High-performance core-shell-type FeSiCr@MnZn soft magnetic composites for high-frequency applications

Soft magnetic composites (SMCs) are widespread utilized in modern electronic components such as inductors, transformers, and electrical motors. They have attracted much attention for use in high-and ultra-high-frequency applications for their advantages over conventional ferrite core materials. However, to make SMCs meet the requirements of high-frequency, miniature and lightweight electrical systems, it is necessary to suppress core losses P-cv and obtain excellent frequency characteristics, which is a tremendous challenge. Herein, we improve the high-frequency characteristics of core losses P-cv by coating FeSiCr powders with different concentrations of MnZn ferrites (0.0-10.0 wt%). The microstructure, magnetic, electric and core losses characteristics of the FeSiCr@MnZn soft magnetic composites are analyzed in detail. A remarkable coating quality is revealed by energy-dispersive X-ray spectroscopy mapping. The core losses P-cv (at 25-800 kHz, 10 mT and 25 degrees C) are separated into hysteresis losses P-h and eddy current losses P-e. With increasing MnZn ferrite concentration, P-cv, P-h and P-e present an initial decrease and subsequent increase. SMCs with 4.0 wt% MnZn ferrites exhibit the best electromagnetic properties in terms of saturated magnetization M-s (149 emu/g), effective permeability mu(e) (48 at 10 kHz-1 MHz), resistivity rho (8.46 x 10(3)Omega m), and core losses P-cv (45 mW/cm(3) at 800 kHz, 10 mT and 25 degrees C). These FeSiCr@MnZn SMCs have outstanding electromagnetic performance, giving them great potential for application to power devices and components. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Soft magnetic composites (SMCs) are widely used in electronic components, and their high-frequency characteristics can be improved by coating FeSiCr powders with different concentrations of MnZn ferrites. In the experiment, SMCs with 4.0 wt% MnZn ferrites showed the best electromagnetic properties.