Phase relationships in bulk and thin film Ba-Y-Cu-O high-Tc superconductor system were determined at processing conditions relevant for industrial production of coated conductors. Our results demonstrated that the absence of BaY2CuO5 (which has a critical effect on flux pinning) at 735 ºC a typical temperature employed in production of coated conductors in thin films processed in situ from the BaF2 precursor is caused by the sluggish reaction kinetics rather than by the presence of fluorine in the system. Thermodynamic calculations combined with annealing experiments confirmed that BaY2CuO5 is thermodynamically stable but forms at temperatures higher than 735 ºC.
Citation: Applied Physics Letters
Pub Type: Journals
Ba-Y-Cu-O, coated-conductor, combinatorial approach, phase formation in films