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At least 451 records · Page 25
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Eu3U by Materials Project

UEu3 is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. U is bonded in a distorted body-centered cubic geometry to fourteen Eu atoms. There are eight shorter (3.82 Å) and six longer (4.41 Å) U–Eu bond lengths. There are two inequivalent Eu sites. In the first Eu site, Eu is bonded in a distorted body-centered cubic geometry to four equivalent U and four equivalent Eu atoms. All Eu–Eu bond lengths are 3.82 Å. In the second Eu site, Eu is bonded in a 8-coordinate geometry to six equivalent U and eight equivalent Eu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu5Sn3H by Materials Project

Eu5Sn3H crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. there are two inequivalent Eu sites. In the first Eu site, Eu is bonded to six Sn atoms to form distorted corner-sharing EuSn6 octahedra. The corner-sharing octahedra tilt angles range from 0–53°. There are four shorter (3.32 Å) and two longer (3.81 Å) Eu–Sn bond lengths. In the second Eu site, Eu is bonded in a distorted single-bond geometry to five Sn and one H atom. There are a spread of Eu–Sn bond distances ranging from 3.36–3.48 Å. The Eu–H bond length is 2.47 Å. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded in a 10-coordinate geometry to ten Eu atoms. In the second Sn site, Sn is bonded in a 9-coordinate geometry to eight Eu and one Sn atom. The Sn–Sn bond length is 2.95 Å. H is bonded in a tetrahedral geometry to four equivalent Eu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiEu3 by Materials Project

LiEu3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Li is bonded to twelve Eu atoms to form LiEu12 cuboctahedra that share corners with four equivalent LiEu12 cuboctahedra, corners with eight equivalent EuLi4Eu8 cuboctahedra, edges with eight equivalent LiEu12 cuboctahedra, edges with sixteen equivalent EuLi4Eu8 cuboctahedra, faces with four equivalent LiEu12 cuboctahedra, and faces with fourteen EuLi4Eu8 cuboctahedra. There are four shorter (3.68 Å) and eight longer (3.87 Å) Li–Eu bond lengths. There are two inequivalent Eu sites. In the first Eu site, Eu is bonded to four equivalent Li and eight Eu atoms to form EuLi4Eu8 cuboctahedra that share corners with twelve equivalent EuLi4Eu8 cuboctahedra, edges with eight equivalent LiEu12 cuboctahedra, edges with sixteen EuLi4Eu8 cuboctahedra, faces with four equivalent LiEu12 cuboctahedra, and faces with fourteen EuLi4Eu8 cuboctahedra. There are four shorter (3.68 Å) and four longer (3.87 Å) Eu–Eu bond lengths. In the second Eu site, Eu is bonded to four equivalent Li and eight equivalent Eu atoms to form distorted EuLi4Eu8 cuboctahedra that share corners with four equivalent EuLi4Eu8 cuboctahedra, corners with eight equivalent LiEu12 cuboctahedra, edges with twenty-four EuLi4Eu8 cuboctahedra, faces with six equivalent LiEu12 cuboctahedra, and faces with twelve EuLi4Eu8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li8EuSn7 by Materials Project

