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| Author | Zhang, Z.; Lobato, I.; De Backer, A.; Van Aert, S.; Nellist, P. | ||||
| Title | Fast generation of calculated ADF-EDX scattering cross-sections under channelling conditions | Type | A1 Journal article | ||
| Year | 2023 | Publication | Ultramicroscopy | Abbreviated Journal | |
| Volume | 246 | Issue | Pages | 113671 | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | Advanced materials often consist of multiple elements which are arranged in a complicated structure. Quantitative scanning transmission electron microscopy is useful to determine the composition and thickness of nanostructures at the atomic scale. However, significant difficulties remain to quantify mixed columns by comparing the resulting atomic resolution images and spectroscopy data with multislice simulations where dynamic scattering needs to be taken into account. The combination of the computationally intensive nature of these simulations and the enormous amount of possible mixed column configurations for a given composition indeed severely hamper the quantification process. To overcome these challenges, we here report the development of an incoherent non-linear method for the fast prediction of ADF-EDX scattering cross-sections of mixed columns under channelling conditions. We first explain the origin of the ADF and EDX incoherence from scattering physics suggesting a linear dependence between those two signals in the case of a high-angle ADF detector. Taking EDX as a perfect incoherent reference mode, we quantitatively examine the ADF longitudinal incoherence under different microscope conditions using multislice simulations. Based on incoherent imaging, the atomic lensing model previously developed for ADF is now expanded to EDX, which yields ADF-EDX scattering cross-section predictions in good agreement with multislice simulations for mixed columns in a core–shell nanoparticle and a high entropy alloy. The fast and accurate prediction of ADF-EDX scattering cross-sections opens up new opportunities to explore the wide range of ordering possibilities of heterogeneous materials with multiple elements. | ||||
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| Corporate Author | Zezhong Zhang | Thesis | |||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000995063900001 | Publication Date | 2022-12-28 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor  |
2.2 | Times cited | Open Access | OpenAccess | |
| Notes | European Research Council 770887 PICOMETRICS; Fonds Wetenschappelijk Onderzoek No.G.0502.18N; Horizon 2020, 770887 ; Horizon 2020 Framework Programme; European Research Council, 823717 ESTEEM3 ; esteem3reported; esteem3JRa | Approved | Most recent IF: 2.2; 2023 IF: 2.843 | ||
| Call Number | EMAT @ emat @c:irua:195890 | Serial | 7251 | ||
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| Author | Lobato, I.; De Backer, A.; Van Aert, S. | ||||
| Title | Real-time simulations of ADF STEM probe position-integrated scattering cross-sections for single element fcc crystals in zone axis orientation using a densely connected neural network | Type | A1 Journal article | ||
| Year | 2023 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 251 | Issue | Pages | 113769 | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | Quantification of annular dark field (ADF) scanning transmission electron microscopy (STEM) images in terms of composition or thickness often relies on probe-position integrated scattering cross sections (PPISCS). In order to compare experimental PPISCS with theoretically predicted ones, expensive simulations are needed for a given specimen, zone axis orientation, and a variety of microscope settings. The computation time of such simulations can be in the order of hours using a single GPU card. ADF STEM simulations can be efficiently parallelized using multiple GPUs, as the calculation of each pixel is independent of other pixels. However, most research groups do not have the necessary hardware, and, in the best-case scenario, the simulation time will only be reduced proportionally to the number of GPUs used. In this manuscript, we use a learning approach and present a densely connected neural network that is able to perform real-time ADF STEM PPISCS predictions as a function of atomic column thickness for most common face-centered cubic (fcc) crystals (i.e., Al, Cu, Pd, Ag, Pt, Au and Pb) along [100] and [111] zone axis orientations, root-mean-square displacements, and microscope parameters. The proposed architecture is parameter efficient and yields accurate predictions for the PPISCS values for a wide range of input parameters that are commonly used for aberration-corrected transmission electron microscopes. |
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| Language | Wos | 001011617200001 | Publication Date | 2023-06-01 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record | |
| Impact Factor |
2.2 | Times cited | Open Access | OpenAccess | |
| Notes | This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G034621N and G0A7723N) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF), Belgium. | Approved | Most recent IF: 2.2; 2023 IF: 2.843 | ||
| Call Number | EMAT @ emat @c:irua:197275 | Serial | 8812 | ||
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| Author | Şentürk, DG.; Yu, CP.; De Backer, A.; Van Aert, S. | ||||
| Title | Atom counting from a combination of two ADF STEM images | Type | A1 Journal article | ||
| Year | 2024 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 255 | Issue | Pages | 113859 | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | To understand the structure–property relationship of nanostructures, reliably quantifying parameters, such as the number of atoms along the projection direction, is important. Advanced statistical methodologies have made it possible to count the number of atoms for monotype crystalline nanoparticles from a single ADF STEM image. Recent developments enable one to simultaneously acquire multiple ADF STEM images. Here, we present an extended statistics-based method for atom counting from a combination of multiple statistically independent ADF STEM images reconstructed from non-overlapping annular detector collection regions which improves the accuracy and allows one to retrieve precise atom-counts, especially for images acquired with low electron doses and multiple element structures. | ||||
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| Language | Wos | 001089064200001 | Publication Date | 2023-09-23 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.2 | Times cited | Open Access | OpenAccess | |
| Notes | This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G034621N, G0A7723N, and EOS 40007495) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF). | Approved | Most recent IF: 2.2; 2024 IF: 2.843 | ||
| Call Number | EMAT @ emat @c:irua:201008 | Serial | 8964 | ||
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| Author | Şentürk, D.G.; De Backer, A.; Van Aert, S. | ||||
| Title | Element specific atom counting for heterogeneous nanostructures: Combining multiple ADF STEM images for simultaneous thickness and composition determination | Type | A1 Journal Article | ||
| Year | 2024 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 259 | Issue | Pages | 113941 | |
| Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
