Permeability Estimations of SMC Material Particles

In this study, we estimate the locally defined permeability of the magnetizing particles in a soft magnetic composite (SMC) material whose effective permeability, observed by macroscopic measurements, is known. This procedure is repeated for a wide range of geometries whose electrical insulation layer thicknesses between the magnetizing particles are altered. It is shown that even if the effective permeability of the material is known by some measurement, the permeabilities of the individual particles cannot be immediately determined but remain heavily dependent on the thicknesses of the insulation films. This dependence is quantified. It is shown that when using periodic geometries to imitate SMC materials, one also has to use higher local permeabilities for the magnetizing particles or thinner insulations between the particles compared with the situation where randomized structures are used in order to obtain the effective permeability determined by measurements.