A GGA + U investigation into the effects of cations on the electromagnetic properties of transition metal spinels

Abstract

Spinel oxides are promising low-cost catalysts with manifold and controllable physicochemical properties. Trial and error strategies cannot achieve the effective screening of high-performance spinel catalysts. Therefore, unraveling the structure-performance relationship is the foundation for their rational design. Herein, the effects of cations in tetrahedral and octahedral sites on the electronic structures of spinels were systematically investigated using GGA + U calculations based on ACr2O4(A = Mn, Fe, Co, Ni, and Zn) and Zn/LiB2O4(B = Cr, Mn, Fe, Co and Ni). The results indicate that the octahedrally coordinated B cations have notable influence on the electronic structures of spinels. The Jahn-Teller active ions Fe2+, Ni2+, Mn3+, Ni3+, Cr4+and Fe4+can remarkably reduce the band gaps of spinels and even change their electroconductibilities. These results will provide theoretical insights into the electronic properties of 3d transition metal spinels.