Separation of the Oxide and Halide Part in the Oxohalide Fe3Te3O10Cl Due to High Lewis Acidity of the Cations

A new iron tellurite halide Fe3Te3O10Cl has been identified that crystallizes in the monoclinic space group P2(1)/c. The crystal structure comprises channels where the Cl ions and also the stereochemically active lone-pair electrons on Te4+ are located. The Cl-atoms rather act as counterions than being part of the covalent/ionic network. The magnetic susceptibility indicates antiferromagnetic ordering below T-N similar to 100 K with a marked splitting of the field cooled (fc) and the zero-field cooled (zfc) susceptibility at low magnetic fields; the splitting disappears at higher magnetic fields. Heat capacity measurements confirm the long-range ordering at below this temperature. Only moderate shifts are observed with Raman spectroscopy at the magnetic transition.