DOE OSTI2020
Ba5W2Fe3O15 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with twelve equivalent BaO12 cuboctahedra, faces with six BaO12 cuboctahedra, faces with four equivalent WO6 octahedra, and faces with four equivalent FeO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.89–2.91 Å. In the second Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with twelve BaO12 cuboctahedra, faces with six BaO12 cuboctahedra, faces with three equivalent WO6 octahedra, and faces with five FeO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.82–2.99 Å. W6+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six FeO6 octahedra and faces with eight BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of W–O bond distances ranging from 1.96–1.98 Å. There are three inequivalent Fe+2.67+ sites. In the first Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share a cornercorner with one FeO6 octahedra, corners with five equivalent WO6 octahedra, and faces with eight BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 1–2°. There are a spread of Fe–O bond distances ranging from 1.99–2.18 Å. In the second Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with four equivalent WO6 octahedra, and faces with eight equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (1.98 Å) and four longer (2.13 Å) Fe–O bond lengths. In the third Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO6 octahedra and faces with eight equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are four shorter (2.07 Å) and two longer (2.14 Å) Fe–O bond lengths. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four Ba2+, one W6+, and one Fe+2.67+ atom. In the second O2- site, O2- is bonded to four equivalent Ba2+ and two Fe+2.67+ atoms to form a mixture of distorted corner and face-sharing OBa4Fe2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ba2+, one W6+, and one Fe+2.67+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to four Ba2+, one W6+, and one Fe+2.67+ atom. In the fifth O2- site, O2- is bonded to four equivalent Ba2+ and two Fe+2.67+ atoms to form a mixture of distorted corner and face-sharing OBa4Fe2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the sixth O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ba2+, one W6+, and one Fe+2.67+ atom. In the seventh O2- site, O2- is bonded in a distorted linear geometry to four Ba2+, one W6+, and one Fe+2.67+ atom.