Application of Weak-Beam Dark-Field STEM for Dislocation Loop Analysis†.

Autor:	Lin YR; Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA., Li Y; Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996, USA.; Materials Physics and Applications Division, Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA., Zinkle SJ; Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.; Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996, USA., Arregui-Mena JD; Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA., Burke MG; Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.; Characterization and Post-Irradiation Examination, Idaho National Laboratory, Idaho Falls, ID 83415, USA.
Jazyk:	angličtina
Zdroj:	Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada [Microsc Microanal] 2024 Aug 21; Vol. 30 (4), pp. 681-691.
DOI:	10.1093/mam/ozae067
Abstrakt:	Nanoscale dislocation loops formed by irradiation can significantly contribute to both irradiation hardening and embrittlement of materials when subjected to extreme nuclear reactor environments. This study explores the application of weak-beam dark-field (WBDF) scanning transmission electron microscopy (STEM) methods for quantitative irradiation-induced defect analysis in crystalline materials, with a specific focus on dislocation loop imaging and analysis. A high-purity Fe-5 wt% Cr model alloy was irradiated with 8 MeV Fe2+ ions at 450°C to a fluence of 8.8 × 1019 m-2, inducing dislocation loops for analysis. While transmission electron microscopy (TEM) has traditionally been the primary tool for dislocation imaging, recent advancements in STEM technology have reignited interest in using STEM for defect imaging. This study introduces and compares three WBDF STEM methods, demonstrating their effectiveness in suppressing background contrasts, isolating defect information for dislocation loop type classification, providing finer dislocation line images for small loop analysis, and presenting inside-outside contrast for identifying loop nature. Experimental findings indicate that WBDF STEM methods surpass traditional TEM approaches, yielding clearer and more detailed images of dislocation loops. The study concludes by discussing the potential applications of WBDF STEM techniques in defect analysis, emphasizing their adaptability across various material systems beyond nuclear materials. Competing Interests: Conflict of Interest: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. (Published by Oxford University Press on behalf of the Microscopy Society of America 2024.)
Databáze:	MEDLINE
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