Vortex pinning due to strong quasiparticle scattering at antiphase boundaries in YBa2Cu3O7-delta

Using a recently developed quantitative magneto-optical method we investiga ted the vortex pinning mechanism in YBa2Cu3O7-delta films. Parallel oriente d planar antiphase boundaries (APB's), generated in epitaxial thin films gr own on vicinal SrTiO3 (001), serve as well defined pinning sites, yielding extraordinary high pinning forces and an anisotropic critical current densi ty j(c) up to approximate to 30% of the depairing current. The measured ang ular and temperature dependence as well as the magnitude of j(c) prove that pinning at APB's is dominated by quasiparticle scattering induced variatio n of condensation energy, characteristic of superconductors with anisotropi c order parameter. [S0031-9007(98)08137-X].