Superconductor comprising superconducting thin film formed on the surface of an alumina single crystal substrate, and method for forming a superconducting thin film on the surface of an alumina single crystal substrate

摘要

PROBLEM TO BE SOLVED: To form an epitaxial thin film comprising a rare earth metal and aluminum on the surface of an alumina single crystal substrate by dissolving a rare earth oxide and an aluminum-containing compound into a solvent, then stirring the mixture to obtain a uniform solution, coating the solution on the surface of the alumina single crystal, drying to form a thin film and heating/ firing the coated film, and to form a superconducting film on the single crystal alumina substrate by forming the superconducting film on the surface of the epitaxial thin film mentioned above, being used as an intermediate layer. SOLUTION: The epitaxial thin film of a multiple oxide having a compositional ratio of rare earth metal:aluminum:oxygen of 1:1:3 is obtained by dissolving a compound containing a rare earth metal into a solvent, then stirring the mixture to obtain a uniform solution, coating the solution on the surface of an alumina single crystal substrate, drying to form a thin film and heating/firing the coated thin film. The superconductor is constituted of a YBa2 Cu3O7 yttrium-based superconductor epitaxial thin film.