Abstract: Magnetic metal absorbers exhibit remarkable microwave absorption capacity. However, their practical application is severely limited due to their susceptibility to corrosion, particularly in marine environments. To address this challenge, we propose a novel approach involving the modification and control of FeCo/rGO microwave absorbers using rare earth lanthanum (La). This strategy aims to achieve both high-performance microwave absorption and enhanced resistance to marine corrosion. In this study, we employ a La₂O₃ modifying control strategy to refine the FeCo magnetic particles and coat them with CoFe₂O₄ on the surface, leveraging the pinning effect of in situ generated La₂O₃. This process enhances the interface polarization of the absorbers, thereby improving their electromagnetic performance and marine corrosion resistance. Consequently, the La₂O₃ modified FeCo@rGO composites exhibit broadband absorption, covering a wide frequency range of 6.11 GHz at 1.55 mm. Notably, the electromagnetic properties of the La₂O₃ modified FeCo@rGO absorbers remain stable even after prolonged exposure to a 3.5 wt% NaCl solution, simulating marine conditions, for at least 15 days. Furthermore, we perform first-principle calculations on FeCo and FeCoO to validate the corrosion resistance of the La₂O₃ modified FeCo@rGO composites at the atomic level. This comprehensive investigation explores the control of rare earth lanthanum modification on the size of magnetic metal particles, enabling efficient electromagnetic wave absorption and marine corrosion resistance. The results of this study provide a novel and facile strategy for the control of microwave absorbers, offering promising prospects for future research and development in this field.

Key words: Rare earth lanthanum, FeCo@rGO, Microwave absorption, Marine, corrosion resistance