Engineering Papers⌕ Search

DOE OSTI · 1263296

Materials Data on Ca9PrF20 by Materials Project

Abstract

Ca9PrF20 is Fluorite-derived structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are nine inequivalent Ca sites. In the first Ca site, Ca is bonded in a body-centered cubic geometry to eight F atoms. There are a spread of Ca–F bond distances ranging from 2.37–2.41 Å. In the second Ca site, Ca is bonded in a body-centered cubic geometry to eight F atoms. There are a spread of Ca–F bond distances ranging from 2.37–2.41 Å. In the third Ca site, Ca is bonded in a body-centered cubic geometry to eight F atoms. There are a spread of Ca–F bond distances ranging from 2.37–2.42 Å. In the fourth Ca site, Ca is bonded in a body-centered cubic geometry to eight F atoms. There are a spread of Ca–F bond distances ranging from 2.40–2.43 Å. In the fifth Ca site, Ca is bonded in a body-centered cubic geometry to eight F atoms. There are a spread of Ca–F bond distances ranging from 2.38–2.44 Å. In the sixth Ca site, Ca is bonded in a body-centered cubic geometry to eight F atoms. There are a spread of Ca–F bond distances ranging from 2.38–2.45 Å. In the seventh Ca site, Ca is bonded in a body-centered cubic geometry to eight F atoms. There are a spread of Ca–F bond distances ranging from 2.37–2.41 Å. In the eighth Ca site, Ca is bonded in a body-centered cubic geometry to eight F atoms. There are a spread of Ca–F bond distances ranging from 2.37–2.42 Å. In the ninth Ca site, Ca is bonded in a body-centered cubic geometry to eight F atoms. There are a spread of Ca–F bond distances ranging from 2.37–2.43 Å. Pr is bonded in a body-centered cubic geometry to eight F atoms. There are seven shorter (2.48 Å) and one longer (2.49 Å) Pr–F bond lengths. There are twenty inequivalent F sites. In the first F site, F is bonded to three Ca and one Pr atom to form FCa3Pr tetrahedra that share corners with sixteen FCa3Pr tetrahedra and edges with six FCa4 tetrahedra. In the second F site, F is bonded to three Ca and one Pr atom to form FCa3Pr tetrahedra that share corners with sixteen FCa4 tetrahedra and edges with six FCa3Pr tetrahedra. In the third F site, F is bonded to four Ca atoms to form FCa4 tetrahedra that share corners with sixteen FCa4 tetrahedra and edges with six FCa3Pr tetrahedra. In the fourth F site, F is bonded to four Ca atoms to form FCa4 tetrahedra that share corners with sixteen FCa4 tetrahedra and edges with six FCa3Pr tetrahedra. In the fifth F site, F is bonded to four Ca atoms to form a mixture of corner and edge-sharing FCa4 tetrahedra. In the sixth F site, F is bonded to three Ca and one Pr atom to form a mixture of corner and edge-sharing FCa3Pr tetrahedra. In the seventh F site, F is bonded to four Ca atoms to form a mixture of corner and edge-sharing FCa4 tetrahedra. In the eighth F site, F is bonded to four Ca atoms to form a mixture of corner and edge-sharing FCa4 tetrahedra. In the ninth F site, F is bonded to four Ca atoms to form a mixture of corner and edge-sharing FCa4 tetrahedra. In the tenth F site, F is bonded to four Ca atoms to form FCa4 tetrahedra that share corners with sixteen FCa4 tetrahedra and edges with six FCa3Pr tetrahedra. In the eleventh F site, F is bonded to three Ca and one Pr atom to form a mixture of corner and edge-sharing FCa3Pr tetrahedra. In the twelfth F site, F is bonded to four Ca atoms to form a mixture of corner and edge-sharing FCa4 tetrahedra. In the thirteenth F site, F is bonded to three Ca and one Pr atom to form FCa3Pr tetrahedra that share corners with sixteen FCa4 tetrahedra and edges with six FCa3Pr tetrahedra. In the fourteenth F site, F is bonded to four Ca atoms to form a mixture of corner and edge-sharing FCa4 tetrahedra. In the fifteenth F site, F is bonded to four Ca atoms to form a mixture of corner and edge-sharing FCa4 tetrahedra. In the sixteenth F site, F is bonded to four Ca atoms to form a mixture of corner and edge-sharing FCa4 tetrahedra. In the seventeenth F site, F is bonded to four Ca atoms to form a mixture of corner and edge-sharing FCa4 tetrahedra. In the eighteenth F site, F is bonded to three Ca and one Pr atom to form a mixture of corner and edge-sharing FCa3Pr tetrahedra. In the nineteenth F site, F is bonded to three Ca and one Pr atom to form a mixture of corner and edge-sharing FCa3Pr tetrahedra. In the twentieth F site, F is bonded to three Ca and one Pr atom to form a mixture of corner and edge-sharing FCa3Pr tetrahedra.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-04-29. Materials Data on Ca9PrF20 by Materials Project. https://doi.org/10.17188/1263296

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↗