|   | 
Details
   web
Records
Author Mallick, S.; Zhang, W.; Batuk, M.; Gibbs, A.S.; Hadermann, J.; Halasyamani, P.S.; Hayward, M.A.
Title The crystal and defect structures of polar KBiNb2O7 Type A1 Journal article
Year 2022 Publication Journal of the Chemical Society : Dalton transactions Abbreviated Journal Dalton T
Volume 51 Issue 5 Pages 1866-1873
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract KBiNb2O7 was prepared from RbBiNb2O7 by a sequence of cation exchange reactions which first convert RbBiNb2O7 to LiBiNb2O7, before KBiNb2O7 is formed by a further K-for-Li cation exchange. A combination of neutron, synchrotron X-ray and electron diffraction data reveal that KBiNb2O7 adopts a polar, layered, perovskite structure (space group A11m) in which the BiNb2O7 layers are stacked in a (0, ½, z) arrangement, with the K+ cations located in half of the available 10-coordinate interlayer cation sites. The inversion symmetry of the phase is broken by a large displacement of the Bi3+ cations parallel to the y-axis. HAADF-STEM images reveal that KBiNb2O7 exhibits frequent stacking faults which convert the (0. ½, z) layer stacking to (½, 0, z) stacking and vice versa, essentially switching the x- and y-axes of the material. By fitting the complex diffraction peak shape of the SXRD data collected from KBiNb2O7 it is estimated that each layer has approximately an ~11% chance of being defective – a high level which is attributed to the lack of cooperative NbO6 tilting in the material, which limits the lattice strain associated with each fault.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000741540300001 Publication Date 2022-01-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1477-9226 ISBN Additional Links UA library record; WoS full record
Impact Factor 4 Times cited Open Access OpenAccess
Notes Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award “Oxford/Warwick Solid State Chemistry BAG to probe composition-structure-property relationships in solids” (EE18786). Experiments at the ISIS pulsed neutron facility were supported by a beam time allocation from the STFC (RB 2000148). SM thanks Somerville College for an Oxford Ryniker Lloyd scholarship. PSH and WZ thank the National Science Foundation (DMR-2002319) for support. Approved Most recent IF: 4
Call Number EMAT @ emat @c:irua:185504 Serial 6951
Permanent link to this record
 

 
Author Zhang, Y.; Qin, S.; Claes, N.; Schilling, W.; Sahoo, P.K.; Ching, H.Y.V.; Jaworski, A.; Lemière, F.; Slabon, A.; Van Doorslaer, S.; Bals, S.; Das, S.
Title Direct Solar Energy-Mediated Synthesis of Tertiary Benzylic Alcohols Using a Metal-Free Heterogeneous Photocatalyst Type A1 Journal article
Year 2022 Publication ACS Sustainable Chemistry and Engineering Abbreviated Journal Acs Sustain Chem Eng
Volume 10 Issue 1 Pages 530-540
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Organic synthesis (ORSY)
Abstract Direct hydroxylation via the functionalization of tertiary benzylic C(sp3)-H bond is of great significance for obtaining tertiary alcohols which find wide applications in pharmaceuticals as well as in fine chemical industries. However, current synthetic procedures use toxic reagents and therefore, the development of a sustainable strategy for the synthesis of tertiary benzyl alcohols is highly desirable. To solve this problem, herein, we report a metal-free

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

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

 
Author Robert, Hl.; Lobato, I.; Lyu, Fj.; Chen, Q.; Van Aert, S.; Van Dyck, D.; Müller-Caspary, K.
Title Dynamical diffraction of high-energy electrons investigated by focal series momentum-resolved scanning transmission electron microscopy at atomic resolution Type A1 Journal article
Year 2022 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 233 Issue Pages 113425
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract We report a study of scattering dynamics in crystals employing momentum-resolved scanning transmission

electron microscopy under varying illumination conditions. As we perform successive changes of the probe

focus, multiple real-space signals are obtained in dependence of the shape of the incident electron wave.

With support from extensive simulations, each signal is shown to be characterised by an optimum focus for

which the contrast is maximum and which differs among different signals. For instance, a systematic focus

mismatch is found between images formed by high-angle scattering, being sensitive to thickness and chemical

composition, and the first moment in diffraction space, being sensitive to electric fields. It follows that a single

recording at one specific probe focus is usually insufficient to characterise materials comprehensively. Most

importantly, we demonstrate in experiment and simulation that the second moment (
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000734396800009 Publication Date 2021-11-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.2 Times cited Open Access OpenAccess
Notes We thank Dr. Florian Winkler for valuable discussions and experimental work at the early stages of this study. This work was supported by the Initiative and Network Fund of the Helmholtz Association (Germany) under contracts VH-NG-1317 and ZT-I-0025. This project furthermore received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 770887). Approved Most recent IF: 2.2
Call Number EMAT @ emat @c:irua:184833 Serial 6898
Permanent link to this record
 

 
Author Jannis, D.; Hofer, C.; Gao, C.; Xie, X.; Béché, A.; Pennycook, Tj.; Verbeeck, J.
Title Event driven 4D STEM acquisition with a Timepix3 detector: Microsecond dwell time and faster scans for high precision and low dose applications Type A1 Journal article
Year 2022 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 233 Issue Pages 113423
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Four dimensional scanning transmission electron microscopy (4D STEM) records the scattering of electrons in a material in great detail. The benefits offered by 4D STEM are substantial, with the wealth of data it provides facilitating for instance high precision, high electron dose efficiency phase imaging via centre of mass or ptychography based analysis. However the requirement for a 2D image of the scattering to be recorded at each probe position has long placed a severe bottleneck on the speed at which 4D STEM can be performed. Recent advances in camera technology have greatly reduced this bottleneck, with the detection efficiency of direct electron detectors being especially well suited to the technique. However even the fastest frame driven pixelated detectors still significantly limit the scan speed which can be used in 4D STEM, making the resulting data susceptible to drift and hampering its use for low dose beam sensitive applications. Here we report the development of the use of an event driven Timepix3 direct electron camera that allows us to overcome this bottleneck and achieve 4D STEM dwell times down to 100 ns; orders of magnitude faster than what has been possible with frame based readout. We characterize the detector for different acceleration voltages and show that the method is especially well suited for low dose imaging and promises rich datasets without compromising dwell time when compared to conventional STEM imaging.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000734396800003 Publication Date 2021-11-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.2 Times cited 31 Open Access OpenAccess
Notes This project has received funding from the Euro- pean Union’s Horizon 2020 Research Infrastructure – Integrating Activities for Advanced Communities under grant agreement No 823717 – ESTEEM3. J.V. and A.B. acknowledge funding from FWO project G093417N (‘Compressed sensing enabling low dose imaging in transmission electron microscopy’). J.V. and D.J. ac- knowledge funding from FWO project G042920N ‘Co- incident event detection for advanced spectroscopy in transmission electron microscopy’. We acknowledge funding under the European Union’s Horizon 2020 re- search and innovation programme (J.V. and D.J un- der grant agreement No 101017720, FET-Proactive EBEAM, and C.H., C.G., X.X. and T.J.P. from the Eu- ropean Research Council (ERC) Grant agreement No. 802123-HDEM).; esteem3JRA; esteem3reported Approved Most recent IF: 2.2
Call Number EMAT @ emat @c:irua:183948 Serial 6828
Permanent link to this record
 

