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Author Idrissi, H.; Béché, A.; Gauquelin, N.; Ul-Haq, I.; Bollinger, C.; Demouchy, S.; Verbeeck, J.; Pardoen, T.; Schryvers, D.; Cordier, P. url  doi
openurl 
  Title On the formation mechanisms of intragranular shear bands in olivine by stress-induced amorphization Type A1 Journal article
  Year 2022 Publication Acta materialia Abbreviated Journal Acta Mater  
  Volume 239 Issue Pages 118247-118249  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract (up) Intragranular amorphization shear lamellae are found in deformed olivine aggregates. The detailed trans-mission electron microscopy analysis of intragranular lamella arrested in the core of a grain provides novel information on the amorphization mechanism. The deformation field is complex and heteroge-neous, corresponding to a shear crack type instability involving mode I, II and III loading components. The formation and propagation of the amorphous lamella is accompanied by the formation of crystal defects ahead of the tip. These defects are geometrically necessary [001] dislocations, characteristics of high-stress deformation in olivine, and rotational nanodomains which are tentatively interpreted as disclinations. We show that these defects play an important role in dictating the path followed by the amorphous lamella. Stress-induced amorphization in olivine would thus result from a direct crystal-to -amorphous transformation associated with a shear instability and not from a mechanical destabilization due to the accumulation of high number of defects from an intense preliminary deformation. The pref-erential alignment of some lamellae along (010) is a proof of the lower ultimate mechanical strength of these planes.(c) 2022 The Authors. Published by Elsevier Ltd on behalf of Acta Materialia Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000861076600004 Publication Date 2022-08-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1359-6454 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.4 Times cited 5 Open Access OpenAccess  
  Notes The QuanTEM microscope was partially funded by the Flemish government. The K2 camera was funded by FWO Hercules fund G0H4316N 'Direct electron detector for soft matter TEM'. A. Beche acknowledges funding from FWO project G093417N ('Compressed sensing enabling low dose imaging in transmission electron microscopy'). H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). This work was supported by the FNRS under Grant PDR – T011322F and by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme under grant agreement No 787,198 Time Man. J-L Rouviere is acknowledged for his support with the GPA softawre. Approved Most recent IF: 9.4  
  Call Number UA @ admin @ c:irua:191432 Serial 7186  
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Author Savchenko, T.M.; Buzzi, M.; Howald, L.; Ruta, S.; Vijayakumar, J.; Timm, M.; Bracher, D.; Saha, S.; Derlet, P.M.; Béché, A.; Verbeeck, J.; Chantrell, R.W.; Vaz, C.A.F.; Nolting, F.; Kleibert, A. pdf  url
doi  openurl
  Title Single femtosecond laser pulse excitation of individual cobalt nanoparticles Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B  
  Volume 102 Issue 20 Pages 205418  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) Laser-induced manipulation of magnetism at the nanoscale is a rapidly growing research topic with potential for applications in spintronics. In this work, we address the role of the scattering cross section, thermal effects, and laser fluence on the magnetic, structural, and chemical stability of individual magnetic nanoparticles excited by single femtosecond laser pulses. We find that the energy transfer from the fs laser pulse to the nanoparticles is limited by the Rayleigh scattering cross section, which in combination with the light absorption of the supporting substrate and protective layers determines the increase in the nanoparticle temperature. We investigate individual Co nanoparticles (8 to 20 nm in size) as a prototypical model system, using x-ray photoemission electron microscopy and scanning electron microscopy upon excitation with single femtosecond laser pulses of varying intensity and polarization. In agreement with calculations, we find no deterministic or stochastic reversal of the magnetization in the nanoparticles up to intensities where ultrafast demagnetization or all-optical switching is typically reported in thin films. Instead, at higher fluences, the laser pulse excitation leads to photo-chemical reactions of the nanoparticles with the protective layer, which results in an irreversible change in the magnetic properties. Based on our findings, we discuss the conditions required for achieving laser-induced switching in isolated nanomagnets.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000589602000005 Publication Date 2020-11-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9950 ISBN Additional Links UA library record; WoS full record  
  Impact Factor 3.7 Times cited 1 Open Access OpenAccess  
  Notes This work received funding by the Swiss National Foundation (SNF) (Grants No. 200021160186 and No. 2002153540), the Swiss Nanoscience Institute (SNI) (Grant No. SNI P1502), the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 737093 (FEMTOTERABYTE), and the COST Action CA17123 (MAGNETOFON). Part of this work was performed at the SIM beamline of the Swiss Light Source (SLS), Paul Scherrer Institut, Villigen, Switzerland. Part of the simulations were undertaken on the VIKING cluster, which is a high-performance compute facility provided by the University of York. We kindly acknowledge Anja Weber from PSI for preparation of substrates with marker structures. A.B. and Jo Verbeeck acknowledge funding through FWO Project No. G093417N (“Compressed sensing enabling low dose imaging in transmission electron microscopy”) from the Flanders Research Fund. Jo Verbeeck acknowledges funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 823717 – ESTEEM3. S.S. acknowledges ETH Zurich Post-Doctoral fellowship and Marie Curie actions for people COFUND program.; esteem3JRA; esteem3reported Approved Most recent IF: 3.7; 2020 IF: 3.836  
  Call Number EMAT @ emat @c:irua:174273 Serial 6669  
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Author Prabhakara, V.; Jannis, D.; Guzzinati, G.; Béché, A.; Bender, H.; Verbeeck, J. url  doi
openurl 
  Title HAADF-STEM block-scanning strategy for local measurement of strain at the nanoscale Type A1 Journal article
  Year 2020 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 219 Issue Pages 113099  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) Lattice strain measurement of nanoscale semiconductor devices is crucial for the semiconductor industry as strain substantially improves the electrical performance of transistors. High resolution scanning transmission electron microscopy (HR-STEM) imaging is an excellent tool that provides spatial resolution at the atomic scale and strain information by applying Geometric Phase Analysis or image fitting procedures. However, HR-STEM images regularly suffer from scanning distortions and sample drift during image acquisition. In this paper, we propose a new scanning strategy that drastically reduces artefacts due to drift and scanning distortion, along with extending the field of view. It consists of the acquisition of a series of independent small subimages containing an atomic resolution image of the local lattice. All subimages are then analysed individually for strain by fitting a nonlinear model to the lattice images. The method allows flexible tuning of spatial resolution and the field of view within the limits of the dynamic range of the scan engine while maintaining atomic resolution sampling within the subimages. The obtained experimental strain maps are quantitatively benchmarked against the Bessel diffraction technique. We demonstrate that the proposed scanning strategy approaches the performance of the diffraction technique while having the advantage that it does not require specialized diffraction cameras.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000594768500006 Publication Date 2020-09-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.2 Times cited 4 Open Access OpenAccess  
  Notes A.B. D.J. and J.V. acknowledge funding through FWO project G093417N ('Compressed sensing enabling low dose imaging in transmission electron microscopy') from the Flanders Research Fund. J.V acknowledges funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3. The Qu-Ant-EM microscope and the direct electron detector used in the diffraction experiments was partly funded by the Hercules fund from the Flemish Government. This project has received funding from the GOA project “Solarpaint” of the University of Antwerp. GG acknowledges support from a postdoctoral fellowship grant from the Fonds Wetenschappelijk Onderzoek – Vlaanderen (FWO). Special thanks to Dr. Thomas Nuytten, Prof. Dr. Wilfried Vandervorst, Dr. Paola Favia, Dr. Olivier Richard from IMEC, Leuven and Prof. Dr. Sara Bals from EMAT, Antwerp for their continuous support and collaboration with the project and to the IMEC processing group for the device fabrication. Approved Most recent IF: 2.2; 2020 IF: 2.843  
  Call Number EMAT @ emat @c:irua:172485 Serial 6404  
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Author Guzzinati, G.; Béché, A.; McGrouther, D.; Verbeeck, J. pdf  url
doi  openurl
  Title Prospects for out-of-plane magnetic field measurements through interference of electron vortex modes in the TEM Type A1 Journal article
  Year 2019 Publication Journal of optics Abbreviated Journal J Optics-Uk  
  Volume 21 Issue 12 Pages 124002  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) Magnetic field mapping in transmission electron microscopy is commonplace, but all conventional methods provide only a projection of the components of the magnetic induction perpendicular to the electron trajectory. Recent experimental advances with electron vortices have shown that it is possible to map the out of plane magnetic induction in a TEM setup via interferometry with a specifically prepared electron vortex state carrying high orbital angular momentum (OAM). The method relies on the Aharonov?Bohm phase shift that the electron undergoes when going through a longitudinal field. Here we show how the same effect naturally occurs for any electron wave function, which can always be described as a superposition of OAM modes. This leads to a clear connection between the occurrence of high-OAM partial waves and the amount of azimuthal rotation in the far field angular distribution of the beam. We show that out of plane magnetic field measurement can thus be obtained with a much simpler setup consisting of a ring-like aperture with azimuthal spokes. We demonstrate the experimental setup and explore the achievable sensitivity of the magnetic field measurement.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000499367800001 Publication Date 2019-10-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2040-8978 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.741 Times cited 3 Open Access  
  Notes The authors thank V Grillo and T Harvey for interesting and fruitful discussion. GG acknowledges support from a postdoctoral fellow-ship grant from the Fonds Wetenschappelijk Onderzoek – Vlaanderen (FWO). The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3. AB acknowledges funding from FWO project G093417N ('Compressed sensing enabling low dose imaging in transmission electron microscopy'). DM gratefully acknowledges funding of the FEBID capability through joint funding by University of Glasgow & EPSRC through a Strategic Equipment Grant (EP/P001483/1). Approved Most recent IF: 1.741  
  Call Number UA @ admin @ c:irua:165116 Serial 6319  
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Author Kleibert, A.; Balan, A.; Yanes, R.; Derlet, P.M.; Vaz, C.A.F.; Timm, M.; Fraile Rodríguez, A.; Béché, A.; Verbeeck, J.; Dhaka, R.S.; Radovic, M.; Nowak, U.; Nolting, F. pdf  url
doi  openurl
  Title Direct observation of enhanced magnetism in individual size- and shape-selected 3d transition metal nanoparticles Type A1 Journal article
  Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 95 Issue 95 Pages 195404  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) Magnetic nanoparticles are critical building blocks for future technologies ranging from nanomedicine to spintronics. Many related applications require nanoparticles with tailored magnetic properties. However, despite significant efforts undertaken towards this goal, a broad and poorly understood dispersion of magnetic properties is reported, even within monodisperse samples of the canonical ferromagnetic 3d transition metals. We address this issue by investigating the magnetism of a large number of size- and shape-selected, individual nanoparticles of Fe, Co, and Ni using a unique set of complementary characterization techniques. At room temperature, only superparamagnetic behavior is observed in our experiments for all Ni nanoparticles within the investigated sizes, which range from 8 to 20 nm. However, Fe and Co nanoparticles can exist in two distinct magnetic states at any size in this range: (i) a superparamagnetic state, as expected from the bulk and surface anisotropies known for the respective materials and as observed for Ni, and (ii) a state with unexpected stable magnetization at room temperature. This striking state is assigned to significant modifications of the magnetic properties arising from metastable lattice defects in the core of the nanoparticles, as concluded by calculations and atomic structural characterization. Also related with the structural defects, we find that the magnetic state of Fe and Co nanoparticles can be tuned by thermal treatment enabling one to tailor their magnetic properties for applications. This paper demonstrates the importance of complementary single particle investigations for a better understanding of nanoparticle magnetism and for full exploration of their potential for applications.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000400665300002 Publication Date 2017-05-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 21 Open Access OpenAccess  
  Notes We thank A. Weber, R. Schelldorfer, and J. Krbanjevic (Paul Scherrer Institut) for technical assistance. This paper was supported by the Swiss Nanoscience Institute, University of Basel. A.F.R. acknowledges support from the MICIIN “Ramón y Cajal” Programme. A.B. and J.V. acknowledge funding from the European Union under the European Research Council (ERC) Starting Grant No. 278510 VORTEX and under a contract for Integrated Infrastructure Initiative ESTEEM2 No. 312483. R.Y. and U.N. thank the Deutsche Forschungsgemeinschaft for financial support via Sonderforschungsbereich 1214. Part of this work was performed at the Surface/Interface: Microscopy (SIM) beamline of the Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland. Approved Most recent IF: 3.836  
  Call Number EMAT @ emat @ c:irua:143634UA @ admin @ c:irua:143634 Serial 4575  
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Author Bhat, S.G.; Gauquelin, N.; Sebastian, N.K.; Sil, A.; Béché, A.; Verbeeck, J.; Samal, D.; Kumar, P.S.A. pdf  doi
openurl 
  Title Orthorhombic vs. hexagonal epitaxial SrIrO3 thin films : structural stability and related electrical transport properties Type A1 Journal article
  Year 2018 Publication Europhysics letters Abbreviated Journal Epl-Europhys Lett  
  Volume 122 Issue 2 Pages 28003  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) Metastable orthorhombic SrIrO3 (SIO) is an arch-type spin-orbit coupled material. We demonstrate here a controlled growth of relatively thick (200 nm) SIO films that transform from bulk “6H-type” structure with monoclinic distortion to an orthorhombic lattice by controlling growth temperature. Extensive studies based on high-resolution X-ray diffraction and transmission electron microscopy infer a two distinct structural phases of SIO. Electrical transport reveals a weak temperature-dependent semi-metallic character for both phases. However, the temperature-dependent Hall-coefficient for the orthorhombic SIO exhibits a prominent sign change, suggesting a multiband character in the vicinity of E-F. Our findings thus unravel the subtle structure-property relation in SIO epitaxial thin films. Copyright (C) EPLA, 2018  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Paris Editor  
  Language Wos 000435517300001 Publication Date 2018-06-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0295-5075 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.957 Times cited 4 Open Access Not_Open_Access  
  Notes ; SGB and DS acknowledge useful discussions with E. P. Houwman, University of Twente, on X-ray diffraction. DS would like to thank H. Takagi, Max-Planck Institute for Solid State Research, Stuttgart, for the fruitful discussion on the transport properties of SIO thin films. SGB and NKS thank A. Aravind, Bishop Moore College, Mavelikara, for his valuable inputs while depositing the thin films of SIO. SGB, NKS and PSAK acknowledge Nano Mission Council, Department of Science & Technology, India, for the funding. DS acknowledges the financial support from Max-Planck Society through MaxPlanck Partner Group. NG, AB and JV acknowledge funding from GOA project “Solarpaint” of the University of Antwerp and FWO project G093417N. ; Approved Most recent IF: 1.957  
  Call Number UA @ lucian @ c:irua:152074UA @ admin @ c:irua:152074 Serial 5034  
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Author Prabhakara, V.; Jannis, D.; Béché, A.; Bender, H.; Verbeeck, J. url  doi
openurl 
  Title Strain measurement in semiconductor FinFET devices using a novel moiré demodulation technique Type A1 Journal article
  Year 2019 Publication Semiconductor science and technology Abbreviated Journal Semicond Sci Tech  
  Volume Issue Pages  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract (up) Moiré fringes are used throughout a wide variety of applications in physics and

