Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Ce-Fe-O-Rb”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

Materials Data on Rb2Ce2Fe4O11 by Materials Project

Rb2Ce2Fe4O11 crystallizes in the orthorhombic Pmna space group. The structure is three-dimensional. Rb1+ is bonded to twelve O2- atoms to form distorted RbO12 cuboctahedra that share corners with four equivalent RbO12 cuboctahedra, faces with four equivalent RbO12 cuboctahedra, faces with four equivalent FeO6 octahedra, and faces with four equivalent FeO5 trigonal bipyramids. There are a spread of Rb–O bond distances ranging from 2.81–3.26 Å. Ce4+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ce–O bond distances ranging from 2.46–2.73 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to five O2- atoms to form distorted FeO5 trigonal bipyramids that share corners with three equivalent FeO6 octahedra, corners with two equivalent FeO5 trigonal bipyramids, and faces with four equivalent RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–30°. There are a spread of Fe–O bond distances ranging from 1.90–2.08 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form distorted FeO6 octahedra that share corners with three equivalent FeO6 octahedra, corners with three equivalent FeO5 trigonal bipyramids, and faces with four equivalent RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–19°. There are a spread of Fe–O bond distances ranging from 1.96–2.17 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Rb1+ and two Fe3+ atoms to form a mixture of distorted corner and edge-sharing ORb4Fe2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ce4+ and two equivalent Fe3+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Rb1+, two equivalent Ce4+, and two Fe3+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Rb1+, two equivalent Ce4+, and two equivalent Fe3+ atoms. In the fifth O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Rb1+, two equivalent Ce4+, and two equivalent Fe3+ atoms.

36 MATERIALS SCIENCE↗