Materials Data on BaFe12O19 by Materials Project

BaFe12O19 crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with six equivalent BaO12 cuboctahedra, edges with six FeO6 octahedra, edges with three equivalent FeO5 trigonal bipyramids, and faces with six FeO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.89–3.01 Å. There are eight inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- 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 BaO12 cuboctahedra, and edges with five FeO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are a spread of Fe–O bond distances ranging from 1.96–2.14 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- 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 BaO12 cuboctahedra, and edges with five FeO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are a spread of Fe–O bond distances ranging from 1.97–2.15 Å. In the third Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent FeO6 octahedra, corners with three equivalent FeO5 trigonal bipyramids, faces with three equivalent BaO12 cuboctahedra, and a faceface with one FeO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are three shorter (2.01 Å) and three longer (2.11 Å) Fe–O bond lengths. In the fourth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent FeO6 octahedra, corners with three equivalent FeO5 trigonal bipyramids, faces with three equivalent BaO12 cuboctahedra, and a faceface with one FeO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are three shorter (2.02 Å) and three longer (2.09 Å) Fe–O bond lengths. In the fifth Fe3+ site, Fe3+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–59°. There is three shorter (1.94 Å) and one longer (1.96 Å) Fe–O bond length. In the sixth Fe3+ site, Fe3+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–59°. All Fe–O bond lengths are 1.95 Å. In the seventh Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra and edges with six FeO6 octahedra. There are three shorter (2.03 Å) and three longer (2.04 Å) Fe–O bond lengths. In the eighth Fe3+ site, Fe3+ is bonded to five O2- atoms to form distorted FeO5 trigonal bipyramids that share corners with twelve FeO6 octahedra and edges with three equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 37–60°. There are a spread of Fe–O bond distances ranging from 1.90–2.48 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and three Fe3+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe3+ atoms. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe3+ atoms. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Ba2+ and three Fe3+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to four Fe3+ atoms. In the sixth O2- site, O2- is bonded in a distorted tetrahedral geometry to four Fe3+ atoms. In the seventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe3+ atoms. In the eighth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe3+ atoms. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and three Fe3+ atoms.