Interface microstructure and electromagnetic properties of phosphorylated FeSiB@Fe3O4 amorphous soft magnetic composites via thermal decomposition
Runpeng Fu, Jia Xu, Jiayi He, Min Nie, Bang Zhou, Xin Liu, Haoran Chen, Hai Guo, Hongya Yu, Liu Hon, Guangze Han
Abstract
Herein, the phosphorylated FeSiB@Fe 3 O 4 amorphous soft magnetic composites (ASMCs) were designed and fabricated via powder metallurgy technology using high-temperature thermal decomposition. The influence of Fe 3 O 4 content on the microstructure, interface, and electromagnetic properties of phosphorylated FeSiB ASMCs was systematically investigated. Uniformly distributed Fe 3 O 4 magnetic nanoparticles (17.9 nm average size) with high saturation magnetization and low coercivity were synthesized, effectively filling powder gaps and enhancing resistivity from 0.585 Ω m to 1.187 Ω m, which mitigates magnetic dilution and reduces eddy current losses. Three-dimensional loss separation analysis confirms optimal Fe 3 O 4 addition decreases hysteresis, eddy current, and excess losses. However, excessive Fe 3 O 4 causes severe agglomeration, significantly increasing hysteresis loss. As a result, the phosphorylated FeSiB@Fe 3 O 4 ASMCs with 0.2 wt% Fe 3 O 4 nanoparticles achieve the lowest core loss of 118 kW/m 3 (at 100 kHz/50 mT) and high effective permeability of 65. This work provides a novel approach for designing high performance and ultralow loss SMCs for high frequency applications.