Tunable Impedance of Cobalt Loaded Carbon for Wide‐Range Electromagnetic Wave Absorption

Impedance matching modulation of the electromagnetic wave (EMW) absorbers toward broad effective absorption bandwidth (EAB) is the ultimate aim in EMW attenuation applications. Here, a Joule heating strategy is reported for preparation of the Co‐loaded carbon (Co/C) absorber with tunable impedance c...

Full description

Saved in:
Bibliographic Details
Published in:Small (Weinheim an der Bergstrasse, Germany) Germany), 2024-06, Vol.20 (24), p.e2308970-n/a
Main Authors: Wang, Xiaonong, Wang, Zhongliao, Xi, Dawei, Li, Jiayi, Li, Xiaoxia, Bai, Xiujun, Wang, Bin, Low, Jingxiang, Xiong, Yujie
Format: Article
Language:English
Subjects:
Absorbers
Absorption
Attenuation
Carbon
carbon material
Dielectric loss
Electromagnetic losses
Electromagnetic radiation
electromagnetic wave absorption
Graphitization
Impedance matching
Ohmic dissipation
Resistance heating
single‐atom
tunable band adsorption
ultrafine Co nanocrystal
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Impedance matching modulation of the electromagnetic wave (EMW) absorbers toward broad effective absorption bandwidth (EAB) is the ultimate aim in EMW attenuation applications. Here, a Joule heating strategy is reported for preparation of the Co‐loaded carbon (Co/C) absorber with tunable impedance characteristics. Typically, the size of the Co can be regulated to range from single‐atoms to clusters, and to nanocrystals. The varied sizes of the Co combined with different graphitization degrees of carbon can result in different relative input impedances and electromagnetic loss, leading to the tunable EMW absorption properties of the Co/C absorber. By meticulously coalescing the different prepared Co/C, the working frequency can be easily tuned, covering Ku, X, and C bands. Furthermore, the Co/C demonstrates a high EMW attenuation due to its unique dielectric loss capability and magnetic loss characteristics. The abundant interfaces of Co/C can also contribute to the enhanced interfacial polarization for improving EMW attenuation. This work demonstrates the importance of optimizing the metal and carbon interaction to the impedance matching toward wide EAB of the EMW absorbers. Carbon thermal shock method is employed to prepare Co/C composites, with Co size changing from single‐atom (Co/C‐600) to clusters (Co/C‐900), and to nanoparticles (Co/C‐900). By meticulously coalescing the different prepared Co/C, the working frequency can be easily tuned, covering Ku, X and C bands.
ISSN:1613-6810
1613-6829
DOI:10.1002/smll.202308970