Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “La”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Synthesis challenges, thermodynamic stability, and growth kinetics of La–Si–P ternary compounds

Although many new compounds have been recently predicted with the help of machine learning, the successful experimental synthesis of these compounds remains challenging. Computational insights about the thermodynamic stability and phase formation kinetics among the ground state and competing metastable phases are highly desirable to rationalize and attempt to overcome synthesis challenges experimentally. In this work, we explore synthetic challenges within ternary La–Si–P compounds through feedback between experimental and computational studies. We discuss the experimental challenges in forming three computationally predicted ternary phases (La 2 SiP, La 5 SiP 3 , and La 2 SiP 3 ). To understand the synthetic challenges, we performed molecular dynamics (MD) simulations using an accurate and efficient artificial neural network machine learning (ANN-ML) interatomic potential. We study the phase stability and formation kinetics of these ternary phases in relation to the reported and synthesized La 2 SiP 4 phase. While the growth of the La 2 SiP 4 phase can be reproduced by our MD simulation, our results indicate that the rapid formation of a Si-substituted LaP crystalline phase is a major barrier to the synthesis of the predicted La 2 SiP, La 5 SiP 3 , and La 2 SiP 3 ternary compounds, agreeing well with experimental observations. Our simulations also suggest that there is a narrow temperature window in which the La 2 SiP 3 phase can be grown from the solid–liquid interface.

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

La 4 Co 4 X ( X = Pb , Bi , Sb ) : A demonstration of antagonistic pairs as a route to quasi-low-dimensional ternary compounds

We outline how pairs of strongly immiscible elements, referred to here as antagonistic pairs, can be used to synthesize ternary compounds with low or quasi-reduced-dimensional motifs intrinsically built into their crystal structures. By identifying third elements that are mutually compatible with a given antagonistic pair, ternary compounds can be formed in which the third element segregates the immiscible atoms into spatially separated substructures. Quasi-low-dimensional structural units, such as sheets, chains, or clusters are a natural consequence of the immiscible atoms seeking to avoid close contact in the solid state. Further, as proof of principle, we present the discovery, crystal growth, and basic physical properties of La 4 ⁢Co 4 ⁢$\mathrm{X}$ (X = Pb, Bi, Sb), a family of intermetallic compounds based on the antagonistic pairs Co-Pb and Co-Bi. La 4 ⁢Co 4 ⁢$\mathrm{X}$ adopts an orthorhombic crystal structure (space group Pbam) containing quasi-two-dimensional Co slabs and La-X polyhedra that stack in an alternating manner along the α axis. Consistent with our proposal, the La atoms separate the Co and X substructures, ensuring there are no direct contacts between the members of the immiscible (antagonistic) pair. Within the Co slabs, the atoms occupy the vertices of corner sharing tetrahedra and triangles, and this bonding motif produces narrow electronic bands near the Fermi level that favor magnetism. The Co is moment bearing in each La 4 ⁢Co 4 $\mathrm{X}$ compound studied, and we show that whereas La 4 ⁢Co 4 ⁢Pb behaves as a three-dimensional antiferromagnet with T N =220K, La 4 ⁢Co 4 ⁢Bi and La 4⁢ Co 4 ⁢Sb have behavior consistent with low-dimensional magnetic coupling and ordering, with T N =153K and 143 K, respectively. In addition to the Pb-, Bi-, and Sb-based La 4 ⁢Co 4 ⁢$\mathrm{X}$ compounds, we also were likely able to produce an analogous La 4 ⁢Co 4 ⁢Sn in polycrystalline form, although we were unable to isolate single crystals. We anticipate that identifying and using mutually compatible third elements together with an antagonistic pair represents a generalizable design principle for discovering new materials and new structure types containing low-dimensional substructures.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(In2Ni)3 by Materials Project