Li8EuSn7 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are five inequivalent Li sites. In the first Li site, Li is bonded in a 8-coordinate geometry to two equivalent Li, one Eu, and five Sn atoms. Both Li–Li bond lengths are 2.96 Å. The Li–Eu bond length is 3.21 Å. There are one shorter (2.78 Å) and four longer (2.97 Å) Li–Sn bond lengths. In the second Li site, Li is bonded to eight Li and four equivalent Sn atoms to form LiLi8Sn4 cuboctahedra that share corners with two equivalent LiLi8Sn4 cuboctahedra, edges with four equivalent SnLi8Eu2Sn2 cuboctahedra, faces with two equivalent LiLi8Sn4 cuboctahedra, and faces with four equivalent SnLi8Eu2Sn2 cuboctahedra. There are two shorter (2.93 Å) and four longer (2.98 Å) Li–Li bond lengths. All Li–Sn bond lengths are 3.22 Å. In the third Li site, Li is bonded in a 3-coordinate geometry to two equivalent Li, one Eu, and six Sn atoms. Both Li–Li bond lengths are 3.20 Å. The Li–Eu bond length is 3.27 Å. There are a spread of Li–Sn bond distances ranging from 2.86–3.30 Å. In the fourth Li site, Li is bonded in a 3-coordinate geometry to one Li, one Eu, and five Sn atoms. The Li–Eu bond length is 3.23 Å. There are a spread of Li–Sn bond distances ranging from 2.79–3.04 Å. In the fifth Li site, Li is bonded in a 4-coordinate geometry to two equivalent Li and five Sn atoms. There are a spread of Li–Sn bond distances ranging from 2.88–3.31 Å. Eu is bonded in a 7-coordinate geometry to five Li and ten Sn atoms. There are four shorter (3.39 Å) and six longer (3.44 Å) Eu–Sn bond lengths. There are five inequivalent Sn sites. In the first Sn site, Sn is bonded to eight Li, two equivalent Eu, and two Sn atoms to form distorted SnLi8Eu2Sn2 cuboctahedra that share corners with two equivalent SnLi8Eu2Sn2 cuboctahedra, edges with two equivalent LiLi8Sn4 cuboctahedra, edges with two equivalent SnLi8Eu2Sn2 cuboctahedra, faces with two equivalent LiLi8Sn4 cuboctahedra, and faces with four equivalent SnLi8Eu2Sn2 cuboctahedra. There are one shorter (2.96 Å) and one longer (2.99 Å) Sn–Sn bond lengths. In the second Sn site, Sn is bonded in a 4-coordinate geometry to four equivalent Li and two equivalent Eu atoms. In the third Sn site, Sn is bonded in a 7-coordinate geometry to seven Li and two equivalent Sn atoms. Both Sn–Sn bond lengths are 3.07 Å. In the fourth Sn site, Sn is bonded in a 6-coordinate geometry to four Li and four Sn atoms. Both Sn–Sn bond lengths are 3.44 Å. In the fifth Sn site, Sn is bonded in a 3-coordinate geometry to five Li, two equivalent Eu, and two Sn atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BaEu3 by Materials Project

BaEu3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba is bonded to twelve Eu atoms to form BaEu12 cuboctahedra that share corners with four equivalent BaEu12 cuboctahedra, corners with eight equivalent EuBa4Eu8 cuboctahedra, edges with eight equivalent BaEu12 cuboctahedra, edges with sixteen equivalent EuBa4Eu8 cuboctahedra, faces with four equivalent BaEu12 cuboctahedra, and faces with fourteen EuBa4Eu8 cuboctahedra. There are four shorter (4.06 Å) and eight longer (4.13 Å) Ba–Eu bond lengths. There are two inequivalent Eu sites. In the first Eu site, Eu is bonded to four equivalent Ba and eight Eu atoms to form EuBa4Eu8 cuboctahedra that share corners with twelve equivalent EuBa4Eu8 cuboctahedra, edges with eight equivalent BaEu12 cuboctahedra, edges with sixteen EuBa4Eu8 cuboctahedra, faces with four equivalent BaEu12 cuboctahedra, and faces with fourteen EuBa4Eu8 cuboctahedra. There are four shorter (4.06 Å) and four longer (4.13 Å) Eu–Eu bond lengths. In the second Eu site, Eu is bonded to four equivalent Ba and eight equivalent Eu atoms to form distorted EuBa4Eu8 cuboctahedra that share corners with four equivalent EuBa4Eu8 cuboctahedra, corners with eight equivalent BaEu12 cuboctahedra, edges with twenty-four EuBa4Eu8 cuboctahedra, faces with six equivalent BaEu12 cuboctahedra, and faces with twelve EuBa4Eu8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KEu3 by Materials Project

KEu3 is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. K is bonded in a body-centered cubic geometry to fourteen Eu atoms. There are eight shorter (4.04 Å) and six longer (4.67 Å) K–Eu bond lengths. There are two inequivalent Eu sites. In the first Eu site, Eu is bonded in a distorted body-centered cubic geometry to four equivalent K and four equivalent Eu atoms. All Eu–Eu bond lengths are 4.04 Å. In the second Eu site, Eu is bonded in a 8-coordinate geometry to six equivalent K and eight equivalent Eu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbEu3 by Materials Project

