The magnetic, electronic, optical, and structural properties of the AB2O4 (A = Mn, Fe, co; B = Al, Ga, In) spinels: Ab initio study

Abstract

The effect of cation composition on the magnetic, electronic, optical, and structural properties of the spinel oxides AB2O4 (A = Fe, Mn, Co; B = Al, Ga, In) were studied within DFT-GGA + U approximation. The spinels were considered both in the normal and inverse structure. FeB2O4 (B = Al, Ga, In) spinels have an inverse structure, whereas AB2O4 (A = Mn, Co; B = Al, Ga, In) prefer a normal structure. We find that the studied spinels are antiferromagnetic materials with the composition-dependent bandgap. The bandgap width is determined by the minimum of the conductive s-band formed by B-site cations states and can be increased by the applied pressure. The microscopic mechanisms of the relationship between composition, structural and electronic properties are analyzed. The ability to manipulate the structural, electronic, and optical properties is attributed to the different s-orbital energies and sizes of the B-site cations.