Defect structures of stoichiometric and non-stoichiometric perovskite thin films epitaxially grown on (100) SrTiO3 substrates by pulsed laser deposition were studied by using transmission electron microscopy and X-ray diffraction. The major defects in partially relaxed stoichiometric BaTiO3 thin films were misfit dislocations with Burgers vectors of the type a<100>, threading dislocations connected to that dislocation, and inclined threading dislocations with Burgers vectors of the type a<110>. On the other hand, non-stoichiometric perovskite films showed unique defect structures. A-site excess BaTiO3 thin films were epitaxially grown with a Ruddlesden–Popper fault on the (100) plane and multiple nano-twin lamella.

Defects in Epitaxially Grown Perovskite Thin films. M.Fujimoto: Journal of Crystal Growth, 2002, 237-239[1], 430-7