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 YBa2Cu3O7-delta (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.