Critical current density of Y-Ba-Cu-O thick films prepared by a liquid-phase processing method

Abstract

High-Tc screen-printed Y-Ba-Cu-O films were prepared on YSZ substrates by a liquid-phase processing method. The films, which were heated rapidly at 1060-1075 degrees C and then exposed to rare gas flow until the furnace cooled to 1010 degrees C, showed high Jc values, of about 1700-2000 A cm-2 (77 K, 0 T), 6-7 times larger than values obtained by film-firing in flowing oxygen. These films have an aligned grain structure consisting of large needle-like and plate-like grains over a wide area. Rough calculation shows that the orientation factor f of these films is about 0.85. However, there still remain various defects, such as second phases (Y2BaCuO5, CuO+BaCuO2), an interface reaction product (BaZrO3) and microcracks.