Ferromagnetism in Mo-doped TiO2 Rutile from Ab Initio Study

Abstract

First-principles calculations based on spin density functional theory (DFT) within the general gradient approximation (GGA) are performed to study the spin-resolved electronic properties of TiO2 Rutile doped with 6.25 and 12.5% of Mo. The Mo impurity is found spin polarized and the calculated band structures suggest a 100% polarization of the conduction carriers. The local moment of Molybdenum is slightly dependent on its concentration. The Fermi level is shifted to the bottom of the conduction band with increasing concentration of Mo. This leads to the increase of states density, just above the Fermi level, and consequently the 4d orbitals are strongly hybridized with Ti 3d ones to form a d-nature conduction band, without impurity states in the in-gap region. The Mo-doped TiO2 favors ferromagnetic ground state which can be explained in terms of p–d hybridization mechanism for 6.25% of Mo, this mechanism depends on the Mo concentration. This suggests that the Mo-doped TiO2 is a promising dilute magnetic semiconductor and may find applications in the field of spintronics.