FeIV disproportionation (2Fe1V→FeIII+FeV) in AFeO3 (A=Ca, Sr) Perovskite lattices studied by 119Sn diamagnetic probe Mössbauer spectroscopy

Using 119 Sn IV as a diamagnetic probe in the perovskite lattice of AFeO 3 oxides (A=Ca, Sr), the Fe IV disproportionation (2Fe IV ⇄ Fe III + Fe V ) is discussed. An electronic phenomenon previously described for CaFeO 3 is detected in SrFeO 3 due to the local breakdown of the electronic delocalisation. Steric interactions seem to be the predominant factor for explaining the oxidation state of iron in the Sn IV environment