DOE OSTI2020
CuTeO4 is zeta iron carbide-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with four equivalent CuO6 octahedra, corners with four equivalent TeO6 octahedra, and edges with two equivalent TeO6 octahedra. The corner-sharing octahedra tilt angles range from 52–60°. There are a spread of Cu–O bond distances ranging from 1.91–2.32 Å. In the second Cu2+ site, Cu2+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with four equivalent CuO6 octahedra, corners with four equivalent TeO6 octahedra, and edges with two equivalent TeO6 octahedra. The corner-sharing octahedra tilt angles range from 50–60°. There are a spread of Cu–O bond distances ranging from 1.99–2.35 Å. Te6+ is bonded to six O2- atoms to form TeO6 octahedra that share corners with four CuO6 octahedra, corners with four equivalent TeO6 octahedra, and edges with two CuO6 octahedra. The corner-sharing octahedra tilt angles range from 43–53°. There are a spread of Te–O bond distances ranging from 1.90–2.04 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to two Cu2+ and one Te6+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cu2+ and one Te6+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Cu2+ and two equivalent Te6+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cu2+ and two equivalent Te6+ atoms.