Synthesis and tunable microwave absorption characteristics of flower-like Ni/SiC composites

In the present study, dielectric and microwave absorption behavior of flower-like Ni/SiC composites has been studied in the 2–18 GHz frequency range. Single-phase flower-like Ni particles were successfully synthesized via a facile hydrothermal method. The synthesized flower-like Ni particles were mixed with SiC using mortar pestle in varying SiC:Ni weight ratios viz. 4:1, 1:1, and 1:4. The phase and morphology of prepared materials were studied using X-ray diffraction and FE-SEM techniques, respectively. The dielectric results show improvement in the complex permittivity and complex permeability values for the prepared composites with the increase in the concentration of synthesized Ni particles in SiC. Improvement in the dielectric properties translates into better microwave absorption behavior for flower-like Ni/SiC composites as compared to pure SiC. The synthesized flower-like Ni/SiC composites exhibited a minimum reflection loss of −31.04 dB and −28.53 dB for samples with 1:1 and 1:4 compositions, respectively. The corresponding −10 dB absorption bandwidth is 3.44 GHz and 2.89 GHz, respectively. The reflection loss results suggest that flower-like Ni/SiC composites may be tuned for optimal operation in C, X and, Ku bands by varying the Ni concentration and the thickness of absorber. In addition, the radar cross section (RCS) studies were simulated using HFSS. The RCS study of perfect electric conductor (PEC) substrate coated with flower-like Ni/SiC composite coatings indicate the effectiveness of the developed composites in reducing the RCS by efficiently suppressing the strong microwave scatterings.