title: Electronic structure and magnetic couplings in anatase TiO(2):V codoped with N, F, Cl.
abstract: Using first-principles calculations, we have discussed the stability of the defect charge state and magnetic properties of V(Ti) defects in anatase TiO(2). While N, F, and Cl are typical nonmetal dopants for photocatalytic activity enhancement of TiO(2), their influence on the magnetism of TiO(2):V is also investigated. We find that V(Ti)(+) (i.e. V(5+)) would be favored in the p-type region and V(Ti)(0) (i.e. V(4+)) and V(Ti)(-) (i.e. V(3+)) would be stable in the n-type region. It is demonstrated that while V(5+) does not carry any local moment, both V(4+) and V(3+) defects are preferred to ferromagnetic ordering. Thus, n-type dopants (such as F and Cl) in TiO(2):V samples, which could stabilize V as V(3+), are suggested for their many applications requiring combined magnetic and optical functionality, while p-type dopants (such as N) are not suggested.
authors.affiliation: School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Dan
authors.initials: D
authors.lastname: Huang
authors.forename: Yu-Jun
authors.initials: YJ
authors.lastname: Zhao
authors.forename: Di-Hu
authors.initials: DH
authors.lastname: Chen
authors.forename: Yuan-Zhi
authors.initials: YZ
authors.lastname: Shao