Theoretical Perspective of Fe-Induced Ferromagnetism in Antimonene: A Hybrid Functional Study

Using the Heyd-Scuseria-Ernzerhof hybrid functional method, we present a systematic study on the electronic and magnetic properties of Fe-doped antimonene. One and two Fe substitutions in an 8 x 8 supercell of antimonene are examined, and the thermodynamic and kinetic stability of Fe dopants in antimonene is thoroughly addressed. Results show that with a single Fe dopant in antimonene, the spins on the dopant are parallel to the induced spins on the surrounding Sb atoms via the hybridization between Sb 5p and Fe 3d orbitals, giving rise to ferromagnetism. Two Fe dopants in antimonene tend to stay at the substitutional sites next nearest to each other via the strong attraction, leading to the formation of the Fe-Sb-Fe cluster. With such a cluster, apart from the p-d hybridization between Fe and the surrounding Sb atoms (like the case of a single Fe dopant), two Fe atoms are found to couple ferromagnetically to each other via the mediation of the common nearest Sb atom. The ferromagnetic mechanisms between two Fe dopants are discussed and analyzed. This work offers useful theoretical guidance for promoting the applications of antimonene to spintronics.