Abstract: A method for producing a superconducting copper oxide based helical resonator coil exhibiting improved quality factor, Q. A copper oxide based superconductor powder is mixed with a binder melt at about 45-65% solids by volume. The binder is an RCOOR' ester wax with R and R' each a long chain hydrocarbon group of at least 6 carbons. The ester wax has a melting point of about 40.degree.-100.degree. C. and a viscosity of about 94-2000 centipoise at its melting point. The binder/powder mixture is extruded and wrapped around a mandrel to form a helical coil. The coil is embedded in a setter powder and heated in an oxidizing atmosphere at up to about 2.degree. C./min to about 450.degree.-650.degree. C., and held for a time sufficient to remove the binder. The coil is then heated in the oxidizing atmosphere at up to about 3.degree. C./min to at least about 920.degree. C., and held at about 920.degree.-990.degree. C. for a time sufficient to achieve a density of at least about 93% of theoretical density.

Abstract: According to this method of manufacturing a superconductor, powder materials of Y.sub.2 O.sub.3, BaCO.sub.3 and CuO are first prepared as raw materials and blended and mixed to the composition Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.x. The mixed powder thus obtained is compression-molded and thereafter sintered. A sintered body thus obtained shows the Meissner effect under the temperature of liquid nitrogen. This sintered body is pulverized into fine particles. A magnetic field is applied to the fine particles at the temperature of liquid nitrogen, thereby to select only superconductive particles. The selected superconductive particles are compression-molded during application of a magnetic field and then sintered, thereby to obtain a superconductor having high critical current density.

Abstract: To produce more complex molded bodies from precursors of high-temperature superconductors based on the oxides of bismuth, strontium, calcium and copper, the homogeneous melt of these oxides is cast in molds at temperatures of 870.degree. to 1000.degree. C. In this process, the geometrically appropriately shaped molds are composed of a material having a melting point of at least 1000.degree. C. Finally, the molds containing solidified melt of the oxides of bismuth, strontium, calcium and copper are treated with dilute hydrofluoric acid at temperatures of 20.degree. to 90.degree. C. until the molds are dissolved.

Abstract: A method of manufacturing a bismuth oxide superconductor, wherein a molded body of a bismuth oxide superconducting substance comprising bismuth, an alkaline earth metal, copper, and oxygen or a precursor thereof is subjected to a heat treatment for producing a superconducting phase and then subjected to one step selected from (1) a step of cooling the heated body from 700.degree. C. to 200.degree. C. in an atmosphere having an oxygen partial pressure of not less than 0.1 atm at a cooling rate of not less than 10.degree. C./min, (2) a step of cooling the heated body from 700.degree. C. in an atmosphere having an oxygen partial pressure of less than 0.1 atm at a cooling rate of less than 10.degree. C./min, and (3) a step of cooling the heated body, and then performing a heat treatment for the cooled heated body in an atmosphere having an oxygen partial pressure of not more than 0.1 atm at a temperature from 700.degree. C. to 200.degree. C.

Abstract: A method of manufacturing a superconductive conductor containing a superconductive ceramic material generally expressed by the composition AaBbCc, where A represents at least a sort of element selected from a group of those belonging to the groups Ia, IIa and IIIb of the periodic table, B represent at least a single element selected from a group consisting of groups Ib, IIb and IIIa of the periodic table, C represents at least a single sort of element selected from a group of oxygen, carbon, nitrogen, fluorine and sulfur and a, b and c represent numbers showing composition ratios of A, B and C respectively, includes a step of melting a material generally expressed by a formula AaBb, a step of continuously drawing out a melt of AaBb from a hole provided in a frame, a step of solidifying the AaBb melt drawn out from the hole and a step of heating a solidified body of AaBb in an atmosphere containing C.

Abstract: An elongated, flexible superconductive wire or strip is fabricated by pulling it through and out of a melt of metal oxide material at a rate conducive to forming a crystalline coating of superconductive metal oxide material on an elongated, flexible substrate wire or strip. A coating of crystalline superconductive material, such as Bi.sub.2 Sr.sub.2 CaCu.sub.2 O.sub.8, is annealed to effect conductive contact between adjacent crystalline structures in the coating material, which is then cooled to room temperature. The container for the melt can accommodate continuous passage of the substrate through the melt. Also, a second pass-through container can be used to simultaneously anneal and overcoat the superconductive coating with a hot metallic material, such as silver or silver alloy. A hollow, elongated tube casting method of forming an elongated, flexible superconductive wire includes drawing the melt by differential pressure into a heated tubular substrate.

