Search NASA⌕ Search

DOE OSTI · 1675832

Materials Data on NdN2 by Materials Project

Abstract

NdN2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are three inequivalent Nd2+ sites. In the first Nd2+ site, Nd2+ is bonded in a 8-coordinate geometry to eight N1- atoms. There are a spread of Nd–N bond distances ranging from 2.24–2.84 Å. In the second Nd2+ site, Nd2+ is bonded in a 7-coordinate geometry to seven N1- atoms. There are a spread of Nd–N bond distances ranging from 2.27–2.76 Å. In the third Nd2+ site, Nd2+ is bonded in a 6-coordinate geometry to six N1- atoms. There are a spread of Nd–N bond distances ranging from 2.30–2.67 Å. There are six inequivalent N1- sites. In the first N1- site, N1- is bonded to four Nd2+ atoms to form distorted corner-sharing NNd4 trigonal pyramids. In the second N1- site, N1- is bonded in a 2-coordinate geometry to four Nd2+ and one N1- atom. The N–N bond length is 1.25 Å. In the third N1- site, N1- is bonded in a 4-coordinate geometry to three Nd2+ and one N1- atom. The N–N bond length is 1.20 Å. In the fourth N1- site, N1- is bonded in a distorted T-shaped geometry to three Nd2+ atoms. In the fifth N1- site, N1- is bonded in a 5-coordinate geometry to four Nd2+ and one N1- atom. In the sixth N1- site, N1- is bonded in a 4-coordinate geometry to three Nd2+ and one N1- atom.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-05-03. Materials Data on NdN2 by Materials Project. https://doi.org/10.17188/1675832

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↗