Bimetallic Oxalate Rod-Derived NiFe/Fe₃O₄@C Composites with Tunable Magneto-dielectric Properties for High-Performance Microwave Absorption

Abstract

Development of microwave absorbing materials (MAMs) with strong and broadband absorption at thin thickness to address electromagnetic radiation and interference is still a huge challenge. Herein, bimetallic oxalate rod-derived NiFe/Fe 3 O 4 @ carbon rods (NiFe/Fe 3 O 4 @CRs) composites as MAMs were structured by a facile coprecipitation followed by a carbothermal reduction process. The multiple interfaces existing in the composite can enhance the dielectric loss, and the rod structure can decrease the density of the NiFe/Fe 3 O 4 @carbon. The composite shows excellent microwave absorption properties. The minimum reflection loss (RL) value reaches −44.9 dB at an absorber thickness of 2.2 mm, and the efficient absorption bandwidth (RL ≤ −10 dB) is 5.1 GHz with a small thickness of only 1.58 mm. The high-performance microwave absorption mechanisms of the as-prepared NiFe/Fe 3 O 4 @CRs composites were mainly attributed to the synergistic of impedance matching, magnetic loss, and electrical loss. This work opens up a new prospect for developing high-performance microwave absorbers.

A coral-like nano-PCF composite as a broad-bandwidth microwave absorber

“…With the advancement of modern wireless communication, in particular the increasing demand for 5G technology, different types of microwave absorbers (MWAs) have been developed to shield against the broadening bandwidth of electromagnetic interference (EMI) in the microwave frequency range 2-18 GHz. 1,2 A magneto-dielectric synergistic microwave absorber formed by coating polyaniline (PANI) on the surface of CoFe 2 O 4 (CFO), has demonstrated excellent microwave absorption due to the dielectric loss of PANI synergized with the great magnetic loss of CFO, 3,4 in which PANI and CFO consumed the electric and magnetic components of the microwaves, respectively, and the microwave absorption was enhanced when they were synergized with each other. 5 Praveena et al 6 synthesized a PCF composite to shield against EMI.…”

“…A magneto-dielectric synergistic microwave absorber formed by coating polyaniline (PANI) on the surface of CoFe 2 O 4 (CFO), has demonstrated excellent microwave absorption due to the dielectric loss of PANI synergized with the great magnetic loss of CFO, 3,4 in which PANI and CFO consumed the electric and magnetic components of the microwaves, respectively, and the microwave absorption was enhanced when they were synergized with each other. 5 Praveena et al 6 synthesized a PCF composite to shield against EMI.…”

Lightweight and Thin with High-Frequency Performance Microwave Absorbing Heterostructure Carbon Derived from Ashoka-leafs Ash

“…These composites can be tailored to have the desired electromagnetic properties for e cient microwave absorption. By adjusting the composition and structure of heterostructure carbon ash, you can tune its electrical conductivity and magnetic properties to match the frequency of the incident microwaves [9], [10], [11], [12], [13], [14], [15], [16]. Designing the heterostructure carbon ash with multiple absorption peaks across a wide range of microwave frequencies can improve its overall performance as a microwave absorber.…”

Constructing Multiphase‐Induced Interfacial Polarization to Surpass Defect‐Induced Polarization in Multielement Sulfide Absorbers

“…Inspired by conventional interface engineering, [18][19][20][21][22][23][24] a novel multiphase interfacial engineering provides a possible approach to implement the above research framework. Specifically, the stronger reaction activity provides certain atoms with significant chemical reaction advantages, leading to the preferential formation of specific chemical components during the reaction process, and impeding the attempts of less activity atoms to substitute within the original lattice.…”