Advances in Fe-based electromagnetic wave absorbers: Multiscale engineering from atomic defects to macroscopic architectures for performance optimization

• Fe-based electromagnetic wave absorbers offer cost-effective, high-saturation magnetization and superior magnetic loss, making them highly effective for EWA applications. • The review systematically covers pristine Fe-based absorbers including carbonyl iron, ferrites, alloys, high-entropy alloys, and layered ternary transition-metal borides. • Performance enhancement strategies such as doping, in-situ oxidation, porous structuring, and composite construction are critically analyzed to optimize absorption efficiency. • The synergy between Fe-based and high-entropy materials enables next-generation EWA for stealth technology, wearable electronics, and harsh environment applications.