Regensburg 2013 – scientific programme
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DS: Fachverband Dünne Schichten
DS 7: Multiferroics 2 (jointly with DF, KR, MA, TT)
DS 7.13: Talk
Monday, March 11, 2013, 18:15–18:30, H3
Multiferroic Ni3V2O8 measured in THz range at low temperatures and in high magnetic fields — •Malte Langenbach1, Tobias Hissen1, Komalavalli Thirunavukkuarasu1, Holger Schmitz1, Iván Cámara Mayorga2, Rolf Güsten2, Joachim Hemberger1, and Markus Grüninger1 — 1II. Physikalisches Institut, Universität zu Köln, Köln, Germany; — 2Max-Planck-Institut für Radioastronomie, Bonn, Germany;
THz spectroscopy in high magnetic fields is an important technique to probe materials
with strong magneto-electric coupling. Here, we discuss the Kagomé-staircase compound Ni3V2O8.
The triangle-based lattice gives rise to a frustration of the short-range antiferromagnetic couplings.
This causes a rich variety of magnetic and structural phases at low temperatures.
Below TN=9.8 K, a incommensurate phase with collinear sinusoidal spin structure is established. This phase is followed by a cycloidal spin structure which is accompanied by the onset of ferroelectricity. Finally, below 3.9 K, the structure changes to a commensurate canted antiferromagnetic phase [1].
We report on elementary excitations in the THz range observed between 2 K and 50 K in fields up to 8 T.
Work supported by the DFG through SFB 608.
[1] G. Lawes et al., Phys. Rev. Lett. 95, 087205 (2005)