suppressed low, which in turn realizes the reduction of the load on a freezer and the amount of evaporated cooling solvent, with respect to a superconducting coil.Type: GrantFiled: November 15, 1999Date of Patent: May 22, 2001Assignee: International Superconductivity Technology CenterInventors: Junya Maeda, Teruo Izumi, Yuichi Imagawa, Satoshi Matsuoka, Yuh Shiohara, Shoji Tanaka, Hiroshi Okamoto
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Patent number: 6226858Abstract: 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° C. or more in a non-oxidizing atmosphere, whereby obtaining a rolled textured structure which is oriented such that the [100] 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° 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.Type: GrantFiled: June 2, 1998Date of Patent: May 8, 2001Assignees: The Furukawa Electric Co., Ltd., International Superconductivity Technology CenterInventors: Kaname Matsumoto, Naoki Koshizuka, Yasuzo Tanaka
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Patent number: 6207067Abstract: A method for fabricating an oxide superconducting device includes the steps of: forming a V-shaped groove on a substrate by a converging ion beam and forming a barrier with reduced superconductivity on the oxide superconducting thin-film on the groove to form a Josephson Junction, wherein the irradiation ion amount of the converging ion beam is varied according to the position of the beam within the groove in such a manner that an inclination angle of the inclined portion of the substrate is fixed. An oxide superconducting device (a Josephson Junction device) having a high degree of flexibility in arrangement and with high reproducibility, and having a high degree of uniformity is provided.Type: GrantFiled: September 29, 1998Date of Patent: March 27, 2001Assignees: Mitsubishi Denki Kabushiki Kaisha, International Superconductivity Technology CenterInventors: Naoki Yutani, Katsumi Suzuki, Youichi Enomoto, Jian-Guo Wen
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Patent number: 6163713Abstract: In a high frequency transmission line having a dielectric substrate and a conductor line which is provided on the dielectric substrate for allowing electric current to flow therethrough, the conductor line has a non-grain-boundary oxide superconductor layer with twin walls but without grain boundaries. The high frequency transmission line is in the form of a plane circuit. It is preferable that an oriented oxide superconductor layer is provided between the dielectric substrate and the non-grain-boundary oxide superconductor layer.Type: GrantFiled: March 5, 1998Date of Patent: December 19, 2000Assignees: NEC Corporation, Sumitomo Electric Industries, Ltd., International Superconductivity Technology CenterInventors: Katsumi Suzuki, Sadahiko Miura, Takayuki Inoue, Koji Muranaka, Hideaki Zama, Youichi Enomoto, Tadataka Morishita, Shoji Tanaka
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Patent number: 6131050Abstract: A control device having control logics that respectively generate operated quantities by simutaneously parallel-processing observed quantities obtained from a controlled object. A switch selectively outputs one of the operated quantities to the controlled object based on instruction data.Type: GrantFiled: June 11, 1997Date of Patent: October 10, 2000Assignees: International Superconductivity Technology Center, The Juridical Foundation, Ishikawajima-Harima Heavy Industries Co., Ltd., Ishikawajima SystemInventors: Masahiro Egami, Yuh Shiohara, Tetsuya Minegishi, Yasuyuki Hisashi, Takashi Sato, Hiromitsu Morimoto
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Patent number: 6121205Abstract: A bulk superconductor including a plurality of units each composed of a substrate and a superconductive layer of R--Ba--Cu--O, where R is selected from La, Nd, Sm, Eu, Gd, Y, Dy, Ho, Er, Tm, Yb and mixtures thereof, formed on the substrate. The units are arranged in a row or in a matrix such that the superconductive layers of respective units are superconductively joined with each other.Type: GrantFiled: May 13, 1997Date of Patent: September 19, 2000Assignees: International Superconductivity Technology Center, Railway Technical Research InstituteInventors: Masato Murakami, Kazuhiko Sawada, Naomichi Sakai, Takamitsu Higuchi
