Rapid production of buffered substrates and long length coated conductor development using IBAD, PLD methods and "Self-Epitaxial" ceria buffer

Activities at SRL-Nagoya Coated Conductor Center (NCCC) are presented including rapid production of 100 to 220 m buffered substrate tapes and a 46 m YBCO coated conductor using reel-to-reel equipment of both IBAD and PLD systems. A 220 m long IBAD and a 100 m long CeO₂ capped substrate have been successfully and stably produced. Furthermore, the PLD-CeO₂, which we call the "Self-Epitaxial" method, is found to be effective to increase a production rate. The combination of IBAD and PLD-CeO₂ enhanced the overall buffer processing rate up to 2 m/h. This is much higher than the rate of 0.5 to 1 m/h of the conventional IBAD method. We also recently introduced a new PLD system for YBCO, which utilizes a multi-plume and multi-turn deposition, MPT-PLD method. This system is now successfully operating and then very recently we have achieved the record of I_c×L (critical current times length) of 8335 Am. A 45.8 m long YBCO coated conductor carried the high I_c of 182 A. The MPT-PLD method is also effective to increase the thickness of YBCO with high J_c. Consequently, I_c as high as 300 A was also obtained for a short sample test. Therefore, the new system of MPT-PLD is very promising for long YBCO tape fabrication.