We report here on the fluorination of the perovskite-related phases La1xSrxFe1yCoyO3d. The introduction of fluorine in place of oxygen is achieved through a low-temperature (400 1C) reaction with poly(vinylidene fluoride). X-ray powder diffraction data show that in all cases the 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 and/or cobalt. This reduction in oxidation state is confirmed by X-ray absorption- and Mo¨ ssbauer-spectroscopy. The Mo¨ ssbauer spectra show complex magnetically split hyperfine patterns for the fluorinated samples, reflecting the interactions between Fe3+ ions, which are not possible in oxides containing Fe4+.