Model for the Spin Dynamics of the Multiferroic (NH<sub>4</sub>)<sub>2</sub>FeCl<sub>5</sub> (H<sub>2</sub>O)

ORAL

Abstract

The multiferroic behavior of any material sensitively depends on the microscopic interactions between the spins. We evaluate the magnetic interactions in the multiferroic erythrodsiderite (NH4)2FeCl5 (H2O) by comparing inelastic neutron scattering spectra of a single crystal sample with a simple Heisenberg model containing five exchange interactions and an easy-plane anisotropy. The cycloidal spin state in every bc plane is produced by two competing exchange interactions. Using the observed wavevector of this cycloidal spin state is used as a constraint, excellent agreement is found between the observed and predicted spectra. The resulting exchange and anisotropy parameters are compared with the predictions of first-principle calculations.

*Research sponsored by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.

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Presenters

  • Randy Fishman

    • Oak Ridge National Lab
    • Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN
    • Materials Science and Technology Division, OakRidge National Laboratory

Authors

  • Randy Fishman

    • Oak Ridge National Lab
    • Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN
    • Materials Science and Technology Division, OakRidge National Laboratory

  • Wei Tian

    • Oak Ridge National Lab
    • Neutron Scattering Division, Oak Ridge National Laboratory

  • Jaime Fernandez-Baca

    • Oak Ridge National Lab
    • Oak Ridge National Laboratory
    • Neutron Scattering Division, Oak Ridge National Laboratory

  • Janice L Musfeldt

    • University of Tennessee
    • Chemistry, University of Tennessee, Knoxville

  • Jun Hee Lee

    • Ulsan National Institute of Science and Technology

  • Minseong Lee

    • Ulsan National Institute of Science and Technology

  • John Singleton

    • National High Magnetic Field Lab, Los Alamos
    • Los Alamos National Laboratory
    • NHMFL, Los Alamos National Laboratory
    • National High Magnetic Field Laboratory, Los Alamos National Laboratory
    • NHMFL, Los Alamos National Lab
    • Los Alamos National Lab.