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Author Li, K.; Béché, A.; Song, M.; Sha, G.; Lu, X.; Zhang, K.; Du, Y.; Ringer, S.P.; Schryvers, D.
Title Atomistic structure of Cu-containing \beta" precipitates in an Al-Mg-Si-Cu alloy Type A1 Journal article
Year 2014 Publication Scripta materialia Abbreviated Journal (up) Scripta Mater
Volume 75 Issue Pages 86-89
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The beta '' precipitates in a peak-aged Al-Mg-Si-Cu alloy were measured with an average composition of 28.6Al-38.7Mg-26.5Si-5.17Cu (at.%) using atom probe tomography. High-angle annular dark-field observations revealed that Cu incompletely substitutes for the Mg-1 and Si-3 columns, preferentially for one column in each pair of Si-3. Cu-free Si columns form a parallelogram-shaped network that constitutes the basis of subsequent precipitates in the system, with a = 0.37 nm, b = 0.38 nm, gamma = 113 degrees and c = 0.405 nm. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000331025200022 Publication Date 2013-12-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6462; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.747 Times cited 22 Open Access
Notes Approved Most recent IF: 3.747; 2014 IF: 3.224
Call Number UA @ lucian @ c:irua:115749 Serial 201
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Author Wang, X.; Li, K.; Schryvers, D.; Verlinden, B.; Van Humbeeck, J.
Title R-phase transition and related mechanical properties controlled by low-temperature aging treatment in a Ti50.8 at.% Ni thin wire Type A1 Journal article
Year 2014 Publication Scripta materialia Abbreviated Journal (up) Scripta Mater
Volume 72-73 Issue Pages 21-24
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract A cold-drawn Ti50.8 at.% Ni wire was annealed at 600 °C for 30 min, followed by aging at 250 °C for different times. A microstructure with small grains and nanoscaled precipitates was obtained. The thermally induced martensite transformation is suppressed in the samples aged for 4 h or longer, leaving a one-stage R-phase transition between −150 and +150 °C. The transformation behavior, work output and recovery stress associated with the R-phase transition are presented.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000329148500006 Publication Date 2013-10-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6462; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.747 Times cited 27 Open Access
Notes Fwo Approved Most recent IF: 3.747; 2014 IF: 3.224
Call Number UA @ lucian @ c:irua:111847 Serial 2806
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Author Chizhov, A.S.; Rumyantseva, M.N.; Vasiliev, R.B.; Filatova, D.G.; Drozdov, K.A.; Krylov, I.V.; Abakumov, A.M.; Gaskov, A.M.
Title Visible light activated room temperature gas sensors based on nanocrystalline ZnO sensitized with CdSe quantum dots Type A1 Journal article
Year 2014 Publication Sensors and actuators : B : chemical Abbreviated Journal (up) Sensor Actuat B-Chem
Volume 205 Issue Pages 305-312
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract This work reports the study of photoconductivity and visible light activated room temperature gas sensors properties of nanocrystalline ZnO thick films sensitized with colloidal CdSe quantum dots (QDs). Nanocrystalline zinc oxide (ZnO) was synthesized by the precipitation method. Colloidal CdSe quantum dots were obtained by high temperature colloidal synthesis. Sensitization was effectuated by three different procedures including direct adsorption of CdSe QDs stabilized with oleic acid on ZnO surface, anchoring to the ZnO surface through a bifunctional molecule of mercaptopropionic acid (MPA), and coating of CdSe QDs with a monolayer of MPA with subsequent adsorption on ZnO surface. Sensor measurements demonstrated that obtained QD CdSe/ZnO nanocomposites can be used for NO2 detection under visible (green) light illumination at room temperature without any thermal heating. (C) 2014 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Lausanne Editor
Language Wos 000343117600041 Publication Date 2014-09-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-4005; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.401 Times cited 36 Open Access
Notes Approved Most recent IF: 5.401; 2014 IF: 4.097
Call Number UA @ lucian @ c:irua:121107 Serial 3848
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Author Rather, J.A.; Pilehvar, S.; De Wael, K.
