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Updated: Mar 7, 2026
Sample Preparation and Experimental Design for In Situ Multi-Beam Transmission Electron Microscopy Irradiation Experiments
Published on: June 27, 2022
Correlative micro-diffraction and differential phase contrast study of mean inner potential and subtle beam-specimen
Mingjian Wu1, Erdmann Spiecker1
1Institute of Micro- and Nanostructure Research & Center for Nanoanalysis and Electron Microscopy (CENEM), Department of Materials Science, Universität Erlangen-Nürnberg, Cauerstraße 6, D-91058 Erlangen, Germany.
We determined the mean inner potential (MIP) of silicon and gallium arsenide using correlative micro-diffraction and differential phase contrast STEM. Subtle beam-specimen interactions were explained through experiment and simulation, enabling potential probing in sensitive samples.
Area of Science:
- Materials Science
- Electron Microscopy
- Solid-State Physics
Background:
- Accurate determination of the mean inner potential (MIP) is crucial for quantitative analysis in transmission electron microscopy.
- Understanding beam-specimen interactions, especially at sample edges, is essential for reliable measurements.
- Differential Phase Contrast (DPC) and micro-diffraction are powerful techniques for nanoscale material characterization.
Purpose of the Study:
- To precisely measure the MIP of silicon (Si) and gallium arsenide (GaAs) using correlative micro-diffraction and DPC-STEM.
- To investigate and explain the origin of subtle electron beam-specimen interactions at the edges of wedge-shaped crystals.
- To assess the impact of Fresnel fringes on DPC-STEM measurements and explore their potential for contactless probing.
Main Methods:
- Correlative micro-diffraction and DPC studies were performed using scanning transmission electron microscopy (STEM).
- MIP values were determined by directly evaluating electron beam refraction in micro-diffraction mode.
- Numerical simulations were implemented to reproduce and analyze the effect of the specimen on Fresnel fringe patterns.
Main Results:
- MIP values for Si and GaAs were measured as 12.48 ± 0.22 V and 14.15 ± 0.22 V, respectively.
- DPC-STEM measurements yielded highly consistent MIP values.
- Excellent agreement was achieved between experimental observations and numerical simulations of Fresnel fringe displacements near sample edges.
Conclusions:
- The study successfully determined the MIP of Si and GaAs with high accuracy.
- Subtle beam-specimen interactions, including Fresnel fringe effects, were quantitatively understood through combined experimental and simulation approaches.
- The findings suggest a novel method for pseudo-contactless probing of weak potential differences in beam-sensitive materials by analyzing Fresnel fringe displacements.
