|   | 
Details
   web
Records
Author van der Rest, A.; Idrissi, H.; Henry, F.; Favache, A.; Schryvers, D.; Proost, J.; Raskin, J.-P.; Van Overmeere, Q.; Pardoen, T.
Title Mechanical behavior of ultrathin sputter deposited porous amorphous Al2O3 films Type A1 Journal article
Year 2017 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 125 Issue 125 Pages 27-37
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The determination of the mechanical properties of porous amorphous Al2O3 thin films is essential to address reliability issues in wear-resistant, optical and electronic coating applications. Testing the mechanical properties of Al2O3 films thinner than 200 nm is challenging, and the link between the mechanical behavior and the microstructure of such films is largely unknown. Herein, we report on the elastic and viscoplastic mechanical properties of amorphous Al2O3 thin films synthesized by reactive magnetron sputtering using a combination of internal stress, nanoindentation, and on-chip uniaxial tensile testing, together with mechanical homogenization models to separate the effect of porosity from intrinsic variations of the response of the sound material. The porosity is made of voids with 2e30 nm diameter. The Young's modulus and hardness of the films decrease by a factor of two when the deposition pressure increases from 1.2 to 8 mTorr. The contribution of porosity was found to be small, and a change in the atomic structure of the amorphous Al2O3 matrix is hypothesized to be the main contributing factor. The activation volume associated to the viscoplastic deformation mechanism is around 100 Å3. Differences in the atomic structure of the films could not be revealed by electron diffraction, pointing to a minute effect of atomic arrangement on the elastic properties.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000394201500003 Publication Date 2016-12-02
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 5 Open Access OpenAccess
Notes This work has been funded by the Belgian Science Policy through the IAP 7/21 project. The support of the ‘Fonds Belge pour la Recherche dans l’Industrie et l’Agriculture (FRIA)’ for A.v.d.R. is also gratefully acknowledged, as well as the support of FNRS through the grant PDR T.0122.13 “Mecano”. Approved Most recent IF: 5.301
Call Number EMAT @ emat @ c:irua:138990 Serial 4330
Permanent link to this record
 

 
Author Schalm, O.; Crabbé, A.; Storme, P.; Wiesinger, R.; Gambirasi, A.; Grieten, E.; Tack, P.; Bauters, S.; Kleber, C.; Favaro, M.; Schryvers, D.; Vincze, L.; Terryn, H.; Patelli, A.
Title The corrosion process of sterling silver exposed to a Na2S solution: monitoring and characterizing the complex surface evolution using a multi-analytical approach Type A1 Journal article
Year 2016 Publication Applied Physics A-Materials Science & Processing Abbreviated Journal Appl Phys A-Mater
Volume 122 Issue 122 Pages 903
Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Abstract Many historical ‘silver’ objects are composed of sterling silver, a silver alloy containing small amounts of copper. Besides the dramatic impact of copper on the corrosion process, the chemical composition of the corrosion layer evolves continuously. The evolution of the surface during the exposure to a Na2S solution was monitored by means of visual observation at macroscopic level, chemical analysis at microscopic level and analysis at the nanoscopic level. The corrosion process starts with the preferential oxidation of copper, forming mixtures of oxides and sulphides while voids are being created beneath the corrosion layer. Only at a later stage, the silver below the corrosion layer is consumed. This results in the formation of jalpaite and at a later stage of acanthite. The acanthite is found inside the corrosion layer at the boundaries of jalpaite grains and as individual grains between the jalpaite grains but also as a thin film on top of the corrosion layer. The corrosion process could be described as a sequence of 5 subsequent surface states with transitions between these states.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000384753800033 Publication Date 2016-09-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0947-8396 ISBN Additional Links
Impact Factor 1.455 Times cited 9 Open Access
Notes The authors are grateful for the financial support by the EU-FP7 Grant PANNA No. 282998 and for the opportunity to perform SR-XPS measurements at the NanoESCA beamline of the Elettra storage ring, under the approval of the advisory Committee (Proposal No. 20135164), as well as the opportunity to perform XANES measurements at the DUBBLE beamline of the ESRF storage ring (Proposal No. 26-01-990). The authors are grateful for the financial support by the STIMPRO Project FFB150215 of the University of Antwerp. Pieter Tack is funded by a Ph.D. Grant of the Agency for Innovation by Science and Technology (IWT). We would also like to thank Peter Van den Haute for the XRD measurements that were performed at the University of Ghent. Approved Most recent IF: 1.455
Call Number EMAT @ emat @ Serial 4331
Permanent link to this record
 

 
Author Heidari, H.; Rivero, G.; Idrissi, H.; Ramachandran, D.; Cakir, S.; Egoavil, R.; Kurttepeli, M.; Crabbé, A.C.; Hauffman, T.; Terryn, H.; Du Prez, F.; Schryvers, D.
Title Melamine–Formaldehyde Microcapsules: Micro- and Nanostructural Characterization with Electron Microscopy Type A1 Journal article
Year 2016 Publication Microscopy and microanalysis Abbreviated Journal Microsc Microanal
Volume 22 Issue 22 Pages 1222-1232
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A systematic study has been carried out to compare the surface morphology, shell thickness, mechanical properties, and binding behavior of melamine–formaldehyde microcapsules of 5–30 μm diameter size with various amounts of core content by using scanning and transmission electron microscopy including electron tomography, in situ nanomechanical tensile testing, and electron energy-loss spectroscopy. It is found that porosities are present on the outside surface of the capsule shell, but not on the inner surface of the shell. Nanomechanical tensile tests on the capsule shells reveal that Young’s modulus of the shell material is higher than that of bulk melamine–formaldehyde and that the shells exhibit a larger fracture strain compared with the bulk. Core-loss elemental analysis of microcapsules embedded in epoxy indicates that during the curing process, the microcapsule-matrix interface remains uniform and the epoxy matrix penetrates into the surface micro-porosities of the capsule shells.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000393853100011 Publication Date 2016-12-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.891 Times cited 2 Open Access
Notes This work was supported by SIM vzw, Technologiepark 935, BE-9052 Zwijnaarde, Belgium, within the InterPoCo project of the H-INT-S horizontal program. The authors are also thankful to Stijn Van den Broeck and Dr. Frederic Leroux for help in sample preparation and to S. Bals and J. Verbeeck for valuable discussions. H.I. acknowledges the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs, under Contract No. P7/21. Approved Most recent IF: 1.891
Call Number EMAT @ emat @ c:irua:138980 Serial 4333
Permanent link to this record
 

 
Author Li, K.; Idrissi, H.; Sha, G.; Song, M.; Lu, J.; Shi, H.; Wang, W.; Ringer, S.P.; Du, Y.; Schryvers, D.
Title Quantitative measurement for the microstructural parameters of nano-precipitates in Al-Mg-Si-Cu alloys Type A1 Journal article
Year 2016 Publication Materials characterization Abbreviated Journal Mater Charact
Volume 118 Issue 118 Pages 352-362
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Size, number density and volume fraction of nano-precipitates are important microstructural parameters controlling the strengthening of materials. In this work a widely accessible, convenient, moderately time efficient method with acceptable accuracy and precision has been provided for measurement of volume fraction of nano-precipitates in crystalline materials. The method is based on the traditional but highly accurate technique of measuring foil thickness via convergent beam electron diffraction. A new equation is proposed and verified with the aid of 3-dimensional atom probe (3DAP) analysis, to compensate for the additional error resulted from the hardly distinguishable contrast of too short incomplete precipitates cut by the foil surface. The method can be performed on a regular foil specimen with a modem LaB6 or field-emission-gun transmission electron microscope. Precisions around +/- 16% have been obtained for precipitate volume fractions of needle-like beta ''/C and Q precipitates in an aged Al-Mg-Si-Cu alloy. The measured number density is dose to that directly obtained using 3DAP analysis by a misfit of 45%, and the estimated precision for number density measurement is about +/- 11%. The limitations of the method are also discussed.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000383292000042 Publication Date 2016-06-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.714 Times cited 9 Open Access
Notes This work is financially supported by National Natural Science Foundation of China (51501230 and 51531009) and Postdoctoral Science Foundation of Central South University (502042057). H.I. acknowledges the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs under Contract No. P7/21 and FWO project G.0576.09N. Approved Most recent IF: 2.714
Call Number EMAT @ emat @ c:irua:137171 Serial 4334
Permanent link to this record
 

