Superconductor Next To Two Or More Nonsuperconductive Layers Patents (Class 505/237)
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Patent number: 5906965Abstract: A high temperature superconductor (HTS) tri-layer structure and a method for providing the same are described. Preferable two dimensional growth for all layers is provided resulting in smooth surfaces and highly crystalline layers. Full oxygenation of HTS under-layer(s) is provided despite having thick intervening dielectric mid-layer. HTS over- and under-layers are preferably structurally and electrically similar and have high crystallinity, the HTS layers have high T.sub.c (e.g. >90K) comparable to T.sub.c of single layer superconductor layers and a high J.sub.c (e.g. >10.sup.6 A/cm.sup.2), the tri-layer properties do not significantly degrade as the thickness of the layers is increased, and the dielectric mid-layer has high resistivity and is substantially pin-hole free.Type: GrantFiled: October 23, 1996Date of Patent: May 25, 1999Assignee: Superconductor Technologies, Inc.Inventor: Muralidhar R. Rao
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Patent number: 5898020Abstract: A biaxially textured article includes a rolled and annealed, biaxially textured substrate of a metal having a face-centered cubic, body-centered cubic, or hexagonal close-packed crystalline structure; and an epitaxial superconductor or other device epitaxially deposited thereon.Type: GrantFiled: May 22, 1996Date of Patent: April 27, 1999Inventors: Amit Goyal, John D. Budai, Donald M. Kroeger, David P. Norton, Eliot D. Specht, David K. Christen
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Patent number: 5877124Abstract: A superconducting oxide ceramic pattern is described. The pattern is comprised of a high Tc superconducting region and a low Tc superconducting region which exhibits a resistivity at the liquid nitrogen temperature while the high Tc region is superconducitive at that temperature. The low Tc region is doped with impurity such as Si and then subjected to thermal treatment to oxidizing the impurity.Type: GrantFiled: May 17, 1995Date of Patent: March 2, 1999Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventor: Shumpei Yamazaki
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Patent number: 5872080Abstract: A superconducting article including a flexible polycrystalline metal substrate, a layer of an adhesion layer material upon the surface of the flexible polycrystalline metal substrate, a layer of a cubic oxide material upon the adhesion layer material, the first layer of cubic oxide material deposited by ion beam assisted deposition, a layer of a buffer material upon the ion beam assisted deposited cubic oxide material layer, and, a layer of YBCO upon the buffer material layer is provided and has demonstrated J.sub.c 's of 1.3.times.10.sup.6 A/cm.sup.2, and I.sub.c 's of 120 Amperes across a sample 1 cm wide.Type: GrantFiled: April 19, 1995Date of Patent: February 16, 1999Assignee: The Regents of the University of CaliforniaInventors: Paul N. Arendt, Xin Di Wu, Steve R. Foltyn
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Patent number: 5866252Abstract: This invention permits superconducting ceramics, as well as other ceramic materials, to be spray deposited onto indefinitely large sheets of metallic substrate from a carboxylic acid salt solution. Elemental metal precursors of the superconductor are introduced into the solution as carboxylic acid salts. The deposit formed on the malleable metallic substrate is then thermomechanically calcined to form c-axis textured metal-superconductor composite sheet structures. These composite sheet structures can be formed by pressing together two ceramic-substrate structures, ceramic face-to-face, to form a metal-ceramic-metal sheet structure, or by overlaying a metal sheet over the deposited structure. Once the structure has been thermomechanically calcined, the c-axis of the superconductor is oriented parallel to the vector defining the plane of the metal sheet, i.e., perpendicular to the surface of the plane.Type: GrantFiled: October 18, 1996Date of Patent: February 2, 1999Assignee: The United States of America as represented by the Secretary of the Air ForceInventors: L. Pierre de Rochemont, Michael J. Suscavage, Daniel F. Ryder, Jr., Mikhail Klugerman
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Patent number: 5861361Abstract: A FET type superconducting device comprises a thin superconducting channel, a superconducting source region and a superconducting drain region formed of an oxide superconductor over a principal surface of the substrate, and a gate electrode on a gate insulator disposed on the superconducting channel for controlling the superconducting current flowing through the superconducting channel by a signal voltage applied to the gate electrode. The superconducting channel is formed of(Pr.sub.w Y.sub.1-w)Ba.sub.2 Cu.sub.3 O.sub.7-z (0<w<1, 0<z<1) oxide superconductororY.sub.1 Ba.sub.2 Cu.sub.3-v CO.sub.V O.sub.7-u (0<v<3, 0<u<1) oxide superconductor.These oxide superconductors have smaller carrier densities than the conventional oxide superconductor so that the superconducting channel has a larger thickness than the one funned of the conventional oxide superconductor.Type: GrantFiled: April 17, 1996Date of Patent: January 19, 1999Assignee: Sumitomo Electric Industries, Ltd.Inventors: Takao Nakamura, Michitomo Iiyama
