Unveiling the Magnetic Origin of the High Curie Temperature in Fe ₃ XY ₂ (X = Zn, Ga, Ge, As; Y = Te, I) Family

Two-dimensional (2D) magnetic materials show promise for spintronic applications but are hindered by low Curie temperatures (Tc). This study systematically investigates the Fe3XY2 material family (X = Ga, Ge, As; Y = Te, I), a rare class of 2D magnets that has demonstrated room-temperature ferromagnetism in experiments. First-principles calculations reveal that the interlayer interaction is closely correlated with the hybridization between the Fe-d orbitals and X-p orbitals. Reducing the number of valence electrons at the X site enhances intralayer ferromagnetic (FM) interactions, which serve as the dominant factor in achieving stronger magnetic ordering and higher Tc. Additionally, the chemical composition at the X/Y site significantly alters the direction of magnetic anisotropy by modulating the electronic band structure along the K–H high-symmetry path. Based on these mechanisms, two high-Tc 2D ferromagnets, Fe3ZnTe2 and Fe3ZnI2, have been successfully predicted, with an estimated Tc of 390 and 560 K, respectively.