ABSTRACT
High-7. critical temperature oxide superconducting materials are expected to be used in various technological fields. One of the most important applications of superconductors is a magnet. However, superconducting magnets fabricated with conventional metallic superconductors are usually operated at 4.2 K using liquid helium, which prevents superconducting magnets from being widely used. Superconducting magnets which can be operated using cryocooler without liquid helium will be very useful in many technological areas. It is expected that high-7. oxide superconductors enable such superconducting magnets.