engineering to bring out small variations in an underlying lattice by comparing with another reference lattice. This method was recently demonstrated in Scanning Transmission Electron Microscopy imaging to provide local strain measurement in crystals by comparing the crystal lattice with the scanning raster that then serves as the reference. The images obtained in this way contain a beating fringe pattern with a local period that represents the deviation of the lattice from the reference. In order to obtain the actual strain value, a region containing a full period of the fringe is required, which results in a compromise between strain sensitivity and spatial resolution. In this paper we propose an advanced setup making use of an optimised scanning pattern and a novel phase stepping demodulation scheme. We demonstrate the novel method on a series of 16 nm Si-Ge semiconductor FinFET devices in which strain plays a crucial role in modulating the charge carrier mobility. The obtained results are compared with both Nano-beam diffraction and the recently proposed Bessel beam diffraction technique. The setup provides a much improved spatial resolution over conventional moiré imaging in STEM while at the same time being fast and requiring no specialised diffraction camera as opposed to the diffraction techniques we compare to.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000537721200002 Publication Date 2019-11-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0268-1242 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.305 Times cited 8 Open Access  
  Notes The Qu-Ant-EM microscope and the direct electron detector used in the diffraction experiments was partly funded by the Hercules fund from the Flemish Government. This project has received funding from the GOA project “Solarpaint” of the University of Antwerp. We would also like to thank Dr. Thomas Nuytten and Prof. Dr. Wilfried Vandervorst from IMEC, Leuven for their continuous support and collaboration with the project. Approved Most recent IF: 2.305  
  Call Number EMAT @ emat @c:irua:165794 Serial 5445  
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Author Rouvière, J.-L.; Béché, A.; Martin, Y.; Denneulin, T.; Cooper, D. doi  openurl
  Title Improved strain precision with high spatial resolution using nanobeam precession electron diffraction Type A1 Journal article
  Year 2013 Publication Applied physics letters Abbreviated Journal Appl Phys Lett  
  Volume 103 Issue Pages 241913  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) NanoBeam Electron Diffraction is a simple and efficient technique to measure strain in nanostructures. Here, we show that improved results can be obtained by precessing the electron beam while maintaining a few nanometer probe size, i.e., by doing Nanobeam Precession Electron Diffraction (N-PED). The precession of the beam makes the diffraction spots more uniform and numerous, making N-PED more robust and precise. In N-PED, smaller probe size and better precision are achieved by having diffraction disks instead of diffraction dots. Precision in the strain measurement better than 2 × 10−4 is obtained with a probe size approaching 1 nm in diameter.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000328706500031 Publication Date 2013-12-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6951; 1077-3118 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.411 Times cited 53 Open Access  
  Notes Approved Most recent IF: 3.411; 2013 IF: 3.515  
  Call Number UA @ lucian @ c:irua:136442 Serial 4502  
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Author Gauquelin, N.; van den Bos, K.H.W.; Béché, A.; Krause, F.F.; Lobato, I.; Lazar, S.; Rosenauer, A.; Van Aert, S.; Verbeeck, J. pdf  url
doi  openurl
  Title Determining oxygen relaxations at an interface: A comparative study between transmission electron microscopy techniques Type A1 Journal article
  Year 2017 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 181 Issue 181 Pages 178-190  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) Nowadays, aberration corrected transmission electron microscopy (TEM) is a popular method to characterise nanomaterials at the atomic scale. Here, atomically resolved images of nanomaterials are acquired, where the contrast depends on the illumination, imaging and detector conditions of the microscope. Visualization of light elements is possible when using low angle annular dark field (LAADF) STEM, annular bright field (ABF) STEM, integrated differential phase contrast (iDPC) STEM, negative spherical aberration imaging (NCSI) and imaging STEM (ISTEM). In this work, images of a NdGaO3-La0.67Sr0.33MnO3 (NGO-LSMO) interface are quantitatively evaluated by using statistical parameter estimation theory. For imaging light elements, all techniques are providing reliable results, while the techniques based on interference contrast, NCSI and ISTEM, are less robust in terms of accuracy for extracting heavy column locations. In term of precision, sample drift and scan distortions mainly limits the STEM based techniques as compared to NCSI. Post processing techniques can, however, partially compensate for this. In order to provide an outlook to the future, simulated images of NGO, in which the unavoidable presence of Poisson noise is taken into account, are used to determine the ultimate precision. In this future counting noise limited scenario, NCSI and ISTEM imaging will provide more precise values as compared to the other techniques, which can be related to the mechanisms behind the image recording.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000411170800022 Publication Date 2017-06-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 34 Open Access OpenAccess  
  Notes The authors acknowledge financial support from Flanders (FWO, Belgium) through project fundings (G.0044.13N, G.0374.13N, G.0368.15N, G.0369.15N), and by a Ph.D. grant to K.H.W.v.d.B. The Qu-Ant-EM microscope used for this study was partly funded by the Hercules fund from the Flemish Government. A.B. and N.G. acknowledge the EUROTAPES project (FP7-NMP.2011.2.2-1 Grant no.280432) which partly funded this study. N.G., A.B. and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. The research leading to these results has received funding from the Deutsche Forschungsgemeinschaft under Contract No. RO 2057/4-2 and the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2. We thank Prof. G. Koster from the University of Twente for kindly providing us with the LSMO-NGO test sample. Approved Most recent IF: 2.843  
  Call Number EMAT @ emat @ c:irua:144435UA @ admin @ c:irua:144435 Serial 4620  
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Author Vanrompay, H.; Béché, A.; Verbeeck, J.; Bals, S. pdf  doi
openurl 
  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 (up) 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.  
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  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language 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  
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Author Guzzinati, G.; Béché, A.; Lourenço-Martins, H.; Martin, J.; Kociak, M.; Verbeeck, J. pdf  url
doi  openurl
  Title Probing the symmetry of the potential of localized surface plasmon resonances with phase-shaped electron beams Type A1 Journal article
  Year 2017 Publication Nature communications Abbreviated Journal Nat Commun  
  Volume 8 Issue 8 Pages 14999  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract (up) Plasmonics, the science and technology of the interaction of light with metallic objects, is fundamentally changing the way we can detect, generate and manipulate light. Although the field is progressing swiftly, thanks to the availability of nanoscale manufacturing and analysis methods, fundamental properties such as the plasmonic excitations’ symmetries cannot be accessed directly, leading to a partial, sometimes incorrect, understanding of their properties. Here we overcome this limitation by deliberately shaping the wave function of an electron beam to match a plasmonic excitations’ symmetry in a modified transmission electron microscope. We show experimentally and theoretically that this offers selective detection of specific plasmon modes within metallic nanoparticles, while excluding modes with other symmetries. This method resembles the widespread use of polarized light for the selective excitation of plasmon modes with the advantage of locally probing the response of individual plasmonic objects and a far wider range of symmetry selection criteria.  
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  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000399084300001 Publication Date 2017-04-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 12.124 Times cited 84 Open Access OpenAccess  
  Notes ; We thank F.J. Garcia de Abajo and D.M. Ugarte for interesting and fruitful discussion. This work was supported by funding from the European Research Council under the 7th Framework Program (FP7) ERC Starting Grant 278510 VORTEX. Financial support from the European Union under the Framework 7 program under a contract for an Integrated Infrastructure Initiative (Reference number 312483 ESTEEM2) is also gratefully acknowledged. Aluminum nanostructures were fabricated using the Nanomat nanofabrication facility. ; Approved Most recent IF: 12.124  
  Call Number EMAT @ emat @ c:irua:142205UA @ admin @ c:irua:142205 Serial 4548  
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Author Lepot, K.; Addad, A.; Knoll, A.H.; Wang, J.; Troadec, D.; Béché, A.; Javaux, E.J. pdf  url
doi  openurl
  Title Iron minerals within specific microfossil morphospecies of the 1.88 Ga Gunflint Formation Type A1 Journal article
  Year 2017 Publication Nature communications Abbreviated Journal Nat Commun  
  Volume 8 Issue 8 Pages 14890  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract (up) Problematic microfossils dominate the palaeontological record between the Great Oxidation Event 2.4 billion years ago (Ga) and the last Palaeoproterozoic iron formations, deposited 500–600 million years later. These fossils are often associated with iron-rich sedimentary rocks, but their affinities, metabolism, and, hence, their contributions to Earth surface oxidation and Fe deposition remain unknown. Here we show that specific microfossil populations of the 1.88 Ga Gunflint Iron Formation contain Fe-silicate and Fe-carbonate nanocrystal concentrations in cell interiors. Fe minerals are absent in/on all organically preserved cell walls. These features are consistent with in vivo intracellular Fe biomineralization, with subsequent in situ recrystallization, but contrast with known patterns of post-mortem Fe mineralization. The Gunflint populations that display relatively large cells (thick-walled spheres, filament-forming rods) and intra-microfossil Fe minerals are consistent with oxygenic photosynthesizers but not with other Fe-mineralizing microorganisms studied so far. Fe biomineralization may have protected oxygenic photosynthesizers against Fe2+ toxicity during the Palaeoproterozoic.  
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  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000397129900001 Publication Date 2017-03-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 12.124 Times cited 20 Open Access OpenAccess  
  Notes We thank J.-P. Cullus (thin sections), G. Spronck and C. Henrist (TEM), M. Cabié and C. Dominici (FIB), S. Bernard and C. Karunakaran (STXM), F. Bourdelle and G. Ji (EELS), P. Recourt (SEM). This study was co-funded by FRFC Grant no. 2.4558.09F (E.J.J.), CNRS-INSU (K.L.), FNRS (K.L.), ERC StG ELiTE Grant no. 308074 (E.J.J.), BELSPO IAP PLANET TOPERS (E.J.J.), NASA Astrobiology Institute (A.H.K.), Conseil Régional du Nord-Pas de Calais+European Regional Development Fund+CNRS-INSU (TEM in Lille), FP7-ESMI no. 262348 (TEM at EMAT Antwerp) and ANR-15-CE31-0003-01 (M6fossils, K.L.). We thank Noah Planavsky and two anonymous reviewers for thorough reviews that helped improve the paper. Approved Most recent IF: 12.124  
  Call Number EMAT @ emat @ c:irua:141919 Serial 4536  
Permanent link to this record
 

