Magnetic field dependence of<i>J</i>_cfor Gd-123 coated conductor on PLD-CeO₂capped IBAD-GZO substrate tapes

Abstract

We prepared GdBa2Cu3O7−δ (Gd-123) coated conductors by the pulsed laser deposition (PLD) method on PLD-CeO2/ion-beam assisted deposition (IBAD)-Gd2Zr2O7 (GZO)/hastelloy metal substrate tapes. The Gd-123 film showed a higher critical current density (Jc) in magnetic fields (B) and higher critical temperature (Tc) than those of YBa2Cu3O7−δ (Y-123) film. The Gd-123 film exhibited a high Jc value of 0.19 MA cm−2 at 3 T () in liquid nitrogen (77 K), and the Tc value was 93.8 K. The Jc value at 3 T was twice as high as that of Y-123 film. Moreover, the angular dependence in magnetic fields of Jc for Gd-123 was also superior to that of Y-123. The reduction of Jc 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 Jc on the magnetic field angle curve (Jc–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 Jc and low anisotropy in Jc–θ, show promise for future applications.