Synthesis and microwave absorption properties of sandwich microstructure Ce2Fe17N3-δ/expanded graphite composites

• Published in: Journal of alloys and compounds Vol. 907; p. 164445
• Main Authors: Zhu, Shiqi, Lei, Zhenkuang, Liu, Zhonghao, Wu, Fangyi, Song, Jiali, Yang, Zhen, Tan, Guoguo, Man, Qikui, Liu, Xincai
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 25.06.2022; Elsevier BV
• Subjects: Coercivity; Composite materials; Electromagnetic radiation; Expanded graphite; Graphite; Impedance matching; Impedance matching: effective absorption bandwidth; Interlayers; Irregular particles; Magnetic properties; Magnetic saturation; Microstructure; Microwave absorption; Multilayers; Optimization; Thickness; Expanded graphite; Impedance matching: effective absorption bandwidth; Microwave absorption
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.164445

Sandwich microstructure composites composed of Ce2Fe17N3-δ and different mass fractions of expanded graphite (0, 1, 2, 3 wt%) were prepared, and their microwave absorption properties were studied. The microscopic morphology, composition, soft magnetic properties, chemical structure, electromagnetic parameters, and absorption properties of the Ce2Fe17N3-δ/EG composites were analyzed. The results show that Ce2Fe17N3-δ is an irregular particle with an average particle size of about 3 µm and EG is a multi-layer structure with an average interlayer spacing of about 2.7 µm. The saturation magnetization (Ms) value of Ce2Fe17N3-δ is 135 emu/g, and the coercivity (Hc) is 53 Oe. The effect of the loading of expanded graphite in the Ce2Fe17N3-δ/EG composites on their microwave absorbing properties is discussed. It was found that the well-designed two-component and appropriately loaded expanded graphite endowed the Ce2Fe17N3-δ/EG composites with excellent absorption properties. When the mass fraction of expanded graphite was 1% and the thickness of the absorber was 1.42 mm, the reflection loss reached −67.3 dB at 14.9 GHz with an effective bandwidth of 5.74 GHz. Compared with other expanded graphite-based absorbing materials, Ce2Fe17N3-δ/EG composites exhibited better electromagnetic wave absorption performance at a lower thickness. The enhancement of the absorption performance is attributed to the optimization of impedance matching and the synergistic action between multiple loss mechanisms. •Sandwich microstructure Ce2Fe17N3-δ/EG composites were prepared and charactered.•The introduction of Ce2Fe17N3-δ improved the absorption performance of expanded graphite-based absorbers.•The minimum RL of −67.3 dB and bandwidth of 5.74 GHz were obtained at 1.42 mm.•The balance between impedance matching and electromagnetic attenuation of Ce2Fe17N3-δ/EG absorbers was obtained.