Core/shell-structured nickel/nitrogen-doped onion-like carbon nanocapsules with improved electromagnetic wave absorption properties

Niandu Wu, Xianguo Liu, Siu Wing Or

Research output: Journal article publicationJournal articleAcademic researchpeer-review

19 Citations (Scopus)

Abstract

Core/shell-structured nickel/nitrogen-doped onion-like carbon (Ni/(C, N)) nanocapsules are synthesized by a modified arc-discharge method using N2gas as the source of N atoms. Core/shell-structured Ni/C nanocapsules are also prepared for comparison. The Ni/(C, N) nanocapsules with diameters of 10-80 nm exhibit a clear core/shell structure. The doping of N atoms introduces more lattice defects into the (C, N) shells and creates more disorderly C in the (C, N) shells. This leads to a slight shift in the dielectric resonance peak to the lower frequency side and an increase in the dielectric loss tangent for the Ni/(C, N) nanocapsules in comparison with the Ni/C nanocapsules. The magnetic permeability of both types of nanocapsules remains almost unaltered since the N atoms exist only in the (C, N) shells. The reflection loss (RL) of the Ni/(C, N) nanocapsules not only reaches a high value of -35 dB at 13.6 GHz, but also is generally improved in the low-frequency S and C microwave bands covering 2-8 GHz as a result of the N-doping-induced additional dipolar polarization and dielectric loss from the (C, N) shells.
Original languageEnglish
Article number056206
Pages (from-to)1-6
Number of pages6
JournalAIP Advances
Volume6
Issue number5
DOIs
Publication statusPublished - 1 May 2016

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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