Isotropic Jc-B properties of YBa2Cu3O7−x thin films containing fine precipitates by metalorganic chemical vapor deposition

Y1Ba2Cu3O7−x superconducting thin films which have isotropic Jc-B properties were prepared onto SrTiO3 (100) substrates at 700 °C by metalorganic chemical vapor deposition. The Jc did not depend on directions of the field either perpendicular or parallel to the c axis of the films and the films had a high Jc of 6.1×104 and 7.1×104 A/cm2 at 77 K and 5 T perpendicular and parallel to the c axis, respectively. Transmission electron microscopy observation and x-ray energy dispersive spectroscopy analysis indicated that the films contained many fine Y2BaCuO5-like precipitates with diameter of ∼10 nm and they were distributed uniformly with the density Np as high as 1023/m3.