The Magnetic Properties of Transition-Metal Atom Adsorbed Two Dimensional GaAs Nanosheet

By using first-principles calculations within the framework of density functional theory,[1] the magnetic properties of 3d transitional metal (TM) atoms (from Sc to Zn) adsorbed two dimensional (2D) GaAs nanosheets (GaAsNSs) are systematically investigated. The 2D GaAsNS is composed of 16 Ga and 16 As atoms, which are repeated along the x-and y-directions. 3d TM atoms adsorbed on hollow site (center of the hexagonal ring formed by 3 Ga and 3 As atoms). [2]–[3] Upon TM atom adsorption, GaAsNS, which is a nonmagnetic semiconductor, with an estimated gap of 1.29 eV[4] can be tuned into a magnetic semiconductor (Sc, V, and Fe adsorption), a half-metal (Mn adsorption), or a metal (Co and Cu adsorption). The magnetic moment of Sc, V, Fe and Mn adsorbed GaAsNS is 1 $\mu_{\text{B}}, 1\ \mu_{\text{B}}, 1\ \mu_{\text{B}}$ and 2 $\mu_{\text{B}}$ respectively. Our calculations show that the strong p-d hybridization between 3d orbit of TM atoms and 4p orbit of neighboring As atoms is responsible for the formation of chemical bonds and the origin of magnetism in the GaAsNSs with Sc, V and Fe adsorption. However, Mn 3d orbit with more unpaired electrons hybridizes with not only As 4p but also Ga 4p orbits, resulting in a stronger exchange interaction. Our results may be useful for electronic and magnetic applications of GaAsNS-based materials. Fig. 1. Bandstructure of fe and mn adsorbed gaasns