Electronic structure and absorption mechanism of Fe-doped Y _0.9 Sr _0.1 CoO ₃ perovskite microwave absorbers

YCoO₃ exhibits unique advantages in functional applications owing to its exceptional lattice stability, valence adaptability, and environmental resistance, yet its potential for microwave absorption remains largely unexplored. In this study, Y_0.9Sr_0.1Co_1-xFe_xO₃ (x=0-0.2) perovskite absorbers were synthesized via a sol-gel method, demonstrating superior microwave absorption performance. Oxygen vacancy engineering facilitates Co redox cycling, significantly enhancing oxygen ion mobility and conductivity loss. First-principles calculations reveal that Fe³⁺ doping not only intensifies crystal polarization but also improves magnetic properties, thereby synergistically optimizing dipole polarization and magnetic losses. Additionally, the nanoscale particle morphology enhances interfacial polarization effects. The optimal composition (x = 0.1) achieves an effective absorption bandwidth of 5.71 GHz with a reflection loss of −47.18 dB at a thickness below 1.8 mm, demonstrating a significant enhancement compared to the undoped material. This work provides new insights into designing ultrathin, high-performance absorbers while elucidating the fundamental loss mechanisms in perovskite-based systems.