The effect of oxygen vacancy on the half-metallic nature of double perovskite Sr2FeMoO6: A theoretical study

The effect of oxygen vacancy on the half-metallic characteristic of perovskite oxide Sr2FeMoO6 has been investigated using density-functional calculations. The results reveal that the compounds behave as half-metal in the whole range of oxygen vacancies discussed in this work, and the energy gap in the spin-up channel decreases with increasing the content of oxygen vacancy. For all compounds, the electronic configurations of Fe and Mo ions are in the high-spin and intermediate-spin states, respectively. With increasing the content of oxygen vacancy, the magnetic moment of Fe ion decreases and that of Mo ion increases. The above fact hints that Sr2FeMoO6−δ possesses half-metallic nature in a large range of δ, which may open a promising way to experimentally synthesize the practical half-metal with a few ineluctable oxygen vacancies.