Effects of single oxygen vacancy on electronic structure and ferromagnetism for V-doped TiO2

The electronic structure and ferromagnetism of V-doped rutile and anatase TiO2 without vacancy and with single oxygen vacancy are studied by means of first principle calculations based on the density- functional theory and pseudopotential method. It can be found that V-doped rutile and anatase TiO2 undergo a transition from half-metallic behaviour to metallic behaviour when single oxygen is taken away. The total magnetic moments are obtained for all cases, and have a giant increase when single oxygen is taken away for V-doped rutile and anatase TiO2. (C) 2007 Elsevier Ltd. All rights reserved.