Abstract: A process for manufacturing a wire made of oxide which is applicable for manufacturing a superconducting coil or the like. The process includes steps comprising preparing a mass of oxide having superconductivity from powder material, covering the mass of oxide with a metal pipe, and then reducing the diameter of the metal pipe containing the mass of oxide therein into a wire form by such plastic deformation that exert mainly compressive strain upon the metal pipe. The mass of oxide may be a compound oxide having Perovskite-type crystal structure exhibiting superconductivity. The metal pipe may be made of a metal selected from a group comprising Cu, Al, Nb, V, Mo, Ta, and Ag and of an alloy including these metals as the base. The mass of oxide may be produced by steps including extruding a powder material into a rod shape and then sintering the molded rod at a temperature ranging from 700.degree. to 1,000.degree. C.

Abstract: A joining product of oxide superconducting materials having a high current density and process for producing the same. A joining product comprising a plurality of oxide superconducting materials having an identical crystal orientation joined with each other through a superconducting phase of the same type as described above which has the same crystal orientation as the oxide superconducting materials and a lower peritectic temperature than the oxide superconducting materials.

Abstract: The hole density of an oxide superconductor having holes as carriers is higher than the hole density to bring the highest value of the superconductivity critical temperature Tc thereof, and it can be made higher than the optimal density to bring the highest Tc value by treating the oxide superconductor with heat in an oxidizing gas atmosphere, or by replacing positive ions constituting the oxide superconductor except for copper with ions of a low valence number. Accordingly, it is possible to substantially reduce the rate of decrease of the critical current density owing to an applied magnetic field when the magnetic field is applied parallel to the crystal c axis, and to allow a current conductor produced by using the oxide superconductor to have high critical current density.

Abstract: A biaxially textured article includes a rolled and annealed, biaxially textured substrate of a metal having a face-centered cubic, body-centered cubic, or hexagonal close-packed crystalline structure; and an epitaxial superconductor or other device epitaxially deposited thereon.

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

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

Abstract: The present invention provides an oxide superconductor which is expressed in the composition formula(Pb.sub.1-x-y M.sub.x (A1).sub.y)(A2).sub.2 (A3).sub.n-1 (Cu).sub.n (O).sub.2n+3+z(wherein 0.ltoreq.0.6, 0.ltoreq.y.ltoreq.0.6, x+y.ltoreq.0.6, n denotes integers of 1 or more, -0.6.ltoreq.z.ltoreq.0.5, M denotes Cu or Cd, and A1, A2 and A3 denote at least one element of Ba, Sr, and Ca, respectively) and which has a crystal structure stacking rock salt structure based portions and infinite layer structure portions, wherein the rock salt structure based portion has a structure that an atoms layer having 0.5-1.5 oxygen atoms, in case the total atoms number of Pb, M and A1 is one, and an atoms layer having one or less oxygen atoms per one A2 atom, are stacked and the infinite layer structure portion has a structure that an atoms layer having 2 oxygen atoms per one Cu atom and an atoms layer of A3 atoms only, are stacked.

Abstract: A strongly-linked polycrystalline oxide superconductor article includes an oxide superconductor selected from the group consisting 124-type and 247-type oxide superconductors having fine, highly aligned oxide superconductor grains less than 50 .mu.m along a longest dimension. The oxide superconductor article has at least a 25% retention of critical current density in a 0.1 Tesla field.

Abstract: An oxide superconductor composed of Cu, O and at least one of Ba, Sr and Ca and including alternately arranged at least one oxygen-deficient perovskite structure section and at least one infinite layer structure section, wherein the perovskite structure section consists of two first atomic layers and a second atomic layer sandwiched between the first layers, and wherein the infinite layer structure section consists of alternately arranged, third and fourth atomic layers. Each of the first layers consists of O and an element M.sup.1 selected from Ba, Sr and Ca and has an atomic ratio O/M.sup.1 of 1 or less, while the second layer consists of O and Cu and has an atomic ratio O/Cu of 2 or less. Each of the third layers consists of O and Cu and has an atomic ratio O/Cu of 2, while each of the fourth layers consists of an element M.sup.2 selected from Ba, Sr and Ca. A superconductor having a superconducting critical temperature of over 100 K. may be produced by heat treatment at 800.degree.-1,200.degree.C.

Abstract: In order to prevent expansion of a metal sheath which is heat treated in order to form an oxide high-temperature superconductor therein, the heat treatment temperature is held at a certain level in an intermediate stage of temperature rising in a step of heat treating the metal sheath after filling raw material for an oxide high-temperature superconductor into the metal sheath. After the heat treatment temperature is thus held at the certain level, the metal sheath is again heated to a target temperature. Preferably, the heat treatment temperature is held at a level which is selected in a range of at least 500.degree. C. and not more than 750.degree. C.

Abstract: A process for producing a sintered body from untra-fine superconductive particles. In the first step of this process, a ceramic precursor material containing yttrium, barium and copper cations, a nitrogen-containing material, a solvent, and an anion capable of participating in an anionic oxidation-reduction reaction with the nitrogen-containing material, is provided; the nitrogen-containing material contains at least three nitrogen atoms, at least one oxygen atom, and at least one carbon atom. In the second step of the process, droplets of such ceramic precursor material are formed. In the third step of the process, the droplets are dried until particles which contain less than about 15 weight percent of solvent are produced. In the fourth step of this process, such particles are ignited in an atmosphere which contains substantially less than about 60 weight percent of the solvent's saturation value in such atmosphere.

Abstract: A method of manufacturing an oxide superconductor, including the steps of mixing oxide materials of the metals contained in an oxide superconductor represented by HgBa.sub.2 Ca.sub.2 Cu.sub.3 O.sub.8+y to prepare a powder mixture of the composition noted above, molding the powder mixture to prepare a molded body of a desired shape, and applying a heat treatment to the molded body within a hermetic container at a temperature sufficient for bringing about a solid phase reaction of the oxide materials for at least 20 hours.

Abstract: Described is a process for manufacturing thin films by periodically depositing (DEP) a number of block layers consisting of different base materials on a substrate (multilayer deposition), wherein the thickness of the layers (LT) is restricted to one to 20 monolayers and deposition as well as crystallization of the thin film is completed at approximately constant temperature without performing a separate annealing step. The method can be used to produce thin films of high-T.sub.c -superconductors. It allows a better control of the crystal growth of ternary or higher compounds with comparatively large unit cells.

Abstract: A process for preparing an YBCO oxide thin film which has a crystalline, clean and smooth surface on a substrate. The process is conducted by using an apparatus comprising a vacuum chamber in which an oxidizing gas of O.sub.2 including O.sub.3 can be supplied near the substrate so that pressure around the substrate can be increased while maintaining high vacuum near an evaporation source and K cell evaporation sources arranged in the vacuum chamber wherein the substrate is heated, molecular beam of constituent atoms of the oxide excluding oxygen are supplied from the K cell evaporation sources, and a chilled oxidizing gas is locally supplied to the vicinity of the substrate.

Abstract: A process for removing contaminants from a surface of a thin film of oxide superconductor deposited on a substrate. The thin film of oxide superconductor is heat-treated in ultra-high vacuum at a temperature which is within a range of -100.degree. C. to +100.degree. C. of the temperature at which oxygen enter into the oxide superconductor.The process is used for removing photo-resist from a surface of thin film of oxide superconductor and for producing a layered structure containing at least one thin film of oxide superconductor such as Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x having a contaminated surface. On the cleaned surface, another thin film of oxide superconductor or non-superconductor is deposited. The resulting structure of layered thin films is used for fabricating superconducting transistor, Josephson junctions, superconducting circuits or the like.

Abstract: A method of forming a high-Tc microbridge superconductor device is disclosed, which comprises the steps of forming an inclined step on the surface of a substrate, the inclined step having an angle of inclination of from about 20 to about 80 degrees; depositing a layer of c-axis oriented superconductor material overlying the substrate such that there is a break in the layer of superconductor material at the inclined step; and depositing a layer of normal material overlying the layer of c-axis oriented superconductor material.

Abstract: A melt textured growth process for bulk YBCO at temperatures below 950.degree. C. is provided so that the material (YBCO) can be combined with silver to produce bulk superconductors by providing a combination of precursors that provide melting at 950.degree. C. or lower temperatures. After melting of the thoroughly mixed precursors, the sample is cooled in a controlled temperature environment. The process makes it possible to use metallic silver or other normal metals such as gold, as components in the fabrication of long YBCO wires and cables while achieving a high critical current density.

