Preparation of high Jc YBCO films on LAO by spray pyrolysis process using nitrate precursors

High J(c) over 1 MA/cm(2) YBCO film has been successfully prepared using nitrate precursors by a spray pyrolysis method. Precursor mists generated using a concentric spray nozzle were directly sprayed on a LaAlO3 (100) single crystal substrate. The cation ratio of precursor solution was Y:Ba:Cu = 1:2.65:1.35. The distance between nozzle and substrate was 15 cm. Deposition temperature was ranged from 760 to 800 degrees C and deposition pressure was 100 Torr. Oxygen partial pressure was varied from 10 Torr to 50 Torr. The microstructure, phase formation, texture development and superconducting properties of deposited films were largely changed with oxygen partial pressure and deposition area. Deposited films showed a texture with (001) planes parallel to substrate plane. High quality film was obtained when the film was deposited at 760 degrees C with an oxygen partial pressure of 30 Torr. The critical current density (J(c)) of the YBCO film was 1.75 MA/cm(2) at 77 K and self-field. (C) 2007 Elsevier B.V. All rights reserved.