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Records |
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Author |
Van den Broek, W.; Jannis, D.; Verbeeck, J. |
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Title |
Convexity constraints on linear background models for electron energy-loss spectra |
Type |
A1 Journal Article |
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Year |
2023 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
254 |
Issue |
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Pages |
113830 |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
In this paper convexity constraints are derived for a background model of electron energy loss spectra (EELS) that is linear in the fitting parameters. The model outperforms a power-law both on experimental and simulated backgrounds, especially for wide energy ranges, and thus improves elemental quantification results. Owing to the model’s linearity, the constraints can be imposed through fitting by quadratic programming. This has important advantages over conventional nonlinear power-law fitting such as high speed and a guaranteed unique solution without need for initial parameters. As such, the need for user input is significantly reduced, which is essential for unsupervised treatment of large datasets. This is demonstrated on a demanding spectrum image of a semiconductor device sample with a high number of elements over a wide energy range. |
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Wos |
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Publication Date |
2023-08-15 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0304-3991 |
ISBN |
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Additional Links |
UA library record |
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Impact Factor |
2.2 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
ECSEL, 875999 ; Horizon 2020; Horizon 2020 Framework Programme; Electronic Components and Systems for European Leadership; |
Approved |
Most recent IF: 2.2; 2023 IF: 2.843 |
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Call Number |
EMAT @ emat @c:irua:200588 |
Serial |
8961 |
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Permanent link to this record |
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Author |
Cao, S.; Tirry, W.; van den Broek, W.; Schryvers, D. |
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Title |
3D reconstruction of Ni4Ti3 precipitates in a Ni51Ti49 alloy in a FIB/SEM dual-beam system |
Type |
A1 Journal article |
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Year |
2008 |
Publication |
Materials science forum |
Abbreviated Journal |
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Volume |
583 |
Issue |
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Pages |
277-284 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
Ni4Ti3 precipitates play an important role in the shape memory and superelastic behaviour of thermo-mechanically treated Ni-Ti material. The 3D morphology and distribution of such precipitates with lenticular shape and rhombohedral atomic structure in the austenitic B2 matrix of a binary Ni-rich Ni-Ti alloy has been elucidated via a slice view procedure in a Dual-Beam FIB/SEM system. With the sequence of cross-section SE images obtained from the SEM, a 3D reconstruction has been achieved after proper alignment and image processing, from which both qualitative and quantitative analysis can be performed. Careful imaging is needed to ensure that all variants of the precipitates are observed with equal probability, regardless sample orientation. Moreover, due to the weak contrast of the precipitates, proper imaging conditions need to be selected to allow for semi-automated image treatment. Finally, a volume ratio of 10.2% for the Ni4Ti3 precipitates could be calculated, summed over all variants, which yields a net composition of Ni50.36Ti49.64 for the matrix, leading to an increase of 113 degrees for the martensitic start temperature Ms. Also, the expected relative orientation of the different variants of the precipitates could be confirmed. In the near future, other quantitative measures on the distribution of the precipitates can be expected. |
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Place of Publication |
Lausanne |
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Publication Date |
2009-03-11 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1662-9752; |
ISBN |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
Multimat; Fwo |
Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:77454 |
Serial |
16 |
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Permanent link to this record |
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Author |
van den Broek, W.; Verbeeck, J.; de Backer, S.; Scheunders, P.; Schryvers, D. |
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Title |
Acquisition of the EELS data cube by tomographic reconstruction |
Type |
A1 Journal article |
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Year |
2006 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
106 |
Issue |
4/5 |
Pages |
269-276 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
Energy filtered TEM, EFTEM, provides three-dimensional data, two spatial and one spectral dimension. We propose to acquire these data by measuring a series of images with a defocused energy filter. It will be shown that each image is a projection of the data on the detector and that reconstruction of the data out of a sufficient number of such projections using a tomographic reconstruction algorithm is possible. This technique uses only a fraction of the electron dose an energy filtered series (EFS) needs for the same spectral and spatial resolution and the same mean signal-to-noise ratio. (c) 2005 Elsevier B.V. All rights reserved. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000236042300003 |
Publication Date |
2005-11-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0304-3991; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
6 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.843; 2006 IF: 1.706 |
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Call Number |
UA @ lucian @ c:irua:56910UA @ admin @ c:irua:56910 |
Serial |
55 |
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Permanent link to this record |
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Author |
Goris, B.; Bals, S.; van den Broek, W.; Carbó-Argibay, E.; Gómez-Graña, S.; Liz-Marzán, L.M.; Van Tendeloo, G. |
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Title |
Atomic-scale determination of surface facets in gold nanorods |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
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Volume |
11 |
Issue |
11 |
Pages |
930-935 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
It is widely accepted that the physical properties of nanostructures depend on the type of surface facets1, 2. For Au nanorods, the surface facets have a major influence on crucial effects such as reactivity and ligand adsorption and there has been controversy regarding facet indexing3, 4. Aberration-corrected electron microscopy is the ideal technique to study the atomic structure of nanomaterials5, 6. However, these images correspond to two-dimensional (2D) projections of 3D nano-objects, leading to an incomplete characterization. Recently, much progress was achieved in the field of atomic-resolution electron tomography, but it is still far from being a routinely used technique. Here we propose a methodology to measure the 3D atomic structure of free-standing nanoparticles, which we apply to characterize the surface facets of Au nanorods. This methodology is applicable to a broad range of nanocrystals, leading to unique insights concerning the connection between the structure and properties of nanostructures. |
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Place of Publication |
London |
Editor |
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Wos |
000310434600015 |
Publication Date |
2012-10-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1476-1122;1476-4660; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
39.737 |
Times cited |
261 |
Open Access |
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Notes |
262348 ESMI; Hercules 3; 24691 COUNTATOMS; 267867 PLASMAQUO |
Approved |
Most recent IF: 39.737; 2012 IF: 35.749 |
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Call Number |
UA @ lucian @ c:irua:101778 |
Serial |
182 |
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Permanent link to this record |
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Author |
van den Broek, W.; Rosenauer, A.; Goris, B.; Martinez, G.T.; Bals, S.; Van Aert, S.; van Dyck, D. |
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Title |
Correction of non-linear thickness effects in HAADF STEM electron tomography |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
116 |
Issue |
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Pages |
8-12 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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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. |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000304473700002 |
Publication Date |
2012-03-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0304-3991; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
67 |
Open Access |
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Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
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Call Number |
UA @ lucian @ c:irua:96558 |
Serial |
518 |
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Permanent link to this record |
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Author |
Goris, B.; van den Broek, W.; Batenburg, K.J.; Heidari Mezerji, H.; Bals, S. |
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Title |
Electron tomography based on a total variation minimization reconstruction technique |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
113 |
Issue |
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Pages |
120-130 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
The 3D reconstruction of a tilt series for electron tomography is mostly carried out using the weighted backprojection (WBP) algorithm or using one of the iterative algorithms such as the simultaneous iterative reconstruction technique (SIRT). However, it is known that these reconstruction algorithms cannot compensate for the missing wedge. Here, we apply a new reconstruction algorithm for electron tomography, which is based on compressive sensing. This is a field in image processing specialized in finding a sparse solution or a solution with a sparse gradient to a set of ill-posed linear equations. Therefore, it can be applied to electron tomography where the reconstructed objects often have a sparse gradient at the nanoscale. Using a combination of different simulated and experimental datasets, it is shown that missing wedge artefacts are reduced in the final reconstruction. Moreover, it seems that the reconstructed datasets have a higher fidelity and are easier to segment in comparison to reconstructions obtained by more conventional iterative algorithms. |
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Corporate Author |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000300554400006 |
Publication Date |
2011-11-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0304-3991; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
171 |
Open Access |
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Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
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Call Number |
UA @ lucian @ c:irua:93637 |
Serial |
987 |
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Permanent link to this record |
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Author |
Goris, B.; Bals, S.; van den Broek, W.; Verbeeck, J.; Van Tendeloo, G. |
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Title |
Exploring different inelastic projection mechanisms for electron tomography |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
111 |
Issue |
8 |
Pages |
1262-1267 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
Several different projection mechanisms that all make use of inelastically scattered electrons are used for electron tomography. The advantages and the disadvantages of these methods are compared to HAADFSTEM tomography, which is considered as the standard electron tomography technique in materials science. The different inelastic setups used are energy filtered transmission electron microscopy (EFTEM), thickness mapping based on the log-ratio method and bulk plasmon mapping. We present a comparison that can be used to select the best inelastic signal for tomography, depending on different parameters such as the beam stability and nature of the sample. The appropriate signal will obviously also depend on the exact information which is requested. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000300461100039 |
Publication Date |
2011-03-07 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0304-3991; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
21 |
Open Access |
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Notes |
Fwo; Iap; Esteem 026019 |
Approved |
Most recent IF: 2.843; 2011 IF: 2.471 |
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Call Number |
UA @ lucian @ c:irua:91260UA @ admin @ c:irua:91260 |
Serial |
1151 |
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Permanent link to this record |
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Author |
van den Broek, W.; Van Aert, S.; van Dyck, D. |
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Title |
Fully automated measurement of the modulation transfer function of charge-coupled devices above the Nyquist frequency |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Microscopy and microanalysis |
Abbreviated Journal |
Microsc Microanal |
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Volume |
18 |
Issue |
2 |
Pages |
336-342 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
The charge-coupled devices used in electron microscopy are coated with a scintillating crystal that gives rise to a severe modulation transfer function (MTF). Exact knowledge of the MTF is imperative for a good correspondence between image simulation and experiment. We present a practical method to measure the MTF above the Nyquist frequency from the beam blocker's shadow image. The image processing has been fully automated and the program is made public. The method is successfully tested on three cameras with various beam blocker shapes. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge, Mass. |
Editor |
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Language |
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Wos |
000302084700011 |
Publication Date |
2012-02-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1431-9276;1435-8115; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.891 |
Times cited |
15 |
Open Access |
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Notes |
Fwo |
Approved |
Most recent IF: 1.891; 2012 IF: 2.495 |
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Call Number |
UA @ lucian @ c:irua:96557 |
Serial |
1297 |
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Permanent link to this record |
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Author |
Verbeeck, J.; Béché, A.; van den Broek, W. |
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Title |
A holographic method to measure the source size broadening in STEM |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
120 |
Issue |
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Pages |
35-40 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Source size broadening is an important resolution limiting effect in modern STEM experiments. Here, we propose an alternative method to measure the source size broadening making use of a holographic biprism to create interference patterns in an empty Ronchigram. This allows us to measure the exact shape of the source size broadening with a much better sampling than previously possible. We find that the shape of the demagnified source deviates considerably from a Gaussian profile that is often assumed. We fit the profile with a linear combination of a Gaussian and a bivariate Cauchy distribution showing that even though the full width at half maximum is similar to previously reported measurements, the tails of the profile are considerable wider. This is of fundamental importance for quantitative comparison of STEM simulations with experiments as these tails make the image contrast dependent on the interatomic distance, an effect that cannot be reproduced by a single Gaussian profile of fixed width alone. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000308082600005 |
Publication Date |
2012-06-01 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0304-3991; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
29 |
Open Access |
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Notes |
This work was supported by funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant no. 246791 COUNTATOMS and ERC Starting Grant 278510 VORTEX. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. W. Van den Broek acknowledges funding from the Condor project, a project under the supervision of the Embedded Systems Institute (ESI) and FEI. This project is partially supported by the Dutch Ministry of Economic Affairs under the BSIK program. ECASJO_; |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
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Call Number |
UA @ lucian @ c:irua:100466UA @ admin @ c:irua:100466 |
Serial |
1483 |
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Permanent link to this record |
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Author |
Van den Broek, W.; Rosenauer, A.; Van Aert, S.; Sijbers, J.; van Dyck, D. |
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Title |
A memory efficient method for fully three-dimensional object reconstruction with HAADF STEM |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
141 |
