Berlin 2008 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 20: Multiferroics

MA 20.5: Vortrag

Mittwoch, 27. Februar 2008, 15:00–15:15, EB 202

Relaxation dynamics of multiferroic rare-earth manganites — •Florian Schrettle¹, Peter Lunkenheimer¹, Joachim Hemberger², and Alois Loidl¹ — ¹Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, 86135 Augsburg, Germany — ²Institute of Physics II, University of Cologne, 50937 Cologne, Germany

In recent years, multiferroic compounds attracted an enormous scientific and technological interest [1]. This rare class of materials combines ferroelectricity with (anti-)ferromagnetism in a single phase. In rare cases both order parameters are strongly coupled, leading to pronounced magnetocapacitive effects. Prominent examples for such systems are rare-earth manganites like, e.g., TbMnO₃. In these compounds partial frustration of the Mn-spins leads to spiral magnetic structures, which allow for a finite ferroelectric polarization. Besides the transition to the multiferroic phases, dielectric spectroscopy reveals a relaxation along the c-direction in these materials. We provide the results of a detailed investigation of the relaxation dynamics in several rare-earth manganites (GdMnO₃, Eu:YMnO₃, TbMnO₃, DyMnO₃). This dynamics seems to play an important role for the magnetocapacitive properties of these compounds.

[1] T. Kimura et al., Nature 426, 55 (2003); T. Lottermoser et al., Nature 430, 541 (2004); T. Goto et al., Phys. Rev. Lett. 92, 257201 (2004).