Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Fe-Ni”

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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Tungsten and molybdenum isotopic evidence for an impact origin of pallasites

The origin of pallasites—stony-iron meteorites mainly composed of olivine and Fe-Ni metal—is debated and proposed formation scenarios broadly range from models that explain pallasite formation by internal processes in the mantle of a differentiated planetesimal to those that involve impact–induced mixing of core and mantle materials. Here, the origin of pallasites is examined by studying the nebular source regions of their precursor material using Mo isotopes and their history of metal-silicate segregation using Hf-W chronometry. We report new Mo and W isotopic data for a large suite of pallasite metal samples, alongside Pt isotope data to quantify superimposed cosmic ray exposure effects. Most main-group pallasites exhibit uniform pre-exposure 182 W and Mo isotopic compositions that bear an excellent similarity to those of IIIAB iron meteorites. Four main-group pallasites and the IIIAB iron Thunda have more radiogenic pre-exposure 182 W compositions, but display the same Mo isotopic composition as other main-group pallasites and IIIAB irons. This strong chronological and genetic link strongly suggests that main-group pallasite metal originated in the IIIAB parent body core. This, combined with prior Pd-Ag chronometric evidence for an early collisional disruption of the IIIAB parent body, implies that main-group pallasites formed by impact–induced mixing of metal and silicates rather than by an internal process on the IIIAB parent body. This mixing led to elevated 182 W compositions in some pallasites, which are best accounted for by partial re-equilibration of IIIAB metal with radiogenic 182 W from the colliding body. Altogether, our results support models that explain main-group pallasite formation by injection of pallasite metal into the mantle of another differentiated body, implying that pallasite silicates did not primarily derive from the IIIAB mantle, but instead from that of the colliding body.

58 GEOSCIENCES↗
DOE OSTI2022

Formation, cooling history and age of impact events on the IIE iron parent body: Evidence from the Miles meteorite

Most iron meteorites formed in planetary cores during differentiation, but the IIE iron meteorites have chemical and physical features that are inconsistent with this origin. By combining mineral chemistry, mineral modes and three-dimensional petrography, we reconstruct the bulk chemistry of the felsic silicate-bearing Miles IIE iron meteorite and demonstrate that the silicate inclusion compositions are similar to partial melts produced experimentally from an H chondrite composition. We use the reconstructed bulk composition, mineralogy and thermodynamic modelling to show that melting above ~ 1200°C under reducing conditions formed metal (Fe-Ni alloy) and felsic silicate partial melts. Upon cooling, the melts crystallized Mg-rich pyroxenes, Na- and K-rich feldspars, and tridymite. Importantly, this mechanism enriches cosmochemically volatile elements (i.e., those with a 50% condensation temperature of ~430–830°C, like Na and K) to the level found in the felsic silicate inclusions. The presence of crystallographically disordered srilankite (only stable above 1160°C) and an absence of Widmanstätten texture require both high peak temperatures and rapid cooling, which cannot be explained by core formation. Instead, they point to small melt volumes, a transient heat pulse, and small thermal mass, and imply efficient physical segregation of silicate and metallic melts through buoyancy separation followed by rapid cooling that arrested the separation of metal and silicate liquid phases. In situ 207 Pb/ 206 Pb age of 4542.3 ± 4.0 Ma in Zr-oxide and phosphate minerals dates the melting event that formed the silicate inclusions. This age aligns with the earliest ages found in other IIE iron meteorite silicates and requires a heating event ~25 million years after the solar system formed. We found 39 Ar/ 40 Ar ages of 3495 ± 52 Ma (low-T) and 4303 ± 7 Ma (high-T) in a K-feldspar grain, with the 3495 Ma age aligning with later thermal events recorded in other IIE iron meteorites. Dating reveals the complex petrogenetic and thermal history of Miles and the IIE iron meteorites. This is the first IIE iron meteorite found to record evidence of heating at 4.5 and 3.5 Ga likely from impact events. We propose that high-velocity impact(s) into an iron-rich, porous chondritic parent body at ~4.54 Ga produced immiscible metal and silicate melts that cooled rapidly and trapped low density silicate inclusions within high density metal. Other IIE irons that formed at lower peak temperatures (900–1000°C) contain chondritic silicate inclusions and relict chondrules, supporting this conceptual model. In conclusion, this petrogenesis is consistent with thermodynamic modelling, experimental data and the wide range of peak temperatures and cooling rates observed in the IIE iron meteorites.

