Engineering Dielectric Loss of FeCo/Polyvinylpyrrolidone Core‐Shell Nanochains@Graphene Oxide Composites with Excellent Microwave Absorbing Properties

Abstract

FeCo alloy nanoparticles, as a kind of material with high saturation magnetization, have attracted wide attention in electromagnetic (EM) wave research. However, its application as a wave‐absorbing material is limited by its poor magnetic anisotropy and antioxidant properties. Herein, novel FeCo/Polyvinylpyrrolidone core‐shell nanochains@graphene oxide (GO) composites are successfully fabricated with superior microwave‐absorbing properties. The composites perform excellently in absorbing EM wave, with a strong reflection loss (RL) of −40.94 dB at 14.25 GHz, covering from 10.95 to 15.85 GHz (RL < −10 dB) with a matching thickness of 2.0 mm. The superior absorption properties are mainly attributed to the cooperation between amorphous magnetic FeCo nanoparticles and graphene, which contribute to the magnetic and dielectric loss, respectively. Moreover, the FeCo/PVP core‐shell morphology enhances the interfacial relaxation and surface chemical stability of the FeCo nanochains. Thus, this work provides a template for the new‐designed and facile‐synthesized EM wave‐absorbing material.

1D Colloidal chains: recent progress from formation to emergent properties and applications

“…These materials can be in general non-conductive polymers such as PVP and poly(vinylidene fluoride) (PVDF), to enhance polarization losses. 645,701,[709][710][711] Conductive materials including carbon nanotubes, 648,712 carbon nanofibers, 296,642 graphene, 650,713 and polypyrrole, 714 are also commonly used to combine with 1D magnetic colloidal chains to improve their permeability-permittivity matching (Fig. 26b).…”

“…The wide and rapid spread of electronic devices is accompanied by electromagnetic wave pollution, which causes severe electromagnetic interference as well as potential health issues. Metal, 700,701 ferrites, 702 conductive polymers, 703 carbon materials, 704 and ceramics 646,705 have been introduced as radiation absorption materials based on their ability to generate magnetic and dielectric loss. 1D ferromagnets and ferrites are typical early stage prototypes to demonstrate that geometric anisotropy has profound influences on the effect of radiation absorption.…”

Lotus Leaf-Derived Gradient Hierarchical Porous C/MoS2 Morphology Genetic Composites with Wideband and Tunable Electromagnetic Absorption Performance

“…range of 2-18 GHz are evaluated on the basis of transmission and Debye theory, which can be depicted as Eqs. 5 and 6 [41]:…”

Corrosion-Resistant Graphene-Based Magnetic Composite Foams for Efficient Electromagnetic Absorption

“…Moreover, it is worth noting that other loss can be confirmed by the presence of the line tail in the curve of GN foam (Figure d). It can be identified as the conductive loss originated from interconnected conductive graphene network (Scheme b). − After being incorporated with the FePc hybrid, the plot of GN/FePc hybrid foam exhibits multiple Cole–Cole semicircles distinguished from GN foam. The corresponding relaxation processes might be caused by the interfacial polarization between the GN skeleton and FePc hybrid and FePc and Fe 3 O 4 in hybrids, being beneficial to the attenuation of microwave energy.…”