Materials Data on Fe2NiO4 by Materials Project

Abstract

NiFe2O4 is Spinel-like structured and crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. there are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with six equivalent FeO6 octahedra and corners with six equivalent NiO6 octahedra. The corner-sharing octahedra tilt angles range from 56–57°. There is two shorter (1.90 Å) and two longer (1.93 Å) Fe–O bond length. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent FeO6 octahedra, and edges with four equivalent NiO6 octahedra. There are two shorter (2.02 Å) and four longer (2.05 Å) Fe–O bond lengths. Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent NiO6 octahedra, and edges with four equivalent FeO6 octahedra. There are four shorter (2.08 Å) and two longer (2.09 Å) Ni–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Fe3+ and two equivalent Ni2+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Ni2+ atom.