Abstract: Provided is a method of manufacturing a superconducting accelerator cavity in which a plurality of half cells having opening portions (equator portions and iris portions) at both ends thereof in an axial direction are placed one after another in the axial direction, contact portions where the corresponding opening portions come into contact with each other are joined by welding, and thus, a superconducting accelerator cavity is manufactured, the half cells to be joined are arranged so that the axial direction thereof extends in a vertical direction; and concave portions that are concave towards an outer side are also formed at inner circumferential surfaces located below the contact portions of the half cells positioned at a bottom; and the contact portions are joined from outside by penetration welding.

Abstract: A superconducting accelerating cavity production method with which a high-quality superconducting accelerating cavity can be produced with a compact device configuration and at low cost. The method of producing a superconducting accelerating cavity (1) includes arranging, in an axial direction (L), a plurality of half-cells (5) having openings at both ends in the axial direction and joining the openings to one another by welding. The half-cells (5) are joined by welding with a laser beam from the inside of the superconducting accelerating cavity (1) in which a vacuum atmosphere is created.

Abstract: A method of producing a superconductive material involves the step (1) of applying a solution of an organic compound of metals, oxides of the metals forming a superconductive material, onto a support body to be subsequently dried, a provisional baking step (2) of causing organic components of the organic compound of the metals to undergo thermal decomposition, and a main baking process step (3) of causing transformation of the oxides of the metals into the superconductive material, thereby producing an epitaxially-grown superconductive coating material, wherein at the time of irradiation of a surface of the support body coated with the solution of the organic compound of the metals for forming the superconductive material, and/or of a surface of the support body, opposite to the surface coated with the solution of the organic compound of the metals, with the laser light, during a period between the steps (1) and (2).

Abstract: A method of joining superconductor materials is described. A microwave chamber including a first heat absorption plate and a second heat absorption plate corresponding to the first absorption plate is provided. A first superconductor material and a second superconductor material are disposed between the first heat absorption plate and the second heat absorption plate in the microwave chamber. The first superconductor material and the second superconductor material have an overlapping region therebetween, and a pressure is applied to the first heat absorption plate and the second heat absorption plate. Microwave power is supplied to the microwave chamber. The first heat absorption plate and the second heat absorption plate transform the microwave power into thermal energy so as to join the first superconductor material and the second superconductor material at the overlapping region.

Abstract: A method of forming an underlying layer of an alignment film for an oxide superconducting conductor, includes arranging two or more kinds of targets along a lengthwise direction of a base material so as to face a surface of the base material; simultaneously irradiating an ion beam on surfaces of the two or more kinds of targets to deposit constituent particles of the targets on the surface of the base material in the order of the arrangement of the two or more kinds of targets; and forming a laminate in which two or more kinds of thin films are repeatedly laminated on the surface of the base material by passing the base material through a deposition region of the constituent particles a plurality of times so that the constituent particles of the targets are repeatedly deposited on the surface of the base material at each passage.

Abstract: Method for joining wires using low resistivity joints is provided. More specifically, methods of joining one or more wires having superconductive filaments, such as magnesium diboride filaments, are provided. The wires are joined by a low resistivity joint to form wires of a desired length for applications, such in medical imaging applications.

Abstract: An ion source impinging on the surface of the substrate to be coated is used to enhance a MOCVD, PVD or other process for the preparation of superconducting materials.

Abstract: The present invention provides a superconducting accelerating cavity production method with which a high-quality superconducting accelerating cavity can be produced with a compact device configuration and at low cost. In a method of producing a superconducting accelerating cavity (1), in which the superconducting accelerating cavity (1) is produced by arranging, in an axial direction (L), a plurality of half-cells (5) having openings at both ends in the axial direction and joining the openings to one another by welding, the half-cells (5) are joined by welding with a laser beam from the inside of the superconducting accelerating cavity (1) in which a vacuum atmosphere is created.

Abstract: Niobium or its alloy based Superconducting Radio Frequency (SCRF) Cavities involving atleast one laser beam welded components in the SCRF cavity welded from inside surface of the wall of cavity directed to achieving more than half the thickness to full depth penetration with minimum HAZ, minimizing distortion and shrinkage. The method ensures improved weld quality and surface finish substantially free of any weld defects. Also disclosed is the welding nozzle system and welding rigs adapted to facilitate such laser welding of the Niobium or its alloy based Superconducting Radio Frequency (SCRF) Cavities. The invention is thus directed to enhancing productivity, ensuring consistent quality and reliability, enhanced weld penetration with minimum HAZ, smooth finish of weld joints at possible reduced costs.

