Abstract: The following two problems arise when carbon is added to a starting material powder in the process of production of an MgB2 superconductor: (1) an impurity phase increases; and (2) the degree of substitution of carbon at boron sites is spatially non-uniform. This superconductor production method comprises: a mixing step of mixing a starting material powder and an additive; and a heat treatment step of heat-treating the mixture prepared in the mixing step. The starting material powder is MgB2 powder or a mixed powder of magnesium and boron, and the additive is an Mg—B—C compound containing three elements of magnesium, boron and carbon.

Abstract: A method for producing a Sn based alloy (15) comprising a metal matrix of a metal matrix material, wherein the metal matrix material comprises Sn, and inclusions of a compound material, further referred to as compound inclusions, wherein the compound material contains one element or a combination of elements of the group Ti, V, Zr, Hf, further referred to as dopant, and one or a plurality of other elements, in particular Sn, Cu and/or Nb. Particles of the metal matrix material, further referred to as matrix particles, are mixed with particles of the compound material, further referred to as compound particles, and the matrix particles and the compound particles are compacted during and/or after their mixing. A Sn based alloy containing finer compound inclusion of a dopant can be prepared, in order to produce Nb3Sn superconductor material with a superior current carrying capacity.

Abstract: To prepare a superconducting fault-current limiting element having a high sharing electric field at low cost, a superconducting fault-current limiting element includes an insulator substrate; a superconductive thin film formed on the insulator substrate; and an alloy layer formed on the superconducting thin film, said alloy layer having a room-temperature resistivity higher by twice or more than the room-temperature resistivity of a pure metal, in which, when the superconducting thin film goes into a normal conductive state by an overcurrent, the overcurrent flowing through the superconducting thin film is transferred only to the alloy layer.

Abstract: A precursor for fabricating a Nb3Sn superconducting wire by an internal Sn process includes one or a plurality of stabilizing copper portions collectively disposed in the center, each stabilizing copper portion being provided with a diffusion barrier layer in the periphery thereof, and a superconducting matrix portion disposed so as to surround the one or the plurality of stabilizing copper portions, the superconducting matrix portion including a Nb or Nb-based alloy core and a Sn or Sn-based alloy core embedded in a Cu or Cu-based alloy matrix.

Abstract: A method of synthesizing a superconducting material, comprising mixing starting materials comprising magnesium, boron, silicon and carbon; heating the mixture of starting materials to a temperature in the range between 650° C. and 2000° C. to produce a material comprising magnesium boride doped with silicon carbide; and cooling the resulting material to a temperature below the critical temperature of the material to render the material capable of superconducting.

Abstract: A precursor for manufacturing a Nb3Sn superconducting wire according to the present invention includes a mono-element wire including a Sn or Sn-based alloy core disposed at the, a Cu or Cu-based alloy matrix and a plurality of Nb or Nb-based alloy filaments surrounding the Sn or Sn-based alloy core, and a diffusion barrier layer and a stabilizing copper layer surrounding the Cu or Cu-based alloy matrix. In a final shape after a reduction process, the average diameter of the Nb or Nb-based alloy filaments is set to 5 ?m to 30 ?m, and the average distance between the Sn or Sn-based alloy core and the Nb or Nb-based alloy filaments nearest the Sn or Sn-based alloy core is set to 100 ?m or less.

Abstract: A solid structure includes a substrate and a layer located on a surface of the substrate. The layer includes crystalline or polycrystalline MgB2.

Abstract: The composition of compounds containing a multiplicity of different elements are optimized in general by full or partial substitutions of one or more of the atoms in such compounds so as to effect an Ne/? value which represents a peak or near peak value in ? (the electron-phonon coupling constant) so as to maximize Tc for such compositions of matter.

Abstract: There are provided an intermetallic-compound superconductor that is high in superconducting transition temperature, and an alloy superconductor that is high in superconducting transition temperature and excels in malleability and ductility, as well as a method of making such a superconductor with good reproducibility and at a low cost of manufacture. This entirely new intermetallic compound superconductor is made of magnesium (Mg) and beryllium (Be) and has a chemical composition expressed by formula: Mg1Be2, has a hexagonal AlB2 type crystallographic structure and has a superconducting transition temperature (Tc) of 35 K. An alloy containing this intermetallic compound excels in malleability and ductility and constitutes the alloy superconductor having a superconducting transition temperature (Tc) of 35 K and being low in specific resistance for normal conduction at a temperature ranging from the superconducting transition temperature to a room temperature.

