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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Machine learning guided discovery of ternary compounds involving La and immiscible Co and Pb elements

Abstract Ternary compounds with an immiscible pair of elements are relatively unexplored but promising for novel quantum materials discovery. Exploring what third element and its ratio that can be added to make stable ternary compounds out of an immiscible pair of elements remains a great challenge. In this work, we combine a machine learning (ML) method with ab initio calculations to efficiently search for the energetically favorable ternary La-Co-Pb compounds containing immiscible elements Co and Pb. Three previously reported structures are correctly captured by our approach. Moreover, we predict a ground state La 3 CoPb compound and 57 low-energy La-Co-Pb ternary compounds. Attempts to synthesize La 3 CoPb via multiple techniques produce mixed or multi-phases samples with, at best, ambiguous signals of the predicted lowest-energy La 3 CoPb and the second lowest-energy La 18 Co 28 Pb 3 phases. The calculated results of Gibbs free energy are consistent with experiments, and will provide very useful guidance for further experimental synthesis.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Prediction of s ± -Wave Superconductivity Enhanced by Electronic Doping in Trilayer Nickelates La 4 Ni 3 O 10 under Pressure

Motivated by the recently reported signatures of superconductivity in trilayer La 4 ⁢Ni 3 ⁢O 10 under pressure, here we comprehensively study this system using ab initio and random-phase approximation techniques. Without electronic interactions, the Ni d 3z 2 –r 2 orbitals show a bonding-antibonding and nonbonding splitting behavior via the O p z orbitals inducing a “trimer” lattice in La 4⁢ Ni 3 ⁢O 10 , analogous to the dimers of La 3 ⁢Ni 2 ⁢O 7 . The Fermi surface consists of three electron sheets with mixed e g orbitals, and a hole and an electron pocket made up of the d 3⁢z 2 –r 2 orbital, suggesting a Ni two-orbital minimum model. In addition, we find that superconducting pairing is induced in the s ± -wave channel due to partial nesting between the M = (π,π) centered pockets and portions of the Fermi surface centered at the Γ = (0,0) point. With changing electronic density n, the s ± instability remains leading and its pairing strength shows a domelike behavior with a maximum around n = 4.2 ( ~6.7% electron doping). The superconducting instability disappears at the same electronic density as that in the new 1313 stacking La 3 ⁢Ni 2 ⁢O 7 , correlated with the vanishing of the hole pocket that arises from the trilayer sublattice, suggesting that the high-T c superconductivity of La 3⁢ Ni 2 ⁢O 7 does not originate from a trilayer and monolayer structure. Furthermore, we confirm the experimentally proposed spin state in La 4 ⁢Ni 3 ⁢O 10 with an in-plane (π, π) order and antiferromagnetic coupling between the top and bottom Ni layers, and spin zero in the middle layer.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2023

Evaluation of 134 Ce/ 134 La as a PET Imaging Theranostic Pair for 225 Ac α-Radiotherapeutics

