GROWTH-INDUCED IN PLANE ANISOTROPY OF FLUX-LINE PINNING IN YBA2CU3O7 THIN-FILMS

Recent progress in tailoring periodic step structures in vicinal SrTiO 3 single crystal substrate surfaces enable a systematic study of the i nterplay of growth mediated defect structures and transport properties in HTS thin films. UHV annealed (001) oriented SrTiO3 substrates with a 10(0) miscut towards the [010] direction show after a UHV annealing a regular nanoscale step structure which generates an almost periodic terrace-like surface structure of the YBa2Cu3O7 film. Cross-sectional as well as planar view TEM reveals an anisotropic defect structure ar ising from the nanoscale step structure of the substrate surface. Tran sport measurements and magneto-optical analysis of the flux penetratio n show a growth-induced in plane anisotropy and an anisotropic enhance ment of the critical current up to values close to the depairing limit .