Magnetic properties of SrFe0.5Nb0.5O3 regulated by cationic vacancy

Based on the first principles, the parent and configurations of SrFe 0.5 Nb 0.5 O 3 containing cationic vacancies are built by using Materials Studio software, and the CASTEP module is chosen to investigate the effect of A-site or B-site cationic vacancy on the structural and magnetic properties. All the configurations are optimized by LDA+CA-PZ correlation function, and the stable geometries are obtained as the research foundation. The calculated results indicates that the configuration changes to conductor from semiconductor and the band gap decreases into 0.00eV from 0.528eV owing to the introduction of cationic vacancies. SrFe 0.5 Nb 0.5 O 3 with cationic vacancies exhibits magnetic properties, because below Fermi energy level, the spin up and spin down total density of states are asymmetrical relative to the energy symmetry axis, indicating that the cationic vacancy does produce magnetic properties. According to the conservation of valence, the molar content of Fe ³⁺ and Fe ⁴⁺ ions are obtained, and the theoretical magnetic moment calculated by parallel arrangement of their magnetic moment is larger than that obtained by the analysis of the density of states, indicating there is an angle between the Fe ³⁺ and Fe ⁴⁺ ions. The cationic vacancy acting as p-type dopants and as a negative charge center influences the charge density, different charge density, and electron localization function of the materials, indicating potentially application in regulating the electrical transport properties of double perovskite materials.