RbEu3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Rb is bonded to twelve Eu atoms to form RbEu12 cuboctahedra that share corners with four equivalent RbEu12 cuboctahedra, corners with eight equivalent EuRb4Eu8 cuboctahedra, edges with eight equivalent RbEu12 cuboctahedra, edges with sixteen equivalent EuRb4Eu8 cuboctahedra, faces with four equivalent RbEu12 cuboctahedra, and faces with fourteen EuRb4Eu8 cuboctahedra. There are four shorter (4.22 Å) and eight longer (4.25 Å) Rb–Eu bond lengths. There are two inequivalent Eu sites. In the first Eu site, Eu is bonded to four equivalent Rb and eight Eu atoms to form EuRb4Eu8 cuboctahedra that share corners with twelve equivalent EuRb4Eu8 cuboctahedra, edges with eight equivalent RbEu12 cuboctahedra, edges with sixteen EuRb4Eu8 cuboctahedra, faces with four equivalent RbEu12 cuboctahedra, and faces with fourteen EuRb4Eu8 cuboctahedra. There are four shorter (4.22 Å) and four longer (4.25 Å) Eu–Eu bond lengths. In the second Eu site, Eu is bonded to four equivalent Rb and eight equivalent Eu atoms to form distorted EuRb4Eu8 cuboctahedra that share corners with four equivalent EuRb4Eu8 cuboctahedra, corners with eight equivalent RbEu12 cuboctahedra, edges with twenty-four EuRb4Eu8 cuboctahedra, faces with six equivalent RbEu12 cuboctahedra, and faces with twelve EuRb4Eu8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu5CdCu2 by Materials Project

Eu5Cu2Cd crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. there are two inequivalent Eu sites. In the first Eu site, Eu is bonded in a 4-coordinate geometry to four equivalent Cu and two equivalent Cd atoms. All Eu–Cu bond lengths are 3.26 Å. Both Eu–Cd bond lengths are 3.72 Å. In the second Eu site, Eu is bonded to three equivalent Cu and two equivalent Cd atoms to form a mixture of distorted face, edge, and corner-sharing EuCd2Cu3 trigonal bipyramids. There are two shorter (3.12 Å) and one longer (3.26 Å) Eu–Cu bond lengths. Both Eu–Cd bond lengths are 3.44 Å. Cu is bonded in a 9-coordinate geometry to eight Eu and one Cu atom. The Cu–Cu bond length is 2.64 Å. Cd is bonded in a 10-coordinate geometry to ten Eu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu5Pt2 by Materials Project

Eu5Pt2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent Eu sites. In the first Eu site, Eu is bonded in a 2-coordinate geometry to three equivalent Pt atoms. There are a spread of Eu–Pt bond distances ranging from 2.99–3.60 Å. In the second Eu site, Eu is bonded to four equivalent Pt atoms to form distorted edge-sharing EuPt4 tetrahedra. There are two shorter (3.09 Å) and two longer (3.10 Å) Eu–Pt bond lengths. In the third Eu site, Eu is bonded in a 3-coordinate geometry to three equivalent Pt atoms. There are a spread of Eu–Pt bond distances ranging from 3.05–3.25 Å. Pt is bonded in a 8-coordinate geometry to eight Eu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KEu3 by Materials Project

