Abstract: The electrical contact material includes a base material, a coating layer provided on a surface of the base material, and an oxide layer provided on a surface of the coating layer. The base material contains Cu. The coating layer includes an undercoat layer, a first layer, and a second layer that are provided in that order from the base material side. The undercoat layer contains Ni. The first layer contains Ni, Zn, Cu, and Sn. The second layer contains Sn. The oxide layer is constituted by an oxide containing Zn, Cu, and Sn. The undercoat layer has a thickness larger than 0.5 ?m.

Abstract: A process to fabricate ultra-fine grain metal wire, comprising: inserting a plurality of metal strands into a flexible elastic polyurethane sheath having an accommodating slot for each of the strands of metal to form a sheathed strand assembly; equal channel angular pressing (ECAP pressing) the sheathed strand assembly through an ECAP die having a plurality of die channels corresponding to the plurality of metal strands. The process is designed to improve electric conductance and mechanical properties of elongated metal parts and is especially applicable to optimize the conductance and tensile strength of copper cables, wires, strings, and rods.

Abstract: A composite barrier-type Nb3Al superconducting multifilament wire material comprises Nb barrier filaments, Ta barrier filaments, Nb bulk dummy filaments, and a Nb or Ta covering. In the composite barrier-type Nb3Al superconducting multifilament wire material, the Nb barrier filaments and Ta barrier filaments are disposed in the wire material so that the Nb barrier filaments are concentrated in a filament region near a core formed from the Nb bulk dummy filaments and only the Ta barrier filaments are disposed or the Nb barrier filaments are dispersed in the Ta barrier filaments in an outer layer portion formed from a region outside the Nb barrier filaments, excluding the Nb or Ta covering.

Abstract: A superconducting wire (12), containing NbTi superconducting material and Cu, comprising a multiplicity of hexagonal elements, which, as seen in cross-section perpendicular to the longitudinal direction of the superconducting wire (12), have an at least approximately hexagonal outside contour is characterized in that at least a portion of the hexagonal elements is constituted as Cu—Al composite elements (3), wherein, in cross-section perpendicular to the longitudinal direction of the superconducting wire (12), the Cu—Al composite elements (3) are each constituted with an Al core (4) and a Cu sheath (5) that surrounds the Al core (4). The NbTi superconducting wire is thereby stabilized and has low weight as well as a reduced risk of crack formation during manufacturing, especially during wire drawing.

Abstract: A conductor for transmitting electrical power having a cylindrical core (1) clad with a strip of metallic material (2), possibly comprising a superconductor, placed, in the shape of a tube, longitudinally around said core (I), its longitudinal edges being welded to each other along a weld seam (3). The core (1) has a slot (4, 4?) placed under said weld seam (3).

Abstract: A system is specified having at least one superconducting cable (SK) which has at least one superconducting conductor (2), and having a cryostat (KR) which surrounds the same and has two metallic tubes, an inner tube (6) and an outer tube (7), which are arranged concentrically at a distance from one another, are corrugated transversely with respect to their longitudinal direction and between which vacuum insulation (8) is arranged. The cable (SK) has a central tubular support (1) for passing a coolant through, on which the superconducting conductor (2) rests. The cable (SK) is surrounded all around by a buffer layer (5) which protects the same against mechanical damage and consists of insulating material, and the inner tube (6) of the cryostat (KR) at least rests in a sealed manner on the buffer layer (5).

Abstract: The invention relates to an assembly (1, 35, 71) of metal elements constituting a precursor for a superconductor. The assembly comprises at least one conductor element (5, 41, 73) adapted to provide a superconducting filament in the finished superconductor, and at least one doping element (7, 43, 75) providing a doping source for doping the conductor element. The invention also relates to a method suitable for producing a superconductor.

Abstract: An induction heating apparatus that can operate at current frequencies of greater than 60 Hz and at least 1 kW. The induction heating apparatus includes a high frequency power supply, a superconductive induction coil, and a fluid cooling system. A fluid cooling system is designed to cause a cooling fluid to flow at least partially about and/or through the superconductive induction coil.

