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  Method of patterning oxide superconducting filmsRelated Patent Categories: Superconductor Technology: Apparatus, Material, Process, High Temperature (tc Greater Than 30 K) Devices, Systems, Apparatus, Com- Ponents, Or Stock, Or Processes Of Using, High Frequency Waveguides, Resonators, Electrical Networks, Or Other Devices Of The Waveguide Type (e.g., Phase Shifters, Cavity Filters, Etc.)The Patent Description & Claims data below is from USPTO Patent Application 20070197395. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit under 35 U.S.C. .sctn.119(e) of U.S. Provisional Patent Application No. 60/757,855, filed on Jan. 10, 2006, entitled Method of Patterning Oxide Superconducting Films, which is incorporated herein by reference in its entirety. BACKGROUND [0002] 1. Field of the Invention [0003] This invention relates to methods of manufacturing high temperature superconductor ("HTS") wire. In particular, the invention relates to facile methods for patterning long lengths of high temperature superconductor wire. The invention also relates to methods and superconductor articles suitable for use in alternating current (ac) and time varying magnetic field applications. Additionally the invention relates to methods to a securely slit HTS strips processed in wider widths to narrow wires to meet industry requirements. [0004] 2. Background of the Invention [0005] Since the discovery of high-temperature superconducting (HTS) materials (superconducting above the liquid nitrogen temperature of 77 K) there have been efforts to develop various engineering applications using such HTS materials. In thin film superconductor devices and wires, significant progress has been made with fabrication of devices utilizing an oxide superconductor including yttrium, barium, copper and oxygen in the well-known basic composition of YBa.sub.2Cu.sub.3O.sub.7-x (hereinafter referred to as "YBCO"). Biaxially textured superconducting metal oxides, such as YBCO, have achieved high critical current densities in a coated conductor architecture, often referred to as second generation HTS wires, or a "coated conductor." The expression "HTS wire" indicates a HTS conductor with attributes that make it useful for the construction of a superconducting device; its cross-sectional geometry can vary from tape-like to round. [0006] Typically, second generation HTS wires 10 include a metal substrate 11, buffer layer(s) 13, and an active layer 14, e.g., a superconductor, as illustrated in FIG. 1. The metal substrate, such as Ni, Ag, or Ni alloys, provides flexibility for the article and can be fabricated over long lengths and large areas. The metal can include a textured surface 12 for producing an epitaxially grown layer. The buffer layer(s) consists of metal oxide layers, such as LaAlO.sub.3, Y.sub.2O.sub.3, CeO.sub.2, or yttria-stabilized zirconia (YSZ) and serves as a chemical barrier layer between the metal substrate and the active layer. The buffer layer(s) reduces oxidation of the substrate and also reduces the diffusion of chemical species between the substrate and the superconductor layer. Moreover, the buffer layer(s) can have a coefficient of thermal expansion that is well matched with the superconductor material. A RABiTS.TM. (rolling-assisted, biaxially textured substrates) textured template is typically used. A RABiTS.TM. substrate is a roll-textured and annealed metal tape, e.g., nickel or nickel alloy such as NiW with a sharp cube texture, covered in an epitaxial manner with one or more oxide or metal buffer or conditioning layers. Another variation used to prepare the textured template is ion beam assisted deposition or IBAD. The resulting textured base serves as a template for the HTS compound, e.g., yttrium-barium-copper-oxide (YBCO). [0007] In large-scale production, the second generation HTS wires will be continuously processed as strips that are four or more centimeter wide and 100 s of meters long. Once the process is complete, the wide strip will be cut or slit into narrower wires, typically about 4 mm in width (a current industry standard). Thus, eight or more HTS wires can be obtained from each processed strip, thereby significantly reducing the processing costs. [0008] Slitting of a coated conductor is challenging due to the many different mechanical properties of the different metal/alloys and ceramic oxides of the coated conductor. In particular, the oxide superconductor is very brittle, and the conventional slitting processes may damage the edge of the superconducting layer causing cracks or delamination of HTS layer. If the oxide superconductor is damaged during slitting, the electrical and mechanical properties of the conductor may be degraded. [0009] Many potential applications for HTS wire involve operating the superconductor in the presence of ramped magnetic or oscillating magnetic fields, or require that the HTS wire carry alternating current. In the presence of time-varying magnetic fields or currents, there are a variety of mechanisms that give rise to energy dissipation, hereinafter referred to as "ac losses." Although second generation HTS wire is currently suitable for many types of electric power devices, including power transmission cables and rotor sections of motors, the ac losses from the current HTS wires are too high for use in demanding HTS applications in which the alternating magnetic fields have a higher amplitude or frequency. The use of an HTS wire with greatly reduced ac losses would enhance the application of these wires in a variety of novel, HTS-based devices. [0010] It has been proposed to divide an oxide superconducting film into narrow filaments to suppress ac loss in a superconducting oxide thin film. FIG. 2A is a perspective view of a portion of a coated conductor article in which the superconducting film is arranged as a thin filament array. The multilayer article 20 includes a metal substrate 21 having a textured surface and epitaxially grown buffer layer(s) 22. Superconductor filaments 23 run substantially continuously along the length of the base to form an array of substantially parallel filaments. [0011] Currently, many different approaches are being explored to create oxide superconductor filaments, including laser patterning, sand blasting, direct ink-jet printing and photolithography, most of which are carried out after the oxide superconductor has already been formed. Each of the methods are limited in some respect by the cost of the process, damage caused to the oxide superconductor and its feasibility in a continuous process. SUMMARY [0012] Methods for patterning superconductor films are described. The methods provide narrow HTS wires from wide coated strips without detriment to the performance of the superconductor wire. The methods also provide HTS wires having narrow filaments for improved ac loss. [0013] In one aspect of the invention, a method for preparing a superconductor article includes depositing an intermediate metaloxy, e.g., metal oxyfluoride, film on a substrate, the intermediate metaloxy fluoride film containing precursor components to a rare earth-alkaline earth metal-transition metal oxide; removing selected portions of the intermediate metaloxy fluoride film from the substrate to obtain a patterned intermediate film; and treating the patterned intermediate film to form a rare earth-alkaline earth metal-transition metal oxide superconductor. [0014] In one or more embodiments, the intermediate film is deposited from a precursor solution onto a substrate to form a precursor film, the precursor solution containing precursor components to a rare earth-alkaline earth metal-transition metal oxide in one or more solvents, and decomposing the precursor film to form an intermediate film containing the rare earth metal, the alkaline earth metal, and the transition metal. The precursor solution includes a mixture of at least one rare earth element cation, an alkaline earth metal cation, and of a transition metal cation. The intermediate film can be a metal oxyfluoride film greater than 2 .mu.m in thickness. [0015] In one or more embodiments, the intermediate film is deposited by e-beam deposition. [0016] In one or more embodiments, the step of removing selected portions of the intermediate film includes contacting a tool with the intermediate film, the tool having a plurality of scribing surfaces, and removing selected regions of the intermediate film at contact points of the scribing surfaces with the film. [0017] In one or more embodiments, the scribing surface of the tool comprises a plurality of protrusions, or the plurality of scribing surfaces are positioned on a base to provide scribing surfaces spaced apart at distances commensurate with the width of a high temperature superconductor wire, or the plurality of scribing surfaces are arranged on a base to provide scribing surfaces spaced apart at distances commensurate with the width of a high temperature superconductor filament, or the scribing surfaces have a base and a tip, and the tip-to-tip distance is commensurate with the width of a high temperature superconductor wire, or the scribing surfaces have a base and a tip, and the tip-to-tip distance is commensurate with the width of a high temperature superconductor filament. A wire is an article that contains at least one superconductor filament. [0018] In one or more embodiments, the scribing surfaces have a base and a tip and the tip is rounded, or the tip is truncated or flattened to increase area contact of the tip with the intermediate film. [0019] The step of removing selected portions from the intermediate film can include a materials removal step selected from the group consisting of mechanical removal, chemical etching, laser etching and physical bombardment. [0020] In some embodiments, the patterned film includes a plurality of longitudinally located regions of HTS or intermediate material having gaps the between regions and the gaps have a width of about 0.1 to about 0.5 mm. [0021] In some embodiments, the patterned intermediate film is a filament array having a plurality of HTS or intermediate material filaments extending substantially along the length of the substrate and spaced apart from adjacent filaments across the width of the substrate. The article includes about 2 to about 100 filaments and the filaments are about 50 to 5000 .mu.m in width, and the gap is between 10 and 100 .mu.m. Continue reading... Full patent description for Method of patterning oxide superconducting films Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Method of patterning oxide superconducting films patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. 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