First principles study of the electronic and magnetic properties of (Co,Ga) co-doped LiNbO3

Abstract

Based on the density functional theory first-principles method, we have investigated the electronic structures and magnetic properties of Co mono-doped and (Co,Ga) co-doped LiNbO3 systems. The results demonstrate that Co mono-doped LiNbO3 favors a spin-polarized state. The total magnetic moment is 2.04μB, and the doped Co atom provides magnetic moments of 1.05μB. It is found that the 2Co doped LiNbO3 system is ferromagnetic at room temperature with ΔEFM of −34.6meV. Furthermore, for the (Co,Ga) co-doped LiNbO3 system, the ferromagnetic state is more stable than the anti-ferromagnetic state with ΔEFM of −172.4meV. It is intriguing that the ferromagnetic stability is increased significantly. Although Ga itself has no contribution to the magnetic moments, (Co,Ga) co-doped LiNbO3 can induce spin-polarization. These results provide a new route for the potential applications of dilute magnetic semiconductors in spintronic devices by employing (Co,Ga) co-doped LiNbO3.