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Author Béché, A.; Goris, B.; Freitag, B.; Verbeeck, J.
Title (up) Development of a fast electromagnetic beam blanker for compressed sensing in scanning transmission electron microscopy Type A1 Journal article
Year 2016 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 108 Issue 108 Pages 093103
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The concept of compressed sensing was recently proposed to significantly reduce the electron dose in scanning transmission electron microscopy (STEM) while still maintaining the main features in the image. Here, an experimental setup based on an electromagnetic beam blanker placed in the condenser plane of a STEM is proposed. The beam blanker deflects the beam with a random pattern, while the scanning coils are moving the beam in the usual scan pattern. Experimental images at both the medium scale and high resolution are acquired and reconstructed based on a discrete cosine algorithm. The obtained results confirm that compressed sensing is highly attractive to limit beam damage in experimental STEM even though some remaining artifacts need to be resolved.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000375329200043 Publication Date 2016-03-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 40 Open Access
Notes A.B and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX and under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2), from the GOA project SOLARPAINT and the POC project I13/009 from the University of Antwerp. B.G. acknowledges the Research Foundation Flanders (FWO Vlaanderen) for a postdoctoral research grant. The QuAnTem microscope was partially funded by the Hercules Foundation. We thank Zhaoliang Liao from the Mesa+ laboratory at the University of Twente for the perovskite test sample.; esteem2jra3 ECASJO; Approved Most recent IF: 3.411
Call Number c:irua:131895 c:irua:131895UA @ admin @ c:irua:131895 Serial 4023
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Author Roegiers, J.
Title (up) Development of combined photocatalytic and active carbon fiber technology for indoor air purification based on Multiphysics models Type Doctoral thesis
Year 2021 Publication Abbreviated Journal
Volume Issue Pages XXX, 197 p.
Keywords Doctoral thesis; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL)
Abstract Exposure to volatile organic compounds (VOCs) remains a major public health concern. Indoor VOC concentrations typically far exceed outdoor levels due to a variety of emission sources and the stringent insulation measures that are imposed today. Many attempts have been made to use photocatalysis for indoor air purification. In an ideal situation, photocatalysis is capable of complete mineralization of VOCs to H2O and CO2, without any byproduct formation. Moreover, the process can take place at standard atmospheric conditions, i.e. ambient temperature and atmospheric pressure. However, successful exploitation is still impeded due to low conversion efficiency, significant pressure loss (and hence a high energy consumption) and byproduct formation. In the first part of this thesis an attempt was made to tackles these problems by designing a novel type of photocatalytic (PCO) reactor. The PCO device consists of a cylindrical vessel filled with TiO2-coated glass tubes and equipped with UV fluorescence lamps. It was investigated in terms of fluid dynamics, coating properties, UV-light distribution and photocatalytic activity. Experimental data was later used to develop and calibrate a Multiphysics model. The model proved to be a useful tool for designing and upscaling the PCO reactor. Consequently, an optimized prototype reactor was constructed and tested according the CEN-EN-16846-1 standard for VOC removal. Although the prototype showed promising results for lab-scale conditions, it struggled with byproduct formation when purifying ppb-level VOCs. In the second part of this thesis, activated carbon adsorption was investigated in order to combine it with photocatalysis. Activated carbon fiber was opted for its fast kinetics, high adsorption capacity and thermo-electrical regeneration. The filter was studied in detail regarding the adsorption of polar and apolar VOCs at indoor air concentration levels and regeneration capabilities. Experimental data was used to develop a Multiphysics model for activated carbon adsorption as well. Consequently, a novel type of ACF filter was developed using the Multiphysics model, which was equipped with electrodes in the tips of the pleats for effective thermal regeneration. In the last part, the combination of both ACF and PCO was studied using a realistic case study. Based on the Multiphysics model, the feasibility of a so-called hybrid air purification device could be investigated. The Multiphysics model shows promising results for this hybrid PCO-ACF system and hence, a demo setup was constructed for future research.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:181137 Serial 6860
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Author Ribbens, S.; Meynen, V.; Van Tendeloo, G.; Ke, X.; Mertens, M.; Maes, B.U.W.; Cool, P.; Vansant, E.F.
Title (up) Development of photocatalytic efficient Ti-based nanotubes and nanoribbons by conventional and microwave assisted synthesis strategies Type A1 Journal article
Year 2008 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat
Volume 114 Issue 1/3 Pages 401-409
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA); Organic synthesis (ORSY)
Abstract Titanate nanotubes were prepared via a hydrothermal treatment of TiO2 powders (Riedel De Haen) in a basic solution. Morphology and structure of the prepared samples were characterized by high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), XRD, FT-Raman spectroscopy, nitrogen sorption and DSC. The photocatalytic activity was evaluated by photocatalytic oxidation of rhodamine 6G. Trititanate nanotubes (TTNT) with inner pore diameters between 4 and 4.2 nm and surface areas up till 360 m(2)/g could be synthesized. The synthesis route was modified by introduction of a calcination step, by applying a lower hydrothermal temperature and microwave irradiation in order to increase the photocatalytic activity of the porous photoactive nanotubular materials. Calcination and a softer hydrothermal treatment led to the formation of anatase without affecting the surface area and nanotubular shape of the samples. In this way, the photocatalytic activity of the original trititanate nanotubes could be significantly increased. By making use of microwave assisted synthesis, the photocatalytic activity call also be increased due to the presence of anatase. However, by applying microwave synthesis, a different structure was obtained, nanoribbons (NR) instead of nanotubcs, resulting in a decrease in surface area and porosity.
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Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000258432100040 Publication Date 2008-02-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1387-1811; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.615 Times cited 47 Open Access
Notes Fwo; Crp (Ua) Approved Most recent IF: 3.615; 2008 IF: 2.555
Call Number UA @ lucian @ c:irua:69696 Serial 683
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Author Razdobarin, A.G.; Mukhin, E.E.; Semenov, V.V.; Tolstyakov, S.Y.; Kochergin, M.M.; Kurskiev, G.S.; Podushnikova, K.A.; Kirilenko, D.A.; Sitnikova, A.A.; Konovalov, V.G.; Solodovchenko, S.I.; Nekhaieva, O.M.; Skorik, O.A.; Bondarenko, V.N.; Voitsenya, V.S.;
Title (up) Diagnostic mirrors with transparent protection layer for ITER Type A1 Journal article
Year 2011 Publication Fusion engineering and design Abbreviated Journal Fusion Eng Des
Volume 86 Issue 6-8 Pages 1341-1344
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Fast degradation of in-vessel optics is one of the most serious problems for all optical diagnostics in ITER. To provide the resistance to mechanical and thermal stresses along with a high stability of optical characteristics under deposition-dominated conditions we suggest using high-reflective metallic (Ag or Al) film mirrors coated on silicon substrate and protected with thin oxide film in the divertor Thomson Scattering (TS) diagnostics. The mirrors coated with Al2O3 and ZrO2 films were tested under irradiation by deuterium ions. The experimental results on the oxide films sputtering are discussed in the context of their applicability for the first mirror protection in ITER.
