Lattice dynamics and phonon dispersion of van der Waals layered ferromagnet Fe3GaTe2

TL;DR

This study combines Raman spectroscopy and first-principles calculations to analyze the lattice dynamics, phonon dispersion, and spin-phonon coupling in the vdW ferromagnet Fe3GaTe2, revealing temperature-dependent phonon behaviors and room-temperature spin-phonon interaction.

Contribution

It provides the first detailed analysis of lattice dynamics and spin-phonon coupling in Fe3GaTe2 using combined experimental and theoretical methods.

Findings

Identification of phonon modes at 126.0 and 143.5 cm-1

Observation of room-temperature spin-phonon coupling with strength ~0.81 cm-1

Detection of Raman anomalies below Curie temperature

Abstract

Despite the tremendous progress in spintronic studies of van der Waals (vdW) room-temperature ferromagnet Fe3GaTe2, much less effort has been spent on its lattice dynamics and possible interaction with spintronic degrees of freedom. In this work, by combining Raman spectroscopy in a wide range of pressure (atmospheric pressure~19.5 GPa) and temperature (80~690 K) with first-principles calculation, we systematically studied the lattice dynamics and phonon dispersion of Fe3GaTe2. Our results show that the phonon energies of Fe3GaTe2 located at 126.0 cm-1 and 143.5 cm-1 originate from the anharmonic and harmonic vibration modes, respectively. Furthermore, the first room-temperature spin-phonon coupling in vdW ferromagnet is observed with strength of ~0.81 cm-1 at 300 K, by identifying Raman anomalies in both phonon energy and full width at half maximum (FWHM) of below Curie temperature of Fe3GaTe2. Our findings are valuable for fundamental and applied studies of vdW materials under variable conditions.