The Electron Migration Polarization Boosting Electromagnetic Wave Absorption Based on Ce Atoms Modulated yolk@shell Fe<i>_x</i>N@NGC

Abstract

The electron migration polarization is considered as a promising approach to optimize electromagnetic waves (EMW) dissipation. However, it is still difficult to realize well-controlled electron migration and elucidate the related EMW loss mechanisms for current researches. Herein, a novel Fe_xN@NGC/Ce system to construct an effective electron migration model based on the electron leaps among the 4f/5d/6s orbitals of Ce ions is explored. In Fe₄N@NGC/Ce_SA+Cs+NPs, Ce single-atoms (SA) mainly represent a +3 valence state, which can feed the electrons to Ce⁴⁺ of clusters (Cs) and CeO₂ nanoparticles (NPs) through a conductive network under EMW, leading to the electron migration polarization. Such electron migration loss combined with excellent magnetic loss provided by Fe₄N core, results in the optimal EMW attenuation performance with a minimum reflection loss exceeds -85.1 dB and a broadened absorption bandwidth up to 7.5 GHz at 1.5 mm. This study clarifies the in-depth relationship between electron migration polarization and EMW dissipation, providing profound insights into developing well-coordinated magnetic-dielectric nanocomposites for EMW absorption engineering.