Materials Data on Sr8Fe4Co4O23 by Materials Project

Abstract

Sr8Co4Fe4O23 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Sr sites. In the first Sr site, Sr is bonded in a distorted q6 geometry to eleven O atoms. There are a spread of Sr–O bond distances ranging from 2.66–2.90 Å. In the second Sr site, Sr is bonded to twelve O atoms to form SrO12 cuboctahedra that share corners with six equivalent SrO12 cuboctahedra, faces with two equivalent SrO12 cuboctahedra, faces with two equivalent CoO6 octahedra, faces with four equivalent FeO6 octahedra, and faces with two equivalent CoO5 square pyramids. There are a spread of Sr–O bond distances ranging from 2.64–2.93 Å. Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with two equivalent CoO6 octahedra, corners with two equivalent CoO5 square pyramids, and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–11°. There are a spread of Fe–O bond distances ranging from 1.95–2.08 Å. There are two inequivalent Co sites. In the first Co site, Co is bonded to five O atoms to form CoO5 square pyramids that share corners with four equivalent FeO6 octahedra, a cornercorner with one CoO5 square pyramid, and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 15°. There is four shorter (1.86 Å) and one longer (1.87 Å) Co–O bond length. In the second Co site, Co is bonded to six O atoms to form CoO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with four equivalent FeO6 octahedra, and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There is four shorter (1.93 Å) and two longer (1.94 Å) Co–O bond length. There are five inequivalent O sites. In the first O site, O is bonded in a 6-coordinate geometry to four Sr, one Fe, and one Co atom. In the second O site, O is bonded in a 6-coordinate geometry to four Sr and two equivalent Fe atoms. In the third O site, O is bonded to four Sr, one Fe, and one Co atom to form a mixture of distorted face, edge, and corner-sharing OSr4FeCo octahedra. The corner-sharing octahedra tilt angles range from 0–60°. In the fourth O site, O is bonded in a distorted linear geometry to four equivalent Sr and two equivalent Co atoms. In the fifth O site, O is bonded to four Sr and two equivalent Co atoms to form distorted OSr4Co2 octahedra that share corners with two equivalent OSr4Co2 octahedra and faces with eight equivalent OSr4FeCo octahedra. The corner-sharing octahedral tilt angles are 0°.