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Quantitative Atomic-Site Analysis of Functional Dopants/Point Defects in Crystalline Materials by Electron-Channeling-Enhanced Microanalysis
Published on: May 10, 2021
Measurement of potential distribution function on object surface by using an electron microscope in the mirror
1Institute of Physics, University Mainz, Staudingerweg 7, 55099 Mainz, Germany. nepijko@uni-mainz.de
Journal of Microscopy
|April 14, 2010
Summary
This study presents a quantitative theory for electron microscope image contrast in mirror operation mode. It enables calculating surface potential and microfields from observed current density distributions.
Area of Science:
- Surface science
- Electron microscopy
- Physical chemistry
Background:
- Electron microscopes in mirror operation mode are crucial for surface analysis.
- Understanding image contrast is key to interpreting surface potential and electric fields.
- Previous theories lacked quantitative correlation for microfield analysis.
Purpose of the Study:
- To develop a quantitative theory for image contrast in electron microscopy (mirror operation mode).
- To establish a method for calculating surface potential distribution from electron microscope screen data.
- To enable the quantification of local electric microfields on object surfaces.
Main Methods:
- Development of a quantitative theory relating object surface potential to electron microscope screen current density.
- Utilizing the theory to calculate potential distribution from measured current density data.
- Analysis of electron trajectory perturbations caused by local electric fields.
Main Results:
- A quantitative theory for image contrast in mirror operation mode electron microscopy was established.
- The theory allows calculation of surface potential distribution from screen current density.
- Local electric fields were quantitatively correlated with current density redistribution, enabling microfield magnitude calculation.
- Analysis of spiral adsorbate structures on Pt(110) during CO oxidation revealed contact potential differences of a few hundredths of a volt.
Conclusions:
- The developed theory provides a robust method for quantitative surface potential and microfield analysis using electron microscopy.
- This approach is applicable to studying surface phenomena like adsorbate structures and reactions.
- The findings demonstrate the potential for precise measurement of surface properties at the microscale.
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