DOE OSTI2020
Sr2Fe23O38 is beta indium sulfide-derived structured and crystallizes in the triclinic P1 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 distorted SrO12 cuboctahedra that share corners with six equivalent SrO12 cuboctahedra, edges with six FeO6 octahedra, edges with three equivalent FeO5 trigonal bipyramids, and faces with six FeO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.78–3.00 Å. In the second Sr site, Sr is bonded to twelve O atoms to form distorted SrO12 cuboctahedra that share corners with six equivalent SrO12 cuboctahedra, edges with six FeO6 octahedra, and faces with six FeO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.82–3.05 Å. There are twenty-three inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three FeO4 tetrahedra, a cornercorner with one FeO5 trigonal bipyramid, an edgeedge with one SrO12 cuboctahedra, and edges with five FeO6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of Fe–O bond distances ranging from 1.94–2.15 Å. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three FeO4 tetrahedra, a cornercorner with one FeO5 trigonal bipyramid, an edgeedge with one SrO12 cuboctahedra, and edges with five FeO6 octahedra. The corner-sharing octahedra tilt angles range from 52–53°. There are a spread of Fe–O bond distances ranging from 1.95–2.13 Å. In the third Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six FeO6 octahedra, faces with three equivalent SrO12 cuboctahedra, and a faceface with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 50–53°. There are a spread of Fe–O bond distances ranging from 1.86–2.03 Å. In the fourth Fe site, Fe is bonded to four O atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–61°. There is three shorter (1.93 Å) and one longer (1.95 Å) Fe–O bond length. In the fifth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three FeO4 tetrahedra, a cornercorner with one FeO5 trigonal bipyramid, an edgeedge with one SrO12 cuboctahedra, and edges with five FeO6 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Fe–O bond distances ranging from 1.92–2.06 Å. In the sixth Fe site, Fe is bonded to six O atoms to form distorted FeO6 octahedra that share corners with six FeO6 octahedra, faces with three equivalent SrO12 cuboctahedra, and a faceface with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are a spread of Fe–O bond distances ranging from 1.95–2.06 Å. In the seventh Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra and edges with six FeO6 octahedra. There is four shorter (1.97 Å) and two longer (1.98 Å) Fe–O bond length. In the eighth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.01–2.05 Å. In the ninth Fe site, Fe is bonded to five O atoms to form FeO5 trigonal bipyramids that share corners with twelve FeO6 octahedra and edges with three equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 39–64°. There are a spread of Fe–O bond distances ranging from 1.88–2.34 Å. In the tenth Fe site, Fe is bonded to four O atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–60°. There are a spread of Fe–O bond distances ranging from 1.91–1.95 Å. In the eleventh Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three FeO4 tetrahedra, a cornercorner with one FeO5 trigonal bipyramid, an edgeedge with one SrO12 cuboctahedra, and edges with five FeO6 octahedra. The corner-sharing octahedra tilt angles range from 52–53°. There are a spread of Fe–O bond distances ranging from 1.95–2.13 Å. In the twelfth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three FeO4 tetrahedra, a cornercorner with one FeO5 trigonal bipyramid, an edgeedge with one SrO12 cuboctahedra, and edges with five FeO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Fe–O bond distances ranging from 1.95–2.14 Å. In the thirteenth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three FeO4 tetrahedra, a cornercorner with one FeO5 trigonal bipyramid, an edgeedge with one SrO12 cuboctahedra, and edges with five FeO6 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Fe–O bond distances ranging from 1.92–2.05 Å. In the fourteenth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three FeO4 tetrahedra, an edgeedge with one SrO12 cuboctahedra, and edges with five FeO6 octahedra. The corner-sharing octahedra tilt angles range from 52–53°. There are a spread of Fe–O bond distances ranging from 1.90–2.14 Å. In the fifteenth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three FeO4 tetrahedra, an edgeedge with one SrO12 cuboctahedra, and edges with five FeO6 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Fe–O bond distances ranging from 1.92–2.18 Å. In the sixteenth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six FeO6 octahedra, corners with three equivalent FeO5 trigonal bipyramids, faces with three equivalent SrO12 cuboctahedra, and a faceface with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of