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	Author	De Backer, A.; van den Bos, K.H.W.; Van den Broek, W.; Sijbers, J.; Van Aert, S.
	Title	StatSTEM: An efficient program for accurate and precise model-based quantification of atomic resolution electron microscopy images			Type	P1 Proceeding
	Year	2017	Publication	Journal of physics : conference series T2 – Electron Microscopy and Analysis Group Conference 2017 (EMAG2017), 3-6 July 2017, Manchester, UK	Abbreviated Journal	J. Phys.: Conf. Ser.
	Volume	902	Issue		Pages	012013
	Keywords	P1 Proceeding; Electron microscopy for materials research (EMAT); Vision lab
	Abstract	An efficient model-based estimation algorithm is introduced in order 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 the 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, is investigated. The highest attainable precision is reached even for low dose images. Furthermore, advantages of the model- based approach taking into account overlap between neighbouring columns are highlighted. 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	000416370700013	Publication Date	2017-10-16
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1742-6588	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited	1	Open Access	OpenAccess
	Notes	The authors acknowledge nancial support from the Research Foundation Flanders (FWO, Belgium) through project funding (G.0374.13N, G.0368.15N, G.0369.15N, WO.010.16N) and a PhD 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.			Approved	Most recent IF: NA
	Call Number	EMAT @ emat @c:irua:147188			Serial	4764
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	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	Akamine, H.; Van den Bos, K.H.W.; Gauquelin, N.; Farjami, S.; Van Aert, S.; Schryvers, D.; Nishida, M.
	Title	Determination of the atomic width of an APB in ordered CoPt using quantified HAADF-STEM			Type	A1 Journal article
	Year	2015	Publication	Journal of alloys and compounds	Abbreviated Journal	J Alloy Compd
	Volume	644	Issue	644	Pages	570-574
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
	Abstract	Anti-phase boundaries (APBs) in an ordered CoPt alloy are planar defects which disturb the ordered structure in their vicinity and decrease the magnetic properties. However, it has not yet been clarified to what extend the APBs disturb the ordering. In this study, high-resolution HAADF-STEM images are statistically analysed based on the image intensities estimated by the statistical parameter estimation theory. In the procedure, averaging intensities, fitting the intensity profiles to specific functions, and assessment based on a statistical test are performed. As a result, the APBs in the stable CoPt are found to be characterised by two atomic planes, and a contrast transition range as well as the centre of an inclined APB is determined. These results show that the APBs are quite sharp and therefore may have no notable effect on the net magnetic properties due to their small volume fraction. (C) 2015 Elsevier B.V. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000357143900083	Publication Date	2015-05-07
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0925-8388;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.133	Times cited	12	Open Access
	Notes	FWO G036815N; G036915N; G037413N; 278510 VORTEX; Hercules; ECASJO_;			Approved	Most recent IF: 3.133; 2015 IF: 2.999
	Call Number	c:irua:127008 c:irua:127008			Serial	675
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	Author	De Backer, A.; De Wael, A.; Gonnissen, J.; Martinez, G.T.; Béché, A.; MacArthur, K.E.; Jones, L.; Nellist, P.D.; Van Aert, S.
	Title	Quantitative annular dark field scanning transmission electron microscopy for nanoparticle atom-counting: What are the limits?			Type	P1 Proceeding
	Year	2015	Publication	Journal of physics : conference series	Abbreviated Journal
	Volume	644	Issue	644	Pages	012034
	Keywords	P1 Proceeding; Electron microscopy for materials research (EMAT)
	Abstract	Quantitative atomic resolution annular dark field scanning transmission electron microscopy (ADF STEM) has become a powerful technique for nanoparticle atom-counting. However, a lot of nanoparticles provide a severe characterisation challenge because of their limited size and beam sensitivity. Therefore, quantitative ADF STEM may greatly benefit from statistical detection theory in order to optimise the instrumental microscope settings such that the incoming electron dose can be kept as low as possible whilst still retaining single-atom precision. The principles of detection theory are used to quantify the probability of error for atom-counting. This enables us to decide between different image performance measures and to optimise the experimental detector settings for atom-counting in ADF STEM in an objective manner. To demonstrate this, ADF STEM imaging of an industrial catalyst has been conducted using the near-optimal detector settings. For this experiment, we discussed the limits for atom-counting diagnosed by combining a thorough statistical method and detailed image simulations.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000366826200034	Publication Date	2015-10-13
	Series Editor		Series Title		Abbreviated Series Title	Electron Microscopy and Analysis Group Conference (EMAG), JUN 02-JUL 02, 2015, Manchester, ENGLAND
	Series Volume		Series Issue		Edition
	ISSN	1742-6588	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor		Times cited		Open Access
	Notes	The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project funding (G.0368.15N, G.0369.15N, and G.0374.15N) and a PhD 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), ERC Starting Grant 278510 Vortex, and the UK Engineering and Physical Sciences Research Council (EP/K032518/1). The authors acknowledge Johnson-Matthey for providing the sample and PhD funding to K E MacArthur. A Rosenauer is acknowledged for providing the STEMsim program.; esteem2jra2; ECASJO;			Approved	Most recent IF: NA
	Call Number	c:irua:130314 c:irua:130314			Serial	4050
Permanent link to this record



	Author	de Backer, A.; De wael, A.; Gonnissen, J.; Martinez, G.T.; Béché, A.; MacArthur, K.E.; Jones, L.; Nellist, P.D.; Van Aert, S.
	Title	Quantitative annular dark field scanning transmission electron microscopy for nanoparticle atom-counting : what are the limits?			Type	A1 Journal article
	Year	2015	Publication	Journal of physics : conference series	Abbreviated Journal
	Volume	644	Issue		Pages	012034-4
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	Quantitative atomic resolution annular dark field scanning transmission electron microscopy (ADF STEM) has become a powerful technique for nanoparticle atom-counting. However, a lot of nanoparticles provide a severe characterisation challenge because of their limited size and beam sensitivity. Therefore, quantitative ADF STEM may greatly benefit from statistical detection theory in order to optimise the instrumental microscope settings such that the incoming electron dose can be kept as low as possible whilst still retaining single-atom precision. The principles of detection theory are used to quantify the probability of error for atom-counting. This enables us to decide between different image performance measures and to optimise the experimental detector settings for atom-counting in ADF STEM in an objective manner. To demonstrate this, ADF STEM imaging of an industrial catalyst has been conducted using the near-optimal detector settings. For this experiment, we discussed the limits for atomcounting diagnosed by combining a thorough statistical method and detailed image simulations.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Bristol	Editor
	Language		Wos		Publication Date
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1742-6588; 1742-6596	ISBN		Additional Links	UA library record
	Impact Factor		Times cited		Open Access
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ lucian @ c:irua:129198			Serial	4506
Permanent link to this record



	Author	Van Aert, S.; Batenburg, K.J.; Rossell, M.D.; Erni, R.; Van Tendeloo, G.
	Title	Three-dimensional atomic imaging of crystalline nanoparticles			Type	A1 Journal article
	Year	2011	Publication	Nature	Abbreviated Journal	Nature
	Volume	470	Issue	7334	Pages	374-377
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
	Abstract	Determining the three-dimensional (3D) arrangement of atoms in crystalline nanoparticles is important for nanometre-scale device engineering and also for applications involving nanoparticles, such as optoelectronics or catalysis. A nanoparticles physical and chemical properties are controlled by its exact 3D morphology, structure and composition1. Electron tomography enables the recovery of the shape of a nanoparticle from a series of projection images2, 3, 4. Although atomic-resolution electron microscopy has been feasible for nearly four decades, neither electron tomography nor any other experimental technique has yet demonstrated atomic resolution in three dimensions. Here we report the 3D reconstruction of a complex crystalline nanoparticle at atomic resolution. To achieve this, we combined aberration-corrected scanning transmission electron microscopy5, 6, 7, statistical parameter estimation theory8, 9 and discrete tomography10, 11. Unlike conventional electron tomography, only two images of the targeta silver nanoparticle embedded in an aluminium matrixare sufficient for the reconstruction when combined with available knowledge about the particles crystallographic structure. Additional projections confirm the reliability of the result. The results we present help close the gap between the atomic resolution achievable in two-dimensional electron micrographs and the coarser resolution that has hitherto been obtained by conventional electron tomography.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	London	Editor
	Language		Wos	000287409100037	Publication Date	2011-02-02
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0028-0836;1476-4687;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	40.137	Times cited	341	Open Access
	Notes	Esteem 026019			Approved	Most recent IF: 40.137; 2011 IF: 36.280
	Call Number	UA @ lucian @ c:irua:86745			Serial	3644
Permanent link to this record



	Author	Monai, M.; Jenkinson, K.; Melcherts, A.E.M.; Louwen, J.N.; Irmak, E.A.; Van Aert, S.; Altantzis, T.; Vogt, C.; van der Stam, W.; Duchon, T.; Smid, B.; Groeneveld, E.; Berben, P.; Bals, S.; Weckhuysen, B.M.
	Title	Restructuring of titanium oxide overlayers over nickel nanoparticles during catalysis			Type	A1 Journal article
	Year	2023	Publication	Science	Abbreviated Journal
	Volume	380	Issue	6645	Pages	644-651
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
	Abstract	Reducible supports can affect the performance of metal catalysts by the formation of suboxide overlayers upon reduction, a process referred to as the strong metal-support interaction (SMSI). A combination of operando electron microscopy and vibrational spectroscopy revealed that thin TiOx overlayers formed on nickel/titanium dioxide catalysts during 400 degrees C reduction were completely removed under carbon dioxide hydrogenation conditions. Conversely, after 600 degrees C reduction, exposure to carbon dioxide hydrogenation reaction conditions led to only partial reexposure of nickel, forming interfacial sites in contact with TiOx and favoring carbon-carbon coupling by providing a carbon species reservoir. Our findings challenge the conventional understanding of SMSIs and call for more-detailed operando investigations of nanocatalysts at the single-particle level to revisit static models of structure-activity relationships.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000999020900010	Publication Date	2023-05-11
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0036-8075; 1095-9203	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	56.9	Times cited	29	Open Access	Not_Open_Access
	Notes	This work was supported by BASF and NWO CHIPP (research grant to B.M.W.); the MCEC NWO Gravitation Program (B.M.W.); the ARC-CBBC NWO Program (B.M.W.); the European Research Council (grant 770887 PICOMETRICS to S.V.A.); and the European Research Council (grant 815128 REALNANO to S.B.).			Approved	Most recent IF: 56.9; 2023 IF: 37.205
	Call Number	UA @ admin @ c:irua:197432			Serial	8923
Permanent link to this record



	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
	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	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	Not_Open_Access
	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	Lu, J.; Martinez, G.T.; Van Aert, S.; Schryvers, D.
	Title	Lattice deformations in quasi-dynamic strain glass visualised and quantified by aberration corrected electron microscopy			Type	A1 Journal article
	Year	2014	Publication	Physica status solidi: B: basic research	Abbreviated Journal	Phys Status Solidi B
	Volume	251	Issue	10	Pages	2034-2040
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	Advanced transmission electron microscopy and statistical parameter estimated quantification procedures were applied to study the room temperature quasi-dynamical strain glass state in NiTi alloys. Nanosized strain pockets are visualised and the displacements of the atom columns are quantified. A comparison is made with conventional high-resolution transmission electron microscopy images of point defect induced strains in NiAl alloys.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Berlin	Editor
	Language		Wos	000344360000009	Publication Date	2014-03-31
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0370-1972;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.674	Times cited	2	Open Access
	Notes	Fwo			Approved	Most recent IF: 1.674; 2014 IF: 1.489
	Call Number	UA @ lucian @ c:irua:120471			Serial	1801
Permanent link to this record



	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	Open_Access
	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	Zhang, Z.; Lobato, I.; De Backer, A.; Van Aert, S.; Nellist, P.
	Title	Fast generation of calculated ADF-EDX scattering cross-sections under channelling conditions			Type	A1 Journal article
	Year	2023	Publication	Ultramicroscopy	Abbreviated Journal
	Volume	246	Issue		Pages	113671
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	Advanced materials often consist of multiple elements which are arranged in a complicated structure. Quantitative scanning transmission electron microscopy is useful to determine the composition and thickness of nanostructures at the atomic scale. However, significant difficulties remain to quantify mixed columns by comparing the resulting atomic resolution images and spectroscopy data with multislice simulations where dynamic scattering needs to be taken into account. The combination of the computationally intensive nature of these simulations and the enormous amount of possible mixed column configurations for a given composition indeed severely hamper the quantification process. To overcome these challenges, we here report the development of an incoherent non-linear method for the fast prediction of ADF-EDX scattering cross-sections of mixed columns under channelling conditions. We first explain the origin of the ADF and EDX incoherence from scattering physics suggesting a linear dependence between those two signals in the case of a high-angle ADF detector. Taking EDX as a perfect incoherent reference mode, we quantitatively examine the ADF longitudinal incoherence under different microscope conditions using multislice simulations. Based on incoherent imaging, the atomic lensing model previously developed for ADF is now expanded to EDX, which yields ADF-EDX scattering cross-section predictions in good agreement with multislice simulations for mixed columns in a core–shell nanoparticle and a high entropy alloy. The fast and accurate prediction of ADF-EDX scattering cross-sections opens up new opportunities to explore the wide range of ordering possibilities of heterogeneous materials with multiple elements.
	Address
	Corporate Author	Zezhong Zhang			Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000995063900001	Publication Date	2022-12-28
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0304-3991	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.2	Times cited		Open Access	OpenAccess
	Notes	European Research Council 770887 PICOMETRICS; Fonds Wetenschappelijk Onderzoek No.G.0502.18N; Horizon 2020, 770887 ; Horizon 2020 Framework Programme; European Research Council, 823717 ESTEEM3 ; esteem3reported; esteem3JRa			Approved	Most recent IF: 2.2; 2023 IF: 2.843
	Call Number	EMAT @ emat @c:irua:195890			Serial	7251
Permanent link to this record



	Author	Sentürk, D.G.; De Backer, A.; Friedrich, T.; Van Aert, S.
	Title	Optimal experiment design for element specific atom counting using multiple annular dark field scanning transmission electron microscopy detectors			Type	A1 Journal article
	Year	2022	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	242	Issue		Pages	113626
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	This paper investigates the possible benefits for counting atoms of different chemical nature when analysing multiple 2D scanning transmission electron microscopy (STEM) images resulting from independent annular dark field (ADF) detector regimes. To reach this goal, the principles of statistical detection theory are used to quantify the probability of error when determining the number of atoms in atomic columns consisting of multiple types of elements. In order to apply this theory, atom-counting is formulated as a statistical hypothesis test, where each hypothesis corresponds to a specific number of atoms of each atom type in an atomic column. The probability of error, which is limited by the unavoidable presence of electron counting noise, can then be computed from scattering-cross sections extracted from multiple ADF STEM images. Minimisation of the probability of error as a function of the inner and outer angles of a specified number of independent ADF collection regimes results in optimal experimental designs. Based on simulations of spherical Au@Ag and Au@Pt core–shell nanoparticles, we investigate how the combination of two non-overlapping detector regimes helps to improve the probability of error when unscrambling two types of atoms. In particular, the combination of a narrow low angle ADF detector with a detector formed by the remaining annular collection regime is found to be optimal. The benefit is more significant if the atomic number Z difference becomes larger. In addition, we show the benefit of subdividing the detector regime into three collection areas for heterogeneous nanostructures based on a structure consisting of three types of elements, e.g., a mixture of Au, Ag and Al atoms. Finally, these results are compared with the probability of error resulting when one would ultimately use a pixelated 4D STEM detector and how this could help to further reduce the incident electron dose.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000873778100001	Publication Date	0000-00-00
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0304-3991	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.2	Times cited		Open Access	OpenAccess
	Notes	This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert and Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0346.21N and EOS 30489208) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF).; esteem3reported; esteem3jra			Approved	Most recent IF: 2.2
	Call Number	EMAT @ emat @c:irua:190925			Serial	7118
Permanent link to this record



	Author	Robert, Hl.; Lobato, I.; Lyu, Fj.; Chen, Q.; Van Aert, S.; Van Dyck, D.; Müller-Caspary, K.
	Title	Dynamical diffraction of high-energy electrons investigated by focal series momentum-resolved scanning transmission electron microscopy at atomic resolution			Type	A1 Journal article
	Year	2022	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	233	Issue		Pages	113425
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
	Abstract	We report a study of scattering dynamics in crystals employing momentum-resolved scanning transmission electron microscopy under varying illumination conditions. As we perform successive changes of the probe focus, multiple real-space signals are obtained in dependence of the shape of the incident electron wave. With support from extensive simulations, each signal is shown to be characterised by an optimum focus for which the contrast is maximum and which differs among different signals. For instance, a systematic focus mismatch is found between images formed by high-angle scattering, being sensitive to thickness and chemical composition, and the first moment in diffraction space, being sensitive to electric fields. It follows that a single recording at one specific probe focus is usually insufficient to characterise materials comprehensively. Most importantly, we demonstrate in experiment and simulation that the second moment (
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000734396800009	Publication Date	2021-11-13
	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	2.2	Times cited		Open Access	OpenAccess
	Notes	We thank Dr. Florian Winkler for valuable discussions and experimental work at the early stages of this study. This work was supported by the Initiative and Network Fund of the Helmholtz Association (Germany) under contracts VH-NG-1317 and ZT-I-0025. This project furthermore received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 770887).			Approved	Most recent IF: 2.2
	Call Number	EMAT @ emat @c:irua:184833			Serial	6898
Permanent link to this record



	Author	Klingstedt, M.; Sundberg, M.; Eriksson, L.; Haigh, S.; Kirkland, A.; Grüner, D.; de Backer, A.; Van Aert, S.; Tarasaki, O.
	Title	Exit wave reconstruction from focal series of HRTEM images, single crystal XRD and total energy studies on Sb_xWO_3+y (x\sim0.11)			Type	A1 Journal article
	Year	2012	Publication	Zeitschrift für Kristallographie	Abbreviated Journal	Z Krist-Cryst Mater
	Volume	227	Issue	6	Pages	341-349
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	A new tungsten bronze in the SbWO system has been prepared in a solid state reaction from Sb2O3, WO3 and W metal powder. The average structure was determined by single crystal X-ray diffraction. SbxWO3+y (x ∼ 0.11) crystallizes in the orthorhombic space group Pm21n (no. 31), a = 27.8135(9) Å, b = 7.3659(2) Å and c = 3.8672(1) Å. The structure belongs to the (n)-ITB class of intergrowth tungsten bronzes. It contains slabs of hexagonal channels formed by six WO6 octahedra. These slabs are separated by three layers of WO6 octahedra that are arranged in a WO3-type fashion. The WO6 octahedra share all vertices to build up a three-dimensional framework. The hexagonal channels are filled with Sb atoms to ∼80% and additional O atoms. The atoms are shifted out of the center of the channels. Exit-wave reconstruction of focal series of high resolution-transmission-electron-microscope (HRTEM) images combined with statistical paramäeter estimation techniques allowed to study local ordering in the channels. Sb atoms in neighbouring channels tend to be displaced in the same direction, which is in agreement with total energy calculations on ordered structure models, but the ratio of the occupation of the two possible Sb sites varies from channel to channel. The structure of SbxWO3+y exhibits pronounced local modulations.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	München	Editor
	Language		Wos	000307314200003	Publication Date	2012-06-06
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2194-4946;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.179	Times cited	4	Open Access
	Notes	Fwo; Esteem 026019			Approved	Most recent IF: 3.179; 2012 IF: NA
	Call Number	UA @ lucian @ c:irua:101218			Serial	1131
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	Author	Fatermans, J.; den Dekker, Aj.; Müller-Caspary, K.; Gauquelin, N.; Verbeeck, J.; Van Aert, S.
	Title	Atom column detection from simultaneously acquired ABF and ADF STEM images			Type	A1 Journal article
	Year	2020	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	219	Issue		Pages	113046
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
	Abstract	In electron microscopy, the maximum a posteriori (MAP) probability rule has been introduced as a tool to determine the most probable atomic structure from high-resolution annular dark-field (ADF) scanning transmission electron microscopy (STEM) images exhibiting low contrast-to-noise ratio (CNR). Besides ADF imaging, STEM can also be applied in the annular bright-field (ABF) regime. The ABF STEM mode allows to directly visualize light-element atomic columns in the presence of heavy columns. Typically, light-element nanomaterials are sensitive to the electron beam, limiting the incoming electron dose in order to avoid beam damage and leading to images exhibiting low CNR. Therefore, it is of interest to apply the MAP probability rule not only to ADF STEM images, but to ABF STEM images as well. In this work, the methodology of the MAP rule, which combines statistical parameter estimation theory and model-order selection, is extended to be applied to simultaneously acquired ABF and ADF STEM images. For this, an extension of the commonly used parametric models in STEM is proposed. Hereby, the effect of specimen tilt has been taken into account, since small tilts from the crystal zone axis affect, especially, ABF STEM intensities. Using simulations as well as experimental data, it is shown that the proposed methodology can be successfully used to detect light elements in the presence of heavy elements.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000594768500005	Publication Date	2020-06-01
	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	2.2	Times cited	9	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, EOS 30489208). 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 funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 823717 – ESTEEM3. The direct electron detector (Medipix3, Quantum Detectors) was funded by the Hercules fund from the Flemish Government. K. M. C. acknowledges funding from the Initiative and Network Fund of the Helmholtz Association (Germany) under contract VH-NG-1317. The authors thank Mark Huijben from the University of Twente (Enschede, The Netherlands) for providing the LiMn2O4 sample used in section 4.2 of this study. N. G., J. V., and S. V. A. acknowledge funding from the University of Antwerp through the Concerted Research Actions (GOA) project Solarpaint and the TOP project.			Approved	Most recent IF: 2.2; 2020 IF: 2.843
	Call Number	EMAT @ emat @c:irua:169706			Serial	6373
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	Author	De wael, A.; De Backer, A.; Van Aert, S.
	Title	Hidden Markov model for atom-counting from sequential ADF STEM images: Methodology, possibilities and limitations			Type	A1 Journal article
	Year	2020	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	219	Issue		Pages	113131
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	We present a quantitative method which allows us to reliably measure dynamic changes in the atomic structure of monatomic crystalline nanomaterials from a time series of atomic resolution annular dark field scanning transmission electron microscopy images. The approach is based on the so-called hidden Markov model and estimates the number of atoms in each atomic column of the nanomaterial in each frame of the time series. We discuss the origin of the improved performance for time series atom-counting as compared to the current state-of-the-art atom-counting procedures, and show that the so-called transition probabilities that describe the probability for an atomic column to lose or gain one or more atoms from frame to frame are particularly important. Using these transition probabilities, we show that the method can also be used to estimate the probability and cross section related to structural changes. Furthermore, we explore the possibilities for applying the method to time series recorded under variable environmental conditions. The method is shown to be promising for a reliable quantitative analysis of dynamic processes such as surface diffusion, adatom dynamics, beam effects, or in situ experiments.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000594770500003	Publication Date	2020-10-03
	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	2.2	Times cited		Open Access	OpenAccess
	Notes	This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 770887 and No. 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through grants to A.D.w. and A.D.B. and projects G.0502.18N and EOS 30489208.			Approved	Most recent IF: 2.2; 2020 IF: 2.843
	Call Number	EMAT @ emat @c:irua:172449			Serial	6417
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	Author	van den Bos, K.H.W.; Janssens, L.; De Backer, A.; Nellist, P.D.; Van Aert, S.
	Title	The atomic lensing model: new opportunities for atom-by-atom metrology of heterogeneous nanomaterials			Type	A1 Journal article
	Year	2019	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	203	Issue		Pages	155
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	The atomic lensing model has been proposed as a promising method facilitating atom-counting in heterogeneous nanocrystals [1]. Here, image simulations will validate the model, which describes dynamical diffraction as a superposition of individual atoms focussing the incident electrons. It will be demonstrated that the model is reliable in the annular dark field regime for crystals having columns containing dozens of atoms. By using the principles of statistical detection theory, it will be shown that this model gives new opportunities for detecting compositional differences.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000465021000020	Publication Date	2018-12-06
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0304-3991	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.843	Times cited	4	Open Access	OpenAccess
	Notes	The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0369.15N, G.0502.18N and WO.010.16N), and by personal grants to K.H.W. van den Bos and A. De Backer. This project has received funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (grant agreement No. 770887).			Approved	Most recent IF: 2.843
	Call Number	EMAT @ emat @UA @ admin @ c:irua:155721			Serial	5074
Permanent link to this record



	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	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
Permanent link to this record



	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	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
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	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	Alania, M.; Lobato Hoyos, I.P.; Van Aert, S.
	Title	Frozen lattice and absorptive model for high angle annular dark field scanning transmission electron microscopy : a comparison study in terms of integrated intensity and atomic column position measurement			Type	A1 Journal article
	Year	2018	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	184	Issue	A	Pages	188-198
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	<script type='text/javascript'>document.write(unpmarked('In this paper, both the frozen lattice (FL) and the absorptive potential (AP) approximation models are compared in terms of the integrated intensity and the precision with which atomic columns can be located from an image acquired using high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM). The comparison is made for atoms of Cu, Ag, and Au. The integrated intensity is computed for both an isolated atomic column and an atomic column inside an FCC structure. The precision has been computed using the so-called Cramer-Rao Lower Bound (CRLB), which provides a theoretical lower bound on the variance with which parameters can be estimated. It is shown that the AP model results into accurate measurements for the integrated intensity only for small detector ranges under relatively low angles and for small thicknesses. In terms of the attainable precision, both methods show similar results indicating picometer range precision under realistic experimental conditions. (C) 2017 Elsevier B.V. All rights reserved.'));
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000415650200022	Publication Date	2017-09-12
	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		Open Access	OpenAccess
	Notes	; 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). A. Rosenauer is acknowledged for providing the STEMsim program. ;			Approved	Most recent IF: 2.843
	Call Number	UA @ lucian @ c:irua:147658			Serial	4877
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	Author	Alania, M.; De Backer, A.; Lobato, I.; Krause, F.F.; Van Dyck, D.; Rosenauer, A.; Van Aert, S.
	Title	How precise can atoms of a nanocluster be located in 3D using a tilt series of scanning transmission electron microscopy images?			Type	A1 Journal article
	Year	2017	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	181	Issue	181	Pages	134-143
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
	Abstract	In this paper, we investigate how precise atoms of a small nanocluster can ultimately be located in three dimensions (3D) from a tilt series of images acquired using annular dark field (ADF) scanning transmission electron microscopy (STEM). Therefore, we derive an expression for the statistical precision with which the 3D atomic position coordinates can be estimated in a quantitative analysis. Evaluating this statistical precision as a function of the microscope settings also allows us to derive the optimal experimental design. In this manner, the optimal angular tilt range, required electron dose, optimal detector angles, and number of projection images can be determined.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000411170800016	Publication Date	2016-12-15
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0304-3991	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.843	Times cited	3	Open Access	OpenAccess
	Notes	The authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483-ESTEEM2. The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0369.15N, G.0368.15N, and WO.010.16N) and a post-doctoral grant to A. De Backer, and from the DFG under contract No. RO-2057/4-2.			Approved	Most recent IF: 2.843
	Call Number	EMAT @ emat @ c:irua:144432			Serial	4618
Permanent link to this record



	Author	Gauquelin, N.; van den Bos, K.H.W.; Béché, A.; Krause, F.F.; Lobato, I.; Lazar, S.; Rosenauer, A.; Van Aert, S.; Verbeeck, J.
	Title	Determining oxygen relaxations at an interface: A comparative study between transmission electron microscopy techniques			Type	A1 Journal article
	Year	2017	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	181	Issue	181	Pages	178-190
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	Nowadays, aberration corrected transmission electron microscopy (TEM) is a popular method to characterise nanomaterials at the atomic scale. Here, atomically resolved images of nanomaterials are acquired, where the contrast depends on the illumination, imaging and detector conditions of the microscope. Visualization of light elements is possible when using low angle annular dark field (LAADF) STEM, annular bright field (ABF) STEM, integrated differential phase contrast (iDPC) STEM, negative spherical aberration imaging (NCSI) and imaging STEM (ISTEM). In this work, images of a NdGaO3-La0.67Sr0.33MnO3 (NGO-LSMO) interface are quantitatively evaluated by using statistical parameter estimation theory. For imaging light elements, all techniques are providing reliable results, while the techniques based on interference contrast, NCSI and ISTEM, are less robust in terms of accuracy for extracting heavy column locations. In term of precision, sample drift and scan distortions mainly limits the STEM based techniques as compared to NCSI. Post processing techniques can, however, partially compensate for this. In order to provide an outlook to the future, simulated images of NGO, in which the unavoidable presence of Poisson noise is taken into account, are used to determine the ultimate precision. In this future counting noise limited scenario, NCSI and ISTEM imaging will provide more precise values as compared to the other techniques, which can be related to the mechanisms behind the image recording.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000411170800022	Publication Date	2017-06-03
	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	34	Open Access	OpenAccess
	Notes	The authors acknowledge financial support from Flanders (FWO, Belgium) through project fundings (G.0044.13N, G.0374.13N, G.0368.15N, G.0369.15N), and by a Ph.D. grant to K.H.W.v.d.B. The Qu-Ant-EM microscope used for this study was partly funded by the Hercules fund from the Flemish Government. A.B. and N.G. acknowledge the EUROTAPES project (FP7-NMP.2011.2.2-1 Grant no.280432) which partly funded this study. N.G., A.B. and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. 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 LSMO-NGO test sample.			Approved	Most recent IF: 2.843
	Call Number	EMAT @ emat @ c:irua:144435UA @ admin @ c:irua:144435			Serial	4620
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	Author	De wael, A.; De Backer, A.; Jones, L.; Nellist, P.D.; Van Aert, S.
