High-resolution transmission electron microscopy was used to investigate SrTiO3/SrRuO3 bilayer films which were epitaxially grown onto a LaAlO3 substrate. At the SrRuO3/LaAlO3 interface, dissociated super-dislocations were frequently observed in connection with Ruddlesden–Popper-type planar defects. These super-dislocations could contribute to misfit relaxation equivalent to a perfect misfit dislocation with Burgers vector a<110>. The formation and the geometry of this defect arrangement was considered in detail. The Sr-rich Ruddlesden–Popper-defect could be introduced by composition fluctuations during film deposition. It could be concluded that it could act as a source for the generation of misfit dislocations.

A New Mechanism for Misfit Dislocation Generation- Superdislocations Associated with Ruddlesden–Popper Planar Defects. J.S.Wu, C.L.Jia, K.Urban, J.H.Hao, X.X.Xi: Journal of Crystal Growth, 2002, 234[2-3], 603-9