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Updated: Jan 31, 2026
08:04
Preparation and Observation of Thick Biological Samples by Scanning Transmission Electron Tomography
Published on: March 12, 2017
9.9K
Large angle illumination enabling accurate structure reconstruction from thick samples in scanning transmission
H G Brown1, R Ishikawa2, G S Anchez-Santolino3
1School of Physics and Astronomy, Monash University, Victoria 3800, Australia.
Ultramicroscopy
|December 30, 2018
Summary
Large-angle-illumination scanning transmission electron microscopy (STEM) enables accurate electrostatic potential reconstruction in thicker samples. This advanced technique overcomes limitations of previous methods, allowing for better quantification in materials beyond tens of Ångströms.
Area of Science:
- Materials Science
- Electron Microscopy
- Physics
Background:
- Accurate electrostatic potential reconstruction is crucial for atomic-resolution imaging.
- Conventional methods are limited to thin, weakly scattering samples (tens of Ångströms).
Purpose of the Study:
- To develop and demonstrate a method for accurate electrostatic potential reconstruction in thicker samples.
- To overcome the limitations of existing techniques in electron microscopy.
Main Methods:
- Utilizing large-angle-illumination scanning transmission electron microscopy (STEM).
- Employing a probe-forming aperture with a convergence angle > 50 mrad.
- Applying the weak phase object approximation more effectively.
Main Results:
- Demonstrated accurate electrostatic potential reconstruction in samples over 100 Å thick.
- Showed improved adherence to the weak phase object approximation with large-angle illumination.
Conclusions:
- Large-angle-illumination STEM significantly enhances the capability for quantitative electrostatic potential mapping in thicker specimens.
- This advancement expands the applicability of electron microscopy for analyzing a wider range of materials.
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