Development of high-temperature superconducting thin film tape manufactured using the ISD method

In tape formation using the pulsed laser deposition method, development of the inclined substrate deposition (ISD) method for inclining the substrate relative to the plasma direction enabled formation of a thin film with a structure similar to that of a single crystal even on a polycrystalline substrate. Using this technology, we succeeded in raising the critical current density (on the order of 10⁴ A/cm² (77.3 K) in conventional polycrystalline superconducting thin film) by an order of magnitude to 10⁵ A/cm² (77.3 K). The superconducting tape fabricated using this method not only improved J_c but was also found to possess improved durability of J_c to external magnetic fields and improved mechanical strength. In parallel with this tape development, we are also studying equipment applications. We have conducted a feasibility study of a power transmission cable using thin film tape, and have fabricated and evaluated two types of fault-current limiter.