| Abstract | In this paper, a methodology is presented to count the number of atoms in heterogeneous nanoparticles based on the combination of multiple annular dark field scanning transmission electron microscopy (ADF STEM) images. The different non-overlapping annular detector collection regions are selected based on the principles of optimal statistical experiment design for the atom-counting problem. To count the number of atoms, the total intensities of scattered electrons for each atomic column, the so-called scattering cross-sections, are simultaneously compared with simulated library values for the different detector regions by minimising the squared differences. The performance of the method is evaluated for simulated Ni@Pt and Au@Ag core-shell nanoparticles. Our approach turns out to be a dose efficient alternative for the investigation of beam-sensitive heterogeneous materials as compared to the combination of ADF STEM and energy dispersive X-ray spectroscopy. | ||||
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| Language | Wos | Publication Date | 2024-02-19 | ||
| Series Editor | Series Title | Abbreviated Series Title | |||
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| ISSN | 0304-3991 | ISBN | Additional Links | UA library record | |
| Impact Factor |
2.2 | Times cited | Open Access | OpenAccess | |
| Notes | This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0346.21N, GOA7723N, and EOS 40007495) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF). | Approved | Most recent IF: 2.2; 2024 IF: 2.843 | ||
| Call Number | EMAT @ emat @c:irua:204353 | Serial | 8996 | ||
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| Author | Van Holsbeke, C.S.; Verhulst, S.L.; Vos, W.G.; de Backer, J.W.; Vinchurkar, S.C.; Verdonck, P.R.; van Doorn, J.W.D.; Nadjmi, N.; de Backer, W.A. | ||||
| Title | Change in upper airway geometry between upright and supine position during tidal nasal breathing | Type | A1 Journal article | ||
| Year | 2014 | Publication | Journal Of Aerosol Medicine And Pulmonary Drug Delivery | Abbreviated Journal | J Aerosol Med Pulm D |
| Volume | 27 | Issue | 1 | Pages | 51-57 |
| Keywords | A1 Journal article; Biophysics and Biomedical Physics; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP); Translational Neurosciences (TNW) | ||||
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| Language | Wos | 000331144500007 | Publication Date | 2013-03-19 | |
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| ISSN | 1941-2711;1941-2703; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.528 | Times cited | 16 | Open Access | |
| Notes | ; ; | Approved | Most recent IF: 2.528; 2014 IF: 2.798 | ||
| Call Number | UA @ lucian @ c:irua:115759 | Serial | 308 | ||
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| Author | Guzzinati, G.; Altantzis, T.; Batuk, M.; De Backer, A.; Lumbeeck, G.; Samaee, V.; Batuk, D.; Idrissi, H.; Hadermann, J.; Van Aert, S.; Schryvers, D.; Verbeeck, J.; Bals, S. | ||||
| Title | Recent Advances in Transmission Electron Microscopy for Materials Science at the EMAT Lab of the University of Antwerp | Type | A1 Journal article | ||
| Year | 2018 | Publication | Materials | Abbreviated Journal | Materials |
| Volume | 11 | Issue | 11 | Pages | 1304 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | The rapid progress in materials science that enables the design of materials down to the nanoscale also demands characterization techniques able to analyze the materials down to the same scale, such as transmission electron microscopy. As Belgium’s foremost electron microscopy group, among the largest in the world, EMAT is continuously contributing to the development of TEM techniques, such as high-resolution imaging, diffraction, electron tomography, and spectroscopies, with an emphasis on quantification and reproducibility, as well as employing TEM methodology at the highest level to solve real-world materials science problems. The lab’s recent contributions are presented here together with specific case studies in order to highlight the usefulness of TEM to the advancement of materials science. | ||||
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| Language | Wos | 000444112800041 | Publication Date | 2018-07-28 | |
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| ISSN | 1996-1944 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.654 | Times cited | 15 | Open Access | OpenAccess |
| Notes | Fonds Wetenschappelijk Onderzoek, G.0502.18N, G.0267.18N, G.0120.12N, G.0365.15N, G.0934.17N, S.0100.18N AUHA13009 ; European Research Council, COLOURATOM 335078 ; Universiteit Antwerpen, GOA Solarpaint ; G. Guzzinati, T. Altantzis and A. De Backer have been supported by postdoctoral fellowship grants from the Research Foundation Flanders (FWO). Funding was also received from the European Research Council (starting grant no. COLOURATOM 335078), the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 770887), the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0502.18N, G.0267.18N, G.0120.12N, G.0365.15N, G.0934.17N, S.0100.18N, G.0401.16N) and from the University of Antwerp through GOA project Solarpaint. Funding for the TopSPIN precession system under grant AUHA13009, as well as for the Qu-Ant-EM microscope, is acknowledged from the HERCULES Foundation. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (F.R.S.-FNRS). (ROMEO:green; preprint:; postprint:can ; pdfversion:can); saraecas; ECAS_Sara; | Approved | Most recent IF: 2.654 | ||
| Call Number | EMAT @ emat @c:irua:153737UA @ admin @ c:irua:153737 | Serial | 5064 | ||
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| Author | van Holsbeke, C.; de Backer, J.; Vos, W.; Verdonck, P.; van Ransbeeck, P.; Claessens, T.; Braem, M.; Vanderveken, O.; de Backer, W. | ||||
| Title | Anatomical and functional changes in the upper airways of sleep apnea patients due to mandibular repositioning: a large scale study | Type | A1 Journal article | ||
| Year | 2011 | Publication | Journal of biomechanics | Abbreviated Journal | J Biomech |
| Volume | 44 | Issue | 3 | Pages | 442-449 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT); Vision lab; Laboratory Experimental Medicine and Pediatrics (LEMP); Translational Neurosciences (TNW) | ||||
| Abstract | The obstructive sleep apnea-hypopnea syndrome (OSAHS) is a sleep related breathing disorder. A popular treatment is the use of a mandibular repositioning appliance (MRA) which advances the mandibula during the sleep and decreases the collapsibility of the upper airway. The success rate of such a device is, however, limited and very variable within a population of patients. Previous studies using computational fluid dynamics have shown that there is a decrease in upper airway resistance in patients who improve clinically due to an MRA. In this article, correlations between patient-specific anatomical and functional parameters are studied to examine how MRA induced biomechanical changes will have an impact on the upper airway resistance. Low-dose computed tomography (CT) scans are made from 143 patients suffering from OSAHS. A baseline scan and a scan after mandibular repositioning (MR) are performed in order to study variations in parameters. It is found that MR using a simulation bite is able to induce resistance changes by changing the pharyngeal lumen. The change in minimal cross-sectional area is the best parameter to predict the change in upper airway resistance. Looking at baseline values, the ideal patients for MR induced resistance decrease seem to be women with short airways, high initial resistance and no baseline occlusion. | ||||
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| Publisher | Place of Publication | New York, N.Y. | Editor | ||
