Berlin 2015 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 10: Multiferroics I (DF with DS/KR/MA/TT)
DF 10.7: Vortrag
Mittwoch, 18. März 2015, 11:00–11:15, EB 107
Dielectric properties and electrical switching behavior of the spin-driven multiferroic LiCuVO4 — •Alexander Ruff1, Stephan Krohns1, Peter Lunkenheimer1, Andrey Prokofiev2, and Alois Loidl1 — 1Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, Germany — 2Solid State Physics, Vienna University of Technology, Austria
The spin-1/2 chain cuprate LiCuVO4 exhibits both ferroelectric and magnetic order at low temperatures. This so-called multiferroic behavior is of great scientific interest due to the underlying complex physical mechanisms, especially in the case of strong magnetoelectric coupling. Here we thoroughly discuss the multiferroic properties of the prototypical spin-driven ferroelectric material LiCuVO4. At temperatures below about 2.5 K, it exhibits a three dimensional helical spiral spin order, with propagation in the b direction and a spin helix in the ab plane, which induces via an inverse Dzyaloshinskii-Moriya interaction a ferroelectric polarization in the a direction. In an external magnetic field, the direction of the spin spiral and thus the direction of the electrical polarization can be switched. This switching behavior of the polarization was demonstrated via dielectric spectroscopy on a single crystalline sample oriented in two different directions in magnetic fields up to 9 T. Detailed magnetic-field and temperature-dependent ferroelectric hysteresis-loop measurements imply the electric control of the spin helicity [1]. This rarely documented feature indicates the close coupling of electric and magnetic order of LiCuVO4.
A. Ruff et al., J. Phys.: Condens. Matter, 26:485901 (2014).