La(NiIn2)3 crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. La is bonded in a 10-coordinate geometry to two equivalent Ni and thirteen In atoms. Both La–Ni bond lengths are 3.35 Å. There are a spread of La–In bond distances ranging from 3.33–3.92 Å. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded in a 9-coordinate geometry to two equivalent La and seven In atoms. There are a spread of Ni–In bond distances ranging from 2.58–2.75 Å. In the second Ni site, Ni is bonded in a 8-coordinate geometry to one Ni and seven In atoms. The Ni–Ni bond length is 2.63 Å. There are a spread of Ni–In bond distances ranging from 2.59–2.73 Å. There are four inequivalent In sites. In the first In site, In is bonded in a 12-coordinate geometry to two equivalent La, three equivalent Ni, and one In atom. The In–In bond length is 3.12 Å. In the second In site, In is bonded in a 12-coordinate geometry to three equivalent La, three equivalent Ni, and six In atoms. There are a spread of In–In bond distances ranging from 3.04–3.33 Å. In the third In site, In is bonded in a 1-coordinate geometry to two equivalent La, three Ni, and four equivalent In atoms. In the fourth In site, In is bonded in a 6-coordinate geometry to one La and six equivalent Ni atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(ClO)3 by Materials Project

La(OCl)3 crystallizes in the orthorhombic Pnma space group. The structure is two-dimensional and consists of two La(OCl)3 sheets oriented in the (0, 0, 1) direction. La is bonded in a 2-coordinate geometry to four O and five Cl atoms. There are a spread of La–O bond distances ranging from 2.41–3.14 Å. There are a spread of La–Cl bond distances ranging from 2.72–2.92 Å. There are two inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to one La and one O atom. The O–O bond length is 1.24 Å. In the second O site, O is bonded in a linear geometry to two equivalent La atoms. There are two inequivalent Cl sites. In the first Cl site, Cl is bonded in a water-like geometry to two equivalent La atoms. In the second Cl site, Cl is bonded in a single-bond geometry to one La atom.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Pressure‐Dependent “Insulator–Metal–Insulator” Behavior in Sr‐Doped La 3 Ni 2 O 7

Abstract Recently, superconductivity at high temperatures is observed in bulk La 3 Ni 2 O 7−δ under high pressure. However, the attainment of high‐purity La 3 Ni 2 O 7−δ single crystals remains a formidable challenge. Here, the crystal structure and physical properties of single crystals of Sr‐doped La 3 Ni 2 O 7 synthesized at high pressure (20 GPa) and high temperature (1400 °C) are reported. Through single crystal X‐ray diffraction, it is shown that high‐pressure‐synthesized paramagnetic Sr‐doped La 3 Ni 2 O 7 crystallizes in an orthorhombic structure with Ni─O─Ni bond angles of 173.4(2)° out‐of‐plane and 175.0(2)°and 176.7(2)°in plane. The substitution of Sr alters in band filling and the ratio of Ni 2+ /Ni 3+ in Sr‐doped La 3 Ni 2 O 7 , aligning them with those of “La 3 Ni 2 O 7.05” , thereby leading to significant modifications in properties under high pressure relative to the unsubstituted parent phase. At ambient pressure, Sr‐doped La 3 Ni 2 O 7 exhibits insulating properties, and the conductivity increases as pressure goes up to 10 GPa. However, upon further increasing pressure beyond 10.7 GPa, Sr‐doped La 3 Ni 2 O 7 transits back from a metal‐like behavior to an insulator. The insulator–metal–insulator trend under high pressure dramatically differs from the behavior of the parent compound La 3 Ni 2 O 7−δ , despite their similar behavior in the low‐pressure regime. These experimental results underscore the considerable challenge in achieving superconductivity in nickelates.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Spectrophotometric determination of the stability of La hydroxyl complexes at near neutral to alkaline pH from 25 to 75 °C

