Search NASA⌕ Search

DOE OSTI · 1684194

Materials Data on Ca3Nd8(RuO6)4 by Materials Project

Abstract

Ca3Nd8(RuO6)4 crystallizes in the tetragonal I4_1 space group. The structure is three-dimensional. there are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.41–2.51 Å. In the second Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.40–2.86 Å. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with two equivalent RuO6 octahedra and edges with two equivalent RuO6 octahedra. The corner-sharing octahedral tilt angles are 77°. There are a spread of Ca–O bond distances ranging from 2.38–2.46 Å. There are four inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Nd–O bond distances ranging from 2.26–2.97 Å. In the second Nd3+ site, Nd3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Nd–O bond distances ranging from 2.43–2.82 Å. In the third Nd3+ site, Nd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Nd–O bond distances ranging from 2.26–2.92 Å. In the fourth Nd3+ site, Nd3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Nd–O bond distances ranging from 2.43–2.86 Å. There are two inequivalent Ru+4.50+ sites. In the first Ru+4.50+ site, Ru+4.50+ is bonded to six O2- atoms to form RuO6 octahedra that share a cornercorner with one CaO6 octahedra. The corner-sharing octahedral tilt angles are 77°. There are a spread of Ru–O bond distances ranging from 1.98–2.10 Å. In the second Ru+4.50+ site, Ru+4.50+ is bonded to six O2- atoms to form RuO6 octahedra that share an edgeedge with one CaO6 octahedra. There are a spread of Ru–O bond distances ranging from 1.97–2.03 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ca2+, two Nd3+, and one Ru+4.50+ atom to form distorted OCaNd2Ru tetrahedra that share corners with five OCaNd2Ru tetrahedra and an edgeedge with one ONd3Ru tetrahedra. In the second O2- site, O2- is bonded in a distorted see-saw-like geometry to three Nd3+ and one Ru+4.50+ atom. In the third O2- site, O2- is bonded to one Ca2+, two Nd3+, and one Ru+4.50+ atom to form distorted OCaNd2Ru tetrahedra that share corners with five OCaNd2Ru tetrahedra and an edgeedge with one ONd3Ru tetrahedra. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to one Ca2+, three Nd3+, and one Ru+4.50+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, three Nd3+, and one Ru+4.50+ atom. In the sixth O2- site, O2- is bonded in a 5-coordinate geometry to one Ca2+, three Nd3+, and one Ru+4.50+ atom. In the seventh O2- site, O2- is bonded in a 6-coordinate geometry to two Ca2+, three Nd3+, and one Ru+4.50+ atom. In the eighth O2- site, O2- is bonded to three Nd3+ and one Ru+4.50+ atom to form a mixture of distorted edge and corner-sharing ONd3Ru tetrahedra. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, three Nd3+, and one Ru+4.50+ atom. In the tenth O2- site, O2- is bonded in a 5-coordinate geometry to one Ca2+, three Nd3+, and one Ru+4.50+ atom. In the eleventh O2- site, O2- is bonded in a 5-coordinate geometry to one Ca2+, three Nd3+, and one Ru+4.50+ atom. In the twelfth O2- site, O2- is bonded to three Nd3+ and one Ru+4.50+ atom to form a mixture of distorted edge and corner-sharing ONd3Ru tetrahedra.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-04-29. Materials Data on Ca3Nd8(RuO6)4 by Materials Project. https://doi.org/10.17188/1684194

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↗