Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8037947 | Ultramicroscopy | 2016 | 19 Pages |
Abstract
Low-angle annular dark field (LAADF) scanning transmission electron microscopy (STEM) imaging is presented as a method that is sensitive to the oxidation state of cerium ions in CeO2 nanoparticles. This relationship was validated through electron energy loss spectroscopy (EELS), in situ measurements, as well as multislice image simulations. Static displacements caused by the increased ionic radius of Ce3+ influence the electron channeling process and increase electron scattering to low angles while reducing scatter to high angles. This process manifests itself by reducing the high-angle annular dark field (HAADF) signal intensity while increasing the LAADF signal intensity in close proximity to Ce3+ ions. This technique can supplement STEM-EELS and in so doing, relax the experimental challenges associated with acquiring oxidation state information at high spatial resolutions.
Related Topics
Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
Aaron C. Johnston-Peck, Jonathan P. Winterstein, Alan D. Roberts, Joseph S. DuChene, Kun Qian, Brendan C. Sweeny, Wei David Wei, Renu Sharma, Eric A. Stach, Andrew A. Herzing,