Details
| Original language | English |
|---|---|
| Pages (from-to) | 1467-1472 |
| Number of pages | 6 |
| Journal | Chemistry of materials |
| Volume | 13 |
| Issue number | 5 |
| Publication status | Published - 13 Apr 2001 |
Abstract
The properties of mesostructured iron oxhydroxide - surfactant composites prepared from weakly acidic (pH between 2.3 and 2.6) Fe(III) solutions by the addition of dodecyl sulfate are studied. The mesocomposites exhibit superparamagnetic behavior with the magnetic ordering within the inorganic part being antiferromagnetic. Mössbauer spectra indicate the presence of significant interparticle interactions, as deduced from the closeness of the blocking temperature in these measurements and the peak temperature of zero-field-cooled magnetic susceptibility data. The blocking temperature in static magnetic measurements is dependent on the aging time of the mesostructured composites in the mother liquor and varies between 17 K and around 30 K. This shift is attributed to an internal restructuring process within the inorganic part of the mesostructured composites, namely, further cross-linking between not fully connected [Fe(O,OH)6] octahedra. This is supported by X-ray absorption spectroscopy: Shortly aged samples, that is, 1 or 2 days, have an inorganic part resembling that of bulk lepidocrocite (γ-FeOOH) with dominantly corner-linked [Fe(O,OH)6] units. With increasing aging time, further cross-linking within the inorganic part results in an increase of edge-sharing octahedra, making the local structures similar to those of goethite and akaganéite. The increase in the blocking temperature with aging time can be interpreted in terms of growth of the magnetically active domains.
ASJC Scopus subject areas
- Chemistry(all)
- General Chemistry
- Chemical Engineering(all)
- General Chemical Engineering
- Materials Science(all)
- Materials Chemistry
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In: Chemistry of materials, Vol. 13, No. 5, 13.04.2001, p. 1467-1472.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Mesostructured iron oxyhydroxides
T2 - 2. Soft hydrothermal restructuring processes
AU - Wirnsberger, G.
AU - Gatterer, K.
AU - Fritzer, H. P.
AU - Grogger, W.
AU - Pillep, B.
AU - Behrens, Peter
AU - Hansen, M. F.
AU - Bender Koch, C.
PY - 2001/4/13
Y1 - 2001/4/13
N2 - The properties of mesostructured iron oxhydroxide - surfactant composites prepared from weakly acidic (pH between 2.3 and 2.6) Fe(III) solutions by the addition of dodecyl sulfate are studied. The mesocomposites exhibit superparamagnetic behavior with the magnetic ordering within the inorganic part being antiferromagnetic. Mössbauer spectra indicate the presence of significant interparticle interactions, as deduced from the closeness of the blocking temperature in these measurements and the peak temperature of zero-field-cooled magnetic susceptibility data. The blocking temperature in static magnetic measurements is dependent on the aging time of the mesostructured composites in the mother liquor and varies between 17 K and around 30 K. This shift is attributed to an internal restructuring process within the inorganic part of the mesostructured composites, namely, further cross-linking between not fully connected [Fe(O,OH)6] octahedra. This is supported by X-ray absorption spectroscopy: Shortly aged samples, that is, 1 or 2 days, have an inorganic part resembling that of bulk lepidocrocite (γ-FeOOH) with dominantly corner-linked [Fe(O,OH)6] units. With increasing aging time, further cross-linking within the inorganic part results in an increase of edge-sharing octahedra, making the local structures similar to those of goethite and akaganéite. The increase in the blocking temperature with aging time can be interpreted in terms of growth of the magnetically active domains.
AB - The properties of mesostructured iron oxhydroxide - surfactant composites prepared from weakly acidic (pH between 2.3 and 2.6) Fe(III) solutions by the addition of dodecyl sulfate are studied. The mesocomposites exhibit superparamagnetic behavior with the magnetic ordering within the inorganic part being antiferromagnetic. Mössbauer spectra indicate the presence of significant interparticle interactions, as deduced from the closeness of the blocking temperature in these measurements and the peak temperature of zero-field-cooled magnetic susceptibility data. The blocking temperature in static magnetic measurements is dependent on the aging time of the mesostructured composites in the mother liquor and varies between 17 K and around 30 K. This shift is attributed to an internal restructuring process within the inorganic part of the mesostructured composites, namely, further cross-linking between not fully connected [Fe(O,OH)6] octahedra. This is supported by X-ray absorption spectroscopy: Shortly aged samples, that is, 1 or 2 days, have an inorganic part resembling that of bulk lepidocrocite (γ-FeOOH) with dominantly corner-linked [Fe(O,OH)6] units. With increasing aging time, further cross-linking within the inorganic part results in an increase of edge-sharing octahedra, making the local structures similar to those of goethite and akaganéite. The increase in the blocking temperature with aging time can be interpreted in terms of growth of the magnetically active domains.
UR - http://www.scopus.com/inward/record.url?scp=0034857554&partnerID=8YFLogxK
U2 - 10.1021/cm9912122
DO - 10.1021/cm9912122
M3 - Article
AN - SCOPUS:0034857554
VL - 13
SP - 1467
EP - 1472
JO - Chemistry of materials
JF - Chemistry of materials
SN - 0897-4756
IS - 5
ER -