Abstract: A process of manufacturing a superconducting compound including mixing stoichiometric amounts of a metallic oxide, copper oxide and a metallic carbonate wherein the metal of the metallic oxide is one other than yttrium and is selected and identified by its intrinsic massivity which is close in value to the intrinsic massivity of yttrium and wherein the interplanar distance on the C axis between Cu--O planes that exchange electrons through the electron-hopping mechanism in the ceramic perovskite is within the range of 1.97 .ANG. and 1.01 .ANG.. The mixture is subjected to pressure to form pellets and the pellets are then heated in forming the compound. The compound produced by the process and ceramic compositions having the formulas Mn Sr.sub.2 Cu.sub.3 O.sub.7-x and Mn.sub.2 Sr.sub.2 Cu.sub.3 O.sub.7-x.

Abstract: Disclosed are a composition and a method of preparing a composition of the formula R.sub.2 Q.sub.4 Cu.sub.7 O.sub.x, wherein R is a rare-earth ion or a mixture of rare earth ions, and Q is Ba, or Ba combined with either Sr or Ca or both Sr and Ca. Such compositions have a unique crystalline structure and are superconducting oxides.

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

Abstract: A superconductive ceramic composite material with high strength and capable of plastic deformation is prepared by mixing and sintering a superconductive powder represented by (RE.sub.x AE.sub.1-x).sub.1-y Cu.sub.y O.sub.z (RE represents Y or a rare-earth element having an atomic number of 57-71, or a combination of at least two of these elements, AE is at least one of alkaline earth elements Ca, Sr and Ba, x is 0.13-0.67, y is 0.25-0.67, and z is 1.08-1.17) and a metal powder M (M represents at least one of noble metals Rh, Pd, Ag, Ir, Pt and Au), in a defined ratio. The deformation (e.g., rolling) is followed by reheat-treatment (resintering). The powder mixture can be enclosed in a metallic capsule or made into a clad sheet by interposing the powder within two metallic sheets, and deformed (drawn or press formed into a desired shape) followed by sintering. The composite material may contain a superconductive network of such grains.

Abstract: A method of preparing a superconducting oxide by combining the metallic elements of the oxide to form an alloy, followed by oxidation of the alloy to form the oxide. Superconducting oxide-metal composites are prepared in which a noble metal phase intimately mixed with the oxide phase results in improved mechanical properties. The superconducting oxides and oxide-metal composites are provided in a variety of useful forms.

Abstract: A family of mercury-containing Sr-(Ca.cndot.Y)-Cu-O superconducting materials having a zero-resistance temperature, T.sub.c(zero), greater than 90 K so that they can be cooled to and maintain the desired superconducting characteristics using relatively less expensive liquid nitrogen, are disclosed. The high-temperature superconductor is represented by the formula of: (Pb.sub.0.5 Hg.sub.0.5)(Sr.sub.2-x Ba.sub.x)(Ca.sub.0.7 Y.sub.0.3)Cu.sub.2 O.sub.7-.delta. ; wherein the value of x ranges between about 0.1 and about 0.6, preferably between about 0.2 and about 0.3. These superconducting materials are prepared by first grinding and mixing in open air constituent oxide powders of PbO, HgO, SrO.sub.2, BaO.sub.2, CaO, Y.sub.2 O.sub.3, and CuO. After mixing, the powder mixture is pressed under a pressure of about 5 ton/cm.sup.2 to form a pellet having a diameter of 8 mm and a thickness of 3 mm. Thereafter, the pressed pellet is wrapped with a gold foil (with a thickness of 0.

Abstract: A process for producing a layered structure containing at least one thin film of oxide superconductor (1) such as Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x having a contaminated surface on a substrate (3). The contaminated surface of the thin film of oxide superconductor is heat-treated in an atmosphere containing oxygen of high purity of higher than 5N and a partial pressure of 25 Torr at a temperature of 350.degree. to 700.degree. C. On the thin film of oxide superconductor (1), another thin film (2) of oxide superconductor or non-superconductor is deposited.The resulting structure of layered thin films is used for fabricating superconducting transistor, Josephson junctions, superconducting circuits or the like.

Abstract: Provided is an Hg-Ba-Ca-Cu-O oxide superconductor having a high superconductivity transition temperature Tc and a method which can prepare the same in excellent reproducibility. This oxide superconductor consists essentially of Hg, Ba, Ca, Cu and O, and is expressed in a chemical formula (Hg.sub.1-X Cu.sub.X)Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub.Y, wherein X=0.05 to 0.7 and Y=8 to 8.75. A method of preparing the oxide superconductor comprises a step of mixing raw materials of Hg, Ba, Ca and Cu with each other so that (Hg+Ba):Ca:Cu=b:1:C and Hg:Ba=(1-a):a, wherein 0.625.ltoreq.a.ltoreq.0.714, 1.ltoreq.b.ltoreq.3 and 1.667.ltoreq.c.ltoreq.3.444, in mole ratio, and compression-molding the mixture, and a step of heat treating a compact obtained by the compression molding. This oxide superconductor has a superconductivity transition temperature Tc of 134 K., which is the highest at present.

