Large spin-driven dielectric response and magnetoelectric coupling in the buckled honeycomb Fe<sub>4</sub>Nb<sub>2</sub>O<sub>9</sub>

ORAL

Abstract

A significant spin-driven dielectric anomaly near the magnetic ordering temperature has been observed in single crystal Fe4Nb2O9. By combining neutron and x-ray single crystal diffraction, we unambiguously determined its magnetic symmetry and studied the structural phase transition. The temperature-dependent static dielectric constant is strongly anisotropic, rendering two dielectric anomalies along the a axis in the hexagonal lattice with the first one coupled to the magnetic ordering around TN = 97 K and the second one accompanying with a first-order structural transition around TS = 70 K. Below TN , we found that the anomalous dielectric constant is practically proportional to the square of the magnetic moment from neutron diffraction data, indicating that the exchange striction is likely responsible for the strong spin-lattice coupling.

L. Ding et al., Phy. Rev. Mater. 4, 084403, (2020).

*The research was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Early Career Research Program Award KC0402010, under Contract DE- AC05-00OR22725. This research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by Oak Ridge National Laboratory.

–

Presenters

  • Huibo Cao

    • Oak Ridge National Lab
    • Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Neutron Scattering, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory

Authors

  • Huibo Cao

    • Oak Ridge National Lab
    • Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Neutron Scattering, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory

  • LEI DING

    • Oak Ridge National Lab
    • Oak Ridge National Laboratory

  • Minseong Lee

    • National High Magnetic Field Laboratory
    • Pulsed Field Facility, Los Alamos National Lab
    • National High Magnetic Field Laboratory, Los Alamos National Laboratory
    • Los Alamos National Lab
    • Los Alamos National Laboratory

  • Eun Sang Choi

    • National High Magnetic Field Laboratory, Florida State University
    • National High Magnetic Field Laboratory
    • National High Magnetic Field Laboratory and Department of Physics, Florida State University
    • National High Magnetic Field Lab
    • Physics, Florida State University
    • National High Field Magnet Laboratory
    • Florida Sate University

  • Yan Wu

    • Oak Ridge National Lab

  • Ryan P Sinclair

    • University of Tennessee, Knoxville
    • Department of Physics and Astronomy, University of Tennessee

  • Bryan C Chakoumakos

    • Oak Ridge National Lab

  • Haidong Zhou

    • Dep. Physics and Astronomy, University of Tennessee, Knoxville TN
    • Department of Physics and Astronomy, University of Tennessee, Knoxville
    • University of Tenessee
    • University of Tennessee, Knoxville
    • Physics and Astronomy, University of Tennessee at Knoxville
    • University of Tennessee
    • Department of Physics and Astronomy, University of Tennessee