Low temperature fluorination of Sr3Fe2O7−x with polyvinylidine fluoride: An X-ray powder diffraction and Mössbauer spectroscopy study

► The fluorination of Sr3Fe2O7−x using PVDF. ► The control of the fluorine content with amount of PVDF used. ► The synthesis of three new Fe based oxide fluorides. ► The identification of the structures of these oxide fluorides.