CRITICAL CURRENT-DENSITY OF HIGH-QUALITY BI2SR2CA2CU3OX THIN-FILMS PREPARED BY METALORGANIC CHEMICAL-VAPOR DEPOSITION

Critical current densities J(c) were measured in as-deposited, c-axis-oriented Bi2Sr2Ca2Cu3Ox thin films with T(c) values as high as 97 K, which were prepared by metalorganic chemical-vapor deposition. These films showed high J(c) (> 10(9) A/m2) at 77.3 K in high magnetic fields (greater-than-or-equal-to 1 T, H parallel-to a-b plane). The best values are 3.3 X 10(9) A/m2 at 1 T and 9.1 X 10(8) A/m2 at 8 T, which are the highest J(c) for Bi-oxide thin films among those reported so far. There were no signs of weak links in the J(c)(H) behavior, and the surface morphology examined by scanning electron microscopy showed no apparent grain boundaries. The values of J(c) decreased sharply when the applied field deviated from the a-b plane, and went to zero at the angles where the field component in the c direction is nearly equal to the irreversibility field H(c2)* parallel to the c axis. The angular dependence of J(c) of these films is most reasonably explained by the theory of intrinsic pinning.