Towards an accurate volume reconstruction in atom probe tomography

Area of Science:

• Materials Science
• Analytical Chemistry
• Computational Physics

Background:

• Atom probe tomography (APT) is a powerful technique for 3D material analysis.
• Traditional APT reconstruction methods can introduce geometric distortions, particularly with complex sample topographies or varying material properties.
• Accurate reconstruction is crucial for reliable interpretation of nanoscale material structures.

Purpose of the Study:

• To develop and present an alternative concept for atom probe data reconstruction.
• To improve the geometric accuracy of reconstructed 3D material structures compared to existing methods.
• To address limitations of traditional reconstruction schemes in handling samples with significant variations.

Main Methods:

• A novel reconstruction concept based on calculating realistic ion trajectories.
• Utilizing a recursive refinement process for trajectory calculation.
• Solving the electrostatic problem on a Delaunay tessellation.
• Inverting the reconstruction order to reconstruct the last detected atom first.

Main Results:

• The proposed method successfully reconstructs 3D model tips with precipitates and embedded layers.
• Significant improvements in the geometric accuracy of layers and particles were observed.
• The new approach mitigates distortions common in traditional reconstruction methods for challenging samples.
• The defined emitter shape throughout reconstruction enhances trajectory accuracy.

Conclusions:

• The electrostatically informed reconstruction approach offers superior geometric fidelity for atom probe data.
• This method provides a more accurate representation of nanoscale material features, especially for complex architectures.
• The inverted reconstruction order and realistic trajectory calculations are key to the improved performance.