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Author Spreitzer, M.; Klement, D.; Egoavil, R.; Verbeeck, J.; Kovac, J.; Zaloznik, A.; Koster, G.; Van Tendeloo, G.; Suvorov, D.; Rijnders, G.
Title Growth mechanism of epitaxial SrTiO3 on a (1 x 2) + (2 x 1) reconstructed Sr(1/2 ML)/Si(001) surface Type A1 Journal article
Year 2020 Publication Journal Of Materials Chemistry C Abbreviated Journal J Mater Chem C
Volume 8 Issue 2 Pages 518-527
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Sub-monolayer control over the growth at silicon-oxide interfaces is a prerequisite for epitaxial integration of complex oxides with the Si platform, enriching it with a variety of functionalities. However, the control over this integration is hindered by the intense reaction of the constituents. The most suitable buffer material for Si passivation is metallic strontium. When it is overgrown with a layer of SrTiO3 (STO) it can serve as a pseudo-substrate for the integration with functional oxides. In our study we determined a mechanism for epitaxial integration of STO with a (1 x 2) + (2 x 1) reconstructed Sr(1/2 ML)/Si(001) surface using all-pulsed laser deposition (PLD) technology. A detailed analysis of the initial deposition parameters was performed, which enabled us to develop a complete protocol for integration, taking into account the peculiarities of the PLD growth, STO critical thickness, and process thermal budget, in order to kinetically trap the reaction between STO and Si and thus to minimize the thickness of the interface layer. The as-prepared oxide layer exhibits STO(001)8Si(001) out-of-plane and STO[110]8Si[100] in-plane orientation and together with recent advances in large-scale PLD tools these results represent a new technological solution for the implementation of oxide electronics on demand.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000506852400036 Publication Date 2019-10-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2050-7526; 2050-7534 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.4 Times cited 12 Open Access OpenAccess
Notes ; The research was financially supported by the Slovenian Research Agency (Project No. P2-0091, J2-9237) and Ministry of Education, Science and Sport of the Republic of Slovenia (SIOX projects). This work was also funded by the European Union Council under the 7th Framework Program grant no. NMP3-LA-2010-246102 IFOX. J. V. and G. V. T. acknowledge funding from the Fund for Scientific Research Flanders under project no. G.0044.13N. ; Approved Most recent IF: 6.4; 2020 IF: 5.256
Call Number UA @ admin @ c:irua:165672 Serial 6298
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Author Bliokh, K.Y.; Karimi, E.; Padgett, M.J.; Alonso, M.A.; Dennis, M.R.; Dudley, A.; Forbes, A.; Zahedpour, S.; Hancock, S.W.; Milchberg, H.M.; Rotter, S.; Nori, F.; Ozdemir, S.K.; Bender, N.; Cao, H.; Corkum, P.B.; Hernandez-Garcia, C.; Ren, H.; Kivshar, Y.; Silveirinha, M.G.; Engheta, N.; Rauschenbeutel, A.; Schneeweiss, P.; Volz, J.; Leykam, D.; Smirnova, D.A.; Rong, K.; Wang, B.; Hasman, E.; Picardi, M.F.; Zayats, A.V.; Rodriguez-Fortuno, F.J.; Yang, C.; Ren, J.; Khanikaev, A.B.; Alu, A.; Brasselet, E.; Shats, M.; Verbeeck, J.; Schattschneider, P.; Sarenac, D.; Cory, D.G.; Pushin, D.A.; Birk, M.; Gorlach, A.; Kaminer, I.; Cardano, F.; Marrucci, L.; Krenn, M.; Marquardt, F.
Title Roadmap on structured waves Type A1 Journal article
Year 2023 Publication Journal of optics Abbreviated Journal
Volume 25 Issue 10 Pages 103001-103079
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Structured waves are ubiquitous for all areas of wave physics, both classical and quantum, where the wavefields are inhomogeneous and cannot be approximated by a single plane wave. Even the interference of two plane waves, or of a single inhomogeneous (evanescent) wave, provides a number of nontrivial phenomena and additional functionalities as compared to a single plane wave. Complex wavefields with inhomogeneities in the amplitude, phase, and polarization, including topological----- structures and singularities, underpin modern nanooptics and photonics, yet they are equally important, e.g. for quantum matter waves, acoustics, water waves, etc. Structured waves are crucial in optical and electron microscopy, wave propagation and scattering, imaging, communications, quantum optics, topological and non-Hermitian wave systems, quantum condensed-matter systems, optomechanics, plasmonics and metamaterials, optical and acoustic manipulation, and so forth. This Roadmap is written collectively by prominent researchers and aims to survey the role of structured waves in various areas of wave physics. Providing background, current research, and anticipating future developments, it will be of interest to a wide cross-disciplinary audience.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001061350200001 Publication Date 2023-07-26
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 2.1 Times cited 7 Open Access Not_Open_Access: Available from 30.03.2024
Notes This work is funded by the Royal Society and EPSRC under the Grant Number EP/M01326X/1.M A A acknowledges funding from the Excellence Initiative of Aix Marseille University-A*MIDEX, a French Investissements d'Avenir' programme, and from the Agence Nationale de Recherche (ANR) through project ANR-21-CE24-0014-01.M R D acknowledges support from the EPSRC Centre for Doctoral Training in Topological Design(EP/S02297X/1).S R acknowledges support by the Austrian Science Fund (FWF, Grant P32300 WAVELAND) and by the European Commission (Grant MSCA-RISE 691209 NHQWAVE). FN is supported in part by NTT Research, and S K OE by the Air Force Office of Scientific Research (AFOSR) Multidisciplinary University Research Initiative (MURI) Award No. FA9550-21-1-0202.The authors thank their co-workers Yaron Bromberg, Hasan Yilmaz, and collaborators Joerg Bewersdorf and Mengyuan Sun for their contributions to the works presented here. They also acknowledge financial support from the Office of Naval Research (N00014-20-1-2197) and the National Science Foundation (DMR-1905465).H R acknowledges a support from the Australian Research Council DECRA Fellowship DE220101085. Y K acknowledges a support from the Australian Research Council (Grant DP210101292).M G S acknowledges partial support from Simons Foundation/Collaboration on Extreme Wave Phenomena Based on Symmetries, from the Institution of Engineering and Technology (IET) under the A F Harvey Research Prize 2018, and from Instituto de Telecomunicacoes under project UIDB/50008/2020. N E acknowledges partial support from Simons Foundation/Collaboration on Extreme Wave Phenomena Based on Symmetries, and from the US Air Force Office of Scientific Research (AFOSR) Multidisciplinary University Research Initiative (MURI) grant number FA9550-21-1-0312.We acknowledge funding by the Alexander von Humboldt Foundation in the framework of the Alexander von Humboldt Professorship endowed by the Federal Ministry of Education and Research. Moreover, financial support from the European Union's Horizon 2020 research and innovation program under Grant Agreement No. 899275 (DAALI) is gratefully acknowledged.D L acknowledges a support from the National Research Foundation, Singapore and A*STAR under its CQT Bridging Grant. D A S acknowledges support from the Australian Research Council (FT230100058).The authors gratefully acknowledge financial support from the Israel Science Foundation (ISF), the U.S. Air Force Office of Scientific Research (FA9550-18-1-0208) through their program on Photonic Metamaterials, the