Title A graphene oxide amplification platform tagged with tyrosinase-zinc oxide quantum dot hybrids for the electrochemical sensing of hydroxylated polychlorobiphenyls Type A1 Journal article
Year 2014 Publication Sensors and actuators : B : chemical Abbreviated Journal (up) Sensor Actuat B-Chem
Volume 190 Issue Pages 612-620
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Graphene oxide can act as an amplification platform for the immobilization of a hybrid structure composed of tyrosinase (Tyr) and zinc oxide quantum dots (ZnO QDs). This article describes how this platform increases the sensitivity for the detection of hydroxylated polychlorobiphenyls (OH-PCBs). The adsorption of Tyr (with low isoelectric point) on the positively charged surface of ZnO QDs is based on electrostatic interactions. The scanning electron microscopic images and UVvis spectroscopic analysis demonstrated the adsorption of Tyr on ZnO QDs. The stepwise assembly process of the fabricated biosensor was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The synthesized ZnO QDs and graphene oxide were characterized by Raman spectroscopy, infrared spectroscopy, X-ray diffraction and scanning electron microscopic techniques. The determination of OH-PCBs was carried out by using square wave voltammetry over the concentration range of 2.827.65 μM with a detection limit of 0.15 μM with good reproducibility, selectivity and acceptable stability. The high value of surface coverage of ZnO QDs and small value of MichaelisMenten constant (View the MathML source) confirmed an excellent loading of the Tyr and a high affinity of the biosensor toward the detection of OH-PCBs. This biosensor and the described sensing platform offer a great potential for rapid, cost-effective and on-field analysis of OH-PCBs.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000326687700082 Publication Date 2013-09-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-4005 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.401 Times cited 26 Open Access
Notes ; The authors are highly thankful for the mobility grant (Non-Europe Postdoc Fellowship) for one of the author (Jahangir Ahmad Rather) supported by the Belgian Federal Science Policy (Belspo) co-funded by the Marie Curie Actions from the European Commission. Sanaz Pilehvar is funded by BOF-DOCPRO UA. We are also thankful to the EMAT (Electron Microscopy for Materials Science) group and Laboratory of adsorption and catalysis group of the University of Antwerp for the XRD, Raman and FTIR characterization of samples (GO and ZnO QDs). ; Approved Most recent IF: 5.401; 2014 IF: 4.097
Call Number UA @ admin @ c:irua:110566 Serial 5636
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Author Pilehvar, S.; Dierckx, T.; Blust, R.; Breugelmans, T.; De Wael, K.
Title An electrochemical impedimetric aptasensing platform for sensitive and selective detection of small molecules such as chloramphenicol Type A1 Journal article
Year 2014 Publication Sensors Abbreviated Journal (up) Sensors-Basel
Volume 14 Issue 7 Pages 12059-12069
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Applied Electrochemistry & Catalysis (ELCAT)
Abstract We report on the aptadetection of chloramphenicol (CAP) using electrochemical impedance spectroscopy. The detection principle is based on the changes of the interfacial properties of the electrode after the interaction of the ssDNA aptamers with the target molecules. The electrode surface is partially blocked due to the formation of the aptamer-CAP complex, resulting in an increase of the interfacial electron-transfer resistance of the redox probe detected by electrochemical impedance spectroscopy or cyclic voltammetry. We observed that the ratio of polarization resistance had a linear relationship with the concentrations of CAP in the range of 1.76127 nM, and a detection limit of 1.76 nM was obtained. The covalent binding of CAP-aptamer on the electrode surface combined with the unique properties of aptamers and impedimetric transduction leads to the development of a stable and sensitive electrochemical aptasensor for CAP.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000340035700041 Publication Date 2014-07-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1424-8220 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.677 Times cited 34 Open Access
Notes ; We are thankful to UA-DOCPRO and UA-BOFACA for financial support. ; Approved Most recent IF: 2.677; 2014 IF: 2.245
Call Number UA @ admin @ c:irua:117845 Serial 5592
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Author Rehor, I.; Slegerova, J.; Kucka, J.; Proks, V.; Petrakova, V.; Adam, M.P.; Treussart, F.; Turner, S.; Bals, S.; Sacha, P.; Ledvina, M.; Wen, A.M.; Steinmetz, N.F.; Cigler, P.;
Title Fluorescent nanodiamonds embedded in biocompatible translucent shells Type A1 Journal article
