Dresden 2014 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 55: Poster II
MA 55.99: Poster
Freitag, 4. April 2014, 10:30–13:30, P2
Microscopic and macroscopic studies on the magnetoelectric coupling in chiral multiferroics — •Tobias Cronert1, Jonas Stein1, Jeannis Leist3, Joachim Hemberger1, Petra Becker-Bohatý2, Ladislav Bohatý2, Agung Nugroho4, Karin Schmalzl5, Götz Eckold3, and Markus Braden1 — 1II. Physikalisches Institut, Universität zu Köln — 2Institut für Kristallographie, Universität zu Köln — 3Institut für Physikalische Chemie, Universität Göttingen — 4Institut Teknologi Bandung — 5JCNS at Institut Laue-Langevin Grenoble
In the chiral magnets MnWO4 and RMnO3 ferroelectric polarisation is directly induced by the non-collinear magnetic structure. We present microscopic neutron scattering studies and macroscopic measurements of the ferroelectric polarisation and of the magnetic structure in these materials. Using a stroboscopic method the control of the chiral magnetism by an external electric field is determined by polarised neutrons while the switching of ferroelectric order can be directly followed in the time-domain with a sawyertower-like circuit. MnWO4 exhibits rather long rise times of 10ms and strong asymmetries that depend on the cooling history. Relaxation times and hysteresis curves of DyMnO3 in dependence of electric field, temperature and thickness were also recorded indicating a non regular behavior.