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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.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	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
Permanent link to this record



	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; Atomic resolution scanning transmission electron microscopy; Atom counting; Heterogeneous nanostructures; Multivariate Gaussian mixture model; 4D STEM; Electron Microscopy for Materials Science (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.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	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
	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.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos		Publication Date	2024-02-19
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0304-3991	ISBN		Additional Links
	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 @			Serial	8996
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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	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
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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
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	Author	Egoavil, R.; Gauquelin, N.; Martinez, G.T.; Van Aert, S.; Van Tendeloo, G.; Verbeeck, J.
	Title	Atomic resolution mapping of phonon excitations in STEM-EELS experiments			Type	A1 Journal article
	Year	2014	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	147	Issue		Pages	1-7
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	Atomically resolved electron energy-loss spectroscopy experiments are commonplace in modern aberration-corrected transmission electron microscopes. Energy resolution has also been increasing steadily with the continuous improvement of electron monochromators. Electronic excitations however are known to be delocalized due to the long range interaction of the charged accelerated electrons with the electrons in a sample. This has made several scientists question the value of combined high spatial and energy resolution for mapping interband transitions and possibly phonon excitation in crystals. In this paper we demonstrate experimentally that atomic resolution information is indeed available at very low energy losses around 100 meV expressed as a modulation of the broadening of the zero loss peak. Careful data analysis allows us to get a glimpse of what are likely phonon excitations with both an energy loss and gain part. These experiments confirm recent theoretical predictions on the strong localization of phonon excitations as opposed to electronic excitations and show that a combination of atomic resolution and recent developments in increased energy resolution will offer great benefit for mapping phonon modes in real space.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000343157400001	Publication Date	2014-05-29
	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	22	Open Access
	Notes	246102 IFOX; 278510 VORTEX; 246791 COUNTATOMS; Hercules; 312483 ESTEEM2; esteem2jra3 ECASJO;			Approved	Most recent IF: 2.843; 2014 IF: 2.436
	Call Number	UA @ lucian @ c:irua:118332UA @ admin @ c:irua:118332			Serial	177
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	Author	van den Broek, W.; Rosenauer, A.; Goris, B.; Martinez, G.T.; Bals, S.; Van Aert, S.; van Dyck, D.
	Title	Correction of non-linear thickness effects in HAADF STEM electron tomography			Type	A1 Journal article
	Year	2012	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	116	Issue		Pages	8-12
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
	Abstract	In materials science, high angle annular dark field scanning transmission electron microscopy is often used for tomography at the nanometer scale. In this work, it is shown that a thickness dependent, non-linear damping of the recorded intensities occurs. This results in an underestimated intensity in the interior of reconstructions of homogeneous particles, which is known as the cupping artifact. In this paper, this non-linear effect is demonstrated in experimental images taken under common conditions and is reproduced with a numerical simulation. Furthermore, an analytical derivation shows that these non-linearities can be inverted if the imaging is done quantitatively, thus preventing cupping in the reconstruction.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000304473700002	Publication Date	2012-03-09
	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	67	Open Access
	Notes	Fwo			Approved	Most recent IF: 2.843; 2012 IF: 2.470
	Call Number	UA @ lucian @ c:irua:96558			Serial	518
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	Author	Wang, A.; Chen, F.R.; Van Aert, S.; van Dyck, D.
	Title	Direct structure inversion from exit waves: part 1: theory and simulations			Type	A1 Journal article
	Year	2010	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	110	Issue	5	Pages	527-534
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
	Abstract	In order to interpret the amplitude and phase of the exit wave in terms of mass and position of the atoms, one has to invert the dynamic scattering of the electrons in the object so as to obtain a starting structure which can then be used as a seed for further quantitative structure refinement. This is especially challenging in case of a zone axis condition when the interaction of the electrons with the atom column is very strong. Based on the channelling theory we will show that the channelling map not only yields a circle on the Argand plot but also a circular defocus curve for every column. The former gives the number of atoms in each column, while the latter provides the defocus value for each column, which reveals the surface roughness at the exit plane with single atom sensitivity.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000279065700019	Publication Date	2009-12-12
	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
	Notes	Fwo			Approved	Most recent IF: 2.843; 2010 IF: 2.063
	Call Number	UA @ lucian @ c:irua:83691			Serial	723
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	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	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	den Dekker, A.J.; Van Aert, S.; van Dyck, D.; van den Bos, A.; Geuens, P.
