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 ( T c ). This study systematically investigates the Fe 3 XY 2 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 T c . 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- T c 2D ferromagnets, Fe 3 ZnTe 2 and Fe 3 ZnI 2, have been successfully predicted, with an estimated T c of 390 and 560 K, respectively.