High anisotropy 2D large-size iron-based coral for C-band ultra-wide microwave absorption

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-11, Vol.500, p.156973, Article 156973
• Main Authors: Ding, Chunyan, Shao, Chengshuai, Li, Zhuoyang, Ren, Xiaozhen, Wu, Songsong, Zhang, Qianqian, Wei, Chuncheng, Xia, Long, Zhong, Bo, Wen, Guangwu, Huang, Xiaoxiao
• Format: Article
• Language: English
• Subjects: C-band; Low filling; Magnetic loss; Microwave absorption; Natural resonance; Two-dimensional materials; Wide absorption bandwidth
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.156973

Highly anisotropic 2D large-sized iron-based coral were produced using an ammonium nitrate-assisted blow molding strategy in order to achieve a coverage of 100 % for C-band. [Display omitted] •High anisotropy 2D LCIC were successfully fabricated using the NH4NO3-assisted blow molding separation strategy.•The LCIC hierarchical configuration was formed without any significant agglomeration.•The high anisotropy of the two-dimensional large-size layer structure significantly enhances the magnetic properties.•The LCIC exhibits excellent full C-band microwave absorption.•A 2D coralloid structure allows for the production of lightweight microwave absorption materials (20 wt.%). Lightweight microwave-absorbing (MA) materials with broadband absorption in the C-band remain challenging to date. Recent studies have shown that promoting anisotropy in materials is expected to break the Snoek limit and enhance the absorption performance of magnetic materials in the C-band. In this paper, two-dimensional (2D) large-size coral-like iron-based composites (LCIC) were prepared using an NH4NO3-assisted blow molding separation strategy. The special structure with large shape anisotropy realizes a wide and strong natural magnetic resonance, leading to strong magnetic loss. The enhanced natural resonance effectively broadens the effective absorption bandwidth (EAB) of the LCIC in the C-band. The minimum reflection loss (RLmin) of LCIC is −41.64 dB, and the EAB is 5.42 GHz (3.83–9.25 GHz), covering the entire C-band. Strong natural resonance is necessary to improve the dissipation of magnetic losses in low-frequency electromagnetic waves. This work explores the important role of size effect in enhancing the C-band absorption properties of magnetic materials. It provides a feasible reference for the preparation of C-band broadband, strongly absorbing MA materials.