Abstract: A superconducting article is provided which includes a superconducting tape assembly. The superconducting tape assembly includes a superconducting tape layer, having one or more superconducting tapes, and a high-permeability magnetic material layer coupled to the superconducting tape layer. The high-permeability magnetic material layer includes a high-permeability magnetic material which remains magnetically soft at a critical temperature Tc of the superconducting tape, and with presence of an ac magnetic field acting on the superconducting tape assembly, re-magnetizes to divert at least a portion of a normal component of the ac magnetic field therethrough, which reduces ac loss in the superconducting tape layer by modifying the ac magnetic field distribution within the superconducting tape of the superconducting tape layer.

Abstract: A method of manufacturing a superconducting wire includes the step of drawing a wire formed by coating raw material powder for a superconductor with a metal or a wire with a multifilamentary structure, the step of sealing an end portion of a clad wire or a multifilamentary wire after the step of drawing, and the step of first rolling, rolling the multifilamentary wire after the step of sealing. With this method, a superconducting wire having high and uniform performance can be obtained.

Abstract: By adding an aromatic hydrocarbon such as benzene to the powder mixture of magnesium (Mg) or magnesium hydride (MgH2) and boron (B) as raw materials of a superconductor MgB2, high superconducting critical current density (Jc) is obtained.

Abstract: Disclosed herein is a method of manufacturing round wire using superconducting tape, including the steps of: slitting superconducting tape into superconducting tape strips; silver-coating the slit superconducting tape strips; laminating the silver-coated superconducting tape strips to form a superconducting tape laminate having a square cross-section; holding the superconducting tape laminate; heat-treating the fixed superconducting tape laminate to cause diffusion junction between silver; and copper-plating the heat-treated superconducting tape laminate to have a circular section.

Abstract: A method for successfully heat treating magnet coils of braided Bi2Sr2Ca1Cu2Ox (Bi-2212) strand. The Bi-2212 coil is fabricated using standard round wire powder-in-tube techniques, and braided with a ceramic-glass braid with integrated carbonaceous binder. The coil is heated in an atmosphere controlled furnace below the high current density phase reaction sequence to burn off the carbonaceous binder and evacuated to remove unwanted gases from the inner windings. The oxygen environment is then reintroduced and the coil is heat treated to the high Jc reaction temperature and then processed as normal. As the local atmosphere around the surface of the wire, particularly the concentration of oxygen, is critical to a successful reaction sequence, high current Bi-2212 coils can thereby be obtained.

Abstract: A superconductor structure is manufactured by forming a channel within a substrate along a surface of the substrate, depositing a material within the channel of the substrate, where the material includes one of a superconductor material and a precursor for a superconductor material, and thermally treating the substance within the channel of the substrate so as to form an elongated superconductor wire formed as a single, cohesive structure. The substrate can further include a plurality of channels with superconductor wires formed within the channels. In addition, a cable is formed including a bundle of individual superconductor wires arranged at different spatial positions with respect to each other.

Abstract: An HTS cable assembly is provided which includes a cryostat or housing, an HTS wire bundle disposed longitudinally within the cryostat, and plural support members disposed between the HTS wire bundle and the cryostat. The support members are elongate, tubular members having resiliency in both the axial and radial directions. The support members are disposed between the HTS wire bundle and the inner surface of the cryostat in an arrangement that maintains and supports the HTS wire bundle in a spaced-apart relationship with respect to the inner surface of the cryostat. In addition, the plural support members are configured to substantially prevent relative movement between the HTS wire bundle and the cryostat.

Abstract: A superconductor coating inclusive, tape-like electrical conductor and windings using such conductor for magnets and electrical machines, etc. The described windings are suited for inclusion of successor superconductor materials such as yttrium barium copper oxide wherein magnetic flux related losses can potentially be excessive and preclude successful machine operation. Winding orientation and configuration of the conductor in an alternating current machine for lower losses are disclosed along with methods and apparatus for achieving the desired windings. Windings intended for differing locations within a machine of this type are made possible by the invention. Equations relating to magnetic losses incurred in such windings are also disclosed.

Abstract: In a metal sheath MgB2 superconducting wire, it is intended to achieve a wire having increased current density and a long length at the same time, by densitying superconducting core part. The superconducting wire is manufactured by forming diffusion hardened layer on the inner surface of the sheath such that the hardness of the inner surface becomes higher than that of the outer surface, filling MgB2 superconductor, and further if necessary, a critical current density increasing material such as indium, copper, and tin, in a metal sheath, to subject it to wire drawing. For the metal sheath, a material with toughness such as steel is used. Even if the sheath is made to a long wire, it does not break, thereby, enabling to density superconducting core part.