Abstract: A multi-filament superconducting wire in which the filaments comprise zirconia-stabilized ultra-fine grain Nb3Sn. The superconducting wire is formed by wire-drawing a preform comprising a metallic matrix and at least one niobium alloy rod having zirconium and oxygen in solid solution and heat treating the drawn wire in the presence of tin to yield at least one continuous filament comprising ultra-fine grain Nb3Sn having semi-coherent ZrO2 precipitates disposed therein. The ZrO2 precipitates serve to stabilize the ultra-fine grain microstructure of the Nb3Sn at temperatures up to 1100° C. and allows Nb3Sn to maintain the ultra-fine grain microstructure when heat treated at temperatures that are greater than those previously used. By using higher temperatures to form Nb3Sn, the time required for heat treatment can be significantly reduced.

Abstract: The invention includes superconducting titanium-containing compositions having less than 200 ppm, by weight, of a combined total of interstitial materials selected from the group consisting of nitrogen, oxygen, carbon and hydrogen. The invention also includes methods of forming superconducting titanium-containing superconducting compositions containing less than 100 ppm, by weight, of a combined total of interstitial materials selected from the group consisting of nitrogen, oxygen, carbon and hydrogen.

Abstract: There are provided an intermetallic compound superconductor that is high in superconducting transition temperature, and an alloy superconductor that is high in superconducting transition temperature and excels in malleability and ductility, as well as a method of making such a superconductor with good reproducibility and at a low cost of manufacture. This entirely new intermetallic compound superconductor is made of magnesium (Mg) and boron (B) and has a chemical composition expressed by formula: Mg1B2, has a hexagonal AlB2 type crystallographic structure and has a superconducting transition temperature (Tc) of 39 K. An alloy containing this intermetallic compound excels in malleability and ductility and constitutes the alloy superconductor having a superconducting transition temperature (Tc) of 39 K. In the method of manufacture, a Mg containing feedstock powder and a B containing feedstock powder are mixed together to form a mixture thereof which is, e.g., hot pressed to produce a semiconductor product.

Abstract: There are provided an intermetallic compound superconductor that is high in superconducting transition temperature, and an alloy superconductor that is high in superconducting transition temperature and excels in malleability and ductility, as well as a method of making such a superconductor with good reproducibility and at a low cost of manufacture. This entirely new intermetallic compound superconductor is made of magnesium (Mg) and boron (B) and has a chemical composition expressed by formula: Mg1B2, has a hexagonal AlB2 type crystallographic structure and has a superconducting transition temperature (Tc) of 39 K. An alloy containing this intermetallic compound excels in malleability and ductility and constitutes the alloy superconductor having a superconducting transition temperature (Tc) of 39 K. In the method of manufacture, a Mg containing feedstock powder and a B containing feedstock powder are mixed together to form a mixture thereof which is, e.g., hot pressed to produce a semiconductor product.

Abstract: The present invention relates to an MgB2-based superconductor that is easy to manufacture and well suited to mass production, and that exhibits excellent superconducting characteristics (such as a high critical current density) while still retaining the high critical temperature characteristics of MgB2. A powder mixture of magnesium, boron, and titanium is pressed into a pellet, and this product is sintered under an atmospheric pressure and other conditions (preferably at 600° C. or higher) to manufacture an MgB2-based superconductor in which titanium and/or a titanium compound are dispersed in polycrystalline MgB2. The composition of the MgB2-based superconductor is preferably adjusted to have an atomic ratio of Mg:B:Ti=x:2:y, 0.7<x<1.2 and 0.05<y<0.3, and more preferably 0.07<y<0.2, by adjusting the amounts in which the raw materials are added.