	Title	Does a monochromator improve the precision in quantitative HRTEM?			Type	A1 Journal article
	Year	2001	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	89	Issue		Pages	275-290
	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	000172667000004	Publication Date	2002-07-25
	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	22	Open Access
	Notes				Approved	Most recent IF: 2.843; 2001 IF: 1.890
	Call Number	UA @ lucian @ c:irua:47518			Serial	746
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	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
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	Author	Van Aert, S.; Chang, L.Y.; Bals, S.; Kirkland, A.I.; Van Tendeloo, G.
	Title	Effect of amorphous layers on the interpretation of restored exit waves			Type	A1 Journal article
	Year	2009	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	109	Issue	3	Pages	237-246
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	The effects of amorphous layers on the quality of exit wave restorations have been investigated. Two independently developed software implementations for exit wave restoration have been used to simulated focal series of images of SrTiO3 with amorphous carbon layers incorporated. The restored exit waves have been compared both qualitatively and quantitatively. We have shown that amorphous layers have a strong impact on the quantitative measurements of atomic column positions, however, the error in the position measurements is still in the picometer range.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000264280200005	Publication Date	2008-11-15
	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	10	Open Access
	Notes	Fwo; Esteem 026019			Approved	Most recent IF: 2.843; 2009 IF: 2.067
	Call Number	UA @ lucian @ c:irua:76421			Serial	796
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	Author	Croitoru, M.D.; van Dyck, D.; Van Aert, S.; Bals, S.; Verbeeck, J.
	Title	An efficient way of including thermal diffuse scattering in simulation of scanning transmission electron microscopic images			Type	A1 Journal article
	Year	2006	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	106	Issue	10	Pages	933-940
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Vision lab
	Abstract	We propose an improved image simulation procedure for atomic-resolution annular dark-field scanning transmission electron microscopy (STEM) based on the multislice formulation, which takes thermal diffuse scattering fully into account. The improvement with regard to the classical frozen phonon approach is realized by separating the lattice configuration statistics from the dynamical scattering so as to avoid repetitive calculations. As an example, the influence of phonon scattering on the image contrast is calculated and investigated. STEM image simulation of crystals can be applied with reasonable computing times to problems involving a large number of atoms and thick or large supercells.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000240397200006	Publication Date	2006-05-10
	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	18	Open Access
	Notes	Fwo; Fwo-V			Approved	Most recent IF: 2.843; 2006 IF: 1.706
	Call Number	UA @ lucian @ c:irua:87604UA @ admin @ c:irua:87604			Serial	876
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	Author	Van Aert, S.; Geuens, P.; van Dyck, D.; Kisielowski, C.; Jinschek, J.R.
	Title	Electron channelling based crystallography			Type	A1 Journal article
	Year	2007	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	107	Issue	6/7	Pages	551-558
	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	000245341300015	Publication Date	2006-12-13
	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	32	Open Access
	Notes				Approved	Most recent IF: 2.843; 2007 IF: 1.996
	Call Number	UA @ lucian @ c:irua:64286			Serial	913
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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	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	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
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	Author	Dunin-Borkowski, R.E.; Lichte, H.; Tillmann, K.; Van Aert, S.; Van Tendeloo, G.
	Title	Introduction to a special issue in honour of W. Owen Saxton, David J. Smith and Dirk Van Dyck on the occasion of their 65th birthdays			Type	Editorial
	Year	2013	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	134	Issue		Pages	1-1
	Keywords	Editorial; Electron microscopy for materials research (EMAT)
	Abstract
	Address
	Corporate Author				Thesis
	Publisher	Elsevier science bv	Place of Publication	Amsterdam	Editor
	Language		Wos	000324474900001	Publication Date	2013-07-24
	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	1	Open Access
	Notes				Approved	Most recent IF: 2.843; 2013 IF: 2.745
	Call Number	UA @ lucian @ c:irua:109917			Serial	1721
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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	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
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	Author	Van Aert, S.; Chen, J.H.; van Dyck, D.
