Atomically thin dilute magnetism in Co-doped phosphorene

Abstract

Two-dimensional dilute magnetic semiconductors can provide fundamental insights into the very nature of magnetic order and their manipulation through electron and hole doping. Besides the fundamental interest, due to the possibility of control of charge density, they can be extremely important in spintronics applications such as spin valve and spin-based transistors. In this paper, we studied a two-dimensional dilute magnetic semiconductor consisting of a phosphorene monolayer doped with cobalt atoms in substitutional and interstitial defects. We show that these defects can be stabilized and are electrically active. Furthermore, by including holes or electrons by a potential gate, the exchange interaction and magnetic order can be engineered, and may even induce a ferromagnetic-to-antiferromagnetic phase transition in $p$-doped phosphorene. At a Co concentration of 2.7%, we estimate a Curie temperature of ${T}_{\text{C}}^{MFA}=466$ K in the mean-field approximation.