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O: Fachverband Oberflächenphysik
O 87: Methods: Other (experimental)
O 87.6: Vortrag
Freitag, 26. März 2010, 12:30–12:45, H42
Surfaces of Customary Materials - a LEEM Study on Polycrystalline Iron — •Benjamin Borkenhagen1, Thorsten Franz2, Gerhard Lilienkamp1, and Winfried Daum1 — 1Institute of Energy Research and Physical Technologies, TU Clausthal, Leibnizstr. 4, 38678 Clausthal-Zellerfeld — 2ELMITEC GmbH, Albrecht-von-Grodeck-Str. 3, 38678 Clausthal-Zellerfeld
Most contemporary surface science studies are focussed on single crystal surfaces and adsorbates on single crystalline substrates with a limited variety of structural details and surface symmetries. Customary materials, however, are mainly polycrystalline with a large variety of defects and surface orientations which frequently have an important influence on surface processes. The study of such samples needs simultaneously high lateral resolution, information about the local surface symmetry and laterally resolved spectroscopic data. We have applied low energy electron microscopy (LEEM) to polished polycrystalline Fe samples which have been cut from pure bulk material to demonstrate that LEEM/PEEM-related methods meet these requirements. First results exhibit characteristic surface structures depending on the orientation of the grains. Single atomic steps and step bunches are well resolved, and the run of the steps is strongly influenced by grain boundaries and local tension in the microstructure. Small-area LEED with the microscope supplies first information concerning surface lattice and orientation of the grains. Due to the fast image acquisition investigations of thermally activated transformations of the texture and surface reactions appear promising.