Fe–O bond distances ranging from 2.01–2.09 Å. In the seventeenth Fe site, Fe is bonded to four O atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–60°. There are a spread of Fe–O bond distances ranging from 1.93–1.95 Å. In the eighteenth Fe site, Fe is bonded to four O atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–60°. There is two shorter (1.93 Å) and two longer (1.95 Å) Fe–O bond length. In the nineteenth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six FeO6 octahedra, corners with three equivalent FeO5 trigonal bipyramids, faces with three equivalent SrO12 cuboctahedra, and a faceface with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 52–53°. There are a spread of Fe–O bond distances ranging from 2.00–2.09 Å. In the twentieth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three FeO4 tetrahedra, an edgeedge with one SrO12 cuboctahedra, and edges with five FeO6 octahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Fe–O bond distances ranging from 1.96–2.15 Å. In the twenty-first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three FeO4 tetrahedra, an edgeedge with one SrO12 cuboctahedra, and edges with five FeO6 octahedra. The corner-sharing octahedra tilt angles range from 51–52°. There are a spread of Fe–O bond distances ranging from 1.93–2.15 Å. In the twenty-second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three FeO4 tetrahedra, an edgeedge with one SrO12 cuboctahedra, and edges with five FeO6 octahedra. The corner-sharing octahedra tilt angles range from 50–51°. There are a spread of Fe–O bond distances ranging from 1.93–2.16 Å. In the twenty-third Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three FeO4 tetrahedra, an edgeedge with one SrO12 cuboctahedra, and edges with five FeO6 octahedra. The corner-sharing octahedra tilt angles range from 50–53°. There are a spread of Fe–O bond distances ranging from 1.96–2.15 Å. There are thirty-eight inequivalent O sites. In the first O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the second O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the third O site, O is bonded in a 4-coordinate geometry to one Sr and three Fe atoms. In the fourth O site, O is bonded in a 4-coordinate geometry to one Sr and three Fe atoms. In the fifth O site, O is bonded in a distorted L-shaped geometry to two equivalent Sr and two Fe atoms. In the sixth O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the seventh O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the eighth O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the ninth O site, O is bonded in a trigonal non-coplanar geometry to three Fe atoms. In the tenth O site, O is bonded in a trigonal non-coplanar geometry to three Fe atoms. In the eleventh O site, O is bonded to four Fe atoms to form a mixture of distorted edge and corner-sharing OFe4 tetrahedra. In the twelfth O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the thirteenth O site, O is bonded to four Fe atoms to form distorted corner-sharing OFe4 trigonal pyramids. In the fourteenth O site, O is bonded in a distorted L-shaped geometry to two equivalent Sr and two Fe atoms. In the fifteenth O site, O is bonded in a 4-coordinate geometry to one Sr and three Fe atoms. In the sixteenth O site, O is bonded in a 4-coordinate geometry to one Sr and three Fe atoms. In the seventeenth O site, O is bonded in a distorted L-shaped geometry to two equivalent Sr and two Fe atoms. In the eighteenth O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the nineteenth O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the twentieth O site, O is bonded in a 4-coordinate geometry to one Sr and three Fe atoms. In the twenty-first O site, O is bonded in a 4-coordinate geometry to one Sr and three Fe atoms. In the twenty-second O site, O is bonded in a 4-coordinate geometry to one Sr and three Fe atoms. In the twenty-third O site, O is bonded in a 4-coordinate geometry to one Sr and three Fe atoms. In the twenty-fourth O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the twenty-fifth O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the twenty-sixth O site, O is bonded in a 5-coordinate geometry to two equivalent Sr and three Fe atoms. In the twenty-seventh O site, O is bonded in a 4-coordinate geometry to one Sr and three Fe atoms. In the twenty-eighth O site, O is bonded in a 4-coordinate geometry to one Sr and three Fe atoms. In the twenty-ninth O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the thirtieth O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the thirty-first O site, O is bonded in a 5-coordinate geometry to two equivalent Sr and three Fe atoms. In the thirty-second O site, O is bonded in a rectangular see-saw-like geometry to four Fe atoms. In the thirty-third O site, O is bonded in a rectangular see-saw-like geometry to four Fe atom