Magneto-ionic vortices: voltage-reconfigurable swirling-spin analog-memory nanomagnets.

Spasojevic, Irena; Ma, Zheng; Barrera, Aleix; Celegato, Federica; Magni, Alessandro; Ruiz-Gómez, Sandra; Foerster, Michael; Palau, Anna et al. · Nat Commun · 2025

basic_science · Level V

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Abstract

Rapid progress in information technologies has spurred the need for innovative memory concepts, for which advanced data-processing methods and tailor-made materials are required. Here we introduce a previously unexplored nanoscale magnetic object: an analog magnetic vortex controlled by electric-field-induced ion motion, termed magneto-ionic vortex or "vortion". This state arises from paramagnetic FeCoN through voltage gating and gradual N<sup>3-</sup> ion extraction within patterned nanodots. Unlike traditional vortex states, vortions offer comprehensive analog adjustment of key properties such as magnetization amplitude, nucleation/annihilation fields, or coercivity using voltage as an energy-efficient tuning knob. This manipulation occurs post-synthesis, obviating the need for energy-demanding methods like laser pulses or spin-torque currents. By leveraging an overlooked aspect of N<sup>3-</sup> magneto-ionics-planar ion migration within nanodots-precise control of the magnetic layer's thickness is achieved, which enables reversible transitions among paramagnetic, single-domain, and vortion states, offering future prospects for analog computing, multi-state data storage, or brain-inspired devices.