58 GEOSCIENCES↗
DOE OSTI2020

Coupling computational thermodynamics with density-function-theory based calculations to design L12 precipitates in Fe Ni based alloys

Achieving a high-volume fraction of thermodynamically stable L12-type precipitates that are resistant to coarsening is of great importance for the development of low-cost FeNi based austenitic steels. With the aid of computational thermodynamics, this work designed two model alloys: Fe-37.4Ni-6.1Al-2.9Ti (FNAT) and Fe-45.2Ni-5.9Al-8.5Si (FNAS). Both alloys were designed to contain a similar amount of L1 2 precipitate in Fe-Ni matrix without forming other precipitates. Density-Function-Theory (DFT) calculation was coupled with computational thermodynamics to predict the critical radius at which the precipitates change shape from spherical to cuboidal. The calculation results suggest that critical radius for the FNAT alloy is about two orders of magnitude larger than that for the FeNiAlSi alloy. Phase stability and morphology of the L1 2 precipitates in these two alloys were experimentally investigated through X-ray diffraction, atom probe tomography, and scanning and transmission electron microscopy. The L1 2 precipitates in the FeNiAlSi system were found to be cuboidal and rod shaped, with much larger size than the spherical ones in the FeNiAlTi system, agreeing with the calculation results. This work suggested that coupling computational thermodynamics with DFT calculations can be reliably used to design L1 2 precipitates in FeNi based alloys.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Superstoichiometric Alloying of H and Close‐Packed Fe‐Ni Metal Under High Pressures: Implications for Hydrogen Storage in Planetary Core

Although high pressure enables alloying between hydrogen and iron, hydrogen-to-iron molar ratio (H/Fe) so far found in experiments is mostly limited to 1 in the close-packed iron metal under high pressure. We report a H/(Fe + Ni) ratio of 1.8 ± 0.1 from (Fe,Ni)H x (or x ≥ 1.8) quenched from liquid, exceeding the amounts so far reported for densely packed Fe alloys. From the metastable behavior of the frozen (Fe,Ni)Hx liquid during decompression, we infer that the amount is a lower bound and therefore even a greater amount of H can be dissolved in the liquid part of Fe-rich cores of planets. The significant H storage capacity of liquid Fe-Ni alloy is important to consider for potential storage of H in the interiors of low-density planets as well as rocky planets.

58 GEOSCIENCES↗
DOE OSTI2023

Hydrogen and Silicon Effects on Hexagonal Close Packed Fe Alloys at High Pressures: Implications for the Composition of Earth's Inner Core

Hexagonal close-packed (hcp) structured Fe-Ni alloy is believed to be the dominant phase in the Earth's inner core. This phase is expected to contain 4%–5% light elements, such as Si and H. While the effects of individual light element candidates on the equation of state (EoS) of the hcp Fe metal have been studied, their combined effects remain largely unexplored. Here, in this study, we report the equations of state for two hcp-structured Fe-Si-H alloys, namely Fe 0.83 Si 0.17 H 0.07 and Fe 0.83 Si 0.17 H 0.46 , using synchrotron X-ray diffraction measurements up to 125 GPa at 300 K. These alloys were synthesized by cold compression of Fe-9wt%Si in either pure H 2 or Ar-H 2 mixture medium in diamond-anvil cells. The volume increase caused by a H atom in hcp Fe-Si-H alloys is approximately eight times greater than that by a Si atom. We used the improved data set to develop a composition-dependent EoS that covers a wide range of compositions. Our calculated density and bulk sound velocity of hcp Fe-Si-H alloys suggest a large trade-off between Si and H contents in fitting the seismic properties of the inner core. Combining our new EoS with geophysical and geochemical constraints, we propose 1.6–3 wt% Si and 0.15–0.6 wt% H in the Earth's inner core.

58 GEOSCIENCES↗
DOE OSTI2023

Development & Validation of Low-Cost, Highly-Durable, Spinel-Based Materials for SOFC Cathode-Side Contact (Final Report)

