Fabrication of ZnO/Fe rod-like core-shell structure as high-performance microwave absorber

Abstract

This research reports on design and synthesis of rod-like ZnO@Fe core-shell composite. In this type of composite, hexagonal-rod like of ZnO was prepared first by the hydrothermal route and then coated by the Fe nanoparticles. Subsequently, it leaded to the core-shell structure, original hexagonal-rod simultaneously converted into cylinder-like shape. Enhanced electromagnetic absorption properties could be found for the ZnO@Fe sample as compared to the single component ZnO. A minimum reflection loss value of −48.0 dB was achieved for this ZnO@Fe at the layer thickness of 1.5 mm. The bandwidth (RLmin < −10 dB) could reach to 4.0 GHz. When d = 2.0 mm, the frequency bandwidth approximately 6.4 GHz. This superior electromagnetic absorption mechanism is probably due to the synergy effect of dielectric and magnetic loss, as discussed in depth.