Calculation of High Frequency Complex Permeability of Carbonyl Iron Flakes in a Nomagnetic Matrix

The carbonyl iron flakes are fabricated by high-energy ball milling. The effective permeability is measured and calculated for the composite consisting of flakes embedded in a nonmagnetic matrix. The magnetic flakes with a shape anisotropy and random spatial distribution of normal direction areconsidered to calculate the complex permeability of magnetic flake materials. Its analytical model is derived from the Landau--Lifshitz--Gilbert equation and Bruggeman's effective medium theory. The calculated results agree well with the experiment.