Search NASA⌕ Search

DOE OSTI · 1687934

Materials Data on TaFe by Materials Project

Abstract

FeTa is Frank-Kasper $\mu$ Phase-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are seven inequivalent Ta sites. In the first Ta site, Ta is bonded in a 6-coordinate geometry to eight Ta and six equivalent Fe atoms. There are a spread of Ta–Ta bond distances ranging from 2.66–3.12 Å. All Ta–Fe bond lengths are 2.66 Å. In the second Ta site, Ta is bonded in a 8-coordinate geometry to eight Ta and six equivalent Fe atoms. There are a spread of Ta–Ta bond distances ranging from 2.76–3.11 Å. All Ta–Fe bond lengths are 2.68 Å. In the third Ta site, Ta is bonded in a 9-coordinate geometry to seven Ta and nine equivalent Fe atoms. There are three shorter (2.84 Å) and three longer (2.91 Å) Ta–Ta bond lengths. There are three shorter (2.83 Å) and six longer (2.99 Å) Ta–Fe bond lengths. In the fourth Ta site, Ta is bonded in a 12-coordinate geometry to four Ta and twelve Fe atoms. All Ta–Ta bond lengths are 2.91 Å. There are a spread of Ta–Fe bond distances ranging from 2.77–2.93 Å. In the fifth Ta site, Ta is bonded in a 6-coordinate geometry to nine Ta and six Fe atoms. All Ta–Ta bond lengths are 2.81 Å. There are three shorter (2.79 Å) and three longer (2.83 Å) Ta–Fe bond lengths. In the sixth Ta site, Ta is bonded in a 6-coordinate geometry to nine Ta and six Fe atoms. There are three shorter (2.78 Å) and three longer (2.82 Å) Ta–Fe bond lengths. In the seventh Ta site, Ta is bonded to six equivalent Ta and six equivalent Fe atoms to form distorted TaTa6Fe6 cuboctahedra that share corners with twelve equivalent FeTa8Fe4 cuboctahedra, edges with six equivalent TaTa6Fe6 cuboctahedra, and faces with eighteen equivalent FeTa8Fe4 cuboctahedra. All Ta–Fe bond lengths are 2.55 Å. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded to seven Ta and five Fe atoms to form FeTa7Fe5 cuboctahedra that share corners with fifteen FeTa7Fe5 cuboctahedra, edges with five FeTa8Fe4 cuboctahedra, and faces with thirteen FeTa7Fe5 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.42–2.46 Å. In the second Fe site, Fe is bonded to eight Ta and four equivalent Fe atoms to form distorted FeTa8Fe4 cuboctahedra that share corners with two equivalent TaTa6Fe6 cuboctahedra, corners with thirteen FeTa7Fe5 cuboctahedra, edges with five FeTa8Fe4 cuboctahedra, faces with three equivalent TaTa6Fe6 cuboctahedra, and faces with ten equivalent FeTa8Fe4 cuboctahedra. There are two shorter (2.38 Å) and two longer (2.49 Å) Fe–Fe bond lengths. In the third Fe site, Fe is bonded to six equivalent Ta and six equivalent Fe atoms to form FeTa6Fe6 cuboctahedra that share corners with twelve equivalent FeTa7Fe5 cuboctahedra, edges with six equivalent FeTa6Fe6 cuboctahedra, and faces with eighteen equivalent FeTa7Fe5 cuboctahedra.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-05-02. Materials Data on TaFe by Materials Project. https://doi.org/10.17188/1687934

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↗