Ferroelectricity induced by acentric spin-density waves in YMn2O5

ORAL

Abstract

The commensurate and incommensurate magnetic structures of the magnetoelectric system YMn$_{2}$O$_{5}$, as determined from neutron diffraction, were found to be spin-density waves lacking a global center of symmetry. We propose a model, based on a simple magneto-elastic coupling to the lattice, which enables us to predict the polarization based entirely on the observed magnetic structure. Our data accurately reproduce the temperature-dependence of the spontaneous polarization, in particular its sign reversal at the commensurate-incommensurate transition.

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Authors

  • Graeme R. Blake

    ISIS Facility, Rutherford Appleton Laboratory

  • Laurent C. Chapon

    ISIS Facility, Rutherford Appleton Laboratory, UK

  • Paolo G. Radaelli

    ISIS, Rutherford Appleton Laboratory, ISIS Facility, Rutherford Appleton Laboratory, UK, ISIS-Rutherford Laboratory

  • S. Park

    Rutgers University, USA

  • Sang-Wook Cheong

    Dept. of Physics \& Astronomy, Rutgers, Rutgers University, Department of Physics, Rutgers University, Rutgers University, USA, Rutgers Center for Emergent Materials and Department of Physics \& Astronomy, Rutgers University, Piscataway, New Jersey 08854, Rutgers Center for Emergent Materials