Preparation of YBa/sub 2/Cu/sub 3/O/sub x/ film deposited on various substrates by MOCVD Processing

YBa/sub 2/Cu/sub 3/O/sub x/ films were deposited on various substrates (MgO, SrTiO/sub 3/, IBAD, and textured Ni) by metalorganic chemical vapor deposition (MOCVD) processing. The deposition condition was optimized using MgO and SrTiO/sub 3/ single crystal substrates. At low deposition temperatures (T/sub d/) below 700/spl deg/C, a-axis films were obtained, a-axis and c-axis films at the intermediated T/sub d/ of 720/spl deg/C-740/spl deg/C, and fully c-axis films were obtained at T/sub d/ above 740/spl deg/C. The critical current (I/sub c/) of the YBCO films with the film thickness of 0.6 /spl mu/m was 49 A/cm-width (J/sub c/=0.82 MA/cm/sup 2/). When the film thickness increased to 1.6 /spl mu/m, the I/sub c/ increased to 84.4 A/cm-width, but J/sub c/ decreased to 0.53 MA/cm/sup 2/. The degradation of J/sub 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 (CeO/sub 2//Y-stabilized ZrO/sub 2/(YSZ)/CeO/sub 2/ on textured Ni), CYY(CeO/sub 2//YSZ/Y/sub 2/O/sub 3/ on textured Ni), and IBAD(CeO/sub 2//YSZ on stainless steel) templates. The I/sub c/s of the YBCO films were 9.5 A/cm-width, 45.8 A/cm-width, and 46.3 A/cm-width, respectively.