Results for “Bi-K-O-Sr” | Engineering Papers

DOE OSTI2020

Materials Data on KSr(BiO3)2 by Materials Project

KSr(BiO3)2 crystallizes in the tetragonal I-42m space group. The structure is three-dimensional. K is bonded to eight O atoms to form distorted KO8 cuboctahedra that share corners with four equivalent KO8 cuboctahedra and edges with eight equivalent BiO6 octahedra. There are four shorter (2.83 Å) and four longer (3.00 Å) K–O bond lengths. Sr is bonded in a 8-coordinate geometry to eight O atoms. There are four shorter (2.59 Å) and four longer (3.00 Å) Sr–O bond lengths. Bi is bonded to six O atoms to form BiO6 octahedra that share corners with six equivalent BiO6 octahedra and edges with four equivalent KO8 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–28°. All Bi–O bond lengths are 2.18 Å. There are two inequivalent O sites. In the first O site, O is bonded in a 4-coordinate geometry to one K, one Sr, and two equivalent Bi atoms. In the second O site, O is bonded to two equivalent K, two equivalent Sr, and two equivalent Bi atoms to form a mixture of distorted edge and corner-sharing OK2Sr2Bi2 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on KSr2(BiO3)3 by Materials Project

KSr2(BiO3)3 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with six equivalent KO12 cuboctahedra, corners with six equivalent SrO12 cuboctahedra, faces with six equivalent SrO12 cuboctahedra, and faces with eight BiO6 octahedra. There are six shorter (3.06 Å) and six longer (3.24 Å) K–O bond lengths. Sr2+ is bonded to twelve O2- atoms to form distorted SrO12 cuboctahedra that share corners with three equivalent KO12 cuboctahedra, corners with nine equivalent SrO12 cuboctahedra, faces with three equivalent KO12 cuboctahedra, faces with three equivalent SrO12 cuboctahedra, and faces with eight BiO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.73–3.26 Å. There are two inequivalent Bi+4.33+ sites. In the first Bi+4.33+ site, Bi+4.33+ is bonded to six O2- atoms to form BiO6 octahedra that share corners with six BiO6 octahedra, faces with three equivalent KO12 cuboctahedra, and faces with five equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–10°. There are three shorter (2.14 Å) and three longer (2.23 Å) Bi–O bond lengths. In the second Bi+4.33+ site, Bi+4.33+ is bonded to six equivalent O2- atoms to form BiO6 octahedra that share corners with six equivalent BiO6 octahedra, faces with two equivalent KO12 cuboctahedra, and faces with six equivalent SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 10°. All Bi–O bond lengths are 2.16 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to two equivalent K1+, two equivalent Sr2+, and two equivalent Bi+4.33+ atoms. In the second O2- site, O2- is bonded in a 6-coordinate geometry to one K1+, three equivalent Sr2+, and two Bi+4.33+ atoms.

36 MATERIALS SCIENCE↗