| Resumenes
Vol. 37 No.1 de 2005 |
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| PHYSICAL PROPERTIES OF AKAGANEITE
OBTAINED BY HYDROLISIS OF Fe3+ IN THE PRESENCE OF Al3+, Cr3+,
AND Cu2+ |
| K.E. García, A.L. Morales, C.A. Barrero,
and J.M. Greneche |
This paper deals with the influence of Al, Cr, and Cu ions
on the formation of akaganeite. Powder samples were prepared
by thermal hydrolysis of several mixtures of iron and the
other cations so-lutions at 70°C during 48 hours. X-ray
diffraction and Mössbauer spectrometry at 77 K and
300 K demonstrate that akaganeite is the only iron phase
being formed. The X-ray patterns for all sam-ples were adequately
adjusted through Rietveld method with the monoclinic space
group (C2/m:b3). This symmetry requires the existence of
two distinct iron octahedral sites which is also confirmed
by the Mössbauer spectrum in the paramagnetic state.
No appreciable difference in the crystallographic parameters
for all the samples were observed. The Mössbauer parameters
both in the paramagnetic and in the magnetic states did
not change appreciably. These results suggest that the metallic
cations did not enter into the akaganeite`s crystallographic
structure in a detectable amount.
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