toggle visibility
Search within Results:
Display Options:

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Xu, Q.; Zandbergen, H.W.; van Dyck, D. pdf  doi
openurl 
  Title Applying an information transmission approach to extract valence electron information from reconstructed exit waves Type A1 Journal article
  Year 2011 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume (up) 111 Issue 7 Pages 912-919  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract The knowledge of the valence electron distribution is essential for understanding the properties of materials. However this information is difficult to obtain from HREM images because it is easily obscured by the large scattering contribution of core electrons and by the strong dynamical scattering process. In order to develop a sensitive method to extract the information of valence electrons, we have used an information transmission approach to describe the electron interaction with the object. The scattered electron wave is decomposed in a set of basic functions, which are the eigen functions of the Hamiltonian of the projected electrostatic object potential. Each basic function behaves as a communication channel that transfers the information of the object with its own transmission characteristic. By properly combining the components of the different channels, it is possible to design a scheme to extract the information of valence electron distribution from a series of exit waves. The method is described theoretically and demonstrated by means of computer simulations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000300461000024 Publication Date 2011-02-02  
  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 Fwo Approved Most recent IF: 2.843; 2011 IF: 2.471  
  Call Number UA @ lucian @ c:irua:93623 Serial 146  
Permanent link to this record
 

 
Author de Backer, A.; Van Aert, S.; van Dyck, D. pdf  url
doi  openurl
  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 (up) 111 Issue 9/10 Pages 1475-1482  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract In this paper, it has been investigated how to measure atom column positions as accurately and precisely as possible using a focal series of images. In theory, it is expected that the precision would considerably improve using a maximum likelihood estimator based on the full series of focal images. As such, the theoretical lower bound on the variances of the unknown atom column positions can be attained. However, this approach is numerically demanding. Therefore, maximum likelihood estimation has been compared with the results obtained by fitting a model to a reconstructed exit wave rather than to the full series of focal images. Hence, a real space model-based exit wave reconstruction technique based on the channelling theory is introduced. Simulations show that the reconstructed complex exit wave contains the same amount of information concerning the atom column positions as the full series of focal images. Only for thin samples, which act as weak phase objects, this information can be retrieved from the phase of the reconstructed complex exit wave.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000300461200004 Publication Date 2011-07-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 8 Open Access  
  Notes Fwo Approved Most recent IF: 2.843; 2011 IF: 2.471  
  Call Number UA @ lucian @ c:irua:91879 Serial 1438  
Permanent link to this record
 

 
Author Wang, A.; Chen, F.R.; Van Aert, S.; van Dyck, D. pdf  doi
openurl 
  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 (up) 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  
Permanent link to this record
 

 
Author van den Broek, W.; Van Aert, S.; Goos, P.; van Dyck, D. pdf  doi
openurl 
  Title Throughput maximization of particle radius measurements by balancing size and current of the electron probe Type A1 Journal article
  Year 2011 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume (up) 111 Issue 7 Pages 940-947  
  Keywords A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT); Vision lab  
  Abstract In thispaperweinvestigatewhichprobesizemaximizesthethroughputwhenmeasuringtheradiusof nanoparticlesinhighangleannulardarkfieldscanningtransmissionelectronmicroscopy(HAADFSTEM). The sizeandthecorrespondingcurrentoftheelectronprobedeterminetheprecisionoftheestimateofa particlesradius.Maximizingthroughputmeansthatamaximumnumberofparticlesshouldbeimaged withinagiventimeframe,sothataprespecifiedprecisionisattained.WeshowthatBayesianstatistical experimentaldesignisaveryusefulapproachtodeterminetheoptimalprobesizeusingacertainamount of priorknowledgeaboutthesample.Thedependenceoftheoptimalprobesizeonthedetectorgeometry and thediameter,variabilityandatomicnumberoftheparticlesisinvestigated.Anexpressionforthe optimalprobesizeintheabsenceofanykindofpriorknowledgeaboutthespecimenisderivedaswell.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000300461000026 Publication Date 2010-11-25  
  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 7 Open Access  
  Notes Approved Most recent IF: 2.843; 2011 IF: 2.471  
  Call Number UA @ lucian @ c:irua:89657 Serial 3659  
Permanent link to this record
 

 
Author Wang, A.; Van Aert, S.; Goos, P.; van Dyck, D. pdf  doi
openurl 
  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 (up) 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  
Permanent link to this record
 

 
Author van den Broek, W.; Rosenauer, A.; Goris, B.; Martinez, G.T.; Bals, S.; Van Aert, S.; van Dyck, D. pdf  doi
openurl 
  Title Correction of non-linear thickness effects in HAADF STEM electron tomography Type A1 Journal article
  Year 2012 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume (up) 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  
Permanent link to this record
 

 
Author Wang, A.; Chen, F.R.; Van Aert, S.; van Dyck, D. pdf  doi
openurl 
  Title Direct structure inversion from exit waves : part 2 : a practical example Type A1 Journal article
  Year 2012 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume (up) 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  
Permanent link to this record
 

 
Author Lobato, I.; van Dyck, D. doi  openurl
  Title Improved multislice calculations for including higher-order Laue zones effects Type A1 Journal article
  Year 2012 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume (up) 119 Issue Pages 63-71  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract A new method for including higher-order Laue zones (HOLZs) effects in an efficient way in electron scattering simulations has been developed and tested by detail calculations. The calculated results by the conventional multislice (CMS) method and the improved conventional multislice (ICMS) method using a large dynamical aperture to avoid numerical errors are compared with accurate results. We have found that the zero-order Laue zones (ZOLZs) reflection cannot be properly described only using the projected potential in the whole unit cell; in general, we need to subslice the electrostatic potential inside the unit cell. It is shown that the ICMS method has higher accuracy than the CMS method for the calculation of the ZOLZ, HOLZ and Pseudo-HOLZ reflections. Hence, ICMS method allows to use a larger slice thickness than the CMS method and reduces the calculation time. (C) 2012 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000308079200011 Publication Date 2012-01-14  
  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 Approved Most recent IF: 2.843; 2012 IF: 2.470  
  Call Number UA @ lucian @ c:irua:101902 Serial 1567  
Permanent link to this record
 

 
Author Amelinckx, S.; van Heurck, C.; van Dyck, D.; Van Tendeloo, G. pdf  doi
openurl 
  Title A peculiar diffraction effect in FCC crystals of C60 Type A1 Journal article
  Year 1992 Publication Physica status solidi: A: applied research Abbreviated Journal  
  Volume (up) 131 Issue Pages 589-604  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Berlin Editor  
  Language Wos A1992JE20400030 Publication Date 2007-01-13  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-8965;1521-396X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 13 Open Access  
  Notes Approved no  
  Call Number UA @ lucian @ c:irua:4371 Serial 2568  
Permanent link to this record
 

 
Author Wang, A.; Turner, S.; Van Aert, S.; van Dyck, D. pdf  url
doi  openurl
  Title An alternative approach to determine attainable resolution directly from HREM images Type A1 Journal article
  Year 2013 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume (up) 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  
Permanent link to this record
 

 
Author Van Aert, S.; den Dekker, A.J.; van Dyck, D.; van den Bos, A. doi  openurl
  Title High-resolution electron microscopy and electron tomography: resolution versus precision Type A1 Journal article
  Year 2002 Publication Journal of structural biology Abbreviated Journal J Struct Biol  
  Volume (up) 138 Issue Pages 21-33  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York Editor  
  Language Wos 000177978800003 Publication Date 2002-09-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1047-8477; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.767 Times cited 33 Open Access  
  Notes Approved Most recent IF: 2.767; 2002 IF: 4.194  
  Call Number UA @ lucian @ c:irua:47520 Serial 1446  
Permanent link to this record
 

 
Author Van den Broek, W.; Rosenauer, A.; Van Aert, S.; Sijbers, J.; van Dyck, D. pdf  url
doi  openurl
  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 (up) 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  
Permanent link to this record
 

