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

Abstract

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/Al2O3 as a robust barrier to FeSiAl core is introduced to mitigate corrosion resistance. The FeSiAl@ZnO@Al2O3 layer 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@Al2O3 exhibits record-high microwave absorbing performance in low-frequency bands covering L and S bands with a minimum reflection loss (RLmin) of -50.6 dB at 3.4 GHz. Compared with pure FeSiAl (RLmin of -13.5 dB, a bandwidth of 0.5 GHz), the RLmin value 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|0.01 Hz, and frequency time constant of FeSiAl@ZnO@Al2O3. The research demonstrates a promising platform toward the design of next-generation MAs with improved anti-corrosion properties.

Oxygen Vacancy‐Induced Dielectric Polarization Prevails in the Electromagnetic Wave‐Absorbing Mechanism for Mn‐Based MOFs‐Derived Composites

“…[22][23][24] Among the diverse magnetic-based absorbers, Co-and Ni-based composites have demonstrated remarkable EM attenuation potential owing to their high saturation magnetization and strong anisotropy field. [25][26][27][28] Significantly, the synergistic mechanism of Co and Ni metal atoms in the multifaceted MOFs-derived species is well elucidated owing to their well-defined atomic structure, which provides an essential material platform for the accurate investigation of the effect of heteroatoms and interfaces on EMA performance.…”

Synergistic Polarization Loss of MoS2‐Based Multiphase Solid Solution for Electromagnetic Wave Absorption

“…The EMW absorption mechanism was analyzed on the basic of dielectric (tan δ ε ) and magnetic loss tangent (tan δ μ ) values first (Figure S10, Supporting Information). [ 36 ] It can be generalized that better absorption performance always accompanied with higher tan δ ε , indicating that the EMW absorption was mainly attributed to the dielectric loss. [ 37 ]…”

“…The EMW absorption mechanism was analyzed on the basic of dielectric (tanδ ε ) and magnetic loss tangent (tanδμ) values first (Figure S10, Supporting Information). [36] It can be generalized that better absorption performance always accompanied with higher tanδ ε , indicating that the EMW absorption was mainly attributed to the dielectric loss. [37] In this case, three kinds of heterogeneous structure models can be built to analyze corresponding polarization performance according to traditional polarization theory.…”

Identification of the Intrinsic Dielectric Properties of Metal Single Atoms for Electromagnetic Wave Absorption

“…5 i) and is thus expected to have optimal EMW absorption properties. The EMW absorption performance of the 3D M–N x Cs and 3D NC were evaluated in terms of the reflection loss ( R L ) based on the transmission line theory [ 38 , 39 ]. Figure 7 a–f shows the R L – f curves and the corresponding 3D plots of the 3D M–N x Cs and 3D NC with a thickness of 1.0–5.0 mm over the 2–18 GHz range.…”