Spin Waves and Magnetic Interaction in the Multiferroic Antiferromagnet MnWO4

ORAL

Abstract

The spin wave excitations of the multiferroic MnWO4 have been measured in the low-temperature collinear commensurate phase using high-resolution inelastic scattering. The spin excitations can be well described by a Heisenberg model with competing exchange interactions up to 11th nearest neighbors. We find the magnetic exchange couplings are highly frustrated within each zigzag spin chain along c-axis and between chains along the a-axis. However, the magnetic interactions are much weaker between chains along the b-axis. Our measurements suggest that the delicate balance of long range magnetic couplings is subject to small perturbations that can lead to a complex magnetic configuration exhibiting magnetoelectric behavior.

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Authors

  • J.A. Fernandez-Baca

    ORNL

  • Feng Ye

    ORNL, Oak Ridge National Laboratory, Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

  • R.S. Fishman

    Materials Science and Technology Division, Oak Ridge National Laboratory, 37831 Oak Ridge, USA, Oak Ridge National Laboratory

  • A. Podlesnyak

    ORNL

  • Georg Ehlers

    NScD, Oak Ridge National Laboratory, 37831 Oak Ridge, USA, ORNL, Spallation Neutron Source, Oak Ridge National Laboratory

  • H.A. Mook

    ORNL

  • Y.Q. Wang

    Univ of Houston

  • Bernd Lorenz

    Department of Physics and TcSUH at the University of Houston, Department of Physics, TcSUH, University of Houston, Univ of Houston, TCSUH and Department of Physics, University of Houston, Houston, Texas 77024-5002, USA, Dept. of Physics and TcSUH, University of Houston

  • Paul C. W. Chu

    Texas Center for Superconductivity at University of Houston and Department of Physics,Lawrence Berkeley National Laboratory, Department of Physics and TcSUH at the University of Houston; Lawrence Berkeley National Laboratory, Department of Physics, TcSUH, University of Houston and Lawrence Berkeley National Laboratory, Dept. of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5002, Univ of Houston, TCSUH and Department of Physics, University of Houston, Houston, Texas 77024-5002, USA, Department of Physics and TcSUH, University of Houston, Dept. of Physics and TcSUH, University of Houston, Texas Center for Superconductivity, University of Houston and Lawrence Berkeley National Laboratory