Search NASA⌕ Search

DOE OSTI · 1268904

Materials Data on Sr9Zn4(CuO7)2 by Materials Project

Abstract

Sr9Zn4(CuO7)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are five inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to six O2- atoms to form SrO6 octahedra that share corners with three SrO6 octahedra, edges with seven SrO6 octahedra, and edges with two equivalent ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 1–59°. There are a spread of Sr–O bond distances ranging from 2.48–2.65 Å. In the second Sr2+ site, Sr2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Sr–O bond distances ranging from 2.56–2.86 Å. In the third Sr2+ site, Sr2+ is bonded to six O2- atoms to form SrO6 octahedra that share corners with two equivalent SrO6 octahedra, a cornercorner with one ZnO4 tetrahedra, edges with five SrO6 octahedra, and edges with two equivalent ZnO4 tetrahedra. The corner-sharing octahedral tilt angles are 1°. There are a spread of Sr–O bond distances ranging from 2.45–2.71 Å. In the fourth Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Sr–O bond distances ranging from 2.46–2.88 Å. In the fifth Sr2+ site, Sr2+ is bonded to six O2- atoms to form SrO6 octahedra that share corners with two equivalent SrO6 octahedra, corners with four equivalent ZnO4 tetrahedra, and edges with two equivalent SrO6 octahedra. The corner-sharing octahedral tilt angles are 59°. There are two shorter (2.45 Å) and four longer (2.62 Å) Sr–O bond lengths. Cu1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.81 Å) and one longer (1.86 Å) Cu–O bond length. There are two inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with three SrO6 octahedra, corners with three ZnO4 tetrahedra, and edges with two equivalent SrO6 octahedra. The corner-sharing octahedra tilt angles range from 3–71°. There are a spread of Zn–O bond distances ranging from 1.97–2.05 Å. In the second Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with three ZnO4 tetrahedra and edges with two equivalent SrO6 octahedra. There are a spread of Zn–O bond distances ranging from 1.97–2.10 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to four Sr2+ and one Cu1+ atom. In the second O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+ and two Zn2+ atoms. In the third O2- site, O2- is bonded to five Sr2+ and one Cu1+ atom to form OSr5Cu octahedra that share corners with four OSr5Zn octahedra, corners with two equivalent OSr2Zn2 tetrahedra, and edges with eight OSr5Cu octahedra. The corner-sharing octahedra tilt angles range from 4–8°. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to three Sr2+ and two equivalent Zn2+ atoms. In the fifth O2- site, O2- is bonded to two Sr2+ and two equivalent Zn2+ atoms to form distorted OSr2Zn2 tetrahedra that share corners with three OSr5Cu octahedra, corners with two equivalent OSr2Zn2 tetrahedra, and edges with two equivalent OSr5Zn octahedra. The corner-sharing octahedra tilt angles range from 23–69°. In the sixth O2- site, O2- is bonded to five Sr2+ and one Zn2+ atom to form distorted OSr5Zn octahedra that share corners with four OSr5Cu octahedra, a cornercorner with one OSr2Zn2 tetrahedra, and edges with eight OSr5Cu octahedra. The corner-sharing octahedra tilt angles range from 4–12°. In the seventh O2- site, O2- is bonded to five Sr2+ and one Zn2+ atom to form OSr5Zn octahedra that share corners with four OSr5Cu octahedra, edges with eight OSr5Cu octahedra, and edges with two equivalent OSr2Zn2 tetrahedra. The corner-sharing octahedra tilt angles range from 8–12°.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-05-03. Materials Data on Sr9Zn4(CuO7)2 by Materials Project. https://doi.org/10.17188/1268904

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↗