Abstract: Nanometer-sized non-superconducting particulates in superconductive REBCO films, where RE is a rare earth metal, for flux pinning enhancement and a method of forming are disclosed. A target with a second phase material sector portion and a superconductive material portion is used in a pulse laser deposition process to form films on substrates according to the present invention. The films consist of 10-20 nm-sized precipitates. In a 0.5 ?m thick film, a transport critical current density (Jc)>3 MA/cm2 at 77K in self-field was measured. In one embodiment, magnetization Jc at 77 K and 65K showed significant improvements in a composite YBCO films with fine precipitates produced according to the present invention as compared to non-doped (standard) YBCO films (>10 times increase at 9 T, 65 K).

Abstract: A method for production of hollow bodies, in particular for radio-frequency resonators is shown and described. The object to provide a hollow bodies and a resonator, respectively, having improved electrical properties is achieved by a method comprising the following steps: Providing a substrate having a monocrystalline region, defining a cut area through the substrate, fitting markings on both sides of the cut area, producing two wafers by cutting along the cut area, wherein the wafers are completely removed from the monocrystalline region, forming the wafers into half-cells, wherein the half-cells have a joining area, joining together the half-cells to form a hollow body, wherein the joining areas bear on one another, and wherein the markings on the half-cells are oriented with respect to one another on both sides of the joining area as on both sides of the cut areas.

Abstract: A method of continuously coating at least one substrate with a buffer layer as a support for a ceramic superconducting material is disclosed. The method includes loading the at least one substrate onto a respective feed spool and feeding the at least one substrate through a vacuum deposition chamber. The method further includes coating the at least one substrate while the at least one substrate is bombarded by ion beams from dual RF-ion sources forming at least one coated substrate, and reloading the at least one coated substrate onto a respective take up spool.

Abstract: Laminated, biaxially textured superconductors include Ir-based buffer layers and/or substrates.

Abstract: A method of forming a superconductive device is provided, including providing a substrate having a dimension ratio of not less than about 102, depositing a buffer film to overlie the substrate by ion beam assisted deposition utilizing and ion beam, monitoring spatial ion beam density of the ion beam over a target area, and depositing a superconductor layer to overlie the buffer film. Monitoring may be carried out by utilizing an ion detector having an acceptance angle of not less than 10°.

Abstract: A superconducting device operable at temperatures in excess of 30° K. and a method for making the device are described. A representative device is an essentially coplanar SQUID device formed in a single layer of high Tc superconducting material, the SQUID device being operable at temperatures in excess of 60° K. High energy beams, for example ion beams, are used to convert selected portions of the high Tc superconductor to nonsuperconductive properties so that the material now has both superconductive regions and nonsuperconductive regions. In this manner a superconducting loop having superconducting weak links can be formed to comprise the SQUID device.

Abstract: A method and an apparatus for spraying materials onto a substrate to produce a coating thereon is described which allows very thick layers of complex metal oxides to be produced. The apparatus and method are particularly suitable for producing superconducting coatings.

Abstract: Methods for temperature control in microwave processing of materials, for example microwave sintering, annealing and other forms of microwave heating, are disclosed in which the material is formed into a selected shape and size such that at least a part of the materials reaches a state of thermal equilibrium at a desired temperature.

Abstract: The present invention includes a method for oxygenating oxide superconductive materials, and superconductive oxide materials made by said method. In broadest terms, the method of the present invention is based on an oxygenation strategy which uses temperatures higher than those typically used in the final stages of the oxygenation processes of the prior art. In the method of the present invention, higher oxygen chemical potentials are used to access higher temperatures to allow for higher oxygen diffusivity without a significant decrease in oxygen solubility.

