Near- or Above-Room-Temperature Two-Dimensional Ferromagnetic Fe-M-Te (M = Ge, Ga) Compounds for van der Waals Spintronics

Two-dimensional (2D) van der Waals (vdW) ferromagnets are promising for the development of novel physical paradigms and next-generation spintronics. However, their practical applications are limited by a low Curie temperature (TC) and the strong thickness dependence of TC, which decreases significantly toward the 2D limit. 2D Fe-M-Te (M = Ge, Ga) compounds have emerged as key platforms, exhibiting intrinsic ferromagnetism below but near room temperature in few-layer Fe-Ge-Te and above room temperature in few-layer Fe-Ga-Te. This review discusses their recent advances and challenges, especially about the first well above-room-temperature intrinsic 2D vdW ferromagnet Fe3GaTe2 which makes room-temperature practical 2D spintronic and quantum devices possible. The preparation and properties are first summarized, followed by magnetism regulation strategies (e.g., doping, pressure, electrical control, and interfacial engineering) and vdW spintronics (e.g., topological spin textures, vertical spin valves, and spin/orbital torque devices). Finally, some fundamental and technological challenges are highlighted, providing insights into room-temperature spintronics based on vdW ferromagnets.