Search NASA⌕ Search

DOE OSTI · 1187384

Materials Data on RbNd2CuS4 by Materials Project

Abstract

RbNd2CuS4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Rb1+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Rb–S bond distances ranging from 3.29–3.83 Å. Nd3+ is bonded to six S2- atoms to form NdS6 octahedra that share corners with three equivalent NdS6 octahedra, a cornercorner with one CuS4 tetrahedra, edges with five equivalent NdS6 octahedra, and edges with two equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 0–35°. There are a spread of Nd–S bond distances ranging from 2.78–2.93 Å. Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with two equivalent NdS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with four equivalent NdS6 octahedra. The corner-sharing octahedral tilt angles are 4°. There are two shorter (2.36 Å) and two longer (2.40 Å) Cu–S bond lengths. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Rb1+ and four equivalent Nd3+ atoms to form a mixture of distorted corner and edge-sharing SRb2Nd4 octahedra. The corner-sharing octahedra tilt angles range from 3–46°. In the second S2- site, S2- is bonded in a 6-coordinate geometry to two equivalent Rb1+, two equivalent Nd3+, and two equivalent Cu1+ atoms. In the third S2- site, S2- is bonded to two equivalent Rb1+, three equivalent Nd3+, and one Cu1+ atom to form distorted SRb2Nd3Cu octahedra that share corners with six SRb2Nd4 octahedra, edges with seven SRb2Nd4 octahedra, and a faceface with one SRb2Nd3Cu octahedra. The corner-sharing octahedra tilt angles range from 3–68°.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-07-14. Materials Data on RbNd2CuS4 by Materials Project. https://doi.org/10.17188/1187384

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↗