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At least 577 records · Page 32
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on LiEu3 by Materials Project

LiEu3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Li is bonded to twelve equivalent Eu atoms to form LiEu12 cuboctahedra that share corners with six equivalent LiEu12 cuboctahedra, corners with twelve equivalent EuLi4Eu8 cuboctahedra, edges with eighteen equivalent EuLi4Eu8 cuboctahedra, faces with eight equivalent LiEu12 cuboctahedra, and faces with twelve equivalent EuLi4Eu8 cuboctahedra. There are six shorter (3.79 Å) and six longer (3.80 Å) Li–Eu bond lengths. Eu is bonded to four equivalent Li and eight equivalent Eu atoms to form EuLi4Eu8 cuboctahedra that share corners with four equivalent LiEu12 cuboctahedra, corners with fourteen equivalent EuLi4Eu8 cuboctahedra, edges with six equivalent LiEu12 cuboctahedra, edges with twelve equivalent EuLi4Eu8 cuboctahedra, faces with four equivalent LiEu12 cuboctahedra, and faces with sixteen equivalent EuLi4Eu8 cuboctahedra. There are a spread of Eu–Eu bond distances ranging from 3.74–3.86 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PmEu3 by Materials Project

Eu3Pm is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Eu is bonded to eight equivalent Eu and four equivalent Pm atoms to form EuPm4Eu8 cuboctahedra that share corners with four equivalent PmEu12 cuboctahedra, corners with fourteen equivalent EuPm4Eu8 cuboctahedra, edges with six equivalent PmEu12 cuboctahedra, edges with twelve equivalent EuPm4Eu8 cuboctahedra, faces with four equivalent PmEu12 cuboctahedra, and faces with sixteen equivalent EuPm4Eu8 cuboctahedra. There are a spread of Eu–Eu bond distances ranging from 3.75–3.89 Å. There are two shorter (3.77 Å) and two longer (3.82 Å) Eu–Pm bond lengths. Pm is bonded to twelve equivalent Eu atoms to form PmEu12 cuboctahedra that share corners with six equivalent PmEu12 cuboctahedra, corners with twelve equivalent EuPm4Eu8 cuboctahedra, edges with eighteen equivalent EuPm4Eu8 cuboctahedra, faces with eight equivalent PmEu12 cuboctahedra, and faces with twelve equivalent EuPm4Eu8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu3Ho by Materials Project

HoEu3 is Magnesium-derived structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ho is bonded to twelve equivalent Eu atoms to form HoEu12 cuboctahedra that share corners with six equivalent HoEu12 cuboctahedra, corners with twelve equivalent EuEu8Ho4 cuboctahedra, edges with eighteen equivalent EuEu8Ho4 cuboctahedra, faces with eight equivalent HoEu12 cuboctahedra, and faces with twelve equivalent EuEu8Ho4 cuboctahedra. There are six shorter (3.75 Å) and six longer (3.82 Å) Ho–Eu bond lengths. Eu is bonded to four equivalent Ho and eight equivalent Eu atoms to form EuEu8Ho4 cuboctahedra that share corners with four equivalent HoEu12 cuboctahedra, corners with fourteen equivalent EuEu8Ho4 cuboctahedra, edges with six equivalent HoEu12 cuboctahedra, edges with twelve equivalent EuEu8Ho4 cuboctahedra, faces with four equivalent HoEu12 cuboctahedra, and faces with sixteen equivalent EuEu8Ho4 cuboctahedra. There are a spread of Eu–Eu bond distances ranging from 3.74–3.90 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on EuEr by Materials Project

ErEu is Magnesium-derived structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Er is bonded to six equivalent Er and six equivalent Eu atoms to form ErEu6Er6 cuboctahedra that share corners with eighteen equivalent ErEu6Er6 cuboctahedra, edges with six equivalent ErEu6Er6 cuboctahedra, edges with twelve equivalent EuEu6Er6 cuboctahedra, faces with eight equivalent ErEu6Er6 cuboctahedra, and faces with twelve equivalent EuEu6Er6 cuboctahedra. All Er–Er bond lengths are 3.66 Å. All Er–Eu bond lengths are 3.69 Å. Eu is bonded to six equivalent Er and six equivalent Eu atoms to form EuEu6Er6 cuboctahedra that share corners with eighteen equivalent EuEu6Er6 cuboctahedra, edges with six equivalent EuEu6Er6 cuboctahedra, edges with twelve equivalent ErEu6Er6 cuboctahedra, faces with eight equivalent EuEu6Er6 cuboctahedra, and faces with twelve equivalent ErEu6Er6 cuboctahedra. All Eu–Eu bond lengths are 3.66 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KEu3 by Materials Project

