Enhancement of microwave absorption performance of FeSiCr magnetic powder by dielectric polarization modulation

The Fe3O4@C@FeSiCr composite was successfully prepared by compounding flaky FeSiCr magnetic powder with an organo-metallic frameworks (MIL-88(Fe)), and then subjecting to carbonization heat treatment. The dielectric polarization characteristics is regulated by adjusting the heat treatment temperature. The absorbing performance is optimum when the carbonization heat treatment temperature is 700 degrees C, the minimum value of reflection loss (RLmin) is -35.71 dB at 5.68 GHz. The effective absorption bandwidth (RL <= -10 dB) of the composite material covers 4-16 GHz when the coating thickness is from 1.0 to 3.0 mm. This work provides an important value for the application of FeSi-based soft magnetic materials in the field of microwave absorption.