Development of High Critical Current YBCO Coated Conductors By Photo-Assisted MOCVD

摘要

YBa_2Cu_3O_7 (YBCO) films have been deposited by photo-assisted MOCVD at rates of greater than 0.3μm/min on both single crystal oxide substrates and atomically textured metallic substrates. The YBCO films of thickness from 0.5μm to 3μm deposited on LaAlO_3 substrates are shown to be highly alomically ordered with J_c > 1 X 10~6 A/cm~2. CeO_2 buffer layers have also been developed by photo-assisted MOCVD for the integration of YBCO with metallic substrates. The CeO_2 layers were found to be crack-free when grown on nickel even above 1 micron thickness, and exhibited crystal orientation and in-plane alignment similar to that of the atomically textured Ni substrates. YBCO films grown on the thick CeO_2 buffer layers on nickel substrates have shown promising results with J_c～6 X 10~5 A/cm~2.