Abstract: The invention provides a wide frequency band high temperature superconductor mixer antenna which allows a superconductor feed line, which exhibits a high resistance loss in a high frequency region, to be used in a low frequency region with a low loss and which is provided with a same structure as a mixer which has a wide band twice or more the frequency of a millimeter or more wave while keeping a characteristic of a high integration array antenna, which makes most of the high integrity of superconductor feed lines. The wide frequency band high temperature superconductor mixer antenna includes one or a plurality of planar structure antenna patterns of the log-periodical type or the log-spiral type and a plurality of oxide superconductor thin film feed line wiring patterns formed on a same face of a main surface of a substrate, a central portion of each of the planar structure antenna patterns being formed from an oxide superconductor thin film on which a non-linear element part is provided.

Abstract: A superconducting patch antenna array, operative at a temperature lower than or equal to that of liquid nitrogen, includes a superconducting mixer comprising at least one non-linear Josephson junction to transform the received high frequency signal to a lower intermediate frequency for purposes of reducing the transmission loss and thereby increasing the antenna performance.

Abstract: When a cuprate oxide LnBa.sub.2 Cu.sub.3 O.sub.7-x (Ln=Y, Pr or Sm; 0.30.ltoreq.x.ltoreq.1) single crystal is heated for growing a film epitaxially on the crystal or for smoothing a damaged surface of the single crystal, many large protrusions occur on the surface of the oxide single crystal substrate or the film. The smooth surface of the oxides becomes rugged by the protrusions. According to the present invention, however, the oxide substrate or the oxide superconductor film can be heated in an atmosphere including oxygen of a partial pressure between 50 mTorr and 200 mTorr to prevent the protrusions from originating on the surface of the heated oxides.

Abstract: A superconducting element is disclosed which includes a substrate and a superconducting layer provided on the substrate and formed of an oxide having the following chemical formula:RBa.sub.2 (Cu.sub.1-x M.sub.x).sub.3 O.sub.7wherein R represents at least one element selected from the group consisting of Y, La, Nd, Pm, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu, M represents at least one element selected from the group consisting of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Zn and Ga, and x represents a number of less than 1 but greater than 0.

Abstract: A superconducting film is disclosed which has the following composition:(Nd, Ba).sub.3 Cu.sub.3 O.sub.7-dwhere d is a number greater than 0 but smaller than 0.5. The superconducting film has the same crystal structure as that of YBa.sub.2 Cu.sub.3 O.sub.7 except that part of the Nd sites and/or part of the Ba sites are occupied by Ba and Nd atoms, respectively.

Abstract: A superconducting device having a superconducting film measures a characteristic such as its resonance frequency while in an environment having a temperature that is less than or equal to its superconducting transition temperature. A laser then thermally etches the superconducting film on the basis of said measurement in the environment having a temperature that is less than or equal to a superconducting transition temperature.

Abstract: A superconductor junction material is disclosed which comprises a substrate of a single crystal, and at least flux flow element, and optionally at least one Josephson junction element, provided on the surface, each of the flux flow and Josephson junction elements being formed of a superconducting oxide layer having a weak link. The flux flow and Josephson junction elements are prepared by vacuum deposition at different oxygen partial pressures.

Abstract: A Josephson junction is disclosed which includes a substrate of a single crystal having a substantially flat surface, a wiring pattern of an oxide superconductor formed on the flat surface of the substrate, and an altered region formed having a width of 300 nm or less and formed in the wiring pattern to intersect the wiring pattern, the crystal orientations of the wiring pattern on both sides of the altered region being equal to each other.

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 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: An oxide superconductor thin film of Y.sub.1.+-..alpha. Ba.sub.2.+-..beta. Cu.sub.3.+-..gamma. O.sub.7-.delta. with a smooth surface having a low density of particles being generated without decreasing superconductivity is produced by the steps of applying a pulsed laser beam to the target formed of an oxide material having an apparent density of 95% or more, substantially composed of Y.sub.1.+-..alpha. Ba.sub.2.+-..beta. Cu.sub.3.+-..gamma. O.sub.7-.delta., which is obtained from a molded body of an amorphous powder by subjecting it to partial melting, followed by gradual cooling, depositing and accumulating an irradiated and evaporated oxide material of the target on a substrate.

Abstract: A tunneling Josephson junction is disclosed in which first and second superposed superconducting electrode layers are formed of thin films of oxide superconducting materials having a perovskite structure of BaPB.sub.1-x Bi.sub.x O.sub.3. A barrier layer interposed between these superconducting electrode layers is a thin film of long service life which is stable and breakdown free under heat cycles from room temperature to ultra low temperatures. This film is made of an oxide with perovskite structure which has the same crystal structure and thermal expansion coefficient as those of the first and second superconducting layers for functioning as an insulator or a semiconductor. The oxide with perovskite structure may be BaSnO.sub.3, Ba.sub.1-y Sr.sub.y Pb.sub.1-x Bi.sub.x O.sub.3 (wherein 0.ltoreq.x.ltoreq.0.3, y>0.3) or BaPb.sub.1-x (A.sub.1-y Bi.sub.y)O.sub.3 (wherein A is at least one member selected from the group consisting of V, Nb, Ta and Sb; 0.1.ltoreq.x.ltoreq.0.3; and 0.ltoreq.y.ltoreq.0.5).