Abstract
In this paper the influence of Bloch wave states on high angle annular dark field image contrast is studied quantitatively by Bloch wave and multislice simulations. We show that states are excited beyond a critical value and cause a long period oscillation of the electron probe wave function that significantly influences the contrast. As a result, we find that the contrast for high alloys remains thickness dependent up to high sample thicknesses and this effect has to be considered for compositional analysis. In the special case of ordered alloys, the impact of excitations on intensity provides a way to quantify long-range order phenomena in alloys with known composition.
- Received 23 May 2019
- Revised 6 September 2019
DOI:https://doi.org/10.1103/PhysRevB.100.184106
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