Superparamagnetic Fe3O4/MWCNTs heterostructures for high frequency microwave absorption. Issue 71 (14th July 2016)

• Record Type: Journal Article
• Authors: Yuan, Honglei; Xu, Yanling; Jia, Huanxia; Zhou, Shaomin
• Is Part Of: RSC advances. Volume 6:Issue 71(2016)
• Page Start: 67218
• Page End: 67225
• Publication Date: 2016-07-14
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra11610h
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Superparamagnetic Fe3 O4 nanocrystals anchored on multiwalled carbon nanotubes (MWCNTs) were fabricated using co-precipitating technique which nicely integrates the magnetic and dielectric components into a synergistic microwave absorber. Abstract : Superparamagnetic Fe3 O4 nanocrystals anchored on multiwalled carbon nanotubes (MWCNTs) were fabricated via a straightforward co-precipitating technique which nicely integrates the magnetic and dielectric components into a synergistic microwave absorber. A complex permeability analysis indicates that the resonance frequency of Fe3 O4 /MWCNTs heterostructures appears at 9.1 GHz relying on superparamagnetic relaxation, which is much higher than that of conventional Fe3 O4 ferromagnetic particles. As a result of the blue-shift of the resonance frequency, the Fe3 O4 /MWCNTs nanocomposites exhibit remarkably improved microwave absorption performances in a high frequency range (Ku-band). Moreover, combing the synergistic effect between ultra small Fe3 O4 nanocrystals and MWCNTs, the Fe3 O4 /MWCNTs hybrids exhibit a bandwidth of frequency less than −20 dB, almost covering the whole 2–18 GHz range by adjusting the absorber thickness. The results provide a new approach to enhance the resonance frequency break of the Snoek limit, which significantly optimizes microwave absorption ability for high frequency applications.