Diffraction effects and inelastic electron transport in angle-resolved microscopic imaging applications
We analyse the signal formation process for scanning electronmicroscopic imaging applications on crystalline specimens. Inaccordance with previous investigations, we find nontrivialeffects of incident beam diffraction on the backscattered elec-tron distribution in energy and momentum. Specifically,...
| Päätekijät: | , , , , , , , |
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| Aineistotyyppi: | Journal article |
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Wiley
2017
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| _version_ | 1826269928928313344 |
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| author | Winkelmann, A Nolze, G Vespucci, S Naresh-Kumar-Cowan, G Trager-Cowan, C Vilalta-Clementes, A Wilkinson, A Vos, M |
| author_facet | Winkelmann, A Nolze, G Vespucci, S Naresh-Kumar-Cowan, G Trager-Cowan, C Vilalta-Clementes, A Wilkinson, A Vos, M |
| author_sort | Winkelmann, A |
| collection | OXFORD |
| description | We analyse the signal formation process for scanning electronmicroscopic imaging applications on crystalline specimens. Inaccordance with previous investigations, we find nontrivialeffects of incident beam diffraction on the backscattered elec-tron distribution in energy and momentum. Specifically, inci-dent beam diffraction causes angular changes of the backscat-tered electron distribution which we identify as the dominantmechanism underlying pseudocolour orientation imaging us-ing multiple, angle-resolving detectors. Consequently, diffrac-tion effects of the incident beam and their impact on the sub-sequent coherent and incoherent electron transport need tobe taken into account for an in-depth theoretical modelling ofthe energy- and momentum distribution of electrons backscat-tered from crystalline sample regions. Our findings have impli-cations for the level of theoretical detail that can be necessaryfor the interpretation of complex imaging modalities such aselectron channelling contrast imaging (ECCI) of defects in crys-tals. If the solid angle of detection is limited to specific regionsof the backscattered electron momentum distribution, the im-age contrast that is observed in ECCI and similar applicationscan be strongly affected by incident beam diffraction and topo-graphic effects from the sample surface. As an application, wedemonstrate characteristic changes in the resulting images ifdifferent properties of the backscattered electron distributionare used for the analysis of a GaN thin film sample containingdislocations. |
| first_indexed | 2024-03-06T21:32:53Z |
| format | Journal article |
| id | oxford-uuid:4543c03a-a3da-43d1-94cc-6c43ffa43ec8 |
| institution | University of Oxford |
| last_indexed | 2024-03-06T21:32:53Z |
| publishDate | 2017 |
| publisher | Wiley |
| record_format | dspace |
| spelling | oxford-uuid:4543c03a-a3da-43d1-94cc-6c43ffa43ec82022-03-26T15:06:48ZDiffraction effects and inelastic electron transport in angle-resolved microscopic imaging applicationsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:4543c03a-a3da-43d1-94cc-6c43ffa43ec8Symplectic Elements at OxfordWiley2017Winkelmann, ANolze, GVespucci, SNaresh-Kumar-Cowan, GTrager-Cowan, CVilalta-Clementes, AWilkinson, AVos, MWe analyse the signal formation process for scanning electronmicroscopic imaging applications on crystalline specimens. Inaccordance with previous investigations, we find nontrivialeffects of incident beam diffraction on the backscattered elec-tron distribution in energy and momentum. Specifically, inci-dent beam diffraction causes angular changes of the backscat-tered electron distribution which we identify as the dominantmechanism underlying pseudocolour orientation imaging us-ing multiple, angle-resolving detectors. Consequently, diffrac-tion effects of the incident beam and their impact on the sub-sequent coherent and incoherent electron transport need tobe taken into account for an in-depth theoretical modelling ofthe energy- and momentum distribution of electrons backscat-tered from crystalline sample regions. Our findings have impli-cations for the level of theoretical detail that can be necessaryfor the interpretation of complex imaging modalities such aselectron channelling contrast imaging (ECCI) of defects in crys-tals. If the solid angle of detection is limited to specific regionsof the backscattered electron momentum distribution, the im-age contrast that is observed in ECCI and similar applicationscan be strongly affected by incident beam diffraction and topo-graphic effects from the sample surface. As an application, wedemonstrate characteristic changes in the resulting images ifdifferent properties of the backscattered electron distributionare used for the analysis of a GaN thin film sample containingdislocations. |
| spellingShingle | Winkelmann, A Nolze, G Vespucci, S Naresh-Kumar-Cowan, G Trager-Cowan, C Vilalta-Clementes, A Wilkinson, A Vos, M Diffraction effects and inelastic electron transport in angle-resolved microscopic imaging applications |
| title | Diffraction effects and inelastic electron transport in angle-resolved microscopic imaging applications |
| title_full | Diffraction effects and inelastic electron transport in angle-resolved microscopic imaging applications |
| title_fullStr | Diffraction effects and inelastic electron transport in angle-resolved microscopic imaging applications |
| title_full_unstemmed | Diffraction effects and inelastic electron transport in angle-resolved microscopic imaging applications |
| title_short | Diffraction effects and inelastic electron transport in angle-resolved microscopic imaging applications |
| title_sort | diffraction effects and inelastic electron transport in angle resolved microscopic imaging applications |
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