| Language | Wos | 000287551000014 | Publication Date | 2010-10-23 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0021-9290; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.664 | Times cited | 23 | Open Access | |
| Notes | ; ; | Approved | Most recent IF: 2.664; 2011 IF: 2.434 | ||
| Call Number | UA @ lucian @ c:irua:85305 | Serial | 112 | ||
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| Author | de Backer, J.W.; Vos, W.G.; Devolder, A.; Verhulst, S.L.; Germonpré, P.; Wuyts, F.L.; Parizel, P.M.; de Backer, W. | ||||
| Title | Computational fluid dynamics can detect changes in airway resistance in asthmatics after acute bronchodilation | Type | A1 Journal article | ||
| Year | 2008 | Publication | Journal of biomechanics | Abbreviated Journal | J Biomech |
| Volume | 41 | Issue | 1 | Pages | 106-113 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP) | ||||
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| Publisher | Place of Publication | New York, N.Y. | Editor | ||
| Language | Wos | 000253062100014 | Publication Date | 2007-08-15 | |
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| ISSN | 0021-9290; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.664 | Times cited | 53 | Open Access | |
| Notes | Approved | Most recent IF: 2.664; 2008 IF: 2.784 | |||
| Call Number | UA @ lucian @ c:irua:64859 | Serial | 456 | ||
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| Author | Vos, W.; de Backer, J.; Devolder, A.; Vanderveken, O.; Verhulst, S.; Salgado, R.; Germonpré, P.; Partoens, B.; Wuyts, F.; Parizel, P.; de Backer, W. | ||||
| Title | Correlation between severity of sleep apnea and upper airway morphology based on advanced anatomical and functional imaging | Type | A1 Journal article | ||
| Year | 2007 | Publication | Journal of biomechanics | Abbreviated Journal | J Biomech |
| Volume | 40 | Issue | 10 | Pages | 2207-2213 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP); Translational Neurosciences (TNW) | ||||
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| Publisher | Place of Publication | New York, N.Y. | Editor | ||
| Language | Wos | 000248468000011 | Publication Date | 2006-12-19 | |
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| ISSN | 0021-9290; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.664 | Times cited | 86 | Open Access | |
| Notes | Approved | Most recent IF: 2.664; 2007 IF: 2.897 | |||
| Call Number | UA @ lucian @ c:irua:62425 | Serial | 523 | ||
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| Author | de Backer, J.W.; Vanderveken, O.M.; Vos, W.G.; Devolder, A.; Verhulst, S.L.; Verbraecken, J.A.; Parizel, P.M.; Braem, M.J.; van de Heyning, P.H.; de Backer, W.A. | ||||
| Title | Functional imaging using computational fluid dynamics to predict treatment success of mandibular advancement devices in sleep-disordered breathing | Type | A1 Journal article | ||
| Year | 2007 | Publication | Journal of biomechanics | Abbreviated Journal | J Biomech |
| Volume | 40 | Issue | 16 | Pages | 3708-3714 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP); Translational Neurosciences (TNW) | ||||
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| Publisher | Place of Publication | New York, N.Y. | Editor | ||
| Language | Wos | 000251845100020 | Publication Date | 2007-08-01 | |
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| Series Volume | Series Issue | Edition | |||
| ISSN | 0021-9290; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.664 | Times cited | 66 | Open Access | |
| Notes | Approved | Most recent IF: 2.664; 2007 IF: 2.897 | |||
| Call Number | UA @ lucian @ c:irua:64860 | Serial | 1299 | ||
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| Author | Vos, W.; de Backer, J.; Poli, G.; De Volder, A.; Ghys, L.; Van Holsbeke, C.; Vinchurkar, S.; De Backer, L.; de Backer, W. | ||||
| Title | Novel functional imaging of changes in small airways of patients treated with extrafine beclomethasone/formoterol | Type | A1 Journal article | ||
| Year | 2013 | Publication | Respiration | Abbreviated Journal | Respiration |
| Volume | 86 | Issue | 5 | Pages | 393-401 |
| Keywords | A1 Journal article; Biophysics and Biomedical Physics; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP) | ||||
| Abstract | Background: Inhaled formulations using extrafine particles of long-acting beta(2)-agonists and corticosteroids were developed to optimize asthma treatment. Findings that these combinations reach and treat smaller airways more effectively are predominantly based on general non-specific outcomes with little information on regional characteristics. Objectives: This study aims to assess long-term effects of extrafine beclomethasone/formoterol on small airways of asthmatic patients using novel functional imaging methods. Methods: Twenty-four stable asthma patients were subdivided into three groups (steroid naive, n = 7; partially controlled, n = 6; well controlled, n = 11). Current treatment was switched to a fixed combination of extrafine beclomethasone/formoterol (Foster (R); Chiesi Pharmaceuticals, Parma, Italy). Patients underwent lung function evaluation and thorax high-resolution computerized tomography (HRCT) scan. Local airway resistance was obtained from computational fluid dynamics (CFD). Results: After 6 months, the entire population showed improvement in pre-bronchodilation imaging parameters, including small airway volume (p = 0.0007), resistance (p = 0.011), and asthma control score (p = 0.016). Changes in small airway volume correlated with changes in asthma control score (p = 0.004). Forced expiratory volume in 1 s (p = 0.044) and exhaled nitric oxide (p = 0.040) also improved. Functional imaging provided more detail and clinical relevance compared to lung function tests, especially in the well-controlled group where only functional imaging parameters showed significant improvement, while the correlation with asthma control score remained. Conclusions: Extrafine beclomethasone/formoterol results in a significant reduction of small airway obstruction, detectable by functional imaging (HRCT/CFD). Changes in imaging parameters correlated significantly with clinically relevant improvements. This indicates that functional imaging is a useful tool for sensitive assessment of changes in the respiratory system after asthma treatment. Copyright (C) 2013 S. Karger AG, Basel | ||||
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| Publisher | Place of Publication | Basel | Editor | ||
| Language | Wos | 000329046200006 | Publication Date | 2013-04-12 | |
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| Series Volume | Series Issue | Edition | |||
| ISSN | 1423-0356;0025-7931; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.772 | Times cited | 30 | Open Access | |
| Notes | ; ; | Approved | Most recent IF: 2.772; 2013 IF: 2.924 | ||
| Call Number | UA @ lucian @ c:irua:113762 | Serial | 2376 | ||
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| Author | De wael, A.; De Backer, A.; Yu, C.-P.; Sentürk, D.G.; Lobato, I.; Faes, C.; Van Aert, S. | ||||
| Title | Three Approaches for Representing the Statistical Uncertainty on Atom-Counting Results in Quantitative ADF STEM | Type | A1 Journal article | ||
| Year | 2022 | Publication | Microscopy and microanalysis | Abbreviated Journal | Microsc Microanal |
| Volume | Issue | Pages | 1-9 | ||
