Abstract: An article including a substrate, a layer of an inert oxide material upon the surface of the substrate, (generally the inert oxide material layer has a smooth surface, i.e., a RMS roughness of less than about 2 nm), a layer of an amorphous oxide or oxynitride material upon the inert oxide material layer, a layer of an oriented cubic oxide material having a rock-salt-like structure upon the amorphous oxide material layer is provided together with additional layers such as at least one layer of a buffer material upon the oriented cubic oxide material layer or a HTS top-layer of YBCO directly upon the oriented cubic oxide material layer. With a HTS top-layer of YBCO upon at least one layer of a buffer material in such an article, Jc's of 1.4×106 A/cm2 have been demonstrated with projected Ic's of 210 Amperes across a sample 1 cm wide.

Abstract: A multi-layer passivation barrier (24) for, and a method of, passivating a superconducting layer (22) of a microelectronic device (20). The passivation barrier includes a passivating layer (32) and a barrier buffering layer (30). The passivating layer provides a barrier to moisture, salts, alkali metals and the like located outside the device. The passivating layer also provides a barrier to outdiffusion of oxygen from the superconducting layer. The buffering layer permits oxygen to diffuse therethrough and provides a barrier to prevent diffusion of one or more constituent chemical elements of the passivating layer into the superconducting layer. The method includes the steps of depositing the barrier buffering layer (30) onto the superconducting layer (22) and depositing the passivating layer (32) onto the buffering layer.

Abstract: The present invention provides an oxide superconducting wire including a component provided in the form of a tape and a metal tape. The component in the form of a tape has an oxide superconducting member and a metal coating member formed mainly of silver and coating a surface of the oxide superconducting member. The metal tape, bonded in a heat treatment (e.g., fusion- or diffusion-bonded) to a surface of the component in the form of a tape, does not contain any superconducting material and it is formed mainly of silver and it also contains at least one component other than silver.

Abstract: An oxide superconductor article is provided having an oxide superconductor film having a thickness of greater than 0.5 microns disposed on a substrate, said article having a transport critical current density (Jc) of greater than or equal to about 105 A/cm2 at 77K, zero field. The oxide superconductor film is characterized by high Jc and high volume percent of c-axis epitaxial oxide grains, even with thicknesses of up to 1 micron.

Abstract: A superconducting substrate structure with a high temperature superconducting (HTS) ground plane, for epitaxial growth of multilayers thereon is provided. The substrate structure includes a composite substrate structure with a first and a second substrate layer each covered by an HTS film, which HTS films are bonded together through annealing to form a buried superconducting layer wherein one of the substrate layers is polished to form a smooth insulating layer adjacent to an HTS layer. A method of producing a superconducting substrate structure is provided including the steps of arranging two substrate layers on which HTS films are provided such that the HTS films come in close contact to one another, applying a high pressure in an oxygen atmosphere and at an elevated temperature such that the HTS films are annealed and bonded together, and subsequently polishing one of the substrate layers to form a smooth insulator.

Abstract: The present invention concerns the improvement of the supercurrent carrying capabilities, i.e. the increase of critical current densities, of bicrystalline or polycrystalline superconductor structures, especially of high-Tc superconductors. By providing an appropriate predetermined dopant profile across the superconductor structure, in particular within or in the vicinity of the grain boundaries, the space-charge layers at the grain boundaries are reduced and thereby the current transport properties of the superconductor significantly improved. Simultaneously, the influence of magnetic fields on the critical current densities is significantly reduced, which in turn enhances the overall supercurrent carrying capabilities while keeping the supercurrent transport properties of the grains at good values.

Abstract: The present invention relates to an oxide superconducting wire. The wire has a filament made essentially of an oxide superconductor, and a stabilizing metal covering the oxide superconductor. The stabilizing metal includes a silver alloy having at least either higher mechanical strength or higher specific electrical resistance than that of silver. In one embodiment, the stabilizing metal further includes a first portion directly covering the oxide superconductor and a second portion covering the first portion. The first portion is adapted to prevent the component of the second portion from diffusing into and reacting with the oxide superconductor. The first and second portions have different materials, and the first portion is made essentially of an Ag—Sb alloy. In another embodiment, the stabilizing metal further has a first portion directly covering the oxide superconductor, a second portion covering the first portion and a third portion covering the second portion.

