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 invention continuously deposits materials used to grow a superconductor layer onto a moving tape. The invention preferably uses a pay-out reel and take-up reel to respectively dispense and spool the tape substrate at a constant rate. The invention preferably uses a series of stages to form the superconductor layer on the tape, and includes at least one reactor or reaction chamber to deposit one or more materials onto the tape substrate that is used to form the superconductor layer, and one or more chambers to deposit buffer layers between the superconductor and the metal tape substrate or between layers of superconductor, as well as for the deposition of coating layers. The invention also preferably uses transition chambers between the stages to isolate each stage from the other stages.

Abstract: A process is described for formation of oxide films independent of thickness from precursor films comprising metals, metal oxides, and metal fluorides with properties and structures similar to those previously only obtained in thin films, for example less than about 0.4 microns.

Abstract: An epitaxial article and method for forming the same includes a substrate having a textured surface, and an electrochemically deposited substantially single orientation epitaxial layer disposed on and in contact with the textured surface. The epitaxial article can include an electromagnetically active layer and an epitaxial buffer layer. The electromagnetically active layer and epitaxial buffer layer can also be deposited electrochemically.

Abstract: The method of preparing an oxide superconducting wire comprises steps of preparing a wire by coating raw material powder for a Bi—Pb—Sr—Ca—Cu—O based oxide superconductor including a 2223 phase with a metal and heat treating the wire in a pressurized atmosphere containing oxygen in a prescribed partial pressure, and the total pressure of the pressurized atmosphere is at least 0.5 MPa. The pressure heat treatment apparatus comprises a pressure furnace storing and heat treating a target in a pressurized atmosphere, a pressure regulator for measuring the total pressure in the pressure furnace, an oxygen concentration meter for measuring the oxygen concentration in the pressure furnace and a controller for controlling the oxygen partial pressure in the pressure furnace in response to the total pressure measured by the pressure regulator and the oxygen concentration measured by the oxygen concentration meter.

Abstract: A superconductor composite material consists of sintering products of interaction of superconductor ceramics with silicone material. The superconductor composite material can also include at least one metal, metal oxide or halogen element dope that interacts with superconductor ceramics and silicone residuals at sintering high temperature. The suspension or slurry of superconductor ceramics, silicone and dope powders can be used for coating of the particular substrate. Such coating employs modified forming methods including dip coating, painting, slip casting, cladding, printing, and spraying in order to produce continuous superconductor filament, wire, tape, coil, large size screen, and small chip or electronic element. The condensed suspension is used for extrusion, injection molding, and pressing continuous and short superconductor tubes, rods, beams, rails as well as disks, rings and other bulk shaped materials.

Abstract: A method for coating a device with superconducting material is disclosed. The method includes coating a thin pre-layer of superconducting material on the device, heat treating the thin pre-layer, coating a second layer on the heat-treated thin pre-layer and heat treating the second and thin pre-layers. The method prevents or substantially prevents bleeding of superconducting material into uncoated regions of the device. Another disclosed method involves the mechanical polishing of the device prior to coating with the superconducting material. Such a preliminary mechanical polishing reduces scratches and surface defects which, by way of capillary action, can contribute to the bleeding of the superconducting material from a coated region into an uncoated region of the device.

Abstract: A Mg-doped high-temperature superconductor having low superconducting anisotropy includes a two-dimensional layered structure constituted by a charge reservoir layer and a superconducting layer, wherein some or all atoms constituting the charge reservoir layer are Cu and O atoms, metallizing or rendering the charge reservoir layer superconducting, a portion of the Ca of the CunCan+1O2n constituting the superconducting layer is replaced by Mg, increasing superconductive coupling between CuO2 layers, a thickness of the superconducting layer is increased, and therefore coherence length in a thickness direction is increased based on the uncertainty principle, lowering superconducting anisotropy.

