Observations of He Platelets During He Ion Irradiation in 3C SiC

Abstract Polycrystalline 3C SiC was irradiated and observed in-situ via Transmission Electron Microscopy with a 20keV He ion beam at 400, 800, 1000 and 1200°C at the Microscopes and Ion Accelerators for Materials Investigations facility. During the 400, 800, 1000 and 1200°C irradiations, black-spot damage was observed at 3.1, 1.1, 2.1 and 2.1 dpa respectively. Helium bubbles were observed after 6.3 dpa at 400°C and 2.1 dpa at 800°C, and He platelets were seen after 1.1 dpa at 800, 1000 and 1200°C but not observed during the 400°C irradiation. This work shows for the first time, the preferential nucleation of platelets within stacking faults in 3C SiC. The dependence of He platelet diameter with temperature and dose has also been observed.