Vortex confinement in oxygen-deficient Y-Ba-Cu-O films.

The aim of this work is to investigate the mechanisms controlling the currentcarrying capability of YBa2Cu3O7[sub -delta] thin films. A comparison between the magnetic properties of as-grown films and films crossed by columnar defects, produced through 0.25 GeV gold-ion irradiation, is shown. The central issue concerns the investigation of the plateau-like features characterizing the log-log field dependence of the critical current density and the analysis of the irreversibility line. Data and models suggest that the inter grain pinning of the flux vortices channelling along a network of Josephson junctions dominates in the high-current low-temperature regime, while the intra grain pinning is effective near the irreversibility line. [ABSTRACT FROM AUTHOR]