| abstract |
An oxide superconductor film formed on a substrate includes an oxide containing at least one metal M selected from the group consisting of yttrium and lanthanoid metals, provided that cerium, praseodymium, and promethium are excluded, and barium and copper, in which the film has an average thickness of 350 nm or more, an average amount of residual carbon of 3×10 19 atoms/cc or more, and an amount of residual fluorine in a range of 5×10 17 to 1×10 19 atoms/cc, and in which, when divided the film into a plurality of regions from a surface of the film or from an interface between the film and the substrate, each region having a thickness of 10 nm, atomic ratios of copper, fluorine, oxygen and carbon between two adjacent regions are in a range of ⅕ times to 5 times. |