Design and microwave absorption properties of thistle-like CoNi enveloped in dielectric Ag decorated graphene composites.

Affiliation

MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, School of Science, Northwestern Polytechnical University, Xi'an 710072, PR China. Electronic address: [Email]

Abstract

A novel hierarchical composites for coupling thistle-like CoNi with dielectric Ag decorated graphene in paraffin wax as high performance microwave absorber has been synthesized by a facile two-step strategy. The components, particle size, microstructure and morphology of the resulting composites are characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectra, scanning electron microscope, transmission electron microscopy and energy dispersive X-ray spectroscopy, etc. Due to the unique flower structure and good synergistic effect of dielectric loss and magnetic loss, thistle-like CoNi@dielectric Ag decorated graphene composites have showed glorious microwave absorption intensity and frequency width. The maximum reflection loss of -61.9 dB can be gained at 6.96 GHz, which has rarely been reported yet. In addition, the corresponding effective bandwidth with reflection loss less than -10 dB is 5.6 GHz ranging from 12.4 to 18 GHz at only 1.67 mm thickness. This highly efficient and broad band features endow thistle-like CoNi@dielectric Ag decorated graphene composites with promising applications in microwave absorption, electromagnetic shielding, information safety, direct broadcast satellite and military radar fields.

Keywords

Dielectric Ag decorated graphene,Interfacial polarization,Microwave absorption,Thistle-like CoNi,