title: Impact of interfacial coupling of oxygen octahedra on ferromagnetic order in La0.7Sr0.3MnO3/SrTiO3heterostructures.
abstract: La0.7Sr0.3MnO3, a half-metallic ferromagnet with full spin polarization, is generally used as a standard spin injector in heterostructures. However, the magnetism of La0.7Sr0.3MnO3is strongly modified near interfaces, which was addressed as "dead-layer" phenomenon whose origin is still controversial. Here, both magnetic and structural properties of La0.7Sr0.3MnO3/SrTiO3heterostructures were investigated, with emphasis on the quantitative analysis of oxygen octahedral rotation (OOR) across interfaces using annular-bright-field imaging. OOR was found to be significantly altered near interface for both La0.7Sr0.3MnO3and SrTiO3, as linked to the magnetism deterioration. Especially in La0.7Sr0.3MnO3/SrTiO3superlattices, the almost complete suppression of OOR in 4 unit-cell-thick La0.7Sr0.3MnO3results in a canted ferromagnetism. Detailed comparisons between strain and OOR relaxation and especially the observation of an unexpected La0.7Sr0.3MnO3lattice c expansion near interfaces, prove the relevance of OOR for the magnetic properties. These results indicate the capability of tuning the magnetism by engineering OOR at the atomic scale.
authors.affiliation: Stuttgart Center for Electron Microscopy, Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart, Germany.|Laboratoire de Physique des Solides, CNRS UMR 8502, Université Paris Sud, 91405 Orsay, France.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Li
authors.affiliation: Universität zu Köln, II. Physikalisches Institut, Zülpicher Str. 77, D-50937 Köln, Germany.
authors.forename: Ionela
authors.initials: I
authors.lastname: Lindfors-Vrejoiu
authors.affiliation: Universität Leipzig, Fakultät für Physik und Geowissenschaften, Abteilung Supraleitung und Magnetismus, Linnéstrasse 5, D-04103 Leipzig, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Ziese
authors.affiliation: Laboratoire de Physique des Solides, CNRS UMR 8502, Université Paris Sud, 91405 Orsay, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Gloter
authors.affiliation: Stuttgart Center for Electron Microscopy, Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart, Germany.
authors.forename: Peter A
authors.initials: PA
authors.lastname: van Aken