The hydrolysis of rare earth elements (REE) potentially controls their mobility during fluid-rock interaction in a broad range of pH and temperature conditions. However, there is still a lack of thermodynamic data for modeling accurately the stability of REE hydroxyl complexes in hydrothermal aqueous fluids. Here, in this study, UV–Vis spectrophotometric experiments were conducted from 25 to 75 °C in near-neutral to alkaline NaOH-bearing aqueous solutions with varying lanthanum (La) concentrations (0 to ∼0.23 mmol/kg). The color indicator m-cresol purple was used to determine in situ pH and derive the average OH− ligand number ($\overrightarrow{n}$) and formation constants for the La hydroxyl complexes (LaOH 2+ , La(OH) 2 + , and La(OH) 3 0 ). From 25 to 50 °C, $\overrightarrow{n}$ ranges between ∼1 and 2 at pH from 7.0 to 9.3. At 75 °C, $\overrightarrow{n}$ ranges between ∼1.5 and 3 at pH from 6.3 to 8.8. These results suggest the predominance of LaOH 2+ and La(OH) 2 + complexes from 25 to 50 °C, and an increased predominance of La(OH) 3 0 at 75 °C. The cumulative formation constants (β n °, n = 1 to 3) are derived for the reaction La 3+ + nOH − = La(OH) n 3-n , and fitted between 25 and 250 °C by combining the UV–Vis and literature solubility data. The resulting logβ n ° are expressed as function of temperature (T in Kelvin): logβ 1 ° = −1.786 + 0.0133 T + 1.049·10 3 /T; logβ 2 ° = −5.797 + 0.0267 T + 2.713·10 3 /T; logβ 3 ° = 6.435 + 0.0223 T + 512.7/T. A comparison between these new fits and existing extrapolations using the Helgeson-Kirkham-Flowers equation of state indicates significant differences in the predicted hydrolysis of La. The latter extrapolations should therefore be updated for the hydrolysis of REE.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on La(Mg2Al)4 by Materials Project

La(Mg2Al)4 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to six Mg, two equivalent La, and four equivalent Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.01–3.20 Å. Both Mg–La bond lengths are 3.61 Å. All Mg–Al bond lengths are 2.88 Å. In the second Mg site, Mg is bonded in a 10-coordinate geometry to five Mg, one La, and four equivalent Al atoms. The Mg–Mg bond length is 2.99 Å. The Mg–La bond length is 3.43 Å. All Mg–Al bond lengths are 3.02 Å. La is bonded in a 4-coordinate geometry to twelve Mg and eight equivalent Al atoms. All La–Al bond lengths are 3.78 Å. Al is bonded in a 12-coordinate geometry to eight Mg, two equivalent La, and two equivalent Al atoms. Both Al–Al bond lengths are 2.92 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(GeIr)2 by Materials Project

La(IrGe)2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. La is bonded in a 12-coordinate geometry to eight Ir and eight Ge atoms. There are four shorter (3.27 Å) and four longer (3.40 Å) La–Ir bond lengths. All La–Ge bond lengths are 3.31 Å. There are two inequivalent Ir sites. In the first Ir site, Ir is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Ge atoms. All Ir–Ge bond lengths are 2.54 Å. In the second Ir site, Ir is bonded in a 9-coordinate geometry to four equivalent La and five Ge atoms. There are one shorter (2.49 Å) and four longer (2.53 Å) Ir–Ge bond lengths. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Ir atoms. In the second Ge site, Ge is bonded in a 9-coordinate geometry to four equivalent La and five Ir atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(AsRh)2 by Materials Project

La(RhAs)2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. La is bonded in a 4-coordinate geometry to eight Rh and eight As atoms. There are four shorter (3.32 Å) and four longer (3.36 Å) La–Rh bond lengths. There are four shorter (3.28 Å) and four longer (3.29 Å) La–As bond lengths. There are two inequivalent Rh sites. In the first Rh site, Rh is bonded in a 12-coordinate geometry to four equivalent La and four equivalent As atoms. All Rh–As bond lengths are 2.57 Å. In the second Rh site, Rh is bonded in a 9-coordinate geometry to four equivalent La and five As atoms. There are one shorter (2.46 Å) and four longer (2.48 Å) Rh–As bond lengths. There are two inequivalent As sites. In the first As site, As is bonded in a 8-coordinate geometry to four equivalent La and four equivalent Rh atoms. In the second As site, As is bonded in a 9-coordinate geometry to four equivalent La and five Rh atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(Al5Cu)2 by Materials Project

