Effects of defects and anions on the geometry, electronic structures and exchange interaction of Fe-doped 2H-MoSe2 monolayer

Abstract

The stability, electronic structure and magnetic properties of Fe doped, Fe-VSe and Fe-NM (NM = B, N) codoped 2H-MoSe2 monolayers with a high concentration of 12.5% are systematically investigated using first-principles calculations. The results show that the Fe dopants are coupled ferromagnetically via p-d exchange mechanism with high d4 spin configuration in the zigzag direction, ascribing to the antiferromagnetic coupling between the localized Fe 3d orbitals and delocalized Se 4p orbitals. Due to large distortion around Fe dopants, the introducing of Se vacancy alters the trigonal prismatic coordination field and causes Hund’s exchange splitting of Fe 3d orbitals, further leading to obvious ferromagnetic coupling and high ferromagnetic stability (ΔEFM-AFM = −724.0 meV) for the Fe-VSe codoped MoSe2 configurations. The non-compensated Fe-NM (NM = B, N) codoping can largely enhance the total moments and structural stability of Fe-doped MoSe2 monolayer due to strong electrostatic attraction and synergistic interaction of anionic dopants. The Fe-doped MoSe2 monolayer is an attractive route to achieve stable room temperature spintronic devices by precise control of synthesis conditions, such as the introducing of Se vacancies and nonmagnetic elements.