Abstract: A superconducting thin film formed on a semiconductor substrate, which comprises at least one superconducting region formed of an oxide superconductor on the principal surface of the semiconductor substrate and at least one isolation region formed of an oxide insulator including component atoms of the oxide superconductor, which surrounds the superconducting region, and the superconductor thin film has a planar upper surface.

Abstract: A lanthanum aluminate (LaAlO.sub.3) substrate on which thin films of layered perovskite copper oxide superconductors are formed. Lanthanum aluminate, with a pseudo-cubic perovskite crystal structure, has a crystal structure and lattice constant that closely match the crystal structures and lattice constants of the layered perovskite superconductors. Therefore, it promotes epitaxial film growth of the superconductors, with the crystals being oriented in the proper direction for good superconductive electrical properties, such as a high critical current density. In addition, LaAlO.sub.3 has good high frequency properties, such as a low loss tangent and low dielectric constant at superconductive temperatures. Finally, lanthanum aluminate does not significantly interact with the superconductors. Lanthanum aluminate can also be used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.

Abstract: A superconductor element includes a first layer of an oxide superconductor, a second layer of an insulator, semiconductor, or metal, and an interlayer interposed between the first and second layers and formed of AgO.sub.x (where in 0<.times.< 1/2) .

Abstract: The edge-defined, film-fed growth technique process is modified to produce a thin ribbon of bi-crystalline sapphire wherein the grain boundary is an essentially straight boundary and the angle is predetermined by selective cutting of the two seeds which are placed closely together during growth. The angle selection is optimized based on the superconducting material to be deposited and the application intended. After the ribbon is pulled, the ribbon is processed by cutting an appropriate section therefrom with the grain boundary. The substrate is polished and the high Tc superconducting material is deposited thereon to produce devices which rely on weak link Josephson junctions.

Abstract: A superconducting device comprising a substrate having a principal surface, a non-superconducting oxide layer having a similar crystal structure to that of the oxide superconductor, a first and a second superconducting regions formed of c-axis oriented oxide superconductor thin films on the non-superconducting oxide layer separated from each other and gently inclining to each other, a third superconducting region formed of an extremely thin c-axis oriented oxide superconductor thin film between the first and the second superconducting regions, which is continuous to the first and the second superconducting regions.

Abstract: Proposed is a method for operating a field-effect device comprised of a superconducting current channel having source and drain electrodes connected thereto, said superconducting current channel being separated from a gate electrode by an insulating layer, where the resistance of said current channel is controlled by varying the critical current of the superconducting material through the application of an electrical field across the superconducting current channel, which in turn changes the density of the mobile charge carriers in the superconducting material. Taught is also an inverted MISFET device for performing that method, the device being characterized in that on an electrically conductive substrate an insulating layer is provided which in turn carries a layer consisting of a superconducting material, and that a gate electrode is attached to said substrate, and source and drain electrodes are electrically connected to said superconductor layer.

Abstract: A Josephson junction device comprising a single crystalline substrate including a principal surface, a layer of the same material as the substrate formed on the principal surface of the substrate so as to form a step on the principal surface, and an oxide superconductor thin film formed on the principal surface of the substrate. The oxide superconductor thin film includes a first and a second superconducting portions respectively positioned above and below the step, which are constituted of single crystals of the oxide superconductor, a junction portion between the first and the second superconducting portions, which is constituted of a single crystal of the oxide superconductor of which crystal orientation is different from those of the first and second superconducting portions, and grain boundaries between the first superconducting portion and the junction portion and between the second superconducting portion and the junction portion, which constitute one weak link of the Josephson junction.

Abstract: A lanthanum aluminate ( LaAlO.sub.3) substrate on which thin films of layered perovskite copper oxide superconductors are formed. Lanthanum aluminate, with a pseudo-cubic perovskite crystal structure, has a crystal structure and lattice constant that closely match the crystal structures and lattice constants of the layered perovskite superconductors. Therefore, it promotes epitaxial film growth of the superconductors, with the crystals being oriented in the proper direction for good superconductive electrical properties, such as a high critical current density. In addition, LaAlO.sub.3 has good high frequency properties, such as a low loss tangent and low dielectric constant at superconductive temperatures. Finally, lanthanum aluminate does not significantly interact with the superconductors. Lanthanum aluminate can also used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.

