Novel interpretation of the mean structure of feroxyhyte

• The structure of feroxyhyte (δ-FeOOH) proposed in literature is discussed.
• The structure of goethite (α-FeOOH) is analyzed.
• A structural relationship between feroxyhyte and goethite is found.
• New interpretation of the mean structure of δ-FeOOH is given.

The structure of the iron oxyhydroxide called feroxyhyte (δ-FeOOH), which shows an elusive X-ray powder diffraction pattern, has been represented so far using models describing a mean structure based on the crystalline network of the iron(III) oxide hematite (α-Fe2O3). In this paper, a novel description of the mean structure of feroxyhyte is presented, which is based on the structure of the thermodynamically stable iron oxyhydroxide goethite. Starting from different local arrangements present in the goethite network, a mean structural model is determined which shows an X-ray powder diffraction pattern almost coincident with previous studies. This outcome enables to integrate the structure of feroxyhyte among those of other well characterized iron oxyhydroxides.

The structure of the iron oxy-hydroxide feroxyhyte can be described by local arrangements present in the goethite networkFigure optionsDownload as PowerPoint slide