Search NASA⌕ Search

SEARCH · Search NASA

Results for “Eu-Ge-S”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

3 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Materials Data on EuGeS3 by Materials Project

EuGeS3 is Esseneite-derived structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are three inequivalent Eu2+ sites. In the first Eu2+ site, Eu2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Eu–S bond distances ranging from 3.00–3.25 Å. In the second Eu2+ site, Eu2+ is bonded to six S2- atoms to form EuS6 octahedra that share corners with six GeS4 tetrahedra and an edgeedge with one EuS6 octahedra. There are a spread of Eu–S bond distances ranging from 2.92–3.03 Å. In the third Eu2+ site, Eu2+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Eu–S bond distances ranging from 2.97–3.24 Å. There are three inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four S2- atoms to form GeS4 tetrahedra that share corners with two equivalent EuS6 octahedra and corners with two GeS4 tetrahedra. The corner-sharing octahedra tilt angles range from 64–71°. There are a spread of Ge–S bond distances ranging from 2.21–2.27 Å. In the second Ge4+ site, Ge4+ is bonded to four S2- atoms to form GeS4 tetrahedra that share a cornercorner with one EuS6 octahedra and corners with two GeS4 tetrahedra. The corner-sharing octahedral tilt angles are 66°. There are a spread of Ge–S bond distances ranging from 2.20–2.28 Å. In the third Ge4+ site, Ge4+ is bonded to four S2- atoms to form GeS4 tetrahedra that share corners with three equivalent EuS6 octahedra and corners with two GeS4 tetrahedra. The corner-sharing octahedra tilt angles range from 58–64°. There are a spread of Ge–S bond distances ranging from 2.21–2.30 Å. There are nine inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to three Eu2+ and one Ge4+ atom. In the second S2- site, S2- is bonded in a 2-coordinate geometry to one Eu2+ and two Ge4+ atoms. In the third S2- site, S2- is bonded in a 2-coordinate geometry to one Eu2+ and two Ge4+ atoms. In the fourth S2- site, S2- is bonded in a 4-coordinate geometry to three Eu2+ and one Ge4+ atom. In the fifth S2- site, S2- is bonded to three Eu2+ and one Ge4+ atom to form a mixture of distorted edge and corner-sharing SEu3Ge tetrahedra. In the sixth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Eu2+ and one Ge4+ atom. In the seventh S2- site, S2- is bonded in a 3-coordinate geometry to one Eu2+ and two Ge4+ atoms. In the eighth S2- site, S2- is bonded in a 4-coordinate geometry to three Eu2+ and one Ge4+ atom. In the ninth S2- site, S2- is bonded to three Eu2+ and one Ge4+ atom to form a mixture of distorted edge and corner-sharing SEu3Ge tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu2GeS4 by Materials Project

Eu2GeS4 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Eu2+ sites. In the first Eu2+ site, Eu2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Eu–S bond distances ranging from 2.96–3.53 Å. In the second Eu2+ site, Eu2+ is bonded in a 6-coordinate geometry to eight S2- atoms. There are a spread of Eu–S bond distances ranging from 2.93–3.58 Å. Ge4+ is bonded in a tetrahedral geometry to four S2- atoms. There are one shorter (2.22 Å) and three longer (2.23 Å) Ge–S bond lengths. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded to four Eu2+ and one Ge4+ atom to form a mixture of distorted corner, edge, and face-sharing SEu4Ge square pyramids. In the second S2- site, S2- is bonded in a 3-coordinate geometry to four Eu2+ and one Ge4+ atom. In the third S2- site, S2- is bonded in a 3-coordinate geometry to four Eu2+ and one Ge4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu2GeS4 by Materials Project

Eu2GeS4 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are two inequivalent Eu2+ sites. In the first Eu2+ site, Eu2+ is bonded to seven S2- atoms to form distorted EuS7 pentagonal bipyramids that share corners with eight EuS7 pentagonal bipyramids, a cornercorner with one GeS4 tetrahedra, edges with two equivalent EuS7 pentagonal bipyramids, edges with three equivalent GeS4 tetrahedra, and faces with two equivalent EuS7 pentagonal bipyramids. There are a spread of Eu–S bond distances ranging from 2.96–3.16 Å. In the second Eu2+ site, Eu2+ is bonded to seven S2- atoms to form distorted EuS7 pentagonal bipyramids that share corners with eight EuS7 pentagonal bipyramids, corners with three equivalent GeS4 tetrahedra, edges with two equivalent EuS7 pentagonal bipyramids, edges with two equivalent GeS4 tetrahedra, and faces with two equivalent EuS7 pentagonal bipyramids. There are a spread of Eu–S bond distances ranging from 2.99–3.14 Å. Ge4+ is bonded to four S2- atoms to form GeS4 tetrahedra that share corners with four EuS7 pentagonal bipyramids and edges with five EuS7 pentagonal bipyramids. There are two shorter (2.24 Å) and two longer (2.25 Å) Ge–S bond lengths. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to three Eu2+ and one Ge4+ atom. In the second S2- site, S2- is bonded in a distorted see-saw-like geometry to three Eu2+ and one Ge4+ atom. In the third S2- site, S2- is bonded to four Eu2+ and one Ge4+ atom to form a mixture of distorted corner, edge, and face-sharing SEu4Ge trigonal bipyramids. In the fourth S2- site, S2- is bonded to four Eu2+ and one Ge4+ atom to form a mixture of distorted corner, edge, and face-sharing SEu4Ge square pyramids.

36 MATERIALS SCIENCE↗