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Corporate Author Thesis
Publisher Elsevier science sa Place of Publication Amsterdam Editor
Language Wos 000297426500203 Publication Date 2011-03-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0920-3796; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.319 Times cited 6 Open Access
Notes Approved Most recent IF: 1.319; 2011 IF: 1.490
Call Number UA @ lucian @ c:irua:93631 Serial 686
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Author Doenen, M.; Zhang, L.; Erni, R.; Williams, O.A.; Hardy, A.; van Bael, M.K.; Wagner, P.; Haenen, K.; Nesladek, M.; Van Tendeloo, G.
Title (up) Diamond nucleation by carbon transport from buried nanodiamond TiO2 sol-gel composites Type A1 Journal article
Year 2009 Publication Advanced materials Abbreviated Journal Adv Mater
Volume 21 Issue 6 Pages 670-673
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000263492000007 Publication Date 2008-12-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648;1521-4095; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 19.791 Times cited 20 Open Access
Notes Fwo; Iap-P6/42; Esteem 026019 Approved Most recent IF: 19.791; 2009 IF: NA
Call Number UA @ lucian @ c:irua:76329 Serial 688
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Author Van Eynde, E.; Hu, Z.-Y.; Tytgat, T.; Verbruggen, S.W.; Watte, J.; Van Tendeloo, G.; Van Driessche, I.; Blust, R.; Lenaerts, S.
Title (up) Diatom silica-titania photocatalysts for air purification by bio-accumulation of different titanium sources Type A1 Journal article
Year 2016 Publication Environmental science : nano Abbreviated Journal Environ Sci-Nano
Volume 3 Issue 5 Pages 1052-1061
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL)
Abstract We present a green, biological production route for silica-titania photocatalysts using diatom microalgae. Diatoms are single-celled, eukaryotic microalgae (2-2000 mu m) that self-assemble soluble silicon (Si(OH)(4)) into intricate silica cell walls, called frustules. These diatom frustules are formed under ambient conditions and consist of hydrated silica with specific 3D morphologies and micro-meso or macroporosity. A remarkable characteristic of diatoms is their ability to bioaccumulate soluble titanium from cell culture medium and incorporate them into their nanostructured silica cell wall. Controlled cultivation of the diatom Pinnularia sp. on soluble titanium in a batch process resulted in the biological immobilisation of titanium dioxide in the porous 3D architecture of the frustules. Six different titanium sources are tested. The silica-titania frustules were isolated by treating the harvested Pinnularia cells with nitric acid (65%) or by high temperature treatment. Thermal annealing converted the amorphous titania into crystalline titania. The produced silica-titania material is evaluated towards photocatalytic activity for acetaldehyde (C2H4O) abatement. Frustules cultivated with TiBaldH showed the highest photocatalytic performance. Comparison of the photocatalytic activity with P25 reveals that P25 has a 4 fold higher photocatalytic activity, but when photocatalytic activity is normalized for titania content, the frustules show double activity. Further material characterization (morphology, crystallinity, surface area and elemental distribution) of the TiBaldH silica-titania frustules provides additional insight into their structure-activity relationship. These natural biosilicatitania materials have excellent properties for photocatalytic purposes, including high surface area (108 m(2) g(-1)) and good porosity, and show reliable immobilization of TiO2 in the ordered structure of the diatom frustule.
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Publisher Royal Society of Chemistry Place of Publication Cambridge Editor
Language Wos 000385257900011 Publication Date 2016-07-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2051-8153; 2051-8161 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.047 Times cited 7 Open Access
Notes ; ; Approved Most recent IF: 6.047
Call Number UA @ lucian @ c:irua:144751 Serial 4644
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Author Gan, Y.; Christensen, D.V.; Zhang, Y.; Zhang, H.; Krishnan, D.; Zhong, Z.; Niu, W.; Carrad, D.J.; Norrman, K.; von Soosten, M.; Jespersen, T.S.; Shen, B.; Gauquelin, N.; Verbeeck, J.; Sun, J.; Pryds, N.; Chen, Y.
Title (up) Diluted oxide interfaces with tunable ground states Type A1 Journal article
Year 2019 Publication Advanced materials Abbreviated Journal Adv Mater
Volume 31 Issue 10 Pages 1805970
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The metallic interface between two oxide insulators, such as LaAlO3/SrTiO3 (LAO/STO), provides new opportunities for electronics and spintronics. However, due to the presence of multiple orbital populations, tailoring the interfacial properties such as the ground state and metal-insulator transitions remains challenging. Here, an unforeseen tunability of the phase diagram of LAO/STO is reported by alloying LAO with a ferromagnetic LaMnO3 insulator without forming lattice disorder and at the same time without changing the polarity of the system. By increasing the Mn-doping level, x, of LaAl1-xMnxO3/STO (0 <= x <= 1), the interface undergoes a Lifshitz transition at x = 0.225 across a critical carrier density of n(c) = 2.8 x 10(13) cm(-2), where a peak T-SC approximate to 255 mK of superconducting transition temperature is observed. Moreover, the LaAl1-xMnxO3 turns ferromagnetic at x >= 0.25. Remarkably, at x = 0.3, where the metallic interface is populated by only d(xy) electrons and just before it becomes insulating, a same device with both signatures of superconductivity and clear anomalous Hall effect (7.6 x 10(12) cm(-2) < n(s) <= 1.1 x 10(13) cm(-2)) is achieved reproducibly. This provides a unique and effective way to tailor oxide interfaces for designing on-demand electronic and spintronic devices.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000460329300004 Publication Date 2019-01-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 19.791 Times cited 31 Open Access Not_Open_Access
Notes ; The authors thank the technical help from J. Geyti. J.R.S. acknowledges the support of the National Basic Research of China (2016YFA0300701, 2018YFA0305704), the National Natural Science Foundation of China (11520101002), and the Key Program of the Chinese Academy of Sciences. N.G., D.K., and J.V. acknowledge funding from the Geconcentreerde Onderzoekacties (GOA) project “Solarpaint” of the University of Antwerp, Belgium. ; Approved Most recent IF: 19.791
Call Number UA @ admin @ c:irua:158553 Serial 5245
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Author Mourdikoudis, S.; Chirea, M.; Altantzis, T.; Pastoriza-Santos, I.; Perez-Juste, J.; Silva, F.; Bals, S.; Liz-Marzan, L.M.
