Atomic-Scale Layer-by-Layer Deposition of Fe SiAl@ZnO@Al2O3 Hybrid with Threshold Anti-Corrosion and Ultra-High Microwave Absorption Properties in Low-Frequency Bands

Developing highly efficient magnetic microwave absorbers(MAs) is crucial,and yet challenging for anti-corrosion properties in extremely humid and salt-induced foggy environments.Herein,a dual-oxide shell of ZnO/AlOas a robust barrier to FeSiAl core is introduced to mitigate corrosion resistance.The FeSiAl@ZnO@AlOlayer by layer hybrid structure is realized with atomic-scale precision through the atomic layer deposition technique.Owing to the unique hybrid structure,the FeSiAl@ZnO@AlOexhibits record-high microwave absorbing performance in low-frequency bands covering L and S bands with a minimum reflection loss(RL) of-50.6 dB at 3.4 GHz.Compared with pure FeSiAl(RLof-13.5 dB,a bandwidth of0.5 GHz),the RLvalue and effective bandwidth of this designed novel absorber increased up to ～3.7 and ～3 times,respectively.Furthermore,the inert ceramic dual-shells have improved 9.0 times the anti-corrosion property of FeSiAl core by multistage barriers towards corrosive medium and obstruction of the electric circuit.This is attributed to the large charge transfer resistance,increased impedance modulus |Z|,and frequency time constant of FeSiAl@ZnO@AlO.The research demonstrates a promising platform toward the design of next-generation MAs with improved anti-corrosion properties.