Abstract: Impurities in an oxide superconducting layer or at a surface of the oxide superconducting layer at an intermediate layer side are reduced. A superconducting wire rod has a configuration that includes a metal substrate 10; an intermediate layer 20 formed on the metal substrate 10 and containing a rare-earth element that reacts with Ba; a reaction suppressing layer 28 formed on the intermediate layer 20 and mainly containing LaMnO3+?1, wherein ?1 represents an amount of non-stoichiometric oxygen; and an oxide superconducting layer 30 formed on the reaction suppressing layer 28 and mainly containing an oxide superconductor containing Ba.

Abstract: A superconducting cable system in which at least one superconducting electrical cable is arranged in a cryostat which consists of two metallic tubes, which are arranged concentrically and at a distance from one another. Vacuum insulation is fitted in the circumferential gap formed by the distance between the tubes, which vacuum insulation consists of spaces composed of a material having low thermal conductivity and plastic films coated with a metal and having high reflectivity. The gap is evacuated. In addition, thermally insulating material (9) is arranged in the gap, and its thermally insulating characteristics are independent of the vacuum which is produced between the two tubes (5, 6).

Abstract: In a method of manufacturing a copper clad aluminum channel superconductive conductor, an electrically conductive wire comprising a metal or alloy core is formed with a longitudinally extending groove in a surface thereof. A wire made of a material that exhibits superconducting properties within a defined temperature range is soldered into the groove.

Abstract: A current terminal structure of a superconductor has a former, and a superconducting wire wound around the former in one or more layers and including a substrate and a superconducting layer formed on the substrate. A first layer superconducting wire wound around immediately above the former is arranged so that a substrate side thereof becomes outside and a superconducting layer side thereof becomes inside. A surface of the superconducting layer at an end of the first layer superconducting wire, which is directed toward the inside, and part of a surface of the superconducting layer of a connection superconducting wire, which is directed toward the outside, are faced and connected to each other.

Abstract: A superconducting article is provided which includes a superconducting tape assembly. The superconducting tape assembly includes a superconducting tape layer, having one or more superconducting tapes, and a high-permeability magnetic material layer coupled to the superconducting tape layer. The high-permeability magnetic material layer includes a high-permeability magnetic material which remains magnetically soft at a critical temperature Tc of the superconducting tape, and with presence of an ac magnetic field acting on the superconducting tape assembly, re-magnetizes to divert at least a portion of a normal component of the ac magnetic field therethrough, which reduces ac loss in the superconducting tape layer by modifying the ac magnetic field distribution within the superconducting tape of the superconducting tape layer.

Abstract: In a method and apparatus for joining a number of superconductive cables to establish electrical connection therebetween, a cup-like member having a base, a sidewall, and an opening to receive electrically conductive ends of said cables is provided. The base of the cup-like member is attached to a holder device. The holder device is attached to a cryogenically cooled surface. The ends of the superconductive cables are connected together within the cup-like member.

Abstract: An arrangement is specified for current limiting having a superconducting cable (SK) which is arranged in a cryostat (KR) which has an outer wall which comprises two metallic tubes (1, 2) which are arranged concentrically with respect to one another and between which vacuum insulation (3) is incorporated. The cryostat (KR) surrounds a free space (FR) for a coolant to pass through, in which free space (FR) the superconducting cable (SK) is arranged. It also has an inner wall (IW) which surrounds a cylindrical cavity (HR) and likewise comprises two metallic tubes (4, 5) which are arranged concentrically with respect to one another, between which vacuum insulation (6) is incorporated, and which is located within the outer wall (AW) and is separated therefrom by the free space (FR). The superconducting cable (SK) which has a superconducting conductor, a dielectric surrounding the same and a superconducting screen which is arranged above the same, is wound in a helical shape around the inner wall (IW).

Abstract: A crystalline article includes a single-crystal ceramic fiber, tape or ribbon. The fiber, tape or ribbon has at least one crystallographic facet along its length, which is generally at least one meter long. In the case of sapphire, the facets are R-plane, M-plane, C-plane or A-plane facets. Epitaxial articles, including superconducting articles, can be formed on the fiber, tape or ribbon.

