Yixuan Han, Mukun He, Jinwen Hu, Panbo Liu, Zhongwu Liu, Zhonglei Ma, Wenbo Ju* and Junwei Gu*. Hierarchical Design of FeCo-Based Microchains for Enhanced Microwave Absorption in C band. Nano Research, 2023, 16(1): 1773-1778. 2021IF=10.269（1区材料科学Top期刊，中国科技期刊卓越行动计划-领军类期刊项目）https://doi.org/10.1007/s12274-022-5111-y

Abstract

FeCo-based magnetic microwave absorbing materials (MAMs) are hydrothermally synthesized via amagnetic-field-induced process. Composition and morphology of the MAMs are capable of being adjusted simultaneously by the atomic ratio of Fe2+ to Co2+ in the precursor. The hierarchical magnetic microchain, which has a core-shell structure of two dimensional FexCo1?xOOH nanosheets anchored vertically on the surface of a one-dimensional (1D) Co microchain, shows significantly enhanced microwave absorption in C band, resulting in a reflection loss (RL) of lower than -20 dB at frequencies ranging from 4.4 to 8.0 GHz under a suitable matching thickness. Magnetic coupling of Co microcrystals and the double-loss mechanisms out of the core-shell structure are considered to promote the microwave attenuation capability. The hierarchical design of 1D magnetic MAMs provides a feasible strategy to solve the electromagnetic pollution in C band.

本文采用磁力诱导-水热还原法，通过调整投料比、预热温度、反应温度、反应时间及NaOH用量等条件合成了FeCo合金纳米颗粒（0D-P）、FeCo合金微米链（1D-MC）及核壳结构FexCo1-xOOH@Co微米链（2D@1D-MC）三种FeCo合金磁性吸波剂及FeCo基微波吸收材料（MAMs）。特殊的核壳结构（二维FexCo1-xOOH纳米片垂直锚定在一维Co微链表面）显著增强了2D@1D-MC材料在C波段的吸波性能，在C波段（4.4 GHz~8.0 GHz）实现小于-20 dB的反射损耗。一维磁性MAMs的分层结构设计为解决C波段的电磁污染提供了可行方案。

本文亮点

1. 通过优化调控前驱体溶液中的Fe2+和Co2+比例成功合成制备出了颗粒状0D-P、长链状1D-MC、核壳链状2D@1D-MC三种FeCo合金磁性吸波剂。

2. FexCo1-xOOH@Co合金磁性吸波剂中的长链结构有助于提升电损耗，核壳结构的引入也能够在提升磁损耗的同时平衡低频阻抗匹配，共同提升2D@1D-MC的低频吸波性能。

3. 当2D@1D-MC 质量分数为20 wt%、厚度为2.8 mm时，其RLmin和fE分别为-48.8 dB和3.4 GHz（7.2~10.6 GHz），优于同等质量分数的0D-P（-7.2 dB，0 GHz）和1D-MC（-32.6 dB和5.0 GHz（13.0~18.0 GHz））。厚度大于3 mm的2D@1D-MC/石蜡复合材料在C波段具有良好的微波吸收能力，而0D-P和1D-MC不能有效吸收C波段的微波。

第一作者：韩逸旋

邮件地址：hanyixuan@mail.nwpu.edu.cn

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