Investigation on microwave dielectric behavior of flaky carbonyl iron composites
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The corresponding mechanism of high complex permittivity for micro flaky Fe-filled composites was still not apparent. In this letter, the dielectric behaviors of flaky carbonyl iron/epoxy resin composites within 2–18 GHz were studied experimentally and theoretically. Results show that an obvious increase both in real and imaginary part of permittivity can be observed as the volume fractions of FCI is up to the percolation threshold. Considering the influence of conduction current, a revised Debye model of permittivity has been proposed to reveal the mechanism of dielectric behavior in composites. The best fitting result demonstrate that conduction loss played an important role in increasing the permittivity after percolation. Fe3O4 was used as encapsulated shell on surface of the FCI to control the conduction and enhance the percolation threshold, resulting in better microwave absorption from better balance between the complex permittivity and permeability.
This work was supported by the National Key Research and Development Program of China (No. 2017YFA0204600), and the Fundamental Research Funds for the Central Universities of Central South University (No. 2017zzts064) .
- 2.Z.Y. Zhang, X.X. Liu, H.F. Zhang, E. Li, Electromagnetic and microwave absorption properties of carbon fibers coated with carbonyl iron. J. Mater. Sci.: Mater. Electron. 26(9), 6518–6525 (2015)Google Scholar
- 3.J. Zhang, P. Xiao, W. Zhou, W. Hong, H. Luo, Preparation and microwave absorbing properties of carbon fibers/epoxy composites with grid structure. J. Mater. Sci.: Mater. Electron. 26(2), 651–658 (2015)Google Scholar
- 6.X. Zhang, W.F. Zhu, W.D. Zhang, S.R. Zheng, S.H. Qi, Preparation of TiO2/Fe3O4/CF composites for enhanced microwave absorbing performance. J. Mater. Sci.: Mater. Electron. 29(6), 1–9 (2018)Google Scholar
- 8.P.C. Ji, G.Z. Xie, N.Y. Xie, J. Li, J.W. Chen, R.Q. Xu, J. Chen, Fabrication and microwave absorption properties of the flaky carbonyl iron/FeSiAl composite in S-band. J. Mater. Sci.: Mater. Electron. 29(6), 1–6 (2018)Google Scholar
- 30.Y. Liu, Y.Y. Li, F. Luo, X.L. Su, J. Xu, J.B. Wang, Y.H. Qu, Y.M. Shi, Mechanical, dielectric and microwave absorption properties of TiC/cordierite composite ceramics. J. Mater. Sci.: Mater. Electron. 28(16), 12115–12121 (2017)Google Scholar
- 32.H. Luo, S.F. Zeng, Y.Q. Tan, H.B. Zhang, S.M. Peng, Mechanism of microwave dielectric response in carbon nanofibers enabled BCN composites. J. Mater. Sci.: Mater. Electron. 27(10), 10435–10441 (2016)Google Scholar