La(CuAl5)2 crystallizes in the orthorhombic Fmmm space group. The structure is three-dimensional. La is bonded in a 12-coordinate geometry to four equivalent Cu and sixteen Al atoms. All La–Cu bond lengths are 3.59 Å. There are a spread of La–Al bond distances ranging from 3.24–3.42 Å. Cu is bonded in a 12-coordinate geometry to two equivalent La and eight Al atoms. There are four shorter (2.60 Å) and four longer (2.70 Å) Cu–Al bond lengths. There are three inequivalent Al sites. In the first Al site, Al is bonded in a 10-coordinate geometry to one La, two equivalent Cu, and seven Al atoms. There are a spread of Al–Al bond distances ranging from 2.71–2.91 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to two equivalent La, two equivalent Cu, and six Al atoms. Both Al–Al bond lengths are 2.71 Å. In the third Al site, Al is bonded to two equivalent La and ten Al atoms to form a mixture of corner and face-sharing AlLa2Al10 cuboctahedra. Both Al–Al bond lengths are 2.62 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Level structure of light neutron-rich La isotopes beyond the 𝑁 = 82 shell closure

Here, the high spin excited states of Lanthanum isotopes 140–143 La, above the 𝑁 = 82 closed shell, were populated in fission reactions. The prompt 𝛾-ray transitions were measured using two complementary methods: (a) in coincidence with the isotopically identified fragments produced in the fission of the 238 U + 9 Be system using the Variable Mode Spectrometer (VAMOS++) and the Advanced Gamma Tracking Array (AGATA) spectrometer, and (b) high statistics threefold 𝛾−𝛾−𝛾 and fourfold 𝛾−𝛾−𝛾−𝛾 coincidence data from the spontaneous fission of 252 Cf using the Gammasphere. This work reports the first identification of a pair of parity doublet structures in 143 La and the new high spin level structure in 140–142 La from prompt 𝛾-ray spectroscopy. The level structures are interpreted in terms of the systematics of neighboring odd-𝑍 nuclei above the 𝑍 = 50 shell closure and large-scale shell model calculations. The present results indicate the presence of stable octupole deformation in 143 La. The excitation energy pattern and their comparison with neighboring isotones, moving away from the 𝑁 = 82 closed shell, point towards a transition from single-particle structures to an alternating parity rotational band structure in the La isotopic chain.

Navin, A. [Centre National de la Recherche Scienti↗
DOE OSTI2022

Mechanism for Acetone and Crotonaldehyde Production during Steam Reforming of Ethanol over La 0.7 Sr 0.3 MnO 3–x Perovskite: Evidence for a Shared C4 Aldol Addition Intermediate

Here a mechanistic study was conducted on the catalytic conversion of ethanol over La 0.7 Sr 0.3 MnO 3–x perovskite catalysts in the presence and absence of water. The study sought insights into the path of C–C coupling toward acetone and crotonaldehyde and also into clarifying whether the lack of previous reports of C–C coupling over La 0.7 Sr 0.3 MnO 3–x (100) could be due to a “pressure gap”. Several types of experiments were performed at 400–800 K: flow experiments with a torr range reactant gas flown over La 0.7 Sr 0.3 MnO 3–x powders; ultra-high vacuum experiments with continuous gas exposures to a La 0.7 Sr 0.3 MnO 3–x (100) single-crystal sample; and torr range continuous gas exposures to a La 0.7 Sr 0.3 MnO 3–x (100) single-crystal sample. When ethanol and water were flown over La 0.7 Sr 0.3 MnO 3–x powders at 400–800 K, the products detected were ethene, acetaldehyde, acetone, crotonaldehyde, CO, CO 2 , and H 2 . Acetone was catalytically produced over both the La 0.7 Sr 0.3 MnO 3–x powder and the La 0.7 Sr 0.3 MnO 3–x (100) single-crystal sample at temperatures of 700–800 K when reaction conditions were on the order of 1 Torr of reactant gas and with an excess of water relative to ethanol (1 ethanol/9 water). Isotopic labeling with deuterium was used to gain insights into the C–C coupling reaction mechanism and paths in species with three and four carbons (C 3 and C 4 species). Additionally, steady-state isotopic transient kinetic analysis (SSITKA) experiments + simulations using carbon labeling of the ethanol feed were performed. Three mechanistic paths were considered for the C–C coupling step: the first two paths, A and B, involve coupling between two intermediates which are both in oxygen vacancies; and the third path, C, involves coupling between one intermediate in an oxygen vacancy and one intermediate outside of an oxygen vacancy. The results suggest that the dominant path to the C 3 product, acetone, depends on the conditions. The less active path (attributed to path A or B) occurs at 600–700 K and involves coupling between two irreversibly bound species. The more active path (attributed to path C) requires an excess of water, becomes dominant at 600–800 K, and involves coupling between one irreversibly bound species and one reversibly bound species. Based on these various observations from experiments and simulations, an elementary step is proposed for acetone formation involving a previously unreported C 4 transition state that is formed after aldol addition. Density functional theory calculations were performed based on this hypothesis, and it confirmed that this specific and previously unreported aldol addition path to acetone does exist and that this path consistent with the experimental data. In this path, C–C formation occurs to create a C 4 intermediate that is bound to an oxygen vacancy, then a hydrogen transfer with C–C bond breaking occurs that results in the production of the acetone molecule. The proposed mechanism is also consistent with the experimental observation that acetone formation has a greater than first-order dependence on the water vapor pressure.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on La(GePt)2 by Materials Project