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Patent number: 6083886Abstract: Provided is a method of preparing a large-sized oxide superconducting bulk body having excellent characteristics and high homogeneity. The method is adapted to prepare an oxide superconducting bulk body by melt growth through a seed crystal method, and comprises steps of preparing a precursor by press-molding material powder obtained by mixing REBa.sub.2 Cu.sub.3 O.sub.7-z powder with RE.sub.2 BaCuO.sub.5 or RE.sub.4 Ba.sub.2 Cu.sub.2 O.sub.10 powder and a platinum additive, homogeneously semi-melting the precursor by holding the same at a holding temperature T.sub.1 .degree. C. (t.sub.1 +20.ltoreq.T.sub.1 .ltoreq.t.sub.1 +80 assuming that the melting point of the oxide superconducting bulk body is t.sub.1 .degree. C.) for a prescribed time, and crystal-growing the precursor at a temperature not more than the melting point t.sub.1 .degree. C.Type: GrantFiled: July 6, 1998Date of Patent: July 4, 2000Assignees: Sumitomo Electric Industries, Ltd., International Superconductivity Technology CenterInventors: Noriki Hayashi, Masato Murakami
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Patent number: 6034036Abstract: The present invention is aimed to provide a means for manufacturing a RE123 system oxide superconductor showing good superconductivity characteristics under atmospheric ambiance.Type: GrantFiled: September 25, 1997Date of Patent: March 7, 2000Assignees: International Superconductivity Technology Center, Ishikawajima-Harima Jukogyo Kabushiki KaishaInventors: Minoru Tagami, Xin Yao, Makoto Kambara, Yuh Shiohara, Shoji Tanaka
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Patent number: 6016433Abstract: Any oxide superconductor Josephson junction element having an oxide superconductor oriented in the c-axis direction with respect to a substrate, and a needle-like, a-axis (or b-axis) oriented oxide superconductor. Both sides of the needle-like, a-axis (or b-axis) oriented oxide superconductor are sandwiched between the c-axis oriented superconductors. The crystal boundary sections between the needle-like, a-axis (or b-axis) oriented oxide superconductor and each of the c-axis oriented superconductors form a weak link of the Josephson junction. The needle-like, a-axis (or b-axis) oriented oxide superconductor is grown such that the c-axis direction thereof is oriented in the (110) direction which is inclined at an angle of 45 degrees with respect to the (100) direction or (010) direction of the c-axis oriented superconductors.Type: GrantFiled: September 2, 1997Date of Patent: January 18, 2000Assignees: International Superconductivity Technology Center, Sharp Kabushiki KaishaInventors: Yuuji Mizuno, Yoshihiro Ishimaru, Youichi Enomoto
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Patent number: 6011981Abstract: 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.Type: GrantFiled: March 10, 1997Date of Patent: January 4, 2000Assignee: International Superconductivity Technology CenterInventors: Gustavo Alvarez, Furen Wang, Jian-Guo Wen, Naoki Koshizuka, Youichi Enomoto, Tadashi Utagawa, Shoji Tanaka
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Patent number: 5998050Abstract: A composite material is disclosed which includes a substrate, an oriented film provided on a surface of the substrate and formed of a crystal of a Y123 metal oxide of the formula LnBa.sub.2 Cu.sub.3 O.sub.y wherein Ln stands for Y or an element belonging to the lanthanoid and y is a number of 6-7, and a layer of a Y123 metal oxide of the formula LnBa.sub.2 Cu.sub.3 O.sub.y wherein Ln stands for Y or an element belonging to the lanthanoid and y is a number of 6-7 formed on the oriented film.Type: GrantFiled: December 19, 1996Date of Patent: December 7, 1999Assignees: International Superconductivity Technology Center, Hitachi Cable Ltd., Hokkaido Electric Power Co., Inc., Kyushu Electric Power Co., Inc., The Kansai Electric Power Co., Inc.,, Fujikura, Ltd.Inventors: Yasuji Yamada, Masaru Nakamura, Noriyuki Tatsumi, Jiro Tsujino, Kanshi Ohtsu, Yasuo Kanamori, Minoru Tagami, Atsushi Kume, Yuh Shiohara, Shoji Tanaka
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Patent number: 5974336Abstract: An oxide superconductor comprises a base material consisting of a single crystalline oxide, an oxide superconductor film consisting of a Y123 compound and formed on the single crystalline oxide base material, and a coating film consisting essentially of a Ba--Cu--O oxide and covering the surface of the oxide superconductor film, the coating film having a thermal expansion coefficient higher than that of the oxide superconductor film.Type: GrantFiled: October 15, 1997Date of Patent: October 26, 1999Assignees: Kabushiki Kaisha Toshiba, International Superconductivity Technology CenterInventors: Yasuji Yamada, Tamaki Masegi, Junichi Kawashima, Yusuke Niiori, Izumi Hirabayashi
