Dresden 2017 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 32: Microstructure and Phase Transformations - detection methods

MM 32.6: Vortrag

Dienstag, 21. März 2017, 13:00–13:15, IFW B

Trajectory-based reconstruction in atom probe tomography — •Daniel Beinke, Christian Oberdorfer, and Guido Schmitz — Institut für Materialwissenschaft, Universität Stuttgart

Atom probe tomography provides detailed three dimensional chemical information of a wide range of materials by the field evaporation of needle-shaped specimens. The field-evaporated ions are accelerated towards a detector and the time-of-flight as well as the hit position is measured. The reconstruction of the recorded detector events is critical in order to access the three dimensional information of the analyzed material. The standard reconstruction approach, introduced by Bas et al. [1], is based on a linear point projection between the measured detector position and a projection point located on the tip axis. The most remarkable success of this technique is the ability to recover lattice planes. However, characteristic artifacts occur, especially in the case of significantly different evaporation fields, i.e. near grain boundaries or in multicomponent layer structures. In this work, a concept for a reconstruction technique based on the calculation of realistic ion trajectories is presented. In a first step, the approach is tested on a rigid lattice [2]. Afterwards, the technique is expanded in order to deal with a limited detector efficiency and an unrestricted set of possible positions for the reconstruction of single atoms.

[1] P. Bas et al., Appl Surf Sci 87 (1995) 298-304. [2] D. Beinke et al., Ultramicroscopy 165 (2016) 34-41.