A study on native defects and magnetic properties in undoped rutile TiO₂ using LDA and LDA+U_Op+U_Tid methods

The native defects and magnetic properties in undoped rutile TiO₂ are studied using local density approximation (LDA) and LDA adding Hubbard parameters (U) schemes. The band gap is adjusted to experimental value of 3.0 eV by combination of U_Tid=4.2 eV and U_Op=4.8 eV. This LDA+U methodology overcomes the band-gap problem and renders the approach more predictive. The formation energies of oxygen vacancy (V_O), oxygen interstitial (O_i), titanium vacancy (V_Ti), titanium interstitial (Ti_i), oxygen anti-sites (O_Ti), and titanium anti-sites (Ti_O) are investigated by the LDA and LDA+U methods. In addition, some ground state configurations can be obtained by optimization of total spin. It is found that native defects can induce spin polarization and produce magnetic moment. - Highlights: • The formation and ionization energies of native defects in undoped TiO₂ are investigated. • Some ground state configurations are obtained by optimization of total spin. • Impact of native defects on magnetic moment is discussed.