Electronic and magnetic properties of double-impurities-doped TiO ₂ (rutile): First-principles calculations

The electronic and magnetic properties of double-impurities-doped TiO2 (rutile) are explored using first-principles calculations within the generalized gradient approximation to examine their potential use as spintronic system. Calculations are performed on all possible sets of double impurities (M1 and M2) from M1 =Cr, Mn, Fe, Co, and Ni, and M2 =Mo, W, and Re. The results show the overlapping of the highest occupied impurity states with the bottom of the conduction band of the host system and the half-metallic nature in Fe- and W-doped TiO2, making them suitable as spintronic systems. These impurities preferentially substitute adjacent Ti sites and form a stable magnetic complex with oxygen atoms.