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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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Processing, structure, and thermal properties of ZrW 2 O 8 , HfW 2 O 8 , HfMgW 3 O 12 , Al(HfMg) 0.5 W 3 O 12 , and Al 0.5 Sc 1.5 W 3 O 12 negative and zero thermal expansion coefficient ceramics

Negative and zero coefficient of thermal expansion (CTE) materials are of interest for developing polymer composites in electronic circuits that match the expansion of Si and in zero CTE supports for optical components, e.g., mirrors. In this work, the processing challenges and stability of ZrW 2 O 8 , HfW 2 O 8 , HfMgW 3 O 12 , Al(HfMg) 0.5 W 3 O 12 , and Al 0.5 Sc 1.5 W 3 O 12 negative and zero thermal expansion coefficient ceramics are discussed. Al 0.5 Sc 1.5 W 3 O 12 is demonstrated to be a relatively simple oxide to fabricate in large quantity and is shown to exhibit single phase up to 1300 °C in air and inert N 2 environments. The negative and zero CTE behavior was confirmed with dilatometry. Thermal conductivity and heat capacity were reported for the first time for HfMgW 3 O 12 and Al 0.5 Sc 1.5 W 3 O 12 and thermal conductivity was found to be very low (~0.5 W/mK). Grüneisen parameter is also estimated. Methods for integration of Al 0.5 Sc 1.5 W 3 O 12 with other materials was examined and embedding 50 vol% of the ceramic powder in flexible epoxy was demonstrated with a commercial vendor.

36 MATERIALS SCIENCE↗
DOE OSTI2022

SC Wall-to-RC Basemat Over-Strength Connection: Behavior and Design

This paper presents results from experimental and analytical investigations conducted to evaluate the lateral load behavior and capacity of steel-plate composite (SC) wall-to-reinforced concrete (RC) basemat connections. Two SC wall-to-reinforced concrete basemat connection specimens were tested. These SC wall specimens had a height-to-length ratio of 0.6 and did not include boundary elements. The experimental results include the lateral force-displacement (V-Δ) responses of the specimens and observations of local damage such as steel plate local buckling and concrete crushing. 3D finite element models were developed and benchmarked using the experimental results. The benchmarked models were used to conduct analytical parametric studies, expand the database, and gain additional insights into the behavior of SC wall-to-RC basemat connections. The parameters included in analytical investigations were the wall aspect ratio (h/lw), reinforcement ratio (ρ), and wall thickness (T).

Kurt, Efe G.↗
DOE OSTI2020

Materials Data on Sc(IO3)3 by Materials Project

Sc(IO3)3 crystallizes in the trigonal R-3 space group. The structure is two-dimensional and consists of three Sc(IO3)3 sheets oriented in the (0, 0, 1) direction. Sc3+ is bonded in an octahedral geometry to six O2- atoms. There are three shorter (2.12 Å) and three longer (2.13 Å) Sc–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Sc3+ and one I5+ atom. The O–I bond length is 1.83 Å. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one I5+ atom. The O–I bond length is 1.84 Å. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Sc3+ and one I5+ atom. The O–I bond length is 1.85 Å. I5+ is bonded in a 4-coordinate geometry to three O2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sc(HO)3 by Materials Project

Sc(OH)3 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are two inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded to six equivalent O2- atoms to form corner-sharing ScO6 octahedra. The corner-sharing octahedral tilt angles are 43°. All Sc–O bond lengths are 2.14 Å. In the second Sc3+ site, Sc3+ is bonded to six O2- atoms to form corner-sharing ScO6 octahedra. The corner-sharing octahedra tilt angles range from 43–44°. There are a spread of Sc–O bond distances ranging from 2.12–2.17 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two Sc3+ and one H1+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Sc3+ and one H1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sc(HO)3 by Materials Project

Sc(OH)3 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are two inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded to six O2- atoms to form corner-sharing ScO6 octahedra. The corner-sharing octahedra tilt angles range from 44–46°. There are two shorter (2.11 Å) and four longer (2.16 Å) Sc–O bond lengths. In the second Sc3+ site, Sc3+ is bonded to six equivalent O2- atoms to form corner-sharing ScO6 octahedra. The corner-sharing octahedral tilt angles are 46°. All Sc–O bond lengths are 2.15 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.01 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Sc3+ and one H1+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two Sc3+ and one H1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sc(PO)2 by Materials Project