Abstract: The superconductor structure has a metallic, biaxially textured mount, an intermediate layer system deposited on the mount and including at least two intermediate layers composed of different oxidic materials and, on this, a high-Tc superconducting layer of the M2Cu3Ox type (RE=rare earth; M=alkaline-earth metal). The intermediate layer which faces the mount is composed of Y2O3, and the relatively thinner intermediate layer which faces the superconducting layer is composed of CeO2. The layers are preferably grown heteroepitaxially.

Abstract: A method of producing an oriented oxide superconducting film. A metal oxyfluoride film is provided on a substrate. The metal oxyfluoride film comprises the constituent metallic elements of an oxide superconductor in substantially stoichiometric proportions. The film is then converted into the oxide superconductor in a processing gas having a total pressure less than atmospheric pressure.

Abstract: An aqueous solution of mixed metal acetate including one kind or more of element selected from lanthanide series and yttrium, barium and copper is mixed with trifluoroacetic acid to prepare a solution of mixed metal trifluoroacetate. From a solution of mixed metal trifluoroacetate obtained thus, purified mixed metal trifluoroacetate of which total content of water and acetic acid is 2% by weight or less is prepared. With purified mixed metal trifluoroacetate, an oxide superconductor of excellent performance may be prepared.

Abstract: A superconducting article having a high bulk sheath resistivity, and methods of manufacture of such an article. High-temperature superconductor filaments are disposed in a ductile matrix comprising a high silver content. The matrix is then coated with a solute and heated to a temperature high enough to allow the solute to diffuse into the matrix, but not high enough to allow substantive degradation or poisoning of the superconductor. After diffusion and cooling, the matrix comprises a silver alloy having a higher bulk resistivity than the pure silver.

Abstract: An oxide superconducting wire includes oxide superconducting filaments 1, a matrix 2, a covering layer 3, and an insulating layer 4. The matrix 2 is placed so as to enclose the oxide superconducting filaments 1 and is made of silver. The covering layer 3 is placed so as to enclose the matrix 2, contains silver and manganese, and has a thickness of 10 &mgr;m to 50 &mgr;m. The insulating layer 4 is placed so as to enclose the covering layer 3.

Abstract: Manufacturing process of an electrically insulating and mechanically structuring sheath on an electric conductor.

Abstract: The invention relates to an article with an improved buffer layer architecture comprising a substrate having a metal surface, and an epitaxial buffer layer on the surface of the substrate. The epitaxial buffer layer comprises at least one of the group consisting of ZrO2, HfO2, and compounds having at least one of Ca and a rare earth element stabilizing cubic phases of ZrO2 and/or HfO2. The article can also include a superconducting layer deposited on the epitaxial buffer layer. The article can also include an epitaxial capping layer between the epitaxial buffer layer and the superconducting layer. A method for preparing an epitaxial article comprises providing a substrate with a metal surface, depositing on the metal surface an epitaxial buffer layer comprising at least one material selected from the group consisting of ZrO2, HfO2, and compounds having at least one of Ca and a rare earth element stabilizing cubic phases of at least one of ZrO2 and HfO2.

Abstract: An oxide superconductor wire is prepared by preparing a length of precursor wire for processing into an oxide superconductor wire and coating the precursor wire with an isolating layer. The coated wire is wound onto a reel in a spiralling manner, such that each turn of the spiral is in alignment with the preceding turn of the spiral along an axis perpendicular to the axis of winding. The wound precursor wire is then heated to form the oxide superconductor. The removable isolating layer is prepared by coating the wire with a solution including a metal oxide and a porosity-inducing component, and heating the coated wire so as to induce porosity and control grain size of the metal oxide so as to render the coating removable. The coating should function to isolate the overlapping turns of the wound wire from neighboring wires, so that not diffusion bonding or adherence between the turns occurs.