A cathode-side contact layer is required to provide and maintain stable electrical conduction paths between the interconnect and cathode in a solid oxide fuel cell (SOFC) stack assembly and thus minimize the ohmic resistance and stack power loss. Current cathode-interconnect contact materials are based on noble metals, electrically-conductive perovskites, their composite materials, etc. These materials are either too expensive or do not possess the overall balanced performance required for the cathode-side contact application. To achieve the DOE SOFC system cost and performance stability goals, a new generation of low-cost, high-performance contact materials needs to be developed. In this project, spinel-based materials thermally converted from the Fe-Ni and Co-Mn based alloy precursors were developed and validated for the cathode-side contact application. The precursor alloy compositions were optimized via a combination of composition screening in the (Ni,Fe) 3 O 4 and (Mn,Co) 3 O 4 spinel system, alloy design using physical metallurgy principles, and cost considerations. The alloy powders with the desired composition and particle size were manufactured via gas atomization. The optimal process parameters for thermal conversion of these alloy precursor layers to a spinel-based layer were identified, i.e., 900°C x 2h in air, which is close to the initial stack firing condition. The area-specific resistances (ASRs) of the interconnect/contact/cathode test assemblies with the developed contact layer were determined for various durations (up to 5000 h) under simulated cathodic operation conditions. Some of the alloy-derived spinel contacts exhibited the lowest ASR and ASR degradation rate. The in-stack performance of the most promising alloy-derived contact layer is currently being evaluated via stack testing. To reduce the stack cost, the Co-Mn based alloy powders were utilized as the precursor for synthesis of dense spinel-based interconnect coating. By optimizing both the initial powder size/distribution and the alloy powder composition, a dense (Mn,Co) 3 O 4 -based spinel coating was achieved. Furthermore, co-sintering of the coating/contact dual-layer structure under the initial stack firing condition was realized by utilizing the tailored Co-Mn alloy precursors. Cost analysis of the developed technology indicated a total stack cost reduction of around 10.6% with the implementation of co-sintering of the interconnect coating and the contact layer during initial stack firing. Since low-cost processes such as screen printing is utilized in the precursor application and no reduction heat treatment is needed for the coating formation, the developed technology can be readily implemented at the industrial partner’s manufacturing facilities with no additional capital investment needed.

08 HYDROGEN↗
DOE OSTI2021

Ultrafast X-ray Diffraction Study of a Shock-Compressed Iron Meteorite above 100 GPa

Natural kamacite samples (Fe92.5Ni7.5) from a fragment of the Gibeon meteorite were studied as a proxy material for terrestrial cores to examine phase transition kinetics under shock compression for a range of different pressures up to 140 GPa. In situ time-resolved X-ray diffraction (XRD) data were collected of a body-centered cubic (bcc) kamacite section that transforms to the high-pressure hexagonal close-packed (hcp) phase with sub-nanosecond temporal resolution. The coarse-grained crystal of kamacite rapidly transformed to highly oriented crystallites of the hcp phase at maximum compression. The hcp phase persisted for as long as 9.5 ns following shock release. Comparing the c/a ratio with previous static and dynamic work on Fe and Fe-rich Fe-Ni alloys, it was found that some shots exhibit a larger than ideal c/a ratio, up to nearly 1.65. This work represents the first time-resolved laser shock compression structural study of a natural iron meteorite, relevant for understanding the dynamic material properties of metallic planetary bodies during impact events and Earth’s core elasticity.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Atomic Iron and Nickel in the Coma of C/1996 B2 (Hyakutake): Production Rates, Emission Mechanisms, and Possible Parents

Abstract Two papers recently reported the detection of gaseous nickel and iron in the comae of over 20 comets from observations collected over two decades, including interstellar comet 2I/Borisov. To evaluate the state of the laboratory data in support of these identifications, we reanalyzed archived spectra of comet C/1996 B2 (Hyakutake), one of the nearest and brightest comets of the past century, using a combined experimental and computational approach. We developed a new, many-level fluorescence model that indicates that the fluorescence emissions of Fe I and Ni I vary greatly with heliocentric velocity. Combining this model with laboratory spectra of an Fe-Ni plasma, we identified 22 lines of Fe I and 14 lines of Ni I in the spectrum of Hyakutake. Using Haser models, we estimate the nickel and iron production rates as Q Ni = (2.6–4.1) × 10 22 s −1 and Q Fe = (0.4–2.8) × 10 23 s −1 . From derived column densities, the Ni/Fe abundance ratio log 10 [Ni/Fe] = −0.15 ± 0.07 deviates significantly from solar abundance ratios, and it is consistent with the ratios observed in solar system comets. Possible production and emission mechanisms are analyzed in the context of existing laboratory measurements. Based on the observed spatial distributions, excellent fluorescence model agreement, and Ni/Fe ratio, our findings support an origin consisting of a short-lived unknown parent followed by fluorescence emission. Our models suggest that the strong heliocentric velocity dependence of the fluorescence efficiencies can provide a meaningful test of the physical process responsible for the Fe I and Ni I emission.

