Structural refinement and morphology of synthetic akaganèite crystals, [β-FeO(OH)]

•Synthetic akaganèite prepared at 90 °C.•The solid was characterized by XRD-Synchrotron light.•Crystals formed have dimension of 200 nm and somatoidal morphology.•The crystal size is the same for the products obtained at lower temperatures.•Akaganèite synthesized at the temperature of 90 °C, different from what was suggested in past works, contains hematite as a contaminant.

In this study, the synthesis and characterization of the akaganèite, phase β-FeO(OH), was performed. Scanning electronic microscopy images revealed that the crystals formed in the first 4 h of hydrolysis had the same morphology as those of crystals formed at the end. X-ray diffractometry and vibrational spectra showed that the principal phase obtained from the hydrolysis of iron chloride at 90 °C was akaganèite. Rietvield refinement revealed that hematite formed along with the akaganèite at this temperature, in the proportion of 10% and 90%, respectively. Simultaneous thermal analysis showed the characteristic profile of only the akaganèite.