Structural study of nickelate based heterostructures
Lucia Varbaro,
Bernat Mundet,
Subhadeep Bandyopadhyay,
Claribel Domínguez,
Jennifer Fowlie,
Lukas Korosec,
Chih-Ying Hsu,
Duncan T. L. Alexander,
Philippe Ghosez,
Jean-Marc Triscone
Affiliations
Lucia Varbaro
DQMP, University of Geneva, Geneva, Switzerland
Bernat Mundet
DQMP, University of Geneva, Geneva, Switzerland
Subhadeep Bandyopadhyay
CESAM Research Unit, Université de Liège, Liège, Belgium
Claribel Domínguez
DQMP, University of Geneva, Geneva, Switzerland
Jennifer Fowlie
Department of Applied Physics, Stanford University, Stanford, California 94305, USA
Lukas Korosec
DQMP, University of Geneva, Geneva, Switzerland
Chih-Ying Hsu
DQMP, University of Geneva, Geneva, Switzerland
Duncan T. L. Alexander
Electron Spectrometry and Microscopy Laboratory (LSME), Institute of Physics (IPHYS), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
Philippe Ghosez
CESAM Research Unit, Université de Liège, Liège, Belgium
Heterostructures consisting of SmNiO3 and NdNiO3 alternating layers with additional LaAlO3 spacer layers were grown and fully characterized by means of x-ray diffraction, atomic force microscopy, and scanning transmission electron microscopy. A change in the orientation of the orthorhombic long-axis of the nickelate layers is observed when a single unit cell of LaAlO3 is inserted between SmNiO3 and NdNiO3, in agreement with density functional theory calculations. At the same time, the structure of the ultra-thin rhombohedral LaAlO3 layers is affected by their proximity to orthorhombic nickelate layers, with both scanning transmission electron microscopy studies and density functional theory calculations revealing a weak antipolar motion of the La-cation in the LaAlO3 layers that is not present in the bulk rhombohedral structure of this compound.
