X-Ray Absorption and Mössbauer Spectroscopies Characterization of Iron Nanoclusters Prepared by the Gas Aggregation Technique

Partially oxidized iron nanoclusters have been prepared by the gas-phase aggregation technique with typical sizes of 2–3 nm. This preparation technique has been reported to obtain clusters with interesting magnetic properties such as very large exchange bias. In this paper, a sample composition study carried out by Mössbauer and X-ray absorption spectroscopies is reported. The information reached by these techniques, which is based on the iron short range order, results to be an ideal way to have a characterization of the whole sample since the obtained data are an average over a very large amount of the clusters. In addition, our results indicate the presence of ferrihydrite, which is a compound typically ignored when studying this type of systems.