Bromley, S. J. (ORCID:0000000321108152)↗
DOE OSTI2022

Nanostructure refinement and phase formation of flash annealed FeNi-based soft magnetic alloys

In this work, the resulting nanocomposite microstructures of FeNi nanocrystallites under different heating and cooling rates (5 °C/min vs 400-500 °C/s) is investigated. Conventional furnace annealing under low heating rates and slow cooling resulted in both BCC α-FeNi and FCC γ-FeNi nanocrystallites with an average grain size on the order of 25-27 nm whereas high heating rates achieved via flash annealing techniques have enabled a dramatically refined microstructure consisting of 5-7 nm grains with FCC γ-FeNi phase and found to be the dominant phase following primary crystallization. Grain size refinement and phase identity optimization yielded low values of coercivities-17 A/m and high permeability similar to 11 x 10 3 measured at 400 Hz/1 kA/m in flash annealed samples at 450 °C for 5 s. The magnetic behavior and the underlying mechanism of optimal soft magnetic properties are discussed in terms of the critical role of the grain size in domain wall pinning and coercivity.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeNi3 by Materials Project

Ni3Fe is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Fe is bonded to twelve equivalent Ni atoms to form FeNi12 cuboctahedra that share corners with twelve equivalent FeNi12 cuboctahedra, edges with twenty-four equivalent NiFe4Ni8 cuboctahedra, faces with six equivalent FeNi12 cuboctahedra, and faces with twelve equivalent NiFe4Ni8 cuboctahedra. All Fe–Ni bond lengths are 2.50 Å. Ni is bonded to four equivalent Fe and eight equivalent Ni atoms to form NiFe4Ni8 cuboctahedra that share corners with twelve equivalent NiFe4Ni8 cuboctahedra, edges with eight equivalent FeNi12 cuboctahedra, edges with sixteen equivalent NiFe4Ni8 cuboctahedra, faces with four equivalent FeNi12 cuboctahedra, and faces with fourteen equivalent NiFe4Ni8 cuboctahedra. All Ni–Ni bond lengths are 2.50 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeNi by Materials Project

NiFe is Tetraauricupride structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Fe is bonded to four equivalent Fe and eight equivalent Ni atoms to form FeFe4Ni8 cuboctahedra that share corners with twelve equivalent FeFe4Ni8 cuboctahedra, edges with eight equivalent FeFe4Ni8 cuboctahedra, edges with sixteen equivalent NiFe8Ni4 cuboctahedra, faces with eight equivalent NiFe8Ni4 cuboctahedra, and faces with ten equivalent FeFe4Ni8 cuboctahedra. All Fe–Fe bond lengths are 2.51 Å. All Fe–Ni bond lengths are 2.52 Å. Ni is bonded to eight equivalent Fe and four equivalent Ni atoms to form NiFe8Ni4 cuboctahedra that share corners with twelve equivalent NiFe8Ni4 cuboctahedra, edges with eight equivalent NiFe8Ni4 cuboctahedra, edges with sixteen equivalent FeFe4Ni8 cuboctahedra, faces with eight equivalent FeFe4Ni8 cuboctahedra, and faces with ten equivalent NiFe8Ni4 cuboctahedra. All Ni–Ni bond lengths are 2.51 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe3Ni by Materials Project

Fe3Ni is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Fe is bonded to eight equivalent Fe and four equivalent Ni atoms to form FeFe8Ni4 cuboctahedra that share corners with twelve equivalent FeFe8Ni4 cuboctahedra, edges with eight equivalent NiFe12 cuboctahedra, edges with sixteen equivalent FeFe8Ni4 cuboctahedra, faces with four equivalent NiFe12 cuboctahedra, and faces with fourteen equivalent FeFe8Ni4 cuboctahedra. All Fe–Fe bond lengths are 2.53 Å. All Fe–Ni bond lengths are 2.53 Å. Ni is bonded to twelve equivalent Fe atoms to form NiFe12 cuboctahedra that share corners with twelve equivalent NiFe12 cuboctahedra, edges with twenty-four equivalent FeFe8Ni4 cuboctahedra, faces with six equivalent NiFe12 cuboctahedra, and faces with twelve equivalent FeFe8Ni4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe3Ni by Materials Project

