Development of Long-Length BMO-Doped REBCO Coated Conductors by Hot-Wall PLD Process

Fujikura Ltd., Chiba, Japan, has developed stable and high-throughput production techniques for REBCO coated conductors (CC) by using large-area ion-beam-assisted-deposition (IBAD), and hot-wall type pulsed-laser-deposition (PLD). Recently, we have been attempting to dope BaMO
₃
(BMO, M: Zr or Hf) to REBCO layer in order to enhance in-field critical current density (J
_c
). In the course of optimizing deposition conditions of PLD for BaHfO
₃
doped EuBCO films on IBAD templates, “high J
_c
condition” and “high growth rate condition” were found. For samples prepared under these conditions, the magnetic field angle dependence of I
_c
and REBCO thickness dependence were investigated. Finally, we succeeded in fabricating a 300-m-long CC with uniform I
_c
distribution at the high-growth-rate condition. The longitudinal I
_c
homogeneity (defined as standard deviation divided by average) at 77 K evaluated by magnetization method was 2.6%, which is comparable to nondoped conductors. Transport in-field I
_c
for the both end points were 1756 and 1786 A/cm at 30 K, 2 T, respectively.