Israel Ministry of Science, Technology and Space. The fabrication was performed at the Micro-Nano Fabrication & Printing Unit(MNF & PU), Technion.This work was supported by the European Research Council projects iCOMM (789340) and Starting Grant ERC-2016-STG-714151-PSINFONI.Our work in this area has been funded by the National Science Foundation, the Office of Naval Research, and the Simons Foundation.This work was supported by the Australian Research Council Discovery Project DP190100406.J V acknowledges funding from the eBEAM Project supported by the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 101017720 (FET-Proactive EBEAM), FWO Project G042820N Exploring adaptive optics in transmission electron microscopy' and European Union's Horizon 2020 Research Infrastructure-Integrating Activities for Advanced Communities Grant Agreement No. 823717-ESTEEM3. P S acknowledges the support of the Austrian Science Fund under Project Nr. P29687-N36.; The authors would like to thank their many collaborators including Wangchun Chen, Charles W Clark, Lisa DeBeer-Schmitt, Huseyin Ekinci, Melissa Henderson, Michael Huber, Connor Kapahi, Ivar Taminiau, and Kirill Zhernenkov. The authors would also like to acknowledge their funding sources: the Canadian Excellence Research Chairs (CERC) program, the Natural Sciences and Engineering Research Council of Canada (NSERC), the Canada First Research Excellence Fund (CFREF).E K acknowledges the support of Canada Research Chairs, Ontario's Early Research Award, and NRC-uOttawa Joint Centre for Extreme Quantum Photonics (JCEP) via the High Throughput and Secure Networks Challenge Program at the National Research Council of Canada. Approved Most recent IF: 2.1; 2023 IF: 1.741
Call Number UA @ admin @ c:irua:199327 Serial 8925
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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 (down) 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
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Author Prabhakara, V.; Nuytten, T.; Bender, H.; Vandervorst, W.; Bals, S.; Verbeeck, J.
Title Linearized radially polarized light for improved precision in strain measurements using micro-Raman spectroscopy Type A1 Journal article
Year 2021 Publication Optics Express Abbreviated Journal Opt Express
Volume 29 Issue 21 Pages 34531
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Strain engineering in semiconductor transistor devices has become vital in the semiconductor industry due to the ever-increasing need for performance enhancement at the nanoscale. Raman spectroscopy is a non-invasive measurement technique with high sensitivity to mechanical stress that does not require any special sample preparation procedures in comparison to characterization involving transmission electron microscopy (TEM), making it suitable for inline strain measurement in the semiconductor industry. Indeed, at present, strain measurements using Raman spectroscopy are already routinely carried out in semiconductor devices as it is cost effective, fast and non-destructive. In this paper we explore the usage of linearized radially polarized light as an excitation source, which does provide significantly enhanced accuracy and precision as compared to linearly polarized light for this application. Numerical simulations are done to quantitatively evaluate the electric field intensities that contribute to this enhanced sensitivity. We benchmark the experimental results against TEM diffraction-based techniques like nano-beam diffraction and Bessel diffraction. Differences between both approaches are assigned to strain relaxation due to sample thinning required in TEM setups, demonstrating the benefit of Raman for nondestructive inline testing.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000708940500144 Publication Date 2021-10-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1094-4087 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.307 Times cited 2 Open Access OpenAccess
Notes Horizon 2020 Framework Programme, 823717 – ESTEEM3 ; GOA project, “Solarpaint” ; Herculesstichting;; esteem3jra; esteem3reported; Approved Most recent IF: 3.307
Call Number EMAT @ emat @c:irua:182472 Serial 6816
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Author Velazco, A.; Nord, M.; Béché, A.; Verbeeck, J.
Title Evaluation of different rectangular scan strategies for STEM imaging Type A1 Journal article
Year 2020 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume Issue Pages 113021
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) STEM imaging is typically performed by raster scanning a focused electron probe over a sample. Here we investigate and compare three different scan patterns, making use of a programmable scan engine that allows to arbitrarily set the sequence of probe positions that are consecutively visited on the sample. We compare the typical raster scan with a so-called ‘snake’ pattern where the scan direction is reversed after each row and a novel Hilbert scan pattern that changes scan direction rapidly and provides an homogeneous treatment of both scan directions. We experimentally evaluate the imaging performance on a single crystal test sample by varying dwell time and evaluating behaviour with respect to sample drift. We demonstrate the ability of the Hilbert scan pattern to more faithfully represent the high frequency content of the image in the presence of sample drift. It is also shown that Hilbert scanning provides reduced bias when measuring lattice parameters from the obtained scanned images while maintaining similar precision in both scan directions which is especially important when e.g. performing strain analysis. Compared to raster scanning with flyback correction, both snake and Hilbert scanning benefit from dose reduction as only small probe movement steps occur.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000544042800007 Publication Date 2020-05-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.2 Times cited 13 Open Access OpenAccess
Notes A.V., A.B. and J.V. acknowledge funding through FWO project G093417N ('Compressed sensing enabling low dose imaging in transmission electron microscopy') from the Flanders Research Fund. M.N. received support for this work from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 838001. J.V acknowledges funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3. Approved Most recent IF: 2.2; 2020 IF: 2.843
Call Number EMAT @ emat @c:irua:169225 Serial 6369
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Author Fix, T.; Ulhaq-Bouillet, C.; Colis, S.; Dinia, A.; Bertoni, G.; Verbeeck, J.; Van Tendeloo, G.
Title Nanoscale analysis of interfaces in a metal/oxide/oxide trilayer obtained by pulsed laser deposition Type A1 Journal article
Year 2007 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 91 Issue 2 Pages 023106-023106,3
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Sr2FeMoO6/SrTiO3/CoFe2 trilayers grown by pulsed laser deposition on SrTiO3 (001) are investigated by transmission electron microscopy and electron energy loss spectroscopy. The stack is epitaxial, independent of whether the CoFe2 electrode is grown at 500 or at 50 degrees C. Thus it is possible to obtain epitaxy near room temperature. The SrTiO3/CoFe2 interface is quite sharp, while the Sr2FeMoO6/SrTiO3 interface presents regions of Fe depletion. The chemical composition of the films is close to the nominal stoichiometries. These results could be useful for the growth of heteroepitaxial devices and magnetic tunnel junctions. (C) 2007 American Institute of Physics.
