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arXiv · 1406.7334

Spin-phonon coupling in BaFe12O19 M-type hexaferrite

Flávio M. Silva Júnior·Carlos W. A. Paschoal
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Abstract

The spin-phonon coupling in magnetic materials is due to the modulation of the exchange integral by lattice vibrations. BaFe12O19 M-type hexaferrite, which is the most used magnetic material as permanent magnet, transforms into ferromagnet at high temperatures, but no spin-phonon coupling was previously observed at this transition. In this letter, we investigated the temperature-dependent Raman spectra of polycrystalline BaFe12O19 M-type hexaferrite from room temperature up to 780 K to probe spin-phonon coupling at the ferrimagnetic transition. An anomaly was observed in the position of the phonon attributed to the Fe(4)O6 octahedra, evidencing the presence of a spin-phonon coupling in BaM in the ferrimagnetic transition at 720 K. The results also confirmed the spin-phonon coupling is different for each phonon even when they couple with the same spin configuration.

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Flávio M. Silva Júnior, Carlos W. A. Paschoal. 2014-07-11. Spin-phonon coupling in BaFe12O19 M-type hexaferrite. https://doi.org/10.1063/1.4904062

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