Reel-to-reel deposition of YBCO films by spray pyrolysis using nitrate precursors

YBCO films were deposited on a moving substrate by a spray pyrolysis method using nitrate aqueous solution as a precursor. Deposition was done on LaAlO3( 100) single crystal substrate by spraying the precursor mist generated by a concentric nozzle. The cation ratio of the precursor solution was Y:Ba:Cu= 1:2.65:4.5. The distance between the nozzle and the substrate was 15 cm. The substrate was transported with a speed ranging from 0.23 to 0.5 cm min(-1). Films were deposited at a pressure of 10 and 20 Torr and the substrate temperature varied from 740 to 790 degrees C. The oxygen partial pressure was controlled between 1 and 5 Torr. Scanning electron microscope (SEM) and x-ray diffraction (XRD) observations revealed that the films are smooth and highly textured with (00l) planes parallel to the substrate. The highest J(c) was 1.04 MA cm(-2) at 77 K and self-field for film with a thickness of 0.5 mu m.