High-Temperature Ferromagnetism in an FeP Monolayer with a Large Magnetic Anisotropy.

For the development of high-performance spintronic nanodevices, one of the most urgent and challenging tasks is the preparation of two-dimensional materials with room-temperature ferromagnetism and a large magnetic anisotropic energy (MAE). Through first-principles swarm-intelligence structural search calculations, we identify an ideal ferromagnetic FeP monolayer, in which Fe atoms show a perfect Kagome lattice, leading to strong in-plane Fe-Fe coupling. The predicted Curie temperature of FeP reaches ∼420 K, and its MAE is comparable to those of ferromagnetic materials, such as Fe and FeSi. Moreover, the FeP monolayer remains as an above room-temperature ferromagnet under biaxial strains as large as 10%. Its lattice can be retained at temperatures of ≤1000 K, exhibiting a high thermodynamic stability. All of these desirable properties make the FeP monolayer a promising candidate for applications in spintronic nanodevices.