225 Ac-targeted α-radiotherapy is a promising approach to treating malignancies, including prostate cancer. However, α-emitting isotopes are difficult to image because of low administered activities and a low fraction of suitable γ-emissions. The in vivo generator 134 Ce/ 134 La has been proposed as a potential PET imaging surrogate for the therapeutic nuclides 225 Ac and 227 Th. In this report, we detail efficient radiolabeling methods using the 225 Ac-chelators DOTA and MACROPA. These methods were applied to radiolabeling of prostate cancer imaging agents, including PSMA-617 and MACROPA-PEG 4 -YS5, for evaluation of their in vivo pharmacokinetic characteristics and comparison to the corresponding 225 Ac analogs. Methods: Radiolabeling was performed by mixing DOTA/MACROPA chelates with 134 Ce/ 134 La in NH 4 OAc, pH 8.0, at room temperature, and radiochemical yields were monitored by radio–thin-layer chromatography. In vivo biodistributions of 134 Ce-DOTA/MACROPA.NH 2 complexes were assayed through dynamic small-animal PET/CT imaging and ex vivo biodistribution studies over 1 h in healthy C57BL/6 mice, compared with free 134 CeCl 3 . In vivo, preclinical imaging of 134 Ce-PSMA-617 and 134 Ce-MACROPA-PEG 4 -YS5 was performed on 22Rv1 tumor–bearing male nu/nu-mice. Ex vivo biodistribution was performed for 134 Ce/ 225 Ac-MACROPA-PEG 4 -YS5 conjugates. Results: 134 Ce-MACROPA.NH 2 demonstrated near-quantitative labeling with 1:1 ligand-to-metal ratios at room temperature, whereas a 10:1 ligand-to-metal ratio and elevated temperatures were required for DOTA. Rapid urinary excretion and low liver and bone uptake were seen for 134 Ce/ 225 Ac-DOTA/MACROPA. NH 2 conjugates in comparison to free 134 CeCl 3 confirmed high in vivo stability. An interesting observation during the radiolabeling of tumor-targeting vectors PSMA-617 and MACROPA-PEG 4 -YS5—that the daughter 134 La was expelled from the chelate after the decay of parent 134 Ce—was confirmed through radio–thin-layer chromatography and reverse-phase high-performance liquid chromatography. Both conjugates, 134 Ce-PSMA-617 and 134 Ce-MACROPA-PEG 4 -YS5, displayed tumor uptake in 22Rv1 tumor–bearing mice. The ex vivo biodistribution of 134 Ce-MACROPA.NH 2 , 134 Ce-DOTA and 134 Ce-MACROPA-PEG 4 -YS5 corroborated well with the respective 225 Ac-conjugates. Conclusion: These results demonstrate the PET imaging potential for 134 Ce/ 134 La-labeled small-molecule and antibody agents. The similar 225 Ac and 134 Ce/ 134 La-chemical and pharmacokinetic characteristics suggest that the 134 Ce/ 134 La pair may act as a PET imaging surrogate for 225 Ac-based radioligand therapies.

07 ISOTOPE AND RADIATION SOURCES↗
NASA NTRS2024

High Precision and Spatial Resolution Chemical Interrogation of Planetary Materials Using fs-LA/LIBS in Tandem With Multi-Collector ICP-MS

Combining femtosecond laser ablation (fs-LA) with laser-induced breakdown spectroscopy (LIBS), together with multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS), can provide remarkable insights into the composition, structure, and therefore geologic history of planetary materials and their terrestrial analogs. Using the Applied Spectra iX-fs-Tandem LA-LIBS Instrument and the Nu SP1700 MC-ICP-MS housed within the Center for Isotope Cosmochemistry and Geochronology at NASA Johnson Space Center, we present preliminary tandem fs-LA-(MC)-ICP-MS/LIBS measurements of planetary analog materials. The synergistic integration of fs-LA-LIBS offers high spatial resolution elemental mapping, enabling the identification of microscale variations within samples. Simultaneously, the MC-ICP-MS can deliver precise isotopic analyses, and integrating the two datasets yields a wealth of geochemical information for a given sample. LA-based chemical mapping experiment designs are contingent on the information sought (i.e., quantitative, or semi-quantitative) and the preferred or available volume of material removed for the analysis. For example, occasionally, there are significant limitations in the depth of ablation due to the sample value, the amount of material available, or simply the need to coordinate with other in-situ techniques. In these limited sample scenarios, the “depth-controlled” chemical maps allow for precise post-mapping ion-polishing of the sample, while the isotopic and elemental maps can be used for targeting future analyses (e.g., conventional LA analyses, SIMS analyses, and micro milling for solution ICP-MS/TIMS). The emerging methodology will establish a powerful tool for investigation of astromaterials and materials returned by future planetary sample science missions.