Sc(PO)2 crystallizes in the tetragonal I4_1/amd space group. The structure is zero-dimensional and consists of eight Sc(PO)2 clusters. Sc2+ is bonded in a linear geometry to two equivalent O2- atoms. Both Sc–O bond lengths are 2.05 Å. P1+ is bonded in a single-bond geometry to one O2- atom. The P–O bond length is 1.59 Å. O2- is bonded in a water-like geometry to one Sc2+ and one P1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sc(NF2)3 by Materials Project

Sc(NF2)3 crystallizes in the monoclinic P2_1/c space group. The structure is one-dimensional and consists of two Sc(NF2)3 ribbons oriented in the (1, 1, 0) direction. Sc3+ is bonded in an octahedral geometry to six F1- atoms. There are a spread of Sc–F bond distances ranging from 1.90–2.34 Å. There are two inequivalent N1+ sites. In the first N1+ site, N1+ is bonded in a linear geometry to two equivalent F1- atoms. Both N–F bond lengths are 1.82 Å. In the second N1+ site, N1+ is bonded in a single-bond geometry to one F1- atom. The N–F bond length is 1.39 Å. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Sc3+ atom. In the second F1- site, F1- is bonded in a bent 120 degrees geometry to one Sc3+ and one N1+ atom. In the third F1- site, F1- is bonded in a bent 150 degrees geometry to one Sc3+ and one N1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sc(CO2)3 by Materials Project

Sc(CO2)3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Sc2+ sites. In the first Sc2+ site, Sc2+ is bonded in an octahedral geometry to six O2- atoms. There are four shorter (2.11 Å) and two longer (2.13 Å) Sc–O bond lengths. In the second Sc2+ site, Sc2+ is bonded in an octahedral geometry to six O2- atoms. There are a spread of Sc–O bond distances ranging from 2.10–2.14 Å. There are three inequivalent C+3.33+ sites. In the first C+3.33+ site, C+3.33+ is bonded in a bent 120 degrees geometry to two O2- atoms. Both C–O bond lengths are 1.25 Å. In the second C+3.33+ site, C+3.33+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.25 Å) C–O bond length. In the third C+3.33+ site, C+3.33+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.25 Å) C–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Sc2+ and one C+3.33+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Sc2+ and one C+3.33+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Sc2+ and one C+3.33+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Sc2+ and one C+3.33+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one Sc2+ and one C+3.33+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one Sc2+ and one C+3.33+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sc(AsO)2 by Materials Project

Sc(AsO)2 crystallizes in the tetragonal I4_1/amd space group. The structure is zero-dimensional and consists of eight Sc(AsO)2 clusters. Sc2+ is bonded in a linear geometry to two equivalent O2- atoms. Both Sc–O bond lengths are 1.96 Å. As1+ is bonded in a single-bond geometry to one O2- atom. The As–O bond length is 1.78 Å. O2- is bonded in a distorted linear geometry to one Sc2+ and one As1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2024

The Significance of the 'Insignificant': Non-covalent Interactions in CO 2 Reduction Reactions with 3C-TM (TM=Sc-Zn) Single-Atom Catalysts

With energy shortages and excessive CO 2 emissions driving climate change, converting CO 2 into high-value-added products offers a promising solution for carbon recycling. We investigate CO 2 reduction reactions (CO2RR) catalyzed by 10 single-atom catalysts (SACs), incorporating weak non-covalent interactions, specifically lone pair-π and H-π interactions. The SACs, consisting of transition metals coordinated by three carbon atoms in a defective graphene substrate (3C-TM, TM=Sc-Zn), leverage these interactions to influence the energy fluctuations of intermediates and the limiting potentials of CO 2 RR, without altering the overall reaction pathway. Further, our findings show that SACs based on early transition metals (Sc, Ti, V, Cr) can serve as catalysts for C 1 products, including HCOOH, HCHO, CH 3 OH, and CH 4 , while those based on Fe and Co are suitable for CO formation. Driving force analysis helps bridge theoretical results with experimental observations and propose a modified approach for assessing hydrogen evolution reactions (HER) competition. SACs based on Ni and Cu exhibit moderate HER tolerance, while early transition metals excel in selective CO 2 reduction. We also identify a linear scaling relationship between the free energies of *COOH and *CO. This study offers valuable insights for future experimental studies and large-scale computational screenings.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Construction of the Bioconjugate Py‐Macrodipa‐PSMA and Its In Vivo Investigations with Large 132/135 La 3+ and Small 47 Sc 3+ Radiometal Ions

To harness radiometals in clinical settings, a chelator forming a stable complex with the metal of interest and targets the desired pathological site is needed. Toward this goal, we previously reported a unique set of chelators that can stably bind to both large and small metal ions, via a conformational switch. Within this chelator class, py-macrodipa is particularly promising based on its ability to stably bind several medicinally valuable radiometals including large 132/135 La 3+ , 213 Bi 3+ , and small 44 Sc 3+ . Here, in this study, we report a 10-step organic synthesis of its bifunctional analogue py-macrodipa-NCS, which contains an amine-reactive −NCS group that is amenable for bioconjugation reactions to targeting vectors. The hydrolytic stability of py-macordipa-NCS was assessed, revealing a half-life of 6.0 d in pH 9.0 aqueous buffer. This bifunctional chelator was then conjugated to a prostate-specific membrane antigen (PSMA)-binding moiety, yielding the bioconjugate py-macrodipa-PSMA, which was subsequently radiolabeled with large 132/135 La 3+ and small 47 Sc 3+ , revealing efficient and quantitative complex formation. The resulting radiocomplexes were injected into mice bearing both PSMA-expressing and PSMA-non-expressing tumor xenografts to determine their biodistribution patterns, revealing delivery of both 132/135 La 3+ and 47 Sc 3+ to PSMA+ tumor sites. However, partial radiometal dissociation was observed, suggesting that py-macrodipa-PSMA needs further structural optimization.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Design and Characterization of Hierarchically-Strengthened, Cast Al-Ce-Ni-Mn-Sc-Zr Alloys for High-Temperature Applications

We characterize the microstructure and mechanical properties of cast Al-Ce-Ni-Mn-Sc-Zr alloys designed for structural use above 300 °C. We first report on the effect of Ni on the as-cast phase formation, where all alloys consist of fine Al11Ce3 and Ni-rich eutectic phases, but the identity of the Ni-rich phase varies with Ni content. Furthermore, these alloys contain four coarsening-resistant strengthening phases as determined from SEM and APT investigations: (i) Al11Ce3 and (ii) Ni-rich micron-scale platelets formed during eutectic solidification, (iii) L12-Al3(Sc,Zr) nanoprecipitates formed during secondary aging, and (iv) Mn solute in the α-Al matrix. The Al-Ce-Ni-Mn-Sc-Zr alloy possesses higher microhardness and creep resistance than compositionally simpler alloys containing fewer of the strengthening phases, indicating that these strengthening mechanisms synergize to provide increased ambient- and elevated-temperature strength.

Ekaputra, Clement↗
DOE OSTI2022

Evaluation of hydroxamate-based resins towards a more clinically viable 44 Ti/ 44 Sc radionuclide generator

For this research, several hydroxamate-based resins were synthesized and tested for use in 44 Ti/ 44 Sc generator systems in small scale experiments (740 kBq 44 Ti). The most promising resin was tested further in larger scale generator studies (37 MBq). This resin displayed impressive retention of 44 Ti over several elutions, and high quantities of 44 Sc were obtained in small volumes of dilute HCl eluents. Initial radiolabeling experiments were conducted and demonstrated the possibility of direct radiolabeling of the generator produced 44 Sc with DOTA.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2022

Assessing Mg–Sc–(rare earth) ternary phase stability via constituent binary cluster expansions

The disordered Mg–Sc body-centered cubic (bcc) phase is both lightweight and strong; however, the system is impractical for general industrial use due to the high cost of scandium. Here we propose a computationally efficient metric that assesses ternary rare earth element additions that may stabilize the bcc phase at lower Sc concentrations. We find that the bcc phase is stabilized by the ternary addition of Y or Er, but not by La, Ce, or Nd, and we validate these predictions by experimental production and characterization of Mg–Sc–(Y,Er,Nd) alloys. The results suggest a computationally efficient method to anticipate integration of ternary elements into binary systems using cluster expansions of constituent binaries.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Protein-based approach for high-purity Sc, Y, and grouped lanthanide separation

