Microwave absorption properties of the carbon-coated nickel nanocapsules

Abstract

The carbon-coated Ni(C) nanocapsules were prepared by a modified arc-discharge method in methane atmosphere. Its electromagnetic parameters were measured at 2–18GHz. It is observed that the natural resonance which appeared at 5.5GHz is dominant among microwave absorption properties of Ni(C) nanocapsules, as the consequence of the increased surface anisotropic energy for nanosized particles. The measured relative complex permittivity indicates that a high resistivity existed in Ni(C) nanocapsules samples. The maximum reflection loss of Ni(C) nanocomposites can reach 32dB at 13GHz with 2mm in thickness. The microwave absorptive mechanisms of Ni(C) nanocapsule absorbent were discussed.

High-frequency permeability of Ni and Co particle assemblies

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Remarkable improvement in microwave absorption by cloaking a micro-scaled tetrapod hollow with helical carbon nanofibers

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Microwave absorption properties of helical carbon nanofibers-coated carbon fibers

“…The curve (ii) shows that the maximum RL is −32 dB at 9 GHz and the widest bandwidth under −10 dB is 9.8 GHz (from 8.2 to 18 GHz) with 2.5 mm in composite thickness. Such absorption property, especially for the bandwidth under −10 dB, is superior to that of other materials such as T-CNC, 3 HCNTs, 1 Fe 3 O 4 -coated CFs, 17 carbon-coated nickel nanocapsules 18 and porous carbon/Co nanocomposites. 19 Curve (v) in Fig.…”