Abstract: A superconductive element containing Nb3Sn, in particular a multifilament wire, comprising at least one superconductive filament (8) which is obtained by a solid state diffusion reaction from a preliminary filament structure (1), said preliminary filament structure (1) containing an elongated hollow pipe (2) having an inner surface (3) and an outer surface (4), wherein said hollow pipe (2) consists of Nb or an Nb alloy, in particular NbTa, wherein the outer surface (4) is in close contact with a surrounding bronze matrix (5) containing Cu and Sn, and wherein the inner surface (3) is in close contact with an inner bronze matrix (5) also containing Cu and Sn, is characterized in that the inner bronze matrix (5) of the preliminary filament structure (1) encloses in its central region an elongated core (6) consisting of a metallic material, said metallic material having at room temperature (=RT) a thermal expansion coefficient ?core<17*10?6K?1, preferably ?core?8*10?6 K?1, said metallic material having at RT a

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: Disclosed herein is a wire for an Nb.sub.3 X superconducting wire, which is improved in workability and soundness of a diffusion barrier layer without increasing the diffusion barrier layer in thickness. This wire for an Nb.sub.3 X superconducting wire comprises a wire which is prepared by superposing and winding up a first sheet consisting of pure Nb or an Nb alloy and a second sheet consisting of metal atoms X, reacting with Nb for forming a compound exhibiting superconductivity, or an X alloy, a stabilizing material layer which is provided to enclose the wire, and a diffusion barrier layer which is provided between an outer surface of the wire and an inner surface of the stabilizing material layer for preventing the metal atoms X from being diffused in the stabilizing material layer, and the diffusion barrier layer is made of a metal material having larger tensile strength than that of the first sheet. It is possible to obtain a high-performance Nb.sub.

Abstract: A method of manufacturing an Nb.sub.3 Al superconducting wire includes a step of forming a wire by a jelly-roll process, a first thermal step of heating the obtained wire at a temperature of 500.degree. to 700.degree. C. for at least 10 hours for diffusing Al in Nb while suppressing formation of Nb.sub.3 Al, and a second thermal step of heating the wire, after the first thermal step, at a temperature of 800.degree. to 1050.degree. C. for about 0.01 to 10 hours, thereby forming Nb.sub.3 Al. In the jelly-roll process, a sheet of Nb and a sheet of Al are lap-wound on a copper core. The material obtained by such lap winding is inserted in a copper pipe, and then subjected to drawing. The drawn wire is cut to obtain a plurality of segments. The plurality of segments are bundled and charged in a copper pipe, and then subjected to drawing. The resulting drawn wire is subjected to the first and second thermal steps.

Abstract: A process is disclosed of producing on a crystalline silicon substrate a barrier layer triad capable of protecting a rare earth alkaline earth copper oxide conductive coating from direct interaction with the substrate. A silica layer of at least 2000 .ANG. in thickness is deposited on the silicon substrate, and followed by deposition on the silica layer of a Group 4 heavy metal to form a layer having a thickness in the range of from 1500 to 3000 .ANG.. Heating the layers in the absence of a reactive atmosphere to permit oxygen migration from the silica layer forms a barrier layer triad consisting of a silica first triad layer located adjacent the silicon substrate, a heavy Group 4 metal oxide third triad layer remote from the silicon substrate, and a Group 4 heavy metal silicide second triad layer interposed between the first and third triad layers.