Electromagnetic and microwave absorbing properties of multi-walled carbon nanotubes filled with Ni nanowire

Microwave absorption, complex permittivity and permeability of Ni nanowire filled multi-walled carbon nanotubes (MWNTs), which were synthesized by CVD of methane using Ni/Al2O3 as the catalyst, have been investigated. The real and imaginary parts of permittivity and permeability of Ni nanowire filled MWNTs composites increase with increasing Ni nanowire filled MWNTs concentration. The Ni nanowire filled MWNTs/paraffin composite achieves a reflection loss below -10 dB (90% absorption) at 6.4-11 GHz, and the minimum value is -23.1 dB at 8.0 GHz. The microwave absorption of Ni nanowire filled MWNTs/paraffin composites was attributed to both dielectric and magnetic loss. The microwave-absorbing peaks of composites containing Ni nanowire filled MWNTs shift to low frequencies with increasing concentration of Ni nanowire filled MWNTs. (C) 2010 Elsevier B.V. All rights reserved.