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Author van Dyck, D.; Van Aert, S.; den Dekker, A.J.; van den Bos, A.
Title Is atomic resolution transmission electron microscopy able to resolve and refine amorphous structures? Type A1 Journal article
Year 2003 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 98 Issue Pages (up) 27-42
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000186831500003 Publication Date 2003-04-25
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 26 Open Access
Notes Approved Most recent IF: 2.843; 2003 IF: 1.665
Call Number UA @ lucian @ c:irua:47516 Serial 1749
Permanent link to this record
 
 
Author de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S.
Title Statistical parameter estimation theory : principles and simulation studies Type H2 Book chapter
Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal
Volume Issue Pages (up) 29-72
Keywords H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab
Abstract In this chapter, the principles of statistical parameter estimation theory for a quantitative analysis of atomic-resolution electron microscopy images are introduced. Within this framework, electron microscopy images are described by a parametric statistical model. Here, parametric models are introduced for different types of electron microscopy images: reconstructed exit waves, annular dark-field (ADF) scanning transmission electron microscopy (STEM) images, and simultaneously acquired ADF and annular bright-field (ABF) STEM images. Furthermore, the Cramér-Rao lower bound (CRLB) is introduced, i.e. a theoretical lower bound on the variance of any unbiased estimator. This CRLB is used to quantify the precision of the structure parameters of interest, such as the atomic column positions and the integrated atomic column intensities.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2021-03-06
Series Editor Series Title Abbreviated Series Title
Series Volume 217 Series Issue Edition
ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record
Impact Factor Times cited Open Access Not_Open_Access
Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:177527 Serial 6788
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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 (up) 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
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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 (up) 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.
Address
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
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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 (up) 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
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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 (up) 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
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Author Wang, A.; Turner, S.; Van Aert, S.; van Dyck, D.
Title An alternative approach to determine attainable resolution directly from HREM images Type A1 Journal article
Year 2013 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 133 Issue Pages (up) 50-61
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract The concept of resolution in high-resolution electron microscopy (HREM) is the power to resolve neighboring atoms. Since the resolution is related to the width of the point spread function of the microscope, it could in principle be determined from the image of a point object. However, in electron microscopy there are no ideal point objects. The smallest object is an individual atom. If the width of an atom is much smaller than the resolution of the microscope, this atom can still be considered as a point object. As the resolution of the microscope enters the sub-Å regime, information about the microscope is strongly entangled with the information about the atoms in HREM images. Therefore, we need to find an alternative method to determine the resolution in an object-independent way. In this work we propose to use the image wave of a crystalline object in zone axis orientation. Under this condition, the atoms of a column act as small lenses so that the electron beam channels through the atom column periodically. Because of this focusing, the image wave of the column can be much more peaked than the constituting atoms and can thus be a much more sensitive probe to measure the resolution. Our approach is to use the peakiness of the image wave of the atom column to determine the resolution. We will show that the resolution can be directly linked to the total curvature of the atom column wave. Moreover, we can then directly obtain the resolution of the microscope given that the contribution from the object is known, which is related to the bounding energy of the atom. The method is applied on an experimental CaTiO3 image wave.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000324471800007 Publication Date 2013-05-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record
Impact Factor 2.843 Times cited Open Access
Notes FWO; Hercules; Esteem2; esteem2_jra2 Approved Most recent IF: 2.843; 2013 IF: 2.745
Call Number UA @ lucian @ c:irua:109919 Serial 90
Permanent link to this record
 
 
Author Batenburg, J.; Van Aert, S.
Title Three-dimensional reconstruction of a nanoparticle at atomic resolution Type A2 Journal article
Year 2011 Publication ERCIM news Abbreviated Journal
Volume 86 Issue Pages (up) 52
Keywords A2 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Le Chesnay Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0926-4981 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:94120 Serial 3655
Permanent link to this record
 
 
Author Zheng, Y.-R.; Vernieres, J.; Wang, Z.; Zhang, K.; Hochfilzer, D.; Krempl, K.; Liao, T.-W.; Presel, F.; Altantzis, T.; Fatermans, J.; Scott, S.B.; Secher, N.M.; Moon, C.; Liu, P.; Bals, S.; Van Aert, S.; Cao, A.; Anand, M.; Nørskov, J.K.; Kibsgaard, J.; Chorkendorff, I.
