Magnetic, electronic and optical properties of SrFe12-xAlxO19 (x = 0.5; 1; 1.5) solid solutions by first principles

Abstract

This theoretical work presents magnetic, electronic and optical properties of SrFe12-xAlxO19 (x = 0.5; 1; 1.5) solid solutions using first-principles calculations based on density functional theory. A decrease in the magnetic properties of SrFe12O19 is predicted when doped with the Al ions. It was found that the Al ions preferentially replace Fe ions at 2a and 12k sites. On the other hand, SrFe11.5Al0.5O19 and SrFe11Al1O19 solid solutions behave like a semiconductor, while SrFe10.5Al1.5O19 solid solution showed a metallic response. From the optical analysis, incorporating the Al ions can benefit the polarizability of the medium. For the SrFe11.5Al0.5O19 (Al[2a]) and SrFe11Al1O19 (Al[2a-2a]) solid solutions, the incorporation of Aluminum ions results in the reduction of the gap, making it a more useful material for catalytic applications.