The electronic, magnetic, and optical properties of rutile Ti1-xTMxO2 (where TM: V, Fe, Co, Ni and x = 0.125) have been investigated by the density functional theory using the electron full-potential linearized-augmented-plane-wave method (FP-LAPW) by adopting WIEN2k code. Recently introduced Tran and Blaha’s modified Becke–Johnson (TB-mBJ) exchange potential and generalized gradient approximation (GGA ) correlation potential were used in the present work. All the calculations were performed using 24-atom supercell of rutile TiO 2 with one Ti atom replaced by a dopant transition metal atom. The energy gap obtained by TB-mBJ method agrees well with the experimental results. Further, the band structure of transition metal-doped rutile phase indicates the reduction of band gap leading to improvement in the optical properties of TiO 2 as well as enhancement in its magnetic properties. The observed magnetism is explained on the basis of spin polarization of d states of Ti with dopants. Optical properties such as dielectric function, refractive index, extinction coefficient, absorption, reflectivity, optical conductivity, and energy loss function as a function of photon energy were presented. These theoretical calculations gave a meaningful information and excellent prediction to develop TiO 2 for spintronics applications and photocatalytic applications in the visible region.