Year 2014 Publication Small Abbreviated Journal (up) Small
Volume 10 Issue 6 Pages 1106-1115
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract High pressure high temperature (HPHT) nanodiamonds (NDs) represent extremely promising materials for construction of fluorescent nanoprobes and nanosensors. However, some properties of bare NDs limit their direct use in these applications: they precipitate in biological solutions, only a limited set of bio-orthogonal conjugation techniques is available and the accessible material is greatly polydisperse in shape. In this work, we encapsulate bright 30-nm fluorescent nanodiamonds (FNDs) in 1020-nm thick translucent (i.e., not altering FND fluorescence) silica shells, yielding monodisperse near-spherical particles of mean diameter 66 nm. High yield modification of the shells with PEG chains stabilizes the particles in ionic solutions, making them applicable in biological environments. We further modify the opposite ends of PEG chains with fluorescent dyes or vectoring peptide using click chemistry. High conversion of this bio-orthogonal coupling yielded circa 2000 dye or peptide molecules on a single FND. We demonstrate the superior properties of these particles by in vitro interaction with human prostate cancer cells: while bare nanodiamonds strongly aggregate in the buffer and adsorb onto the cell membrane, the shell encapsulated NDs do not adsorb nonspecifically and they penetrate inside the cells.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000333538000012 Publication Date 2014-02-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1613-6810; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.643 Times cited 79 Open Access Not_Open_Access
Notes 262348 ESMI; Hercules; FWO Approved Most recent IF: 8.643; 2014 IF: 8.368
Call Number UA @ lucian @ c:irua:115566 Serial 1234
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Author Kundu, S.; Kundu, P.; Van Tendeloo, G.; Ravishankar, N.
Title Au2Sx/CdS nanorods by cation exchange : mechanistic insights into the competition between cation-exchange and metal ion reduction Type A1 Journal article
Year 2014 Publication Small Abbreviated Journal (up) Small
Volume 10 Issue 19 Pages 3895-3900
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Thumbnail image of graphical abstract It is well known that metals with higher electron affinity like Au tend to undergo reduction rather than cation-exchange. It is experimentally shown that under certain conditions cation-exchange is dominant over reduction. Thermodynamic calculation further consolidates the understanding and paves the way for better predictability of cation-exchange/reduction reactions for other systems.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000344451900011 Publication Date 2014-06-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1613-6810; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.643 Times cited 8 Open Access
Notes countatoms Approved Most recent IF: 8.643; 2014 IF: 8.368
Call Number UA @ lucian @ c:irua:118010 Serial 3514
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Author Gaouyat, L.; He, Z.; Colomer, J.-F.; Lambin, P.; Mirabella, F.; Schryvers, D.; Deparis, O.
Title Revealing the innermost nanostructure of sputtered NiCrOx solar absorber cermets Type A1 Journal article
Year 2014 Publication Solar energy materials and solar cells Abbreviated Journal (up) Sol Energ Mat Sol C
Volume 122 Issue Pages 303-308
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Conversion of solar energy into thermal energy helps reducing consumption of non-renewable energies. Cermets (ceramicmetal composites) are versatile materials suitable, amongst other applications, for solar selective absorbers. Although the presence of metallic Ni particles in the dielectric matrix is a prerequisite for efficient solar selective absorption in NiCrOx cermets, no clear evidence of such particles is reported so far. By combining comprehensive chemical and structural analyses, we reveal the presumed nanostructure which is at the origin of the remarkable optical properties of this cermet material. Using sputtered NiCrOx layers in a solar absorber multilayer stack on aluminium substrate allows us to achieve solar absorptance as high as α=96.1% while keeping thermal emissivity as low as ε=2.2%, both values being comparable to best values recorded so far. With the nanostructure of sputtered NiCrOx cermets eventually revealed, further optimization of solar absorbers can be anticipated and technological exploitation of cermet materials in other applications can be foreseen.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000331494200040 Publication Date 2013-11-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0927-0248; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.784 Times cited 12 Open Access
Notes Approved Most recent IF: 4.784; 2014 IF: 5.337
