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arXiv · 2609.32954

Impact of Phonon-Magnon Scattering on Thermal Transport across Antiferromagnetic and Ferromagnetic Oxides

Zeyu Xiang·Bolin Liao
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Abstract

Phonon--magnon coupling has been extensively studied in ferromagnets, whereas its microscopic mechanisms in antiferromagnets remain less understood. Here, we combine first-principles calculations with spin--lattice dynamics to investigate phonon--magnon interactions and their impact on thermal transport in antiferromagnetic NiO and MnO, which are put in contrast to the ferromagnetic EuO with an identical crystal structure. Green--Kubo and spectral energy density analyses show that spin dynamics reduce phonon thermal conductivity and lifetimes, with the strongest effects in MnO. Comparison of the excitation spectra indicates that spin-induced phonon scattering depends sensitively on the relative phonon and magnon energy scales, while the contrasting behavior of MnO and EuO further highlights the role of magnetic order. A simplified phase-space model further illustrates that, for comparable phonon and magnon energy scales, the antiferromagnetic case can support a larger phonon--magnon scattering phase space than the ferromagnetic case, suggesting a greater number of kinematically allowed scattering channels. These results identify excitation energy scales and magnetic order as key factors governing phonon--magnon scattering in magnetic materials.

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Zeyu Xiang, Bolin Liao. 2026-09-26. Impact of Phonon-Magnon Scattering on Thermal Transport across Antiferromagnetic and Ferromagnetic Oxides. https://arxiv.org/abs/2609.32954

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