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Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000248017300079 Publication Date 2007-07-10
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 16 Open Access
Notes Approved Most recent IF: 3.411; 2007 IF: 3.596
Call Number UA @ lucian @ c:irua:94653UA @ admin @ c:irua:94653 Serial 2263
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Author Verbeeck, J.; Béché, A.; van den Broek, W.
Title A holographic method to measure the source size broadening in STEM Type A1 Journal article
Year 2012 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 120 Issue Pages 35-40
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Source size broadening is an important resolution limiting effect in modern STEM experiments. Here, we propose an alternative method to measure the source size broadening making use of a holographic biprism to create interference patterns in an empty Ronchigram. This allows us to measure the exact shape of the source size broadening with a much better sampling than previously possible. We find that the shape of the demagnified source deviates considerably from a Gaussian profile that is often assumed. We fit the profile with a linear combination of a Gaussian and a bivariate Cauchy distribution showing that even though the full width at half maximum is similar to previously reported measurements, the tails of the profile are considerable wider. This is of fundamental importance for quantitative comparison of STEM simulations with experiments as these tails make the image contrast dependent on the interatomic distance, an effect that cannot be reproduced by a single Gaussian profile of fixed width alone.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000308082600005 Publication Date 2012-06-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 29 Open Access
Notes This work was supported by funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant no. 246791 COUNTATOMS and ERC Starting Grant 278510 VORTEX. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. W. Van den Broek acknowledges funding from the Condor project, a project under the supervision of the Embedded Systems Institute (ESI) and FEI. This project is partially supported by the Dutch Ministry of Economic Affairs under the BSIK program. ECASJO_; Approved Most recent IF: 2.843; 2012 IF: 2.470
Call Number UA @ lucian @ c:irua:100466UA @ admin @ c:irua:100466 Serial 1483
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Author Molina, L.; Tan, H.; Biermans, E.; Batenburg, K.J.; Verbeeck, J.; Bals, S.; Van Tendeloo, G.
Title Barrier efficiency of sponge-like La2Zr2O7 buffer layers for YBCO-coated conductors Type A1 Journal article
Year 2011 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 24 Issue 6 Pages 065019-065019,8
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract (down) Solution derived La2Zr2O7 films have drawn much attention for potential applications as thermal barriers or low-cost buffer layers for coated conductor technology. Annealing and coating parameters strongly affect the microstructure of La2Zr2O7, but different film processing methods can yield similar microstructural features such as nanovoids and nanometer-sized La2Zr2O7 grains. Nanoporosity is a typical feature found in such films and the implications for the functionality of the films are investigated by a combination of scanning transmission electron microscopy (STEM), electron energy-loss spectroscopy (EELS) and quantitative electron tomography. Chemical solution based La2Zr2O7 films deposited on flexible Ni5 at.%W substrates with a {100}lang001rang biaxial texture were prepared for an in-depth characterization. A sponge-like structure composed of nanometer-sized voids is revealed by high-angle annular dark-field scanning transmission electron microscopy in combination with electron tomography. A three-dimensional quantification of nanovoids in the La2Zr2O7 film is obtained on a local scale. Mostly non-interconnected highly faceted nanovoids compromise more than one-fifth of the investigated sample volume. The diffusion barrier efficiency of a 170 nm thick La2Zr2O7 film is investigated by STEM-EELS, yielding a 1.8 ± 0.2 nm oxide layer beyond which no significant nickel diffusion can be detected and intermixing is observed. This is of particular significance for the functionality of YBa2Cu3O7 − δ coated conductor architectures based on solution derived La2Zr2O7 films as diffusion barriers.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000290472900021 Publication Date 2011-04-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 31 Open Access
Notes Esteem 026019; Fwo Approved Most recent IF: 2.878; 2011 IF: 2.662
Call Number UA @ lucian @ c:irua:88639UA @ admin @ c:irua:88639 Serial 221
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Author Turner, S.; Lebedev, O.I.; Shenderova, O.; Vlasov, I.I.; Verbeeck, J.; Van Tendeloo, G.
Title Determination of size, morphology, and nitrogen impurity location in treated detonation nanodiamond by transmission electron microscopy Type A1 Journal article
Year 2009 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
Volume 19 Issue 13 Pages 2116-2124
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Size, morphology, and nitrogen impurity location, all of which are all thought to be related to the luminescent properties of detonation nanodiamonds, are determined in several detonation nanodiamond samples using a combination of transmission electron microscopy techniques. Results obtained from annealed and cleaned detonation nanodiamond samples are compared to results from conventionally purified detonation nanodiamond. Detailed electron energy loss spectroscopy combined with model-based quantification provides direct evidence for the sp3 like embedding of nitrogen impurities into the diamond cores of all the studied nanodiamond samples. Simultaneously, the structure and morphology of the cleaned detonation nanodiamond particles are studied using high resolution transmission electron microscopy. The results show that the size and morphology of detonation nanodiamonds can be modified by temperature treatment and that by applying a special cleaning procedure after temperature treatment, nanodiamond particles with clean facets almost free from sp2 carbon can be prepared. These clean facets are clear evidence that nanodiamond cores are not necessarily in coexistence with a graphitic shell of non-diamond carbon.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000268297800012 Publication Date 2009-05-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301X;1616-3028; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 100 Open Access
Notes Esteem 026019 Approved Most recent IF: 12.124; 2009 IF: 6.990
Call Number UA @ lucian @ c:irua:78261UA @ admin @ c:irua:78261 Serial 674
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Author Goris, B.; Bals, S.; van den Broek, W.; Verbeeck, J.; Van Tendeloo, G.
Title Exploring different inelastic projection mechanisms for electron tomography Type A1 Journal article
Year 2011 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 111 Issue 8 Pages 1262-1267
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract (down) Several different projection mechanisms that all make use of inelastically scattered electrons are used for electron tomography. The advantages and the disadvantages of these methods are compared to HAADFSTEM tomography, which is considered as the standard electron tomography technique in materials science. The different inelastic setups used are energy filtered transmission electron microscopy (EFTEM), thickness mapping based on the log-ratio method and bulk plasmon mapping. We present a comparison that can be used to select the best inelastic signal for tomography, depending on different parameters such as the beam stability and nature of the sample. The appropriate signal will obviously also depend on the exact information which is requested.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000300461100039 Publication Date 2011-03-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 21 Open Access
Notes Fwo; Iap; Esteem 026019 Approved Most recent IF: 2.843; 2011 IF: 2.471
Call Number UA @ lucian @ c:irua:91260UA @ admin @ c:irua:91260 Serial 1151
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Author Morozov, V.A.; Lazoryak, B.I.; Shmurak, S.Z.; Kiselev, A.P.; Lebedev, O.I.; Gauquelin, N.; Verbeeck, J.; Hadermann, J.; Van Tendeloo, G.
