Nanophase BaFe₁₂O₁₉ synthesized from a nonaqueous microemulsion with Ba- and Fe-containing surfactants

Ultrafine BaFe₁₂O₁₉ with uniform particle size was synthesized from an alcohol-in-oil (nonaqueous) microemulsion system where the metal ions were supplied by the surfactant (metal di-2-ethylhexylsulfosuccinate) molecules themselves. A monodisperse, fine-grained precipitate (Ba-Fe oxalate) was ensured by the steric barrier provided by the surfactant monolayer, while the nonaqueous environment promoted stoichiometric coprecipitation. Pure BaFe₁₂O₁₉ was obtained by calcining the oxalate precursor at or above 950 °C. Structural and magnetic properties of the resulting ultrafine magnetic material are reported.