Preparation and microwave absorption property of the core-nanoshell composite absorbers with magnetic fly-ash hollow cenosphere as nuclear

摘要

The core-nanoshell composite absorbers with magnetic fly-ash hollow cenosphere as nuclear were prepared by a solid-state reaction method. The results of X-ray diffraction analysis (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and vector network analyzer (VNA) analysis indicated that the hollow cenosphere is dielectric loss; the exchange-coupling interaction happens between ferrite of hollow cenosphere and nanocrystalline magnetic material coating. The exchange-coupling interaction enhance magnetic loss of composite absorbers. They have a perfect electromagnetic parameters at high and low microwave frequency. In the frequency between 2 GHz and 18 GHz, The reflectivity is lower than 10dB in low-frequency, and it is consistent with requirements of the microwave absorbing material at the low-frequency absorption. The microwave absorptivity of the core-nanoshell composite absorbers is better than single material.