Call Number UA @ lucian @ c:irua:113086 Serial 2902
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Author Wang, H.; Picot, T.; Houben, K.; Moorkens, T.; Grigg, J.; Van Haesendonck, C.; Biermans, E.; Bals, S.; Brown, S.A.; Vantomme, A.; Temst, K.; Van Bael, M.J.;
Title The superconducting proximity effect in epitaxial Al/Pb nanocomposites Type A1 Journal article
Year 2014 Publication Superconductor science and technology Abbreviated Journal (up) Supercond Sci Tech
Volume 27 Issue 1 Pages 015008-8
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We have investigated the superconducting properties of Pb nanoparticles with a diameter ranging from 8 to 20 nm, synthesized by Pb+ ion implantation in a crystalline Al matrix. A detailed structural characterization of the nanocomposites reveals the highly epitaxial relation between the Al crystalline matrix and the Pb nanoparticles. The Al/Pb nanocomposites display a single superconducting transition, with the critical temperature T-c increasing with the Pb content. The dependence of T-c on the Pb/Al volume ratio was compared with theoretical models of the superconducting proximity effect based on the bulk properties of Al and Pb. A very good correspondence with the strong-coupling proximity effect model was found, with an electron-phonon coupling constant in the Pb nanoparticles slightly reduced compared to bulk Pb. Our result differs from other studies on Pb nanoparticle based proximity systems where weak-coupling models were found to better describe the T-c dependence. We infer that the high interface quality resulting from the ion implantation synthesis method is a determining factor for the superconducting properties. Critical field and critical current measurements support the high quality of the nanocomposite superconducting films.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000328275000010 Publication Date 2013-11-28
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 2 Open Access Not_Open_Access
Notes ; This work was supported by the Research Foundation-Flanders (FWO), the KU Leuven BOF Concerted Research Action programs (GOA/09/006, the KU Leuven BOF CREA/12/015 project, and GOA/14/007) and the EU FP7 program SPIRIT (227012). TP and KH are postdoctoral research fellow and doctoral fellow of the FWO. ; Approved Most recent IF: 2.878; 2014 IF: 2.325
Call Number UA @ lucian @ c:irua:112833 Serial 3599
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Author Bothner, D.; Seidl, R.; Misko, V.R.; Kleiner, R.; Koelle, D.; Kemmler, M.
Title Unusual commensurability effects in quasiperiodic pinning arrays induced by local inhomogeneities of the pinning site density Type A1 Journal article
Year 2014 Publication Superconductor science and technology Abbreviated Journal (up) Supercond Sci Tech
Volume 27 Issue 6 Pages 065002
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We experimentally investigate the magnetic field dependence of the critical current I-c(B) of superconducting niobium thin films patterned with periodic and quasiperiodic antidot arrays on the submicron scale. For this purpose we monitor current-voltage characteristics at different values of B and temperature T. We investigate samples with antidots positioned at the vertices of two different tilings with quasiperiodic symmetry, namely the Shield Tiling and the Tuebingen Triangle Tiling. For reference we investigate a sample with a triangular antidot lattice. We find modulations of the critical current for both quasiperiodic tilings, which have partly been predicted by numerical simulations but not observed in experiments yet. The particularity of these commensurability effects is that they correspond to magnetic field values slightly above an integer multiple of the matching field. The observed matching effects can be explained by the caging of interstitial vortices in quasiperiodically distributed cages and the formation of symmetry-induced giant vortices.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000336494900003 Publication Date 2014-04-03
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 7 Open Access
Notes ; This work has been supported by the European Research Council via SOCATHES and by the Deutsche Forschungsgemeinschaft via the SFB/TRR 21. DB gratefully acknowledges support by the Evangelisches Studienwerk e.V. Villigst. MK gratefully acknowledges support by the Carl-Zeiss Stiftung. VRM gratefully acknowledges support by the 'Odysseus' Program of the Flemish Government and the Flemish Science Foundation (FWO-VI). The authors thank Franco Nori for fruitful discussions on quasiperiodic pinning arrays. ; Approved Most recent IF: 2.878; 2014 IF: 2.325
Call Number UA @ lucian @ c:irua:117763 Serial 3817
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Author Lamas, J.S.; Leroy, W.P.; Lu, Y.-G.; Verbeeck, J.; Van Tendeloo, G.; Depla, D.
Title Using the macroscopic scale to predict the nano-scale behavior of YSZ thin films Type A1 Journal article
Year 2014 Publication Surface and coatings technology Abbreviated Journal (up) Surf Coat Tech
Volume 238 Issue Pages 45-50
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In this work, Yttria-stabilized zirconia (YSZ) thin films were deposited using dual reactive magnetron sputtering. By varying the deposition conditions, the film morphology and texture of the thin films are tuned and biaxial alignment is obtained. Studying the crystallographic and microstructural properties of the YSZ thin films, a tilted columnar growth was identified. This tilt is shown to be dependent on the compositional gradient of the sample. The variation of composition within a single YSZ column measured via STEM-EDX is demonstrated to be equal to the macroscopic variation on a full YSZ sample when deposited under the same deposition parameters. A simple stress model was developed to predict the tilt of the growing columns. The results indicate that this model not only determines the column bending of the growing film but also confirms that a macroscopic approach is sufficient to determine the compositional gradient in a single column of the YSZ thin films. (C) 2013 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Lausanne Editor
Language Wos 000331028200005 Publication Date 2013-10-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0257-8972; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.589 Times cited 8 Open Access
Notes 246791 Countatoms; 278510 Vortex;Nmp3-La-2010-246102 Ifox; 312483 Esteem2; esteem2jra3 ECASJO; Approved Most recent IF: 2.589; 2014 IF: 1.998
Call Number UA @ lucian @ c:irua:115765 Serial 3827
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Author E. Zaghi, A.; Buffière, M.; Koo, J.; Brammertz, G.; Batuk, M.; Verbist, C.; Hadermann, J.; Kim, W.K.; Meuris, M.; Poortmans, J.; Vleugels, J.;
Title Effect of selenium content of CuInSex alloy nanopowder precursors on recrystallization of printed CuInSe2 absorber layers during selenization heat treatment Type A1 Journal article
Year 2014 Publication Thin solid films : an international journal on the science and technology of thin and thick films Abbreviated Journal (up) Thin Solid Films
Volume Issue Pages 1-7
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Polycrystalline CuInSe2 semiconductors are efficient light absorber materials for thin film solar cell technology, whereas printing is one of the promising low cost and non-vacuum approaches for the fabrication of thin film solar cells. The printed precursors are transformed into a dense polycrystalline CuInSe2 semiconductor film via thermal treatment in ambient selenium atmosphere (selenization). In this study, the effect of the selenium content in high purity mechanically synthesized CuInSex (x = 2, 1.5, 1 or 0.5) alloy precursors on the recrystallization of the CuInSe2 phase during the selenization process was investigated. The nanostructure and phase variation of CuInSex nanopowders were investigated by different characterization techniques. The recrystallization process of the 12 μm thick CuInSex coatings into the CuInSe2 phase during selenization in selenium vapor was investigated via in-situ high temperature X-ray diffraction. The CuInSex precursors with lower selenium content showed a more pronounced phase conversion into CuInSe2 compared to the higher selenium content CuInSex precursors. Moreover, the CuInSex (x = 0.5 and 1) precursor resulted in a denser polycrystalline CuInSe2 semiconductor film with larger crystals. This could be attributed to a more intensive atomic interdiffusion within the CuInSex precursor system compared to a CuInSe2 phase precursor, and the formation of intermediate CuSe and CuSe2 fluxing phases during selenization.
Address
Corporate Author Thesis
Publisher Place of Publication Lausanne Editor
Language Wos 000352225900004 Publication Date 2014-10-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0040-6090; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.879 Times cited 7 Open Access
Notes Approved Most recent IF: 1.879; 2014 IF: 1.759
Call Number c:irua:121330 Serial 834
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Author Shenderova, O.; Vargas, A.; Turner, S.; Ivanov, D.M.; Ivanov, M.G.