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Patent number: 5849669Abstract: A high critical temperature superconducting Josephson device includes a bicrystal substrate formed of a first single crystal substrate and a second single crystal substrate, with end faces of the first and second single crystal substrates having different crystal orientations and being joined to each other. A first superconducting electrode formed of a first film of a high critical temperature superconductor material is located on the first single crystal substrate, whereas a second superconducting electrode formed of a second film of a high critical temperature superconductor material is located on the second single crystal substrate. A bridge is formed of a third film of a high critical temperature superconductor material and located on the bicrystal substrate across a joint between said first and said second single crystal substrates.Type: GrantFiled: May 30, 1996Date of Patent: December 15, 1998Assignee: Oki Electric Industry Co., Ltd.Inventor: Zhongmin Wen
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Patent number: 5846909Abstract: Use of monolayer films for the direct modification of high-T.sub.c superconductor structures and devices. Methods for the formation of superconductor localized monolayer films have been discovered based on the spontaneous adsorption of molecules containing ligating functionalities, such as alkylamine, arylamine, and alkylthiol moieties. Molecules containing these types of functionalities are found to bind tenaciously to the metal ions which form the high-T.sub.c superconductor surface. The derivatized superconductor structures can be prepared simply by soaking the high-T.sub.c, superconductor structure or device in a dry organic solvent system which contains the derivatizing agent. Large changes in the superconductor interfacial properties can be achieved with such procedures allowing for the atomic level control of the surface properties of the superconductor.Type: GrantFiled: May 22, 1995Date of Patent: December 8, 1998Assignees: University of Texas System, Northwestern UniversityInventors: John T. McDevitt, Chad A. Mirkin
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Patent number: 5834405Abstract: A superconducting multilayer ceramic substrate is disclosed, prepared by firing a laminate of at least two polymer bonded cast sheets of a ceramic dielectric oxide powder, at least one sheet of which has a metallization pattern provided thereon, to thereby form a superconducting oxide reaction layer at the interface between the sintered ceramic material and the embedded metallic conductor lines of the metallization pattern.Type: GrantFiled: February 24, 1992Date of Patent: November 10, 1998Assignee: International Business Machines CorporationInventors: Byung Tae Ahn, Robert Bruce Beyers, Emanuel Israel Cooper, Edward August Giess, Eugene John O'Sullivan, Judith Marie Roldan, Lubomyr Taras Romankiw
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Patent number: 5831279Abstract: A device with weak links (Josephson junctions) in a superconducting film has two single crystals connected through an interconnecting arrangement that may have one or more sublayers. At least two grain boundaries or at least one barrier are/is formed in the substrate.Type: GrantFiled: May 3, 1995Date of Patent: November 3, 1998Assignee: Telefonktiebolaget LM EricssonInventors: Erland Wikborg, Evgeni Stepantsov, Zdravko Ivanov, Tord Claeson
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Patent number: 5814584Abstract: Compounds of the general formula A.sub.2 MeSbO.sub.6 wherein A is either barium (Ba) or strontium (Sr) and Me is a non-magnetic ion selected from the group consisting of scandium (Sc), indium (In) and gallium (Ga) have been prepared and included in high critical temperature thin film superconductor structures.Type: GrantFiled: June 30, 1995Date of Patent: September 29, 1998Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Arthur Tauber, William D. Wilber, Steven C. Tidrow, Robert D. Finnegan, Donald W. Eckart
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Patent number: 5814583Abstract: A high-temperature superconducting thin film of compound oxide selected from the group consisting of:Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Ho.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Lu.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,Sm.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Nd.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Gd.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,Eu.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Er.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Dy.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,Tm.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Yb.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, La.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,(La, Sr).sub.2 CuO.sub.4-x,which is deposited on a substrate of MgO or SrTiO.sub.3, with the outer surface of the high-temperature superconducting thin film being covered with a protective crystalline film of SrTiO.sub.3.Type: GrantFiled: July 1, 1996Date of Patent: September 29, 1998Assignee: Sumitomo Electric Industries, Ltd.Inventors: Hideo Itozaki, Saburo Tanaka, Nobuhiko Fujita, Shuji Yazu, Tetsuji Jodai