Title (up) Dimethylformamide-mediated synthesis of water-soluble platinum nanodendrites for ethanol oxidation electrocatalysis Type A1 Journal article
Year 2013 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 5 Issue 11 Pages 4776-4784
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Herein we describe the synthesis of water-soluble platinum nanodendrites in dimethylformamide (DMF), in the presence of polyethyleneimine (PEI) as a stabilizing agent. The average size of the dendrites is in the range of 20-25 nm while their porosity can be tuned by modifying the concentration of the metal precursor. Electron tomography revealed different crystalline orientations of nanocrystallites in the nanodendrites and allowed a better understanding of their peculiar branching and porosity. The high surface area of the dendrites (up to 22 m(2) g(-1)) was confirmed by BET measurements, while X-ray diffraction confirmed the abundance of high-index facets in the face-centered-cubic crystal structure of Pt. The prepared nanodendrites exhibit excellent performance in the electrocatalytic oxidation of ethanol in alkaline solution. Sensing, selectivity, cycleability and great tolerance toward poisoning were demonstrated by cyclic voltammetry measurements.
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Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000319008700028 Publication Date 2013-04-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364;2040-3372; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 50 Open Access
Notes Esf; 262348 Esmi Approved Most recent IF: 7.367; 2013 IF: 6.739
Call Number UA @ lucian @ c:irua:109060 Serial 705
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Author Ben Dkhil, S.; Perkhun, P.; Luo, C.; Mueller, D.; Alkarsifi, R.; Barulina, E.; Quiroz, Y.A.A.; Margeat, O.; Dubas, S.T.; Koganezawa, T.; Kuzuhara, D.; Yoshimoto, N.; Caddeo, C.; Mattoni, A.; Zimmermann, B.; Wuerfel, U.; Pfannmöller, M.; Bals, S.; Ackermann, J.; Videlot-Ackermann, C.
Title (up) Direct correlation of nanoscale morphology and device performance to study photocurrent generation in donor-enriched phases of polymer solar cells Type A1 Journal article
Year 2020 Publication Acs Applied Materials & Interfaces Abbreviated Journal Acs Appl Mater Inter
Volume 12 Issue 25 Pages 28404-28415
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The nanoscale morphology of polymer blends is a key parameter to reach high efficiency in bulk heterojunction solar cells. Thereby, research typically focusing on optimal blend morphologies while studying nonoptimized blends may give insight into blend designs that can prove more robust against morphology defects. Here, we focus on the direct correlation of morphology and device performance of thieno[3,4-b]-thiophene-alt-benzodithiophene (PTB7):[6,6]phenyl C-71 butyric acid methyl ester (PC71BM) bulk heterojunction (BHJ) blends processed without additives in different donor/acceptor weight ratios. We show that while blends of a 1:1.5 ratio are composed of large donor-enriched and fullerene domains beyond the exciton diffusion length, reducing the ratio below 1:0.5 leads to blends composed purely of polymer-enriched domains. Importantly, the photocurrent density in such blends can reach values between 45 and 60% of those reached for fully optimized blends using additives. We provide here direct visual evidence that fullerenes in the donor-enriched domains are not distributed homogeneously but fluctuate locally. To this end, we performed compositional nanoscale morphology analysis of the blend using spectroscopic imaging of low-energy-loss electrons using a transmission electron microscope. Charge transport measurement in combination with molecular dynamics simulations shows that the fullerene substructures inside the polymer phase generate efficient electron transport in the polymer-enriched phase. Furthermore, we show that the formation of densely packed regions of fullerene inside the polymer phase is driven by the PTB7:PC71BM enthalpy of mixing. The occurrence of such a nanoscale network of fullerene clusters leads to a reduction of electron trap states and thus efficient extraction of photocurrent inside the polymer domain. Suitable tuning of the polymer-acceptor interaction can thus introduce acceptor subnetworks in polymer-enriched phases, improving the tolerance for high-efficiency BHJ toward morphological defects such as donor-enriched domains exceeding the exciton diffusion length.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000543780900058 Publication Date 2020-06-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1944-8244 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.5 Times cited 7 Open Access OpenAccess
Notes ; J.A., O.M., and C.V.-A. acknowledge financial support by the French Fond Unique Interministeriel (FUI) under the project “SFUMATO” (Grant Number: F1110019V/ 201308815) as well as by the European Commission under the Project “SUNFLOWER” (FP7-ICT-2011-7, Grant Number: 287594). J.A., C.V.-A., and E.B. acknowledge the Association Nationale de la Recherche et de la Technologie (ANRT) and the Ministere de l'Enseignement Superieur, de la Recherche et de l'Innovation, awarded through the company Dracula Technologies (Valence, France), for framework of a CIFRE Ph.D. grant 2017/0529. J.A. and P.P. received funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant agreement no. 713750. They further acknowledge support of the Regional Council of Provence-Alpes-Cote d'Azur, A*MIDEX (no. ANR-11-IDEX-0001-02), and the Investissements d'Avenir project funded by the French Government, managed by the French National Research Agency (ANR). J.A. and Y.A.A.Q. acknowledge the French Research Agency for funding through the project NFA-15 (ANR-17-CE05-0020-01). N.Y. acknowledges that the synchrotron radiation experiments were performed at BL19B2 in SPring-8 with the approval of Japan Synchrotron Radiation Research Institute (JASRI) (proposal nos. 2017B1629 and 2018B1791). S.B. acknowledges financial support from the European Research Council (ERC Consolidator Grant 815128-REALNANO) and from FWO (G.0381.16N). M.P. gratefully acknowledges funding by the Ministerium fur Wissenschaft, Forschung und Kunst Baden-Wurttemberg through the HEiKA materials research centre FunTECH-3D (MWK, 33-753-30-20/3/3) and the Large-Scale-Data-Facility (LSDF) sds@hd through grant INST 35/1314-1 FUGG. A.M. acknowledges Italian MIUR for funding through the project PON04a2 00490 M2M Netergit, PRACE, for awarding access to Marconi KNL at CINECA, Italy, through projects DECONVOLVES (2018184466) and PROVING-IL (2019204911). C.C. acknowledges the CINECA award under the ISCRA initiative for the availability of high-performance computing resources and support (project MITOMASC). ; sygma Approved Most recent IF: 9.5; 2020 IF: 7.504
Call Number UA @ admin @ c:irua:170703 Serial 6484
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Author Bertoni, G.; Grillo, V.; Brescia, R.; Ke, X.; Bals, S.; Catellani, A.; Li, H.; Manna, L.