 
Author Van Aelst, J.; Philippaerts, A.; Bartholomeeusen, E.; Fayad, E.; Thibault-Starzyk, F.; Lu, J.; Schryvers, D.; Ooms, R.; Verboekend, D.; Jacobs, P.; Sels, B.
Title Towards biolubricant compatible vegetable oils by pore mouth hydrogenation with shape-selective Pt/ZSM-5 catalysts Type A1 Journal article
Year 2016 Publication Catalysis science & technology Abbreviated Journal Catal Sci Technol
Volume 6 Issue 6 Pages 2820-2828
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Pt/ZSM-5 catalysts with various crystal sizes were prepared via competitive ion-exchange, followed by a slow activation procedure. Even when using very large ZSM-5 crystals, highly dispersed Pt nano-clusters were contained within the zeolite crystal's voids, as ascertained by 2D pressure-jump IR spectroscopy of adsorbed CO and focussed ion-beam transmission electron microscopy. The shape-selective properties of the Pt/ZSM-5 catalysts were evaluated in the partial hydrogenation of soybean oil. Unique hydrogenation selectivities were observed, as the fatty acids located at the central position of the triacylglycerol (TAG) molecules were preferentially hydrogenated. The resulting oil has therefore high levels of intermediately melting TAGs, which are compatible with biolubricants due to their improved oxidative stability and still appropriate low-temperature fluidity. The TAG distribution in the partially hydrogenated soybean oil samples was independent from the zeolite crystal size, while the hydrogenation activity linearly increases with the crystal's external surface area. This trend was confirmed with a Pt loaded mesoporous ZSM-5 zeolite, obtained via a mild alkaline treatment. These observations imply and confirm a genuine pore mouth catalysis mechanism, in which only one fatty acid chain of the TAG is able to enter the micropores of ZSM-5, where the double bonds are hydrogenated by the crystal encapsulated Pt-clusters.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000374790200031 Publication Date 2016-03-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2044-4753 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.773 Times cited 5 Open Access
Notes The research was funded through a PhD grant to J. V. A. of the Agency for Innovation by Science and Technology in Flanders (IWT). A. P. and D. V. acknowledge the F. W. O.-Vlaanderen (Research Foundation Flanders) for a post-doctoral fellowship. E. B. was kindly funded by an F. W. O.-Vlaanderen project. This work was performed in the framework of an Associated International Laboratory between FWO and CNRS. Approved Most recent IF: 5.773
Call Number EMAT @ emat @ c:irua:138981 Serial 4335
Permanent link to this record
 

 
Author Schouteden, K.; Amin-Ahmadi, B.; Li, Z.; Muzychenko, D.; Schryvers, D.; Van Haesendonck, C.
Title Electronically decoupled stacking fault tetrahedra embedded in Au(111) films Type A1 Journal article
Year 2016 Publication Nature communications Abbreviated Journal Nat Commun
Volume 7 Issue 7 Pages 14001
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Stacking faults are known as defective structures in crystalline materials that typically lower the structural quality of the material. Here, we show that a particular type of defects, i.e., stacking fault tetrahedra (SFTs), exhibits quantized, particle-in-a-box electronic behaviour, revealing a potential synthetic route to decoupled nanoparticles in metal films. We report on the electronic properties of SFTs that exist in Au(111) films, as evidenced by scanning tunnelling microscopy and confirmed by transmission electron microscopy. We find that the SFTs reveal a remarkable decoupling from their metal surroundings, leading to pronounced energy level quantization effects within the SFTs. The electronic behaviour of the SFTs can be described well by the particle-in-a-box model. Our findings demonstrate that controlled preparation of SFTs may offer an alternative way to achieve well decoupled nanoparticles of high crystalline quality in metal thin films without the need of thin insulating layers.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000390367700001 Publication Date 2016-12-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 7 Open Access
Notes The research in Leuven has been supported by the Research Foundation – Flanders (FWO, Belgium), and by the Flemish Concerted Research Action program (BOF KU Leuven, Project No. GOA/14/007). Z.L. acknowledges the support from the China Scholarship Council (No. 2011624021) and from Internal Funds KU Leuven. K.S. acknowledges additional support from the FWO. The research in Moscow has been supported by grants of the Russian Foundation for Basic Research (RFBR). Approved Most recent IF: 12.124
Call Number EMAT @ emat @ c:irua:138983 Serial 4336
Permanent link to this record
 

 
Author Sánchez-Iglesias, A.; Winckelmans, N.; Altantzis, T.; Bals, S.; Grzelczak, M.; Liz-Marzán, L.M.
Title High-Yield Seeded Growth of Monodisperse Pentatwinned Gold Nanoparticles through Thermally Induced Seed Twinning Type A1 Journal article
Year 2016 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
Volume 139 Issue 139 Pages 107-110
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We show here that thermal treatment of small seeds results in extensive twinning and a subsequent drastic yield improvement (>85%) in the formation of pentatwinned nanoparticles, with pre-selected morphology (nanorods, bipyramids and decahedra) and aspect ratio. The “quality” of the seeds thus defines the yield of the obtained nanoparticles, which in the case of nanorods avoids the need for additives such as Ag+ ions. This modified seeded growth method also improves reproducibility, as the seeds can be stored for extended periods of time without compromising the quality of the final nanoparticles. Additionally, minor modification of the seeds with Pd allows their localization within the final particles, which opens new avenues toward mechanistic studies. All together, these results represent a paradigm shift in anisotropic gold nanoparticle synthesis.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000392036900025 Publication Date 2016-12-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-7863 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.858 Times cited 267 Open Access OpenAccess
Notes Financial support is acknowledged from the European Research Council through ERC Advanced Grant Plasmaquo and the ERC Starting Grant COLOURATOM. T.A. acknowledges financial support from the Research Foundation Flanders (FWO, Belgium) through a postdoctoral grant. (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ECAS_Sara Approved Most recent IF: 13.858
Call Number EMAT @ emat @ c:irua:139018UA @ admin @ c:irua:139018 Serial 4339
Permanent link to this record
 