KEu3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. K is bonded to twelve Eu atoms to form KEu12 cuboctahedra that share corners with four equivalent KEu12 cuboctahedra, corners with eight equivalent EuK4Eu8 cuboctahedra, edges with eight equivalent KEu12 cuboctahedra, edges with sixteen equivalent EuK4Eu8 cuboctahedra, faces with four equivalent KEu12 cuboctahedra, and faces with fourteen EuK4Eu8 cuboctahedra. There are four shorter (4.13 Å) and eight longer (4.20 Å) K–Eu bond lengths. There are two inequivalent Eu sites. In the first Eu site, Eu is bonded to four equivalent K and eight Eu atoms to form EuK4Eu8 cuboctahedra that share corners with twelve equivalent EuK4Eu8 cuboctahedra, edges with eight equivalent KEu12 cuboctahedra, edges with sixteen EuK4Eu8 cuboctahedra, faces with four equivalent KEu12 cuboctahedra, and faces with fourteen EuK4Eu8 cuboctahedra. There are four shorter (4.13 Å) and four longer (4.20 Å) Eu–Eu bond lengths. In the second Eu site, Eu is bonded to four equivalent K and eight equivalent Eu atoms to form distorted EuK4Eu8 cuboctahedra that share corners with four equivalent EuK4Eu8 cuboctahedra, corners with eight equivalent KEu12 cuboctahedra, edges with twenty-four EuK4Eu8 cuboctahedra, faces with six equivalent KEu12 cuboctahedra, and faces with twelve EuK4Eu8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Entrapped Molecule‐Like Europium‐Oxide Clusters in Zinc Oxide with Nearly Unaffected Host Structure

Abstract Nanocrystalline ZnO sponges doped with 5 mol% EuO 1.5 are obtained by heating metal–salt complex based precursor pastes at 200–900 °C for 3 min. X‐ray diffraction, transmission electron microscopy, and extended X‐ray absorption fine structure (EXAFS) show that phase separation into ZnO:Eu and c ‐Eu 2 O 3 takes place upon heating at 700 °C or higher. The unit cell of the clean oxide made at 600 °C shows only ≈0.4% volume increase versus undoped ZnO, and EXAFS shows a ZnO local structure that is little affected by the Eu‐doping and an average Eu 3+ ion coordination number of ≈5.2. Comparisons of 23 density functional theory‐generated structures having differently sized Eu‐oxide clusters embedded in ZnO identify three structures with four or eight Eu atoms as the most energetically favorable. These clusters exhibit the smallest volume increase compared to undoped ZnO and Eu coordination numbers of 5.2–5.5, all in excellent agreement with experimental data. ZnO defect states are crucial for efficient Eu 3+ excitation, while c ‐Eu 2 O 3 phase separation results in loss of the characteristic Eu 3+ photoluminescence. The formation of molecule‐like Eu‐oxide clusters, entrapped in ZnO, proposed here, may help in understanding the nature of the unexpected high doping levels of lanthanide ions in ZnO that occur virtually without significant change in ZnO unit cell dimensions.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Electrochemical reduction of europium(iii) using tetra- n -octyl diglycolamide functionalized ordered mesoporous carbon microelectrodes

This work investigates the one-electron reduction of Eu(III) to Eu(II) with ordered mesoporous carbon (OMC) in cavity microelectrode (CME) systems. OMC materials with and without tetra-n-octyl diglycolamide (TODGA) functionalization were subjected to voltammetric measurements and compared with commercial carbon black Vulcan® XC-72. The electrochemical reduction of solution Eu(III) with unfunctionalized OMC, XC-72, and TODGA-functionalized OMC—both within the electrode matrix and on the electrode surface—is reported. The complexation of Eu(III) by TODGA-functionalized OMC prior to electrode preparation incorporates Eu(III) as part of the bulk electrode matrix. Under these conditions, the high capacitance obscures the Eu(III)/Eu(II) redox couple. A signal emerges above the background (capacitive) currents when 2-octanol is added to the TODGA-functionalized OMC as a wetting agent. In contrast, surface Eu(III)–TODGA complexation, when Eu(III) contacts the electrode surface exclusively after electrode preparation, provides a strong response. The addition of 2-octanol to TODGA reduces the capacitance of the electrode and narrows the Eu(III)/Eu(II) redox peak widths. In conclusion, the desorption by reductive stripping of Eu(II) was demonstrated using a 2-octanol modified TODGA OMC CME, opening the possibility for selective separation of Eu from adjacent trivalent lanthanides.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2017