LaPt2Ge2 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. La is bonded in a 1-coordinate geometry to eight Pt and eight Ge atoms. There are a spread of La–Pt bond distances ranging from 3.34–3.42 Å. There are a spread of La–Ge bond distances ranging from 3.32–3.43 Å. There are two inequivalent Pt sites. In the first Pt site, Pt is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Ge atoms. There are a spread of Pt–Ge bond distances ranging from 2.56–2.58 Å. In the second Pt site, Pt is bonded in a 5-coordinate geometry to four equivalent La and five Ge atoms. There are one shorter (2.50 Å) and four longer (2.55 Å) Pt–Ge bond lengths. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Pt atoms. In the second Ge site, Ge is bonded in a 5-coordinate geometry to four equivalent La and five Pt atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(GePt)2 by Materials Project

LaPt2Ge2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. La is bonded in a 12-coordinate geometry to eight Pt and eight Ge atoms. There are a spread of La–Pt bond distances ranging from 3.24–3.55 Å. There are a spread of La–Ge bond distances ranging from 3.24–3.60 Å. There are two inequivalent Pt sites. In the first Pt site, Pt is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Ge atoms. There are a spread of Pt–Ge bond distances ranging from 2.52–2.61 Å. In the second Pt site, Pt is bonded in a 5-coordinate geometry to four equivalent La and five Ge atoms. There are a spread of Pt–Ge bond distances ranging from 2.52–2.56 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Pt atoms. In the second Ge site, Ge is bonded in a 5-coordinate geometry to four equivalent La and five Pt atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(CuSn)2 by Materials Project

Cu2LaSn2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. La is bonded in a 12-coordinate geometry to eight Cu and eight Sn atoms. There are four shorter (3.40 Å) and four longer (3.48 Å) La–Cu bond lengths. There are four shorter (3.43 Å) and four longer (3.57 Å) La–Sn bond lengths. There are two inequivalent Cu sites. In the first Cu site, Cu is bonded in a 9-coordinate geometry to four equivalent La and five Sn atoms. There are one shorter (2.55 Å) and four longer (2.67 Å) Cu–Sn bond lengths. In the second Cu site, Cu is bonded in a 12-coordinate geometry to four equivalent La and four equivalent Sn atoms. All Cu–Sn bond lengths are 2.63 Å. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded in a 12-coordinate geometry to four equivalent La and four equivalent Cu atoms. In the second Sn site, Sn is bonded in a 9-coordinate geometry to four equivalent La and five Cu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(NiSn)2 by Materials Project

LaNi2Sn2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. La is bonded in a 12-coordinate geometry to eight Ni and eight Sn atoms. There are four shorter (3.34 Å) and four longer (3.44 Å) La–Ni bond lengths. There are four shorter (3.40 Å) and four longer (3.46 Å) La–Sn bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded in a 8-coordinate geometry to four equivalent La and four equivalent Sn atoms. All Ni–Sn bond lengths are 2.58 Å. In the second Ni site, Ni is bonded in a 9-coordinate geometry to four equivalent La and five Sn atoms. There are one shorter (2.54 Å) and four longer (2.60 Å) Ni–Sn bond lengths. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded in a 12-coordinate geometry to four equivalent La and four equivalent Ni atoms. In the second Sn site, Sn is bonded in a 9-coordinate geometry to four equivalent La and five Ni atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(AlPd)2 by Materials Project