Title Influence of the structure on the properties of NaxEuy(MoO4)z red phosphors Type A1 Journal article
Year 2014 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 26 Issue 10 Pages 3238-3248
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Scheelite related compounds (A',A '')(n)[(B',B '')O-4](m) with B', B '' = W and/or Mo are promising new materials for red phosphors in pc-WLEDs (phosphor-converted white-light-emitting-diode) and solid-state lasers. Cation substitution in CaMoO4 of Ca2+ by the combination of Na+ and Eu3+, with the creation of A cation vacancies, has been investigated as a factor for controlling the scheelite-type structure and the luminescent properties. Na5Eu(MoO4)(4) and NaxEu(2-x)/33+square(2-x)/3MoO4 (0.138 <= x <= 0.5) phases with a scheelite-type structure were synthesized by the solid state method; their structural characteristics were investigated using transmission electron microscopy. Contrary to powder synchrotron X-ray diffraction before, the study by electron diffraction and high resolution transmission electron microscopy in this paper revealed that Na0.286Eu0.571MoO4 has a (3 + 2)D incommensurately modulated structure and that (3 + 2)D incommensurately modulated domains are present in Na0.200Eu0.600MoO4. It also confirmed the (3 + 1)D incommensurately modulated character of Na(0.138)Eu(0.621)Mo04. The luminescent properties of all phases under near-ultraviolet (n-UV) light have been investigated. The excitation spectra of these phosphors show the strongest absorption at about 395 nm, which matches well with the commercially available n-UV-emitting GaN-based LED chip. The emission spectra indicate an intense red emission due to the D-5(0) -> F-7(2) transition of Eu3+, with local minima in the intensity at Na0.286Eu0.571MoO4 and Na0.200Eu0.600MoO4 for similar to 613 nm and similar to 616 nm bands. The phosphor Na5Eu(MoO4)(4) shows the brightest red light emission among the phosphors in the Na2MoO4-Eu2/3MoO4 system and the maximum luminescence intensity of Na5Eu(MoO4)(4) (lambda(ex) = 395 nm) in the D-5(0) -> F-7(2) transition region is close to that of the commercially used red phosphor YVO4:Eu3+ (lambda(ex) = 326 nm). Electron energy loss spectroscopy measurements revealed the influence of the structure and Na/Eu cation distribution on the number and positions of bands in the UV-optical-infrared regions of the EELS spectrum.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000336637000028 Publication Date 2014-05-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 53 Open Access
Notes Fwo G039211n; Fwo G004413n; 278510 Vortex ECASJO_; Approved Most recent IF: 9.466; 2014 IF: 8.354
Call Number UA @ lucian @ c:irua:117765UA @ admin @ c:irua:117765 Serial 1652
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Author van den Broek, W.; Verbeeck, J.; Schryvers, D.; de Backer, S.; Scheunders, P.
Title Tomographic spectroscopic imaging; an experimental proof of concept Type A1 Journal article
Year 2009 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 109 Issue 4 Pages 296-303
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract (down) Recording the electron energy loss spectroscopy data cube with a series of energy filtered images is a dose inefficient process because the energy slit blocks most of the electrons. When recording the data cube by scanning an electron probe over the sample, perfect dose efficiency is attained; but due to the low current in nanoprobes, this often is slower, with a smaller field of view. In W. Van den Broek et al. [Ultramicroscopy, 106 (2006) 269], we proposed a new method to record the data cube, which is more dose efficient than an energy filtered series. It produces a set of projections of the data cube and then tomographically reconstructs it. In this article, we demonstrate these projections in practice, we present a simple geometrical model that allows for quantification of the projection angles and we present the first successful experimental reconstruction, all on a standard post-column instrument.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000265345400003 Publication Date 2008-12-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 1 Open Access
Notes Esteem 026019 Approved Most recent IF: 2.843; 2009 IF: 2.067
Call Number UA @ lucian @ c:irua:77271 Serial 3671
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Author Wang, J.; Shin, Y.; Gauquelin, N.; Yang, Y.; Lee, C.; Jannis, D.; Verbeeck, J.; Rondinelli, J.M.; May, S.J.
Title Physical properties of epitaxial SrMnO2.5−δFγoxyfluoride films Type A1 Journal article
Year 2019 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 31 Issue 36 Pages 365602
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Recently, topotactic fluorination has become an alternative way of doping epitaxial perovskite oxides through anion substitution to engineer their electronic properties instead of the more commonly used cation substitution. In this work, epitaxial oxyfluoride SrMnO2.5−δ F γ films were synthesized via topotactic fluorination of SrMnO2.5 films using polytetrafluoroethylene as the fluorine source. Oxidized SrMnO3 films were also prepared for comparison with the fluorinated samples. The F content, probed by x-ray photoemission spectroscopy, was systematically controlled by adjusting fluorination conditions. Electronic transport measurements reveal that increased F content (up to γ  =  0.14) systematically increases the electrical resistivity, despite the nominal electron-doping induced by F substitution for O in these films. In contrast, oxidized SrMnO3 exhibits a decreased resistivity and conduction activation energy. A blue-shift of optical absorption features occurs with increasing F content. Density functional theory calculations indicate that F acts as a scattering center for electronic transport, controls the observed weak ferromagnetic behavior of the films, and reduces the inter-band optical transitions in the manganite films. These results stand in contrast to bulk electron-doped La1−x Ce x MnO3, illustrating how aliovalent anionic substitutions can yield physical behavior distinct from A-site substituted perovskites with the same nominal B-site oxidation states.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000472232000002 Publication Date 2019-09-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 5 Open Access
Notes Work at Drexel was supported by the National Science Foundation (NSF), grant number CMMI-1562223. Thin film synthesis utilized deposition instrumentation acquired through an Army Research Office DURIP grant (W911NF-14-1-0493). Y.S and J.M.R. were supported by NSF (Grant No. DMR-1454688). Calculations were performed using the QUEST HPC Facility at Northwestern, the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by NSF Grant No. ACI-1053575, and the Center for Nanoscale Materials (Carbon Cluster). Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. J.V. and N. G. acknowledge funding from a GOA project “Solarpaint” of the University of Antwerp. D.J. acknowledges funding from FWO project G093417N from the Flemish fund for scientific research. Approved Most recent IF: 2.649
Call Number EMAT @ emat @UA @ admin @ c:irua:161174 Serial 5293
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Author van den Bos, K.H.W.; Krause, F.F.; Béché, A.; Verbeeck, J.; Rosenauer, A.; Van Aert, S.
