Engineering Papers⌕ Search

DOE OSTI · 1724723

Materials Data on SrCa3Mn2O8 by Materials Project

Abstract

SrCa3Mn2O8 is (La,Ba)CuO4-derived structured and crystallizes in the tetragonal P4mm space group. The structure is three-dimensional. Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.39–2.68 Å. There are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ca–O bond distances ranging from 2.28–2.69 Å. In the second Ca2+ site, Ca2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ca–O bond distances ranging from 2.39–2.68 Å. In the third Ca2+ site, Ca2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ca–O bond distances ranging from 2.28–2.69 Å. There are two inequivalent Mn4+ sites. In the first Mn4+ site, Mn4+ is bonded to six O2- atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are a spread of Mn–O bond distances ranging from 1.89–2.00 Å. In the second Mn4+ site, Mn4+ is bonded to six O2- atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are a spread of Mn–O bond distances ranging from 1.89–1.94 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded to four Ca2+ and two equivalent Mn4+ atoms to form distorted OCa4Mn2 octahedra that share corners with fourteen OCa4Mn2 octahedra, edges with two equivalent OCa4Mn2 octahedra, and faces with eight OSrCa4Mn octahedra. The corner-sharing octahedra tilt angles range from 1–55°. In the second O2- site, O2- is bonded to two equivalent Sr2+, two equivalent Ca2+, and two equivalent Mn4+ atoms to form distorted OSr2Ca2Mn2 octahedra that share corners with fourteen OSr2Ca2Mn2 octahedra, edges with two equivalent OSr2Ca2Mn2 octahedra, and faces with eight OCa5Mn octahedra. The corner-sharing octahedra tilt angles range from 2–56°. In the third O2- site, O2- is bonded to one Sr2+, four equivalent Ca2+, and one Mn4+ atom to form distorted OSrCa4Mn octahedra that share corners with seventeen OSrCa4Mn octahedra, edges with eight OSrCa4Mn octahedra, and faces with four equivalent OCa4Mn2 octahedra. The corner-sharing octahedra tilt angles range from 0–55°. In the fourth O2- site, O2- is bonded to five Ca2+ and one Mn4+ atom to form distorted OCa5Mn octahedra that share corners with seventeen OCa5Mn octahedra, edges with eight OCa5Mn octahedra, and faces with four equivalent OSr2Ca2Mn2 octahedra. The corner-sharing octahedra tilt angles range from 0–54°. In the fifth O2- site, O2- is bonded to four equivalent Sr2+, one Ca2+, and one Mn4+ atom to form distorted OSr4CaMn octahedra that share corners with seventeen OCa5Mn octahedra, edges with eight OSrCa4Mn octahedra, and faces with four equivalent OSr2Ca2Mn2 octahedra. The corner-sharing octahedra tilt angles range from 0–56°. In the sixth O2- site, O2- is bonded to five Ca2+ and one Mn4+ atom to form distorted OCa5Mn octahedra that share corners with seventeen OSrCa4Mn octahedra, edges with eight OCa5Mn octahedra, and faces with four equivalent OCa4Mn2 octahedra. The corner-sharing octahedra tilt angles range from 0–55°.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-05-02. Materials Data on SrCa3Mn2O8 by Materials Project. https://doi.org/10.17188/1724723

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↗