Hydrothermal Synthesis of the Oxofluoride FeSbOF-An Anti-ferromagnetic Spin S = 5/2 Compound.

The new oxofluoride compound FeSbOF was synthesized by hydrothermal techniques at 230 °C. Its crystal structure was determined from single-crystal X-ray diffraction data. The compound crystallizes in the monoclinic space group C2/c with one crystallographic site for Fe and Sb, respectively. The crystal structure is made of [FeOF] octahedra and seesaw [SbO] building blocks. These are connected to form [FeOF] layers and [SbO] chains that bond together via the oxygen atoms to form the three-dimensional framework structure. Magnetic susceptibility and heat capacity measurements indicate long-range anti-ferromagnetic ordering below a Néel temperature of ∼175 K. Two-dimensional anti-ferromagnetic short-range order in the square planar net of the Fe cations extends to temperatures far above the Néel temperature.