CONTROLLED CONVERSION OF METAL OXYFLUORIDES INTO SUPERCONDUCTING OXIDES

• Main Authors: SMITH JOHN A, SONNENBERG NEVILLE, CIMA MICHAEL J
• Format: Patent
• Language: English
• Published: 19.02.2009
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; BASIC ELECTRIC ELEMENTS; CABLES; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSESC01D OR C01F; CONDUCTORS; CRYSTAL GROWTH; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRICITY; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; INORGANIC CHEMISTRY; INSULATORS; METALLURGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING ORDIELECTRIC PROPERTIES; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

PROBLEM TO BE SOLVED: To provide a thick film of an oxide superconductor having high epitaxial alignment, preferably c-axis epitaxial alignment by a metal oxyfluoride precursor film. SOLUTION: The oxide superconductor film is characterized by high Jcand high volume percent of c-axis epitaxial oxide grains, even with thicknesses of up to 1 μm. The oxide superconductor article is prepared by providing a metal oxyfluoride film, the metal oxyfluoride film comprising the constituent metallic elements of an oxide superconductor in substantially stoichiometric proportions; and converting the metal oxyfluoride into the oxide superconductor at a rate of conversion selected by adjusting a reaction parameter selected from the group consisting of temperature, PH2O, PO2, and time and combinations thereof, such that an oxide superconductor film having a transport critical current density of greater than or equal to about 105A/cm2at 77 K, zero field is obtained. COPYRIGHT: (C)2009,JPO&INPIT