OATAO - Open Archive Toulouse Archive Ouverte Open Access Week

Synthesis and characterization of Fe/Co/Ni alloys-MgO nanocomposite powders

Baco-Carles, Valérie and Laurent, Christophe and Brieu, Marc and Rousset, Abel Synthesis and characterization of Fe/Co/Ni alloys-MgO nanocomposite powders. (1999) Journal of Materials Chemistry, vol. 9 (n° 4). pp. 1003-1009. ISSN 0959-9428

[img]
Preview
(Document in English)

PDF (Author's version ) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
274kB

Official URL: http://dx.doi.org/10.1039/a809642b

Abstract

A mixed oxalate β-Mg 0.896 Fe 0.047 Co 0.034 Ni 0.023 C 2 O 4 ·2H 2 O of well controlled size and morphology was prepared by coprecipitation. The corresponding quaternary solid solution between MgO, FeO, CoO and NiO was prepared by thermal decomposition and calcination in a H 2 /H 2 O/N 2 atmosphere. The selective reduction of the solid solution in an H 2 atmosphere was studied by a combination of X-ray diffraction, Mössbauer spectroscopy, transmission electron microscopy and associated analysis. This work has brought to light the very high stability of Fe 2+ , Co 2+ and notably Ni 2+ when substituted for Mg 2+ in the MgO rocksalt lattice. It is necessary to perform the reduction at 1300 °C fully to reduce the transition metal ions. The alloy particles are either distributed as relatively large particles (tens to hundreds of nanometers) at the surface of the MgO grains or as much smaller particles (≤20 nm) probably located inside the matrix grains and epitaxial with it. The composition distribution of the large surface particles is fairly broad when the reduction was performed at 1100 and 1300 °C. In contrast, it is much narrower in the powder prepared by reduction at 1200 °C, although the particles are still low in Ni compared to the target composition.

Item Type:Article
Additional Information:Thanks to Royal Society of Chemistry editor. The definitive version is available at http://pubs.rsc.org The original PDF of the article can be found at Journal of Materials Chemistry website : http://dx.doi.org/10.1039/a809642b
HAL Id:hal-01102345
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - INPT (FRANCE)
Université de Toulouse > Université Paul Sabatier-Toulouse III - UPS (FRANCE)
Laboratory name:
Statistics:download
Deposited By: cirimat webmestre
Deposited On:25 Feb 2014 10:10

Repository Staff Only: item control page