Quasi-2D magnon identification in antiferromagnetic FePS3 via magneto-Raman spectroscopy

Jeffrey Simpson; Amber McCreary; Thuc Mai; Robert McMichael; Jason E Douglas; Nicholas Butch; Cindi Dennis; Angela Hight Walker; Rolando Valdes Aguilar

Quasi-2D magnon identification in antiferromagnetic FePS3 via 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 (T_N ≈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 T_N 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.

March 5, 2020, 4:03 PM – March 5, 2020, 4:15 PM

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