The influence of preparation methods on magnetic properties of Fe/SiO2 soft magnetic composites

Abstract

An analysis of several variants of the Fe/polymer/SiO2 composites in terms of the impact of iron powder particle shape (irregular, spherical), of the content (0.4-2.0 wt%), of the polymer type (shellac, thermoset SL450) and the method of its application as well as the effect of the preparation procedure of the composites (mixing and/or vacuum-pressure impregnation) on properties of electrical insulating layer (thickness and coherence), electrical resistivity and magnetic properties was carried out. It was found that the main governing factor of the microstructure formation is the shape, surface microgeometry of the iron particles and the insulator layer. These determine not only the uniformity of thickness and cohesion of the insulating layer of the applied polymer or its hybrid modification (polymer+SiO2 nanoparticles), but also the most suitable method of preparation in terms of the achieved values of electrical and magnetic properties of the composites.