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Patent number: 5795849Abstract: A method for producing a superconductor assembly includes preparing a first bulk ceramic superconductor having a first essentially random pattern of superconductor domains of a copper-oxide ceramic superconductor and non-superconductor domains at a critical temperature, and preparing a second bulk ceramic superconductor having a second essentially random pattern of superconductor domains of a copper-oxide ceramic superconductor and non-superconductor domains at the critical temperature. The method further includes juxtaposing a first surface of the first bulk ceramic superconductor proximate with a first surface of the second bulk ceramic superconductor to form a superconductor assembly where superconductor domains of the first bulk ceramic superconductor and superconductor domains of the second bulk ceramic superconductor are only randomly aligned due to the different first essentially random pattern and second essentially random pattern.Type: GrantFiled: June 7, 1995Date of Patent: August 18, 1998Inventor: Paul L. Hickman
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Patent number: 5793055Abstract: A step junction is provided for superconductor/semiconductor heterostructure hybrid devices like tunneling transistors, in a body of p-InAs with a vertical side connecting the low plateau and high plateau on which superconductors, preferably of niobium, are applied.Type: GrantFiled: November 30, 1995Date of Patent: August 11, 1998Assignee: Forschungszentrum Julich GmbHInventor: Alexander Kastalsky
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Patent number: 5759960Abstract: A superconductive device (e.g., magnet) having a superconductive lead assembly and cooled by a cryocooler coldhead having first and second stages. A first ceramic superconductive lead has a first end thermally connected to the first stage and a second end thermally connected to the second stage. A jacket of open cell material (e.g., polystyrene foam) is in surrounding compressive contact with the first ceramic superconductive lead, and a rigid, nonporous support tube surrounds the jacket. This protects the first ceramic superconductive lead against shock and vibration while in the device. The rigid support tube has a first end and a second end, with the second end thermally connected to the second stage.Type: GrantFiled: May 16, 1996Date of Patent: June 2, 1998Assignee: General Electric CompanyInventors: Robert Adolph Ackermann, Kenneth Gordon Herd, Evangelos Trifon Laskaris, Richard Andrew Ranze
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Patent number: 5760463Abstract: A superconductor device which includes a first wiring part and a second wiring part which together form a superconductive wiring. The first wiring part is arranged onto a substrate and is made of a superconductor material. The second wiring part is made of a non-oxide semiconductor material. The second wiring part is adjacent to the first wiring part and jointly forms a superconductive wiring with the first wiring part by becoming at least partly superconductive due to proximity effect with the first wiring part. The second wiring part has a smaller penetration length of magnetic field than that for the first wiring part. This structure enhances the propagation velocity of a signal within the superconductive wiring.Type: GrantFiled: February 14, 1996Date of Patent: June 2, 1998Assignee: Fujitsu LimitedInventor: Tsunehiro Hato
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Patent number: 5736488Abstract: This invention relates to multilayered superconductive composites, particularly to composites based on thallium-containing superconducting oxides, and their process of manufacture.Type: GrantFiled: January 26, 1996Date of Patent: April 7, 1998Assignee: E. I. du Pont de Nemours and CompanyInventors: Dean Willett Face, Kirsten Elizabeth Myers
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Patent number: 5721196Abstract: A Josephson junction device comprises a single crystalline substrate including a principal surface, an oxide layer formed on the principal surface of the substrate having a step on its surface and an oxide superconductor thin film formed on the surface of the oxide layer. The oxide superconductor thin film includes a first and a second portions respectively positioned above and below the step of the oxide layer, which are constituted of single crystals of the oxide superconductor, and a step-edge junction made up of a grain boundary on the step of the oxide layer, which constitutes a weak link of the Josephson junction.Type: GrantFiled: August 16, 1996Date of Patent: February 24, 1998Assignee: Sumitomo Electric Industries, Ltd.Inventors: Takao Nakamura, Michitomo Iiyama
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Patent number: 5714767Abstract: For manufacturing a superconducting device, a compound layer which is composed of the same constituent elements of an oxide superconductor is formed on a surface of the substrate, and a gate electrode is formed on a portion of the compound layer. Portions of the compound layer at both sides of die gate electrode are etched using die gate electrode as a mask, so that a shallow step is formed on an upper surface of the compound layer and side surfaces of the step exposed. After that electric power is applied to the gate electrode to heat the gate electrode so as to carry out a heat-treatment on the portion of die compound layer under the gate electrode locally, so that a gate insulator formed directly under the the gate electrode and a superconducting channel which is constituted an extremely thin superconducting region composed of the oxide superconductor and formed under die gate insulator are produced in a self alignment to die gate electrode.Type: GrantFiled: November 1, 1995Date of Patent: February 3, 1998Assignee: Sumitomo Electric Industries, Ltd.Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama
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Patent number: 5712227Abstract: A substrate having a superconducting thin film of compound oxide thereon. An intermediate layer consists of at least one layer of copper-containing oxide is interposed between the substrate and the superconducting thin film.Type: GrantFiled: January 25, 1995Date of Patent: January 27, 1998Assignee: Sumitomo Electric Industries, Ltd.Inventors: Kenjiro Higaki, Keizo Harada, Takashi Matsuura, Hitoshi Oyama, Hideo Itozaki, Shuji Yazu
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Patent number: 5661112Abstract: Excellent films of a high Tc superconductor are easily produced on metal coated substrates at a temperature below 700.degree. C. These metal buffer films are made of Pt, Au, Ag, Pd, Ni or Ti. The film superconductivity is significantly improved by the metal buffer layer. Since it is easy to form this metal coating on a substrate, the invention can increase the potential number of usable substrates such as fibers, amorphous solids or semiconductors.Type: GrantFiled: July 22, 1988Date of Patent: August 26, 1997Inventors: Shinichiro Hatta, Hidetaka Higashino, Kumiko Hirochi, Hideaki Adachi
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Patent number: 5644143Abstract: Various techniques for forming superconductive lines are described whereby superconductive lines can be formed by stamping, etching, polishing, or by rendering selected areas of a superconductive film (layer) non-superconductive. The superconductive material can be "perfected" (or optimized) after it is formed into lines (traces). In one embodiment, trenches are etched in a substrate, the trenches are filled with superconductive material, and any excess superconductive material overfilling the trenches is removed, such as by polishing. In another embodiment, superconductive lines are formed by rendering selected areas of a superconductive layer (i.e., areas other than the desired superconductive lines) non-superconductive by "damaging" the superconductive material by laser beam heating, or by ion implantation. Superconductive lines formed according to the invention can be used to protect semiconductor devices (e.g.Type: GrantFiled: May 30, 1995Date of Patent: July 1, 1997Assignee: LSI Logic CorporationInventors: Michael D. Rostoker, Mark Schneider, Nicholas F. Pasch, Abraham Yee, William C. Schneider
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Patent number: 5637555Abstract: A method for manufacturing a three-terminal superconducting device is disclosed. A superconducting channel constituted in an oxide superconductor thin film is deposited on a deposition surface of a substrate. A gate electrode for the device is formed through a gate insulator layer on the superconducting channel of the device. The steps of forming the gate electrode include forming a thin film that stands upright with respect to the insulator layer for the gate.Type: GrantFiled: August 23, 1995Date of Patent: June 10, 1997Assignee: Sumitomo Electric Industries, Ltd.Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama
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Patent number: 5635730Abstract: A superconducting oxide thin film device is composed of a LaAlO.sub.3 substrate and a YBCO thin film with a BaCeO.sub.3 buffer layer disposed between the two. The adhesion between the film and the substrate is increased by the presence of the buffer layer. The buffer layer also inhibits peeling of the film from the substrate and diffusion of Ba from the film into the substrate.Type: GrantFiled: June 6, 1995Date of Patent: June 3, 1997Assignee: Advanced Mobile Telecommunication Technology Inc.Inventor: Nobuyoshi Sakakibara
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Patent number: 5635453Abstract: A superconducting thin film system (10) is provided for high frequency microwave applications where a single crystal high temperature superconducting layer (18) is integrated with a garnet substrate (12). A first perovskite compound buffer layer (14) is epitaxially grown on an upper surface of the garnet substrate layer (12) and defines a lattice constant less than the lattice constant of the garnet substrate layer (12). A second perovskite layer (16) is epitaxially grown on an upper surface of the first perovskite layer (14) and defines a lattice constant less than the lattice constant of the first perovskite layer. A high temperature superconducting layer (18) is epitaxially grown on an upper surface of the second perovskite layer (16) and is lattice matched to the second perovskite compound layer (16) for incorporation of passive components within the high temperature superconducting layer (18) having high frequency microwave applications.Type: GrantFiled: December 23, 1994Date of Patent: June 3, 1997Assignee: Neocera, Inc.Inventors: Alberto Pique, Kolagani S. Harshavardhan, Thirumalai Venkatesan
