A Novel And Facile Route For The In Situ Formation Of Composites With Dual Coupling Interactions For Considerable Millimeter Wave Absorption Performance

A hard/soft magnetic exchange coupling or ferroelectric-ferromagnetic coupling has been proved to be beneficial for improving microwave absorption properties. Herein, we propose a BaZrxFe12-xO19/Fe3O4/BaZrO3 composite to integrate the advantages of the two couplings. However, the synthesis of BaFe12O19/Fe(3)O(4)in situ still remains a challenge due to the different degrees of oxidation resistance. In this work, by delicately exploiting the reducibility of graphene at high temperatures, the BaZrxFe12-xO19/Fe3O4/BaZrO3 composite was successfully prepared in situ by a hydrothermal process combined with a subsequent heat treatment at 600 degrees C. The two integrable couplings provide good impedance matching and attenuation characteristics for the material system, making it reach a considerable millimeter wave absorption performance around an atmospheric window of 35 GHz with a broad bandwidth of >7.36 GHz (32.64-40.00+ GHz) and a strong RL of -25.4 dB under an extremely thin thickness of 1.00 mm. The strategy provides a novel and facile pathway to design outstanding millimeter wave absorbers.