Quantitative Structure Determination from Experimental Four-Dimensional Scanning Transmission Electron Microscopy via...

Area of Science:

• Materials Science
• Crystallography
• Electron Microscopy

Background:

• Determining sample potential from 4D scanning transmission electron microscopy (STEM) data is challenging for thick samples due to multiple scattering.
• Existing algorithms require further development to handle complex scattering phenomena.

Purpose of the Study:

• To advance the scattering matrix approach for accurate structure determination from STEM data.
• To improve handling of partial spatial coherence, probe defocus, and dark-field imaging in electron microscopy.

Main Methods:

• Development of an enhanced scattering matrix approach for 4D STEM data analysis.
• Simulations to validate modifications for partial coherence, probe defocus, and dark-field data incorporation.
• Reconstruction of electrostatic potential using the refined method.

Main Results:

• The modified scattering matrix approach effectively handles multiple scattering in thick samples.
• Simulations demonstrated successful incorporation of partial spatial coherence, unknown probe defocus, and dark-field information.
• Accurate reconstruction of the electrostatic potential for a strontium titanate (SrTiO3) crystal was achieved.

Conclusions:

• The enhanced scattering matrix method provides a robust tool for 4D STEM-based structure determination.
• This approach offers improved quantitative agreement with expected crystal structures, even for complex samples.