Abstract: A multi-domained bulk REBa2CU3Ox with low-angle domain boundaries which resemble a quasi-single domained material and a method for producing the same comprising arranging multiple seeds, which can be small single crystals, single domained melt-textured REBa2CU3Ox pieces, textured substrates comprises of grains with low misorientation angles, or thick film REBa2CU3Ox deposited on such textured substrate, such seeds being tailored for various REBa2CU3Ox compounds, in specific pattern and relative seed orientations on a superconductor precursor material which may be placed in contact with a porous substrate so as to reduce the amount of liquid phase in the melt. Because seeds can be arranged in virtually any pattern, high quality REBa2CU3Ox elements of virtually unlimited size and complex geometry can be fabricated.

Abstract: An automated system for dip coating a superconducting material on a substrate is disclosed. The system includes an actuator, a pick up station, a dip coating station that comprises a reservoir of a dip coating formulation, a drying station that includes a source of heated air and a conveyor for moving the actuator from the pick up station to the dip coating station and from the dip coating station to the drying station. The actuator includes an arm for carrying a substrate. The arm is capable of being moved vertically downward to submerse the substrate in the dip coating reservoir and the arm is also capable of being moved vertically upward to lift the substrate out of the dip coating reservoir. A method for automatically dip coating a substrate with a superconducting material is also disclosed.

Abstract: An alloy that contains at least two metals and can be used as a substrate for a superconductor is disclosed. The alloy can contain an oxide former. The alloy can have a biaxial or cube texture. The substrate can be used in a multilayer superconductor, which can further include one or more buffer layers disposed between the substrate and the superconductor material. The alloys can be made a by process that involves first rolling the alloy then annealing the alloy. A relatively large volume percentage of the alloy can be formed of grains having a biaxial or cube texture.

Abstract: An alloy capable of forming a (100) [001] cube-texture by thermo-mechanical techniques has 5 to 45 atomic percent nickel with the balance being copper. The alloy is useful as a conductive substrate for superconducting composites where the substrate is coated with a superconducting oxide. A buffer layer can optionally be coated on the substrate to enhance deposition of the superconducting oxide. Methods for producing the alloys, substrates, and superconductors are included.

Abstract: Superconducting composite materials having particles of superconducting material disposed in a metal matrix material with a high electron-boson coupling coefficient (&lgr;). The superconducting particles can comprise any type of superconductor including Laves phase materials, Chevrel phase materials, A15 compounds, and perovskite cuprate ceramics. The particles preferably have dimensions of about 10-500 nanometers. The particles preferably have dimensions larger than the superconducting coherence length of the superconducting material. The metal matrix material has a &lgr; greater than 0.2, preferably the &lgr; is much higher than 0.2. The metal matrix material is a good proximity superconductor due to its high &lgr;. When cooled, the superconductor particles cause the metal matrix material to become superconducting due to the proximity effect. In cases where the particles and the metal matrix material are chemically incompatible (i.e.

Abstract: According to one aspect of the invention a method is provided for forming a superconductor composite. A salt is heated to a melting temperature of the salt. Superconductor particles are added to the salt. A metal composition is added to the salt. The metal composition is decomposed into a metal substance and another substance. The metal substance plates out onto surfaces of the superconductor particles to form metal plated particles. The metal plated superconductor particles are removed from the salt.

Abstract: An SrTiO3 monocrystal substrate having a crystallographic plane (100) or (110) is anisotropically etched in an H3PO4 solution using an SiO2 thin film as an etching mask. The H3PO4 solution is maintained at a boiling point of approximately 150 deg. C. for increasing an etching rate and enhancing selectivity for protection with the SiO2 thin film mask.

Abstract: There is described a method of applying insulative coating on high temperature superconductors and low temperature superconductors from sol-gel solutions prepared from Zr, or Zr with one of Mg, Y, Ce, In and Sn based precursor materials. The solution is prepared with isopropanol as a solvent and acetyl acetone as a catalyst. The conductors are dipped into the solution and thereafter dried at a temperature effective to evaporate the solvent. Thereafter, heat treatment in the presence of oxygen is applied at a temperature sufficient to oxidize the precursors to result in a ceramic insulative coating on the conductor.

