Materials Data on MgCrFeO4 by Materials Project

Abstract

MgFeCrO4 is Spinel-derived structured and crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with six equivalent CrO6 octahedra and corners with six equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 58–59°. There are two shorter (2.00 Å) and two longer (2.01 Å) Mg–O bond lengths. Cr3+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six equivalent MgO4 tetrahedra, edges with two equivalent CrO6 octahedra, and edges with four equivalent FeO6 octahedra. All Cr–O bond lengths are 2.04 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent MgO4 tetrahedra, edges with two equivalent FeO6 octahedra, and edges with four equivalent CrO6 octahedra. All Fe–O bond lengths are 2.05 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to one Mg2+, two equivalent Cr3+, and one Fe3+ atom to form a mixture of distorted corner and edge-sharing OMgCr2Fe trigonal pyramids. In the second O2- site, O2- is bonded to one Mg2+, one Cr3+, and two equivalent Fe3+ atoms to form a mixture of distorted corner and edge-sharing OMgCrFe2 trigonal pyramids.