 
Author Canossa, S.; Ferrari, E.; Sippel, P.; Fischer, J.K.H.; Pfattner, R.; Frison, R.; Masino, M.; Mas-Torrent, M.; Lunkenheimer, P.; Rovira, C.; Girlando, A.
Title Tetramethylbenzidine-TetrafluoroTCNQ (TMB-TCNQF(4)) : a narrow-gap semiconducting salt with room-temperature relaxor ferroelectric behavior Type A1 Journal article
Year 2021 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C
Volume 125 Issue 46 Pages 25816-25824
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract We present an extension and revision of the spectroscopic and structural data of the mixed-stack charge-transfer (CT) crystal 3,3 ',5,5 '-tetramethylbenzidine-tetrafluorotetracyano-quinodimethane (TMB-TCNQF4), associated with new electric and dielectric measurements. Refinement of synchrotron structural data at low temperature has led to revise the previously reported C2/m structure. The revised structure is P2(1)/m, with two dimerized stacks per unit cell, and is consistent with the low temperature vibrational data. However, polarized Raman data in the low-frequency region also indicate that by increasing temperature above 200 K, the structure presents an increasing degree of disorder, mainly along the stack axis. X-ray diffraction data at room temperature have confirmed that the correct structure is P2(1)/ m -no phase transitions -but did not allow substantiating the presence of disorder. On the other hand, dielectric measurements have evidenced a typical relaxor ferroelectric behavior already at room temperature, with a peak in the real part of dielectric constant epsilon'(T,v) around 200 K and 0.1 Hz. The relaxor behavior is explained in terms of the presence of spin solitons separating domains of opposite polarity that yield to ferroelectric nanodomains. TMB-TCNQF(4) is confirmed to be a narrow-gap band semiconductor (Ea similar to 0.3 eV) with a room-temperature conductivity of similar to 10(-4) Omega(-1) cm(-1).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000731170500008 Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited Open Access Not_Open_Access
Notes A.G. thanks Prof. Pascale Foury-Leylekian for very helpful discussions about the crystallographic issues. R.F. thanks Prof. Anthony Linden for his help in the X-ray diffraction data collection. J.K.H.F. and P.L. acknowledge funding from the Deutsche Forschungsgemeinschaft (DFG) via the Transregional Collaborative Research Center TRR80 (Augsburg, Munich). R.P. and M.M.-T. acknowledge support from the Marie Curie Cofund, Beatriu de Pinós Fellowships (Grant nos. AGAUR 2017 BP 00064). This work was also supported by the Spanish Ministry project GENESIS PID2019-111682RBI00, the “Severo Ochoa” Programme for Centers of Excellence in R&D (FUNFUTURE, CEX2019-000917-S), and the Generalitat de Catalunya (2017-SGR-918). The Elettra Synchrotron (CNR Trieste) is acknowledged for granting the beamtime at the single-crystal diffraction beamline XRD1 (Proposal ID 20185483). In Parma, the work has benefited from the equipment and support of the COMP-HUB Initiative, funded by the “Departments of Excellence” program of the Approved Most recent IF: 4.536
Call Number UA @ admin @ c:irua:184866 Serial 7066
Permanent link to this record
 

 
Author Feng, X.; Jena, H.S.; Krishnaraj, C.; Arenas-Esteban, D.; Leus, K.; Wang, G.; Sun, J.; Rüscher, M.; Timoshenko, J.; Roldan Cuenya, B.; Bals, S.; Voort, P.V.D.
Title Creation of Exclusive Artificial Cluster Defects by Selective Metal Removal in the (Zn, Zr) Mixed-Metal UiO-66 Type A1 Journal article
Year 2021 Publication Journal Of The American Chemical Society Abbreviated Journal J Am Chem Soc
Volume Issue Pages jacs.1c05357
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The differentiation between missing linker defects

and missing cluster defects in MOFs is difficult, thereby limiting the

ability to correlate materials properties to a specific type of defects.

Herein, we present a novel and easy synthesis strategy for the

creation of solely “missing cluster defects” by preparing mixed-metal

(Zn, Zr)-UiO-66 followed by a gentle acid wash to remove the Zn

nodes. The resulting material has the reo UiO-66 structure, typical

for well-defined missing cluster defects. The missing clusters are

thoroughly characterized, including low-pressure Ar-sorption, iDPCSTEM

at a low dose (1.5 pA), and XANES/EXAFS analysis. We

show that the missing cluster UiO-66 has a negligible number of missing linkers. We show the performance of the missing cluster

UiO-66 in CO2 sorption and heterogeneous catalysis.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000730569500001 Publication Date 2021-12-07
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 29 Open Access OpenAccess
Notes Agentschap Innoveren en Ondernemen, HBC.2019.0110 HBC.2021.0254 ; Universiteit Gent; Fonds Wetenschappelijk Onderzoek, 665501 ; Dalian University of Technology; China Scholarship Council, 201507565009 ; National Natural Science Foundation of China, 22101039 ; H2020 European Research Council, 815128 REALNANO ; sygmaSB Approved Most recent IF: 13.858
Call Number EMAT @ emat @c:irua:183951 Serial 6833
Permanent link to this record
 

 
Author Zheng, Y.-R.; Vernieres, J.; Wang, Z.; Zhang, K.; Hochfilzer, D.; Krempl, K.; Liao, T.-W.; Presel, F.; Altantzis, T.; Fatermans, J.; Scott, S.B.; Secher, N.M.; Moon, C.; Liu, P.; Bals, S.; Van Aert, S.; Cao, A.; Anand, M.; Nørskov, J.K.; Kibsgaard, J.; Chorkendorff, I.
Title Monitoring oxygen production on mass-selected iridium–tantalum oxide electrocatalysts Type A1 Journal article
Year 2021 Publication Nature Energy Abbreviated Journal Nat Energy
Volume Issue Pages
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract Development of low-cost and high-performance oxygen evolution reaction catalysts is key to implementing polymer electrolyte membrane water electrolyzers for hydrogen production. Iridium-based oxides are the state-of-the-art acidic oxygen evolution reactio catalysts but still suffer from inadequate activity and stability, and iridium's scarcity motivates the discovery of catalysts with lower iridium loadings. Here we report a mass-selected iridium-tantalum oxide catalyst prepared by a magnetron-based cluster source with considerably reduced noble-metal loadings beyond a commercial IrO2 catalyst. A sensitive electrochemistry/mass-spectrometry instrument coupled with isotope labelling was employed to investigate the oxygen production rate under dynamic operating conditions to account for the occurrence of side reactions and quantify the number of surface active sites. Iridium-tantalum oxide nanoparticles smaller than 2 nm exhibit a mass activity of 1.2 ± 0.5 kA “g” _“Ir” ^“-1” and a turnover frequency of 2.3 ± 0.9 s-1 at 320 mV overpotential, which are two and four times higher than those of mass-selected IrO2, respectively. Density functional theory calculations reveal that special iridium coordinations and the lowered aqueous decomposition free energy might be responsible for the enhanced performance.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000728458000001 Publication Date 2021-12-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2058-7546 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 95 Open Access OpenAccess
Notes Y.-R.Z. and Z.W acknowledge funding from the Toyota Research Institute. This project has received funding from VILLUM FONDEN (grant no. 9455) and the European Research Council under the European Union’s Horizon 2020 research and innovation programme (grants no. 741860-CLUNATRA, no. 815128−REALNANO and no. 770887−PICOMETRICS). S.B. and S.V.A. acknowledge funding from the Research Foundation Flanders (FWO, G026718N and G050218N). T.A. acknowledges the University of Antwerp Research Fund (BOF). STEM measurements were supported by the European Union's Horizon 2020 Research Infrastructure-Integrating Activities for Advanced Communities under grant agreement No 823717 – ESTEEM3.; sygmaSB Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:184794 Serial 6903
Permanent link to this record
 

