Goethite multidomainic

Fischer L., Muhlen E.Z., Brummer G.W., Niehus H. Atomic force microscopy investigations of the surface topography of a multidomain porous goethite. European J Soil Sci 1996 47 329-334. 

Conditions which promote multi-domainic goethites are high ionic strength (either [KOH] or salt) and also low synthesis temperature (<40°C). In alkaline solutions, multi-domainic character decreases and domain width increases as Al substitution increases to Al/(Fe-i-Al) of 0.15, whereas at Al/( Al-nFe) >0.15 single domain crystals result (Schulze Schwertmaim, 1984 Mann et al., 1985). Multidomainic goethites can recrystallize to single domain crystals as a result of hydrothermal treatment at 125-180 °C (Fig. 4.9) (Schwertmann et al., 1985). 

Fig. 4.10 Coethite twinning. Upper left Twins grown at pH 4 and 25 °C consist of two (a) or three armed (b) twin pieces (Schwertmann. Murad, 1983,with permission). Upperright Multidomainic star-like twin grown at [OH] = 0.3 ML" and 70°C with stirring (courtesy P. Weidler).Lower/ejt Schematic drawing of a twin-zone in a singly-branched goethite twin showing the lattice planes and the coherent and incoherent boundary (Maeda. Hirono, 1981, with permission).

Fischer, I. zur Miihlen, E. Briimmer, G.W. Niehus, H. (1996) Atomic force microscopy (AFM) investigations of the surface topography of a multidomainic porous goethite. Eur. J. Soil ScL 47 329-334... 

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