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Patent number: 5629269Abstract: Disclosed is a process for forming a super-conducting film, which a multi-layer metal film (buffer film) is formed at a specific temperature on a ceramic substrate and a superconducting film is formed at a specific temperature on the multi-layer metal film. According to this process, a superconducting film having a high critical temperature can be formed over the ceramic substrate while controlling or suppressing the occurrence of a chemical reaction between the substrate and the superconducting film, and required superconducting performances can be manifested or exhibited.Type: GrantFiled: October 31, 1994Date of Patent: May 13, 1997Assignee: Fujitsu LimitedInventors: Kazunori Yamanaka, Takuya Uzumaki, Nobuo Kamehara, Koichi Niwa
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Patent number: 5604375Abstract: A superconducting active lumped component for microwave device application including a dielectric substrate, a first superconducting portion of an oxide superconductor provided on said dielectric substrate, an insulator layer formed on the first superconducting portion and a second conductive portion arranged on the insulator layer in which the conductivity of the first superconducting electrode and the dielectric property of the insulator layer can be changed by a dc bias voltage applied between the first and the second conductive portion so that capacitance and/or inductance and/or microwave resistance can be changed.Type: GrantFiled: February 28, 1994Date of Patent: February 18, 1997Assignees: Sumitomo Electric Industries, Ltd., University of MarylandInventors: Alp T. Findikoglu, Michitomo Iiyama
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Patent number: 5600172Abstract: A surface of a thin film superconductor element is coated with a layer containing pre-selected dye, or multiple dyes, alone or in combination with intermediate reflective coatings (best mode), which, when maintained near T.sub.c, upon exposure to a selected frequency of light acts as a narrow bandwidth absorber to change the resistive property of the underlying superconductor following energy transfer from the dye to the superconductor. The resistance change is electronically detectable to function as a wavelength selective high speed optoelectronic switch or sensor element.Type: GrantFiled: November 3, 1994Date of Patent: February 4, 1997Assignee: Electric Power Research InstituteInventors: John T. McDevitt, David C. Jurbergs
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Patent number: 5594257Abstract: A superconducting device comprises a substrate having a principal surface, a non-superconducting oxide layer having a similar crystal structure to that of an oxide superconductor formed on the principal surface, which can compensates the lattice mismatch between the substrate and the oxide superconductor, a superconducting source region and a superconducting drain region formed of c-axis oriented oxide superconductor thin films on the non-superconducting oxide layer, and an insulating region formed of a doped oxide superconductor on the non-superconducting oxide layer separating the superconducting source region and the superconducting drain region between them. On the insulating region an extremely thin superconducting channel formed of a c-axis oriented oxide superconductor thin film is arranged.Type: GrantFiled: June 24, 1993Date of Patent: January 14, 1997Assignee: Sumitomo Electric Industries, Ltd.Inventors: Takao Nakamura, Michitomo Iiyama
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Patent number: 5593951Abstract: An epitaxial structure comprising a silicon containing substrate and a high T.sub.c copper-oxide-based superconducting layer, which may include an intermediate layer between the silicon substrate and the superconductor layer. Epitaxial deposition is accomplished by depositing a superconductor on a (001) surface of silicon in a manner in which the unit cell of the superconductor layer has two out of three of its crystallographic axes rotated 45 degrees with respect to the corresponding axes of the silicon unit cell, the remaining axis of the superconductor unit cell being normal to the Si (001) surface.Type: GrantFiled: May 18, 1995Date of Patent: January 14, 1997Assignee: International Business Machines CorporationInventor: Franz J. Himpsel
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Patent number: 5571777Abstract: A superconducting thin film formed on a semiconductor substrate, which comprises at least one superconducting region formed of an oxide superconductor on the principal surface of the semiconductor substrate and at least one isolation region formed of an oxide insulator including component atoms of the oxide superconductor, which surrounds the superconducting region, and the superconductor thin film has a planar upper surface.Type: GrantFiled: June 7, 1995Date of Patent: November 5, 1996Assignee: Sumitomo Electric Industries, Ltd.Inventors: So Tanaka, Michitomo Iiyama
