In-situ TEM study on irradiation-induced amorphization of 3C-SiC under 800 keV Kr 2+ irradiation at 150°C

This study investigates the irradiation-induced amorphization behavior of 3C-SiC using in-situ transmission electron microscopy. A polycrystalline 3C-SiC sample was irradiated with 800 keV Kr2+ ions at 150°C. The amorphization process was monitored in real-time at varying distances from grain boundaries. The results show an amorphization threshold dose of approximately 2.795 dpa. Regions farther from grain boundaries were more susceptible to amorphization. The observed behavior supports a composite model combining ‘direct impact/defect-stimulated growth’ and ‘defect accumulation’ mechanisms. Grain boundaries act as effective defect sinks. They delay amorphization in adjacent areas by promoting point defect annihilation. Notably, the amorphization dose under in-situ conditions (∼2.795 dpa) is significantly higher than the ∼0.9 dpa typical for ex-situ irradiation. Possible reasons for this difference are discussed. This work clarifies the role of grain boundaries in irradiation damage evolution. It provides new insights and strategies for designing irradiation-resistant SiC materials with optimized microstructures.