Abstract: A alloy (Mg—X) of metal (X) and Mg in a liquid phase is made to react with B in a solid phase at a low temperature to manufacture a superconductor, which contains a large amount of MgB2 potential for MRI, linear motorcar, superconducting cavity, electric power transmission cable, high-magnetic field magnet for medical units, electric power storage (SMES), and the like and is formed in the shape of bulk, wire, and foil, by heat treatment performed at a low temperature for a short time and at low cost.

Abstract: The present invention provides an oxide superconductor thick film which is formed on a substrate or a board and has a high Jc and Ic and a method for manufacturing the same. Predetermined amounts of materials containing elements of Bi, Pb, Sr, Ca and Cu are weighed, mixed and subjected to steps of calcining, milling, and drying, and thereafter an organic binder and an organic vehicle are added thereto to prepare a (Bi, Pb)2+aSr2Ca2Cu3O2 superconductive paste, which is applied to the surface of a substrate or a board in a thickness of 260 ?m or more and dried. Thereafter, the paste is first subjected to burning at temperatures of 835° C. to 840° C. for 100 hours, then pressurization, and further burning at temperatures of 835° C. to 840° C. for 100 hours, thereby preparing an oxide superconductor thick film having a film thickness of 130 ?m or more having a high Jc and Ic.

Abstract: The inventive method of manufacturing an oxide superconducting wire comprises a step (S1, S2) of preparing a wire formed by covering raw material powder of an oxide superconductor with a metal and a step (S4, S6) of heat-treating the wire in a pressurized atmosphere, and the total pressure of the pressurized atmosphere is at least 1 MPa and less than 50 MPa. Thus, formation of voids between oxide superconducting crystals and blisters of the oxide superconducting wire is suppressed while the partial oxygen pressure can be readily controlled in the heat treatment, whereby the critical current density can be improved.

Abstract: A method for reducing the concentration of non-superconducting phases during the heat treatment of Pb doped Ag/Bi-2223 composites having Bi-2223 and Bi-2212 superconducting phases is disclosed. A Pb doped Ag/Bi-2223 composite having Bi-2223 and Bi-2212 superconducting phases is heated in an atmosphere having an oxygen partial pressure not less than about 0.04 atmospheres and the temperature is maintained at the lower of a non-superconducting phase take-off temperature and the Bi-2223 superconducting phase grain growth take-off temperature. The oxygen partial pressure is varied and the temperature is varied between about 815° C. and about 835° C. to produce not less than 80 percent conversion to Pb doped Bi-2223 superconducting phase and not greater than about 20 volume percent non-superconducting phases. The oxygen partial pressure is preferably varied between about 0.04 and about 0.21 atmospheres. A product by the method is disclosed.

Abstract: Compositions having the nominal formula BiaSrbCacCu3Ox wherein a is from about 1 to 3, b is from about ? to 4, c is from about {fraction (3/16)} to 2, x=(1.5 a+b+c+y) where y is from about 2 to 5, with the proviso that “b+c” is from about {fraction (3/2)} to 5, containing a metal oxide phase of the formula Bi2Sr3?zCazCu2O8+w wherein z is from about 0.1 to 0.9 w is greater than zero but less than 1, are superconducting. Processes for manufacturing such compositions and for using them are disclosed.

Abstract: A method for maximising critical current density (Jc) of high temperature superconducting cuprate materials (HTSC) which comprises controlling the doping state or hole concentration of the materials to be higher than the doping state or hole concentration of the material that provides a maximum superconducting transition temperature (Tc), and to lie at about a value where the normal-state pseudogap reduces to a minimum. Jc is maximised1 at hole concentration p≈0.19. HTSC compounds are also claimed.

