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| Author | Velazco, A.; Béché, A.; Jannis, D.; Verbeeck, J. | ||||
| Title | Reducing electron beam damage through alternative STEM scanning strategies, Part I: Experimental findings | Type | A1 Journal article | ||
| Year | 2022 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 232 | Issue | Pages  |
113398 | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | The highly energetic electrons in a transmission electron microscope (TEM) can alter or even completely destroy the structure of samples before sufficient information can be obtained. This is especially problematic in the case of zeolites, organic and biological materials. As this effect depends on both the electron beam and the sample and can involve multiple damage pathways, its study remained difficult and is plagued with irreproducibility issues, circumstantial evidence, rumors, and a general lack of solid data. Here we take on the experimental challenge to investigate the role of the STEM scan pattern on the damage behavior of a commercially available zeolite sample with the clear aim to make our observations as reproducible as possible. We make use of a freely programmable scan engine that gives full control over the tempospatial distribution of the electron probe on the sample and we use its flexibility to obtain multiple repeated experiments under identical conditions comparing the difference in beam damage between a conventional raster scan pattern and a newly proposed interleaved scan pattern that provides exactly the same dose and dose rate and visits exactly the same scan points. We observe a significant difference in beam damage for both patterns with up to 11 % reduction in damage (measured from mass loss). These observations demonstrate without doubt that electron dose, dose rate and acceleration voltage are not the only parameters affecting beam damage in (S)TEM experiments and invite the community to rethink beam damage as an unavoidable consequence of applied electron dose. | ||||
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| 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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| Author | Jannis, D.; Hofer, C.; Gao, C.; Xie, X.; Béché, A.; Pennycook, Tj.; Verbeeck, J. | ||||
| Title | Event driven 4D STEM acquisition with a Timepix3 detector: Microsecond dwell time and faster scans for high precision and low dose applications | Type | A1 Journal article | ||
| Year | 2022 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 233 | Issue | Pages |
113423 | |
| Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
| Abstract | Four dimensional scanning transmission electron microscopy (4D STEM) records the scattering of electrons in a material in great detail. The benefits offered by 4D STEM are substantial, with the wealth of data it provides facilitating for instance high precision, high electron dose efficiency phase imaging via centre of mass or ptychography based analysis. However the requirement for a 2D image of the scattering to be recorded at each probe position has long placed a severe bottleneck on the speed at which 4D STEM can be performed. Recent advances in camera technology have greatly reduced this bottleneck, with the detection efficiency of direct electron detectors being especially well suited to the technique. However even the fastest frame driven pixelated detectors still significantly limit the scan speed which can be used in 4D STEM, making the resulting data susceptible to drift and hampering its use for low dose beam sensitive applications. Here we report the development of the use of an event driven Timepix3 direct electron camera that allows us to overcome this bottleneck and achieve 4D STEM dwell times down to 100 ns; orders of magnitude faster than what has been possible with frame based readout. We characterize the detector for different acceleration voltages and show that the method is especially well suited for low dose imaging and promises rich datasets without compromising dwell time when compared to conventional STEM imaging. | ||||
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| Language | Wos | 000734396800003 | Publication Date | 2021-11-13 | |
| 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 | 31 | Open Access | OpenAccess |
| Notes | This project has received funding from the Euro- pean Union’s Horizon 2020 Research Infrastructure – Integrating Activities for Advanced Communities under grant agreement No 823717 – ESTEEM3. J.V. and A.B. acknowledge funding from FWO project G093417N (‘Compressed sensing enabling low dose imaging in transmission electron microscopy’). J.V. and D.J. ac- knowledge funding from FWO project G042920N ‘Co- incident event detection for advanced spectroscopy in transmission electron microscopy’. We acknowledge funding under the European Union’s Horizon 2020 re- search and innovation programme (J.V. and D.J un- der grant agreement No 101017720, FET-Proactive EBEAM, and C.H., C.G., X.X. and T.J.P. from the Eu- ropean Research Council (ERC) Grant agreement No. 802123-HDEM).; esteem3JRA; esteem3reported | Approved | Most recent IF: 2.2 | ||
| Call Number | EMAT @ emat @c:irua:183948 | Serial | 6828 | ||
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| Author | Jannis, D.; Velazco, A.; Béché, A.; Verbeeck, J. | ||||
| Title | Reducing electron beam damage through alternative STEM scanning strategies, Part II: Attempt towards an empirical model describing the damage process | Type | A1 Journal article | ||
| Year | 2022 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | Issue | Pages |
113568 | ||
| Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
| Abstract | In this second part of a series we attempt to construct an empirical model that can mimick all experimental observations made regarding the role of an alternative interleaved scan pattern in STEM imaging on the beam damage in a specific zeolite sample. We make use of a 2D diffusion model that describes the dissipation of the deposited beam energy in the sequence of probe positions that are visited during the scan pattern. The diffusion process allows for the concept of trying to ‘outrun’ the beam damage by carefully tuning the dwell time and distance between consecutively visited probe positions. We add a non linear function to include a threshold effect and evaluate the accumulated damage in each part of the image as a function of scan pattern details. Together, these ingredients are able to describe qualitatively all aspects of the experimental data and provide us with a model that could guide a further optimisation towards even lower beam damage without lowering the applied electron dose. We deliberately remain vague on what is diffusing here which avoids introducing too many sample specific details. This provides hope that the model can be applied also in sample classes that were not yet studied in such great detail by adjusting higher level parameters: a sample dependent diffusion constant and damage threshold. | ||||
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| Language | Wos | 000832788000003 | Publication Date | 0000-00-00 | |
| 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 | D.J., A.V, 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 .; esteem3reported; esteem3jra; | Approved | Most recent IF: 2.2 | ||
| Call Number | EMAT @ emat @c:irua:188535 | Serial | 7071 | ||
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| Author | Ghidelli, M.; Orekhov, A.; Bassi, A.L.; Terraneo, G.; Djemia, P.; Abadias, G.; Nord, M.; Béché, A.; Gauquelin, N.; Verbeeck, J.; Raskin, J.-p.; Schryvers, D.; Pardoen, T.; Idrissi, H. | ||||
| Title | Novel class of nanostructured metallic glass films with superior and tunable mechanical properties | Type | A1 Journal article | ||
| Year | 2021 | Publication | Acta Materialia | Abbreviated Journal | Acta Mater |
| Volume | Issue | Pages |
116955 | ||
| Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
| Abstract | A novel class of nanostructured Zr50Cu50 (%at.) metallic glass films with superior and tunable mechanical properties is produced by pulsed laser deposition. The process can be controlled to synthetize a wide range of film microstructures including dense fully amorphous, amorphous embedded with nanocrystals and amorphous nano-granular. A unique dense self-assembled nano-laminated atomic arrangement characterized by alternating Cu-rich and Zr/O-rich nanolayers with different local chemical enrichment and amorphous or amorphous-crystalline composite nanostructure has been discovered, while significant in-plane clustering is reported for films synthetized at high deposition pressures. This unique nanoarchitecture is at the basis of superior mechanical properties including large hardness and elastic modulus up to 10 and 140 GPa, respectively and outstanding total elongation to failure (>9%), leading to excellent strength/ductility balance, which can be tuned by playing with the film architecture. These results pave the way to the synthesis of novel class of engineered nanostructured metallic glass films with high structural performances attractive for a number of applications in microelectronics and coating industry. |
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| Language | Wos | 000670077800004 | Publication Date | 2021-05-12 | |
| 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 | 5.301 | Times cited | 27 | Open Access | OpenAccess |
| Notes | H.I. is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). This work was supported by the Fonds de la Recherche Scientifique – FNRS under Grant T.0178.19 and Grant CDR– J011320F. We acknowledge funding for the direct electron detector used in the 4D stem studies from the Hercules fund 'Direct electron detector for soft matter TEM' from the Flemish Government J.V acknowledges funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 823717 – ESTEEM3. A.O. has received partial funding from the GOA project “Solarpaint” of the University of Antwerp. 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.G. and A.L.B acknowledge Chantelle Ekanem for support in PLD depositions. | Approved | Most recent IF: 5.301 | ||
| Call Number | EMAT @ emat @c:irua:178142 | Serial | 6761 | ||
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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. | ||||
| 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 | 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/ ) | ||||
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| Language | Wos | 000861076600004 | Publication Date | 2022-08-05 | |
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| 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 | 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. | ||||
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| Language | Wos | 000499367800001 | Publication Date | 2019-10-28 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
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| 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 | Cooper, D.; Denneulin, T.; Barnes, J.-P.; Hartmann, J.-M.; Hutin, L.; Le Royer, C.; Béché, A.; Rouvière, J.-L. | ||||
| 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 | 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. | ||||
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| Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
| Language | Wos | 000312829400128 | Publication Date | 2012-12-19 | |
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| 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 | ||
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| 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. |
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| Language | Wos | 000464450200022 | Publication Date | 2019-04-08 | |
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| 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 | ||
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| 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. | ||||
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| Language | Wos | 000326087100003 | Publication Date | 2013-10-21 | |
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| 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 | ||
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| 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. | ||||
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| Language | Wos | 000363023700011 | Publication Date | 2015-10-20 | |
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| 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 | ||
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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. | ||||
| 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. | ||||
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| Language | Wos | 000400665300002 | Publication Date | 2017-05-05 | |
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| 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 | 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 | Jones, E.; Cooper, D.; Rouvière, J.-L.; Béché, A.; Azize, M.; Palacios, T.; Gradecak, S. | ||||
| Title | Towards rapid nanoscale measurement of strain in III-nitride heterostructures | Type | A1 Journal article | ||
| Year | 2013 | Publication | Applied Physics Letters | Abbreviated Journal | Appl Phys Lett |
| Volume | 103 | Issue | Pages |
231904 | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | We report the structural and compositional nanoscale characterization of InAlN/GaN nanoribbon-structured high electron mobility transistors (HEMTs) through the use of geometric phase analysis (GPA) and nanobeam electron diffraction (NBED). The strain distribution in the HEMT layer is quantified and compared to the expected strain profile for the nominal structure predicted by finite element analysis (FEA). Using the experimental strain results, the actual structure is determined and used to modify the FEA model. The improved fit of the model demonstrates that GPA and NBED provide a powerful platform for routine and rapid characterization of strain in III-V semiconducting device systems leading to insights into device evolution during processing and future device optimization. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
| Language | Wos | 000328634900025 | Publication Date | 2013-12-03 | |
| 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 | 6 | Open Access | |
| Notes | Approved | Most recent IF: 3.411; 2013 IF: 3.515 | |||
| Call Number | UA @ lucian @ c:irua:136443 | Serial | 4513 | ||
| Permanent link to this record | |||||
| Author | Cooper, D.; Le Royer, C.; Béché, A.; Rouvière, J.-L. | ||||
| Title | Strain mapping for the silicon-on-insulator generation of semiconductor devices by high-angle annular dark field scanning electron transmission microscopy | Type | A1 Journal article | ||
| Year | 2012 | Publication | Applied Physics Letters | Abbreviated Journal | Appl Phys Lett |
| Volume | 100 | Issue | Pages |
233121 | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | The strain in pMOS p-type metal-oxide-semiconductor devicesgrown on silicon-on-insulator substrates has been measured by using the geometrical phase analysis of high angle annular dark field scanning electron microscopy. We show that by using the latest generations of electron microscopes, the strain can now be quantitatively measured with a large field of view, a spatial resolution as low as 1 nm with a sensitivity as good as 0.15%. This technique is extremely flexible, provides both structural and strain information, and can be applied to all types of nanoscale materials both quickly and easily. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
| Language | Wos | Publication Date | 2012-06-08 | ||
| 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 | Open Access | ||
| Notes | Approved | Most recent IF: 3.411; 2012 IF: 3.794 | |||
| Call Number | UA @ lucian @ c:irua:136432 | Serial | 4509 | ||
| Permanent link to this record | |||||
| Author | Rouvière, J.-L.; Béché, A.; Martin, Y.; Denneulin, T.; Cooper, D. | ||||
| 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 | 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 | ||
| 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 | Cooper, D.; Rouvière, J.-L.; Béché, A.; Kadkhodazadeh, S.; Semenova, E.S.; Dunin-Borkowsk, R. | ||||
| Title | Quantitative strain mapping of InAs/InP quantum dots with 1 nm spatial resolution using dark field electron holography | Type | A1 Journal article | ||
| Year | 2011 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
| Volume | 99 | Issue | Pages |
261911-261913 | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | The optical properties of semiconductor quantum dots are greatly influenced by their strain state. Dark field electron holography has been used to measure the strain in InAsquantum dotsgrown in InP with a spatial resolution of 1 nm. A strain value of 5.4% ± 0.1% has been determined which is consistent with both measurements made by geometrical phase analysis of high angle annular dark field scanning transmission electron microscopy images and with simulations. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
| Language | Wos | 000298638500027 | Publication Date | 2012-01-03 | |
| 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 | 26 | Open Access | |
| Notes | Approved | Most recent IF: 3.411; 2011 IF: 3.844 | |||
| Call Number | UA @ lucian @ c:irua:136428 | Serial | 4507 | ||
| Permanent link to this record | |||||
| Author | Vanrompay, H.; Béché, A.; Verbeeck, J.; Bals, S. | ||||
| Title | Experimental Evaluation of Undersampling Schemes for Electron Tomography of Nanoparticles | Type | A1 Journal article | ||
| Year | 2019 | Publication | Particle and particle systems characterization | Abbreviated Journal | Part Part Syst Char |
| Volume | 36 | Issue | 36 | Pages |
1900096 |
| Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
| Abstract | One of the emerging challenges in the field of 3D characterization of nanoparticles by electron tomography is to avoid degradation and deformation of the samples during the acquisition of a tilt series. In order to reduce the required electron dose, various undersampling approaches have been proposed. These methods include lowering the number of 2D projection images, reducing the probe current during the acquisition, and scanning a smaller number of pixels in the 2D images. A comparison is made between these approaches based on tilt series acquired for a gold nanoparticle. | ||||
| Address | |||||
| 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 | ||
| Permanent link to this record | |||||
| Author | Vega Ibañez, F.; Béché, A.; Verbeeck, J. | ||||
| Title | Can a programmable phase plate serve as an aberration corrector in the transmission electron microscope (TEM)? | Type | A1 Journal article | ||
| Year | 2022 | Publication | Microscopy and microanalysis | Abbreviated Journal | Microsc Microanal |
| Volume | Issue | Pages |
Pii S1431927622012260-10 | ||
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | Current progress in programmable electrostatic phase plates raises questions about their usefulness for specific applications. Here, we explore different designs for such phase plates with the specific goal of correcting spherical aberration in the transmission electron microscope (TEM). We numerically investigate whether a phase plate could provide down to 1 angstrom ngstrom spatial resolution on a conventional uncorrected TEM. Different design aspects (fill factor, pixel pattern, symmetry) were evaluated to understand their effect on the electron probe size and current density. Some proposed designs show a probe size () down to 0.66 angstrom, proving that it should be possible to correct spherical aberration well past the 1 angstrom limit using a programmable phase plate consisting of an array of electrostatic phase-shifting elements. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000849975400001 | Publication Date | 2022-09-21 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1431-9276 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 2.8 | Times cited | 3 | Open Access | OpenAccess |
| Notes | All authors acknowledge funding from the Flemish Research Fund under contract G042820N “Exploring adaptive optics in transmission electron microscopy”. J.V. acknowledges funding from the European Union’s Horizon 2020 Research Infrastructure – Integrating Activities for Advanced Communities under grant agreement No 823717 – ESTEEM3 and from the University of Antwerp through a TOP BOF project.; esteem3reported; esteem3jra | Approved | Most recent IF: 2.8 | ||
| Call Number | UA @ admin @ c:irua:190627 | Serial | 7134 | ||
| Permanent link to this record | |||||