 
Author Samaeeaghmiyoni, V.; Idrissi, H.; Groten, J.; Schwaiger, R.; Schryvers, D.
Title Quantitative in-situ TEM nanotensile testing of single crystal Ni facilitated by a new sample preparation approach Type A1 Journal article
Year 2017 Publication Micron Abbreviated Journal Micron
Volume 94 Issue 94 Pages 66-73
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Twin-jet electro-polishing and Focused Ion Beam (FIB) were combined to produce small size Nickel single crystal specimens for quantitative in-situ nanotensile experiments in the transmission electron microscope. The combination of these techniques allows producing samples with nearly defect-free zones in the centre in contrast to conventional FIB-prepared samples. Since TEM investigations can be performed on the electro-polished samples prior to in-situ TEM straining, specimens with desired crystallographic orientation and initial microstructure can be prepared. The present results reveal a dislocation nucleation controlled plasticity, in which small loops induced by FIB near the edges of the samples play a central role.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000393247300008 Publication Date 2016-12-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0968-4328 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.98 Times cited 11 Open Access OpenAccess
Notes This research has been performed with the financial support of the Belgian Science Policy (Belspo) under the framework of the interuniversity attraction poles program, IAP7/21. Financial support from the Flemish (FWO) and German Research Foundation (DFG) through the European M-ERA.NET project “FaSS” (Fatigue Simulation near Surfaces) under the grant numbers GA.014.13N and SCHW855/5-1, respectively, is gratefully acknowledged. V. Samaeeaghmiyoni also acknowledges the FWO research project G012012N “Understanding nanocrystalline mechanical behaviour from structural investigations”. H. Idrissi is currently mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). Approved Most recent IF: 1.98
Call Number EMAT @ emat @ c:irua:139515 Serial 4341
Permanent link to this record
 

 
Author Garzia Trulli, M.; Claes, N.; Pype, J.; Bals, S.; Baert, K.; Terryn, H.; Sardella, E.; Favia, P.; Vanhulsel, A.
Title Deposition of aminosilane coatings on porous Al2O3microspheres by means of dielectric barrier discharges Type A1 Journal article
Year 2017 Publication Plasma processes and polymers Abbreviated Journal Plasma Process Polym
Volume 14 Issue 14 Pages 1600211
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Abstract Advances in the synthesis of porous microspheres and in their functionalization are increasing the interest in applications of alumina. This paper deals with coatings plasma deposited from 3-aminopropyltriethoxysilane by means of dielectric barrier discharges on alumina porous microspheres, shaped by a vibrational droplet coagulation technique. Aims of the work are the functionalization of the particles with active amino groups, as well as the evaluation of their surface coverage and of the penetration of the coatings into their pores. A multi-diagnostic approach was used for the chemical/morphological characterization of the particles. It was found that 5 min exposure to plasma discharges promotes the deposition of homogeneous coatings onto the microspheres and within their pores, down to 1 μm.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000410773200003 Publication Date 2017-01-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1612-8850 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.846 Times cited 8 Open Access OpenAccess
Notes The technical assistance of the VITO staff (Materials Dpt.) is gratefully acknowledged, especially D. Havermans, E. Van Hoof, R. Kemps (SEM-EDX), and A. De Wilde (Hg Porosimetry). Drs. S. Mullens and G. Scheltjens are kindly acknowledged for constructive discussions. Strategic Initiative Materials in Flanders (SIM) is gratefully acknowledged for its financial support. This research was carried out in the framework of the SIM-TRAP program (Tools for rational processing of nano-particles: controlling and tailoring nanoparticle based or nanomodified particle based materials). N. Claes and S. Bals acknowledge financial support from European Research Council (ERC Starting Grant #335078-COLOURATOM). (ROMEO:white; preprint:; postprint:restricted ; pdfversion:cannot); saraecas; ECAS_Sara; Approved Most recent IF: 2.846
Call Number EMAT @ emat @ c:irua:139511UA @ admin @ c:irua:139511 Serial 4342
Permanent link to this record
 

 
Author Rodal-Cedeira, S.; Montes-García, V.; Polavarapu, L.; Solís, D.M.; Heidari, H.; La Porta, A.; Angiola, M.; Martucci, A.; Taboada, J.M.; Obelleiro, F.; Bals, S.; Pérez-Juste, J.; Pastoriza-Santos, I.
Title Plasmonic Au@Pd Nanorods with Boosted Refractive Index Susceptibility and SERS Efficiency: A Multifunctional Platform for Hydrogen Sensing and Monitoring of Catalytic Reactions Type A1 Journal article
Year 2016 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 28 Issue 28 Pages 9169-9180
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Palladium nanoparticles (NPs) have received tremendous attention over the years due to their high catalytic activity for various chemical reactions. However, unlike other noble metal nanoparticles such as Au and Ag NPs, they exhibit poor plasmonic properties with broad extinction spectra and less scattering efficiency, and thus limiting their applications in the field of plasmonics. Therefore, it has been challenging to integrate tunable and strong plasmonic properties into catalytic Pd nanoparticles. Here we show that plasmonic Au@Pd nanorods (NRs) with relatively narrow and remarkably tunable optical responses in the NIR region can be obtained by directional growth of Pd on penta-twinned Au NR seeds. We found the presence of bromide ions facilitates the stabilization of facets for the directional growth of Pd shell to obtain Au@Pd nanorods (NR) with controlled length scales. Interestingly, it turns out the Au NR supported Pd NRs exhibit much narrow extinction compared to pure Pd NRs, which makes them suitable for plasmonic sensing applications. Moreover, these nanostructures display, to the best of our knowledge, one of the highest ensemble refractive index sensitivity values reported to date (1067 nm per refractive index unit, RIU). Additionally, we showed the application of such plasmonic Au@Pd NRs for localized surface plasmon resonance (LSPR)-based sensing of hydrogen both in solution as well as on substrate. Finally, we demonstrate the integration of excellent plasmonic properties in catalytic palladium enables the in situ monitoring of a reaction progress by surface-enhanced Raman scattering. We postulate the proposed approach to boost the plasmonic properties of Pd nanoparticles will ignite the design of complex shaped plasmonic Pd NPs to be used in various plasmonic applications such as sensing and in situ monitoring of various chemical reactions.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000391080900036 Publication Date 2016-12-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 80 Open Access OpenAccess
Notes Funding from Spanish Ministerio de Economía y Competitividad (Grants MAT2013-45168-R and MAT2016-77809-R) is gratefully acknowledge. A.L.P. and S.B. acknowledge support by the European Research Council through an ERC Starting Grant (#335078-COLOURATOMS). L. P. acknowledges the financial support from by the Alexander von Humboldt-Stiftung. V. M.-G. acknowledges the financial support from FPU scholarship from the Spanish MINECO. (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ECAS_Sara Approved Most recent IF: 9.466
Call Number EMAT @ emat @ c:irua:139513 Serial 4344
Permanent link to this record
 

 
Author Lu, J.; Bartholomeeusen, E.; Sels, B.F.; Schryvers, D.
Title Internal architecture of coffin-shaped ZSM-5 zeolite crystals with hourglass contrast unravelled by focused ion beam-assisted transmission electron microscopy: INTERNAL ARCHITECTURE OF COFFIN-SHAPED Type A1 Journal article
Year 2017 Publication Journal of microscopy Abbreviated Journal J Microsc-Oxford
Volume 265 Issue 265 Pages 27-33
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Optical microscopy, focused ion beam and transmission electron microscopy are combined to study the internal architecture in a coffin-shaped ZSM-5 crystal showing an hourglass contrast in optical microscopy. Based on parallel lamellas from different positions in the crystal, the orientation relationships between the intergrowth components of the crystal are studied and the internal architecture and growth mechanism are illustrated. The crystal is found to contain two pyramid-like components aside from a central component. Both pyramid-like components are rotated by 90 degrees along the common c-axis and with respect to the central component while the interfaces between the components show local zig-zag feature, the latter indicating variations in relative growth velocity of the two components. The pyramid-like intergrowth components are larger and come closer to one another in the middle of the crystal than at the edges, but they do not connect. A model of multisite nucleation and growth of 90 degrees intergrowth components is proposed.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000392487400004 Publication Date 2016-08-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2720 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.692 Times cited 4 Open Access OpenAccess
Notes Fonds Wetenschappelijk Onderzoek, G.0603.10N ; Approved Most recent IF: 1.692
Call Number EMAT @ emat @ c:irua:141015 Serial 4437
Permanent link to this record
 

