Effect of ferrite content and temperature on the magnetic properties of Fe@SiO2@Mn-Zn-ferrite SMC materials.

Building upon previous studies that have reported promising soft magnetic performance of Fe/Mn-Zn ferrite-based soft magnetic composites (SMCs), the present work focuses on effect of ferrite content and temperature on the magnetic properties of Fe@SiO2@Mn-Zn-ferrite SMC materials. A series of five Fe/SiO/Mn-Zn SMCs were fabricated using powder metallurgy and compaction. Structural characterization and detailed magnetic property measurements were performed to assess their soft magnetic behavior. The composites were synthesized with varying mass ratios of Fe/SiO to Mn-Zn ferrite powders, specifically 100:0, 99:1, 98:2, 97:3, 96:4, and 90:10. Key magnetic parameters evaluated included complex permeability, maximum permeability, total core loss, and its components: hysteresis loss, classical eddy current loss, and excess loss. Furthermore, frequency-temperature loss maps were constructed to evaluate the magnetic performance under different thermal and frequency conditions. Considering the specific operational frequency requirements, the optimal ferrite concentration within the composite was determined to be in the range of 2-4%. The investigation highlighted the influence of excess magnetic losses, especially within the medium-frequency range. The modified composites demonstrated improved thermal stability, retaining favorable soft magnetic properties after thermal cycling up to 200 °C. These results highlight the potential applicability of the developed composites in environments demanding reliable high-temperature magnetic performance.