Title Monitoring oxygen production on mass-selected iridium–tantalum oxide electrocatalysts Type A1 Journal article
Year 2021 Publication Nature Energy Abbreviated Journal Nat Energy
Volume Issue Pages (up)
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract Development of low-cost and high-performance oxygen evolution reaction catalysts is key to implementing polymer electrolyte membrane water electrolyzers for hydrogen production. Iridium-based oxides are the state-of-the-art acidic oxygen evolution reactio catalysts but still suffer from inadequate activity and stability, and iridium's scarcity motivates the discovery of catalysts with lower iridium loadings. Here we report a mass-selected iridium-tantalum oxide catalyst prepared by a magnetron-based cluster source with considerably reduced noble-metal loadings beyond a commercial IrO2 catalyst. A sensitive electrochemistry/mass-spectrometry instrument coupled with isotope labelling was employed to investigate the oxygen production rate under dynamic operating conditions to account for the occurrence of side reactions and quantify the number of surface active sites. Iridium-tantalum oxide nanoparticles smaller than 2 nm exhibit a mass activity of 1.2 ± 0.5 kA “g” _“Ir” ^“-1” and a turnover frequency of 2.3 ± 0.9 s-1 at 320 mV overpotential, which are two and four times higher than those of mass-selected IrO2, respectively. Density functional theory calculations reveal that special iridium coordinations and the lowered aqueous decomposition free energy might be responsible for the enhanced performance.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000728458000001 Publication Date 2021-12-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2058-7546 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 95 Open Access OpenAccess
Notes Y.-R.Z. and Z.W acknowledge funding from the Toyota Research Institute. This project has received funding from VILLUM FONDEN (grant no. 9455) and the European Research Council under the European Union’s Horizon 2020 research and innovation programme (grants no. 741860-CLUNATRA, no. 815128−REALNANO and no. 770887−PICOMETRICS). S.B. and S.V.A. acknowledge funding from the Research Foundation Flanders (FWO, G026718N and G050218N). T.A. acknowledges the University of Antwerp Research Fund (BOF). STEM measurements were supported by the European Union's Horizon 2020 Research Infrastructure-Integrating Activities for Advanced Communities under grant agreement No 823717 – ESTEEM3.; sygmaSB Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:184794 Serial 6903
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 (up) 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 Martinez, G.T.; de Backer, A.; Rosenauer, A.; Verbeeck, J.; Van Aert, S.
Title The effect of probe inaccuracies on the quantitative model-based analysis of high angle annular dark field scanning transmission electron microscopy images Type A1 Journal article
Year 2014 Publication Micron Abbreviated Journal Micron
Volume 63 Issue Pages (up) 57-63
Keywords A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT)
Abstract Quantitative structural and chemical information can be obtained from high angle annular dark field scanning transmission electron microscopy (HAADF STEM) images when using statistical parameter estimation theory. In this approach, we assume an empirical parameterized imaging model for which the total scattered intensities of the atomic columns are estimated. These intensities can be related to the material structure or composition. Since the experimental probe profile is assumed to be known in the description of the imaging model, we will explore how the uncertainties in the probe profile affect the estimation of the total scattered intensities. Using multislice image simulations, we analyze this effect for Cs corrected and non-Cs corrected microscopes as a function of inaccuracies in cylindrically symmetric aberrations, such as defocus and spherical aberration of third and fifth order, and non-cylindrically symmetric aberrations, such as 2-fold and 3-fold astigmatism and coma.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000338402500011 Publication Date 2014-01-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0968-4328; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.98 Times cited 25 Open Access
Notes FWO (G.0393.11; G.0064.10; G.0374.13; G.0044.13); European Research Council under the 7th Framework Program (FP7); ERC GrantNo. 246791-COUNTATOMS and ERC Starting Grant No. 278510-VORTEX. A.R. thanks the DFG under contract number RO2057/8-1.The research leading to these results has received funding fromthe European Union 7th Framework Programme [FP7/2007-2013]under grant agreement no. 312483 (ESTEEM2).; esteem2ta ECASJO; Approved Most recent IF: 1.98; 2014 IF: 1.988
Call Number UA @ lucian @ c:irua:113857UA @ admin @ c:irua:113857 Serial 831
Permanent link to this record
 
 
Author Schryvers, D.; Shi, H.; Martinez, G.T.; Van Aert, S.; Frenzel, J.; Van Humbeeck, J.