KEu3 is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. K is bonded to twelve equivalent Eu atoms to form KEu12 cuboctahedra that share corners with twelve equivalent KEu12 cuboctahedra, edges with twenty-four equivalent EuK4Eu8 cuboctahedra, faces with six equivalent KEu12 cuboctahedra, and faces with twelve equivalent EuK4Eu8 cuboctahedra. All K–Eu bond lengths are 4.16 Å. Eu is bonded to four equivalent K and eight equivalent Eu atoms to form EuK4Eu8 cuboctahedra that share corners with twelve 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 equivalent EuK4Eu8 cuboctahedra. All Eu–Eu bond lengths are 4.16 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on EuNi9Ge4 by Materials Project

EuNi9Ge4 crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. Eu is bonded in a 8-coordinate geometry to sixteen Ni and eight equivalent Ge atoms. There are eight shorter (3.43 Å) and eight longer (3.48 Å) Eu–Ni bond lengths. All Eu–Ge bond lengths are 3.40 Å. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded in a 12-coordinate geometry to two equivalent Eu, six Ni, and four equivalent Ge atoms. There are a spread of Ni–Ni bond distances ranging from 2.43–2.66 Å. There are two shorter (2.55 Å) and two longer (2.59 Å) Ni–Ge bond lengths. In the second Ni site, Ni is bonded in a cuboctahedral geometry to eight Ni and four equivalent Ge atoms. All Ni–Ni bond lengths are 2.45 Å. All Ni–Ge bond lengths are 2.43 Å. In the third Ni site, Ni is bonded in a 12-coordinate geometry to two equivalent Eu, eight Ni, and two equivalent Ge atoms. There are two shorter (2.49 Å) and one longer (2.72 Å) Ni–Ni bond lengths. Both Ni–Ge bond lengths are 2.52 Å. Ge is bonded in a 12-coordinate geometry to two equivalent Eu, seven Ni, and three equivalent Ge atoms. There are two shorter (2.68 Å) and one longer (2.70 Å) Ge–Ge bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Impact of europium and samarium on growth and metabolism of two anaerobic wastewater microorganisms: Sporacetigenium mesophilum and Clostridium sporogenes

Increases in environmental fluxes of rare earth elements (REEs) stemming from increased demand for these technology critical elements may affect microbial ecosystem functions important for pollutant degradation and nutrient cycling. Here, this study investigates the responses of Sporacetigenium mesophilum and Clostridium sporogenes, two anaerobic fermenters, to varying concentrations of two REE, namely europium and samarium. Eu and Sm are adjacent lanthanides but differ significantly in their redox behavior. We tested Eu and Sm concentrations ranging from < 1 to 600 µM. Despite the close phylogenetic relatedness of the two bacteria, we observed species-specific as well as REE-specific and incubation time-dependent sensitivities. S. mesophilum exhibited pronounced inhibition of hydrogen production and growth with exposure to ≥ 60 µM of Eu, but with 6 µM Eu, a hormetic effect was observed—hydrogen production was enhanced relative to the control. With Sm, the only impact observed on S. mesophilum was inhibition at the highest concentration (600 µM) tested. For C. sporogenes, growth inhibition was observed only at 600 µM Eu or Sm, and no hormesis was observed with either REE. This study offers both significant benefits and novelty by addressing the emerging environmental concern of REE pollution, particularly the effects of Eu and Sm on anaerobic microorganisms relevant to wastewater treatment. It provides valuable insights into REE impacts under anaerobic conditions, which are essential for understanding potential disruptions to organic matter degradation and nutrient cycling processes.

