Abstract: In one embodiment, a superconducting coil includes a tertiary parallel superconductor unit (60) composed of superposed in parallel a plurality of layers of secondary parallel superconductor units (50). The layers of secondary parallel superconductor units include a plurality of superconductor elements (40) arranged in parallel along the axial direction of the coil, forming a superconducting conductor unit. The tertiary parallel superconductor unit is wound on a bobbin (55). In another embodiment, the superconducting coil includes one or more layers of the secondary parallel superconductor unit wound on the bobbin. In both embodiments, the secondary parallel superconductor unit can include at least one non-superconducting conductor element (70). The layer of the secondary parallel superconductor unit forming an outer side of the tertiary parallel superconductor unit can include at least one non-superconducting conductor element.

Abstract: The invention provides a method for stably preparing a bismuth-based high temperature superconductor of a Bi-2223 single-phase or a Bi/Pb-2223 single phase, wherein a second phase is not allowed to reside, at a low cost and efficiently. With the method described above, mixed powders of raw materials (mixed powders of oxides and carbonates), obtained by mixing the raw materials such that a mixing ratio of constituents, Bi:Sr:Ca:Cu or (Bi, Pb):Sr:Ca:Cu, becomes identical to the stoichiometric ratio of a crystal of the superconductor Bi2Sr2Ca2Cu3Oz, or (Bi, Pb) 2Sr2Ca2Cu3Oz, respectively, are used as raw material for sintering, and the sintering is applied thereto, using KCl as a flux. In this case, the raw material for the sintering as calcinated is preferably used, and the sintering is preferably applied at a sintering temperature kept at a constant level.

Abstract: Methods for implementing production of an oxide superconductor joined member, excellent in electric current transmission performance, without a need of going through particularly complex steps, are provided. When joining together oxide superconductors by use of a solder composed of an oxide superconducting material, a finally solidified portion of the solder is positioned in a region where a transmission path of electric current flowing between oxide superconductor base materials as joined together is not obstructed by, for example, disposing the solder on a face of the oxide superconductor base materials, other than butting surfaces of the oxide superconductor base materials, so as to straddle both the base materials like bridge-building. Current flow is also not obstructed by, for example, shaping junction faces of the oxide superconductor base materials such that at least portions of the butting surfaces thereof are in the shape of sloped open faces, parting from each other.

Abstract: There is provided a method for preparing a large and perfect oxide crystal useful for oxide superconductors and laser transmitting elements. In the present method for preparing a large oxide single crystalline material such as superconductive crystals of RE123, a crystal precursor material is supercooled prior to the solidification thereof in the course of crystal growth of the oxide by a supercooling solidification process, followed by subjecting said precursor material to continuous slow heating while keeping the supercooled condition to promote crystal growth, as shown in FIG. 7. Seed crystals may be added to the crystal precursor material prior to solidification, if necessary, as also shown in FIG. 7.

Abstract: There is provided RE-Ba-Cu-O oxide bulk superconductors in which considerably high critical current density is obtained at relatively high temperature. In the present RE-Ba-Cu-O bulk superconductors, RE is a combination of two or more elements selected from La, Nd, Sm, Eu and Gd, at least one of them being La, Nd and Sm and the remainder being Eu or Gd, in which a parent phase thereof comprises a RE.sub.1+x Ba.sub.2-x Cu.sub.3 O.sub.y crystal wherein -0.1<x<0.2 and 6.7<y<7.1, and 5 to 50% by volume of a RE.sub.2 Ba.sub.2 CuO.sub.5 fine dispersed phase having partide size of 0.01 to 0.5 .mu.m. Preferably, a total amount of Eu and Gd in the RE site is 40% by weight or less, while a slight amount of Pt may be added. As a result, the critical current density at liquid nitrogen temperature can be improved to 10,000 A/cm.sup.2 or more under a condition where a magnetic field of 3T is impressed parallel to c axis of the crystal.

Abstract: There is provided a method for stably preparing rare earth (RE) 123 type oxide superconductors exhibiting outstanding superconductive properties in the atmosphere. In the method for preparing RE 123-type oxide superconductors by melting, cooling and solidifying a starting composition containing one or more than two kinds of RE such as Y, Sm, Nd, etc., and Ba, Cu and O as constituent elements to crystallize the RE 123-type oxide superconductors, the quantity of replacement between RE and Ba in "RE 123 crystals to be formed" is controlled by changing the initial constitution of the starting composition, for example, by changing the initial constitution to a more Ba-rich side than a composition on a 123-211 (or 422) tie line on a phase diagram to yield RE 123-type oxide superconductors in the atmosphere, which exhibits a critical temperature of 90 K or above and higher critical current density (Jc) in a magnetic field. A trace amount of Pt or CeO.sub.

Abstract: A process for controlling crystalline orientation of an oxide superconductive film includes a first-heat-treatment step, and a second-heat-treatment step. In the first-heat-treatment step, an oxide superconductive film is heated and held in non-oxidizing atmosphere. Accordingly, partial oxygen deficiency is caused in the oxide superconductive film. In the second-heat-treatment step, the oxide superconductive film is heated and held in oxygen-rich atmosphere. Consequently, oxygen is re-introduced into the oxide superconductive film. Thus, crystalline orientation of the oxide superconductive film is altered. The process enables to readily form not only an "a"-axis-oriented oxide superconductive film but also a "b"-axis-oriented oxide superconductive film.

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 substrate material for the preparation of an oxide superconductor includes two different rare earth elements A' and A" in the IIIa group, Ga, and 0, the atomic ratio of these elements being expressed as A'1-xA"xGaO.sub.3 (where 0<x<1), and a mixed crystal material forming a perovskite-type structure having a composition of AGaO.sub.3 with A being at least one of the two rare earth elements A' and A" in the IIIa group, a substrate material for preparing an oxide superconductor includes a mixed crystal material made up of Nd, La, Ga, and O in an atomic ratio of La.sub.1-x Nd.sub.x GaO.sub.3 wherein 0.2.ltoreq.x<1.0, the substrate material forming a GdFeO.sub.3 -type structure; a substrate material for preparing an oxide superconductor includes a mixed material made up of Nd, A.sup.1, Ga, and O in an atomic ratio of A.sup.1.sub.1-x Nd.sub.x GaO.sub.3 where A.sup.1 is a rare earth element excluding La and Nd, and 0.2.ltoreq.x<1.0, the mixed crystal material forming a GdFeO.sub.3 -type structure.