Scale up of a single source MOCVD system for deposition of YBCO onto travelling tapes

Abstract
MOCVD is a promising economic method for the production of YBCO tapes. An enlarged single source MOCVD-system for continuous deposition of YBCO on metal tapes was developed. Computer simulations with FLUENT code were used for the design of the new tape system, which is based on a former small tape system. The calculated temperature distribution, precursor mole fractions and gas flows lead to a better understanding of the important aspects of the design. In this new system single crystals, IBAD buffered tapes and buffered textured Ni-tapes were transported through the deposition zone and coated with YBCO. On Single crystals, IBAD buffered substrates and textured Ni the best critical current densities at 77 K of the 300-500 nm thick YBCO films were 4.8 MA/cm², 2.5 MA/cm² and 0.25 MA/cm² respectively. The velocity for the tape transport was 4 m/h for these substrates. The XRD-measurements of the YBCO-film on single crystalline LaAlO₃ showed only c-axis orientation with FWHM(OO5) = 0.10° for the rocking curve and with FWHM(102) = 0.7° for the phi scan.