Application of New Partition Coefficients to Modeling Plagioclase

Previously, studies that determined the partition coefficient for an element, i, between plagioclase and the residual basaltic melt (Di plag) have been conducted using experimental conditions dissimilar from the Moon, and thus these values are not ideal for modeling plagioclase fractionation in a lunar system. However, recent work [1] has determined partition coefficients for plagioclase at lunar oxygen fugacities, and resulted in plagioclase with Anorthite contents ≥An90; these are significantly more calcic than plagioclase in previous studies, and the An content has a profound effect on partition coefficient values [2,3]. Plagioclase D-values, which are dependent on the An content of the crystal [e.g., 2-6], can be determined using published experimental data and the correlative An contents. Here, we examine new experimental data from [1] to ascertain their effect on the calculation of equilibrium liquids from Apollo 16 sample 60635,2. This sample is a coarse grained, subophitic impact melt composed of ~55% plagioclase laths with An94.4-98.7 [7,8], distinctly more calcic than of previous partition coefficient studies (e.g., [3-6, 9-10]). Sample 60635,2 is notable as having several plagioclase trace element analyses containing a negative Europium anomaly (-Eu) in the rare-earth element (REE) profile, rather than the typical positive Eu anomaly (+Eu) [7-8] (Fig. 1). The expected +Eu is due to the similarity in size and charge with Ca2+, thereby allowing Eu2+ to be easily taken up by the plagioclase crystal structure, in contrast to the remaining REE3+. Some 60635,2 plagioclase crystals only have +Eu REE profiles, some only have -Eu REE profiles, and some +Eu and -Eu analyses in different areas on a single crystal [7, 8]. Moreover, there does not seem to be any core-rim association with the +Eu or -Eu analyses, nor does there appear to be a correlation between the size, shape, or location of a particular crystal within the sample and the sign of its Eu anomaly, which suggests a complex evolution. In order to investigate this sample further, we can calculate the equilibrium liquids, but with An contents distinct from previous experimental studies, we must calculate the appropriate partition coefficients for each trace element analysis.

Fagan, A. L.↗
DOE OSTI2020

Materials Data on Eu2Si3Pd by Materials Project

Eu2PdSi3 is hexagonal omega structure-derived structured and crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. there are two inequivalent Eu sites. In the first Eu site, Eu is bonded to four equivalent Pd and eight equivalent Si atoms to form a mixture of face and edge-sharing EuSi8Pd4 cuboctahedra. All Eu–Pd bond lengths are 3.23 Å. All Eu–Si bond lengths are 3.25 Å. In the second Eu site, Eu is bonded to twelve equivalent Si atoms to form a mixture of face and edge-sharing EuSi12 cuboctahedra. All Eu–Si bond lengths are 3.21 Å. Pd is bonded in a 3-coordinate geometry to six equivalent Eu and three equivalent Si atoms. All Pd–Si bond lengths are 2.44 Å. Si is bonded in a 1-coordinate geometry to six Eu, one Pd, and two equivalent Si atoms. Both Si–Si bond lengths are 2.37 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu5(ZrS4)3 by Materials Project

Eu5Zr3S12 crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. there are two inequivalent Eu+2.40+ sites. In the first Eu+2.40+ site, Eu+2.40+ is bonded to seven S2- atoms to form distorted EuS7 pentagonal bipyramids that share corners with two equivalent ZrS6 octahedra, corners with two equivalent EuS7 pentagonal bipyramids, edges with four equivalent ZrS6 octahedra, and edges with two equivalent EuS7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 50°. There are a spread of Eu–S bond distances ranging from 2.89–2.91 Å. In the second Eu+2.40+ site, Eu+2.40+ is bonded in a 9-coordinate geometry to nine S2- atoms. There are six shorter (2.99 Å) and three longer (3.41 Å) Eu–S bond lengths. Zr4+ is bonded to six S2- atoms to form ZrS6 octahedra that share corners with two equivalent EuS7 pentagonal bipyramids, edges with two equivalent ZrS6 octahedra, and edges with four equivalent EuS7 pentagonal bipyramids. There are a spread of Zr–S bond distances ranging from 2.56–2.62 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded to four Eu+2.40+ and one Zr4+ atom to form distorted SEu4Zr trigonal bipyramids that share corners with seven equivalent SEu4Zr trigonal bipyramids, corners with two equivalent SEu2Zr2 trigonal pyramids, edges with five equivalent SEu4Zr trigonal bipyramids, and edges with two equivalent SEu2Zr2 trigonal pyramids. In the second S2- site, S2- is bonded to two equivalent Eu+2.40+ and two equivalent Zr4+ atoms to form distorted SEu2Zr2 trigonal pyramids that share corners with four equivalent SEu4Zr trigonal bipyramids, corners with four equivalent SEu2Zr2 trigonal pyramids, and edges with four equivalent SEu4Zr trigonal bipyramids. In the third S2- site, S2- is bonded in a 5-coordinate geometry to three Eu+2.40+ and two equivalent Zr4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu2Cd2As3 by Materials Project

