Homogeneous maghemite (γ-Fe2O3) nanoparticles with an average crystal size around 5 nm were synthesized by successive hydrolysis, oxidation, and dehydration of tetrapyridino-ferrous chloride. Morphological, thermal, and structural properties were investigated by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and x-ray diffraction (XRD) techniques. Rietveld refinement indicated a cubic cell. The superstructure reflections, related to the ordering of cation lattice vacancies, were not detected in the diffraction pattern. Kinetics of the solid-state phase transition of nanocrystalline maghemite to hematite (α-Fe2O3), investigated by energy dispersive x-ray diffraction (EDXRD), indicates that direct transformation from nanocrystalline maghemite to microcrystalline hematite takes place during isothermal treatment at 385°C. This temperature is lower than that observed both for microcrystalline maghemite and for nanocrystalline maghemite supported on silica.
Characterization of nanocrystalline γ-Fe2O3 prepared by wet chemical method / G. Ennas, G. Marongiu, A. Musinu, A. Falqui, P. Ballirano, R. Caminiti. - In: JOURNAL OF MATERIALS RESEARCH. - ISSN 0884-2914. - 14:4(1999), pp. 1570-1575.
|Titolo:||Characterization of nanocrystalline γ-Fe2O3 prepared by wet chemical method|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Data di pubblicazione:||1999|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1557/JMR.1999.0210|
|Appare nelle tipologie:||01 - Articolo su periodico|