Simultaneous determination of the two recoilless f-fractions of akaganeite using a single Mössbauer spectrum

We propose a simple method for simultaneously calculating the two room temperature relative recoilless f-fractions of akaganeite without using the Debye approximation and by taking a single Mössbauer spectrum. The method relays on the correct determination of the two subspectral areas associated to the two akaganeite's iron sites relative to the subspectral area of a standard sample and also on its crystallographic structure. It was found that the recoilless f-fraction of the first iron site of akaganeite relative to that of standard iron powder, fFe, was of 0.95±0.08 and that for the second site was of 0.98±0.15. Additionally, we propose a methodology to estimate a parameter directly related with the chloride concentration in given akaganeite sample by using only Mössbauer spectrometry at two different temperatures.

► We propose a simple method of calculating the relative f-fractions of the two sites of akaganeite.
► In previous works, the relative recoilless f-fraction of only one iron site is calculated.
► This methodology can allow the estimation of the chloride occupancy using only Mössbauer spectrometry.