Development of long YBCO coated conductors by IBAD–PLD method

Abstract

On the substrate that a CeO2 cap layer deposited by PLD method on a Gd2Zr2O7 buffered Hastelloy tape by IBAD method, we have investigated YBa2Cu3O7−x (YBCO) coated conductor fabricated by ion beam assisted deposition (IBAD)/multi-plume and multi-turn (MPMT) pulsed laser deposition (PLD) method. Our MPMT–PLD method has been improved for rapid deposition, high critical current (Ic) and long and stable operation. To enlarge the deposition area, we increased the number of the turn of the substrate tape, from three to four. This increase in the number of substrate-transferring turns enhanced the deposition rate by 25%. High critical current density (Jc) exceeding 2.7MA/cm2 was also obtained for each turn. Therefore, for obtain high deposition rate and high Ic, it is effective to have increased the number of turns. Using these results by short sample and high speeded 30m/h, we have successfully fabricated 212.6m long YBCO coated conductor by the MPMT–PLD method and reel-to-reel tape transferring system. This YBCO coated conductor exhibited Ic of 245A and thus the multiplication of Ic and length (Ic×L) achieved the new record of 52087 Am.