Quasi-2D magnon identification in antiferromagnetic FePS<sub>3</sub> <i>via</i> magneto-Raman spectroscopy

ORAL

Abstract

The recent discovery that van der Waals-bonded magnetic materials retain long range magnetic ordering down to a single layer stimulates a thorough magneto-Raman study of one such material, FePS3, a large spin (S = 2) Mott insulator where the Fe atoms form a honeycomb lattice. Bulk FePS3 was shown to be a quasi-2D Ising antiferromagnet, with additional features in the Raman spectra emerging below the Neel temperature (TN ≈120 K). Using temperature and magnetic field dependent Raman spectroscopy as an optical probe of magnetic structure, we demonstrate that one of these Raman-active modes below TN is a magnon with a frequency of ≈3.7 THz (122 cm-1). Contrary to previous work, which interpreted this feature as a phonon, our Raman data shows the expected frequency shifting and splitting of the magnon as a function of temperature and magnetic field, respectively, were we find the g-factor ≈2. In addition, the symmetry behavior of the magnon is studied by polarization-dependent Raman spectroscopy and explained using the magnetic point group of FePS3. Temperature dependence of the Raman-active phonons will also be discussed.

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Presenters

  • Jeffrey Simpson

    • Towson Univ
    • Towson University
    • Physics, Towson University
    • Department of Physics, Towson University

Authors

  • Jeffrey Simpson

    • Towson Univ
    • Towson University
    • Physics, Towson University
    • Department of Physics, Towson University

  • Amber McCreary

    • NIST
    • National Institute of Standards and Technology

  • Thuc Mai

    • NIST
    • National Institute of Standards and Technology

  • Robert McMichael

    • NIST
    • National Institute of Standards and Technology

  • Jason E Douglas

    • NIST

  • Nicholas Butch

    • NIST Center for Neutron Research, National Institute of Standards and Technology
    • National Institute of Standards and Technology
    • Center of Neutron Research, National Institute of Standards and Technology
    • Center for Neutron Research, National Institute of Standards and Technology
    • NIST Center for Neutron Research
    • NIST center for neutron research
    • NIST
    • NIST Center for Neutron Research, National Institute of Standards and Technology,
    • University of Maryland, College Park & NIST
    • National Institute of Standards and Technology Center for Neutron Research

  • Cindi Dennis

    • National Institute of Standards and Technology
    • NIST

  • Angela Hight Walker

    • National Institute of Standards and Technology
    • NIST
    • National Institute of Standards and Technology (NIST)

  • Rolando Valdes Aguilar

    • Ohio State Univ - Columbus
    • Ohio State Univ
    • Physics, The Ohio State University
    • Ohio State University
    • Department of Physics, The Ohio State University