Room temperature ferromagnetism in N-doped rutile TiO2 films

Room temperature ferromagnetism has been experimentally observed in TiO2:N films prepared by pulse laser deposition under N2O atmosphere. The ferromagnetism appears when the N2O partial pressure is higher than 10−5 Torr. XPS study has revealed that N substitutes O at the partial pressure of 10−5 Torr, whereas additional N atoms occupy interstitial sites besides substituting N at higher N2O partial pressures. Our study indicates that the origin of the ferromagnetism is the O substitution with N. Each substituted N has a magnetic moment of approximately 0.9 μB. The substitution of O also resulted in p-type behavior, accompanied with magnetoresistance and anomalous Hall effect.