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: The present invention is directed to a method for growing a superconductive film on a superconductive substrate in order to produce a bulk single crystal. According to a preferred embodiment, an oxide superconductive film of a material which is the same or similar to the substrate material is epitaxially grown at a temperature between 450.degree. C. and 800.degree. C. so that the film and substrate have the same lattice orientations. According to the present invention, problems associated with conventional films having non-superconductor substrates (e.g., MgO and SrTiO.sub.3) are avoided.

Abstract: A superconducting device comprising a substrate having a principal surface, a non-superconducting oxide layer having a similar crystal structure to that of the oxide superconductor, a first and a second superconducting regions formed of c-axis oriented oxide superconductor thin films on the non-superconducting oxide layer separated from each other and gently inclining to each other, a third superconducting region formed of an extremely thin c-axis oriented oxide superconductor thin film between the first and the second superconducting regions, which is continuous to the first and the second superconducting regions.

Abstract: In a high-temperature superconductive conductor winding (1) comprising a tape-shaped high-temperature superconducting wire (2) which is combined with a metal 5 and wound into the form of a double pancake coil, the length of a throughout portion (5) provided between pancakes (4, 6) is at least four times the width of the tape-shaped high-temperature superconducting wire. Thus, it is possible to suppress generation of shearing stress at 10 the throughout portion (5), thereby preventing reduction of the critical current density caused by such shearing stress.

Abstract: A superconducting device has a substrate and a superconducting film formed on the substrate. A surface of the substrate has a first surface portion of which a curvature is constant or changes continuously, a second surface portion of which a curvature is constant or changes continuously, and a third surface portion at which the first and second surface portions meet and at which the curvatures of the first and second surface portions become discontinuous. The superconducting film formed on the surface of said substrate has a grain boundary serving as a junction only in a portion corresponding to the third surface portion of the substrate.

Abstract: There is disclosed a superconductor junction structure comprising: a first superconducting layer of an oxide superconductor formed in a desired pattern on a substrate; a non-superconducting layer of a non-superconductor formed on at least a part of the side faces of the first superconducting layer, a portion of the surface of the substrate near the part, and a top face of the first superconducting layer; and a second superconducting layer of the oxide superconductor formed on the non-superconducting layer, the non-superconducting layer being formed thin at the part, and forming a tunnel barrier.

Abstract: A layered structure formed on a substrate comprising an oxide superconductor thin film deposited on the substrate, a noble metal monolayer deposited on the oxide superconductor thin film and an insulator thin film deposited on the noble metal monolayer. The noble metal monolayer prevents interdiffusion between the oxide superconductor thin film and the insulator thin film so that they have excellent properties.

Abstract: A multi-layer microstrip structure includes a substrate and a first superconducting layer deposited on the substrate. A first dielectric layer, made at least partially of benzocyclobutene (BCB), is deposited on the first superconducting layer. Additional superconducting dielectric and superconducting layers can be employed. Preferably the superconducting layers are made from niobium. The multilayer microstrip structure is ideally suited for use in passive circuit components of microwave circuits and in multi-chip modules.

Abstract: A structure including a thin film of a conductive alkaline earth metal oxide selected from the group consisting of strontium ruthenium trioxide, calcium ruthenium trioxide, barium ruthenium trioxide, lanthanum-strontium cobalt oxide or mixed alkaline earth ruthenium trioxides thereof upon a thin film of a noble metal such as platinum is provided.

Abstract: A superconducting device includes a superconducting channel constituted in an oxide superconductor the film deposited on a deposition surface of a substrate. A source electrode and a drain electrode are formed on the oxide superconductor thin film at opposite ends of the superconducting channel, so that a superconducting current can flow through be superconducting channel between the superconductor source electrode and the superconductor drain electrode. A gate electrode is formed through a gate insulator layer on the superconducting channel so as to control the superconducting current flowing through the superconducting channel. The gate electrode is in the form of a thin film and stands upright with respect to the gate insulator layer.