Abstract: An epitaxial compound structure has a crystal structure including fluorite crystal on which is epitaxially grown a film of simple perovskite crystal with a (011) orientation.

Abstract: A multifilamentary superconductor composite having a high fill factor is formed from a plurality of stacked monofilament precursor elements, each of which includes a low density superconductor precursor monofilament. The precursor elements all have substantially the same dimensions and characteristics, and are stacked in a rectilinear configuration and consolidated to provide a multifilamentary precursor composite. The composite is thereafter thermomechanically processed to provide a superconductor composite in which each monofilament is less than about 50 microns thick.

Abstract: The invention features a superconducting conductor for use in a preselected fluid cryogen including a composite ceramic superconducting wire having an outer surface along its length; and a sealing structure hermetically surrounding the outer surface to prevent the cryogen from infiltrating into the wire and degrading its superconducting properties, even under pressurized conditions. The superconducting conductor can be used in superconducting cabling and coil applications. The sealing structure can be formed by laminating metallic tapes to the wire, encircling at least one metallic sheet around the outer surface of the wire, welding a plurality of metallic sheets to one another to encircle the outer surface of the wire, or forming a polymer coating completely covering the outer surface of the wire.

Abstract: Ceramic high-temperature superconductors (1) which are intended to be used as current limiters in alternating-current lines should have a bypass layer (2) whose electrical resistivity is increased by more than 10 times with respect to that of a pure noble-metal bypass layer. In order to achieve this, the noble-metal bypass layer (2) of the high-temperature superconductor (1), preferably of silver, is alloyed with a base metal, preferably Pb or Bi or Ga, by a thermal treatment. The ratio of the bypass layer thickness (d2) of the noble-metal bypass layer (2) to the superconductor layer thickness (d1) is adjusted to <1/5. A base-metal bypass layer (3) of steel whose electrical resistivity is in the range between 10 &mgr;&OHgr;×cm and 100 &mgr;&OHgr;×cm at 77 K is soldered on or applied under isostatic pressure over the noble-metal-containing bypass layer (2).

Abstract: A connection structure for superconducting conductors which can simply connect superconducting conductors with each other with small connection resistance and no sophisticated technology is provided. In a connection structure for multifilamentary superconducting conductors, superconducting wires forming the superconducting conductors respectively are joined with each other through solder.

Abstract: A superconductor structure is disclosed, comprising a composite body made of an electrically insulating substrate to which an intermediate layer is bonded, a buffer layer is deposited on the intermediate layer and a layer of a metal-oxide high Tc superconductor material is deposited on the buffer layer. The intermediate layer comprises a glass material with a coefficient of thermal expansion greater than 6×10−6 K−1. To produce the structure, at least one deposition process is selected in which the maximum temperature is at most 150 K higher than the transformation temperature of the glass material.

Abstract: A superconducting wire having a stacked structure comprising (a) a substrate composed of an electrically conductive material, (b) an oxide superconductor material, and (c) an electrically conductive material which is substantially not reactive with said oxide superconductor material (b), wherein said electrically conductive material (c) is impregnated in said oxide superconductor material (b) by way of heat fusion such that gaps among crystal grains contained in said oxide superconductor material (b) are filled with said electrically conductive material (c). And a process for the production of said superconducting wire.

Abstract: Improvements in critical current capacity for superconducting film structures are disclosed and include the use of, e.g., multilayer YBCO structures where individual YBCO layers are separated by a layer of an insulating material such as CeO2 and the like, a layer of a conducting material such as strontium ruthenium oxide and the like or by a second superconducting material such as SmBCO and the like.

Abstract: A buffer layer structure based on doped ceria for providing optimized lattice match with a YBCO layer in a conductor, a lattice matching layer for use in said structure and process of manufacturing thereof. Said buffer layer comprises a CeO2 layer doped with a dopant, and has a superconductive layer of YBCO on said CeO2 layer. The invention is characterized in that the CeO2 layer is a lattice matching layer.