 
Author Juchtmans, R.; Clark, L.; Lubk, A.; Verbeeck, J.
Title Spiral phase plate contrast in optical and electron microscopy Type A1 Journal article
Year 2016 Publication Physical review A Abbreviated Journal Phys Rev A
Volume 94 Issue 94 Pages 023838
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The use of phase plates in the back focal plane of a microscope is a well-established technique in optical microscopy to increase the contrast of weakly interacting samples and is gaining interest in electron microscopy as well. In this paper we study the spiral phase plate (SPP), also called helical, vortex, or two-dimensional Hilbert phase plate, which adds an angularly dependent phase of the form exp(iℓϕk) to the exit wave in Fourier space. In the limit of large collection angles, we analytically calculate that the average of a pair of l=+-1

SPP filtered images is directly proportional to the gradient squared of the exit wave, explaining the edge contrast previously seen in optical SPP work. We discuss the difference between a clockwise-anticlockwise pair of SPP filtered images and derive conditions under which the modulus of the wave's gradient can be seen directly from one SPP filtered image. This work provides the theoretical background to interpret images obtained with a SPP, thereby opening new perspectives for new experiments to study, for example, magnetic materials in an electron microscope.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000381882800011 Publication Date 2016-08-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9926 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.925 Times cited 10 Open Access
Notes The authors acknowledge support from the FWO (Aspirant Fonds Wetenschappelijk Onderzoek – Vlaanderen) and the EU under the Seventh Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483-ESTEEM2 and ERC Starting Grant No. 278510 VORTEX.; ECASJO_ Approved Most recent IF: 2.925
Call Number EMAT @ emat @ c:irua:140086 Serial 4418
Permanent link to this record
 

 
Author Lubk, A.; Vogel, K.; Wolf, D.; Krehl, J.; Röder, F.; Clark, L.; Guzzinati, G.; Verbeeck, J.
Title Fundamentals of Focal Series Inline Electron Holography Type H1 Book chapter
Year 2016 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics / Hawkes, P.W. [edit.] Abbreviated Journal
Volume Issue Pages 105-147
Keywords H1 Book chapter; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Elsevier BV Place of Publication (up) Editor
Language Wos Publication Date 2016-09-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1076-5670; http://id.crossref.org/isbn/9780128048115 ISBN 9780128048115 Additional Links UA library record
Impact Factor Times cited Open Access
Notes L.C., G.G., and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant no. 278510 VORTEX. A.L., K.V., J. K., D.W., and F.R. acknowledge funding from the DIP of the Deutsche Forschungsgesellschaft.; ECASJO_; Approved Most recent IF: NA
Call Number EMAT @ emat @ c:irua:140097UA @ admin @ c:irua:140097 Serial 4419
Permanent link to this record
 

 
Author Verduyckt, J.; Van Hoof, M.; De Schouwer, F.; Wolberg, M.; Kurttepeli, M.; Eloy, P.; Gaigneaux, E.M.; Bals, S.; Kirschhock, C.E.A.; De Vos, D.E.
Title PdPb-catalyzed decarboxylation of proline to pyrrolidine : highly selective formation of a biobased amine in water Type A1 Journal article
Year 2016 Publication ACS catalysis Abbreviated Journal Acs Catal
Volume 6 Issue 6 Pages 7303-7310
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Amino acids have huge potential as platform chemicals in the biobased industry. Pd-catalyzed decarboxylation is a very promising route for the valorization of these natural compounds derived from protein waste or fermentation. We report that the highly abundant and nonessential amino acid L-proline is very reactive in the Pd-catalyzed decarboxylation. Full conversions are obtained with Pd/C and different Pd/MeOx catalysts; this allowed the identification of the different side reactions and the mapping of the reaction network. Due to the high reactivity of pyrrolidine, the selectivity for pyrrolidine was initially low. By carefully modifying Pd/ZrO2 with Pb in a controlled manner-via two incipient wetness impregnation steps-the selectivity increased remarkably. Finally, a thorough investigation of the reaction parameters resulted in an increased activity of this modified catalyst and an even further enhanced selectivity under a low H-2 pressure of 4 bar at 235 degrees C in water. This results in a very selective and sustainable production route for the highly interesting pyrrolidine.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000387306100005 Publication Date 2016-09-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2155-5435 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 10.614 Times cited 27 Open Access OpenAccess
Notes ; J.V. and F.D.S. thank Fonds Wetenschappelijk Onderzoek (FWO) and Agency for Innovation by Science and Technology (IWT) for doctoral fellowships. D.D.V. acknowledges IWT and FWO for research project funding. D.D.V. and C.E.A.K. acknowledge the Flemish government for long-term structural funding through Methusalem. D.D.V. and S.B. acknowledge Belspo (IAP-PAI 7/05) for financial support. S.B. is grateful for funding by the European Research Council (ERC starting grant no. 335078-COLOURATOMS). The authors also thank the Department of Chemistry, University of Cologne, Germany for use of their XRD equipment. Finally, the assistance of Karel Duerinckx, Werner Wouters, Walter Vermandel, Ivo Stassen, Dries Jonckheere, Sabina Accardo and Bart Bueken with 11-1 NMR, pressure reactors, CO chemisorption, N<INF>2</INF> physisorption, SEM, gas phase FTIR and high-throughput XRD, respectively, is very much appreciated. ; ecas_Sara Approved Most recent IF: 10.614
Call Number UA @ lucian @ c:irua:139171 Serial 4445
Permanent link to this record
 

 
Author Grzelczak, M.; Sanchez-Iglesias, A.; Heidari, H.; Bals, S.; Pastoriza-Santos, I.; Perez-Juste, J.; Liz-Marzan, L.M.
Title Silver Ions Direct Twin-Plane Formation during the Overgrowth of Single-Crystal Gold Nanoparticles Type A1 Journal article
Year 2016 Publication ACS Omega Abbreviated Journal
Volume 1 Issue 1 Pages 177-181
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract It is commonly agreed that the crystalline structure of seeds dictates the crystallinity of final nanoparticles in a seeded-growth process. Although the formation of monocrystalline particles does require the use of single-crystal seeds, twin planes may stem from either single-or polycrystalline seeds. However, experimental control over twin-plane formation remains difficult to achieve synthetically. Here, we show that a careful interplay between kinetics and selective surface passivation offers a unique handle over the emergence of twin planes (in decahedra and triangles) during the growth over single-crystalline gold nanoparticles of quasi-spherical shape. Twinning can be suppressed under conditions of slow kinetics in the presence of silver ions, yielding single-crystalline particles with high-index facets.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000391203300002 Publication Date 2016-08-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-1343;2470-1343; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 18 Open Access OpenAccess
Notes ; This work was supported by the Spanish Ministerio de Economia y Competitividad MINECO (grants: MAT2013-46101-R, MAT2013-49375-EXP, MAT2013-45168-R). Financial support is acknowledged by the European Research Council (ERC Advanced Grant # 267867, PLASMAQUO; ERC Starting Grant #335078-COLOURATOM). ; ecas_Sara Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:140398 Serial 4446
Permanent link to this record
 

 
Author Blommaerts, N.; Asapu, R.; Claes, N.; Bals, S.; Lenaerts, S.; Verbruggen, S.W.
Title Gas phase photocatalytic spiral reactor for fast and efficient pollutant degradation Type A1 Journal article
Year 2017 Publication Chemical engineering journal Abbreviated Journal Chem Eng J
Volume 316 Issue 316 Pages 850-856
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL)
Abstract Photocatalytic reactors for the degradation of gaseous organic pollutants often suffer from major limitations such as small reaction area, sub-optimal irradiation conditions and thus limited reaction rate. In this work, an alternative solution is presented that involves a glass tube coated on the inside with (silvermodified) TiO2 and spiraled around a UVA lamp. First, the spiral reactor is coated from the inside with TiO2 using an experimentally verified procedure that is optimized toward UV light transmission. This procedure is kept as simple as possible and involves a single casting step of a 1 wt% suspension of TiO2 in ethanol through the spiral. This results in a coated tube that absorbs nearly all incident UV light under the experimental conditions used. The optimized coated spiral reactor is then benchmarked to a conventional annular photoreactor of the same outer dimensions and total catalyst loading over a broad range of experimental conditions. Although residence time distribution experiments indicate slightly longer dwelling of molecules in the spiral reactor, no significant difference in by-passing of gas between the spiral reactor and the annular reactor can be claimed. Acetaldehyde degradation efficiency of 100% is obtained with the spiral reactor for a residence time as low as 60 s, whereas the annular reactor could not achieve full degradation even at 1000 s residence time. In a final case study, addition of long-term stable silver nanoparticles, protected by an ultra-thin polymer shell applied via the layer-by-layer (LbL) method, to the spiral reactor coating is shown to double the degradation efficiency and provides an interesting strategy to cope with higher pollutant concentrations without changing the overall dimensions.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000398985200089 Publication Date 2017-02-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1385-8947 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.216 Times cited 30 Open Access OpenAccess
Notes N.B. wishes to thank the University of Antwerp – Belgium for financial support. N.C. and S.B. acknowledge financial support from European Research Council (ERC Starting Grant #335078- COLOURATOM). S.W.V. acknowledges the Research Foundation – Flanders (FWO) for a postdoctoral fellowship. (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); ecas_sara Approved Most recent IF: 6.216
Call Number EMAT @ emat @ c:irua:140925UA @ admin @ c:irua:140925 Serial 4481
Permanent link to this record
 

 
Author Zhong, Z.; Goris, B.; Schoenmakers, R.; Bals, S.; Batenburg, K.J.
Title A bimodal tomographic reconstruction technique combining EDS-STEM and HAADF-STEM Type A1 Journal article
Year 2017 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 174 Issue 174 Pages 35-45
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A three-dimensional (3D) chemical characterization of nanomaterials can be obtained using tomography based on high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) or energy dispersive X-ray spectroscopy (EDS) STEM. These two complementary techniques have both advantages and disadvantages. The Z-contrast images have good image quality but lack robustness in the compositional analysis, while the elemental maps give more element-specific information, but at a low signal-to-noise ratio and a longer exposure time. Our aim is to combine these two types of complementary information in one single tomographic reconstruction process. Therefore, an imaging model is proposed combining both HAADF-STEM

and EDS-STEM. Based on this model, the elemental distributions can be reconstructed using both types of information simultaneously during the reconstruction process. The performance of the new technique is evaluated using simulated data and real experimental data. The results demonstrate that combining two imaging modalities leads to tomographic reconstructions with suppressed noise and enhanced contrast.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000403342200005 Publication Date 2016-12-11
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 26 Open Access OpenAccess
Notes This research is supported by the Dutch Technology Foundation STW (http://www.stw.nl/), which is part of the Netherlands Organization for Scientific Research (NWO), and which is partly funded by the Ministry of Economic Affairs, Agriculture and Innovation under project number 13314. It is also supported by the Flemish research foundation (FWO Vlaanderen) by project funding (G038116N) and a postdoctoral research grant to B.G. Funding from the European Research Council (Starting Grant No. COLOURATOMS 335078) is acknowledged by S.B. The authors would like to thank Dr. Bernd Rieger and Dr. Richard Aveyard for useful discussions, and Prof. Dr. Luis M. Liz-Marzan for providing the investigated samples. We also acknowledge COST Action MP1207 for networking support. (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); saraecas; ECAS_Sara; Approved Most recent IF: 2.843
Call Number EMAT @ emat @ c:irua:141719UA @ admin @ c:irua:141719 Serial 4484
Permanent link to this record
 

 
Author Zhuge, X.; Jinnai, H.; Dunin-Borkowski, R.E.; Migunov, V.; Bals, S.; Cool, P.; Bons, A.-J.; Batenburg, K.J.
Title Automated discrete electron tomography – Towards routine high-fidelity reconstruction of nanomaterials Type A1 Journal article
Year 2017 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 175 Issue 175 Pages 87-96
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Abstract Electron tomography is an essential imaging technique for the investigation of morphology and 3D structure of nanomaterials. This method, however, suffers from well-known missing wedge artifacts due to a restricted tilt range, which limits the objectiveness, repeatability and efficiency of quantitative structural analysis. Discrete tomography represents one of the promising reconstruction techniques for materials science, potentially capable of delivering higher fidelity reconstructions by exploiting the prior knowledge of the limited number of material compositions in a specimen. However, the application of discrete tomography to practical datasets remains a difficult task due to the underlying challenging mathematical problem. In practice, it is often hard to obtain consistent reconstructions from experimental datasets. In addition, numerous parameters need to be tuned manually, which can lead to bias and non-repeatability. In this paper, we present the application of a new

iterative reconstruction technique, named TVR-DART, for discrete electron tomography. The technique is capable of consistently delivering reconstructions with significantly reduced missing wedge artifacts for a variety of challenging data and imaging conditions, and can automatically estimate its key parameters. We describe the principles of the technique and apply it to datasets from three different types of samples acquired under diverse imaging modes. By further reducing the available tilt range and number of projections, we show that the

proposed technique can still produce consistent reconstructions with minimized missing wedge artifacts. This new development promises to provide the electron microscopy community with an easy-to-use and robust tool for high-fidelity 3D characterization of nanomaterials.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000403342500008 Publication Date 2017-01-24
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 OpenAccess
Notes This work has been supported in part by the Stichting voor de Technische Wetenschappen (STW) through a personal grant (Veni,13610), and was in part by ExxonMobil Chemical Europe Inc. The authors further acknowledge financial support from the University of Antwerp through BOF GOA funding. S.B. acknowledges financial support from the European Research Council (ERC Starting Grant #335078-COLOURATOMS). R.D.B. is grateful for funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007–2013)/ ERC grant agreement number 320832. Thomas Altantzis is gratefully acknowledged for acquiring the Anatase nanosheets dataset. (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); saraecas; ECAS_Sara; Approved Most recent IF: 2.843
Call Number EMAT @ emat @ c:irua:141218UA @ admin @ c:irua:141218 Serial 4485
Permanent link to this record
 