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: An Oxide Precursor Powder from the Pb—Bi—Sr—Ca—Cu—O 2223 System can be produced by heat treating powder, produced using the Spray Pyrolysis Process as described in: GB2210605 or EP0681989 between 700° C. and 850° C. in an atmosphere containing between 0.1% and 21% O2. Heat Treatment of the pyrolysis powder under controlled conditions produces a powder with a particular phase composition, that is highly homogeneous and has a small particle size distribution, that is inherently more reactive than powders heat treated in the same way but produced using other processes.

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: The invention provides a method for stably preparing a bismuth-based high temperature superconductor of a Bi-2223 single-phase or a Bi/Pb-2223 single phase, wherein a second phase is not allowed to reside, at a low cost and efficiently. With the method described above, mixed powders of raw materials (mixed powders of oxides and carbonates), obtained by mixing the raw materials such that a mixing ratio of constituents, Bi:Sr:Ca:Cu or (Bi, Pb):Sr:Ca:Cu, becomes identical to the stoichiometric ratio of a crystal of the superconductor Bi2Sr2Ca2Cu3Oz, or (Bi, Pb) 2Sr2Ca2Cu3Oz, respectively, are used as raw material for sintering, and the sintering is applied thereto, using KCl as a flux. In this case, the raw material for the sintering as calcinated is preferably used, and the sintering is preferably applied at a sintering temperature kept at a constant level.

Abstract: A method of producing a composite material of a bismuth 2212 phase and a metallic substrate, wherein the first and second baking are conducted as an isothermal heat treatment. According to this process, temperature control is easy, high productivity is obtained, and the critical current density is improved.

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: 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 high-temperature superconductor having low superconducting anisotropy includes a two-dimensional layered structure of crystal unit cells each consisting of a pair of superconducting layer and charge reservoir layer. At least a portion of the atoms of the charge reservoir layer are replaced by atoms giving superconductivity, rendering the charge reservoir layer superconducting and lowering the superconducting anisotropy by increasing the coherence length in the thickness direction.

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: 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)≧3.5×1010 exp(−32,000/T+273) and an upper bound defined by the equation, PO2(upper)≦1.1×1012 exp(−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: Improved Hg-containing superconducting films and thermoelectric materials are provided. The films are fabricated by annealing starting Tl-containing films (e.g., Tl-1212 or Tl-2212) in an Hg-vapor environment so as to cause a substitution of Tl by Hg without substantial alteration of the crystalline structure of the starting films. Preferably, a body comprising a substrate having an epitaxial Tl-containing film thereon is annealed under vacuum conditions with a Hg-based bulk; typical annealing conditions are 600-900° C. for a period of from about 1-20 hours. The final Hg-containing film products have a Jc of at least about 106 A/cm2 (100 K, OT) and a Xmin of up to about 50%. The thermoelectric materials are prepared by perturbing a crystalline precursor having a structure similar to the final material so as to cause a first molecule to be released from the precursor.

Abstract: The present invention provides a (Bi,Pb)SCCO-2223 oxide superconductor composite which exhibits improved critical current density and critical current density retention in the presence of magnetic fields. Retention of critical current density in 0.1 T fields (77 K, ⊥ ab plane) of greater than 35% is disclosed. Significant improvements in oxide superconductor wire current carrying capacity in a magnetic field are obtained by subjecting the oxide superconductor composite to a post-processing heat treatment which reduces the amount of lead in the (Bi,Pb)SCCO-2223 phase and forms a lead-rich non-superconducting phase. The heat treatment is carried out under conditions which localize the lead-rich phase at high energy sites in the composite.

Abstract: A process for centrifugal slip casting a textured hollow tube. A slip made up of a carrier fluid and a suspended powder is introduced into a porous mold which is rotated at a speed sufficient to create a centrifugal force that forces the slip radially outward toward the inner surface of the mold. The suspended powder, which is formed of particles having large dimensional aspect ratios such as particles of superconductive BSCCO, settles in a textured fashion radially outward toward the mold surface. The carrier fluid of the slip passes by capillary action radially outward around the settled particles and into the absorbent mold. A layer of mold release material is preferably centrifugally slip cast to cover the mold inner surface prior to the introduction of the BSCCO slip, and the mold release layer facilitates removal of the BSCCO greenbody from the mold without fracturing.

