TY - JOUR
T1 - Synthesis and characterization of hollow α-Fe2O3 sub-micron spheres prepared by sol-gel
AU - León, Lizbet
AU - Bustamante, Angel
AU - Osorio, Ana
AU - Olarte, G. S.
AU - De Los Valladares, Luis Santos
AU - Barnes, Crispin H.W.
AU - Majima, Yutaka
PY - 2011/11/1
Y1 - 2011/11/1
N2 - In this work we report the preparation of magnetic hematite hollow sub-micron spheres (α-Fe2O3) by colloidal suspensions of ferric nitrate nine-hydrate (Fe(NO3)3·9H2O) particles in citric acid solution by following the sol-gel method. After the gel formation, the samples were annealed at different temperatures in an oxidizing atmosphere. Annealing at 180°C resulted in an amorphous phase, without iron oxide formation. Annealing at 250°C resulted in coexisting phases of hematite, maghemite and magnetite, whereas at 400°C, only hematite and maghemite were found. Pure hematite hollow sub-micron spheres with porous shells were formed after annealing at 600°C. The characterization was performed by X-ray diffraction (XRD), Mössbauer spectroscopy (MS) and scanning electron microscopy (SEM). © 2011 Springer Science+Business Media B.V.
AB - In this work we report the preparation of magnetic hematite hollow sub-micron spheres (α-Fe2O3) by colloidal suspensions of ferric nitrate nine-hydrate (Fe(NO3)3·9H2O) particles in citric acid solution by following the sol-gel method. After the gel formation, the samples were annealed at different temperatures in an oxidizing atmosphere. Annealing at 180°C resulted in an amorphous phase, without iron oxide formation. Annealing at 250°C resulted in coexisting phases of hematite, maghemite and magnetite, whereas at 400°C, only hematite and maghemite were found. Pure hematite hollow sub-micron spheres with porous shells were formed after annealing at 600°C. The characterization was performed by X-ray diffraction (XRD), Mössbauer spectroscopy (MS) and scanning electron microscopy (SEM). © 2011 Springer Science+Business Media B.V.
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U2 - 10.1007/s10751-011-0353-1
DO - 10.1007/s10751-011-0353-1
M3 - Article
SN - 0304-3843
SP - 131
EP - 137
JO - Hyperfine Interactions
JF - Hyperfine Interactions
ER -