 
Author Windels, S.; Diefenhardt, T.; Jain, N.; Marquez, C.; Bals, S.; Schlummer, M.; De Vos, D.E.
Title Catalytic upcycling of PVC waste-derived phthalate esters into safe, hydrogenated plasticizers Type A1 Journal article
Year 2022 Publication Green chemistry : cutting-edge research for a greener sustainable future Abbreviated Journal Green Chem
Volume 24 Issue 2 Pages 754-766
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Recycling of end-of-life polyvinyl chloride (PVC) calls for solutions to deal with the vast amounts of harmful phthalate plasticizers that have historically been incorporated in PVC. Here, we report on the upcycling of such waste-extracted phthalate esters into analogues of the much safer diisononyl 1,2-cyclohexanedicarboxylate plasticizer (DINCH), via a catalytic one-pot (trans)esterification-hydrogenation process. For most of the virgin phthalates, Ru/Al2O3 is a highly effective hydrogenation catalyst, yielding >99% ring-hydrogenated products under mild reaction conditions (0.1 mol% Ru, 80 degrees C, 50 bar H-2). However, applying this reaction to PVC-extracted phthalates proved problematic, (1) as benzyl phthalates are hydrogenolyzed to benzoic acids that inhibit the Ru-catalyst, and (2) because impurities in the plasticizer extract (PVC, sulfur) further retard the hydrogenation. These complications were solved by coupling the hydrogenation to an in situ (trans)esterification with a higher alcohol, and by pretreating the extract with an activated carbon adsorbent. In this way, a real phthalate extract obtained from post-consumer PVC waste was eventually completely (>99%) hydrogenated to phthalate-free, cycloaliphatic plasticizers.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000726865200001 Publication Date 2021-11-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9262; 1463-9270 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.8 Times cited 8 Open Access Not_Open_Access
Notes This project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement no. 821366 (programma acronym: Circular Flooring). D. E. D. V. thanks FWO for project funding (SBO project S001819N Triple Cycle); N. J. and S. B. acknowledge the financial support from FWO and FNRS (EOS 30489208). Finally, the authors also thank S. Smolders for assistance with the TGA-MS experiments and D. Paredaens for his experimental contribution Approved Most recent IF: 9.8
Call Number UA @ admin @ c:irua:184746 Serial 6958
Permanent link to this record
 

 
Author Shi, R.; Choudhuri, D.; Kashiwar, A.; Dasari, S.; Wang, Y.; Banerjee, R.; Banerjee, D.
Title α phase growth and branching in titanium alloys Type A1 Journal article
Year 2021 Publication Philosophical magazine Abbreviated Journal Philos Mag
Volume Issue Pages
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The morphology and spatial distribution of alpha (α) precipitates have been mapped as a function of Mo content in Ti-Mo binary alloys employing a combinatorial approach. Heat-treatments were carried out on compositionally graded Ti-xMo samples processed using a rapid throughput laser engineered net shape (LENS) process. The composition space spans 1.5 at% to 6 at% Mo with ageing at 750°C, 650°C and 600°C following a β solution treatment. Three distinct regimes of α morphology and distribution were observed. These are colony-dominated microstructures originating from grain boundary α allotriomorphs, bundles of intragranular α laths, and homogeneously distributed individual fine-scale α laths. Branching of the α precipitates was observed in all these domains in a manner reminiscent of solid-state dendritic growth. The phenomenon is particularly apparent at low volume fractions of α. Similar features are present in a wide variety of alloy compositions. 3-dimensional features of such branched structures have been analysed. Simulation of the branching process by phase field methods incorporating anisotropy in the α/β interface energy and elasticity suggests that it can be initiated at growth ledges present at broad faces of the α laths, driven by the enhancement of the diffusion flux at these steps. The dependence of branching on various parameters such as supersaturation and diffusivity, and microstructural features like ledge height and distribution and the presence of adjacent α variants has been evaluated.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000722082700001 Publication Date 2021-11-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1478-6435 ISBN Additional Links UA library record; WoS full record
Impact Factor 1.505 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 1.505
Call Number UA @ admin @ c:irua:183616 Serial 6849
Permanent link to this record
 

 
Author Lezaack, M.B.; Hannard, F.; Zhao, L.; Orekhov, A.; Adrien, J.; Miettinen, A.; Idrissi, H.; Simar, A.
Title Towards ductilization of high strength 7XXX aluminium alloys via microstructural modifications obtained by friction stir processing and heat treatments Type A1 Journal article
Year 2021 Publication Materialia Abbreviated Journal
Volume 20 Issue Pages 101248
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract High strength 7XXX aluminium series reach exceptional strength, higher than all other industrial aluminium alloys. However, they suffer from a lack of ductility compared to softer series. This work presents a procedure to improve the ductility of 7475 Al alloy in high strength condition, reaching a true fracture strain of 70% at full 500 MPa T6 yield strength. Using friction stir processing (FSP) and post-FSP heat treatments, 100% of industrial rolled material T6 yield stress is maintained but a 180% increase in fracture strain is measured for the processed material. This ductility improvement is studied by in-situ synchrotron X-ray tomography and is explained by the reduction of intermetallic particles size and the homogenization of their spatial distribution. Furthermore, the microstructure after FSP shows equiaxed refined grains which favour crack deviation as opposed to large cracks parallel to the elongated coarse grains in rolled plate. These results are paving the way to better formability and crashworthiness of 7XXX alloys.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000718127100006 Publication Date 2021-10-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2589-1529 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:184145 Serial 6894
Permanent link to this record
 

 
Author Arslan Irmak, E.; Liu, P.; Bals, S.; Van Aert, S.
Title 3D Atomic Structure of Supported Metallic Nanoparticles Estimated from 2D ADF STEM Images: A Combination of Atom – Counting and a Local Minima Search Algorithm Type A1 Journal article
Year 2021 Publication Small methods Abbreviated Journal Small Methods
Volume Issue Pages 2101150
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Determining the three-dimensional (3D) atomic structure of nanoparticles (NPs) is critical to understand their structure-dependent properties. It is hereby important to perform such analyses under conditions relevant for the envisioned application. Here, we investigate the 3D structure of supported Au NPs at high temperature, which is of importance to understand their behavior during catalytic reactions. To overcome limitations related to conventional high-resolution electron tomography at high temperature, 3D characterization of NPs with atomic resolution has been performed by applying atom-counting using atomic resolution annular darkfield scanning transmission electron microscopy (ADF STEM) images followed by structural relaxation. However, at high temperatures, thermal displacements, which affect the ADF STEM intensities, should be taken into account. Moreover, it is very likely that the structure of a NP investigated at elevated temperature deviates from a ground state configuration, which is difficult to determine using purely computational energy minimization approaches. In this paper, we therefore propose an optimized approach using an iterative local minima search algorithm followed by molecular dynamics (MD) structural relaxation of candidate structures associated with each local minimum. In this manner, it becomes possible to investigate the 3D atomic structure of supported NPs, which may deviate from their ground state configuration.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000716511600001 Publication Date 2021-11-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2366-9608 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 12 Open Access OpenAccess
Notes This work was supported by the European Research Council (Grant 815128 REALNANO to SB, Grant 770887 PICOMETRICS to SVA, Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project funding (G.0267.18N, G.0502.18N, G.0346.21N).; sygmaSB; esteem3jra; esteem3reported Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:183289 Serial 6820
Permanent link to this record
 

