About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advanced Characterization Techniques for Quantifying and Modeling Deformation
|
| Presentation Title |
Characterization of Nanoscale Dislocation Loops Via High-Accuracy g·b Analysis with Higher Order Reflections |
| Author(s) |
Yao Li, Austin Houston, Ziang Yu, Zehui Qi, Siwei Chen, Yajie Zhao, Steven Zinkle, Gerd Duscher, Blas Uberuaga, Benjamin Derby |
| On-Site Speaker (Planned) |
Yao Li |
| Abstract Scope |
Dynamic environments, like irradiation and stress loading, can induce dislocation loops into materials, whose formation and evolution significantly alter the material’s mechanical performance. To extract the properties of dislocation loops, electron-diffraction-based techniques are key tools. Among them, the g·b invisibility criterion is the exclusive method to determine a dislocation’s Burgers vector, especially in conventional or scanning transmission electron microscopy (CTEM or STEM). However, residual contrast arising from the edge component undermines the criterion, leading to unreliability in analyzing tiny loops with diameters < ~10 nm in typical bright field imaging in CTEM. This presentation will report on a novel method to image dislocation loops, whose diameters are close to the resolution limit of electron diffraction contrast techniques (~1 nm) by a combination of weak-beam dark-field imaging in STEM formed by second-order reflection beams. We also provide a new routine to reveal the vacancy vs. interstitial loop nature of tiny loops. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, Nanotechnology, Iron and Steel |