Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “FeF3”

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.

9 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on FeF3 by Materials Project

FeF3 is alpha Rhenium trioxide structured and crystallizes in the trigonal P321 space group. The structure is three-dimensional. there are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six F1- atoms to form corner-sharing FeF6 octahedra. The corner-sharing octahedra tilt angles range from 1–2°. All Fe–F bond lengths are 1.95 Å. In the second Fe3+ site, Fe3+ is bonded to six equivalent F1- atoms to form corner-sharing FeF6 octahedra. The corner-sharing octahedral tilt angles are 1°. All Fe–F bond lengths are 1.95 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a linear geometry to two Fe3+ atoms. In the second F1- site, F1- is bonded in a linear geometry to two equivalent Fe3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeF3 by Materials Project

FeF3 crystallizes in the trigonal P321 space group. The structure is three-dimensional. there are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six F1- atoms to form corner-sharing FeF6 octahedra. The corner-sharing octahedra tilt angles range from 24–34°. There is three shorter (1.96 Å) and three longer (1.97 Å) Fe–F bond length. In the second Fe3+ site, Fe3+ is bonded to six equivalent F1- atoms to form distorted corner-sharing FeF6 octahedra. The corner-sharing octahedral tilt angles are 24°. All Fe–F bond lengths are 1.97 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a bent 150 degrees geometry to two Fe3+ atoms. In the second F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent Fe3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeF3 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeF3 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe3OF9 by Materials Project

(FeF3)6O2 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional and consists of four water molecules and one FeF3 framework. In the FeF3 framework, there are two inequivalent Fe sites. In the first Fe site, Fe is bonded to six F atoms to form corner-sharing FeF6 octahedra. The corner-sharing octahedra tilt angles range from 28–37°. All Fe–F bond lengths are 1.96 Å. In the second Fe site, Fe is bonded to six F atoms to form corner-sharing FeF6 octahedra. The corner-sharing octahedra tilt angles range from 31–37°. There is four shorter (1.97 Å) and two longer (1.98 Å) Fe–F bond length. There are four inequivalent F sites. In the first F site, F is bonded in a bent 150 degrees geometry to two equivalent Fe atoms. In the second F site, F is bonded in a bent 150 degrees geometry to two Fe atoms. In the third F site, F is bonded in a bent 150 degrees geometry to two equivalent Fe atoms. In the fourth F site, F is bonded in a bent 150 degrees geometry to two equivalent Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Revisiting metal fluorides as lithium-ion battery cathodes

Metal fluorides, promising lithium-ion battery cathode materials, have been classified as conversion materials due to the reconstructive phase transitions widely presumed to occur upon lithiation. We challenge this view by studying FeF 3 using X-ray total scattering and electron diffraction techniques that measure structure over multiple length scales coupled with density functional theory calculations, and by revisiting prior experimental studies of FeF 2 and CuF 2 . Metal fluoride lithiation is instead dominated by diffusion-controlled displacement mechanisms, and a clear topological relationship between the metal fluoride F- sublattices and that of LiF is established. Initial lithiation of FeF3 forms FeF2 on the particle's surface, along with a cation-ordered and stacking-disordered phase, A-Li x Fe y F 3 , which is structurally related to alpha-/beta-LiMn 2+ Fe 3+ F 6 and which topotactically transforms to B- and then C-Li x Fe y F 3 , before forming LiF and Fe. Lithiation of FeF 2 and CuF 2 results in a buffer phase between FeF 2 /CuF 2 and LiF. Overall, the resulting principles will aid future developments of a wider range of isomorphic metal fluorides.

25 ENERGY STORAGE↗
DOE OSTI2020

Materials Data on Fe(NF2)3 by Materials Project

FeF3(NF)3 is alpha bismuth trifluoride structured and crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one ferric fluoride molecule and three monofluoroamine molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Structure and Stability of Iron Fluoride at High Pressure–Temperature and Implication for a New Reservoir of Fluorine in the Deep Earth

Fluorine (F) is the most abundant halogen in the bulk silicate Earth. F plays an important role in geochemical and biological systems, but its abundance and distribution in the terrestrial mantle are still unclear. Recent studies suggested that F reservoirs in the deep mantle are potentially hosted in terrestrial oxide minerals, especially in aluminous bridgmanite. However, the knowledge about the formation and stability field of fluoride in the Earth’s interior is rare. In this study, we combine in situ laser-heated diamond anvil cell, synchrotron X-ray diffraction, and first-principles structure search to show that a new tetragonal structure of FeF 3 is stable at pressures of 78–130 GPa and temperatures up to ~1900 K. Simulation predicted the tetragonal phase takes a much denser structure due to the rotation of FeF 6 octahedral units. The equations of states of tetragonal FeF3 are determined by experiment and verified by simulation. Our results indicate that FeF 3 can be a potential key phase for storing F in the Earth’s lower mantle and may explain some mantle-derived magma with high F concentration.

58 GEOSCIENCES↗