Polycrystalline 3C-SiC was sequentially irradiated at 400 and 750°C with 120 keV He2+ and 4 MeV Kr15+ ions to E21 and 4E20 ions/m2 with profiles of the implanted species peaked at 450 and 1500 nm, respectively. The masked overlapping irradiation created three study areas of He2+, Kr15+ and He2+ + Kr15+ implanted SiC. The doses at the depth of the peak He concentration in He2+ and He2+ + Kr15+ implanted SiC correspond to 4 and 25 dpa. The sample was subsequently annealed at 1600°C for 3 h in vacuum and characterized using cross-sectional transmission electron microscopy and energy-dispersive x-ray spectroscopy. Compared to the He2+ implanted SiC, He cavities show a smaller size and higher density in the co-implanted SiC. At 25 dpa, He presence in the co-implanted 3C-SiC significantly promotes He cavity growth, as contrasted to the smaller voids formed without He in the Kr15+ irradiated SiC at the same dose. In addition, local Kr migration and trapping at cavities occur, but long-range Kr diffusion in SiC is not observed up to 1600°C.
Revised: July 25, 2020 |
Published: November 24, 2016
Citation
Zang H., W. Jiang, W. Liu, A. Devaraj, D.J. Edwards, C.H. Henager, and R.J. Kurtz, et al. 2016.Vacancy effects on the formation of He and Kr cavities in 3C-SiC irradiated and annealed at elevated temperatures.Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms 389-390.PNNL-SA-119364.doi:10.1016/j.nimb.2016.11.017