60 - APPLIED LIFE SCIENCES↗
DOE OSTI2023

Solution Structures of Europium Terpyridyl Complexes with Nitrate and Triflate Counterions in Acetonitrile

Lanthanide–ligand complexes are key components of technological applications, and their properties depend on their structures in the solution phase, which are challenging to resolve experimentally or computationally. The coordination structure of the Eu 3+ ion in different coordination environments in acetonitrile is examined using ab initio molecular dynamics (AIMD) simulations and extended X-ray absorption fine structure (EXAFS) spectroscopy. AIMD simulations are conducted for the solvated Eu 3+ ion in acetonitrile, both with or without a terpyridyl ligand, and in the presence of either triflate or nitrate counterions. EXAFS spectra are calculated directly from AIMD simulations and then compared to experimentally measured EXAFS spectra. In acetonitrile solution, both nitrate and triflate anions are shown to coordinate directly to the Eu 3+ ion forming either ten- or eight-coordinate solvent complexes where the counterions are binding as bidentate or monodentate structures, respectively. Coordination of a terpyridyl ligand to the Eu 3+ ion limits the available binding sites for the solvent and anions. In certain cases, the terpyridyl ligand excludes any solvent binding and limits the number of coordinated anions. The solution structure of the Eu-terpyridyl complex with nitrate counterions is shown to have a similar arrangement of Eu 3+ coordinating molecules as the crystal structure. Finally, this study illustrates how a combination of AIMD and EXAFS can be used to determine how ligands, solvent, and counterions coordinate with the lanthanide ions in solution.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Using molten salts to probe outer-coordination sphere effects on lanthanide( III )/( II ) electron-transfer reactions

Controlling structure and reactivity by manipulating the outer-coordination sphere around a given reagent represents a longstanding challenge in chemistry. Despite advances toward solving this problem, it remains difficult to experimentally interrogate and characterize outer-coordination sphere impact. Here, this work describes an alternative approach that quantifies outer-coordination sphere effects. It shows how molten salt metal chlorides (MCl n ; M = K, Na, n = 1; M = Ca, n = 2) provided excellent platforms for experimentally characterizing the influence of the outer-coordination sphere cations (M n+ ) on redox reactions accessible to lanthanide ions; Ln 3+ + e 1– → Ln 2+ (Ln = Eu, Yb, Sm; e 1– = electron). As a representative example, X-ray absorption spectroscopy and cyclic voltammetry results showed that Eu 2+ instantaneously formed when Eu 3+ dissolved in molten chloride salts that had strongly polarizing cations (like Ca 2+ from CaCl 2 ) via the Eu 3+ + Cl 1– → Eu 2+ + ½Cl 2 reaction. Conversely, molten salts with less polarizing outer-sphere M 1+ cations (e.g., K 1+ in KCl) stabilized Ln 3+ . For instance, the Eu 3+ /Eu 2+ reduction potential was >0.5 V more positive in CaCl 2 than in KCl. In accordance with first-principle molecular dynamics (FPMD) simulations, we postulated that hard M n+ cations (high polarization power) inductively removed electron density from Ln n+ across Ln–Cl···M n+ networks and stabilized electron-rich and low oxidation state Ln 2+ ions. Conversely, less polarizing M n+ cations (like K 1+ ) left electron density on Lnn+ and stabilized electron-deficient and high-oxidation state Ln 3+ ions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Strongly anisotropic antiferromagnetic coupling in EuFe 2 As 2 revealed by stress detwinning

Of all parent compounds of iron-based high-temperature superconductors, EuFe 2 As 2 exhibits by far the largest magnetostructural coupling due to the sizable biquadratic interaction between Eu and Fe moments. While the coupling between Eu antiferromagnetic order and Fe structural/antiferromagnetic domains enables rapid field detwinning, this prevents simple magnetometry measurements from extracting the critical fields of the Eu metamagnetic transitions. Furthermore we measure these critical fields by combining x-ray magnetic circular dichroism spectroscopy with in-situ tunable uniaxial stress and applied magnetic field. The combination of two tuning knobs allows us to separate the stressdetwinning of structural domains from the field-induced reorientation of Eu moments. Intriguingly, from the critical field values we find that the Eu interplanar interaction is strongly anisotropic. We argue that this anisotropic exchange term is likely a consequence of the strong anisotropy in the magnetically ordered Fe layer, which highlights the non-trivial interplay between Eu-Fe magnetism in this system.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2023

Crystal Growth and Characterization of Europium-Doped Rubidium Calcium Bromide Scintillators

