Soft magnetic properties enhancement of FeGaB composites through alumina lamination and its mechanism

Better soft magnetic properties of magnetic thin films are needed as micro-electromechanical systems electromagnetic devices become high-frequency, miniaturized, and integrated. Multilayer magnetic composites outperform single-layer materials in performance and flexibility, attracting interest. However, lamination’s effect on the soft magnetic properties of magnetic composites remains unclear. This study created a Comsol finite-element simulation model of the magnetic film to evaluate how lamination affects the eddy current suppression rate (SR) and magnetostriction performance reduction rate (RR). In addition, incorporating the experimental findings related to the soft magnetic properties, the magnetic composite material had been effectively developed: after inserting ten layers of 5 nm alumina film, the eddy current SR reached 92.8%, while the magnetostriction RR and coercive force were found to be merely 7.1% and 2 × 79.6 A/m, respectively. Furthermore, an investigation of the microscopic mechanism behind the impact of lamination on the properties of the magnetic film is also being addressed. It is found that the substrate and thickness effect simultaneously determine the properties of the single-layer magnetic film. In addition, the complex interlayer coupling effect between the isolated magnetic films is another critical factor affecting the soft magnetic properties of the magnetic composites. This study provides an optimal design approach for magnetic composite materials and clarifies the internal effect mechanism to improve the soft magnetic properties of those materials. The findings offer guidance for the application of high-frequency magnetic devices.