Abstract: Improved Hg-containing superconducting films and thermoelectric materials are provided. The films are fabricated by annealing starting Tl-containing films (e.g., Tl-1212 or Tl-2212) in an Hg-vapor environment so as to cause a substitution of Tl by Hg without substantial alteration of the crystalline structure of the starting films. Preferably, a body comprising a substrate having an epitaxial Tl-containing film thereon is annealed under vacuum conditions with a Hg-based bulk; typical annealing conditions are 600-900° C. for a period of from about 1-20 hours. The final Hg-containing film products have a Jc of at least about 106 A/cm2 (100 K, OT) and a Xmin of up to about 50%. The thermoelectric materials are prepared by perturbing a crystalline precursor having a structure similar to the final material so as to cause a first molecule to be released from the precursor.

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 simple and low-cost method for producing a thin film of ribbon-like oxide high-temperature (high-Tc) superconductor, which comprises placing a solid starting material for the oxide high-temperature superconductor on a substrate and heating it at a temperature in the vicinity of the melting point of the solid starting material under ambient pressure in an oxygen atmosphere.

Abstract: Highly oriented HgBa2Ca2Cu3O8+&dgr; on Ni-tapes with a buffer layer of Cr/Ag or Cr/(Ag—Pd) have been described with a high transition temperature are described along with, one and two step methods of manufacture.

Abstract: 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.

Abstract: To improve the chemical stability, as well as the critical current density (JC) of a superconductive material in an external magnetic field, copper-oxide coating materials have been developed. In some embodiments, these coating materials include a composition with the formula R1−xCaxBa2−yLayCu3−zMzO7−&dgr;, where R is a rare-earth element (e.g., La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or Y), M is a transition metal (e.g., Mn, Re, Fe, Os, Co, Rh, Ir, Ni, Pd, Pt, Ag, Au, Zn, Cd, or Hg), 0≦x≦0.4, 0≦y≦0.4, and 0≦z≦1.0.

Abstract: A method for joining high temperature superconducting components while minimizing critical current degradation is provided. The articles formed have critical currents that are at least 80 % of the critical current of the high temperature superconducting components. The invention further provides splicing geometries that facilitate wrapping joined components around a mandrel, tube or the like with minimal critical current degradation and without kinking or flexion of the joined components.

Abstract: A substrate for a superconducting microwave component is composed of a pair of oxide superconductor thin films formed on opposite surfaces of a dielectric substrate, respectively. After Tl-type oxide superconducting thin films are deposited the opposite surfaces of the dielectric substrate, respectively, am annealing is performed in a thallium atmosphere.

Abstract: A novel ceramic substrate useful for the preparation of superconductors, said substrate having the formula Ba.sub.2 DyMO.sub.5.5 where M represents at least one of the metals Zr, Sn and Hf and a process for the preparation of said ceramic substrate, which comprises (i) Reacting salts of dysprosium, barium and Zr, Sn or Hf in an organic medium, (ii) Pressing the resultant mixture in the form of pellets, (iii) Calcining the pellets by heating at a temperature in the range of 1000 to 1200.degree. C., (iv) Repeating the calcination process for 30-45 h at temperature in the range of 1000-1200.degree. C. until a highly homogenous mixture is formed. (v) Grinding the calcined material and pelletising at a pressure in the range of 3 to 4 tons/cm.sup.2, (vi) Sintering the resultant product at a temperature in the range of 1200 to 1600.degree. C. for a period of 10 to 30 h, and then furnace cooled to room temperature.

Abstract: 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.

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 high temperature superconductor composite material, which is suitable for production of filaments, wires, coils and other shaped products, has a ceramic powder of a material selected from the group consisting of, for example, YBa.sub.2 Cu.sub.3 O.sub.7-x and Bi.sub.2 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.10 ; a solution of a material selected from the group consisting of rubber silicone or lacquer silicone in a substance selected from the group consisting of toluene or acetone; and an ultra-fine silver powder dope, and is produced by using an emulsion mixture of the three major components with ultrasonic homogenization of the mixture, primer cladding of a glue-exterior layer on a silver core filament, high temperature superconductor coating of the silver core by chemical adhesion, and polymerization of the coating applied by low temperature heating, whereafter the composition is treated by magnetic treatment, gamma irradiation, and microwave supported fast heating.

