| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1677637 | Ultramicroscopy | 2012 | 6 Pages |
We discuss interesting haloing effects observed in experimental images of gold nanoparticles obtained using aberration-corrected scanning transmission electron microscopy (STEM) employing the low-angle annular dark-field (LAADF) imaging mode. The LAADF images contained bright rings of intensity (halos) with a diameter equal to or smaller than the diameter of the nanoparticle, the diameter varying as a function of the defocus of the STEM probe. Numerical simulations reveal that the halos are only present if the nanoparticles are imaged down a zone axis. Since the halos were observed in nearly all experimental images, this suggests that the nanoparticles become oriented along crystal zone axes during imaging.
► Haloing effects were observed in experimental LAADF images of gold nanoparticles. ► The diameter of the halos varied as a function of the defocus of the STEM probe. ► Halos are only present if the nanoparticles are imaged down a zone axis. ► Halos were ubiquitous, suggesting orientation along zone axes during imaging.
