ANISOTROPIC FLUX-PENETRATION AND CURRENT DISTRIBUTION IN (001)TILTED YBA2CU3O7-DELTA-THIN-FILMS

The growth of YBCO thin films on miscut SrTiO3 substrates with various tilt angles towards [010] allows the controlled generation of planar defects, which are aligned to the surface steps of the substrate in [1 00] (L)direction. Due to the anisotropic microstructure we observe a s trong anisotropy of flux penetration and critical current density by m eans of magneto-optics. The critical current density in the (ab)-plane of these c-axis oriented thin films is determined by a new method of high resolution inversion of Biot-Savart's law. New features Like peri odic streaky flux patterns in L-direction and a strongly different mag netic field dependence of the critical current density longitudinal to the defect planes, j(c,L), and transversal, j(c,T), are observed. Thi s gives rise to a magnetic field dependence of the anisotropy ratio of the critical current densities.