Preprint Open Access

# Insights into image contrast from dislocations in ADF-STEM

Oveisi, E; Spadaro, M.C.; Rotunno, Enzo; Grillo, Vincenzo; Hébert, C

### Citation Style Language JSON Export

{
"DOI": "10.1016/j.ultramic.2019.02.004",
"author": [
{
"family": "Oveisi, E"
},
{
},
{
"family": "Rotunno, Enzo"
},
{
"family": "Grillo, Vincenzo"
},
{
"family": "H\u00e9bert, C"
}
],
"issued": {
"date-parts": [
[
2020,
5,
20
]
]
},
"abstract": "<p>Competitive mechanisms contribute to image contrast from dislocations in annular dark-field scanning&nbsp;<a href=\"https://www.sciencedirect.com/topics/physics-and-astronomy/transmission-electron-microscopy\">transmission electron microscopy</a>&nbsp;(ADF-STEM). A clear theoretical understanding of the mechanisms underlying the ADF-STEM contrast is therefore essential for correct interpretation of dislocation images. This paper reports on a systematic study of the ADF-STEM contrast from dislocations in a GaN specimen, both experimentally and computationally. Systematic experimental ADF-STEM images of the edge-character dislocations reveal a number of characteristic contrast features that are shown to depend on both the angular detection range and specific position of the dislocation in the sample. A theoretical model based on electron channelling and Bloch-wave scattering theories, supported by numerical simulations based on Grillo&#39;s strain-channelling equation, is proposed to elucidate the physical origin of such complex contrast phenomena.</p>",
"title": "Insights into image contrast from dislocations in ADF-STEM",
"type": "article",
"id": "3836149"
}
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