Oxide superconductor, oriented oxide thin film, and method for manufacturing oxide superconductor

摘要

According to one embodiment, an oxide superconductor (1, 2) includes an oriented superconductor layer (15) and an oxide layer (13, 21). The oriented superconductor layer contains fluorine at 2.0×1016-5.0×1019 atoms/cc and carbon at 1.0×1018-5.0×1020 atoms/cc. The oriented superconductor layer contains in 90% or more a portion oriented along c-axis with an in-plane orientation degree (Δφ) of 10 degrees or less, and contains a LnBa2Cu3O7-X superconductor material (Ln being yttrium (Y) or a lanthanoid except cerium, praseodymium, promethium, and lutetium. The oxide layer is provided in contact with a lower surface of the oriented superconductor layer and oriented with an in-plane orientation degree (Δφ) of 10 degrees or less with respect to one crystal axis of the oriented superconductor layer. Area of a portion of the lower surface of the oriented superconductor layer in contact with the oxide layer is 0.3 or less of area of a region directly below the oriented superconductor layer.