Achieving Multiple-Resonance Permeability at Centimeter Waveband by Joint Strategies of Hard/Soft Exchange-Coupling and Selective Doping for Superior Microwave Absorption

With the prosperous development of radar technology and 5G communication, the microwave absorbing materials have become extremely crucial to improve the service life of weapons and working quality of equipment in modern society. However, it still remains a huge challenge to achieve broad absorption bandwidth at centimeter waveband due to the frequency-dependent quarter-wavelength matching thickness. In this work, the Ba­(ZrNi)0.6Fe10.8O19/NiFe2O4 composites are proposed and prepared by an in situ sol–gel method. Herein, the hard/soft magnetic exchange-coupling and the selective doping strategies are dexterously integrated to achieve multiple-resonance permeability at centimeter waveband. In addition, by changing the ratio of hard and soft magnetic phases, the coupling effect is regulated to modify the multimagnetic resonance effect and optimize the absorption bandwidth. Finally, the maximum absorption bandwidth of the Ba­(ZrNi)0.6Fe10.8O19/NiFe2O4 composites reaches (RL < −5 dB) to 8.6 GHz, exhibiting a promising prospect in centimeter-wave absorption.