Abstract: The invention relates to a high-temperature superconductor composed of the oxides of bismuth, strontium, calcium and copper and, optionally, of lead, and having the composition Bi.sub.2-a+b+c Pb.sub.a (Sr, Ca).sub.3-b-c Cu.sub.2+d O.sub.x, where a=0 to 0.7; b+c=0 to 0.5; d=-0.1 to 0.1 and x=7 to 10 and a Sr:Ca ratio of 2.8:1 to 1:2.8 as well as of strontium and/or barium sulfates. Said superconductor can be prepared by intimately mixing the oxides of bismuth, strontium, calcium and copper and optionally of lead with strontium and/or barium sulfates, melting the mixture by heating to temperatures of 870 to 1300.degree. C., higher temperatures being required for higher strontium and/or barium sulfate contents, pouring the melt into molds and allowing it to solidify slowly therein and subjecting the moldings removed from the molds to a heat treatment at temperatures of 700 to 900.degree. C. in an oxygen-containing atmosphere.

Abstract: A process for superplastically forming and shaping a solid object including 123 superconductor, including preparing a solid object having grains of 123 superconductor that have an average grain size of less than 10 microns, and superplastically deforming the prepared solid object by heating the solid object to between 500.degree. and 1015.degree. C. while simultaneously applying to said solid object stress which is less than the fracture strength of the solid object, thereby producing a strain rate in the solid object. The solid object may be a composite including silver or gold.

Abstract: Improved superconducting materials with high maximum magnetization, remanent magnetization and diamagnetic susceptibility can be made by enriching the base Y-Ba-Cu-O composition, Y:Ba:Cu=1:2:3, with respect to Y, or adding other trivalent or pentavalent elements (e.g. rare earths, Nb) to this composition. The mixed oxide materials are heated to melt a substantial fraction of their weight, quenched to a low temperature, re-heated to a temperature lower than the one initially used to effect melting, and annealed by slow cooling under air or oxygen.

Abstract: A method of fabricating a superconducting ceramic pipe including the steps of: melting a ceramic powder having a predetermined composition to form a melt; filling a supporting tube with the melt by a suction caused by a vacuum pressure; partially solidifying an outer part of the melt near the tube to form a shell (i.e., a ceramic pipe); discharging an inner unsolidified part at the center of the tube from the tube by gravity, to form a solidified ceramic pipe on the inside surface of the tube; and heat treating the ceramic pipe to convert it into a superconducting pipe. When a supporting tube with a bottom plate is used, the melt is poured into the tube, and the tube is turned over to remove an unsolidified melt, whereby a superconducting ceramic pipe with a bottom is fabricated.

Abstract: A ceramic oxide superconductive composite material comprising a ceramic oxide superconductor and a non-superconductive material comprising at least one element which does not react with any of the elements of the ceramic oxide superconductor has improved superconductive properties such as a higher critical temperature and a larger critical current density.

Abstract: In the process for producing molded bodies from precursors of oxidic high-temperature superconductors of the BSCCO type, a copper mold of the desired shape which encloses a solidified bismuth strontium calcium cuprate melt is wired as anode in a direct current circuit composed of anode, cathode and an electrolyte, a dilute sulfuric acid is used as electrolyte and the electrolyte is subjected to a direct current of 1 to 50 mA.cm.sup.-2 until the copper mold wired as anode is dissolved and the BSCCO molded body is laid bare.

Abstract: A process for the production of a shaped article of a ceramic material in which a composition comprising particulate ceramic material and a liquid medium is shaped, the liquid medium is removed from the shaped composition, and the composition is heated to sinter the particles of ceramic material in which the composition is subjected to high shear mixing such that in the shaped article which is produced the mean maximum size of flaw is less than 25 microns. Also, a shaped article of sintered particulate ceramic material in which the mean maximum size of flaw is less than 25 microns and in which the minimum dimension of the shaped article is in excess of 0.1 mm.

Abstract: A process is disclosed for forming shaped superconductors of the metal oxide type by electrophoretic deposition of superconducting particles which comprises providing particulate superconducting material of the metal oxide type coated with a fusible binder, electrophoretically depositing such coated superconducting particles on a substrate, heating the coated substrate sufficiently to fuse the binder to the substrate, fabricating the coated substrate into a desired shape, removing the binder, and then sintering the coated substrate to sinter the superconducting particles together. In a preferred embodiment the process further comprises immersing the coated substrate in an electrostatic field during the fusion step to both orient and maintain the superconducting particles in a desired direction.

