Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “K-O-Th”

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 K2ThO3 by Materials Project

K2ThO3 is High Pressure (4-7GPa) Tellurium-derived structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to six O2- atoms to form distorted KO6 octahedra that share corners with two equivalent KO6 octahedra, corners with four ThO6 octahedra, edges with four ThO6 octahedra, and edges with eight KO6 octahedra. The corner-sharing octahedra tilt angles range from 16–19°. There are a spread of K–O bond distances ranging from 2.70–3.06 Å. In the second K1+ site, K1+ is bonded to six O2- atoms to form distorted KO6 octahedra that share corners with six KO6 octahedra, edges with six KO6 octahedra, and edges with six ThO6 octahedra. The corner-sharing octahedra tilt angles range from 19–20°. All K–O bond lengths are 2.77 Å. In the third K1+ site, K1+ is bonded to six O2- atoms to form distorted KO6 octahedra that share corners with two equivalent KO6 octahedra, corners with four ThO6 octahedra, edges with four ThO6 octahedra, and edges with eight KO6 octahedra. The corner-sharing octahedra tilt angles range from 15–20°. There are a spread of K–O bond distances ranging from 2.66–3.03 Å. There are two inequivalent Th4+ sites. In the first Th4+ site, Th4+ is bonded to six O2- atoms to form ThO6 octahedra that share corners with six KO6 octahedra, edges with three equivalent ThO6 octahedra, and edges with nine KO6 octahedra. The corner-sharing octahedra tilt angles range from 15–16°. There are four shorter (2.35 Å) and two longer (2.37 Å) Th–O bond lengths. In the second Th4+ site, Th4+ is bonded to six O2- atoms to form ThO6 octahedra that share corners with six KO6 octahedra, edges with three equivalent ThO6 octahedra, and edges with nine KO6 octahedra. The corner-sharing octahedra tilt angles range from 15–16°. There are two shorter (2.35 Å) and four longer (2.36 Å) Th–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four K1+ and two Th4+ atoms. In the second O2- site, O2- is bonded in a 6-coordinate geometry to four K1+ and two Th4+ atoms. In the third O2- site, O2- is bonded to four K1+ and two Th4+ atoms to form a mixture of distorted corner and edge-sharing OK4Th2 octahedra. The corner-sharing octahedra tilt angles range from 0–14°.

36 MATERIALS SCIENCE↗