The capacitive loss of microwave energy in Ni@SiC@C core/bi-shell nanoparticles

Abstract

Developing the excellent electromagnetic (EM) wave absorption materials with the characteristics of “Thin, Light, Wide, Strong” to mitigate EM wave pollution is still a huge challenge. In this work, a series of Ni@SiC@C double-shell nanoparticles were synthesized by preparation technology of thermal arc plasma nanoparticle. The thickness of the shell layer is regulated by modulating the concentration of methane (CH4) to increase the interfacial polarization sites and further improve the dielectric and EM wave absorption properties in the full wave band (0.1–18 GHz). Surprisingly, the EM wave absorption property is improved as the CH4 concentration increases. It is discovered that the effect of core Ni, dielectric material SiC and graphite C essentially increases the polarization source in the nanoparticles, resulting in outstanding complex permittivity and high reflection loss. Meanwhile, Ni@SiC@C double shell structure is equivalent to capacitance Cp and resistor Rp, as parallel circuit to manufacture interfacial polarization. This study provides a vivid picture of how a new absorbing material worked. More broadly, it can demonstrate that double shell structure is the effective ways to dramatically enhance potential in the application of absorbing devices.