Abstract: A multifilamentary superconductor composite having a high fill factor is formed from a plurality of stacked monofilament precursor elements, each of which includes a low density superconductor precursor monofilament. The precursor elements all have substantially the same dimensions and characteristics, and are stacked in a rectilinear configuration and consolidated to provide a multifilamentary precursor composite. The composite is thereafter thermomechanically processed to provide a superconductor composite in which each monofilament is less than about 50 microns thick.

Abstract: This invention provides a radiation curable coating composition for superconducting wires. The coating composition comprises at least one (meth)acrylate terminated urethane oligomer, at least one adhesion promoter, at least one (meth)acrylate functionalized diluent and at least one free radical photoinitiator.

Abstract: An oxide superconductive wire having practically sufficient tensile strength and superconductive properties is claimed. A first aspect of the present invention includes a first metallic layer made of a silver based alloy containing a metal selected from the group consisting of copper, antimony, tin, germanium, gallium, indium, zinc, platinum and palladium; a second metallic layer having a tensile strength higher than that of silver and fixed to the first metallic layer; and an oxide superconductor layer formed on the first metallic layer. Another aspect of the present invention provides an oxide superconductive wire having first and a second layers and an oxide superconductive wire. The first metallic layer is made of silver and oriented along crystallographic (210) plane. The second metallic layer has a tensile strength higher than that of silver and is fixed to the first metallic layer. The present invention also provides a superconductive device using each of the oxide superconductive wires.

Abstract: A powder in tube type method of making an HTc superconductive multifilament strand having a silver-based matrix, and an HTc superconductive multifilament strand having a silver-based matrix. The method includes, prior to the monofilament step, preparing a composite multilayer material is including at least one silver-based sheet, and at least one layer of non-superconductive ceramic material that is permeable to oxygen. During the monofilament step, a thickness of composite multilayer material is interposed between first and second thicknesses of silver-based material, thereby forming the first silver-based envelope.

Abstract: A lanthanum aluminate (LaAlO3) 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, LaAlO3 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 be used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.

Abstract: A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy perform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100}<100> orientation texture; and further having a Curie temperature less than that of pure Ni.

Abstract: A lanthanum aluminate (LaAlO3) 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, LaAlO3 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.

Abstract: A laminate article comprises a substrate and a biaxially textured (RExA(1−x))2O2−(x/2) buffer layer over the substrate, wherein 0<x≦0.70 and RE is selected from the group consisting of La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. A is selected from the group consisting of Zr+4, Ce+4, Sn+4, and Hf+4. The (RExA(1−x))2O2−(x/2) buffer layer can be deposited using sol-gel or metal-organic decomposition. The laminate article can include a layer of YBCO over the (RExA(1−x))2O2−(x/2) buffer layer. A layer of CeO2 between the YBCO layer and the (RExA(1−x))2O2−(x/2) buffer layer can also be include. Further included can be a layer of YSZ between the CeO2 layer and the (RExA(1−x))2O2−(x/2) buffer layer. The substrate can be a biaxially textured metal, such as nickel. A method of forming the laminate article is also disclosed.

Abstract: A high temperature oxide superconductor is efficiently protected from the affects of water and acids by forming a passivation layer of a fluoride. The fluoride layer comprises a fluoride composed of one or more elements composing the oxide superconductor and/or one or more elements that can compose an oxide superconductor by replacing at least in part one or more elements composing the oxide superconductor.

Abstract: A superconducting ceramic includes a laminate and a superconducting ceramic tape joined to the laminate. The laminate and superconductor tape are joined such that the tape is under a compressive stress. The compressive stress is of a greater amount than compressive stress which results from differences in thermal expansion of the tape and the laminate. The greater compressive stress can be achieved by putting the laminate under a greater tension than the superconducting ceramic tape during joining of the superconducting ceramic tape to the laminate.

Abstract: 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.

Abstract: A method of preparing a biaxially textured article comprises the steps of providing a metal preform, coating or laminating the preform with a metal layer, deforming the layer to a sufficient degree, and rapidly recrystallizing the layer to produce a biaxial texture. A superconducting epitaxial layer may then be deposited on the biaxial texture. In some embodiments the article further comprises buffer layers, electromagnetic devices or electro-optical devices.

Abstract: 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.