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | A decade ago, a statistics-based method was introduced to count the number of atoms from annular dark-field scanning transmission electron microscopy (ADF STEM) images. In the past years, this method was successfully applied to nanocrystals of arbitrary shape, size, and composition (and its high accuracy and precision has been demonstrated). However, the counting results obtained from this statistical framework are so far presented without a visualization of the actual uncertainty about this estimate. In this paper, we present three approaches that can be used to represent counting results together with their statistical error, and discuss which approach is most suited for further use based on simulations and an experimental ADF STEM image. | ||||
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| Language | Wos | 000854930500001 | Publication Date | 2022-09-19 | |
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| ISSN | 1431-9276 | ISBN | Additional Links | UA library record; WoS full record | |
| Impact Factor |
2.8 | Times cited | Open Access | OpenAccess | |
| Notes | This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 770887 and No. 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through grants to A.D.w. and A.D.B. and projects G.0502.18N, G.0267.18N, and EOS 30489208. S.V.A. acknowledges TOP BOF funding from the University of Antwerp. The authors are grateful to L.M. Liz-Marzán (CIC biomaGUNE and Ikerbasque) for providing the samples. esteem3reported; esteem3jra | Approved | Most recent IF: 2.8 | ||
| Call Number | EMAT @ emat @c:irua:190585 | Serial | 7119 | ||
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| Author | van den Broek, W.; Verbeeck, J.; de Backer, S.; Scheunders, P.; Schryvers, D. | ||||
| Title | Acquisition of the EELS data cube by tomographic reconstruction | Type | A1 Journal article | ||
| Year | 2006 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 106 | Issue | 4/5 | Pages | 269-276 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
| Abstract | Energy filtered TEM, EFTEM, provides three-dimensional data, two spatial and one spectral dimension. We propose to acquire these data by measuring a series of images with a defocused energy filter. It will be shown that each image is a projection of the data on the detector and that reconstruction of the data out of a sufficient number of such projections using a tomographic reconstruction algorithm is possible. This technique uses only a fraction of the electron dose an energy filtered series (EFS) needs for the same spectral and spatial resolution and the same mean signal-to-noise ratio. (c) 2005 Elsevier B.V. All rights reserved. | ||||
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| Publisher | Place of Publication | Amsterdam | Editor | ||
| Language | Wos | 000236042300003 | Publication Date | 2005-11-30 | |
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| ISSN | 0304-3991; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 6 | Open Access | |
| Notes | Approved | Most recent IF: 2.843; 2006 IF: 1.706 | |||
| Call Number | UA @ lucian @ c:irua:56910UA @ admin @ c:irua:56910 | Serial | 55 | ||
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| Author | de Backer, A.; Martinez, G.T.; Rosenauer, A.; Van Aert, S. | ||||
| Title | Atom counting in HAADF STEM using a statistical model-based approach : methodology, possibilities, and inherent limitations | Type | A1 Journal article | ||
| Year | 2013 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 134 | Issue | Pages | 23-33 | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | In the present paper, a statistical model-based method to count the number of atoms of monotype crystalline nanostructures from high resolution high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) images is discussed in detail together with a thorough study on the possibilities and inherent limitations. In order to count the number of atoms, it is assumed that the total scattered intensity scales with the number of atoms per atom column. These intensities are quantitatively determined using model-based statistical parameter estimation theory. The distribution describing the probability that intensity values are generated by atomic columns containing a specific number of atoms is inferred on the basis of the experimental scattered intensities. Finally, the number of atoms per atom column is quantified using this estimated probability distribution. The number of atom columns available in the observed STEM image, the number of components in the estimated probability distribution, the width of the components of the probability distribution, and the typical shape of a criterion to assess the number of components in the probability distribution directly affect the accuracy and precision with which the number of atoms in a particular atom column can be estimated. It is shown that single atom sensitivity is feasible taking the latter aspects into consideration. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Amsterdam | Editor | ||
| Language | Wos | 000324474900005 | Publication Date | 2013-05-17 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 48 | Open Access | |
| Notes | FWO; Esteem2; FP 2007-2013; esteem2_jra2 | Approved | Most recent IF: 2.843; 2013 IF: 2.745 | ||
| Call Number | UA @ lucian @ c:irua:109916 | Serial | 162 | ||
| Permanent link to this record | |||||
| Author | de Backer, A.; Martinez, G.T.; MacArthur, K.E.; Jones, L.; Béché, A.; Nellist, P.D.; Van Aert, S. | ||||
| Title | Dose limited reliability of quantitative annular dark field scanning transmission electron microscopy for nano-particle atom-counting | Type | A1 Journal article | ||
| Year | 2015 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 151 | Issue | 151 | Pages | 56-61 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | Quantitative annular dark field scanning transmission electron microscopy (ADF STEM) has become a powerful technique to characterise nano-particles on an atomic scale. Because of their limited size and beam sensitivity, the atomic structure of such particles may become extremely challenging to determine. Therefore keeping the incoming electron dose to a minimum is important. However, this may reduce the reliability of quantitative ADF STEM which will here be demonstrated for nano-particle atom-counting. Based on experimental ADF STEM images of a real industrial catalyst, we discuss the limits for counting the number of atoms in a projected atomic column with single atom sensitivity. We diagnose these limits by combining a thorough statistical method and detailed image simulations. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Amsterdam | Editor | ||
| Language | Wos | 000351237800008 | Publication Date | 2014-12-03 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 29 | Open Access | |
| Notes | 312483 Esteem2; 278510 Vortex; Fwo G039311; G006410; G037413; esteem2ta; ECASJO; | Approved | Most recent IF: 2.843; 2015 IF: 2.436 | ||
| Call Number | c:irua:123927 c:irua:123927 | Serial | 753 | ||
| Permanent link to this record | |||||
| Author | den Dekker, A.J.; Gonnissen, J.; de Backer, A.; Sijbers, J.; Van Aert, S. | ||||
| Title | Estimation of unknown structure parameters from high-resolution (S)TEM images : what are the limits? | Type | A1 Journal article | ||
| Year | 2013 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 134 | Issue | Pages | 34-43 | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
