TEM Study of Facet Junctions in YBa2Cu3O7-δ/PrBa2Cu3O7-δ Thin Film Patterned Multilayer Structures

Transmission Electron Microscopy has been used to examine the growth of an YBa₂Cu₃0_7-δ thin film over a patterned step in an epitaxial PrBa₂Cu₃O_7-δ thin film on (001) MgO. The YBa₂Cu₃O_7-δ grows epitaxially over the step, but in cross-section strong strain contrast features were observed running from the facet junction at the step to the film surface. Selected Area Diffraction Patterns from such regions show that there is a small misorientation (<0.3°) across the feature which can be accommodated by dislocations as in a low angle grain boundary or elastically as the strain field of an interfacial wedge disclination at the facet junction.