LaPd2Al2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. La is bonded in a 8-coordinate geometry to eight Pd and eight Al atoms. There are four shorter (3.35 Å) and four longer (3.37 Å) La–Pd bond lengths. There are four shorter (3.37 Å) and four longer (3.38 Å) La–Al bond lengths. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Al atoms. All Pd–Al bond lengths are 2.54 Å. In the second Pd site, Pd is bonded in a 5-coordinate geometry to four equivalent La and five Al atoms. There are one shorter (2.52 Å) and four longer (2.57 Å) Pd–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to four equivalent La and four equivalent Pd atoms to form a mixture of distorted edge and face-sharing AlLa4Pd4 tetrahedra. In the second Al site, Al is bonded in a 5-coordinate geometry to four equivalent La and five Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(CoP3)20 by Materials Project

La(CoP3)20 is Skutterudite-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. La is bonded to twelve P atoms to form LaP12 cuboctahedra that share corners with eight PCo2P2 tetrahedra and faces with eight CoP6 octahedra. There are four shorter (2.98 Å) and eight longer (3.02 Å) La–P bond lengths. There are six inequivalent Co sites. In the first Co site, Co is bonded to six P atoms to form CoP6 octahedra that share corners with six CoP6 octahedra, corners with six PCo2P2 tetrahedra, and a faceface with one LaP12 cuboctahedra. The corner-sharing octahedra tilt angles range from 58–62°. There are a spread of Co–P bond distances ranging from 2.23–2.25 Å. In the second Co site, Co is bonded to six P atoms to form CoP6 octahedra that share corners with six CoP6 octahedra and corners with twelve PCo2P2 tetrahedra. The corner-sharing octahedral tilt angles are 60°. There are five shorter (2.23 Å) and one longer (2.24 Å) Co–P bond lengths. In the third Co site, Co is bonded to six P atoms to form CoP6 octahedra that share corners with six CoP6 octahedra and corners with twelve PCo2P2 tetrahedra. The corner-sharing octahedral tilt angles are 60°. There are four shorter (2.23 Å) and two longer (2.24 Å) Co–P bond lengths. In the fourth Co site, Co is bonded to six P atoms to form CoP6 octahedra that share corners with six CoP6 octahedra, corners with four PCo2P2 tetrahedra, and faces with two equivalent LaP12 cuboctahedra. The corner-sharing octahedra tilt angles range from 60–62°. There are two shorter (2.24 Å) and four longer (2.26 Å) Co–P bond lengths. In the fifth Co site, Co is bonded to six P atoms to form CoP6 octahedra that share corners with six CoP6 octahedra and corners with ten PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 58–60°. There are a spread of Co–P bond distances ranging from 2.22–2.24 Å. In the sixth Co site, Co is bonded to six P atoms to form CoP6 octahedra that share corners with six CoP6 octahedra and corners with twelve PCo2P2 tetrahedra. The corner-sharing octahedral tilt angles are 60°. There are three shorter (2.23 Å) and three longer (2.24 Å) Co–P bond lengths. There are twenty inequivalent P sites. In the first P site, P is bonded to two Co and two P atoms to form distorted PCo2P2 tetrahedra that share a cornercorner with one LaP12 cuboctahedra, corners with four CoP6 octahedra, and corners with seven PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 67–69°. There are one shorter (2.27 Å) and one longer (2.30 Å) P–P bond lengths. In the second P site, P is bonded to two Co and two P atoms to form distorted PCo2P2 tetrahedra that share corners with four CoP6 octahedra, corners with ten PCo2P2 tetrahedra, and an edgeedge with one PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–70°. There are one shorter (2.26 Å) and one longer (2.34 Å) P–P bond lengths. In the third P site, P is bonded to two Co and two equivalent P atoms to form distorted PCo2P2 tetrahedra that share corners with four CoP6 octahedra, corners with ten PCo2P2 tetrahedra, and an edgeedge with one PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–70°. There are one shorter (2.26 Å) and one longer (2.34 Å) P–P bond lengths. In the fourth P site, P is bonded to two Co and two P atoms to form distorted PCo2P2 tetrahedra that share corners with four CoP6 octahedra, corners with ten PCo2P2 tetrahedra, and an edgeedge with one PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–70°. The P–P bond length is 2.26 Å. In the fifth P site, P is bonded in a 2-coordinate geometry to one La, two Co, and two P atoms. The P–P bond length is 2.30 Å. In the sixth P site, P is bonded in a 2-coordinate geometry to one La, two Co, and two equivalent P atoms. There are one shorter (2.27 Å) and one longer (2.34 Å) P–P bond lengths. In the seventh P site, P is bonded to two Co and two P atoms to form distorted PCo2P2 tetrahedra that share corners with four CoP6 octahedra, corners with ten PCo2P2 tetrahedra, and an edgeedge with one PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–70°. There are one shorter (2.26 Å) and one longer (2.34 Å) P–P bond lengths. In the eighth P site, P is bonded to two Co and two P atoms to form distorted PCo2P2 tetrahedra that share corners with four CoP6 octahedra, corners with ten PCo2P2 tetrahedra, and an edgeedge with one PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–70°. There are one shorter (2.26 Å) and one longer (2.34 Å) P–P bond lengths. In the ninth P site, P is bonded to two Co and two P atoms to form distorted PCo2P2 tetrahedra that share corners with four CoP6 octahedra, corners with ten PCo2P2 tetrahedra, and an edgeedge with one PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–70°. The P–P bond length is 2.34 Å. In the tenth P site, P is bonded to two Co and two P atoms to form distorted PCo2P2 tetrahedra that share corners with four CoP6 octahedra, corners with seven PCo2P2 tetrahedra, and an edgeedge with one PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 68–70°. The P–P bond length is 2.32 Å. In the eleventh P site, P is bonded to two equivalent Co and two P atoms to form distorted PCo2P2 tetrahedra that share a cornercorner with one LaP12 cuboctahedra, corners with four equivalent CoP6 octahedra, and corners with ten PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 68–69°. There are one shorter (2.26 Å) and one longer (2.32 Å) P–P bond lengths. In the twelfth P site, P is bonded to two equivalent Co and two P atoms to form distorted PCo2P2 tetrahedra that share corners with four equivalent CoP6 octahedra, corners with ten PCo2P2 tetrahedra, and an edgeedge with one PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–70°. There are one shorter (2.26 Å) and one longer (2.34 Å) P–P bond lengths. In the thirteenth P site, P is bonded to two equivalent Co and two equivalent P atoms to form distorted PCo2P2 tetrahedra that share corners with four equivalent CoP6 octahedra, corners with ten PCo2P2 tetrahedra, and an edgeedge with one PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–70°. There are one shorter (2.26 Å) and one longer (2.34 Å) P–P bond lengths. In the fourteenth P site, P is bonded to two equivalent Co and two P atoms to form distorted PCo2P2 tetrahedra that share corners with four equivalent CoP6 octahedra, corners with ten PCo2P2 tetrahedra, and an edgeedge with one PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–70°. There are one shorter (2.26 Å) and one longer (2.33 Å) P–P bond lengths. In the fifteenth P site, P is bonded in a 2-coordinate geometry to one La, two equivalent Co, and two P atoms. There are one shorter (2.30 Å) and one longer (2.31 Å) P–P bond lengths. In the sixteenth P site, P is bonded to two equivalent Co and two P atoms to form distorted PCo2P2 tetrahedra that share a cornercorner with one LaP12 cuboctahedra, corners with four CoP6 octahedra, and corners with four PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 68–69°. In the seventeenth P site, P is bonded to two equivalent Co and two P atoms to form distorted PCo2P2 tetrahedra that share corners with four CoP6 octahedra, corners with ten PCo2P2 tetrahedra, and an edgeedge with one PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–70°. In the eighteenth P site, P is bonded to two equivalent Co and two equivalent P atoms to form distorted PCo2P2 tetrahedra that share corners with four equivalent CoP6 octahedra, corners with ten PCo2P2 tetrahedra, and an edgeedge with one PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–70°. In the nineteenth P site, P is bonded to two equivalent Co and two P atoms to form distorted PCo2P2 tetrahedra that share corners with four CoP6 octahedra, corners with ten PCo2P2 tetrahedra, and an edgeedge with one PCo2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–70°. In the twentieth P site, P is bonded in a 2-coordinate geometry to one La, two equivalent Co, and two P atoms.

36 MATERIALS SCIENCE↗