	Title	Hybrid statistics-simulations based method for atom-counting from ADF STEM images			Type	A1 Journal article
	Year	2017	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	177	Issue	177	Pages	69-77
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	A hybrid statistics-simulations based method for atom-counting from annular dark field scanning transmission electron microscopy (ADF STEM) images of monotype crystalline nanostructures is presented. Different atom-counting methods already exist for model-like systems. However, the increasing relevance of radiation damage in the study of nanostructures demands a method that allows atom-counting from low dose images with a low signal-to-noise ratio. Therefore, the hybrid method directly includes prior knowledge from image simulations into the existing statistics-based method for atom-counting, and accounts in this manner for possible discrepancies between actual and simulated experimental conditions. It is shown by means of simulations and experiments that this hybrid method outperforms the statistics-based method, especially for low electron doses and small nanoparticles. The analysis of a simulated low dose image of a small nanoparticle suggests that this method allows for far more reliable quantitative analysis of beam-sensitive materials.
	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	Schryvers, D.; Salje, E.K.H.; Nishida, M.; De Backer, A.; Idrissi, H.; Van Aert, S.
	Title	Quantification by aberration corrected (S)TEM of boundaries formed by symmetry breaking phase transformations			Type	A1 Journal article
	Year	2017	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	176	Issue		Pages	194-199
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	The present contribution gives a review of recent quantification work of atom displacements, atom site occupations and level of crystallinity in various systems and based on aberration corrected HR(S)TEM images. Depending on the case studied, picometer range precisions for individual distances can be obtained, boundary widths at the unit cell level determined or statistical evolutions of fractions of the ordered areas calculated. In all of these cases, these quantitative measures imply new routes for the applications of the respective materials.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000403992200026	Publication Date	2017-01-09
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0304-3991	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.843	Times cited	1	Open Access	OpenAccess
	Notes	The authors acknowledge financial support from the Fund for Scientific Research-Flanders (G.0064.10N, G.0393.11N, G.0374.13N, G.0368.15N, G.0369.15N) and the Flemish Hercules 3 program for large infrastructure as well as financial support from the European Union Seventh Framework Programme (FP7/2007 – 2013) under Grant agreement no. 312483 (ESTEEM2). EKHS thanks EPSRC (EP/ K009702/1) and the Leverhulme trust (EM-2016-004) for support. DS and MN acknowledge financial support from the Japan Society for the Promotion of Science (JSPS, Japan) through the Grant-in-Aid for Scientific Research (A: No. 26249090) and the Strategic Young Researcher Overseas Visits Program for Accelerating Brain Circulation (R2408).			Approved	Most recent IF: 2.843
	Call Number	EMAT @ emat @c:irua:149654			Serial	4914
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	Author	De Backer, A.; van den Bos, K.H.W.; Van den Broek, W.; Sijbers, J.; Van Aert, S.
	Title	StatSTEM: An efficient approach for accurate and precise model-based quantification of atomic resolution electron microscopy images			Type	A1 Journal article
	Year	2016	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	171	Issue	171	Pages	104-116
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
	Abstract	An efficient model-based estimation algorithm is introduced to quantify the atomic column positions and intensities from atomic resolution (scanning) transmission electron microscopy ((S)TEM) images. This algorithm uses the least squares estimator on image segments containing individual columns fully accounting for overlap between neighbouring columns, enabling the analysis of a large field of view. For this algorithm, the accuracy and precision with which measurements for the atomic column positions and scattering cross-sections from annular dark field (ADF) STEM images can be estimated, has been investigated. The highest attainable precision is reached even for low dose images. Furthermore, the advantages of the model-based approach taking into account overlap between neighbouring columns are highlighted. This is done for the estimation of the distance between two neighbouring columns as a function of their distance and for the estimation of the scattering cross-section which is compared to the integrated intensity from a Voronoi cell. To provide end-users this well-established quantification method, a user friendly program, StatSTEM, is developed which is freely available under a GNU public license.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000389106200014	Publication Date	2016-09-09
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0304-3991	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.843	Times cited	43	Open Access
	Notes	The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0393.11, G.0064.10 and G.0374.13), a Ph.D. research grant to K.H.W. van den Bos, and a postdoctoral research grant to A. De Backer. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative-I3). A. Rosenauer is acknowledged for providing the STEMsim program.; esteem2_jra2			Approved	Most recent IF: 2.843
	Call Number	EMAT @ emat @ c:irua:135516			Serial	4280
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	Author	Gonnissen, J.; De Backer, A.; den Dekker, A.J.; Sijbers, J.; Van Aert, S.
