Magnetoelectronic properties of GaN codoped with (V, Mn) impurities for spintronic devices: Ab-initio and Monte Carlo studies

In this work, we investigate the Magnetoelectronic properties of (V, Mn) codoped GaN using first principles calculations (FPCs) for the spintronic applications. We have obtained the ferromagnetic behavior in (Ga, V)N codoped with Mn atoms, which is believed to be caused by the double exchange mechanism. Moreover, it is observed that our system is halfmetallic at the Fermi level, with 100% spin polarization. The total magnetic moment of (V, Mn) codoped GaN is mainly originated from the V and Mn atoms, and the magnetic moment of V impurities rises with the concentration of V atoms while keeping constant that of the Mn atoms. In addition to that, the exchange coupling is obtained from FPCs and using the Ising model. The Monte Carlo method founded on the Heat Bath algorithm support our FPCs, by investigating the influence of the addition of Mn impurities to (Ga, V)N compound on the critical temperature TCMC, the magnetization per site M, the magnetic susceptibility χ and the specific heat CV. We have found that TCMC is above room temperature as well as the stability of the ferromagnetic state in (Ga, V)N becomes more important after the inclusion of the Manganese.