Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Gd”

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.

At least 361 records · Page 20
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Gd3Pd2 by Materials Project

Gd3Pd2 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. there are two inequivalent Gd sites. In the first Gd site, Gd is bonded in a 6-coordinate geometry to six equivalent Pd atoms. There are two shorter (3.02 Å) and four longer (3.08 Å) Gd–Pd bond lengths. In the second Gd site, Gd is bonded in a square co-planar geometry to four equivalent Pd atoms. All Gd–Pd bond lengths are 3.10 Å. Pd is bonded in a 8-coordinate geometry to eight Gd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GdB2Rh3 by Materials Project

GdRh3B2 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Gd is bonded in a 12-coordinate geometry to two equivalent Gd, twelve equivalent Rh, and six equivalent B atoms. Both Gd–Gd bond lengths are 3.13 Å. All Gd–Rh bond lengths are 3.15 Å. All Gd–B bond lengths are 3.15 Å. Rh is bonded in a distorted square co-planar geometry to four equivalent Gd and four equivalent B atoms. All Rh–B bond lengths are 2.22 Å. B is bonded in a 6-coordinate geometry to three equivalent Gd and six equivalent Rh atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GdB2Ru3 by Materials Project

GdRu3B2 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Gd is bonded in a 12-coordinate geometry to two equivalent Gd, twelve equivalent Ru, and six equivalent B atoms. Both Gd–Gd bond lengths are 3.03 Å. All Gd–Ru bond lengths are 3.15 Å. All Gd–B bond lengths are 3.19 Å. Ru is bonded in a distorted square co-planar geometry to four equivalent Gd and four equivalent B atoms. All Ru–B bond lengths are 2.20 Å. B is bonded in a 6-coordinate geometry to three equivalent Gd and six equivalent Ru atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Gd2Br3N by Materials Project

Gd2NBr3 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded in a 2-coordinate geometry to two N3- and four Br1- atoms. There are one shorter (2.24 Å) and one longer (2.29 Å) Gd–N bond lengths. There are a spread of Gd–Br bond distances ranging from 2.84–3.33 Å. In the second Gd3+ site, Gd3+ is bonded in a 2-coordinate geometry to two equivalent N3- and five Br1- atoms. There are one shorter (2.25 Å) and one longer (2.30 Å) Gd–N bond lengths. There are a spread of Gd–Br bond distances ranging from 2.95–3.17 Å. In the third Gd3+ site, Gd3+ is bonded in a 6-coordinate geometry to two N3- and four Br1- atoms. There are one shorter (2.26 Å) and one longer (2.29 Å) Gd–N bond lengths. There are a spread of Gd–Br bond distances ranging from 2.86–3.20 Å. In the fourth Gd3+ site, Gd3+ is bonded in a 2-coordinate geometry to two equivalent N3- and five Br1- atoms. There are one shorter (2.24 Å) and one longer (2.27 Å) Gd–N bond lengths. There are a spread of Gd–Br bond distances ranging from 2.98–3.36 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to four Gd3+ atoms to form edge-sharing NGd4 tetrahedra. In the second N3- site, N3- is bonded to four Gd3+ atoms to form edge-sharing NGd4 tetrahedra. There are six inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 3-coordinate geometry to three Gd3+ atoms. In the second Br1- site, Br1- is bonded in a 4-coordinate geometry to four Gd3+ atoms. In the third Br1- site, Br1- is bonded in a 3-coordinate geometry to three Gd3+ atoms. In the fourth Br1- site, Br1- is bonded in a 3-coordinate geometry to three Gd3+ atoms. In the fifth Br1- site, Br1- is bonded in a 3-coordinate geometry to three Gd3+ atoms. In the sixth Br1- site, Br1- is bonded in a 2-coordinate geometry to two Gd3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Gd2B(OF)3 by Materials Project

