Extended dislocation-based pinning mechanism in superconducting YBa2Cu3O7 films

To describe the critical current density (Jc) as the function of applied magnetic field (Ba) in high quality YBa2Cu3O7 (YBCO) superconducting films, the vortex pinning mechanism along the structural domain boundaries of the films is developed. The boundaries, assumed to have low misorientation angles, are quantitatively considered to consist of individual edge dislocations acting as pinning wells, rather than a continuous boundary. This extended model accurately describes the experimental Jc(Ba) over the wide field and temperature ranges. Marginal deviations of the model from the experimental Jc(Ba) curves are observed at high fields and temperatures where thermally activated depinning is significant. This pinning model is verified to provide precise structural properties of the films which can be obtained by other considerations.