Reel-to-reel MOCVD for YBCO coated conductor

A reel-to reel MOCVD system has been developed for a fast and economic process to get high quality YBCO coated conductor tapes. Several oxides buffer layer sequences (based on YSZ, CeO/sub 2/, Y/sub 2/O/sub 3/...) were then grown epitaxially on two kinds of tape. Effective stacking for MOCVD reported here are YSZ/Y/sub 2/O/sub 3//YBCO and YSZ/CeO/sub 2//YBCO, respectively, on oxidized Ni RABiTS microalloys (0,1% W) and on SS/YSZ (IBAD) tapes. First, EBSD and AFM techniques have been used to characterize the substrates. Superconducting YBCO films were fully characterized by SEM, XRD and AC susceptibility measurements Epitaxial growth was depicted with a strong in-plane and out-of plane texture: FWHM of YBCO /spl phi/-scans were 8.5/spl deg/ on Ni tape and 9/spl deg/ on IBAD Hastelloy tapes. High performances were also measured by AC susceptibility, with J/sub c/ values of 0.6 MA/cm/sup 2/ at 77 K (0 T) on Ni tape and close to 1 MA/cm/sup 2/ on IBAD substrates, with a sharp transition (/spl Delta/T/sub c/ < 0.4 K) and a T/sub c/ onset at 90 K. Deposition of 2 meter buffered YSZ and CeO/sub 2//YBCO films have also been performed showing good in-plane alignment (/spl phi/-scan YSZ: FWHM = 11/spl deg/) with a tape velocity set at 4 m/h.