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arXiv · 2107.14623

Phonon anomalies associated with spin reorientation in the Kagome ferromagnet Fe3Sn2

Ge He·Leander Peis·Ramona Stumberger·Lilian Prodan·Vladimir Tsurkan·Nico Unglert·Liviu Chioncel·István Kézsmárki·Rudi Hackl
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Abstract

Polarization- and temperature-dependent Raman data along with theoretical simulations are presented for the Kagome ferromagnet Fe_3Sn_2. Eight out of nine expected phonon modes were identified. The experimental energies compare well with those from the simulations. The analysis of the line widths indicates relatively strong phonon-phonon coupling in the range 0.1 to 1. The temperature-dependent frequencies of three A_{1g} modes show weak anomalies at approximately 100 K. In contrast, the linewidths of all phonon modes follow the conventional exponential broadening up to room temperature except for the softest A_{1g} mode, whose width exhibits a kink close to 100 K and becomes nearly constant for T > 100 K. These features are indicative of a spin reorientation taking place in the temperature range above 100 K which might arise from spin-phonon coupling. The low-energy part of the electronic continuum in E_g symmetry depends strongly on temperature. The possible reasons include particle-hole excitation tracking the resistivity, a spin-dependent gap or spin fluctuations.

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Ge He, Leander Peis, Ramona Stumberger, Lilian Prodan, Vladimir Tsurkan, Nico Unglert, Liviu Chioncel, István Kézsmárki, Rudi Hackl. 2021-07-30. Phonon anomalies associated with spin reorientation in the Kagome ferromagnet Fe3Sn2. https://doi.org/10.1002/pssb.202100169

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