Non-periodic magnetic structure in chiral helimagnet Mn<sub>1/3</sub>NbS<sub>2</sub>

ORAL

Abstract

We have investigated the magnetic state of Mn1/3NbS2 through ac-magnetic susceptibility, Small-angle Neutron Scattering (SANS), Lorentz Transmission Electron Microscopy (LTEM) and micromagnetic simulations. The ac susceptibility displays temperature, field, and frequency dependencies which define a complex phase diagram below the critical temperature for magnetic ordering, TC = 45 K. SANS reveals a streak of magnetic scattering along the c-axis near Q = 0 appearing below TC, demonstrating a disordered ferromagnetic (FM) or helical spin ordering in this system. The width of this streak shortens and becomes more intense near TC and is gradually suppressed by the application of H along the beam. Micromagnetic simulations of thin lamella are in agreement with LTEM images of Mn1/3NbS2 where extended FM regions result from a shape anisotropy in thin samples that are separated by the chiral domain walls.

*This material is based upon the work supported by the U.S. Department of Energy under EPSCoR Grant No. DE-SC0012432 with additional support from the Louisiana Board of Regents.

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Presenters

  • Sunil Karna

    • Department of Physics and Astronomy, Louisiana State University, Baton Rouge
    • Physics, Louisiana State University

Authors

  • Sunil Karna

    • Department of Physics and Astronomy, Louisiana State University, Baton Rouge
    • Physics, Louisiana State University

  • Michalis Charilaou

    • Department of Physics, University of Louisiana at Lafayette

  • Andras Kovács

    • Ernst Ruska–Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute,

  • Lisa DeBeer-Schmitt

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

  • David P Young

    • Department of Physics and Astronomy, Louisiana State University, Baton Rouge
    • Louisiana State University, Baton Rouge
    • Physics, Louisiana State University

  • John Ditusa

    • Department of Physics and Astronomy, Louisiana State University, Baton Rouge
    • Louisiana State University, Baton Rouge
    • Physics, Louisiana State University