 
Author Benetti, G.; Cavaliere, E.; Canteri, A.; Landini, G.; Rossolini, G.M.; Pallecchi, L.; Chiodi, M.; Van Bael, M.J.; Winckelmans, N.; Bals, S.; Gavioli, L.
Title Direct synthesis of antimicrobial coatings based on tailored bi-elemental nanoparticles Type A1 Journal article
Year 2017 Publication APL materials Abbreviated Journal Apl Mater
Volume 5 Issue 5 Pages 036105
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Ultrathin coatings based on bi-elemental nanoparticles (NPs) are very promising to limit the surface-related spread of bacterial pathogens, particularly in nosocomial environments. However, tailoring the synthesis, composition, adhesion to substrate, and antimicrobial spectrum of the coating is an open challenge. Herein, we report on a radically new nanostructured coating, obtained by a one-step gas-phase deposition technique, and composed of bi-elemental Janus type Ag/Ti NPs. The NPs are characterized by a cluster-in-cluster mixing phase with metallic Ag nano-crystals embedded in amorphous TiO2 and present a promising antimicrobial activity including also multidrug resistant strains. We demonstrate the flexibility of the method to tune the embedded Ag nano-crystals dimension, the total relative composition of the coating, and the substrate type, opening the possibility of tailoring the dimension, composition, antimicrobial spectrum, and other physical/chemical properties of such multi-elemental systems. This work is expected to significantly spread the range of applications of NPs coatings, not only as an effective tool in the prevention of healthcare-associated infections but also in other technologically relevant fields like sensors or nano-/micro joining.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000398951000014 Publication Date 2017-03-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2166-532X ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.335 Times cited 21 Open Access OpenAccess
Notes We thank Urs Gfeller for the XRF measurements, Francesco Banfi for valuable discussions on the manuscript and Giulio Viano for his valuable support in the microbiological analysis. The authors acknowledge the financial support of Universita Cattolica del Sacro Cuore through D.2.2 and D.3.1 grants and from the European Union through the 7th Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2). REFERENCES Approved Most recent IF: 4.335
Call Number EMAT @ emat @ c:irua:141723UA @ admin @ c:irua:141723 Serial 4479
Permanent link to this record
 

 
Author Tunca, B.; Lapauw, T.; Karakulina, O.M.; Batuk, M.; Cabioc’h, T.; Hadermann, J.; Delville, R.; Lambrinou, K.; Vleugels, J.
Title Synthesis of MAX Phases in the Zr-Ti-Al-C System Type A1 Journal article
Year 2017 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
Volume 56 Issue 56 Pages 3489-3498
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract This study reports on the synthesis and characterization of MAX phases in the (Zr,Ti)n+1AlCn system. The MAX phases were synthesized by reactive hot pressing and pressureless sintering in the 1350–1700 °C temperature range. The produced ceramics contained large fractions of 211 and 312 (n = 1, 2) MAX phases, while strong evidence of a 413 (n = 3) stacking was found. Moreover, (Zr,Ti)C, ZrAl2, ZrAl3, and Zr2Al3 were present as secondary phases. In general, the lattice parameters of the hexagonal 211 and 312 phases followed Vegard’s law over the complete Zr-Ti solid solution range, but the 312 phase showed a non-negligible deviation from Vegard’s law around the (Zr0.33,Ti0.67)3Al1.2C1.6 stoichiometry. High-resolution scanning transmission electron microscopy combined with X-ray diffraction demonstrated ordering of the Zr and Ti atoms in the 312 phase, whereby Zr atoms occupied preferentially the central position in the close-packed M6X octahedral layers. The same ordering was also observed in 413 stackings present within the 312 phase. The decomposition of the secondary (Zr,Ti)C phase was attributed to the miscibility gap in the ZrC-TiC system.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000397171100045 Publication Date 2017-03-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-1669 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.857 Times cited 26 Open Access OpenAccess
Notes Fonds Wetenschappelijk Onderzoek, G.0431.10N.F ; Agentschap voor Innovatie door Wetenschap en Technologie, 131081 ; European Atomic Energy Community, 604862 ; SCK-CEN Academy for Nuclear Science and Technology; Hercules Foundation, Project/Award no: AKUL/1319 Project/Award no: ZW09-09 ; Approved Most recent IF: 4.857
Call Number EMAT @ emat @ c:irua:141794 Serial 4491
Permanent link to this record
 

 
Author van der Stam, W.; Geuchies, J.J.; Altantzis, T.; van den Bos, K.H.W.; Meeldijk, J.D.; Van Aert, S.; Bals, S.; Vanmaekelbergh, D.; de Mello Donega, C.
Title Highly Emissive Divalent-Ion-Doped Colloidal CsPb1–xMxBr3Perovskite Nanocrystals through Cation Exchange Type A1 Journal article
Year 2017 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
Volume 139 Issue 139 Pages 4087-4097
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Colloidal CsPbX3 (X = Br, Cl, and I) perovskite nanocrystals (NCs) have emerged as promising phosphors and solar cell materials due to their remarkable optoelectronic properties. These properties can be tailored by not only controlling the size and shape of the NCs but also postsynthetic composition tuning through topotactic

anion exchange. In contrast, property control by cation exchange is still underdeveloped for colloidal CsPbX3 NCs. Here, we present a method that allows partial cation exchange in colloidal CsPbBr3 NCs, whereby Pb2+ is exchanged for several isovalent cations, resulting in doped CsPb1−xMxBr3 NCs (M= Sn2+, Cd2+, and Zn2+; 0 < x ≤ 0.1), with preservation of the original NC shape. The size of the parent NCs is also preserved in the product NCs, apart from a small (few

%) contraction of the unit cells upon incorporation of the guest cations. The partial Pb2+ for M2+ exchange leads to a blue-shift of the optical spectra, while maintaining the high photoluminescence quantum yields (>50%), sharp absorption features, and narrow emission of the parent CsPbBr3 NCs. The blue-shift in the optical spectra is attributed to the lattice contraction that accompanies the Pb2+ for M2+ cation exchange and is observed to scale linearly with the lattice contraction. This work opens up new possibilities to engineer the properties of halide perovskite NCs, which to date are demonstrated to be the only known

system where cation and anion exchange reactions can be sequentially combined while preserving the original NC shape, resulting in compositionally diverse perovskite NCs.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000397477700027 Publication Date 2017-03-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-7863 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.858 Times cited 535 Open Access OpenAccess
Notes W.v.d.S. and C.d.M.D. acknowledge financial support from the division of Chemical Sciences (CW) of The Netherlands Organization for Scientific Research (NWO) under grant number ECHO.712.012.001. J.J.G. and D.V. acknowledge financial support from the Debye Graduate program. S.B. acknowledges financial support from the European Research Council (ERC Starting Grant # 335078-COLOURATOMS). K.H.W.v.d.B., S.B., S.V.A. and T.A. acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0368.15N, G.0369.15N), a Ph.D. grant to K.H.W.v.d.B, and a postdoctoral research grant to T.A. (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ECAS_Sara Approved Most recent IF: 13.858
Call Number EMAT @ emat @ c:irua:141754UA @ admin @ c:irua:141754 Serial 4482
Permanent link to this record
 

 
Author Lepot, K.; Addad, A.; Knoll, A.H.; Wang, J.; Troadec, D.; Béché, A.; Javaux, E.J.
Title Iron minerals within specific microfossil morphospecies of the 1.88 Ga Gunflint Formation Type A1 Journal article
Year 2017 Publication Nature communications Abbreviated Journal Nat Commun
Volume 8 Issue 8 Pages 14890
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Problematic microfossils dominate the palaeontological record between the Great Oxidation Event 2.4 billion years ago (Ga) and the last Palaeoproterozoic iron formations, deposited 500–600 million years later. These fossils are often associated with iron-rich sedimentary rocks, but their affinities, metabolism, and, hence, their contributions to Earth surface oxidation and Fe deposition remain unknown. Here we show that specific microfossil populations of the 1.88 Ga Gunflint Iron Formation contain Fe-silicate and Fe-carbonate nanocrystal concentrations in cell interiors. Fe minerals are absent in/on all organically preserved cell walls. These features are consistent with in vivo intracellular Fe biomineralization, with subsequent in situ recrystallization, but contrast with known patterns of post-mortem Fe mineralization. The Gunflint populations that display relatively large cells (thick-walled spheres, filament-forming rods) and intra-microfossil Fe minerals are consistent with oxygenic photosynthesizers but not with other Fe-mineralizing microorganisms studied so far. Fe biomineralization may have protected oxygenic photosynthesizers against Fe2+ toxicity during the Palaeoproterozoic.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000397129900001 Publication Date 2017-03-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 20 Open Access OpenAccess
Notes We thank J.-P. Cullus (thin sections), G. Spronck and C. Henrist (TEM), M. Cabié and C. Dominici (FIB), S. Bernard and C. Karunakaran (STXM), F. Bourdelle and G. Ji (EELS), P. Recourt (SEM). This study was co-funded by FRFC Grant no. 2.4558.09F (E.J.J.), CNRS-INSU (K.L.), FNRS (K.L.), ERC StG ELiTE Grant no. 308074 (E.J.J.), BELSPO IAP PLANET TOPERS (E.J.J.), NASA Astrobiology Institute (A.H.K.), Conseil Régional du Nord-Pas de Calais+European Regional Development Fund+CNRS-INSU (TEM in Lille), FP7-ESMI no. 262348 (TEM at EMAT Antwerp) and ANR-15-CE31-0003-01 (M6fossils, K.L.). We thank Noah Planavsky and two anonymous reviewers for thorough reviews that helped improve the paper. Approved Most recent IF: 12.124
Call Number EMAT @ emat @ c:irua:141919 Serial 4536
Permanent link to this record
 

 
Author Willhammar, T.; Sentosun, K.; Mourdikoudis, S.; Goris, B.; Kurttepeli, M.; Bercx, M.; Lamoen, D.; Partoens, B.; Pastoriza-Santos, I.; Pérez-Juste, J.; Liz-Marzán, L.M.; Bals, S.; Van Tendeloo, G.
Title Structure and vacancy distribution in copper telluride nanoparticles influence plasmonic activity in the near-infrared Type A1 Journal article
Year 2017 Publication Nature communications Abbreviated Journal Nat Commun
Volume 8 Issue 8 Pages 14925
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract Copper chalcogenides find applications in different domains including photonics, photothermal therapy and photovoltaics. CuTe nanocrystals have been proposed as an alternative to noble metal particles for plasmonics. Although it is known that deviations from stoichiometry are a prerequisite for plasmonic activity in the near-infrared, an accurate description of the material and its (optical) properties is hindered by an insufficient understanding of the atomic structure and the influence of defects, especially for materials in their nanocrystalline form. We demonstrate that the structure of Cu1.5±xTe nanocrystals canbe determined using electron diffraction tomography. Real-space high-resolution electron tomography directly reveals the three-dimensional distribution of vacancies in the structure. Through first-principles density functional theory, we furthermore demonstrate that the influence of these vacancies on the optical properties of the nanocrystals is determined. Since our methodology is applicable to a variety of crystalline nanostructured materials, it is expected to provide unique insights concerning structure–property correlations.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000397799700001 Publication Date 2017-03-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 37 Open Access OpenAccess
Notes The work was financially supported by the European Research Council through an ERC Starting Grant (#335078-COLOURATOMS). T.W. acknowledges the Swedish Research Council for an international postdoc grant. We acknowledge financial support of FWO-Vlaanderen through project G.0216.14N, G.0369.15N and a postdoctoral research grant to B.G. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO-Vlaanderen and the Flemish Government–Department EWI. The work was further supported by the Spanish MINECO (MAT2013-45168-R). S.M. thanks the Action ooSupporting Postdoctoral Researchers44 of the Operational Program ‘Education and Lifelong Learning’ (Action’s Beneficiary: General Secretariat for Research and Technology of Greece), which was co-financed by the European Social Fund (ESF) and the Greek State. (ROMEO:green; preprint:; postprint:can ; pdfversion:can); ECAS_Sara Approved Most recent IF: 12.124
Call Number EMAT @ emat @ c:irua:142203UA @ admin @ c:irua:142203 Serial 4538
Permanent link to this record
 

 
Author Stefan Löffler; Matthieu Bugnet; Nicolas Gauquelin; Sorin Lazar; Elias Assmann; Karsten Held; Gianluigi A. Botton; Peter Schattschneider
Title Real-space mapping of electronic orbitals Type A1 Journal article
Year 2017 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 177 Issue 177 Pages 26-29
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Electronic states are responsible for most material properties, including chemical bonds, electrical and thermal conductivity, as well as optical and magnetic properties. Experimentally, however, they remain mostly elusive. Here, we report the real-space mapping of selected transitions between p and d states on the Ångström scale in bulk rutile (TiO2) using electron energy-loss spectrometry (EELS), revealing information on individual bonds between atoms. On the one hand, this enables the experimental verification of theoretical predictions about electronic states. On the other hand, it paves the way for directly investigating electronic states under conditions that are at the limit of the current capabilities of numerical simulations such as, e.g., the electronic states at defects, interfaces, and quantum dots.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000401219800004 Publication Date 2017-01-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record
Impact Factor 2.843 Times cited Open Access Not_Open_Access
Notes ; St.L. thanks Walid Hetaba for discussions about WIEN2k. St.L. and P.S. thank Ralf Hambach and Ute Kaiser for many valuable discussions. M.B. thanks Vienna University of Technology for travel support. St.L. and P.S. acknowledge financial support by the Austrian Science Fund (FWF) under grant number 1543-N20, SFB F45 FOXSI; St.L. also acknowledges financial support by the Austrian Science Fund (FWF) under grant number J3732-N27. M.B., N.G., S.L. and G.A.B. performed the experimental work at the Canadian Center for Electron Microscopy, a national facility supported by McMaster University and the Natural Sciences and Engineering Research Council of Canada (NSERC). G.A.B. is grateful to NSERC for supporting this work. ; Approved Most recent IF: 2.843
Call Number EMAT @ emat @ c:irua:142201 Serial 4539
Permanent link to this record
 

 
Author Colin D. Judge, Nicolas Gauquelin, Lori Walters, Mike Wright, James I. Cole, James Madden, Gianluigi A. Botton, Malcolm Griffiths
Title Intergranular fracture in irradiated Inconel X-750 containing very high concentrations of helium and hydrogen Type A1 Journal Article
Year 2015 Publication Journal of Nuclear Materials Abbreviated Journal
Volume 457 Issue 457 Pages 165-172
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract In recent years, it has been observed that Inconel X-750 spacers in CANDU reactors exhibits lower ductility with reduced load carrying capacity following irradiation in a reactor environment. The fracture behaviour of ex-service material was also found to be entirely intergranular at high doses. The thermalized flux spectrum in a CANDU reactor leads to transmutation of 58Ni to 59Ni. The 59Ni itself has unusually high thermal neutron reaction cross-sections of the type: (n, γ), (n, p), and (n, α). The latter two reactions, in particular, contribute to a significant enhancement of the atomic displacements in addition to creating high concentrations of hydrogen and helium within the material. Microstructural examinations by transmission electron microscopy (TEM) have confirmed the presence of helium bubbles in the matrix and aligned along grain boundaries and matrix–precipitate interfaces. Helium bubble size and density are found to be highly dependent on the irradiation temperature and material microstructure; the bubbles are larger within grain boundary precipitates. TEM specimens extracted from fracture surfaces and crack tips provide information that is consistent with crack propagation along grain boundaries due to the presence of He bubbles.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000349169100022 Publication Date 2014-11-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links
Impact Factor Times cited 29 Open Access
Notes Approved Most recent IF: NA
Call Number EMAT @ emat @ Serial 4540
Permanent link to this record
 