Abstract: A high performance superconducting ceramic article for use in a liquid cryogen bath is provided. It includes a superconducting ceramic tape having at least one surface vulnerable to cryogenic infiltration is sealed on each vulnerable surface to a non-porous metallic laminate, which also provides the desired support structure, in substantially impervious relation by a non-porous metallic bonding agent. This results in greater protection of the superconducting ceramic tape from cryogen infiltration, and permits greater thermal cycling of the superconductor during use without causing degradation of the tape's critical current carrying capacity.

Abstract: A superconductor-normal conductor junction device comprises first and second regions (1, 3) of normal material forming first and second junctions with a superconducting material (2), the Fermi level of the first region of normal material being so arranged relative to a given energy level in the superconducting material that charge carriers in the first normal material undergo Andreev reflection at the first junction, resulting in pairs of the charge carriers entering said given energy level in the superconducting material, and the Fermi level of the second region of normal material being so arranged relative to said given level in the superconducting material that said charge carriers conduct from the superconducting material through the second region.

Abstract: A process for forming a laminate of 123-type copper oxide superconductor thin films having dissimilar crystal axis orientations, a laminate of 123-type thin copper oxide superconductor layers exhibiting excellent superconducting property, and wiring for Josephson junction. A c-axis oriented single crystalline thin film of an oxide superconductor having a Y:Ba:Cu atomic ratio of substantially 1:2:3 and a lattice constant of 11.60 angstroms.ltoreq.c.ltoreq.11.70 angstroms at a temperature of 20.degree. C. under an oxygen partial pressure of 160 Torr is formed on a single crystalline substrate, and an a-axis oriented single crystalline thin film of said oxide superconductor is formed on the above laminated film relying upon a sputter deposition method.

Abstract: A superconducting garnet thin film system (10) is provided for high frequency microwave applications where a single crystal high temperature superconducting (HTSC) 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) with the first perovskite layer being aligned in a cube on cube parallel orientation with respect to the garnet substrate layer (12). A second perovskite layer (16) is epitaxially grown on an upper surface of the first perovskite layer (14) at an orientation of 45.degree. to first layer (14) and defines a lattice constant less than the lattice constant of the first perovskite layer.

Abstract: A thin film structure including a lanthanum aluminum oxide substrate, a thin layer of homoepitaxial lanthanum aluminum oxide thereon, and a layer of a nonlinear dielectric material thereon the thin layer of homoepitaxial lanthanum aluminum oxide is provided together with microwave and electro-optical devices including such a thin film structure.

Abstract: 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.

Abstract: A superconductive composite member comprises a core of oxide ceramic superconducting material that is disposed in a metal envelope comprising a silver alloy which is hardenable by an oxide dispersion. Preferably, the silver alloy is an alloy of Ag--Mg--Ni, Ag--Mn--Ni or Ag--Al alloy which may also include one or more precious metal elements selected from a group consisting of Ru, Rh, Pd, Os, Ir, Pd and Au. The composite member is formed by introducing the superconductive material into the silver alloy envelope, cross section-reducing the assembly of the envelope and core and, subsequently, thermal treatment for the recovery and setting of the oxygen concentration.

Abstract: A FET type superconducting device comprises a substrate having a principal surface, a thin superconducting channel formed of an oxide superconductor layer over the principal surface of the substrate, a superconducting source region and a superconducting drain region formed of an oxide superconductor layer over the principal surface of the substrate at the both ends of the superconducting channel which connects the superconducting source region and the superconducting drain region, so that superconducting current can flow through the superconducting channel between the superconducting source region and the superconducting drain region 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, wherein the superconducting device is isolated by a isolation layer directly formed on the principal surface of the substrate, the superconducting layer of the su

Abstract: A method for the production of a superconducting oxide tape having a Bi.sub.2 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.10 (Bi-2223) structure interposed between silver sheets, which method consists essentially of preparing a sandwich structure having interposed between silver sheets a molded layer of a superconducting oxide precursor powder consisting essentially of Bi, Pb, Sr, Ca, Cu, and O obtained from a raw material substance composed of, in atomic composition ratio, 1.00 of Bi, 0-0.2 of Pb, 0.9-1.1 of Sr, 0.9-1.1 of Ca and 1.3-1.7 of Cu, and O, heating the sandwich structure in an atmosphere consisting of oxygen and an inert gas, having an oxygen partial pressure in the range of 0-5%, and kept at a temperature in the range of 830-850.degree. C., thereby melting the molded layer, then causing the atmosphere to retain the heating temperature and meanwhile increasing the oxygen partial pressure, thereby inducing precipitation of crystal grains possessing a Bi.sub.2 Sr.sub.2 CaCu.sub.2 O.sub.

