The near-interface region of an epitaxial Ba0.3Sr0.7TiO3 thin film, grown onto LaAlO3 (001), was found to consist of a high density of stacking faults bounded by partial dislocations. The stacking faults could extend over more than 50nm. The atomic structures of the faults were identified by using high-resolution electron microscopy, simulations and energy-filtered imaging. The faults were found to lie predominantly on the {100} and {110} planes. The faults on (010), (110) and (¯110) had never before been observed in perovskites. The stacking faults on {100} had a structure which consisted of a double layer of edge-sharing TiO6 octahedra. The excess of Ti was detected by energy-filtered imaging. The formation of the extended stacking faults was attributed to a small amount of excess Ti, present during film deposition, which could originate from a non-stoichiometry of BaTiO3 or SrTiO3. It was also enhanced by misfit-induced compressive strains in the early stages of film growth.

High-Resolution Identification of Stacking Faults in Epitaxial Ba0.3Sr0.7TiO3 Thin Films. C.J.Lu, L.A.Bendersky, K.Chang, I.Takeuchi: Philosophical Magazine, 2003, 83[13], 1565-95