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以粉末状与气态二茂铁为原料,以氢气和氧气混合气体为爆轰能源,采用气相爆轰法进行了合成碳包覆铁纳米颗粒实验。XRD和TEM实验结果表明,采用两种不同状态的二茂铁,均得到了纳米碳包覆铁颗粒。该包覆颗粒的组成核为铁或铁碳化合物,外层壳主要由石墨碳组成,大部分球形纳米颗粒尺寸分布于5~30 nm之间。通过对比发现,采用气态二茂铁爆轰时,所得到的碳包铁粒度分布较为集中,壳层厚度比较均匀,且粒子具有较好的球形状。最后结合铁碳合金相图,从热处理角度对气相爆轰合成碳包覆铁纳米颗粒的机理进行了分析,得出产物中α-Fe与Fe_3C的形成过程。分析了碳包覆铁纳米颗粒的磁滞回线,其表现出硬磁性与顺磁性双重性质。
Using powdered and gaseous ferrocene as raw material and mixed gas of hydrogen and oxygen as detonation energy, carbon-coated iron nanoparticles were tested by gas-phase detonation method. XRD and TEM experimental results show that, using two different states of ferrocene, have been carbon nano-coated iron particles. The core of the coated particles is iron or iron-carbon compound, the outer shell is mainly composed of graphite carbon, and most of the spherical nanoparticles are distributed between 5 and 30 nm in size. By comparison, it is found that when the gaseous ferrocene is detonated, the particle size distribution of the carbon coated iron is more concentrated, the thickness of the shell is more uniform, and the particles have better spherical shape. Finally, the mechanism of carbon-coated iron nanoparticles synthesized by gas-phase detonation was analyzed from the perspective of heat treatment, and the formation process of α-Fe and Fe_3C in the product was obtained. The hysteresis loops of carbon-coated iron nanoparticles were analyzed, showing the dual nature of hard and paramagnetic.