Development of Long IBAD-PLD YBCO Coated Conductor

—Long Length Conductor and Rapid Production Rate for Industrialization—

Abstract

For a practical long YBCO coated conductor fabrication, PLD and IBAD methods have been investigated by using reel to reel deposition systems. We discussed critical current density, in-plane texturing, surface roughness, film deposition rate and wire production speed. Consequently, we successfully fabricated a 100 m long IBAD substrate tape. Furthermore, recently we have found the Self-Epitaxial Effect in PLD-CeO₂ film on the IBAD layer. This resulted in the better alignment and fast production rate than the conventional IBAD process. This method is very promising for the realization of the mass production of the buffer layer in coated conductors. Using the PLD-CeO₂, 50 to 100 m long substrate tapes were successfully fabricated. On this CeO₂ layer, YBCO film was deposited by a reel to reel PLD system. Critical current density was increased with increasing the degree of in-plane texturing. At present, we obtained 1 m to 10 m long YBCO with critical current density around 10¹⁰ A/m² at 77 K. Although, by using PLD and IBAD method, the realization of YBCO practical superconducting wire will not be far, we need further improvement, especially, in the production speed.