| Abstract | Statistical parameter estimation theory is proposed as a quantitative method to measure unknown structure parameters from electron microscopy images. Images are then purely considered as data planes from which structure parameters have to be determined as accurately and precisely as possible using a parametric statistical model of the observations. For this purpose, an efficient algorithm is proposed for the estimation of atomic column positions and intensities from high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) images. Furthermore, the so-called CramérRao lower bound (CRLB) is reviewed to determine the limits to the precision with which continuous parameters such as atomic column positions and intensities can be estimated. Since this lower bound can only be derived for continuous parameters, alternative measures using the principles of detection theory are introduced for problems concerning the estimation of discrete parameters such as atomic numbers. An experimental case study is presented to show the practical use of these measures for the optimization of the experiment design if the purpose is to decide between the presence of specific atom types using STEM images. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Amsterdam | Editor | ||
| Language | Wos | 000324474900006 | Publication Date | 2013-06-01 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 31 | Open Access | |
| Notes | FWO; FP 2007-2013; Esteem2; esteem2_jra2 | Approved | Most recent IF: 2.843; 2013 IF: 2.745 | ||
| Call Number | UA @ lucian @ c:irua:109240 | Serial | 1083 | ||
| Permanent link to this record | |||||
| Author | de Backer, A.; Van Aert, S.; van Dyck, D. | ||||
| Title | High precision measurements of atom column positions using model-based exit wave reconstruction | Type | A1 Journal article | ||
| Year | 2011 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 111 | Issue | 9/10 | Pages | 1475-1482 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
| Abstract | In this paper, it has been investigated how to measure atom column positions as accurately and precisely as possible using a focal series of images. In theory, it is expected that the precision would considerably improve using a maximum likelihood estimator based on the full series of focal images. As such, the theoretical lower bound on the variances of the unknown atom column positions can be attained. However, this approach is numerically demanding. Therefore, maximum likelihood estimation has been compared with the results obtained by fitting a model to a reconstructed exit wave rather than to the full series of focal images. Hence, a real space model-based exit wave reconstruction technique based on the channelling theory is introduced. Simulations show that the reconstructed complex exit wave contains the same amount of information concerning the atom column positions as the full series of focal images. Only for thin samples, which act as weak phase objects, this information can be retrieved from the phase of the reconstructed complex exit wave. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Amsterdam | Editor | ||
| Language | Wos | 000300461200004 | Publication Date | 2011-07-28 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 8 | Open Access | |
| Notes | Fwo | Approved | Most recent IF: 2.843; 2011 IF: 2.471 | ||
| Call Number | UA @ lucian @ c:irua:91879 | Serial | 1438 | ||
| Permanent link to this record | |||||
| Author | de Backer, A.; De wael, A.; Gonnissen, J.; Van Aert, S. | ||||
| Title | Optimal experimental design for nano-particle atom-counting from high-resolution STEM images | Type | A1 Journal article | ||
| Year | 2015 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 151 | Issue | 151 | Pages | 46-55 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | In the present paper, the principles of detection theory are used to quantify the probability of error for atom-counting from high resolution scanning transmission electron microscopy (HR STEM) images. Binary and multiple hypothesis testing have been investigated in order to determine the limits to the precision with which the number of atoms in a projected atomic column can be estimated. The probability of error has been calculated when using STEM images, scattering cross-sections or peak intensities as a criterion to count atoms. Based on this analysis, we conclude that scattering cross-sections perform almost equally well as images and perform better than peak intensities. Furthermore, the optimal STEM detector design can be derived for atom-counting using the expression for the probability of error. We show that for very thin objects LAADF is optimal and that for thicker objects the optimal inner detector angle increases. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Amsterdam | Editor | ||
| Language | Wos | 000351237800007 | Publication Date | 2014-11-11 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 24 | Open Access | |
| Notes | 312483 Esteem2; Fwo G039311; G037413; esteem2_jra2 | Approved | Most recent IF: 2.843; 2015 IF: 2.436 | ||
| Call Number | c:irua:123926 c:irua:123926 | Serial | 2481 | ||
| Permanent link to this record | |||||
| Author | Martinez, G.T.; Rosenauer, A.; de Backer, A.; Verbeeck, J.; Van Aert, S. | ||||
| Title | Quantitative composition determination at the atomic level using model-based high-angle annular dark field scanning transmission electron microscopy | Type | A1 Journal article | ||
| Year | 2014 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 137 | Issue | Pages | 12-19 | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | High angle annular dark field scanning transmission electron microscopy (HAADF STEM) images provide sample information which is sensitive to the chemical composition. The image intensities indeed scale with the mean atomic number Z. To some extent, chemically different atomic column types can therefore be visually distinguished. However, in order to quantify the atomic column composition with high accuracy and precision, model-based methods are necessary. Therefore, an empirical incoherent parametric imaging model can be used of which the unknown parameters are determined using statistical parameter estimation theory (Van Aert et al., 2009, [1]). In this paper, it will be shown how this method can be combined with frozen lattice multislice simulations in order to evolve from a relative toward an absolute quantification of the composition of single atomic columns with mixed atom types. Furthermore, the validity of the model assumptions are explored and discussed. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Amsterdam | Editor | ||
| Language | Wos | 000331092200003 | Publication Date | 2013-11-09 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 74 | Open Access | |
| Notes | FWO; FP7; ERC Countatoms; ESTEEM2; esteem2_ta | Approved | Most recent IF: 2.843; 2014 IF: 2.436 | ||
| Call Number | UA @ lucian @ c:irua:111579UA @ admin @ c:irua:111579 | Serial | 2749 | ||
| Permanent link to this record | |||||
| Author | Martinez, G.T.; Jones, L.; de Backer, A.; Béché, A.; Verbeeck, J.; Van Aert, S.; Nellist, P.D. | ||||
| Title | Quantitative STEM normalisation : the importance of the electron flux | Type | A1 Journal article | ||