 
Author Sanchez-Iglesias, A.; Jenkinson, K.; Bals, S.; Liz-Marzan, L.M.
Title Kinetic regulation of the synthesis of pentatwinned gold nanorods below room temperature Type A1 Journal article
Year 2021 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C
Volume 125 Issue 43 Pages 23937-23944
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The synthesis of gold nanorods requires the presence of symmetry-breaking and shape-directing additives, among which bromide ions and quaternary ammonium surfactants have been reported as essential. As a result, hexadecyltrimethylammonium bromide (CTAB) has been selected as the most efficient surfactant to direct anisotropic growth. One of the difficulties arising from this selection is the low solubility of CTAB in water at room temperature, and therefore the seeded growth of gold nanorods is usually performed at 25 degrees C or above, which has restricted so far the analysis of kinetic effects derived from lower temperatures. We report a systematic study of the synthesis of gold nanorods from pentatwinned seeds using hexadecyltrimethylammonium chloride (CTAC) as the principal surfactant and a low concentration of bromide as shape-directing agent. Under these conditions, the synthesis can be performed at temperatures as low as 8 degrees C, and the corresponding kinetic effects can be studied, resulting in temperature-controlled aspect ratio tunability.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000716453300038 Publication Date 2021-10-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 6 Open Access OpenAccess
Notes realnano; sygmaSB; This work was supported by the National Science Foundation (NSF) under award NSF CHE-1808502 (P.C. and I.J.). This work made use of the EPIC facility of Northwestern University's NUANCE Center, which has received support from the SHyNE Resource (NSF ECCS-2025633), the IIN, and Northwestern's MRSEC program (NSF DMR-1720139). D.A E. and S.B. acknowledge funding from the European Research Council under the European Union's Horizon 2020 research and innovation program (ERC Consolidator Grants No. 815128 REALNANO and Grant Agreement No. 731019 EUSMI). Approved Most recent IF: 4.536
Call Number UA @ admin @ c:irua:184104 Serial 6868
Permanent link to this record
 

 
Author Velazco, A.; Béché, A.; Jannis, D.; Verbeeck, J.
Title Reducing electron beam damage through alternative STEM scanning strategies, Part I: Experimental findings Type A1 Journal article
Year 2022 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 232 Issue Pages 113398
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The highly energetic electrons in a transmission electron microscope (TEM) can alter or even completely destroy the structure of samples before sufficient information can be obtained. This is especially problematic in the case of zeolites, organic and biological materials. As this effect depends on both the electron beam and the sample and can involve multiple damage pathways, its study remained difficult and is plagued with irreproducibility issues, circumstantial evidence, rumors, and a general lack of solid data. Here we take on the experimental challenge to investigate the role of the STEM scan pattern on the damage behavior of a commercially available zeolite sample with the clear aim to make our observations as reproducible as possible. We make use of a freely programmable scan engine that gives full control over the tempospatial distribution of the electron probe on the sample and we use its flexibility to obtain multiple repeated experiments under identical conditions comparing the difference in beam damage between a conventional raster scan pattern and a newly proposed interleaved scan pattern that provides exactly the same dose and dose rate and visits exactly the same scan points. We observe a significant difference in beam damage for both patterns with up to 11 % reduction in damage (measured from mass loss). These observations demonstrate without doubt that electron dose, dose rate and acceleration voltage are not the only parameters affecting beam damage in (S)TEM experiments and invite the community to rethink beam damage as an unavoidable consequence of applied electron dose.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000714819200002 Publication Date 2021-10-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.2 Times cited 18 Open Access OpenAccess
Notes A.V., D.J., A.B. and J.V. acknowledge funding from FWO project G093417N (’Compressed sensing enabling low dose imaging in transmission electron microscopy’) and G042920N (’Coincident event detection for advanced spectroscopy in transmission electron microscopy’). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 823717 ESTEEM3. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. J.V. acknowledges funding from GOA project “Solarpaint” of the University of Antwerp.; JRA; reported Approved Most recent IF: 2.2
Call Number EMAT @ emat @c:irua:183282 Serial 6818
Permanent link to this record
 

 
Author Bartholomeeusen, E.; De Cremer, G.; Kennes, K.; Hammond, C.; Hermans, I.; Lu, J.-B.; Schryvers, D.; Jacobs, P.A.; Roeffaers, M.B.J.; Hofkens, J.; Sels, B.F.; Coutino-Gonzalez, E.
Title Optical encoding of luminescent carbon nanodots in confined spaces Type A1 Journal article
Year 2021 Publication Chemical Communications Abbreviated Journal Chem Commun
Volume 57 Issue 90 Pages 11952-11955
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Stable emissive carbon nanodots were generated in zeolite crystals using near infrared photon irradiation gradually converting the occluded organic template, originally used to synthesize the zeolite crystals, into discrete luminescent species consisting of nano-sized carbogenic fluorophores, as ascertained using Raman microscopy, and steady-state and time-resolved spectroscopic techniques. Photoactivation in a confocal laser fluorescence microscope allows 3D resolved writing of luminescent carbon nanodot patterns inside zeolites providing a cost-effective and non-toxic alternative to previously reported metal-based nanoclusters confined in zeolites, and opens up opportunities in bio-labelling and sensing applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000711122000001 Publication Date 2021-10-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-7345; 1364-548x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.319 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 6.319
Call Number UA @ admin @ c:irua:184147 Serial 6876
Permanent link to this record
 

 
Author Hudry, D.; De Backer, A.; Popescu, R.; Busko, D.; Howard, I.A.; Bals, S.; Zhang, Y.; Pedrazo‐Tardajos, A.; Van Aert, S.; Gerthsen, D.; Altantzis, T.; Richards, B.S.
Title Interface Pattern Engineering in Core‐Shell Upconverting Nanocrystals: Shedding Light on Critical Parameters and Consequences for the Photoluminescence Properties Type A1 Journal article
Year 2021 Publication Small Abbreviated Journal Small
Volume Issue Pages 2104441
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract Advances in controlling energy migration pathways in core-shell lanthanide (Ln)-based hetero-nanocrystals (HNCs) have relied heavily on assumptions about how optically active centers are distributed within individual HNCs. In this article, it is demonstrated that different types of interface patterns can be formed depending on shell growth conditions. Such interface patterns are not only identified but also characterized with spatial resolution ranging from the nanometer- to the atomic-scale. In the most favorable cases, atomic-scale resolved maps of individual particles are obtained. It is also demonstrated that, for the same type of core-shell architecture, the interface pattern can be engineered with thicknesses of just 1 nm up to several tens of nanometers. Total alloying between the core and shell domains is also possible when using ultra-small particles as seeds. Finally, with different types of interface patterns (same architecture and chemical composition of the core and shell domains) it is possible to modify the output color (yellow, red, and green-yellow) or change (improvement or degradation) the absolute upconversion quantum yield. The results presented in this article introduce an important paradigm shift and pave the way toward the emergence of a new generation of core-shell Ln-based HNCs with better control over their atomic-scale organization.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000710758000001 Publication Date 2021-10-25
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 17 Open Access OpenAccess
Notes The authors would like to acknowledge the financial support provided by the Helmholtz Recruitment Initiative Fellowship (B.S.R.) and the Helmholtz Association's Research Field Energy (Materials and Technologies for the Energy Transition program, Topic 1 Photovoltaics and Wind Energy). The authors would like to thank the Karlsruhe Nano Micro Facility (KNMF) for STEM access. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (Grant agreement no. 770887 PICOMETRICS to S.V.A. and Grant agreement no. 815128 REALNANO to S.B.). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through Projects no. G.0502.18N, G.0267.18N, and a postdoctoral grant to A.D.B. T.A. acknowledges funding from the University of Antwerp Research fund (BOF). This project had received funding (EUSMI proposal #E181100205) from the European Union's Horizon 2020 Research and Innovation Programme under Grant agreement no 731019 (EUSMI). D.H. would like to thank “CGFigures” for helpful tutorials on 3D graphics with Blender.; sygmaSB Approved Most recent IF: 8.643
Call Number EMAT @ emat @c:irua:183285 Serial 6817
Permanent link to this record
 

