Bimetallic Oxalate Rod-Derived NiFe/Fe<sub>3</sub>O<sub>4</sub>@C Composites with Tunable Magneto-dielectric Properties for High-Performance Microwave Absorption
Hui Luo, Beibei Ma, Fu Chen, Shan‐Shan Zhang, Yao Xiong, Yongzhi Cheng, Rongzhou Gong
Abstract
Development of microwave absorbing materials (MAMs) with strong and broadband absorption at thin thickness to address electromagnetic radiation and interference is still a huge challenge. Herein, bimetallic oxalate rod-derived NiFe/Fe3O4@carbon rods (NiFe/Fe3O4@CRs) composites as MAMs were structured by a facile coprecipitation followed by a carbothermal reduction process. The multiple interfaces existing in the composite can enhance the dielectric loss, and the rod structure can decrease the density of the NiFe/Fe3O4@carbon. The composite shows excellent microwave absorption properties. The minimum reflection loss (RL) value reaches −44.9 dB at an absorber thickness of 2.2 mm, and the efficient absorption bandwidth (RL ≤ −10 dB) is 5.1 GHz with a small thickness of only 1.58 mm. The high-performance microwave absorption mechanisms of the as-prepared NiFe/Fe3O4@CRs composites were mainly attributed to the synergistic of impedance matching, magnetic loss, and electrical loss. This work opens up a new prospect for developing high-performance microwave absorbers.