Abstract: A method is specified for operation of an arrangement having at least one superconducting cable, which is surrounded by a cryostat which consists of two metallic tubes, which are arranged concentrically with respect to one another and enclose vacuum insulation between them. The cryostat surrounds not only the cable but also a cavity for a pressurized coolant to pass through. A reservoir area, which is connected to the cryostat, for the coolant is arranged at least at one end of the cryostat and a pump is used which forces the coolant into the cryostat during operation of the arrangement. A valve is arranged at least in the supply path of the coolant from the reservoir area to the cryostat, which valve is open during operation of the arrangement, is connected to at least one unit monitoring the soundness of the cryostat and is blocked when a signal which corresponds to a fault message is present from the monitoring unit, in order to interrupt the supply of the coolant to the cryostat.

Abstract: A conductor for transmitting electrical power having a cylindrical core (1) clad with a strip of metallic material (2), possibly comprising a superconductor, placed, in the shape of a tube, longitudinally around said core (I), its longitudinal edges being welded to each other along a weld seam (3). The core (1) has a slot (4, 4?) placed under said weld seam (3).

Abstract: An oxide superconductor member is composed of a tape-shaped substrate, an intermediate layer formed on this substrate and an oxide superconductor thin film layer formed on this intermediate layer. A surface of the tape-shaped substrate is polished by continuously running the tape-shaped substrate. The polishing step includes initial polishing process and finishing process which are carried out such that the average surface roughness Ra of the substrate becomes 2 nanometers or less and the in-plane directionality of the intermediate layer becomes 5° or less after the polishing step.

Abstract: An oxide superconductor member is composed of a tape-shaped substrate, an intermediate layer formed on this substrate and an oxide superconductor thin film layer formed on this intermediate layer. A surface of the tape-shaped substrate is polished by continuously running the tape-shaped substrate. The polishing step includes initial polishing process and finishing process which are carried out such that the average surface roughness Ra of the substrate becomes 2 nanometers or less and the in-plane directionality of the intermediate layer becomes 5° or less after the polishing step.

Abstract: A method for manufacturing a superconducting wire includes the following steps. A laminate metal having a first metal layer and a Ni layer formed on the first metal layer is prepared. An intermediate layer is formed on the Ni layer of the laminate metal. A superconducting layer is formed on the intermediate layer. By subjecting the laminate metal to a heat treatment after at least either of the step of forming a intermediate layer and the step of forming a superconducting layer, a nonmagnetic Ni alloy layer is formed from the laminate metal.

Abstract: A coated conductor with simplified layer architecture includes a biaxial textured substrate, a template buffer layer composed of a material having the general formula RE2?xB2+xO7 with RE being at least one lanthanoid metal, B being at least one metal selected from Zr and Hf and ?0.4?x?+0.7, where the superconductor layer is obtainable by hybrid liquid phase epitaxy and can be deposited directly onto the template buffer layer.

Abstract: A superconductive cable is provided which upon normal state, restricts flowing of electric current to a former to the maximum extent to thereby keep a cryogenic state in the superconductive cable stable. The superconductive cable includes a former surrounded by a superconductive layer and a cryostat provided at the outside of the superconductive layer, wherein the former includes a metal wire-wound part around which a plurality of wires is wound and an eddy-current prevention layer provided on the outer face of the wire-wound part, and the metal wires and the eddy-current prevention layer are made of a copper alloy.

Abstract: A coated conductor with simplified layer architecture includes a biaxial textured substrate, a template buffer layer composed of a material having the general formula RE2?xB2+xO7 with RE being at least one lanthanoid metal, B being at least one metal selected from Zr and Hf and ?0.4?x?+0.7, where the superconductor layer is obtainable by hybrid liquid phase epitaxy and can be deposited directly onto the template buffer layer.

Abstract: A cryogenically-cooled HTS cable is configured to be included within a utility power grid having a maximum fault current that would occur in the absence of the cryogenically-cooled HTS cable. The cryogenically-cooled HTS cable includes a continuous liquid cryogen coolant path for circulating a liquid cryogen. A continuously flexible arrangement of HTS wires has an impedance characteristic that attenuates the maximum fault current by at least 10%. The continuously flexible arrangement of HTS wires is configured to allow the cryogenically-cooled HTS cable to operate, during the occurrence of a maximum fault condition, with a maximum temperature rise within the HTS wires that is low enough to prevent the formation of gas bubbles within the liquid cryogen.

