Abstract
Raman scattering is performed on Fe3GeTe2 (FGT) at temperatures from 8 to 300 K and under pressures from the ambient pressure to 9.43 GPa. Temperature-dependent and pressure-dependent Raman spectra are reported. The results reveal respective anomalous softening and moderate stiffening of the two Raman active modes as a result of the increase of pressure. The anomalous softening suggests anharmonic phonon dynamics and strong spin–phonon coupling. Pressure-dependent density functional theory and phonon calculations are conducted and used to study the magnetic properties of FGT and assign the observed Raman modes E^2_2g and A^1_1g. The calculations proved the strong spin–phonon coupling for the E^2_2g mode. In addition, a synergistic interplay of pressure-induced reduction of spin exchange interactions and spin–orbit coupling effect accounts for the softening of the E^2_2g mode as pressure increases.
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@article{Cai2023,
title = {Spin\textendashPhonon Interactions and Anharmonic Lattice Dynamics in Fe3GeTe2},
author = {Qingan Cai and Yuemei Zhang and Diana Luong and Christopher A. Tulk and Boniface P.T. Fokwa and Chen Li},
url = {https://onlinelibrary.wiley.com/doi/10.1002/apxr.202200089},
doi = {doi.org/10.1002/apxr.202200089},
year = {2023},
date = {2023-03-24},
journal = {Advanced Physics Research},
number = {2200089},
abstract = {Raman scattering is performed on Fe3GeTe2 (FGT) at temperatures from 8 to 300 K and under pressures from the ambient pressure to 9.43 GPa. Temperature-dependent and pressure-dependent Raman spectra are reported. The results reveal respective anomalous softening and moderate stiffening of the two Raman active modes as a result of the increase of pressure. The anomalous softening suggests anharmonic phonon dynamics and strong spin\textendashphonon coupling. Pressure-dependent density functional theory and phonon calculations are conducted and used to study the magnetic properties of FGT and assign the observed Raman modes E^2_2g and A^1_1g. The calculations proved the strong spin\textendashphonon coupling for the E^2_2g mode. In addition, a synergistic interplay of pressure-induced reduction of spin exchange interactions and spin\textendashorbit coupling effect accounts for the softening of the E^2_2g mode as pressure increases.},
keywords = {anharmonicity, DFT, high pressure, magnon-phonon, Raman, selenide},
pubstate = {published},
tppubtype = {article}
}