 
Author Jannis, D.; Müller-Caspary, K.; Béché, A.; Verbeeck, J.
Title Coincidence Detection of EELS and EDX Spectral Events in the Electron Microscope Type A1 Journal article
Year 2021 Publication Applied Sciences-Basel Abbreviated Journal Appl Sci-Basel
Volume 11 Issue 19 Pages 9058
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Recent advances in the development of electron and X-ray detectors have opened up the possibility to detect single events from which its time of arrival can be determined with nanosecond resolution. This allows observing time correlations between electrons and X-rays in the transmission electron microscope. In this work, a novel setup is described which measures individual events using a silicon drift detector and digital pulse processor for the X-rays and a Timepix3 detector for the electrons. This setup enables recording time correlation between both event streams while at the same time preserving the complete conventional electron energy loss (EELS) and energy dispersive X-ray (EDX) signal. We show that the added coincidence information improves the sensitivity for detecting trace elements in a matrix as compared to conventional EELS and EDX. Furthermore, the method allows the determination of the collection efficiencies without the use of a reference sample and can subtract the background signal for EELS and EDX without any prior knowledge of the background shape and without pre-edge fitting region. We discuss limitations in time resolution arising due to specificities of the silicon drift detector and discuss ways to further improve this aspect.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000710160300001 Publication Date 2021-09-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2076-3417 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.679 Times cited 9 Open Access OpenAccess
Notes Fonds Wetenschappelijk Onderzoek, G042920 ; Horizon 2020 Framework Programme, 101017720 ; Helmholtz-Fonds, VH-NG-1317 ; Approved Most recent IF: 1.679
Call Number EMAT @ emat @c:irua:183336 Serial 6821
Permanent link to this record
 

 
Author Villarreal, R.; Lin, P.-C.; Faraji, F.; Hassani, N.; Bana, H.; Zarkua, Z.; Nair, M.N.; Tsai, H.-C.; Auge, M.; Junge, F.; Hofsaess, H.C.; De Gendt, S.; De Feyter, S.; Brems, S.; Ahlgren, E.H.; Neyts, E.C.; Covaci, L.; Peeters, F.M.; Neek-Amal, M.; Pereira, L.M.C.
Title Breakdown of universal scaling for nanometer-sized bubbles in graphene Type A1 Journal article
Year 2021 Publication Nano Letters Abbreviated Journal Nano Lett
Volume 21 Issue 19 Pages 8103-8110
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We report the formation of nanobubbles on graphene with a radius of the order of 1 nm, using ultralow energy implantation of noble gas ions (He, Ne, Ar) into graphene grown on a Pt(111) surface. We show that the universal scaling of the aspect ratio, which has previously been established for larger bubbles, breaks down when the bubble radius approaches 1 nm, resulting in much larger aspect ratios. Moreover, we observe that the bubble stability and aspect ratio depend on the substrate onto which the graphene is grown (bubbles are stable for Pt but not for Cu) and trapped element. We interpret these dependencies in terms of the atomic compressibility of the noble gas as well as of the adhesion energies between graphene, the substrate, and trapped atoms.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000709549100026 Publication Date 2021-09-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1530-6984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.712 Times cited 24 Open Access OpenAccess
Notes Approved Most recent IF: 12.712
Call Number UA @ admin @ c:irua:184137 Serial 6857
Permanent link to this record
 

 
Author Prabhakara, V.; Nuytten, T.; Bender, H.; Vandervorst, W.; Bals, S.; Verbeeck, J.
Title Linearized radially polarized light for improved precision in strain measurements using micro-Raman spectroscopy Type A1 Journal article
Year 2021 Publication Optics Express Abbreviated Journal Opt Express
Volume 29 Issue 21 Pages 34531
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Strain engineering in semiconductor transistor devices has become vital in the semiconductor industry due to the ever-increasing need for performance enhancement at the nanoscale. Raman spectroscopy is a non-invasive measurement technique with high sensitivity to mechanical stress that does not require any special sample preparation procedures in comparison to characterization involving transmission electron microscopy (TEM), making it suitable for inline strain measurement in the semiconductor industry. Indeed, at present, strain measurements using Raman spectroscopy are already routinely carried out in semiconductor devices as it is cost effective, fast and non-destructive. In this paper we explore the usage of linearized radially polarized light as an excitation source, which does provide significantly enhanced accuracy and precision as compared to linearly polarized light for this application. Numerical simulations are done to quantitatively evaluate the electric field intensities that contribute to this enhanced sensitivity. We benchmark the experimental results against TEM diffraction-based techniques like nano-beam diffraction and Bessel diffraction. Differences between both approaches are assigned to strain relaxation due to sample thinning required in TEM setups, demonstrating the benefit of Raman for nondestructive inline testing.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000708940500144 Publication Date 2021-10-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1094-4087 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.307 Times cited 2 Open Access OpenAccess
Notes Horizon 2020 Framework Programme, 823717 – ESTEEM3 ; GOA project, “Solarpaint” ; Herculesstichting;; esteem3jra; esteem3reported; Approved Most recent IF: 3.307
Call Number EMAT @ emat @c:irua:182472 Serial 6816
Permanent link to this record
 

 
Author Baral, P.; Orekhov, A.; Dohmen, R.; Coulombier, M.; Raskin, J.P.; Cordier, P.; Idrissi, H.; Pardoen, T.
Title Rheology of amorphous olivine thin films characterized by nanoindentation Type A1 Journal article
Year 2021 Publication Acta Materialia Abbreviated Journal Acta Mater
Volume 219 Issue Pages 117257
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The rheological properties of amorphous olivine thin films deposited by pulsed laser deposition have been studied based on ambient temperature nanoindentation under constant strain-rate as well as re-laxation conditions. The amorphous olivine films exhibit a viscoelastic-viscoplastic behavior with a significant rate dependency. The strain-rate sensitivity m is equal to similar to 0 . 05 which is very high for silicates, indicating a complex out-of-equilibrium structure. The minimum apparent activation volume determined from nanoindentation experiments corresponds to Mg and Fe atomic metallic sites in the (Mg,Fe)(2)SiO4 crystalline lattice. The ambient temperature creep behavior of the amorphous olivine films differs very much from the one of single crystal olivine. This behavior directly connects to the recent demonstration of the activation of grain boundary sliding in polycrystalline olivine following grain boundary amorphization under high-stress. (C) 2021 The Authors. Published by Elsevier Ltd on behalf of Acta Materialia Inc.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000706867800004 Publication Date 2021-08-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6454 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.301 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 5.301
Call Number UA @ admin @ c:irua:182592 Serial 6882
Permanent link to this record
 

