Effects of dopant separation on electronic states and magnetism in monolayer MoS2

Abstract

Abstract The effects of vanadium (V) dopant on the electronic and magnetic properties of monolayer MoS2 are investigated by first-principles calculation. The substitutionally doped V produces antiferromagnetic (AFM) or ferromagnetic (FM) states depending on the separation between V dopants. When the separation between V dopants is smaller than 6.38 A and the maximum dopant concentration is 25%, the superexchange interaction between V atoms is stronger than the double exchange interaction between the localized V 3d orbitals and Mo 4d orbitals, resulting in the AFM state in monolayer MoS2. However, the double exchange interaction between the V and Mo atoms becomes stronger than the superexchange interaction between V atoms if the separation between V dopants is larger than 9.57 A when the maximum dopant concentration is 11.11%. Consequently, the FM state is observed from the monolayer MoS2 and 100% spin polarization takes place if the separation between V atoms is further increased to 12.76 A at a dopant concentration of 6.25%. The results suggest potential applications of monolayer MoS2 as diluted magnetic semiconductors (DMS) in spintronics.