Title Nano- and microcrystal investigations of precipitates, interfaces and strain fields in Ni-Ti-Nb by various TEM techniques Type P1 Proceeding
Year 2013 Publication Materials science forum T2 – 9th European Symposium on Martensitic Transformations (ESOMAT 2012), SEP 09-16, 2012, St Petersburg, RUSSIA Abbreviated Journal
Volume 738/739 Issue Pages (up) 65-71
Keywords P1 Proceeding; Electron microscopy for materials research (EMAT)
Abstract In the present contribution several advanced electron microscopy techniques are employed in order to describe chemical and structural features of the nano- and microstructure of a Ni45.5Ti45.5Nb9 alloy. A line-up of Nb-rich nano-precipitates is found in the Ni-Ti-rich austenite of as-cast material. Concentration changes of the matrix after annealing are correlated with changes in the transformation temperatures. The formation of rows and plates of larger Nb-rich precipitates and particles is described. The interaction of a twinned martensite plate with a Nb-rich nano-precipitate is discussed and the substitution of Nb atoms on the Ti-sublattice in the matrix is confirmed.
Address
Corporate Author Thesis
Publisher Place of Publication Lausanne Editor
Language Wos 000316089000011 Publication Date 2013-03-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1662-9752; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 2 Open Access
Notes Fwo Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:104692 Serial 2247
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 (up) 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.
Address
Corporate Author Thesis
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
Permanent link to this record
 
 
Author Van Aert, S.; De Backer, A.; Martinez, G.T.; den Dekker, A.J.; Van Dyck, D.; Bals, S.; Van Tendeloo, G.
Title Advanced electron crystallography through model-based imaging Type A1 Journal article
Year 2016 Publication IUCrJ Abbreviated Journal Iucrj
Volume 3 Issue 3 Pages (up) 71-83
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab; Engineering Management (ENM)
Abstract The increasing need for precise determination of the atomic arrangement of non-periodic structures in materials design and the control of nanostructures explains the growing interest in quantitative transmission electron microscopy. The aim is to extract precise and accurate numbers for unknown structure parameters including atomic positions, chemical concentrations and atomic numbers. For this purpose, statistical parameter estimation theory has been shown to provide reliable results. In this theory, observations are considered purely as data planes, from which structure parameters have to be determined using a parametric model describing the images. As such, the positions of atom columns can be measured with a precision of the order of a few picometres, even though the resolution of the electron microscope is still one or two orders of magnitude larger. Moreover, small differences in average atomic number, which cannot be distinguished visually, can be quantified using high-angle annular dark-field scanning transmission electron microscopy images. In addition, this theory allows one to measure compositional changes at interfaces, to count atoms with single-atom sensitivity, and to reconstruct atomic structures in three dimensions. This feature article brings the reader up to date, summarizing the underlying theory and highlighting some of the recent applications of quantitative model-based transmisson electron microscopy.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000368590900010 Publication Date 2015-11-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2052-2525; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.793 Times cited 30 Open Access OpenAccess
Notes The authors gratefully acknowledge the Research Foundation Flanders (FWO, Belgium) for funding and for a PhD grant to ADB. The research leading to these results has received funding from the European Union 7th Framework Program (FP7/20072013) under grant agreement No. 312483 (ESTEEM2). SB and GVT acknowledge the European Research Council under the 7th Framework Program (FP7), ERC grant No. 335078 – COLOURATOMS and ERC grant No. 246791 – COUNTATOMS.; esteem2jra2; ECASSara; (ROMEO:green; preprint:; postprint:can ; pdfversion:can); Approved Most recent IF: 5.793
Call Number c:irua:129589 c:irua:129589 Serial 3965
Permanent link to this record
 
 
Author de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S.
Title Efficient fitting algorithm Type H2 Book chapter
Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal
Volume Issue Pages (up) 73-90
Keywords H2 Book chapter; Electron microscopy for materials research (EMAT)
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 neighboring columns, enabling the analysis of a large field of view. To provide end-users with this well-established quantification method, a user friendly program, StatSTEM, is developed which is freely available under a GNU public license. In this chapter, this efficient algorithm is applied to three different nanostructures for which the analysis of a large field of view is required.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2021-03-06
Series Editor Series Title Abbreviated Series Title
Series Volume 217 Series Issue Edition
ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record
Impact Factor Times cited Open Access Not_Open_Access
Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:177528 Serial 6778
Permanent link to this record
 
 
Author van den Bos, K.H.W.; Krause, F.F.; Béché, A.; Verbeeck, J.; Rosenauer, A.; Van Aert, S.
