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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.

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At least 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Thermo-mechanical behavior of hypoeutectic Ni-Y-Zr alloys

Microstructure refinement and optimized alloying can improve metallic alloy performance: stable nanocrystalline (NC) alloys with immiscible second phases, e.g., Cu-Ta, are stronger than unstable NC alloys and their coarse-grained (CG) counterparts, but higher melting point matrices are needed. Hypoeutectic, CG Ni-Y-Zr alloys were produced via arc-melting to explore their potential as high-performance materials. Microstructures were studied to determine phases present, local composition and length scales, while heat treatments allowed investigating microstructural stability. Alloys had a stable, hierarchical microstructure with ~250 nm ultrafine eutectic, ~10 µm dendritic arm spacing and ~1 mm grain size. Hardness and uniaxial compression tests revealed that mechanical properties of Ni-0.5Y-1.8Zr (in wt%) were comparable to Inconel 617 despite the small alloying additions, due to its hierarchical microstructure. Here, uniaxial compression at 600 °C showed that ternary alloys outperformed Ni-Zr and Ni-Y binary alloys in flow stress and hardening rates, which indicates that the Ni 17 Y 2 phase was an effective reinforcement for the eutectic, which supplemented the matrix hardening due to increased solubility of Zr. Results suggest that ternary Ni-Y-Zr alloys hold significant promise for high temperature applications.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Crystal structure of the CoV-Y domain of SARS-CoV-2 nonstructural protein 3

Abstract Replication of the coronavirus genome starts with the formation of viral RNA-containing double-membrane vesicles (DMV) following viral entry into the host cell. The multi-domain nonstructural protein 3 (nsp3) is the largest protein encoded by the known coronavirus genome and serves as a central component of the viral replication and transcription machinery. Previous studies demonstrated that the highly-conserved C-terminal region of nsp3 is essential for subcellular membrane rearrangement, yet the underlying mechanisms remain elusive. Here we report the crystal structure of the CoV-Y domain, the most C-terminal domain of the SARS-CoV-2 nsp3, at 2.4 Å-resolution. CoV-Y adopts a previously uncharacterized V-shaped fold featuring three distinct subdomains. Sequence alignment and structure prediction suggest that this fold is likely shared by the CoV-Y domains from closely related nsp3 homologs. NMR-based fragment screening combined with molecular docking identifies surface cavities in CoV-Y for interaction with potential ligands and other nsps. These studies provide the first structural view on a complete nsp3 CoV-Y domain, and the molecular framework for understanding the architecture, assembly and function of the nsp3 C-terminal domains in coronavirus replication. Our work illuminates nsp3 as a potential target for therapeutic interventions to aid in the on-going battle against the COVID-19 pandemic and diseases caused by other coronaviruses.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Epitaxial Er-doped Y 2 O 3 on silicon for quantum coherent devices

Rare-earth ions have incomplete 4f shells and possess narrow optical intra-4f transitions due to shielding from electrons in the 5s and 5p orbitals, making them good candidates for solid-state optical quantum memory. The emission of Er 3+ in the telecom C-band (1530 nm – 1565 nm) makes it especially attractive for this application. In order to build practical, scalable devices, the REI needs to be embedded in a non-interacting host material, preferably one that can be integrated with silicon. In this paper, we show that Er 3+ can be isovalently incorporated into epitaxial Y 2 O 3 thin films on Si (111). We report on the synthesis of epitaxial, single-crystalline Er:Y 2 O 3 on Si with a narrow inhomogeneous linewidth in the photoluminescence spectra, 5.1 GHz (<100 mK) and an optical excited state lifetime of 8.1 ms. The choice of Y 2 O 3 was driven by its low nuclear spin and small lattice mismatch with Si. Using photoluminescence (PL) and electron paramagnetic resonance, we show that Er 3+ substitutes for Y in the crystal lattice. The role of interfacial SiO x , diffusion of silicon into the film, and the effect of buffer layers on inhomogeneous PL linewidth are examined. We also find that the linewidth decreased monotonically with film thickness but surprisingly exhibits no correlation with the film crystalline quality as measured by the x-ray rocking curve scans suggesting other factors at play that limit the inhomogeneous broadening in Y 2 O 3 films.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Crystal structure and magnetic properties in semiconducting Eu 3-δ Zn x Sn y As 3 with Eu-Eu dimers

