Results for “Ce-N-O-Si” | Engineering Papers

DOE OSTI2020

Materials Data on CeSiNO2 by Materials Project

CeSiO2N crystallizes in the hexagonal P-6c2 space group. The structure is three-dimensional. there are three inequivalent Ce3+ sites. In the first Ce3+ site, Ce3+ is bonded to six equivalent N3- and six equivalent O2- atoms to form CeN6O6 cuboctahedra that share edges with six CeO6 octahedra, faces with two equivalent CeN6O6 cuboctahedra, and faces with six equivalent SiN2O2 tetrahedra. All Ce–N bond lengths are 2.92 Å. All Ce–O bond lengths are 2.79 Å. In the second Ce3+ site, Ce3+ is bonded to six equivalent O2- atoms to form distorted CeO6 octahedra that share corners with six equivalent SiN2O2 tetrahedra, edges with three equivalent CeN6O6 cuboctahedra, and edges with three equivalent CeO6 octahedra. All Ce–O bond lengths are 2.44 Å. In the third Ce3+ site, Ce3+ is bonded to six equivalent O2- atoms to form distorted CeO6 octahedra that share corners with six equivalent SiN2O2 tetrahedra, edges with three equivalent CeN6O6 cuboctahedra, and edges with three equivalent CeO6 octahedra. All Ce–O bond lengths are 2.47 Å. Si4+ is bonded to two equivalent N3- and two equivalent O2- atoms to form SiN2O2 tetrahedra that share corners with four CeO6 octahedra, corners with two equivalent SiN2O2 tetrahedra, and faces with two equivalent CeN6O6 cuboctahedra. The corner-sharing octahedral tilt angles are 57°. There is one shorter (1.69 Å) and one longer (1.70 Å) Si–N bond length. Both Si–O bond lengths are 1.67 Å. N3- is bonded in a distorted bent 120 degrees geometry to two equivalent Ce3+ and two equivalent Si4+ atoms. O2- is bonded in a 1-coordinate geometry to three Ce3+ and one Si4+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ce4Si4N6O5 by Materials Project

Ce4Si4N6O5 crystallizes in the cubic P2_13 space group. The structure is three-dimensional. there are two inequivalent Ce3+ sites. In the first Ce3+ site, Ce3+ is bonded to three N3- and four O2- atoms to form distorted CeN3O4 hexagonal pyramids that share corners with four equivalent CeN3O4 hexagonal pyramids, corners with three SiN3O tetrahedra, edges with two equivalent CeN3O4 hexagonal pyramids, and edges with three SiN3O tetrahedra. There are a spread of Ce–N bond distances ranging from 2.56–2.71 Å. There are a spread of Ce–O bond distances ranging from 2.37–2.53 Å. In the second Ce3+ site, Ce3+ is bonded in a 4-coordinate geometry to three equivalent N3- and four O2- atoms. All Ce–N bond lengths are 2.55 Å. There are one shorter (2.28 Å) and three longer (2.95 Å) Ce–O bond lengths. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to three N3- and one O2- atom to form SiN3O tetrahedra that share corners with two equivalent CeN3O4 hexagonal pyramids, corners with three SiN3O tetrahedra, and edges with two equivalent CeN3O4 hexagonal pyramids. There are a spread of Si–N bond distances ranging from 1.71–1.73 Å. The Si–O bond length is 1.68 Å. In the second Si4+ site, Si4+ is bonded to three equivalent N3- and one O2- atom to form SiN3O tetrahedra that share corners with three equivalent CeN3O4 hexagonal pyramids, corners with three equivalent SiN3O tetrahedra, and edges with three equivalent CeN3O4 hexagonal pyramids. All Si–N bond lengths are 1.69 Å. The Si–O bond length is 1.67 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a 4-coordinate geometry to two equivalent Ce3+ and two Si4+ atoms. In the second N3- site, N3- is bonded in a 4-coordinate geometry to two Ce3+ and two equivalent Si4+ atoms. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to three equivalent Ce3+ and one Si4+ atom to form distorted corner-sharing OCe3Si tetrahedra. In the second O2- site, O2- is bonded to four Ce3+ atoms to form corner-sharing OCe4 tetrahedra. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Ce3+ and one Si4+ atom.

36 MATERIALS SCIENCE↗