Abstract: Method for joining parts of ceramic high-temperature superconductor material of the composition Bi.sub.(2+a-b) (Sr.sub.1-c) Ca.sub.c) .sub.(3-a) Pb.sub.b Cu.sub.(2+d) O.sub.x, where a is 0 to 0.3, b is 0 to 0.5, c is 0.1 to 0.9 and d is 0 to 2 and x has a value depending on the state of oxidation of the metals present, the end faces of the parts located at a gap spacing apart from one another are heated by means of a fuel gas/oxygen flame to temperatures from 750.degree. to 875.degree. C. Simultaneously, a rod of the same material above the spacing gap is heated until the melt thereof drips off into the gap between the end faces of the two parts, completely filling the gap. At least the joint region between the two parts is then heat-treated for 7 to 100 hours at temperatures between 780.degree. and 850.degree. C.

Abstract: A method for preparing tertiary butyl alcohol wherein a solution of a tertiary butyl hydroperoxide in tertiary butyl alcohol is charged to a hydroperoxide decomposition reaction zone containing a catalytically effective amount of a hydroperoxide decomposition catalyst consisting essentially of a superconductor such as a superconductor consisting essentially of the oxides of strontium, calcium, copper and bismuth and is brought into contact with the superconductor type catalyst in liquid phase with agitation under hydroperoxide decomposition reaction conditions to convert the tertiary butyl hydroperoxide to decomposition products, principally tertiary butyl alcohol.

Abstract: A superconducting device has an oxide superconducting material with a passivation or blocking film formed on its surface. The film helps to maintain a uniform oxygen concentration of the superconducting material through its thickness. The superconducting material is thus superconductive throughout its cross-section, and particularly in the vicinity of the surface bearing the film.

Abstract: A method of manufacturing an oxide superconductor including (a) alternately laminating at least one first layer including an oxide superconductor or a precursor thereof with at least one second layer including a metal material to form a laminated body, (b) forming an outermost metal coating layer of the metal material on the laminated body to form a laminated structure, and (c) heating and cooling the laminated structure or elongating the laminated structure into a desired shape and then carrying out heating and cooling.

Abstract: Process for producing superconducting metal-oxide textiles comprising impregnating a preformed, organic textile material with metal compounds in a desired atomic ratio, heating the material in a weakly oxidizing atmosphere to pyrolize and oxidize the organic material, maintaining the material at temperature in an oxidizing atmosphere, and cooling the material in an oxidizing atmosphere, so as to form a crystalline structure capable of superconducting.

Abstract: A machinable high Tc ceramic superconductor is formed by weighing and mixing appropriate stoichiometric amounts of Bi.sub.2 O.sub.3, SrCO.sub.3, CaCO.sub.3, and CuO (BSCCO), removing carbonates from the mixture, melting the mixture, casting the melted mixture into a mold, and inducing superconductivity and growth of randomly oriented platelets in the cast.

Abstract: A method for forming elongated articles including metallic oxide superconductor material by hydrostatic extrusion at temperatures less than about 800.degree. C., and even at temperatures less than about 450.degree. C. The method includes providing superconductive core material that is substantially free of carbon or organic additives and that has an equivalent density at least about 55% of full density, and enclosing the densified material in a metal container, to become a cladding, prior to extrusion. In a preferred embodiment, the cladding material is a dispersion hardened metal or metal alloy.

Abstract: A method of forming a superconducting tape having a silver sheath and a polycrystalline oxide superconductor core includes, forming at least one silver foil to have a receiving surface for supporting a deposit, and at least one enclosing surface that can cover the deposit and overlap another portion of the foil so that the surfaces form the sheath. The foil has a first thickness at the receiving surface and a second thickness at the enclosing surface. A precursor deposit of the superconductor is formed on the receiving surface. The enclosing surface is wrapped to cover the deposit and overlap another portion of the foil to form the sheath. The first and second thicknesses being preselected so that the thickness of the overlapping foils is equivalent to the thickness of foil oppositely facing the overlapping foils. The overlapping foils are sealed, and annealed to reaction-sinter the sealed deposit and form the tape.

Abstract: A process of forming on a substrate a coating of a precursor of a crystalline rear earth alkaline earth copper oxide or heavy pnictide mixed alkaline earth copper oxide electrical conductor and converting the precursor to the crystalline electrical conductor.

