DOE OSTI2020
Al(SnO2)2 is Spinel structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with twelve SnO6 octahedra. The corner-sharing octahedra tilt angles range from 46–54°. There is one shorter (1.76 Å) and three longer (1.86 Å) Al–O bond length. There are two inequivalent Sn+2.50+ sites. In the first Sn+2.50+ site, Sn+2.50+ is bonded to six O2- atoms to form distorted SnO6 octahedra that share corners with six equivalent AlO4 tetrahedra and edges with six SnO6 octahedra. There are two shorter (2.45 Å) and four longer (2.51 Å) Sn–O bond lengths. In the second Sn+2.50+ site, Sn+2.50+ is bonded to six equivalent O2- atoms to form SnO6 octahedra that share corners with six equivalent AlO4 tetrahedra and edges with six equivalent SnO6 octahedra. All Sn–O bond lengths are 2.16 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Al3+ and three Sn+2.50+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Al3+ and three equivalent Sn+2.50+ atoms.