Regensburg 2025 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 34: Development of Calculation Methods

MM 34.1: Vortrag

Freitag, 21. März 2025, 10:15–10:30, H10

Enhancing 3D Volume Reconstruction in Atom Probe Tomography through Curvature-Based Tip Shape Analysis — Sebastian Eich and •Guido Schmitz — Department for Materials Physics, Institute for Materials Science, University of Stuttgart

Atom Probe Tomography (APT) provides chemical analysis of nanometric volumes with single-atom sensitivity in 3D. Traditionally, reconstruction assumes a hemispherical tip shape, which can lead to significant distortions, especially due to local magnification effects.

Instead of relying on in-situ correlative microscopy, we propose a numerical method to extract the emitter shape from the event density statistics on the 2D detector plane. This method is based on the fundamental relationship between event density and the local Gaussian curvature of the tip surface, with no mathematical restrictions other than convexity. By knowing the curvature and assuming suitable boundary conditions, the surface profile can be uniquely reconstructed, bypassing the need for a hemispherical assumption.

The method is implemented as an easy-to-use Python module, which will be demonstrated using various simulated and experimental datasets involving complex tip shapes. This approach significantly reduces the local magnification effects at material interfaces with contrasting evaporation thresholds and is expected to improve the accuracy of atom probe reconstructions.