Abstract: In a method for producing laminate, a buffer layer is applied to a substrate, with the buffer layer material being evaporated from the buffer layer material dispensing devices at an angle &agr;1≠0 at the normal to the substrate surface onto the latter, before an oriented thin layer is evaporated. According to the invention, provision is made such that (a) following evaporation of the buffer layer and prior to the evaporation of the oriented thin layer, at least one cover layer is evaporated under deposition conditions that vary from those under which the buffer layer was applied, especially at a different pressure, different temperature, different rate, and/or different angle &agr;2≠&agr;1, especially &agr;2<&agr;1, preferably &agr;2≈0° to the substrate surface normal, and/or is evaporated on the buffer layer in such fashion that the buffer layer has a biaxial texture and/or facets.

Abstract: A method is presented for making a polycrystalline thin film (B) by depositing particles emitted from a target (36) on a substrate base (A) to form the film (B) constituted by the target material while concurrently irradiating the depositing particles with an ion beam generated by an ion source (39) at an angle of incidence, in a range of 50 to 60 degrees to a normal (H) to a film surface, and maintaining a film temperature at less than 300 degrees Celsius. This method is effective in producing an excellent alignment of crystal axes of the grains in the film when the film thickness exceeds 200 nm. The target material includes yttrium-stabilized zirconia but other material can also be used. A layer (C) of a superconducting substance formed on top of the polycrystalline thin film (B) produces a superconducting film (22) exhibiting excellent superconducting properties.

Abstract: The front surface of a semiconductor substrate is formed with a trench. An insulating film is formed on the front surface of the semiconductor substrate including the trench while the bottom of the trench is kept at a higher temperature than the surface opening of the trench. To this end, the back surface of the semiconductor substrate is kept at a higher temperature than the front surface. This is done by heating the back surface of the semiconductor substrate with a halogen lamp. Alternatively, the front surface temperature is made lower than the back surface temperature by blowing a gas for forming an insulating film against the front surface of the semiconductor substrate.

Abstract: A process for preparing an oxide thin film which has a crystalline, clean and smooth surface on a substrate. The process is conducted by using an apparatus comprising a vacuum chamber in which an oxidizing gas of O2 including O3 can be supplied near the substrate so that pressure around the substrate can be increased while maintaining high vacuum near an evaporation source and Knudsen cell evaporation sources arranged in the vacuum chamber wherein the substrate is heated, molecular beam of constituent atoms of the oxide excluding oxygen are supplied from the K cell evaporation sources, an oxidizing gas is locally supplied to the vicinity of the substrate and a growing thin film is illuminated by ultraviolet.

Abstract: The present invention includes a method of oxygenating an oxide superconductive material having an initial oxygen content, the method comprising the steps: (a) obtaining an oxide superconductive material, the material having an initial oxygen content; and (b) placing the oxide superconductive material in contact an oxygen-containing media having an oxygen chemical potential greater than that of pure diatomic oxygen at 1 atmosphere pressure and at 300.degree. C., and raising the temperature of the oxide superconductive material to a temperature above about 400.degree. C., and maintaining the oxide superconductive material at the temperature and under the chemical potential of oxygen for sufficient time so as to alter the oxygen content of the oxide superconductive material from the initial oxygen content.

Abstract: A chemical vapor deposition (CVD) method for forming a multi-component oxide layer. There is first provided a chemical vapor deposition (CVD) reactor chamber. There is then positioned within the chemical vapor deposition (CVD) reactor chamber a substrate. There is then formed over the substrate a multi-component oxide precursor layer. The multi-component oxide precursor layer is formed from at minimum a first precursor reactant source material and a second precursor reactant source material introduced simultaneously into the chemical vapor deposition (CVD) reactor chamber in absence of an oxidant reactant source material. There is then oxidized with the oxidant reactant source material within the chemical vapor deposition (CVD) reactor chamber the multi-component oxide precursor layer formed over the substrate to form a multi-component oxide layer formed over the substrate.

Abstract: There is disclosed herein an invention for increasing the current carrying capability of high-Tc superconductor materials. The inventive method includes irradiating such superconductors with light particles, such as neutrons, protons and thermal neutrons, having energy sufficient to cause fission of one or more elements in the superconductor material at a dose rate and for a time sufficient to create highly splayed (dispersed in orientation) extended columns of damaged material therein. These splayed tracks significantly enhance the pinning of magnetic vortices thereby effectively reducing the vortex creep at high temperatures resulting in increased current carrying capability.

