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Author Chen, D.; Goris, B.; Bleichrodt, F.; Heidari Mezerji, H.; Bals, S.; Batenburg, K.J.; de With, G.; Friedrich, H. pdf  url
doi  openurl
  Title The properties of SIRT, TVM, and DART for 3D imaging of tubular domains in nanocomposite thin-films and sections Type A1 Journal article
  Year 2014 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 147 Issue Pages 137-148  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract In electron tomography, the fidelity of the 3D reconstruction strongly depends on the employed reconstruction algorithm. In this paper, the properties of SIRT, TVM and DART reconstructions are studied with respect to having only a limited number of electrons available for imaging and applying different angular sampling schemes. A well-defined realistic model is generated, which consists of tubular domains within a matrix having slab-geometry. Subsequently, the electron tomography workflow is simulated from calculated tilt-series over experimental effects to reconstruction. In comparison with the model, the fidelity of each reconstruction method is evaluated qualitatively and quantitatively based on global and local edge profiles and resolvable distance between particles. Results show that the performance of all reconstruction methods declines with the total electron dose. Overall, SIRT algorithm is the most stable method and insensitive to changes in angular sampling. TVM algorithm yields significantly sharper edges in the reconstruction, but the edge positions are strongly influenced by the tilt scheme and the tubular objects become thinned. The DART algorithm markedly suppresses the elongation artifacts along the beam direction and moreover segments the reconstruction which can be considered a significant advantage for quantification. Finally, no advantage of TVM and DART to deal better with fewer projections was observed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000343157400015 Publication Date 2014-08-19  
  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 42 Open Access OpenAccess  
  Notes Fwo Approved Most recent IF: 2.843; 2014 IF: 2.436  
  Call Number UA @ lucian @ c:irua:119073 Serial 2729  
Permanent link to this record
 

 
Author Guzzinati, G.; Clark, L.; Béché, A.; Juchtmans, R.; Van Boxem, R.; Mazilu, M.; Verbeeck, J. pdf  url
doi  openurl
  Title Prospects for versatile phase manipulation in the TEM : beyond aberration correction Type A1 Journal article
  Year 2015 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 151 Issue 151 Pages 85-93  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract In this paper we explore the desirability of a transmission electron microscope in which the phase of the electron wave can be freely controlled. We discuss different existing methods to manipulate the phase of the electron wave and their limitations. We show how with the help of current techniques the electron wave can already be crafted into specific classes of waves each having their own peculiar properties. Assuming a versatile phase modulation device is feasible, we explore possible benefits and methods that could come into existence borrowing from light optics where the so-called spatial light modulators provide programmable phase plates for quite some time now. We demonstrate that a fully controllable phase plate building on Harald Rose׳s legacy in aberration correction and electron optics in general would open an exciting field of research and applications.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000351237800012 Publication Date 2014-10-22  
  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 19 Open Access  
  Notes 278510 Vortex; Fwo; 312483 Esteem2; esteem2jra2; esteem2jra3 ECASJO_; Approved Most recent IF: 2.843; 2015 IF: 2.436  
  Call Number c:irua:121405 c:irua:121405UA @ admin @ c:irua:121405 Serial 2731  
Permanent link to this record
 

 
Author Bertoni, G.; Beyers, E.; Verbeeck, J.; Mertens, M.; Cool, P.; Vansant, E.F.; Van Tendeloo, G. pdf  doi
openurl 
  Title Quantification of crystalline and amorphous content in porous TiO2 samples from electron energy loss spectroscopy Type A1 Journal article
  Year 2006 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 106 Issue 7 Pages 630-635  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)  
  Abstract We present an efficient method for the quantification of crystalline versus amorphous phase content in mesoporous materials, making use of electron energy loss spectroscopy. The method is based on fitting a superposition of core-loss edges using the maximum likelihood method with measured reference spectra. We apply the method to mesoporous TiO2 samples. We show that the absolute amount of the crystalline phase can be determined with an accuracy below 5%. This method takes also the amorphous phase into account, where standard X-ray diffraction is only quantitative for crystalline phases and not for amorphous phase. (c) 2006 Elsevier B.V.. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000238479300011 Publication Date 2006-04-28  
  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 83 Open Access  
  Notes Iap-V; Goa-2005; Fwo Approved Most recent IF: 2.843; 2006 IF: 1.706  
  Call Number UA @ lucian @ c:irua:58823UA @ admin @ c:irua:58823 Serial 2741  
Permanent link to this record
 

