W.S. Zhang
材料科学技术（英）
The boron-oxide coated iron nanocapsules have been prepared by arc-discharge in a mixture of diborane and nitrogen, and then the boron-nitride coated iron nanocapsules by a subsequent annealing under a nitrogen atmosphere at 1100°C. After the arc-discharge, the boron-oxide coated iron nanocapsules form, which show an amorphous surface layer of B2O3 (and/or B) and a core of γ-Fe, α-Fe, FeB phases. After being annealed, part of the α-Fe phase transforms to the γ-Fe phase, and the FeB phase decomposes while the BN phase forms. The BN shell structure formed in the BN encapsulating iron nanocapsules is incomplete. Magnetic properties of the boron-oxide coated and the boron-nitride coated iron nanocapsules were compared and discussed in terms of the particles sizes, the phase components, and the surface structures.
关键词:
Arc discharge
,
nanocapsules
,
magnetic properties
邢刚
,
贾申利
,
史宗谦
新型炭材料
doi:10.3969/j.issn.1007-8827.2007.04.009
利用特制的电弧放电装置,研究了水或液氮中碳电弧放电形成炭纳米材料的机理.借助高分辨率透射电子显微镜对电弧放电生成的产物进行了观察和分析.结果表明:在水或液氮中碳电弧放电可以生成多壁碳纳米管和碳纳米洋葱结构,液氮中碳电弧放电可以生成单壁碳纳米角,水中钴催化碳电弧放电可以生成碳包裹的纳米钴颗粒.横向低频交变磁场会影响碳纳米材料的形核过程,并且可以推测磁场交变的频率5 Hz与纳米管、纳米洋葱等结构的生长周期存在某种拟合.根据实验现象,提出了一种解释液体中碳电弧放电过程纳米材料生成的理论模型.
关键词:
电弧
,
炭纳米材料
,
制备
