Atom counting in HAADF STEM using a statistical model-based approach: methodology, possibilities, and inherent...

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Accurate atom counting in nanostructures is crucial for understanding material properties.
• High-resolution imaging techniques like HAADF-STEM provide atomic-scale information.
• Existing methods may have limitations in precision and sensitivity.

Purpose of the Study:

• To develop and validate a statistical model-based method for quantifying atom numbers in monotype crystalline nanostructures.
• To assess the capabilities and limitations of this novel atom-counting approach.
• To demonstrate the feasibility of achieving single-atom sensitivity.

Main Methods:

• Utilizing high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) for image acquisition.
• Applying statistical parameter estimation theory to determine scattered intensities.
• Inferring probability distributions of atom counts based on experimental intensity data.

Main Results:

• A quantitative method for estimating the number of atoms per atom column was established.
• The accuracy and precision are influenced by factors like atom column number and distribution width.
• Single-atom sensitivity was demonstrated to be achievable under specific conditions.

Conclusions:

• The developed statistical method offers a robust approach for atom counting in nanostructures.
• The study highlights the importance of statistical modeling for precise atomic quantification.
• This technique advances the capabilities of electron microscopy for nanoscale material characterization.