Journal of Radioanalytical and Nuclear Chemistry, 2026 (SCI-Expanded, Scopus)
Vacancy-type defects in 6H-SiC single crystals and their evolution under irradiation were investigated using positron annihilation spectroscopy. Immediately after irradiation, silicon monovacancies (VSi) aggregate into stable (VSi-VC)3 hexavacancy clusters, which persist across the full dose range, indicating early defect saturation and the absence of further clustering. With increasing fluence, additional VSi are primarily eliminated through recombination with interstitials, which becomes the dominant defect-annihilation mechanism. An increase of the irradiation temperature enhances VSi mobility and accelerates the onset of saturation. These results demonstrate that (VSi-VC)3 represents the final, highly stable aggregated form and radiation-resistant vacancy configuration in 6H-SiC under the present irradiation conditions. This remarkable radiation tolerance of 6H-SiC confirms its suitability for next-generation nuclear systems and radiation-hardened electronic devices.