Jacob B Setera↗
DOE OSTI2020

Materials Data on La(CoGe)2 by Materials Project

LaCo2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. La is bonded in a 8-coordinate geometry to eight equivalent Co and eight equivalent Ge atoms. All La–Co bond lengths are 3.28 Å. All La–Ge bond lengths are 3.23 Å. Co is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Ge atoms. All Co–Ge bond lengths are 2.36 Å. Ge is bonded in a 9-coordinate geometry to four equivalent La, four equivalent Co, and one Ge atom. The Ge–Ge bond length is 2.80 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(NiGe)2 by Materials Project

LaNi2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. La is bonded in a 8-coordinate geometry to eight equivalent Ni and eight equivalent Ge atoms. All La–Ni bond lengths are 3.25 Å. All La–Ge bond lengths are 3.26 Å. Ni is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Ge atoms. All Ni–Ge bond lengths are 2.39 Å. Ge is bonded in a 9-coordinate geometry to four equivalent La, four equivalent Ni, and one Ge atom. The Ge–Ge bond length is 2.66 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(CuGe)2 by Materials Project

LaCu2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. La is bonded in a 8-coordinate geometry to eight equivalent Cu and eight equivalent Ge atoms. All La–Cu bond lengths are 3.32 Å. All La–Ge bond lengths are 3.25 Å. Cu is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Ge atoms. All Cu–Ge bond lengths are 2.47 Å. Ge is bonded in a 9-coordinate geometry to four equivalent La, four equivalent Cu, and one Ge atom. The Ge–Ge bond length is 2.55 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(FeGe)2 by Materials Project

LaFe2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. La is bonded in a 8-coordinate geometry to eight equivalent Fe and eight equivalent Ge atoms. All La–Fe bond lengths are 3.40 Å. All La–Ge bond lengths are 3.20 Å. Fe is bonded to four equivalent La and four equivalent Ge atoms to form a mixture of distorted corner, edge, and face-sharing FeLa4Ge4 tetrahedra. All Fe–Ge bond lengths are 2.45 Å. Ge is bonded in a 9-coordinate geometry to four equivalent La, four equivalent Fe, and one Ge atom. The Ge–Ge bond length is 2.73 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(GePd)2 by Materials Project

LaPd2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. La is bonded in a 8-coordinate geometry to eight equivalent Pd and eight equivalent Ge atoms. All La–Pd bond lengths are 3.37 Å. All La–Ge bond lengths are 3.37 Å. Pd is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Ge atoms. All Pd–Ge bond lengths are 2.55 Å. Ge is bonded in a 9-coordinate geometry to four equivalent La, four equivalent Pd, and one Ge atom. The Ge–Ge bond length is 2.53 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(GePt)2 by Materials Project

LaPt2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. La is bonded in a 8-coordinate geometry to eight equivalent Pt and eight equivalent Ge atoms. All La–Pt bond lengths are 3.37 Å. All La–Ge bond lengths are 3.41 Å. Pt is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Ge atoms. All Pt–Ge bond lengths are 2.55 Å. Ge is bonded in a 9-coordinate geometry to four equivalent La, four equivalent Pt, and one Ge atom. The Ge–Ge bond length is 2.58 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(NiSn)2 by Materials Project

LaNi2Sn2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. La is bonded in a 8-coordinate geometry to eight equivalent Ni and eight equivalent Sn atoms. All La–Ni bond lengths are 3.45 Å. All La–Sn bond lengths are 3.48 Å. Ni is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Sn atoms. All Ni–Sn bond lengths are 2.53 Å. Sn is bonded in a 9-coordinate geometry to four equivalent La, four equivalent Ni, and one Sn atom. The Sn–Sn bond length is 2.90 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(AlGa)2 by Materials Project

LaAl2Ga2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. La is bonded in a 8-coordinate geometry to eight equivalent Ga and eight equivalent Al atoms. All La–Ga bond lengths are 3.29 Å. All La–Al bond lengths are 3.52 Å. Ga is bonded in a 9-coordinate geometry to four equivalent La, one Ga, and four equivalent Al atoms. The Ga–Ga bond length is 2.56 Å. All Ga–Al bond lengths are 2.63 Å. Al is bonded to four equivalent La and four equivalent Ga atoms to form a mixture of distorted corner, edge, and face-sharing AlLa4Ga4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(AlZn)2 by Materials Project

