Morphology-Control Synthesis of a Core-Shell Structured NiCu Alloy with Tunable Electromagnetic-Wave Absorption Capabilities
Morphology-Control Synthesis of a Core-Shell Structured NiCu Alloy with Tunable Electromagnetic-Wave Absorption Capabilities
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DOI：
10.1021/acsami.5b02716
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发表时间：
2015-06-17
影响因子：
9.5
通讯作者：
Zhang, Rui
中科院分区：
文献类型：
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作者：
Zhao, Biao;Zhao, Wanyu;Zhang, Rui
在这项工作中，树枝状和棒状的NiCu合金制备通过一锅水热工艺在不同的反应温度（120，140，和160摄氏度）。通过扫描电子显微镜、能谱仪、X射线衍射仪和透射电子显微镜对合金的结构和形貌进行了分析，结果表明NiCu合金具有以Ni为壳、Cu为核的核-壳异质结构。并对核壳结构的形成机理进行了讨论。在140 ℃下获得的均匀且完美的枝晶状NiCu合金显示出优异的电磁波吸收性能。在14.3 GHz处观察到最低反射损耗（RL）为-31.13dB，有效吸收（低于-10 dB，90%衰减）带宽可在4.4至18 GHz之间调节，吸收体厚度在1.2-4.0 mm范围内。出色的电磁波吸收性能归因于空间-由NiCu合金的异质结构引起的电荷极化、合金与石蜡之间的界面极化、以及由在140 ℃下制备的NiCu的均匀且完美的树枝状形状引起的连续微网和振动微电流耗散。
In this work, dendritelike and rodlike NiCu alloys were prepared by a one-pot hydrothermal process at various reaction temperatures (120, 140, and 160 degrees C). The structure and morphology were analyzed by scanning electron microscopy, energy-dispersive spectrometry, X-ray diffraction, and transmission electron microscopy, which that demonstrate NiCu alloys have core shell heterostructures with Ni as the shell and Cu as the core. The formation mechanism of the core-shell structures was also discussed. The uniform and perfect dendritelike NiCu alloy obtained at 140 degrees C shows outstanding electromagnetic-wave absorption properties. The lowest reflection loss (RL) of -31.13 dB was observed at 14.3 GHz, and the effective absorption (below -10 dB, 90% attenuation) bandwidth can be adjusted between 4.4 and 18 GHz with a thin absorber thickness in the range of 1.2-4.0 mm. The outstanding electromagnetic-wave-absorbing properties are ascribed to space-charge polarization arising from the heterogeneous structure of the NiCu alloy, interfacial polarization between the alloy and paraffin, and continuous micronetworks and vibrating microcurrent dissipation originating from the uniform and perfect dendritelike shape of NiCu prepared at 140 degrees C.