Enhanced Pinning Properties of ${GdBa}_{2}{Cu}_{3}{O}_{7-\delta}$ Coated Conductors via a Post-Annealing Process

The in-field pinning properties of GdBa
₂
Cu
₃
O
_7-δ
(GdBCO) coated conductors (CCs) could be remarkably improved through the post-annealing process in a low oxygen pressure (PO
₂
). At the annealing temperature of 800°C in a low PO
₂
of 300 mtorr, the T
_c,zero
value of as-prepared GdBCO CCs by SuNAM Co. via reactive co-evaporation deposition and reaction (RCE-DR) was increased from 89.9 to 93.7 K after 5 min annealing, whereas it was degraded after annealing longer than 10 min. The angular dependence of critical current density J
_c
at 77 K in 1 and 3 T and at 65 K in 3 T revealed that GdBCO CCs post-annealed for 5 min exhibited greatly improved pinning properties along the c-axis of the GdBCO film, which is attributable to piled-up stacking faults along the c-axis of the GdBCO matrix.