Regensburg 2007 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 11: Poster Session
DF 11.30: Poster
Donnerstag, 29. März 2007, 14:30–18:00, Poster C
High-pressure infrared study of the multiferroic BiFeO3 — •A. Pashkin1, C. A. Kuntscher1, R. Haumont2, and J. Kreisel3 — 1Experimentalphysik II, Universität Augsburg, 86159 Augsburg, Germany — 2Laboratoire de Physico-Chimie de l’Etat Solide ICMMO - UMR CNRS, Université Paris Sud, 91405 Orsay Cedex, France — 3Laboratoire des Matériaux et du Génie Physique (CNRS), INP Grenoble - MINATEC 38016 Grenoble, France
Magnetoelectric multiferroics currently attract much attention. BiFeO3 is one example, which exhibits antiferromagnetic (TN ∼ 370 ∘C) and ferroelectric (TC∼ 830 ∘C) orders up to very high temperatures. A recent attempt has been made to understand the role of phonons for the multiferroic character of BiFeO3 by temperature-dependent Raman measurements [1]. Besides temperature or electric/magnetic field, pressure is a good parameter to find out more about the underlying mechanism of multiferroicity.
We report a high-pressure infrared spectroscopic study of BiFeO3 in the far-infrared range up to 21 GPa. The eigenfrequencies of the phonons appreciably increase with increasing pressure. Moreover, several modes show a non-linear pressure dependence with kinks at around 5 and 12 GPa, supporting the results of recent pressure-dependent Raman studies.
Supported by the DFG. Provision of beamtime at the ANKA Angströmquelle Karlsruhe is acknowledged.
[1] R. Haumont et al., Phys. Rev. B 73, 132101 (2006).