| Year | 2015 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 159 | Issue | 159 | Pages | 46-58 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | Annular dark-field (ADF) scanning transmission electron microscopy (STEM) has become widely used in quantitative studies based on the opportunity to directly compare experimental and simulated images. This comparison merely requires the experimental data to be normalised and expressed in units of fractional beam-current. However, inhomogeneities in the response of electron detectors can complicate this normalisation. The quantification procedure becomes both experiment and instrument specific, requiring new simulations for the particular response of each instrument's detector, and for every camera-length used. This not only impedes the comparison between different instruments and research groups, but can also be computationally very time consuming. Furthermore, not all image simulation methods allow for the inclusion of an inhomogeneous detector response. In this work, we propose an alternative method for normalising experimental data in order to compare these with simulations that consider a homogeneous detector response. To achieve this, we determine the electron flux distribution reaching the detector by means of a camera-length series or a so-called atomic column cross-section averaged convergent beam electron diffraction (XSACBED) pattern. The result is then used to determine the relative weighting of the detector response. Here we show that the results obtained by this new electron flux weighted (EFW) method are comparable to the currently used method, while considerably simplifying the needed simulation libraries. The proposed method also allows one to obtain a metric that describes the quality of the detector response in comparison with the ideal detector response. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Amsterdam | Editor | ||
| Language | Wos | 000366220000006 | Publication Date | 2015-08-01 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 27 | Open Access | |
| Notes | 246791 Countatoms; 278510 Vortex; 312483 Esteem2; Fwo G036815; G036915; G037413; G004413; esteem2ta ECASJO; | Approved | Most recent IF: 2.843; 2015 IF: 2.436 | ||
| Call Number | c:irua:127293 c:irua:127293UA @ admin @ c:irua:127293 | Serial | 2762 | ||
| Permanent link to this record | |||||
| Author | van den Broek, W.; Verbeeck, J.; Schryvers, D.; de Backer, S.; Scheunders, P. | ||||
| Title | Tomographic spectroscopic imaging; an experimental proof of concept | Type | A1 Journal article | ||
| Year | 2009 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 109 | Issue | 4 | Pages | 296-303 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
| Abstract | Recording the electron energy loss spectroscopy data cube with a series of energy filtered images is a dose inefficient process because the energy slit blocks most of the electrons. When recording the data cube by scanning an electron probe over the sample, perfect dose efficiency is attained; but due to the low current in nanoprobes, this often is slower, with a smaller field of view. In W. Van den Broek et al. [Ultramicroscopy, 106 (2006) 269], we proposed a new method to record the data cube, which is more dose efficient than an energy filtered series. It produces a set of projections of the data cube and then tomographically reconstructs it. In this article, we demonstrate these projections in practice, we present a simple geometrical model that allows for quantification of the projection angles and we present the first successful experimental reconstruction, all on a standard post-column instrument. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Amsterdam | Editor | ||
| Language | Wos | 000265345400003 | Publication Date | 2008-12-10 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 1 | Open Access | |
| Notes | Esteem 026019 | Approved | Most recent IF: 2.843; 2009 IF: 2.067 | ||
| Call Number | UA @ lucian @ c:irua:77271 | Serial | 3671 | ||
| Permanent link to this record | |||||
| Author | Gonnissen, J.; De Backer, A.; den Dekker, A.J.; Sijbers, J.; Van Aert, S. | ||||
| Title | Detecting and locating light atoms from high-resolution STEM images: The quest for a single optimal design | Type | A1 Journal article | ||
| Year | 2016 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 170 | Issue | 170 | Pages | 128-138 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
| Abstract | In the present paper, the optimal detector design is investigated for both detecting and locating light atoms from high resolution scanning transmission electron microscopy (HR STEM) images. The principles of detection theory are used to quantify the probability of error for the detection of light atoms from HR STEM images. To determine the optimal experiment design for locating light atoms, use is made of the so-called Cramer-Rao Lower Bound (CRLB). It is investigated if a single optimal design can be found for both the detection and location problem of light atoms. Furthermore, the incoming electron dose is optimised for both research goals and it is shown that picometre range precision is feasible for the estimation of the atom positions when using an appropriate incoming electron dose under the optimal detector settings to detect light atoms. | ||||
| Address | Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium. Electronic address: sandra.vanaert@uantwerpen.be | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | English | Wos | 000386925500014 | Publication Date | 2016-07-26 |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 6 | Open Access | |
| Notes | The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0368.15, G.0369.15 and G.0374.13) and a postdoctoral research grant to A. De Backer. The research leading to these results has also received funding from the European Union Seventh Framework Programme [FP7/2007-2013] under Grant agreement no. 312483 (ESTEEM2). The authors would also like to thank A. Rosenauer for providing access to the STEMsim software and Gerardo T. Martinez for fruitful discussions.; esteem2_jra2 | Approved | Most recent IF: 2.843 | ||
| Call Number | c:irua:135337 c:irua:135337 | Serial | 4128 | ||
| Permanent link to this record | |||||
| Author | De Backer, A.; van den Bos, K.H.W.; Van den Broek, W.; Sijbers, J.; Van Aert, S. | ||||
| Title | StatSTEM: An efficient approach for accurate and precise model-based quantification of atomic resolution electron microscopy images | Type | A1 Journal article | ||
| Year | 2016 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 171 | Issue | 171 | Pages | 104-116 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
| Abstract | An efficient model-based estimation algorithm is introduced to quantify the atomic column positions and intensities from atomic resolution (scanning) transmission electron microscopy ((S)TEM) images. This algorithm uses the least squares estimator on image segments containing individual columns fully accounting for overlap between neighbouring columns, enabling the analysis of a large field of view. For this algorithm, the accuracy and precision with which measurements for the atomic column positions and scattering cross-sections from annular dark field (ADF) STEM images can be estimated, has been investigated. The highest attainable precision is reached even for low dose images. Furthermore, the advantages of the model-based approach taking into account overlap between neighbouring columns are highlighted. This is done for the estimation of the distance between two neighbouring columns as a function of their distance and for the estimation of the scattering cross-section which is compared to the integrated intensity from a Voronoi cell. To provide end-users this well-established quantification method, a user friendly program, StatSTEM, is developed which is freely available under a GNU public license. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000389106200014 | Publication Date | 2016-09-09 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 43 | Open Access | |