 
Author Macke, S.; Radi, A.; Hamann-Borrero, J.E.; Verna, A.; Bluschke, M.; Brück, S.; Goering, E.; Sutarto, R.; He, F.; Cristiani, G.; Wu, M.; Benckiser, E.; Habermeier, H.-U.; Logvenov, G.; Gauquelin, N.; Botton, G.A; Kajdos, A.P.; Stemmer, S.; Sawatzky,G.A.; Haverkort, M.W.; Keimer, B.; Hinkov, V.
Title Element Specific Monolayer Depth Profiling Type A1 Journal Article
Year 2014 Publication Advanced Materials Abbreviated Journal Adv Mater
Volume 26 Issue 38 Pages 6554-6559
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT)
Abstract The electronic phase behavior and functionality of interfaces and surfaces in complex materials are strongly correlated to chemical composition profiles, stoichiometry and intermixing. Here a novel analysis scheme for resonant X-ray reflectivity maps is introduced to determine such profiles, which is element specific and non-destructive, and which exhibits atomic-layer resolution and a probing depth of hundreds of nanometers.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000343763200004 Publication Date 2014-08-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1521-4095 ISBN Additional Links
Impact Factor 19.791 Times cited 34 Open Access
Notes Approved Most recent IF: 19.791; 2014 IF: NA
Call Number EMAT @ emat @ Serial 4541
Permanent link to this record
 

 
Author N. Gauquelin, D. G. Hawthorn, G. A. Sawatzky, R. X. Liang, D. A. Bonn, W. N. Hardy & G.A. Botton
Title Atomic scale real-space mapping of holes in YBa2Cu3O6+δ Type A1 Journal Article
Year 2014 Publication Nature Communications Abbreviated Journal
Volume 5 Issue Pages 4275
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract The high-temperature superconductor YBa2Cu3O6+δ consists of two main structural units—a bilayer of CuO2 planes that are central to superconductivity and a CuO2+δ chain layer. Although the functional role of the planes and chains has long been established, most probes integrate over both, which makes it difficult to distinguish the contribution of each. Here we use electron energy loss spectroscopy to directly resolve the plane and chain contributions to the electronic structure in YBa2Cu3O6 and YBa2Cu3O7. We directly probe the charge transfer of holes from the chains to the planes as a function of oxygen content, and show that the change in orbital occupation of Cu is large in the chain layer but modest in CuO2 planes, with holes in the planes doped primarily into the O 2p states. These results provide direct insight into the local electronic structure and charge transfers in this important high-temperature superconductor.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000340615100002 Publication Date 2014-07-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links
Impact Factor Times cited 22 Open Access
Notes Approved Most recent IF: NA
Call Number EMAT @ emat @ Serial 4542
Permanent link to this record
 

 
Author Shuhui Sun, Gaixia Zhang, Nicolas Gauquelin, Ning Chen, Jigang Zhou, Songlan Yang, Weifeng Chen, Xiangbo Meng, Dongsheng Geng, Mohammad N. Banis, Ruying Li, Siyu Ye, Shanna Knights, Gianluigi A. Botton, Tsun-Kong Sham & Xueliang Sun
Title Single-atom Catalysis Using Pt/Graphene Achieved through Atomic Layer Deposition Type A1 Journal Article
Year 2013 Publication Scientific Reports Abbreviated Journal
Volume 3 Issue Pages 1775
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract Platinum-nanoparticle-based catalysts are widely used in many important chemical processes and

automobile industries. Downsizing catalyst nanoparticles to single atoms is highly desirable to maximize

their use efficiency, however, very challenging. Here we report a practical synthesis for isolated single Pt

atoms anchored to graphene nanosheet using the atomic layer deposition (ALD) technique. ALD offers the

capability of precise control of catalyst size span from single atom, subnanometer cluster to nanoparticle.

The single-atom catalysts exhibit significantly improved catalytic activity (up to 10 times) over that of the

state-of-the-art commercial Pt/C catalyst. X-ray absorption fine structure (XAFS) analyses reveal that the

low-coordination and partially unoccupied densities of states of 5d orbital of Pt atoms are responsible for the

excellent performance. This work is anticipated to form the basis for the exploration of a next generation of

highly efficient single-atom catalysts for various applications.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000318334300004 Publication Date 2013-05-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links
Impact Factor Times cited 345 Open Access
Notes Approved Most recent IF: NA
Call Number EMAT @ emat @ Serial 4543
Permanent link to this record
 

 
Author N. Gauquelin, E. Benckiser, M. K. Kinyanjui, M. Wu, Y. Lu, G. Christiani, G. Logvenov, H.-U. Habermeier, U. Kaiser, B. Keimer, and G. A. Botton
Title Atomically resolved EELS mapping of the interfacial structure of epitaxially strained LaNiO3/LaAlO3 superlattices Type A1 Journal Article
Year 2014 Publication Physical Review B Abbreviated Journal
Volume 90 Issue Pages 195140
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract The interfacial atomic structure of a metallic LaNiO3/LaAlO3 superlattice grown on a LaSrAlO4 substrate was

investigated using a combination of atomically resolved electron energy loss spectroscopy (EELS) at the Al K,

Al L2,3, Sr L2,3, Ni L2,3, La M4,5, and O K edges as well as hybridization mapping of selected features of the O

K-edge fine structure.We observe an additional La1−xSrxAl1−yNiyO3 layer at the substrate-superlattice interface,

possibly linked to diffusion of Al and Sr into the growing film or a surface reconstruction due to Sr segregation.

The roughness of the LaNiO3/LaAlO3 interfaces is found to be on average around one pseudocubic unit cell. The

O K-edge EELS spectra revealed reduced spectral weight of the prepeak derived from Ni-O hybridized states in

the LaNiO3 layers. We rule out oxygen nonstoichiometry of the LaNiO3 layers and discuss changes in the Ni-O

hybridization due to heterostructuring as possible origin.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000345467000003 Publication Date 2014-11-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links
Impact Factor Times cited 17 Open Access
Notes Approved Most recent IF: NA
Call Number EMAT @ emat @ Serial 4544
Permanent link to this record
 

 
Author M. K. Kinyanjui, N. Gauquelin, E. Benckiser, H. –U. Habermeier, B. Keimer, U. Kaiser and G.A. Botton
Title Local lattice distortion and anisotropic modulation in Epitaxially Strained LaNiO3/LaAlO3 hetero-structures Type A1 Journal Article
Year 2014 Publication Applied Physics Letters Abbreviated Journal
Volume 104 Issue Pages 221909
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract Using a complementary combination of x-ray diffraction and atomically resolved imaging we investigated the lattice structure of epitaxial LaNiO3/LaAlO3 superlattices grown on a compressive-strain inducing LaSrAlO4 (001) substrate. A refinement of the structure obtained from the x-ray data revealed the monoclinic I 2/c 1 1 space group. The (Ni/Al)O6 octahedral rotation angle perpendicular to the superlattice plane is enhanced, and the one parallel to the plane is reduced with respect to the corresponding bulk values. High-angle annular dark field imaging was used to determine the lattice parameters within the superlattice unit cell. High-resolution electron microscopy images of the oxygen atoms are consistent with the x-ray results.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Wos 000337161700029 Publication Date 2014-06-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links
Impact Factor Times cited 22 Open Access
Notes Approved Most recent IF: NA
Call Number EMAT @ emat @ Serial 4545
Permanent link to this record