Ni–Co–Cu/Carbon Nanocomposites: Synthesis, Characterization and Magnetic Properties

The advanced two-stage synthesis method of the Ni–Co–Cu/carbon magnetic nanocomposite as promising material for electromagnetic wave absorption was proposed. Synthesis condition for consolidated Ni–Co–Cu solid solution nanoparticles with an average size of less than 100[Formula: see text]nm uniformly distributed in the carbon matrix was discussed. The effect of different pyrolysis temperatures (500–700∘C) and Cu concentration in the precursor (from 5 to 30[Formula: see text]wt.%) on the microstructure of Ni–Co–Cu nanocomposite, its particle size and magnetic properties was investigated by of XRD, TEM and magnetic hysteresis. The saturation magnetization and remanence showed non-monotonic dependences on Cu concentration in samples. The coercive force was varied from 110 to 177[Formula: see text]Oe depending on Cu content in nanoparticles. The correlation between magnetic properties and microstructure of Ni–Co–Cu/carbon nanocomposites was discussed assuming the transition of nanoparticles to superparamagnetic and single-domain states depending on their sizes.