METHOD FOR POLISHING TAPE SUBSTRATE FOR OXIDE SUPERCONDUCTOR, OXIDE SUPERCONDUCTOR, AND BASE MATERIAL FOR OXIDE SUPERCONDUCTOR

摘要

Provided is a surface polishing method for improving crystalline orientation of the surface of a tape-shaped metal base material so as to improve the critical current of a superconducting thin film. An oxide superconductor is composed of the tape-shaped base material, an intermediate layer formed on the tape-shaped base material, and an oxide superconducting thin film layer formed on the intermediate layer. In the method for polishing the surface of the tape-shaped base material to be polished, the surface to be polished is polished by continuously running the tape-shaped base material. The polishing step includes initial polishing and final polishing. At the end of the step, the surface average roughness (Ra) of the surface to be polished is 2 nanometers or less, and in-plane orientation (DeltaTheta) of the intermediate layer is 5° or less.