Abstract: A thin film of oxide superconductor consisting of more than two portions (10, 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 the thin film of oxide superconductor is deposited on a thin under-layer (4, 100) which facilitates crystal growth of the selected portion 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: A superconducting device has a stacked structure including a first superconducting layer, a first insulating layer, a second superconducting layer, a second insulating layer and a third superconducting layer stacked on a substrate in this given order. The stacked structure has an end surface portion extending from the first insulating layer to the second insulating layer. A fourth superconducting layer is formed to cover the end surface of the stacked structure. A third insulating layer separates the stacked structure end surface and the fourth superconducting layer. The fourth superconducting layer is electrically connected to the first and third superconducting layers but is isolated from the second superconducting layer by the third insulating layer. The first through fourth superconducting layers are formed of an oxide superconductor thin film.

Abstract: An outer surface of a superconducting thin film of compound oxide such as YBa.sub.2 Cu.sub.3 O.sub.7-.delta. deposited on a substrate such as MgO and SrTiO.sub.3 is protected with a protective layer which is composed of amorphous inorganic material such as inorganic glass, amorphous oxide.

Abstract: A superconducting device comprising a substrate having a principal surface, a superconducting source region and a superconducting drain region formed of an oxide superconductor on the principal surface of the substrate separated from each other, a superconducting channel formed of the oxide superconductor between the superconducting source region and the superconducting drain region. The superconducting channel electrically connects the superconducting source region to a superconducting drain region, so that a superconducting current can flow through the superconducting channel between the superconducting source region and the superconducting drain region. The superconducting device comprises a gate electrode through a gate insulator on the superconducting channel for controlling the superconducting current flowing through the superconducting channel, and non-superconducting oxide layers having a similar crystal structure to that of the oxide superconductor.

Abstract: For manufacturing a superconducting device, a first 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. A second oxide superconductor thin film is grown on an exposed surface of the first oxide superconductor thin film, using the gate electrode as a mask, so that first and second superconducting regions having a relatively thick thickness are formed at opposite sides of the gate electrode, electrically isolated from the gate electrode. A source electrode and a drain electrode are formed on the first and second oxide superconducting regions. The superconducting device thus formed can function as a super-FET.

Abstract: A superconducting transistor having a source region and a drain region are formed by a YBCO film on a barrier layer, which is composed of a PBCO film formed on an STO substrate. A gate electrode is disposed on the thinner wall at the back of the STO substrate. In a superconducting transistor so constructed the electric field created by the gate voltage works effectively at an interface with the barrier layer, more carriers can be drawn out relative to the applied gate voltage, and it becomes possible for a large superconduction current to flow.

Abstract: A thin-film superconductor includes a substrate, a ferroelectric film, and a superconducting oxide film. The ferroelectric film extends on the substrate. The ferroelectric film is made of a crystal contains Bi and O. The superconducting oxide film extends on the ferroelectric film, and containing Bi, Cu, and an alkaline-earth metal element. The superconducting oxide film may contain at least two different alkaline-earth metal elements.

Abstract: A superconducting thin film formed on a substrate, comprising at least one oxide superconductor layer formed on the principal surface of said substrate and at least one oxide layer formed of an oxide which compensates for crystalline incompleteness at the surface of said oxide superconductor layer, and which is arranged on or under the superconducting layer.

Abstract: A Josephson junction device comprising a single crystalline substrate including a principal surface having two horizontal planes and a smooth slope between the two horizontal planes, and an oxide superconductor thin film formed on the principal surface of the substrate. The oxide superconductor thin film includes a first and a second superconducting portions of a single crystalline oxide superconductor respectively positioned on the two horizontal planes of the substrate, a junction portion of a single crystalline oxide superconductor having a different crystal orientation from the two superconducting portions positioned on the slope of the substrate and two grain boundaries between each of the two superconducting portions and the junction portion. The grain boundaries constitutes one weak link of the Josephson junction.

Abstract: A high frequency superconducting device structure is disclosed which comprises an alkaline earth fluoride substrate with a magnesium oxide lower buffer layer on the alkaline earth substrate and an upper buffer layer epitaxial template layer on the magnesium oxide layer for providing a template for epitaxial growth of a high temperature superconducting film on the upper buffer layer, providing reduced dielectric and conducting losses at high frequencies. The disclosed structure may be incorporated into a multi-chip module (MCM) for providing very high speed interconnections.

Abstract: A LnBaCuO-series superconducting thin film is provided over a surface of a substrate of Y.sub.2 O.sub.3 single crystal to form a composite superconductor. Ln stands for Y or a lanthanoid element. The composite superconductor has an improved interfacial diffusion.