Magnetic structure and crystal symmetry, which primarily determine the time-reversal and inversion symmetry, may give rise to numerous exotic quantum phenomena in magnetic semiconductors and semimetals when arranged in different patterns. Here, a new layered magnetic semiconductor, Eu 3-δ Zn x Sn y As 3 , was discovered and high-quality single crystals were grown using the Sn flux. According to structural characterization by x-ray diffraction and atomic-resolution scanning transmission electron microscopy, Eu 3-δ Zn x Sn y As 3 is found to crystallize in a hexagonal symmetry with the space group P6 3 /mmc (No. 194). After examining different specimens, we conclude that their stoichiometry is fixed at ~Eu 2.6 Zn 0.65 Sn 0.85 As 3 , which meets the chemical charge balance. Eu 3-δ Zn x Sn y As 3 is composed of septuple (Eu 1-δ Sn y As 2 )-Eu-(Zn x As)-Eu sequences. The shortest Eu–Eu distance in the system is between two Eu layers separated by Zn x As along the c-axis. Magnetization measurement shows an antiferromagnetic ordering in Eu 3-δ Zn x Sn y As 3 at T N ~ 12 K, where the magnetic easy-axis is along the c-axis, and Mössbauer spectroscopy observes magnetic hyperfine splitting on Eu and Sn at 6 K. Magnetic anisotropy is significantly different from the ones along the ab-plane in other layered Eu-based magnetic semimetals. Heat capacity measurements confirm the magnetic transition around 12 K. Electrical resistivity measurement indicates semiconductor behavior with a band gap of ~0.86 eV. Finally, various Eu-based magnetic semiconductors could provide a tunable platform to study potential topological and magnetic properties.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Y-12 Groundwater Protection Program Groundwater and Surface Water Sampling and Analysis Plan for Calendar Year 2022

This plan provides a description of the groundwater and surface water quality monitoring activities planned for calendar year (CY) 2022 at the U.S. Department of Energy Y-12 National Security Complex (Y-12) that will be managed by the Y-12 Groundwater Protection Program (GWPP). Groundwater and surface water monitoring will be performed in three hydrogeologic regimes at Y-12: the Bear Creek Hydrogeologic Regime (Bear Creek Regime), the Upper East Fork Poplar Creek Hydrogeologic Regime (East Fork Regime), and the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime). The Bear Creek and East Fork regimes are located in Bear Creek Valley and the Chestnut Ridge Regime is located south of Y-12. Additional surface water monitoring will be performed north of Pine Ridge along the boundary of the Oak Ridge Reservation. The following sections of this report provide details regarding the CY 2022 groundwater and surface water monitoring activities. Section 2 describes the monitoring locations in each regime and the processes used to select the sampling locations. A description of the field measurements and laboratory analytes is provided in Section 3. Sample collection methods and procedures are described in Section 4, and Section 5 lists the documents cited for more detailed operational and technical information.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2026

Understanding_the_deactivation_mechanisms_of_ethanol_conversion_over_Cu-Y_Beta_catalyst

Direct conversion of bioethanol to C₃⁺olefins is a promising pathway for sustainable aviation fuel (SAF) production, but catalyst deactivation limits long-term operation. The stability and deactivation mechanisms of multifunctional Cu–Y/Beta zeolite catalysts were investigated for ethanol-to-olefins conversion over 300 h time-on-stream in the presence of H2. Catalytic testing reveals progressive losses in ethanol conversion and C₃⁺ olefin selectivity accompanied by increased acetaldehyde formation. The catalyst testing studies correlate with a suite of characterizations of fresh, spent, and regenerated catalysts to identify the deactivation factors. The loss of Y Lewis acid sites is the primary deactivation element. Reversible acid site deactivation is caused by coke deposition, which blocks Y-derived Lewis acid sites responsible for aldol condensation, MPV reduction, and alcohol dehydration. Minor irreversible deactivation is observed and possibly results from hydrothermal dehydroxylation of Y–silanol interactions, resulting in permanent loss of Lewis acidity without zeolite framework degradation or Y aggregation. Cu sites undergo limited agglomeration into small nanoparticles but contribute insignificantly to catalyst deactivation, under the investigated time frame. Oxidative regeneration removes coke and redistributes Cu sites, leading to full recovery of the initial catalytic performance though the Y Lewis acid sites are unable to fully recover. These findings establish Lewis acid site degradation as the primary deactivation mechanism impacting long-term catalyst stability

