Quantitative Description of Critical Current Density in YBCO Films and Multilayers

The vortex pinning model based on the presence of the large number of edge dislocations in high quality YBa 2 Cu 3 O 7 (YBCO) films and multilayers has been refined. By introducing the pinning potential of a chain of individual edge dislocations, we have been able not only to describe the critical current density dependence on the applied magnetic field over its entire range, but also to extract the microstructural parameters in the films, such as inter-dislocation spacing and average domain size, without employing sophisticated microstructural analysis. The model applicability and its results have been verified with the help of microstructural characterization combined with magneto-optical imaging in YBCO films and multilayers with different properties.