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 perovskite type superconductor film having a high content, almost a single phase, of the high Tc phase is formed by the steps of: depositing at least one first film of a first material (e.g., a composite oxide of Bi-Sr-Ca-Cu-O system or Tl-Ba-Ca-Cu-O system) constituting a perovskite type superconductor over a substrate; depositing at least one second film of a second material containing an oxide or element (Bi.sub.2 O.sub.3, Tl.sub.2 O.sub.3, PbO.sub.x, etc., particularly PbO.sub.x) having a vapor pressure of more than 10.sup.-4 Pa at 800.degree. C. at least as a main component over the substrate; to thereby form a stack of the first and second films; and heat treating the stack of the first and second films to form the perovskite type superconductor film on the substrate. Further, preferred compositions of the as-deposited films or stack are determined.

Abstract: A thin film of oxide superconductor consisting of more than two portions (1, 11, 12) each possessing a predetermined crystal orientation and deposited on a common surface of a substrate (2). At least one selected portion (10) of thin film of oxide superconductor is deposited on a thin under-layer (4, 100) which facilitates crystal growth of selected portions and which is deposited previously on the substrate. The selected portions (10) may consist of a-axis oriented thin film portions while non-selected portions (11, 12) may consists of c-axis oriented thin film portions. The thin under-layer can be a buffer layer (4) or a very thin film (100) of oxide superconductor.

Abstract: This invention relates to a process of forming multilayered thallium-containing superconducting composites, wherein a first thallium-containing superconducting layer, an intermediate thallium-containing oxide layer and a second thallium-containing superconducting layer are successively deposited on a substrate by a vapor phase process by controlling the heating temperature, pressure of oxidizing gas and thallium vapor pressure during post-deposition annealing of the superconducting films.

Abstract: For manufacturing a superconducting device having a tunnel junction formed of an extremely thin insulator layer sandwiched between a pair of oxide superconductor thin films, a first superconducting layer of oxide superconductor thin film is formed on a substrate, and a MgO thin film is deposited on the first superconducting layer at a substrate temperature of not higher than 200.degree. C. The MgO thin film is heat-treated so that crystallinity of the deposited MgO thin film is improved, and thereafter, a second superconducting layer of oxide superconductor thin film is formed on the MgO thin film.

Abstract: Disclosed are methods of forming superconducting devices including a type having a structure of a superconductor--a normal-conductor (or a semiconductor)--a superconductor, and a type having a superconducting weak-link portion between superconductors.The superconductors constituting the superconducting device are made of an oxide of either of perovskite type and K.sub.2 NiF.sub.4 type crystalline structures, containing at least one element selected from the group consisting of Ba, Sr, Ca, Mg, and Ra; at least one element selected from the group consisting of La, Y, Ce, Sc, Sm, Eu, Er, Gd, Ho, Yb, Nd, Pr, Lu, and Tb; Cu; and O. In addition, the c-axis of the crystal of the superconductor is substantially perpendicular to the direction of current flowing through this superconductor.

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: The present invention comprises a high quality, epitaxial thallium-based HTS thin film on MgO and other substrates and methods of providing the same. The present invention is achieved using a nucleation layer which provides a template for subsequent growth. Specifically, YBCO and/or YBCO analog films (films having growth characteristics and physical structures analogous to YBCO) are used as nucleation layer(s) on MgO and other substrates to enable the growth of epitaxial thallium-based HTS films.

Abstract: A process for making high temperature superconducting oxide films comprising using a sintered body of Y-Ba-Cu-O or Bi-Sr-Ca-Cu-O oxide as a sputtering target and using a mixture of argon and oxygen as a sputtering gas, forming glow discharge between the substrate and the target under a pressure of 0.5-2.5 torr and at a sputtering current density of 5-35 mA/cm.sup.2, and then cooling the substrate after the oxide film has been grown to a desired thickness. The critical temperature of the in-situ produced superconducting oxide film of Y-Ba-Cu-O is 90 K and that of Ba-Sr-Ca-Cu-O is 80 K.An apparatus for the preparation of high temperature superconducting oxide films is also provided. The apparatus for in-situ making such high temperature superconducting oxide film is easy to heat the substrate and control its temperature without problems of conventional deposition methods.

