Morphology and magnetic properties of FeCo particles synthesized with different compositions of Co and Fe through co-precipitation, flux treatment, and reduction

FeCo alloy particles with Co to Fe compositions ranging from molar ratios of 0:1-1:1 in a precursor were synthesized through co-precipitation, flux treatment, and reduction. By adding Co2+ to Fe ions, particle size was remarkably reduced to 10-50 nm from 50 to 250 nm of Fe particles. The lattice parameter calculated from the (1 1 0) peak of the (bcc) structure decreased from 0.2870 nm in Fe particles to 0.2854 nm in FeCo particles. The coercive force increased with increasing Co/Fe composition ratio, showing a value of approximately 80 kA/m at the Co/Fe composition ratio of 1.0, at which the lattice parameter corresponded to a composition of approximately Fe62Co38. A maximum saturation magnetization of approximately 160 Am-2/kg was obtained at a Co/Fe composition ratio of around 0.2-0.5.