Rare earth elements (REEs: Sc, Y, La- Lu) are irreplaceable components in many clean energy and consumer technologies. However, the extraction and subsequent separation of individual REEs from ore-based feedstocks remains a significant economic and environmental challenge. Here in this work, we investigated the intra-REE separation potential of lanmodulin (LanM), a natural protein from Methylorubrum extorquens that has emerged as a sustainable potential alternative to conventional solvent extraction-based separation. By determining the intra-REE selectivity of immobilized LanM and systematically testing pH-based and small chelator-based (i.e., citrate and malonate) desorption processes, we established the framework and methodology for achieving select individual and grouped REE separations from a mixed REE feedstock. We show that Sc forms the tightest complex with LanM among REEs but can be readily and selectively desorbed using malonate to generate high-purity Sc (>99 % purity, >99 % yield) in a single adsorption/desorption cycle. We further show that the intrinsic REE selectivity of LanM is sufficient to achieve heavy REE (HREE) separation from light and middle REEs (L-MREEs), yielding an yttrium-enriched product. This separation effect is further magnified by pairing LanM’s unique M-LREE preference with a HREE-preferring chelator in the desorption process, which enriches HREE and MREE fractions relative to low value, abundant La/Ce. Finally, by combining pH- and citrate-based desorption processes in a two-cycle separation scheme, we demonstrate the generation of fractions highly enriched in Y, Gd-Lu, Pr-Eu, and La-Ce. Collectively, these data support the application of a LanM-based approach for achieving impactful REE separations from mixed REE feedstocks.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Real-Space Infrared Spectroscopy of Ferroelectric Domain Walls in Multiferroic h -(Lu,Sc)FeO 3

Herein we employ synchrotron-based near-field infrared spectroscopy to image the phononic properties of ferroelectric domain walls in hexagonal ( h ) Lu 0.6 Sc 0.4 FeO 3 , and we compare our findings with a detailed symmetry analysis, lattice dynamics calculations, and prior models of domain-wall structure. Rather than metallic and atomically thin as observed in the rare-earth manganites, ferroelectric walls in h -Lu 0.6 Sc 0.4 FeO 3 are broad and semiconducting, a finding that we attribute to the presence of an A -site substitution-induced intermediate phase that reduces strain and renders the interior of the domain wall nonpolar. Mixed Lu/Sc occupation on the A site also provides compositional heterogeneity over micron-sized length scales, and we leverage the fact that Lu and Sc cluster in different ratios to demonstrate that the spectral characteristics at the wall are robust even in different compositional regimes. This work opens the door to broadband imaging of physical and chemical heterogeneity in ferroics and represents an important step toward revealing the rich properties of these flexible defect states.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Ferroelectric behavior of sputter deposited Al 0.72 Sc 0.28 N approaching 5 nm thickness

Ferroelectric Al 1-x Sc x N has raised much interest in recent years due to its unique ferroelectric properties and complementary metal oxide semiconductor back-end-of-line compatible processing temperatures. Potential applications in embedded nonvolatile memory, however, require ferroelectric materials to switch at relatively low voltages. One approach to achieving a lower switching voltage is to significantly reduce the Al 1-x Sc x N thickness. In this work, ferroelectric behavior in 5-27 nm films of sputter deposited Al 0.72 Sc 0.28 N has been studied. We find that the 10 kHz normalized coercive field increases from 4.4 to 7.3 MV/cm when reducing the film thickness from 27.1 to 5.4 nm, while over the same thickness range, the characteristic breakdown field of a 12.5 μm radius capacitor increases from 8.3 to 12.1 MV/cm. In conclusion, the 5.4 nm film demonstrates ferroelectric switching at 5.5 V when excited with a 500 ns pulse and a switching speed of 60 ns.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2024

Evolution of shell gaps in the neutron-poor calcium region from invariant-mass spectroscopy of 37,38 Sc, 35 Ca, 34 K

A fast secondary beam of 37 Ca impinged on a 9 Be target resulting in a set of reactions populating proton-rich nuclei including 35 Ca and the first observations of 37,38 Sc and 34 K. Invariant-mass spectroscopy, used to reconstruct proton decays for these nuclei, yielded three new ground-state masses and information on their low-lying structures. The newly measured mass excesses are: ΔM( 37 Sc) = 3500(410) keV, ΔM( 38 Sc) = –4656(14) keV, and ΔM( 34 K) = –1487(17) keV. These nuclei straddle the well-known Z = 20 shell closure as well as the N = 16 subshell closure. Furthermore, trends in separation energies help elucidate how nuclear structure evolves showing a fading of the Z = 20 shell gap for N ≥ 18 and indications of a N = 16 subshell gap.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