Hydrothermal synthesis flaky FeSiAl/Mn3O4 composites with enhanced Ku-band microwave absorption

Manganese oxide was fabricated on the surfaces of flaky FeSiAl alloys using hydrothermal method to construct heterogeneous compositions with nanoscale architectures. The crystal structure, morphology, surface chemical states and microwave absorption properties of the composites were then investigated. We found that the high-temperature hydrothermal growth of Mn3O4 did not destroy the crystal structure of the FeSiAl alloy. The Mn3O4 particles grew closely to the surface of the FeSiAl alloy flakes and the adjustable morphology resulted in nano-sheets or nano-particles, which were affected by the loading content of Mn3O4. The attenuation performance of the composites decreased with increasing Mn3O4 load at low frequencies, and vice versa at high frequencies, due to the enhanced dielectric loss. Therefore, at 5 wt.% Mn3O4 content, the minimum reflection loss value of the flaky FeSiAl composites was - 46 dB at 16.5 GHz and 1.05 mm, and the promising results boosted the applications of Ku-band microwave absorbers.

Automated summary

In this study, manganese oxide was fabricated on the surfaces of flaky FeSiAl alloys using hydrothermal method to construct heterogeneous compositions with nanoscale architectures. The research found that the crystal structure of the FeSiAl alloy was not destroyed during the high-temperature hydrothermal growth of Mn3O4. The adjustable morphology of the composites, affected by the loading content of Mn3O4, resulted in nano-sheets or nano-particles. The microwave absorption properties of the composites were also investigated.