磁性Fe、Co、Ni纳米粒子的吸波性能研究

MICROWAVE ABSORPTION CHARACTERISTICS OF FERROMAGNETIC Fe,Co,Ni NANOPARTICLES

利用直流电弧等离子法在101.32 kPa（760 Torr）（H2＋Ar）混合气氛下制备了Fe、Co、Ni纳米粒子,通过XRD、TEM、VSM及TC-436（LECO LTD.）N/O分析仪对纳米粒子进行了形貌和成分的表征,并通过矢量网络分析仪,利用同轴方法对粒子复合材料进行了电磁参数的测定.结果证明：在2～8 GHz频率范围内,Fe、Ni、Co纳米粒子/固体石蜡复合材料的复介电常数虚部ε在3～4 GHz、7～10 GHz、14～16 GHz频段均出现峰值,Fe、Ni纳米粒子/固体石蜡复合材料复磁导率的虚部μ吸收峰值分别在11～13 GHz、4～6 GHz频段处,Co纳米粒子/固体石蜡复合材料复磁导率的虚部μ吸收峰值并没有出现.利用实验所得到的数据模拟了Fe、Ni、Co纳米粒子/固体石蜡复合材料不同厚度的电磁损耗能力,当涂层厚度为2 mm时,Fe纳米粒子/固体石蜡复合材料在8 GHz频率范围达到30 dB的吸收值.在2～18 GHz频率范围内,当涂层厚度为4 mm和5 mm时,Ni纳米粒子/固体石蜡复合材料出现了两个吸收峰,其值均大于10 dB.因此,通过Fe、Co、Ni纳米粒子的复合吸波材料可以展宽吸收电磁波的频段.

The DC arc plasma was used to prepare Fe, Co,Ni nanoparticles in a mixture of H2 and Ar gas atmosphere. The morphology and content of the Fe, Co, Ni nano - particles were investigated by X - ray diffraction （ XRD）, transmission electron microscopy （ TEM）, vibrating sample magnetometer（VSM） and TC - 436 （ LECO LTD. ） N/O analysis. The electromagnetic characteristics of te Fe, Co,Ni nanoparticles composites were measured by Agilent 8722ES microwave network analyzer in the band of 2-18 GHz. The experimental results show that all the ε of Fe, Co, Ni nanoparticle composites have a maximum in the band of 3-4 GHz,7-10 GHz, 14-16 GHz, and the μ of Fe and Ni nanoparticle composites have a maximum value in the band of 11 - 13 GHz, 4-6 GHz respectively, but the maximum value of Co composite was not found the band of 2-18 GHz. The reflection loss R（dB）of the composite materials were simulated with the experimental data. The reflection loss R（dB）of the Fe composite materials 2 mm in thickness reaches to 30 dB at 8 GHz. The Ni composite material has two absorption peaks over 10 dB. The Fe, Co, Ni nanoparticle composites are able to absorb microwaves in the＇band of several GHz.