Abstract: Methods for preparing high quality superconducting oxide precursors which are well suited for further oxidation and annealing to form superconducting oxide films. The method comprises forming a multilayered superconducting precursor on a substrate by providing an electrodeposition bath comprising an electrolyte medium and a substrate electrode, and providing to the bath a plurality of precursor metal salts which are capable of exhibiting superconducting properties upon subsequent treatment. The superconducting precursor is then formed by electrodepositing a first electrodeposited (ED) layer onto the substrate electrode, followed by depositing a layer of silver onto the first electrodeposited (ED) layer, and then electrodepositing a second electrodeposited (ED) layer onto the Ag layer. The multilayered superconducting precursor is suitable for oxidation at a sufficient annealing temperature in air or an oxygen-containing atmosphere to form a crystalline superconducting oxide film.

Abstract: A multicomponent powder useful in the formation of BSCCO-2223 is provided comprised of orthorhombic BSCCO-2212 and alkaline earth cuprate, without formation of undesirable secondary phases such as alkaline earth bismuthates and alkaline earth plumbates. A method for the production of the multicomponent powder includes providing a mixture of raw materials comprising constituent metallic elements in a ratio corresponding to a superconducting BSCCO-2223 material and heating the mixture under conditions which form a dominant amount of the orthorhombic BSCCO phase and the alkaline earth cuprate phase while preventing formation of an undesirable secondary phase selected from the group of alkaline earth plumbates and alkaline earth bismuthates. A subsequent heating step converts the multicomponent powder into the BSCCO-2223 and subsequent deformation and annealing processes may be used to form a substantially single phase, highly textured (Bi,Pb)SCCO-2223 superconductor article.

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 clad superconductive wire or tape of an oxide superconductive material and a silver-copper alloy base containing 0.05-90 atomic % a copper or a silver alloy. The silver-copper alloy base contains one or more elements selected from the group of Zr, Hf, Al, V, Nb and Ta in amounts of from 0.01-3 atomic %, or contains Au in amount of 0.01-10 atomic %. The silver alloy contains one or more elements selected from the group of Ti, Zr, Hf, V, Nb, Ta, Mg, Ca, Sr and Ba in amounts of from 0.01 to 3 atomic %, or one or more elements selected from the group of Au, Al, Ga, In and Sn in amounts of 0.05 to atomic %. The base material is filled with a Bi-containing oxide of Bi1PbuSrxCayCuzOw wherein u=0-0.3, X=0.8-1.2, y=0.2-1.2, and z=0.8-2.0, and processed to obtain a superconductive wire or tape having enhanced mechanical strength, superconductivity and plastic workability.

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 clad superconductive wire or tape of an oxide superconductive material and a silver-copper alloy base containing 0.05-90 atomic % copper or a silver alloy. The silver-copper alloy base contains one or more elements selected from the group of Zr, Hf, Al, V, Nb and Ta in amounts of from 0.01-3 atomic %, or contains Au in amount of 0.01-10 atomic %. The silver alloy contains one or more elements selected from the group of Ti, Zr, Hf, V, Nb, Ta, Mg, Ca, Sr and Ba in amounts of from 0.01 to 3 atomic %, or one or more elements selected from the group of Au, Al, Ga, In and Sn in amounts of 0.05 to atomic %. The base material is filled with a Bi-containing oxide of Bi1PbuSrxCayCuzOw wherein u=0-0.3, X=0.8-1.2, y=0.2-1.2, and z=0.8-2.0, and processed to obtain a superconductive wire or tape having enhanced mechanical strength, superconductivity and plastic workability.

Abstract: A composite for preparation of an oxide superconductor includes a primary alloy phase of constituent elements of a desired oxide superconductor; and a secondary phase comprising copper, the secondary phase supported by the primary alloy phase. The composite may additionally include a matrix material for supporting the primary alloy phase and second phase disposed therein. The composite is oxidized to form an oxide superconductor composite.

Abstract: A superconductor with the Bi 2223 high Tc phase is manufactured by mulitply deforming and annealing a structure composed of a material matrix and at least one core of a fabricated material of the superconductor material. At least during an initial segment of a cooling process following the final annealing, the oxygen partial pressure is lowered with decreasing temperature at least in a temperature range between 800° C. and 750° C. for stabilizing the 2223 phase. A rapid cooling to room temperature advantageously follows.

Abstract: Superconductor tapes are annealed under uniaxial pressure, such a compressive annealing yielding significant improvement in the resultant critical current density. This thermomechanical processing technique obtains improved critical currents with fewer processing steps.

Abstract: A method for preparing an oxide superconductor cable includes transposing a plurality of oxide superconductor strands along a longitudinal axis so as to form a cable and exposing the cable to a two step heat treatment after cabling of the oxide strands, the heat treatment comprising, (a) heating the cable to and maintaining the cable at a first temperature sufficient to partially melt the article, such that a liquid phase co-exists with the desired oxide superconductor phase; and (b) cooling the cable to and maintaining the cable at a second temperature sufficient to substantially transform the liquid phase into the desired oxide superconductor.

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

Abstract: A method for producing a superconducting thick film involves the steps of forming a thick layer comprising a superconducting material on a substrate; firing the thick layer formed on the substrate; subjecting the fired thick layer to cold isostatic pressing; and refiring the thick layer subjected to cold isostatic pressing.

Abstract: The invention provides certain novel metal oxide materials which exhibit superconductivity at elevated temperatures and/or which are useful in electrode, electrolyte, cell and sensor applications, or as electrochemical catalysts. The metal oxide materials are generally within the formulaR.sub.n+1-u-s A.sub.u M.sub.m+e Cu.sub.n 0.sub.w (1)where n.gtoreq.0 and n is an integer or a non-integer, 1.ltoreq.m.ltoreq.2, 0.ltoreq.s.ltoreq.0.4, 0.ltoreq.e.ltoreq.4, and 2n+(1/2)<w<(5/2)n+4, with the provisos that u is 2 for n.ltoreq.1, u is n+1 for 0.ltoreq.

Abstract: A process for increasing the resistivity of a HTS oxide composite sheath including heating a superconductive HTS oxide composite, the composite including a sheath including silver, in the presence of mercury at temperatures sufficient to form a silver--mercury alloy is provided together with a HTS oxide composite which includes a high temperature superconductor oxide core surrounded by a metallic sheath, the metallic sheath including silver and mercury.Also provided is a process for preparing a HTS oxide composite having an enhanced transport critical current density including placing the HTS oxide composite within a sealed, evacuated container, and, heating the HTS oxide composite for time and at temperatures sufficient for enhancement of transport critical current density in comparison to the transport critical current density of the HTS oxide composite prior to the heating.

Abstract: A method for producing a high temperature superconductor system having the composition TlBiBaCaCuO. The system exhibits a T.sub.c of at least 116 K. The method includes the steps of mixing compounds including Tl, Bi, Ba, Ca, Cu, and O to create a mixture. The mixture is heated. The mixture is then cooled.

Abstract: Process for producing an elongated superconductor with a bismuth phase having a high transition temperature and a superconductor produced according to this process. An elongated superconductor with at least one conductor core made of high-T.sub.c Bi-containing superconductor material with the 2212 or 2223 phase is to be manufactured. For this purpose, the cross section of a structure made of Ag matrix material and a precursor of the superconductor material is reduced. Subsequently the raw conductor thus obtained is annealed in an oxygen-containing atmosphere. According to this invention, a temperature variation between a higher temperature (T1) and a lower temperature (T2) is provided for the annealing. The higher temperature (T1) is at most 7 K above the decomposition temperature (Tz), and the lower temperature (T2) is at most 9 K below the decomposition temperature (Tz).

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

Abstract: A precursor is made from a plurality of materials having different vapor pressures. The precursor and a source material are placed in a closed heat treatment furnace. The source material is materials which are the same as some of the materials contained in the precursor and having particular vapor pressures. The precursor and source material is thermally treated in the furnace while the source material is being supplied, so the particular materials in the precursor have their evaporation suppressed, thereby forming compounds. The compounds may be oxide superconductors, oxide dielectric, and so on.

Abstract: A novel process of the production and processing of high quality, high T.sub.c (Bi,Pb)SCCO superconductors starts with fabrication of a precursor article including selected intermediate phases with desired chemical and structural properties. The precursor fabrication includes introducing the reacted mixture having a dominant amount of the tetragonal BSCCO phase into a metal sheath, and sealing the reacted mixture within said sheath, heating the mixture at a second selected processing temperature in an inert atmosphere with a second selected oxygen partial pressure for a second selected time period, the second processing temperature and the second oxygen partial pressure being cooperatively selected to form a dominant amount of an orthorhombic BSCCO phase in the reacted mixture.

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: Provided is a process for preparing a bismuth compound at a heat treatment temperature lower than conventional. A bismuth compound is prepared by the steps of heating under vacuum to form a reduced phase and heating under oxidizing environment of normal or lower pressure.

Abstract: A method of producing a tape-shaped superconducting wire is provided. The wire maintains a high critical temperature and a high critical current density along the overall length thereof. In this method, raw material powder for the oxide superconductor is first charged in a silver sheath and the sheath charged with the powder is subjected to plastic working to prepare a first flat type wire. On the other hand, a second wire consisting of a tape wire formed by coating a surface of a flat type wire having at least an outer surface consisting essentially of silver or a silver alloy with a metal oxide or ceramics, or a tape wire containing ceramics fibers and a binder dissipated by heat treatment is prepared. The first and second wires are layered with each other, and tightly wound in a pancake coil shape. The wires wound in the pancake coil shape are heat treated for sintering the oxide superconductor. After the heat treatment, the first wire is separated from the second wire.

Abstract: Disclosed herein is a method of preparing a bismuth superconductor including the steps of mixing raw materials for forming a bismuth superconductor with each other to obtain mixed powder, heat treating the mixed powder, pulverizing the mixed powder and then covering the mixed powder with a metal sheath. The mixed powder covered with the metal sheath is prepared to have a 2223 composition in a composition of Bi--Sr--Ca--Cu or (Bi,Pb)--Sr--Ca--Cu and to contain a superconducting phase which is mainly composed of a 2212 phase, and is pulverized into a mean particle diameter of not more than 1 .mu.m with no conversion of the 2212 phase to an amorphous state.

Abstract: The present invention is directed to a process for preparing a HgBaCaCuO superconductor by annealing a precursor mixture comprising a lower member of the homologous HgBaCaCuO superconductor series, a source of calcium and a source of copper. The precursor mixture may further comprise a source of oxygen, a source of rhenium, and, if desired, a source of an additional element selected from the group consisting of halogens and metals other than mercury, barium, calcium, copper and rhenium. The process is particularly effective for preparing (Hg.sub.1-x,Re.sub.x)Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub.8-y by annealing a precursor mixture containing (Hg.sub.1-x,Re.sub.x)Ba.sub.2 Ca.sub.1 Cu.sub.2 O.sub.6-y at a temperature below about 850.degree. C., wherein x ranges up to about 0.25 and y is a rational number ranging from about negative 1 to about positive 1.

