Promising electronic structure of double perovskite Sr₂TiMoO₆: Spin-polarized DFT+U approach

The electronic structure of double perovskite Sr₂TiMoO₆ have been systematically investigated using first principle. The spin-polarized electronic band structure and the density of states reveal that the spin-up channel has metal behavior while the spin-down channel expresses semiconductor behavior with direct band gap of 2.92 eV. For valence band, the O-2p states is the mainly contributor for both spin-up and spin-down channels above -5.3eV. Between -7.7eV to -5.3eV, valence band is formed by O-2p states with admixture of Mo-4d states. For conduction band, from range 4 eV to 7.4 eV is mostly formed by Sr-3d. On the other hand, O-2p, Mo-4d as well as Ti-3d states mainly consists of the conduction band near Fermi energy, so those states need to be more concerned. The spin splitting may lead to unusual thermoelectric transport properties. (paper)