Effect of Gd doping on crystal structure and microwave absorbing properties of Sr1-xGdxMnO3

Ion doping can significantly enhance microwave absorption performance. In this paper, powders of Sr 1- x Gd x MnO 3 ( x  = 0, 0.02, 0.04, 0.06) were synthesized via a simple sol-gel process. Comprehensive characterization elucidated the phase evolution, microstructure, valence states, magnetic properties, and electromagnetic attenuation mechanisms of Gd-doped SrMnO 3 . With the incorporation of Gd 3+ , the crystal structure of Sr 1- x Gd x MnO 3 transitions from hexagonal to cubic. The crystal lattice develops substantial defects, while the resulting valence imbalance drives the reduction of Mn 4+ to Mn 3+ . These synergistic effects enhance multipolarization phenomena, including defect polarization and charge polarization. Notably, the addition of an appropriate amount of Gd ions to the material can effectively adjust its electromagnetic parameters and optimizes impedance matching. Among the synthesized samples, Sr 0.94 Gd 0.06 MnO 3 exhibits optimal microwave absorption performance, achieving a minimum reflection loss of −36.6 dB at 9.84 GHz and an effective absorption bandwidth of 3.04 GHz at a thickness of 2.2 mm. Additionally, an effective absorption bandwidth of 4.0 GHz is achieved for x  = 0.02 at a thickness of 1.6 mm. These results not only indicate that Gd 3+ doping significantly enhances the absorbing properties of SrMnO 3 but also provide valuable theoretical guidance for the design of high-efficiency electromagnetic wave absorption materials in future research.