| Records |
Author  |
Vanrompay, H.; Béché, A.; Verbeeck, J.; Bals, S. |
| Title |
Experimental Evaluation of Undersampling Schemes for Electron Tomography of Nanoparticles |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
| Volume |
36 |
Issue |
36 |
Pages |
1900096 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
One of the emerging challenges in the field of 3D characterization of nanoparticles by electron tomography is to avoid degradation and deformation of the samples during the acquisition of a tilt series. In order to reduce the required electron dose, various undersampling approaches have been proposed. These methods include lowering the number of 2D projection images, reducing the probe current during the acquisition, and scanning a smaller number of pixels in the 2D images. A comparison is made between these approaches based on tilt series acquired for a gold nanoparticle. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000477679400014 |
Publication Date |
2019-05-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.474 |
Times cited |
12 |
Open Access |
Not_Open_Access |
| Notes |
H.V. acknowledges financial support by the Research Foundation Flanders (FWO Grant No. 1S32617N). A.B. and J.V. acknowledge FWO project 6093417N “Compressed sensing enabling low dose imaging in STEM.” The authors thank G. González-Rubio, A. Sánchez-Iglesias, and L.M. Liz-Marzán for provision of the samples. |
Approved |
Most recent IF: 4.474 |
| Call Number |
EMAT @ emat @UA @ admin @ c:irua:159986 |
Serial |
5175 |
| Permanent link to this record |
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| |
| Author |
Vanrompay, H.; Skorikov, A.; Bladt, E.; Béché, A.; Freitag, B.; Verbeeck, J.; Bals, S. |
| Title |
Fast versus conventional HAADF-STEM tomography of nanoparticles: advantages and challenges |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
221 |
Issue |
|
Pages |
113191 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
HAADF-STEM tomography is a widely used experimental technique for analyzing nanometer-scale crystalline structures of a large variety of materials in three dimensions. Unfortunately, the acquisition of conventional HAADF-STEM tilt series can easily take up one hour or more, depending on the complexity of the experiment. It is therefore far from straightforward to investigate samples that do not withstand long acquisition or to acquire large amounts of tilt series during a single TEM experiment. The latter would lead to the ability to obtain statistically meaningful 3D data, or to perform in situ 3D characterizations with a much shorter time resolution. Various HAADF-STEM acquisition strategies have been proposed to accelerate the tomographic acquisition and reduce the required electron dose. These methods include tilting the holder continuously while acquiring a projection “movie” and a hybrid, incremental, methodology which combines the benefits of the conventional and continuous technique. However, until now an experimental evaluation has been lacking. In this paper, the different acquisition strategies will be experimentally compared in terms of speed, resolution and electron dose. This evaluation will be performed based on experimental tilt series acquired for various metallic nanoparticles with different shapes and sizes. We discuss the data processing involved with the fast HAADF-STEM tilt series and provide a general guideline when which acquisition strategy should be preferentially used. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000612539600003 |
Publication Date |
2020-12-08 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
15 |
Open Access |
OpenAccess |
| Notes |
We acknowledge Prof. Luis M. Liz-Marzán and co-workers of the Bionanoplasmonics Laboratory, CIC biomaGUNE, Spain for providing the Au@Ag nanoparticles, Prof. Sara. E. Skrabalak and co-workers of Indiana University, United States for the provision of the Au octopods and Prof. Teri W. Odom of Northwestern University, United States for the provision of the Au nanostars. H.V. acknowledges financial support by the Research Foundation Flanders (FWO grant 1S32617N). S.B acknowledges financial support by the Research Foundation Flanders (FWO grant G.0381.16N). This project received funding as well from the European Union’s Horizon 2020 research and innovation program under grant agreement No 731019 (EUSMI) and No 815128 (REALNANO). The authors acknowledge the entire EMAT technical staff for their support.; sygma |
Approved |
Most recent IF: 2.843 |
| Call Number |
EMAT @ emat @c:irua:174551 |
Serial |
6660 |
| Permanent link to this record |
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| Author |
Vatanparast, M.; Egoavil, R.; Reenaas, T.W.; Verbeeck, J.; Holmestad, R.; Vullum, P.E. |
| Title |
Bandgap measurement of high refractive index materials by off-axis EELS |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
182 |
Issue |
|
Pages |
92-98 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
In the present work Cs aberration corrected and monochromated scanning transmission electron microscopy electron energy loss spectroscopy (STEM-EELS) has been used to explore experimental setups that allow bandgaps of high refractive index materials to be determined. Semi-convergence and collection angles in the mu rad range were combined with off-axis or dark field EELS to avoid relativistic losses and guided light modes in the low loss range to contribute to the acquired EEL spectra. Off-axis EELS further supressed the zero loss peak and the tail of the zero loss peak. The bandgap of several GaAs-based materials were successfully determined by simple regression analyses of the background subtracted EEL spectra. The presented set-up does not require that the acceleration voltage is set to below the. Cerenkov limit and can be applied over the entire acceleration voltage range of modern TEMs and for a wide range of specimen thicknesses. (C) 2017 Elsevier B.V. All rights reserved. |
| 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 |
000413436500013 |
Publication Date |
2017-06-21 |
| 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 |
3 |
Open Access |
Not_Open_Access |
| Notes |
; The authors would like to thank Professor Shu Min Wang and Mahdad Sadeghi at the Nanofabrication Laboratory at Chalmers University, Sweden for providing the samples. The Norwegian Research Council is acknowledged for funding the HighQ-IB project under contract no. 10415201. M.V. and T.W.R. acknowledge funding from the EEA Financial Mechanism 2009-2014 under the project contract no 23SEE/30.06.2014. 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) through the system of transnational access. R.E. and J.V. acknowledge funding from GOA project “Solarpaint” of the University of Antwerp. ; |
Approved |
Most recent IF: 2.843 |
| Call Number |
UA @ lucian @ c:irua:146639UA @ admin @ c:irua:146639 |
Serial |
4778 |
| Permanent link to this record |
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| Author |
Vávra, O.; Gaži, S.; Golubović, D.S.; Vávra, I.; Dérer, J.; Verbeeck, J.; Van Tendeloo, G.; Moshchalkov, V.V. |
| Title |
0 and π phase Josephson coupling through an insulating barrier with magnetic impurities |
Type |
A1 Journal article |
| Year |
2006 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
74 |
Issue |
2 |
Pages |
020502 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We have studied the temperature and field dependencies of the critical current I(C) in the Nb-Fe(0.1)Si(0.9)-Nb Josephson junction with a tunneling barrier formed by a paramagnetic insulator. We demonstrate that in these junctions coexistence of both the 0 and the pi states within one tunnel junction occurs, and leads to the appearance of a sharp cusp in the temperature dependence I(C)(T), similar to the I(C)(T) cusp found for the 0-pi transition in metallic pi junctions. This cusp is not related to the 0-pi temperature-induced transition itself, but is caused by the different temperature dependencies of the opposing 0 and pi supercurrents through the barrier. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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| Language |
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Wos |
000239426600010 |
Publication Date |
2006-07-15 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
27 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2006 IF: 3.107 |
| Call Number |
UA @ lucian @ c:irua:60087 c:irua:60087 c:irua:60087 c:irua:60087UA @ admin @ c:irua:60087 |
Serial |
1 |
| Permanent link to this record |
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| |
| Author |
Vega Ibañez, F.; Béché, A.; Verbeeck, J. |
| Title |
Can a programmable phase plate serve as an aberration corrector in the transmission electron microscope (TEM)? |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Microscopy and microanalysis |
Abbreviated Journal |
Microsc Microanal |
| Volume |
|
Issue |
|
Pages |
Pii S1431927622012260-10 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Current progress in programmable electrostatic phase plates raises questions about their usefulness for specific applications. Here, we explore different designs for such phase plates with the specific goal of correcting spherical aberration in the transmission electron microscope (TEM). We numerically investigate whether a phase plate could provide down to 1 angstrom ngstrom spatial resolution on a conventional uncorrected TEM. Different design aspects (fill factor, pixel pattern, symmetry) were evaluated to understand their effect on the electron probe size and current density. Some proposed designs show a probe size () down to 0.66 angstrom, proving that it should be possible to correct spherical aberration well past the 1 angstrom limit using a programmable phase plate consisting of an array of electrostatic phase-shifting elements. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
|
Wos |
000849975400001 |
Publication Date |
2022-09-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1431-9276 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.8 |
Times cited |
3 |
Open Access |
OpenAccess |
| Notes |
All authors acknowledge funding from the Flemish Research Fund under contract G042820N “Exploring adaptive optics in transmission electron microscopy”. J.V. acknowledges funding from the European Union’s Horizon 2020 Research Infrastructure – Integrating Activities for Advanced Communities under grant agreement No 823717 – ESTEEM3 and from the University of Antwerp through a TOP BOF project.; esteem3reported; esteem3jra |
Approved |
Most recent IF: 2.8 |
| Call Number |
UA @ admin @ c:irua:190627 |
Serial |
7134 |
| Permanent link to this record |
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| |
| Author |
Velazco, A.; Béché, A.; Jannis, D.; Verbeeck, J. |
| Title |
Reducing electron beam damage through alternative STEM scanning strategies, Part I: Experimental findings |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
232 |
Issue |
|
Pages |
113398 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The highly energetic electrons in a transmission electron microscope (TEM) can alter or even completely destroy the structure of samples before sufficient information can be obtained. This is especially problematic in the case of zeolites, organic and biological materials. As this effect depends on both the electron beam and the sample and can involve multiple damage pathways, its study remained difficult and is plagued with irreproducibility issues, circumstantial evidence, rumors, and a general lack of solid data. Here we take on the experimental challenge to investigate the role of the STEM scan pattern on the damage behavior of a commercially available zeolite sample with the clear aim to make our observations as reproducible as possible. We make use of a freely programmable scan engine that gives full control over the tempospatial distribution of the electron probe on the sample and we use its flexibility to obtain multiple repeated experiments under identical conditions comparing the difference in beam damage between a conventional raster scan pattern and a newly proposed interleaved scan pattern that provides exactly the same dose and dose rate and visits exactly the same scan points. We observe a significant difference in beam damage for both patterns with up to 11 % reduction in damage (measured from mass loss). These observations demonstrate without doubt that electron dose, dose rate and acceleration voltage are not the only parameters affecting beam damage in (S)TEM experiments and invite the community to rethink beam damage as an unavoidable consequence of applied electron dose. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000714819200002 |
Publication Date |
2021-10-02 |
| 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 |
2.2 |
Times cited |
18 |
Open Access |
OpenAccess |
| Notes |
A.V., D.J., A.B. and J.V. acknowledge funding from FWO project G093417N (’Compressed sensing enabling low dose imaging in transmission electron microscopy’) and G042920N (’Coincident event detection for advanced spectroscopy in transmission electron microscopy’). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 823717 ESTEEM3. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. J.V. acknowledges funding from GOA project “Solarpaint” of the University of Antwerp.; JRA; reported |
Approved |
Most recent IF: 2.2 |
| Call Number |
EMAT @ emat @c:irua:183282 |
Serial |
6818 |
| Permanent link to this record |
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| |
| Author |
Velazco, A.; Nord, M.; Béché, A.; Verbeeck, J. |
| Title |
Evaluation of different rectangular scan strategies for STEM imaging |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
|
Issue |
|
Pages |
113021 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
STEM imaging is typically performed by raster scanning a focused electron probe over a sample. Here we investigate and compare three different scan patterns, making use of a programmable scan engine that allows to arbitrarily set the sequence of probe positions that are consecutively visited on the sample. We compare the typical raster scan with a so-called ‘snake’ pattern where the scan direction is reversed after each row and a novel Hilbert scan pattern that changes scan direction rapidly and provides an homogeneous treatment of both scan directions. We experimentally evaluate the imaging performance on a single crystal test sample by varying dwell time and evaluating behaviour with respect to sample drift. We demonstrate the ability of the Hilbert scan pattern to more faithfully represent the high frequency content of the image in the presence of sample drift. It is also shown that Hilbert scanning provides reduced bias when measuring lattice parameters from the obtained scanned images while maintaining similar precision in both scan directions which is especially important when e.g. performing strain analysis. Compared to raster scanning with flyback correction, both snake and Hilbert scanning benefit from dose reduction as only small probe movement steps occur. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000544042800007 |
Publication Date |
2020-05-21 |
| Series Editor |
|
Series Title |
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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 |
2.2 |
Times cited |
13 |
Open Access |
OpenAccess |
| Notes |
A.V., A.B. and J.V. acknowledge funding through FWO project G093417N ('Compressed sensing enabling low dose imaging in transmission electron microscopy') from the Flanders Research Fund. M.N. received support for this work from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 838001. J.V acknowledges funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3. |
Approved |
Most recent IF: 2.2; 2020 IF: 2.843 |
| Call Number |
EMAT @ emat @c:irua:169225 |
Serial |
6369 |
| Permanent link to this record |
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| |
| Author |
Verbeeck, J. |
| Title |
Interpretation of “Energy-filtered electron-diffracted beam holography” by R.A. Herring |
Type |
A1 Journal article |
| Year |
2006 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
106 |
Issue |
6 |
Pages |
461-465 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
A straightforward application of the theoretical framework presented by Verbeeck et al. [Ultramicroscopy 102 (2005) 239] is presented to explain the energy-filtered electron-diffracted beam holography experiments published by Herring [Ultramicroscopy 104 (2005) 261]. It is shown that the theory is in agreement with all experimental findings, which leads to the interpretation that the experiments are mainly measuring the angular coherence of the source image rather than exposing details on the coherence properties of inelastic scattering. A change in experimental parameters is proposed, which could result in interesting information about the coherence in all inelastic scattering process. (c) 2006 Elsevier B.V. All rights reserved. |
| 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 |
000237491600002 |
Publication Date |
2006-01-18 |
| Series Editor |
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Series Title |
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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 |
8 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2006 IF: 1.706 |
| Call Number |
UA @ lucian @ c:irua:58283UA @ admin @ c:irua:58283 |
Serial |
1710 |
| Permanent link to this record |
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| Author |
Verbeeck, J.; Bals, S.; Lamoen, D.; Luysberg, M.; Huijben, M.; Rijnders, G.; Brinkman, A.; Hilgenkamp, H.; Blank, D.H.A.; Van Tendeloo, G. |
| Title |
Electronic reconstruction at n-type SrTiO3/LaAlO3 interfaces |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
81 |
Issue |
8 |
Pages |
085113,1-085113,6 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Electron-energy-loss spectroscopy (EELS) is used to investigate single layers of LaAlO3 grown on SrTiO3 having an n-type interface as well as multilayers of LaAlO3 and SrTiO3 in which both n- and p-type interfaces occur. Only minor changes in Ti valence at the n-type interface are observed. This finding seems to contradict earlier experiments for other SrTiO3/LaAlO3 systems where large deviations in Ti valency were assumed to be responsible for the conductivity of these interfaces. Ab initio calculations have been carried out in order to interpret our EELS results. Using the concept of Bader charges, it is demonstrated that the so-called polar discontinuity is mainly resolved by lattice distortions and to a far lesser extent by changes in valency for both single layer and multilayer geometries. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000275053300040 |
Publication Date |
2010-02-18 |
| 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 |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
25 |
Open Access |
|
| Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:81768UA @ admin @ c:irua:81768 |
Serial |
1005 |
| Permanent link to this record |
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| |
| Author |
Verbeeck, J.; Béché, A.; Müller-Caspary, K.; Guzzinati, G.; Luong, M.A.; Den Hertog, M. |
| Title |
Demonstration of a 2 × 2 programmable phase plate for electrons |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
190 |
Issue |
|
Pages |
58-65 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
First results on the experimental realisation of a 2 × 2 programmable phase plate for electrons are presented. The design consists of an array of electrostatic elements that influence the phase of electron waves passing through 4 separately controllable aperture holes. This functionality is demonstrated in a conventional transmission electron microscope operating at 300 kV and results are in very close agreement with theoretical predictions. The dynamic creation of a set of electron probes with different phase symmetry is demonstrated, thereby bringing adaptive optics in TEM one step closer to reality. The limitations of the current design and how to overcome these in the future are discussed. Simulations show how further evolved versions of the current proof of concept might open new and exciting application prospects for beam shaping and aberration correction. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000432868800007 |
Publication Date |
2018-04-18 |
| 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 |
|
| ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
73 |
Open Access |
Not_Open_Access: Available from 19.04.2020
|
| Notes |
J.V. and A.B. acknowledge funding from the Fund for Scientific Research Flanders FWO project G093417N and the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX and ERC proof of concept project DLV-789598 ADAPTEM. The Qu-Ant-EM microscope used in this work was partly funded by the Hercules fund from the Flemish Government. MdH acknowledges financial support from the ANRCOSMOS (ANR-12-JS10-0002). MdH and ML acknowledge funding from the Laboratoire d’excellence LANEF in Grenoble (ANR-10-LABX-51-01). |
Approved |
Most recent IF: 2.843 |
| Call Number |
EMAT @ emat @c:irua:150459UA @ admin @ c:irua:150459 |
Serial |
4920 |
| Permanent link to this record |
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| |
| Author |
Verbeeck, J.; Béché, A.; van den Broek, W. |
| Title |
A holographic method to measure the source size broadening in STEM |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
120 |
Issue |
|
Pages |
35-40 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| 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. |
| 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 |
000308082600005 |
Publication Date |
2012-06-01 |
| 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 |
29 |
Open Access |
|
| 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 |
| Call Number |
UA @ lucian @ c:irua:100466UA @ admin @ c:irua:100466 |
Serial |
1483 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Bertoni, G. |
| Title |
Deconvolution of core electron energy loss spectra |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
109 |
Issue |
11 |
Pages |
1343-1352 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Different deconvolution methods for removing multiple scattering and instrumental broadening from core loss electron energy loss spectra are compared with special attention to the artefacts they introduce. The Gaussian modifier method, Wiener filter, maximum entropy, and model based methods are described. Their performance is compared on virtual spectra where the true single scattering distribution is known. A test on experimental spectra confirms the good performance of model based deconvolution in comparison to maximum entropy methods and shows the advantage of knowing the estimated error bars from a single spectrum acquisition. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000270765800005 |
Publication Date |
2009-07-01 |
| 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 |
13 |
Open Access |
|
| Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
| Call Number |
UA @ lucian @ c:irua:79073UA @ admin @ c:irua:79073 |
Serial |
610 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Bertoni, G. |
| Title |
Model-based quantification of EELS: is standardless quantification possible? |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Microchimica acta |
Abbreviated Journal |
Microchim Acta |
| Volume |
161 |
Issue |
3/4 |
Pages |
439-443 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Electron energy loss spectroscopy (EELS) is an ideal tool to obtain chemical information from nanoscale volumes. Quantification of the experimental spectra however has prevented for a long time access to the available information in a reliable and reproducible way. We present recent advances in model-based quantification of EELS spectra and show that we obtain the best possible precision for a given dataset, as well as remarkably good accuracies when applied to three different materials. The results are shown to be far superior over conventional quantification techniques and could hold a promise for standardless quantification of EELS spectra. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000256175600024 |
Publication Date |
2008-02-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0026-3672;1436-5073; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.58 |
Times cited |
5 |
Open Access |
|
| Notes |
Esteem 026019; Fwo; G.0425.05; Iap V; Goa 2005 |
Approved |
Most recent IF: 4.58; 2008 IF: 1.910 |
| Call Number |
UA @ lucian @ c:irua:69292UA @ admin @ c:irua:69292 |
Serial |
2100 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Bertoni, G. |
| Title |
Model-based quantification of EELS spectra: treating the effect of correlated noise |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
108 |
Issue |
2 |
Pages |
74-83 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Correlated noise is generally present in experimentally recorded electron energy loss spectra due to a non-ideal electron detector. In this contribution we describe a method to experimentally measure the noise properties of the detector as well as the consequences it has for model-based quantification using maximum likelihood. The effect of the correlated noise on the maximum likelihood fitting results can be shown to be negligible for the estimated (co)variance of the parameters while an experimentally obtained scaling factor is required to correct the likelihood ratio test for the reduction of noise power with frequency. Both effects are derived theoretically under a set of approximations and tested for a range of signal-to-noise values using numerical experiments. Finally, an experimental example shows that the correction for correlated noise is essential and should always be included in the fitting procedure. (c) 2007 Elsevier B.V. All rights reserved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000252816900002 |
Publication Date |
2007-03-25 |
| 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 |
16 |
Open Access |
|
| Notes |
FWO nr G.0147.06; ESTEEM 026019 |
Approved |
Most recent IF: 2.843; 2008 IF: 2.629 |
| Call Number |
UA @ lucian @ c:irua:67602UA @ admin @ c:irua:67602 |
Serial |
2103 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Bertoni, G.; Lichte, H. |
| Title |
A holographic biprism as a perfect energy filter? |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
111 |
Issue |
7 |
Pages |
887-893 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
It has often been stated that a holographic biprism represents a near perfect energy filter and only elastically scattered electrons can participate in the interference fringes. This is based on the assumption that the reference wave does not contain inelastically scattered electrons. In this letter we show that this is not exactly true because of the delocalised inelastic interaction of the reference wave with the sample. We experimentally and theoretically show that inelastic scattering plays a role in the fringe formation, but it is shown that this contribution is small and can usually be neglected in practice. (C) 2011 Elsevier B.V. All rights reserved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000300461000021 |
Publication Date |
2011-02-05 |
| 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 |
|
| Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 2.843; 2011 IF: 2.471 |
| Call Number |
UA @ lucian @ c:irua:97250UA @ admin @ c:irua:97250 |
Serial |
1482 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Bertoni, G.; Schattschneider, P. |
| 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 |
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 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Guzzinati, G.; Clark, L.; Juchtmans, R.; Van Boxem, R.; Tian, H.; Béché, A.; Lubk, A.; Van Tendeloo, G. |
| Title |
Shaping electron beams for the generation of innovative measurements in the (S)TEM |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Comptes rendus : physique |
Abbreviated Journal |
Cr Phys |
| Volume |
15 |
Issue |
2-3 |
Pages |
190-199 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
In TEM, a typical goal consists of making a small electron probe in the sample plane in order to obtain high spatial resolution in scanning transmission electron microscopy. In order to do so, the phase of the electron wave is corrected to resemble a spherical wave compensating for aberrations in the magnetic lenses. In this contribution, we discuss the advantage of changing the phase of an electron wave in a specific way in order to obtain fundamentally different electron probes opening up new applications in the (S)TEM. We focus on electron vortex states as a specific family of waves with an azimuthal phase signature and discuss their properties, production and applications. The concepts presented here are rather general and also different classes of probes can be obtained in a similar fashion, showing that electron probes can be tuned to optimize a specific measurement or interaction. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Paris |
Editor |
|
| Language |
|
Wos |
000334013600009 |
Publication Date |
2014-02-01 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1631-0705; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.048 |
Times cited |
22 |
Open Access |
|
| Notes |
Vortex ECASJO_; |
Approved |
Most recent IF: 2.048; 2014 IF: 2.035 |
| Call Number |
UA @ lucian @ c:irua:116946UA @ admin @ c:irua:116946 |
Serial |
2992 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Hébert; Rubino, S.; Novák, P.; Rusz, J.; Houdellier, F.; Gatel, C.; Schattschneider, P. |
| Title |
Optimal aperture sizes and positions for EMCD experiments |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
108 |
Issue |
9 |
Pages |
865-872 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The signal-to-noise ratio (SNR) in energy-loss magnetic chiral dichroism (EMCD)the equivalent of X-ray magnetic circular dichroism (XMCD) in the electron microscopeis optimized with respect to the detector shape, size and position. We show that an important increase in SNR over previous experiments can be obtained when taking much larger detector sizes. We determine the ideal shape of the detector but also show that round apertures are a good compromise if placed in their optimal position. We develop the theory for a simple analytical description of the EMCD experiment and then apply it to dynamical multibeam Bloch wave calculations and to an experimental data set. In all cases it is shown that a significant and welcome improvement of the SNR is possible. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000258747600009 |
Publication Date |
2008-03-07 |
| 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 |
27 |
Open Access |
|
| Notes |
This work was supported by the European Commission under contract no. 508971 CHIRALTEM. J.V. and F.H. thank the financial support from the European Union under the Framework 6 program under a contract for an Integrated Infrastructure Initiative. Reference 026019 ESTEEM. Thanks to J.P. Morniroli for making the Fe sample available. |
Approved |
Most recent IF: 2.843; 2008 IF: 2.629 |
| Call Number |
UA @ lucian @ c:irua:76492UA @ admin @ c:irua:76492 |
Serial |
2480 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Lebedev, O.I.; Van Tendeloo, G.; Cagnon, L.; Bougerol, C.; Tourillon, T. |
| Title |
Fe and Co nanowires and nanotubes synthesized by template electrodeposition: a HRTEM and EELS study |
Type |
A1 Journal article |
| Year |
2003 |
Publication |
Journal of the electrochemical society |
Abbreviated Journal |
J Electrochem Soc |
| Volume |
150 |
Issue |
10 |
Pages |
E468-E471 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Co and Fe nanowires and/or nanotubes are electrochemically synthesized through nanoporous membranes. By combining high-resolution transmission electron microscopy (HRTEM), electron energy loss spectroscopy (EELS), and energy filtered TEM techniques, their structural and crystallographic characteristics are precisely determined. The synthesis was shown to produce cigar-shaped single monocrystalline Co and Fe nanowires with a diameter of about 60 nm. All wires were surrounded by an epitaxial oxide layer (Co3O4 or Fe3O4) of roughly 10 nm. The Fe nanotubes were built up of Fe3O4 nanocrystals. Electron diffraction showed that all nanocrystals had a common crystallographic axis, creating a pseudomonocrystalline wall in the nanotubes. (C) 2003 The Electrochemical Society. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000185639800039 |
Publication Date |
2003-09-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0013-4651; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.259 |
Times cited |
41 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.259; 2003 IF: 2.361 |
| Call Number |
UA @ lucian @ c:irua:54858UA @ admin @ c:irua:54858 |
Serial |
1176 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Lebedev, O.I.; Van Tendeloo, G.; Mercey, B. |
| Title |
SrTiO3(100)/(LaMnO3)m(SrMnO3)n layered heterostructures: a combined EELS and TEM study |
Type |
A1 Journal article |
| Year |
2002 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
66 |
Issue |
18 |
Pages |
184426 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Epitaxially grown heterostructures consisting of alternating layers of LaMnO(3) (LMO, 9 or 15 unit cells) and SrMnO(3) (SMO, 4 or 6 unit cells) on a SrTiO(3)(100) (STO(100)) substrate have been studied by a combination of high resolution transmission electron microscopy (HRTEM), electron diffraction, quantitative electron energy loss spectroscopy (EELS) with model fitting, energy filtered TEM (EFTEM) and imaging spectroscopy on an atomic scale. The combination of these techniques is necessary for the structural, chemical, and electronic characterization of these heterostructures. A model is proposed containing chemically and structurally sharp interfaces. The SrMnO(3) layers are stabilized in a Pm3m structure between two LMO layers. Tensile stress causes oxygen deficiency in the SMO layers increasing the number of 3d electrons on the Mn sites to resemble the Mn(3+) sites in LMO. The energy loss near edge structure (ELNES) of O and Mn is compared for both LMO and SMO layers and shows that the Mn-O bonds have a partially covalent character. The absence of a strong valency effect in the Mn ELNES is due to the oxygen vacancies in SMO. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000179633100062 |
Publication Date |
2002-11-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
32 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2002 IF: NA |
| Call Number |
UA @ lucian @ c:irua:54741 |
Serial |
3563 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Lebedev, O.I.; Van Tendeloo, G.; Silcox, J.; Mercey, B.; Hervieu, M.; Haghiri-Gosnet, A.M. |
| Title |
Electron energy-loss spectroscopy study of a (LaMnO3)8(SrMnO3)4 heterostructure |
Type |
A1 Journal article |
| Year |
2001 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
79 |
Issue |
13 |
Pages |
2037-2039 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
An epitaxially grown heterostructure consisting of alternating layers of LaMnO3 (8 unit cells) and SrMnO3 (4 unit cells) on a SrTiO3 substrate has been studied by a combination of electron energy-loss spectroscopy (EELS) and high-resolution transmission electron microscopy (HRTEM) on an atomic scale. Excitation edges of all elements are captured with subnanometer spatial accuracy, and parametrized to obtain chemical profiles. The fine-edge structure of O K and Mn L-2,L-3 edges are interpreted as signatures of the local electronic structure and show a spatial modulation of the concentration of holes with O 2p character. The chemical concentration is found to be different for the bottom and top interface of a SrMnO3 layer. HRTEM complements the EELS results and confirms the asymmetry of the interfaces. (C) 2001 American Institute of Physics. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000171015200036 |
Publication Date |
2002-07-26 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.411 |
Times cited |
19 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.411; 2001 IF: 3.849 |
| Call Number |
UA @ lucian @ c:irua:54799UA @ admin @ c:irua:54799 |
Serial |
933 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Sc hattschneider, P.; Rosenauer, A. |
| Title |
Image simulation of high resolution energy filtered TEM images |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
109 |
Issue |
4 |
Pages |
350-360 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Inelastic image simulation software is presented, implementing the double channeling approximation which takes into account the combination of multiple elastic and single inelastic scattering in a crystal. The approach is described with a density matrix formalism. Two applications in high resolution energy filtered (EFTEM) transmission electron microscopy (TEM) images are presented: thickness-defocus maps for SrTiO3 and exit plane intensities for an (LaAlO3)3(SrTiO3)3 multilayer system. Both systems show a severe breakdown in direct interpretability which becomes worse for higher acceleration voltages, thicker samples and lower excitation edge energies. Since this effect already occurs in the exit plane intensity, it is a fundamental limit and image simulations in EFTEM are indispensable just as they are indispensable for elastic high resolution TEM images. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000265345400009 |
Publication Date |
2009-01-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
36 |
Open Access |
|
| Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
| Call Number |
UA @ lucian @ c:irua:77272UA @ admin @ c:irua:77272 |
Serial |
1552 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Schattschneider, P.; Lazar, S.; Stöger-Pollach, M.; Löffler, S.; Steiger-Thirsfeld, A.; Van Tendeloo, G. |
| Title |
Atomic scale electron vortices for nanoresearch |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
99 |
Issue |
20 |
Pages |
203109-203109,3 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Electron vortex beams were only recently discovered and their potential as a probe for magnetism in materials was shown. Here we demonstrate a method to produce electron vortex beams with a diameter of less than 1.2 Å. This unique way to prepare free electrons to a state resembling atomic orbitals is fascinating from a fundamental physics point of view and opens the road for magnetic mapping with atomic resolution in an electron microscope. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000297786500058 |
Publication Date |
2011-11-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.411 |
Times cited |
90 |
Open Access |
|
| Notes |
Hercules |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:93625UA @ admin @ c:irua:93625 |
Serial |
184 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Tian, H.; Béché, A. |
| Title |
A new way of producing electron vortex probes for STEM |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
113 |
Issue |
|
Pages |
83-87 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
A spiral holographic aperture is used in the condensor plane of a scanning transmission electron microscope to produce a focussed electron vortex probe carrying a topological charge of either −1, 0 or +1. The spiral aperture design has a major advantage over the previously used forked aperture in that the three beams with topological charge m=−1, 0, and 1 are not side by side in the specimen plane, but rather on top of each other, focussed at different heights. This allows us to have only one selected beam in focus on the sample while the others contribute only to a background signal. In this paper we describe the working principle as well as first experimental results demonstrating atomic resolution HAADF STEM images obtained with electron vortex probes. These results pave the way for atomic resolution magnetic information when combined with electron energy loss spectroscopy. |
| 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 |
000300554400002 |
Publication Date |
2011-10-31 |
| 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 |
| Impact Factor |
2.843 |
Times cited |
62 |
Open Access |
|
| Notes |
J.V. wants to thank Miles Padgett for suggesting this setup and pointing to the relevant optics literature. Peter Schattschneider is acknowledged for in depth discussions on related topics. J.V acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant no. 46791-COUN-TATOMS and ERC Starting Grant no. 278510 VORTEX. The Qu-Ant-EM microscope is partially funded by the Hercules fund of the Flemish Government. ECASJO_; |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
| Call Number |
UA @ lucian @ c:irua:93624UA @ admin @ c:irua:93624 |
Serial |
2336 |
| Permanent link to this record |
| |
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| |
| Author |
Verbeeck, J.; Tian, H.; Schattschneider, P. |
| Title |
Production and application of electron vortex beams |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Nature |
Abbreviated Journal |
Nature |
| Volume |
467 |
Issue |
7313 |
Pages |
301-304 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Vortex beams (also known as beams with a phase singularity) consist of spiralling wavefronts that give rise to angular momentum around the propagation direction. Vortex photon beams are widely used in applications such as optical tweezers to manipulate micrometre-sized particles and in micro-motors to provide angular momentum1, 2, improving channel capacity in optical3 and radio-wave4 information transfer, astrophysics5 and so on6. Very recently, an experimental realization of vortex beams formed of electrons was demonstrated7. Here we describe the creation of vortex electron beams, making use of a versatile holographic reconstruction technique in a transmission electron microscope. This technique is a reproducible method of creating vortex electron beams in a conventional electron microscope. We demonstrate how they may be used in electron energy-loss spectroscopy to detect the magnetic state of materials and describe their properties. Our results show that electron vortex beams hold promise for new applications, in particular for analysing and manipulating nanomaterials, and can be easily produced. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
London |
Editor |
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| Language |
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Wos |
000281824900033 |
Publication Date |
2010-09-14 |
| 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 |
0028-0836;1476-4687; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
40.137 |
Times cited |
626 |
Open Access |
|
| Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 40.137; 2010 IF: 36.104 |
| Call Number |
UA @ lucian @ c:irua:84878UA @ admin @ c:irua:84878 |
Serial |
2720 |
| Permanent link to this record |
| |
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| |
| Author |
Verbeeck, J.; Tian, H.; Van Tendeloo, G. |
| Title |
How to manipulate nanoparticles with an electron beam? |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
| Volume |
25 |
Issue |
8 |
Pages |
1114-1117 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
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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 |
Weinheim |
Editor |
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| Language |
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Wos |
000315102600003 |
Publication Date |
2012-11-26 |
| 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 |
0935-9648; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
19.791 |
Times cited |
75 |
Open Access |
|
| Notes |
FWO; VORTEX; Countatoms ECASJO_; |
Approved |
Most recent IF: 19.791; 2013 IF: 15.409 |
| Call Number |
UA @ lucian @ c:irua:105287UA @ admin @ c:irua:105287 |
Serial |
1494 |
| Permanent link to this record |
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| |
| Author |
Verbeeck, J.; Van Aert, S. |
| Title |
Model based quantification of EELS spectra |
Type |
A1 Journal article |
| Year |
2004 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
101 |
Issue |
2/4 |
Pages |
207-224 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Recent advances in model based quantification of electron energy loss spectra (EELS) are reported. The maximum likelihood method for the estimation of physical parameters describing an EELS spectrum, the validation of the model used in this estimation procedure, and the computation of the attainable precision, that is, the theoretical lower bound on the variance of these estimates, are discussed. Experimental examples on An and GaAs samples show the power of the maximum likelihood method and show that the theoretical prediction of the attainable precision can be closely approached even for spectra with overlapping edges where conventional EELS quantification fails. To provide end-users with a low threshold alternative to conventional quantification, a user friendly program was developed which is freely available under a GNU public license. (C) 2004 Elsevier B.V. All rights reserved. |
| Address |
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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 |
000224046100016 |
Publication Date |
2004-07-23 |
| 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 |
| Impact Factor |
2.843 |
Times cited |
147 |
Open Access |
|
| Notes |
Fwo; Iuap P5/01 |
Approved |
Most recent IF: 2.843; 2004 IF: 2.215 |
| Call Number |
UA @ lucian @ c:irua:57130UA @ admin @ c:irua:57130 |
Serial |
2101 |
| Permanent link to this record |
| |
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| |
| Author |
Verbeeck, J.; Van Aert, S.; Bertoni, G. |
| Title |
Model-based quantification of EELS spectra: including the fine structure |
Type |
A1 Journal article |
| Year |
2006 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
106 |
Issue |
11-12 |
Pages |
976-980 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
An extension to model-based electron energy loss spectroscopy (EELS) quantification is reported to improve the possibility of modelling fine structure changes in electron energy loss spectra. An equalisation function is used in the energy loss near edge structure (ELNES) region to model the differences between a single atom differential cross section and the cross section for an atom in a crystal. The equalisation function can be shown to approximate the relative density of unoccupied states for the given excitation edge. On a set of 200 experimental h-BN spectra, this technique leads to statistically acceptable models resulting into unbiased estimates of relative concentrations and making the estimated precisions come very close to the Cramer-Rao lower bound (CRLB). The method greatly expands the useability of model-based EELS quantification to spectra with pronounced fine structure. Another benefit of this model is that one also gets an estimate of the unoccupied density of states for a given excitation edge, without having to do background removal and deconvolution, making the outcome intrinsically more reliable and less noisy. (c) 2006 Elsevier B.V. All rights reserved. |
| Address |
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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 |
000241592900004 |
Publication Date |
2006-07-04 |
| 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 |
| Impact Factor |
2.843 |
Times cited |
38 |
Open Access |
|
| Notes |
Goa; Fwo Iap-V |
Approved |
Most recent IF: 2.843; 2006 IF: 1.706 |
| Call Number |
UA @ lucian @ c:irua:61379UA @ admin @ c:irua:61379 |
Serial |
2102 |
| Permanent link to this record |
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| Author |
Verbeeck, J.; Van Aert, S.; Zhang, L.; Haiyan, T.; Schattschneider, P.; Rosenauer, A. |
| Title |
Computational aspects in quantitative EELS |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Microscopy and microanalysis |
Abbreviated Journal |
Microsc Microanal |
| Volume |
16 |
Issue |
S:2 |
Pages |
240-241 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
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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 |
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Publication Date |
2010-08-26 |
| 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 |
| Impact Factor |
1.891 |
Times cited |
|
Open Access |
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| Notes |
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Approved |
Most recent IF: 1.891; 2010 IF: 3.259 |
| Call Number |
UA @ lucian @ c:irua:96556UA @ admin @ c:irua:96556 |
Serial |
454 |
| Permanent link to this record |
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| Author |
Verbeeck, J.; van Dyck, D.; Lichte, H.; Potapov, P.; Schattschneider, P. |
| Title |
Plasmon holographic experiments: theoretical framework |
Type |
A1 Journal article |
| Year |
2005 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
102 |
Issue |
3 |
Pages |
239-255 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
A theoretical framework is described to understand the results of plasmon holography experiments leading to insight in the meaning of the experimental results and pointing out directions for future experiments. The framework is based on the formalism of mutual intensity to describe how coherence is transferred through an optical system. For the inelastic interaction with the object, an expression for the volume. plasmon excitations in a free electron gas is used as a model for the behaviour of aluminium. The formalism leads to a clear graphical intuitive tool for under-standing the experiments. It becomes evident that the measured coherence is solely related to the angular distribution of the plasmon scattering in the case of bulk plasmons. After describing the framework, the special case of coherence outside a spherical particle is treated and the seemingly controversial idea of a plasmon with a limited coherence length obtained front experiments is clarified. (C) 2004 Elsevier B.V. All rights reserved. |
| 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 |
000226436600010 |
Publication Date |
2004-11-05 |
| 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 |
| Impact Factor |
2.843 |
Times cited |
43 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2005 IF: 2.490 |
| Call Number |
UA @ lucian @ c:irua:57133UA @ admin @ c:irua:57133 |
Serial |
2643 |
| Permanent link to this record |
