![]() ![]() ![]() The raster scan has a primary advantage in that the signal acquired at each scan position can readily be assigned to a pixel, which is the basic unit in image storage and analysis techniques. To date, the only scan path that has been widely adopted in imaging mode is the raster scan, whereby the electron beam scans from left to right rapidly and top to bottom more slowly. Spectroscopy data such as energy dispersive X-ray (EDS) and electron energy loss spectroscopy (EELS) can be simultaneously acquired using the same local probe 6, 7, 8, 9. The electron beam formed in an C s-aberration-corrected STEM is the smallest available probe that can be accessed and controlled for scientific research 2, 4, 5. Scanning transmission electron microscopy (STEM) is an extremely versatile tool for materials characterization, offering sub-Å spatial resolution and sub-second temporal resolution 1, 2, 3. The methodology presented here will be useful for in situ STEM imaging at higher temporal resolution and for imaging beam sensitive materials. Through the combined application of constant linear velocity scanning and beam path corrections, spiral scan images are shown to exhibit less scan distortion than conventional raster scan images. We then show that such characteristic functions can be used to correct image distortions present in more complicated constant linear velocity spirals, where the frequency varies within each scan. “Archimedean” spirals, with a constant angular frequency within each scan, are used to determine the characteristic response at different frequencies. Although spiral scanning avoids the sudden changes in the beam location (fly-back distortion) present in conventional raster scans, it is not distortion-free. image distortions, we use spiral scanning paths, allowing precise control of a sub-Å sized electron probe within an aberration-corrected STEM. ![]() The fast and precise control of the STEM probe is, however, challenging because the true beam location deviates from the assigned location depending on the properties of the deflectors. Atomic-resolution imaging in an aberration-corrected scanning transmission electron microscope (STEM) can enable direct correlation between atomic structure and materials functionality. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |