TRANSPORT-PROPERTIES AND FLUX-PINNING BY SELF-ORGANIZATION IN YBA2CU3O7-DELTA FILMS ON VICINAL SRTIO3(001)

We have observed anisotropic flux pinning and resistivity in the subst rate plane of YBa2Cu3O7-delta (YBCO) thin films grown on vicinal SrTiO 3(001) with the c axis oriented along the SrTiO3[001] direction. Using UHV scanning tunneling microscopy and transmission electron microscop y we demonstrate the influence of a periodic nanoscale step structure of the clean substrate surface on the morphology and defect microstruc ture of subsequently deposited YBCO films. A linear array of dislocati ons generated via self-organization of the YBCO leads to an exceptiona lly large critical current density up to 8 X 10(11)A/m(2) at 4.2 K. Th e findings indicate that the critical current density of high-temperat ure superconductors can be enhanced in a controlled way growing thin f ilms on tailored substrate surfaces.