	Title	Detecting and locating light atoms from high-resolution STEM images: The quest for a single optimal design			Type	A1 Journal article
	Year	2016	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	170	Issue	170	Pages	128-138
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
	Abstract	In the present paper, the optimal detector design is investigated for both detecting and locating light atoms from high resolution scanning transmission electron microscopy (HR STEM) images. The principles of detection theory are used to quantify the probability of error for the detection of light atoms from HR STEM images. To determine the optimal experiment design for locating light atoms, use is made of the so-called Cramer-Rao Lower Bound (CRLB). It is investigated if a single optimal design can be found for both the detection and location problem of light atoms. Furthermore, the incoming electron dose is optimised for both research goals and it is shown that picometre range precision is feasible for the estimation of the atom positions when using an appropriate incoming electron dose under the optimal detector settings to detect light atoms.
	Address	Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium. Electronic address: sandra.vanaert@uantwerpen.be
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	English	Wos	000386925500014	Publication Date	2016-07-26
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0304-3991	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.843	Times cited	6	Open Access
	Notes	The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0368.15, G.0369.15 and G.0374.13) and a postdoctoral research grant to A. De Backer. The research leading to these results has also received funding from the European Union Seventh Framework Programme [FP7/2007-2013] under Grant agreement no. 312483 (ESTEEM2). The authors would also like to thank A. Rosenauer for providing access to the STEMsim software and Gerardo T. Martinez for fruitful discussions.; esteem2_jra2			Approved	Most recent IF: 2.843
	Call Number	c:irua:135337 c:irua:135337			Serial	4128
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	Author	Jain, N.; Hao, Y.; Parekh, U.; Kaltenegger, M.; Pedrazo-Tardajos, A.; Lazzaroni, R.; Resel, R.; Geerts, Y.H.; Bals, S.; Van Aert, S.
	Title	Exploring the effects of graphene and temperature in reducing electron beam damage: A TEM and electron diffraction-based quantitative study on Lead Phthalocyanine (PbPc) crystals			Type	A1 Journal article
	Year	2023	Publication	Micron	Abbreviated Journal
	Volume	169	Issue		Pages	103444
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	High-resolution transmission electron microscopy (TEM) of organic crystals, such as Lead Phthalocyanine (PbPc), is very challenging since these materials are prone to electron beam damage leading to the breakdown of the crystal structure during investigation. Quantification of the damage is imperative to enable high-resolution imaging of PbPc crystals with minimum structural changes. In this work, we performed a detailed electron diffraction study to quantitatively measure degradation of PbPc crystals upon electron beam irradiation. Our study is based on the quantification of the fading intensity of the spots in the electron diffraction patterns. At various incident dose rates (e/Å2/s) and acceleration voltages, we experimentally extracted the decay rate (1/s), which directly correlates with the rate of beam damage. In this manner, a value for the critical dose (e/Å2) could be determined, which can be used as a measure to quantify beam damage. Using the same methodology, we explored the influence of cryogenic temperatures, graphene TEM substrates, and graphene encapsulation in prolonging the lifetime of the PbPc crystal structure during TEM investigation. The knowledge obtained by diffraction experiments is then translated to real space high-resolution TEM imaging of PbPc.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000965998800001	Publication Date	2023-03-21
	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	2.4	Times cited	1	Open Access	OpenAccess
	Notes	This work is supported by FWO and FNRS within the 2Dto3D network of the EOS (Excellence of Science) program (grant number 30489208) and ERC-CoGREALNANO-815128 (to Prof. Dr. Sara Bals). N.J. would like to thank Dr. Kunal S. Mali and Dr. Da Wang for useful and interesting discussions on sample preparation procedures.			Approved	Most recent IF: 2.4; 2023 IF: 1.98
	Call Number	EMAT @ emat @c:irua:196069			Serial	7379
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	Author	Lobato, I.; Van Aert, S.; Verbeeck, J.
	Title	Progress and new advances in simulating electron microscopy datasets using MULTEM			Type	A1 Journal article
	Year	2016	Publication	Ultramicroscopy	Abbreviated Journal	Ultramicroscopy
	Volume	168	Issue	168	Pages	17-27
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	A new version of the open source program MULTEM is presented here. It includes a graphical user interface, tapering truncation of the atomic potential, CPU multithreading functionality, single/double precision calculations, scanning transmission electron microscopy (STEM) simulations using experimental detector sensitivities, imaging STEM (ISTEM) simulations, energy filtered transmission electron microscopy (EFTEM) simulations, STEM electron energy loss spectroscopy (EELS) simulations along with other improvements in the algorithms. We also present a mixed channeling approach for the calculation of inelastic excitations, which allows one to considerably speed up time consuming EFTEM/STEM-EELS calculations.
	Address	EMAT, University of Antwerp, Department of Physics, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	English	Wos	000380754100003	Publication Date	2016-06-11
	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	43	Open Access
	Notes	The authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483- ESTEEM2. The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0369.15N and G.0368.15N).; esteem2jra3; esteem2na3; esteem2_jra2			Approved	Most recent IF: 2.843
	Call Number	c:irua:134088 c:irua:134088UA @ admin @ c:irua:134088			Serial	4093
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