Regensburg 2019 – wissenschaftliches Programm
MA 5.14: Vortrag
Montag, 1. April 2019, 13:00–13:15, H53
The polar distortion and its relation to magnetic order in multiferroic HoMnO3 — •Nazaret Ortiz1, Yoav William Windsor2, Jose Renato Linares Mardegan1, Christof Schneider1, Gareth Nisbet3, and Urs Staub1 — 1Paul Scherrer Institute, Swiss Light Source, Switzerland — 2Fritz Haber Institut der Max Planck Gesellschaft, Germany, — 3Diamond Light Source, United Kingdom
The orthorhombic (Pbnm) HoMnO3 is of particular interest due to its high magnetically-induced polarization values (P) and magnetoelectric coupling strength. The mechanism behind this involves high magnetic frustration, which results in a magnetic order that creates a distortion in the crystal lattice. This distortion breaks inversion symmetry and creates a macroscopic electric polarization P along the a-axis.
We investigated the atomic distortion to identify the broken symmetry of Pbnm in thin films of HoMnO3 at low temperature and the relation between the magnetic order of Ho and the structural distortion. Forbidden reflections for Pbnm has been observed, showing that the distortion does not exclusively affect to the atomic position along the polar axis, it also moves atoms along other directions. Moreover, studying reflections with component along the polar axis we observe the polar distortion directly, visualized by the difference diffraction intensity from opposite domains.