Electronic structures and optic properties of Fe2TiO5 using LSDA+U approach

The magnetic properties, band structure, density of states (DOS) and optical properties of ferromagnetic Fe2TiO5 were calculated by a plane wave pseudopotential method based on the local spin density approximation (LSDA) and the LSDA plus Hubbard U (LSDA+U) theory and compared with the known experimental and theoretical results. By choosing the opportune Hubbard U parameter 4 eV, LSDA+U gives magnetic moments of 3.80 µB/Fe (3d orbital), which contribute the main magnetic moments to Fe2TiO5. The inclusion of U changes the band gap of Fe2TiO5 and gives a value in better agreement with previous experiment. We find that strong correlations dramatically change the density of states and band structures. A detailed analysis shows that the LSDA+U method provides the better description of electronic structures like this system. Series optical properties were explored also. There is no ab-initio study related to Fe2TiO5 at present. These findings provide good theoretical understanding for Fe2TiO5.