Title (up) Direct determination of polarity, faceting, and core location in colloidal core/shell wurtzite semiconductor nanocrystals Type A1 Journal article
Year 2012 Publication ACS nano Abbreviated Journal Acs Nano
Volume 6 Issue 7 Pages 6453-6461
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The ability to determine the atomic arrangement and termination of various facets of surfactant-coated nanocrystals is of great importance for understanding their growth mechanism and their surface properties and represents a critical piece of information that can be coupled to other experimental techniques and to calculations. This is especially appealing in the study of nanocrystals that can be grown in strongly anisotropic shapes, for which the relative growth rates of various facets can be influenced under varying reaction conditions. Here we show that in two representative cases of rod-shaped nanocrystals in the wurtzite phase (CdSe(core)/CdS(shell) and ZnSe(core)/ZnS(shell) nanorods) the terminations of the polar facets can be resolved unambiguously by combining advanced electron microscopy techniques, such as aberration-corrected HRTEM with exit wave reconstruction or aberration-corrected HAADF-STEM. The [0001] and [000-1] polar directions of these rods, which grow preferentially along their c-axis, are revealed clearly, with one side consisting of the Cd (or Zn)-terminated (0001) facet and the other side with a pronounced faceting due to Cd (or Zn)-terminated {10-1-1} facets. The lateral faceting of the rods is instead dominated by three nonpolar {10-10} facets. The core buried in the nanostructure can be localized in both the exit wave phase and HAADF-STEM images.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000306673800079 Publication Date 2012-06-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851;1936-086X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.942 Times cited 63 Open Access
Notes The authors gratefully acknowledge funding from the European Research Council under grant number 240111 (NANO-ARCH) and the financial support from the Flemish Hercules 3 Programme for large infrastructures. G.B. and V.G. thank E. Rotunno for his help with STEM_CELL and IWFR. Approved Most recent IF: 13.942; 2012 IF: 12.062
Call Number UA @ lucian @ c:irua:101138 Serial 710
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Author He, Z.; Ke, X.; Bals, S.; Van Tendeloo, G.
Title (up) Direct evidence for the existence of multi-walled carbon nanotubes with hexagonal cross-sections Type A1 Journal article
Year 2012 Publication Carbon Abbreviated Journal Carbon
Volume 50 Issue 7 Pages 2524-2529
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Carbon nanotubes (CNTs) with a polygonal cross-section have been paid increasing attention since their three-dimensional structure is related to specific physical properties, which are found to be different in comparison to CNTs with a circular cross-section. Here, we report the existence of novel multi-walled CNTs yielding walls with a rounded-hexagonal configuration. This structure was directly confirmed for the first time by both cross-sectional transmission electron microscopy and electron tomography. The morphology of the Fe catalytic particle also exhibits hexagonal characteristics, and is proposed as the origin of the formation of the rounded-hexagonal walls of the CNT. This observation is of great importance with respect to the design of polygonal (such as pentagonal or hexagonal) cross-sectional CNTs. By controlling the morphology of the catalytic nanoparticles it will be possible to grow CNTs with desired electronic and mechanical properties.
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Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000303038400015 Publication Date 2012-02-06
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 8 Open Access
Notes Fwo Approved Most recent IF: 6.337; 2012 IF: 5.868
Call Number UA @ lucian @ c:irua:96956 Serial 711
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Author Nistor, L.; Bender, H.; Vantomme, A.; Wu, M.F.; van Landuyt, J.; O'Donnell, K.P.; Martin, R.; Jacobs, K.; Moerman, I.
Title (up) Direct evidence of spontaneous quantum dot formation in a thick InGaN epilayer Type A1 Journal article
Year 2000 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 77 Issue 4 Pages 507-509
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We report a direct observation of quantum dots formed spontaneously in a thick InGaN epilayer by high resolution transmission electron microscopy. Investigation of a (280 nm thick) In0.22Ga0.78N single layer, emitting in the blue/green spectral region, reveals quantum dots with estimated sizes in the range of 1.5-3 nm. Such sizes are in very good agreement with calculations based on the luminescence spectra of this specimen. (C) 2000 American Institute of Physics. [S0003-6951(00)00930-X].
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Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000088225400016 Publication Date 2002-07-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 44 Open Access
Notes Approved Most recent IF: 3.411; 2000 IF: 3.906
Call Number UA @ lucian @ c:irua:103448 Serial 712
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Author Rossell, M.D.; Abakumov, A.M.; Ramasse, Q.M.; Erni, R.
Title (up) Direct evidence of stacking disorder in the mixed ionic-electronic conductor Sr4Fe6O12+\delta Type A1 Journal article
Year 2013 Publication ACS nano Abbreviated Journal Acs Nano
Volume 7 Issue 4 Pages 3078-3085
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Determining the structure-to-property relationship of materials becomes particularly challenging when the material under investigation is dominated by defects and structural disorder. Knowledge on the exact atomic arrangement at the defective structure is required to understand its influence on the functional properties. However, standard diffraction techniques deliver structural information that is averaged over many unit cells. In particular, information about defects and order-disorder phenomena is contained in the coherent diffuse scattering intensity which often is difficult to uniquely interpret. Thus, the examination of the local disorder in materials requires a direct method to study their structure on the atomic level with chemical sensitivity. Using aberration-corrected scanning transmission electron microscopy in combination with atomic-resolution electron energy-loss spectroscopy, we show that the controversial structural arrangement of the Fe2O2+delta layers in the mixed ionic-electronic conducting Sr4Fe6O12+delta perovskite can be unambiguously resolved. Our results provide direct experimental evidence for the presence of a nanomixture of “ordered” and “disordered” domains in an epitaxial Sr4Fe6O12+delta thin film. The most favorable arrangement is the disordered structure and is interpreted as a randomly occurring but well-defined local shift of the Fe-O chains in the Fe2O2+delta layers. By analyzing the electron energy-loss near-edge structure of the different building blocks in the Sr4Fe6O12+delta unit cell we find that the mobile holes in this mixed ionic-electronic conducting oxide are highly localized in the Fe2O2+delta layers, which are responsible for the oxide-ion conductivity. A possible link between disorder and oxygen-ion transport along the Fe2O2+delta layers is proposed by arguing that the disorder can effectively break the oxygen diffusion pathways.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000318143300021 Publication Date 2013-03-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851;1936-086X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.942 Times cited 4 Open Access
Notes Approved Most recent IF: 13.942; 2013 IF: 12.033
Call Number UA @ lucian @ c:irua:108476 Serial 713
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Author Meledina, M.; Turner, S.; Filippousi, M.; Leus, K.; Lobato, I.; Ramachandran, R.K.; Dendooven, J.; Detavernier, C.; Van Der Voort, P.; Van Tendeloo, G.
Title (up) Direct Imaging of ALD Deposited Pt Nanoclusters inside the Giant Pores of MIL-101 Type A1 Journal article
Year 2016 Publication Particle and particle systems characterization Abbreviated Journal Part Part Syst Char
Volume 33 Issue 33 Pages 382-387
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract MIL-101 giant-pore metal-organic framework (MOF) materials have been loaded with Pt nanoparticles using atomic layer deposition. The final structure has been investigated by aberration-corrected annular dark-field scanning transmission electron microscopy under strictly controlled low dose conditions. By combining the acquired experimental data with image simulations, the position of the small clusters within the individual pores of a metal-organic framework has been determined. The embedding of the Pt nanoparticles is confirmed by electron tomography, which shows a distinct ordering of the highly uniform Pt nanoparticles. The results show that atomic layer deposition is particularly well-suited for the deposition of individual nanoparticles inside MOF framework pores and that, upon proper regulation of the incident electron dose, annular dark-field scanning transmission electron microscopy is a powerful tool for the characterization of this type of materials at a local scale.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000379970000006 Publication Date 2016-02-20
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 11 Open Access
Notes S.T. and J.D. gratefully acknowledge the FWO Vlaanderen for a postdoctoral scholarship. The Titan microscope used for this investigation was partially funded by the Hercules foundation of the Flemish government. This work was supported by the Belgian IAP-PAI network. K.L. acknowledges the financial support from the Ghent University BOF postdoctoral Grant 01P06813T and UGent GOA Grant 01G00710. C.D. thanks the FWO Vlaanderen, BOF-UGent (GOA 01G01513), and the Hercules Foundation (AUGE/09/014) for financial support. Approved Most recent IF: 4.474
Call Number c:irua:131913 Serial 4028
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Author Turner, S.; Idrissi, H.; Sartori, A.F.; Korneychuck, S.; Lu, Y.-G.; Verbeeck, J.; Schreck, M.; Van Tendeloo, G.