| Notes | The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0393.11, G.0064.10 and G.0374.13), a Ph.D. research grant to K.H.W. van den Bos, and a postdoctoral research grant to A. De Backer. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative-I3). A. Rosenauer is acknowledged for providing the STEMsim program.; esteem2_jra2 | Approved | Most recent IF: 2.843 | ||
| Call Number | EMAT @ emat @ c:irua:135516 | Serial | 4280 | ||
| Permanent link to this record | |||||
| Author | Gonnissen, J.; De Backer, A.; den Dekker, A.J.; Sijbers, J.; Van Aert, S. | ||||
| Title | Atom-counting in High Resolution Electron Microscopy: TEM or STEM – that's the question | Type | A1 Journal article | ||
| Year | 2016 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 174 | Issue | 174 | Pages | 112-120 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
| Abstract | In this work, a recently developed quantitative approach based on the principles of detection theory is used in order to determine the possibilities and limitations of High Resolution Scanning Transmission Electron Microscopy (HR STEM) and HR TEM for atom-counting. So far, HR STEM has been shown to be an appropriate imaging mode to count the number of atoms in a projected atomic column. Recently, it has been demonstrated that HR TEM, when using negative spherical aberration imaging, is suitable for atom-counting as well. The capabilities of both imaging techniques are investigated and compared using the probability of error as a criterion. It is shown that for the same incoming electron dose, HR STEM outperforms HR TEM under common practice standards, i.e. when the decision is based on the probability function of the peak intensities in HR TEM and of the scattering cross-sections in HR STEM. If the atom-counting decision is based on the joint probability function of the image pixel values, the dependence of all image pixel intensities as a function of thickness should be known accurately. Under this assumption, the probability of error may decrease significantly for atom-counting in HR TEM and may, in theory, become lower as compared to HR STEM under the predicted optimal experimental settings. However, the commonly used standard for atom-counting in HR STEM leads to a high performance and has been shown to work in practice. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000403342200013 | Publication Date | 2016-10-27 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 2 | Open Access | |
| Notes | The authors gratefully acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0368.15N, G.0369.15N, G.0374.13N, and WO.010.16N) and a postdoctoral grant to A. De Backer. The research leading to these results has received funding from the European Union Seventh Framework Programme [FP7/2007-2013] under Grant agreement no. 312483 (ESTEEM2). | Approved | Most recent IF: 2.843 | ||
| Call Number | EMAT @ emat @ c:irua:137102 | Serial | 4315 | ||
| Permanent link to this record | |||||
| Author | Alania, M.; Altantzis, T.; De Backer, A.; Lobato, I.; Bals, S.; Van Aert, S. | ||||
| Title | Depth sectioning combined with atom-counting in HAADF STEM to retrieve the 3D atomic structure | Type | A1 Journal article | ||
| Year | 2016 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 177 | Issue | 177 | Pages | 36-42 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | Aberration correction in scanning transmission electron microscopy (STEM) has greatly improved the lateral and depth resolution. When using depth sectioning, a technique during which a series of images is recorded at different defocus values, single impurity atoms can be visualised in three dimensions. In this paper, we investigate new possibilities emerging when combining depth sectioning and precise atom-counting in order to reconstruct nanosized particles in three dimensions. Although the depth resolution does not allow one to precisely locate each atom within an atomic column, it will be shown that the depth location of an atomic column as a whole can be measured precisely. In this manner, the morphology of a nanoparticle can be reconstructed in three dimensions. This will be demonstrated using simulations and experimental data of a gold nanorod. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000401219800006 | Publication Date | 2016-11-09 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 13 | Open Access | OpenAccess |
| Notes | The authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483-ESTEEM2. S. Bals acknowledges funding from the European Research Council (Starting Grant No. COLOURATOMS 335078). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0369.15N and G.0368.15N) and a post-doctoral grant to A. De Backer and T. Altantzis. The authors are grateful to Professor Luis M. Liz-Marzán for providing the sample.; ECAS_Sara; (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); | Approved | Most recent IF: 2.843 | ||
| Call Number | EMAT @ emat @ c:irua:138015UA @ admin @ c:irua:138015 | Serial | 4316 | ||
| Permanent link to this record | |||||
| Author | Alania, M.; De Backer, A.; Lobato, I.; Krause, F.F.; Van Dyck, D.; Rosenauer, A.; Van Aert, S. | ||||
| Title | How precise can atoms of a nanocluster be located in 3D using a tilt series of scanning transmission electron microscopy images? | Type | A1 Journal article | ||
| Year | 2017 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 181 | Issue | 181 | Pages | 134-143 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
| Abstract | In this paper, we investigate how precise atoms of a small nanocluster can ultimately be located in three dimensions (3D) from a tilt series of images acquired using annular dark field (ADF) scanning transmission electron microscopy (STEM). Therefore, we derive an expression for the statistical precision with which the 3D atomic position coordinates can be estimated in a quantitative analysis. Evaluating this statistical precision as a function of the microscope settings also allows us to derive the optimal experimental design. In this manner, the optimal angular tilt range, required electron dose, optimal detector angles, and number of projection images can be determined. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000411170800016 | Publication Date | 2016-12-15 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 3 | Open Access | OpenAccess |
| Notes | The authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483-ESTEEM2. The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0369.15N, G.0368.15N, and WO.010.16N) and a post-doctoral grant to A. De Backer, and from the DFG under contract No. RO-2057/4-2. | Approved | Most recent IF: 2.843 | ||
| Call Number | EMAT @ emat @ c:irua:144432 | Serial | 4618 | ||
| Permanent link to this record | |||||
| Author | De wael, A.; De Backer, A.; Jones, L.; Nellist, P.D.; Van Aert, S. | ||||
| Title | Hybrid statistics-simulations based method for atom-counting from ADF STEM images | Type | A1 Journal article | ||
