Preparation of hierarchical NiCo 2 O 4 self-assembled by lamellar flakes and its microwave absorption

In this work, the hierarchical NiCo 2 O 4 self-assembled by lamellar flakes were successfully synthesized by a simple solvothermal route and subsequent thermal treatment. The composition and microstructure of the hierarchical NiCo 2 O 4 were characterized by XRD and SEM, respectively. The microwave absorption properties were also evaluated. An optimum reflection loss (RL) of − 45.5 dB at 4.6 GHz with a composite thickness of 4.2 mm and effective bandwidth (RL < − 10 dB) of 7.7 GHz were obtained. The excellent electromagnetic wave absorption property of the hierarchical NiCo 2 O 4 is due to the conduction loss and dielectric loss of NiCo 2 O 4 , the hierarchical structure could also enhance the microwave absorbing properties by the strong multi-reflections and scattering of microwave between stacking layers.