Entropy-driven microwave absorption enhancement in hexagonal (Ba1/3Sr1/3Ca1/3)FeO3 perovskite

Multi-component occupancies of perovskite materials (ABO₃) have brought diverse crystallographic distortions and highly tunable defect structures. These structural features enable ABO₃ to have customizable dielectric and magnetic properties, offering new opportunities for advancing microwave absorbing materials. In this study, entropy-driven strategies are proposed to improve the microwave absorption capacity of (Ba_1/3Sr_1/3Ca_1/3)FeO₃, including composition optimization, structural/defective design, and microstructure engineering as well as microwave absorbing simulation. A hexagonal perovskite structure (Ba_1/3Sr_1/3Ca_1/3)FeO₃ prepared at 1100 ^oC exhibits exceptional electromagnetic wave absorption properties, with a minimum reflection loss of -40.58 dB at a thickness of 1.2 mm and a maximum effective absorption bandwidth of 4.16 GHz. The results indicate that the interconnection of octahedra, and structural distortions, oxygen vacancies and other defects enhances the dielectric polarization of the material, leading to excellent wave absorption performance. The entropy-driven design strategy for perovskite ABO₃ materials offers valuable insights for the development of advanced electromagnetic wave absorption materials.