 
Author Mallick, S.; Khalsa, G.; Kaaret, J.Z.; Zhang, W.; Batuk, M.; Gibbs, A.S.; Hadermann, J.; Halasyamani, P.S.; Benedek, N.A.; Hayward, M.A.
Title The influence of the 6s² configuration of Bi³+ on the structures of A ' BiNb₂O₇ (A ' = Rb, Na, Li) layered perovskite oxides Type A1 Journal article
Year 2021 Publication Journal of the Chemical Society : Dalton transactions Abbreviated Journal
Volume 50 Issue 42 Pages 15359-15369
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Solid state compounds which exhibit non-centrosymmetric crystal structures are of great interest due to the physical properties they can exhibit. The 'hybrid improper' mechanism – in which two non-polar distortion modes couple to, and stabilize, a further polar distortion mode, yielding an acentric crystal structure – offers opportunities to prepare a range of novel non-centrosymmetric solids, but examples of compounds exhibiting acentric crystal structures stabilized by this mechanism are still relatively rare. Here we describe a series of bismuth-containing layered perovskite oxide phases, RbBiNb2O7, LiBiNb2O7 and NaBiNb2O7, which have structural frameworks compatible with hybrid-improper ferroelectricity, but also contain Bi3+ cations which are often observed to stabilize acentric crystal structures due to their 6s(2) electronic configurations. Neutron powder diffraction analysis reveals that RbBiNb2O7 and LiBiNb2O7 adopt polar crystal structures (space groups I2cm and B2cm respectively), compatible with stabilization by a trilinear coupling of non-polar and polar modes. The Bi3+ cations present are observed to enhance the magnitude of the polar distortions of these phases, but are not the primary driver for the acentric structure, as evidenced by the observation that replacing the Bi3+ cations with Nd3+ cations does not change the structural symmetry of the compounds. In contrast the non-centrosymmetric, but non-polar structure of NaBiNb2O7 (space group P2(1)2(1)2(1)) differs significantly from the centrosymmetric structure of NaNdNb2O7, which is attributed to a second-order Jahn-Teller distortion associated with the presence of the Bi3+ cations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000706651100001 Publication Date 2021-10-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1477-9234 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:182584 Serial 6893
Permanent link to this record
 

 
Author Yang, M.; Orekhov, A.; Hu, Z.-Y.; Feng, M.; Jin, S.; Sha, G.; Li, K.; Samaee, V.; Song, M.; Du, Y.; Van Tendeloo, G.; Schryvers, D.
Title Shearing and rotation of β'' and β' precipitates in an Al-Mg-Si alloy under tensile deformation : in-situ and ex-situ studies Type A1 Journal article
Year 2021 Publication Acta Materialia Abbreviated Journal Acta Mater
Volume 220 Issue Pages 117310
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The interaction between dislocations and nano-precipitates during deformation directly influences hardening response of precipitation-strengthening metals such as Al-Mg-Si alloys. However, how coherent and semi-coherent nano-precipitates accommodate external deformation applied to an Al alloy remains to be elucidated. In-situ tensile experiments in a transmission electron microscope (TEM) were conducted to study the dynamic process of dislocations cutting through coherent needle-like beta '' precipitates with diameters of 3 similar to 8 nm. Comprehensive investigations using in-situ, ex-situ TEM and atom probe tomography uncovered that beta '' precipitates were firstly sheared into small fragments, and then the rotation of the fragments, via sliding along precipitate/matrix interfaces, destroyed their initially coherent interface with the Al matrix. In contrast, semi-coherent beta' precipitates with sizes similar to beta '' were more difficult to be fragmented and accumulation of dislocations at the interface increased interface misfit between beta' and the Al matrix. Consequently, beta' precipitates could basically maintain their needle-like shape after the tensile deformation. This research gains new insights into the interaction between nano-precipitates and dislocations. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000705535300005 Publication Date 2021-09-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6454 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.301 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 5.301
Call Number UA @ admin @ c:irua:182528 Serial 6884
Permanent link to this record
 

 
Author van Thiel, T. c.; Brzezicki, W.; Autieri, C.; Hortensius, J. r.; Afanasiev, D.; Gauquelin, N.; Jannis, D.; Janssen, N.; Groenendijk, D. j.; Fatermans, J.; Van Aert, S.; Verbeeck, J.; Cuoco, M.; Caviglia, A. d.
Title Coupling Charge and Topological Reconstructions at Polar Oxide Interfaces Type A1 Journal article
Year 2021 Publication Physical Review Letters Abbreviated Journal Phys Rev Lett
Volume 127 Issue 12 Pages 127202
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In oxide heterostructures, different materials are integrated into a single artificial crystal, resulting in a breaking of inversion symmetry across the heterointerfaces. A notable example is the interface between polar and nonpolar materials, where valence discontinuities lead to otherwise inaccessible charge and spin states. This approach paved the way for the discovery of numerous unconventional properties absent in the bulk constituents. However, control of the geometric structure of the electronic wave functions in correlated oxides remains an open challenge. Here, we create heterostructures consisting of ultrathin SrRuO3, an itinerant ferromagnet hosting momentum-space sources of Berry curvature, and

LaAlO3, a polar wide-band-gap insulator. Transmission electron microscopy reveals an atomically sharp LaO/RuO2/SrO interface configuration, leading to excess charge being pinned near the LaAlO3/SrRuO3 interface. We demonstrate through magneto-optical characterization, theoretical calculations and transport measurements that the real-space charge reconstruction drives a reorganization of the topological charges in the band structure, thereby modifying the momentum-space Berry curvature in SrRuO3. Our results illustrate how the topological and magnetic features of oxides can be manipulated by engineering charge discontinuities at oxide interfaces.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000704665000010 Publication Date 2021-09-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.462 Times cited 17 Open Access OpenAccess
Notes The authors thank E. Lesne, M. Lee, H. Barakov, M. Matthiesen and U. Filippozzi for discussions. The authors are grateful to E.J.S. van Thiel for producing the illustration in Fig. 4a. This work was supported by the European Research Council under the European Unions Horizon 2020 programme/ERC Grant agreements No. [677458], [770887] and No. [731473] (Quantox of QuantERA ERA-NET Cofund in Quantum Technologies) and by the Netherlands Organisation for Scientific Research (NWO/OCW) as part of the Frontiers of Nanoscience (NanoFront) and VIDI program. The authors acknowledge funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. [823717] – ESTEEM3. N. G., J. V., and S. V. A. acknowledge funding from the University of Antwerp through the Concerted Research Actions (GOA) project Solarpaint and the TOP project. C. A. and W. B. are supported by the Foundation for Polish Science through the International Research Agendas program co-financed by the European Union within the Smart Growth Operational Programme. C. A. acknowledges access to the computing facilities of the Interdisciplinary Center of Modeling at the University of Warsaw, Grant No. G73-23 and G75-10. W.B. acknowledges support from the Narodowe Centrum Nauk (NCN, National Science Centre, Poland) Project No. 2019/34/E/ST3/00404'; esteem3TA; esteem3reported Approved Most recent IF: 8.462
Call Number EMAT @ emat @c:irua:182595 Serial 6824
Permanent link to this record
 

 
Author Zhao, H.; Li, C.-F.; Hu, Z.-Y.; Liu, J.; Li, Y.; Hu, J.; Van Tendeloo, G.; Chen, L.-H.; Su, B.-L.
Title Size effect of bifunctional gold in hierarchical titanium oxide-gold-cadmium sulfide with slow photon effect for unprecedented visible-light hydrogen production Type A1 Journal article
Year 2021 Publication Journal Of Colloid And Interface Science Abbreviated Journal J Colloid Interf Sci
Volume 604 Issue Pages 131-139
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Gold nanoparticles (Au NPs) with surface plasmonic resonance (SPR) effect and excellent internal electron transfer ability have widely been combined with semiconductors for photocatalysis. However, the in-depth effects of Au NPs in multicomponent photocatalysts have not been completely understood. Herein, ternary titanium oxide-gold-cadmium sulfide (TiO2-Au-CdS, TAC) photocatalysts, based on hierarchical TiO2 inverse opal photonic crystal structure with different Au NPs sizes have been designed to reveal the SPR effect and internal electron transfer of Au NPs in the presence of slow photon effect. It appears that the SPR effect and internal electron transfer ability of Au NPs, depending on their sizes, play a synergistic effect on the photocatalytic enhancement. The ternary TAC-10 photocatalyst with – 10 nm Au NPs demonstrates an unprecedented hydrogen evolution rate of 47.6 mmolh-1g 1 under visible-light, demonstrating- 48% enhancement comparing to the sample without slow photon effect. In particular, a 9.83% apparent quantum yield under 450 nm monochromatic light is achieved for TAC-10. A model is proposed and finite-difference time-domain (FDTD) simulations reveal the size influence of Au NPs in ternary TAC photocatalysts. This work suggests that the rational design of bifunctional Au NPs coupling with slow photon effect could largely promote hydrogen production from visible-light driven water splitting. (c) 2021 Elsevier Inc. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000704428600004 Publication Date 2021-07-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-9797 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.233 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 4.233
Call Number UA @ admin @ c:irua:182531 Serial 6886
Permanent link to this record
 

