Título
Preparation of nanoparticles of barium ferrite from precipitation in microemulsions
Autor
JOSE ANDRES MATUTES AQUINO
Nivel de Acceso
Acceso Abierto
Materias
Resumen o descripción
Magnetic nanoparticles of barium ferrite (BaFe12O19) have been synthesized using a microemulsion mediated process.
The aqueous cores of water-in-oil microemulsions were used as constrained microreactors for the precipitation
of precursor carbonate and hydroxide particles. These precursors were then calcined at 925C for 12 h, during
which time they were transformed to the hexagonal ferrite. The pH of reaction was varied between 5 and 12, and
it was found that the fraction of non-magnetic hematite (-Fe2O3) in the particles varied with the pH of reaction,
thus affecting the magnetic properties of the particles. The same precursor particles were also prepared by bulk
co-precipitation reaction for comparison. It was found that the microemulsion derived nanoparticles of barium ferrite
had both higher intrinsic coercivity (Hc) and saturation magnetization (s) than the particles derived from bulk
co-precipitation. Particles were analyzed by electron microscopy, X-ray diffraction, differential thermal analysis
(DTA), thermogravimetric analysis (TGA) and vibrating sample magnetometry (VSM). The best barium ferrite
particles produced by the microemulsion synthesis method yielded an intrinsic coercivity of 4310 Oe and a saturation
magnetization of 60.48 emu/g.
Fecha de publicación
1999
Tipo de publicación
Artículo
Versión de la publicación
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Formato
application/pdf
Idioma
Inglés
Repositorio Orígen
Fuente de Objetos Científicos Open Access
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