Title Nanodiamond-based nanolubricants : investigation of friction surfaces Type A1 Journal article
Year 2014 Publication Tribology transactions Abbreviated Journal (up) Tribol T
Volume 57 Issue 6 Pages 1051-1057
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Synergistic compositions of detonation nanodiamond (DND) particles with polytetrafluoroethylene and molybdenum dialkyldithiophosphate were used in ring-on-ring, four-ball, and block-on-ring tests as an additive to polyalphaolefins and engine oils. Modest to significant reductions in the friction coefficients, wear, or both were observed. In the wear scars produced in the block-on-ring tests, the friction surfaces were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and profilometry. Significant polishing effects of the friction surfaces in lubricants containing DND were revealed in SEM observations and roughness measurements. The roughness of the scar surfaces produced in the presence of DND additives was about 35% lower than the roughness of the scars observed in pure oil experiments.
Address
Corporate Author Thesis
Publisher Place of Publication Park Ridge, Ill. Editor
Language Wos 000345317900009 Publication Date 2014-06-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1040-2004;1547-397X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.685 Times cited 23 Open Access
Notes Approved Most recent IF: 1.685; 2014 IF: 1.349
Call Number UA @ lucian @ c:irua:122161 Serial 2252
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Author Egoavil, R.; Gauquelin, N.; Martinez, G.T.; Van Aert, S.; Van Tendeloo, G.; Verbeeck, J.
Title Atomic resolution mapping of phonon excitations in STEM-EELS experiments Type A1 Journal article
Year 2014 Publication Ultramicroscopy Abbreviated Journal (up) Ultramicroscopy
Volume 147 Issue Pages 1-7
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Atomically resolved electron energy-loss spectroscopy experiments are commonplace in modern aberration-corrected transmission electron microscopes. Energy resolution has also been increasing steadily with the continuous improvement of electron monochromators. Electronic excitations however are known to be delocalized due to the long range interaction of the charged accelerated electrons with the electrons in a sample. This has made several scientists question the value of combined high spatial and energy resolution for mapping interband transitions and possibly phonon excitation in crystals. In this paper we demonstrate experimentally that atomic resolution information is indeed available at very low energy losses around 100 meV expressed as a modulation of the broadening of the zero loss peak. Careful data analysis allows us to get a glimpse of what are likely phonon excitations with both an energy loss and gain part. These experiments confirm recent theoretical predictions on the strong localization of phonon excitations as opposed to electronic excitations and show that a combination of atomic resolution and recent developments in increased energy resolution will offer great benefit for mapping phonon modes in real space.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000343157400001 Publication Date 2014-05-29
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 22 Open Access
Notes 246102 IFOX; 278510 VORTEX; 246791 COUNTATOMS; Hercules; 312483 ESTEEM2; esteem2jra3 ECASJO; Approved Most recent IF: 2.843; 2014 IF: 2.436
Call Number UA @ lucian @ c:irua:118332UA @ admin @ c:irua:118332 Serial 177
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Author Niermann, T.; Verbeeck, J.; Lehmann, M.
Title Creating arrays of electron vortices Type A1 Journal article
Year 2014 Publication Ultramicroscopy Abbreviated Journal (up) Ultramicroscopy
Volume 136 Issue Pages 165-170
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We demonstrate the production of an ordered array of electron vortices making use of an electron optical setup consisting of two electrostatic biprisms. The biprism filaments are oriented nearly orthogonal with respect to each other in a transmission electron microscope. Matching the position of the filaments, we can choose to form different topological features in the electron wave. We outline the working principle of the setup and demonstrate fist experimental results. This setup partially bridges the gap between angular momentum carried by electron spin, which is intrinsic and therefore present in any position of the wave, and angular momentum carried by the vortex character of the wave, which can be extrinsic depending on the axis around which it is measured. (C) 2013 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000327884700021 Publication Date 2013-10-15
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 9 Open Access
Notes FP7; Countatoms; Vortex ECASJO_; Approved Most recent IF: 2.843; 2014 IF: 2.436
Call Number UA @ lucian @ c:irua:112837UA @ admin @ c:irua:112837 Serial 538
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Author Lubk, A.; Javon, E.; Cherkashin, N.; Reboh, S.; Gatel, C.; Hytch, M.
