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Updated: May 12, 2026
08:04
Preparation and Observation of Thick Biological Samples by Scanning Transmission Electron Tomography
Published on: March 12, 2017
Phase-contrast imaging in aberration-corrected scanning transmission electron microscopy
F Krumeich1, E Müller, R A Wepf
1Laboratory of Inorganic Chemistry, ETH Zurich, Wolfgang-Pauli-Strasse 10, 8093 Zurich, Switzerland. krumeich@inorg.chem.ethz.ch
Micron (Oxford, England : 1993)
|April 13, 2013
Summary
Phase-contrast scanning transmission electron microscopy (PC-STEM) offers a powerful alternative for material characterization. This technique provides detailed structural insights, especially for nanoparticles and quasicrystals, by analyzing phase contrast in bright field images.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Electron Microscopy
Background:
- Phase contrast in scanning transmission electron microscopy (STEM) has long been recognized.
- Aberration-corrected microscopes enable systematic exploitation of phase contrast for material structural characterization.
- Phase-contrast STEM (PC-STEM) is emerging as a key alternative to high-resolution transmission electron microscopy (HRTEM).
Purpose of the Study:
- To explore the systematic application of phase-contrast STEM for materials analysis.
- To investigate the imaging behavior of PC-STEM, particularly the projection of crystal potential.
- To demonstrate the utility of PC-STEM through case studies.
Main Methods:
- Utilizing aberration-corrected STEM with large illumination angles for PC-STEM.
- Analyzing image contrast generation, which depends on illumination/collection angles, defocus, and specimen thickness.
- Employing standard HRTEM simulation software based on the principle of reciprocity to study imaging behavior.
Main Results:
- PC-STEM provides a projection of crystal potential in thin specimens.
- Scattering sites appear with either dark or bright contrast at specific defocus values near Gaussian defocus.
- Successful application of PC-STEM to characterize metal nanoparticles and dodecagonal quasicrystals (dd-(Ta,V)₁.₆Te).
Conclusions:
- PC-STEM is a valuable technique for detailed structural analysis of materials.
- The method allows for clear visualization of atomic structures through phase contrast manipulation.
- PC-STEM complements existing microscopy techniques for advanced materials research.
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