Fe3Ni is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are two inequivalent Fe sites. In the first Fe site, Fe is bonded in a distorted body-centered cubic geometry to four equivalent Fe and four equivalent Ni atoms. All Fe–Fe bond lengths are 2.47 Å. All Fe–Ni bond lengths are 2.47 Å. In the second Fe site, Fe is bonded in a 8-coordinate geometry to eight equivalent Fe and six equivalent Ni atoms. All Fe–Ni bond lengths are 2.85 Å. Ni is bonded in a distorted body-centered cubic geometry to fourteen Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeNi3 by Materials Project

Ni3Fe is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Fe is bonded in a distorted body-centered cubic geometry to fourteen Ni atoms. There are eight shorter (2.44 Å) and six longer (2.82 Å) Fe–Ni bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded in a distorted body-centered cubic geometry to four equivalent Fe and four equivalent Ni atoms. All Ni–Ni bond lengths are 2.44 Å. In the second Ni site, Ni is bonded in a 8-coordinate geometry to six equivalent Fe and eight equivalent Ni atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeNi3 by Materials Project

Ni3Fe is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Fe is bonded to twelve Ni atoms to form FeNi12 cuboctahedra that share corners with four equivalent FeNi12 cuboctahedra, corners with eight equivalent NiFe4Ni8 cuboctahedra, edges with eight equivalent FeNi12 cuboctahedra, edges with sixteen equivalent NiFe4Ni8 cuboctahedra, faces with four equivalent FeNi12 cuboctahedra, and faces with fourteen NiFe4Ni8 cuboctahedra. All Fe–Ni bond lengths are 2.50 Å. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded to four equivalent Fe and eight equivalent Ni atoms to form NiFe4Ni8 cuboctahedra that share corners with four equivalent NiFe4Ni8 cuboctahedra, corners with eight equivalent FeNi12 cuboctahedra, edges with twenty-four NiFe4Ni8 cuboctahedra, faces with six equivalent FeNi12 cuboctahedra, and faces with twelve NiFe4Ni8 cuboctahedra. All Ni–Ni bond lengths are 2.50 Å. In the second Ni site, Ni is bonded to four equivalent Fe and eight Ni atoms to form NiFe4Ni8 cuboctahedra that share corners with twelve equivalent NiFe4Ni8 cuboctahedra, edges with eight equivalent FeNi12 cuboctahedra, edges with sixteen NiFe4Ni8 cuboctahedra, faces with four equivalent FeNi12 cuboctahedra, and faces with fourteen NiFe4Ni8 cuboctahedra. All Ni–Ni bond lengths are 2.50 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe3Ni by Materials Project

Fe3Ni is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Fe sites. In the first Fe site, Fe is bonded to eight equivalent Fe and four equivalent Ni atoms to form FeFe8Ni4 cuboctahedra that share corners with four equivalent FeFe8Ni4 cuboctahedra, corners with eight equivalent NiFe12 cuboctahedra, edges with twenty-four FeFe8Ni4 cuboctahedra, faces with six equivalent NiFe12 cuboctahedra, and faces with twelve FeFe8Ni4 cuboctahedra. All Fe–Fe bond lengths are 2.57 Å. All Fe–Ni bond lengths are 2.49 Å. In the second Fe site, Fe is bonded to eight Fe and four equivalent Ni atoms to form FeFe8Ni4 cuboctahedra that share corners with twelve equivalent FeFe8Ni4 cuboctahedra, edges with eight equivalent NiFe12 cuboctahedra, edges with sixteen FeFe8Ni4 cuboctahedra, faces with four equivalent NiFe12 cuboctahedra, and faces with fourteen FeFe8Ni4 cuboctahedra. All Fe–Fe bond lengths are 2.49 Å. All Fe–Ni bond lengths are 2.57 Å. Ni is bonded to twelve Fe atoms to form NiFe12 cuboctahedra that share corners with four equivalent NiFe12 cuboctahedra, corners with eight equivalent FeFe8Ni4 cuboctahedra, edges with eight equivalent NiFe12 cuboctahedra, edges with sixteen equivalent FeFe8Ni4 cuboctahedra, faces with four equivalent NiFe12 cuboctahedra, and faces with fourteen FeFe8Ni4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeNi3 by Materials Project

