Highly anisotropic Fe3C microflakes constructed by solid-state phase transformation for efficient microwave absorption

• Published in: Nature communications Vol. 15; no. 1; pp. 1497 - 9
• Main Authors: Zhao, Rongzhi, Gao, Tong, Li, Yixing, Sun, Zhuo, Zhang, Zhengyu, Ji, Lianze, Hu, Chenglong, Liu, Xiaolian, Zhang, Zhenhua, Zhang, Xuefeng, Qin, Gaowu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19.02.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 147/135; 147/137; 147/143; 639/301/357/997; 639/925/357/551; Absorption; Anisotropy; Cementite; Crystal structure; Dealloying; Electrochemistry; Ferromagnetic resonance; Ferromagnetism; Functional materials; Genetic transformation; Humanities and Social Sciences; Iron carbides; Magnetic anisotropy; Magnetic materials; Microwave absorbers; Microwave absorption; multidisciplinary; Permeability; Phase transitions; Quenching; Resonant frequencies; Science; Science (multidisciplinary); Solid state; Thickness
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-45815-w

Soft magnetic materials with flake geometry can provide shape anisotropy for breaking the Snoek limit, which is promising for achieving high-frequency ferromagnetic resonances and microwave absorption properties. Here, two-dimensional (2D) Fe 3 C microflakes with crystal orientation are obtained by solid-state phase transformation assisted by electrochemical dealloying. The shape anisotropy can be further regulated by manipulating the thickness of 2D Fe 3 C microflakes under different isothermally quenching temperatures. Thus, the resonant frequency is adjusted effectively from 9.47 and 11.56 GHz under isothermal quenching from 700 °C to 550 °C. The imaginary part of the complex permeability can reach 0.9 at 11.56 GHz, and the minimum reflection loss ( RL min ) is −52.09 dB (15.85 GHz, 2.90 mm) with an effective absorption bandwidth (EAB ≤−10 dB ) of 2.55 GHz. This study provides insight into the preparation of high-frequency magnetic loss materials for obtaining high-performance microwave absorbers and achieves the preparation of functional materials from traditional structural materials. Fe 3 C microflakes with high magnetic anisotropy are prepared through solid-state phase transformation and electrochemical dealloying. The magnetic anisotropy can be tuned by adjusting the morphology, resulting in optimized ferromagnetic resonance behavior for microwave absorption