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6 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Ba4Hf3O10 by Materials Project

Ba4Hf3O10 crystallizes in the orthorhombic Cmce 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 eight equivalent BaO12 cuboctahedra, faces with five equivalent BaO12 cuboctahedra, and faces with eight HfO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.85–3.09 Å. In the second Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.70–2.98 Å. There are two inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded to six O2- atoms to form HfO6 octahedra that share corners with six HfO6 octahedra and faces with eight equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–9°. There are two shorter (2.10 Å) and four longer (2.11 Å) Hf–O bond lengths. In the second Hf4+ site, Hf4+ is bonded to six O2- atoms to form HfO6 octahedra that share corners with five HfO6 octahedra and faces with four equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are a spread of Hf–O bond distances ranging from 2.09–2.13 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to four equivalent Ba2+ and two equivalent Hf4+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to four Ba2+ and two equivalent Hf4+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ba2+ and two Hf4+ atoms. In the fourth O2- site, O2- is bonded to five equivalent Ba2+ and one Hf4+ atom to form a mixture of distorted corner and edge-sharing OBa5Hf octahedra. The corner-sharing octahedral tilt angles are 5°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba3Hf2O7 by Materials Project

Ba3Hf2O7 crystallizes in the tetragonal I4/mmm 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 four equivalent BaO12 cuboctahedra, faces with four equivalent BaO12 cuboctahedra, and faces with eight equivalent HfO6 octahedra. All Ba–O bond lengths are 2.97 Å. In the second Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.70–2.97 Å. Hf4+ is bonded to six O2- atoms to form HfO6 octahedra that share corners with five equivalent HfO6 octahedra and faces with four equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Hf–O bond distances ranging from 2.09–2.13 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ba2+ and two equivalent Hf4+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to four Ba2+ and two equivalent Hf4+ atoms. In the third O2- site, O2- is bonded to five equivalent Ba2+ and one Hf4+ atom to form a mixture of distorted edge and corner-sharing OBa5Hf octahedra. The corner-sharing octahedral tilt angles are 5°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba2HfO4 by Materials Project

Ba2HfO4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.69–2.97 Å. Hf4+ is bonded to six O2- atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.10 Å) and two longer (2.11 Å) Hf–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to five equivalent Ba2+ and one Hf4+ atom to form a mixture of distorted corner and edge-sharing OBa5Hf octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the second O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ba2+ and two equivalent Hf4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba6HfO8 by Materials Project

Ba6HfO8 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Ba2+ is bonded to six O2- atoms to form BaO6 octahedra that share corners with six equivalent BaO6 octahedra, edges with two equivalent HfO6 octahedra, and edges with eight equivalent BaO6 octahedra. The corner-sharing octahedra tilt angles range from 0–23°. There are two shorter (2.72 Å) and four longer (2.78 Å) Ba–O bond lengths. Hf4+ is bonded to six equivalent O2- atoms to form HfO6 octahedra that share edges with twelve equivalent BaO6 octahedra. All Hf–O bond lengths are 2.16 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to four equivalent Ba2+ and one Hf4+ atom. In the second O2- site, O2- is bonded to six equivalent Ba2+ atoms to form corner-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba2Hf7O16 by Materials Project

Ba2Hf7O16 crystallizes in the trigonal R-3 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 2.69–2.73 Å. There are two inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded to six equivalent O2- atoms to form corner-sharing HfO6 octahedra. All Hf–O bond lengths are 2.10 Å. In the second Hf4+ site, Hf4+ is bonded to seven O2- atoms to form distorted HfO7 pentagonal bipyramids that share a cornercorner with one HfO6 octahedra, corners with two equivalent HfO7 pentagonal bipyramids, and edges with seven equivalent HfO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 35°. There are a spread of Hf–O bond distances ranging from 2.04–2.36 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ba2+ and three equivalent Hf4+ atoms to form a mixture of distorted corner and edge-sharing OBaHf3 tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three equivalent Hf4+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+ and two Hf4+ atoms. In the fourth O2- site, O2- is bonded to four equivalent Hf4+ atoms to form a mixture of distorted corner and edge-sharing OHf4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BaHfO3 by Materials Project

BaHfO3 is (Cubic) Perovskite structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with twelve equivalent BaO12 cuboctahedra, faces with six equivalent BaO12 cuboctahedra, and faces with eight equivalent HfO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.95–3.00 Å. Hf4+ is bonded to six O2- atoms to form HfO6 octahedra that share corners with six equivalent HfO6 octahedra and faces with eight equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are four shorter (2.10 Å) and two longer (2.11 Å) Hf–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ba2+ and two equivalent Hf4+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ba2+ and two equivalent Hf4+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ba2+ and two equivalent Hf4+ atoms.

36 MATERIALS SCIENCE↗