Ni3Fe is beta Cu3Ti structured and crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. Fe is bonded to twelve Ni atoms to form FeNi12 cuboctahedra that share corners with two equivalent FeNi12 cuboctahedra, corners with sixteen NiFe4Ni8 cuboctahedra, edges with six equivalent FeNi12 cuboctahedra, edges with twelve equivalent NiFe4Ni8 cuboctahedra, faces with six equivalent FeNi12 cuboctahedra, and faces with fourteen NiFe4Ni8 cuboctahedra. There are eight shorter (2.50 Å) and four longer (2.51 Å) Fe–Ni bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded to four equivalent Fe and eight equivalent Ni atoms to form NiFe4Ni8 cuboctahedra that share corners with eight equivalent FeNi12 cuboctahedra, corners with ten NiFe4Ni8 cuboctahedra, edges with eighteen NiFe4Ni8 cuboctahedra, faces with six equivalent FeNi12 cuboctahedra, and faces with fourteen NiFe4Ni8 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.48–2.53 Å. In the second Ni site, Ni is bonded to four equivalent Fe and eight Ni atoms to form NiFe4Ni8 cuboctahedra that share corners with four equivalent FeNi12 cuboctahedra, corners with fourteen NiFe4Ni8 cuboctahedra, edges with six equivalent FeNi12 cuboctahedra, edges with twelve NiFe4Ni8 cuboctahedra, faces with four equivalent FeNi12 cuboctahedra, and faces with sixteen NiFe4Ni8 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.48–2.52 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeNi3 by Materials Project

Ni3Fe is alpha La-derived structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Fe is bonded to six equivalent Fe and six equivalent Ni atoms to form FeFe6Ni6 cuboctahedra that share corners with six equivalent FeFe6Ni6 cuboctahedra, corners with six equivalent NiNi12 cuboctahedra, edges with six equivalent FeFe6Ni6 cuboctahedra, edges with eighteen NiFe3Ni9 cuboctahedra, faces with six equivalent FeFe6Ni6 cuboctahedra, and faces with twelve equivalent NiFe3Ni9 cuboctahedra. All Fe–Fe bond lengths are 2.50 Å. All Fe–Ni bond lengths are 2.49 Å. There are five inequivalent Ni sites. In the first Ni site, Ni is bonded to three equivalent Fe and nine Ni atoms to form NiFe3Ni9 cuboctahedra that share corners with twelve equivalent NiFe3Ni9 cuboctahedra, edges with six equivalent FeFe6Ni6 cuboctahedra, edges with eighteen NiFe3Ni9 cuboctahedra, faces with six equivalent FeFe6Ni6 cuboctahedra, and faces with twelve NiFe3Ni9 cuboctahedra. There are six shorter (2.50 Å) and three longer (2.51 Å) Ni–Ni bond lengths. In the second Ni site, Ni is bonded to twelve Ni atoms to form NiNi12 cuboctahedra that share corners with six equivalent FeFe6Ni6 cuboctahedra, corners with six equivalent NiNi12 cuboctahedra, edges with six equivalent FeFe6Ni6 cuboctahedra, edges with eighteen NiFe3Ni9 cuboctahedra, and faces with eighteen NiFe3Ni9 cuboctahedra. All Ni–Ni bond lengths are 2.50 Å. In the third Ni site, Ni is bonded to three equivalent Fe and nine Ni atoms to form NiFe3Ni9 cuboctahedra that share corners with seventeen NiFe3Ni9 cuboctahedra, edges with six equivalent FeFe6Ni6 cuboctahedra, edges with sixteen NiFe3Ni9 cuboctahedra, faces with six equivalent FeFe6Ni6 cuboctahedra, and faces with fifteen NiFe3Ni9 cuboctahedra. All Ni–Fe bond lengths are 2.49 Å. There are six shorter (2.50 Å) and three longer (2.51 Å) Ni–Ni bond lengths. In the fourth Ni site, Ni is bonded to sixteen Ni atoms to form NiNi16 cuboctahedra that share corners with six equivalent FeFe6Ni6 cuboctahedra, corners with sixteen NiFe3Ni9 cuboctahedra, edges with six equivalent FeFe6Ni6 cuboctahedra, edges with eighteen NiFe3Ni9 cuboctahedra, and faces with thirty-four NiFe3Ni9 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.50–5.00 Å. In the fifth Ni site, Ni is bonded to three equivalent Fe and nine Ni atoms to form NiFe3Ni9 cuboctahedra that share corners with seventeen NiFe3Ni9 cuboctahedra, edges with six equivalent FeFe6Ni6 cuboctahedra, edges with sixteen NiFe3Ni9 cuboctahedra, faces with six equivalent FeFe6Ni6 cuboctahedra, and faces with fifteen NiNi16 cuboctahedra. All Ni–Fe bond lengths are 2.49 Å. All Ni–Ni bond lengths are 2.50 Å.

36 MATERIALS SCIENCE↗