Magneto-ionic control of perpendicular anisotropy in epitaxial Mn4N films

SPICE Workshop on Young Research Leaders Group Workshop: Transport and transfer of angular momentum: magnons, chiral phonons and beyond June 9th - 11th, 2026

Silvia Damerio

The increasing dependence of everyday life on information processing requires the development of advanced computing technologies for energy efficient manipulation and storage of large amounts of data. Such technologies often require individual chips to display mixed functionality, such as co-localized memory and logic capabilities as well as volatile and non-volatile storage [1]. In this work, we realize gate-tunable devices where the local control of the materials properties allows to switch dynamically between different states. We grow Mn₄N thin films on MgO(100) substrates, exhibiting bulk-like magnetization and strain-induced perpendicular magnetic anisotropy (PMA), also promoted by capping the film with material with large spin-orbit coupling. We demonstrate that the magnetism and interfacial anisotropy of Mn₄N can be reversibly tuned through voltage-driven nitrogen ion migration when Mn₄N is in contact with a nitrogen-affine metals [2], such as Ta and V. We also show that solid-state gating effectively enhances the spin-orbit torque (SOT) switching efficiency by reducing the coercive field (H_C) without compromising interface transparency. Finally, we demonstrate that gate-tunable devices can be harnessed for efficient non-volatile memory functionality [3].

Figure 1: Magneto-ionic control of interfacial magnetism. (a) Schematic representation of the device and contacts scheme. (b) Plot of the time (t) evolution of the coercive field (H_C) for different applied gate voltages (V_G). Inset: H_C change percentage as a function of V_G. Plot of t evolution of H_C at V_G=0 for different temperatures (c) and capping layer materials (d).

References

[1] J. Grollier, et al., Neuromorphic spintronics, Nature Electronics 3, 360–370 (2020).

[2] N. López-Pintó, et. al., Room-Temperature Solid-State Nitrogen-Based Magneto-Ionics in Co_xMn_1−xN Films, Advanced Functional Materials 34, 2404487 (2024).

[3] S. Damerio, et al., Magneto-ionic control of perpendicular anisotropy in epitaxial Mn₄N films, Applied Physics Letters 127, 262405 (2025).