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

YBa₂Cu₃O_7-δ films exhibit two orders of magnitude higher critical current density, J_c, and a few times higher microwave surface resistance, R_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_c(H,T,θ) and R_s(T)-dependencies along with X-ray and HREM data for films grown via various modes allows to differentiate contributions to J_c and R_s from out-of-plane and in-plane edge dislocations. The higher the density of edge dislocations within YBCO film the higher are J_c and R_s. Stress-strain field calculations allow one to comprehend the difference between out-of-plane and in-plane dislocations effects