Fluorination of perovskite-related SrFeO3−δ

We report here on the fluorination of the perovskite-related phase SrFeO3−δ through a low temperature (400 °C) reaction with poly(vinylidene fluoride). X-ray powder diffraction shows that fluorination leads to an expansion in the unit cell which is consistent with partial replacement of oxygen by fluorine and consequent reduction in the oxidation state of iron giving SrFeO2F. This reduction in oxidation state is confirmed by X-ray absorption- and Mössbauer-spectroscopy. The latter show complex magnetically split hyperfine patterns for the fluorinated sample, reflecting the interactions between Fe3+ ions which are not possible in oxides containing Fe4+.