Issue |
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Pages |
22-31 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000335766600004 |
Publication Date |
2014-03-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0304-3991; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
6 |
Open Access |
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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 |
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Call Number |
UA @ lucian @ c:irua:117650 |
Serial |
1992 |
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Permanent link to this record |
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Author |
van den Broek, W.; Van Aert, S.; van Dyck, D. |
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Title |
A model based atomic resolution tomographic algorithm |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
109 |
Issue |
12 |
Pages |
1485-1490 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
Tomography with high angular annular dark field scanning transmission electron microscopy at atomic resolution can be greatly improved if one is able to take advantage of prior knowledge. In this paper we present a reconstruction technique that explicitly takes into account the microscope parameters and the atomic nature of the projected object. This results in a more accurate estimate of the atomic positions and in a good resistance to noise. The reconstruction is a maximum likelihood estimator of the object. Moreover, the limits to the precision have been explored, allowing for a prediction of the amount of expected noise in the reconstruction for a certain experimental setup. We believe that the proposed reconstruction technique can be generalized to other tomographic experiments. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000271840200010 |
Publication Date |
2009-08-28 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0304-3991; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
17 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
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Call Number |
UA @ lucian @ c:irua:78588 |
Serial |
2097 |
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Permanent link to this record |
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Author |
Van Aert, S.; van den Broek, W.; Goos, P.; van Dyck, D. |
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Title |
Model-based electron microscopy : from images toward precise numbers for unknown structure parameters |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Micron |
Abbreviated Journal |
Micron |
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Volume |
43 |
Issue |
4 |
Pages |
509-515 |
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Keywords |
A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT); Vision lab |
|
|
Abstract |
Statistical parameter estimation theory is proposed as a method to quantify electron microscopy images. It aims at obtaining precise and accurate values for the unknown structure parameters including, for example, atomic column positions and types. In this theory, observations are purely considered as data planes, from which structure parameters have to be determined using a parametric model describing the images. The method enables us to measure positions of atomic columns with a precision of the order of a few picometers even though the resolution of the electron microscope is one or two orders of magnitude larger. Moreover, small differences in averaged atomic number, which cannot be distinguished visually, can be quantified using high-angle annular dark field scanning transmission electron microscopy images. Finally, it is shown how to optimize the experimental design so as to attain the highest precision. As an example, the optimization of the probe size for nanoparticle radius measurements is considered. It is also shown how to quantitatively balance signal-to-noise ratio and resolution by adjusting the probe size. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Oxford |
Editor |
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|
|
Language |
|
Wos |
000301702400003 |
Publication Date |
2011-11-03 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0968-4328; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
1.98 |
Times cited |
7 |
Open Access |
|
|
|
Notes |
Fwo |
Approved |
Most recent IF: 1.98; 2012 IF: 1.876 |
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|
Call Number |
UA @ lucian @ c:irua:94114 |
Serial |
2099 |
|
Permanent link to this record |
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|
|
Author |
van den Broek, W.; Van Aert, S.; van Dyck, D. |
|
|
Title |
A model based reconstruction technique for depth sectioning with scanning transmission electron microscopy |
Type |
A1 Journal article |
|
Year |
2010 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
|
Volume |
110 |
Issue |
5 |
Pages |
548-554 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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|
Abstract |
Depth sectioning in high angular annular dark field scanning transmission electron microscopy is considered a candidate for three-dimensional characterization on the atomic scale. However at present the depth resolution is still far from the atomic level, due to strong limitations in the opening angle of the beam. In this paper we introduce a new, parameter based tomographic reconstruction algorithm that allows to make maximal use of the prior knowledge about the constituent atom types and the microscope settings, so as to retrieve the atomic positions and push the resolution to the atomic level in all three dimensions. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
|
Wos |
000279065700022 |
Publication Date |
2009-09-21 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.843 |
Times cited |
16 |
Open Access |
|
|
|
Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2010 IF: 2.063 |
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Call Number |
UA @ lucian @ c:irua:83690 |
Serial |
2104 |
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Permanent link to this record |
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Author |
Cao, S.; Tirry, W.; van den Broek, W.; Schryvers, D. |
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Title |
Optimization of a FIB/SEM slice-and-view study of the 3D distribution of Ni4Ti3 precipitates in NiTi |
Type |
A1 Journal article |
|
Year |
2009 |
Publication |
Journal of microscopy |
Abbreviated Journal |
J Microsc-Oxford |
|
|
Volume |
233 |
Issue |
1 |
Pages |
61-68 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
|
|
Abstract |
The 3D morphology and distribution of lenticular Ni4Ti3 precipitates in the austenitic B2 matrix of a binary Ni51Ti49 alloy has been investigated by a slice-and-view procedure in a dual-beam focused ion beam/scanning electron microscope system. Due to the weak contrast of the precipitates, proper imaging conditions need to be selected first to allow for semi-automated image treatment. Knowledgeable imaging is further needed to ensure that all variants of the precipitates are observed with equal probability, regardless of sample orientation. Finally, a volume ratio of 10.2% for the Ni4Ti3 precipitates could be calculated, summed over all variants, which yields a net composition of Ni50.27Ti49.73 for the matrix, leading to an increase of 125 degrees for the martensitic start temperature. Also, the expected relative orientation of the different variants of the precipitates could be confirmed. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
|
Wos |
000262511900008 |
Publication Date |
2009-01-15 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0022-2720;1365-2818; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
1.692 |
Times cited |
22 |
Open Access |
|
|
|
Notes |
Multimat Fwo; G0465.05 |
Approved |
Most recent IF: 1.692; 2009 IF: 1.612 |
|
|
Call Number |
UA @ lucian @ c:irua:76026 |
Serial |
2486 |
|
Permanent link to this record |
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Author |
Heidari Mezerji, H.; van den Broek, W.; Bals, S. |
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Title |
A practical method to determine the effective resolution in incoherent experimental electron tomography |
Type |
A1 Journal article |
|
Year |
2011 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
|
Volume |
111 |
Issue |
5 |
Pages |
330-336 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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|
Abstract |
It is not straightforward to determine resolution for a 3D reconstruction when performing an electron tomography experiment. Different contributions such as missing wedge and misalignment add up and often influence the final resolution in an anisotropic manner. The conventional resolution measures can not be used for all of the reconstruction techniques, especially for iterative techniques which are more commonly used for electron tomography in materials science. Here we define a quantitative resolution measure that determines the resolution in three orthogonal directions of the reconstruction. As an application we use this measure to determine the optimum number of simultaneous iterative reconstruction technique (SIRT) iterations to reconstruct the gold nanoparticles, based on a high angle annular dark field STEM (HAADF-STEM) tilt series. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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|
|
Language |
|
Wos |
000289396900005 |
Publication Date |
2011-01-24 |
|
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.843 |
Times cited |
26 |
Open Access |
|
|
|
Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 2.843; 2011 IF: 2.471 |
|
|
Call Number |
UA @ lucian @ c:irua:87606 |
Serial |
2688 |
|
Permanent link to this record |
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|
|
Author |
Heidari, H.; van den Broek, W.; Bals, S. |
|
|
Title |
Quantitative electron tomography : the effect of the three-dimensional point spread function |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
|
Volume |
135 |
Issue |
|
Pages |
1-5 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Amsterdam |
Editor |
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|
|
Language |
|
Wos |
000326941500001 |
Publication Date |
2013-06-21 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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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 |
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|
Call Number |
UA @ lucian @ c:irua:111397 |
Serial |
2756 |
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Permanent link to this record |
|
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|
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Author |
van den Broek, W.; Van Aert, S.; Goos, P.; van Dyck, D. |
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|
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 |
111 |
Issue |
7 |
Pages |
940-947 |
|
|
Keywords |
A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT); Vision lab |
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|
Abstract |
In thispaperweinvestigatewhichprobesizemaximizesthethroughputwhenmeasuringtheradiusof nanoparticlesinhighangleannulardarkfieldscanningtransmissionelectronmicroscopy(HAADFSTEM). The sizeandthecorrespondingcurrentoftheelectronprobedeterminetheprecisionoftheestimateofa particlesradius.Maximizingthroughputmeansthatamaximumnumberofparticlesshouldbeimaged withinagiventimeframe,sothataprespecifiedprecisionisattained.WeshowthatBayesianstatistical experimentaldesignisaveryusefulapproachtodeterminetheoptimalprobesizeusingacertainamount of priorknowledgeaboutthesample.Thedependenceoftheoptimalprobesizeonthedetectorgeometry and thediameter,variabilityandatomicnumberoftheparticlesisinvestigated.Anexpressionforthe optimalprobesizeintheabsenceofanykindofpriorknowledgeaboutthespecimenisderivedaswell. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Amsterdam |
Editor |
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|
Language |
|
Wos |
000300461000026 |
Publication Date |
2010-11-25 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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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 |
|
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|
|
Author |
van den Broek, W.; Verbeeck, J.; Schryvers, D.; de Backer, S.; Scheunders, P. |
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|
Title |
Tomographic spectroscopic imaging; an experimental proof of concept |
Type |
A1 Journal article |
|
Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
|
Volume |
109 |
Issue |
4 |
Pages |
296-303 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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|
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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
|
|
Language |
|
Wos |
000265345400003 |
Publication Date |
2008-12-10 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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|
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 |
|
Permanent link to this record |
|
|
|
|
Author |
De Backer, A.; van den Bos, K.H.W.; Van den Broek, W.; Sijbers, J.; Van Aert, S. |
|
|
Title |
StatSTEM: An efficient approach for accurate and precise model-based quantification of atomic resolution electron microscopy images |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
|
Volume |
171 |
Issue |
171 |
Pages |
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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
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|
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 |
|
Permanent link to this record |
|
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|
|
Author |
Leemans, A.; Sijbers, J.; van den Broek, W.; Yang, Z. |
|
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Title |
An interactive curvature based rigid-body image registartion technique: an application of EFTEM |
Type |
P3 Proceeding |
|
Year |
2004 |
Publication |
|
Abbreviated Journal |
|
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|
Volume |
|
Issue |
|
Pages |
|
|
|
Keywords |
P3 Proceeding; Vision lab; Electron microscopy for materials research (EMAT) |
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Abstract |
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Address |
|
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Corporate Author |
|
Thesis |
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Publisher |
|
Place of Publication |
s.l. |
Editor |
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Language |
|
Wos |
|
Publication Date |
|
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
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ISSN |
|
ISBN |
|
Additional Links |
UA library record |
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|
Impact Factor |
|
Times cited |
|
Open Access |
|
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|
Notes |
|
Approved |
Most recent IF: NA |
|
|
Call Number |
UA @ lucian @ c:irua:48300 |
Serial |
4503 |
|
Permanent link to this record |
|
|
|
|
Author |
De Backer, A.; van den Bos, K.H.W.; Van den Broek, W.; Sijbers, J.; Van Aert, S. |
|
|
Title |
StatSTEM: An efficient 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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
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|
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 |
Van den Broek, W.; Reed, B.W.; Béché, A.; Velazco, A.; Verbeeck, J.; Koch, C.T. |
|
|
Title |
Various compressed sensing setups evaluated against Shannon sampling under constraint of constant illumination |
Type |
A1 Journal article |
|
Year |
2019 |
Publication |
IEEE transactions on computational imaging |
Abbreviated Journal |
|
|
|
Volume |
5 |
Issue |
3 |
Pages |
502-514 |
|
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Under the constraint of constant illumination, an information criterion is formulated for the Fisher information that compressed sensing measurements in optical and transmission electron microscopy contain about the underlying parameters. Since this approach requires prior knowledge of the signal's support in the sparse basis, we develop a heuristic quantity, the detective quantum efficiency (DQE), that tracks this information criterion well without this knowledge. In this paper, it is shown that for the investigated choice of sensing matrices, and in the absence of read-out noise, i.e., with only Poisson noise present, compressed sensing does not raise the amount of Fisher information in the recordings above that of Shannon sampling. Furthermore, enabled by the DQE's analytical tractability, the experimental designs are optimized by finding out the optimal fraction of on pixels as a function of dose and read-out noise. Finally, we introduce a regularization and demonstrate, through simulations and experiment, that it yields reconstructions attaining minimum mean squared error at experimental settings predicted by the DQE as optimal. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
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|
|
Language |
|
Wos |
000480352600013 |
Publication Date |
2019-01-24 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2333-9403 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4.546 |
Times cited |
7 |
Open Access |
|
|
|
Notes |
; This work was supported by the Hercules fund from the Flemish Government (Qu-Ant-EM microscope used for the experimental data). The work of W. Van den Broek was supported by the DFG under Grant BR 5095/2-1 (Compressed sensing in ptychography and transmission electron microscopy). The work of A. Beche, A. Velazco, and J. Verbeeck was supported by the FWO under Grant G093417N (Compressed sensing enabling low dose imaging in transmission electron microscopy). The work of Christoph T. Koch was supported by the DFG under Grant CRC 951. The associate editor coordinating the review of this manuscript and approving it for publication was Dr. Chrysanthe Preza. ; |
Approved |
Most recent IF: NA |
|
|
Call Number |
UA @ admin @ c:irua:161792 |
Serial |
5368 |
|
Permanent link to this record |