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8 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Y2Hf2O7 by Materials Project

Y2Hf2O7 crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Y3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are two shorter (2.28 Å) and six longer (2.53 Å) Y–O bond lengths. Hf4+ is bonded to six equivalent O2- atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles are 53°. All Hf–O bond lengths are 2.08 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Y3+ and two equivalent Hf4+ atoms to form a mixture of distorted edge and corner-sharing OY2Hf2 tetrahedra. In the second O2- site, O2- is bonded to four equivalent Y3+ atoms to form a mixture of edge and corner-sharing OY4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y2HfO5 by Materials Project

Y2HfO5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Y–O bond distances ranging from 2.29–2.86 Å. In the second Y3+ site, Y3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Y–O bond distances ranging from 2.27–2.50 Å. Hf4+ is bonded to five O2- atoms to form distorted corner-sharing HfO5 trigonal bipyramids. There are a spread of Hf–O bond distances ranging from 1.98–2.13 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Y3+ and two equivalent Hf4+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to three equivalent Y3+ and one Hf4+ atom. In the third O2- site, O2- is bonded to three Y3+ and one Hf4+ atom to form distorted OY3Hf tetrahedra that share corners with three OY3Hf tetrahedra and edges with two equivalent OY4 tetrahedra. In the fourth O2- site, O2- is bonded to four Y3+ atoms to form OY4 tetrahedra that share corners with five OY3Hf tetrahedra and edges with three OY4 tetrahedra. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Y3+ and one Hf4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y2HfO5 by Materials Project

Y2HfO5 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Y3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Y–O bond distances ranging from 2.19–2.59 Å. Hf4+ is bonded to six O2- atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles are 54°. There are a spread of Hf–O bond distances ranging from 2.08–2.15 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Y3+ and one Hf4+ atom. In the second O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Y3+ and one Hf4+ atom. In the third O2- site, O2- is bonded to two equivalent Y3+ and two equivalent Hf4+ atoms to form distorted corner-sharing OY2Hf2 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y2HfO5 by Materials Project

Y2HfO5 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Y3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Y–O bond distances ranging from 2.20–2.46 Å. Hf4+ is bonded to six O2- atoms to form distorted corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles are 34°. There are a spread of Hf–O bond distances ranging from 2.03–2.18 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Y3+ and one Hf4+ atom. In the second O2- site, O2- is bonded to three equivalent Y3+ and one Hf4+ atom to form a mixture of distorted edge and corner-sharing OY3Hf tetrahedra. In the third O2- site, O2- is bonded to two equivalent Y3+ and two equivalent Hf4+ atoms to form distorted OY2Hf2 tetrahedra that share corners with four OY2Hf2 tetrahedra and edges with four equivalent OY3Hf tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y2Hf2O7 by Materials Project

Y2Hf2O7 crystallizes in the tetragonal P4_12_12 space group. The structure is three-dimensional. Y3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Y–O bond distances ranging from 2.21–2.58 Å. Hf4+ is bonded to five O2- atoms to form a mixture of distorted edge and corner-sharing HfO5 trigonal bipyramids. There are a spread of Hf–O bond distances ranging from 1.98–2.27 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Y3+ and two equivalent Hf4+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Y3+ and one Hf4+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Y3+ and one Hf4+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Hf4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y2HfO5 by Materials Project

