Microwave absorption performance of Fe@Fe 4 N/amorphous carbon submicron fibers: critical role of the interface
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Microwave absorption performance of Fe@Fe4N/ amorphous carbon submicron fibers: critical role of the interface Qi Zheng1, Meijie Yu1,* YouYong Dai2 1 2
, Xueping Gao1, Yanjun Wang1, Ze Zhang1, Haiping Zhou1, and
College of Materials Science and Engineering, Shandong University, Jinan 250061, China College of Physics, Shandong University, Jinan 250100, China
Received: 14 April 2020
ABSTRACT
Accepted: 30 August 2020
Two kinds of Fe/amorphous carbon (a-C) submicron fibers were prepared by electrospinning using polyvinylpyrrolidone (PVP) and polyacrylonitrile (PAN) as precursor polymer, followed by carbonization under the same conditions. Contributed to the different reaction mechanisms during the annealing process, different phases namely graphite carbon (g-C) and Fe4N formed at the interface between the Fe nanoparticles and the a-C matrix. Electromagnetic absorption properties have shown that the Fe@Fe4N submicron fibers have superior absorption performance than the Fe@g-C ones. The minimal reflection loss (RL) value of the former is - 39.8 dB at 5.4 GHz with the absorber thickness of 5.0 mm, and the effective absorption bandwidth (RL B - 10 dB) can reach 5.0 GHz when the absorber thickness is 2.5 mm. By contrast, the Fe@g-C submicron fibers have little absorption. The attenuation constant, impedance matching coefficient, complex permittivity and complex permeability were investigated in detail. The microstructure and composition were explored various superior tools. The results revealed that the interface Fe4N has a critical role in affecting the magnetic loss and dielectric loss, which brings better impedance matching and relatively low dielectric loss. Therefore, the Fe@Fe4N submicron fibers have excellent microwave absorbing properties.
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Springer Science+Business
Media, LLC, part of Springer Nature 2020
Handling Editor: Dale Huber.
Address correspondence to E-mail: [email protected]
https://doi.org/10.1007/s10853-020-05189-y
J Mater Sci
GRAPHIC ABSTRACT
Introduction Following the relentless march of electronic technology in daily life and the requirements for military secrecy in recent years, microwave absorption materials (MAM) have been attached more importance for eliminating adverse electromagnetic waves [1–4]. According to the dissipation mechanism, the MAMs consist of two kinds: dielectric loss materials and magnetic loss materials. Fe, Co, Ni and their oxides are widely studied as magnetic loss materials because of their strong absorbing properties [5–8]. However, their high densities, narrow bandwidth and skin effect limit their further application [9]. Dielectric loss materials including graphene, carbon black, carbon fibers, mesoporous carbon, carbon nanotubes, ceramics, etc., are often used as lightweight absorbers [10–13]. However, single-component MAMs with
poor impedance matching cannot achieve an ideal absorption performance, which hinders their practical applications [14, 15]. Thus, more focal points have been transferred into the complex MAMs consisted with dielectric loss ma
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