Materials Data on Mg2Fe7O12 by Materials Project

Abstract

Mg2Fe7O12 is Spinel-like structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six FeO4 tetrahedra, an edgeedge with one MgO6 octahedra, and edges with five FeO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.09–2.11 Å. There are five inequivalent Fe+2.86+ sites. In the first Fe+2.86+ site, Fe+2.86+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with four equivalent MgO6 octahedra and corners with eight FeO6 octahedra. The corner-sharing octahedra tilt angles range from 55–59°. There is two shorter (1.92 Å) and two longer (1.97 Å) Fe–O bond length. In the second Fe+2.86+ site, Fe+2.86+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with four equivalent MgO6 octahedra and corners with eight FeO6 octahedra. The corner-sharing octahedra tilt angles range from 55–58°. There are a spread of Fe–O bond distances ranging from 1.92–1.97 Å. In the third Fe+2.86+ site, Fe+2.86+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra, edges with two equivalent MgO6 octahedra, and edges with four FeO6 octahedra. There are four shorter (2.13 Å) and two longer (2.14 Å) Fe–O bond lengths. In the fourth Fe+2.86+ site, Fe+2.86+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra, edges with three equivalent MgO6 octahedra, and edges with three FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.03–2.07 Å. In the fifth Fe+2.86+ site, Fe+2.86+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra, edges with two equivalent MgO6 octahedra, and edges with four FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.04–2.08 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe+2.86+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Fe+2.86+ atoms. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Fe+2.86+ atoms. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Fe+2.86+ atoms. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg2+ and two Fe+2.86+ atoms. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Fe+2.86+ atoms.