Gd2(BO3)F3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded in a 9-coordinate geometry to four O2- and five F1- atoms. There are a spread of Gd–O bond distances ranging from 2.38–2.42 Å. There are a spread of Gd–F bond distances ranging from 2.35–2.64 Å. In the second Gd3+ site, Gd3+ is bonded in a 9-coordinate geometry to three O2- and five F1- atoms. There are two shorter (2.38 Å) and one longer (2.50 Å) Gd–O bond lengths. There are a spread of Gd–F bond distances ranging from 2.28–2.60 Å. In the third Gd3+ site, Gd3+ is bonded in a 9-coordinate geometry to four O2- and five F1- atoms. There are a spread of Gd–O bond distances ranging from 2.38–2.62 Å. There are a spread of Gd–F bond distances ranging from 2.27–2.47 Å. In the fourth Gd3+ site, Gd3+ is bonded in a 9-coordinate geometry to seven O2- and two F1- atoms. There are a spread of Gd–O bond distances ranging from 2.34–2.67 Å. There are one shorter (2.30 Å) and one longer (2.52 Å) Gd–F bond lengths. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.38–1.40 Å. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.38–1.40 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three Gd3+ and one B3+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three Gd3+ and one B3+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to three Gd3+ and one B3+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to three Gd3+ and one B3+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to three Gd3+ and one B3+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Gd3+ and one B3+ atom. There are six inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted bent 120 degrees geometry to two equivalent Gd3+ atoms. In the second F1- site, F1- is bonded in a 3-coordinate geometry to three Gd3+ atoms. In the third F1- site, F1- is bonded in a 3-coordinate geometry to three Gd3+ atoms. In the fourth F1- site, F1- is bonded in a 3-coordinate geometry to three Gd3+ atoms. In the fifth F1- site, F1- is bonded in a 3-coordinate geometry to three Gd3+ atoms. In the sixth F1- site, F1- is bonded in a 3-coordinate geometry to three Gd3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GdOF by Materials Project

GdOF crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded to four O2- and two F1- atoms to form a mixture of distorted edge and corner-sharing GdO4F2 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 67–68°. There are two shorter (2.31 Å) and two longer (2.33 Å) Gd–O bond lengths. Both Gd–F bond lengths are 2.29 Å. In the second Gd3+ site, Gd3+ is bonded to four O2- and two F1- atoms to form a mixture of distorted edge and corner-sharing GdO4F2 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 1–2°. There are a spread of Gd–O bond distances ranging from 2.30–2.33 Å. Both Gd–F bond lengths are 2.29 Å. In the third Gd3+ site, Gd3+ is bonded to four O2- and two F1- atoms to form a mixture of distorted edge and corner-sharing GdO4F2 octahedra. There are two shorter (2.31 Å) and two longer (2.33 Å) Gd–O bond lengths. Both Gd–F bond lengths are 2.29 Å. In the fourth Gd3+ site, Gd3+ is bonded to four O2- and two F1- atoms to form a mixture of distorted edge and corner-sharing GdO4F2 pentagonal pyramids. The corner-sharing octahedral tilt angles are 60°. There are two shorter (2.31 Å) and two longer (2.33 Å) Gd–O bond lengths. Both Gd–F bond lengths are 2.29 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to four Gd3+ atoms to form a mixture of distorted edge and corner-sharing OGd4 tetrahedra. In the second O2- site, O2- is bonded to four Gd3+ atoms to form a mixture of distorted edge and corner-sharing OGd4 tetrahedra. In the third O2- site, O2- is bonded to four Gd3+ atoms to form a mixture of distorted edge and corner-sharing OGd4 tetrahedra. In the fourth O2- site, O2- is bonded to four Gd3+ atoms to form a mixture of distorted edge and corner-sharing OGd4 tetrahedra. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a linear geometry to two Gd3+ atoms. In the second F1- site, F1- is bonded in a linear geometry to two Gd3+ atoms. In the third F1- site, F1- is bonded in a linear geometry to two Gd3+ atoms. In the fourth F1- site, F1- is bonded in a linear geometry to two Gd3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GdV2Fe10N by Materials Project

