Coated Conductor Development of Thick Y–Gd–Ba–Cu–O Layer With Heavy Ba–Zr–O Doping Using a Reel-to-Reel System Furnace

Abstract

We fabricated uniform long-length Y–Gd–Ba–Cu–O coated conductors with 10 mol% $\text{BaZrO}_{3}$ (BZO) nanoparticles (YGd10BZO CCs) in batch and reel-to-reel (RTR) furnaces. The standard deviations of the self-field critical currents ($I_\text{c}$) in the batch- and RTR-fabricated YGd10BZO CCs were 22.8% and 3.2%, respectively, indicating that the RTR furnace is more suitable for stable production of long-length CCs than the batch furnace. To further improve the in-field $I_\text{c}$, we fabricated heavily doped (15 mol%) BZO and thick (3.0 μm) YGd15BZO CCs in the RTR system furnace. The in-field $I_\text{c}$ of the CCs was 21.7 A/4-mm-width at 77 K and 3 T (B||c). This study demonstrates that thick YGd15BZO CCs can be fabricated without deteriorating their pinning properties.