Abstract: The films of this invention are high temperature superconducting (HTS) thin films specifically optimized for microwave and RF applications. In particular, this invention focuses on compositions with a significant deviation from the 1:2:3 stoichiometry in order to create the films optimized for microwave/RF applications. The RF/microwave HTS applications require the HTS thin films to have superior microwave properties, specifically low surface resistance, Rs, and highly linear surface reactance, Xs, i.e. high JIMD. As such, the invention is characterized in terms of its physical composition, surface morphology, superconducting properties, and performance characteristics of microwave circuits made from these films.

Abstract: Porous ceramic superconductors having a film thickness over 0.5 microns are provided. The superconducting material is applied to a vicinal substrate and optionally nanoparticles are inserted to release local strain. The resultant superconductors exhibit improved Jc values compared to nonvicinal (flat) counterparts and those having no nanoparticles.

Abstract: The films of this invention are high temperature superconducting (HTS) thin films specifically optimized for microwave and RF applications. In particular, this invention focuses on compositions with a significant deviation from the 1:2:3 stoichiometry in order to create the films optimized for microwave/RF applications. The RF/microwave HTS applications require the HTS thin films to have superior microwave properties, specifically low surface resistance, Rs, and highly linear surface reactance, Xs, i.e. high JIMD. As such, the invention is characterized in terms of its physical composition, surface morphology, superconducting properties, and performance characteristics of microwave circuits made from these films.

Abstract: The resistive current-limiting device contains a strip-shaped superconductor having a conductive structure which is made of a metallic substrate strip, an insulating, oxidic buffer layer, a super-conductive layer made of a type AB2Cu3Ox oxidically high-Tc-super conductive material, an insulating buffer layer which is arranged therebetween, and a metal cover layer. At least one of the lateral edges of the conductive structure is mechanically deformed such that the cover layer and the substrate strip are arranged in electric contact.

Abstract: Described is a superconducting composition comprising an oxide complex of the formula [L1?xMx]aAbOy wherein L is lanthanum, lutetium, yttrium or scandium; A is copper, bismuth, titanium, tungsten, zirconium, tantalum, niobium, or vanadium; M is barium, strontium, calcium, magnesium or mercury; and “a” is 1 to 2; “b” is 1; “x” is a number in the range of 0.01 to 0.5 and preferably 0.075 to 0.5; and “y” is about 2 to about 4. The oxide complexes of the invention are prepared by solid-state reaction procedure which produce oxide complexes having enhanced superconducting transition temperatures compared to an oxide complex of like empirical composition prepared by a coprecipitation—high temperature decomposition procedure. With a solid-state reaction prepared oxide complex of the invention a transition temperature as high as 100° K has been observed even under atmospheric pressure.

Abstract: A new class of fundamental devices and methods for their manufacture and use. The bulk magnetic field replicators of the present invention require no precision machining or alignment to accurately reproduce magnetic fields of any complexity, nor extreme positional stability to maintain superconductivity. Such bulk devices may be formed of either low or high critical temperature superconductive materials, but are particularly adapted to formation from high critical temperature materials.

Abstract: Superconducting ceramics having relatively high critical temperatures are composed of rare earth metals, alkaline earth metals and copper. They have few defects and a limited polycrystalline interfacial area.

Abstract: Described is a superconducting composition comprising an oxide complex of the formula [L1?xMx]aAbOy wherein L is lanthanum, lutetium, yttrium, or scandium; A is copper, bismuth, titanium, tungsten, zirconium, tantalum, niobium, or vanadium; M is barium, strontium, calcium, magnesium or mercury; and “a” is 1 to 2; “b” is 1; and “x” is a number in the range of 0.01 to 1.0; and “y” is about 2 to about 4. The oxide complexes of the invention are prepared by a solid-state reaction procedure which produces an oxide complex having an enhanced superconducting transition temperature compared to an oxide complex of like empirical composition prepared by a coprecipitation—high temperature decomposition procedure. With an oxide complex prepared by the solid-state reaction of the invention a transition temperature as high as 100°K has been observed even under atmospheric pressure.