Abstract: The present invention discloses an integrated circuit that is wired with a high-temperature superconductive material that is superconductive at temperatures of about 70.degree. K and above, and methods of making the integrated circuit. The front-end manufactured semiconductor structure is patterned with a preferred precursor metal or metal oxide and a complementary compound is superposed and reacted to form wiring lines of superconductor ceramics that complete integrated circuits within the front-end manufactured semiconductor structure. The front-end manufactured semiconductor structure is alternatively patterned first with the complementary compound and the precursor metal is thinly patterned by ion implantation. The front-end manufactured semiconductor structure is then treated to form wiring lines of superconductor ceramics that complete integrated circuits within structure.

Abstract: Herein disclosed is a method for depositing a high Tc superconducting thin film. The superconducting thin film is deposited on one surface of a substrate. The substrate is exposed to an electromagnetic wave to heat the substrate during the process for depositing the superconducting thin film. Before the processes for depositing the superconducting thin film and exposing the substrate to the electromagnetic wave, a dummy film is formed on the other surface of the substrate. The dummy film has absorbency of the electromagnetic wave which is higher than that of the substrate. The dummy film together with the substrate is exposed to the electromagnetic wave while the superconducting thin film is deposited on the one surface of the substrate. The superconducting thin film thus deposited has superconductivity and high quality crystal structure.

Abstract: An oxide is formed which will form an oxide superconductor containing a Cu-O atomic layer. The oxide is hydrogenated. The oxide is oxidized after it is hydrogenated. The hydrogenation and the oxidization are executed simultaneously with or after the oxide is formed. The hydrogenation and the oxidization improve the superconducting characteristics of the oxide superconductor.

Abstract: A process for controlling crystalline orientation of an oxide superconductive film includes a first-heat-treatment step, and a second-heat-treatment step. In the first-heat-treatment step, an oxide superconductive film is heated and held in non-oxidizing atmosphere. Accordingly, partial oxygen deficiency is caused in the oxide superconductive film. In the second-heat-treatment step, the oxide superconductive film is heated and held in oxygen-rich atmosphere. Consequently, oxygen is re-introduced into the oxide superconductive film. Thus, crystalline orientation of the oxide superconductive film is altered. The process enables to readily form not only an "a"-axis-oriented oxide superconductive film but also a "b"-axis-oriented oxide superconductive film.

Abstract: Method for increasing the critical current density in Type II superconducting materials. The generation of a regular pattern of defects for pinning vortices, where the density of pinning sites is matched to the density of vortices produced by a chosen magnetic field in the particular superconducting material, is described. It is anticipated that such a defect pattern will substantially increase the critical current density carrying capability of the superconducting material so patterned. The fabrication of thick superconductors and conductors having chosen shapes is also described.

Abstract: Circuit board devices are provided based on use of high temperature superconducting ceramic polymers comprising high temperature superconducting ceramic powders distributed in electrically insulative organic polymers which are thermosetting by reaction of a two-part liquid mixture or by catalytic or photoinitiation of a one-part liquid. The ceramic domains transmit their superconductivity across the insulating barriers of organic polymers enabling formation of superconductive lines and superconducting bonds to electronic devices to be adhered to circuit boards, and providing superconducting circuitry.

Abstract: A method for improving the phase purity of a multiphase ceramic high temperature superconductor by selective microwave heating of undesired phases in a multiphase material to cause a phase transformation of the undesired phase to the desired phase. The selective microwave heating may be employed during initial firing and sintering of the ceramic superconductor compound or as a subsequent annealing step. Plane polarized microwave energy may be employed to enhance the two dimensional anisotropy of the compound by similar selective heating.

Abstract: 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.

Abstract: A method of treating a part made of a superconductive ceramic of the (Ln).sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-.delta. type, where Ln is chosen from the rare earth elements other than cerium and terbium, the method being designed to reduce the value of .delta., in which method said part is heat treated in an oxidizing atmosphere, said method being wherein, during said treatment, an electric current with a density lying in the range 0.1 A/cm.sup.2 to 2 A/cm.sup.2 is caused to flow through said part, said treatment atmosphere having a partial pressure of oxygen lying in the range 0.1 atmospheres to 1 atmosphere, the treatment temperature lying in the range 200.degree. C. to 500.degree. C., and the duration of said treatment lying in the range 1 hour to 200 hours.