 
Author De wael, A.; De Backer, A.; Lobato, I.; Van Aert, S.
Title Modelling ADF STEM images using elliptical Gaussian peaks and its effects on the quantification of structure parameters in the presence of sample tilt Type A1 Journal article
Year 2021 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume Issue Pages 113391
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A small sample tilt away from a main zone axis orientation results in an elongation of the atomic columns in ADF STEM images. An often posed research question is therefore whether the ADF STEM image intensities of tilted nanomaterials should be quantified using a parametric imaging model consisting of elliptical rather than the currently used symmetrical peaks. To this purpose, simulated ADF STEM images corresponding to different amounts of sample tilt are studied using a parametric imaging model that consists of superimposed 2D elliptical Gaussian peaks on the one hand and symmetrical Gaussian peaks on the other hand. We investigate the quantification of structural parameters such as atomic column positions and scattering cross sections using both parametric imaging models. In this manner, we quantitatively study what can be gained from this elliptical model for quantitative ADF STEM, despite the increased parameter space and computational effort. Although a qualitative improvement can be achieved, no significant quantitative improvement in the estimated structure parameters is achieved by the elliptical model as compared to the symmetrical model. The decrease in scattering cross sections with increasing sample tilt is even identical for both types of parametric imaging models. This impedes direct comparison with zone axis image simulations. Nonetheless, we demonstrate how reliable atom-counting can still be achieved in the presence of small sample tilt.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000704334200001 Publication Date 2021-09-24
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 Open Access OpenAccess
Notes This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 770887 and No. 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through grants to A.D.w. and A.D.B. and projects G.0502.18N, G.0267.18N, and EOS 30489208. S.V.A. acknowledges TOP BOF funding from the University of Antwerp.; esteem3JRA; esteem3reported Approved Most recent IF: 2.843
Call Number EMAT @ emat @c:irua:181462 Serial 6810
Permanent link to this record
 

 
Author Choukroun, D.; Pacquets, L.; Li, C.; Hoekx, S.; Arnouts, S.; Baert, K.; Hauffman, T.; Bals, S.; Breugelmans, T.
Title Mapping composition–selectivity relationships of supported sub-10 nm Cu–Ag nanocrystals for high-rate CO₂ electroreduction Type A1 Journal article
Year 2021 Publication Acs Nano Abbreviated Journal Acs Nano
Volume 15 Issue 9 Pages 14858-14872
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract Colloidal Cu–Ag nanocrystals measuring less than 10 nm across are promising candidates for integration in hybrid CO2 reduction reaction (CO2RR) interfaces, especially in the context of tandem catalysis and selective multicarbon (C2–C3) product formation. In this work, we vary the synthetic-ligand/copper molar ratio from 0.1 to 1.0 and the silver/copper atomic ratio from 0 to 0.7 and study the variations in the nanocrystals’ size distribution, morphology and reactivity at rates of ≥100 mA cm–2 in a gas-fed recycle electrolyzer operating under neutral to mildly basic conditions (0.1–1.0 M KHCO3). High-resolution electron microscopy and spectroscopy are used in order to characterize the morphology of sub-10 nm Cu–Ag nanodimers and core–shells and to elucidate trends in Ag coverage and surface composition. It is shown that Cu–Ag nanocrystals can be densely dispersed onto a carbon black support without the need for immediate ligand removal or binder addition, which considerably facilitates their application. Although CO2RR product distribution remains an intricate function of time, (kinetic) overpotential and processing conditions, we nevertheless conclude that the ratio of oxygenates to hydrocarbons (which depends primarily on the initial dispersion of the nanocrystals and their composition) rises 3-fold at moderate Ag atom % relative to Cu NCs-based electrodes. Finally, the merits of this particular Cu–Ag/C system and the recycling reactor employed are utilized to obtain maximum C2–C3 partial current densities of 92–140 mA cm–2 at −1.15 VRHE and liquid product concentrations in excess of 0.05 wt % in 1 M KHCO3 after short electrolysis periods.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000703553600082 Publication Date 2021-08-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.942 Times cited 25 Open Access OpenAccess
Notes D.C. acknowledges Thomas Kenis for configuring the analytical instrumentation (HPLC/GC-FID/ICP-MS), Hannelore Andries for assistance with ICP-MS measurements, and Dr. Saeid Pourbabak and Dr. Tine Derez for assistance with Cu sputtering. L.P. was supported by Research Foundation of Flanders (FWO 1S56920N). S.B. acknowledges financial support from ERC Consolidator grant number 815128 REALNANO. S.B. and T.B. acknowledge financial support from the university research fund (BOF-GOA-PS ID no. 33928).; sygmaSB Approved Most recent IF: 13.942
Call Number UA @ admin @ c:irua:180305 Serial 6844
Permanent link to this record
 

 
Author Herzog, M.J.; Gauquelin, N.; Esken, D.; Verbeeck, J.; Janek, J.
Title Increased Performance Improvement of Lithium-Ion Batteries by Dry Powder Coating of High-Nickel NMC with Nanostructured Fumed Ternary Lithium Metal Oxides Type A1 Journal article
Year 2021 Publication ACS applied energy materials Abbreviated Journal ACS Appl. Energy Mater.
Volume 4 Issue 9 Pages 8832-8848
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Dry powder coating is an effective approach to protect the surfaces of layered cathode active materials (CAMs) in lithium-ion batteries. Previous investigations indicate an incorporation of lithium ions in fumed Al2O3, ZrO2, and TiO2 coatings on LiNi0.7Mn0.15Co0.15O2 during cycling, improving the cycling performance. Here, this coating approach is transferred for the first time to fumed ternary LiAlO2, Li4Zr3O8, and Li4Ti5O12 and directly compared with their lithium-free equivalents. All materials could be processed equally and their nanostructured small aggregates accumulate on the CAM surfaces to quite homogeneous coating layers with a certain porosity. The LiNixMnyCozO2 (NMC) coated with lithium-containing materials shows an enhanced improvement in overall capacity, capacity retention, rate performance, and polarization behavior during cycling, compared to their lithium-free analogues. The highest rate performance was achieved with the fumed ZrO2 coating, while the best long-term cycling stability with the highest absolute capacity was obtained for the fumed LiAlO2-coated NMC. The optimal coating agent for NMC to achieve a balanced system is fumed Li4Ti5O12, providing a good compromise between high rate capability and good capacity retention. The coating agents prevent CAM particle cracking and degradation in the order LiAlO2 ≈ Al2O3 > Li4Ti5O12 > Li4Zr3O8 > ZrO2 > TiO2. A schematic model for the protection and electrochemical performance enhancement of high-nickel NMC with fumed metal oxide coatings is sketched. It becomes apparent that physical and chemical characteristics of the coating significantly influence the performance of NMC. A high degree of coating-layer porosity is favorable for the rate capability, while a high coverage of the surface, especially in vulnerable grain boundaries, enhances the long-term cycling stability and improves the cracking behavior of NMCs. While zirconium-containing coatings possess the best chemical properties for high rate performances, aluminum-containing coatings feature a superior chemical nature to protect high-nickel NMCs.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000703338600018 Publication Date 2021-09-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2574-0962 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 15 Open Access OpenAccess
Notes For his support in scanning electron microscopy analysis, the authors thank Erik Peldszus. N. G. and J. V. acknowledge funding from GOA project “Solarpaint” of the University of Antwerp and from the Flemish Research Fund (FWO) project G0F1320N. The Qu-Ant-EM microscope and the direct electron detector were partly funded by the Hercules fund from the Flemish Government Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:183949 Serial 6823
Permanent link to this record
 