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

Abstract: A high temperature superconductor and composite structure. A superconductor is disposed on a silver substrate without interdiffusion. The superconductor is formed by heating to a temperature not exceeding the peritectic point of the superconductor material, providing an oxidizing atmosphere while not exceeding the melting point of silver and disposing the superconductor on the silver substrate.

Abstract: A ceramic superconductor is produced by close control of oxygen partial pressure during sintering of the material. The resulting microstructure of YBa.sub.2 Cu.sub.3 O.sub.x indicates that sintering kinetics are enhanced at reduced p(O.sub.2). The density of specimens sintered at 910.degree. C. increased from 79 to 94% theoretical when p(O.sub.2) was decreased from 0.1 to 0.0001 MPa. The increase in density with decrease in p(O.sub.2) derives from enhanced sintering kinetics, due to increased defect concentration and decreased activation energy of the rate-controlling species undergoing diffusion. Sintering at 910.degree. C. resulted in a fine-grain microstructure, with an average grain size of approximately 4 .mu.m. Such a microstructure results in reduced microcracking, strengths as high as 191 MPa and high critical current density capacity.

Abstract: The present invention provides a process for the preparation of YBa.sub.2 Cu.sub.3 O.sub.7-x superconductor which comprises surrounding a sintered material in which the molar ratio of Y:Ba:Cu is 2:1:1 with liquid-forming powder and subjecting the powder compact to isothermal heat-treatment at a temperature below the peritectic temperature of YBa.sub.2 Cu.sub.3 O.sub.7-x. The YBa.sub.2 Cu.sub.3 O.sub.7-x superconductors prepared according to the present invention have aligned grain structure in one direction and thus exhibit a high critical current density.

Abstract: A high critical temperature and high critical current density superconductor is disclosed which contains a metal oxide expressed by the following formula (I):(R.sup.1.sub.1-x,Ba.sub.x)Ba.sub.2 Cu.sub.3 O.sub.d (I)wherein R.sup.1 stands for at least one element selected from the group consisting of La, Nd, Sm, Eu and Gd, x is a number greater than 0 but not greater than 0.5 and d is a number between 6.2 and 7.2. Fine phases of RE211, RE422 and/or a metal oxide expressed by the formula (R.sup.2.sub.1-z, Ba.sub.z) (Ba.sub.1-y, R.sup.2.sub.y).sub.2 Cu.sub.3 O.sub.p (R.sup.2 =La, Nd, Sm, Eu or Gd) may be dispersed in a matrix of the matrix phase of the formula (I). The above superconductor may be obtained by cooling a melt having a temperature of 1,000.degree.-1,300.degree. C. and containing R.sup.1, Ba, Cu and O at a cooling rate of 5.degree. C./hour or less under a partial pressure of oxygen of between 0.00001 and 0.05 atm, followed by annealing at 250.degree.-600.degree. C. in an oxygen atmosphere.

Abstract: In accordance this invention, there is provided a process for making a bulk superconductive material. In the first step of this process, a diffusion couple is formed from superconductor oxide and impurity oxide. Thereafter, the diffusion couple is heated to a temperature in excess of 800 degrees Centigrade, cooled at a controlled rate, and annealed.

Abstract: Disclosed are ceramic materials and methods of making the same comprising yttrium, barium, silver, and either selenium or sulfur. Those ceramic materials show changes in magnetic susceptibility at around 373.degree. K. with selenium and 195.degree. K. with sulfur.

Abstract: A novel metallic oxide of a Ln-Ca-Sr-Ba-Cu-B-O type and a process for manufacturing such a metallic oxide. The above metallic oxide has a composition expressed by the following formula (I):(Ln.sub.1-a Ca.sub.a)(Sr.sub.2-b Ba.sub.b)(Cu.sub.3-c B.sub.c)O.sub.d(I)wherein Ln is one or more kinds of elements selected from the group consisting of Y and lanthanoid elements except for Ce and Tb and wherein the following conditions are met: 0.1.ltoreq.a.ltoreq.0.5, 0.7.ltoreq.b.ltoreq.1.7, 0.1.ltoreq.c.ltoreq.0.5, and 6.5.ltoreq.d.ltoreq.7.5. A process for manufacturing the metallic oxide has the following steps. A mixture of materials including H.sub.3 BO.sub.3 used as a starting material of B is prepared. The resultant mixture is heated at a rate of 5.degree. C. or lower per minute up to 900.degree. C. or lower. Then, it is heated in an oxygen atmosphere at a range from 900.degree.-1050.degree. C.

