The Effect of d-orbital Electrons of Transition Metals on the Electronic and Magnetic Properties of GaN:TM (TM: Cr, Mn, Fe, Co)

Based on the density functional theory and using the plane wave pseudopotential method, we study the effect of number of d-orbital electrons on the electronic and magnetic properties of GaN:TM (TM: Cr, Mn, Fe, Co). We consider the TM impurity in the samples studied to be 6.25%. Self- and non-self-consistent calculations are performed to calculate the density of states (DOSs) of the samples. Our results show that doping magnetic ions on the host semiconductor can induce spin polarization in the band gap of the doped sample. Cr and Mn doping leads to the ferromagnetic phase, while Fe and Co doping leads to the anti-ferromagnetic phase. In other words, as the number of d-orbital electrons increase, a transition from ferromagnetic to antiferromagnetic phase is observed. Besides, the gap between the valence band and the non-bonding states of the d-orbitals is reduced, and a reverse behavior is observed for the gap between the conduction band and the antibonding states of the d-orbitals. In addition, the magnetic moment of each transition metal is calculated.