J.S. Wu, C.L. Jia, K. Urban, J.H. Hao¹, and X.X. Xi^1
1Department of Physics, The Pennsylvania State University, USA

We have studied the microstructure of SrTiO3 films on LaAlO3 substrates with SrRuO3 buffer layer using high-resolution transmission electron microscopy. The {III} stacking fault in the SrRuO3 buffer layer propagates into the SrTiO3 film, giving rise to a new type of antiphase boundary in the {110} plane with a crystallographic shear vector of a/2{001}. The boundary is a conservative one which does not lead to any charge defects. A model based on dislocation interactions is proposed to explain the generation mechanism of the antiphase boundary.