Tuning the multiferroic mechanisms of TbMnO3by epitaxial strain.
A current challenge in the field of magnetoelectric multiferroics is to identify systems that allow a controlled tuning of states displaying distinct magnetoelectric responses. Here we show that the multiferroic ground state of the archetypal multiferroic TbMnO3is dramatically modified by epitaxial strain. Neutron diffraction reveals that in highly strained films the magnetic order changes from the bulk-like incommensurate bc-cycloidal structure to commensurate magnetic order. Concomitant with the modification of the magnetic ground state, optical second-harmonic generation (SHG) and electric measurements show an enormous increase of the ferroelectric polarization, and a change in its direction from along the c- to the a-axis. Our results suggest that the drastic change of multiferroic properties results from a switch of the spin-current magnetoelectric coupling in bulk TbMnO3to symmetric magnetostriction in epitaxially-strained TbMnO3. These findings experimentally demonstrate that epitaxial strain can be used to control single-phase spin-driven multiferroic states.
Laboratory for Multiscale Materials Experiments, Paul Scherrer Institut, CH 5232, Villigen-PSI, Switzerland.
Kenta
K
Shimamoto
Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, CH 5232, Villigen-PSI, Switzerland.
Saumya
S
Mukherjee
Department of Materials, ETH Zurich, CH 8093, Zurich, Switzerland.
Sebastian
S
Manz
Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, CH 5232, Villigen-PSI, Switzerland.
Jonathan S
JS
White
Department of Materials, ETH Zurich, CH 8093, Zurich, Switzerland.
Morgan
M
Trassin
Laboratory for Scientific Development and Novel Materials, Paul Scherrer Institut, CH 5232, Villigen-PSI, Switzerland.
Michel
M
Kenzelmann
Institut Laue Langevin, BP 156X, 38042, Grenoble, France.
Laurent
L
Chapon
Laboratory for Multiscale Materials Experiments, Paul Scherrer Institut, CH 5232, Villigen-PSI, Switzerland.|Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, CH, 8093, Zurich, Switzerland.
Thomas
T
Lippert
Department of Materials, ETH Zurich, CH 8093, Zurich, Switzerland.
Manfred
M
Fiebig
Laboratory for Multiscale Materials Experiments, Paul Scherrer Institut, CH 5232, Villigen-PSI, Switzerland.
Christof W
CW
Schneider
Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, CH 5232, Villigen-PSI, Switzerland.
Christof
C
Niedermayer