Optimized electromagnetic absorbing performances of FeSiAl/phosphate flakes

Suppressed conductive loss of flower-like NiCo2O4-wrapped flaky FeSiAl for excellent low-frequency microwave absorption

“…For the single flaky FeSiAl sample, a large ε r of 57.84 − j15.95 was measured at 2.0 GHz, and it decreased decreases with increasing frequency, accompanied by wellobserved multi-peak characteristics. Such multi-peak phenomena can be mainly attributed to the co-existence of multiple polarisation mechanisms under the action of external EM fields [34]. Comparatively, ε r of NiCo 2 O 4 @flaky FeSiAl at 2.0 GHz reached 41.43 − j9.94 and exhibited a similar frequency-dependent variation, which implied that surfacecoated NiCo 2 O 4 can effectively reduce value of ε r .…”

Fabrication and Microwave Absorption Properties of FeSiAl@PANI Composites

“…8,9 However, the drawbacks of narrow absorption bandwidth, high conductivity, and insufficient interfacial polarization limit their practical application in many fields. 10,11 Previous studies have shown that the dielectric constant of FeSiAl can be reduced, and good impedance matching can be obtained by surface oxidization and cladding insulating layers such as SiO 2 and Al 2 O 3.…”

“…Ferrite absorber has low permeability and dielectric constant in L and S frequency bands, which requires a large filling ratio and thickness to realize the effect of wave absorption . While FeSiAl alloys have high starting permeability and saturation magnetic induction strength, which are favorable for obtaining lower thickness and higher reflection loss, and thus have gained widespread attention. , However, the drawbacks of narrow absorption bandwidth, high conductivity, and insufficient interfacial polarization limit their practical application in many fields. , Previous studies have shown that the dielectric constant of FeSiAl can be reduced, and good impedance matching can be obtained by surface oxidization and cladding insulating layers such as SiO 2 and Al 2 O 3. − Meanwhile, compounding with carbon-based materials can introduce dielectric losses and enhance the electromagnetic loss capability of the materials. , Therefore, excellent FeSiAl-based wave-absorbing materials are usually obtained by adjusting the particle size, surface morphology, chemical composition, and compounding with other materials. − …”