First-principle study on the magnetic and optical properties of SnO2 doped with Fe2+/3+ and oxygen vacancies at different ratios

Abstract

The effects of different ratios of Fe2+/3+ and oxygen vacancy doping on the magneto-optical properties and mechanism of SnO2 have not been fully investigated. Therefore, the electronic structure and magneto-optical properties of SnO2 doped with different concentrations of Fe and oxygen vacancies were studied through geometry optimization and energy calculation in accordance with the first-principle generalized gradient approximation + U(GGA + U) method of density functional theory. The effects of changes in Fe2+/3+ and oxygen vacancy concentration on the electronic structure, energy, magnetic exchange mode, and optical absorption properties of SnO2 materials were explored. Calculation results showed that doping with different concentrations of Fe2+/3+ and oxygen vacancies made the stability and magnetic moment of the doping system vary. The comparison of several doping systems with the same high magnetic moment showed that the Sn22[Fe3+]2O46 system demonstrates the best stability and magnetic value. Doping with different concentrations of Fe2+/3+ and oxygen vacancies exerted varying effects on the energy band structure and optical properties of the doped system. The static dielectric constant of all doping systems increased, and the absorption band edge was red-shifted, which helped improve the photocatalytic activity of SnO2.