Vacancy effects on the formation of helium and krypton cavities in 3-C-SiC irradiated and annealed at elevated temperatures

Book · Mon Feb 27 04:00:00 EST 2017

OSTI ID:1373853

Zang, Hang; Liu, Wenbo; Li, Tao; He, Chaohui; Yun, Di; Jiang, Weilin; Devaraj, Arun; Edwards, Danny J.; Henager, Charles H.; Kurtz, Richard J.; Wang, Zhiguang

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.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1373853
• Report Number(s): PNNL-SA--124009; AT2030110
• Country of Publication: United States
• Language: English

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36 MATERIALS SCIENCE