GdV2Fe10N crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Gd is bonded in a linear geometry to two equivalent V, ten Fe, and two equivalent N atoms. Both Gd–V bond lengths are 3.08 Å. There are two shorter (3.07 Å) and eight longer (3.25 Å) Gd–Fe bond lengths. Both Gd–N bond lengths are 2.38 Å. V is bonded in a 10-coordinate geometry to one Gd, one V, and twelve Fe atoms. The V–V bond length is 2.42 Å. There are a spread of V–Fe bond distances ranging from 2.61–2.92 Å. There are four inequivalent Fe sites. In the first Fe site, Fe is bonded in a single-bond geometry to two equivalent V, six Fe, and one N atom. There are four shorter (2.46 Å) and two longer (2.64 Å) Fe–Fe bond lengths. The Fe–N bond length is 1.92 Å. In the second Fe site, Fe is bonded in a single-bond geometry to two equivalent V, six Fe, and one N atom. There are four shorter (2.45 Å) and two longer (2.65 Å) Fe–Fe bond lengths. The Fe–N bond length is 1.92 Å. In the third Fe site, Fe is bonded to two equivalent Gd, two equivalent V, and eight Fe atoms to form distorted FeGd2V2Fe8 cuboctahedra that share corners with ten equivalent FeGd2V2Fe8 cuboctahedra, corners with two equivalent NGd2Fe4 octahedra, edges with four equivalent FeGd2V2Fe8 cuboctahedra, faces with six equivalent FeGd2V2Fe8 cuboctahedra, and faces with two equivalent NGd2Fe4 octahedra. The corner-sharing octahedral tilt angles are 69°. There are two shorter (2.38 Å) and two longer (2.63 Å) Fe–Fe bond lengths. In the fourth Fe site, Fe is bonded in a 2-coordinate geometry to one Gd, four equivalent V, and nine Fe atoms. The Fe–Fe bond length is 2.39 Å. N is bonded to two equivalent Gd and four Fe atoms to form NGd2Fe4 octahedra that share corners with eight equivalent FeGd2V2Fe8 cuboctahedra, corners with two equivalent NGd2Fe4 octahedra, and faces with eight equivalent FeGd2V2Fe8 cuboctahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Gd5Si2BO13 by Materials Project

Gd5BSi2O13 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are eight inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Gd–O bond distances ranging from 2.24–2.39 Å. In the second Gd3+ site, Gd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Gd–O bond distances ranging from 2.26–2.67 Å. In the third Gd3+ site, Gd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Gd–O bond distances ranging from 2.22–2.59 Å. In the fourth Gd3+ site, Gd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Gd–O bond distances ranging from 2.21–2.64 Å. In the fifth Gd3+ site, Gd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Gd–O bond distances ranging from 2.23–2.85 Å. In the sixth Gd3+ site, Gd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Gd–O bond distances ranging from 2.26–2.69 Å. In the seventh Gd3+ site, Gd3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Gd–O bond distances ranging from 2.35–2.87 Å. In the eighth Gd3+ site, Gd3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Gd–O bond distances ranging from 2.36–2.80 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of B–O bond distances ranging from 1.50–1.52 Å. In the second B3+ site, B3+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of B–O bond distances ranging from 1.47–1.53 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There is one shorter (1.62 Å) and three longer (1.64 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the third Si4+ site, Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There is three shorter (1.63 Å) and one longer (1.64 Å) Si–O bond length. In the fourth Si4+ site, Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.64 Å) and two longer (1.65 Å) Si–O bond length. There are twenty inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three Gd3+ and one B3+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three Gd3+ and one Si4+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Gd3+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to three Gd3+ and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to three Gd3+ and one B3+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to three Gd3+ and one Si4+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to three Gd3+ and one B3+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Gd3+ and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to three Gd3+ and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to three Gd3+ and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a distorted single-bond geometry to three Gd3+ and one B3+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to three Gd3+ and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a distorted single-bond geometry to three Gd3+ and one B3+ atom. In the fourteenth O2- site, O2- is bonded in a 1-coordinate geometry to three Gd3+ and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to three Gd3+ and one Si4+ atom. In the sixteenth O2- site, O2- is bonded in a distorted tetrahedral geometry to three Gd3+ and one Si4+ atom. In the seventeenth O2- site, O2- is bonded in a 1-coordinate geometry to three Gd3+ and one B3+ atom. In the eighteenth O2- site, O2- is bonded in a distorted single-bond geometry to three Gd3+ and one Si4+ atom. In the nineteenth O2- site, O2- is bonded in a trigonal planar geometry to three Gd3+ atoms. In the twentieth O2- site, O2- is bonded in a trigonal planar geometry to three Gd3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Gd3Se2NO by Materials Project

