Investigation of ferromagnetism in (Mn, Ga) co-doped LiNbO3 by density functional theory

Abstract

First-principles calculations are performed to investigate the electronic structures and magnetic properties of (Mn, Ga) co-doped LiNbO3. The results show that it is available to tune the magnetism of Mn mono-doped LiNbO3, and the spin-polarized states and the magnetic moments mainly come from the unpaired 3d orbitals of Mn atoms. Furthermore, corresponding to the two Mn doped LiNbO3 system. Eight kinds of Mn atom positions are reviewed and the most stable configuration is verified. Several doping configurations indicate the presence of anti-ferromagnetic (AFM) coupling between two Mn dopants. And then we calculated (2Mn, Ga) co-doped LiNbO3 system. The exciting results show that the existence of ferromagnetic (FM) coupling between Mn and Ga dopants. The results demonstrate that the doped Mn atom will induce additional electron carrier into the LiNbO3. Ga itself does not contribute to magnetism, while (Mn, Ga) co-doped LiNbO3 can induce spin-polarization, indicating that Ga dopant significantly increases FM stability.