Linear defects in epitaxial Y-Ba-Cu-O films: their role in anisotropic vortex pinning and microwave surface resistance

YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// films exhibit two orders of magnitude higher critical current density, J/sub c/, and a few times higher microwave surface resistance, R/sub s/, than single crystals. This evidences a different nature of crystal defects, which are responsible for the pinning and HF losses. Several types of dislocation arrays are identified in YBCO films by TEM/HREM and XRD. An analysis of J/sub c/(H,T,/spl theta/) and R/sub s/(T)-dependencies along with X-ray and HREM data for films grown via various modes allows to differentiate contributions to J/sub c/ and R/sub s/ from out-of-plane and in-plane edge dislocations. The higher the density of edge dislocations within YBCO film the higher are J/sub c/ and R/sub s/. Stress-strain field calculations allow one to comprehend the difference between out-of-plane and in-plane dislocations effects.