Re: Lepidocrocite Structure

Alan Hewat, ILL Grenoble ( (no email) )
Thu, 14 May 1998 08:49:09 +0200

>Lepidocrocite, gamma-FeO(OH), is a rather important phase in ferrous
>corrosion scenarios. Does anybody know of a more recent structural
>analysis than the one referenced in Structure Reports 44A, 1978A
>(which does not relate well to real world samples).

Is that the work of Axel Christensen in Acta Chem.Scand.Ser.A 32
(1978) P. 87-88 ? What do you mean it doesn't relate to real world
samples :-) The structure looks reasonable to me, with planes of
edge-linked FeO octahedra connected by hydrogen bonds in CMC21.

However, you might also look at A. Oles et al. who choose CMCM
for their neutron powder diffraction study reported in Physica Status
Solidi 41 (1970) P. 173-177. This gives a slightly different hydrogen
bond network (but if you are using X-rays, you probably won't notice :-)

But no, I don't know of a more recent study. Please tell us what's wrong
with the present structure. Maybe ther'e a misprint in Structure Reports ?

Alan H.

Alan Hewat, ILL Grenoble, FRANCE <hewat@ill.fr> tel (33) 4.76.20.72.13
ftp://ftp.ill.fr/pub/dif fax (33) 4.76.48.39.06 http://www.ill.fr/dif/