Abstract: The present invention concerns the improvement of the supercurrent carrying capabilities, i.e. the increase of critical current densities, of bicrystalline or polycrystalline superconductor structures, especially of high-Tc superconductors. By providing an appropriate predetermined dopant profile across the superconductor structure, in particular within or in the vicinity of the grain boundaries, the space-charge layers at the grain boundaries are reduced and thereby the current transport properties of the superconductor significantly improved. Simultaneously, the influence of magnetic fields on the critical current densities is significantly reduced, which in turn enhances the overall supercurrent carrying capabilities while keeping the supercurrent transport properties of the grains at good values.

Abstract: The present invention concerns an enhancement of the supercurrent carrying capabilities of bicrystalline or polycrystalline high-Tc superconductors, i.e. the critical current densities in such superconductors. The current transport properties are improved by chemically altering, especially doping, the superconductors. It seems that a modification of the space-charge layers at the boundary, e.g. by an increase of the mobile charge carrier concentrations particularly in the superconductor's grain boundaries, which concentrations differ from those resulting in optimum superconducting properties of the grains, are responsible for this positive effect.

Abstract: A process is provided for preparing solid superconducting mixed-metal oxides whereby the superconductor can be formed into any predetermined shape by way of viscous sol precursors. The superconductors are also formed by this process into homogeneous phases.

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 &mgr;m long a longest dimension. The oxide superconductor article has at least a 25% retention of critical current density in a 0.1 Tesla field.

Abstract: The present invention relates to a sodium-intervened superconductor and its manufacturing method and more particularly, to the sodium-intervened superconductor expressed by the following Formula 1 and its manufacturing method, wherein the superconductor, prepared from a stoichiometric mixture of Y.sub.2 O.sub.3, NaCuO.sub.2, BaCuO.sub.2, Ln.sub.2 O.sub.3 (Ln: lanthanide ion) and CuO under the atmosphere of oxygen, has some advantages in that a) through the use of NaCuO.sub.2, a ternary oxide, as a reactant, the formation of impurities and sodium evaporation may be prevent, and b) through partial substitution of a divalent barium by a trivalent lanthanide group ion, the superconductor is stable in air with a higher critical current density and critical temperature.Formula 1(Na.sub.1-x Y.sub.x)(Ba.sub.1-y Ln.sub.y).sub.2 Cu.sub.3 O.sub.6+.delta.wherein, Ln is a trivalent lanthanide ion other than Ce and Pr; 0.1<x<0.9; and 0.1<y<0.3.

Abstract: Articles according to the invention comprise a superconductive cuprate (e.g., YBa.sub.2 Cu.sub.3 O.sub.7) body containing elongate grains measuring at least about 10 .mu.m along the long axis and having an aspect ratio of at least 10:1. Bodies according to the invention can have relatively high critical current density, as compared to analogous non-textured bodies.

Abstract: A superconductor comprising a compound of the formula (II):R.sub.1+x Ba.sub.2-x Cu.sub.3 O.sub.7-y1 (II)wherein not less than 40% of a crystal of the superconductor shows phase separation, and at (temperature, magnetic field) of (77?K!, O?T!) and (77?K!, 4?T!), a critical current density is not less than 10,000 A/cm.sup.2, which is obtained by heating a precursor which is a solid solution of the formula (I):R.sub.1+x Ba.sub.2-x Cu.sub.3 O.sub.7-y (I)wherein not more than 10% of a crystal of the solid solution shows phase separation, so that phase separation is formed in the crystals at a phase separation temperature, and introducing oxygen; and a superconductor comprising a compound of the formula (II):R.sub.1+x Ba.sub.2-x Cu.sub.3 O.sub.7-y1 (II)wherein not more than 10% of a crystal of the superconductor shows phase separation, and in a magnetic field of not less than 1?T! at a constant temperature of 77?K!, a critical current density is less than 10,000 A/cm.sup.

