Fe4Si2Sn7O16: Eine Kombination von FeSn6-Oktaedern mit Schichten von (Fe3Sn)O6-Oktaedern; Präparation,Eigenschaften und Kristallstruktur [1]

Fe₄Si₂Sn₇O₁₆: A Combination of FeSn₆-Octahedra with Layers of (Fe₃Sn)O₆-Octahedra; Preparation, Properties, and Crystal Structure Fe₄Si₂Sn₇O₁₆ has been prepared by a solid state reaction at 900 °C from a mixture of Fe₂O₃, SnO₂, Sn, and Si. The compound is a paramagnetic semiconductor. Results of Mössbauer and suszeptibility measurements as well as bond length-bond strength calculations lead to the possible ionic formulation Fe₄²⁺Si₂⁴⁺Sn₁²⁺Sn₁⁴⁺O₁₆^2–. The compound crystallizes in the trigonal space group P3m1 (no. 164), with one formula unit per cell. Lattice parameters obtained by powder measurements are: a = 6.8243(6) Å, c = 9.1404(6) Å, γ = 120°, V = 368.6(1) ų. The structure consists of layers of edge linked oxygen octehedra exactly centered by Sn and Fe in the ratio 1 : 3. Three plains of isolated SiO₄ tetrahedra, FeSn₆ octahedra and again SiO₄ terahedra are inserted between two such layers. The layers are stacked along 001] and linked three-dimensionally by oxygen.