Title Locating light and heavy atomic column positions with picometer precision using ISTEM Type A1 Journal article
Year 2016 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 172 Issue 172 Pages 75-81
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Recently, imaging scanning transmission electron microscopy (ISTEM) has been proposed as a promising new technique combining the advantages of conventional TEM (CTEM) and STEM [1]. The ability to visualize light and heavy elements together makes it a particularly interesting new, spatially incoherent imaging mode. Here, we evaluate this technique in term of precision with which atomic column locations can be measured. By using statistical parameter estimation theory, we will show that these locations can be accurately measured with a precision in the picometer range. Furthermore, a quantitative comparison is made with HAADF STEM imaging to investigate the advantages of ISTEM.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000390600200009 Publication Date 2016-10-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 8 Open Access
Notes The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0368.15N, G.0369.15N), and by a Ph.D. grant to K.H.W. van den Bos. The research leading to these results has received funding from the Deutsche Forschungsgemeinschaft under Contract No. RO 2057/4-2 and the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2. We thank Prof. G. Koster from the University of Twente for kindly providing us with the PbTiO3 test sample. Approved Most recent IF: 2.843
Call Number EMAT @ emat @ c:irua:136109UA @ admin @ c:irua:136109 Serial 4288
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Author Van Boxem, R.; Partoens, B.; Verbeeck, J.
Title Inelastic electron-vortex-beam scattering Type A1 Journal article
Year 2015 Publication Physical review : A : atomic, molecular and optical physics Abbreviated Journal Phys Rev A
Volume 91 Issue 91 Pages 032703
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract (down) Recent theoretical and experimental developments in the field of electron-vortex-beam physics have raised questions about what exactly this novelty in the field of electron microscopy (and other fields, such as particle physics) really provides. An important part of the answer to these questions lies in scattering theory. The present investigation explores various aspects of inelastic quantum scattering theory for cylindrically symmetric beams with orbital angular momentum. The model system of Coulomb scattering on a hydrogen atom provides the setting to address various open questions: How is momentum transferred? Do vortex beams selectively excite atoms, and how can one employ vortex beams to detect magnetic transitions? The analytical approach presented here provides answers to these questions. OAM transfer is possible, but not through selective excitation; rather, by pre- and postselection one can filter out the relevant contributions to a specific signal.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000351035000004 Publication Date 2015-03-16
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 31 Open Access
Notes Fwo; 312483 Esteem2; 278510 Vortex; esteem2jra3 ECASJO; Approved Most recent IF: 2.925; 2015 IF: 2.808
Call Number c:irua:123925 c:irua:123925UA @ admin @ c:irua:123925 Serial 1607
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Author Janssens, K.; van der Snickt, G.; Vanmeert, F.; Legrand, S.; Nuyts, G.; Alfeld, M.; Monico, L.; Anaf, W.; de Nolf, W.; Vermeulen, M.; Verbeeck, J.; De Wael, K.
Title Non-invasive and non-destructive examination of artistic pigments, paints, and paintings by means of X-Ray methods Type A1 Journal article
Year 2016 Publication Topics in Current Chemistry Abbreviated Journal Topics Curr Chem
Volume 374 Issue 374 Pages 81
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (down) Recent studies are concisely reviewed, in which X-ray beams of (sub)micrometre to millimetre dimensions have been used for non-destructive analysis and characterization of pigments, minute paint samples, and/or entire paintings from the seventeenth to the early twentieth century painters. The overview presented encompasses the use of laboratory and synchrotron radiation-based instrumentation and deals with the use of several variants of X-ray fluorescence (XRF) as a method of elemental analysis and imaging, as well as with the combined use of X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS). Microscopic XRF is a variant of the method that is well suited to visualize the elemental distribution of key elements, mostly metals, present in paint multi-layers, on the length scale from 1 to 100 μm inside micro-samples taken from paintings. In the context of the characterization of artists pigments subjected to natural degradation, the use of methods limited to elemental analysis or imaging usually is not sufficient to elucidate the chemical transformations that have taken place. However, at synchrotron facilities, combinations of μ-XRF with related methods such as μ-XAS and μ-XRD have proven themselves to be very suitable for such studies. Their use is often combined with microscopic Fourier transform infra-red spectroscopy and/or Raman microscopy since these methods deliver complementary information of high molecular specificity at more or less the same length scale as the X-ray microprobe techniques. Since microscopic investigation of a relatively limited number of minute paint samples, taken from a given work of art, may not yield representative information about the entire artefact, several methods for macroscopic, non-invasive imaging have recently been developed. Those based on XRF scanning and full-field hyperspectral imaging appear very promising; some recent published results are discussed.
Address
Corporate Author Thesis
Publisher Springer international publishing ag Place of Publication Cham Editor
Language Wos 000391178900006 Publication Date 2016-11-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2365-0869;2364-8961; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.033 Times cited 50 Open Access
Notes ; ; Approved Most recent IF: 4.033
Call Number UA @ lucian @ c:irua:139930UA @ admin @ c:irua:139930 Serial 4443
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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 (down) 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
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Author Verbeeck, J.; Van Aert, S.
Title Model based quantification of EELS spectra Type A1 Journal article
Year 2004 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 101 Issue 2/4 Pages 207-224
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Recent advances in model based quantification of electron energy loss spectra (EELS) are reported. The maximum likelihood method for the estimation of physical parameters describing an EELS spectrum, the validation of the model used in this estimation procedure, and the computation of the attainable precision, that is, the theoretical lower bound on the variance of these estimates, are discussed. Experimental examples on An and GaAs samples show the power of the maximum likelihood method and show that the theoretical prediction of the attainable precision can be closely approached even for spectra with overlapping edges where conventional EELS quantification fails. To provide end-users with a low threshold alternative to conventional quantification, a user friendly program was developed which is freely available under a GNU public license. (C) 2004 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000224046100016 Publication Date 2004-07-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 147 Open Access
Notes Fwo; Iuap P5/01 Approved Most recent IF: 2.843; 2004 IF: 2.215
Call Number UA @ lucian @ c:irua:57130UA @ admin @ c:irua:57130 Serial 2101
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Author Hasanli, N.; Gauquelin, N.; Verbeeck, J.; Hadermann, J.; Hayward, M.A.
