Control of octahedral rotations via octahedral connectivity in an epitaxially strained [1 u.c.//4 u.c.] LaNiO3/LaGaO3 superlattice

Media New York 2016 ABSTRACT For ABO3 perovskites, the magnetic and electronic properties couple strongly to the BO6 octahedral rotations and distortions. Therefore, precise control of the octahedral rotations and distortions via epitaxial strain and interfacial octahedral connectivity has become the key for engineering novel functionalities in ABO3 heterostructures and superlattices. In this paper, we investigated the local octahedral rotations in a [(1 unit cell (u.c.)//4 u.c.) 9 13] LaNiO3/LaGaO3 superlattice grown on a (001) SrTiO3 substrate. By using aberration-corrected high-resolution transmission electron microscopy, we found that the octahedral rotations of NiO6 adopted the same [100] and [010] rotational magnitudes as the neighboring GaO6 till the surface of the superlattice. Our results indicate that in LaNiO3-based superlattices, the NiO6 rotations can be precisely controlled via interfacial octahedral connectivity when the thickness of the LaNiO3 layer is only 1 unit cell.