Materials Data on Ta4FeCoO12 by Materials Project

Abstract

Ta4FeCoO12 is beta Vanadium nitride-derived structured and crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. there are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four equivalent TaO6 octahedra, corners with four equivalent CoO6 octahedra, an edgeedge with one TaO6 octahedra, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 43–50°. There are a spread of Ta–O bond distances ranging from 1.98–2.03 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four equivalent TaO6 octahedra, corners with four equivalent FeO6 octahedra, an edgeedge with one TaO6 octahedra, and an edgeedge with one CoO6 octahedra. The corner-sharing octahedra tilt angles range from 43–51°. There are a spread of Ta–O bond distances ranging from 1.99–2.02 Å. Fe2+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with eight equivalent TaO6 octahedra and edges with two equivalent TaO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are two shorter (2.13 Å) and four longer (2.16 Å) Fe–O bond lengths. Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with eight equivalent TaO6 octahedra and edges with two equivalent TaO6 octahedra. The corner-sharing octahedra tilt angles range from 49–50°. There are four shorter (2.05 Å) and two longer (2.15 Å) Co–O bond lengths. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ta5+ and one Fe2+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ta5+ and one Co2+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ta5+ and one Co2+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two Ta5+ and one Fe2+ atom.