Materials Data on CdFe4NiO8 by Materials Project

Abstract

Fe4NiCdO8 is Spinel-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent NiO6 octahedra and corners with nine equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 57–58°. There is three shorter (1.96 Å) and one longer (2.01 Å) Fe–O bond length. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three equivalent FeO4 tetrahedra, corners with three equivalent CdO4 tetrahedra, edges with two equivalent NiO6 octahedra, and edges with four equivalent FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.99–2.13 Å. Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with three equivalent FeO4 tetrahedra, corners with three equivalent CdO4 tetrahedra, and edges with six equivalent FeO6 octahedra. There are three shorter (2.06 Å) and three longer (2.16 Å) Ni–O bond lengths. Cd2+ is bonded to four O2- atoms to form CdO4 tetrahedra that share corners with three equivalent NiO6 octahedra and corners with nine equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 59–62°. There are three shorter (2.13 Å) and one longer (2.14 Å) Cd–O bond lengths. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Fe3+ and one Ni2+ atom. In the second O2- site, O2- is bonded to four Fe3+ atoms to form distorted OFe4 trigonal pyramids that share corners with six equivalent OCdFe2Ni tetrahedra and corners with three equivalent OCdFe3 trigonal pyramids. In the third O2- site, O2- is bonded to two equivalent Fe3+, one Ni2+, and one Cd2+ atom to form distorted OCdFe2Ni tetrahedra that share corners with two equivalent OCdFe2Ni tetrahedra, corners with three OCdFe3 trigonal pyramids, edges with two equivalent OCdFe2Ni tetrahedra, and an edgeedge with one OCdFe3 trigonal pyramid. In the fourth O2- site, O2- is bonded to three equivalent Fe3+ and one Cd2+ atom to form distorted OCdFe3 trigonal pyramids that share corners with three equivalent OCdFe2Ni tetrahedra, corners with three equivalent OFe4 trigonal pyramids, and edges with three equivalent OCdFe2Ni tetrahedra.