 
Author Van Aert, S.; Verbeeck, J.; Erni, R.; Bals, S.; Luysberg, M.; van Dyck, D.; Van Tendeloo, G. pdf  doi
openurl 
  Title Quantitative atomic resolution mapping using high-angle annular dark field scanning transmission electron microscopy Type A1 Journal article
  Year 2009 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 109 Issue 10 Pages 1236-1244  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract A model-based method is proposed to relatively quantify the chemical composition of atomic columns using high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) images. The method is based on a quantification of the total intensity of the scattered electrons for the individual atomic columns using statistical parameter estimation theory. In order to apply this theory, a model is required describing the image contrast of the HAADF STEM images. Therefore, a simple, effective incoherent model has been assumed which takes the probe intensity profile into account. The scattered intensities can then be estimated by fitting this model to an experimental HAADF STEM image. These estimates are used as a performance measure to distinguish between different atomic column types and to identify the nature of unknown columns with good accuracy and precision using statistical hypothesis testing. The reliability of the method is supported by means of simulated HAADF STEM images as well as a combination of experimental images and electron energy-loss spectra. It is experimentally shown that statistically meaningful information on the composition of individual columns can be obtained even if the difference in averaged atomic number Z is only 3. Using this method, quantitative mapping at atomic resolution using HAADF STEM images only has become possible without the need of simultaneously recorded electron energy loss spectra.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000270015200004 Publication Date 2009-05-28  
  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 166 Open Access  
  Notes Fwo; Esteem 026019 Approved Most recent IF: 2.843; 2009 IF: 2.067  
  Call Number UA @ lucian @ c:irua:78585UA @ admin @ c:irua:78585 Serial 2748  
Permanent link to this record
 

 
Author Martinez, G.T.; Rosenauer, A.; de Backer, A.; Verbeeck, J.; Van Aert, S. pdf  doi
openurl 
  Title Quantitative composition determination at the atomic level using model-based high-angle annular dark field scanning transmission electron microscopy Type A1 Journal article
  Year 2014 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 137 Issue Pages 12-19  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract High angle annular dark field scanning transmission electron microscopy (HAADF STEM) images provide sample information which is sensitive to the chemical composition. The image intensities indeed scale with the mean atomic number Z. To some extent, chemically different atomic column types can therefore be visually distinguished. However, in order to quantify the atomic column composition with high accuracy and precision, model-based methods are necessary. Therefore, an empirical incoherent parametric imaging model can be used of which the unknown parameters are determined using statistical parameter estimation theory (Van Aert et al., 2009, [1]). In this paper, it will be shown how this method can be combined with frozen lattice multislice simulations in order to evolve from a relative toward an absolute quantification of the composition of single atomic columns with mixed atom types. Furthermore, the validity of the model assumptions are explored and discussed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000331092200003 Publication Date 2013-11-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 74 Open Access  
  Notes FWO; FP7; ERC Countatoms; ESTEEM2; esteem2_ta Approved Most recent IF: 2.843; 2014 IF: 2.436  
  Call Number UA @ lucian @ c:irua:111579UA @ admin @ c:irua:111579 Serial 2749  
Permanent link to this record
 

 
Author Heidari, H.; van den Broek, W.; Bals, S. pdf  url
doi  openurl
  Title Quantitative electron tomography : the effect of the three-dimensional point spread function Type A1 Journal article
  Year 2013 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 135 Issue Pages 1-5  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The intensity levels in a three-dimensional (3D) reconstruction, obtained by electron tomography, can be influenced by several experimental imperfections. Such artifacts will hamper a quantitative interpretation of the results. In this paper, we will correct for artificial intensity variations by determining the 3D point spread function (PSF) of a tomographic reconstruction based on high angle annular dark field scanning transmission electron microscopy. The large tails of the PSF cause an underestimation of the intensity of smaller particles, which in turn hampers an accurate radius estimate. Here, the error introduced by the PSF is quantified and corrected a posteriori.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000326941500001 Publication Date 2013-06-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 6 Open Access  
  Notes Esteem2; Sunflower; esteem2_jra4 Approved Most recent IF: 2.843; 2013 IF: 2.745  
  Call Number UA @ lucian @ c:irua:111397 Serial 2756  
Permanent link to this record
 

 
Author Martinez, G.T.; Jones, L.; de Backer, A.; Béché, A.; Verbeeck, J.; Van Aert, S.; Nellist, P.D. pdf  url
doi  openurl
  Title Quantitative STEM normalisation : the importance of the electron flux Type A1 Journal article
  Year 2015 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 159 Issue 159 Pages 46-58  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Annular dark-field (ADF) scanning transmission electron microscopy (STEM) has become widely used in quantitative studies based on the opportunity to directly compare experimental and simulated images. This comparison merely requires the experimental data to be normalised and expressed in units of fractional beam-current. However, inhomogeneities in the response of electron detectors can complicate this normalisation. The quantification procedure becomes both experiment and instrument specific, requiring new simulations for the particular response of each instrument's detector, and for every camera-length used. This not only impedes the comparison between different instruments and research groups, but can also be computationally very time consuming. Furthermore, not all image simulation methods allow for the inclusion of an inhomogeneous detector response. In this work, we propose an alternative method for normalising experimental data in order to compare these with simulations that consider a homogeneous detector response. To achieve this, we determine the electron flux distribution reaching the detector by means of a camera-length series or a so-called atomic column cross-section averaged convergent beam electron diffraction (XSACBED) pattern. The result is then used to determine the relative weighting of the detector response. Here we show that the results obtained by this new electron flux weighted (EFW) method are comparable to the currently used method, while considerably simplifying the needed simulation libraries. The proposed method also allows one to obtain a metric that describes the quality of the detector response in comparison with the ideal detector response.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000366220000006 Publication Date 2015-08-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 27 Open Access  
  Notes 246791 Countatoms; 278510 Vortex; 312483 Esteem2; Fwo G036815; G036915; G037413; G004413; esteem2ta ECASJO; Approved Most recent IF: 2.843; 2015 IF: 2.436  
  Call Number c:irua:127293 c:irua:127293UA @ admin @ c:irua:127293 Serial 2762  
Permanent link to this record
 

 
Author Schattschneider, P.; Verbeeck, J.; Hamon, A.L. doi  openurl
  Title Real space maps of atomic transitions Type A1 Journal article
  Year 2009 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 109 Issue 7 Pages 781-787  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Considering the rapid technical development of transmission electron microscopes, we investigate the possibility to map electronic transitions in real space on the atomic scale. To this purpose, we analyse the information carried by the scatterer's initial and final state wave functions and the role of the different atomic transition channels for the inelastic scattering cross section. It is shown that the change in the magnetic quantum number in the transition can be mapped. Two experimental set-ups are proposed, one blocking half the diffraction plane, the other one using a cylinder lens for imaging. Both methods break the conventional circular symmetry in the electron microscope making it possible to detect the handedness of electronic transitions as an asymmetry in the image intensity. This finding is of important for atomic resolution energy-loss magnetic chiral dichroism (EMCD), allowing to obtain the magnetic moments of single atoms.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000266787900002 Publication Date 2009-03-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 10 Open Access  
  Notes J.V. acknowledges the FWO-Vlaanderen for support (contract no. G.0147.06) and the European Union under the Framework 6 program under a contract for an Integrated Infrastructure Initiative. Reference 026019 ESTEEM. Approved Most recent IF: 2.843; 2009 IF: 2.067  
  Call Number UA @ lucian @ c:irua:77360UA @ admin @ c:irua:77360 Serial 2829  
Permanent link to this record
 

 
Author Schattschneider, P.; Ennen, I.; Stoger-Pollach, M.; Verbeeck, J.; Mauchamp, V.; Jaouen, M. pdf  doi
openurl 
  Title Real space maps of magnetic moments on the atomic scale: theory and feasibility Type A1 Journal article
  Year 2010 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 110 Issue 8 Pages 1038-1041  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The recently discovered EMCD technique (energy loss magnetic chiral dichroism) can detect atom specific magnetic moments with nanometer resolution, exploiting the spin selectivity of electronic transitions in energy loss spectroscopy. Yet, direct imaging of magnetic moments on the atomic scale is not possible. In this paper we present an extension of EMCD that can overcome this limit. As a model system we chose bcc Fe. We present image simulations of the L3 white line signal, based on the kinetic equation for the density matrix of the 200 kV probe electron. With actual progress in instrumentation (high brightness sources, aberration corrected lenses) this technique should allow direct imaging of spin moments on the atomic scale.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000281216600016 Publication Date 2009-12-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 10 Open Access  
  Notes --- Approved Most recent IF: 2.843; 2010 IF: 2.063  
  Call Number UA @ lucian @ c:irua:84439UA @ admin @ c:irua:84439 Serial 2830  
Permanent link to this record
 

 
Author Zhang, X.B.; Zhang, X.F.; Amelinckx, S.; Van Tendeloo, G.; van Landuyt, J. doi  openurl
  Title The reciprocal space of carbon tubes: a detailed interpretation of the electron diffraction effects Type A1 Journal article
  Year 1994 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 54 Issue Pages 237-249  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos A1994PA59800016 Publication Date 2002-10-18  
  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 2.436 Times cited 59 Open Access  
  Notes Approved  
  Call Number UA @ lucian @ c:irua:10006 Serial 2844  
Permanent link to this record
 

 
Author Müller, K.; Schowalter, M.; Jansen, J.; Tsuda, K.; Titantah, J.; Lamoen, D.; Rosenauer, A. pdf  doi
openurl 
  Title Refinement of the 200 structure factor for GaAs using parallel and convergent beam electron nanodiffraction data Type A1 Journal article
  Year 2009 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 109 Issue 7 Pages 802-814  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We present a new method to measure structure factors from electron spot diffraction patterns recorded under almost parallel illumination in transmission electron microscopes. Bloch wave refinement routines have been developed to refine the crystal thickness, its orientation and structure factors by comparison of experimentally recorded and calculated intensities. Our method requires a modicum of computational effort, making it suitable for contemporary personal computers. Frozen lattice and Bloch wave simulations of GaAs diffraction patterns are used to derive optimised experimental conditions. Systematic errors are estimated from the application of the method to simulated diffraction patterns and rules for the recognition of physically reasonable initial refinement conditions are derived. The method is applied to the measurement of the 200 structure factor for GaAs. We found that the influence of inelastically scattered electrons is negligible. Additionally, we measured the 200 structure factor from zero loss filtered two-dimensional convergent beam electron diffraction patterns. The precision of both methods is found to be comparable and the results agree well with each other. A deviation of more than 20% from isolated atom scattering data is observed, whereas close agreement is found with structure factors obtained from density functional theory [A. Rosenauer, M. Schowalter, F. Glas, D. Lamoen, Phys. Rev. B 72 (2005), 085326-1], which account for the redistribution of electrons due to chemical bonding via modified atomic scattering amplitudes.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000266787900005 Publication Date 2009-03-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 8 Open Access  
  Notes Fwo; G.0425.05; Esteem; Ant 200611271505 Approved Most recent IF: 2.843; 2009 IF: 2.067  
  Call Number UA @ lucian @ c:irua:77361 Serial 2856  
Permanent link to this record
 

 
Author Amelinckx, S.; Milat, O.; Van Tendeloo, G. doi  openurl
  Title Selective imaging of sublattices in complex structures Type A1 Journal article
  Year 1993 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 51 Issue Pages 90-108  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos A1993LN79100010 Publication Date 2002-10-18  
  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 2.436 Times cited 8 Open Access  
  Notes Approved CHEMISTRY, PHYSICAL 54/144 Q2 # PHYSICS, ATOMIC, MOLECULAR & CHEMICAL 9/35 Q2 #  
  Call Number UA @ lucian @ c:irua:6835 Serial 2964  
Permanent link to this record
 

 
Author Milat, O.; Van Tendeloo, G.; Amelinckx, S. doi  openurl
  Title Selective imaging of the “substructures” in incommensurately modulated intergrowth crystal structures Type A1 Journal article
  Year 1992 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 41 Issue Pages 65-76  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos A1992HX68100006 Publication Date 2002-10-18  
  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 2.436 Times cited 5 Open Access  
  Notes Approved MATERIALS SCIENCE, MULTIDISCIPLINARY 96/271 Q2 #  
  Call Number UA @ lucian @ c:irua:4437 Serial 2966  
Permanent link to this record
 

 
Author Zhang, X.F.; Zhang, X.B.; Bernaerts, D.; Van Tendeloo, G.; Amelinckx, S.; van Landuyt, J.; Werner, H. pdf  doi
openurl 
  Title A simple preparation method for air-sensitive specimens for transmission electron microscopy demonstrated by Rb6C60 Type A1 Journal article
  Year 1994 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 55 Issue Pages 25-30  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract In this paper a particularly simple but efficient method is presented by which samples of alkali-doped C-60 materials or other air-sensitive materials can be prepared and transferred into a transmission electron microscope for direct observations and investigations. Flexible, transparent glove bags are used which are filled to a slight overpressure with dry nitrogen. Under this protective atmosphere, the air-sensitive sample is mounted in the specimen holder and inserted in the vacuum of the electron microscope. Rb6C60 which is prepared and transferred into the microscope in this way has been investigated by transmission electron microscopy (TEM). The results confirm the bcc structure and especially the location of the rubidium atoms.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos A1994PE30800005 Publication Date 2002-10-18  
  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 2.436 Times cited 2 Open Access  
  Notes Approved CHEMISTRY, PHYSICAL 77/144 Q3 # MATHEMATICS, INTERDISCIPLINARY 19/101 Q1 # PHYSICS, ATOMIC, MOLECULAR & CHEMICAL 17/35 Q2 #  
  Call Number UA @ lucian @ c:irua:10007 Serial 3002  
Permanent link to this record
 

 
Author Lichtert, S.; Verbeeck, J. pdf  doi
openurl 
  Title Statistical consequences of applying a PCA noise filter on EELS spectrum images Type A1 Journal article
  Year 2013 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 125 Issue Pages 35-42  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Principal component analysis (PCA) noise filtering is a popular method to remove noise from experimental electron energy loss (EELS) spectrum images. Here, we investigate the statistical behaviour of this method by applying it on a simulated data set with realistic noise levels. This phantom data set provides access to the true values contained in the data set as well as to many different realizations of the noise. Using least squares fitting and parameter estimation theory, we demonstrate that even though the precision on the estimated parameters can be better as the CramérRao lower bound, a significant bias is introduced which can alter the conclusions drawn from experimental data sets. The origin of this bias is in the incorrect retrieval of the principal loadings for noisy data. Using an expression for the bias and precision of the singular values from literature, we present an evaluation criterion for these singular values based on the noise level and the amount of information present in the data set. This criterion can help to judge when to avoid PCA noise filtering in practical situations. Further we show that constructing elemental maps of PCA noise filtered data using the background subtraction method, does not guarantee an increase in the signal to noise ratio due to correlation of the spectral data as a result of the filtering process.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000314679700006 Publication Date 2012-10-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 54 Open Access  
  Notes Fwo; Countatoms; Vortex; Esteem 312483; esteem2jra3 ECASJO; Approved Most recent IF: 2.843; 2013 IF: 2.745  
  Call Number UA @ lucian @ c:irua:105293 Serial 3153  
Permanent link to this record
 

 
Author Béché, A.; Rouviere, J.L.; Barnes, J.P.; Cooper, D. doi  openurl
  Title Strain measurement at the nanoscale : comparison between convergent beam electron diffraction, nano-beam electron diffraction, high resolution imaging and dark field electron holography Type A1 Journal article
  Year 2013 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 131 Issue Pages 10-23  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Convergent beam electron diffraction (CBED), nano-beam electron diffraction (NBED or NBD), high resolution imaging (HRTEM and HRSTEM) and dark field electron holography (DFEH or HoloDark) are five TEM based techniques able to quantitatively measure strain at the nanometer scale. In order to demonstrate the advantages and disadvantages of each technique, two samples composed of epitaxial silicon-germanium layers embedded in a silicon matrix have been investigated. The five techniques are then compared in terms of strain precision and accuracy, spatial resolution, field of view, mapping abilities and ease of performance and analysis. (C) 2013 Elsevier By. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000322631200002 Publication Date 2013-04-06  
  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 73 Open Access  
  Notes Approved Most recent IF: 2.843; 2013 IF: 2.745  
  Call Number UA @ lucian @ c:irua:109774 Serial 3171  
Permanent link to this record
 

 
Author Van Tendeloo, G.; Amelinckx, S.; Muto, S.; Verheijen, M.A.; van Loosdrecht, P.H.M.; Meijer, G. doi  openurl
  Title Structures and phase transitions in C60 and C70 fullerites Type A1 Journal article
  Year 1993 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 51 Issue Pages 168-188  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos A1993LN79100017 Publication Date 2002-10-18  
  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 2.436 Times cited 17 Open Access  
  Notes Approved PHYSICS, APPLIED 28/145 Q1 #  
  Call Number UA @ lucian @ c:irua:6836 Serial 3319  
Permanent link to this record
 

 
Author Schattschneider, P.; Stöger-Pollach, M.; Löffler, S.; Steiger-Thirsfeld, A.; Hell, J.; Verbeeck, J. pdf  doi
openurl 
  Title Sub-nanometer free electrons with topological charge Type A1 Journal article
  Year 2012 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 115 Issue Pages 21-25  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The holographic mask technique is used to create freely moving electrons with quantized angular momentum. With electron optical elements they can be focused to vortices with diameters below the nanometer range. The understanding of these vortex beams is important for many applications. Here, we produce electron vortex beams and compare them to a theory of electrons with topological charge. The experimental results show excellent agreement with simulations. As an immediate application, fundamental experimental parameters like spherical aberration and partial coherence are determined. (C) 2012 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000302962400004 Publication Date 2012-01-30  
  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 24 Open Access  
  Notes vortex ECASJO_; Approved Most recent IF: 2.843; 2012 IF: 2.470  
  Call Number UA @ lucian @ c:irua:98279 Serial 3344  
Permanent link to this record
 

 
Author Ke, X.; Bals, S.; Romo Negreira, A.; Hantschel, T.; Bender, H.; Van Tendeloo, G. pdf  doi
openurl 
  Title TEM sample preparation by FIB for carbon nanotube interconnects Type A1 Journal article
  Year 2009 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 109 Issue 11 Pages 1353-1359  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A powerful method to study carbon nanotubes (CNTs) grown in patterned substrates for potential interconnects applications is transmission electron microscopy (TEM). However, high-quality TEM samples are necessary for such a study. Here, TEM specimen preparation by focused ion beam (FIB) has been used to obtain lamellae of patterned samples containing CNTs grown inside contact holes. A dual-cap Pt protection layer and an extensive 5 kV cleaning procedure are applied in order to preserve the CNTs and avoid deterioration during milling. TEM results show that the inner shell structure of the carbon nanotubes has been preserved, which proves that focused ion beam is a useful technique to prepare TEM samples of CNT interconnects.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000270765800006 Publication Date 2009-07-11  
  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 21 Open Access  
  Notes Esteem 026019; Iap Approved Most recent IF: 2.843; 2009 IF: 2.067  
  Call Number UA @ lucian @ c:irua:79074 Serial 3485  
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Author van Landuyt, J. doi  openurl
  Title The evolution of HVEM application in antwerp Type A1 Journal article
  Year 1991 Publication Ultramicroscopy T2 – 2nd Osaka International Symp.on High-Voltage Electron Microscopy : New Directions and Future Aspects of High Voltage Electron Microscopy, November 8-10, 1990, Osaka University, Osaka, Japan Abbreviated Journal (down) Ultramicroscopy  
  Volume 39 Issue 1-4 Pages 287-298  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The evolution of the use of the 1250 keV high-voltage electron microscope in Antwerp is sketched by illustrating a non-exhaustive set of examples in various fields. One of the main present fields of application gets some more attention, i.e. the defect studies as produced by processing steps in microelectronic devices: (i) strain-induced dislocations at the edges of various device isolation interlayers, (ii) morphologies resulting from high-energy ion implantation creating buried layers for silicon on insulator (SOI) and other implantation technologies.  
  Address  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Amsterdam Editor  
  Language Wos A1991GY23100034 Publication Date 2002-10-18  
  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 2.436 Times cited Open Access  
  Notes Approved PHYSICS, APPLIED 47/145 Q2 #  
  Call Number UA @ lucian @ c:irua:95973 Serial 3579  
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Author Verbeeck, J.; Bertoni, G.; Schattschneider, P. pdf  doi
openurl 
  Title The Fresnel effect of a defocused biprism on the fringes in inelastic holography Type A1 Journal article
  Year 2008 Publication Ultramicroscopy T2 – 16th International Microscopy Congress, SEP 03-08, 2006, Sapporo, JAPAN Abbreviated Journal (down) Ultramicroscopy  
  Volume 108 Issue 3 Pages 263-269  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We present energy filtered holography experiments on a thin foil of Al. By propagating the reduced density matrix of the probe electron through the microscope, we quantitatively predict the fringe contrast as a function of energy loss. Fringe contrast simulations include the effect of Fresnel fringes created at the edges of the defocused biprism, the effect of partial coherence in combination with inelastic scattering, and the effect of a finite energy distribution of the incoming beam. (c) 2007 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000253389100011 Publication Date 2007-11-02  
  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 15 Open Access  
  Notes Fwo G.0147.06; Esteem 026019 Approved Most recent IF: 2.843; 2008 IF: 2.629  
  Call Number UA @ lucian @ c:irua:104035 Serial 3582  
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Author Schattschneider, P.; Verbeeck, J. pdf  url
doi  openurl
  Title Theory of free electron vortices Type A1 Journal article
  Year 2011 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 111 Issue 9/10 Pages 1461-1468  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The recent creation of electron vortex beams and their first practical application motivates a better understanding of their properties. Here, we develop the theory of free electron vortices with quantized angular momentum, based on solutions of the Schrödinger equation for cylindrical boundary conditions. The principle of transformation of a plane wave into vortices with quantized angular momentum, their paraxial propagation through round magnetic lenses, and the effect of partial coherence are discussed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000300461200002 Publication Date 2011-07-26  
  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 57 Open Access  
  Notes Esteem 026019 Approved Most recent IF: 2.843; 2011 IF: 2.471  
  Call Number UA @ lucian @ c:irua:91882 Serial 3617  
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 (down) Ultramicroscopy  
  Volume 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 van den Broek, W.; Verbeeck, J.; Schryvers, D.; de Backer, S.; Scheunders, P. pdf  doi
openurl 
  Title Tomographic spectroscopic imaging; an experimental proof of concept Type A1 Journal article
  Year 2009 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 109 Issue 4 Pages 296-303  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract Recording the electron energy loss spectroscopy data cube with a series of energy filtered images is a dose inefficient process because the energy slit blocks most of the electrons. When recording the data cube by scanning an electron probe over the sample, perfect dose efficiency is attained; but due to the low current in nanoprobes, this often is slower, with a smaller field of view. In W. Van den Broek et al. [Ultramicroscopy, 106 (2006) 269], we proposed a new method to record the data cube, which is more dose efficient than an energy filtered series. It produces a set of projections of the data cube and then tomographically reconstructs it. In this article, we demonstrate these projections in practice, we present a simple geometrical model that allows for quantification of the projection angles and we present the first successful experimental reconstruction, all on a standard post-column instrument.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000265345400003 Publication Date 2008-12-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 1 Open Access  
  Notes Esteem 026019 Approved Most recent IF: 2.843; 2009 IF: 2.067  
  Call Number UA @ lucian @ c:irua:77271 Serial 3671  
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Author van Aarle, W.; Palenstijn, W.J.; De Beenhouwer, J.; Altantzis, T.; Bals, S.; Batenburg, K.J.; Sijbers, J. pdf  url
doi  openurl
  Title The ASTRA Toolbox: A platform for advanced algorithm development in electron tomography Type A1 Journal article
  Year 2015 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 157 Issue 157 Pages 35-47  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract We present the ASTRA Toolbox as an open platform for 3D image reconstruction in tomography. Most of the software tools that are currently used in electron tomography offer limited flexibility with respect to the geometrical parameters of the acquisition model and the algorithms used for reconstruction. The ASTRA Toolbox provides an extensive set of fast and flexible building blocks that can be used to develop advanced reconstruction algorithms, effectively removing these limitations. We demonstrate this flexibility, the resulting reconstruction quality, and the computational efficiency of this toolbox by a series of experiments, based on experimental dual-axis tilt series.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Wos 000361002400005 Publication Date 2015-05-06  
  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 562 Open Access OpenAccess  
  Notes The authors acknowledge financial support from the iMinds ICONMetroCT project,the IWT SBO Tom Food project and from the Netherlands Organisation for Scientific Research (NWO),Project no. 639.072.005. Networking support was provided by the EXTREMA COST Action MP 1207. Sara Bals acknowledges financial support from the European Research Council (ERC Starting Grant #335078 COLOURATOMS).; ECAS_Sara; (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); Approved Most recent IF: 2.843; 2015 IF: 2.436  
  Call Number c:irua:127834 Serial 3974  
Permanent link to this record
 

