Abstract In-situ TEM was used to observe the microstructural changes of SiC nanotubes under ion irradiation, and the results are significantly different from those of bulk SiC. The nanotubes possess better resistance against amorphization by irradiation, having a higher critical irradiation dose at room temperature. At room temperature, both the outer and inner diameters of the SiC nanotubes increase during irradiation till complete amorphization, and decrease afterwards. The lattice plane spacing of SiC crystals increases with increasing ion fluence due to the increasing disorder. At 700 °C, both the inner and outer diameters change very little during ion irradiation; and the lattice plane spacing decreases slightly, which is not consistent with previous studies of bulk SiC. The reason is that, in the nanotubes, the number of inherent defects that buffer the residual stress in it can be reduced. A new structure with smaller crystal segments is produced in the SiC grains of nanotubes to relieve the residual stress, instead of inducing structural defects and nanotube contraction. From these results, ion irradiation clearly induces novel microstructural changes in SiC nanotubes, due to the nanosizing and tubal configuration of the material.

中文翻译：

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离子辐射诱导碳化硅纳米管的新型微观结构变化

摘要 采用原位透射电镜观察离子辐照下碳化硅纳米管的微观结构变化，结果与体碳化硅有显着差异。纳米管具有更好的抗辐照非晶化能力，在室温下具有更高的临界辐照剂量。在室温下，碳化硅纳米管的外径和内径在辐照过程中均增大，直至完全非晶化，之后减小。由于无序度的增加，SiC 晶体的晶格面间距随着离子注量的增加而增加。在 700 °C 时，内径和外径在离子辐照期间变化很小；晶面间距略有减小，这与之前对体碳化硅的研究不一致。原因是，在纳米管中，可以减少缓冲残余应力的固有缺陷的数量。在纳米管的 SiC 晶粒中产生具有更小的晶段的新结构以减轻残余应力，而不是引起结构缺陷和纳米管收缩。从这些结果来看，由于材料的纳米尺寸和管状结构，离子辐照显然会导致 SiC 纳米管发生新的微观结构变化。