Abstract: A process for preparing a superconducting thin film of K.sub.2 NiF.sub.4 -type oxides such as [La, Ba ].sub.2 CuO.sub.4, or [La, Sr ].sub.2 CuO having higher transition temperature of superconductivity which can be used for Josephson Junctions devices or the like by sputtering technique.The process of the present invention is characterized in that the target used in the sputtering technique is composed of a mixture of compounds which .contain at least La, one element M selected from a group of Ia, IIa and IIIa elements of the Periodic Table, and Cu. The compounds may be oxides, carbonates, nitrate or sulfates of La, said element M, and Cu. Said mixture which is used as the target is preferably sintered into a form of a sintered body. The substrate on which the thin film is deposited is preferably heated at a temperature between 100 and 1,200.degree. C. during sputtering and the deposited thin film is preferably heat-treated at a temperature between 600.degree. and 1,200.degree. C.

Abstract: The invention relates to a process for producing thin films in which the pressure of the process gas is kept constant in a process chamber with a gas inlet and outlet, a target and a substrate, while material is sputtered from the target and deposited on the substrate. The invention also relates to a process for producing thin films. It is the purpose of the invention to create a process providing a more homogenous film. According to the invention, to this end the process gas is caused to reach the plasma. Alternatively, either one or several emission lines may be spectroscopically detected in a spatial region and, after a desired cross sectional shape has been set, it is kept constant in time by subsequently regulating the process gas mixing ratio.

Abstract: Disclosed is a method of manufacturing a thin film of an oxide superconductor represented by formula Sr.sub.1-x Nd.sub.x CuO.sub.2 on a substrate. The oxide superconductor has a tetragonal crystal structure, the lattice constant in a-axis falling within a range of between 0.385 nm and 0.410 nm, and the lattice constant in c-axis being an integer number of times as much as a level falling within a range of between 0.310 nm and 0.350 nm. The method includes the steps of forming by epitaxial growth a film of a crystal having lattice constants close to those of the crystal of said oxide superconductor on a substrate, and forming a thin film of the oxide superconductor of a tetragonal crystal structure represented by general formula (I) by a thin film-forming technique.

Abstract: A method of manufacturing YBCO superconducting thin films is obtained which is capable of providing superconducting thin films having excellent crystallinity in a high yield by introducing a new film formation parameter in a hybrid plasma sputtering method. When a Y--Ba--Cu--O type superconducting thin film is formed by using a parallel plate sputtering method, a high-frequency voltage generated by a high-frequency power source is superimposed on a DC voltage generated by a DC power source and applied to the cathode electrode at the same time, an electrically conductive YBCO target is placed on the cathode, and the film formation conditions are controlled on the basis of the difference between the voltage drops in each ion sheath formed on the substrate and directly on the target by applying a DC voltage to a substrate holder from the DC power source.

Abstract: A method of manufacturing a superconducting device involves forming a thin film on the surface of a substrate, forming a superconducting gate electrode on a portion of the thin film, etching the portions of the thin film using the gate electrode as a mask thereby providing a superconducting channel under the gate, forming a step portion on the superconducting channel and under the gate, converting the oxide portion of the step portion into a gate insulation portion by heating the substrate in a vacuum, forming a second oxide superconducting film on the exposed surface of the channel so that superconducting source and drain electrodes are formed on each side of the gate such that the drain and source have a thickness greater than that of the channel and are electrically isolated from the gate electrode.

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 process for making high temperature superconducting oxide films comprising using a sintered body of Y--Ba--Cu--O or Bi--Sr--Ca--Cu--O oxide as a sputtering target and using a mixture of argon and oxygen as a sputtering gas, forming glow discharge between the substrate and the target under a pressure of 0.5-2.5 torr and at a sputtering current density of 5-35 mA/cm.sup.2, and then cooling the substrate after the oxide film has been grown to a desired thickness. The critical temperature of the in-situ produced superconducting oxide film of Y--Ba--Cu--O is 90 K. and that of Ba--Sr--Ca--Cu--O is 80 K.An apparatus for the preparation of high temperature superconducting oxide films is also provided. The apparatus for in-situ making such high temperature superconducting oxide film is easy to heat the substrate and control its temperature without problems of conventional deposition methods.