Abstract: A method is provided for producing a superconductive electrical conductor, in which a layer of an yttrium-barium-copper oxide (YBCO) is applied as a superconductive material onto a textured metal substrate, and is subjected to a heat treatment. In order to produce a wire-shaped conductor, a textured metal substrate, provided as a strip (2), is initially shaped in its longitudinal direction around an elongate metal support (1) with a circular cross section to form a slotted tube (3) having edges extending in the longitudinal direction and adjoining one another at a slot (4). The slotted tube (3) is next closed by welding the slot (4) shut, and the closed tube (9) is then contracted by pulling until it bears on the support (1). The layer (12) of superconductive YBCO material is thereupon applied all around, and the heat treatment is finally carried out.

Abstract: The invention provides an improved method of manufacturing an HTS tape coil for an MRI device with enhanced protection, the method comprising attaching high-Q capacitors at each end of an HTS wire, removing substantially all electrically conductive sheathing material on an inner side of the HTS wire, while retaining substantially all electrically conductive sheathing material on an outer side of the HTS wire. The invention also provides an HTS wire made in accordance with the foregoing method.

Abstract: A superconducting wire, a method of manufacturing the superconducting wire, an antenna coil and a NMR system are disclosed. At least a superconducting material, a paramagnetic material and a diamagnetic material are closely attached and integrated with each other to form a longitudinally continuous wire. The paramagnetic material and the diamagnetic material are arranged in such a manner that the magnetic properties of the paramagnetic material and the diamagnetic material substantially offset each other in the longitudinal and diametrical directions. A superconducting layer is exposed to a part or the whole of the outer periphery of the wire. A low-resistance material layer is formed inside the superconducting layer.

Abstract: An object of the invention is to offer a method of producing an oxide superconducting wire that has a uniform performance throughout its length so that a wire can be obtained with just the intended length. The method of producing an oxide superconducting wire comprises a drawing step for drawing a wire having a configuration in which a precursor powder of a (Bi, Pb) 2223 superconducting body is covered with a metal sheath, a primary rolling step for rolling the wire having undergone the drawing step, a primary heat-treating step for heat-treating the wire having undergone the primary rolling step, a secondary rolling step for rolling the wire having undergone the primary heat-treating step, and a secondary heat-treating step for heat-treating the wire having undergone the secondary rolling step.

Abstract: An object of the present invention is to provide a method of manufacturing a bismuth-based oxide superconductor capable of obtaining a high critical current density and a superconducting wire containing a bismuth-based oxide superconductor manufactured by this method. The present invention is directed to a method of manufacturing a bismuth-based oxide superconductor containing a 2223 phase having a 2223 composition in a composition Bi—Sr—Ca—Cu or (Bi,Pb)—Sr—Ca—Cu, comprising a first step of charging a raw material containing a 2212 phase having a 2212 composition in a composition Bi—Sr—Ca—Cu or (Bi,Pb)—Sr—Ca—Cu with a critical temperature of not more than 70 K into a metal sheath, a second step of performing plastic working on the metal sheath charged with the raw material and a third step of performing heat treatment on the metal sheath charged with the raw material.

Abstract: A method of manufacturing a superconducting wire is provided. A MgB2 superconducting wire capable of obtaining a stabilizer through an inexpensive process can have high critical current density and magnetic field characteristics without separate plastic. A seamed portion of the wire can be welded to make it possible to plate the wire with conductive materials and inhibit a decrease in quality of superconducting powder. It is possible to obtain a stabilizer without inserting the superconducting powder into a tube.

Abstract: A superconductive wire wherein the superconductive wire has a core portion containing magnesium diboride as the main component and a continuous metallic sheath firmly adhered to the core portion; the core portion is kept substantially vacuum; and the content of an inert gas such as an Ar gas contained in the core portion is in the range of 0.00002 to 10 ppm. Further, disclosed is a method for producing a superconductive wire, wherein the method comprises the steps of mixing powder of a source material constituting magnesium diboride to form a core portion of the superconductive wire in an inert gas, filling a pipe with the mixed material powder in vacuum environment, sealing the pipe with vacuum after filled with the material powder, forming magnesium diboride powder by heating the vacuum-sealed pipe (sheath), and forming the core portion by wiredrawing the pipe in the state where the magnesium diboride powder is sealed with vacuum, and the core portion firmly sticks to the wiredrawn metallic pipe.

Abstract: The present invention provides a simple, energy efficient and cost effective process for continuous production of high quality MgB2 based superconducting wires, tapes, bulk bodies and powders with better phase purity, microstructure and superconducting properties by introducing some innovative steps namely processing the reactants in evacuated and sealed metal tubes by electrical self-heating cum hot rolling followed by annealing under electrical self-heating, thereby overcoming various deficiencies and shortcomings associated with the prior art.

Abstract: A substrate for a superconducting wire is made of Ni or Ni alloy, with a ratio of cube texture of 95% or above constant in a width direction of a substrate body, a ratio of low-angle (15 or less) grain boundary of 99% or above regularly distributed in the width direction, a thickness of 40-150 ?m, an average grain size of 100 ?m or less, and a surface roughness of RMS 50 nm or less. A method for fabricating the substrate includes rolling a Ni or Ni-alloy rod with a rectangular section; and thermally treating the rolled rod, the rolling step having a reduction ratio of 5 to 15% at each rolling, the rod being moved between rollers for the rolling process at a linear velocity of 100 m/min or less, the thermally treating process being conducted by heating above a recrystallization temperature with flowing an inert gas including hydrogen gas.

Abstract: A method of manufacturing a superconducting wire includes the step of drawing a wire formed by coating raw material powder for a superconductor with a metal or a wire with a multifilamentary structure, the step of sealing an end portion of a clad wire or a multifilamentary wire after the step of drawing, and the step of first rolling, rolling the multifilamentary wire after the step of sealing. With this method, a superconducting wire having high and uniform performance can be obtained.

Abstract: Disclosed is a method of manufacturing a continuous disk winding. A high-temperature superconducting wire is lapped using Kapton films to insulate the high-temperature superconducting wire. The high-temperature superconducting wire is wound on a bobbin by a predetermined number of turns to form a layer of windings. An annular disk having a slit formed therein is fitted onto the bobbin. The slit is formed along the circumference of the disk and to be inclined from the inner side of the disk towards the outer side thereof. The high-temperature superconducting wire is inserted into the slit of the disk to pass through the annular disk smoothly along the inclined slit and wound again by the predetermined number of turns to form a next layer of windings. The above steps of fitting an annular disk, and inserting and winding the high-temperature superconducting wire are repeated to form multiple layers of windings.

Abstract: Disclosed herein is method for making a wire comprising contacting a first end of a first superconducting wire with a second end of a second superconducting wire, wherein the superconducting wire comprises a superconducting filament having a superconducting composition comprising magnesium diboride; heating the first end of the first superconducting wire with the second end of the second superconducting wire at a point to form a joint, wherein the superconducting filament having the superconducting composition is in continuous electrical contact with any other part of the superconducting filament after the formation of the joint.

Abstract: Processes for the fabrication of MgB2 powder and wires are provided. Powders are produced by mechanically alloying magnesium- and boron-containing precursors under controlled conditions to avoid secondary phase and impurity formation. Powders are also prepared by vapor phase reaction of volatile magnesium- and boron-containing precursors. Wires, tapes, films and coatings are provided.

Abstract: A method and article for producing a high transition temperature superconducting tape or wire with a normal metal sheath and at least two surface layers, an inner electrically insulating layer and an outer low friction layer. The method includes mechanical deformation and a plurality of annealing steps, and the application of at least one surface layer after the final annealing step. The coating materials are selected based on their electrical insulation and friction, as well as their compatibility with cryogenic conditions and coating methods.

Abstract: A method of manufacturing an oxide superconducting wire, through which dimensional precision of width or thickness of the wire can be improved and an oxide superconducting wire with high superconducting performance can be obtained, is provided. The method of manufacturing the oxide superconducting wire includes preparing a composite by covering with metal powder containing an oxide superconductor or raw material for an oxide superconductor, and rolling the composite using a lubricant having kinematic viscosity of 20×10−6 mm2/s or smaller.

Abstract: There is disclosed a continuous process for the formation of a superconducting wire utilizing magnesium diboride powder. The process provides a long length, low cost strand of superconducting wire which can be used in a monofilament or multifilament form.

Abstract: A method is described for the production of superconductive wires based on hollow filaments made of MgB2, which comprises: a) the formation of a composite billet by means of the coaxial insertion in a tubular metallic container of a cylindrical bar made of metallic magnesium and amorphous boron powder in the interspace between the container and bar, said powder being pressed between the metallic container and the magnesium bar, in such a quantity that the weight ratio magnesium/boron is higher than 1.2; b) at least one plastic deformation treatment of the composite billet thus obtained until a wire with a pre-fixed diameter is obtained, with the subsequent winding of the wire onto a support; c) a thermal treatment of the filament product thus obtained, at a temperature ranging from 700° C. to 950° C. for a time ranging from 15 minutes to three hours.

Abstract: A method for forming an electronically active biaxially textured article includes the steps of providing a substrate having a single crystal metal or metal alloy surface, deforming the substrate to form an elongated substrate surface having biaxial texture and depositing an epitaxial electronically active layer on the biaxially textured surface. The method can include at least one annealing step after the deforming step to produce the biaxially textured substrate surface. The invention can be used to form improved biaxially textured articles, such as superconducting wire and tape articles having improved Jc values.

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: A method for increasing the critical temperature, Tc, of a high critical temperature superconducting (HTS) film (104) grown on a substrate (102) and a superconducting structure (100) made using the method. The HTS film has an a-b plane parallel to the surface of the substrate and a c-direction normal to the surface of the substrate. Generally, the method includes providing the substrate, growing the HTS film on the substrate and, after the HTS film has been grown, inducing into the HTS film a residual compressive strain the a-b plane and a residual tensile strain into the c-direction.

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 forming an electronically active biaxially textured article includes the steps of providing a substrate having a single crystal metal or metal alloy surface, deforming the substrate to form an elongated substrate surface having biaxial texture and depositing an epitaxial electronically active layer on the biaxially textured surface. The method can include at least one annealing step after the deforming step to produce the biaxially textured substrate surface. The invention can be used to form improved biaxially textured articles, such as superconducting wire and tape articles having improved JC values.

Abstract: A method for producing a high-Tc superconductor having a strip shape and having at least one superconductive conductor core by forming a conductor initial product and annealing. The forming is in this case intended to include at least two flattening steps. A flattening step which follows a preceding flattening step is intended to result in the percentage thickness reduction in the cross section of the at least one conductor core being greater than that from the preceding flattening step. The strip conductor produced in this way advantageously has a plurality of conductor cores that are embedded in a Ag material and are composed of a bi-cuprate.

Abstract: A method of making an oxide superconductor article includes subjecting an oxide superconductor precursor to a texturing operation to orient grains of the oxide superconductor precursor to obtain a highly textured precursor; and converting the textured oxide superconducting precursor into an oxide superconductor, while simultaneously applying a force to the precursor which at least matches the expansion force experienced by the precursor during phase conversion to the oxide superconductor. The density and the degree of texture of the oxide superconductor precursor are retained during phase conversion. The constraining force may be applied isostatically.

Abstract: Powder of not more than 1 &mgr;m in mean particle diameter is prepared to contain a mixture of superconducting phases mainly composed of 2212 phases of Bi—Sr—Ca—Cu or (Bi, Pb)—Sr—Ca—Cu and non-superconducting phases which is obtained by calcining and pulverizing raw material powder at least once, this powder is heat treated at a high temperature and thereafter coated with a metal to prepare a round wire by deformation processing, thereafter a tape type or flat type wire is prepared by deformation processing, then the wire is heat treated under conditions for allowing phase transformation of the 2212 phases of main superconducting phases to 2223 phases with facilitation of grain growth, thereafter the as-formed 2223 phases are highly densified by deformation processing or pressurization, and the wire is again heat treated so that the 2223 phases are strongly bonded with each other and the non-superconducting phases are finely dispersed.

Abstract: A high temperature superconducting composite conductor is provided including a high temperature superconducting material surrounded by a noble metal layer, the high temperature superconducting composite conductor characterized as having a fill factor of greater than about 40. Additionally, the conductor can be further characterized as containing multiple cores of high temperature superconducting material surrounded by a noble metal layer, said multiple cores characterized as having substantially uniform geometry in the cross-sectional dimensions. Processes of forming such a high temperature superconducting composite conductor are also provided.

