Materials Data on Sr8Fe8O23 by Materials Project

Abstract

Sr8Fe8O23 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 to twelve O atoms to form SrO12 cuboctahedra that share corners with six equivalent SrO12 cuboctahedra, faces with two equivalent SrO12 cuboctahedra, faces with six FeO6 octahedra, and faces with two equivalent FeO5 square pyramids. There are a spread of Sr–O bond distances ranging from 2.63–2.97 Å. In the second Sr site, Sr is bonded in a 11-coordinate geometry to eleven O atoms. There are a spread of Sr–O bond distances ranging from 2.66–2.93 Å. There are four inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six FeO6 octahedra and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Fe–O bond lengths are 1.96 Å. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four FeO6 octahedra, corners with two equivalent FeO5 square pyramids, and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–13°. There are a spread of Fe–O bond distances ranging from 1.96–2.05 Å. In the third Fe site, Fe is bonded to five O atoms to form FeO5 square pyramids that share corners with four equivalent FeO6 octahedra, a cornercorner with one FeO5 square pyramid, and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 16°. There is four shorter (1.91 Å) and one longer (1.92 Å) Fe–O bond length. In the fourth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six FeO6 octahedra and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Fe–O bond lengths are 1.96 Å. There are five inequivalent O sites. In the first O site, O is bonded to four Sr and two equivalent Fe atoms to form a mixture of distorted face and corner-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O site, O is bonded to four Sr and two Fe atoms to form a mixture of distorted edge, face, and corner-sharing OSr4Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–61°. In the third O site, O is bonded in a 6-coordinate geometry to four Sr and two equivalent Fe atoms. In the fourth O site, O is bonded in a 6-coordinate geometry to four Sr and two Fe atoms. In the fifth O site, O is bonded to four equivalent Sr and two equivalent Fe atoms to form distorted corner-sharing OSr4Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–61°.