Abstract: A superconductive ceramic wire or film comprises 100 parts by weight of superconductive oxide crystal composed of a rare earth element, an alkaline earth metal, copper, and oxygen, and 0.2-5.0 parts by weight of copper oxide, thereof.

Abstract: Disclosed is a method of improving the physical properties of superconducting materials which comprises:a. applying a high strain rate deformation to said materiThe United States Government has rights in this invention pursuant to Contract No. W-7405-ENG-48 between the U.S. Department of Energy and the University of California, for the operation of Lawrence Livermore National Laboratory.

Abstract: Bulk form of superconducting materials are produced by pouring a melt a O.sub.2 -containing superconducting material into a heated mold, cooling the mold until solidification begins, removing the cast object from the mold, gradually cooling the cast object to prevent the development of thermal stresses, and then annealing the cast, cooled object to restore O.sub.2 to near equilibrium levels. The bulk form produced according to the present invention may be used as a sputtering target in the production of wires, or as a bulk form semiconductor.

Abstract: An oriented superconducting material may be made by cold pressing a nonoriented superconducting material selected from the group consisting of Bi.sub.1, Bi.sub.2, Tl.sub.1, Tl.sub.2, Pb substituted Bi.sub.1, Pb substituted Bi.sub.2, Pb substituted Tl.sub.1, and Pb substituted Tl.sub.2 superconductor materials at a pressure sufficient to form an oriented superconducting material.

Abstract: A compacted and highly oriented microstructure of the bulk-shaped Bi-Sr-Ca-Cu-O system oxide superconductor is obtained by the intermediate pressing method of the present invention. The growth rate of the high critical temperature phase in the bulk of Pb-doped Bi-Sr-Ca-Cu-O system oxide superconductor is also much improved and the sintering duration for obtaining a single phase having a high critical temperature is shorteneed by this method. Additionally, a higher critcal current density of Bi-Sr-Ca-Cu-O system oxide superconductor is obtained by the working under pressure process after cooling between a first and a second sintering step. Furthermore, the magnetic field dependence of the critical current density of Bi-Sr-Ca-Cu-O system oxide superconductor is also improved by the method of the present invention.

Abstract: A technique which produces macroscopically homogeneous-shaped parts utilizes oxide-metal superconductor composites by providing a mixture of a superconductor oxide, a metal and either a oxygen or a fluorine donor.

Abstract: This invention provides a process for producing a ceramic body by heating a ceramic material, such as particulate zirconium oxide, to a temperature greater than about 30 percent of the material's melting temperature, but less than said melting temperature, and thereafter applying sufficient isostatic pressure to consolidate the ceramic material into a body having a density of at least 85 percent of the theoretical density of the material.This invention also provides a process for producing superconducting ceramic articles such as those represented by the general formula YBa.sub.2 Cu.sub.3 O.sub.7-x where 0<x<0.6. Starting materials for such articles include sources of yttria, cupric oxide and barium monoxide. The general process parameters for the ceramic body process are modified to accomodate the starting materials.

Abstract: A new high temperature superconducting system with transition temperature above 120 K is disclosed. One superconductor in that system in a preferred embodiment comprises TlRBaCuO wherein R is chosen from Group 2A elements excluding Ba. In a preferred embodiment, the superconductor is TlCaBaCuO. In another preferred embodiment, the superconductor comprises TlSrCuO. Processes for making high temperature superconducting system are also disclosed.

Abstract: The present invention relates to a superconducting material that is, substances having compositions expressed by empirical formulae Y.sub.1-x Ba.sub.x CuO.sub.3, YBa.sub.2 Cu.sub.3 O.sub.7 and LnBa.sub.2 Cu.sub.3 O.sub.7 and critical temperatures of 90 K. or more, and to a method of producing the same in which for example Y.sub.2 O.sub.3, BaCO.sub.3 and CuO are blended at a mixture molar ratio of 1:2:6 and the resulting mixture is molded under pressure followed by slowly cooling in an oxidizing atmosphere.

Abstract: A method of growing a superconducting ribbon from a molten region of a Bi-based superconducting source material using two parallel platinum support wires is described. A method of annealing the ribbon in air to reduce the quantity of nonsuperconducting phases is also described.

