Distribution and magnetization of Co impurities in anatase TiO2 -: art. no. 060402

Using the first-principles density-functional approaches, impurity distributions and magnetic properties of Co-doped anatase TiO2 were investigated. From the total energies calculated for various possible configurations, Co atoms were found to prefer the non-uniform doping mode with short Co-Co distances. This non-uniform distribution furthermore is crucial for the ferromagnetic ordering observed in CoxTi1-xO2, whereas the antiferromagnetic state prevails in uniformly doped cases investigated (x=0.0625). Large exchange parameters appear to explain high T-c.