Integrative Atom Probe Tomography Using Scanning Transmission Electron Microscopy-Centric Atom Placement as a Step...

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Current atom probe tomography (APT) reconstruction methods suffer from geometric artifacts.
• These artifacts arise from reliance on empirical factors in volume reconstruction.
• Accurate 3D atomic-scale visualization is crucial for materials characterization.

Purpose of the Study:

• To develop a new APT reconstruction technique that eliminates geometric artifacts.
• To enable accurate 3D reconstruction of atomic positions and specimen geometry.
• To provide a more reliable method for analyzing nanostructured materials.

Main Methods:

• Utilized transmission electron microscopy (TEM) and diffraction to define specimen geometry and crystal structure before and after APT analysis.
• Implemented a bottom-up reconstruction approach using post-APT TEM images to guide data placement.
• Employed transmission electron diffraction to quantify the relationship between atomic positions and evaporated volume.

Main Results:

• Successfully reconstructed a ZnMgO:Ga epitaxial layer on c-plane sapphire with correct 3D geometry and atomic spacings.
• Demonstrated APT data reconstruction without empirical parameters in the reverse projection algorithm.
• Validated the new method's ability to overcome traditional geometric artifacts.

Conclusions:

• The developed APT reconstruction technique provides artifact-free 3D volumes.
• Integrating TEM and diffraction data with APT analysis offers superior geometric accuracy.
• This method advances the precise characterization of materials at the atomic scale.