Abstract: A composite superconducting wire using ceramic superconductor material in which one or more elongated superconductor material are accommodated in one or more grooves formed on an elongated reinforcing member so that a long size superconductor wire can be provided. Various methods of producing such composite superconductor wire are also disclosed.

Abstract: A method for forming unsegregated metal oxide-silver composites includes preparing a precursor alloy comprising silver and precursor elements of a desired metal oxide and oxidizing the alloy under conditions of high oxygen activity selected to permit diffusion of oxygen into silver while significantly restricting the diffusion of the precursor elements into silver, such that oxidation of the precursor elements to the metal oxide occurs before diffusion of the metallic elements into silver. Further processing of the metal oxide composite affords an oxide superconducting composite with a highly unsegregated microstructure.

Abstract: A process for the production of a YBa.sub.2 Cu.sub.3 O.sub.7-x or YBa.sub.2 Cu.sub.3 O.sub.7-x -AgO superconductor includes: providing the appropriate powder or mix of powders, pressing the powder to form the desired specimen, sintering the specimen to achieve fusion of the powder, heat treating the sintered specimen, and subjecting the specimen to an oxygenation process. The material exhibits bifurcation in its critical current density versus temperature curve.

Abstract: A method of fabricating a thin-film Hg-containing oxide superconductor is disclosed, which comprises forming a thin film on a substrate, said thin film containing mercury, an alkaline earth element, and copper as main components thereof; and subjecting said substrate with the thin film to a heat treatment in an oxygen-containing atmosphere at an oxygen partial pressure of 1/500 to 1/10 atm, to convert said thin film to the thin-film superconductor.

Abstract: A superconductor material having a current density, J, of from about 30,000 to about 85,000 amps/cm.sup.2 at zero magnetic field and 77.degree. K is disclosed. The 123 superconductor, of the formula L.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. wherein L is preferably yttrium, is capable of entrapping sufficiently high magnetic fields and exhibits a low microwave surface resistance. The process of preparing the superconductor comprises compacting the bulk product, L.sub.1 Ba.sub.2 Cu.sub.3 O, and then sintering the reaction product at a temperature between about 40.degree. C. to about 90.degree. C. below its melting point, i.e., for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. at a temperature of approximately 940.degree. C. The composition is then heated in a preheated chamber maintained at approximately 1090.degree. C. to about 1,200.degree. C. (approximately 1,100.degree. C. for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta.

Abstract: A method of producing a high-performance connection between a metal and a solid superconductive ceramic member is effected by introducing into a mold, in juxtaposition, grains or powder of the ceramic or of its precursors and a volume of silver or gold powder, and ceramic grains or powder at the level of an incorporated silver, gold or copper porous body of the foam, straw or lattice type prior to compression of the ceramic powder and sintering of the same. The electrical connection so formed exhibits a low electrical resistance capable of carrying high currents at rated temperature without interfering with the zero resistance state of the superconductive ceramic, with the metal connection free of cracking and having a contact resistance that is substantially constant throughout the range of superconductive material operating conditions.

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

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

Abstract: The oxide superconductor according to the present invention is represented by (Hg.sub.1-x Pb.sub.x)Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub..delta. (0.08.ltoreq.x.ltoreq.0.41, 7.625.ltoreq..delta..ltoreq.9.15), and has a crystal structure in which a lamination unit of (Hg, Pb)O.sub.z -BaO-CuO.sub.2 -Ca-CuO.sub.2 -Ca-CuO.sub.2 -BaO is laminated in a c-axial direction of the crystal structure (0.625.ltoreq.z.ltoreq.2.15). Further, the method of manufacturing an oxide superconductor, according to the present invention, includes the steps of: mixing material powders of HgO, PbO, BaO, CaO and CuO at a mole ratio of (Hg.sub.1-x Pb.sub.x):Ba:Ca:Cu=a:2:b:c (1.ltoreq.a.ltoreq.2.5, 2.ltoreq.b.ltoreq.3, 2.5.ltoreq.c.ltoreq.4) and compression-molding the mixture powder into a compact; and subjecting the compact to a thermal treatment at 600.degree.-750.degree. C.