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

Y-12 NATIONAL SECURITY COMPLEX LEU-MO FEEDSTOCK FABRICATION UPDATE

The Y-12 National Security Complex (Y-12) participates in the fuel fabrication pillar of lhe National Nuclear Security Administration's (NNSA's) Office of Material Minimization and Management (M3) Office of Conversion Pillar. Y-12's primary responsibility is to establish a reliable fabrication process of low-enriched uranium-molybdenum (LEU-Mo) feedstock tor United States High Performance Research Reactors (US HPRRs). This update compares US HPRR LEU-Mo feedstock fabrication ettorts over the past several casting campaigns at Y-12 which vary in process methodologies and fabrication parameters. With recent changes to the latest feedstock casting campaign, Process Design Standard-2 (PD-STD-2). Y-12 has seen a significant decrease in isotopic uranium variability of the fuel feedstock fabricated.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2022

Y-12 Nuclear Criticality Safety Program Health Model: Development, Use and Benefits

The Y-12 National Security Complex (Y-12) operates seven diverse enriched uranium processing facilities and maintains a comprehensive nuclear criticality safety (NCS) program. Given the magnitude of the hazard, the NCS program receives significant oversight. Describing the scope and health of the Y-12 NCS program to sometimes non-expert stakeholders with limited time had historically focused on recent events and “hot topics” which did not always convey sufficient context (i.e., how to differentiate between an individual performance issue and a systemic concern). Y-12 created the NCS Program Health (NCSPH) Model to provide a complete and holistic framework to quantify and communicate NCS program health. The model is constructed in a tiered fashion with the top tier broken into three (3) Tier 2 elements, fourteen (14) Tier 3 elements, and 104 Tier 4 and 5 elements. This granularity ensures every feature of the NCS Program is accounted for and stakeholders can see how these features support the collective whole. The model is used as the framework for NCS communications including program plans, reports, health surveys, and meeting agendas. The model has substantially improved stakeholder appreciation for the entirety of the NCS program and how events and assessment results factor into an overarching conclusion on NCS program health. While some details are Y-12 specific, the NCSPH model can easily be tailored for any other site with an NCS program.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2023

Estudio de Resiliencia de la Red Electrica de Puerto Rico y Transiciones a Energia 100% Renovable (PR100)

Puerto Rico se ha comprometido a satisfacer sus necesidades de energia 100% renovable para 2050, ademas de alcanzar metas intermedias del 40% para 2025, 60% para 2040, la eliminacion gradual de la generacion a carbon para 2028 y una mejora del 30% en la eficiencia energetica para 2040, segun lo establecido en la Ley de Politica Publica Energetica de Puerto Rico (Ley 17). Para cumplir con estos objetivos y apoyar la electrificacion generalizada, Puerto Rico esta explorando la energia renovable y el almacenamiento de energia, la generacion distribuida, el control de distribucion, los vehiculos electricos y las cargas receptivas y eficientes energeticas que se pueden implementar en las comunidades de Puerto Rico. See NREL/FS-6A20-85442 (https://www.nrel.gov/docs/fy23osti/85442.pdf) for the English translation.

ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2020

Materials Data on Y(PdO2)2 by Materials Project

Y(PdO2)2 crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Y is bonded in a 8-coordinate geometry to eight equivalent O atoms. There are four shorter (2.34 Å) and four longer (2.46 Å) Y–O bond lengths. Pd is bonded in a square co-planar geometry to four equivalent O atoms. There are two shorter (2.03 Å) and two longer (2.05 Å) Pd–O bond lengths. O is bonded to two equivalent Y and two equivalent Pd atoms to form a mixture of edge and corner-sharing OY2Pd2 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(MnSn)6 by Materials Project

YMn6Sn6 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Y is bonded to eight Sn atoms to form distorted edge-sharing YSn8 hexagonal bipyramids. There are two shorter (3.00 Å) and six longer (3.15 Å) Y–Sn bond lengths. Mn is bonded in a 12-coordinate geometry to six Sn atoms. There are a spread of Mn–Sn bond distances ranging from 2.74–2.84 Å. There are three inequivalent Sn sites. In the first Sn site, Sn is bonded in a 6-coordinate geometry to six equivalent Mn atoms. In the second Sn site, Sn is bonded in a 12-coordinate geometry to three equivalent Y and six equivalent Mn atoms. In the third Sn site, Sn is bonded in a 8-coordinate geometry to one Y, six equivalent Mn, and one Sn atom. The Sn–Sn bond length is 3.00 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(MnGe)6 by Materials Project

YMn6Ge6 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Y is bonded to eight Ge atoms to form distorted edge-sharing YGe8 hexagonal bipyramids. There are two shorter (2.81 Å) and six longer (2.99 Å) Y–Ge bond lengths. Mn is bonded in a 12-coordinate geometry to six Ge atoms. There are a spread of Mn–Ge bond distances ranging from 2.52–2.70 Å. There are three inequivalent Ge sites. In the first Ge site, Ge is bonded in a 9-coordinate geometry to three equivalent Y and six equivalent Mn atoms. In the second Ge site, Ge is bonded in a 8-coordinate geometry to one Y, six equivalent Mn, and one Ge atom. The Ge–Ge bond length is 2.53 Å. In the third Ge site, Ge is bonded in a 6-coordinate geometry to six equivalent Mn atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(PO3)3 by Materials Project

Y(PO3)3 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are three inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded to six equivalent O2- atoms to form YO6 octahedra that share corners with six equivalent PO4 tetrahedra. All Y–O bond lengths are 2.24 Å. In the second Y3+ site, Y3+ is bonded to six O2- atoms to form YO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Y–O bond distances ranging from 2.21–2.30 Å. In the third Y3+ site, Y3+ is bonded to six equivalent O2- atoms to form YO6 octahedra that share corners with six equivalent PO4 tetrahedra. All Y–O bond lengths are 2.29 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two YO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 3–20°. There is two shorter (1.50 Å) and two longer (1.60 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent YO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 8–29°. There are a spread of P–O bond distances ranging from 1.50–1.61 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent YO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 27–44°. There are a spread of P–O bond distances ranging from 1.50–1.62 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two YO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–33°. There are a spread of P–O bond distances ranging from 1.50–1.61 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two P5+ atoms. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to one Y3+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Y3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one Y3+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a linear geometry to one Y3+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Y3+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Y3+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Y3+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Y3+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(BIr)4 by Materials Project

Y(IrB)4 is alpha Pu-derived structured and crystallizes in the tetragonal P4_2/n space group. The structure is three-dimensional. Y is bonded in a 4-coordinate geometry to four equivalent B atoms. All Y–B bond lengths are 2.90 Å. Ir is bonded in a 4-coordinate geometry to four equivalent B atoms. There are a spread of Ir–B bond distances ranging from 2.10–2.18 Å. B is bonded in a 6-coordinate geometry to one Y, four equivalent Ir, and one B atom. The B–B bond length is 1.84 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(CuO2)3 by Materials Project