National security strategies like gamma spectroscopy and high-energy X-ray radiography are limited, in part, by the scintillator used, prompting research into novel materials with improved properties. In this paper, Eu 2+ activated rubidium calcium bromide scintillators were grown via the vertical Bridgman method with a range of dopant concentrations. Light yield, energy resolution, and the afterglow of Rb 4 CaBr 6 :Eu and RbCaBr 3 :Eu improved with increasing Eu 2+ concentration, and scintillation decay time increased. The highest light yields of Rb 4 CaBr 6 :Eu and RbCaBr 3 :Eu were 71000 and 45000 ph/MeV, respectively.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Toward white light emission from plasmonic-luminescent hybrid nanostructures

We study the light emission of plasmonic-luminescent hybrid nanostructures consisting of Ag nanoparticles (NPs) embedded in europium oxide (EuO X ). The Ag NPs present a bidimensional organization in the nanostructures and they optically behave as oblate spheroids. The photoluminescence (PL) spectral response of the nanostructures evolves from a narrow red emission characteristic of Eu 3+ ions in absence of Ag NPs to a broad blue-green emission band associated with Eu 2+ ions when the layer of Ag NPs is present. This behavior is not related to a change in the Eu 2+ /Eu 3+ ratio, which is verified by compositional analysis. Instead, a detailed investigation of the PL emission of the nanostructures suggests that the coupling of the Ag NPs to the Eu 2+ ions present in the EuO X layer, which manifests itself in an efficient sensitization of these ions, enhances their broad visible emission. In particular, the longitudinal mode of the Ag NPs surface plasmon is considered to be responsible for the efficient energy transfer for the non-normal incidence excitation PL configuration used. Finally, the use of a capping amorphous Al 2 O 3 layer allows improving the robustness of hybrid nanostructures and further enhances their PL emission. These findings provide a new path to actively control the selective excitation of Eu 2+ and Eu 3+ ions via a controlled coupling with the surface plasmon resonance modes of the Ag NPs and points to these nanostructures as promising building blocks for the development of integrable white light sources.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Abundances of Neutron-capture Elements in 62 Stars in the Globular Cluster Messier 15

M15 is a globular cluster with a known spread in neutron-capture elements. This paper presents abundances of neutron-capture elements for 62 stars in M15. Spectra were obtained with the Michigan/Magellan Fiber System spectrograph, covering a wavelength range from ~4430 to 4630 Å. Spectral lines from Fe I , Fe II , Sr I , Zr II , Ba II , La II , Ce II , Nd II , Sm II , Eu II , and Dy II were measured, enabling classifications and neutron-capture abundance patterns for the stars. Of the 62 targets, 44 are found to be highly Eu-enhanced r-II stars, another 17 are moderately Eu-enhanced r-I stars, and one star is found to have an s-process signature. The neutron-capture patterns indicate that the majority of the stars are consistent with enrichment by the r-process. The 62 target stars are found to show significant star-to-star spreads in Sr, Zr, Ba, La, Ce, Nd, Sm, Eu, and Dy, but no significant spread in Fe. The neutron-capture abundances are further found to have slight correlations with sodium abundances from the literature, unlike what has been previously found; follow-up studies are needed to verify this result. The findings in this paper suggest that the Eu-enhanced stars in M15 were enhanced by the same process, that the nucleosynthetic source of this Eu pollution was the r-process, and that the r-process source occurred as the first generation of cluster stars was forming.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

Wash Penalty Factors: Insight into the Effects of Water Wash Down of Building Materials for Radionuclide/Nuclear (Rn) Decontamination - 20153