Abstract: An Nb3Sn-based superconductive wire which, when used in a superconductive magnet, manifests sufficient strength also against force along the radius direction in operating the magnet and reveals little deterioration in properties due to mechanical strain ascribable to the force along the radius direction is provided. An Nb3Sn-based superconductive wire comprising a bronze/filament aggregate obtained by placing a lot of niobium (Nb) or niobium alloy filaments in a copper (Cu)-tin (Sn)-based alloy matrix, wherein said niobium or niobium alloy filament constituting the bronze/filament aggregate 3? is a composite filament 5 obtained by combining with a filament reinforcing material having mechanical strength under temperature not more than room temperature after thermal treatment for producing an Nb3Sn-based superconductive compound, larger than the mechanical strength of the niobium or niobium alloy.

Abstract: A Nb3Al superconducting wire and method for fabricating the same wherein Nb and Al powders in combination, or Nb—Al alloy powders are encapsulated in a metal tube, preferably copper or copper-alloy (e.g., CuNi), and the resultant composite is processed by conventional means to fine wire. Multifilamentary composites are produced by rebundling of the powder-filled wires into metal tubes followed by conventional processing to wire of a desired size. It is required for the use of Nb and Al powders in combination that the Nb and Al powder particle size be less than 100 nm. In the use of Nb—Al alloy powders, it is preferred, but not required, that the powder particle size be similarly of a nanometer scale. The use of nanometer-scale powders is beneficial to wire fabrication, allowing the production of long wire piece-lengths. At final wire size, the wires produced by practice of the present invention are heat treated at temperatures below the melting point of copper (1083° C.

Abstract: This invention provides a production method of Nb3Al superconducting multifilamentary wire based on rapid-heating, quenching and transformation method, capable of producing a high-performance Nb3Al superconducting multifilamentary wire by improving critical temperature thereof, upper critical field and critical current density. Upon a first stage heat treatment of beating a composite, in which bcc phase Nb—Al supersaturated solid solution is dispersed in Nb matrix, the bcc phase Nb—Al supersaturated solid solution ordered in temperature rise process is made disordered at an initial phase thereof and a non-reacting portion located adjacent is heated using a reaction heat generated when transforming this disordered bcc phase to A15 phase. Then, disordering of the bcc phase is promoted while propagating a high-temperature transformation region so as to automatically progress high-temperature beat treatment.

Abstract: A method for manufacturing a Sn-based alloy containing a finely dispersed Sn—Ti compound includes melting Sn by heating to a temperature in a range from 1300 to 1500° C. in vacuum or an inert gas atmosphere, adding 0.1 to 5% by weight of Ti followed by melting by heating, and casting the molten alloy into a copper mold directly or through a pouring cup. The Sn-based alloy obtained by this method contains the Sn—Ti compound having a maximum particle diameter of 30 &mgr;m and a mean particle diameter of 5 to 20 &mgr;m. A precursor of a Nb3Sn wire is also obtained by an inner diffusion method using this Sn-based alloy. The Nb3Sn wire manufactured by using the Sn-based alloy of the present invention exhibits excellent superconductive characteristics. The method of the present invention enables the ingot to be free from a shrinkage cavity appearing during prior art manufacturing processes.

Abstract: A process of preparing superconducting magnesium diboride powder by heating an admixture of solid magnesium and amorphous boron powder or pellet under an inert atmosphere in a Mg:B ratio of greater than about 0.6:1 at temperatures and for time sufficient to form said superconducting magnesium diboride. The process can further include exposure to residual oxygen at high synthesis temperatures followed by slow cooling. In the cooling process oxygen atoms dissolved into MgB2 segregated to form nanometer-sized coherent Mg(B,O) precipitates in the MgB2 matrix, which can act as flux pinning centers.

Abstract: A high-performance Nb3Al extra-fine multifilamentary superconducting wire is produced simply and inexpensively through the improvement of critical values, Tc, Hc2 and Jc, without the addition of third elements such as Ge, Si and Cu. A first rapid heating and quenching treatment is applied to an Nb/Al composite wire having an atomic ratio of Al to Nb from 1:2.5 to 1:3.5 and having an extra-fine multifilamentary structure to form a BCC alloy phase comprising Nb with Al supersaturatedly dissolved therein wherein the treatment comprises heating the composite wire up to a temperature not lower than 1900° C. within two seconds and then introducing it into a molten metal at a temperature not higher than 400° C. to rapidly quench it.