Abstract: There is provided a superconductive cable capable of absorbing an amount of contracting a superconductive wire member in cooling by a simple constitution. A superconductive cable according to the invention is a cable including a superconductive wire member constituting a superconductive layer (a conductor layer 13, a return line conductor 17) by being wound spirally, a stress relaxation layer (an inner side stress relaxation layer 12, and insulating layer/outer side stress relaxation layer 16) provided on an inner side of the superconductive layer, and a cable constituting member (a former 11) provided on an inner side of the stress relaxation layer. The cable is constituted to absorb an amount of contracting the superconductive layer in accordance with cooling the superconductive wire member by a refrigerant in a diameter direction by the stress relaxation layer.

Abstract: A target surface of a tape-shaped substrate of an oxide superconductor with an intermediate layer formed on this target surface and an oxide superconductor thin film is polished by causing the tape-shaped substrate to continuously run. The polishing step includes an initial polishing process for carrying out random polishing of the target surface and a finishing process that is carried out after the initial polishing process for forming grooves on the target surface along the running direction of the substrate. The intermediate layer has an in-plane directionality of 7° or less. The tape-shaped substrate is fabricated by rolling nickel, a nickel alloys or stainless steel.

Abstract: An AC-tolerant high temperature superconductor tape with transposed filaments having two layers of high temperature superconducting material with striations and corresponding filaments and an insulating layer positioned therebetween.

Abstract: A method is provided for producing a superconductive electrical conductor (7) in which a layer of an yttrium-barium-copper oxide (YBCO) is applied as a superconductive material onto a textured metal base directly or after prior application of a buffer layer, and is subjected to a heat treatment. To this end an interlayer of a metallic material which is compatible with the crystal structure of YBCO, or with the structure of a buffer layer suitable for the application of YBCO, is initially applied all around onto an elongate metal support (1). The support (1) provided with the interlayer is subsequently processed so that predetermined texturing is imparted to the interlayer as a metal base for the layer of YBCO material or for the buffer layer. The layer of superconductive YBCO material is then applied all around, directly onto the textured interlayer or onto the buffer layer previously applied thereon, and the heat treatment is finally carried out.

Abstract: A superconducting composite wire with superconducting phase of magnesium diboride comprises: a core of conductive metal (1); a plurality of filaments in which each filament (3) comprises a core of magnesium diboride (5), placed around said conductive metal core (1); —an outer metallic sheath (4) for containment and mechanical reinforcement, surrounding the said plurality of filaments; and—at least one layer (2, 2a, 2b) of metal chemically compatible with magnesium diboride and capable of acting as an obstacle to the diffusion of the conductive metal of said conductive metal core (1) towards the said filaments (3), up to 980° C. where the said at least one layer is applied a) as a coating (2) of the said conductive metal core and/or b) as a coating (2a) of the said filaments (3), and/or c) as a coating (2b) of the said magnesium diboride core (5) of the said filaments (3).

Abstract: A method is provided for producing a superconductive electrical conductor, in which a layer of an yttrium-barium-copper oxide (YBCO) is applied as a superconductive material onto a textured metal substrate, and is subjected to a heat treatment. In order to produce a wire-shaped conductor, a textured metal substrate, provided as a strip (2), is initially shaped in its longitudinal direction around an elongate metal support (1) with a circular cross section to form a slotted tube (3) having edges extending in the longitudinal direction and adjoining one another at a slot (4). The slotted tube (3) is next closed by welding the slot (4) shut, and the closed tube (9) is then contracted by pulling until it bears on the support (1). The layer (12) of superconductive YBCO material is thereupon applied all around, and the heat treatment is finally carried out.

Abstract: A superconducting wire having at least a superconducting thin film and a stabilizing film formed one on top of another in order on a substrate having a predetermined width and a predetermined length, the superconducting wire having at least one cut made along a direction of the length of the superconducting wire, the superconducting wire being bendable at the cut in a width direction.

