Preparation of YBa₂Cu₃O_X film deposited on various substrates by MOCVD processing

YBa₂Cu₃O_x films were deposited on various substrates (MgO, SrTiO₃, IBAD, and textured Ni) by metalorganic chemical vapor deposition (MOCVD) processing. The deposition condition was optimized using MgO and SrTiO₃ single crystal substrates. At low deposition temperatures (T_d) below 700°C, a-axis films were obtained, a-axis and c-axis films at the intermediated T_d of 720°C-740°C, and fully c-axis films were obtained at T_d above 740°C. The critical current (I_c) of the YBCO films with the film thickness of 0.6 μm was 49 A/cm-width (J_c = 0.82 MA/cm ²). When the film thickness increased to 1.6 μm, the I_c increased to 84.4 A/cm-width, but J_c decreased to 0.53 MA/cm ². The degradation of J_c is attributed to the formation of a-axis grains and grains misoriented from the c-axis in the upper part of the films. The YBCO films were successfully deposited on CYC (CeO₂/Y - stabilized ZrO₂(YSZ)/CeO₂ on textured Ni), CYY(CeO ₂/YSZ/Y₂O₃ on textured Ni), and IBAD(CeO ₂/YSZ on stainless steel) templates. The I_cs of the YBCO films were 9.5 A/cm-width, 45.8 A/cm-width, and 46.3 A/cm-width, respectively.