Epitaxial thick film of YBCO by high temperature spray pyrolysis for coated conductors

YBCO thick films have been synthesized using a low cost spray pyrolysis method. We used an all nitrate precursor approach to grow epitaxial HTS oxide film on SrTiO3 (001) substrate at a high deposition rate and at high temperature (over 800 degreesC). In these experiments thick YBCO films (mum) were grown in situ at 850 degreesC within 4 min; the final sintering process is performed at the same temperature for 2 h under oxygen atmosphere before low temperature oxygen loading. X-ray diffraction results (theta-2theta scans and phi scans) show that the films have not only a strong c-axis texture (mis-orientation similar to0.4degrees) but also a sharp in-plane biaxial orientation (mis-orientation is similar to1.4degrees). The critical temperature (T-c) was 91 K and the critical current density (J(c)) higher than 1.4 x 10(6) A/cm(2) (at 77 K, 0 T), while film thickness is over 1 mum. Spray pyrolysis is a promising technique for coated conductors. (C) 2002 Elsevier Science B.V. All rights reserved.