Effects of oxygen vacancy on the magnetic properties of Cr-doped SnO2: Density functional investigation

Magnetic properties of Cr-doped SnO₂ and the effects of oxygen vacancy (V_O) on the magnetic properties are examined to understand the origin of ferromagnetism in Cr-doped SnO₂ and explain the observed discrepant phenomena. Cr-doped SnO₂ shows a p-d hopping ferromagnetic interaction that decreases gradually with the increase in Cr-Cr distance. In Cr-doped SnO₂ with V_O, ferromagnetic interaction is obviously weakened. Exchange constants indicate that the ferromagnetic exchange interaction in Cr-doped SnO₂ is similar to that in Co-doped SnO₂, while it is similar to that in Fe-doped SnO₂ and/or undoped SnO₂ with tin vacancy (V_Sn) in the presence of V_O.