Eu2Cd2As3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Eu+2.50+ sites. In the first Eu+2.50+ site, Eu+2.50+ is bonded to six As3- atoms to form EuAs6 octahedra that share corners with six equivalent EuAs7 pentagonal bipyramids, corners with seven CdAs4 tetrahedra, edges with four equivalent EuAs6 octahedra, an edgeedge with one EuAs7 pentagonal bipyramid, edges with five CdAs4 tetrahedra, and a faceface with one EuAs7 pentagonal bipyramid. There are a spread of Eu–As bond distances ranging from 3.06–3.19 Å. In the second Eu+2.50+ site, Eu+2.50+ is bonded to seven As3- atoms to form distorted EuAs7 pentagonal bipyramids that share corners with six equivalent EuAs6 octahedra, corners with seven CdAs4 tetrahedra, an edgeedge with one EuAs6 octahedra, edges with four equivalent EuAs7 pentagonal bipyramids, edges with three CdAs4 tetrahedra, a faceface with one EuAs6 octahedra, and faces with three equivalent EuAs7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 37–47°. There are a spread of Eu–As bond distances ranging from 3.10–3.46 Å. There are two inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to four As3- atoms to form CdAs4 tetrahedra that share corners with three equivalent EuAs6 octahedra, corners with three equivalent EuAs7 pentagonal bipyramids, corners with four CdAs4 tetrahedra, edges with three equivalent EuAs6 octahedra, edges with two equivalent EuAs7 pentagonal bipyramids, and edges with two equivalent CdAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 13–56°. There are a spread of Cd–As bond distances ranging from 2.73–2.79 Å. In the second Cd2+ site, Cd2+ is bonded to four As3- atoms to form CdAs4 tetrahedra that share corners with four equivalent EuAs6 octahedra, corners with four equivalent EuAs7 pentagonal bipyramids, corners with four CdAs4 tetrahedra, edges with two equivalent EuAs6 octahedra, an edgeedge with one EuAs7 pentagonal bipyramid, and edges with three CdAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 16–58°. There are a spread of Cd–As bond distances ranging from 2.70–2.95 Å. There are three inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to six Eu+2.50+, one Cd2+, and one As3- atom. The As–As bond length is 2.56 Å. In the second As3- site, As3- is bonded in a 7-coordinate geometry to four Eu+2.50+ and three Cd2+ atoms. In the third As3- site, As3- is bonded to three equivalent Eu+2.50+ and four Cd2+ atoms to form distorted edge-sharing AsEu3Cd4 pentagonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu2CuS3 by Materials Project

Eu2CuS3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Eu+2.50+ sites. In the first Eu+2.50+ site, Eu+2.50+ is bonded to seven S2- atoms to form distorted EuS7 pentagonal bipyramids that share corners with six equivalent EuS6 octahedra, corners with three equivalent CuS4 tetrahedra, edges with four equivalent EuS6 octahedra, edges with two equivalent EuS7 pentagonal bipyramids, edges with three equivalent CuS4 tetrahedra, and faces with two equivalent EuS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 19–69°. There are a spread of Eu–S bond distances ranging from 2.95–3.24 Å. In the second Eu+2.50+ site, Eu+2.50+ is bonded to six S2- atoms to form EuS6 octahedra that share corners with two equivalent EuS6 octahedra, corners with six equivalent EuS7 pentagonal bipyramids, edges with two equivalent EuS6 octahedra, edges with four equivalent EuS7 pentagonal bipyramids, and edges with four equivalent CuS4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. There are a spread of Eu–S bond distances ranging from 2.81–2.86 Å. Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with three equivalent EuS7 pentagonal bipyramids, corners with two equivalent CuS4 tetrahedra, edges with four equivalent EuS6 octahedra, and edges with three equivalent EuS7 pentagonal bipyramids. There are a spread of Cu–S bond distances ranging from 2.30–2.38 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 6-coordinate geometry to five Eu+2.50+ and one Cu1+ atom. In the second S2- site, S2- is bonded to four Eu+2.50+ and one Cu1+ atom to form distorted SEu4Cu square pyramids that share corners with four equivalent SEu4Cu2 octahedra, edges with three equivalent SEu4Cu2 octahedra, and edges with two equivalent SEu4Cu square pyramids. The corner-sharing octahedra tilt angles range from 49–81°. In the third S2- site, S2- is bonded to four Eu+2.50+ and two equivalent Cu1+ atoms to form distorted SEu4Cu2 octahedra that share corners with two equivalent SEu4Cu2 octahedra, corners with four equivalent SEu4Cu square pyramids, edges with two equivalent SEu4Cu2 octahedra, and edges with three equivalent SEu4Cu square pyramids. The corner-sharing octahedral tilt angles are 7°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr2Eu3Ge10 by Materials Project