Title Locating light and heavy atomic column positions with picometer precision using ISTEM Type A1 Journal article
Year 2016 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 172 Issue 172 Pages (up) 75-81
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Recently, imaging scanning transmission electron microscopy (ISTEM) has been proposed as a promising new technique combining the advantages of conventional TEM (CTEM) and STEM [1]. The ability to visualize light and heavy elements together makes it a particularly interesting new, spatially incoherent imaging mode. Here, we evaluate this technique in term of precision with which atomic column locations can be measured. By using statistical parameter estimation theory, we will show that these locations can be accurately measured with a precision in the picometer range. Furthermore, a quantitative comparison is made with HAADF STEM imaging to investigate the advantages of ISTEM.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000390600200009 Publication Date 2016-10-09
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 8 Open Access
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 by a Ph.D. grant to K.H.W. van den Bos. The research leading to these results has received funding from the Deutsche Forschungsgemeinschaft under Contract No. RO 2057/4-2 and the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2. We thank Prof. G. Koster from the University of Twente for kindly providing us with the PbTiO3 test sample. Approved Most recent IF: 2.843
Call Number EMAT @ emat @ c:irua:136109UA @ admin @ c:irua:136109 Serial 4288
Permanent link to this record
 
 
Author Wang, A.; Chen, F.R.; Van Aert, S.; van Dyck, D.
Title Direct structure inversion from exit waves : part 2 : a practical example Type A1 Journal article
Year 2012 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 116 Issue Pages (up) 77-85
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract This paper is the second part of a two-part paper on direct structure inversion from exit waves. In the first part, a method has been proposed to quantitatively determine structure parameters with atomic resolution such as atom column positions, surface profile and the number of atoms in the atom columns. In this part, the theory will be demonstrated by means of a Au[110] exit wave reconstructed from a set of focal-series images. The procedures to analyze the experimentally reconstructed exit wave in terms of quantitative structure information are described in detail.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000304473700011 Publication Date 2012-03-28
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; 2012 IF: 2.470
Call Number UA @ lucian @ c:irua:96660 Serial 724
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Author Fatermans, J.; Van Aert, S.; den Dekker, A.J.
Title The maximum a posteriori probability rule for atom column detection from HAADF STEM images Type A1 Journal article
Year 2019 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 201 Issue Pages (up) 81-91
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract Recently, the maximum a posteriori (MAP) probability rule has been proposed as an objective and quantitative method to detect atom columns and even single atoms from high-resolution high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) images. The method combines statistical parameter estimation and model-order selection using a Bayesian framework and has been shown to be especially useful for the analysis of the structure of beam-sensitive nanomaterials. In order to avoid beam damage, images of such materials are usually acquired using a limited incoming electron dose resulting in a low contrast-to-noise ratio (CNR) which makes visual inspection unreliable. This creates a need for an objective and quantitative approach. The present paper describes the methodology of the MAP probability rule, gives its step-by-step derivation and discusses its algorithmic implementation for atom column detection. In addition, simulation results are presented showing that the performance of the MAP probability rule to detect the correct number of atomic columns from HAADF STEM images is superior to that of other model-order selection criteria, including the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). Moreover, the MAP probability rule is used as a tool to evaluate the relation between STEM image quality measures and atom detectability resulting in the introduction of the so-called integrated CNR (ICNR) as a new image quality measure that better correlates with atom detectability than conventional measures such as signal-to-noise ratio (SNR) and CNR.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000466343800009 Publication Date 2019-02-04
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 Research Foundation Flanders (FWO, Belgium) through project fundings (No. W.O.010.16N, No. G.0368.15N, No. G.0502.18N). 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:157176 Serial 5153
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Author den Dekker, A.J.; Van Aert, S.; van den Bos, A.; van Dyck, D.
Title Maximum likelihood estimation of structure parameters from high resolution electron microscopy images: part 1: a theoretical framework Type A1 Journal article
Year 2005 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 104 Issue 2 Pages (up) 83-106
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000230526400001 Publication Date 2005-04-09
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 70 Open Access
Notes Approved Most recent IF: 2.843; 2005 IF: 2.490
Call Number UA @ lucian @ c:irua:57229 Serial 1959
Permanent link to this record
 
 
Author Martinez, G.T.; van den Bos, K.H.W.; Alania, M.; Nellist, P.D.; Van Aert, S.