Gd3NSe2O crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded in a 4-coordinate geometry to two equivalent N3-, three equivalent Se2-, and two equivalent O2- atoms. Both Gd–N bond lengths are 2.37 Å. There are one shorter (3.08 Å) and two longer (3.12 Å) Gd–Se bond lengths. There are one shorter (2.31 Å) and one longer (2.36 Å) Gd–O bond lengths. In the second Gd3+ site, Gd3+ is bonded in a 6-coordinate geometry to one N3-, three Se2-, and two equivalent O2- atoms. The Gd–N bond length is 2.25 Å. There are one shorter (2.98 Å) and two longer (3.06 Å) Gd–Se bond lengths. Both Gd–O bond lengths are 2.31 Å. In the third Gd3+ site, Gd3+ is bonded to one N3- and five Se2- atoms to form distorted edge-sharing GdSe5N octahedra. The Gd–N bond length is 2.19 Å. There are a spread of Gd–Se bond distances ranging from 2.88–3.26 Å. N3- is bonded to four Gd3+ atoms to form NGd4 tetrahedra that share corners with five equivalent SeGd5 square pyramids, corners with two equivalent NGd4 tetrahedra, corners with two equivalent OGd4 tetrahedra, and edges with two equivalent OGd4 tetrahedra. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 6-coordinate geometry to six Gd3+ atoms. In the second Se2- site, Se2- is bonded to five Gd3+ atoms to form distorted SeGd5 square pyramids that share corners with two equivalent OGd4 tetrahedra, corners with five equivalent NGd4 tetrahedra, edges with four equivalent SeGd5 square pyramids, and an edgeedge with one OGd4 tetrahedra. O2- is bonded to four Gd3+ atoms to form OGd4 tetrahedra that share corners with two equivalent SeGd5 square pyramids, corners with two equivalent NGd4 tetrahedra, corners with two equivalent OGd4 tetrahedra, an edgeedge with one SeGd5 square pyramid, an edgeedge with one OGd4 tetrahedra, and edges with two equivalent NGd4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GdCu5Sn by Materials Project

GdCu5Sn crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Gd is bonded in a 6-coordinate geometry to fifteen Cu and four equivalent Sn atoms. There are a spread of Gd–Cu bond distances ranging from 2.90–3.39 Å. There are a spread of Gd–Sn bond distances ranging from 3.28–3.40 Å. There are four inequivalent Cu sites. In the first Cu site, Cu is bonded to three equivalent Gd, seven Cu, and two equivalent Sn atoms to form a mixture of face, edge, and corner-sharing CuGd3Cu7Sn2 cuboctahedra. There are a spread of Cu–Cu bond distances ranging from 2.49–2.58 Å. Both Cu–Sn bond lengths are 2.82 Å. In the second Cu site, Cu is bonded to three equivalent Gd, seven Cu, and two equivalent Sn atoms to form a mixture of face, edge, and corner-sharing CuGd3Cu7Sn2 cuboctahedra. There are a spread of Cu–Cu bond distances ranging from 2.50–2.55 Å. There are one shorter (2.77 Å) and one longer (2.80 Å) Cu–Sn bond lengths. In the third Cu site, Cu is bonded in a 12-coordinate geometry to three equivalent Gd, six Cu, and one Sn atom. The Cu–Cu bond length is 3.05 Å. The Cu–Sn bond length is 2.79 Å. In the fourth Cu site, Cu is bonded in a 4-coordinate geometry to three equivalent Gd, five Cu, and three equivalent Sn atoms. There are one shorter (2.64 Å) and two longer (3.03 Å) Cu–Sn bond lengths. Sn is bonded in a 1-coordinate geometry to four equivalent Gd and ten Cu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GdB2Ir3 by Materials Project

