The arc-discharged Ni-cored carbon onions with enhanced microwave absorption performances

Abstract Carbon-based microwave absorbers are important for the rapid development of electronic devices. Herein Ni-cored carbon onions with wide particle size distribution were prepared via arc discharge method, and their structures were characterized by electron microscope, X-ray diffraction, Raman spectroscopy. The three-dimension porous structure, thick carbon shell and large number of defects endows Ni-cored carbon onions with various polarization centers that can stimulate multiple dielectric resonances, leading to wide response frequency bandwidth and multiple strong microwave absorption features. It was evidenced that the bandwidths over -10 dB were from 3.4 to 18.0 GHz when the thickness of samples ranged from 1.5 to 5.0 mm.