Title Dynamic scattering theory for dark-field electron holography of 3D strain fields Type A1 Journal article
Year 2014 Publication Ultramicroscopy Abbreviated Journal (up) Ultramicroscopy
Volume 136 Issue Pages 42-49
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Dark-held electron holography maps strain in crystal lattices into reconstructed phases over large fields of view. Here we investigate the details of the lattice strain-reconstructed phase relationship by applying dynamic scattering theory both analytically and numerically. We develop efficient analytic linear projection rules for 3D strain fields, facilitating a straight-forward calculation of reconstructed phases from 3D strained materials. They are used in the following to quantify the influence of various experimental parameters like strain magnitude, specimen thickness, excitation error and surface relaxation. (C) 2013 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000327884700006 Publication Date 2013-07-29
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 18 Open Access
Notes European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative (Reference312483 – ESTEEM2); esteem2_jra4 Approved Most recent IF: 2.843; 2014 IF: 2.436
Call Number UA @ lucian @ c:irua:112836 Serial 766
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Author Javon, E.; Lubk; Cours, R.; Reboh, S.; Cherkashin, N.; Houdellier, F.; Gatel, C.; Hytch, M.J.
Title Dynamical effects in strain measurements by dark-field electron holography Type A1 Journal article
Year 2014 Publication Ultramicroscopy Abbreviated Journal (up) Ultramicroscopy
Volume 147 Issue Pages 70-85
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Here, we study the effect of dynamic scattering on the projected geometric phase and strain maps reconstructed using dark-field electron holography (DFEH) for non-uniformly strained crystals. The investigated structure consists of a {SiGe/Si} superlattice grown on a (001)-Si substrate. The three dimensional strain held within the thin TEM lamella is modelled by the finite element method. The observed projected strain is simulated in two ways by multiplying the strain at each depth in the crystal by a weighting function determined from a recently developed analytical two-beam dynamical theory, and by simply taking the average value. We demonstrate that the experimental results need to be understood in terms of the dynamical theory and good agreement is found between the experimental and simulated results. Discrepancies do remain for certain cases and are likely to be from an imprecision in the actual two-beam diffraction conditions, notably the deviation parameter, and points to limitations in the 2-beam approximation. Finally, a route towards a 3D reconstruction of strain fields is proposed. (C) 2014 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000343157400009 Publication Date 2014-07-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 10 Open Access
Notes Approved Most recent IF: 2.843; 2014 IF: 2.436
Call Number UA @ lucian @ c:irua:121108 Serial 769
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Author Schattschneider, P.; Löffler, S.; Stöger-Pollach, M.; Verbeeck, J.
Title Is magnetic chiral dichroism feasible with electron vortices? Type A1 Journal article
Year 2014 Publication Ultramicroscopy Abbreviated Journal (up) Ultramicroscopy
Volume 136 Issue Pages 81-85
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We discuss the feasibility of detecting magnetic transitions with focused electron vortex probes, suggested by selection rules for the magnetic quantum number. We theoretically estimate the dichroic signal strength in the L2,3 edge of ferromagnetic d metals. It is shown that under realistic conditions, the dichroic signal is undetectable for nanoparticles larger than View the MathML source. This is confirmed by a key experiment with nanometer-sized vortices.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000327884700011 Publication Date 2013-07-26
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 64 Open Access
Notes Countatoms; Vortex; Esteem2; esteem2jra3 ECASJO; Approved Most recent IF: 2.843; 2014 IF: 2.436
Call Number UA @ lucian @ c:irua:110952UA @ admin @ c:irua:110952 Serial 1750
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Author Van den Broek, W.; Rosenauer, A.; Van Aert, S.; Sijbers, J.; van Dyck, D.
Title A memory efficient method for fully three-dimensional object reconstruction with HAADF STEM Type A1 Journal article
Year 2014 Publication Ultramicroscopy Abbreviated Journal (up) Ultramicroscopy
Volume 141 Issue Pages 22-31
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract The conventional approach to object reconstruction through electron tomography is to reduce the three-dimensional problem to a series of independent two-dimensional slice-by-slice reconstructions. However, at atomic resolution the image of a single atom extends over many such slices and incorporating this image as prior knowledge in tomography or depth sectioning therefore requires a fully three-dimensional treatment. Unfortunately, the size of the three-dimensional projection operator scales highly unfavorably with object size and readily exceeds the available computer memory. In this paper, it is shown that for incoherent image formation the memory requirement can be reduced to the fundamental lower limit of the object size, both for tomography and depth sectioning. Furthermore, it is shown through multislice calculations that high angle annular dark field scanning transmission electron microscopy can be sufficiently incoherent for the reconstruction of single element nanocrystals, but that dynamical diffraction effects can cause classification problems if more than one element is present. (C) 2014 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000335766600004 Publication Date 2014-03-22
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 6 Open Access
Notes ResearchFoundationFlanders(FWO;G.0393.11; G.0064.10;andG.0374.13); European Union Seventh Frame- workProgramme [FP7/2007-2013]under Grant agreement no. 312483 (ESTEEM2).; esteem2jra2; esteem2jra4 Approved Most recent IF: 2.843; 2014 IF: 2.436
Call Number UA @ lucian @ c:irua:117650 Serial 1992
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Author Chen, D.; Goris, B.; Bleichrodt, F.; Heidari Mezerji, H.; Bals, S.; Batenburg, K.J.; de With, G.; Friedrich, H.
Title The properties of SIRT, TVM, and DART for 3D imaging of tubular domains in nanocomposite thin-films and sections Type A1 Journal article
Year 2014 Publication Ultramicroscopy Abbreviated Journal (up) Ultramicroscopy
Volume 147 Issue Pages 137-148
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In electron tomography, the fidelity of the 3D reconstruction strongly depends on the employed reconstruction algorithm. In this paper, the properties of SIRT, TVM and DART reconstructions are studied with respect to having only a limited number of electrons available for imaging and applying different angular sampling schemes. A well-defined realistic model is generated, which consists of tubular domains within a matrix having slab-geometry. Subsequently, the electron tomography workflow is simulated from calculated tilt-series over experimental effects to reconstruction. In comparison with the model, the fidelity of each reconstruction method is evaluated qualitatively and quantitatively based on global and local edge profiles and resolvable distance between particles. Results show that the performance of all reconstruction methods declines with the total electron dose. Overall, SIRT algorithm is the most stable method and insensitive to changes in angular sampling. TVM algorithm yields significantly sharper edges in the reconstruction, but the edge positions are strongly influenced by the tilt scheme and the tubular objects become thinned. The DART algorithm markedly suppresses the elongation artifacts along the beam direction and moreover segments the reconstruction which can be considered a significant advantage for quantification. Finally, no advantage of TVM and DART to deal better with fewer projections was observed.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000343157400015 Publication Date 2014-08-19
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 42 Open Access OpenAccess
Notes Fwo Approved Most recent IF: 2.843; 2014 IF: 2.436
Call Number UA @ lucian @ c:irua:119073 Serial 2729
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Author Martinez, G.T.; Rosenauer, A.; de Backer, A.; Verbeeck, J.; Van Aert, S.
Title Quantitative composition determination at the atomic level using model-based high-angle annular dark field scanning transmission electron microscopy Type A1 Journal article
Year 2014 Publication Ultramicroscopy Abbreviated Journal (up) Ultramicroscopy
Volume 137 Issue Pages 12-19
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract High angle annular dark field scanning transmission electron microscopy (HAADF STEM) images provide sample information which is sensitive to the chemical composition. The image intensities indeed scale with the mean atomic number Z. To some extent, chemically different atomic column types can therefore be visually distinguished. However, in order to quantify the atomic column composition with high accuracy and precision, model-based methods are necessary. Therefore, an empirical incoherent parametric imaging model can be used of which the unknown parameters are determined using statistical parameter estimation theory (Van Aert et al., 2009, [1]). In this paper, it will be shown how this method can be combined with frozen lattice multislice simulations in order to evolve from a relative toward an absolute quantification of the composition of single atomic columns with mixed atom types. Furthermore, the validity of the model assumptions are explored and discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000331092200003 Publication Date 2013-11-09
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 74 Open Access
Notes FWO; FP7; ERC Countatoms; ESTEEM2; esteem2_ta Approved Most recent IF: 2.843; 2014 IF: 2.436
Call Number UA @ lucian @ c:irua:111579UA @ admin @ c:irua:111579 Serial 2749
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