Synthesis of novel hybrid carbon nanomaterials inside silicon carbide nanotubes by ion irradiation
Synthesis of novel hybrid carbon nanomaterials inside silicon carbide nanotubes by ion irradiation
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DOI：
10.1016/j.actamat.2019.05.007
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发表时间：
2019-07
期刊：
影响因子：
9.4
通讯作者：
T. Taguchi;S. Yamamoto;H. Ohba
中科院分区：
文献类型：
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作者：
T. Taguchi;S. Yamamoto;H. Ohba
采用离子辐照C-碳化硅同轴纳米管的方法合成了一种新型杂化碳纳米材料。该杂化材料由直径小于50 nm的一维堆叠的石墨烯纳米盘和位于无定形碳化硅管层内的圆柱形多壁碳纳米管组成。离子辐照后，在显微结构中突然出现了新的连续石墨化层，这些石墨层垂直于纳米管的长度方向。同轴碳-碳化硅纳米管中的碳化硅晶体也是由于离子辐照而变成非晶态的，尽管非晶化临界剂量高于体相碳化硅。最值得注意的是，即使在辐射剂量高于20 dpa(每原子位移)之后，碳层仍保持结晶状态。这些结果表明，在离子辐照下，这些碳层比C-SiC同轴纳米管中的碳化层具有更好的抗非晶化性能。当辐照损伤导致碳化硅晶体完全非晶化时，碳层的晶面间距增大，之后开始减小。这表明，在离子辐照过程中，碳层经历了很高的压应力。因此，离子辐照碳-碳化硅同轴纳米管引起了微结构的新发展，可被认为是制备新型碳纳米材料的新工艺之一。
A novel hybrid carbon nanomaterial was synthesized by ion irradiation of a C–SiC coaxial nanotube. The hybrid consisted of one-dimensionally stacked graphene nanodisks with diameters less than 50 nm and cylindrical multiwalled carbon nanotubes inside an amorphous SiC tubular layer. A sudden emergence of new continuous graphitic layers in the microstructure were observed byin situtransmission electron microscopy following ion irradiation, where these layers were perpendicular to the nanotube's length direction. The SiC crystals in the C–SiC coaxial nanotube became amorphous, also due to the ion irradiation, although the critical amorphization dose was higher than that for bulk SiC. Most remarkably, the carbon layer remained crystalline, even after an irradiation dose higher than 20 dpa (displacement per atom). Such results show that these carbon layers possess better resistance against amorphization when subjected to ion irradiation than the SiC layers in the C–SiC coaxial nanotube. The lattice plane spacing of the carbon layer increases up to the point when irradiation damage lead to the complete amorphization of SiC crystals, after which it starts to decrease. This demonstrates that the carbon layer experiences high compression stress during ion irradiation. Thus, the ion irradiation of C–SiC coaxial nanotubes gives rise to a novel development of the microstructure and can be considered as one of the new synthetic processes for making novel carbon nanomaterials.