Abstract: A novel intermetallic superconductor with surprisingly high transition temperature is disclosed. The material comprises B and C, and can form a bulk superconductor. Exemplary of the novel superconductors is material of nominal composition YPd.sub.5 B.sub.3 C.sub.x, with x chosen such that the C:B ratio is in the range 0.05-2. An exemplary bulk sample of such composition has T, (onset) of 22.5 K, with more than 15 volume % of the sample being superconducting.

Abstract: A novel intermetallic superconductor with surprisingly high transition temperature is disclosed. The material comprises B and C, and can form a bulk superconductor. Exemplary of the novel superconductors is material of nominal composition YPd.sub.5 B.sub.3 C.sub.x, with x chosen such that the C:B ratio is in the range 0.05-2. An exemplary bulk sample of such composition has T.sub.c (onset) of 22.5 K, with more than 15 volume % of the sample being superconducting.

Abstract: The production of compact molded bodies of rare-earth transition-metal boron carbide and boron nitride compounds configured so as to avoid a selective evaporation of individual components in the production process and enable an exact adjustment of the desired stoichiometry. The process is characterized in thata) a powder mixture with particles sizes from 1 to 250 .mu.

Abstract: Object of the present invention is to obtain a Nb.sub.3 Al group superconductor having a high critical current density under a whole range of magnetic field from low to high such as 20 T level, manufacturing methods thereof, a Nb.sub.3 Al group superconducting precursory composition, and a magnet for high magnetic field. In a process for manufacturing Nb.sub.3 Al phase by a diffusion reaction of Nb.sub.2 Al phase and Nb phase, a part of the Nb.sub.2 Al phase is remained and dispersed in the Nb.sub.3 Al phase homogeneously as for magnetic flux pinning centers for a high magnetic field. As for a method for dispersing the Nb.sub.2 Al phase homogeneously, a Nb.sub.3 Al group superconducting precursory composition obtained by dispersing Nb particles and Nb.sub.2 Al ultrafine particles by a mechanical alloying method is used, and further, by a conventional method for generating Nb.sub.3 Al phase by a diffusion reaction of Nb and an aluminum alloy, the object of the present invention can be achieved.

Abstract: A method for making triniobium tin superconductor with improved critical current density is disclosed where an annealed niobium-base substrate is passed through a tin alloy bath containing tin, copper, and bismuth, to coat the substrate with tin and then annealing the coated substrate to form triniobium tin superconductor. A tin alloy bath containing up to twenty weight percent copper and up to one weight percent bismuth is disclosed.

Abstract: Material comprising an effective amount of a novel intermetallic bulk superconductor compound is disclosed. The compound has the composition LnNi.sub.2 B.sub.2 C, with Ln being Y or a rare earth (atomic number 57-71), preferably Tm, Er, Ho or Ln. A compound of composition XPt.sub.2 B.sub.2 C, with X=Y and/or La, is also a superconductor.

Abstract: A novel intermetallic superconductor with surprisingly high transition temperature is disclosed. Exemplary of the novel superconductor is material of overall composition Y.sub.1.5 Pd.sub.4.5 B.sub.4. A bulk sample of that composition has T.sub.c (onset) of 22.6K, with about 0.5 volume % of the sample being superconducting.

Abstract: The present invention provides an Nb-Ti alloy type superconducting wire having a superconducting filament including a member made of Nb-Ti alloy and a pinning member made of Nb or Nb alloy having no superconducting properties under operating magnetic field, the Nb-Ti based alloy containing Ti in a content of 48 to 65% by weight and the superconducting filament containing Nb or an Nb alloy (A) in a ratio of 20 to 35% by volume. The present invention further provides an Nb-Ti alloy type superconducting wire having a superconducting filament including a member made of Nb-Ti alloy and a pinning member made of Ti or Ti alloy having a critical temperature lower than that of the Nb-Ti alloy and/or having no superconducting properties; the Nb-Ti based alloy containing Ti in a content of 25 to 45% by weight and the superconducting filament containing Ti or a Ti alloy in a ratio of 20 to 35% by volume.

