FeCo-BN magnetic composite membrane prepared via an atomized aerosol process for electromagnetic wave absorption and thermal management

Abstract

Soft magnetic materials with high magnetic flux density and low coercive force exhibit a significant reflection loss, generating effective electromagnetic waves (EMWs) in the S-band to K-band frequency range. However, the limited complex permeabilities of commonly available soft magnetic materials at higher frequencies restrict their EMW absorption bandwidth. Here, we present a new class of thin EMW absorbing composite membrane comprising shape-modulated soft magnetic FeCo and thermally conductive boron nitride (BN) particles. The designed chemical process facilitates a one-step synthesis of composites with diverse structures, including spheres, cubes, and hollows, without requiring any shape-controlling additives. The FeCo/BN composite membrane, which was only 1.5 mm thick, demonstrated enhanced permeability and effective impedance matching, resulting in a high reflection loss value of − 46.4 dB at 11.3 GHz. Furthermore, the incorporation of BN nanoparticles with thermal conductivity enabled the thermal dissipation of the absorbed EMW energy. This study comprehensively investigated the correlation between shape modulation and complex permeability, which can provide valuable insights for the development of advanced EMW-absorbing materials.