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6 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Sr2Ta2O7 by Materials Project

Sr2Ta2O7 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. There are four shorter (2.51 Å) and two longer (2.59 Å) Sr–O bond lengths. In the second Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with six equivalent SrO12 cuboctahedra, faces with four equivalent SrO12 cuboctahedra, and faces with eight TaO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.65–2.88 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and faces with two equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 10–16°. There are a spread of Ta–O bond distances ranging from 1.88–2.17 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with six equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–12°. There are a spread of Ta–O bond distances ranging from 1.92–2.09 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four equivalent Sr2+ and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to three equivalent Sr2+ and two equivalent Ta5+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+ and two Ta5+ atoms. In the fourth O2- site, O2- is bonded to three equivalent Sr2+ and one Ta5+ atom to form a mixture of distorted edge and corner-sharing OSr3Ta tetrahedra. In the fifth O2- site, O2- is bonded in a distorted T-shaped geometry to one Sr2+ and two equivalent Ta5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr2Ta2O7 by Materials Project

Sr2Ta2O7 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with six equivalent SrO12 cuboctahedra, faces with four equivalent SrO12 cuboctahedra, and faces with eight TaO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.65–2.92 Å. In the second Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Sr–O bond distances ranging from 2.50–2.62 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with six equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–15°. There are a spread of Ta–O bond distances ranging from 1.91–2.10 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four TaO6 octahedra and faces with two equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 6–16°. There are a spread of Ta–O bond distances ranging from 1.88–2.18 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded to three equivalent Sr2+ and one Ta5+ atom to form distorted corner-sharing OSr3Ta tetrahedra. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Sr2+ and two Ta5+ atoms. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to one Sr2+ and two equivalent Ta5+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to three equivalent Sr2+ and two equivalent Ta5+ atoms. In the fifth O2- site, O2- is bonded in a distorted linear geometry to four equivalent Sr2+ and two equivalent Ta5+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+ and two Ta5+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Sr2+ and one Ta5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrTa2O6 by Materials Project

SrTa2O6 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.57–2.72 Å. Ta5+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 21–40°. There are a spread of Ta–O bond distances ranging from 1.92–2.15 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+ and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+ and two equivalent Ta5+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+ and two equivalent Ta5+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+ and two equivalent Ta5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrTa4O11 by Materials Project

SrTa4O11 crystallizes in the hexagonal P6_322 space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are six shorter (2.55 Å) and two longer (2.69 Å) Sr–O bond lengths. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded in an octahedral geometry to six equivalent O2- atoms. All Ta–O bond lengths are 2.00 Å. In the second Ta5+ site, Ta5+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ta–O bond distances ranging from 1.97–2.52 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Sr2+ and three equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to three equivalent Ta5+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+ and two Ta5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr6Ta2O11 by Materials Project

Sr6Ta2O11 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.64–3.10 Å. In the second Sr2+ site, Sr2+ is bonded to five O2- atoms to form distorted SrO5 square pyramids that share corners with four equivalent TaO6 octahedra and a cornercorner with one TaO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 10°. There are four shorter (2.30 Å) and one longer (2.85 Å) Sr–O bond lengths. In the third Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are two shorter (2.32 Å) and four longer (2.57 Å) Sr–O bond lengths. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to five O2- atoms to form distorted TaO5 trigonal bipyramids that share a cornercorner with one SrO5 square pyramid. There is one shorter (1.91 Å) and four longer (1.97 Å) Ta–O bond length. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four equivalent SrO5 square pyramids. There is two shorter (1.95 Å) and four longer (2.01 Å) Ta–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to five Sr2+ and one Ta5+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to five Sr2+ and one Ta5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Sr2+ and one Ta5+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to five Sr2+ and one Ta5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr5Ta4O15 by Materials Project

Sr5Ta4O15 crystallizes in the trigonal P-3c1 space group. The structure is three-dimensional. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 12-coordinate geometry to six O2- atoms. There are three shorter (2.57 Å) and three longer (2.63 Å) Sr–O bond lengths. In the second Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. There are three shorter (2.57 Å) and three longer (2.59 Å) Sr–O bond lengths. In the third Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form distorted SrO12 cuboctahedra that share corners with six equivalent SrO12 cuboctahedra and faces with eight TaO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.62–3.08 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with three equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 13–17°. There are three shorter (1.96 Å) and three longer (2.06 Å) Ta–O bond lengths. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form distorted TaO6 octahedra that share corners with three equivalent TaO6 octahedra and a faceface with one SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 17°. There are three shorter (1.89 Å) and three longer (2.19 Å) Ta–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to three Sr2+ and one Ta5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Sr2+ and two Ta5+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Sr2+ and two equivalent Ta5+ atoms.

36 MATERIALS SCIENCE↗