Abstract: A method of manufacture of a textured layer of a high temperature superconductor on a substrate. The method involves providing an untextured high temperature superconductor material having a characteristic ambient pressure peritectic melting point, heating the superconductor to a temperature below the peritectic temperature, establishing a reduced pO.sub.2 atmosphere below ambient pressure causing reduction of the peritectic melting point to a reduced temperature which causes melting from an exposed surface of the superconductor and raising pressure of the reduced pO.sub.2 atmosphere to cause solidification of the molten superconductor in a textured surface layer.

Abstract: A system for applying a volatile element-HTS layer, such as Tl-HTS, to a substrate in a multiple zone furnace, said method includes heating at higher temperature, in one zone of the furnace, a substrate and adjacent first source of Tl-HTS material, to sublimate Tl-oxide from the source to the substrate; and heating at lower temperature, in a separate zone of the furnace, a second source of Tl-oxide to replenish the first source of Tl-oxide from the second source.

Abstract: A method for forming a conductor element comprising a Tl or Hg-based high temperature superconductor (HTSC) material, comprises providing at least one first precursor material within an outer sheath for the conductor element; providing at least one second precursor material within the conductor sheath and separated from the first precursor material(s) by a barrier layer formed from a Noble metal for example between the first and second precursor materials; and heating the conductor sheath containing the precursors to a temperature at which the barrier layer melts to allow the precursor materials to mix and react, or to a temperature at which one of the precursor material(s) diffuses through the barrier layer sufficiently allow the precursor materials to mix and react, to form the Tl or Hg-HTSC material within the outer conductor sheath.

Abstract: This invention concerns a method for the production of an oxide superconducting tape material having a composition of Bi.sub.2 Sr.sub.2 CaCu.sub.2 O.sub.8, which method consists essentially of forming a sandwich structure comprising a layer formed of a superconducting powder consisting essentially of Bi, Sr, Ca, Cu, and O and having an essential structure of Bi.sub.2 Sr.sub.2 CaCu.sub.2 O.sub.8 and silver sheet layers, the superconducting powder layer being interposed between the silver sheet layers, heating the sandwich structure at a temperature in the range of 810.degree.-910.degree. C. in an atmosphere consisting of oxygen and an inert gas and having an oxygen partial pressure in the range of 0-90%, thereby melting the superconducting powder layer, and then elevating the oxygen partial pressure of the atmosphere while retaining the same heating temperature, thereby crystallizing the molten superconducting powder layer.

Abstract: In order to provide a Tl--Ba--Ca--Cu--O superconductive material which can obtain a stable superconducting state and a method of preparing the same, the oxide superconductive material is expressed in the following composition formula:Tl.sub.x Ba.sub.2 Ca.sub.y Cu.sub.3 O.sub.zwhere x, y and z are in relations satisfying 1.5.ltoreq.x.ltoreq.2.0, 2.0.ltoreq.y.ltoreq.2.5, x+y=4.0 and 9.0.ltoreq.z.ltoreq.11.0, and comprises tetragonal system superconducting phases having lattice constants of a=0.385 to 0.386 nm and c longer than 3.575 nm, to exhibit zero resistance under a temperature of at least 125 K, while the method comprises a step of mixing powder raw materials in blending ratios for satisfying the above composition formula, a step of sintering the as-formed mixed powder in an oxygen jet or in the atmosphere to obtain a sintered body, and a step of annealing the sintered body in a closed atmosphere at 700.degree. to 800.degree. C. for at least 10 hours.

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

Abstract: The invention relates to a spray pyrolytic process for the preparation of multi-element metal oxide powders useful as precursors of high temperature superconductor ceramics. Aerosols of aqueous solutions containing corresponding metal salts admixed in the required stoichiometric proportion are sprayed through an independently operated hydrogen/oxygen flame in such a way that a flame temperature of 800.degree.-1100.degree. C. is maintained to form said powders. Any contact of the aerosols and powders generated during the process with carbon or carbon-containing compounds or materials is strictly avoided.