Hierarchical La-doped Bi₂Fe₄O₉/polypyrrole heterostructures with truncated pyramid nanostructure: A novel design for enhanced electromagnetic wave absorption

Abstract

This paper presents a novel design for electromagnetic wave (EMW) absorbing materials, focusing on a composite heterostructure of La-doped Bi₂Fe₄O₉ (BLFO) and polypyrrole (PPy) with a truncated pyramid nanostructure. This research aims to overcome the limitations of traditional EMW absorbers by leveraging the unique nano-morphology and properties of the BLFO@PPy composite. The unique microstructure of BLFO endows the composite with abundant interface polarization, while PPy significantly enhances the conduction loss. The resulting synergistic effect substantially improves the EMW absorption performance. The study demonstrates that La doping in Bi₂Fe₄O₉ leads to the formation of a truncated pyramid nanosheet array. When combined with PPy, this structure significantly enhances interface polarization, scattering, and absorption of EMWs. Specifically, the sample BLFO@PPy-3 exhibits superior EMW absorption performance, achieving a minimum reflection loss (RL_min) of − 64.20 dB and an effective absorption bandwidth (EAB) of 7.20 GHz. The effectiveness of this design is validated through comprehensive electromagnetic simulations. The simulation of the radar cross-section (RCS) indicates that BLFO@PPy-3 significantly enhances the stealth performance of unmanned combat aerial vehicles (UCAVs). Furthermore, the paper investigates the thermal conductivity properties of the composite, highlighting its potential for thermal management alongside EMW absorption. By optimizing the PPy content, the thermal properties of the composite can be precisely controlled, ensuring stable performance in practical applications. These findings offer valuable insights into the design and development of next-generation multifunctional EMW absorbing materials for diverse military and industrial applications.