Polycrystalline 3C-SiC was sequentially irradiated at 400 and 750°C with 120 keV He2+ and 4 MeV Kr15+ ions to 1017 and 41016 cm-2, respectively. The Kr15+ ions penetrated the entire depth of the He2+ ion implantation region. Three areas of He2+, Kr15+ and He2+ + Kr15+ ion implanted 3C-SiC were created through masked overlapping irradiations. The sample was subsequently annealed at 1600°C in vacuum and characterized using cross-sectional transmission electron microscopy and energy-dispersive x-ray spectroscopy. Compared to the He2+ ion only implanted 3C-SiC, helium cavities in the He2+ and Kr15+ co-implanted 3C-SiC had a smaller size but higher density. At 25 dpa, presence of He in the co-implanted 3C-SiC significantly promoted cavity growth; much smaller voids were formed in the Kr15+ ion only irradiated 3C-SiC at the same dose. In addition, local Kr migration and trapping at cavities occurred, but long-range Kr diffusion in 3C-SiC was not observed up to 1600°C.
Revised: July 25, 2020 |
Published: February 27, 2017
Citation
Zang H., W. Liu, T. Li, C. He, D. Yun, W. Jiang, and A. Devaraj, et al. 2017.VACANCY EFFECTS ON THE FORMATION OF HELIUM AND KRYPTON CAVITIES IN 3C-SiC IRRADIATED AND ANNEALED AT ELEVATED TEMPERATURES. In Fusion Materials Semiannual Progress Report For Period Ending December 31, 2016, edited by Dl Clark. 67-68. Oak Ridge, Tennessee:Oak Ridge National Laboratory.PNNL-SA-124009.