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Imaging Point Defects with Quantitative STEM

Au NP Arrow Plot

Imaging Point Defects with Quantitative STEM

PIs: Paul M. Voyles, Dane Morgan (UW-Madison)

Staff, Students, and post-docs: Alex Kvit, Andrew Yankovich, Jie Feng, Yipeng Cao, Chenyu Zhang

Support: Department of Energy Basic Energy Sciences DE-FG02-08ER46547

This project develops new, computationally-assisted tools for quantitative high-resolution scanning transmission electron microscopy (STEM) characterization of the structure of materials. By adapting tools from data science and image processing, we can overcome instrumental limitations and achieve unprecedented data quality and precision, including resolving positions of atoms to better than 1 pm (10-12 m).  We have applied these techniques to the surface structure of nanocatalysts and direct imaging of single point defects in fuel cell materials. For additional information: http://tem.msae.wisc.edu/research/stem-imaging/

Watch a video of the Non-rigid registration of STEM images:

 

photo caption: High precision STEM image of a Au nanoparticle, derived by non-rigid registration and averaging of a series of short exposure images. Each red dot marks the position of a column of Au atoms.  The arrows represent the displacements (strains) of surface atoms away from their ideal lattice positions, multiplied by 10 to make them visible.  Even though each atomic column is covered by only 16 pixels in the image, their center positions can be located to better than 2 pm precision.