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: In-situ process are provided for 1) depositing on a substrate a crystalline thin film of a high temperature superconducting oxide by exposing the back surface of the substrate, i.e., the surface of the substrate opposite the surface on which the thin film is deposited, to radiation from a direct radiant heat source, thereby heating the substrate to the desired growth temperature, and maintaining the radiation and thereby the desired growth temperature during the deposition of the thin film, and 2) depositing a crystalline thin film of high temperature superconducting oxides onto both the front and back surfaces of a substrate.

Abstract: For manufacturing a superconducting device, a first c-axis orientated oxide superconductor thin film having a very thin thickness is formed on a principal surface of a substrate, and a stacked structure of a gate insulator and a gate electrode is formed on a portion of the first oxide superconductor thin film. An a-axis orientated oxide superconductor thin film is grown, using the gate electrode as a mask, so that second and third superconducting regions having a relatively thick thickness are formed at both sides of the gate electrode, electrically isolated from the gate electrode. The superconducting device thus formed can functions as a super-FET.

Abstract: c-axis oriented YBa.sub.2 Cu.sub.3 O.sub.7 layers are grown with intervening SrTiO.sub.3 layers bridged over steps at which there is a transformation to a-axis crystal-oriented growth. The multilayer superconductor has YBa.sub.2 Cu.sub.3 O.sub.7 layers which are not thicker than 500 nm while the intervening layers of SrTiO.sub.3 have thicknesses of 20 to 30 nm.

Abstract: A structure having a silicon substrate with an epitaxially grown magnesium oxide layer on a surface onto which is epitaxially grown, either directly or on an intermediary layer, a layer of high temperature superconducting material.

Abstract: An in-situ process for preparing thin films which contain relatively volatile and involatile oxides is disclosed, in particular, crystalline thin films of oxides of conductors, superconductors or ferroelectric materials, wherein separate sources of the relatively volatile and involatile oxides during depositon of the thin film are employed.

Abstract: The sputtering source of the present invention comprises a means for providing DC or RF power and cooling to a conical target electrode with magnets thereabout and anode at the bottom. At the center of the sputtering source is a grounded anode. A plurality of magnets which form rings are located behind the conical target electrode so that the magnetic field lines point to the anode. The conical target electrode has an inner surface which is slightly inclined from a centerline. The conical target electrode is concentrically located about the vertical centerline. A ground shield is placed about and above the magnets and the conical electrode and further acts to eliminate high energy ions from reaching the substrate because of the shape thereof. An opening in the shield allows for the exit of low energy particles of the target material sputtered from the conical target electrode. The sputtering source provides a narrow beam of target material for deposition on a substrate located at a distance from the source.

Abstract: A thin film superconductor assembly is disclosed along with a method of fabricating same. The assembly comprises a self-supporting substrate defining at least a portion of a containment for a flow of cryogenic fluid, a dielectric layer adherent to a surface of the substrate, a thin film superconductor adherent to the dielectric layer and a moisture and oxygen impervious electrically insulating coating covering the thin film superconductor. A method of forming such thin film superconductor assembly, wherein the dielectric layer consists essentially of aluminum nitride, comprises growing the aluminum nitride dielectric layer integrally on the surface of the substrate.

Abstract: A method of manufacture of thin film devices involves the sputtering of an epitaxial barrier layer (11) of a metallic oxide such as magnesia on to which a further epitaxial thin film (12) is deposited. The substrate is preferably alumina and the thin film may be a high temperature superconductive compound of yttrium, barium, copper and oxygen.

Abstract: A process for preparing a thin film of superconducting material is disclosed in which films are deposited from a defined target. The thin films prepared by the process are characterized by high critical temperature of superconductivity and a smaller discrepancy between the critical temperature and the onset temperature at which superconductivity is observed.

Abstract: A superconducting Tl--Pb--Sr--Ca--Cu--O thin film comprised of at least one phase of the formula Tl.sub.0.5 Pb.sub.0.5 Sr.sub.2 Ca.sub.1+n Cu.sub.2+n O.sub.7+2n where n=0, 1 or 2 is disclosed, which is prepared by a process comprising sputtering an oxide film onto a dielectric substrate from an oxide target containing preselected amounts of Tl, Pb, Sr, Ca and Cu, and heating an oxygen-containing atmosphere in the deposited film in the presence of a source of thallium oxide and lead oxide and cooling the film.

