The Fe oxidation states and possible cationic distributions were determined by 57 Fe Mössbauer spectroscopy using an apparatus (Halder Electronics, Germany) in horizontal arrangement ( 57 Fe Co/Rh single-line thin source, constant acceleration model with symmetric triangular velocity shape, a multi-channel analyzer with 1024 channels, regular velocity calibration against metallic Fe). Data evaluation was performed using the program Recoil allowing the use of a full static hyperfine interaction Hamiltonian analysis with Lorentzian-shaped doublets, but also a Voigt-based hyperfine parameter distribution analysis.