Abstract: Superconductors formed by powder metallurgy have a matrix of niobium-titanium alloy with discrete pinning centers distributed therein which are formed of a compatible metal. The artificial pinning centers in the Nb-Ti matrix are reduced in size by processing steps to sizes on the order of the coherence length, typically in the range of 1 to 10 nm. To produce the superconductor, powders of body centered cubic Nb-Ti alloy and the second phase flux pinning material, such as Nb, are mixed in the desired percentages. The mixture is then isostatically pressed, sintered at a selected temperature and selected time to produce a cohesive structure having desired characteristics without undue chemical reaction, the sintered billet is reduced in size by deformation, such as by swaging, the swaged sample receives heat treatment and recrystallization and additional swaging, if necessary, and is then sheathed in a normal conducting sheath, and the sheathed material is drawn into a wire.

Abstract: A Type II superconducting filament is formed by surrounding a Type II superconducting alloy ingot with layers of a fine grain Type II superconducting alloy sheet, a barrier layer and a copper extrusion can. The composite is then reduced to a filament by hot and cold working.

Abstract: Ceramic superconductor materials, e.g., of rare earth/alkaline earth metal/transition metal/oxygen type, contain an effective stabilizing amount of fluorine atoms distributed therein in a concentration gradient decreasing from the external face surface of the material to the core region thereof; advantageously the fluorine atoms are principally distributed in an external protective diffusion barrier layer.

Abstract: A Type II superconducting alloy is formed into a wire by extruding a billet of the alloy encased in a copper extrusion can. The extrusion can may include a nose and a tail section having a k factor equal to or greater than that of the body of the core. The nose section may also have a convex inner transverse surface, while the tail section has a concave inner transverse surface. The nose and tail section may be formed of a copper alloy which is of equal or greater stiffness than the alloy of the body of the core. Alternatively, a multifilament wire may be formed by extruding a billet composed of a plurality of separate superconducting wires encased in a copper extrusion can. The nose and tail section of the can may be modified as for the aforementioned monofilament billet.

Abstract: A composite member is prepared which comprises a core which will have a compound superconducting layer when heat-treated, and a stock for forming a stabilizing member made of copper and surrounding the core. The composite member is heat-treated in an oxidizing atmosphere, thus forming a copper-oxide thin layer on the surface of the stock. Thereafter, the composite member is heat-treated in a non-oxidizing atmosphere or in an atmosphere having an oxygen partial pressure which is too low to allow the forming of copper oxide. As a result, a compound superconducting wire is made which comprises a member including a compound superconductor, a diffusion-preventing layer made of oxide and surrounding the member, and a stabilizing member made of copper and surrounding the layer.

Abstract: A method is disclosed for fabricating a wire from niobium tin produced in situ in a filamentous structure capable of achieving the superconducting state which comprises overlapping a tin alloy core comprised of tin-magnesium eutectic alloy with alternating layers of copper and foraminous layers followed by drawing the thus-formed niobium filaments into wire, then heating the wire at sufficiently high temperature to cause the eutectic alloy to homogeneously diffuse through the length of the copper wire and rods to react with the Nb, forming the A-15 crystal structure of Nb.sub.3 Sn, characterized by refined grain structure therein and improved current carrying capability.

Abstract: A superconducting material made of tungsten or molybdenum containing a specified amount of silicon, a wiring made of this superconducting material, and a semiconductor device using this wiring.The above-mentioned superconducting material undegoes no damage even in the steps of heat treatments effected after the formation of a wiring therefrom by virtue of its high melting point, and can be very easily patterned by reactive ion etching using SF.sub.6 as an etching gas, which has heretofore been generally employed. These features, in which conventional superconducting materials are lacking, allow the superconducting material of the present invention to exhibit excellent properties particularly when used in the wirings of a semiconductor device.

Abstract: Ceramic superconductor materials, e.g., of rare earth/alkaline earth metal/transition metal/oxygen type, contain an effective stabilizing amount of fluorine atoms distributed therein in a concentration gradient decreasing from the external face surface of the material to the core region thereof; advantageously the fluorine atoms are principally distributed in an external protective diffusion barrier layer.

