DOE OSTI2020
NaDy3Ti2(SbO7)2 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. Na1+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.36–2.68 Å. There are three inequivalent Dy3+ sites. In the first Dy3+ site, Dy3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Dy–O bond distances ranging from 2.20–2.75 Å. In the second Dy3+ site, Dy3+ is bonded to eight O2- atoms to form distorted DyO8 hexagonal bipyramids that share edges with two equivalent DyO8 hexagonal bipyramids, edges with two equivalent TiO6 octahedra, and edges with four SbO6 octahedra. There are a spread of Dy–O bond distances ranging from 2.20–2.56 Å. In the third Dy3+ site, Dy3+ is bonded to eight O2- atoms to form distorted DyO8 hexagonal bipyramids that share edges with two equivalent DyO8 hexagonal bipyramids, edges with two equivalent SbO6 octahedra, and edges with four TiO6 octahedra. There are a spread of Dy–O bond distances ranging from 2.20–2.58 Å. There are two inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with four SbO6 octahedra, and edges with two equivalent DyO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 43–46°. There are a spread of Ti–O bond distances ranging from 1.92–2.02 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with four SbO6 octahedra, and edges with four DyO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 43–48°. There are a spread of Ti–O bond distances ranging from 1.94–1.99 Å. There are two inequivalent Sb5+ sites. In the first Sb5+ site, Sb5+ is bonded to six O2- atoms to form SbO6 octahedra that share corners with two equivalent SbO6 octahedra, corners with four TiO6 octahedra, and edges with four DyO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 46–49°. There are a spread of Sb–O bond distances ranging from 1.98–2.02 Å. In the second Sb5+ site, Sb5+ is bonded to six O2- atoms to form SbO6 octahedra that share corners with two equivalent SbO6 octahedra, corners with four TiO6 octahedra, and edges with two equivalent DyO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 46–49°. There are a spread of Sb–O bond distances ranging from 1.98–2.02 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded to one Na1+ and three Dy3+ atoms to form ONaDy3 tetrahedra that share corners with six ONaDy3 tetrahedra and an edgeedge with one ONaDySb2 tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Dy3+, one Ti4+, and one Sb5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Dy3+, one Ti4+, and one Sb5+ atom. In the fourth O2- site, O2- is bonded to one Na1+, one Dy3+, and two Sb5+ atoms to form a mixture of distorted edge and corner-sharing ONaDySb2 tetrahedra. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two Dy3+ and two Ti4+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two Dy3+, one Ti4+, and one Sb5+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two Dy3+, one Ti4+, and one Sb5+ atom.