Abstract: 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.

Abstract: A composite high Tc superconductor film is applied to a substrate, said film as applied having a thickness of at least 5000 Angstrom and an outer surface having an average roughness not exceeding 250 Angstrom.

Abstract: A method and apparatus for temperature activated protection of electronic components from interfering electromagnetic radiation comprising the step of shielding of a component with a thin film of superconducting material characterized by a critical temperature of at least 93.degree.K, and exposing the film to a temperature below the critical temperature. To allow transmissions to and from the component, the shield is converted to a window by heating the film to a temperature above the critical temperature.

Abstract: A superconducting ceramic includes a laminate and a superconducting ceramic tape joined to the laminate. The laminate and superconductor tape are joined such that the tape is under a compressive stress. The compressive stress is of a greater amount than the compressive stress which results from differences in thermal expansion of the tape and the laminate. The greater compressive stress can be achieved by putting the laminate under a greater tension than the superconducting ceramic tape during joining of the superconducting ceramic tape to the laminate.

Abstract: A superconducting article includes a biaxially-textured Ni substrate, and epitaxial buffer layers of Pd (optional), CeO.sub.2 and YSZ, and a top layer of in-plane aligned, c-axis oriented YBCO having a critical current density (J.sub.c) in the range of at least 100,000 A/cm.sup.2 at 77 K.

Abstract: A biaxially textured alloy article includes a rolled and annealed biaxially textured base metal substrate characterized by an x-ray diffraction phi scan peak of no more than 20.degree. FWHM; and a biaxially textured layer of an alloy or another material on a surface thereof. The article further includes at least one of an electromagnetic device or an electro-optical device epitaxially joined to the alloy.

Abstract: A starting material which is converted to a continuous body of an oxide superconductor by a heat treatment is filled in a tubular Ag sheath member. The diameter of the filled member is reduced by extrusion to form a wire. The wire is subjected to a heat treatment so that the starting material inside the sheath member is converted to a continuous body of an oxide superconductor. A superconducting wire constituted by the sheath member and the oxide superconductor filled inside the sheath member is obtained. A superconducting coil can be obtained by winding the superconducting wire.

Abstract: A method of fabricating a low-inductance, in-line resistor includes the steps of: depositing a superconductive layer 12 on a base layer 14; patterning an interconnect region 16 on the superconductive layer 12; and converting the interconnect region 16 of the superconductive layer 12 to a resistor material region 18. The resistor region 18 and the superconductive layer 12 are substantially in the same plane. The method can further include the steps of depositing a conductive layer 22 on the resistor region 18 and on the photo-resist layer 20, and lifting off the photo-resist layer 20 to leave the conductive layer 22 on the resistor region 18. As such, the conductive layer 22 provides a low sheet resistivity for the resistor region 18.

Abstract: A semiconductor substrate comprising a single crystal substrate base such a silicon and a superconducting thin film layer deposited on said substrate base and composed of compound oxide such as Ln.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-.delta.. (Ln is lanthanide).

Abstract: A superconducting oxide composite structure including a superconducting oxide member, a metal layer surrounding the superconducting oxide member, and an insulating layer of a complex oxide formed in situ adjacent to the superconducting oxide member and the metal layer is provided together with a method of forming such a superconducting oxide composite structure including encapsulating a superconducting oxide member or precursor within a metal matrix layer from the group of: (i) a reactive metal sheath adjacent to the superconducting oxide member or precursor, the reactive metal sheath surrounded by a second metal layer or (ii) an alloy containing a reactive metal; to form an intermediate product, and, heating the intermediate product at temperatures and for time sufficient to form an insulating layer of a complex oxide in situ, the insulating layer to the superconducting oxide member or precursor and the metal matrix layer.

Abstract: 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.

Abstract: 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.