GdIr3B2 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Gd is bonded in a 12-coordinate geometry to two equivalent Gd, twelve equivalent Ir, and six equivalent B atoms. Both Gd–Gd bond lengths are 3.15 Å. All Gd–Ir bond lengths are 3.17 Å. All Gd–B bond lengths are 3.18 Å. Ir is bonded in a distorted square co-planar geometry to four equivalent Gd and four equivalent B atoms. All Ir–B bond lengths are 2.24 Å. B is bonded in a 6-coordinate geometry to three equivalent Gd and six equivalent Ir atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Gd2AlFe3 by Materials Project

Gd2Fe3Al is Cubic Laves-derived structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Gd is bonded in a 12-coordinate geometry to four equivalent Gd, nine equivalent Fe, and three equivalent Al atoms. There are one shorter (3.13 Å) and three longer (3.24 Å) Gd–Gd bond lengths. There are six shorter (3.06 Å) and three longer (3.09 Å) Gd–Fe bond lengths. All Gd–Al bond lengths are 3.09 Å. Fe is bonded to six equivalent Gd, four equivalent Fe, and two equivalent Al atoms to form FeGd6Al2Fe4 cuboctahedra that share corners with four equivalent AlGd6Fe6 cuboctahedra, corners with fourteen equivalent FeGd6Al2Fe4 cuboctahedra, edges with six equivalent FeGd6Al2Fe4 cuboctahedra, faces with six equivalent AlGd6Fe6 cuboctahedra, and faces with twelve equivalent FeGd6Al2Fe4 cuboctahedra. All Fe–Fe bond lengths are 2.63 Å. Both Fe–Al bond lengths are 2.61 Å. Al is bonded to six equivalent Gd and six equivalent Fe atoms to form AlGd6Fe6 cuboctahedra that share corners with six equivalent AlGd6Fe6 cuboctahedra, corners with twelve equivalent FeGd6Al2Fe4 cuboctahedra, edges with six equivalent AlGd6Fe6 cuboctahedra, and faces with eighteen equivalent FeGd6Al2Fe4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Gd8Rh5C12 by Materials Project

