Low Temperature Solution Synthesis and Microwave Absorption Properties of Multiwalled Carbon Nanotubes/Fe 3 O 4 Composit
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Low Temperature Solution Synthesis and Microwave Absorption Properties of Multiwalled Carbon Nanotubes/Fe3 O4 Composites Q.C. Liu · J.M. Dai · Z.F. Zi · A.B. Pang · Q.Z. Liu · D.J. Wu · Y.P. Sun
Received: 4 June 2012 / Accepted: 13 September 2012 / Published online: 27 September 2012 © Springer Science+Business Media New York 2012
Abstract Multiwalled carbon nanotubes (MWCNTs)/Fe3 O4 nanocomposites were synthesized via a simple low temperature solution method. The phase structures and morphologies of the composite were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the Fe3 O4 spheres of about 150 nm were linked with MWCNTs. The microwave absorption properties of the MWCNTs/Fe3 O4 nanocomposites were measured by vector network analysis (VNA). A wide region of microwave absorption was achieved due to dual magnetic and dielectric losses. When the matching thickness is 2 mm, the reflection loss (RL) of the sample exceeding −10 dB was obtained at the frequency range of 9.9–12.4 GHz, with an optimal RL of −29.8 dB at 11.04 GHz. A possible mechanism of the improved microwave absorption properties of the composites was discussed. Keywords Composite materials · Chemical synthesis · Microwave absorption
1 Introduction In recent years, the microwave absorption materials have attracted much attention because of their potential applications in wireless data communication, local area network, satellite television and self-concealing [1]. Therefore, the demands to develop Q.C. Liu · J.M. Dai () · Z.F. Zi · D.J. Wu · Y.P. Sun Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, P.R. China e-mail: [email protected] Q.C. Liu · Z.F. Zi · A.B. Pang · Q.Z. Liu School of Physics and Electronics Information, Huaibei Normal University, Huaibei, Anhui 235000, P.R. China
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J Low Temp Phys (2013) 170:261–267
electromagnetic absorbents with light weight and strong absorption over a broad frequency are ever increasing [2]. Traditional materials, such as carbon black, graphite and ferrite, cannot reach the standards because of their relatively low absorbing abilities [3]. As unilateral dielectric loss or magnetic loss materials are hard to attain impedance match condition, it still remains a great challenge to prepare new types of materials with excellent electromagnetic absorbing properties [4]. Multiwalled carbon nanotubes (MWCNTs) have attracted most interest in the microwave absorption and the applications in the electromagnetic interference shielding owing to their high complex permittivity, low density, and unique electrical transport behaviors [5]. However, the pure MWCNTs contribute to electromagnetic wave energy absorption mostly because of the dielectric loss. The dielectric permittivity and magnetic permeability are out of balance. Therefore, most of the electromagnetic wave radiation incident on MWCNTs is reflected, rather than absorbed. To optimize the performan
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