Title Thickness dependence of scattering cross-sections in quantitative scanning transmission electron microscopy Type A1 Journal article
Year 2018 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 187 Issue Pages (up) 84-92
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In quantitative scanning transmission electron microscopy (STEM), scattering cross-sections have been shown to be very sensitive to the number of atoms in a column and its composition. They correspond to the integrated intensity over the atomic column and they outperform other measures. As compared to atomic column peak intensities, which saturate at a given thickness, scattering cross-sections increase monotonically. A study of the electron wave propagation is presented to explain the sensitivity of the scattering cross-sections. Based on the multislice algorithm, we analyse the wave propagation inside the crystal and its link to the scattered signal for the different probe positions contained in the scattering cross-section for detector collection in the low-, middle- and high-angle regimes. The influence to the signal from scattering of neighbouring columns is also discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000428131200011 Publication Date 2018-01-31
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 Not_Open_Access: Available from 01.02.2020
Notes 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 PhD grant to K.H.W.v.d.B. The research leading to these results has received funding from the European Union 7th Framework Programme [ FP7 /2007-2013] under Grant agreement no. 312483 (ESTEEM2). The authors are grateful to A. Rosenauer for providing access to the StemSim software. Approved Most recent IF: 2.843
Call Number EMAT @ emat @c:irua:149384 Serial 4809
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Author Shi, H.; Frenzel, J.; Martinez, G.T.; Van Rompaey, S.; Bakulin, A.; Kulkova, A.; Van Aert, S.; Schryvers, D.
Title Site occupation of Nb atoms in ternary Ni-Ti-Nb shape memory alloys Type A1 Journal article
Year 2014 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 74 Issue Pages (up) 85-95
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Nb occupancy in the austenite B2-NiTi matrix and Ti2Ni phase in NiTiNb shape memory alloys was investigated by aberration-corrected scanning transmission electron microscopy and precession electron diffraction. In both cases, Nb atoms were found to prefer to occupy the Ti rather than Ni sites. A projector augmented wave method within density functional theory was used to calculate the atomic and electronic structures of the austenitic B2-NiTi matrix phase and the Ti2Ni precipitates both with and without addition of Nb. The obtained formation energies and analysis of structural and electronic characteristics explain the preference for Ti sites for Nb over Ni sites.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000338621400009 Publication Date 2014-05-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6454; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.301 Times cited 21 Open Access
Notes Approved Most recent IF: 5.301; 2014 IF: 4.465
Call Number UA @ lucian @ c:irua:118334 Serial 3028
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Author de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S.
Title Atom counting Type H2 Book chapter
Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal
Volume Issue Pages (up) 91-144
Keywords H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab
Abstract In this chapter, a statistical model-based method to count the number of atoms of monotype crystalline nanostructures from high-resolution annular dark-field (ADF) scanning transmission electron microscopy (STEM) images is discussed in detail together with a thorough study on the possibilities and inherent limitations. We show that this method can be applied to nanocrystals of arbitrary shape, size, and atom type. The validity of the atom-counting results is confirmed by means of detailed image simulations and it is shown that the high sensitivity of our method enables us to count atoms with single atom sensitivity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2021-03-06
Series Editor Series Title Abbreviated Series Title
Series Volume 217 Series Issue Edition
ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record
Impact Factor Times cited Open Access Not_Open_Access
Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:177529 Serial 6776
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Author Müller-Caspary, K.; Krause, F.F.; Winkler, F.; Béché, A.; Verbeeck, J.; Van Aert, S.; Rosenauer, A.