Sr2Eu3Ge10 is High Pressure (4-7GPa) Tellurium-derived structured and crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Sr is bonded to six Ge atoms to form SrGe6 octahedra that share corners with three equivalent GeEu3Ge3 octahedra, edges with three equivalent GeEu3Ge3 octahedra, and edges with six equivalent SrGe6 octahedra. The corner-sharing octahedral tilt angles are 18°. There are three shorter (3.16 Å) and three longer (3.17 Å) Sr–Ge bond lengths. There are two inequivalent Eu sites. In the first Eu site, Eu is bonded to six Ge atoms to form EuGe6 octahedra that share corners with three equivalent GeEu3Ge3 octahedra, edges with three equivalent GeEu3Ge3 octahedra, and edges with six equivalent EuGe6 octahedra. The corner-sharing octahedral tilt angles are 17°. There are three shorter (3.12 Å) and three longer (3.14 Å) Eu–Ge bond lengths. In the second Eu site, Eu is bonded to six equivalent Ge atoms to form EuGe6 octahedra that share corners with six equivalent GeEu3Ge3 octahedra, edges with six equivalent EuGe6 octahedra, and edges with six equivalent GeEu3Ge3 octahedra. The corner-sharing octahedral tilt angles are 17°. All Eu–Ge bond lengths are 3.14 Å. There are five inequivalent Ge sites. In the first Ge site, Ge is bonded to three equivalent Eu and three equivalent Ge atoms to form distorted GeEu3Ge3 octahedra that share corners with three equivalent EuGe6 octahedra, corners with three equivalent GeEu3Ge3 octahedra, edges with three equivalent EuGe6 octahedra, and edges with nine GeEu3Ge3 octahedra. The corner-sharing octahedra tilt angles range from 0–17°. All Ge–Ge bond lengths are 2.62 Å. In the second Ge site, Ge is bonded to three equivalent Eu and three equivalent Ge atoms to form distorted GeEu3Ge3 octahedra that share corners with three equivalent EuGe6 octahedra, corners with three equivalent GeEu3Ge3 octahedra, edges with three equivalent EuGe6 octahedra, and edges with nine equivalent GeEu3Ge3 octahedra. The corner-sharing octahedra tilt angles range from 0–17°. In the third Ge site, Ge is bonded to three equivalent Eu and three equivalent Ge atoms to form distorted GeEu3Ge3 octahedra that share corners with three equivalent SrGe6 octahedra, corners with three equivalent GeEu3Ge3 octahedra, edges with three equivalent SrGe6 octahedra, and edges with nine GeEu3Ge3 octahedra. The corner-sharing octahedra tilt angles range from 0–18°. All Ge–Ge bond lengths are 2.61 Å. In the fourth Ge site, Ge is bonded in a 6-coordinate geometry to three equivalent Sr and three equivalent Ge atoms. All Ge–Ge bond lengths are 2.61 Å. In the fifth Ge site, Ge is bonded in a 6-coordinate geometry to three equivalent Sr and three equivalent Ge atoms.

36 MATERIALS SCIENCE↗