Electronic structures and magnetic stabilities of 2D Mn-doped GaAs nanosheets: The role of long-range exchange interactions and doping strategies

We investigate the structural, electronic and magnetic properties of Mn atoms doped two-dimensional (2D) hexagonal GaAs nanosheets (GaAsNSs) using both first-principle calculations and Monte Carlo simulations. The first-principle molecular dynamics is first used to test the structural stability of Mn-doped GaAsNS ((Ga,Mn)AsNS). The analysis of spin-resolved electronic structures and determination of magnetic exchange interactions based on density functional theory (DFT) calculations reveals the existence of long-range exchange interaction in the system. Finally, Metropolis Monte Carlo simulation is employed to estimate Curie temperatures (T(C)s) of (Ga, Mn) AsNSs with different doping concentrations by different doping strategies. The results indicate that a T-C up to 82K can be obtained in regularly-doped (Ga,Mn) AsNSs and doping strategies have prominent impact on T(C)s of the systems, which emphasizes the importance of both long-range interactions and doping strategies in reduced dimensional diluted magnetic semiconductors (DMSs). (C) 2014 AIP Publishing LLC.