Abstract: In a superconducting thin film composed of compound oxide containing at least one of element selected from a group comprising Y, La, Gd, Ho, Er, Tm, Yb, Dy, Sm, Eu and Lu, Ba and Cu, improvement in that said thin film consists of a single crystal or polycrystal whose c-axis is orientated to a predetermined direction or mono-directionally.

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 superconducting thin film obtained by laminating a Cu-O atomic pair film and another oxide film while growing in one direction shows a higher superconducting critical temperature (Tc). By alternately laminating a thin film of A.sub.2 CuO.sub.4 and a thin film of L.sub.2 CuO.sub.4, wherein A and L are different rare earth elements, the Tc can be enhanced remarkably.

Abstract: The invention provides a method of forming thin layers of superconducting materials and a superconducting device. In accordance with the invention, such layers are formed by the epitaxial growth, on a substrate, of the different constituent elements by regulating the admission of the different constituents so as to obtain a superconducting layer whose mesh parameter substantially matches that of the substrate. Epitaxying may also be carried out directly from a superconducting material.

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: Lanthanum cuprate, La.sub.2 CuO.sub.4, is a superconductive oxide. In order to prepare a single crystal of lanthanum cuprate, the phase diagram of La.sub.2 O.sub.3 -CuO system is determined utilizing their differential thermal analysis and X-ray diffractometry. Cu oxide and at least one of lanthanum oxide and lanthanum carbonate are mixed in the molar ratio of 71.1-92.9:28.9-7.1. The resulting mixture is heated to be molten. While slowly cooling the melt, nuclei of La.sub.2 CuO.sub.4 precipitate from the melt, growing to single crystals in the melt. As a result, large scale single crystals are prepared.

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 superconducting oxide film is prepared by a method of seeding formation and heat treatment which comprises depositing a layer of a metal-oxide precursor on a predetermined substrate, forming a seed of a predetermined superconducting phase only in a locally limited region of the metal-oxide precursor at a boundary surface to the substrate by means of a solid-state reaction triggered by pulsed energy radiation, and then at least partially converting the metal-oxide precursor into the desired superconducting metal-oxide phase by a heat treatment in the oxygen atmosphere at a temperature below 800.degree. C.

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: An oxide-superconductor improved so as to have a high critical temperature (T.sub.c) comprises an oxide having a K.sub.2 NiF.sub.4 crystalline structure similar to a perovskite crystalline structure and represented by the following formula:(Ba.sub.x Sr.sub.z La.sub.1-x-z).sub.2 Cu.sub.1-w Ag.sub.w O.sub.4(1-y)wherein 0.1<x+z<0.3, w=0, and y.gtoreq.0; or 0.ltoreq.x<1, 0.ltoreq.z<1, 0<w<1, and y.gtoreq.0. This invention also relates to an oxide-superconductor wherein an Na, K, Rb, Cs or F atom is contained in an oxide-superconductor of A.sub.3 Cu.sub.3 O.sub.7 type having at least one of a CuO.sub.6 octahedron and a CuO.sub.5 pentahedron.

Abstract: With the method a layer-like composition of an oxide-ceramic superconducting material with a high transition temperature and great current carrying capacity on the basis of a materials system containing metallic components and oxygen can be prepared. The method is to be improved in the direction that layers with great current-carrying capacity can be formed also on non-monocrystalline substrates. It is provided for this purpose that a multi-layer layer of the superconductive material is applied on a fine-crystalline substrate by first making successive layers of individual films with a respective film thickness under 10 nm, and then this multilayer structure is converted into the desired superconducting phase by means of supplying oxygen and at a temperature below 400.degree. C. For developing each individual film, the metallic components of the system are applied to the substrate that may be available, by means of a physical deposition process and while oxygen is being supplied, at a temperature below 400.