Search NASA⌕ Search

DOE OSTI · 1280060

Materials Data on Yb11(Sm2Se11)2 by Materials Project

Abstract

Yb11(Sm2Se11)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are six inequivalent Yb+2.91+ sites. In the first Yb+2.91+ site, Yb+2.91+ is bonded in a 5-coordinate geometry to six Se2- atoms. There are a spread of Yb–Se bond distances ranging from 2.78–3.57 Å. In the second Yb+2.91+ site, Yb+2.91+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of Yb–Se bond distances ranging from 2.89–3.16 Å. In the third Yb+2.91+ site, Yb+2.91+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of Yb–Se bond distances ranging from 2.84–3.46 Å. In the fourth Yb+2.91+ site, Yb+2.91+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing YbSe6 octahedra. The corner-sharing octahedra tilt angles range from 56–71°. There are a spread of Yb–Se bond distances ranging from 2.83–3.15 Å. In the fifth Yb+2.91+ site, Yb+2.91+ is bonded to six Se2- atoms to form distorted YbSe6 octahedra that share a cornercorner with one SeYb3Sm2Se octahedra, corners with three equivalent YbSe6 octahedra, and edges with two equivalent YbSe6 octahedra. The corner-sharing octahedra tilt angles range from 28–71°. There are a spread of Yb–Se bond distances ranging from 2.74–3.36 Å. In the sixth Yb+2.91+ site, Yb+2.91+ is bonded to six Se2- atoms to form YbSe6 octahedra that share corners with four equivalent SeYb3Sm2Se octahedra and edges with two equivalent YbSe6 octahedra. The corner-sharing octahedral tilt angles are 69°. There are two shorter (2.80 Å) and four longer (3.06 Å) Yb–Se bond lengths. There are two inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Sm–Se bond distances ranging from 2.94–3.13 Å. In the second Sm3+ site, Sm3+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Sm–Se bond distances ranging from 2.90–3.22 Å. There are eleven inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four Yb+2.91+ atoms to form distorted SeYb4 tetrahedra that share a cornercorner with one SeYb3Sm2Se octahedra, corners with seven SeYb4 tetrahedra, and edges with two equivalent SeYb4 tetrahedra. The corner-sharing octahedral tilt angles are 11°. In the second Se2- site, Se2- is bonded to four Yb+2.91+ atoms to form SeYb4 tetrahedra that share corners with four SeYb3Sm2Se octahedra, corners with seven SeYb4 tetrahedra, and edges with two equivalent SeYb3Sm2Se octahedra. The corner-sharing octahedra tilt angles range from 83–84°. In the third Se2- site, Se2- is bonded to three Yb+2.91+, two equivalent Sm3+, and one Se2- atom to form distorted SeYb3Sm2Se octahedra that share a cornercorner with one YbSe6 octahedra, corners with four SeYb3Sm2Se octahedra, corners with five SeYb4 tetrahedra, edges with four SeYb3Sm2Se octahedra, and edges with two equivalent SeYb4 tetrahedra. The corner-sharing octahedra tilt angles range from 0–80°. The Se–Se bond length is 2.45 Å. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Yb+2.91+ and three Sm3+ atoms. In the fifth Se2- site, Se2- is bonded to three Yb+2.91+ and one Sm3+ atom to form distorted SeYb3Sm tetrahedra that share corners with two equivalent SeYb3Sm2Se octahedra, corners with seven SeYb4 tetrahedra, and edges with two equivalent SeYb3Sm2Se octahedra. The corner-sharing octahedral tilt angles are 55°. In the sixth Se2- site, Se2- is bonded to three Yb+2.91+ and one Sm3+ atom to form distorted SeYb3Sm tetrahedra that share corners with three SeYb3Sm2Se octahedra, corners with six SeYb4 tetrahedra, and an edgeedge with one SeYb3Sm2Se octahedra. The corner-sharing octahedra tilt angles range from 22–32°. In the seventh Se2- site, Se2- is bonded to three Yb+2.91+, two equivalent Sm3+, and one Se2- atom to form distorted SeYb3Sm2Se octahedra that share corners with two equivalent YbSe6 octahedra, corners with two equivalent SeYb3Sm2Se octahedra, corners with five SeYb4 tetrahedra, edges with three SeYb3Sm2Se octahedra, and edges with three SeYb3Sm tetrahedra. The corner-sharing octahedra tilt angles range from 69–80°. In the eighth Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Yb+2.91+, two equivalent Sm3+, and one Se2- atom. The Se–Se bond length is 2.47 Å. In the ninth Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Yb+2.91+ and three Sm3+ atoms. In the tenth Se2- site, Se2- is bonded in a 4-coordinate geometry to three Yb+2.91+, two equivalent Sm3+, and one Se2- atom. In the eleventh Se2- site, Se2- is bonded to four Yb+2.91+ atoms to form a mixture of distorted corner and edge-sharing SeYb4 tetrahedra.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-07-15. Materials Data on Yb11(Sm2Se11)2 by Materials Project. https://doi.org/10.17188/1280060

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↗