【作者】 钟武波；

【导师】 刘顺华； 董星龙；

【作者基本信息】 大连理工大学 ， 材料加工工程， 2005， 硕士

【摘要】 本文采用直流电弧等离子体法分别在760Torr（H₂+Ar）和100Torr甲烷气氛下制备了Fe、Co、Ni、Fe—Ni、Fe—Co、Co（C）、Ni（C）等多种磁性纳米粒子。使用了XRD、TEM、X光电子谱（XPS）技术、气体分析、化学分析、EDAX、振动样品磁强计、网络分析仪、涂层表面电阻率对角线测量技术等多种分析手段,对铁磁性纳米粒子的晶体结构、微观形貌、表层结构、成份、粒度、室温磁性、微波电磁参数、导电性能等进行了研究.用稀盐酸去除纳米镍粉表面的氧化层,然后采用十二烷基苯磺酸钠（SDBS）、油酸、聚苯胺、硅烷偶联剂KH550对纳米镍粉进行表面改性。使用了活化指数实验、红外光谱（FT—IR）、热重分析等多种分析、测试手段,对改性效果进行了研究。 在（H₂+Ar）气氛下制备的Fe、Co、Ni、Fe—Ni、Fe—Co纳米粒子表层为金属氧化物。在2～18GHz频率范围内,Fe纳米粒子的介电损耗能力优于Co、Ni纳米粒子,原因为铁氧化物的含量大,并且铁氧化物的介电性好。Fe、Ni纳米粒子分别在7～18GHz、2.8～8GHz处对电磁波出现磁损耗吸收峰,而Co纳米粒子在2～18GHz频率范围内没有出现磁损耗吸收峰。通过比较几种Fe—Ni合金纳米粒子的电磁参数,发现可以通过调节Fe—Ni纳米粒子中两种元素的配比来展宽磁损耗吸收频带。以前述几种纳米粒子为填料的涂层导电率都较低,这种性质提高了材料的阻抗,能够使更多的电磁波进入吸波材料内部,被吸收损耗。在甲烷气氛下制备的Co（C）、Ni（C）纳米粒子的表层为碳膜,碳膜的存在提高了Co（C）、Ni（C）纳米粒子的抗氧化能力;Co（C）、Ni（C）纳米粒子在2～18GHz频率范围内对电磁波的介电损耗能力分别为氧化物包覆Co、Ni纳米粒子的25倍和14倍,并且具有频响效应;Co（C）纳米粒子对电磁波的磁损耗能力为氧化物包覆Co纳米粒子的4倍。 根据几种改性剂的改性效果和改性后纳米镍粉的微波电磁参数测试结果可知:4wt.%硅烷偶联剂KH550对纳米镍粉能够达到理想的改性效果,KH550改性纳米镍粉具有较好的抗氧化能力,提高了纳米镍粉的介电损耗和磁损耗能力。更多还原

【Abstract】 Nanometer particles of Fe、Co、 Ni、 Fe-Ni、 Fe-Co、 Co(C)、 Ni(C), etc. had been obtained by DC arc plasma in 100Torr methane(CH4) gas and a 760Torr mixture of H2 and Ar atmosphere respectively. The crystal structure, microstructure, surface characterization, composition particle’s size, magnetic properties, electromagnetic parameters, conductivity, etc. had been investigated by means of X-ray diffraction (XRD), transmission electron microscopy(TEM), X-photoelectron spectroscopy(XPS), gas analysis, chemical analysis, EDAX, vibrating sample magnetometer(VSM), network analyzer, surface resistivity diagonal test technique, etc.. The oxide layer on the surface of the nickel nanoparticles had been removed by dilute HC1, and subsequently modified by sodium dodecyl benzene sulfonate, Oleic acid, PAni, silane coupling agent KH550 respectively. The modify result had been investigated by means of active exponent, FT-IR, TGA-SDTA, DSC, TEM, network analyzer, surface resistivity diagonal test technique, etc..The surface layer of nanometer particles of Fe、 Co、 Ni、 Fe-Ni、 Fe-Co etc. prepared in a mixture of H2 and Ar atmosphere was metal oxide. Within the range of 2-18GHz frequency, the electric loss ability of Fe nanometer particle is superior to Co, Ni nanometer particles, because the content and electric ability of the iron oxide is larger than Co, Ni nanometer particles. The magnetic loss peaks of Fe, Ni nanometer particles appear in 10-13 GHz , 4-6GHz separately, but the nanometer particle Co has not presented the magnetic loss peak in the range of 2-18GHz frequency. Through comparing the electromagnetic parameters of several kinds of Fe-Ni alloy nanometer particles, the conclusion can be drawn that the magnetic loss frequency band can be widened by regulating the proportion of Fe, Ni elements. The electric conductivity of above-mentioned nanometer particles is poor which improves the impedance of the material so that more electromagnetic waves can be absorbed and lossed. The surface layer of nanometer particles of Co(C), Ni(C) prepared in methane(CH4) gas is carbon membrane which has improved the anti-oxidant ability of Co(C), Ni(C) nanometer particle. Co(C), Ni(C) nanometer particles have frequency response whose electric loss ability is about 25 times and 14 times of Co, Ni nanometer particles’. The magnetic loss ability of Co(C) nanometer particle is three larger times than Co nanometer particle.By comparing modification result and microwave electromagnetic parameter of modified Ni nanometer particle, the conclusion can be drawn that using 4wt. % silane coupling agent KH550 can reach the ideal modification result, make the nanometer nickel powder have better anti-oxidant ability, improve the electric loss ability and the magnetic loss ability.更多还原