Título

Preparation of nanoparticles of barium ferrite from precipitation in microemulsions

Autor

JOSE ANDRES MATUTES AQUINO

Nivel de Acceso

Acceso Abierto

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

Versión enviada

Formato

application/pdf

Idioma

Inglés

Repositorio Orígen

Fuente de Objetos Científicos Open Access

Descargas

755

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