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arXiv · 2507.03454

Room temperature magnetic vortices in the van der Waals magnet Fe$_5$GeTe$_2$

Elias Sfeir·Carolin Schrader·Florentin Fabre·Jules Courtin·Céline Vergnaud·Alain Marty·Matthieu Jamet·Frédéric Bonell·Isabelle Robert-Philip·Vincent Jacques·Aurore Finco
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Abstract

We investigate the effect of confinement on the magnetic state of a 12 nm-thick Fe$_5$GeTe$_2$ layer grown by molecular beam epitaxy. We use quantitative scanning NV magnetometry to locally extract the magnetization in rectangular uniformly in-plane magnetized microstructures, showing no enhancement of the Curie temperature compared to magnetization measurements performed before patterning the film, in contrast to previous results obtained on thick Fe$_3$GeTe$_2$ flakes. Under the application of a weak out-of-plane magnetic field, we observe the stabilization of magnetic vortices at room temperature in micrometric squares. Finally, we highlight the effect of the size of the patterned micro-discs and micro-squares on the stabilization of the vortices using experiments and micromagnetic simulations. Our work thus proposes and demonstrates a way to stabilize non-collinear textures at room temperature in a van der Waals magnets using confinement, although we also show that this approach alone is not successful to enhance the Curie temperature of Fe$_5$GeTe$_2$ significantly above 300 K.

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Elias Sfeir, Carolin Schrader, Florentin Fabre, Jules Courtin, Céline Vergnaud, Alain Marty, Matthieu Jamet, Frédéric Bonell, Isabelle Robert-Philip, Vincent Jacques, Aurore Finco. 2025-07-04. Room temperature magnetic vortices in the van der Waals magnet Fe$_5$GeTe$_2$. https://arxiv.org/abs/2507.03454

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