Tunable radio-frequency negative permittivity in nickel-alumina “natural” meta-composites
Tunable radio-frequency negative permittivity in nickel-alumina “natural” meta-composites
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DOI：
10.1063/1.4885550
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发表时间：
2014-06
影响因子：
4
通讯作者：
Zhicheng Shi;Shougang Chen;Kai Sun;Xin Wang;R. Fan;Xu-ai Wang
中科院分区：
文献类型：
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作者：
Zhicheng Shi;Shougang Chen;Kai Sun;Xin Wang;R. Fan;Xu-ai Wang
具有本征负介电常数和磁导率的“天然”超材料因其广泛的应用前景和简便的制备工艺而备受关注。为了匹配通常位于射频范围内的负磁导率带，需要射频负介电常数。此外，负介电常数应可调，以满足不同的应用情况。本文采用易湿化学方法制备了由均匀分散在氧化铝中的镍颗粒组成的镍/氧化铝复合材料。出现了渗滤现象，得到了期望的射频负介电常数。此外，还详细研究了负介电常数与复合材料组成和微观结构的关系。结果表明，镍含量越高，负介电常数值越大，负介电常数频率越低。此外，氧化铝颗粒的加入导致了高温。
“Natural” metamaterials with intrinsic negative permittivity and permeability have attracted significant attention because of their wide promising applications and facile preparation processes. In order to match the negative permeability band which is usually located in the radio-frequency range, radio-frequency negative permittivity is desired. Moreover, the negative permittivity should be tunable to satisfy different application circumstances. Herein, nickel/alumina composites consisting of nickel particles homogeneously dispersed in alumina were prepared using a facile wet chemical process. A percolation phenomenon appears, and expected radio-frequency negative permittivity is obtained. Furthermore, the dependences of negative permittivity on the composites' compositions and microstructures are investigated in detail. It is shown that higher nickel content results in higher negative permittivity magnitude and lower negative permittivity frequency. Besides, the addition of alumina particles leads to dec...