|   | 
Details
   web
Records
Author Jannis, D.; Müller-Caspary, K.; Béché, A.; Verbeeck, J.
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 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 Yu, CP.; Vega Ibañez, F.; Béché, A.; Verbeeck, J.
Title Quantum wavefront shaping with a 48-element programmable phase plate for electrons Type A1 Journal Article
Year 2023 Publication SciPost Physics Abbreviated Journal SciPost Phys.
Volume 15 Issue Pages 223
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT)
Abstract We present a 48-element programmable phase plate for coherent electron waves produced by a combination of photolithography and focused ion beam. This brings the highly successful concept of wavefront shaping from light optics into the realm of electron optics and provides an important new degree of freedom to prepare electron quantum states. The phase plate chip is mounted on an aperture rod placed in the C2 plane of a transmission electron microscope operating in the 100-300 kV range. The phase plate's behavior is characterized by a Gerchberg-Saxton algorithm, showing a phase sensitivity of 0.075 rad/mV at 300 kV, with a phase resolution of approximately 3x10e−3π. In addition, we provide a brief overview of possible use cases and support it with both simulated and experimental results.
Address
Corporate Author Thesis
Publisher SciPost Place of Publication Editor
Language English Wos 001116838500002 Publication Date 2023-12-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2542-4653 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.5 Times cited 1 Open Access
Notes This project is the result of a long-term effort involving many differ- ent sources of funding: JV acknowledges funding from an ERC proof of concept project DLV- 789598 ADAPTEM, as well as a University IOF proof of concept project towards launching the AdaptEM spin-off and the eBEAM project, supported by the European Union’s Horizon 2020 research and innovation program FETPROACT-EIC-07-2020: emerging paradigms and com- munities. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 823717 – ESTEEM3 and via The IMPRESS project from the HORIZON EUROPE framework program for research and innovation under grant agreement n. 101094299. FV, JV, and AB acknowledge funding from G042820N ‘Explor- ing adaptive optics in transmission electron microscopy.’ CPY acknowledges funding from a TOP-BOF project from the University of Antwerp. Approved Most recent IF: 5.5; 2023 IF: NA
Call Number EMAT @ emat @c:irua:202037 Serial 8984
Permanent link to this record
 

 
Author Van Aert, S.; De Backer, A.; Jones, L.; Martinez, G.T.; Béché, A.; Nellist, P.D.
Title Control of Knock-On Damage for 3D Atomic Scale Quantification of Nanostructures: Making Every Electron Count in Scanning Transmission Electron Microscopy Type A1 Journal article
Year 2019 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 122 Issue 6 Pages 066101
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Understanding nanostructures down to the atomic level is the key to optimizing the design of advancedmaterials with revolutionary novel properties. This requires characterization methods capable of quantifying the three-dimensional (3D) atomic structure with the highest possible precision. A successful approach to reach this goal is to count the number of atoms in each atomic column from 2D annular dark field scanning transmission electron microscopy images. To count atoms with single atom sensitivity, a minimum electron dose has been shown to be necessary, while on the other hand beam damage, induced by the high energy electrons, puts a limit on the tolerable dose. An important challenge is therefore to develop experimental strategies to optimize the electron dose by balancing atom-counting fidelity vs the risk of knock-on damage. To achieve this goal, a statistical framework combined with physics-based modeling of the dose-dependent processes is here proposed and experimentally verified. This model enables an investigator to theoretically predict, in advance of an experimental measurement, the optimal electron dose resulting in an unambiguous quantification of nanostructures in their native state with the highest attainable precision.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000458824200008 Publication Date 2019-02-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.462 Times cited 3 Open Access OpenAccess
Notes This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 770887). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (WO.010.16N, G.0934.17N, G.0502.18N, G.0267.18N), and a grant to A. D. B. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement No. 312483— ESTEEM2 (Integrated Infrastructure Initiative-I3) and the UK EPSRC (Grant No. EP/M010708/1). Approved Most recent IF: 8.462
Call Number EMAT @ emat @UA @ admin @ c:irua:157175 Serial 5156
Permanent link to this record
 

