Recovery of Close Frenkel Pairs Produced by Low Energy Recoils in SiC

Journal Article · Wed Oct 01 04:00:00 EDT 2003 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.1605254· OSTI ID:15004584

Gao, Fei ^[1]; Weber, William J ^[1]

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1. BATTELLE (PACIFIC NW LAB)

The analysis of defects generated by displacement cascades in silicon carbide shows that most defects are point defects that are displaced at a small distance from their original sites. These defects play important roles in the recovery processes observed experimentally. Only 20% of total the interstitials produced become freely migrating defects that can contribute to microstructural evolution during irradiation of SiC. The stable defect configurations in this study were created with low-energy recoils using molecular dynamics (MD) methodology, with most defects being C Frenkel pairs. These stable Frenkel pairs have been annealed at different temperatures, using MD methods, to determine the time required for interstitials to recombine with vacancies. The MD data have been analyzed using an Arrhenius relation, and the estimated activation energies for defect recovery is between 0.22 and 1.6 eV for C Frenkel pairs and between 0.28 and 0.9 eV for Si Frenkel pairs. The low activation energies qualitatively overlap with experimental values observed during Stage I recovery. Thus, the present results suggest that the Stage I is associated with the spontaneous recovery of Frenkel pairs. Based on the data obtained, the spontaneous recombination distance is determined to be 0.66 and 0.70 ao for the C and Si sublattices, respectively.

• Research Organization: Pacific Northwest National Lab., Richland, WA (US); Environmental Molecular Sciences Laboratory (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 15004584
• Report Number(s): PNNL-SA-38591; 3448; KC0201020
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 7 Vol. 94
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CLOSE-PAIR DEFECTS
ENVIRONMENTAL MOLECULAR SCIENCES LABORATORY
SILICON CARBIDE
FRENKEL DEFECTS
INTERSTITIALS
IRRADIATION
MOLECULAR DYNAMICS
MOLECULAR DYNAMICS METHOD
POINT DEFECTS
RECOMBINATION
SILICON CARBIDES