Temperature- and magnetic field-dependent Raman spectroscopy of layered, antiferromagnetic FePS<sub>3</sub>

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 Raman spectroscopic 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 Néel 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, with a g-factor ≈ 2. Furthermore, we compare our spectra with predictions from density functional theory to discuss the origin and anomalous temperature dependence of additional low-frequency Raman-active modes.

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Presenters

  • Jeffrey Simpson

    • Towson University
    • Towson Univ
    • Physics, Astronomy, and Geosciences, Towson University

Authors

  • Jeffrey Simpson

    • Towson University
    • Towson Univ
    • Physics, Astronomy, and Geosciences, Towson University

  • Amber McCreary

    • National Institute of Standards and Technology
    • National Institute of Standards & Technology
    • Physical Measurement Laboratory, National Institute of Standards and Technology

  • Thuc Mai

    • National Institute of Standards and Technology
    • National Institute of Standards & Technology
    • Physical Measurement Laboratory, National Institute of Standards and Technology

  • Kevin Garrity

    • National Institute of Standards and Technology
    • National Institute of Standards & Technology
    • NIST
    • Materials Measurement Laboratory, National Institute of Standards and Technology

  • Cindi L Dennis

    • National Institute of Standards and Technology
    • National Institute of Standards & Technology

  • Angela Hight Walker

    • National Institute of Standards and Technology
    • National Institute of Standards & Technology
    • NIST
    • Physical Measurement Laboratory, National Institute of Standards and Technology

  • Rolando Valdes Aguilar

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