Search NASA⌕ Search

DOE OSTI · 1744315

Materials Data on Sr5Cr3F19 by Materials Project

Abstract

Sr5Cr3F19 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are ten inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six F1- atoms. There are a spread of Sr–F bond distances ranging from 2.40–2.68 Å. In the second Sr2+ site, Sr2+ is bonded to seven F1- atoms to form distorted SrF7 pentagonal bipyramids that share corners with two CrF6 octahedra, a cornercorner with one SrF7 pentagonal bipyramid, and edges with two CrF6 octahedra. The corner-sharing octahedra tilt angles range from 47–53°. There are a spread of Sr–F bond distances ranging from 2.41–2.64 Å. In the third Sr2+ site, Sr2+ is bonded to seven F1- atoms to form distorted SrF7 pentagonal bipyramids that share corners with three CrF6 octahedra, a cornercorner with one SrF7 pentagonal bipyramid, and an edgeedge with one CrF6 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Sr–F bond distances ranging from 2.47–2.72 Å. In the fourth Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Sr–F bond distances ranging from 2.47–2.94 Å. In the fifth Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Sr–F bond distances ranging from 2.41–3.01 Å. In the sixth Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Sr–F bond distances ranging from 2.37–2.89 Å. In the seventh Sr2+ site, Sr2+ is bonded in a 7-coordinate geometry to seven F1- atoms. There are a spread of Sr–F bond distances ranging from 2.43–2.65 Å. In the eighth Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Sr–F bond distances ranging from 2.38–3.02 Å. In the ninth Sr2+ site, Sr2+ is bonded in a 7-coordinate geometry to seven F1- atoms. There are a spread of Sr–F bond distances ranging from 2.34–2.68 Å. In the tenth Sr2+ site, Sr2+ is bonded in a 1-coordinate geometry to nine F1- atoms. There are a spread of Sr–F bond distances ranging from 2.39–3.11 Å. There are six inequivalent Cr3+ sites. In the first Cr3+ site, Cr3+ is bonded to six F1- atoms to form CrF6 octahedra that share a cornercorner with one CrF6 octahedra and a cornercorner with one SrF7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 1°. There are a spread of Cr–F bond distances ranging from 1.88–2.03 Å. In the second Cr3+ site, Cr3+ is bonded to six F1- atoms to form CrF6 octahedra that share edges with two SrF7 pentagonal bipyramids. There are a spread of Cr–F bond distances ranging from 1.92–2.01 Å. In the third Cr3+ site, Cr3+ is bonded to six F1- atoms to form CrF6 octahedra that share a cornercorner with one CrF6 octahedra, a cornercorner with one SrF7 pentagonal bipyramid, and an edgeedge with one SrF7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 38°. There are a spread of Cr–F bond distances ranging from 1.95–2.05 Å. In the fourth Cr3+ site, Cr3+ is bonded to six F1- atoms to form CrF6 octahedra that share a cornercorner with one CrF6 octahedra and a cornercorner with one SrF7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 1°. There are a spread of Cr–F bond distances ranging from 1.92–2.01 Å. In the fifth Cr3+ site, Cr3+ is bonded to six F1- atoms to form CrF6 octahedra that share a cornercorner with one CrF6 octahedra and a cornercorner with one SrF7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 38°. There are a spread of Cr–F bond distances ranging from 1.92–2.23 Å. In the sixth Cr3+ site, Cr3+ is bonded to six F1- atoms to form CrF6 octahedra that share a cornercorner with one SrF7 pentagonal bipyramid. There are a spread of Cr–F bond distances ranging from 1.91–1.98 Å. There are thirty-eight inequivalent F1- sites. In the first F1- site, F1- is bonded in a 3-coordinate geometry to two Sr2+ and one Cr3+ atom. In the second F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one Sr2+ and one Cr3+ atom. In the third F1- site, F1- is bonded in a 2-coordinate geometry to two Sr2+ and one Cr3+ atom. In the fourth F1- site, F1- is bonded in a distorted trigonal planar geometry to three Sr2+ atoms. In the fifth F1- site, F1- is bonded in a 3-coordinate geometry to two Sr2+ and one Cr3+ atom. In the sixth F1- site, F1- is bonded in a 3-coordinate geometry to two Sr2+ and one Cr3+ atom. In the seventh F1- site, F1- is bonded in a 1-coordinate geometry to two Sr2+ and one Cr3+ atom. In the eighth F1- site, F1- is bonded in a distorted trigonal planar geometry to two Sr2+ and one Cr3+ atom. In the ninth F1- site, F1- is bonded in a 1-coordinate geometry to two Sr2+ and one Cr3+ atom. In the tenth F1- site, F1- is bonded in a distorted trigonal planar geometry to two Sr2+ and one Cr3+ atom. In the eleventh F1- site, F1- is bonded in a distorted trigonal planar geometry to two Sr2+ and one Cr3+ atom. In the twelfth F1- site, F1- is bonded in a 1-coordinate geometry to three Sr2+ and one Cr3+ atom. In the thirteenth F1- site, F1- is bonded in a 2-coordinate geometry to two Sr2+ and one Cr3+ atom. In the fourteenth F1- site, F1- is bonded in a 1-coordinate geometry to two Sr2+ and one Cr3+ atom. In the fifteenth F1- site, F1- is bonded in a 1-coordinate geometry to two Sr2+ and one Cr3+ atom. In the sixteenth F1- site, F1- is bonded in a 2-coordinate geometry to two Sr2+ and one Cr3+ atom. In the seventeenth F1- site, F1- is bonded in a 1-coordinate geometry to two Sr2+ and one Cr3+ atom. In the eighteenth F1- site, F1- is bonded in a 4-coordinate geometry to four Sr2+ atoms. In the nineteenth F1- site, F1- is bonded in a distorted trigonal planar geometry to three Sr2+ atoms. In the twentieth F1- site, F1- is bonded in a 1-coordinate geometry to two Sr2+ and one Cr3+ atom. In the twenty-first F1- site, F1- is bonded in a 3-coordinate geometry to two Sr2+ and one Cr3+ atom. In the twenty-second F1- site, F1- is bonded in a 3-coordinate geometry to two Sr2+ and one Cr3+ atom. In the twenty-third F1- site, F1- is bonded in a distorted single-bond geometry to two Sr2+ and one Cr3+ atom. In the twenty-fourth F1- site, F1- is bonded in a 1-coordinate geometry to three Sr2+ and one Cr3+ atom. In the twenty-fifth F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to two Sr2+ and one Cr3+ atom. In the twenty-sixth F1- site, F1- is bonded in a distorted bent 120 degrees geometry to two Sr2+ and one Cr3+ atom. In the twenty-seventh F1- site, F1- is bonded in a 3-coordinate geometry to two Sr2+ and one Cr3+ atom. In the twenty-eighth F1- site, F1- is bonded in a 3-coordinate geometry to one Sr2+ and two Cr3+ atoms. In the twenty-ninth F1- site, F1- is bonded in a distorted single-bond geometry to one Sr2+ and one Cr3+ atom. In the thirtieth F1- site, F1- is bonded in a distorted single-bond geometry to two Sr2+ and one Cr3+ atom. In the thirty-first F1- site, F1- is bonded in a distorted single-bond geometry to two Sr2+ and one Cr3+ atom. In the thirty-second F1- site, F1- is bonded in a 3-coordinate geometry to two Sr2+ and one Cr3+ atom. In the thirty-third F1- site, F1- is bonded in a 3-coordinate geometry to three Sr2+ atoms. In the thirty-fourth F1- site, F1- is bonded in a 2-coordinate geometry to two Sr2+ and one Cr3+ atom. In the thirty-fifth F1- site, F1- is bonded in a linear geometry to two Cr3+ atoms. In the thirty-sixth F1- site, F1- is bonded in a 1-coordinate geometry to two Sr2+ and one Cr3+ atom. In the thirty-seventh F1- site, F1- is bonded in a 3-coordinate geometry to two Sr2+ and one Cr3+ atom. In the thirty-eighth F1- site, F1- is bonded in a 3-coordinate geometry to two Sr2+ and one Cr3+ atom.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-04-29. Materials Data on Sr5Cr3F19 by Materials Project. https://doi.org/10.17188/1744315

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

Cyclic moisture reactivation of calcium sorbents for long duration thermochemical energy storage

The transition to a flexible and reliable energy infrastructure, using electro-thermal energy generation technologies such as geothermal, concentrated solar power, and nuclear, usually demands simultaneous advancement of thermal energy storage (TES) to support on-demand electricity generation and industrial applications while mitigating the inherent intermittency of renewable energy sources and power outages from direct energy generation. Among TES technologies, thermochemical energy storage (TCES) based on calcium looping emerges as a compelling high-power energy storage candidate due to its high reaction enthalpy, compatibility with elevated operating temperatures, and abundance of low-cost materials. However, the long-term durability of calcium-based sorbents for TCES is hindered by surface sintering and particle aggregation, leading to performance degradation over repeated thermal cycles. This study explores a moisture hydration-based strategy to regenerate a degraded calcium sorbent and mitigate performance degradation for long duration TCES. The addition of moisture transforms calcium oxide into calcium hydroxide and produces intercalation water layers, associated with a regenerated surface area and reduced calcium oxide crystallite size. Both these effects are beneficial in restoring the sorbents' reactivity for carbonization. Additionally, an optimized hydration-assisted reactivation protocol balances the recovered energy storage capacity with heating penalty required for moisture removal from hydrated samples, resulting in an enhanced energy storage capacity up to 176% compared to benchmark sorbents that undergo cycling without reactivation after 60 cycles. In conclusion, these results highlight the potential of hydration-assisted reactivation to enhance the long-term performance of TCES, providing an effective pathway to advancing electro-thermal storage technologies.

36 MATERIALS SCIENCE↗