DOE OSTI2020
Fe4NiZnO8 is Spinel-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are ten inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with two equivalent NiO6 octahedra and corners with ten FeO6 octahedra. The corner-sharing octahedra tilt angles range from 51–60°. There are a spread of Fe–O bond distances ranging from 1.91–1.95 Å. In the second Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with four NiO6 octahedra and corners with eight FeO6 octahedra. The corner-sharing octahedra tilt angles range from 57–60°. There are a spread of Fe–O bond distances ranging from 1.92–1.95 Å. In the third Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three NiO6 octahedra and corners with nine FeO6 octahedra. The corner-sharing octahedra tilt angles range from 54–62°. There are a spread of Fe–O bond distances ranging from 1.92–1.96 Å. In the fourth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three FeO4 tetrahedra, corners with three ZnO4 tetrahedra, an edgeedge with one NiO6 octahedra, and edges with five FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.94–2.02 Å. In the fifth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three FeO4 tetrahedra, corners with three ZnO4 tetrahedra, edges with two NiO6 octahedra, and edges with four FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.98–2.08 Å. In the sixth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three FeO4 tetrahedra, corners with three ZnO4 tetrahedra, an edgeedge with one NiO6 octahedra, and edges with five FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.95–2.00 Å. In the seventh Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three FeO4 tetrahedra, corners with three ZnO4 tetrahedra, an edgeedge with one NiO6 octahedra, and edges with five FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.95–2.02 Å. In the eighth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three FeO4 tetrahedra, corners with three ZnO4 tetrahedra, edges with two equivalent NiO6 octahedra, and edges with four FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.00–2.07 Å. In the ninth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three FeO4 tetrahedra, corners with three ZnO4 tetrahedra, edges with three FeO6 octahedra, and edges with three NiO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.91–2.06 Å. In the tenth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three FeO4 tetrahedra, corners with three ZnO4 tetrahedra, edges with two NiO6 octahedra, and edges with four FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.96–2.13 Å. There are three inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with three FeO4 tetrahedra, corners with three ZnO4 tetrahedra, and edges with six FeO6 octahedra. There are a spread of Ni–O bond distances ranging from 2.05–2.11 Å. In the second Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with three FeO4 tetrahedra, corners with three ZnO4 tetrahedra, an edgeedge with one NiO6 octahedra, and edges with five FeO6 octahedra. There are a spread of Ni–O bond distances ranging from 2.04–2.12 Å. In the third Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with three FeO4 tetrahedra, corners with three ZnO4 tetrahedra, an edgeedge with one NiO6 octahedra, and edges with five FeO6 octahedra. There are a spread of Ni–O bond distances ranging from 2.04–2.12 Å. There are three inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with three NiO6 octahedra and corners with nine FeO6 octahedra. The corner-sharing octahedra tilt angles range from 56–61°. There are a spread of Zn–O bond distances ranging from 1.94–2.02 Å. In the second Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with three NiO6 octahedra and corners with nine FeO6 octahedra. The corner-sharing octahedra tilt angles range from 56–62°. There are a spread of Zn–O bond distances ranging from 1.96–2.05 Å. In the third Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with three NiO6 octahedra and corners with nine FeO6 octahedra. The corner-sharing octahedra tilt angles range from 57–62°. There are three shorter (1.97 Å) and one longer (2.03 Å) Zn–O bond lengths. There are twenty inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe3+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe3+ atoms. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Ni2+ atom. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Ni2+ atom. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Fe3+, one Ni2+, and one Zn2+ atom. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Zn2+ atom. In the seventh O2- site, O2- is bonded to three Fe3+ and one Zn2+ atom to form distorted edge-sharing OZnFe3 trigonal pyramids. In the eighth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Fe3+, one Ni2+, and one Zn2+ atom. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe3+ atoms. In the tenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Ni2+ atom. In the eleventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Fe3+ and one Ni2+ atom. In the twelfth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Ni2+ atom. In the thirteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Ni2+ atom. In the fourteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Ni2+ atom. In the fifteenth O2- site, O2- is bonded to three Fe3+ and one Zn2+ atom to form distorted edge-sharing OZnFe3 trigonal pyramids. In the sixteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Fe3+, one Ni2+, and one Zn2+ atom. In the seventeenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Fe3+, one Ni2+, and one Zn2+ atom. In the eighteenth O2- site, O2- is bonded to three Fe3+ and one Zn2+ atom to form distorted edge-sharing OZnFe3 trigonal pyramids. In the nineteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Fe3+, two Ni2+, and one Zn2+ atom. In the twentieth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Fe3+, one Ni2+, and one Zn2+ atom.