Abstract: A method of fabricating articles from segments of anisotropically conducting 123 superconductor such that the current transport properties of the article are comparable to those of the individual segments. The segments to be joined are examined to determine the orientation of the ab plane. Contact surfaces are formed where necessary and the segments are brought into contact and the ab planes are brought into parallel alignment. The contacted segments are elevated in temperature and static pressure is applied to accelerate reaction across the interface of the contact surfaces. The so-formed coherent article is then cooled at a controlled rate.

Abstract: In a method of preparing an oxide superconducting wire comprising the steps of filling up raw material powder for an oxide superconductor in a metal sheath and rolling the same in this state, frictional force on surfaces of rolls employed for rolling is increased in the rolling step in order to improve denseness of the raw material powder, thereby improving the critical current density of the oxide superconducting wire. In order to increase the frictional force, films having large frictional force are formed on the roll surfaces, a coating material is applied to the roll surfaces during rolling, or the roll surfaces are roughened, for example.

Abstract: A superconductive article is made by inserting a rigid mandrel into an internal cavity of a first metallic tube, said tube having an interior surface and an exterior surface, said interior surface defining the interior cavity, forming a layer of a superconductive material or superconductive precursor upon the exterior surface of said first metallic tube, machining the layer of superconductive material or superconductive precursor to a predetermined diameter to form an intermediate article configured for insertion into a second metallic tube having an interior diameter corresponding to the predetermined diameter, inserting the machined intermediate article into a second metallic tube having an internal diameter corresponding to the predetermined diameter of the intermediate article to form a composite intermediate article, reducing or ironing the composite intermediate article to a predetermined cross-sectional diameter, and sintering the reduced or ironed composite intermediate article at temperatures and for

Abstract: High-Tc superconducting ceramic oxide products and macroscopic and microscopic methods for making such high-Tc superconducting products. Completely sealed high-Tc superconducting ceramic oxide products are made by a macroscopic process including the steps of pressing a superconducting ceramic oxide powder into a hollow body of a material inert to oxygen; heat treating the superconducting ceramic oxide powder packed body under conditions sufficient to sinter the ceramic oxide powder; and then sealing any openings of the body. Optionally, a waveform or multiple pulses of alternate magnetic field can be applied during the heat treatment.

Abstract: Superconducting materials and methods of forming superconducting materials are disclosed. Highly oxidized superconductors are heated at a relatively high temperature so as to release oxygen, which migrates out of the material, and form a non-superconducting phase which does not diffuse out of grains of the material. The material is then reoxidized at a lower temperature, leaving the non-superconducting inclusions inside a superconducting phase. The non-superconducting inclusions act as pinning centers in the superconductor, increasing the critical current thereof.

Abstract: A composite superconducting wire using ceramic superconductor material in which one or more elongated superconductor material are accommodated in one or more grooves formed on an elongated reinforcing member so that a long size superconductor wire can be provided. Various methods of producing such composite superconductor wire are also disclosed.

Abstract: Polycrystalline high-T.sub.c superconductors of the formula M.sub.m E.sub.e RO.sub.x, which contain grains which are crystallographically aligned to the greatest possible extent, where M is at least one trivalent element such as a lanthanide element, E is at least one divalent element such as an alkaline earth element and R is at least one transition metal such as Cu, and x denotes the proportion of oxygen, are obtained by substituting a part of the alkaline earth element by a foreign element, preferably an alkali-metal element, which is no longer present in the product after the reaction sintering and sintering except for contents in the ppm to parts per thousand range and brings about the orientation effect. This produces a material which contains a slight deficit of E and optionally M, has an unaltered critical temperature and is substantially more resistant to external agents than equivalent known materials. A post-treatment in a stream of air or oxygen is unnecessary.

Abstract: The present invention comprises novel oxide materials exhibiting bulk superconductivity up to and exceeding 85K and processes for their synthesis. The oxides are within the formula R.sub.a Ba.sub.b Cu.sub.c O.sub.d wherein 1.9<a<2.1, 3.9<b<4.1, 6.8<c<7.2, 14.4<d<15.2 and wherein R is Y or any of the lanthanide rare earth elements. Certain substitutions such as Ca and La on the R and Ba sites are included.