Regulation of magnetic and electrical performances in core-shell-structured FeSiCr@BaTiO3 soft magnetic composites

Soft magnetic composites (SMCs) are extensively used for designing and manufacturing high-performance electronic devices, such as inductors, filters, mutual inductors and chokes, owing to their high effective permeability ( μ e ) and stable magnetic properties . However, the production of SMCs that meet the demands of high resistivity, high effective permeability ( μ e ), and low core losses ( P cv ), which are required for high-frequency miniaturized electronic systems, is challenging. In this study, we improve the electromagnetic performance of SMCs by coating FeSiCr metal particles with BaTiO 3 dielectric ceramic powder at various concentrations (0.00–3.75 wt%). The micro-morphological, static magnetic, resistivity ( ρ ), and core loss ( P cv ) properties of FeSiCr@BaTiO 3 SMCs are comprehensively investigated. Energy dispersive spectroscopy elemental distribution mapping is used to confirm the formation of core-shell structures with excellent coating quality. With an increase in the BaTiO 3 dielectric powder content, the core losses, P cv (at 800 kHz, 10 mT and 25 °C), initially decrease and subsequently increase, and comprise hysteresis losses ( P h ) and eddy current losses ( P e ). Moreover, owing to the introduction of the non-magnetic-phase BaTiO 3 powder, hysteresis losses increase monotonically, whereas eddy current losses exhibit the opposite trend. The FeSiCr@BaTiO 3 SMCs with 2.25 wt% BaTiO 3 dielectric ceramic powder exhibit outstanding comprehensive electromagnetic properties with an effective permeability of μ e = 48, saturated magnetization of M s = 115 emu/g, core losses of P cv = 42 mW/cm 3 (at 800 kHz, 10 mT and 25 °C), and resistivity of ρ  = 2.74 × 10 5 Ω∙m. These state-of-the-art FeSiCr@BaTiO 3 SMCs present considerable potential for application in high-performance power devices and components.