Neutron Investigation of the Phase Transitions and Dynamics of Multiferroic GaV4S8

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