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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on BaHoFe4O7 by Materials Project

BaHoFe4O7 crystallizes in the cubic F-43m space group. The structure is three-dimensional. Ba2+ is bonded to twelve equivalent O2- atoms to form BaO12 cuboctahedra that share corners with twelve equivalent BaO12 cuboctahedra, edges with twelve equivalent FeO4 tetrahedra, and faces with four equivalent HoO6 octahedra. All Ba–O bond lengths are 3.24 Å. Ho3+ is bonded to six equivalent O2- atoms to form HoO6 octahedra that share corners with twelve equivalent FeO4 tetrahedra and faces with four equivalent BaO12 cuboctahedra. All Ho–O bond lengths are 2.26 Å. Fe+2.25+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent HoO6 octahedra, corners with six equivalent FeO4 tetrahedra, and edges with three equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 51°. There are three shorter (1.98 Å) and one longer (2.10 Å) Fe–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ba2+, one Ho3+, and two equivalent Fe+2.25+ atoms. In the second O2- site, O2- is bonded in a tetrahedral geometry to four equivalent Fe+2.25+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BaHoFe4O7 by Materials Project

BaHoFe4O7 crystallizes in the tetragonal I-4 space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.77 Å) and four longer (3.17 Å) Ba–O bond lengths. Ho3+ is bonded to six O2- atoms to form HoO6 octahedra that share corners with twelve equivalent FeO4 tetrahedra. All Ho–O bond lengths are 2.28 Å. Fe+2.25+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent HoO6 octahedra and corners with six equivalent FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–64°. There are a spread of Fe–O bond distances ranging from 1.96–2.05 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+, one Ho3+, and two equivalent Fe+2.25+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ba2+, one Ho3+, and two equivalent Fe+2.25+ atoms. In the third O2- site, O2- is bonded in a tetrahedral geometry to four equivalent Fe+2.25+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BaHoFe4O7 by Materials Project

BaHoFe4O7 is Hausmannite-derived structured and crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ba–O bond distances ranging from 2.78–3.37 Å. Ho3+ is bonded to six O2- atoms to form HoO6 octahedra that share corners with twelve FeO4 tetrahedra. There are a spread of Ho–O bond distances ranging from 2.23–2.35 Å. There are four inequivalent Fe+2.25+ sites. In the first Fe+2.25+ site, Fe+2.25+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent HoO6 octahedra and corners with six FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–59°. There are a spread of Fe–O bond distances ranging from 1.92–1.94 Å. In the second Fe+2.25+ site, Fe+2.25+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent HoO6 octahedra and corners with six FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–67°. There are a spread of Fe–O bond distances ranging from 1.99–2.06 Å. In the third Fe+2.25+ site, Fe+2.25+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent HoO6 octahedra and corners with six FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–67°. There are a spread of Fe–O bond distances ranging from 1.98–2.08 Å. In the fourth Fe+2.25+ site, Fe+2.25+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent HoO6 octahedra and corners with six FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–63°. There are a spread of Fe–O bond distances ranging from 1.97–2.14 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ba2+, one Ho3+, and two Fe+2.25+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ba2+, one Ho3+, and two Fe+2.25+ atoms. In the third O2- site, O2- is bonded to one Ba2+, one Ho3+, and two Fe+2.25+ atoms to form distorted corner-sharing OBaHoFe2 tetrahedra. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+, one Ho3+, and two Fe+2.25+ atoms. In the fifth O2- site, O2- is bonded to one Ba2+, one Ho3+, and two Fe+2.25+ atoms to form distorted corner-sharing OBaHoFe2 tetrahedra. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+, one Ho3+, and two Fe+2.25+ atoms. In the seventh O2- site, O2- is bonded to four Fe+2.25+ atoms to form corner-sharing OFe4 tetrahedra.

36 MATERIALS SCIENCE↗