Abstract: A process for producing a superconducting material comprising a compound oxide represented by the general formula:(Ba, Ca).sub.x (.alpha., Dy).sub.1-x Tl.sub.y Cu.sub.1-y O.sub.3-zwherein ".alpha." represents Y or La; the atomic ratio of Ca to Ba is between 1% and 90%; the atomic ratio of Dy to .alpha. is between 1% and 90%; x, y and z are within the ranges of 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, and 0.ltoreq.z<1 respectively; and the expression of (Ba, Ca) and (.alpha., Dy) means that the respective elements occupy predetermined sites in a crystal in a predetermined proportion. The process comprises preparing a material powder, compacting the material powder and then subjecting the resulting compact to a final sintering operation and is characterized in that the material powder is(A) a powder mixture composed of powders selected from a group comprising (i) powders of elemental Ba, Cu, Ca, .alpha., Dy and Tl and (ii) powders of compounds each containing at least one of said elements Ba, Cu, Ca, .

Abstract: An oxide superconducting layer is formed on a base material of silver, whose single side is coated with MgO, or single-crystalline MgO for depositing a Bi.sub.2 Sr.sub.2 Ca.sub.2 Cu.sub.3 phase in a crystallographically oriented state by sputtering, CVD or laser ablation. Metal lead or lead oxide is then laid thereon by sputtering to obtain a two-layer structure, and the two-layer structure is heat treated in the atmospheric air. Thus, a bismuth oxide superconducting film, which is excellent in crystal orientation as well as denseness and thereby having high critical current density, is formed on the base material.

Abstract: A Josephson break junction device suitable for highly sensitive electronic detecting systems. A superconductor film such as YBa.sub.2 Cu.sub.3 O.sub.7 is deposited on a substrate such as a simple-crystal MgO. The film is fractured across a narrow strip by at least one indentation in the substrate juxtaposed from the strip to form a break junction. A transducer is affixed to the substrate for applying a bending movement to the substrate to regulate the distance across the gap formed at the fracture to produce a Josephson turned junction effect. Alternatively, or in addition to the transducer, a bridge of a novel metal is applied across the gap to produce a weak-link junction.

Abstract: Chemical reactions of superconducting raw materials with active oxygen atoms and their charged particles are accelerated by using at least oxygen plasma in the fabrication process of a superconductive body. Thereby an ionic crystal is grown in a short time, which provides stable superconducting materials of high quality such as high critical temperature and low resistivity. In another aspect, a substrate is irradiated simultaneously with streams of vapor of metal elements, of which a superconductive body is to be composed, and a stream of gas of ions generated in a plasma chamber and film growth is effected while keeping the substrate at a temperature higher than 400.degree. C. to produce a ceramic type superconductive thin film.

Abstract: An improved cathode for a sputtering system includes a metal cylinder and strips of material bonded to the inside of the metal cylinder and/or material sprayed onto the inside of the metal cylinder. The strips may have various specified compositions and/or configurations and/or other characteristics which enhance the ability of the sputtering system to deposit films of high temperature superconductor material on substrates.

Abstract: A process of making high temperature Tl-based superconductors. The process includes the steps of reacting solid Ba--Ca--Cu-oxides with Tl.sub.2 O.sub.3 vapor. The process allows high quality Tl-based superconductors to be easily fabricated.

Abstract: Improved processes for making thin film and bulk thallium superconductors are described, as well as Tl superconductors having high critical current densities and low surface impedance. An annealing step in a reduced oxygen atmosphere is used to convert compounds containing thallium, calcium, barium and copper to a Tl-2223 superconducting phase or to convert an oxide having the nominal composition Tl.sub.2 Ca.sub.2 Ba.sub.2 Cu.sub.3 O.sub.x to a crystalline Tl-2223 phase. The oxygen pressure during annealing is controlled to be below the thermodynamic stability limit for conversion of Tl-2223 to Tl-2122 and secondary phases. Temperatures less than 880.degree. C. are used, the oxygen pressure being sufficient to prevent excess thallium loss so that the Tl content in the final Tl-2223 phase is Tl.sub.1.6-2.0. Electrical devices including SQUIDs can be made with these improved superconductors.