Magnetic field dependence of critical currents in PLD RE-Ba-Cu-O (RE = Er, Dy, Gd) film prepared on CeO2 capped IBAD-GZO layers

We have fabricated RE1Ba2Cu3O7−δ (RE = Er, Dy, Gd) and YBa2Cu3O7−δ (Y-123) superconductor films with various thickness on pulsed laser deposition (PLD)-CeO2/ion-beam assisted deposition (IBAD)-Gd-Zr-oxide (GZO)/metal substrates by PLD method and investigated the dependence of critical current density (Jc) on applied magnetic field. In order to fabricate a practical high critical current (Ic) coated conductor, we used metal substrate tapes with Δϕ value of 3.7°-7.0° fabricated by the technique of a self-epitaxy method. GdBa2Cu3O7−δ (Gd-123) films showed higher Jc in magnetic fields than that for Y-123 films. Jc value of the Gd-123 film was 179,000 A/cm2 at 3 T and 34,700 A/cm2 at 6 T at 77 K. Transmission electron microscope (TEM) observation showed that Gd-123 film had a more defective structure than Y-123 film. These structures may be attributed to high Jc in high magnetic field.