Abstract: Method for producing single crystals of YBa.sub.2 Cu.sub.3 O.sub.7 which undergo a transition to the superconducting state above 90K, comprising:(a) preparing a flux composition by mixing BaO.sub.2 and CuO powders in the molecular weight ratio of approximately 1:1, layering on top of the mixture powdered YBa.sub.2 Cu.sub.3 O.sub.7 in an amount up to approximately 20% of the total weight of the BaO.sub.2 --CuO mixture, firing the mixture in air at approximately 930.degree. C.-950.degree. C. for approximately 24 hours, and thereafter raising the temperature from 930.degree. C.-950.degree. C. to approximately 1025.degree.-1030.degree. C. within 1/2 hour and maintaining the temperature at approximately 1025.degree. C.-1030.degree. C. for approximately one hour to one and one-half hours;(b) cooling thereafter the flux to approximately 1020.degree. C.-980.degree.;(c) providing an oxygen gas flow to the flux when the temperature is approximately 1020.degree. C.-980.degree. C.

Abstract: A novel method of producing mixed metal oxide powder (e.g., ferrite powder, or high temperature superconductor powder such as YBa.sub.2 Cu.sub.3 O.sub.x powder) is disclosed. The method comprises forming an intimate mixture of appropriate metal salts (e.g., nitrates and acetates), at least one of which is an oxidizing agent with respect to at least one of the others, and heating the mixture to a reaction temperature such that an exothermic redox reaction occurs. Appropriate choice of oxidizing and reducing agents permits control of heat of reaction and reaction temperature. The product of the reaction typically is a precursor of the desired mixed oxide, the precursor typically consisting essentially of the metal constituents of the mixed oxide and oxygen. Heat treatment in an O.sub.2 -containing atmosphere transforms the precursor into the desired mixed oxide powder. The thus produced powder can then be used in conventional fashion, e.g., to produce bodies therefrom by pressing and/or sintering.

Abstract: A composite member is prepared which comprises a core which will have a compound superconducting layer when heat-treated, and a stock for forming a stabilizing member made of copper and surrounding the core. The composite member is heat-treated in an oxidizing atmosphere, thus forming a copper-oxide thin layer on the surface of the stock. Thereafter, the composite member is heat-treated in a non-oxidizing atmosphere or in an atmosphere having an oxygen partial pressure which is too low to allow the forming of copper oxide. As a result, a compound superconducting wire is made which comprises a member including a compound superconductor, a diffusion-preventing layer made of oxide and surrounding the member, and a stabilizing member made of copper and surrounding the layer.

Abstract: A method is disclosed for fabricating a wire from niobium tin produced in situ in a filamentous structure capable of achieving the superconducting state which comprises overlapping a tin alloy core comprised of tin-magnesium eutectic alloy with alternating layers of copper and foraminous layers followed by drawing the thus-formed niobium filaments into wire, then heating the wire at sufficiently high temperature to cause the eutectic alloy to homogeneously diffuse through the length of the copper wire and rods to react with the Nb, forming the A-15 crystal structure of Nb.sub.3 Sn, characterized by refined grain structure therein and improved current carrying capability.

Abstract: A process for preparing a glass-ceramic material with superconducting properties is disclosed.In the first step of this process, a powder batch comprised of a glass-former and of barium oxide, yttrium oxide, and copper oxide (or the precursors of one or more of these oxides) is provided. These oxides (or their precursors) are present in varying amounts for the Ba.sub.2 YCu.sub.3 O.sub.x composition.In the second step of the process, the powder batch is melted at a temperature of from about 1170 to 1300 degrees Celsius while under an oxygen-containing atmosphere.In the third step of the process, the molten batch is rapidly cooled, thereby forming glass.In the fourth step of the process, the glass is heat-treated at a temperature of from about 750 to about 950 degrees Celsius.

