Surface Morphology Studies by Low-Energy Electron Microscopy (LEEM)
| Autor: | Waclaw Swiech, Ernst Bauer, Michael Mundschau, W. Telieps |
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| Rok vydání: | 1990 |
| Předmět: | |
| Zdroj: | Proceedings, annual meeting, Electron Microscopy Society of America. 48:294-295 |
| ISSN: | 2690-1315 0424-8201 |
| DOI: | 10.1017/s0424820100180227 |
| Popis: | The morphology of a surface determines to a large extent its physical and chemical properties. In order to understand these properties it is frequently sufficient to image the surface with a resolution in the 10 nm range, provided that the relevant surface features show sufficient contrast, as is the case in LEEM. The talk discusses the morphology information which can be obtained with LEEM and illustrates it with various examples.Point defects, e.g. emergence points of screw dislocations, or point-like defects such as small impurity clusters cannot be resolved in LEEM but nevertheless imaged by decorating them (screw dislocations) or by their influence on surface processes (pinning centers in sublimation). Line defects, e.g. sublimation steps, growth steps or glide lines, may be imaged directly down to atomic height by geometric phase contrast or indirectly by decoration. If a step separates regions with different structures (e.g. domain orientations), then ordinary diffraction contrast will reveal the shape and location of the step. Planar defects can also be imaged by diffraction contrast but three-dimensional defects such as large sublimation hillocks frequently cause also topographic contrast. |
| Databáze: | OpenAIRE |
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