Abstract: The invention features high performing composite superconducting oxide articles that can be produced from OPIT precursors substantially without poisoning the superconductor. In general, the superconducting oxide is substantially surrounded by a matrix material. The matrix material contains a first constraining material including a noble metal and a second metal. The second metal is a relatively reducing metal which lowers the overall oxygen activity of the matrix material and the article at a precursor process point prior to oxidation of the second metal. The second metal is substantially converted to a metal oxide dispersed in the matrix during or prior to a first phase conversion heat treatment but after formation of the composite, creating an ODS matrix.

Abstract: The invention provides a multifilamentary superconducting composite article comprising multiple substantially electrically decoupled domains, each including one or more fine, preferably twisted filaments of a desired superconducting oxide material. In a preferred embodiment, the article comprises a matrix, which substantially comprises a noble metal, a conductive jacketing layer surrounding the matrix, a plurality of discrete filament decoupling layers, each comprising an insulating material, disposed within the matrix to separate the matrix into a plurality of substantially electrically decoupled domains; a plurality of filaments, each comprising a desired superconducting oxide, which are disposed within and essentially encapsulated by the matrix and chemically isolated thereby from the decoupling layers, each of the electrically decoupled domains containing at least one filament.

Abstract: Powder of not more than 1 &mgr;m in mean particle diameter is prepared to contain a mixture of superconducting phases mainly composed of 2212 phases of Bi—Sr—Ca—Cu or (Bi, Pb)—Sr—Ca—Cu and non-superconducting phases which is obtained by calcining and pulverizing raw material powder at least once, this powder is heat treated at a high temperature and thereafter coated with a metal to prepare a round wire by deformation processing, thereafter a tape type or flat type wire is prepared by deformation processing, then the wire is heat treated under conditions for allowing phase transformation of the 2212 phases of main superconducting phases to 2223 phases with facilitation of grain growth, thereafter the as-formed 2223 phases are highly densified by deformation processing or pressurization, and the wire is again heat treated so that the 2223 phases are strongly bonded with each other and the non-superconducting phases are finely dispersed.

Abstract: An improvement in a process of preparing a composite high temperature oxide superconductive wire is provided and involves conducting at least one cross-sectional reduction step in the processing preparation of the wire at sub-ambient temperatures.

Abstract: The diameter of a first metal tube charged with raw material powder is reduced for obtaining an elementary wire. A plurality of such elementary wires are charged into a second metal tube, which in turn is reduced in diameter for obtaining a round first wire having a plurality of first filaments. The first wire is uniaxially compressed thereby obtaining a tape-like second wire having a plurality of second filaments. The second wire is heat treated thereby obtaining an oxide superconducting wire including a plurality of superconductor filaments. The maximum grain size of the raw material powder is smaller than the minor diameter of the first or second filaments.

Abstract: A superconducting wire having a fine line made of an oxide superconductor which has metal material dispersed therein, the outer periphery of which being coated with a conductive material; and a manufacturing method for the superconducting wire, comprising a process for drawing a metal pipe; filled with an oxide superconductor so as to product the fine line and a process for heating the fine line at a temperature which is higher than the melting point of the metal material constituting the metal pipe.

Abstract: An improvement in a process of preparing a composite high temperature oxide superconductive wire is provided and involves conducting at least one cross-sectional reduction step in the processing preparation of the wire at sub-ambient temperatures.

Abstract: Superconducting, oxidic ceramic materials are worked to filamentary conductors, in that they are filled into silver tubes (2), drawn with the latter to filamentary conductors and then sintered under flowing oxygen. So that such filamentary conductors can be produced industrially with an adequate quality, drawing speed and yield, the silver tube (2) as a sintered sleeve is brought into contact with the ceramic material (1) in a drawing sleeve (3), of soft annealed steel (35) and the resulting sleeve combination undergoes the drawing stages. After drawing the steel drawing sleeve is removed by etching. In a large number of drawing stages, it is necessary to remove the drawing sleeve which has become hard due to the cold working and to replace it by a new, soft annealed sleeve. Simultaneously the sintering sleeve can undergo soft annealing.

Abstract: A method for preparing a BSCCO-2223 oxide superconducting article includes annealing an oxide superconductor article comprised of BSCCO-2223 oxide superconductor at a temperature selected from the range of about 500° C.≦T≦787° C. and an annealing atmosphere having an oxygen pressure selected from within the region having a lower bound defined by the equation, PO2(lower)≧3.5×1010exp(−32,000/T+273) and an upper bound defined by the equation, PO2(upper)≦1.1×1012exp(−32,000/T+273). The article is annealed for a time sufficient to provide at least a 10% increase in critical current density as compared to the critical current density of the pre-anneal oxide superconductor article. An oxide superconductor having the formula Bi2−yPbySr2Ca2Cu3O10+x, where 0≦x≦1.5 and where 0≦y≦0.6 is obtained, the oxide superconductor characterized by a critical transition temperature of greater than 111.0 K, as determined by four point probe method.

Abstract: A long oxide superconducting wire for a coil or a cable, manufacturing method thereof, an oxide superconducting coil and a cable conductor which have high operational frequency are provided. The wire is a tape-like oxide superconducting wire including a plurality of filaments of oxide superconductor embedded in a matrix, and each filament is twisted spirally along the longitudinal direction of the tape wire. By winding the wire in a coil, an oxide superconducting coil is obtained. When a plurality of such wires are collected, an oxide superconducting cable conductor can be obtained.

Abstract: A modified powder-in-tube process produces a superconductor wire having a significantly greater current density than will a superconductor wire of the same nominal superconductor composition produced using conventional draw-swage-extrude-roll deformation. In the process disclosed, a superconductor precursor is placed within a ductile tube, the tube with the powder therein is then deformed into a cross-section substantially corresponding to that of the end product, and the deformed tube is then subject to a plurality of heat treatments to convert the precursor into the desired superconducting ceramic oxide phase. Before the last of the heat treatments, the tube is isostatically pressed to densify and texture the superconductor precursor oxide in the tube.

Abstract: The present invention provides a method to prepare a (Bi,Pb)SrCaCuO-2223 superconductor, in particular a (Bi,Pb)SrCaCuO-2223 superconducting wire with improved critical current density at reduced cost. In the method of preparing a (Bi,Pb)SrCaCuO-2223 superconducting wire comprising the steps of filling precursor powder into a metal sheath, working the same into a wire by performing deformation processing in this state, and heat treating the wire, the precursor powder is prepared from a powder containing a fully doped 2212 phase and a powder containing an under-doped 2212 phase. This precursor powder provides the advantage of better texture formation, faster and more homogeneous reaction to form the 2223 phase, and improved connectivity between the 2223 grains during the heat treatment process, leading to improved critical current density.

Abstract: A method is described to prepare a highly textured oxide superconductor article in a single deformation-sinter process. A precursor article including a plurality of filaments comprising a precursor oxide having a dominant amount of a tetragonal BSCCO 2212 phase and a constraining member substantially surrounding each of the filaments is provided. Each of the filaments extends along the length of the article. The oxide article is subjected to a heat treatment at an oxygen partial pressure and temperature selected to convert a tetragonal BSCCO 2212 oxide into an orthorhombic BSCCO 2212 oxide and, thereafter, roll worked in a high reduction draft in a range of about 40% to 95% in thickness so that the filaments have a constraining dimension is substantially equivalent to a longest dimension of the oxide superconductor grains. The rolled article is sintered to obtain a BSCCO 2223 oxide superconductor.

Abstract: A method of preparing wires or tapes including Bi-2223 superconductor material by providing oxide and carbonate sources of Bi, Sr, Ca, Cu and Pb, milling the material for a time not to exceed about 30 minutes but preferably not greater than 20 minutes to produce a homogeneous mixture. Then heat treating by calcining the milled mixture at a temperature of at least about 830° C. for a time not less than about 12 hours, followed by at least one additional milling for a time not to exceed about 20 minutes and one additional heat treatment, to produce an oxide powder having an average diameter in the 4 to 5 micron range. Then a silver or silver alloy tube is filled with the oxide powder, and shape formed into a rectangular tape. Then alternately thermally treating and mechanically working the tube filled with oxide powder by heating the filled tube to an elevated temperature of about 835° C. to 840° C. and reducing the diameter of the tube, repeating the thermal and mechanical treatment.

Abstract: A process for producing Bi-2223 high Tc superconductor in which fine MgO particles (<0.1 &mgr;m) are homogeneously distributed to provide flux pinning centers in Bi-2223 high Tc superconductor in order to give enhanced critical current density under magnetic field, as compared to the Bi-2223 high Tc superconductor without MgO dispersion, when processed under similar conditions. The process comprises mixing partially converted Bi-2223 powder and MgO fine particles, drying to give mixed powder, filling in silver tube, drawing, rolling and heat-treating at a temperature and for a time sufficient to form Bi-2223 high Tc superconductor in which fine MgO particles are homogeneously distributed.