Abstract: A composite superconducting material made of coated particles of ceramic superconducting material and a metal matrix material. The metal matrix material fills the regions between the coated particles. The coating material is a material that is chemically nonreactive with the ceramic. Preferably, it is silver. The coating serves to chemically insulate the ceramic from the metal matrix material. The metal matrix material is a metal that is susceptible to the superconducting proximity effect. Preferably, it is a NbTi alloy. The metal matrix material is induced to become superconducting by the superconducting proximity effect when the temperature of the material goes below the critical temperature of the ceramic. The material has the improved mechanical properties of the metal matrix material. Preferably, the material consists of approximately 10% NbTi, 90% coated ceramic particles (by volume). Certain aspects of the material and method will depend upon the particular ceramic superconductor employed.

Abstract: 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.

Abstract: A bulk high temperature superconductor single crystal having the formula MBa.sub.2 Cu.sub.3 O.sub.7-x wherein M is selected from the group consisting of Y, Sm, Eu, Gd, Dy, Ho, Er, and Yb; and, x has a number value from about 0.1 to about 1.0; are produced by a novel process incorporating: i) starting powders produced by combustion spray pyrolysis, ii) a novel setter powder, and/or iii) a monitored isothermal growth process.

Abstract: 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.

Abstract: Raw material powder for a bismuth oxide superconductor is molded with addition of an organic vehicle, and the molded raw material is heat treated for removing the organic vehicle before the molded raw material is metal-coated. In this heat treatment, conditions not more than those expressed as T=-1.5.times.logH+600 are applied as to relation between temperature (T) and time (H). Thus, phase transformation of 2212 phases mainly composing the raw material is suppressed so that a large amount of 2223 phases having a relatively high critical temperature are formed when heat treatment is performed after metal coating.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In accordance with the invention, a high density z-direction interconnection medium is made by the steps of providing a non-conductive membrane having z-direction channels, filling the channels with liquid precursor of conductive material, converting the trapped precursor into conductive material within the channels, and, advantageously, forming solder bumps in contact with the conductive material in the channels. The method is particularly useful for forming hollow tubular or porous conductive pathways having enhanced resistance to thermal and mechanical stress.

Abstract: A high-temperature YBa.sub.2 Cu.sub.3 O.sub.x superconducting sintered body is produced through wet grain-coating process in which starting grains are soaked in SnI.sub.4 solution, pressed after the removal of solvent and then sintered at a given temperature, and has a critical current density of at least 500 A/cm.sup.2 at 77 K.

Abstract: A method is disclosed for fabricating a polycrystalline <223> thallium-containing superconductor having high critical current at elevated temperatures and in the presence of a magnetic field. A powder precursor containing compounds other than thallium is compressed on a substrate. Thallium is incorporated in the densified powder precursor at a high temperature in the presence of a partial pressure of a thallium-containing vapor.

Abstract: A superconductive device for helping shield magnetic field comprises at least two members; a layer containing superconductive oxide over each of said members; means for connecting said members to form a substrate; and means for connecting said layers containing superconductive oxide along a joint in which said members are connected.

Abstract: A multilayered structure comprising copper oxide perovskite material having altered superconductive properties is provided by epitaxially depositing on a substrate a layer of a first copper oxide material and then epitaxially depositing on the first layer a layer of a second, different copper oxide perovskite material. Further alternate epitaxially layers of the two copper oxide perovskite materials are then deposited one on the other. The first and second copper oxide perovskite materials in unstressed bulk states have nondistorted crystallographic lattice structures with unit cell dimensions that differ in at least one dimension. In the epitaxial layers, the crystallographic lattice structures of the two copper oxide materials are distorted relative to their nondistorted crystallographic lattice structures.

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 be used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.