An Ab Initio Study of Monolayer Mn₂Mg₂X₅ (X = S, Se), a Novel Family of 2D Half-Metallic Ferromagnets

The recent advances in the synthesis of 2D magnetic materials have raised hopes for their potential use in next-generation spintronics devices. These candidates, however, still possess relatively low magnetic transition temperatures and small magnetic anisotropy energies to achieve efficient functionality. Aiming to find high-performance 2D magnetic crystals, the authors predict Mn2Mg2X5 (X = S, Se) as a novel family of 2D ferromagnets with half-metallic electronic properties. A single-channel spin bandgap of approximate to 2 eV makes them suitable for spin-filtering applications. Their easy-plane magnetic anisotropy is relatively high, especially in the case of Mn2Mg2Se5 (MAE = 1.46 meV/Mn). Furthermore, the magnetic transition temperature of these compounds is relatively high ( T-C approximate to 200 K) compared to those of most synthesized 2D magnetic compounds. The existence of nonmagnetic van der Waals analogs of these compounds, such as Al2Mg2Se5 , accompanied by their energy, dynamic, thermal, and mechanical stability, suggest that they have a good probability of being synthesized.