| Year | 2017 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 177 | Issue | 177 | Pages | 69-77 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | A hybrid statistics-simulations based method for atom-counting from annular dark field scanning transmission electron microscopy (ADF STEM) images of monotype crystalline nanostructures is presented. Different atom-counting methods already exist for model-like systems. However, the increasing relevance of radiation damage in the study of nanostructures demands a method that allows atom-counting from low dose images with a low signal-to-noise ratio. Therefore, the hybrid method directly includes prior knowledge from image simulations into the existing statistics-based method for atom-counting, and accounts in this manner for possible discrepancies between actual and simulated experimental conditions. It is shown by means of simulations and experiments that this hybrid method outperforms the statistics-based method, especially for low electron doses and small nanoparticles. The analysis of a simulated low dose image of a small nanoparticle suggests that this method allows for far more reliable quantitative analysis of beam-sensitive materials. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000401219800010 | Publication Date | 2017-01-25 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 8 | Open Access | OpenAccess |
| Notes | The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0368.15N, G.0369.15N, and WO.010.16N), and a postdoctoral research Grant to A. De Backer. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative-I3). The authors are grateful to G.T. Martinez for providing image simulations. | Approved | Most recent IF: 2.843 | ||
| Call Number | EMAT @ emat @ c:irua:141718 | Serial | 4486 | ||
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| Author | Schryvers, D.; Salje, E.K.H.; Nishida, M.; De Backer, A.; Idrissi, H.; Van Aert, S. | ||||
| Title | Quantification by aberration corrected (S)TEM of boundaries formed by symmetry breaking phase transformations | Type | A1 Journal article | ||
| Year | 2017 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 176 | Issue | Pages | 194-199 | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | The present contribution gives a review of recent quantification work of atom displacements, atom site occupations and level of crystallinity in various systems and based on aberration corrected HR(S)TEM images. Depending on the case studied, picometer range precisions for individual distances can be obtained, boundary widths at the unit cell level determined or statistical evolutions of fractions of the ordered areas calculated. In all of these cases, these quantitative measures imply new routes for the applications of the respective materials. | ||||
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| Language | Wos | 000403992200026 | Publication Date | 2017-01-09 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 1 | Open Access | OpenAccess |
| Notes | The authors acknowledge financial support from the Fund for Scientific Research-Flanders (G.0064.10N, G.0393.11N, G.0374.13N, G.0368.15N, G.0369.15N) and the Flemish Hercules 3 program for large infrastructure as well as financial support from the European Union Seventh Framework Programme (FP7/2007 – 2013) under Grant agreement no. 312483 (ESTEEM2). EKHS thanks EPSRC (EP/ K009702/1) and the Leverhulme trust (EM-2016-004) for support. DS and MN acknowledge financial support from the Japan Society for the Promotion of Science (JSPS, Japan) through the Grant-in-Aid for Scientific Research (A: No. 26249090) and the Strategic Young Researcher Overseas Visits Program for Accelerating Brain Circulation (R2408). | Approved | Most recent IF: 2.843 | ||
| Call Number | EMAT @ emat @c:irua:149654 | Serial | 4914 | ||
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| Author | van den Bos, K.H.W.; Janssens, L.; De Backer, A.; Nellist, P.D.; Van Aert, S. | ||||
| Title | The atomic lensing model: new opportunities for atom-by-atom metrology of heterogeneous nanomaterials | Type | A1 Journal article | ||
| Year | 2019 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 203 | Issue | Pages | 155 | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | The atomic lensing model has been proposed as a promising method facilitating atom-counting in heterogeneous nanocrystals [1]. Here, image simulations will validate the model, which describes dynamical diffraction as a superposition of individual atoms focussing the incident electrons. It will be demonstrated that the model is reliable in the annular dark field regime for crystals having columns containing dozens of atoms. By using the principles of statistical detection theory, it will be shown that this model gives new opportunities for detecting compositional differences. | ||||
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| Language | Wos | 000465021000020 | Publication Date | 2018-12-06 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | 4 | Open Access | OpenAccess |
| Notes | The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0369.15N, G.0502.18N and WO.010.16N), and by personal grants to K.H.W. van den Bos and A. De Backer. This project has received funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (grant agreement No. 770887). | Approved | Most recent IF: 2.843 | ||
| Call Number | EMAT @ emat @UA @ admin @ c:irua:155721 | Serial | 5074 | ||
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| Author | De wael, A.; De Backer, A.; Lobato, I.; Van Aert, S. | ||||
| Title | Modelling ADF STEM images using elliptical Gaussian peaks and its effects on the quantification of structure parameters in the presence of sample tilt | Type | A1 Journal article | ||
| Year | 2021 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | Issue | Pages | 113391 | ||
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | A small sample tilt away from a main zone axis orientation results in an elongation of the atomic columns in ADF STEM images. An often posed research question is therefore whether the ADF STEM image intensities of tilted nanomaterials should be quantified using a parametric imaging model consisting of elliptical rather than the currently used symmetrical peaks. To this purpose, simulated ADF STEM images corresponding to different amounts of sample tilt are studied using a parametric imaging model that consists of superimposed 2D elliptical Gaussian peaks on the one hand and symmetrical Gaussian peaks on the other hand. We investigate the quantification of structural parameters such as atomic column positions and scattering cross sections using both parametric imaging models. In this manner, we quantitatively study what can be gained from this elliptical model for quantitative ADF STEM, despite the increased parameter space and computational effort. Although a qualitative improvement can be achieved, no significant quantitative improvement in the estimated structure parameters is achieved by the elliptical model as compared to the symmetrical model. The decrease in scattering cross sections with increasing sample tilt is even identical for both types of parametric imaging models. This impedes direct comparison with zone axis image simulations. Nonetheless, we demonstrate how reliable atom-counting can still be achieved in the presence of small sample tilt. | ||||
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| Language | Wos | 000704334200001 | Publication Date | 2021-09-24 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor |
2.843 | Times cited | Open Access | OpenAccess | |
| Notes | This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 770887 and No. 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through grants to A.D.w. and A.D.B. and projects G.0502.18N, G.0267.18N, and EOS 30489208. S.V.A. acknowledges TOP BOF funding from the University of Antwerp.; esteem3JRA; esteem3reported | Approved | Most recent IF: 2.843 | ||
| Call Number | EMAT @ emat @c:irua:181462 | Serial | 6810 | ||
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