 
Author Goessens, C.; Schryvers, D.; van Dyck, D.; van Landuyt, J.; de Keyzer, R. pdf  doi
openurl 
  Title Electron-diffraction evidence for ordering of interstitial silver ions in silver bromide microcrystals Type A1 Journal article
  Year 1994 Publication Physica status solidi: A Abbreviated Journal  
  Volume (up) 143 Issue 2 Pages 277-287  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract The occurrence and origin of diffuse intensity contours in electron micrographs of AgBr crystals are investigated. The observations are interpreted in terms of a model, which attributes diffuse scattering to the presence of predominant atom or vacancy clusters of a particular polyhedral type. It is shown that irrespective of the crystal morphology, interstitial Ag ions order in AgBr material in clusters of finite size along 001 type planes. A different geometry of the diffuse intensity locus observed for triangular and hexagonal tabular grains is explained in terms of the different twin plane morphology of these grains.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Berlin Editor  
  Language Wos A1994NW15300010 Publication Date 2007-01-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-8965;1521-396X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 7 Open Access  
  Notes Approved no  
  Call Number UA @ lucian @ c:irua:99870 Serial 919  
Permanent link to this record
 

 
Author Van Tendeloo, G.; op de Beeck, M.; De Meulenaere, P.; van Dyck, D. openurl 
  Title Towards quantitative high resolution electron microscopy? Type A1 Journal article
  Year 1995 Publication Institute of physics conference series Abbreviated Journal  
  Volume (up) 147 Issue Pages 67-72  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract The basics of the interpretation of high resolution images showing detail of the order of 0.1 nm are shortly explained here. The use of a field emission source, a CCD camera and an adapted reconstruction method for restoring the projected crystal potential (focus variation method) allows a quantitative interpretation of HREM images. Examples of partially disordered alloys and carbonate ordering in high Tc superconductors are presented.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos A1995BE67F00014 Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0-7503-0357-3; 0951-3248; 0305-2346 ISBN Additional Links UA library record; WoS full record;  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ lucian @ c:irua:13015 Serial 3688  
Permanent link to this record
 

 
Author Chen, J.H.; van Dyck, D.; op de Beeck, M.; Broeckx, J.; van Landuyt, J. pdf  doi
openurl 
  Title Modification of the multislice method for calculating coherent STEM images Type A1 Journal article
  Year 1995 Publication Physica status solidi: A: applied research Abbreviated Journal  
  Volume (up) 150 Issue Pages 13-22  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Berlin Editor  
  Language Wos A1995RQ21500002 Publication Date 2007-01-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-8965;1521-396X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 5 Open Access  
  Notes Approved no  
  Call Number UA @ lucian @ c:irua:13292 Serial 2159  
Permanent link to this record
 

 
Author Lobato, I.; Van Dyck, D. pdf  doi
openurl 
  Title MULTEM : a new multislice program to perform accurate and fast electron diffraction and imaging simulations using graphics processing units with CUDA Type A1 Journal article
  Year 2015 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume (up) 156 Issue 156 Pages 9-17  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract The main features and the GPU implementation of the MULTEM program are presented and described. This new program performs accurate and fast multislice simulations by including higher order expansion of the multislice solution of the high energy Schrodinger equation, the correct subslicing of the three-dimensional potential and top-bottom surfaces. The program implements different kinds of simulation for CTEM, STEM, ED, PED, CBED, ADF-TEM and ABF-HC with proper treatment of the spatial and temporal incoherences. The multislice approach described here treats the specimen as amorphous material which allows a straightforward implementation of the frozen phonon approximation. The generalized transmission function for each slice is calculated when is needed and then discarded. This allows us to perform large simulations that can include millions of atoms and keep the computer memory requirements to a reasonable level. (C) 2015 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000361001800003 Publication Date 2015-04-28  
  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 32 Open Access  
  Notes Approved Most recent IF: 2.843; 2015 IF: 2.436  
  Call Number UA @ lucian @ c:irua:127848 Serial 4209  
Permanent link to this record
 

 
Author Alania, M.; De Backer, A.; Lobato, I.; Krause, F.F.; Van Dyck, D.; Rosenauer, A.; Van Aert, S. pdf  url
doi  openurl
  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 (up) 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 Robert, Hl.; Lobato, I.; Lyu, Fj.; Chen, Q.; Van Aert, S.; Van Dyck, D.; Müller-Caspary, K. url  doi
openurl 
  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 (up) 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
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: