Garnet-type Na3Te2(FeO4)3

Abstract

Na3Te2(FeO4)3 or Na3Te2Fe3O12, trisodium ditellurium(VI) triiron(III) dodecaoxide, was obtained in the form of single-crystals under hydrothermal conditions. Na3Te2(FeO4)3 adopts the garnet structure type in space group Ia\overline{3}d and comprises one Na (multiplicity 24, Wyckoff letter c, site symmetry 2.22), one Te (16 a, .\overline{3}.), one Fe (24 d, \overline{4}..) and one O atom (96 h, 1) in the asymmetric unit. The three-dimensional framework structure is built of [TeO6] octahedra and [FeO4] tetrahedra by vertex-sharing. The larger Na+ cations are situated in the interstices of the framework and are eightfold coordinated in the form of a distorted dodecahedron. Quantitative structural comparisons with isotypic Na3Te2[(Fe0.5Al0.5)O4]3 and Na3Te2(GaO4)3 show a high degree of similarity between the three crystal structures.