Materials Data on Dy2Ti2O7 by Materials Project

Abstract

Dy2Ti2O7 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are seven 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 2.27–2.88 Å. In the second Dy3+ site, Dy3+ is bonded to six O2- atoms to form distorted DyO6 octahedra that share corners with four equivalent TiO6 octahedra and edges with two equivalent TiO6 octahedra. The corner-sharing octahedral tilt angles are 68°. There are two shorter (2.27 Å) and four longer (2.39 Å) Dy–O bond lengths. In the third Dy3+ site, Dy3+ is bonded to seven O2- atoms to form DyO7 pentagonal bipyramids that share corners with four TiO6 octahedra and edges with two equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 49–66°. There are a spread of Dy–O bond distances ranging from 2.19–2.39 Å. In the fourth Dy3+ site, Dy3+ is bonded to eight O2- atoms to form distorted DyO8 hexagonal bipyramids that share edges with six DyO8 hexagonal bipyramids and edges with six TiO6 octahedra. There are a spread of Dy–O bond distances ranging from 2.21–2.54 Å. In the fifth Dy3+ site, Dy3+ is bonded to eight O2- atoms to form distorted DyO8 hexagonal bipyramids that share edges with six DyO8 hexagonal bipyramids and edges with six TiO6 octahedra. There are a spread of Dy–O bond distances ranging from 2.20–2.52 Å. In the sixth Dy3+ site, Dy3+ is bonded to eight O2- atoms to form distorted DyO8 hexagonal bipyramids that share edges with six DyO8 hexagonal bipyramids and edges with six TiO6 octahedra. There are a spread of Dy–O bond distances ranging from 2.20–2.53 Å. In the seventh Dy3+ site, Dy3+ is bonded to eight O2- atoms to form distorted DyO8 hexagonal bipyramids that share edges with three DyO8 hexagonal bipyramids and edges with six TiO6 octahedra. There are a spread of Dy–O bond distances ranging from 2.15–2.67 Å. There are eight inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ti–O bond distances ranging from 1.88–2.45 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent DyO6 octahedra, corners with four TiO6 octahedra, and edges with two equivalent DyO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 40–68°. There are a spread of Ti–O bond distances ranging from 1.91–2.01 Å. In the third Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with four equivalent TiO6 octahedra, corners with two equivalent DyO7 pentagonal bipyramids, and edges with two equivalent DyO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There is two shorter (1.92 Å) and four longer (2.03 Å) Ti–O bond length. In the fourth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with five TiO6 octahedra, a cornercorner with one DyO7 pentagonal bipyramid, and edges with four DyO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 47–52°. There are a spread of Ti–O bond distances ranging from 1.89–2.06 Å. In the fifth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with five TiO6 octahedra, a cornercorner with one DyO7 pentagonal bipyramid, and edges with four DyO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 47–52°. There are a spread of Ti–O bond distances ranging from 1.91–2.07 Å. In the sixth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TiO6 octahedra and edges with six DyO8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 49°. There are a spread of Ti–O bond distances ranging from 1.97–1.99 Å. In the seventh Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TiO6 octahedra and edges with six DyO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 47–52°. There are a spread of Ti–O bond distances ranging from 1.94–2.00 Å. In the eighth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TiO6 octahedra and edges with six DyO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 47–49°. There is two shorter (1.96 Å) and four longer (1.98 Å) Ti–O bond length. There are twenty inequivalent O2- sites. In the first O2- site, O2- is bonded to three Dy3+ and one Ti4+ atom to form a mixture of edge and corner-sharing ODy3Ti tetrahedra. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Dy3+ and two equivalent Ti4+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two Dy3+ and two Ti4+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two Dy3+ and two Ti4+ atoms. In the fifth O2- site, O2- is bonded to three Dy3+ and one Ti4+ atom to form ODy3Ti tetrahedra that share corners with six ODy3Ti tetrahedra and edges with two ODyTi3 tetrahedra. In the sixth O2- site, O2- is bonded to three Dy3+ and one Ti4+ atom to form a mixture of distorted edge and corner-sharing ODy3Ti tetrahedra. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two Dy3+ and two equivalent Ti4+ atoms. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Dy3+ and two Ti4+ atoms. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two Dy3+ and two Ti4+ atoms. In the tenth O2- site, O2- is bonded to four Dy3+ atoms to form corner-sharing ODy4 tetrahedra. In the eleventh O2- site, O2- is bonded to three Dy3+ and one Ti4+ atom to form a mixture of edge and corner-sharing ODy3Ti tetrahedra. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to two Dy3+ and two Ti4+ atoms. In the thirteenth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Dy3+ and two Ti4+ atoms. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Dy3+ and two Ti4+ atoms. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Dy3+ and two equivalent Ti4+ atoms. In the sixteenth O2- site, O2- is bonded to four Dy3+ atoms to form corner-sharing ODy4 tetrahedra. In the seventeenth O2- site, O2- is bonded in a 4-coordinate geometry to two Dy3+ and two Ti4+ atoms. In the eighteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Dy3+ and two Ti4+ atoms. In the nineteenth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Dy3+ and two Ti4+ atoms. In the twentieth O2- site, O2- is bonded to one Dy3+ and three Ti4+ atoms to form a mixture of distorted edge and corner-sharing ODyTi3 tetrahedra.