Engineering of magnetic anisotropy in MnGeSe3 monolayer via hydrogenation and multiferroic heterostructures

Two-dimensional (2D) ferromagnets with controlled magnetic anisotropy energy (MAE) provide the opportunity to develop emergent magnetic tunnel junctions (MTJs), enabling more energy-efficient memory devices with robust storage stability and low power consumption. Employing first-principles calculations, we study the effect of surface hydrogenation as well as the ferroelectric polarization of In2Se3 on the magnetic properties of layered MnGeSe3 (MGS). Electron injection by hydrogenation triggers a phase transition and spin reorientation with large perpendicular magnetic anisotropy for the functionalized MGS. Notably, our results demonstrate the feasibility to achieve the controlled MAE through the ferroelectric switching of 2D In2Se3 substrate and strain effect, while the multiferroic heterostructures yield distinct strain dependences of the MAE depending on the surface hydrogenation. The underlying mechanism is their synergistic effects of the competitive spin-orbit coupling strength between the modified Se-derived p orbitals. These findings provide an effective strategy to modulate the 2D magnetism of MGS, which may lead to practical applications for the next-generation magnetoelectric memory device.