Ag out-surface diffusion in crystalline SiC with an effective SiO₂ diffusion barrier

Journal Article · Thu May 07 04:00:00 EDT 2015 · Journal of Nuclear Materials

DOI:https://doi.org/10.1016/j.jnucmat.2015.05.001· OSTI ID:1265823

Xue, H. ^[1]; Xiao, H. Y. ^[1]; Zhu, Z. ^[2]; Shutthanandan, V. ^[2]; Snead, L. L. ^[3]; Boatner, L. A. ^[3]; Weber, W. J. ^[4]; Zhang, Y. ^[4]

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1. Univ. of Tennessee, Knoxville, TN (United States)
2. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
4. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

For applications of tristructural isotropic (TRISO) fuel particles in high temperature reactors, release of radioactive Ag isotope (^110mAg) through the SiC coating layer is a safety concern. In order to understand the diffusion mechanism, Ag ion implantations near the surface and in the bulk were performed by utilizing different ion energies and energy-degrader foils. High temperature annealing was carried out on the as-irradiated samples to study the possible out-surface diffusion. Before and after annealing, Rutherford backscattering spectrometry (RBS) and secondary ion mass spectrometry (SIMS) measurements were employed to obtain the elemental profiles of the implanted samples. Our results suggest little migration of buried Ag in the bulk, and an out-diffusion of the implanted Ag in the near-surface region of single crystal SiC. It is also found that a SiO₂ layer, which was formed during annealing, may serve as an effective barrier to reduce or prevent Ag out diffusion through the SiC coating layer.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE); USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1265823
• Journal Information: Journal of Nuclear Materials, Journal Name: Journal of Nuclear Materials Journal Issue: C Vol. 464; ISSN 0022-3115
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE