Magnetic and microwave properties of cobalt nanoplatelets
Magnetic and microwave properties of cobalt nanoplatelets
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DOI：
10.1016/j.mseb.2006.12.001
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发表时间：
2007-04-15
期刊：
影响因子：
--
通讯作者：
Ma, Fei
中科院分区：
文献类型：
--
作者：
Li, Jiangong;Huang, Juanjuan;Ma, Fei
室温下，fcc和hcp晶体结构中均存在直径为120 nm、厚度为10 nm的Co纳米片。由于氧化层的存在，Co纳米片的饱和磁化强度比块体Co的低。在没有外加磁场的情况下，单个Co纳米片的平衡磁构型为涡旋结构，无论是HCP晶体结构还是FeE晶体结构。Co纳米片表面包覆了一层MnO2。在0.1-18 GHz频率范围内，测量了包覆MnO2的Co纳米片状复合材料和石蜡混合物的微波性能。样品的复磁导率出现两个宽谐振峰，复介电常数在0.1-18 GHz的频率范围内出现一个谐振峰。数值模拟表明，在2-11.5 GHz频率范围内，包覆MnO2的Co纳米片状复合材料和石蜡混合物的反射损耗值小于-12分贝。(C)2007 Elsevier B.V.保留所有权利。
The Co nanoplatelets of 120 nm in diameter and 10 nm in thickness exist in both fcc and hcp crystal structures at room temperature. The saturation magnetization of the Co nanoplatelets is lower than that of the bulk Co because of the existence of the oxide layer. The coercivity is higher than that of the bulk Co. The equilibrium magnetic configuration of a single Co nanoplatelet without external magnetic field is a vortex structure, regardless of hcp or fee crystal structure. The Co nanoplatelets were coated by MnO2. The microwave properties of the MnO2-coated Co nanoplatelet composites and paraffin wax mixtures were measured in the 0.1-18 GHz frequency range. The complex permeability of the sample shows two broad resonance peaks and the complex permittivity of the sample shows one resonance peak in the frequency range of 0.1-18 GHz. The numerical simulations show that the reflection loss values of the MnO2-coated Co nanoplatelet composites and paraffin wax mixtures are less than - 12 dB in the 2-11.5 GHz frequency range. (C) 2007 Elsevier B.V. All rights reserved.