 
Author Barbiellini, B.; Kuriplach, J.; Saniz, R.
Title Study of rechargeable batteries using advanced spectroscopic and computational techniques Type Editorial
Year 2021 Publication Condensed Matter Abbreviated Journal
Volume 6 Issue 3 Pages 26
Keywords Editorial; Electron microscopy for materials research (EMAT)
Abstract Improving the efficiency and longevity of energy storage systems based on Li- and Na-ion rechargeable batteries presents a major challenge. The main problems are essentially capacity loss and limited cyclability. These effects are due to a hierarchy of factors spanning various length and time scales, interconnected in a complex manner. As a consequence, and in spite of several decades of research, a proper understanding of the ageing process has remained somewhat elusive. In recent years, however, combinations of advanced spectroscopy techniques and first-principles simulations have been applied with success to tackle this problem. In this Special Issue, we are pleased to present a selection of articles that, by precisely applying these methods, unravel key aspects of the reduction-oxidation reaction and intercalation processes. Furthermore, the approaches presented provide improvements to standard diagnostic and characterisation techniques, enabling the detection of possible Li-ion flow bottlenecks causing the degradation of capacity and cyclability.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000699368400001 Publication Date 2021-07-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2410-3896 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:181630 Serial 6890
Permanent link to this record
 

 
Author Renero-Lecuna, C.; Herrero, A.; Jimenez de Aberasturi, D.; Martínez-Flórez, M.; Valiente, R.; Mychinko, M.; Bals, S.; Liz-Marzán, L.M.
Title Nd3+-Doped Lanthanum Oxychloride Nanocrystals as Nanothermometers Type A1 Journal article
Year 2021 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C
Volume 125 Issue 36 Pages 19887-19896
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The development of optical nanothermometers operating in the near-infrared (NIR) is of high relevance toward temperature measurements in biological systems. We propose herein the use of Nd3+-doped lanthanum oxychloride nanocrystals as an efficient system with intense photoluminescence under NIR irradiation in the first biological transparency window and emission in the second biological window with excellent emission stability over time under 808 nm excitation, regardless of Nd3+ concentration, which can be considered as a particular strength of our system. Additionally, surface passivation through overgrowth of an inert LaOCl shell around optically active LaOCl/Nd3+ cores was found to further enhance the photoluminescence intensity and also the lifetime of the 1066 nm, 4F3/2 to 4I11/2 transition, without affecting its (ratiometric) sensitivity toward temperature changes. As required for biological applications, we show that the obtained (initially hydrophobic) nanocrystals can be readily transferred into aqueous solvents with high, long-term stability, through either ligand exchange or encapsulation with an amphiphilic polymer.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000697335100031 Publication Date 2021-09-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 9 Open Access OpenAccess
Notes The authors thank the financial support of the European Research Council (ERC-AdG-2017 787510, ERC-CoG-2019 815128) and of the European Commission (EUSMI, Grant 731019). This work was performed under the Maria de Maeztu Units of Excellence Program from the Spanish State Research Agency−Grant MDM-2017−0720. Realnano; sygmaSB Approved Most recent IF: 4.536
Call Number EMAT @ emat @c:irua:181671 Serial 6831
Permanent link to this record
 

 
Author Salzmann, B.B.V.; Vliem, J.F.; Maaskant, D.N.; Post, L.C.; Li, C.; Bals, S.; Vanmaekelbergh, D.
Title From CdSe nanoplatelets to quantum rings by thermochemical edge reconfiguration Type A1 Journal article
Year 2021 Publication Chemistry Of Materials Abbreviated Journal Chem Mater
Volume 33 Issue 17 Pages 6853-6859
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The variation in the shape of colloidal semiconductor nanocrystals (NCs) remains intriguing. This interest goes beyond crystallography as the shape of the NC determines its energy levels and optoelectronic properties. While thermodynamic arguments point to a few or just a single shape(s), terminated by the most stable crystal facets, a remarkable variation in NC shape has been reported for many different compounds. For instance, for the well-studied case of CdSe, close-to-spherical quantum dots, rods, two-dimensional nanoplatelets, and quantum rings have been reported. Here, we report how two-dimensional CdSe nanoplatelets reshape into quantum rings. We monitor the reshaping in real time by combining atomically resolved structural characterization with optical absorption and photoluminescence spectroscopy. We observe that CdSe units leave the vertical sides of the edges and recrystallize on the top and bottom edges of the nanoplatelets, resulting in a thickening of the rims. The formation of a central hole, rendering the shape into a ring, only occurs at a more elevated temperature.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000696553600024 Publication Date 2021-08-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756; 1520-5002 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 7 Open Access OpenAccess
Notes Hans Meeldijk is kindly acknowledged for helping with electron microscopy at Utrecht University. B.B.V.S. and D.V. acknowledge the Dutch NWO for financial support via the TOP-ECHO grant no. 715.016.002. D.V. acknowledges financial support from the European ERC Council, ERC Advanced grant 692691 “First Step”. D.V. and L.C.P. acknowledge the Dutch NWO for financial support via the TOP-ECHO grant nr. 718.015.002. S.B acknowledges financial support from the European ERC Council, ERC Consolidator grant 815128. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement no. 731019 (EUSMI). Realnano; sygmaSB Approved Most recent IF: 9.466
Call Number UA @ admin @ c:irua:181550 Serial 6839
Permanent link to this record
 

 
Author Penders, A.; Konstantinovic, M.J.; Van Renterghem, W.; Bosch, R.W.; Schryvers, D.
Title TEM investigation of SCC crack tips in high Si stainless steel tapered specimens Type A1 Journal article
Year 2021 Publication Corrosion Engineering Science And Technology Abbreviated Journal Corros Eng Sci Techn
Volume Issue Pages
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The stress corrosion cracking (SCC) mechanism is investigated in high Si duplex stainless steel in a simulated PWR environment based on TEM analysis of FIB-extracted SCC crack tips. The microstructural investigation in the near vicinity of SCC crack tips illustrates a strain-rate dependence in SCC mechanisms. Detailed analysis of the crack tip morphology, that includes crack tip oxidation and surrounding deformation field, indicates the existence of an interplay between corrosion- and deformation-driven failure as a function of the strain rate. Slow strain-rate crack tips exhibit a narrow cleavage failure which can be linked to the film-induced failure mechanism, while rounded shaped crack tips for faster strain rates could be related to the strain-induced failure. As a result, two nominal strain-rate-dependent failure regimes dominated either by corrosion or deformation-driven cracking mechanisms can be distinguished.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (down) 000695956400001 Publication Date 2021-09-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1478-422x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.879 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 0.879
Call Number UA @ admin @ c:irua:181533 Serial 6892
Permanent link to this record