| Type de publication : |
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Articles dans des revues avec comité de lecture |
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| Domaine : |
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| Titre : |
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Synthesis and characterization of core-shell structure silica-coated Fe29.5Ni70.5 nanoparticles |
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| Auteur(s) : |
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Mehdi Ammar 1, 2, Frédéric Mazaleyrat ( ) 1, 2, Jean-Pierre Bonnet 2, 3, Pierre Audebert 2, 3, Arnaud Brosseau 2, 3, G. Wang 4, Y. Champion 4 |
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| Laboratoire : |
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| Résumé : |
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In view of potential applications of magnetic particles in biomedicine and electromagnetic devices, we made use of the classical Stober method-base-catalyzed hydrolysis and condensation of tetraethoxysilane (TEOS)-to encapsulate FeNi nanoparticles within a silica shell. An original stirring system under high power ultrasound made it possible to disperse the otherwise agglomerated particles. Sonication guaranteed particles remained dispersed during the Stober synthesis and also improved the efficiency of the method. The coated particles are characterized by electron microscopy (TEM) and spectroscopy (EDX) showing a core-shell structure with a uniform layer of silica. Silica coating does not affect the core magnetic properties. Indeed, all samples are ferromagnetic at 77 K and room temperature and the Curie point remains unchanged. Only the coercive force shows an unexpected non-monotonic dependence on silica layer thickness. |
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Langue du texte
intégral : |
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Anglais |
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| Journal : |
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| Nanotechnology |
| Publisher |
Institute of Physics: Hybrid Open Access |
| ISSN |
0957-4484 (eISSN : 1361-6528) |
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| Audience : |
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internationale |
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| Date de publication : |
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2007 |
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| Volume : |
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18 |
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| Numéro : |
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28 |
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| Page, identifiant, ... : |
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285606 |
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| Mots Clés : |
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MAGNETIC-PROPERTIES – PARTICLES – NANOCOMPOSITES – FE – ALLOYS – FILMS – SIZE |
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