Search NASA⌕ Search

DOE OSTI · 1272088

Materials Data on Nd6S4N3Cl by Materials Project

Abstract

Nd6N3S4Cl crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are six inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded in a 2-coordinate geometry to two equivalent N3-, three S2-, and two equivalent Cl1- atoms. Both Nd–N bond lengths are 2.49 Å. There are two shorter (2.89 Å) and one longer (2.92 Å) Nd–S bond lengths. There are one shorter (3.01 Å) and one longer (3.42 Å) Nd–Cl bond lengths. In the second Nd3+ site, Nd3+ is bonded in a 3-coordinate geometry to three equivalent N3- and four S2- atoms. There are one shorter (2.34 Å) and two longer (2.42 Å) Nd–N bond lengths. There are a spread of Nd–S bond distances ranging from 2.96–3.41 Å. In the third Nd3+ site, Nd3+ is bonded in a 6-coordinate geometry to two N3-, two equivalent S2-, and two equivalent Cl1- atoms. There are one shorter (2.37 Å) and one longer (2.38 Å) Nd–N bond lengths. Both Nd–S bond lengths are 2.73 Å. Both Nd–Cl bond lengths are 3.08 Å. In the fourth Nd3+ site, Nd3+ is bonded in a 6-coordinate geometry to two N3-, two equivalent S2-, and two equivalent Cl1- atoms. There are one shorter (2.26 Å) and one longer (2.36 Å) Nd–N bond lengths. Both Nd–S bond lengths are 2.84 Å. Both Nd–Cl bond lengths are 3.02 Å. In the fifth Nd3+ site, Nd3+ is bonded in a 1-coordinate geometry to one N3- and five S2- atoms. The Nd–N bond length is 2.20 Å. There are a spread of Nd–S bond distances ranging from 2.90–3.02 Å. In the sixth Nd3+ site, Nd3+ is bonded in a 2-coordinate geometry to two equivalent N3- and five S2- atoms. Both Nd–N bond lengths are 2.41 Å. There are a spread of Nd–S bond distances ranging from 2.80–3.37 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded to four Nd3+ atoms to form NNd4 tetrahedra that share corners with two equivalent NNd4 tetrahedra, corners with two equivalent SNd4 trigonal pyramids, edges with two equivalent NNd4 tetrahedra, and an edgeedge with one SNd4 trigonal pyramid. In the second N3- site, N3- is bonded to four Nd3+ atoms to form a mixture of corner and edge-sharing NNd4 tetrahedra. In the third N3- site, N3- is bonded to four Nd3+ atoms to form NNd4 tetrahedra that share corners with two equivalent NNd4 tetrahedra, corners with two equivalent SNd4 trigonal pyramids, an edgeedge with one NNd4 tetrahedra, and an edgeedge with one SNd4 trigonal pyramid. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a 6-coordinate geometry to six Nd3+ atoms. In the second S2- site, S2- is bonded in a 5-coordinate geometry to six Nd3+ atoms. In the third S2- site, S2- is bonded in a 5-coordinate geometry to five Nd3+ atoms. In the fourth S2- site, S2- is bonded to four Nd3+ atoms to form distorted SNd4 trigonal pyramids that share corners with four NNd4 tetrahedra, corners with two equivalent SNd4 trigonal pyramids, and edges with two NNd4 tetrahedra. Cl1- is bonded in a 5-coordinate geometry to six Nd3+ atoms.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-04-30. Materials Data on Nd6S4N3Cl by Materials Project. https://doi.org/10.17188/1272088

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↗