Influence of foreign ions on the atomic scale structure of ferric oxyhydroxides

Quantitative X-ray structural analysis coupled with reverse Monte-Carlo (RMC) simulation and infrared spectroscopy have been used for characterizing the atomic scale structure in α-FeOOH particles with and without anions consisting mainly of carbonate. The results showed that these α-FeOOH particles fundamentally have the α-FeOOH structure, but the linkages of FeO6 octahedral structural units in the α-FeOOH particles with the anions are significantly distorted, and the distortion appears to be related with the anions in the α-FeOOH particles. As α-FeOOH are formed through olation and oxolation of iron complexes described by FeO6 structural units with hydrogen in aqueous solution, the atomic scale structure in the α-FeOOH particles may be influenced by anions.