Al2LaZn2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. La is bonded in a 8-coordinate geometry to eight equivalent Zn and eight equivalent Al atoms. All La–Zn bond lengths are 3.26 Å. All La–Al bond lengths are 3.49 Å. Zn is bonded in a 9-coordinate geometry to four equivalent La, one Zn, and four equivalent Al atoms. The Zn–Zn bond length is 2.50 Å. All Zn–Al bond lengths are 2.61 Å. Al is bonded to four equivalent La and four equivalent Zn atoms to form a mixture of distorted corner, edge, and face-sharing AlLa4Zn4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(ClO4)3 by Materials Project

La(ClO4)3 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. La is bonded in a 9-coordinate geometry to nine O atoms. There are six shorter (2.55 Å) and three longer (2.56 Å) La–O bond lengths. There are three inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Cl atom. The O–Cl bond length is 1.42 Å. In the second O site, O is bonded in a bent 150 degrees geometry to one La and one Cl atom. The O–Cl bond length is 1.47 Å. In the third O site, O is bonded in a bent 150 degrees geometry to one La and one Cl atom. The O–Cl bond length is 1.47 Å. Cl is bonded in a tetrahedral geometry to four O atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(ClO3)3 by Materials Project

LaO3(ClO2)3 is Upper Bainite-like structured and crystallizes in the orthorhombic Ama2 space group. The structure is zero-dimensional and consists of twelve hypochlorous acid;hydrate molecules and four LaO3 clusters. In each LaO3 cluster, La is bonded in a trigonal planar geometry to three O atoms. There are one shorter (2.06 Å) and two longer (2.11 Å) La–O bond lengths. There are three inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one La atom. In the second O site, O is bonded in a single-bond geometry to one La atom. In the third O site, O is bonded in a single-bond geometry to one La atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(Al10Cr)2 by Materials Project

La(CrAl10)2 crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. La is bonded in a 4-coordinate geometry to sixteen Al atoms. There are four shorter (3.14 Å) and twelve longer (3.26 Å) La–Al bond lengths. Cr is bonded to twelve Al atoms to form CrAl12 cuboctahedra that share corners with six equivalent CrAl12 cuboctahedra, edges with eighteen equivalent AlLaAl10Cr cuboctahedra, and faces with six equivalent AlLaAl10Cr cuboctahedra. There are six shorter (2.57 Å) and six longer (2.77 Å) Cr–Al bond lengths. There are three inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to two equivalent Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.71–2.82 Å. In the second Al site, Al is bonded in a linear geometry to two equivalent La and twelve equivalent Al atoms. All Al–Al bond lengths are 3.13 Å. In the third Al site, Al is bonded to one La, one Cr, and ten Al atoms to form distorted AlLaAl10Cr cuboctahedra that share corners with fifteen equivalent AlLaAl10Cr cuboctahedra, edges with two equivalent AlLaAl10Cr cuboctahedra, edges with three equivalent CrAl12 cuboctahedra, a faceface with one CrAl12 cuboctahedra, and faces with fifteen equivalent AlLaAl10Cr cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.77–2.89 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La by Materials Project

La is Tungsten structured and crystallizes in the cubic Im-3m space group. The structure is three-dimensional. La is bonded in a distorted body-centered cubic geometry to eight equivalent La atoms. All La–La bond lengths are 3.66 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La by Materials Project

La is Copper structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. La is bonded to twelve equivalent La atoms to form a mixture of edge, corner, and face-sharing LaLa12 cuboctahedra. There are four shorter (3.71 Å) and eight longer (3.76 Å) La–La bond lengths.

36 MATERIALS SCIENCE↗