Title Small-moment paramagnetism and extensive twinning in the topochemically reduced phase Sr2ReLiO5.5 Type A1 Journal article
Year 2018 Publication Journal of the Chemical Society : Dalton transactions Abbreviated Journal Dalton T
Volume 47 Issue 44 Pages 15783-15790
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Reaction of the cation-ordered double perovskite Sr2ReLiO6 with dilute hydrogen at 475 degrees C leads to the topochemical deintercalation of oxide ions from the host lattice and the formation of a phase of composition Sr2ReLiO5.5, as confirmed by thermogravimetric and EELS data. A combination of neutron and electron diffraction data reveals the reduction process converts the -Sr2O2-ReLiO4-Sr2O2-ReLiO4- stacking sequence of the parent phase into a -Sr2O2-ReLiO3-Sr2O2-ReLiO4-, partially anion-vacant ordered sequence. Furthermore a combination of electron diffraction and imaging reveals Sr2ReLiO5.5 exhibits extensive twinning – a feature which can be attributed to the large, anisotropic volume expansion of the material on reduction. Magnetisation data reveal a strongly reduced moment of (eff) = 0.505(B) for the d(1) Re6+ centres in the phase, suggesting there remains a large orbital component to the magnetism of the rhenium centres, despite their location in low symmetry coordination environments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000450208000019 Publication Date 2018-10-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1477-9226 ISBN Additional Links UA library record; WoS full record
Impact Factor 4.029 Times cited Open Access Not_Open_Access
Notes Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award “Oxford Solid State Chemistry BAG to probe composition-structure-property relationships in solids” (EE13284). Experiments at the ISIS pulsed neutron facility were supported by a beam time allocation from the STFC. NH acknowledges funding from the “State Programme on Education of Azerbaijani Youth Abroad in 2007-2015” by the Ministry of Education of Azerbaijan. J. V. and N. G. acknowledge funding through the GOA project “Solarpaint” of the University of Antwerp. The microscope used in this work was partly funded by the Hercules Fund from the Flemish Government. Approved Most recent IF: 4.029
Call Number EMAT @ emat @c:irua:155771 Serial 5137
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Author Martinez, G.T.; de Backer, A.; Rosenauer, A.; Verbeeck, J.; Van Aert, S.
Title The effect of probe inaccuracies on the quantitative model-based analysis of high angle annular dark field scanning transmission electron microscopy images Type A1 Journal article
Year 2014 Publication Micron Abbreviated Journal Micron
Volume 63 Issue Pages 57-63
Keywords A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT)
Abstract (down) Quantitative structural and chemical information can be obtained from high angle annular dark field scanning transmission electron microscopy (HAADF STEM) images when using statistical parameter estimation theory. In this approach, we assume an empirical parameterized imaging model for which the total scattered intensities of the atomic columns are estimated. These intensities can be related to the material structure or composition. Since the experimental probe profile is assumed to be known in the description of the imaging model, we will explore how the uncertainties in the probe profile affect the estimation of the total scattered intensities. Using multislice image simulations, we analyze this effect for Cs corrected and non-Cs corrected microscopes as a function of inaccuracies in cylindrically symmetric aberrations, such as defocus and spherical aberration of third and fifth order, and non-cylindrically symmetric aberrations, such as 2-fold and 3-fold astigmatism and coma.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000338402500011 Publication Date 2014-01-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0968-4328; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.98 Times cited 25 Open Access
Notes FWO (G.0393.11; G.0064.10; G.0374.13; G.0044.13); European Research Council under the 7th Framework Program (FP7); ERC GrantNo. 246791-COUNTATOMS and ERC Starting Grant No. 278510-VORTEX. A.R. thanks the DFG under contract number RO2057/8-1.The research leading to these results has received funding fromthe European Union 7th Framework Programme [FP7/2007-2013]under grant agreement no. 312483 (ESTEEM2).; esteem2ta ECASJO; Approved Most recent IF: 1.98; 2014 IF: 1.988
Call Number UA @ lucian @ c:irua:113857UA @ admin @ c:irua:113857 Serial 831
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Author Palgrave, R.G.; Borisov, P.; Dyer, M.S.; McMitchell, S.R.C.; Darling, G.R.; Claridge, J.B.; Batuk, M.; Tan, H.; Tian, H.; Verbeeck, J.; Hadermann, J.; Rosseinsky, M.J.;
Title Artificial construction of the layered Ruddlesden-Popper manganite La2Sr2Mn3O10 by reflection high energy electron diffraction monitored pulsed laser deposition Type A1 Journal article
Year 2012 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
Volume 134 Issue 18 Pages 7700-7714
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Pulsed laser deposition has been used to artificially construct the n = 3 Ruddlesden Popper structure La2Sr2Mn3O10 in epitaxial thin film form by sequentially layering La1-xSrxMnO3 and SrO unit cells aided by in situ reflection high energy electron diffraction monitoring. The interval deposition technique was used to promote two-dimensional SrO growth. X-ray diffraction and cross-sectional transmission electron microscopy indicated that the trilayer structure had been formed. A site ordering was found to differ from that expected thermodynamically, with the smaller Sr2+ predominantly on the R site due to kinetic trapping of the deposited cation sequence. A dependence of the out-of-plane lattice parameter on growth pressure was interpreted as changing the oxygen content of the films. Magnetic and transport measurements on fully oxygenated films indicated a frustrated magnetic ground state characterized as a spin glass-like magnetic phase with the glass temperature T-g approximate to 34 K. The magnetic frustration has a clear in-plane (ab) magnetic anisotropy, which is maintained up to temperatures of 150 K. Density functional theory calculations suggest competing antiferromagnetic and ferromagnetic long-range orders, which are proposed as the origin of the low-temperature glassy state.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000303696200029 Publication Date 2012-03-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.858 Times cited 27 Open Access
Notes Fwo; Esteem 026019 Approved Most recent IF: 13.858; 2012 IF: 10.677
Call Number UA @ lucian @ c:irua:98947UA @ admin @ c:irua:98947 Serial 153
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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 (down) 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
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Author Lichtert, S.; Verbeeck, J.
Title Statistical consequences of applying a PCA noise filter on EELS spectrum images Type A1 Journal article
Year 2013 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 125 Issue Pages 35-42
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Principal component analysis (PCA) noise filtering is a popular method to remove noise from experimental electron energy loss (EELS) spectrum images. Here, we investigate the statistical behaviour of this method by applying it on a simulated data set with realistic noise levels. This phantom data set provides access to the true values contained in the data set as well as to many different realizations of the noise. Using least squares fitting and parameter estimation theory, we demonstrate that even though the precision on the estimated parameters can be better as the CramérRao lower bound, a significant bias is introduced which can alter the conclusions drawn from experimental data sets. The origin of this bias is in the incorrect retrieval of the principal loadings for noisy data. Using an expression for the bias and precision of the singular values from literature, we present an evaluation criterion for these singular values based on the noise level and the amount of information present in the data set. This criterion can help to judge when to avoid PCA noise filtering in practical situations. Further we show that constructing elemental maps of PCA noise filtered data using the background subtraction method, does not guarantee an increase in the signal to noise ratio due to correlation of the spectral data as a result of the filtering process.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000314679700006 Publication Date 2012-10-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 54 Open Access
Notes Fwo; Countatoms; Vortex; Esteem 312483; esteem2jra3 ECASJO; Approved Most recent IF: 2.843; 2013 IF: 2.745
Call Number UA @ lucian @ c:irua:105293 Serial 3153
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Author Zhou, Y.; Ramaneti, R.; Anaya, J.; Korneychuk, S.; Derluyn, J.; Sun, H.; Pomeroy, J.; Verbeeck, J.; Haenen, K.; Kuball, M.
Title Thermal characterization of polycrystalline diamond thin film heat spreaders grown on GaN HEMTs Type A1 Journal article
Year 2017 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 111 Issue 4 Pages 041901
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Polycrystalline diamond (PCD) was grown onto high-k dielectric passivated AlGaN/GaN-on-Si high electron mobility transistor (HEMT) structures, with film thicknesses ranging from 155 to 1000 nm. Transient thermoreflectance results were combined with device thermal simulations to investigate the heat spreading benefit of the diamond layer. The observed thermal conductivity (k(Dia)) of PCD films is one-to-two orders of magnitude lower than that of bulk PCD and exhibits a strong layer thickness dependence, which is attributed to the grain size evolution. The films exhibit a weak temperature dependence of k(Dia) in the measured 25-225 degrees C range. Device simulation using the experimental jDia and thermal boundary resistance values predicts at best a 15% reduction in peak temperature when the source-drain opening of a passivated AlGaN/GaN-on-Si HEMT is overgrown with PCD. Published by AIP Publishing.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000406779700008 Publication Date 2017-07-24
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 78 Open Access Not_Open_Access
Notes ; The authors are grateful to Professor Michael Uren and Dr. Roland B. Simon (University of Bristol) for helpful discussions and to Dr. Sien Drijkoningen (Hasselt University) for taking the SEM micrographs. This work was in part supported by DARPA under Contract No. FA8650-15-C-7517, monitored by Dr. Avram Bar Cohen and Dr. John Blevins, and supported by Dr. Joseph Maurer and Dr. Abirami Sivananthan. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of DARPA. Y.Z. acknowledges China Scholarship Council for the financial support. S.K. and J.V. acknowledge the FWO-Vlaanderen for financial support under contract G.0044.13N “Charge ordering.” ; Approved Most recent IF: 3.411
Call Number UA @ lucian @ c:irua:145203 Serial 4728
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Author Lu, Y.-G.; Turner, S.; Ekimov, E.A.; Verbeeck, J.; Van Tendeloo, G.
Title Boron-rich inclusions and boron distribution in HPHT polycrystalline superconducting diamond Type A1 Journal article
Year 2015 Publication Carbon Abbreviated Journal Carbon
Volume 86 Issue 86 Pages 156-162
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Polycrystalline boron-doped superconducting diamond, synthesized at high pressure and high temperature (HPHT) via a reaction of a single piece of crystalline boron with monolithic graphite, has been investigated by analytical transmission electron microscopy. The local boron distribution and boron environment have been studied by a combination of (scanning) transmission electron microscopy ((S)TEM) and spatially resolved electron energy-loss spectroscopy (EELS). High resolution TEM imaging and EELS elemental mapping have established, for the first time, the presence of largely crystalline diamond-diamond grain boundaries within the material and have evidenced the presence of substitutional boron dopants within individual diamond grains. Confirmation of the presence of substitutional B dopants has been obtained through comparison of acquired boron K-edge EELS fine structures with known references. This confirmation is important to understand the origin of superconductivity in polycrystalline B-doped diamond. In addition to the substitutional boron doping, boron-rich inclusions and triple-points, both amorphous and crystalline, with chemical compositions close to boron carbide B4C, are evidenced. (C) 2015 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000352922700019 Publication Date 2015-01-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-6223; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.337 Times cited 20 Open Access
Notes FWO; 246791 COUNTATOMS; 278510 VORTEX; Hercules ECASJO_; Approved Most recent IF: 6.337; 2015 IF: 6.196
Call Number c:irua:125994UA @ admin @ c:irua:125994 Serial 250
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Author Do, M.T.; Gauquelin, N.; Nguyen, M.D.; Blom, F.; Verbeeck, J.; Koster, G.; Houwman, E.P.; Rijnders, G.
Title Interface degradation and field screening mechanism behind bipolar-cycling fatigue in ferroelectric capacitors Type A1 Journal article
Year 2021 Publication Apl Materials Abbreviated Journal Apl Mater
Volume 9 Issue 2 Pages 021113
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract (down) Polarization fatigue, i.e., the loss of polarization of ferroelectric capacitors upon field cycling, has been widely discussed as an interface related effect. However, mechanism(s) behind the development of fatigue have not been fully identified. Here, we study the fatigue mechanisms in Pt/PbZr0.52Ti0.48O3/SrRuO3 (Pt/PZT/SRO) capacitors in which all layers are fabricated by pulsed laser deposition without breaking the vacuum. With scanning transmission electron microscopy, we observed that in the fatigued capacitor, the Pt/PZT interface becomes structurally degraded, forming a 5 nm-10 nm thick non-ferroelectric layer of crystalline ZrO2 and diffused Pt grains. We then found that the fatigued capacitors can regain the full initial polarization switching if the externally applied field is increased to at least 10 times the switching field of the pristine capacitor. These findings suggest that polarization fatigue is driven by a two-step mechanism. First, the transient depolarization field that repeatedly appears during the domain switching under field cycling causes decomposition of the metal/ferroelectric interface, resulting in a non-ferroelectric degraded layer. Second, this interfacial non-ferroelectric layer screens the external applied field causing an increase in the coercive field beyond the usually applied maximum field and consequently suppresses the polarization switching in the cycled capacitor. Our work clearly confirms the key role of the electrode/ferroelectric interface in the endurance of ferroelectric-based devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000630052100006 Publication Date 2021-02-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2166-532x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.335 Times cited 5 Open Access OpenAccess
Notes This work was supported by the Nederlandse Organisatie voor Wetenschappelijk Onderzoek through Grant No. F62.3.15559. The Qu-Ant-EM microscope and the direct electron detector were partly funded by the Hercules fund from the Flemish Government. N.G. and J.V. acknowledge funding from the GOA project “Solarpaint” of the University of Antwerp. This work has also received funding from the European Union's Horizon 2020 research and innovation program under Grant No. 823717-ESTEEM3. We acknowledge D. Chezganov for his useful insights. Approved Most recent IF: 4.335
Call Number UA @ admin @ c:irua:177663 Serial 6783
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Author Joy, R.M.; Pobedinskas, P.; Bourgeois, E.; Chakraborty, T.; Goerlitz, J.; Herrmann, D.; Noel, C.; Heupel, J.; Jannis, D.; Gauquelin, N.; D'Haen, J.; Verbeeck, J.; Popov, C.; Houssiau, L.; Becher, C.; Nesladek, M.; Haenen, K.
