DOE OSTI2020
Lu2TiO5 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Lu3+ is bonded to six O2- atoms to form distorted LuO6 pentagonal pyramids that share a cornercorner with one TiO6 octahedra, corners with three equivalent LuO6 pentagonal pyramids, edges with three equivalent TiO6 octahedra, and edges with three equivalent LuO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 29°. There are a spread of Lu–O bond distances ranging from 2.14–2.31 Å. Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with two equivalent LuO6 pentagonal pyramids, and edges with six equivalent LuO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 34°. There is two shorter (1.88 Å) and four longer (2.11 Å) Ti–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Lu3+ and one Ti4+ atom. In the second O2- site, O2- is bonded to three equivalent Lu3+ and one Ti4+ atom to form distorted OLu3Ti trigonal pyramids that share a cornercorner with one OLu2Ti2 tetrahedra, corners with three equivalent OLu3Ti trigonal pyramids, edges with two equivalent OLu2Ti2 tetrahedra, and edges with two equivalent OLu3Ti trigonal pyramids. In the third O2- site, O2- is bonded to two equivalent Lu3+ and two equivalent Ti4+ atoms to form distorted OLu2Ti2 tetrahedra that share corners with two equivalent OLu2Ti2 tetrahedra, corners with two equivalent OLu3Ti trigonal pyramids, and edges with four equivalent OLu3Ti trigonal pyramids.