Dresden 2011 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 31: Postersitzung II
MM 31.25: Poster
Mittwoch, 16. März 2011, 17:15–18:45, P5
Differences of the evaporation field in dependence of the crystallographic direction in Al and W by means of Atom probe tomography — •Torben Boll1,2 and Talaat Al-Kassab1,2 — 1Division of Physical Sciences and Engineering King Abdullah University of Science and Technology, 23955-6900 Thuwal, Saudi Arabia — 2Institut für Materialphysik, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
In field ion microscope (FIM) images the dependence of the brightness of the crystallographic direction is easily observed. This difference in brightness can be related to the evaporation fields at different poles. However this approach allows only a rough qualitative estimation. In this paper an approach will be presented, which utilizes the newly available Wide Angle Atom Probe Tomography (WA-APT) to identify quantitative relations.
The method will be discussed for pure Al- and W-samples. The results are relevant for the development of reconstruction algorithms in WA-APT. Current instruments can analyze a projection angle of about 70∘ compared to 20∘, which was state of the art 10 years ago. Thus the assumption of hemispherical, symmetrical tips for the reconstruction is not valid anymore. Evaporation fields can be used to identify a complex tip shape and lead to more accurate reconstructions.