	Title	Linear versus non-linear structural information limit in high-resolution transmission electron microscopy			Type	A1 Journal article
	Year	2010	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	110	Issue	11	Pages	1404-1410
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
	Abstract	A widely used performance criterion in high-resolution transmission electron microscopy (HRTEM) is the information limit. It corresponds to the inverse of the maximum spatial object frequency that is linearly transmitted with sufficient intensity from the exit plane of the object to the image plane and is limited due to partial temporal coherence. In practice, the information limit is often measured from a diffractogram or from Young's fringes assuming a weak phase object scattering beyond the inverse of the information limit. However, for an aberration corrected electron microscope, with an information limit in the sub-angstrom range, weak phase objects are no longer applicable since they do not scatter sufficiently in this range. Therefore, one relies on more strongly scattering objects such as crystals of heavy atoms observed along a low index zone axis. In that case, dynamical scattering becomes important such that the non-linear and linear interaction may be equally important. The non-linear interaction may then set the experimental cut-off frequency observed in a diffractogram. The goal of this paper is to quantify both the linear and the non-linear information transfer in terms of closed form analytical expressions. Whereas the cut-off frequency set by the linear transfer can be directly related with the attainable resolution, information from the non-linear transfer can only be extracted using quantitative, model-based methods. In contrast to the historic definition of the information limit depending on microscope parameters only, the expressions derived in this paper explicitly incorporate their dependence on the structure parameters as well. In order to emphasize this dependence and to distinguish from the usual information limit, the expressions derived for the inverse cut-off frequencies will be referred to as the linear and non-linear structural information limit. The present findings confirm the well-known result that partial temporal coherence has different effects on the transfer of the linear and non-linear terms, such that the non-linear imaging contributions are damped less than the linear imaging contributions at high spatial frequencies. This will be important when coherent aberrations such as spherical aberration and defocus are reduced.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000282562100008	Publication Date	2010-07-15
	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	6	Open Access
	Notes	Fwo			Approved	Most recent IF: 2.843; 2010 IF: 2.063
	Call Number	UA @ lucian @ c:irua:83689			Serial	1821
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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	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
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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	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
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	Author	Van den Broek, W.; Rosenauer, A.; Van Aert, S.; Sijbers, J.; van Dyck, D.
	Title	A memory efficient method for fully three-dimensional object reconstruction with HAADF STEM			Type	A1 Journal article
	Year	2014	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	141	Issue		Pages	22-31
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
	Abstract	The conventional approach to object reconstruction through electron tomography is to reduce the three-dimensional problem to a series of independent two-dimensional slice-by-slice reconstructions. However, at atomic resolution the image of a single atom extends over many such slices and incorporating this image as prior knowledge in tomography or depth sectioning therefore requires a fully three-dimensional treatment. Unfortunately, the size of the three-dimensional projection operator scales highly unfavorably with object size and readily exceeds the available computer memory. In this paper, it is shown that for incoherent image formation the memory requirement can be reduced to the fundamental lower limit of the object size, both for tomography and depth sectioning. Furthermore, it is shown through multislice calculations that high angle annular dark field scanning transmission electron microscopy can be sufficiently incoherent for the reconstruction of single element nanocrystals, but that dynamical diffraction effects can cause classification problems if more than one element is present. (C) 2014 Elsevier B.V. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000335766600004	Publication Date	2014-03-22
	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	ResearchFoundationFlanders(FWO;G.0393.11; G.0064.10;andG.0374.13); European Union Seventh Frame- workProgramme [FP7/2007-2013]under Grant agreement no. 312483 (ESTEEM2).; esteem2jra2; esteem2jra4			Approved	Most recent IF: 2.843; 2014 IF: 2.436
	Call Number	UA @ lucian @ c:irua:117650			Serial	1992
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	Author	Wang, A.; Chen, F.R.; Van Aert, S.; van Dyck, D.
	Title	A method to determine the local surface profile from reconstructed exit waves			Type	A1 Journal article
	Year	2011	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	111	Issue	8	Pages	1352-1359
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
	Abstract	Reconstructed exit waves are useful to quantify unknown structure parameters such as the position and composition of the atom columns at atomic scale. Existing techniques provide a complex wave in a flat plane which is close to the plane where the electrons leave the atom columns. However, due to local deviation in the flatness of the exit surface, there will be an offset between the plane of reconstruction and the actual exit of a specific atom column. Using the channelling theory, it has been shown that this defocus offset can in principle be determined atom column-by-atom column. As such, the surface roughness could be quantified at atomic scale. However, the outcome strongly depends on the initial plane of reconstruction especially in a crystalline structure. If this plane is further away from the true exit, the waves of the atom columns become delocalized and interfere mutually which strongly complicates the interpretation of the exit wave in terms of the local structure. In this paper, we will study the delocalization with defocus using the channelling theory in a more systematic way.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000300461100049	Publication Date	2011-05-03
	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	3	Open Access
	Notes	Fwo			Approved	Most recent IF: 2.843; 2011 IF: 2.471
	Call Number	UA @ lucian @ c:irua:88941			Serial	2017
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	Author	van den Broek, W.; Van Aert, S.; van Dyck, D.
	Title	A model based atomic resolution tomographic algorithm			Type	A1 Journal article
	Year	2009	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	109	Issue	12	Pages	1485-1490
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
	Abstract	Tomography with high angular annular dark field scanning transmission electron microscopy at atomic resolution can be greatly improved if one is able to take advantage of prior knowledge. In this paper we present a reconstruction technique that explicitly takes into account the microscope parameters and the atomic nature of the projected object. This results in a more accurate estimate of the atomic positions and in a good resistance to noise. The reconstruction is a maximum likelihood estimator of the object. Moreover, the limits to the precision have been explored, allowing for a prediction of the amount of expected noise in the reconstruction for a certain experimental setup. We believe that the proposed reconstruction technique can be generalized to other tomographic experiments.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000271840200010	Publication Date	2009-08-28
	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	17	Open Access
	Notes				Approved	Most recent IF: 2.843; 2009 IF: 2.067
	Call Number	UA @ lucian @ c:irua:78588			Serial	2097
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	Author	Verbeeck, J.; Van Aert, S.
	Title	Model based quantification of EELS spectra			Type	A1 Journal article
	Year	2004	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	101	Issue	2/4	Pages	207-224
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	Recent advances in model based quantification of electron energy loss spectra (EELS) are reported. The maximum likelihood method for the estimation of physical parameters describing an EELS spectrum, the validation of the model used in this estimation procedure, and the computation of the attainable precision, that is, the theoretical lower bound on the variance of these estimates, are discussed. Experimental examples on An and GaAs samples show the power of the maximum likelihood method and show that the theoretical prediction of the attainable precision can be closely approached even for spectra with overlapping edges where conventional EELS quantification fails. To provide end-users with a low threshold alternative to conventional quantification, a user friendly program was developed which is freely available under a GNU public license. (C) 2004 Elsevier B.V. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000224046100016	Publication Date	2004-07-23
	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	2.843	Times cited	147	Open Access
	Notes	Fwo; Iuap P5/01			Approved	Most recent IF: 2.843; 2004 IF: 2.215
	Call Number	UA @ lucian @ c:irua:57130UA @ admin @ c:irua:57130			Serial	2101
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	Author	Verbeeck, J.; Van Aert, S.; Bertoni, G.
	Title	Model-based quantification of EELS spectra: including the fine structure			Type	A1 Journal article
	Year	2006	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	106	Issue	11-12	Pages	976-980
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	An extension to model-based electron energy loss spectroscopy (EELS) quantification is reported to improve the possibility of modelling fine structure changes in electron energy loss spectra. An equalisation function is used in the energy loss near edge structure (ELNES) region to model the differences between a single atom differential cross section and the cross section for an atom in a crystal. The equalisation function can be shown to approximate the relative density of unoccupied states for the given excitation edge. On a set of 200 experimental h-BN spectra, this technique leads to statistically acceptable models resulting into unbiased estimates of relative concentrations and making the estimated precisions come very close to the Cramer-Rao lower bound (CRLB). The method greatly expands the useability of model-based EELS quantification to spectra with pronounced fine structure. Another benefit of this model is that one also gets an estimate of the unoccupied density of states for a given excitation edge, without having to do background removal and deconvolution, making the outcome intrinsically more reliable and less noisy. (c) 2006 Elsevier B.V. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000241592900004	Publication Date	2006-07-04
	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	38	Open Access
	Notes	Goa; Fwo Iap-V			Approved	Most recent IF: 2.843; 2006 IF: 1.706
	Call Number	UA @ lucian @ c:irua:61379UA @ admin @ c:irua:61379			Serial	2102
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	Author	van den Broek, W.; Van Aert, S.; van Dyck, D.
	Title	A model based reconstruction technique for depth sectioning with scanning transmission electron microscopy			Type	A1 Journal article
	Year	2010	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	110	Issue	5	Pages	548-554
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
	Abstract	Depth sectioning in high angular annular dark field scanning transmission electron microscopy is considered a candidate for three-dimensional characterization on the atomic scale. However at present the depth resolution is still far from the atomic level, due to strong limitations in the opening angle of the beam. In this paper we introduce a new, parameter based tomographic reconstruction algorithm that allows to make maximal use of the prior knowledge about the constituent atom types and the microscope settings, so as to retrieve the atomic positions and push the resolution to the atomic level in all three dimensions.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000279065700022	Publication Date	2009-09-21
	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	16	Open Access
	Notes	Fwo			Approved	Most recent IF: 2.843; 2010 IF: 2.063
	Call Number	UA @ lucian @ c:irua:83690			Serial	2104
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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	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	Van Aert, S.; den Dekker, A.J.; van Dyck, D.; van den Bos, A.
	Title	Optimal experimental design of STEM measurement of atom column positions			Type	A1 Journal article
	Year	2002	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	90	Issue		Pages	273-289
	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	000174770900004	Publication Date	2002-07-25
	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	35	Open Access
	Notes				Approved	Most recent IF: 2.843; 2002 IF: 1.772
	Call Number	UA @ lucian @ c:irua:47517			Serial	2483
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	Author	Wang, A.; Van Aert, S.; Goos, P.; van Dyck, D.
	Title	Precision of three-dimensional atomic scale measurements from HRTEM images : what are the limits?			Type	A1 Journal article
	Year	2012	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	114	Issue		Pages	20-30
	Keywords	A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT); Vision lab
	Abstract	In this paper, we investigate to what extent high resolution transmission electron microscopy images can be used to measure the mass, in terms of thickness, and surface profile, corresponding to the defocus offset, of an object at the atomic scale. Therefore, we derive an expression for the statistical precision with which these object parameters can be estimated in a quantitative analysis. Evaluating this expression as a function of the microscope settings allows us to derive the optimal microscope design. Acquiring three-dimensional structure information in terms of thickness turns out to be much more difficult than obtaining two-dimensional information on the projected atom column positions. The attainable precision is found to be more strongly affected by processes influencing the image contrast, such as phonon scattering, than by the specific choice of microscope settings. For a realistic incident electron dose, it is expected that atom columns can be distinguished with single atom sensitivity up to a thickness of the order of the extinction distance. A comparable thickness limit is determined to measure surface steps of one atom. An increase of the electron dose shifts the limiting thickness upward due to an increase in the signal-to-noise ratio.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000301954300003	Publication Date	2012-01-06
	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	5	Open Access
	Notes	Fwo			Approved	Most recent IF: 2.843; 2012 IF: 2.470
	Call Number	UA @ lucian @ c:irua:94116			Serial	2692
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