Mِssbauer spectroscopy and magnetic properties of the three-dimensional cubic phase Ba6Cu12Fe13S27

The complex sulfide Ba6Cu12Fe13S27 constitutes a cubic phase that crystallizes in the djerfisherite structure type. It contains octahedral and tetrahedral sites occupied by transition metal ions and a central SBa6 octahedron. By means of Mِssbauer spectroscopy, the oxidation state and distribution of iron atoms were determined. The results confirm the occupation of site 1b by Fe(III) and the presence of only Fe(II) ions in the tetrahedral sites (24m). The magnetic properties are consistent with the clustering of iron atoms and rule out the possibility of a spin-glass behavior.