Abstract: The disclosed oxide has a general chemical formula of Ca.sub.X-x)-Sr.sub.x -Bi.sub.(Y-y)-Cu.sub.y -O.sub.x X being 2 to 3, 0.ltoreq.x<1, Y being 3 to 4, 0<y.ltoreq.2, and z being 4 to 9, and the oxide shows, at a temperature below 105 to 115 K, both a photoconductivity and an either real or potential superconductivity, namely, "superconductive photoconductivity" in a wavelength range of 530 to 740 nm.The oxide is made by heating a mixture of starting materials for the above composition of Ca.sub.X-x -Sr.sub.x -Bi.sub.Y-y -Cu.sub.y -O.sub.z at 700.degree.-850.degree. C. for 2-10 hours so as to effect primary sintering for causing solid phase reactions in the mixture, cooling gradually, shaping under pressure, reheating the shaped materials at 750.degree.-880.degree. C. for 2-10 hours so as to effect secondary sintering thereon, cooling, keeping the reheated materials at 500.degree.-600.degree. C. for 2-3 hours and cooling the same either extremely quickly at a rate of 1500-900.degree. C.

Abstract: Superconductivity is inhibited in selected regions of a HTS material by subjecting the material to impurity ion bombardment at an energy level selected to implant ions in the material at a selected depth. The concentration of deposited ions varies with depth in the material according to a peaked depth distribution function which has a maximum at the selected depth. The material may be masked before implantation. After low temperature annealing, the material loses its superconducting characteristics in the selected regions but such characteristics are preserved at depths above and below the selected depth. The material's crystalline structure is preserved so additional layers can be epitaxially grown atop the inhibited material Multilayer HTS devices and circuits may be made by repeating the ion implantation and/or masking steps at with different ion energy levels.

Abstract: There is disclosed a method for annealing oxide thin film superconductors having layered structures including at least Cu--O layers in which each oxide thin film superconductor is heated partially by a heating means and the heating portion is moved at a predetermined speed.

Abstract: A manufacturing method of a superconducting pattern is described. A superconducting ceramic film is deposited on a non-conductive surface and partly spoiled in order to form a barrier film by which two superconducting regions is separated. The spoiling is performed by adding a spoiling element into the ceramic film by ion implantation.

Abstract: A superconducting device has a structure of superconductor--normal--conductor (semiconductor)--superconductor. The superconducting regions and the normal-conductor region can be made of the same elements but having different relative proportions of the elements. The device can be fabricated by introducing at least one element into an unmasked region of the superconductor to form a normal conductor region or into unmasked regions of the normal conductor to form superconductor regions.

Abstract: The generation of a reaction product is suppressed between a metallic substrate and plasma in depositing a ceramic intermediate layer on the metallic substrate in a process for depositing an oxide film on the metallic substrate by thermal plasma flash evaporation method. Thus, there is no reaction phase in the ceramic intermediate layer and the metallic substrate, and an intermediated buffer layer of only oxide ceramic is deposited on a flat surface of the metallic substrate. The intermediate ceramic layer is deposited in inert atmosphere of a low oxygen concentration at a temperature of less than 600.degree. C. for the metallic substrate. Then, a superconducting thin film is deposited on the ceramic intermediate layer.

Abstract: Superconducting transition metal oxide films are provided which exhibit very high onsets of superconductivity and superconductivity at temperatures in excess of 40.degree. K. These films are produced by vapor deposition processes using pure metal sources for the metals in the superconducting compositions, where the metals include multi-valent nonmagnetic transition metals, rare earth elements and/or rare earth-like elements and alkaline earth elements. The substrate is exposed to oxygen during vapor deposition, and, after formation of the film, there is at least one annealing step in an oxygen ambient and slow cooling over several hours to room temperature. The substrates chosen are not critical as long as they are not adversely reactive with the superconducting oxide film. Transition metals include Cu, Ni, Ti and V, while the rare earth-like elements include Y, Sc and La. The alkaline earth elements include Ca, Ba and Sr.

Abstract: A superconducting thin oxide film is formed by the steps of mixing a gas of the organometal compound of the alkali earth metal, a gas of at least one organometal compound of the element of the group IIIa and/or a halogenide thereof, and a gas of at least one organometal compound of a transition metal and/or a halogenide thereof, with an inert gas, to produce a gas mixture; mixing an oxygen-containing gas to said gas mixture to produce a gas mixture having a predetermined oxygen partial pressure; and thermally decomposing said gas mixture having the predetermined oxygen partial pressure on a substrate to form a thin film of a complex oxide on said substrate.