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Patent number: 5567674Abstract: A thin film of oxide superconductor consisting of more than two portions (1, 11, 12) each possessing a predetermined crystal orientation and deposited on a common surface of a substrate (2). At least one selected portion (10) of thin film of oxide superconductor is deposited on a thin under-layer (4, 100) which facilitates crystal growth of selected portions and which is deposited previously on the substrate. The selected portions (10) may consist of a-axis oriented thin film portions while non-selected portions (11, 12) may consists of c-axis oriented thin film portions. The thin under-layer can be a buffer layer (4) or a very thin film (100) of oxide superconductor.Type: GrantFiled: June 7, 1995Date of Patent: October 22, 1996Assignee: Sumitomo Electric Industries, Ltd.Inventors: Hiroshi Inada, Michitomo Iiyama
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Patent number: 5552373Abstract: A Josephson junction device is disclosed having a substrate upon which are located overlying and underlying high critical temperature crystalline oxide superconductive layers separated by an interposed impedance controlling layer. The underlying superconductive layer is limited to a selected area of the substrate while the overlying and interposed layers overlie only a portion of the underlying superconductive layer. Nonsuperconducting oxide layer portions laterally abut the superconductive and interposed layers. A first electrical conductor is attached to the underlying superconductive layer at a location free of overlying oxide layers, and a second electrical conductor contacts the overlying superconductive layer and extends laterally over the adjacent laterally abutting nonsuperconductive layer portion.Type: GrantFiled: April 10, 1992Date of Patent: September 3, 1996Assignee: Eastman Kodak CompanyInventors: John A. Agostinelli, Jose M. Mir, Gerrit Lubberts, Samuel Chen
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Patent number: 5545610Abstract: An oxide-based superconductor ccmprising Tl, Pb, Sr, Ca and Cu or Tl, Pb, Ba, Sr, Ca and Cu, prepared by subjecting a low melting point composition comprising the superconductor-constituting elements and a solid composition comprising the superconductor-constituting elements, prepared in advance, to reaction under melting conditions for the low melting point composition, has distinguished current pass characteristics in a high magnetic field due to improvement of electric contact among grains through reduction of non-superconductor phase, increase in crystal grain sizes (reduction of crystal boundaries), orientation of crystal and cleaning of crystal boundaries.Type: GrantFiled: September 2, 1993Date of Patent: August 13, 1996Assignee: Hitachi, Ltd.Inventors: Kazutoshi Higashiyama, Toshiya Doi, Takesi Ozawa, Seizi Takeuchi, Tomoichi Kamo, Shinpei Matsuda, Yutaka Yoshida
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Patent number: 5539215Abstract: A superconducting device comprising a substrate having a principal surface, a non-superconducting oxide layer having a similar crystal structure to that of the oxide superconductor, a first and a second superconducting regions formed of c-axis oriented oxide superconductor thin films on the non-superconducting oxide layer separated from each other and gently inclining to each other, a third superconducting region formed of an extremely thin c-axis oriented oxide superconductor thin film between the first and the second superconducting regions, which is continuous to the first and the second superconducting regions.Type: GrantFiled: December 29, 1994Date of Patent: July 23, 1996Assignee: Sumitomo Electric Industries, Ltd.Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama
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Patent number: 5528052Abstract: Proposed is a method for operating a field-effect device comprised of a superconducting current channel having source and drain electrodes connected thereto, said superconducting current channel being separated from a gate electrode by an insulating layer, where the resistance of said current channel is controlled by varying the critical current of the superconducting material through the application of an electrical field across the superconducting current channel, which in turn changes the density of the mobile charge carriers in the superconducting material. Taught is also an inverted MISFET device for performing that method, the device being characterized in that on an electrically conductive substrate an insulating layer is provided which in turn carries a layer consisting of a superconducting material, and that a gate electrode is attached to said substrate, and source and drain electrodes are electrically connected to said superconductor layer.Type: GrantFiled: December 22, 1993Date of Patent: June 18, 1996Assignee: International Business Machines CorporationInventors: Johannes G. Bednorz, Jochen D. Mannhart, Carl A. Mueller, Darrell G. Schlom
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Patent number: 5523284Abstract: In accordance this invention, there is provided a process for making a bulk superconductive material. In the first step of this process, a diffusion couple is formed from superconductor oxide and impurity oxide. Thereafter, the diffusion couple is heated to a temperature in excess of 800 degrees Centigrade, cooled at a controlled rate, and annealed.Type: GrantFiled: September 30, 1994Date of Patent: June 4, 1996Assignee: Alfred UniversityInventors: James G. Fagan, Jr., Vasantha R. W. Amarakoon
