Kinyanjui, M.K.; Lu, Y.; Gauquelin, N.; Wu, M.; Frano, A.; Wochner, P.; Reehuis, M.; Christiani, G.; Logvenov, G.; Habermeier, H.-U.; Botton, G. .; Kaiser, U.; Keimer, B.; Benckiser, E.: Lattice distortions and octahedral rotations in epitaxially strained LaNiO3/LaAlO3 superlattices. Applied Physics Letters 104 (2014), p. 221909/1-4
Using a complementary combination of x-ray diffraction and atomically resolved imaging we investigated the lattice structure of epitaxial LaNiO3/LaAlO3 superlattices grown on a compressive-strain inducing LaSrAlO4 (001) substrate. A refinement of the structure obtained from the x-ray data revealed the monoclinic I 2/c 1 1 space group. The (Ni/Al)O6 octahedral rotation angle perpendicular to the superlattice plane is enhanced, and the one parallel to the plane is reduced with respect to the corresponding bulk values. High-angle annular dark field imaging was used to determine the lattice parameters within the superlattice unit cell. High-resolution electron microscopy images of the oxygen atoms are consistent with the x-ray results. (C) 2014 AIP Publishing LLC.