Y(CuO2)3 crystallizes in the triclinic P1 space group. The structure is two-dimensional and consists of one Y(CuO2)3 sheet oriented in the (0, 1, 0) direction. there are two inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded to six O2- atoms to form edge-sharing YO6 octahedra. There are a spread of Y–O bond distances ranging from 2.16–2.33 Å. In the second Y3+ site, Y3+ is bonded to six O2- atoms to form edge-sharing YO6 octahedra. There are a spread of Y–O bond distances ranging from 2.15–2.32 Å. There are six inequivalent Cu3+ sites. In the first Cu3+ site, Cu3+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.68 Å) and one longer (1.69 Å) Cu–O bond length. In the second Cu3+ site, Cu3+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.69 Å) and one longer (1.75 Å) Cu–O bond length. In the third Cu3+ site, Cu3+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.69 Å) and one longer (1.72 Å) Cu–O bond length. In the fourth Cu3+ site, Cu3+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.69 Å) and one longer (1.75 Å) Cu–O bond length. In the fifth Cu3+ site, Cu3+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.68 Å) and one longer (1.71 Å) Cu–O bond length. In the sixth Cu3+ site, Cu3+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.69 Å) and one longer (1.72 Å) Cu–O bond length. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one Cu3+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Y3+ and one Cu3+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Y3+ and one Cu3+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Y3+ and one Cu3+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one Cu3+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Y3+ and one Cu3+ atom. In the seventh O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Y3+ and one Cu3+ atom. In the eighth O2- site, O2- is bonded in a single-bond geometry to one Cu3+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Y3+ and one Cu3+ atom. In the tenth O2- site, O2- is bonded in a single-bond geometry to one Cu3+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Y3+ and one Cu3+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Y3+ and one Cu3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(CuO2)3 by Materials Project

(CuO2)(Y)(CuO2)CuO2 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of two copper(ii) hydroxide molecules and one (CuO2)(Y)(CuO2) sheet oriented in the (0, 0, 1) direction. In the (CuO2)(Y)(CuO2) sheet, Y3+ is bonded to six O2- atoms to form edge-sharing YO6 octahedra. All Y–O bond lengths are 2.27 Å. Cu3+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.70 Å) and one longer (1.74 Å) Cu–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Y3+ and one Cu3+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Y3+ and one Cu3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(CuS)2 by Materials Project

Y(CuS)2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Y is bonded to six equivalent S atoms to form distorted YS6 octahedra that share corners with twelve equivalent CuS4 tetrahedra, edges with six equivalent YS6 octahedra, and edges with six equivalent CuS4 tetrahedra. All Y–S bond lengths are 2.84 Å. Cu is bonded to four equivalent S atoms to form distorted CuS4 tetrahedra that share corners with six equivalent YS6 octahedra, corners with six equivalent CuS4 tetrahedra, edges with three equivalent YS6 octahedra, and edges with three equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 25–53°. There are three shorter (2.32 Å) and one longer (2.51 Å) Cu–S bond lengths. S is bonded in a 7-coordinate geometry to three equivalent Y and four equivalent Cu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(Cd10Ni)2 by Materials Project

YNi2Cd20 crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Y is bonded in a 4-coordinate geometry to sixteen Cd atoms. There are four shorter (3.42 Å) and twelve longer (3.46 Å) Y–Cd bond lengths. Ni is bonded to twelve Cd atoms to form NiCd12 cuboctahedra that share corners with six equivalent NiCd12 cuboctahedra, edges with eighteen equivalent CdYCd10Ni cuboctahedra, and faces with six equivalent CdYCd10Ni cuboctahedra. There are six shorter (2.80 Å) and six longer (3.09 Å) Ni–Cd bond lengths. There are three inequivalent Cd sites. In the first Cd site, Cd is bonded in a distorted linear geometry to two equivalent Ni and ten Cd atoms. There are a spread of Cd–Cd bond distances ranging from 2.97–3.12 Å. In the second Cd site, Cd is bonded to one Y, one Ni, and ten Cd atoms to form distorted CdYCd10Ni cuboctahedra that share corners with fifteen equivalent CdYCd10Ni cuboctahedra, edges with two equivalent CdYCd10Ni cuboctahedra, edges with three equivalent NiCd12 cuboctahedra, a faceface with one NiCd12 cuboctahedra, and faces with fifteen equivalent CdYCd10Ni cuboctahedra. There are a spread of Cd–Cd bond distances ranging from 2.90–3.35 Å. In the third Cd site, Cd is bonded in a distorted linear geometry to two equivalent Y and twelve equivalent Cd atoms.

36 MATERIALS SCIENCE↗