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Patent number: 5523282Abstract: A lanthanum aluminate (LaAlO.sub.3) substrate on which thin films of layered perovskite copper oxide superconductors are formed. Lanthanum aluminate, with a pseudo-cubic perovskite crystal structure, has a crystal structure and lattice constant that closely match the crystal structures and lattice constants of the layered perovskite superconductors. Therefore, it promotes epitaxial film growth of the superconductors, with the crystals being oriented in the proper direction for good superconductive electrical properties, such as a high critical current density. In addition, LaAlO.sub.3 has good high frequency properties, such as a low loss tangent and low dielectric constant at superconductive temperatures. Finally, lanthanum aluminate does not significantly interact with the superconductors. Lanthanum aluminate can also used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.Type: GrantFiled: August 18, 1988Date of Patent: June 4, 1996Assignee: TRW Inc.Inventors: Randy W. Simon, Christine E. Platt, Alfred E. Lee, Gregory S. Lee
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Patent number: 5504058Abstract: In a method of manufacturing a superconducting device which has a first thin film of oxide superconductor material formed on a substrate and a second thin film formed on the first thin film of oxide superconductor material, after the second thin film is deposited on the first thin film of oxide superconductor material, a multi-layer structure formed of the first and second thin films is patterned so that a side surface of the first thin film is exposed. In this condition, the whole of the substrate is heated in an O.sub.2 atmosphere or in an O.sub.3 atmosphere so that oxygen is entrapped into the first thin film of oxide superconductor material. Thereafter, the patterned multi-layer structure is preferably covered with a protection coating.Type: GrantFiled: April 20, 1994Date of Patent: April 2, 1996Assignee: Sumitomo Electric Industries, Ltd.Inventors: Sou Tanaka, Mitsuchika Saitoh, Michitomo Iiyama
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Patent number: 5498595Abstract: A method for activating superconducting material comprises generating a species of oxygen ions, heating the material and introducing the oxygen ions to said material by the application of a low-gradient drift field between the source of oxygen ions and a substrate including the superconducting material.Type: GrantFiled: August 16, 1994Date of Patent: March 12, 1996Assignee: British Technology Group LimitedInventor: William Eccleston
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Patent number: 5496798Abstract: A superconducting tube for shielding magnetic fields including a substrate having a tubular wall, a superconducting layer supported by the substrate, and at least two ring-shaped reinforcing members connected to the radially-outer surface of the tubular wall.Type: GrantFiled: January 18, 1995Date of Patent: March 5, 1996Assignee: NGK Insulators, Ltd.Inventors: Hitoshi Sakai, Hitoshi Yoshida
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Patent number: 5488030Abstract: There is disclosed a superconductor junction structure comprising: a first superconducting layer of an oxide superconductor formed in a desired pattern on a substrate; a non-superconducting layer of a non-superconductor formed on at least a part of the side faces of the first superconducting layer, a portion of the surface of the substrate near the part, and a top face of the first superconducting layer; and a second superconducting layer of the oxide superconductor formed on the non-superconducting layer, the non-superconducting layer being formed thin at the part, and forming a tunnel barrier.Type: GrantFiled: December 29, 1994Date of Patent: January 30, 1996Assignee: Sumitomo Electric Industries, Inc.Inventors: Saburo Tanaka, Takashi Matsuura, Hideo Itozaki
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Patent number: 5480861Abstract: A layered structure formed on a substrate comprising an oxide superconductor thin film deposited on the substrate, a noble metal monolayer deposited on the oxide superconductor thin film and an insulator thin film deposited on the noble metal monolayer. The noble metal monolayer prevents interdiffusion between the oxide superconductor thin film and the insulator thin film so that they have excellent properties.Type: GrantFiled: July 14, 1994Date of Patent: January 2, 1996Assignee: Sumitomo Electric Industries Ltd.Inventors: So Tanaka, Michitomo Iiyama
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Patent number: 5471069Abstract: A superconducting device includes a superconducting channel constituted in an oxide superconductor the film deposited on a deposition surface of a substrate. A source electrode and a drain electrode are formed on the oxide superconductor thin film at opposite ends of the superconducting channel, so that a superconducting current can flow through be superconducting channel between the superconductor source electrode and the superconductor drain electrode. A gate electrode is formed through a gate insulator layer on the superconducting channel so as to control the superconducting current flowing through the superconducting channel. The gate electrode is in the form of a thin film and stands upright with respect to the gate insulator layer.Type: GrantFiled: May 13, 1994Date of Patent: November 28, 1995Assignee: Sumitomo Electric Industries, Ltd.Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama
