Magnetic and optical properties of (Mn, Co) co-doped SnO2

Based on density functional theory approach within the GGA + U methods, the magnetic and optical properties of (Mn, Co) co-doped SnO2 system are investigated. The results show that the local magnetic moments of Mn atom and Co atom in Mn monodoped SnO2 and Co monodoped SnO2 systems are 3.05 mu(B) and 0.76 mu(B), respectively. For the (Mn, Co) co-doped SnO2 system, the ferromagnetic state is more stable than the anti-ferromagnetic state with AE of 133 meV. The ferromagnetism of (Mn, Co) co-doped SnO2 comes from the strong hybridization between Mn:3d, Co:3d and O:2p orbitals. Moreover, the band gap becomes narrower with transition metal (TM = Mn, Co atom) introduced to SnO2 system. In the visible light range, the adsorption strength of transition metal (TM = Mn, Co atom) introduce to SnO2 system is obviously enhanced. These results provide a new mute for the potential applications of dilute magnetic semiconductors in spintronic devices by transition metal (TM = Mn, Co atom) doped SnO2.