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

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. (C) 2016 Elsevier B.V. All rights reserved.