Mechanism of multi-defect induced ferromagnetism in undoped rutile TiO{sub 2}
- College of Mathematics, Physics and Information Science, Zhejiang Ocean University, Zhoushan 316000 (China)
- State Key Laboratory of Superhard Materials and Department of Physics, Jilin University, Changchun 130012 (China)
Based on first-principles calculations, the coexistence of Ti vacancies (V{sub Ti}) and O vacancies (V{sub O}) is first considered to study the origin of the ferromagnetic ordering in undoped rutile TiO{sub 2}. The calculations show that V{sub O} can induce local magnetic moments in TiO{sub 2}, however, the ferromagnetic (FM) exchange interaction of two V{sub O} is not strong enough to induce room-temperature (RT) ferromagnetism on their own in undoped TiO{sub 2}. The FM coupling between two V{sub Ti} is about four times stronger than that between two V{sub O}. More importantly, the FM coupling between two V{sub Ti} is further enhanced after V{sub O} is introduced. Our results indicate that the electrons induced by V{sub O} mediate the long-range FM exchange interaction between two distant V{sub Ti}. This maybe the ferromagnetism mechanism in undoped TiO{sub 2}: V{sub Ti} produce local moments while the electrons induced by V{sub O} mediated the long-range FM exchange interaction. The results are in excellent agreement with the experimental evidences that V{sub O} alone cannot induce RT ferromagnetism while V{sub O} can promote the ferromagnetic ordering in undoped TiO{sub 2}.
- OSTI ID:
- 22304016
- Journal Information:
- Journal of Applied Physics, Vol. 115, Issue 23; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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