Abstract: Techniques for the preparation of superconducting perovskites in the MBa.sub.2 Cu.sub.3 O.sub.7-y system wherein M represents yttrium of a rare earth element and y is an integer ranging from 0.1 to 0.8 are described. The techniques involve the use of either a sol-gel or controlled precipitation process in which a barium solution in acetic acid is reacted with copper acetate and either a rare earth hydroxide or rare earth nitrate to form a colloid which is subsequently heated and fired to yield the desired composition. In the embodiment in which the nitrate is employed, the resultant colloid is freeze dried. In both the sol-gel and controlled precipitation processes, heating and firing are required to yield the desired characteristics.

Abstract: A thin film superconducting device is described in which the substrate is a single or mixed single crystal of lanthanum orthogallate grown from a pure melt of lanthanum, gallium and additive oxides. A portion of the gallium single crystal can be replaced by Sc, Al or In and/or a portion of the lanthanum can be replaced by a rare earth element of smaller ionic radius than lanthanum to allow for manipulation of the lattice constant.

Abstract: A method and an apparatus for fabricating single crystals of superconducting ceramics are described. A powedered row oxide mixture is placed and molten in a melting pot. The surface of the molten mixture is approximately at the freezing point of the mixture. From the surface, a single crystal is pulled in accordance with the known pulling crystal technique. The pulled mixture is subjected to a magnetic field normal to the pulling direction. By virtue of the magnetic field, single crystal superconducting oxide ceramics can be obtained without twin crystals.

Abstract: With the method, a layer of a superconductor material with a high transition temperature on the basis of a material system containing metallic components and oxygen is to be prepared. To this end, a layer of metal-oxide preliminary product of the components of the system with a structure still having faults with respect to the superconducting metal oxide phase is first applied to a predetermined substrate with an ordered structure and the desired superconducting metal oxide phase is epitaxially formed subsequently, using a heat treatment and while oxygen is being supplied. It should be possible to carry out the heat treatment such that application in semiconductor technology is possible.

Abstract: A level gauge and measurement method are provided using a sensing element comprising a superconductive alloy represented by the formula:Mo.sub.a Ru.sub.b Z.sub.cwherein Z is phosphorous, boron, or a mixture of phosphorous and boron,b has a value of about 20 to about 40,c has a value of about 10 to about 30, anda+b+c=100.The sensing element has a superconductivity critical temperature of at least 4.2K and is useful for measuring the level of liquid helium independently of pressure fluctuations in the reservoir vessel.

Abstract: A temperature sensor comprises a thin layer of material the composition of which varies gradually over the layer thickness. The material is superconductive below a critical temperature the value of which depends on the composition of the material. The layer is connected, by means of electrodes to an electronic circuit for supplying current to the sensor and processing a temperature-dependent signal produced by the sensor.

Abstract: The invention relates to an improvement in a method of forming deposits of superconducting ceramics. Generally, such ceramics are formed by electrodepositing a mixture of metals of the type and in proportions sufficient to be oxidized into ceramic; oxidizing the electrodeposited mixture under conditions sufficient to result in a superconducting ceramic deposit; and orienting the crystallites in said superconducting ceramic deposit. Crystallite orientation may take place before, after or during the oxidation step.

Abstract: A process is provided for preparing crystalline ceramic superconductor materials, which comprises preparing a mixture of particulate crystalline ceramic superconductor precursors selected to form upon heat processing a crystalline ceramic superconductor material; subjecting said mixture to calcination at an elevated reaction temperature sufficient to form a crystalline ceramic material, while entraining and fluidizing said mixture in a flow of hot calcining gas; and then quenching the crystalline ceramic material to a temperature below calcination temperature; the quenching step can be followed by annealing and cooling the resulting crystalline ceramic material in the presence of oxygen to form and maintain a selected superconducting crystalline structure in the material.

Abstract: A finely divided metal oxide powdery composition, preferably with a narrow particle size distribution, is produced from a particulate, sol-gel derived composition containing agglomerates by heating the particulate composition in the presence of an effective amount of a composition which decomposes upon heating and forms a gas to break at least a portion of the agglomerates so as to yield the desired finely divided ceramic particle composition. Examples of suitable gas-forming agents for use in the present invention include the ammonium salts or amides of organic and inorganic acids, volatile acids, and gases dissolved in a suitable solvent, such as water, alcohol or ammonia.