Magnetic field dependence ofJcfor Gd-123 coated conductor on PLD-CeO₂capped IBAD-GZO substrate tapes

We prepared GdBa 2 Cu 3 O 7−δ (Gd-123) coated conductors by the pulsed laser deposition (PLD) method on PLD-CeO 2 / ion-beam assisted deposition (IBAD)-Gd 2 Zr 2 O 7 (GZO)/hastelloy metal substrate tapes. The Gd-123 film showed a higher critical current density ( J c ) in magnetic fields ( B ) and higher critical temperature ( T c ) than those of YBa 2 Cu 3 O 7−δ (Y-123) film. The Gd-123 film exhibited a high J c value of 0.19 MA cm −2 at 3 T ( ) in liquid nitrogen (77 K), and the T c value was 93.8 K. The J c value at 3 T was twice as high as that of Y-123 film. Moreover, the angular dependence in magnetic fields of J c for Gd-123 was also superior to that of Y-123. The reduction of J c by the magnetic field angle for Gd-123 was less sensitive than that in Y-123. Furthermore, Gd-123 clearly exhibited a peak at 0° ( ) as well as at 90° ( ) in the relationship of J c on the magnetic field angle curve ( J c –θ), while Y-123 had no peak at 0°. These superior characteristics are considered to be due to the existing defects, such as stacking faults, as observed by transmission electron microscopy. PLD-Gd-123 coated conductors, with pinning-effective defects, high J c and low anisotropy in J c –θ, show promise for future applications.