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Patent number: 5968878Abstract: A high critical temperature and high critical current density superconductor containing a matrix phase of a metal oxide expressed by the formula RE.sup.1 Ba.sub.2 Cu.sub.3 O.sub.p wherein RE.sup.1 stands for La, Nd, Sm, Eu or Gd and p is a number of 6.8-7.2, a first dispersed phase of a metal oxide expressed by the formula RE.sup.2.sub.1+d Ba.sub.2-d Cu.sub.3 O.sub.q wherein RE.sup.2 stands for La, Nd, Sm, Eu or Gd, d is a number of 0<d<0.5 and q is a number of 6.0-7.2 and a second dispersed phase of a metal oxide expressed by the formula RE.sup.3.sub.4-2x Ba.sub.2+2x Cu.sub.2-x O.sub.10-y wherein RE stands for La or Nd, x is a number of 0<x .English Pound.0.25 and y is a number of 0<y<0.5. The first and second phases are dispersed in the matrix. The above superconductor may be prepared by cooling a partial melt having a temperature of 1,000.degree.-1,300.degree. C. and containing a major molar amount of RE.sup.1 Ba.sub.2 Cu.sub.3 O.sub.p and a minor molar amount of RE.sup.3.sub.4-2x Ba.sub.Type: GrantFiled: February 27, 1998Date of Patent: October 19, 1999Assignees: International Superconductivity Technology Center, Railway Technical Research InstituteInventors: Hiroki Kojo, Sang-Im Yoo, Masato Murakami
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Patent number: 5962374Abstract: A process for preparing an oxide crystal by means of solution growth in the presence of a solvent is provided. The solvent includes a mixture of an oxide containing at least one member of those elements which constitute the oxide crystal, a halide containing at least one member of those elements which constitute the oxide crystal, and metallic silver.Type: GrantFiled: February 20, 1998Date of Patent: October 5, 1999Assignee: International Superconductivity Technology CenterInventors: Yuusuke Niiori, Yasuji Yamada, Junichi Kawashima, Izumi Hirabayashi
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Patent number: 5958843Abstract: A bulk superconductor is produced by subjecting REBa.sub.2 Cu.sub.3 O.sub.y oxide to oxygen annealing after many holes have been formed in the oxide body.Type: GrantFiled: September 5, 1997Date of Patent: September 28, 1999Assignees: International Superconductivity Technology Center, Railway Technical Research InstituteInventors: Naomichi Sakai, Mikio Takahashi, Ken Nagashima, Masato Murakami
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Patent number: 5942765Abstract: In the random access memory utilizing an oxide high-temperature superconductor, a first high-temperature superconductor layer 1, a non-superconductor layer 2, a second high-temperature superconductor layer 3 and a non-superconductor layer 4 are formed on an insulated substrate. The first high-temperature superconductor layer 1 is formed in a first loop, forming a memory storage superconductor quantum interference device by two Josephson junctions and a control current line I.sub.WX (6) and a bias current line I.sub.WY (8) in order to store the flux quantum. The second high-temperature superconductor layer 3 is formed in a second loop, forming a reading superconducting quantum interference device by two Josephson junctions and a control current line I.sub.RX (5) and a bias current line I.sub.RY (7).Type: GrantFiled: November 20, 1997Date of Patent: August 24, 1999Assignee: International Superconductivity Technology CenterInventors: Kazunori Miyahara, Yoichi Enomoto, Shoji Tanaka
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Patent number: 5936255Abstract: An X-ray, neutron or electron diffraction method, which is devoid of the defects of conventional diffraction apparatus using an imaging plate, which can analyzing a sample, in a non-destructive mode without contact and with a good S/N ratio, even when the sample significantly generates fluorescence or scattered X-rays.Type: GrantFiled: July 9, 1997Date of Patent: August 10, 1999Assignees: Sharp Kabushiki Kaisha, International Superconductivity Technology CenterInventors: Kenji Nakanishi, Akira Tsukamoto, Keiichi Tanabe