The release of radiological material to the urban environment can have a devastating socio-economic impact. In an urban release scenario, areas around the dispersal epicenter and any areas contaminated via atmospheric deposition may require extensive decontamination. Most recently, our group reported the decontamination efficacy of pressurized water washing of common porous building materials, and compared the penetration depth of the contaminations before and after exposure to pressurized tap water. Here, we continue evaluation of the decontamination efficacy of wash solutions based on potassium (K{sup +}) salt for cesium (Cs), strontium (Sr), and europium (Eu) contaminations on common building surfaces. The surfaces included: the cement used in concrete, the aggregate used in concrete, intact concrete, roadway asphalt, asphalt shingles, and latex paint. We deposited solutions of {sup 137}Cs, {sup 85}Sr, and {sup 152}Eu onto numerous common building materials and exposed these materials to a static bath or low-pressure flow of tap water, 0.1 M potassium chloride (KCl), and 0.5 M KCl. The decontamination efficacy and the depth profile for residual contamination were measured to determine the conditions under which applying a wash solution has benefit compared to physically removing the surface material. To aid in these analyses, we introduced a 'wash penalty factor' to quantify the degree to which contamination migrated into the bulk material by the action of the wash method. On asphalt, 70-80% of the radionuclides were found to be within 0.02 mm of the surface. Cs{sup +} bonded to negative charge sites on the surface of the mineral aggregate (used in concrete) so decontamination was improved by ion exchange with K{sup +}. Sr{sup 2+} is soluble and removed by water, while not bonding to aggregate or demonstrating solubility in the liquid asphalt. Eu{sup 3+} is precipitated and not removed in gentle wash but displays mobility within the pore space that suggests its presence as a colloid. Concrete is more porous than asphalt, and 80% of the radionuclides were within 0.2 mm of the surface for {sup 137}Cs and {sup 152}Eu and 50- 80% for {sup 85}Sr. On concrete, Cs{sup +} bonds similarly to asphalt. Sr{sup 2+} bonds to the cement or precipitates from the alkaline pore water. Eu{sup 3+} sorbs to the cement and then precipitates. In brick, the results for Cs{sup +} and Sr{sup 2+} suggested that diffusion of ions from deeper in the coupon was important. Eu{sup 3+} is removed poorly due to precipitation. We will explain and report example wash penalty factors that vary from 0 to > 1 for the various methods and the implications for deciding when to implement wash down methods. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

Selective Detection of Diglycolamide Diastereomers By Metal-Ligand Cluster Formation

Introduction (120 words): Differentiation of isomers using mass spectrometry is a challenge, as these species tend to produce ions of identical mass-to-charge ratio. Therefore, separation with mass spectrometry must rely on chemical differences between isomeric species. Separation of stereoisomers is especially challenging, as these species often have very similar chemistry. However, recent investigations of the solvent extraction behavior of diastereomers of diglycolamide molecules have shown that different stereoisomers can have significantly different lanthanide extraction efficiencies. These studies showed that the R,S stereoisomer of 2,2'-oxybis(N,N-dioctylpropanamide efficiently extracts lanthanides, while the S,S stereoisomer does not. Thus, gas-phase metal complexation may provide a pathway for differentiating these species using mass spectrometry. Methods (120 words): Europium, samarium, and holmium clusters with the R,S, and the S,S diastereomers of 2,2'-oxybis(N,N-didecylpropanamide (trivially tetradecyl diglycolamide, or mTDDGA) were generated in gas-phase using the electrospray ionization source of a Bruker (Billerica, MA, USA) micrOTOF-Q II quadrupole time-of-flight mass spectrometer. Solutions of aqueous lanthanide nitrate and diglycolamide ligands in 2-propanol were added to 50%:50% by volume acetonitrile:2-propanol to generate the spray solutions. Ligand concentration was maintained at approximately 6 µM, while lanthanide concentration was maintained at either 6 µM or 30 µM . High resolution, high mass accuracy spectra were recorded using the time-of-flight. Mass accuracy was ensured using external calibration with Agilent (Santa Clara, CA, USA) ESI-L Low Concentration tuning mix. Preliminary data (300 words): Electrospray of solutions containing only R,S-mTDDGA or S,S-m-TDDGA yield abundant peaks at m/z= 721.7, corresponding to [mTDDGA+H]+1, m/z = 743.7, corresponding to [mTDDGA+Na]+1, and m/z = 1464.4, corresponding to the sodium-bound dimer, [Na(mTDDGA)2]+1. Spray of solutions containing 6 µM europium (Eu) with 3 µM R,S-mTDDGA produced an abundant cluster ion with an isotopic envelope centered at m/z=772.0, corresponding to [Eu(R,S-mTDDGA)3]3+. Europium-containing cluster ions with isotopic envelopes apexing at m/z = 1012.3 and 1189.0 correspond to the [Eu(R,S-mTDDGA)4]3+ and [Eu(R,S-mTDDGA)5]3+ cluster ions, respectively. Protonated and sodiated R,S-mTDDGA are present as well, along with the sodium-bound dimer. In contrast, spray of solutions containing 6 µM europium (Eu) with 3 µM S,S-mTDDGA diastereomer yielded only protonated and sodiated ligand ions; no Eu- S,S-mTDDGA ions were present. This mirrors the solution-phase behavior, where the S,S diestereomer extracts lanthanides with significantly less efficiency than the R,S diestereomer. Experiments with holmium and samarium yielded the same results. Increasing the lanthanide concentration to 30 µM resulted in limited formation of lanthanide-S,S-mTDDGA clusters. However, the abundance of the [Ln(S,S-mTDDGA)3]3+ clusters remained low compared to the abundance of the protonated and sodiated ligand. Additionally, the abundance of the [Ln(R,S-mTDDGA)3]3+ cluster ion was significantly higher than that of the protonated and sodiated ligand in experiments with spray solutions containing 30 µM lanthanide with R,S-mTDDA, supporting the hypothesis that R,S-mTDDGA has a higher intrinsic affinity for the lanthanides than S,S-mTDDGA. Thus, the intrinsic complexation with lanthanides appears to offer a route to differentiate diglycolamide diestereomers in the gas-phase. Novelty (20): Stereoisomers can be differentiated in the gas phase by exploitation of differences in metal complexation chemistry.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Radiative transition probabilities of neutral and singly ionized Europium estimated by laser-induced breakdown spectroscopy (LIBS)

