Magnetic properties of nanocomposites containing Fe-Ni or Fe dispersed in a Mn-Zn ferrite matrix

Composites have been prepared from Mn-Zn and Fe or [Fe.sub.25][Ni.sub.75] nanostructured powders, by melting in a planetary mill, compaction, and subsequent annealing. A solid state oxido-reduction reaction between iron and ferrite degrades the magnetic properties. On the other hand, Permalloy, which is more resistant to this reaction, results in soft magnetic nanocomposites which possess a magnetization higher than those of good ferrites. Index Terms--Composite media, ferrites, magnetic materials, powders.