Microwave Magnetic Properties and Natural Resonance of ε-Co Nanoparticles

Owing to the novel crystal structure, ε-Co nanoparticles with an average diameter of 12 nm are synthesized and the microwave magnetic properties of the epoxy resin composite with 50 vol% εCo particles are measured in the frequency range 0.1-7 GHz. The experimental resonance frequency (4.7 GHz) matches well with the values obtained by the theoretical calculation with the Kittel equation and fitting the experimental permeability dispersion curve via the Landau-Lifshitz equation. Hence the resonance peak is attributed to natural resonance mode. This work is believed to be beneficial for further understanding microwave applications of the novel ε-Co nanoparticles.