Laser-induced breakdown spectroscopy (LIBS) is a versatile technique for compositional analysis for solids, liquids, or gasses. LIBS is an asset for the quantitative or qualitative analysis of resource limited materials like actinides and rare earths because it is quasi-nondestructive. Two Eu 2 O 3 pellets were synthesized to be a test and validation set, respectively. Spectral lines identified from the National Institute of Standards and Technology database with fundamental data reported were used to form Saha-Boltzmann plots. The Saha-Boltzmann plots were used to determine the plasma temperatures and electron densities of the laser-induced plasmas for both samples. These Saha-Boltzmann plots were then used to calculate previously unreported transition probabilities associated with identified peaks. Additionally, the transition probabilities presented in this paper provide the capability for calibration free LIBS to be performed more readily on europium samples and the spectroscopic analysis of stellar bodies. Eight previously unreported transition probabilities are presented in this paper; five for Eu I and three for Eu II. The transition probabilities for Eu I ranged from 0.172 to 7.38 × 10 7 s -1 and those for Eu II ranged from 1.56 to 6.75 × 10 7 s -1 .

47 OTHER INSTRUMENTATION↗
DOE OSTI2020

Materials Data on EuZnSn by Materials Project

EuZnSn crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Eu is bonded in a 12-coordinate geometry to six equivalent Zn and six equivalent Sn atoms. There are a spread of Eu–Zn bond distances ranging from 3.23–3.64 Å. There are a spread of Eu–Sn bond distances ranging from 3.33–3.47 Å. Zn is bonded in a 10-coordinate geometry to six equivalent Eu and four equivalent Sn atoms. There are three shorter (2.79 Å) and one longer (3.03 Å) Zn–Sn bond lengths. Sn is bonded in a 10-coordinate geometry to six equivalent Eu and four equivalent Zn atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on EuMg2Cu9 by Materials Project

EuCu9Mg2 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Mg is bonded in a 12-coordinate geometry to twelve Cu atoms. There are a spread of Mg–Cu bond distances ranging from 2.87–2.97 Å. Eu is bonded in a distorted hexagonal planar geometry to eighteen Cu atoms. There are six shorter (2.93 Å) and twelve longer (3.27 Å) Eu–Cu bond lengths. There are four inequivalent Cu sites. In the first Cu site, Cu is bonded in a 12-coordinate geometry to three equivalent Eu and six equivalent Cu atoms. All Cu–Cu bond lengths are 2.52 Å. In the second Cu site, Cu is bonded to three equivalent Mg, two equivalent Eu, and seven Cu atoms to form a mixture of edge, face, and corner-sharing CuEu2Mg3Cu7 cuboctahedra. There are a spread of Cu–Cu bond distances ranging from 2.46–2.56 Å. In the third Cu site, Cu is bonded in a 12-coordinate geometry to three equivalent Eu and six equivalent Cu atoms. In the fourth Cu site, Cu is bonded to six equivalent Mg and six equivalent Cu atoms to form CuMg6Cu6 cuboctahedra that share corners with twelve equivalent CuEu2Mg3Cu7 cuboctahedra, edges with six equivalent CuMg6Cu6 cuboctahedra, and faces with eighteen equivalent CuEu2Mg3Cu7 cuboctahedra.

36 MATERIALS SCIENCE↗