Submicron carbonyl iron particles as an efficient microwave absorber in the low frequency band

Abstract The microwave properties of spherical carbonyl iron particles with submicron- and micron-sizes are measured and calculated. In contrast to the micron size particles, the submicron size particles have higher permeability and better microwave absorbing performance in the low frequency band. According to the skin-effect criterion, the skin effect is a crucial mechanism in the micron and submicron size and it leads to a large damping factor. By using the Landau–Lifshitz–Gilbert equation and the theory of skin depth, we simulate the resonance peak of spherical particles with different sizes. Our theory simulation agrees well with the experimental data.