Y2HfO5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Y–O bond distances ranging from 2.29–2.62 Å. In the second Y3+ site, Y3+ is bonded to six O2- atoms to form YO6 octahedra that share corners with two equivalent YO6 octahedra, corners with four equivalent HfO6 octahedra, and edges with two equivalent YO6 octahedra. The corner-sharing octahedra tilt angles range from 54–64°. There are a spread of Y–O bond distances ranging from 2.21–2.40 Å. Hf4+ is bonded to six O2- atoms to form HfO6 octahedra that share corners with two equivalent HfO6 octahedra, corners with four equivalent YO6 octahedra, and edges with two equivalent HfO6 octahedra. The corner-sharing octahedra tilt angles range from 36–64°. There are a spread of Hf–O bond distances ranging from 1.99–2.30 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to four Y3+ atoms to form OY4 tetrahedra that share corners with ten OY4 tetrahedra and edges with three OY3Hf tetrahedra. In the second O2- site, O2- is bonded in a 3-coordinate geometry to three equivalent Hf4+ atoms. In the third O2- site, O2- is bonded to three Y3+ and one Hf4+ atom to form a mixture of distorted edge and corner-sharing OY3Hf tetrahedra. In the fourth O2- site, O2- is bonded to three equivalent Y3+ and one Hf4+ atom to form a mixture of edge and corner-sharing OY3Hf tetrahedra. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to three Y3+ and one Hf4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y2HfO5 by Materials Project

Y2HfO5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded to seven O2- atoms to form distorted YO7 hexagonal pyramids that share corners with two equivalent YO7 hexagonal pyramids, corners with three equivalent HfO5 trigonal bipyramids, edges with five YO7 hexagonal pyramids, and edges with two equivalent HfO5 trigonal bipyramids. There are a spread of Y–O bond distances ranging from 2.32–2.41 Å. In the second Y3+ site, Y3+ is bonded to seven O2- atoms to form distorted YO7 hexagonal pyramids that share corners with two equivalent YO7 hexagonal pyramids, a cornercorner with one HfO5 trigonal bipyramid, edges with seven YO7 hexagonal pyramids, and edges with two equivalent HfO5 trigonal bipyramids. There are a spread of Y–O bond distances ranging from 2.35–2.41 Å. Hf4+ is bonded to five O2- atoms to form distorted HfO5 trigonal bipyramids that share corners with four YO7 hexagonal pyramids, corners with two equivalent HfO5 trigonal bipyramids, and edges with four YO7 hexagonal pyramids. There are a spread of Hf–O bond distances ranging from 1.95–2.04 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to four Y3+ atoms to form a mixture of distorted edge and corner-sharing OY4 tetrahedra. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Y3+ and one Hf4+ atom. In the third O2- site, O2- is bonded to three Y3+ and one Hf4+ atom to form distorted OY3Hf tetrahedra that share corners with nine OY4 tetrahedra and edges with five OY3Hf tetrahedra. In the fourth O2- site, O2- is bonded to two Y3+ and two equivalent Hf4+ atoms to form distorted OY2Hf2 tetrahedra that share corners with six OY4 tetrahedra and edges with five OY3Hf tetrahedra. In the fifth O2- site, O2- is bonded to three Y3+ and one Hf4+ atom to form OY3Hf tetrahedra that share corners with nine OY4 tetrahedra and edges with four OY3Hf tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y2Hf2O7 by Materials Project

Y2Hf2O7 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Y3+ is bonded to six O2- atoms to form distorted YO6 pentagonal pyramids that share corners with four equivalent HfO5 trigonal bipyramids, edges with three equivalent YO6 pentagonal pyramids, and edges with two equivalent HfO5 trigonal bipyramids. There are a spread of Y–O bond distances ranging from 2.22–2.37 Å. Hf4+ is bonded to five O2- atoms to form distorted HfO5 trigonal bipyramids that share corners with four equivalent YO6 pentagonal pyramids, a cornercorner with one HfO5 trigonal bipyramid, edges with two equivalent YO6 pentagonal pyramids, and an edgeedge with one HfO5 trigonal bipyramid. There are a spread of Hf–O bond distances ranging from 1.95–2.32 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Y3+ and one Hf4+ atom. In the second O2- site, O2- is bonded to two equivalent Y3+ and two equivalent Hf4+ atoms to form distorted edge-sharing OY2Hf2 trigonal pyramids. In the third O2- site, O2- is bonded in a linear geometry to two equivalent Hf4+ atoms.

36 MATERIALS SCIENCE↗