Parts | Days | Selection | Search | Downloads | Help
PV: Plenarvorträge
PV XII
PV XII: Plenary Talk
Friday, February 29, 2008, 08:30–09:15, H 0105
Multiferroic and Magnetoelectric Materials — •Wolfgang Kleemann — Angewandte Physik, Universität Duisburg-Essen, 47048 Duisburg, Germany
Recently magnetoelectric (ME) materials with a bilinear magnetic and electric free energy contribution, Fme= - α H· E, have become of utmost interest in view of both fundamental understanding and novel desirable applications (Fiebig, 2005). Multiferroic materials with simultaneous polar and magnetic long-range order are expected to optimize the crosslinked responses, viz. magnetization excited by electric fields and electric polarization induced by magnetic ones (Eerenstein et al., 2005). We discuss the occurrence of single phase multiferroicity and of bilinear magnetoelectricity in various systems. Surprisingly most promising applications in spintronics are at present proposed for non-ME multiferroics like BiMnO3 (Gajek et al., 2007), and for non-multiferroic magnetoelectrics like Cr2O3 (Chen et al., 2006). Best performing ME multiferroics are stress-strain coupled heterophase systems like BaTiO3/CoFe2O4 (Ren et al., 2005). Since recently two extensions of the conventional multiferroic scenario have been under debate. Ferromagnetic-ferroelastic multiferroics as realized by Ni2MnGa-like magnetic shape memory alloys (Ullacko et al., 1996) complement the framework of ferroics involved. Even multiglass systems are envisaged. Mn-doped quantum paraelectric (Sr,Mn)TiO3 shows both long-range dipolar and spin-glass ordering and is subject to higher order ME coupling (Bedanta et al., 2007).