Abstract
Image interpretation for Scanning Tunneling Microscopy (STM) is complicated by inadequate tip characterization. Tip and surface features can be difficult to separate, especially for rough surfaces. Figure 1, an STM image of a gold platelet deposited onto graphite, illustrates some of the possible problems. The doubled image of the platelet and step, for example, is a commonly encountered image artifact caused by tunneling from multiple tip asperities. The shape of the platelet(s) may also be an artifact since they are usually round. Ordinarily, to confirm the interpretation of such objects, experiments would be repeated using different tips and specimens to test for reproducibility. This is not an ideal procedure since the exact experimental conditions are difficult to duplicate. Alternatively, by comparing images of the same topography taken by STM and an independent imaging method, one can expose these artifacts.STM image artifacts were studied using an STM operating inside a Philips EM 400T TEM. This allowed imaging of the same region by Reflection Electron Microscopy (REM) and STM, independently of each other.
Publisher
Cambridge University Press (CUP)
Reference5 articles.
1. 5. This work is supported by NSF grant #DMR 90-15867 and the NSF/ASU National Center for High Resolution Electron Microscopy at Arizona State University. Special thanks to Uwe Knipping and the Staff of the Center for HREM and the Physics Machine and Electronic Shops for their technical assistance.
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3. Observation of the graphite surface by reflection electron microscopy during STM operation
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