 
Author Lubk, A.; Béché, A.; Verbeeck, J.
Title Electron Microscopy of Probability Currents at Atomic Resolution Type A1 Journal article
Year 2015 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 115 Issue 115 Pages 176101
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Atomic resolution transmission electron microscopy records the spatially resolved scattered electron density to infer positions, density, and species of atoms. These data are indispensable for studying the relation between structure and properties in solids. Here, we show how this signal can be augmented by the lateral probability current of the scattered electrons in the object plane at similar resolutions and fields of view. The currents are reconstructed from a series of three atomic resolution TEM images recorded under a slight difference of perpendicular line foci. The technique does not rely on the coherence of the electron beam and can be used to reveal electric, magnetic, and strain fields with incoherent electron beams as well as correlations in inelastic transitions, such as electron magnetic chiral dichroism.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000363023700011 Publication Date 2015-10-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007;1079-7114; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.462 Times cited 12 Open Access
Notes J. V. and A. B. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX. The Qu-Ant- EM microscope was partly funded by the Hercules fund from the Flemish Government. All authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483- ESTEEM2. J. V. acknowledges funding from the FWO under Project No. G.0044.13N.; esteem2jra2; esteem2jra3 ECASJO_; Approved Most recent IF: 8.462; 2015 IF: 7.512
Call Number c:irua:129190 c:irua:129190UA @ admin @ c:irua:129190 Serial 3954
Permanent link to this record
 

 
Author Clark, L.; Béché, A.; Guzzinati, G.; Lubk, A.; Mazilu, M.; Van Boxem, R.; Verbeeck, J.
Title Exploiting lens aberrations to create electron-vortex beams Type A1 Journal article
Year 2013 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 111 Issue 6 Pages 064801-64805
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A model for a new electron-vortex beam production method is proposed and experimentally demonstrated. The technique calls on the controlled manipulation of the degrees of freedom of the lens aberrations to achieve a helical phase front. These degrees of freedom are accessible by using the corrector lenses of a transmission electron microscope. The vortex beam is produced through a particular alignment of these lenses into a specifically designed astigmatic state and applying an annular aperture in the condenser plane. Experimental results are found to be in good agreement with simulations.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000322921200009 Publication Date 2013-08-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007;1079-7114; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.462 Times cited 66 Open Access
Notes Vortex; Esteem2; Countatoms; FWO; Esteem2jra3 ECASJO; Approved Most recent IF: 8.462; 2013 IF: 7.728
Call Number UA @ lucian @ c:irua:109340UA @ admin @ c:irua:109340 Serial 1148
Permanent link to this record
 

 
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.
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 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
Permanent link to this record
 

 
Author Juchtmans, R.; Béché, A.; Abakumov, A.; Batuk, M.; Verbeeck, J.
Title Using electron vortex beams to determine chirality of crystals in transmission electron microscopy Type A1 Journal article
Year 2015 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 91 Issue 91 Pages 094112
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We investigate electron vortex beams elastically scattered on chiral crystals. After deriving a general expression for the scattering amplitude of a vortex electron, we study its diffraction on point scatterers arranged on a helix. We derive a relation between the handedness of the helix and the topological charge of the electron vortex on one hand and the symmetry of the higher-order Laue zones in the diffraction pattern on the other for kinematically and dynamically scattered electrons. We then extend this to atoms arranged on a helix as found in crystals which belong to chiral space groups and propose a method to determine the handedness of such crystals by looking at the symmetry of the diffraction pattern. In contrast to alternative methods, our technique does not require multiple scattering, which makes it possible to also investigate extremely thin samples in which multiple scattering is suppressed. In order to verify the model, elastic scattering simulations are performed, and an experimental demonstration on Mn2Sb2O7 is given in which we find the sample to belong to the right-handed variant of its enantiomorphic pair. This demonstrates the usefulness of electron vortex beams to reveal the chirality of crystals in a transmission electron microscope and provides the required theoretical basis for further developments in this field.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000352017000002 Publication Date 2015-03-27
Series Editor Series Title Abbreviated Series Title
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 54 Open Access
Notes Fwo; 312483 Esteem2; 278510 Vortex; esteem2jra1; esteem2jra2 ECASJO_; Approved Most recent IF: 3.836; 2015 IF: 3.736
Call Number c:irua:125512 c:irua:125512 Serial 3825
Permanent link to this record
 

