Magnetic metal absorbers exhibit remarkable microwave absorption capacity.However,their practical application is severely limited due to their susceptibility to corrosion,particularly in marine environ-ments.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 La_(2)O_(3) modifying control strategy to refine the FeCo magnetic particles and coat them with CoFe_(2)O_(4) on the surface,leveraging the pinning effect of in situ generated La_(2)O_(3) .This process enhances the interface polarization of the absorbers,thereby improving their electromagnetic performance and ma-rine corrosion resistance.Consequently,the La_(2)O_(3) modified FeCo@rGO composites exhibit broadband ab-sorption,covering a wide frequency range of 6.11 GHz at 1.55 mm.Notably,the electromagnetic proper-ties of the La_(2)O_(3) modified FeCo@rGO absorbers remain stable even after prolonged exposure to a 3.5 wt% NaCI solution,simulating marine conditions,for at least 15 days.Furthermore,we perform first-principle calculations on FeCo and FeCo-O to validate the corrosion resistance of the La_(2)O_(3) modified FeCo@rGO composites at the atomic level.This comprehensive investigation explores the control of rare earth lan-thanum 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.
Integrated micro and nanostructures,heterogeneous components,defects,and interfaces is the way to develop high-performance microwave absorbing materials.However,there still needs to be more precise experimental routes and effective validation.In this work,by a continuous process of vacuum sintering,hydrothermal,and carbon thermal reduction,magnetic FeCo nanoparticles were successfully embedded on the hollow double-shell mesoporous SiC@C surface,thus solving the challenges of a single component loss mechanism.The hollow double-shell nanostructure introduces air to enhance impedance matching while significantly reducing the density of the material.The extensive defects and heterogeneous grain boundaries effectively enhance the polarization loss capacity.The magnetic loss mechanism introduced by the magnetic particles effectively improves the impedance matching properties of the material.The synergy of these multiple advantages has enabled the SCFC_(2)-8(here SiC@C@FeCo is abbreviated to SCFC,2 represents the initial metal ion content,and 8 represents the hydrothermal time)sample to achieve an adequate absorption bandwidth of 6.09 GHz at 2.0 mm.With a minimum reflection loss of-60.56 dB,the absorption bandwidth can cover the entire C,X,and Ku bands by adjusting the matching thickness(1.3–4.0 mm).This work provides a valuable paradigm for the deeper exploitation of microwave absorption potential and guides the development of other high-performance materials.
Guiyu PengJintang ZhouJiaqi TaoWeize WangJun LiuJunru YaoYijie LiuZhengjun Yao