 
Author Zanaga, D.; Altantzis, T.; Sanctorum, J.; Freitag, B.; Bals, S. pdf  url
doi  openurl
  Title An alternative approach for ζ-factor measurement using pure element nanoparticles Type A1 Journal article
  Year 2016 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 164 Issue 164 Pages 11-16  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract It is very challenging to measure the chemical composition of hetero nanostructures in a reliable and quantitative manner. Here, we propose a novel and straightforward approach that can be used to quantify energy dispersive X-ray spectra acquired in a transmission electron microscope. Our method is based on a combination of electron tomography and the so-called ζ-factor technique. We will demonstrate the reliability of our approach as well as its applicability by investigating Au-Ag and Au-Pt hetero nanostructures. Given its simplicity, we expect that the method could become a new standard in the field of chemical characterization using electron microscopy.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000373526200002 Publication Date 2016-03-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 19 Open Access OpenAccess  
  Notes The authors acknowledge financial support from the European Research Council (ERC Starting Grant # 335078-COLOURATOMS) and the European Union under the FP7 (Integrated Infrastructure Initiative N. 312483 – ESTEEM2). The authors would also like to thank Luis M. Liz-Marzán, Ana Sánchez-Iglesias, Stefanos Mourdikoudis and Cristina Fernández-López for sample provision and useful discussions.; esteem2jra4; ECASSara; (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); Approved Most recent IF: 2.843  
  Call Number EMAT @ emat @ Serial 4019  
Permanent link to this record
 

 
Author Lobato, I.; Van Aert, S.; Verbeeck, J. pdf  doi
openurl 
  Title Progress and new advances in simulating electron microscopy datasets using MULTEM Type A1 Journal article
  Year 2016 Publication Ultramicroscopy Abbreviated Journal (down) 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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Author Béché, A.; Juchtmans, R.; Verbeeck, J. pdf  url
doi  openurl
  Title Efficient creation of electron vortex beams for high resolution STEM imaging Type A1 Journal article
  Year 2017 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 178 Issue 178 Pages 12-19  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The recent discovery of electron vortex beams carrying quantised angular momentum in the TEM has led to an active field of research, exploring a variety of potential applications including the possibility of mapping magnetic states at the atomic scale. A prerequisite for this is the availability of atomic sized electron vortex beams at high beam current and mode purity. In this paper we present recent progress showing that by making use of the Aharonov-Bohm effect near the tip of a long single domain ferromagnetic Nickel needle, a very efficient aperture for the production of electron vortex beams can be realised. The aperture transmits more than 99% of all electrons and provides a vortex mode purity of up to 92%. Placing this aperture in the condenser plane of a state of the art Cs corrected microscope allows us to demonstrate atomic resolution HAADF STEM images with spatial resolution better than 1 Angstrom, in agreement with theoretical expectations and only slightly inferior to the performance of a non-vortex probe on the same instrument.  
  Address EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Wos 000403862900003 Publication Date 2016-05-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 30 Open Access OpenAccess  
  Notes A.B. and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX. J.V. acknowledges funding from FWO project G.0044.13N ('Charge ordering').; ECASJO_; Approved Most recent IF: 2.843  
  Call Number c:irua:134085 c:irua:134085UA @ admin @ c:irua:134085 Serial 4094  
Permanent link to this record
 