Abstract: A method of fabricating bulk superconducting material such as RBa.sub.2 Cu.sub.3 O.sub.7-.delta. where R is La or Y comprising depositing a thin epitaxially oriented film of Nd or Sm (123) on an oxide substrate. The powder oxides of RBa.sub.2 Cu.sub.3 O.sub.7-.delta. or oxides and/or carbonates of R and Ba and Cu present in mole ratios to form RBa.sub.2 Cu.sub.3 O.sub.7-.delta., where R is Y or La are heated, in physical contact with the thin film of Nd or Sm (123) on the oxide substrate to a temperature sufficient to form a liquid phase in the oxide or carbonate mixture while maintaining the thin film solid to grow a large single domain 123 superconducting material. Then the material is cooled. The thin film is between 200 .ANG. and 2000 .ANG.. A construction prepared by the method is also disclosed.

Abstract: A composite based on a superconducting oxide having a high critical temperature, characterized by the fact that it is constituted by glass and said oxide, the glass being such that its vitreous transition temperature is not greater than 750K, the volume fraction of the glass lying in the range 2% to 40%, said oxide existing in the glass in the form of crystallites having substantially the same orientation.

Abstract: An oxide superconductor which exhibits an uniform and high critical current density. Further, a method of manufacturing this oxide superconductor, namely, a RE--Ba--Cu--O oxide superconductor (RE is one or more kinds of rare earth elements including Y) by performing a treatment, which includes at least a burning process to be performed in a range of temperatures that are higher than a melting point of a raw material mixture containing a RE-compound raw material, Ba-compound raw material and a Cu-compound raw material, on the raw material mixture. This method further comprises a step of crushing the raw material mixture into particles and establishing the mean particle diameter of one or all of the raw materials as ranging from 50 to 80 .mu.m.

Abstract: The present invention relate to textured YBa.sub.2 Cu.sub.3 O.sub.x (Y-123) superconductors and a process of preparing them by directional recrystallization of compacts fabricated from quenched YBCO powders at temperatures about 100.degree. C. below the peritectic temperature to provide a superconductor where more than 75% of the YBa.sub.2 Cu.sub.3 O.sub.x phase is obtained without any Y.sub.2 BaCuO.sub.5 .

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.

Abstract: Processes are provided for forming a superconductive composite, comprising a superconductive metal oxide and a ceramic. The composite may be formed in any desired shape. Liquid nitrogen can be held around the superconductor longer and delivered in a more controlled fashion and the composite has improved resistance to shatter and thermal shock. The ceramic also provides protection from atmospheric deterioration of the superconductive oxide.

Abstract: The invention relates to a spray pyrolyric 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.

Abstract: A superconductive material is in composition expressed as Y.sub.0.33 Ba.sub.0.67).sub.a Cu.sub.b (OF).sub.c. The usual a, b and c are so selected as to satisfy a relation expression ax (mix valence of A)+bx (mix valence of B)=cx (mix valence of C).

Abstract: A method for improving the phase purity of a multiphase ceramic high temperature superconductor by selective microwave heating of undesired phases in a multiphase material to cause a phase transformation of the undesired phase to the desired phase. The selective microwave heating may be employed during initial firing and sintering of the ceramic superconductor compound or as a subsequent annealing step. Plane polarized microwave energy may be employed to enhance the two dimensional anisotropy of the compound by similar selective heating.

Abstract: A corrosion resistant high temperature superconductor and a method of preparing said superconductors involving substitution of ions in the lattice to relieve stress and strain caused by mismatched bond lengths. Specific examples of such superconductors are Y.sub.1-y Ca.sub.y Ba.sub.2-y La.sub.y Cu.sub.3 O.sub.7-d where O<y<1.0 and O<d<1 and YBa.sub.2-y Sr.sub.y Cu.sub.3 O.sub.7-d where 0<y<2 and O<d<1. In YBa.sub.2 Cu.sub.3 O.sub.7-d structure, the internal stresses estimated from the difference between the bond valence sum and the formal oxidation state for Ba and Cu ions indicate that the Ba atom is too large for Cu--O cage at oxygen stoichiometric d=0 and too small at d=1. Therefore, the Ba (1.52 .ANG.) is substituted by La (1.27 .ANG.) and for keeping the same oxidation state of Cu as in the prototype material the Ca (1.12 .ANG.) equivalent to La replaces the Y (1.019 .ANG.).

Abstract: Processes are provided for forming a superconductive composite, comprising a superconductive metal oxide and a ceramic. The composite may be formed in any desired shape. Liquid nitrogen can be held around the superconductor longer and delivered in a more controlled fashion and the composite has improved resistance to shatter and thermal shock. The ceramic also provides protection from atmospheric deterioration of the superconductive oxide.

Abstract: Provided is a metal oxide material represented by the composition formula of Ln.sub.a Sr.sub.b Cu.sub.3-x M.sub.x O.sub.c, where 2.7.ltoreq.a+b.ltoreq.3.3; 0.8 .ltoreq.a.ltoreq.1.2; 6.ltoreq.c.ltoreq.9; and 0.05 .ltoreq.x.ltoreq.0.7, Ln is at least one element selected from the group of elements of Y and lanthanoids or an atomic group consisting of said elements, and M is at least one element selected from the group of elements of Ti, V, Ga, Ge, Mo, W and Re or an atomic group consisting of said elements.

Abstract: In the production of a 124-type or 123-type superconductor by a sol-gel method using alkoxides of respective metals, the use of a compound wherein a sec-butoxy group and a hydroxy group are coordinated with a copper atom gives a superconductor composed of flat particles having a broad C plane. The dimensional ratio defined by l/d is at least 6.7 in the case of the 124-type or is at least 8.4 in the case of the 123-type. It shows a superconducting property at a liquid nitrogen temperature. This superconductor shows a higher critical current density than one obtained by a sintering method.

Abstract: Enlargement of a crystal of a bulk oxide superconductor of REBa.sub.2 Cu.sub.3 O.sub.7-x, wherein RE is at least one of Y and rare earth elements, is effected by three dimensionally arranging layers of REBa.sub.2 Cu.sub.3 O.sub.7-x with a different RE in the order of decreasing (123) phase formation temperatures from the center outward, or by forming a stack of layers of RE Ba.sub.2 Cu.sub.3 O.sub.7-x with a different RE in the order of decreasing (123) phase formation temperatures; the size of the layer being enlarged along with a decrease in the (123) phase formation temperature.

Abstract: In the production of a 124-type or 123-type superconductor by a sol-gel method using alkoxides of respective metals, the use of a compound wherein a secbutoxy group and a hydroxy group are coordinated with a copper atom gives a superconductor composed of flat particles having a broad C plane. The dimensional ratio defined by l/d is at least 6.7 in the case of the 124-type or is at least 8.4 in the case of the 123-type. It shows a superconducting property at a liquid nitrogen temperature. This superconductor shows a higher critical current density than one obtained by a sintering method.

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: An apparatus and method for continuously monitoring the liquid nitrogen level a liquid nitrogen container and automatically refilling liquid nitrogen from a liquid nitrogen reservoir when the liquid nitrogen in the container falls below a predetermined level. The apparatus comprises a liquid nitrogen level sensing element, which contains a superconducting material, such as a YbaCuO type superconductiing material, disposed on a non-conducting substrate, such as magnesium oxide. The superconducting material is selected such that it has a critical temperature approximately equal to the boiling point temperature of liquid nitrogen. The superconducting material is placed near the predetermined level and, under normal conditions, the superconducting material exhibits zero or near zero resistance.

Abstract: A method for making metal/ceramic superconductor thick film structures including the steps of preparing a silver/superconductor ink, applying the ink to a substrate, evaporating the ink's binder, decomposing a silver compound in the residue to coat the superconductor grains, sintering the coated superconductor grains, and oxygenating the superconductor grains through the silver coating. The resultant inter-granular silver increases the critical current and mechanical strength of the superconductor.

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 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: 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: 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: 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 method of producing a high-temperature oxide superconducting material, which comprises the steps of (a) preparing a material corresponding to an oxide superconductor of the perovskite type structure consisting essentially of a first member selected from the group consisting yttrium, lanthanoids, thallium and bismuth; at least one alkaline earth metal; copper; and oxygen and (b) heating the material in the presence of an alkali metal selected from the group consisting of potassium, sodium, rubidium and cesium to a temperature around the melting point of the alkali metal or to a higher temperature for a time sufficient to effect grain growth in the superconductor material, thereby to produce the superconductor containing the alkali metal in an amount not larger than 4 mole % based on the first member.

Abstract: The present invention is characterized in that oxides of Y, Ba and Cu having a superconductive substance-forming composition are melted, the melt is rapidly cooled and solidified, the obtained sheet is heated at a temperature of 1000.degree. to 1350.degree. C. to produce a partially melted state thereof, and the sheet is gradually cooled at a rate lower than 200.degree. C./hr, whereby a micro-structure in which precipitates of the RE.sub.2 BaCuO.sub.5 phase having a diameter smaller than 20 .mu.m are dispersed in the REBa.sub.2 Cu.sub.3 O.sub.7-y crystal is obtained.

Abstract: Novel superconducting materials in the form of compounds, structures or phases are formed by performing otherwise known syntheses in a highly oxidizing atmosphere rather than that created by molecular oxygen at atmospheric pressure or below. This leads to the successful synthesis of novel superconducting compounds which are thermodynamically stable at the conditions under which they are formed.

Abstract: BaCuO.sub.2.5 containing precursors for superconducting materials and process for making shaped superconductor articles therefrom.

Abstract: Disclosed herein are high-temperature oxide superconductors of RBa.sub.2 Cu.sub.4 O.sub.8 type, with Ba partly replaced by Sr or Ca, or with R and Ba partly replaced by Ca and Sr, respectively, as represented by the chemical composition formula of R(Ba.sub.1-y Sr.sub.y).sub.2 Cu.sub.4 O.sub.8 or R(Ba.sub.1-z Ca.sub.z).sub.2 Cu.sub.4 O.sub.8 or (R.sub.1-x Ca.sub.x) (Ba.sub.1-y Sr.sub.y).sub.2 Cu.sub.4 O.sub.8. They exhibit superconductivity at high temperatures. Especially, the last one exhibits superconductivity at a higher temperature than the former two. All of them can be made with a less amount of Ba as a deleterious substance, and the first two have improved sinterability. The best results are obtained when they are produced by the process involving the hot hydrostatic pressure treatment of the mixture of raw materials at 850.degree.-1100.degree. C. in an atmosphere composed of an inert gas and oxygen. The process permits a wider selection of Ba raw materials.

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 microcrystalline RBa.sub.2 Cu.sub.3 O.sub.y structure where R denotes a lanthanide chosen from Y, La, Nd, Sm, Eu, Gd, Tb, Ho, Er, Tm, Yb and Lu and where y has a value between 6.9 and 7 starts with a powder of composition [x(123) ; (1-x) (7BaO--18CuO] where (123) denotes the 123 phase of RBaB.sub.2 Cu.sub.3 O.sub.y and where the value of x is between 0.01 and 1. The powder is compressed and sintered at a temperature below 920.degree. C. (the BaCuO.sub.2 and CuO binary eutectic temperature) to form a sample. The sample is placed on an oxide of the lanthanide R. The sample and its support undergo heat treatment enabling chemical reaction between the liquid part of the sample and its support whereby substantially all of the liquid part is consumed and highly regular 123 monocrystals are obtained. Cooling is applied. At least one annealing is carried out in pure oxygen at a temperature between 350.degree. C. and 500.degree. C. to obtain the orthorhombic form characteristic of RBa.sub.2 Cu.

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 thin film, high T.sub.c fluorinated, superconducting having a lattice structure differing from the lattice structure of the material substrate, such as sapphire or stainless steel, upon which it is grown. The superconducting material is characterized by basal plane alignment of the unit cells thereof even though the substrate does not possess a perovskite lattice structure. A laser ablation technique is used to evaporate material from a fluorinated pellet of target material to deposit the fluorinated superconducting material on the substrate. The instant invention provides for a low pressure and relatively low temperature method of depositing a superconducting film which is characterized by (1) a minimal number of high angle grain boundaries typically associated with polycrystalline films, and (2) aligned a, b, and c axes of the unit cells thereof so as to provide for enhanced current carrying capacities.

Abstract: A new copper oxide superconductor of the formula Ln.sub.1-x M.sub.x Sr.sub.2 Cu.sub.3-y Ti.sub.y O.sub.7+.delta. is disclosed, and exhibits a Tc of 60.degree. K. with deviations from linear metallic behavior as high as 130.degree. K.

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.