Abstract: c-axis oriented microwave quality HTSC films are deposited onto single crystals of gadolinium gallium garnet (GGG) using pulsed laser deposition (PLD) with conditions of 85 mTorr of oxygen partial pressure, a block temperature of 730.degree. C., a substrate surface temperature of 790.degree. C. and a laser fluence of 1 to 2 Joules/cm.sub.2 at the target, a laser repetition rate of 10 Hz and a target to substrate distance of 7 cm and in which the a and b lattice parameters of the GGG exhibit a mismatch of less than 2.5 percent with the a and b lattice parameters of the HTSC.

Abstract: A thin film of oxide superconductor deposited on a single crystal substrate of silicon wafer. A buffer layer of (100) or (110) oriented Ln.sub.2 O.sub.3, in which Ln stands for Y or lanthanide elements is interposed between the thin film of oxide superconductor and the silicon wafer. A surface of silicon wafer is preferably cleaned satisfactorily by heat-treatment in vacuum before the buffer layer is deposited. An under-layer of metal oxide; ZrO.sub.2, YSZ or metal Y, Er is preferably interposed between the Ln.sub.2 O.sub.3 buffer layer and the silicon wafer.

Abstract: A superconducting device comprising a substrate having a principal surface, a non-superconducting oxide layer having a similar crystal structure to that of the oxide superconductor, an extremely thin superconducting channel formed of a c-axis oriented oxide superconductor thin film on the non-superconducting oxide layer, a superconducting source region and a superconducting drain region formed of an a-axis oriented oxide superconductor thin film at the both sides of the superconducting channel separated from each other, which are electrically connected each other by the superconducting channel, so that superconducting current can flow through the superconducting channel between the superconducting source region and the superconducting drain region, and a gate electrode of a material which includes silicon through a gate insulator on the superconducting channel for controlling the superconducting current flowing through the superconducting channel, in which the gate electrode is embedded between the supercondu

Abstract: A substantially single phase, single crystalline, highly epitaxial film of Bi.sub.2 CaSr.sub.2 Cu.sub.2 O.sub.8 superconductor which has a T.sub.c (zero resistance) of 83K is provided on a lattice-matched substrate with no intergrowth. This film is produced by a Liquid Phase Epitaxy method which includes the steps of forming a dilute supercooled molten solution of a single phase superconducting mixture of oxides of Bi, Ca, Sr, and Cu having an atomic ratio of about 2:1:2:2 in a nonreactive flux such as KCl, introducing the substrate, e.g., NdGaO.sub.3, into the molten solution at 850.degree. C., cooling the solution from 850.degree. C. to 830.degree. C. to grow the film and rapidly cooling the substrate to room temperature to maintain the desired single phase, single crystalline film structure.

Abstract: This field-effect transistor comprises a conductive substrate (2) serving as the gate electrode, an insulating barrier layer (3), and a superconducting channel layer (1) on top of the barrier layer (3). The superconductor layer (1) carries a pair of mutually spaced electrodes (4, 5) forming source and drain, respectively. The substrate is provided with an appropriate gate contact (6).The substrate (2) consists of a material belonging to the same crystallographic family as the barrier layer (3). In a preferred embodiment, the substrate (2) is niobium-doped strontium titanate, the barrier layer (3) is undoped strontium titanate, and the superconductor (1) is a thin film of a material having a lattice constant at least approximately similar to the one of the materials of the substrate (2) and barrier (3) layers. A preferred material of this type is YBa.sub.2 Cu.sub.3 O.sub.7-.delta., where 0.ltoreq..delta..ltoreq.0.5.

Abstract: An insulating composition consisting of Bi, Sr, RE, Cu, O or of Tl, Ba, RE, Cu, O (wherein; RE is an element selected from a group consisting of Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) aligns properly with a crystal face of an oxide superconductor because its crystal structure is the same as or similar to that of the oxide superconductor. An insulating composition in which a part of Bi is replaced by Pb is further near the oxide superconductor its construction, and the modulation structure in this insulating composition is mitigated or disappears.

Abstract: A superconducting thin film of a compound oxide represented by YBa.sub.2 Cu.sub.3 O.sub.y in which "y" is a number of 6<y<8 and deposited on a substrate, characterized in that a buffer layer of a compound oxide represented by Y.sub.2 BaCuO.sub.x in which "x" is a number of 4<x<6 is interposed between the superconducting thin film and the substrate.