title: Polarization Rotation in Ferroelectric Tricolor PbTiO3/SrTiO3/PbZr0.2Ti0.8O3 Superlattices.
abstract: In ferroelectric thin films, controlling the orientation of the polarization is a key element to controlling their physical properties. We use laboratory and synchrotron X-ray diffraction to investigate ferroelectric bicolor PbTiO3/PbZr0.2Ti0.8O3 and tricolor PbTiO3/SrTiO3/PbZr0.2Ti0.8O3 superlattices and to study the role of the SrTiO3 layers on the domain structure. In the tricolor superlattices, we demonstrate the existence of 180° ferroelectric stripe nanodomains, induced by the depolarization field produced by the SrTiO3 layers. Each ultrathin SrTiO3 layer modifies the electrostatic boundary conditions between the ferroelectric layers compared to the corresponding bicolor structures, leading to the suppression of the a/c polydomain states. Combined with the electrostatic effect, the tensile strain induced by PbZr0.2Ti0.8O3 in the PbTiO3 layers leads to polarization rotation in the system as evidenced by grazing incidence X-ray measurements. This polarization rotation is associated with the monoclinic Mc phase as revealed by the splitting of the (HHL) and (H0L) reciprocal lattice points. This work demonstrates that the tricolor paraelectric/ferroelectric superlattices constitute a tunable system to investigate the concomitant effects of strains and depolarizing fields. Our studies provide a pathway to stabilize a monoclinic symmetry in ferroelectric layers, which is of particular interest for the enhancement of the piezoelectric properties.
authors: Laboratoire de Physique de la Matière Condensée, EA 2081, Université de Picardie Jules Verne , 80039 Amiens, France.
authors: Nathalie
authors: N
authors: Lemée
authors: Laboratoire Structures, Propriétés et Modélisation des Solides, CentraleSupélec, CNRS-UMR 8580, Université Paris-Saclay , 92295 Cedex Châtenay-Malabry, France.
authors: Ingrid C
authors: IC
authors: Infante
authors: Laboratoire de Physique de la Matière Condensée, EA 2081, Université de Picardie Jules Verne , 80039 Amiens, France.
authors: Cécile
authors: C
authors: Hubault
authors: Sciences des Procédés Céramiques et de Traitements de Surface, CNRS UMR 7315, Centre Européen de la Céramique , 87068 Limoges, France.
authors: Alexandre
authors: A
authors: Boulle
authors: University of Grenoble Alpes, Institut NEEL , F-38000 Grenoble, France.|CNRS, Institut NEEL , F-38042 Grenoble, France.
authors: Nils
authors: N
authors: Blanc
authors: University of Grenoble Alpes, Institut NEEL , F-38000 Grenoble, France.|CNRS, Institut NEEL , F-38042 Grenoble, France.
authors: Nathalie
authors: N
authors: Boudet
authors: Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS/Université de Rennes 1 , Campus de Beaulieu, 35042 Rennes, France.
authors: Valérie
authors: V
authors: Demange
authors: Laboratoire de Physique de la Matière Condensée, EA 2081, Université de Picardie Jules Verne , 80039 Amiens, France.
authors: Michael G
authors: MG
authors: Karkut
keywords: Pb(Zr,Ti)O3-based films; domain structure; epitaxial and superlattice film; ferroelectric materials; strain and interface effects