Dzyaloshinskii-Moriya Interaction in Fe<sub>5</sub>GeTe<sub>2</sub> Epitaxial Thin Films.

Sampaio, João; Pascaud, Antoine; Quero, Edgar; Thiaville, André; Polewczyk, Vincent; Marty, Alain; Bonell, Frédéric; Mougin, Alexandra · Nano Lett · 2025

basic_science · Level V

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Abstract

van der Waals ferromagnets, such as Fe<sub>5</sub>GeTe<sub>2</sub>, offer a promising platform for spintronic devices based on chiral magnetic textures, provided a significant Dzyaloshinskii-Moriya interaction (DMI) can be induced to stabilize the textures. Here, we directly measure DMI in epitaxial Fe<sub>5</sub>GeTe<sub>2</sub> thin films using Brillouin light scattering spectroscopy and observe a consistent DMI (<i>D</i> = 0.04 mJ/m<sup>2</sup>) across various thicknesses. Its weak thickness dependence, combined with the nominally symmetric film interfaces, suggests a bulk origin. Although we do not determine the microscopic mechanism, our findings are compatible with <i>ab initio</i> calculations linking DMI to partial ordering of Fe split sites. Additionally, we find a low magnetic dissipation (α < 0.02). The observed DMI, which could be further enhanced by optimizing the Fe site ordering, combined with low dissipation, makes Fe<sub>5</sub>GeTe<sub>2</sub> a strong candidate for exploring the dynamics of chiral magnetic textures in two-dimensional materials.