Abstract: A method and apparatus for manufacturing a superconductor wire has a wire take-up spool and a feed speed control spool. A wire substrate is taken from the feed speed control spool and onto the take-up spool as the wire take-up spool is rotated. The wire passes through a container which holds a diffusion barrier material, where the diffusion barrier material is electrophoretically deposited onto the wire substrate and subsequently sintered. The wire is also passed through a container which holds a superconductor material suspended in solution, and a layer of the superconductor material is electrophoretically deposited onto the diffusion barrier. The grains of the superconductor layer are then magnetically aligned and sintered. Also, a silver coating is electrophoretically deposited onto the superconductor layer and sintered. A diffusion bonding inhibitor material is then applied to the silver coating. Then, the silver-coated superconductor wire is spooled and heated to four hundred degrees centigrade (400.

Abstract: The invention relates to a process for making a superconducting connection between a pair of superconducting ceramic oxide pieces, each of the pieces having been formed by combining the metallic elements of the superconducting oxide in substantially the stoichiometric proportions needed to form the superconducting oxide into a precursor and forming the precursor into a shaped piece. The process comprises the steps of: contacting each of the shaped pieces with the other; connecting each of the shaped pieces to the other by means for forming a metallurgical bond between the shaped pieces; and oxidizing the connected shaped pieces under conditions sufficient to oxidize the metallic elements to the superconducting oxide.In other embodiments of the invention, the process is for forming a superconducting connection between a pair of pieces having a superconducting ceramic oxide/noble metal composition; or for forming a joint between a superconducting ceramic oxide and a normal conductor.

Abstract: Disclosed is a process for the preparation of a composite metal oxide superconductor, in which a composite metal oxide composition comprising Bi, Pb, Sr, Ca and Cu and further containing an alkali metal at a specific ratio is used as the starting material, and this composite metal oxide composition is molded and fired. According to this process, precipitation of the 80 K phase and other impurities is controlled, and a superconductor containing a large quantity of the 110 K phase and a high critical temperature is obtained.

Abstract: Systems for transmitting and/or receiving electromagnetic signal radiation are disclosed. The inventive systems are distinguished from previous such systems in that each includes at least one resonant cavity comprising a housing containing a body, e.g., a cylindrical or helical body, of relatively high T.sub.c superconducting material. Significantly, this body is fabricated using a new, unconventional procedure. As a result, the body exhibits substantially lower surface resistances than either previous such bodies of relatively high T.sub.c superconducting material, fabricated using conventional procedures, or bodies of copper, at 77 Kelvins and at frequencies ranging from about 10 MHz to about 2000 MHz. Moreover, as a consequence, the resonant cavity containing the unconventionally fabricated body exhibits much higher quality factors, Q, at the above temperature and frequencies, than previous such cavities containing either conventionally fabricated bodies of relatively high T.sub.

Abstract: An improved method of manufacturing superconducting ceramics in the form of a thin film are described. The thin film is first formed of a superimposed structure composed of three films which contain a rare earth metal, an alkaline metal and copper respectively. Then the superimposed thin film is fired to convert to superconducting film.

Abstract: In a known process, oxide powders derived from the four-component systems yttrium-barium-copper-oxygen or lanthanum-strontium-copper-oxygen are mixed, pressed, sintered, ground and then heat-treated to produce a superconducting material which can be shaped to the desired cross-section. According to the invention, the powder is compacted by isostatic pressing and the blank so obtained is extruded at a temperature.gtoreq.500.degree. C. to form a metallic sheath with a deformation ratio of at least 50%. The extruded blank is then converted to wire or strip. The current-carrying capacity of the high-temperature superconductor is improved by the extrusion and the resulting alignment of the crystallites. The process can be implemented using known high-temperatures superconducting material.

Abstract: An oxide superconductive material comprising constituent elements mainly composed of ABiCuO in which A comprises at least one element of alkaline earth metals, and having a C-plane orientation, and a method of orienting such superconductive materials by hot extrusion from a rectangular nozzle.

Abstract: A process for producing a superconducting ceramic material using microwave energy and the superconducting ceramic material produced thereby. A preferred process comprises the steps of mixing powders of Y.sub.2 O.sub.3, CuO and at least one member selected from the group consisting of BaCO.sub.3 and BaO, and then subjecting the resultant powder mixture to heat treatment in microwave energy. In a preferred embodiment, the heat treatment step comprises the steps of calcining, sintering and annealing, at least one of the calcining and annealing steps using microwave energy.

