In-situ TEM study of Kr ion irradiation tolerance of SiFeOC nanocomposite

Abstract

In this work, ion irradiation of polymer derived SiFeOC nanocomposite was carried out using 1.2 MeV Kr ions at room temperature and 600°C. The starting composite was composed of Fe3Si, SiC, SiOC, SiO2, and graphitic C. In-situ TEM investigations show uniform distribution of nano-crystalline Fe3Si and SiC phases in the amorphous SiOC matrix. During ion irradiation, the SiOC bulk microstructure and interfaces between Fe3Si or SiC crystallites and the SiOC matrix remain defect-free and demonstrate outstanding ion irradiation resistance. At room temperature, the crystalline domains are stable up to 2 dpa. At 600°C, Fe3Si crystallites are more stable than SiC; SiC crystallites are stable up to 4 dpa while the Fe3Si crystallites are stable up to 10 dpa. These crystallites also coalescence and amorphize simultaneously during ion irradiation. The exceptional tolerance to defect formation and irradiation of the SiFeOC nanocomposite provides important guidance to developing irradiation resistant fuels for advanced gas cooled reactors.