 
Author Tan, H.; Egoavil, R.; Béché, A.; Martinez, G.T.; Van Aert, S.; Verbeeck, J.; Van Tendeloo, G.; Rotella, H.; Boullay, P.; Pautrat, A.; Prellier, W.
Title Mapping electronic reconstruction at the metal-insulator interface in LaVO3/SrVO3 heterostructures Type A1 Journal article
Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 88 Issue 15 Pages 155123-155126
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A (LaVO3)6/(SrVO3)(3) superlattice is studied with a combination of sub-A resolved scanning transmission electron microscopy and monochromated electron energy-loss spectroscopy. The V oxidation state is mapped with atomic spatial resolution enabling us to investigate electronic reconstruction at the LaVO3/SrVO3 interfaces. Surprisingly, asymmetric charge distribution is found at adjacent chemically symmetric interfaces. The local structure is proposed and simulated with a double channeling calculation which agrees qualitatively with our experiment. We demonstrate that local strain asymmetry is the likely cause of the electronic asymmetry of the interfaces. The electronic reconstruction at the interfaces extends much further than the chemical composition, varying from 0.5 to 1.2 nm. This distance corresponds to the length of charge transfer previously found in the (LaVO3)./(SrVO3). metal/insulating and the (LaAlO3)./(SrTiO3). insulating/insulating interfaces.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000326087100003 Publication Date 2013-10-21
Series Editor Series Title Abbreviated Series Title
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 15 Open Access
Notes Hercules; 246791 COUNTATOMS; 278510 VORTEX; 246102 IFOX; 312483 ESTEEM2; FWO; GOA XANES meets ELNES; esteem2jra3 ECASJO; Approved Most recent IF: 3.836; 2013 IF: 3.664
Call Number UA @ lucian @ c:irua:112733UA @ admin @ c:irua:112733 Serial 1944
Permanent link to this record
 

 
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.
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 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
Permanent link to this record
 

 
Author Clark, L.; Guzzinati, G.; Béché, A.; Lubk, A.; Verbeeck, J.
Title Symmetry-constrained electron vortex propagation Type A1 Journal article
Year 2016 Publication Physical review A Abbreviated Journal Phys Rev A
Volume 93 Issue 93 Pages 063840
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Electron vortex beams hold great promise for development in transmission electron microscopy but have yet to be widely adopted. This is partly due to the complex set of interactions that occur between a beam carrying orbital angular momentum (OAM) and a sample. Herein, the system is simplified to focus on the interaction between geometrical symmetries, OAM, and topology. We present multiple simulations alongside experimental data to study the behavior of a variety of electron vortex beams after interacting with apertures of different symmetries and investigate the effect on their OAM and vortex structure, both in the far field and under free-space propagation.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000378197200006 Publication Date 2016-06-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9926 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.925 Times cited 7 Open Access
Notes L.C., A.B., G.G., and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510—VORTEX. J.V. and A.L. acknowledge financial support from the European Union through the 7th Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2). The Qu-Ant-EM microscope was partly funded by the Hercules fund of the Flemish Government.; esteem2jra3; ECASJO; Approved Most recent IF: 2.925
Call Number c:irua:134086 c:irua:134086 Serial 4090
Permanent link to this record
 

 
Author Clark, L.; Béché, A.; Guzzinati, G.; Verbeeck, J.
Title Quantitative measurement of orbital angular momentum in electron microscopy Type A1 Journal article
Year 2014 Publication Physical review : A : atomic, molecular and optical physics Abbreviated Journal Phys Rev A
Volume 89 Issue 5 Pages 053818
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Electron vortex beams have been predicted to enable atomic scale magnetic information measurement, via transfer of orbital angular momentum. Research so far has focused on developing production techniques and applications of these beams. However, methods to measure the outgoing orbital angular momentum distribution are also a crucial requirement towards this goal. Here, we use a method to obtain the orbital angular momentum decomposition of an electron beam, using a multipinhole interferometer. We demonstrate both its ability to accurately measure orbital angular momentum distribution, and its experimental limitations when used in a transmission electron microscope.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000335826300012 Publication Date 2014-05-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1050-2947;1094-1622; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.925 Times cited 23 Open Access
Notes 7th Framework Program (FP7); ERC Starting Grant No. 278510- VORTEX 7th Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2). 7th Framework Program (FP7), ERC Grant No. 246791- COUNTATOMS. SP – 053818-1; esteem2jra3 ECASJO; Approved Most recent IF: 2.925; 2014 IF: 2.808
Call Number UA @ lucian @ c:irua:117093UA @ admin @ c:irua:117093 Serial 2758
Permanent link to this record
 

 
Author Guzzinati, G.; Clark, L.; Béché, A.; Verbeeck, J.
Title Measuring the orbital angular momentum of electron beams Type A1 Journal article
Year 2014 Publication Physical review : A : atomic, molecular and optical physics Abbreviated Journal Phys Rev A
Volume 89 Issue Pages 025803
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The recent demonstration of electron vortex beams has opened up the new possibility of studying orbital angular momentum (OAM) in the interaction between electron beams and matter. To this aim, methods to analyze the OAM of an electron beam are fundamentally important and a necessary next step. We demonstrate the measurement of electron beam OAM through a variety of techniques. The use of forked holographic masks, diffraction from geometric apertures, and diffraction from a knife edge and the application of an astigmatic lens are all experimentally demonstrated. The viability and limitations of each are discussed with supporting numerical simulations.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000332224100014 Publication Date 2014-02-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1050-2947;1094-1622; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.925 Times cited 42 Open Access
Notes Vortex; FP7; Countatoms; ESTEEM2; esteem2jra3 ECASJO; Approved Most recent IF: 2.925; 2014 IF: 2.808
Call Number UA @ lucian @ c:irua:114577UA @ admin @ c:irua:114577 Serial 1972
Permanent link to this record
 

 
Author Guzzinati, G.; Béché, A.; McGrouther, D.; Verbeeck, J.
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 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
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.
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 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.
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 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 Prabhakara, V.; Jannis, D.; Béché, A.; Bender, H.; Verbeeck, J.
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 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
Permanent link to this record
 

 
Author Gao, C.; Hofer, C.; Jannis, D.; Béché, A.; Verbeeck, J.; Pennycook, T.J.
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 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 Guzzinati, G.; Ghielens, W.; Mahr, C.; Béché, A.; Rosenauer, A.; Calders, T.; Verbeeck, J.
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 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 Jannis, D.; Müller-Caspary, K.; Béché, A.; Oelsner, A.; Verbeeck, J.
Title Spectroscopic coincidence experiments in transmission electron microscopy Type A1 Journal article
Year 2019 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 114 Issue 14 Pages 143101
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We demonstrate the feasibility of coincidence measurements on a conventional transmission electron microscope, revealing the temporal

correlation between electron energy loss spectroscopy (EELS) and energy dispersive X-ray (EDX) spectroscopy events. We make use of a

delay line detector with ps-range time resolution attached to a modified EELS spectrometer. We demonstrate that coincidence between both

events, related to the excitation and deexcitation of atoms in a crystal, provides added information not present in the individual EELS or

EDX spectra. In particular, the method provides EELS with a significantly suppressed or even removed background, overcoming the many

difficulties with conventional parametric background fitting as it uses no assumptions on the shape of the background, requires no user input

and does not suffer from counting noise originating from the background signal. This is highly attractive, especially when low concentrations

of elements need to be detected in a matrix of other elements.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000464450200022 Publication Date 2019-04-08
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 18 Open Access OpenAccess
Notes Fonds Wetenschappelijk Onderzoek, G093417 ; Horizon 2020 Framework Programme, 823717 ESTEEM3 ; Helmholtz Association, VH-NG-1327 ; Approved Most recent IF: 3.411
Call Number EMAT @ emat @UA @ admin @ c:irua:159155 Serial 5168
Permanent link to this record
 

 
Author Béché, A.; Goris, B.; Freitag, B.; Verbeeck, J.
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 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 Liu, P.; Arslan Irmak, E.; De Backer, A.; De wael, A.; Lobato, I.; Béché, A.; Van Aert, S.; Bals, S.
Title Three-dimensional atomic structure of supported Au nanoparticles at high temperature Type A1 Journal article
Year 2021 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 13 Issue Pages
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Au nanoparticles (NPs) deposited on CeO2 are extensively used as thermal catalysts since the morphology of the NPs is expected to be stable at elevated temperatures. Although it is well known that the activity of Au NPs depends on their size and surface structure, their three-dimensional (3D) structure at the atomic scale has not been completely characterized as a function of temperature. In this paper, we overcome the limitations of conventional electron tomography by combining atom counting applied to aberration-corrected scanning transmission electron microscopy images and molecular dynamics relaxation. In this manner, we are able to perform an atomic resolution 3D investigation of supported Au NPs. Our results enable us to characterize the 3D equilibrium structure of single NPs as a function of temperature. Moreover, the dynamic 3D structural evolution of the NPs at high temperatures, including surface layer jumping and crystalline transformations, has been studied.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000612999200029 Publication Date 2020-12-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 13 Open Access OpenAccess
Notes This work was supported by the European Research Council (Grant 815128 REALNANO to SB, Grant 770887 PICOMETRICS to SVA, Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through grants to A. D. w. and A. D. B. and project funding G.0267.18N.; sygma; esteem3JRA; esteem3reported Approved Most recent IF: 7.367
Call Number EMAT @ emat @c:irua:174858 Serial 6665
Permanent link to this record
 

 
Author Vanrompay, H.; Bladt, E.; Albrecht, W.; Béché, A.; Zakhozheva, M.; Sánchez-Iglesias, A.; Liz-Marzán, L.M.; Bals, S.
Title 3D characterization of heat-induced morphological changes of Au nanostars by fast in situ electron tomography Type A1 Journal article
Year 2018 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 10 Issue 10 Pages 22792-22801
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract A thorough understanding of the thermal stability and potential reshaping of anisotropic gold nanostars is required for various potential applications. Combination of a tomographic heating holder with fast tilt series acquisition has been used to monitor temperature-induced morphological changes of Au nanostars. The outcome of our 3D investigations can be used as an input for boundary element method simulations, enabling us to investigate the influence of reshaping on the nanostars’ plasmonic properties. Our work leads to a better understanding of the mechanism behind thermal reshaping. In addition, the approach presented here is generic and can hence be applied to a wide variety of nanoparticles made of different materials and with arbitrary morphology.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000453248100010 Publication Date 2018-11-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 55 Open Access OpenAccess
Notes H.V. acknowledges financial support by the Research Foundation Flanders (FWO grant 1S32617N). E.B. acknowledges a post-doctoral grant from the Research Foundation Flanders (FWO, Belgium). W.A. acknowledges an Individual Fellowship funded by the Marie Sklodowska-Curie Actions (MSCA) in Horizon 2020. The authors acknowledge funding from European Commission Grant (EUSMI 731019 to S.B., L.M.L.-M. and M.Z. and MUMMERING 765604 to S.B. and M.Z.). S.B. acknowledges financial support from European Research Council (ERC Starting Grant #335078- COLOURATOMS).; Ecas_sara Approved Most recent IF: 7.367
Call Number EMAT @ emat @c:irua:155718UA @ admin @ c:irua:155718 Serial 5071
Permanent link to this record
 

 
Author Egoavil, R.; Huehn, S.; Jungbauer, M.; Gauquelin, N.; Béché, A.; Van Tendeloo, G.; Verbeeck; Moshnyaga, V.
Title Phase problem in the B-site ordering of La2CoMnO6 : impact on structure and magnetism Type A1 Journal article
Year 2015 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 7 Issue 7 Pages 9835-9843
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Epitaxial double perovskite La2CoMnO6 (LCMO) films were grown by metalorganic aerosol deposition on SrTiO3(111) substrates. A high Curie temperature, T-C = 226 K, and large magnetization close to saturation, M-S(5 K) = 5.8 mu(B)/f.u., indicate a 97% degree of B-site (Co,Mn) ordering within the film. The Co/Mn ordering was directly imaged at the atomic scale by scanning transmission electron microscopy with energy-dispersive X-ray spectroscopy (STEM-EDX). Local electron-energy-loss spectroscopy (EELS) measurements reveal that the B-sites are predominantly occupied by Co2+ and Mn4+ ions in quantitative agreement with magnetic data. Relatively small values of the (1/2 1/2 1/2) superstructure peak intensity, obtained by X-ray diffraction (XRD), point out the existence of ordered domains with an arbitrary phase relationship across the domain boundary. The size of these domains is estimated to be in the range 35-170 nm according to TEM observations and modelling the magnetization data. These observations provide important information towards the complexity of the cation ordering phenomenon and its implications on magnetism in double perovskites, and similar materials.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000354983100060 Publication Date 2015-05-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364;2040-3372; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 37 Open Access
Notes 312483 ESTEEM2; FWO G004413N; 246102 IFOX; Hercules; esteem2_jra3 Approved Most recent IF: 7.367; 2015 IF: 7.394
Call Number c:irua:126423 c:irua:126423 Serial 2586
Permanent link to this record
 

 
Author Parastaev, A.; Muravev, V.; Osta, E.H.; Kimpel, T.F.; Simons, J.F.M.; van Hoof, A.J.F.; Uslamin, E.; Zhang, L.; Struijs, J.J.C.; Burueva, D.B.; Pokochueva, E.V.; Kovtunov, K.V.; Koptyug, I.V.; Villar-Garcia, I.J.; Escudero, C.; Altantzis, T.; Liu, P.; Béché, A.; Bals, S.; Kosinov, N.; Hensen, E.J.M.
Title Breaking structure sensitivity in CO2 hydrogenation by tuning metal–oxide interfaces in supported cobalt nanoparticles Type A1 Journal article
Year 2022 Publication Nature Catalysis Abbreviated Journal Nat Catal
Volume 5 Issue 11 Pages 1051-1060
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract A high dispersion of the active metal phase of transition metals on oxide supports is important when designing efficient heterogeneous catalysts. Besides nanoparticles, clusters and even single metal atoms can be attractive for a wide range of reactions. However, many industrially relevant catalytic transformations suffer from structure sensitivity, where reducing the size of the metal particles below a certain size substantially lowers catalytic performance. A case in point is the low activity of small cobalt nanoparticles in the hydrogenation of CO and CO2. Here we show how engineering of catalytic sites at the metal–oxide interface in cerium oxide–zirconium dioxide (ceria–zirconia)-supported cobalt can overcome this structure sensitivity. Few-atom cobalt clusters dispersed on 3 nm cobalt(II)-oxide particles stabilized by ceria–zirconia yielded a highly active CO2 methanation catalyst with a specific activity higher than that of larger particles under the same conditions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000884939300006 Publication Date 2022-11-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2520-1158 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 37.8 Times cited 32 Open Access OpenAccess
Notes This research was supported by the Applied and Engineering Sciences division of the Netherlands Organization for Scientific Research through the Alliander (now Qirion) Perspective program on Plasma Conversion of CO2. We acknowledge Diamond Light Source for time on beamline B18 under proposal SP20715-1. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3. S.B. acknowledges support from the European Research Council (ERC Consolidator Grant #815128 REALNANO) and T.A. acknowledges funding from the University of Antwerp Research fund (BOF). A.B. received funding from the European Union under grant agreement No 823717 – ESTEEM3. The authors acknowledge funding through the Hercules grant (FWO, University of Antwerp) I003218N “Infrastructure for imaging nanoscale processes in gas/vapour or liquid environments”. I.V.K., D.B.B., and E.V.P. acknowledge the Russian Ministry of Science and Higher Education (contract 075-15-2021-580) for financial support of parahydrogen-based studies. Experiments using synchrotron radiation XPS were performed at the CIRCE beamline at ALBA Synchrotron with the collaboration of ALBA staff. F. Oropeza Palacio and Rim C.J. van de Poll are acknowledged for the help with RPES measurements.; esteem3reported; esteem3jra Approved Most recent IF: 37.8
Call Number EMAT @ emat @c:irua:192068 Serial 7230
Permanent link to this record
 

 
Author Idrissi, H.; Ghidelli, M.; Béché, A.; Turner, S.; Gravier, S.; Blandin, J.-J.; Raskin, J.-P.; Schryvers, D.; Pardoen, T.
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 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 Vijayakumar, J.; Savchenko, T.M.; Bracher, D.M.; Lumbeeck, G.; Béché, A.; Verbeeck, J.; Vajda, Š.; Nolting, F.; Vaz, Ca.f.; Kleibert, A.
Title Absence of a pressure gap and atomistic mechanism of the oxidation of pure Co nanoparticles Type A1 Journal Article
Year 2023 Publication Nature communications Abbreviated Journal Nat Commun
Volume 14 Issue 1 Pages 174
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Understanding chemical reactivity and magnetism of 3<italic>d</italic>transition metal nanoparticles is of fundamental interest for applications in fields ranging from spintronics to catalysis. Here, we present an atomistic picture of the early stage of the oxidation mechanism and its impact on the magnetism of Co nanoparticles. Our experiments reveal a two-step process characterized by (i) the initial formation of small CoO crystallites across the nanoparticle surface, until their coalescence leads to structural completion of the oxide shell passivating the metallic core; (ii) progressive conversion of the CoO shell to Co<sub>3</sub>O<sub>4</sub>and void formation due to the nanoscale Kirkendall effect. The Co nanoparticles remain highly reactive toward oxygen during phase (i), demonstrating the absence of a pressure gap whereby a low reactivity at low pressures is postulated. Our results provide an important benchmark for the development of theoretical models for the chemical reactivity in catalysis and magnetism during metal oxidation at the nanoscale.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000955726400021 Publication Date 2023-01-12
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 16.6 Times cited 1 Open Access OpenAccess
Notes Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, 200021160186 2002153540 ; EC | Horizon 2020 Framework Programme, 810310 823717 ; University of Basel | Swiss Nanoscience Institute, P1502 ; This work is funded by Swiss National Foundation (SNF) (Grants. No 200021160186 and 2002153540) and the Swiss Nanoscience Institut (SNI) (Grant No. SNI P1502). S.V. acknowledges support from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 810310, which corresponds to the J. Heyrovsky Chair project (“ERA Chair at J. Heyrovský Institute of Physical Chemistry AS CR – The institutional approach towards ERA”). The funders had no role in the preparation of the article. Part of this work was performed at the Surface/Interface: Microscopy (SIM) beamline of the Swiss Light Source (SLS), Paul Scherrer Institut, Villigen, Switzerland. We kindly acknowledge Anja Weber and Elisabeth Müller from PSI for their help in fabricating the sample markers. A.B. and J. Verbeeck received funding from the European Union’s Horizon 2020 Research Infrastructure – Integrating Activities for Advanced Communities under grant agreement No. 823717 – ESTEEM3 reported Approved Most recent IF: 16.6; 2023 IF: 12.124
Call Number EMAT @ emat @c:irua:196738 Serial 8804
Permanent link to this record
 

 
Author Becker, M.; Guzzinati, G.; Béché, A.; Verbeeck, J.; Batelaan, H.
Title Asymmetry and non-dispersivity in the Aharonov-Bohm effect Type A1 Journal article
Year 2019 Publication Nature communications Abbreviated Journal Nat Commun
Volume 10 Issue 10 Pages 1700
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Decades ago, Aharonov and Bohm showed that electrons are affected by electromagnetic potentials in the absence of forces due to fields. Zeilinger's theorem describes this absence of classical force in quantum terms as the “dispersionless” nature of the Aharonov-Bohm effect. Shelankov predicted the presence of a quantum “force” for the same Aharonov-Bohm physical system as elucidated by Berry. Here, we report an experiment designed to test Shelankov's prediction and we provide a theoretical analysis that is intended to elucidate the relation between Shelankov's prediction and Zeilinger's theorem. The experiment consists of the Aharonov-Bohm physical system; free electrons pass a magnetized nanorod and far-field electron diffraction is observed. The diffraction pattern is asymmetric confirming one of Shelankov's predictions and giving indirect experimental evidence for the presence of a quantum “force”. Our theoretical analysis shows that Zeilinger's theorem and Shelankov's result are both special cases of one theorem.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000464338100011 Publication Date 2019-04-12
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 12 Open Access OpenAccess
Notes ; H.B. would like to thank Michael Berry for bringing the presence of a quantum “force” to our attention. A.B., G.G. and J.V. acknowledge support from the European Research Council under the 7th Framework Program (FP7) ERC Starting Grant 278510 VORTEX. G.G. acknowledges support from the Fonds Wetenschappelijk Onderzoek -Vlaanderen (FWO). M.B. and H.B. acknowledge support by the U.S. National Science Foundation under Grant No. 1602755. ; Approved Most recent IF: 12.124
Call Number UA @ admin @ c:irua:159341 Serial 5241
Permanent link to this record
 

 
Author Béché, A.; Van Boxem, R.; Van Tendeloo, G.; Verbeeck, J.
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 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
Permanent link to this record
 

 
Author Mueller, K.; Krause, F.F.; Béché, A.; Schowalter, M.; Galioit, V.; Loeffler, S.; Verbeeck, J.; Zweck, J.; Schattschneider, P.; Rosenauer, A.
Title Atomic electric fields revealed by a quantum mechanical approach to electron picodiffraction Type A1 Journal article
Year 2014 Publication Nature communications Abbreviated Journal Nat Commun
Volume 5 Issue Pages 5653
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract By focusing electrons on probes with a diameter of 50 pm, aberration-corrected scanning transmission electron microscopy (STEM) is currently crossing the border to probing subatomic details. A major challenge is the measurement of atomic electric fields using differential phase contrast (DPC) microscopy, traditionally exploiting the concept of a field- induced shift of diffraction patterns. Here we present a simplified quantum theoretical interpretation of DPC. This enables us to calculate the momentum transferred to the STEM probe from diffracted intensities recorded on a pixel array instead of conventional segmented bright- field detectors. The methodical development yielding atomic electric field, charge and electron density is performed using simulations for binary GaN as an ideal model system. We then present a detailed experimental study of SrTiO3 yielding atomic electric fields, validated by comprehensive simulations. With this interpretation and upgraded instrumentation, STEM is capable of quantifying atomic electric fields and high-contrast imaging of light atoms.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000347227700003 Publication Date 2014-12-15
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 197 Open Access
Notes 246791 COUNTATOMS; 278510 VORTEX; Hercules; 312483 ESTEEM2; esteem2ta; ECASJO; Approved Most recent IF: 12.124; 2014 IF: 11.470
Call Number UA @ lucian @ c:irua:122835UA @ admin @ c:irua:122835 Serial 166
Permanent link to this record
 

 
Author Guzzinati, G.; Béché, A.; Lourenço-Martins, H.; Martin, J.; Kociak, M.; Verbeeck, J.
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 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.
Address
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
Permanent link to this record