Title Comparison of first moment STEM with conventional differential phase contrast and the dependence on electron dose Type A1 Journal article
Year 2019 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 203 Issue 203 Pages (up) 95-104
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract This study addresses the comparison of scanning transmission electron microscopy (STEM) measurements of momentum transfers using the first moment approach and the established method that uses segmented annular detectors. Using an ultrafast pixelated detector to acquire four-dimensional, momentum-resolved STEM signals, both the first moment calculation and the calculation of the differential phase contrast (DPC) signals are done for the same experimental data. In particular, we investigate the ability to correct the segment-based signal to yield a suitable approximation of the first moment for cases beyond the weak phase object approximation. It is found that the measurement of momentum transfers using segmented detectors can approach the first moment measurement as close as 0.13 h/nm in terms of a root mean square (rms) difference in 10 nm thick SrTiO3 for a detector with 16 segments. This amounts to 35% of the rms of the momentum transfers. In addition, we present a statistical analysis of the precision of first moment STEM as a function of dose. For typical experimental settings with recent hardware such as a Medipix3 Merlin camera attached to a probe-corrected STEM, we find that the precision of the measurement of momentum transfers stagnates above certain doses. This means that other instabilities such as specimen drift or scan noise have to be taken into account seriously for measurements that target, e.g., the detection of bonding effects in the charge density.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000465021000013 Publication Date 2018-12-30
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 25 Open Access OpenAccess
Notes ; The direct electron detector (Medipix3 Merlin) was funded by the Hercules fund from the Flemish Government. K. Muller-Caspary acknowledges funding from the Initiative and Network Fund of the Helmholtz Association within the framework of the Helmholtz Young Investigator Group moreSTEM (VH-NG-1317) at Forschungszentrum Julich, Germany. F. F. Krause acknowledges funding from the Central Research Development Fund of the University of Bremen, Germany. 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). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) and the Research Fund of the University of Antwerp. ; Approved Most recent IF: 2.843
Call Number UA @ admin @ c:irua:160213 Serial 5242
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Author Van Aert, S.; Bals, S.; Chang, L.Y.; den Dekker, A.J.; Kirkland, A.I.; Van Dyck, D.; Van Tendeloo, G.
Title The benefits of statistical parameter estimation theory for quantitative interpretation of electron microscopy data Type H1 Book chapter
Year 2008 Publication Abbreviated Journal
Volume Issue Pages (up) 97-98
Keywords H1 Book chapter; Electron microscopy for materials research (EMAT); Vision lab
Abstract
Address
Corporate Author Thesis
Publisher Springer Place of Publication Berlin Editor
Language Wos Publication Date 2009-03-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-3-540-85154-7 Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:136865 Serial 4493
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 (up) 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
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Author Bals, S.; Van Aert, S.; Van Tendeloo, G.
Title High resolution electron tomography Type A1 Journal article
Year 2013 Publication Current opinion in solid state and materials science Abbreviated Journal Curr Opin Solid St M
Volume 17 Issue 3 Pages (up) 107-114
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Reaching atomic resolution in 3D has been the ultimate goal in the field of electron tomography for many years. Significant progress, both on the theoretical as well as the experimental side has recently resulted in several exciting examples demonstrating the ability to visualise atoms in 3D. In this paper, we will review the different steps that have pushed the resolution in 3D to the atomic level. A broad range of methodologies and practical examples together with their impact on materials science will be discussed. Finally, we will provide an outlook and will describe future challenges in the field of high resolution electron tomography.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000323869800003 Publication Date 2013-03-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-0286; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.938 Times cited 24 Open Access
Notes Fwo; 312483 Esteem; Countatoms; Approved Most recent IF: 6.938; 2013 IF: 7.167
Call Number UA @ lucian @ c:irua:109454 Serial 1457
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Author Van Aert, S.; den Dekker, A.J.; van den Bos, A.; van Dyck, D.; Chen, J.H.
Title Maximum likelihood estimation of structure parameters from high resolution electron microscopy images : part 2 : a practical example Type A1 Journal article
Year 2005 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 104 Issue 2 Pages (up) 107-125
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000230526400002 Publication Date 2005-04-08
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 37 Open Access
Notes Approved Most recent IF: 2.843; 2005 IF: 2.490
Call Number UA @ lucian @ c:irua:57131 Serial 1960
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 (up) 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.
Address
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 Jones, L.; Martinez, G.T.; Béché, A.; Van Aert, S.; Nellist, P.D.
Title Getting the best from an imperfect detector : an alternative normalisation procedure for quantitative HAADF STEM Type A1 Journal article
Year 2014 Publication Microscopy and microanalysis Abbreviated Journal Microsc Microanal
Volume 20 Issue S3 Pages (up) 126-127
Keywords A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge, Mass. Editor
Language Wos Publication Date 2014-08-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276 ISBN Additional Links UA library record
Impact Factor 1.891 Times cited Open Access
Notes Approved Most recent IF: 1.891; 2014 IF: 1.877
Call Number UA @ lucian @ c:irua:136445 Serial 4500
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 (up) 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