Gd8Rh5C12 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded in a 5-coordinate geometry to nine C+3.33- atoms. There are a spread of Gd–C bond distances ranging from 2.45–2.83 Å. In the second Gd3+ site, Gd3+ is bonded in a 5-coordinate geometry to nine C+3.33- atoms. There are a spread of Gd–C bond distances ranging from 2.46–2.82 Å. In the third Gd3+ site, Gd3+ is bonded in a 1-coordinate geometry to nine C+3.33- atoms. There are a spread of Gd–C bond distances ranging from 2.37–2.97 Å. In the fourth Gd3+ site, Gd3+ is bonded in a 9-coordinate geometry to nine C+3.33- atoms. There are a spread of Gd–C bond distances ranging from 2.38–2.97 Å. In the fifth Gd3+ site, Gd3+ is bonded to six C+3.33- atoms to form GdC6 octahedra that share corners with four CGd4RhC octahedra and faces with two equivalent GdC6 octahedra. The corner-sharing octahedra tilt angles range from 43–105°. There are a spread of Gd–C bond distances ranging from 2.61–2.71 Å. In the sixth Gd3+ site, Gd3+ is bonded to six C+3.33- atoms to form GdC6 octahedra that share corners with four CGd4RhC octahedra and faces with two equivalent GdC6 octahedra. The corner-sharing octahedra tilt angles range from 43–105°. There are a spread of Gd–C bond distances ranging from 2.62–2.70 Å. In the seventh Gd3+ site, Gd3+ is bonded in a 2-coordinate geometry to four C+3.33- atoms. There are a spread of Gd–C bond distances ranging from 2.68–2.99 Å. In the eighth Gd3+ site, Gd3+ is bonded in a 2-coordinate geometry to four C+3.33- atoms. There are a spread of Gd–C bond distances ranging from 2.69–2.99 Å. There are five inequivalent Rh+3.20+ sites. In the first Rh+3.20+ site, Rh+3.20+ is bonded in a linear geometry to two C+3.33- atoms. Both Rh–C bond lengths are 1.97 Å. In the second Rh+3.20+ site, Rh+3.20+ is bonded in a linear geometry to two C+3.33- atoms. Both Rh–C bond lengths are 2.02 Å. In the third Rh+3.20+ site, Rh+3.20+ is bonded in a linear geometry to two C+3.33- atoms. Both Rh–C bond lengths are 2.02 Å. In the fourth Rh+3.20+ site, Rh+3.20+ is bonded in a water-like geometry to two C+3.33- atoms. There are one shorter (2.12 Å) and one longer (2.29 Å) Rh–C bond lengths. In the fifth Rh+3.20+ site, Rh+3.20+ is bonded in a water-like geometry to two C+3.33- atoms. There are one shorter (2.12 Å) and one longer (2.30 Å) Rh–C bond lengths. There are twelve inequivalent C+3.33- sites. In the first C+3.33- site, C+3.33- is bonded to four Gd3+, one Rh+3.20+, and one C+3.33- atom to form distorted CGd4RhC octahedra that share a cornercorner with one CGd4RhC octahedra, corners with two equivalent GdC6 octahedra, and edges with two equivalent CGd4RhC octahedra. The corner-sharing octahedra tilt angles range from 0–105°. The C–C bond length is 1.30 Å. In the second C+3.33- site, C+3.33- is bonded to four Gd3+, one Rh+3.20+, and one C+3.33- atom to form CGd4RhC octahedra that share a cornercorner with one CGd4RhC octahedra, corners with two equivalent GdC6 octahedra, and edges with two equivalent CGd4RhC octahedra. The corner-sharing octahedra tilt angles range from 0–105°. The C–C bond length is 1.30 Å. In the third C+3.33- site, C+3.33- is bonded in a 6-coordinate geometry to four Gd3+, one Rh+3.20+, and one C+3.33- atom. In the fourth C+3.33- site, C+3.33- is bonded in a 6-coordinate geometry to four Gd3+, one Rh+3.20+, and one C+3.33- atom. In the fifth C+3.33- site, C+3.33- is bonded in a 7-coordinate geometry to four Gd3+, two Rh+3.20+, and one C+3.33- atom. The C–C bond length is 1.34 Å. In the sixth C+3.33- site, C+3.33- is bonded in a 7-coordinate geometry to four Gd3+, two Rh+3.20+, and one C+3.33- atom. The C–C bond length is 1.34 Å. In the seventh C+3.33- site, C+3.33- is bonded to five Gd3+ and one C+3.33- atom to form a mixture of distorted edge and corner-sharing CGd5C octahedra. The corner-sharing octahedra tilt angles range from 8–15°. In the eighth C+3.33- site, C+3.33- is bonded to five Gd3+ and one C+3.33- atom to form a mixture of distorted edge and corner-sharing CGd5C octahedra. The corner-sharing octahedra tilt angles range from 7–15°. In the ninth C+3.33- site, C+3.33- is bonded in a 4-coordinate geometry to six Gd3+, one Rh+3.20+, and one C+3.33- atom. The C–C bond length is 1.35 Å. In the tenth C+3.33- site, C+3.33- is bonded in a 4-coordinate geometry to six Gd3+, one Rh+3.20+, and one C+3.33- atom. The C–C bond length is 1.35 Å. In the eleventh C+3.33- site, C+3.33- is bonded to five Gd3+ and one C+3.33- atom to form CGd5C octahedra that share corners with two equivalent GdC6 octahedra, corners with four equivalent CGd5C octahedra, and edges with eight CGd5C octahedra. The corner-sharing octahedra tilt angles range from 8–44°. In the twelfth C+3.33- site, C+3.33- is bonded to five Gd3+ and one C+3.33- atom to form CGd5C octahedra that share corners with two equivalent GdC6 octahedra, corners with four equivalent CGd5C octahedra, and edges with eight CGd5C octahedra. The corner-sharing octahedra tilt angles range from 7–44°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Gd3Au by Materials Project