Title Photoluminescence of germanium-vacancy centers in nanocrystalline diamond films : implications for quantum sensing applications Type A1 Journal article
Year 2024 Publication ACS applied nano materials Abbreviated Journal
Volume 7 Issue 4 Pages 3873-3884
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract (down) Point defects in diamond, promising candidates for nanoscale pressure- and temperature-sensing applications, are potentially scalable in polycrystalline diamond fabricated using the microwave plasma-enhanced chemical vapor deposition (MW PE CVD) technique. However, this approach introduces residual stress in the diamond films, leading to variations in the characteristic zero phonon line (ZPL) of the point defect in diamond. Here, we report the effect of residual stress on germanium-vacancy (GeV) centers in MW PE CVD nanocrystalline diamond (NCD) films fabricated using single crystal Ge as the substrate and solid dopant source. GeV ensemble formation indicated by the zero phonon line (ZPL) at similar to 602 nm is confirmed by room temperature (RT) photoluminescence (PL) measurements. PL mapping results show spatial nonuniformity in GeV formation along with other defects, including silicon-vacancy centers in the diamond films. The residual stress in NCD results in shifts in the PL peak positions. By estimating a stress shift coefficient of (2.9 +/- 0.9) nm/GPa, the GeV PL peak position in the NCD film is determined to be between 598.7 and 603.2 nm. A larger ground state splitting due to the strain on a GeV-incorporated NCD pillar at a low temperature (10 K) is also reported. We also report the observation of intense ZPLs at RT that in some cases could be related to low Ge concentration and the surrounding crystalline environment. In addition, we also observe thicker microcrystalline diamond (MCD) films delaminate from the Ge substrate due to film residual stress and graphitic phase at the diamond/Ge substrate interface (confirmed by electron energy loss spectroscopy). Using this approach, a free-standing color center incorporated MCD film with dimensions up to 1 x 1 cm(2) is fabricated. Qualitative analysis using time-of-flight secondary ion mass spectroscopy reveals the presence of impurities, including Ge and silicon, in the MCD film. Our experimental results will provide insights into the scalability of GeV fabrication using the MW PE CVD technique and effectively implement NCD-based nanoscale-sensing applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001164609600001 Publication Date 2024-02-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2574-0970 ISBN Additional Links UA library record; WoS full record
Impact Factor 5.9 Times cited Open Access
Notes Approved Most recent IF: 5.9; 2024 IF: NA
Call Number UA @ admin @ c:irua:204826 Serial 9164
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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 (down) 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
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Author Krehl, J.; Guzzinati, G.; Schultz, J.; Potapov, P.; Pohl, D.; Martin, J.; Verbeeck, J.; Fery, A.; Büchner, B.; Lubk, A.
Title Spectral field mapping in plasmonic nanostructures with nanometer resolution Type A1 Journal article
Year 2018 Publication Nature communications Abbreviated Journal Nat Commun
Volume 9 Issue 1 Pages 4207
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract (down) Plasmonic nanostructures and -devices are rapidly transforming light manipulation technology by allowing to modify and enhance optical fields on sub-wavelength scales. Advances in this field rely heavily on the development of new characterization methods for the fundamental nanoscale interactions. However, the direct and quantitative mapping of transient electric and magnetic fields characterizing the plasmonic coupling has been proven elusive to date. Here we demonstrate how to directly measure the inelastic momentum transfer of surface plasmon modes via the energy-loss filtered deflection of a focused electron beam in a transmission electron microscope. By scanning the beam over the sample we obtain a spatially and spectrally resolved deflection map and we further show how this deflection is related quantitatively to the spectral component of the induced electric and magnetic fields pertaining to the mode. In some regards this technique is an extension to the established differential phase contrast into the dynamic regime.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000447074200005 Publication Date 2018-10-11
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 15 Open Access OpenAccess
Notes G.G. acknowledges support from a postdoctoral fellowship grant from the Fonds Wetenschappelijk Onderzoke-Vlaanderen (FWO). A.L. and J.K. have received funding from the European Research Council (ERC) under the Horizon 2020 research and innovation program of the European Union (grant agreement no. 715620). Approved Most recent IF: 12.124
Call Number EMAT @ emat @c:irua:154355 Serial 5058
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Author Ovsyannikov, S.V.; Bykov, M.; Bykova, E.; Kozlenko, D.P.; Tsirlin, A.A.; Karkin, A.E.; Shchennikov, V.V.; Kichanov, S.E.; Gou, H.; Abakumov, A.M.; Egoavil, R.; Verbeeck, J.; McCammon, C.; Dyadkin, V.; Chernyshov, D.; van Smaalen, S.; Dubrovinsky, L.S.
Title Charge-ordering transition in iron oxide Fe4O5 involving competing dimer and trimer formation Type A1 Journal article
Year 2016 Publication Nature chemistry Abbreviated Journal Nat Chem
Volume 8 Issue 8 Pages 501-508
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) Phase transitions that occur in materials, driven, for instance, by changes in temperature or pressure, can dramatically change the materials' properties. Discovering new types of transitions and understanding their mechanisms is important not only from a fundamental perspective, but also for practical applications. Here we investigate a recently discovered Fe4O5 that adopts an orthorhombic CaFe3O5-type crystal structure that features linear chains of Fe ions. On cooling below approximately 150 K, Fe4O5 undergoes an unusual charge-ordering transition that involves competing dimeric and trimeric ordering within the chains of Fe ions. This transition is concurrent with a significant increase in electrical resistivity. Magnetic-susceptibility measurements and neutron diffraction establish the formation of a collinear antiferromagnetic order above room temperature and a spin canting at 85 K that gives rise to spontaneous magnetization. We discuss possible mechanisms of this transition and compare it with the trimeronic charge ordering observed in magnetite below the Verwey transition temperature.
Address Bayerisches Geoinstitut, Universitat Bayreuth, Universitatsstrasse 30, D-95447, Bayreuth, Germany
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000374534100019 Publication Date 2016-04-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1755-4330 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 25.87 Times cited 51 Open Access
Notes S.V.O. acknowledges the financial support of the Deutsche Forschungsgemeinschaft (DFG) under project OV-110/1-3. A.E.K. and V.V.S. acknowledge the support of the Russian Foundation for Basic Research (Project 14–02–00622a). H.G. acknowledges the support from the Alexander von Humboldt (AvH) Foundation and the National Natural Science Foundation of China (No. 51201148). A.M.A., R.E. and J.V. acknowledge financial support from the European Commission (EC) under the Seventh Framework Programme (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483- ESTEEM2. R.E. acknowledges support from the EC under FP7 Grant No. 246102 IFOX. A.M.A. acknowledges funding from the Russian Science Foundation (Grant No. 14-13- 00680). A.A.T. acknowledges funding and from the Federal Ministry for Education and Research through the Sofja Kovalevkaya Award of the AvH Foundation. Funding from the Fund for Scientific Research Flanders under FWO Project G.0044.13N is acknowledged. M.B. and S.v.S. acknowledge support from the DFG under Project Sm55/15-2. We acknowledge the European Synchrotron Radiation Facility for the provision of synchrotron radiation facilities.; esteem2jra2; esteem2jra3 Approved Most recent IF: 25.87
Call Number c:irua:133593 c:irua:133593UA @ admin @ c:irua:133593 Serial 4068
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