 
Author Muller-Caspary, K.; Krause, F.F.; Grieb, T.; Loffler, S.; Schowalter, M.; Béché, A.; Galioit, V.; Marquardt, D.; Zweck, J.; Schattschneider, P.; Verbeeck, J.; Rosenauer, A. pdf  url
doi  openurl
  Title Measurement of atomic electric fields and charge densities from average momentum transfers using scanning transmission electron microscopy Type A1 Journal article
  Year 2016 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 178 Issue 178 Pages 62-80  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract This study sheds light on the prerequisites, possibilities, limitations and interpretation of high-resolution differential phase contrast (DPC) imaging in scanning transmission electron microscopy (STEM). We draw particular attention to the well-established DPC technique based on segmented annular detectors and its relation to recent developments based on pixelated detectors. These employ the expectation value of the momentum transfer as a reliable measure of the angular deflection of the STEM beam induced by an electric field in the specimen. The influence of scattering and propagation of electrons within the specimen is initially discussed separately and then treated in terms of a two-state channeling theory. A detailed simulation study of GaN is presented as a function of specimen thickness and bonding. It is found that bonding effects are rather detectable implicitly, e.g., by characteristics of the momentum flux in areas between the atoms than by directly mapping electric fields and charge densities. For strontium titanate, experimental charge densities are compared with simulations and discussed with respect to experimental artifacts such as scan noise. Finally, we consider practical issues such as figures of merit for spatial and momentum resolution, minimum electron dose, and the mapping of larger-scale, built-in electric fields by virtue of data averaged over a crystal unit cell. We find that the latter is possible for crystals with an inversion center. Concerning the optimal detector design, this study indicates that a sampling of 5mrad per pixel is sufficient in typical applications, corresponding to approximately 10x10 available pixels.  
  Address Institut fur Festkr perphysik, Universitat Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Wos 000403862900009 Publication Date 2016-05-12  
  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 93 Open Access  
  Notes K.M.-C. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG) under contract MU3660/1-1. This work was further supported by the DFG under contract RO2057/4-2 and O2057/11-1. J.V. and A.B. acknowledge funding from the European Research Council (ERC) under the 7th Framework Program (FP7), and ERC Starting Grant No. 278510-VORTEX. Experimental results are obtained on the Qu-Ant-EM microscope partly funded by the Hercules fund from the Flemish government. J.V. also acknowledges funding through a GOA project “Solarpaint” of the University of Antwerp. SL and PS acknowledge financial support by the Austrian Science Fund (FWF) under grants No. I543-N20 and J3732-N27. ECASJO_; Approved Most recent IF: 2.843  
  Call Number c:irua:134125UA @ admin @ c:irua:134125 Serial 4098  
Permanent link to this record
 

 
Author Goris, B.; Meledina, M.; Turner, S.; Zhong, Z.; Batenburg, K.J.; Bals, S. pdf  url
doi  openurl
  Title Three dimensional mapping of Fe dopants in ceria nanocrystals using direct spectroscopic electron tomography Type A1 Journal article
  Year 2016 Publication Ultramicroscopy Abbreviated Journal (down) Ultramicroscopy  
  Volume 171 Issue 171 Pages 55-62  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Electron tomography is a powerful technique for the 3D characterization of the morphology of nanostructures. Nevertheless, resolving the chemical composition of complex nanostructures in 3D remains challenging and the number of studies in which electron energy loss spectroscopy (EELS) is combined with tomography is limited. During the last decade, dedicated reconstruction algorithms have been developed for HAADF-STEM tomography using prior knowledge about the investigated sample. Here, we will use the prior knowledge that the experimental spectrum of each reconstructed voxel is a linear combination of a well-known set of references spectra in a so-called direct spectroscopic tomography technique. Based on a simulation experiment, it is shown that this technique provides superior results in comparison to conventional reconstruction methods for spectroscopic data, especially for spectrum images containing a relatively low signal to noise ratio. Next, this technique is used to investigate the spatial distribution of Fe dopants in Fe:Ceria nanoparticles in 3D. It is shown that the presence of the Fe2+ dopants is correlated with a reduction of the Ce atoms from Ce4+ towards Ce3+. In addition, it is demonstrated that most of the Fe dopants are located near the voids inside the nanoparticle.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000389106200007 Publication Date 2016-09-06  
  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 13 Open Access OpenAccess  
  Notes The work was supported by the Research Foundation Flanders (FWO Vlaanderen) by project funding (G038116N, 3G004613) and by a post-doctoral research grants to B.G. S.B. acknowledges funding from the European Research Council (Starting Grant no. COLOURATOMS 335078). K.J.B. acknowledges funding from The Netherlands Organization for Scientific Research (NWO) (program 639.072.005.). We would like to thank Dr. Hilde Poelman, Dr. Vladimir Galvita and Prof. Dr. Guy B. Marin for the synthesis of the investigated sample.; ECAS_Sara; (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); Approved Most recent IF: 2.843  
  Call Number c:irua:135185 c:irua:135185 Serial 4123  
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