Gd3Au is Uranium Silicide structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Gd sites. In the first Gd site, Gd is bonded in a distorted square co-planar geometry to four equivalent Au atoms. All Gd–Au bond lengths are 3.40 Å. In the second Gd site, Gd is bonded in a distorted square co-planar geometry to four equivalent Au atoms. All Gd–Au bond lengths are 3.39 Å. Au is bonded to twelve Gd atoms to form a mixture of corner and face-sharing AuGd12 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Gd2Nb2S7O30 by Materials Project

Gd2Nb2S7O30 crystallizes in the tetragonal P-42_1m space group. The structure is three-dimensional. Gd is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Gd–O bond distances ranging from 2.33–2.49 Å. Nb is bonded to six O atoms to form NbO6 octahedra that share corners with five SO4 tetrahedra. There are a spread of Nb–O bond distances ranging from 1.78–2.18 Å. There are three inequivalent S sites. In the first S site, S is bonded to four O atoms to form SO4 tetrahedra that share corners with two equivalent NbO6 octahedra. The corner-sharing octahedral tilt angles are 17°. There is two shorter (1.48 Å) and two longer (1.49 Å) S–O bond length. In the second S site, S is bonded to four O atoms to form SO4 tetrahedra that share corners with two equivalent NbO6 octahedra. The corner-sharing octahedral tilt angles are 31°. There are a spread of S–O bond distances ranging from 1.45–1.51 Å. In the third S site, S is bonded to four O atoms to form SO4 tetrahedra that share a cornercorner with one NbO6 octahedra. The corner-sharing octahedral tilt angles are 31°. There are a spread of S–O bond distances ranging from 1.46–1.54 Å. There are ten inequivalent O sites. In the first O site, O is bonded in a distorted linear geometry to one Gd and one S atom. In the second O site, O is bonded in a single-bond geometry to one S atom. In the third O site, O is bonded in a distorted linear geometry to one Gd and one S atom. In the fourth O site, O is bonded in a bent 150 degrees geometry to one Gd and one S atom. In the fifth O site, O is bonded in a bent 150 degrees geometry to one Nb and one S atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to one Nb and one S atom. In the seventh O site, O is bonded in a distorted bent 150 degrees geometry to one Gd and one S atom. In the eighth O site, O is bonded in a distorted linear geometry to one Gd and one Nb atom. In the ninth O site, O is bonded in a distorted bent 150 degrees geometry to one Gd and one S atom. In the tenth O site, O is bonded in a distorted linear geometry to one Nb and one S atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Crystal Structure and Atomic Vacancy Optimized Thermoelectric Properties in Gadolinium Selenides

Thermoelectric materials enable the energy conversion of waste heat into electricity, helpful to relieve global energy crisis. Here, we report a systematic investigation on high-temperature thermoelectric gadolinium selenides, cubic Gd 3-x Se 4 (x = 0.16, 0.21 and 0.25) and orthorhombic Gd 2 Se 3-y (y = 0.02, 0.06 and 0.08). High energy synchrotron x-ray diffraction and total scattering have been used to investigate the crystallographic and local structures. Atomic-scale clusters of Gd vacancy in the cubic phase are observed by employing the reverse Monte Carlo simulation. For cubic Gd 3-x Se 4 , adjusting Gd vacancy triggers the effect of multiple conduction bands, confirmed by the increase in effective masses and theoretical calculations. A reasonable peak zT value of 0.27 is achieved at 850 K for Gd 3-x Se 4 (x = 0.16). On the other hand, tuning Se vacancy enables the optimization of electron concentration for the orthorhombic Gd 2 Se 3-y . More significantly, its low deformation potential (Ξ = 12eV) gives rise to enhanced electron mobility and higher peak zT value of 0.54 at 850 K for Gd 2 Se 3-y (y = 0.02). Intriguingly, a higher zT of 1.2 at 1200 K is reasonably predicted by quality factor analysis. Finally, this work extends the scope of high-temperature thermoelectric materials and facilitates the exploration of novel high-temperature thermoelectric materials