Abstract: A method of making an improved YBa.sub.2 Cu.sub.3 O.sub.6+x ceramic superconductor. The method includes the steps of: adding aluminum powder to YBa.sub.2 Cu.sub.3 O.sub.6+x powder to form a powder mixture, pressing the powder mixture, and rolling the pressed mixture into a thin ceramic superconductor. The addition of aluminum results in improved superconducting transition temperature, ductility and formability.

Abstract: A method for treating a ceramic article by hot isostatic pressing provides for the placement of the ceramic article in a capsule with an oxygen donor which is separated from the ceramic article by an oxygen permeable barrier such as silica cloth. The silica cloth barrier allows oxygen to flow from the donor through the barrier and surround the ceramic article. The capsule containing the ceramic article and oxygen donor are then subjected to a high temperature gas at high pressure in order to collapse the capsule around the ceramic article to compact it without substantially reducing its oxygen content.

Abstract: An improved process for preparing superconducting ceramic powder includes calcining superconducting precursor compounds in an atmosphere having a controlled amount of oxygen, generally not more than that found in air, the remainder of the atmosphere composed of a gas or mixture of gases inert with respect to the ceramic. A preferred process includes forming the precursor compounds into a slurry, granulating the slurry, drying the granules (a binder can be added to the slurry to promote green strength), and calcining in the controlled atmosphere to provide the desired HTSC (high temperature superconductor) composition.

Abstract: To produce a high-temperature superconductor of the composition Bi.sub.2 (Sr,Ca).sub.3 Cu.sub.2 O.sub.8+x having a strontium to calcium ratio of 5:1 to 2:1 and a value of x between 0 and 2, the oxides and/or carbonates of bismuth, strontium, calcium and copper are vigorously mixed in a stoichiometric ratio. The mixture is heated at temperatures of 870.degree. to 1100.degree. C. until a homogeneous melt is obtained. The melt is poured into molds and allowed to solidify in them. The cast bodies removed from the molds are annealed for 6 to 30 hours at 780.degree. to 850.degree. C. Finally, the annealed cast bodies are treated for at least 6 hours at temperatures of 600.degree. to 820.degree. C. in an oxygen atmosphere.The cast bodies can be converted into shaped bodies of the desired sizes by mechanical processes before they are annealed.The shape and size of the shaped bodies may also be determined by the shape and dimensioning of the molds used in producing the cast bodies.

Abstract: A superconductor and a method of producing the same include a supporting substrate and a superconducting oxide ceramic material applied to the supporting substrate. At least one thermally and chemically stable intermediate layer is applied directly between the superconducting ceramic material and the substrate.

Abstract: A method for producing insulated superconductor wire including the steps of a tubular glass preform, filling it with a superconductor material, suspending the preform within an oven to heat a section of the preform to approximately its softening point, and drawing the softened preform into a superconductor wire. A plastic coating can be applied to the wire to increase its durability. The completed wire preferably includes a superconductor core having its superconductor phase aligned with the longitudinal axis of the wire, a glass coating over the superconductor core, and a plastic coating over the glass coating.

Abstract: A method for the synthesis of an oxide high-temperature superconductor of defined composition by sintering of the starting oxides, wherein sintering is effected in a chemically and phyically closed system by generating a preset oxygen partial pressure through the use of peroxide additives, and the oxidic starting mixture is chemically shielded against the container material and stabilized thermodynamically.

Abstract: There is disclosed an improved process for preparing a superconducting composition having the formula MBa.sub.2 Cu.sub.3 O.sub.x wherein M is selected from the group consisting of Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu; x is from about 6.5 to about 7.0; said composition having a superconducting transition essentially of mixing M.sub.2 O.sub.3, BaO.sub.2 and CuO in an atomic ratio of M:Ba:Cu of about 1:2:3 to obtain a powder mixture; heating the resulting mixture in an oxygen-containing atmosphere at a temperature from about 850.degree. C. to about 925.degree. C. for a time sufficient to form MBa.sub.2 Cu.sub.3 O.sub.y, where y is from about 6.0 to about 6.4; and maintaining the MBa.sub.2 Cu.sub.3 O.sub.y in an oxygen-containing atmosphere while cooling for a time sufficient to obtain the desired product.

Abstract: A process for preparing a superconducting ceramic and particularly YBa.sub.2 Cu.sub.3 O.sub.7-.delta., where .delta. is in the order of about 0.1-0.4, is carried out using a polymeric binder which decomposes below its ignition point to reduce carbon residue between the grains of the sintered ceramic and a nonhydroxylic organic solvent to limit the problems with water or certain alcohols on the ceramic composition.