Influence of the Ferromagnetic Component on the Magnetic Properties of Polymer-Matrix Soft Magnetic Composites

Abstract The paper presents the study of the influence of different ferromagnetic powders on magnetic properties of polymer-matrix soft magnetic composites. Samples were prepared from pure Fe and Permalloy powders with the same amount of resin and by the same technological process. The coercivity, the real part of complex permeability, saturation magnetic polarization, hysteresis loops and total energy losses and their components were investigated. It was found that the coercivity, DC losses, classical losses, excess losses and thus the total energy losses of composites depended on intrinsic magnetic properties and/or on the size and shape of ferromagnetic powder particles, while the permeability of composites was affected predominantly by inner demagnetizing fields due to the insulation. The numbers of moving domain walls involved in magnetization reversal were analyzed in connection with the magnetic properties.