36 MATERIALS SCIENCE↗
DOE OSTI2022

Development of ultra-pure gadolinium sulfate for the Super-Kamiokande gadolinium project

This paper reports the development and detailed properties of about 13 metric tons of gadolinium sulfate octahydrate, Gd 2 (SO 4 ) 3 • 8H 2 O⁠, which has been dissolved into Super-Kamiokande (SK) in the summer of 2020. We evaluate the impact of radioactive impurities in Gd 2 (SO 4 ) 3 • 8H 2 O on diffuse supernova neutrino background searches and solar neutrino observation and confirm the need to reduce radioactive and fluorescent impurities by about three orders of magnitude from commercially available high-purity Gd 2 (SO 4 ) 3 • 8H 2 O⁠. In order to produce ultra-high-purity Gd 2 (SO 4 ) 3 • 8H 2 O, we have developed a method to remove impurities from gadolinium oxide, Gd 2 O 3 , consisting of acid dissolution, solvent extraction, and pH control processes, followed by a high-purity sulfation process. All of the produced ultra-high-purity Gd 2 (SO 4 ) 3 • 8H 2 O is assayed by inductively coupled plasma mass spectrometry and high-purity germanium detectors to evaluate its quality. Because of the long measurement time of high-purity germanium detectors, we have employed several underground laboratories for making parallel measurements including the Laboratorio Subterráneo de Canfranc in Spain, Boulby in the UK, and Kamioka in Japan. In the first half of production, the measured batch purities were found to be consistent with the specifications. However, in the latter half, the Gd 2 (SO 4 ) 3 • 8H 2 O contained one order of magnitude more 228Ra than the budgeted mean contamination. This was correlated with the corresponding characteristics of the raw material Gd 2 O 3 , in which an intrinsically large contamination was present. Based on their modest impact on SK physics, they were nevertheless introduced into the detector. To reduce 228 Ra for the next stage of gadolinium loading to SK, a new process has been successfully established.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1992

The geophysical signal of the martian global dichotomy

A first-order tectonic question for Mars is the origin and nature of the global dichotomy (GD) separating approximately the northern and southern hemispheres of the planet. It is appropriate to focus on hypotheses for the origin of the GD as well as on geophysical models of related internal structure that are constrained by present-day observations. There are basic planetary scale observations that relate to the GD: (1) the dichotomy boundary separates two fundamentally different elevations on the planet, as the terrain to the north is lower by an average of about 3 km; (2) the boundary separates terrain of regionally distinct crater ages, heavily cratered (older) in the south and sparsely cratered (younger) in the north; (3) the amount of ancient crust apparently removed from north of the dichotomy boundary cannot be accounted for by simple surface erosion and deposition in the south, and the constraint becomes particularly severe if isostatic adjustment is presumed to have accompanied this process. This last point leads to the supposition that some type of interior process must have been responsible for the creation of the GD. An obvious way to create the observed elevation difference between the two hemispheres is with a thinner crust in the north, although a denser cust would also work. Hypotheses for producing a thinner northern crust include preferential sub-crustal erosion, a giant impact, and simply invoking the crustal thickness difference as a primordial feature of the planet. If the GD represents a fundamental change in the crustal thickness of Mars, then there should be geophysical evidence of this. The center-of-figure to center-of-mass offset of the planet may be related to the GD, but the Tharsis topography must certainly also contribute. If the Tharsis and GD effects can be separated, then a crustal thickness model can be tested, though the results will not be unique. The gravity field provides another geophysical constraint on GD models. A simple change in thickness of an isostatically compensated crust should show a characteristic gravity signal across the dichotomy boundary. There is a gravity anomaly that is clearly associated with the boundary in regions where the gravity signal is not cluttered by contributions from other features such as Tharsis and Elysium. The gravity signal has a complex spatial relationship with the boundary, and efforts are presently underway to model this anomaly.

Phillips, Roger J.↗