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: A cryogenically-cooled HTS wire includes a stabilizer having a total thickness in a range of 200-600 micrometers and a resistivity in a range of 0.8-15.0 microOhm cm at approximately 90 K. A first HTS layer is thermally-coupled to at least a portion of the stabilizer.

Abstract: A superconducting cable has a plurality of superconducting wires wound around a core material (former) in a multilayered manner. The superconducting wires employ a twisted filament type superconducting wire having spiral superconducting filaments and an untwisted filament type superconducting wire having straight superconducting filaments. The layer in which an applied magnetic field is large and of which the low loss effect is expected is formed of twisted filament type superconducting wires, and the other layers are formed using the untwisted filament type superconducting wires; thus the AC loss can be reduced effectively. Thus, in the superconducting cable, the AC loss can be effectively reduced while a degradation of the current characteristics and the increase of cost are suppressed.

Abstract: A layered article of manufacture and a method of manufacturing same is disclosed. A substrate has a biaxially textured MgO crystalline layer having the c-axes thereof inclined with respect to the plane of the substrate deposited thereon. A layer of one or more of YSZ or Y2O3 and then a layer of CeO2 is deposited on the MgO. A crystalline superconductor layer with the c-axes thereof normal to the plane of the substrate is deposited on the CeO2 layer. Deposition of the MgO layer on the substrate is by the inclined substrate deposition method developed at Argonne National Laboratory. Preferably, the MgO has the c-axes thereof inclined with respect to the normal to the substrate in the range of from about 10° to about 40° and YBCO superconductors are used.

Abstract: In order to reduce the AC losses in a superconducting conductor element subjected to an external magnetic field and through which a current flows, tapes of superconducting material of each layer are wound at such a mutual distance that the gap between the superconducting material of adjacent tapes is not smaller than a predetermined minimum value. These elements are particularly useful in three-phase warm dielectric superconducting cables.

Abstract: A method is described for the production of superconductive wires based on hollow filaments made of MgB2, which comprises: a) the formation of a composite billet by means of the coaxial insertion in a tubular metallic container of a cylindrical bar made of metallic magnesium and amorphous boron powder in the interspace between the container and bar, said powder being pressed between the metallic container and the magnesium bar, in such a quantity that the weight ratio magnesium/boron is higher than 1.2; b) at least one plastic deformation treatment of the composite billet thus obtained until a wire with a pre-fixed diameter is obtained, with the subsequent winding of the wire onto a support; c) a thermal treatment of the filament product thus obtained, at a temperature ranging from 700° C. to 950° C. for a time ranging from 15 minutes to three hours.

Abstract: A structural arrangement of superconducting composites is provided to protect their superconductivity in such a way that these composites are electrically connected in a certain manner. The invention may be practiced with any desired superconducting material, and bismuth based superconducting materials are preferred. The shape and size of the superconducting composites may vary.

Abstract: A niobium-based superconductor is manufactured by establishing multiple niobium components in a billet of a ductile metal, working the composite billet through a series of reduction steps to form the niobium components into elongated elements, each niobium element having a thickness on the order of 1 to 25 microns, surrounding the billet prior to the last reduction step with a porous confining layer of an acid resistant metal, immersing the confined billet in an acid or a high temperature liquid metal to remove the ductile metal from between the niobium elements while the niobium elements remain confined by said porous layer, exposing the confined mass of niobium elements to a material capable of reacting with Nb to form a superconductor.

Abstract: A method of producing multifilament superconducting Nb3Sn wire with low bridging potential during reaction by introducing a diffusion/reaction barrier between the filaments as a radial sheet. The barrier is made of Ta, Va, a NbTa alloy or other ductile material.

Abstract: A high temperature superconducting composite rod, wire or tape is formed by filling the open cells of a reticulated foam structure made of silver, silver alloy, gold or gold alloy with a superconducting ceramic oxide or precursor, compacting the filled structure and forming it into a rod, wire or tape and heating it to melt and/or texture the superconducting ceramic oxide. The resulting composite has continuous ligaments of metal throughout a continuous region of superconducting ceramic oxide.

