Neutron Investigation of the Phase Transitions and Dynamics of Multiferroic GaV<sub>4</sub>S<sub>8</sub>

ORAL

Abstract

We have carried out neutron diffraction and small angle neutron scattering measurements on a high quality single crystal of the cubic lacunar spinel GaV4S8 multiferroic as a function of magnetic field and temperature. The system undergoes a structural transition at 44 K to rhombohedral symmetry and becomes ferroelectric, and orders magnetically below ~13 K. The magnetic order parameter has been measured and indicates a ferromagnetic response below 8 K, while the intensities strongly suggest that the single spin is distributed across the V4 molecular unit rather than residing on a single V ion. Field-dependent SANS data exhibit the cycloidal and skyrmion phases, which have been investigated in detail as a function of temperature and applied magnetic field. In addition, the neutron time-tagging technique has been employed with a periodic perturbative magnetic field. Varying the amplitude and frequency of the perturbation has been used to reveal important details of the time dependence of the Néel-type skyrmions as well as other aspects of the magnetic order.

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Presenters

  • Jeffrey Lynn

    • NIST Center for Neutron Research
    • NIST center for Neutron Research
    • NIST Center for Neutron Research, National Institute of Standards and Technology
    • National Institute of Standards and Technology
    • NIST
    • NCNR, NIST -Natl Inst of Stds & Tech

Authors

  • Jeffrey Lynn

    • NIST Center for Neutron Research
    • NIST center for Neutron Research
    • NIST Center for Neutron Research, National Institute of Standards and Technology
    • National Institute of Standards and Technology
    • NIST
    • NCNR, NIST -Natl Inst of Stds & Tech

  • William Ratcliff

    • NIST
    • NIST- Natl Inst of Stds & Tech
    • Center for Neutron Research, NIST -Natl Inst of Stds & Tech
    • NIST -Natl Inst of Stds & Tech
    • NCNR, NIST -Natl Inst of Stds & Tech

  • Markus Bleuel

    • National Institute of Standards and Technology
    • NCNR, NIST -Natl Inst of Stds & Tech

  • Lunyong Zhang

    • Max Planck POSTETH, Pohang University of Science and Technology
    • Korea Research Initiative
    • Laboratory for Pohang Emergent Materials and Max Plank POSTECH Center for Complex Phase Materials, Pohang University of Science and Technology

  • Sang-Wook Cheong

    • Rutgers University
    • Department of Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, Rutgers, The State University of New Jersey
    • Physics, Rutgers University
    • Physics and Astronomy, Rutgers University
    • Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University
    • Physics and Astronomy, Rutgers Univ.
    • Rutgers Univ
    • Physics, Rutgers Univesity
    • Department of Physics, Rutgers University
    • Physics and Astronomy, Rutgers Center for Emergent Materials
    • Department of Physics & Astronomy , Rutgers University