Spin-lattice couplings in $3d$ ferromagnets: analysis from first-principles

I. P. Miranda; M. Pankratova; M. Weißenhofer; A. B. Klautau; D. Thonig; M. Pereiro; E. Sjöqvist; A. Delin; M. I. Katsnelson; O. Eriksson; A. Bergman

doi:10.1103/physrevmaterials.9.024409

arXiv · 2409.18274

Spin-lattice couplings in $3d$ ferromagnets: analysis from first-principles

I. P. Miranda·M. Pankratova·M. Weißenhofer·A. B. Klautau·D. Thonig·M. Pereiro·E. Sjöqvist·A. Delin·M. I. Katsnelson·O. Eriksson·A. Bergman

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Abstract

Magnetoelasticity plays a crucial role in numerous magnetic phenomena, including magnetocalorics, magnon excitation via acoustic waves, and ultrafast demagnetization/Einstein-de Haas effect. Despite a long-standing discussion on anisotropy-mediated magnetoelastic interactions of relativistic origin, the exchange-mediated magnetoelastic parameters within an atomistic framework have only recently begun to be investigated. As a result, many of their behaviors and values for real materials remain poorly understood. Therefore, by using a proposed simple modification of the embedded cluster approach that reduces the computational complexity, we critically analyze the properties of exchange-mediated spin-lattice coupling parameters for elemental $3d$ ferromagnets (bcc Fe, fcc Ni, and fcc Co), comparing methods used for their extraction and relating their realistic values to symmetry considerations and orbitally-decomposed contributions. Additionally, we investigate the effects of noncollinearity (spin temperature) and applied pressure on these parameters. For Fe, we find that single-site rotations, associated with spin temperatures around $\sim100$ K, induce significant modifications, particularly in Dzyaloshinskii-Moriya-type couplings; in contrast, such interactions in Co and Ni remain almost configuration independent. Moreover, we demonstrate a notable change in the exchange-mediated magnetoelastic constants for Fe under isotropic contraction. Finally, the conversion between atomistic, quantum-mechanically derived parameters and the phenomenological magnetoelastic theory is discussed, which can be an useful tool towards larger and more realistic dynamics simulations involving coupled subsystems.

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I. P. Miranda, M. Pankratova, M. Weißenhofer, A. B. Klautau, D. Thonig, M. Pereiro, E. Sjöqvist, A. Delin, M. I. Katsnelson, O. Eriksson, A. Bergman. 2025-03-31. Spin-lattice couplings in $3d$ ferromagnets: analysis from first-principles. https://doi.org/10.1103/physrevmaterials.9.024409

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