All Japan efforts on fundamental materials technology developments for HTS applications: Focusing on R&D of coated conductors Original Research Article

The coated conductors using REBa2Cu3O7−δ (RE=rare earth element, Y, Nd, Sm etc.) materials are expected for a lot of electric power applications, since it has a high critical current density at the liquid nitrogen temperature even under high magnetic fields. However, it has been difficult to obtain a bi-axially textured coated conductor, which is necessary to realize its high performance, and there has not been a tape fabricated longer than 1 m. Several different processes have been investigated for realizing the bi-axially textured buffer layers/metal substrates as well as thicker film deposition processes and non-vacuum processes for a superconducting layer. Recently, a 10 m long YBa2Cu3O7−δ tape with high Jc was successfully fabricated. This paper reviews the recent progress of the research and development for the coated conductor with its prospects in Japan.