 
Author Altantzis, T.; Lobato, I.; De Backer, A.; Béché, A.; Zhang, Y.; Basak, S.; Porcu, M.; Xu, Q.; Sánchez-Iglesias, A.; Liz-Marzán, L.M.; Van Tendeloo, G.; Van Aert, S.; Bals, S. url  doi
openurl 
  Title Three-Dimensional Quantification of the Facet Evolution of Pt Nanoparticles in a Variable Gaseous Environment Type A1 Journal article
  Year 2019 Publication Nano letters Abbreviated Journal Nano Lett  
  Volume 19 Issue 19 Pages 477-481  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract (up) Pt nanoparticles play an essential role in a wide variety of catalytic reactions. The activity of the particles strongly depends on their three-dimensional (3D) structure and exposed facets, as well as on the reactive environment. High-resolution electron microscopy has often been used to characterize nanoparticle catalysts but unfortunately most observations so far have been either performed in vacuum and/or using conventional (2D) in situ microscopy. The latter however does not provide direct 3D morphological information. We have implemented a quantitative methodology to measure variations of the 3D atomic structure of nanoparticles under the flow of a selected gas. We were thereby able to quantify refaceting of Pt nanoparticles with atomic resolution during various oxidation−reduction cycles. In a H2 environment, a more faceted surface morphology of the particles was observed with {100} and {111} planes being dominant. On the other hand, in O2 the percentage of {100} and {111} facets decreased and a significant increase of higher order facets was found, resulting in a more rounded morphology. This methodology opens up new opportunities toward in situ characterization of catalytic nanoparticles because for the first time it enables one to directly measure 3D morphology variations at the atomic scale in a specific gaseous reaction environment.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000455561300061 Publication Date 2019-01-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1530-6984 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 12.712 Times cited 82 Open Access OpenAccess  
  Notes This work was supported by the European Research Council (Grant 335078 COLOURATOM to S.B. and Grant 770887 PICOMETRICS to S.V.A.). The authors acknowledge funding from the European Commission Grant (EUSMI 731019 to S.B., L.M.L.-M., and Q.X. and MUMMERING 765604 to S.B. and Q.X.). The authors gratefully acknowledge funding from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0368.15N, G.0369.15N, and G.0267.18N), postdoctoral grants to T.A. and A.D.B, and an FWO [PEGASUS]2 Marie Sklodowska-Curie fellowship to Y.Z. (12U4917N). L.M.L.-M. acknowledges funding from the Spanish Ministerio de Economía y Competitividad (Grant MAT2017-86659-R). We gratefully acknowledge the support of NVIDIA Corporation with the donation of the Titan X Pascal GPU used for this research. ecas_sara Realnano 815128; sygma Approved Most recent IF: 12.712  
  Call Number EMAT @ emat @UA @ admin @ c:irua:156390 Serial 5150  
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Author Gao, C.; Hofer, C.; Jannis, D.; Béché, A.; Verbeeck, J.; Pennycook, T.J. pdf  url
doi  openurl
  Title Overcoming contrast reversals in focused probe ptychography of thick materials: An optimal pipeline for efficiently determining local atomic structure in materials science Type A1 Journal article
  Year 2022 Publication Applied physics letters Abbreviated Journal Appl Phys Lett  
  Volume 121 Issue 8 Pages 081906  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) Ptychography provides highly efficient imaging in scanning transmission electron microscopy (STEM), but questions have remained over its applicability to strongly scattering samples such as those most commonly seen in materials science. Although contrast reversals can appear in ptychographic phase images as the projected potentials of the sample increase, we show here how these can be easily overcome by a small amount of defocus. The amount of defocus is small enough that it not only can exist naturally when focusing using the annular dark field (ADF) signal but can also be adjusted post acquisition. The ptychographic images of strongly scattering materials are clearer at finite doses than other STEM techniques and can better reveal light atomic columns within heavy lattices. In addition, data for ptychography can now be collected simultaneously with the fastest of ADF scans. This combination of sensitivity and interpretability presents an ideal workflow for materials science.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000844403300006 Publication Date 2022-08-22  
  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 4 Times cited 9 Open Access OpenAccess  
  Notes European Research Council, 802123-HDEM ; HORIZON EUROPE European Research Council, 823717-ESTEEM3 ; Fonds Wetenschappelijk Onderzoek, G042920N ; Fonds Wetenschappelijk Onderzoek, G042820N ; Horizon 2020 Framework Programme, 101017720 ; Fonds Wetenschappelijk Onderzoek, G013122N ; esteem3reported; esteem3jra Approved Most recent IF: 4  
  Call Number EMAT @ emat @c:irua:190670 Serial 7120  
Permanent link to this record
 

 
Author de Backer, A.; Martinez, G.T.; MacArthur, K.E.; Jones, L.; Béché, A.; Nellist, P.D.; Van Aert, S. pdf  url
doi  openurl
  Title Dose limited reliability of quantitative annular dark field scanning transmission electron microscopy for nano-particle atom-counting Type A1 Journal article
  Year 2015 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 151 Issue 151 Pages 56-61  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) Quantitative annular dark field scanning transmission electron microscopy (ADF STEM) has become a powerful technique to characterise nano-particles on an atomic scale. Because of their limited size and beam sensitivity, the atomic structure of such particles may become extremely challenging to determine. Therefore keeping the incoming electron dose to a minimum is important. However, this may reduce the reliability of quantitative ADF STEM which will here be demonstrated for nano-particle atom-counting. Based on experimental ADF STEM images of a real industrial catalyst, we discuss the limits for counting the number of atoms in a projected atomic column with single atom sensitivity. We diagnose these limits by combining a thorough statistical method and detailed image simulations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000351237800008 Publication Date 2014-12-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 29 Open Access  
  Notes 312483 Esteem2; 278510 Vortex; Fwo G039311; G006410; G037413; esteem2ta; ECASJO; Approved Most recent IF: 2.843; 2015 IF: 2.436  
  Call Number c:irua:123927 c:irua:123927 Serial 753  
Permanent link to this record
 

 
Author De Backer, A.; De Wael, A.; Gonnissen, J.; Martinez, G.T.; Béché, A.; MacArthur, K.E.; Jones, L.; Nellist, P.D.; Van Aert, S. pdf  url
doi  openurl
  Title Quantitative annular dark field scanning transmission electron microscopy for nanoparticle atom-counting: What are the limits? Type P1 Proceeding
  Year 2015 Publication Journal of physics : conference series Abbreviated Journal  
  Volume 644 Issue 644 Pages 012034  
  Keywords P1 Proceeding; Electron microscopy for materials research (EMAT)  
  Abstract (up) Quantitative atomic resolution annular dark field scanning transmission electron microscopy (ADF STEM) has become a powerful technique for nanoparticle atom-counting. However, a lot of nanoparticles provide a severe characterisation challenge because of their limited size and beam sensitivity. Therefore, quantitative ADF STEM may greatly benefit from statistical detection theory in order to optimise the instrumental microscope settings such that the incoming electron dose can be kept as low as possible whilst still retaining single-atom precision. The principles of detection theory are used to quantify the probability of error for atom-counting. This enables us to decide between different image performance measures and to optimise the experimental detector settings for atom-counting in ADF STEM in an objective manner. To demonstrate this, ADF STEM imaging of an industrial catalyst has been conducted using the near-optimal detector settings. For this experiment, we discussed the limits for atom-counting diagnosed by combining a thorough statistical method and detailed image simulations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000366826200034 Publication Date 2015-10-13  
  Series Editor Series Title Abbreviated Series Title Electron Microscopy and Analysis Group Conference (EMAG), JUN 02-JUL 02, 2015, Manchester, ENGLAND  
  Series Volume Series Issue Edition  
  ISSN 1742-6588 ISBN Additional Links UA library record; WoS full record  
  Impact Factor Times cited Open Access  
  Notes The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project funding (G.0368.15N, G.0369.15N, and G.0374.15N) and a PhD research grant to A De Backer. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative-I3), ERC Starting Grant 278510 Vortex, and the UK Engineering and Physical Sciences Research Council (EP/K032518/1). The authors acknowledge Johnson-Matthey for providing the sample and PhD funding to K E MacArthur. A Rosenauer is acknowledged for providing the STEMsim program.; esteem2jra2; ECASJO; Approved Most recent IF: NA  
  Call Number c:irua:130314 c:irua:130314 Serial 4050  
Permanent link to this record
 

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

 
Author Jannis, D.; Müller-Caspary, K.; Béché, A.; Verbeeck, J. pdf  url
doi  openurl
  Title Coincidence Detection of EELS and EDX Spectral Events in the Electron Microscope Type A1 Journal article
  Year 2021 Publication Applied Sciences-Basel Abbreviated Journal Appl Sci-Basel  
  Volume 11 Issue 19 Pages 9058  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) Recent advances in the development of electron and X-ray detectors have opened up the possibility to detect single events from which its time of arrival can be determined with nanosecond resolution. This allows observing time correlations between electrons and X-rays in the transmission electron microscope. In this work, a novel setup is described which measures individual events using a silicon drift detector and digital pulse processor for the X-rays and a Timepix3 detector for the electrons. This setup enables recording time correlation between both event streams while at the same time preserving the complete conventional electron energy loss (EELS) and energy dispersive X-ray (EDX) signal. We show that the added coincidence information improves the sensitivity for detecting trace elements in a matrix as compared to conventional EELS and EDX. Furthermore, the method allows the determination of the collection efficiencies without the use of a reference sample and can subtract the background signal for EELS and EDX without any prior knowledge of the background shape and without pre-edge fitting region. We discuss limitations in time resolution arising due to specificities of the silicon drift detector and discuss ways to further improve this aspect.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000710160300001 Publication Date 2021-09-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2076-3417 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.679 Times cited 9 Open Access OpenAccess  
  Notes Fonds Wetenschappelijk Onderzoek, G042920 ; Horizon 2020 Framework Programme, 101017720 ; Helmholtz-Fonds, VH-NG-1317 ; Approved Most recent IF: 1.679  
  Call Number EMAT @ emat @c:irua:183336 Serial 6821  
Permanent link to this record
 

 
Author van den Bos, K.H.W.; Krause, F.F.; Béché, A.; Verbeeck, J.; Rosenauer, A.; Van Aert, S. url  doi
openurl 
  Title Locating light and heavy atomic column positions with picometer precision using ISTEM Type A1 Journal article
  Year 2016 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 172 Issue 172 Pages 75-81  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) Recently, imaging scanning transmission electron microscopy (ISTEM) has been proposed as a promising new technique combining the advantages of conventional TEM (CTEM) and STEM [1]. The ability to visualize light and heavy elements together makes it a particularly interesting new, spatially incoherent imaging mode. Here, we evaluate this technique in term of precision with which atomic column locations can be measured. By using statistical parameter estimation theory, we will show that these locations can be accurately measured with a precision in the picometer range. Furthermore, a quantitative comparison is made with HAADF STEM imaging to investigate the advantages of ISTEM.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000390600200009 Publication Date 2016-10-09  
  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 8 Open Access  
  Notes The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0368.15N, G.0369.15N), and by a Ph.D. grant to K.H.W. van den Bos. The research leading to these results has received funding from the Deutsche Forschungsgemeinschaft under Contract No. RO 2057/4-2 and the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2. We thank Prof. G. Koster from the University of Twente for kindly providing us with the PbTiO3 test sample. Approved Most recent IF: 2.843  
  Call Number EMAT @ emat @ c:irua:136109UA @ admin @ c:irua:136109 Serial 4288  
Permanent link to this record
 

 
Author Denneulin, T.; Rouvière, J.L.; Béché, A.; Py, M.; Barnes, J.P.; Rochat, N.; Hartmann, J.M.; Cooper, D. pdf  doi
openurl 
  Title The reduction of the substitutional C content in annealed Si/SiGeC superlattices studied by dark-field electron holography Type A1 Journal article
  Year 2011 Publication Semiconductor science and technology Abbreviated Journal Semicond Sci Tech  
  Volume 26 Issue 12 Pages 1-10  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) Si/Si(1 − x − y)GexCy superlattices are used in the construction of new microelectronic architectures such as multichannel transistors. The introduction of carbon in SiGe allows for compensation of the strain and to avoid plastic relaxation. However, the formation of incoherent β-SiC clusters during annealing limits the processability of SiGeC. This precipitation leads to a modification of the strain in the alloy due to the reduction of the substitutional carbon content. Here, we investigated the strain in annealed Si/Si0.744Ge0.244C0.012 superlattices grown by reduced pressure chemical vapour deposition using dark-field electron holography. The variation of the substitutional C content was calculated by correlating the results with finite-element simulations. The obtained values were then compared with Fourier-transformed infrared spectrometry measurements. It was shown that after annealing for 2 min at 1050 °C carbon no longer has any influence on strain in the superlattice, which behaves like pure SiGe. However, a significant proportion of substitutional C atoms remain in a third-nearest neighbour (3nn) configuration. It was deduced that the influence of 3nn C on strain is negligible and that only isolated atoms have a significant contribution. It was also proposed that the 3nn configuration is an intermediary step during the formation of SiC clusters.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000300151300010 Publication Date 2011-11-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0268-1242 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.305 Times cited Open Access  
  Notes Approved Most recent IF: 2.305; 2011 IF: 1.723  
  Call Number UA @ lucian @ c:irua:136427 Serial 4508  
Permanent link to this record
 

 
Author Verbeeck, J.; Béché, A.; van den Broek, W. pdf  doi
openurl 
  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 (up) 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  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000308082600005 Publication Date 2012-06-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 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 Velazco, A.; Nord, M.; Béché, A.; Verbeeck, J. url  doi
openurl 
  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 (up) 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  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000544042800007 Publication Date 2020-05-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.2 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
 

 
Author Cooper, D.; Denneulin, T.; Barnes, J.-P.; Hartmann, J.-M.; Hutin, L.; Le Royer, C.; Béché, A.; Rouvière, J.-L. doi  openurl
  Title Strain mapping with nm-scale resolution for the silicon-on-insulator generation of semiconductor devices by advanced electron microscopy Type A1 Journal article
  Year 2012 Publication Applied Physics Letters Abbreviated Journal Appl Phys Lett  
  Volume 112 Issue Pages 124505  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) Strain engineering in the conduction channel is a cost effective method of boosting the performance in state-of-the-art semiconductor devices. However, given the small dimensions of these devices, it is difficult to quantitatively measure the strain with the required spatial resolution. Three different transmission electron microscopy techniques, high-angle annular dark field scanning transmission electron microscopy, dark field electron holography, and nanobeam electron diffraction have been applied to measure the strain in simple bulk and SOI calibration specimens. These techniques are then applied to different gate length SiGe SOI pFET devices in order to measure the strain in the conduction channel. For these devices, improved spatial resolution is required, and strain maps with spatial resolutions as good as 1 nm have been achieved. Finally, we discuss the relative advantages and disadvantages of using these three different techniques when used for strain measurement.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000312829400128 Publication Date 2012-12-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6951; 1077-3118 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.411 Times cited 14 Open Access  
  Notes Approved Most recent IF: 3.411; 2012 IF: 3.794  
  Call Number UA @ lucian @ c:irua:136433 Serial 4510  
Permanent link to this record
 

 
Author Guzzinati, G.; Ghielens, W.; Mahr, C.; Béché, A.; Rosenauer, A.; Calders, T.; Verbeeck, J. url  doi
openurl 
  Title Electron Bessel beam diffraction for precise and accurate nanoscale strain mapping Type A1 Journal article
  Year 2019 Publication Applied physics letters Abbreviated Journal Appl Phys Lett  
  Volume 114 Issue 24 Pages 243501  
  Keywords A1 Journal article; ADReM Data Lab (ADReM); Electron microscopy for materials research (EMAT)  
  Abstract (up) Strain has a strong effect on the properties of materials and the performance of electronic devices. Their ever shrinking size translates into a constant demand for accurate and precise measurement methods with a very high spatial resolution. In this regard, transmission electron microscopes are key instruments thanks to their ability to map strain with a subnanometer resolution. Here, we present a method to measure strain at the nanometer scale based on the diffraction of electron Bessel beams. We demonstrate that our method offers a strain sensitivity better than 2.5 × 10−4 and an accuracy of 1.5 × 10−3, competing with, or outperforming, the best existing methods with a simple and easy to use experimental setup.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000472599100019 Publication Date 2019-06-17  
  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 17 Open Access OpenAccess  
  Notes Deutsche Forschungsgemeinschaft, RO2057/12-2 ; Fonds Wetenschappelijk Onderzoek, G.0934.17N ; Approved Most recent IF: 3.411  
  Call Number EMAT @ emat @UA @ admin @ c:irua:160119 Serial 5181  
Permanent link to this record
 

 
Author Li, K.; Béché, A.; Song, M.; Sha, G.; Lu, X.; Zhang, K.; Du, Y.; Ringer, S.P.; Schryvers, D. doi  openurl
  Title Atomistic structure of Cu-containing \beta" precipitates in an Al-Mg-Si-Cu alloy Type A1 Journal article
  Year 2014 Publication Scripta materialia Abbreviated Journal Scripta Mater  
  Volume 75 Issue Pages 86-89  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract (up) The beta '' precipitates in a peak-aged Al-Mg-Si-Cu alloy were measured with an average composition of 28.6Al-38.7Mg-26.5Si-5.17Cu (at.%) using atom probe tomography. High-angle annular dark-field observations revealed that Cu incompletely substitutes for the Mg-1 and Si-3 columns, preferentially for one column in each pair of Si-3. Cu-free Si columns form a parallelogram-shaped network that constitutes the basis of subsequent precipitates in the system, with a = 0.37 nm, b = 0.38 nm, gamma = 113 degrees and c = 0.405 nm. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Oxford Editor  
  Language Wos 000331025200022 Publication Date 2013-12-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1359-6462; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.747 Times cited 22 Open Access  
  Notes Approved Most recent IF: 3.747; 2014 IF: 3.224  
  Call Number UA @ lucian @ c:irua:115749 Serial 201  
Permanent link to this record
 

 
Author Béché, A.; Goris, B.; Freitag, B.; Verbeeck, J. pdf  url
doi  openurl
  Title Development of a fast electromagnetic beam blanker for compressed sensing in scanning transmission electron microscopy Type A1 Journal article
  Year 2016 Publication Applied physics letters Abbreviated Journal Appl Phys Lett  
  Volume 108 Issue 108 Pages 093103  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) The concept of compressed sensing was recently proposed to significantly reduce the electron dose in scanning transmission electron microscopy (STEM) while still maintaining the main features in the image. Here, an experimental setup based on an electromagnetic beam blanker placed in the condenser plane of a STEM is proposed. The beam blanker deflects the beam with a random pattern, while the scanning coils are moving the beam in the usual scan pattern. Experimental images at both the medium scale and high resolution are acquired and reconstructed based on a discrete cosine algorithm. The obtained results confirm that compressed sensing is highly attractive to limit beam damage in experimental STEM even though some remaining artifacts need to be resolved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000375329200043 Publication Date 2016-03-01  
  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 40 Open Access  
  Notes A.B and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX and under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2), from the GOA project SOLARPAINT and the POC project I13/009 from the University of Antwerp. B.G. acknowledges the Research Foundation Flanders (FWO Vlaanderen) for a postdoctoral research grant. The QuAnTem microscope was partially funded by the Hercules Foundation. We thank Zhaoliang Liao from the Mesa+ laboratory at the University of Twente for the perovskite test sample.; esteem2jra3 ECASJO; Approved Most recent IF: 3.411  
  Call Number c:irua:131895 c:irua:131895UA @ admin @ c:irua:131895 Serial 4023  
Permanent link to this record
 

 
Author Jalabert, D.; Pelloux-Gervais, D.; Béché, A.; Hartmann, J.M.; Gergaud, P.; Rouvière, J.L.; Canut, B. doi  openurl
  Title Depth strain profile with sub-nm resolution in a thin silicon film using medium energy ion scattering Type A1 Journal article
  Year 2012 Publication Physica Status Solidi A-Applications And Materials Science Abbreviated Journal Phys Status Solidi A  
  Volume 209 Issue 2 Pages 265-267  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) The depth strain profile in silicon from the Si (001) substrate to the surface of a 2 nm thick Si/12 nm thick SiGe/bulk Si heterostructure has been determined by medium energy ion scattering (MEIS). It shows with sub-nanometer resolution and high strain sensitivity that the thin Si cap presents residual compressive strain caused by Ge diffusion coming from the fully strained SiGe layer underneath. The strain state of the SiGe buffer have been checked by X-ray diffraction (XRD) and nano-beam electron diffraction (NBED) measurements.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000303382700005 Publication Date 2011-11-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1862-6300; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.775 Times cited 3 Open Access  
  Notes Approved Most recent IF: 1.775; 2012 IF: 1.469  
  Call Number UA @ lucian @ c:irua:136430 Serial 4497  
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Author Béché, A.; Van Boxem, R.; Van Tendeloo, G.; Verbeeck, J. url  doi
openurl 
  Title Magnetic monopole field exposed by electrons Type A1 Journal article
  Year 2014 Publication Nature physics Abbreviated Journal Nat Phys  
  Volume 10 Issue 1 Pages 26-29  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract (up) The experimental search for magnetic monopole particles(1-3) has, so far, been in vain. Nevertheless, these elusive particles of magnetic charge have fuelled a rich field of theoretical study(4-10). Here, we created an approximation of a magnetic monopole in free space at the end of a long, nanoscopically thin magnetic needle(11). We experimentally demonstrate that the interaction of this approximate magnetic monopole field with a beam of electrons produces an electron vortex state, as theoretically predicted for a true magnetic monopole(3,11-18). This fundamental quantum mechanical scattering experiment is independent of the speed of the electrons and has consequences for all situations where electrons meet such monopole magnetic fields, as, for example, in solids. The set-up not only shows an attractive way to produce electron vortex states but also provides a unique insight into monopole fields and shows that electron vortices might well occur in unexplored solid-state physics situations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000328940100012 Publication Date 2013-11-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1745-2473;1745-2481; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 22.806 Times cited 131 Open Access  
  Notes Vortex; Countatoms; Fwo ECASJO_; Approved Most recent IF: 22.806; 2014 IF: 20.147  
  Call Number UA @ lucian @ c:irua:113740UA @ admin @ c:irua:113740 Serial 1885  
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Author Idrissi, H.; Ghidelli, M.; Béché, A.; Turner, S.; Gravier, S.; Blandin, J.-J.; Raskin, J.-P.; Schryvers, D.; Pardoen, T. url  doi
openurl 
  Title Atomic-scale viscoplasticity mechanisms revealed in high ductility metallic glass films Type A1 Journal article
  Year 2019 Publication Scientific reports Abbreviated Journal Sci Rep-Uk  
  Volume 9 Issue 1 Pages 13426  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract (up) The fundamental plasticity mechanisms in thin freestanding Zr65Ni35 metallic glass films are investigated in order to unravel the origin of an outstanding strength/ductility balance. The deformation process is homogenous until fracture with no evidence of catastrophic shear banding. The creep/relaxation behaviour of the films was characterized by on-chip tensile testing, revealing an activation volume in the range 100–200 Å3. Advanced high-resolution transmission electron microscopy imaging and spectroscopy exhibit a very fine glassy nanostructure with well-defined dense Ni-rich clusters embedded in Zr-rich clusters of lower atomic density and a ~2–3 nm characteristic length scale. Nanobeam electron diffraction analysis reveals that the accumulation of plastic deformation at roomtemperature

correlates with monotonously increasing disruption of the local atomic order. These results provide experimental evidences of the dynamics of shear transformation zones activation in metallic glasses. The impact of the nanoscale structural heterogeneities on the mechanical properties including the rate dependent behaviour is discussed, shedding new light on the governing plasticity mechanisms in metallic glasses with initially heterogeneous atomic arrangement.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000486139700008 Publication Date 2019-09-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.259 Times cited Open Access  
  Notes H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). This work was supported by the FNRS under Grant PDR – T.0178.19. FWO project G093417N (‘Compressed sensing enabling low dose imaging in transmission electron microscopy’) and Hercules fund ‘Direct electron detector for soft matter TEM’ from Flemish Government are acknowledged. Approved Most recent IF: 4.259  
  Call Number EMAT @ emat @c:irua:162786 Serial 5375  
Permanent link to this record
 

 
Author Velazco, A.; Béché, A.; Jannis, D.; Verbeeck, J. url  doi
openurl 
  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 (up) 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  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000714819200002 Publication Date 2021-10-02  
  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 2.2 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  
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