Title (up) Direct imaging of boron segregation at dislocations in B:diamond heteroepitaxial films Type A1 Journal article
Year 2016 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 8 Issue 8 Pages 2212-2218
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract A thin film of heavily B-doped diamond has been grown epitaxially by microwave plasma chemical vapor deposition on an undoped diamond layer, on top of a Ir/YSZ/Si(001) substrate stack, to study the boron segregation and boron environment at the dislocations present in the film. The density and nature of the dislocations were investigated by conventional and weak-beam dark-field transmission electron microscopy techniques, revealing the presence of two types of dislocations: edge and mixed-type 45 degrees dislocations. The presence and distribution of B in the sample was studied using annular dark-field scanning transmission electron microscopy and spatially resolved electron energy-loss spectroscopy. Using these techniques, a segregation of B at the dislocations in the film is evidenced, which is shown to be intermittent along the dislocation. A single edge-type dislocation was selected to study the distribution of the boron surrounding the dislocation core. By imaging this defect at atomic resolution, the boron is revealed to segregate towards the tensile strain field surrounding the edge-type dislocations. An investigation of the fine structure of the B-K edge at the dislocation core shows that the boron is partially substitutionally incorporated into the diamond lattice and partially present in a lower coordination (sp(2)-like hybridization).
Address EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium. stuart.turner@uantwerpen.be
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000368860900053 Publication Date 2015-12-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 15 Open Access
Notes S. T. acknowledges the fund for scien tific research Flanders (FWO) for a post-doctoral scholarship and under contract number G.0044.13N Approved Most recent IF: 7.367
Call Number c:irua:131597UA @ admin @ c:irua:131597 Serial 4121
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Author Turner, S.; Lebedev, O.I.; Schroeder, F.; Fischer, R.A.; Van Tendeloo, G.
Title (up) Direct imaging of loaded metal-organic framework materials (metal@MOF-5) Type A1 Journal article
Year 2008 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 20 Issue 17 Pages 5622-5627
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We illustrate the potential of advanced transmission electron microscopy for the characterization of a new class of soft porous materials: metal@Zn4O(bdc)3 (metal@MOF-5; bdc = 1,4-benzenedicarboxylate). By combining several electron microscopy techniques (transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), electron diffraction (ED), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and electron tomography) and by carefully reducing the electron dose to avoid beam damage, it is possible to simultaneously characterize the MOF-5 framework material and the loaded metal nanoparticles. We also demonstrate that electron tomography can be used to accurately determine the position and distribution of the particles within the MOF-5 framework. To demonstrate the implementation of these microscopy techniques and what kind of results can be expected, measurements on gas-phase-loaded metal−organic framework materials Ru@MOF-5 and Pd@MOF-5 are presented.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000258941400021 Publication Date 2008-08-07
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 112 Open Access
Notes Esteem 026019 Approved Most recent IF: 9.466; 2008 IF: 5.046
Call Number UA @ lucian @ c:irua:76595 Serial 714
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Author Hoang, D.-Q.; Korneychuk, S.; Sankaran, K.J.; Pobedinskas, P.; Drijkoningen, S.; Turner, S.; Van Bael, M.K.; Verbeeck, J.; Nicley, S.S.; Haenen, K.
Title (up) Direct nucleation of hexagonal boron nitride on diamond : crystalline properties of hBN nanowalls Type A1 Journal article
Year 2017 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 127 Issue Pages 17-24
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Hexagonal boron nitride (hBN) nanowalls were deposited by unbalanced radio frequency sputtering on (100)-oriented silicon, nanocrystalline diamond films, and amorphous silicon nitride (Si3N4) membranes. The hBN nanowall structures were found to grow vertically with respect to the surface of all of the substrates. To provide further insight into the nucleation phase and possible lattice distortion of the deposited films, the structural properties of the different interfaces were characterized by transmission electron microscopy. For Si and Si3N4 substrates, turbostratic and amorphous BN phases form a clear transition zone between the substrate and the actual hBN phase of the bulk nanowalls. However, surprisingly, the presence of these phases was suppressed at the interface with a nanocrystalline diamond film, leading to a direct coupling of hBN with the diamond surface, independent of the vertical orientation of the diamond grain. To explain these observations, a growth mechanism is proposed in which the hydrogen terminated surface of the nanocrystalline diamond film leads to a rapid formation of the hBN phase during the initial stages of growth, contrary to the case of Si and Si3N4 substrates. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos Publication Date
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 Open Access OpenAccess
Notes Approved Most recent IF: 5.301
Call Number UA @ lucian @ c:irua:142398 Serial 4645
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Author Filippousi, M.; Turner, S.; Katsikini, M.; Pinakidou, F.; Zamboulis, D.; Pavlidou, E.; Van Tendeloo, G.
Title (up) Direct observation and structural characterization of natural and metal ion-exchanged HEU-type zeolites Type A1 Journal article
Year 2015 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat
Volume 210 Issue 210 Pages 185-193
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The atomic structure of natural HEU-type zeolite and two ion-exchanged variants of the zeolite, Ag+ (Ag-HEU) and Zn2+ (Zn-HEU) ion exchanged HEU-type zeolites, are investigated using advanced transmission electron microscopy techniques in combination with X-ray powder diffraction and X-ray absorption fine structure measurements. In both ion-exchanged materials, loading of the natural HEU zeolite is confirmed. Using low-voltage, aberration-corrected transmission electron microscopy at low-dose conditions, the local crystal structure of natural HEU-type zeolite is determined and the interaction of the ion-exchanged natural zeolites with the Ag+ and Zn2+ ions is studied. In the case of Ag-HEU, the presence of Ag+ ions and clusters at extra-framework sites as well as Ag nanoparticles has been confirmed. The Ag nanoparticles are preferentially positioned at the zeolite surface. For Zn-HEU, no large Zn(O) nanopartides are present, instead, the HEU channels are evidenced to be decorated by small Zn(O) clusters. (c) 2015 Elsevier Inc. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000353733300024 Publication Date 2015-02-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1387-1811; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.615 Times cited 5 Open Access
Notes 246791 Countatoms; Iap-Pai; Fwo Approved Most recent IF: 3.615; 2015 IF: 3.453
Call Number c:irua:126006 Serial 715
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Author Cui, W.; Lin, W.; Lu, W.; Liu, C.; Gao, Z.; Ma, H.; Zhao, W.; Van Tendeloo, G.; Zhao, W.; Zhang, Q.; Sang, X.
Title (up) Direct observation of cation diffusion driven surface reconstruction at van der Waals gaps Type A1 Journal article
Year 2023 Publication Nature communications Abbreviated Journal
Volume 14 Issue 1 Pages 554-10
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Weak interlayer van der Waals (vdW) bonding has significant impact on the surface/interface structure, electronic properties, and transport properties of vdW layered materials. Unraveling the complex atomistic dynamics and structural evolution at vdW surfaces is therefore critical for the design and synthesis of the next-generation vdW layered materials. Here, we show that Ge/Bi cation diffusion along the vdW gap in layered GeBi2Te4 (GBT) can be directly observed using in situ heating scanning transmission electron microscopy (STEM). The cation concentration variation during diffusion was correlated with the local Te-6 octahedron distortion based on a quantitative analysis of the atomic column intensity and position in time-elapsed STEM images. The in-plane cation diffusion leads to out-of-plane surface etching through complex structural evolutions involving the formation and propagation of a non-centrosymmetric GeTe2 triple layer surface reconstruction on fresh vdW surfaces, and GBT subsurface reconstruction from a septuple layer to a quintuple layer. Our results provide atomistic insight into the cation diffusion and surface reconstruction in vdW layered materials. Weak interlayer van der Waals (vdW) bonding has significant impact on the structure and properties of vdW layered materials. Here authors use in-situ aberration-corrected ADF-STEM for an atomistic insight into the cation diffusion in the vdW gaps and the etching of vdW surfaces at high temperatures.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001076227200001 Publication Date 2023-02-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 16.6 Times cited Open Access
Notes Approved Most recent IF: 16.6; 2023 IF: 12.124
Call Number UA @ admin @ c:irua:201342 Serial 9021
Permanent link to this record
 

 
Author De Meulenaere, P.; Van Tendeloo, G.; van Landuyt, J.
Title (up) Direct observation of clusters in some FCC alloys by HREM Type A1 Journal article
Year 1994 Publication Icem Abbreviated Journal
Volume 13 Issue Pages 447-448
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos A1994BE09X00207 Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record;
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:10052 Serial 716
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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 (up) Direct observation of enhanced magnetism in individual size- and shape-selected 3d transition metal nanoparticles Type A1 Journal article
Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 95 Issue 95 Pages 195404
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Magnetic nanoparticles are critical building blocks for future technologies ranging from nanomedicine to spintronics. Many related applications require nanoparticles with tailored magnetic properties. However, despite significant efforts undertaken towards this goal, a broad and poorly understood dispersion of magnetic properties is reported, even within monodisperse samples of the canonical ferromagnetic 3d transition metals. We address this issue by investigating the magnetism of a large number of size- and shape-selected, individual nanoparticles of Fe, Co, and Ni using a unique set of complementary characterization techniques. At room temperature, only superparamagnetic behavior is observed in our experiments for all Ni nanoparticles within the investigated sizes, which range from 8 to 20 nm. However, Fe and Co nanoparticles can exist in two distinct magnetic states at any size in this range: (i) a superparamagnetic state, as expected from the bulk and surface anisotropies known for the respective materials and as observed for Ni, and (ii) a state with unexpected stable magnetization at room temperature. This striking state is assigned to significant modifications of the magnetic properties arising from metastable lattice defects in the core of the nanoparticles, as concluded by calculations and atomic structural characterization. Also related with the structural defects, we find that the magnetic state of Fe and Co nanoparticles can be tuned by thermal treatment enabling one to tailor their magnetic properties for applications. This paper demonstrates the importance of complementary single particle investigations for a better understanding of nanoparticle magnetism and for full exploration of their potential for applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000400665300002 Publication Date 2017-05-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 21 Open Access OpenAccess
Notes We thank A. Weber, R. Schelldorfer, and J. Krbanjevic (Paul Scherrer Institut) for technical assistance. This paper was supported by the Swiss Nanoscience Institute, University of Basel. A.F.R. acknowledges support from the MICIIN “Ramón y Cajal” Programme. A.B. and J.V. acknowledge funding from the European Union under the European Research Council (ERC) Starting Grant No. 278510 VORTEX and under a contract for Integrated Infrastructure Initiative ESTEEM2 No. 312483. R.Y. and U.N. thank the Deutsche Forschungsgemeinschaft for financial support via Sonderforschungsbereich 1214. Part of this work was performed at the Surface/Interface: Microscopy (SIM) beamline of the Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland. Approved Most recent IF: 3.836
Call Number EMAT @ emat @ c:irua:143634UA @ admin @ c:irua:143634 Serial 4575
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Author Van Aert, S.; Turner, S.; Delville, R.; Schryvers, D.; Van Tendeloo, G.; Salje, E.K.H.
Title (up) Direct observation of ferrielectricity at ferroelastic domain boundaries in CaTiO3 by electron microscopy Type A1 Journal article
Year 2012 Publication Advanced materials Abbreviated Journal Adv Mater
Volume 24 Issue 4 Pages 523-527
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract High-resolution aberration-corrected transmission electron microscopy aided by statistical parameter estimation theory is used to quantify localized displacements at a (110) twin boundary in orthorhombic CaTiO3. The displacements are 36 pm for the Ti atoms and confined to a thin layer. This is the first direct observation of the generation of ferroelectricity by interfaces inside this material which opens the door for domain boundary engineering.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000299156400011 Publication Date 2011-12-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 19.791 Times cited 150 Open Access
Notes Fwo Approved Most recent IF: 19.791; 2012 IF: 14.829
Call Number UA @ lucian @ c:irua:94110 Serial 717
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Author Gonnissen, J.; Batuk, D.; Nataf, G.F.; Jones, L.; Abakumov, A.M.; Van Aert, S.; Schryvers, D.; Salje, E.K.H.
Title (up) Direct Observation of Ferroelectric Domain Walls in LiNbO3: Wall-Meanders, Kinks, and Local Electric Charges Type A1 Journal article
Year 2016 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
Volume 26 Issue 26 Pages 7599-7604
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Direct observations of the ferroelectric domain boundaries in LiNbO3 are performed using high-resolution high-angle annular dark field scanning transmission electron microscopy imaging, revealing a very narrow width of the domain wall between the 180° domains. The domain walls demonstrate local side-way meandering, which results in inclinations even when the overall wall orientation follows the ferroelectric polarization. These local meanders contain kinks with “head-to-head” and “tail-to-tail” dipolar configurations and are therefore locally charged. The charged meanders are confined to a few cation layers along the polarization direction and are separated by longer stretches of straight domain walls.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000388166700006 Publication Date 2016-09-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301X ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 23 Open Access
Notes J.G. acknowledges the support from the Research Foundation Flanders (FWO, Belgium) through various project fundings (G.0368.15N, G.0369.15N, and G.0374.13N), as well as the financial support from the European Union Seventh Framework Program (FP7/2007–2013) under Grant agreement no. 312483 (ESTEEM2). The authors thank J. Hadermann for useful suggestions on the interpretation of the HAADFSTEM images. E.K.H.S. thanks the EPSRC (EP/K009702/1) and the Leverhulme Trust (EM-2016-004) for support. G.F.N. thanks the National Research Fund, Luxembourg (FNR/P12/4853155/Kreisel) for support.; esteem2_jra2 Approved Most recent IF: 12.124
Call Number c:irua:135336 c:irua:135336 Serial 4129
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Author Nistor, L.C.; van Landuyt, J.; Ralchenko, V.G.; Kononenko, T.V.; Obraztsova, E.D.; Strelnitsky, V.E.
Title (up) Direct observation of laser-induced crystallization of a-C : H films Type A1 Journal article
Year 1994 Publication Applied physics A : materials science & processing Abbreviated Journal
Volume 58 Issue 2 Pages 137-144
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The post-growth modification of diamond-like amorphous hydrogenated carbon a-C:H films by laser treatment has been studied by transmission electron microscopy and Raman spectroscopy. a-C:H films grown on Si substrates by benzene decomposition in a rf glow discharge were irradiated with 15 ns pulses of a KrF-excimer laser with fluences in the ran e of E = 50-700 mJ/cm(2). At fluences below 100 mJ/cm(2) an increase in the number of graphitic clusters and in their ordering was evidenced from Raman spectra, while the film structure remained amorphous according to electron microscopy and electron diffraction observations. At higher fluences the appearance of diamond particles of 2-7 nm size, embedded into the lower crystallized graphitic matrix, was observed and simultaneously a progressive growth of graphite nanocrystals with dimensions from 2 nm to 4 nm was deduced from Raman measurements. The maximum thickness of the crystallized surface layer (approximate to 400 nm) and the degree of laser annealing are limited by the film ablation which starts at E > 250 mJ/cm(2). The laser-treated areas lose their chemical inertness. In particular, chemical etching in chromium acid becomes possible, which may be used for patterning the highly inert carbon films.
Address
Corporate Author Thesis
Publisher Place of Publication Heidelberg Editor
Language Wos A1994MU87700005 Publication Date 2004-10-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0721-7250;1432-0630; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 73 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:99924 Serial 718
Permanent link to this record
 

 
Author Chen, L.; Elibol, K.; Cai, H.; Jiang, C.; Shi, W.; Chen, C.; Wang, H.S.; Wang, X.; Mu, X.; Li, C.; Watanabe, K.; Taniguchi, T.; Guo, Y.; Meyer, J.C.; Wang, H.
Title (up) Direct observation of layer-stacking and oriented wrinkles in multilayer hexagonal boron nitride Type A1 Journal article
Year 2021 Publication 2d Materials Abbreviated Journal 2D Mater
Volume 8 Issue 2 Pages 024001
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Hexagonal boron nitride (h-BN) has long been recognized as an ideal substrate for electronic devices due to its dangling-bond-free surface, insulating nature and thermal/chemical stability. These properties of the h-BN multilayer are mainly determined by its lattice structure. Therefore, to analyse the lattice structure and orientation of h-BN crystals becomes important. Here, the stacking order and wrinkles of h-BN are investigated by transmission electron microscopy. It is experimentally confirmed that the layers in the h-BN flakes are arranged in the AA ' stacking. The wrinkles in a form of threefold network throughout the h-BN crystal are oriented along the armchair direction, and their formation mechanism was further explored by molecular dynamics simulations. Our findings provide a deep insight about the microstructure of h-BN and shed light on the structural design/electronic modulations of two-dimensional crystals.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000605937500001 Publication Date 2020-12-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.937 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 6.937
Call Number UA @ admin @ c:irua:174950 Serial 6723
Permanent link to this record
 

 
Author Altantzis, T.; Coutino-Gonzalez, E.; Baekelant, W.; Martinez, G.T.; Abakumov, A.M.; Van Tendeloo, G.; Roeffaers, M.B.J.; Bals, S.; Hofkens, J.
Title (up) Direct Observation of Luminescent Silver Clusters Confined in Faujasite Zeolites Type A1 Journal article
Year 2016 Publication ACS nano Abbreviated Journal Acs Nano
Volume 10 Issue 10 Pages 7604-7611
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract One of the ultimate goals in the study of metal clusters is the correlation between the atomic-scale organization and their physicochemical properties. However, direct observation of the atomic organization of such minuscule metal clusters is heavily hindered by radiation damage imposed by the different characterization techniques. We present direct evidence of the structural arrangement, at an atomic level, of luminescent silver species stabilized in faujasite (FAU) zeolites using aberration-corrected scanning transmission electron microscopy. Two different silver clusters were identified in Ag-FAU zeolites, a trinuclear silver species associated with green emission and a tetranuclear silver species related to yellow emission. By combining direct imaging with complementary information obtained from X-ray powder diffraction and Rietveld analysis, we were able to elucidate the main differences at an atomic scale between luminescent (heat-treated) and nonluminescent (cation-exchanged) Ag-FAU zeolites. It is expected that such insights will trigger the directed synthesis of functional metal nanocluster-zeolite composites with tailored luminescent properties.
Address RIES, Hokkaido University , N20W10, Kita-Ward Sapporo 001-0020, Japan
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000381959100043 Publication Date 2016-07-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.942 Times cited 57 Open Access OpenAccess
Notes The authors gratefully acknowledge financial support from the Belgian Federal government (Belspo through the IAP-VI/27 and IAP-VII/05 programs), the European Union’s Seventh Framework Programme (FP7/2007-2013 under grant agreement no. 310651 SACS and no. 312483-ESTEEM2), the Flemish government in the form of long-term structural funding “Methusalem” grant METH/15/04 CASAS2, the Hercules foundation (HER/11/14), the “Strategisch Initiatief Materialen” SoPPoM program, and the Fund for Scientific Research Flanders (FWO) grants G.0349.12 and G.0B39.15. S.B. acknowledges funding from ERC Starting Grant COLOURATOMS (335078). The authors thank Prof. S. Van Aert for helpful discussions, Dr. T. De Baerdemaeker for XRD measurements, Mr. B. Dieu for the preparation of graphical material, and UOP Antwerp for the kind donation of zeolite samples.; esteem2jra4; ECASSara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); Approved Most recent IF: 13.942
Call Number c:irua:134576 c:irua:134576 Serial 4102
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Author Das, P.; Koblischka, M.R.; Turner, S.; Van Tendeloo, G.; Wolf, T.; Jirsa, M.; Hartmann, U.
Title (up) Direct observation of nanometer-scale pinning sites in (Nd0.33Eu0.20Gd0.47)Ba2Cu3O7-\delta single crystals Type A1 Journal article
Year 2008 Publication Europhysics letters Abbreviated Journal Epl-Europhys Lett
Volume 83 Issue 3 Pages 37005,1-37005,4
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We report on the observation of self-organized stripe-like structures on the as-grown surface and in the bulk of (Nd,Eu,Gd)Ba2Cu3Oy single crystals. The periodicity of the stripes on the surface lies between 500800 nm. These are possibly the growth steps of the crystal. Transmission electron microscopy investigations revealed stripes of periodicity in the range of 2040 nm in the bulk. From electron back scattered diffraction investigations, no crystallographic misorientation due to the nanostripes has been found. Scanning tunneling spectroscopic experiments revealed nonsuperconducting regions, running along twin directions, which presumably constitute strong pinning sites.
Address
Corporate Author Thesis
Publisher Place of Publication Paris Editor
Language Wos 000259022600032 Publication Date 2008-07-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0295-5075;1286-4854; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.957 Times cited 5 Open Access
Notes Approved Most recent IF: 1.957; 2008 IF: 2.203
Call Number UA @ lucian @ c:irua:76496 Serial 719
Permanent link to this record
 

 
Author Jenkinson, K.; Spadaro, M.C.; Golovanova, V.; Andreu, T.; Morante, J.R.; Arbiol, J.; Bals, S.
Title (up) Direct operando visualization of metal support interactions induced by hydrogen spillover during CO₂ hydrogenation Type A1 Journal article
Year 2023 Publication Advanced materials Abbreviated Journal
Volume 35 Issue 51 Pages 2306447-10
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The understanding of catalyst active sites is a fundamental challenge for the future rational design of optimized and bespoke catalysts. For instance, the partial reduction of Ce4+ surface sites to Ce3+ and the formation of oxygen vacancies are critical for CO2 hydrogenation, CO oxidation, and the water gas shift reaction. Furthermore, metal nanoparticles, the reducible support, and metal support interactions are prone to evolve under reaction conditions; therefore a catalyst structure must be characterized under operando conditions to identify active states and deduce structure-activity relationships. In the present work, temperature-induced morphological and chemical changes in Ni nanoparticle-decorated mesoporous CeO2 by means of in situ quantitative multimode electron tomography and in situ heating electron energy loss spectroscopy, respectively, are investigated. Moreover, operando electron energy loss spectroscopy is employed using a windowed gas cell and reveals the role of Ni-induced hydrogen spillover on active Ce3+ site formation and enhancement of the overall catalytic performance.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001106139400001 Publication Date 2023-10-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648 ISBN Additional Links UA library record; WoS full record
Impact Factor 29.4 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 29.4; 2023 IF: 19.791
Call Number UA @ admin @ c:irua:201143 Serial 9022
Permanent link to this record
 

 
Author Lin, K.; Pescarmona, P.P.; Houthoofd, K.; Liang, D.; Van Tendeloo, G.; Jacobs, P.A.
Title (up) Direct room-temperature synthesis of methyl-functionalized Ti-MCM-41 nanoparticles and their catalytic performance in epoxidation Type A1 Journal article
Year 2009 Publication Journal of catalysis Abbreviated Journal J Catal
Volume 263 Issue 1 Pages 75-82
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Methyl-functionalized Ti-MCM-41 nanoparticles with a size of 80 to 160 nm (Me-Ti-MCM-41 NP) were directly prepared via a dilute solution route by the co-condensation of tetraethoxysilane and methylalkoxysilanes in sodium hydroxide medium at room temperature. The characterization results showed the existence of ordered hexagonal mesoporous structure and tetrahedral Ti species in the nanoparticles. In the epoxidation of cyclohexene with tert-butyl hydroperoxide and aqueous H2O2, Me-Ti-MCM-41 NP samples displayed higher turnover frequencies (TOFs) for cyclohexene and initial reaction rates compared to Ti-MCM-41 and methyl-functionalized Ti-MCM-41 with normal particle size and to non-functionalized Ti-MCM-41 nanoparticles. Simultaneously, a higher selectivity for cyclohexene epoxide was observed in the case of aqueous H2O2, suggesting that the hydrolysis of cyclohexene epoxide with water is reduced on Me-Ti-MCM-41 NP samples. The improved catalytic behavior of Me-Ti-MCM-41 NP is discussed both in terms of the nanosize and methylation of the surface of the catalyst particles. The regeneration of Me-Ti-MCM-41 NP with tert-butyl hydroperoxide solution was evaluated via washing and calcination approaches.
Address
Corporate Author Thesis
Publisher Place of Publication San Diego, Calif. Editor
Language Wos 000265000800008 Publication Date 2009-02-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-9517; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.844 Times cited 89 Open Access
Notes Iwt; Iap; Goa Approved Most recent IF: 6.844; 2009 IF: 5.288
Call Number UA @ lucian @ c:irua:76395 Serial 720
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Author Zhang, Y.; Qin, S.; Claes, N.; Schilling, W.; Sahoo, P.K.; Ching, H.Y.V.; Jaworski, A.; Lemière, F.; Slabon, A.; Van Doorslaer, S.; Bals, S.; Das, S.
Title (up) Direct Solar Energy-Mediated Synthesis of Tertiary Benzylic Alcohols Using a Metal-Free Heterogeneous Photocatalyst Type A1 Journal article
Year 2022 Publication ACS Sustainable Chemistry and Engineering Abbreviated Journal Acs Sustain Chem Eng
Volume 10 Issue 1 Pages 530-540
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Organic synthesis (ORSY)
Abstract Direct hydroxylation via the functionalization of tertiary benzylic C(sp3)-H bond is of great significance for obtaining tertiary alcohols which find wide applications in pharmaceuticals as well as in fine chemical industries. However, current synthetic procedures use toxic reagents and therefore, the development of a sustainable strategy for the synthesis of tertiary benzyl alcohols is highly desirable. To solve this problem, herein, we report a metal-free

heterogeneous photocatalyst to synthesize the hydroxylated products using oxygen as the key reagent. Various benzylic substrates were employed into our mild reaction conditions to afford the desirable products in good to excellent yields. More importantly, gram-scale reaction was achieved via harvesting direct solar energy and exhibited high quantity of the product. The high stability of the catalyst was proved via recycling the catalyst and spectroscopic analyses. Finally, a possible mechanism was proposed based on the EPR and other experimental

evidence.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000736518000001 Publication Date 2022-01-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2168-0485 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.4 Times cited 24 Open Access OpenAccess
Notes We thank BOF joint PhD grant (to Y. Z.), Francqui Foundation and FWO research grant (to S.D.), Chinese Scholarship Council (to Y.Z.). A.S. would like to thank the Swedish Energy Agency for financial support (project nr: 5050-1). The SEM microscope was partly funded by the Hercules Fund from the Flemish Government. Approved Most recent IF: 8.4
Call Number EMAT @ emat @c:irua:184744 Serial 6900
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