Controllable Fabrication of Fe3O4/ZnO Core–Shell Nanocomposites and Their Electromagnetic Wave Absorption Performance in the 2–18 GHz Frequency Range

Abstract

In this study, Fe3O4/ZnO core–shell nanocomposites were synthesized through a chemical method of coating the magnetic core (Fe3O4) with ZnO by co-precipitation of Fe3O4 with zinc acetate in a basic medium of ammonium hydroxide. The phase structure, morphology and electromagnetic parameters of the Fe3O4/ZnO core–shell nanocomposites were investigated. The results indicated that the concentration of the solvent was responsible for controlling the morphology of the composites, which further influenced their impedance matching and microwave absorption properties. Moreover, Fe3O4/ZnO nanocomposites exhibited an enhanced absorption capacity in comparison with the naked Fe3O4 nanospheres. Specifically, the minimum reflection loss value reached −50.79 dB at 4.38 GHz when the thickness was 4.5 mm. It is expected that the Fe3O4/ZnO core–shell structured nanocomposites could be a promising candidate as high-performance microwave absorbers.

Review of electromagnetic interference shielding materials fabricated by iron ingredients

“…Hitherto, a lot of studies have been performed on Fe-based core@shell nanostructures. For example, Fe 3 O 4 @ZnO core-shell, 142 ZnO-coated iron nanocapsules, 143 SnO-coated-Fe(Sn) nanocapsules, 77 Fe@Al 2 O 3 , 144 Fe 3 O 4 @SnO 2 double shells, 134 Fe@SiO 2 nanoakes, 145 spinel 148 reported the synergistic effect of magnetic loss and dielectric loss in the Fe/SnO 2 nanocapsules which enhanced its microwave absorption properties. They found two typical dielectric resonances at 3.8 and 16 GHz arising due to a synergistic effect of the Fe nanoparticles cores and SnO 2 shells.…”

“…Hitherto, a lot of studies have been performed on Fe-based core@shell nanostructures. For example, Fe 3 O 4 @ZnO core–shell, 142 ZnO-coated iron nanocapsules, 143 SnO-coated-Fe(Sn) nanocapsules, 77 Fe@Al 2 O 3 , 144 Fe 3 O 4 @SnO 2 double shells, 134 Fe@SiO 2 nanoflakes, 145 spinel Fe 3 O 4 @ TiO 2 , 146 Fe nanoparticles with amorphous Al 2 O 3 /FeO x composites shells, 147 and yolk–shell Fe 3 O 4 @ZrO 2 ( ref. 133 ) have been investigated as effective microwave absorbing materials.…”

Superior Microwave Absorption Properties Derived from the Unique 3D Porous Heterogeneous Structure of a CoS@Fe3O4@rGO Aerogel

“…According to reports in recent years, common wave-absorbing materials include ferrites [8], carbon nanomaterials [9], conductive polymers [10], and transition metal oxides [11]. Because of its low price, good stability, and high permeability, Fe 3 O 4 stands out from many other EMW-absorbing materials and has been widely studied [12][13][14][15][16][17]. With its unique nanostructure and good magnetic loss properties, Fe 3 O 4 shows great EMW absorption potential; however, defects such as easy corrosion, high density, and narrow absorption frequency band seriously limit its practical application.…”

3D-Printed Low-Cost Dielectric-Resonator-Based Ultra-Broadband Microwave Absorber Using Carbon-Loaded Acrylonitrile Butadiene Styrene Polymer

“…In addition, the CaCoTi ferrite composites [ 37 ], (Fe, Ni)/C nanocapsules [ 38 ], carbon-coated iron nanocapsules [ 39 ], Fe 3 O 4 /TiO 2 Core/Shell Nanotubes [ 40 ] and α-Fe 2 O 3 -filled carbon nanorods [ 41 ] are also investigated for EM wave absorption at different operating bands. Most recently, composite materials, such as graphene composite [ 42 ], α-Fe/Fe 3 C/Woodceramic nanocomposite [ 43 ] and Fe 3 O 4 /ZnO core-shell nanocomposite [ 44 ], are also studied. Besides, in recent years, the planar metasurface [ 45 ], materials with near-zero refractive index [ 46 ], emerging graphene [ 47 ], spoof surface plasmon polariton [ 48 , 49 , 50 ] and water [ 51 , 52 , 53 , 54 ] are also introduced in the design of a low-cost absorber with a broad operating bandwidth.…”