All-chemical YBa2Cu3O7-δ coated conductors with preformed BaHfO3 and BaZrO3 nanocrystals on Ni5W technical substrate at the industrial scale

We report a successful fabrication of long-length rolling-assisted biaxially-textured substrate-based coated conductors (CCs) via chemical solution deposition starting from colloidal YBa₂Cu₃O_7-δ (YBCO) solutions containing 5 mol-% preformed BaMO₃ (M = Hf, Zr) (BMO) nanocrystals. Partial optimization of the existing continuous reel-to-reel YBCO processing via design of experiments approach allowed us to obtain YBCO nanocomposites that retain 80%-90% self-field performance of the pristine CC and show a 10%-40% improvement of in-field critical current, which is only a moderate performance improvement compared to similar films on single-crystal substrates prepared on lab-scale. Based on x-ray diffraction and transmission electron microscopy studies, we attribute this to worsening of the YBCO texture and strong coarsening of BMO nanoparticles, particularly, BaZrO₃, during processing. Possible process improvements to overcome these effects are discussed.