Abstract: A process for manufacturing superconducting magnetic coils from strain-tolerant, superconducting multi-filament composite conductors is described. The method involves winding the precursor to a multi-filament composite conductor and an insulating material or its precursor around a mandrel in order to form a coil, and then exposing the coil to high temperatures and an oxidizing environment. The insulating material or its precursor is chosen to permit exposure of the superconductor precursor filaments to the oxidizing environment, and to encase the matrix-forming material enclosing the filaments, which is reversibly weakened during processing.

Abstract: A superconducting cable (1) for high power with at least one phase comprises a superconducting core (2) wherein a plurality of elements (3) are housed, which are structurally independent and magnetically uncoupled, each of which includes—for each phase—a couple of phase and neutral coaxial conductors, each formed by at least a layer of superconducting material, electrically insulated from one another by interposition of a dielectric material (8). Thanks to the distribution of the superconducting material into several coaxial conductive elements (3), the cable (1) allows to transmit high current amounts in conditions of superconductivity, while using a high-temperature superconducting material sensitive to the magnetic field.

Abstract: A superconducting cable for alternating current, comprising conductor layers formed by a plurality of tape-shaped superconducting wires wound around a center member, an electric insulating layer formed outside the conductor layers, and a plurality of shielding layers formed outside the insulating layer, wherein, the conductor layers are formed, where N is a number of layers in the conductor layers and expressed by an integer, by gradually increasing a winding pitch of conductor layers in the same direction from an inner first layer to an N/2 layer when the number of layers is even, or from an inner first layer to a (N−1)/2 layer when the number of layers is odd, and then by gradually decreasing a winding pitch of conductor layers in an opposite direction to the inner layers from a N/2+1 layer to an N layer when the number of layers is even, or from a (N+1)/2 layer to an N layer when the number of layers is odd.

Abstract: An oxide superconducting wire of an anisotropic oxide superconductor comprises a core part of the wire and a superconducting layer enclosing the core part so that specific crystal axes of the oxide superconductor are oriented toward the core part. A method of producing a wire of an anisotropic oxide superconductor comprises the steps of arranging a metal sheath around a metal rod for forming a core part of the wire and charging powder of the oxide superconductor in a clearance between the metal sheath and the metal rod for preparing a composite material, and plastically working the composite material so that the metal sheath is larger in reduction of area than the metal rod.

Abstract: A laminate article comprises a substrate and a biaxially textured (RExA(1−x))2O2−(x/2) buffer layer over the substrate, wherein 0<x≦0.70 and RE is selected from the group consisting of La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. A is selected from the group consisting of Zr+4, Ce+4, Sn+4, and Hf+4. The (RExA(1−x))2O2−(x/2) buffer layer can be deposited using sol-gel or metal-organic decomposition. The laminate article can include a layer of YBCO over the (RExA(1−x))2O2−(x/2) buffer layer. A layer of CeO2 between the YBCO layer and the (RExA(1−x))2O2−(x/2) buffer layer can also be include. Further included can be a layer of YSZ between the CeO2 layer and the (RExA(1−x))2O2−(x/2) buffer layer. The substrate can be a biaxially textured metal, such as nickel. A method of forming the laminate article is also disclosed.

Abstract: A superconducting cable for high power with at least one phase includes a superconducting core wherein a plurality of elements are housed, which are structurally independent and magnetically uncoupled, each of which includes—for each phase—a couple of phase and neutral coaxial conductors, each formed by at least a layer of superconducting material, electrically insulated from one another by interposition of a dielectric material. As a result of the distribution of the superconducting material into several coaxial conductive elements, the cable allows to transmit high current amounts in conditions of superconductivity, while using a high-temperature superconducting material sensitive to the magnetic field. The conductive elements are connected at the ends to yield a mean exploitation efficiency of 100%.

Abstract: In a process in which a composite consisting of a metallic base and a superconductor mainly containing a Bi2Sr2CaCu2Ox superconducting phase is formed into a composite wire or wire, the composite is subjected to calcination and cold working before heat treatment for crystallization from a partial molten state.

Abstract: A high temperature oxide superconductor is efficiently protected from the affects of water and acids by forming a passivation layer of a fluoride. The fluoride layer comprises a fluoride composed of one or more elements composing the oxide superconductor and/or one or more elements that can compose an oxide superconductor by replacing at least in part one or more elements composing the oxide superconductor.