This study reports on ion irradiation‐induced grain size variations in nanocrystalline SiC films on Si substrates. The SiC grains with average size ranging from ~2 to 20 nm were embedded in amorphous SiC matrices. Irradiation was performed using 5 MeV Xe²³⁺ ions to 1.15 × 10¹⁶ ions/cm² at 700 K. The irradiated films were characterized using X‐ray diffraction, transmission electron microscopy, and Raman spectroscopy. Significant grain growth is observed for smaller grains that tend to saturate at ~8 nm. In contrast, irradiation of larger grains (~20 nm in size) leads to a decrease in the grain size, which could be associated with the production of lattice disorder within the grains. Homonuclear C‐C bonds in the irradiated amorphous SiC matrix are found to be graphitized. This bonding transformation could limit or inhibit grain growth and contribute to the size saturation. The results from this study may suggest nanocrystalline SiC as a promising candidate structural or cladding material for applications in advanced nuclear reactors.

中文翻译：

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高温下辐照的纳米晶碳化硅的晶粒尺寸变化

这项研究报告了离子辐照引起的Si基纳米晶SiC膜中晶粒尺寸的变化。平均尺寸范围为〜2至20 nm的SiC晶粒被嵌入非晶SiC矩阵中。使用5 MeV Xe ²³⁺离子以1.15×10 ¹⁶离子/ cm ²进行辐照在700 K下。使用X射线衍射，透射电子显微镜和拉曼光谱对辐照后的薄膜进行表征。对于较小的晶粒，在〜8 nm处趋于饱和，观察到明显的晶粒长大。相反，较大晶粒（尺寸约为20 nm）的照射会导致晶粒尺寸减小，这可能与晶粒内晶格紊乱的产生有关。发现被辐照的非晶SiC基体中的同核C-C键被石墨化。这种键合转变可能会限制或抑制晶粒长大，并导致尺寸饱和。这项研究的结果可能表明，纳米晶SiC是有前途的候选结构或包覆材料，可用于高级核反应堆。