Preparation of coated conductor architectures on Ni composite tapes

An epitaxial Y₂O₃/YSZ/CeO₂ buffer architecture has been prepared using pulsed laser deposition on cube texture Ni–3 at.% W/Ni–10 at.% Cr–1.5 at.% Al and Ni–5 at.% W/Ni–10 at.% W composite tapes. The buffer layer growth was studied in detail and revealed good texture transfer throughout the structure, similar to standard Ni–5 at.% W substrates. YBCO layers were successfully deposited on the buffered tapes and compared to films grown on SrTiO₃ single crystals. A superconducting transition temperature of about 90 K with a small transition width was observed on all metal substrates. A critical current density J_c of about 1 MA cm⁻² was measured at 77 K in a self-field. It was found that J_c is mainly limited by the grain boundary network in magnetic fields below 4 T, whereas similar values as on SrTiO₃ single crystals were measured at higher fields.