About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
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| Symposium
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Four-Dimensional Scanning Transmission Electron Microscopy (4D STEM) for Quantitative Materials Characterization
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| Presentation Title |
Beyond Bragg Peaks: Quantitative Defect Mapping Through Diffuse Scattering in 4D-STEM |
| Author(s) |
Alexandre Richard-Henry Bordas, Madelyn I Payne, Julia Deitz, Andrew M Minor |
| On-Site Speaker (Planned) |
Alexandre Richard-Henry Bordas |
| Abstract Scope |
Conventional analysis of 4D-STEM datasets focuses on Bragg peaks, whose position and intensity reveal crystal orientation, strain, and phase. However, the diffuse scattering between the Bragg peaks, often discarded as background, encodes valuable information about the defects and short-range order that govern material behavior. Here, we shift the focus from Bragg peaks to diffuse scattering to distinguish and spatially map coexisting defect populations within single 4D-STEM scans of FCC metals. By systematically eliminating individual contributions to diffuse scattering and leveraging multi-slice simulations, we isolate specific diffuse scattering signatures for each defect type and reconstruct their spatial distributions within the scanned region. We explore FCC metals exposed to various extreme environments with distinct defect landscapes: electron-irradiated aluminum, helium-irradiated gold, and plastically deformed copper. Within these samples, we show that diffuse scattering distinguishes overlapping forms of structural disorder without additional measurements or sample modification, transforming an underutilized signal into quantitative defect maps. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, |