Towards better 3-D reconstructions by combining electron tomography and atom-probe tomography

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Three-dimensional nanoscale imaging is crucial for materials characterization.
• Scanning transmission electron microscope tomography (STEM tomography) and atom-probe tomography (APT) are powerful but distinct 3D nanoscale techniques.
• Understanding the artifacts and limitations of each technique is essential for accurate data interpretation.

Purpose of the Study:

• To directly compare STEM tomography and APT by analyzing the identical volume of an aluminum-silver (Al-Ag) alloy.
• To experimentally visualize and understand the theoretically known artifacts associated with each technique.
• To provide insights into optimizing reconstruction parameters and assessing data quality for nanoscale 3D materials analysis.

Main Methods:

• Utilized a dual-beam focused ion beam (FIB) system for site-specific sample preparation.
• Acquired 3D datasets from the exact same volume of an Al-Ag alloy using both STEM tomography and APT.
• Correlated and compared the reconstructed 3D datasets from both techniques.

Main Results:

• Direct experimental visualization of artifacts inherent to STEM tomography and APT reconstructions.
• Identification of specific regions and features where each technique excels or shows limitations.
• Quantitative assessment of morphological and compositional accuracy at the nanoscale for both methods.

Conclusions:

• The combined use of STEM tomography and APT enables a more comprehensive and accurate nanoscale materials characterization.
• Experimental artifact visualization aids in selecting optimal parameters for improved reconstruction fidelity.
• This correlative approach advances the understanding and application of 3D nanoscale imaging techniques in materials science.