Public Physic Colloquium in the Winter Terms 2009/2010 in Münster
Place:     Germany, 48149 Münster, Wilhelm-Klemm-Str. 10, IG I, HS 2
Time:     Thursday, 09.12.2010  16:00 h c.t.
Colloquium Coffee at 15:45 h  at the Lecture Hall

Unusual Manifestations of Ferroelectric Order in Multiferroics

M. Fiebig, HISKP, Rheinische Friedrich-Wilhelms-Universität Bonn

Materials with a coexistence of magnetic and electric order, called multiferroics, are rare because (anti)ferromagnetic and ferroelectric order tend to be mutually exclusive. Magnetic order based on transition-metal exchange interactions requires partially filled 3d orbitals while ferroelectricity of the displacive hybridisation type calls for empty 3d shells. In this sense, any occurrence of magnetoelectric multiferroicity inherently involves unusual realisations of ferroelectric order. In my talk I will highlight various examples for "exotic ferroelectrics" and how the unconventional origin of the spontaneous polarization leads to manifestations that may be relevant for future oxide electronic devices. The experiments presented here were conducted by optical second harmonic generation and by piezoresponse force microscopy.