Abstract: In-situ process are provided for 1) depositing on a substrate a crystalline thin film of a high temperature superconducting oxide by exposing the back surface of the substrate, i.e., the surface of the substrate opposite the surface on which the thin film is deposited, to radiation from a direct radiant heat source, thereby heating the substrate to the desired growth temperature, and maintaining the radiation and thereby the desired growth temperature during the deposition of the thin film, and 2) depositing a crystalline thin film of high temperature superconducting oxides onto both the front and back surfaces of a substrate.

Abstract: A weak link is patterned from a high-temperature superconducting film using standard lithographic techniques. Once the area in which the weak link is to be located is defined, the remainder of the film is covered with an oxygen-impermeable material. The oxygen is then removed in the weak link area by placing the sample in a vacuum furnace at a sufficient temperature to drive out the oxygen. Once the oxygen is removed, the weak link becomes non-superconducting. A high power solid state laser is placed in front of the weak link, and superconductivity is restored in the weak link area, in situ. The process is performed in a liquid nitrogen environment.

Abstract: A process for depositing a biaxially aligned intermediate layer over a non-single crystal substrate is disclosed which permits the subsequent deposition thereon of a biaxially oriented superconducting film. The process comprises depositing on a substrate by laser ablation a material capable of being biaxially oriented and also capable of inhibiting the migration of substrate materials through the intermediate layer into such a superconducting film, while simultaneously bombarding the substrate with an ion beam. In a preferred embodiment, the deposition is carried out in the same chamber used to subsequently deposit a superconducting film over the intermediate layer. In a further aspect of the invention, the deposition of the superconducting layer over the biaxially oriented intermediate layer is also carried out by laser ablation with optional additional bombardment of the coated substrate with an ion beam during the deposition of the superconducting film.

Abstract: A method for improving the phase purity of a multiphase ceramic high temperature superconductor by selective microwave heating of undesired phases in a multiphase material to cause a phase transformation of the undesired phase to the desired phase. The selective microwave heating may be employed during initial firing and sintering of the ceramic superconductor compound or as a subsequent annealing step. Plane polarized microwave energy may be employed to enhance the two dimensional anisotropy of the compound by similar selective heating.

Abstract: Herein is disclosed a method of improving or producing an oxide superconductor. An oxide superconductor or starting material of oxide superconductor as an object material is irradiated with active oxygen species. The irradiation process is carried out while keeping the object material at a temperature at which the object material is effectively oxidized with the active oxygen species. The active oxygen species are formed on the inside or in the peripheral portion of a nonequilibrium or equilibrium, high-temperature plasma.

Abstract: A method for manufacturing an oxide superconductor thin film is disclosed, which comprises the steps of: (1) preparing a substrate; depositing an oxide superconductor thin film on said substrate by directing a beam containing constituent elements of an oxide superconductor to said substrate; and supplying excited oxygen to or near a thin film deposition site on said substrate during the deposition of said thin film, wherein said beam is selected from the group consisting of an ion beam, neutral particle beam, molecular beam, cluster beam and cluster ion beam, and wherein said excited oxygen is produced by means of generating discharge in an oxygen gas or oxygen-containing gas or by irradiating an oxygen gas or oxygen-containing gas with a beam.

Abstract: A beam (e.g. a focused laser beam) is utilized to irradiate the entire lateral width of a limited-extent portion of an elongated superconducting thin-film lead. The irradiated portion is converted to be non-superconducting and photoconductive. The converted portion constitutes a photodetector integrated with associated superconducting leads.

Abstract: A method is provided for preparing a precursor of a superconductor containing atoms of oxygen, atoms of copper and atoms of at least two other metals and sufficient atoms of oxygen so that up to, but no more than, one atom of copper is in the trivalent state, in which method there are blended together, in finely divided particulate state, components containing atoms of the metals in the desired proportion with at least one of the components containing oxygen in an amount above that which would put more than one atom of copper into the trivalent state and thereafter milling the components together in a high energy system to a maximum particle size of about 5 microns for at least 99 weight percent of the blend.