Energy Losses in Composite Materials Based on Two Ferromagnets

We focused on the low and high induction loss separation in soft magnetic composites (SMC), which determine the regions of different predominant magnetization processes. These are the low induction losses which are related to domain wall displacements and the high induction losses related to magnetization vector rotation, domain wall annihilation, and nucleation. The composite samples prepared by replacing of Somaloy 700 (polycrystalline iron powder covered by insulating layer) with Vitrovac 6155 (amorphous co-based alloy) have been investigated. We found out that the porosity remained constant up to 5 wt.% of Vitrovac fraction, which led to slight improvement of magnetic properties of the resulting SMC-the maximum permeability increased and the magnetization process was confirmed to be realized to a greater extent by the processes of domain wall displacement, up to a higher magnetic induction. The higher inner demagnetizing fields caused by higher porosity in sample with 20 wt.% of Vitrovac resulted in lower mobility of domain walls, exhibiting by higher energy losses and lower maximum permeability.