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Patent number: 5470668Abstract: A structure including a thin film of a conductive alkaline earth metal oxide selected from the group consisting of strontium ruthenium trioxide, calcium ruthenium trioxide, barium ruthenium trioxide, lanthanum-strontium cobalt oxide or mixed alkaline earth ruthenium trioxides thereof upon a thin film of a noble metal such as platinum is provided.Type: GrantFiled: March 31, 1994Date of Patent: November 28, 1995Assignee: The Regents of the University of Calif.Inventors: Xin D. Wu, Prabhat Tiwari
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Patent number: 5464812Abstract: A thin film of oxide superconductor consisting of more than two portions (10, 11, 12) each possessing a predetermined crystal orientation and deposited on a common surface of a substrate (2). At least one selected portion (10) of the thin film of oxide superconductor is deposited on a thin under-layer (4, 100) which facilitates crystal growth of the selected portion and which is deposited previously on the substrate. The selected portions (10) may consist of a-axis oriented thin film portions while non-selected portions (11, 12) may consists of c-axis oriented thin film portions. The thin under-layer can be a buffer layer (4) or a very thin film (100) of oxide superconductor.Type: GrantFiled: February 24, 1994Date of Patent: November 7, 1995Assignee: Sumitomo Electric Industries, Ltd.Inventors: Hiroshi Inada, Michitomo Iiyama
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Patent number: 5462918Abstract: A superconducting device has a stacked structure including a first superconducting layer, a first insulating layer, a second superconducting layer, a second insulating layer and a third superconducting layer stacked on a substrate in this given order. The stacked structure has an end surface portion extending from the first insulating layer to the second insulating layer. A fourth superconducting layer is formed to cover the end surface of the stacked structure. A third insulating layer separates the stacked structure end surface and the fourth superconducting layer. The fourth superconducting layer is electrically connected to the first and third superconducting layers but is isolated from the second superconducting layer by the third insulating layer. The first through fourth superconducting layers are formed of an oxide superconductor thin film.Type: GrantFiled: May 26, 1994Date of Patent: October 31, 1995Assignee: Sumitomo Electric Industries, Ltd.Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama
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Patent number: 5455223Abstract: In one aspect, the present invention is a precursor powder to an oxide superconductor, namely a coated particle comprising a metal oxide particle core (including a mixed metal oxide, e.g., BSCCO-2212 or YBCO-123) on which is deposited a secondary metal oxide coating (e.g., M.sub.n CuO.sub.x or CuO). The metal oxide particle and secondary metal oxide coating together comprise metallic elements having a stoichiometry appropriate for the formation of a desired oxide superconductor. The metal oxide reacts with the secondary metal oxide under suitable conditions (e.g., heating) to form the desired oxide superconductor (e.g., BSCCO-2223 or YBCO-124). In another aspect, the invention is a method for preparing such a coated particle, comprising: preparing a precursor solution comprising a metal .mu.Type: GrantFiled: February 24, 1993Date of Patent: October 3, 1995Assignee: American Superconductor CorporationInventors: Martin Rupich, Gilbert N. Riley, Jr., William L. Carter
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Patent number: 5447908Abstract: An outer surface of a superconducting thin film of compound oxide such as YBa.sub.2 Cu.sub.3 O.sub.7-.delta. deposited on a substrate such as MgO and SrTiO.sub.3 is protected with a protective layer which is composed of amorphous inorganic material such as inorganic glass, amorphous oxide.Type: GrantFiled: August 15, 1994Date of Patent: September 5, 1995Assignee: Sumitomo Electric Industries, Ltd.Inventors: Hideo Itozaki, Saburo Tanaka, Nobuhiko Fujita, Shuji Yazu, Tetsuji Jodai
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Patent number: 5447907Abstract: A superconducting device comprising a substrate having a principal surface, a superconducting source region and a superconducting drain region formed of an oxide superconductor on the principal surface of the substrate separated from each other, a superconducting channel formed of the oxide superconductor between the superconducting source region and the superconducting drain region. The superconducting channel electrically connects the superconducting source region to a superconducting drain region, so that a superconducting current can flow through the superconducting channel between the superconducting source region and the superconducting drain region. The superconducting device comprises a gate electrode through a gate insulator on the superconducting channel for controlling the superconducting current flowing through the superconducting channel, and non-superconducting oxide layers having a similar crystal structure to that of the oxide superconductor.Type: GrantFiled: December 10, 1992Date of Patent: September 5, 1995Assignee: Sumitomo Electric Industries, Ltd.Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama