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Author Vlasov, E.
Title Exploiting secondary electrons in transmission electron microscopy for 3D characterization of nanoparticle morphologies Type Doctoral thesis
Year 2024 Publication Abbreviated Journal
Volume Issue Pages x, 118 p.
Keywords Doctoral thesis; Electron microscopy for materials research (EMAT)
Abstract Electron tomography (ET) is an indispensable tool for determining the three-dimensional (3D) structure of nanomaterials in (scanning) transmission electron microscopy ((S)TEM). ET enables 3D characterization of a variety of nanomaterials across different fields, including life sciences, chemistry, solid-state physics, and materials science down to atomic resolution. However, the acquisition of a conventional tilt series for ET is a time-consuming process and thus cannot capture fast transformations of materials in realistic conditions. Moreover, only a limited number of nanoparticles (NPs) can be investigated, hampering a general understanding of the average properties of the material. Therefore, alternative characterization techniques that allow for high-resolution characterization of the surface structure without the need to acquire a full tilt series in ET are required which would enable a more time-efficient investigation with better statistical value. In the first part of this work, an alternative technique for the characterization of the morphology of NPs to improve the throughput and temporal resolution of ET is presented. The proposed technique exploits surface-sensitive secondary electron (SE) imaging in STEM employed using a modification of electron beam-induced current (EBIC) setup. The time- and dose efficiency of SEEBIC are tested in comparison with ET and superior spatial resolution is shown compared to conventional scanning electron microscopy. Finally, contrast artefacts arising in SEEBIC images are described, and their origin is discussed. The second part of my thesis focuses on real applications of the proposed technique and introduces a high-throughput methodology that combines images acquired by SEEBIC with quantitative image analysis to retrieve information about the helicity of gold nanorods. It shows that SEEBIC imaging overcomes the limitation of ET providing a general understanding of the connection between structure and chiroptical properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date (down) 2024-06-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:204905 Serial 9149
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Author Van Gordon, K.; Ni, B.; Girod, R.; Mychinko, M.; Bevilacqua, F.; Bals, S.; Liz‐Marzán, L.M.
Title Single Crystal and Pentatwinned Gold Nanorods Result in Chiral Nanocrystals with Reverse Handedness Type A1 Journal Article
Year 2024 Publication Angewandte Chemie International Edition Abbreviated Journal Angew Chem Int Ed
Volume Issue Pages
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract Handedness is an essential attribute of chiral nanocrystals, having a major influence on their properties. During chemical growth, the handedness of nanocrystals is usually tuned by selecting the corresponding enantiomer of chiral molecules involved in asymmetric growth, often known as chiral inducers. We report that, even using the same chiral inducer enantiomer, the handedness of chiral gold nanocrystals can be reversed by using Au nanorod seeds with either single crystalline or pentatwinned structure. This effect holds for chiral growth induced both by amino acids and by chiral micelles. Although it was challenging to discern the morphological handedness for<italic>L</italic>‐cystine‐directed particles, even using electron tomography, both cases showed circular dichroism bands of opposite sign, with nearly mirrored chiroptical signatures for chiral micelle‐directed growth, along with quasi‐helical wrinkles of inverted handedness. These results expand the chiral growth toolbox with an effect that might be exploited to yield a host of interesting morphologies with tunable optical properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date (down) 2024-05-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1433-7851 ISBN Additional Links
Impact Factor 16.6 Times cited Open Access
Notes Ana Sánchez-Iglesias is acknowledged for support in the synthesis of pentatwinned gold nanorods. The authors acknowledge financial support by the European Research Council (ERC CoG No. 815128 REALNANO to S.B.), from MCIN/AEI/10.13039/501100011033 (Grant PID2020- 117779RB-I00 to L.M.L.-M and FPI Fellowship PRE2021- 097588 to K.V.G.), and by KU Leuven (C14/22/085). This work has been funded by the European Union under Project 101131111—DELIGHT. Funding for open access charge: Universidade de Vigo/ CRUE-CISUG. Approved Most recent IF: 16.6; 2024 IF: 11.994
Call Number EMAT @ emat @ Serial 9129
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Author Brognara, A.; Kashiwar, A.; Jung, C.; Zhang, X.; Ahmadian, A.; Gauquelin, N.; Verbeeck, J.; Djemia, P.; Faurie, D.; Dehm, G.; Idrissi, H.; Best, J.P.; Ghidelli, M.
Title Tailoring mechanical properties and shear band propagation in ZrCu metallic glass nanolaminates through chemical heterogeneities and interface density Type A1 Journal article
Year 2024 Publication Small Structures Abbreviated Journal
Volume Issue Pages 2400011-11
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The design of high‐performance structural thin films consistently seeks to achieve a delicate equilibrium by balancing outstanding mechanical properties like yield strength, ductility, and substrate adhesion, which are often mutually exclusive. Metallic glasses (MGs) with their amorphous structure have superior strength, but usually poor ductility with catastrophic failure induced by shear bands (SBs) formation. Herein, we introduce an innovative approach by synthesizing MGs characterized by large and tunable mechanical properties, pioneering a nanoengineering design based on the control of nanoscale chemical/structural heterogeneities. This is realized through a simplified model Zr 24 Cu 76 /Zr 61 Cu 39 , fully amorphous nanocomposite with controlled nanoscale periodicity ( Λ , from 400 down to 5 nm), local chemistry, and glass–glass interfaces, while focusing in‐depth on the SB nucleation/propagation processes. The nanolaminates enable a fine control of the mechanical properties, and an onset of crack formation/percolation (>1.9 and 3.3%, respectively) far above the monolithic counterparts. Moreover, we show that SB propagation induces large chemical intermixing, enabling a brittle‐to‐ductile transition when Λ  ≤ 50 nm, reaching remarkably large plastic deformation of 16% in compression and yield strength ≈2 GPa. Overall, the nanoengineered control of local heterogeneities leads to ultimate and tunable mechanical properties opening up a new approach for strong and ductile materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date (down) 2024-05-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2688-4062 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:205798 Serial 9176
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Author Gao, Y.-J.; Jin, H.; Esteban, D.A.; Weng, B.; Saha, R.A.; Yang, M.-Q.; Bals, S.; Steele, J.A.; Huang, H.; Roeffaers, M.B.J.
Title 3D-cavity-confined CsPbBr₃ quantum dots for visible-light-driven photocatalytic C(sp³)-H bond activation Type A1 Journal article
Year 2024 Publication Carbon Energy Abbreviated Journal
Volume Issue Pages e559
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Metal halide perovskite (MHP) quantum dots (QDs) offer immense potential for several areas of photonics research due to their easy and low-cost fabrication and excellent optoelectronic properties. However, practical applications of MHP QDs are limited by their poor stability and, in particular, their tendency to aggregate. Here, we develop a two-step double-solvent strategy to grow and confine CsPbBr3 QDs within the three-dimensional (3D) cavities of a mesoporous SBA-16 silica scaffold (CsPbBr3@SBA-16). Strong confinement and separation of the MHP QDs lead to a relatively uniform size distribution, narrow luminescence, and good ambient stability over 2 months. In addition, the CsPbBr3@SBA-16 presents a high activity and stability for visible-light-driven photocatalytic toluene C(sp(3))-H bond activation to produce benzaldehyde with similar to 730 mu mol g(-1) h(-1) yield rate and near-unity selectivity. Similarly, the structural stability of CsPbBr3@SBA-16 QDs is superior to that of both pure CsPbBr3 QDs and those confined in MCM-41 with 1D channels.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001223583600001 Publication Date (down) 2024-05-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2637-9368 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:206000 Serial 9133
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Author Vlasov, E.; Heyvaert, W.; Ni, B.; Van Gordon, K.; Girod, R.; Verbeeck, J.; Liz-Marzán, L.M.; Bals, S.
Title High-Throughput Morphological Chirality Quantification of Twisted and Wrinkled Gold Nanorods Type A1 Journal Article
Year 2024 Publication ACS Nano Abbreviated Journal ACS Nano
Volume Issue Pages
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract Chirality in gold nanostructures offers an exciting opportunity to tune their differential optical response to left- and right-handed circularly polarized light, as well as their interactions with biomolecules and living matter. However, tuning and understanding such interactions demands quantification of the structural features that are responsible for the chiral behavior. Electron tomography (ET) enables structural characterization at the single-particle level and has been used to quantify the helicity of complex chiral nanorods. However, the technique is time-consuming and consequently lacks statistical value. To address this issue, we introduce herein a high-throughput methodology that combines images acquired by secondary electron-based electron beam-induced current (SEEBIC) with quantitative image analysis. As a result, the geometric chirality of hundreds of nanoparticles can be quantified in less than 1 h. When combining the drastic gain in data collection efficiency of SEEBIC with a limited number of ET data sets, a better understanding of how the chiral structure of individual chiral nanoparticles translates into the ensemble chiroptical response can be reached.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date (down) 2024-04-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851 ISBN Additional Links
Impact Factor 17.1 Times cited Open Access
Notes The authors acknowledge financial support by the European Research Council (ERC CoG No. 815128 REALNANO to S.B.) and from MCIN/AEI/10.13039/501100011033 (Grant PID2020-117779RB-I00 to L.M.L.-M and FPI Fellowship PRE2021-097588 to K.V.G.). Funded by the European Union under Project 101131111 − DELIGHT, JV acknowledges the eBEAM project supported by the European Union’s Horizon 2020 research and innovation program FETPROACT-EIC-07- 2020: emerging paradigms and communities. Approved Most recent IF: 17.1; 2024 IF: 13.942
Call Number EMAT @ emat @ Serial 9121
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Author Guerrero, R.M.; Lemir, I.D.; Carrasco, S.; Fernández-Ruiz, C.; Kavak, S.; Pizarro, P.; Serrano, D.P.; Bals, S.; Horcajada, P.; Pérez, Y.
Title Scaling-Up Microwave-Assisted Synthesis of Highly Defective Pd@UiO-66-NH2Catalysts for Selective Olefin Hydrogenation under Ambient Conditions Type A1 Journal Article
Year 2024 Publication ACS Applied Materials & Interfaces Abbreviated Journal ACS Appl. Mater. Interfaces
Volume Issue Pages
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract The need to develop green and cost-effective industrial catalytic processes has led to growing interest in preparing more robust, efficient, and selective heterogeneous catalysts at a large scale. In this regard, microwave-assisted synthesis is a fast method for fabricating heterogeneous catalysts (including metal oxides, zeolites, metal–organic frameworks, and supported metal nanoparticles) with enhanced catalytic properties, enabling synthesis scale-up. Herein, the synthesis of nanosized UiO-66-NH2 was optimized via a microwave-assisted hydrothermal method to obtain defective matrices essential for the stabilization of metal nanoparticles, promoting catalytically active sites for hydrogenation reactions (760 kg·m–3·day–1 space time yield, STY). Then, this protocol was scaled up in a multimodal microwave reactor, reaching 86% yield (ca. 1 g, 1450 kg·m–3·day–1 STY) in only 30 min. Afterward, Pd nanoparticles were formed in situ decorating the nanoMOF by an effective and fast microwave-assisted hydrothermal method, resulting in the formation of Pd@UiO-66-NH2 composites. Both the localization and oxidation states of Pd nanoparticles (NPs) in the MOF were achieved using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and X-ray photoelectron spectroscopy (XPS), respectively. The optimal composite, loaded with 1.7 wt % Pd, exhibited an extraordinary catalytic activity (>95% yield, 100% selectivity) under mild conditions (1 bar H2, 25 °C, 1 h reaction time), not only in the selective hydrogenation of a variety of single alkenes (1-hexene, 1-octene, 1-tridecene, cyclohexene, and tetraphenyl ethylene) but also in the conversion of a complex mixture of alkenes (i.e., 1-hexene, 1-tridecene, and anethole). The results showed a powerful interaction and synergy between the active phase (Pd NPs) and the catalytic porous scaffold (UiO-66-NH2), which are essential for the selectivity and recyclability.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date (down) 2024-04-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1944-8244 ISBN Additional Links
Impact Factor 9.5 Times cited Open Access
Notes The authors gratefully acknowledge financial support from “Comunidad de Madrid” and European Regional Development Fund-FEDER through the project HUB MADRID+CIRCULAR; the State Research Agency (MCIN/AEI /10.13039/501100011033) through the grant with reference number CEX2019-000931-M received in the 2019 call for “Severo Ochoa Centres of Excellence” and “María de Maeztu Units of Excellence” of the State Programme for Knowledge Generation and Scientific and Technological Strengthening of the R&D&I System; and MICIU through the project “NAPOLION” (PID2022-139956OB-I00). S.K. acknowledges the Flemish Fund for Scientific Research (FWO Vlaanderen) through a PhD research grant (1181124N). Approved Most recent IF: 9.5; 2024 IF: 7.504
Call Number EMAT @ emat @ Serial 9126
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Author Cioni, M.; Delle Piane, M.; Polino, D.; Rapetti, D.; Crippa, M.; Arslan Irmak, E.; Van Aert, S.; Bals, S.; Pavan, G.M.
Title Sampling real-time atomic dynamics in metal nanoparticles by combining experiments, simulations, and machine learning Type A1 Journal article
Year 2024 Publication Advanced Science Abbreviated Journal
Volume Issue Pages 1-13
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Even at low temperatures, metal nanoparticles (NPs) possess atomic dynamics that are key for their properties but challenging to elucidate. Recent experimental advances allow obtaining atomic-resolution snapshots of the NPs in realistic regimes, but data acquisition limitations hinder the experimental reconstruction of the atomic dynamics present within them. Molecular simulations have the advantage that these allow directly tracking the motion of atoms over time. However, these typically start from ideal/perfect NP structures and, suffering from sampling limits, provide results that are often dependent on the initial/putative structure and remain purely indicative. Here, by combining state-of-the-art experimental and computational approaches, how it is possible to tackle the limitations of both approaches and resolve the atomistic dynamics present in metal NPs in realistic conditions is demonstrated. Annular dark-field scanning transmission electron microscopy enables the acquisition of ten high-resolution images of an Au NP at intervals of 0.6 s. These are used to reconstruct atomistic 3D models of the real NP used to run ten independent molecular dynamics simulations. Machine learning analyses of the simulation trajectories allow resolving the real-time atomic dynamics present within the NP. This provides a robust combined experimental/computational approach to characterize the structural dynamics of metal NPs in realistic conditions. Experimental and computational techniques are bridged to unveil atomic dynamics in gold nanoparticles (NPs), using annular dark-field scanning transmission electron microscopy and molecular dynamics simulations informed by machine learning. The approach provides unprecedented insights into the real-time structural behaviors of NPs, merging state-of-the-art techniques to accurately characterize their dynamics under realistic conditions. image
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001206888000001 Publication Date (down) 2024-04-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2198-3844 ISBN Additional Links UA library record; WoS full record
Impact Factor 15.1 Times cited Open Access
Notes This work was supported by the funding received by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement no. 818776- DYNAPOL, no. 770887 PICOMETRICS and no. 815128 REALNANO). The authors also acknowledge the computational resources provided by the Swiss National Supercomputing Center (CSCS), by CINECA, and the Research Foundation Flanders (FWO, Belgium) G.0346.21N. Approved Most recent IF: 15.1; 2024 IF: 9.034
Call Number UA @ admin @ c:irua:205442 Serial 9171
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Author Chakraborty, J.; Chatterjee, A.; Molkens, K.; Nath, I.; Arenas Esteban, D.; Bourda, L.; Watson, G.; Liu, C.; Van Thourhout, D.; Bals, S.; Geiregat, P.; Van der Voort, P.
Title Decoding Excimer Formation in Covalent–Organic Frameworks Induced by Morphology and Ring Torsion Type A1 Journal Article
Year 2024 Publication Advanced Materials Abbreviated Journal Advanced Materials
Volume Issue Pages
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract A thorough and quantitative understanding of the fate of excitons in covalent–organic frameworks (COFs) after photoexcitation is essential for their augmented optoelectronic and photocatalytic applications via precise structure tuning. The synthesis of a library of COFs having identical chemical backbone with impeded conjugation, but varied morphology and surface topography to study the effect of these physical properties on the photophysics of the materials is herein reported. The variation of crystallite size and surface topography substantified different aggregation pattern in the COFs, which leads to disparities in their photoexcitation and relaxation properties. Depending on aggregation, an inverse correlation between bulk luminescence decay time and exciton binding energy of the materials is perceived. Further transient absorption spectroscopic analysis confirms the presence of highly localized, immobile, Frenkel excitons (of diameter 0.3–0.5 nm) via an absence of annihilation at high density, most likely induced by structural torsion of the COF skeletons, which in turn preferentially relaxes via long‐lived (nanosecond to microsecond) excimer formation (in femtosecond scale) over direct emission. These insights underpin the importance of structural and topological design of COFs for their targeted use in photocatalysis.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001206226700001 Publication Date (down) 2024-04-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648 ISBN Additional Links UA library record; WoS full record
Impact Factor 29.4 Times cited Open Access
Notes PVDV, JC, AC, and IN acknowledge the FWO-Vlaanderen for research grant G020521N and the research board of UGent (BOF) through a Concerted Research Action (GOA010-17). JC acknowledges UGent for BOF postdoctoral grant (2022.0032.01). AC acknowledges FWO- Vlaanderen for postdoctoral grant (12T7521N). KM, DVT and PG acknowledges FWO- Vlaanderen for research grant G0B2921N. SB and DAE acknowledge financial support from ERC Consolidator Grant Number 815128 REALNANO. CHL acknowledges China Scholarship Council doctoral grant (201908110280). PVDV acknowledges Hercules Project AUGE/17/07 for the UV VIS DRS spectrometer and UGent BASBOF BOF20/BAS/015 for the powder X-Ray Diffractometer. PG thanks UGent for support of the Core Facility NOLIMITS. Approved Most recent IF: 29.4; 2024 IF: 19.791
Call Number EMAT @ emat @c:irua:205967 Serial 9118
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Author Chakraborty, J.; Chatterjee, A.; Molkens, K.; Nath, I.; Arenas Esteban, D.; Bourda, L.; Watson, G.; Liu, C.; Van Thourhout, D.; Bals, S.; Geiregat, P.; Van der Voort, P.
Title Decoding Excimer Formation in Covalent–Organic Frameworks Induced by Morphology and Ring Torsion Type A1 Journal Article
Year 2024 Publication Advanced Materials Abbreviated Journal Advanced Materials
Volume Issue Pages
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract A thorough and quantitative understanding of the fate of excitons in covalent–organic frameworks (COFs) after photoexcitation is essential for their augmented optoelectronic and photocatalytic applications via precise structure tuning. The synthesis of a library of COFs having identical chemical backbone with impeded conjugation, but varied morphology and surface topography to study the effect of these physical properties on the photophysics of the materials is herein reported. The variation of crystallite size and surface topography substantified different aggregation pattern in the COFs, which leads to disparities in their photoexcitation and relaxation properties. Depending on aggregation, an inverse correlation between bulk luminescence decay time and exciton binding energy of the materials is perceived. Further transient absorption spectroscopic analysis confirms the presence of highly localized, immobile, Frenkel excitons (of diameter 0.3–0.5 nm) via an absence of annihilation at high density, most likely induced by structural torsion of the COF skeletons, which in turn preferentially relaxes via long‐lived (nanosecond to microsecond) excimer formation (in femtosecond scale) over direct emission. These insights underpin the importance of structural and topological design of COFs for their targeted use in photocatalysis.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001206226700001 Publication Date (down) 2024-04-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648 ISBN Additional Links UA library record; WoS full record
Impact Factor 29.4 Times cited Open Access
Notes PVDV, JC, AC, and IN acknowledge the FWO-Vlaanderen for research grant G020521N and the research board of UGent (BOF) through a Concerted Research Action (GOA010-17). JC acknowledges UGent for BOF postdoctoral grant (2022.0032.01). AC acknowledges FWOVlaanderen for postdoctoral grant (12T7521N). KM, DVT and PG acknowledges FWOVlaanderen for research grant G0B2921N. SB and DAE acknowledge financial support from ERC Consolidator Grant Number 815128 REALNANO. CHL acknowledges China Scholarship Council doctoral grant (201908110280). PVDV acknowledges Hercules Project AUGE/17/07 for the UV VIS DRS spectrometer and UGent BASBOF BOF20/BAS/015 for the powder X-Ray Diffractometer. PG thanks UGent for support of the Core Facility NOLIMITS. Approved Most recent IF: 29.4; 2024 IF: 19.791
Call Number EMAT @ emat @c:irua:205967 Serial 9130
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Author Wu, X.; Ding, J.; Cui, W.; Lin, W.; Xue, Z.; Yang, Z.; Liu, J.; Nie, X.; Zhu, W.; Van Tendeloo, G.; Sang, X.
Title Enhanced electrical properties of Bi2-xSbxTe3 nanoflake thin films through interface engineering Type A1 Journal article
Year 2024 Publication Energy & environment materials Abbreviated Journal
Volume Issue Pages e12755-8
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The structure-property relationship at interfaces is difficult to probe for thermoelectric materials with a complex interfacial microstructure. Designing thermoelectric materials with a simple, structurally-uniform interface provides a facile way to understand how these interfaces influence the transport properties. Here, we synthesized Bi2-xSbxTe3 (x = 0, 0.1, 0.2, 0.4) nanoflakes using a hydrothermal method, and prepared Bi2-xSbxTe3 thin films with predominantly (0001) interfaces by stacking the nanoflakes through spin coating. The influence of the annealing temperature and Sb content on the (0001) interface structure was systematically investigated at atomic scale using aberration-corrected scanning transmission electron microscopy. Annealing and Sb doping facilitate atom diffusion and migration between adjacent nanoflakes along the (0001) interface. As such it enhances interfacial connectivity and improves the electrical transport properties. Interfac reactions create new interfaces that increase the scattering and the Seebeck coefficient. Due to the simultaneous optimization of electrical conductivity and Seebeck coefficient, the maximum power factor of the Bi1.8Sb0.2Te3 nanoflake films reaches 1.72 mW m(-1) K-2, which is 43% higher than that of a pure Bi2Te3 thin film.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001204495900001 Publication Date (down) 2024-04-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:205438 Serial 9148
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Author Yang, C.-Q.; Yin, Z.-W.; Li, W.; Cui, W.-J.; Zhou, X.-G.; Wang, L.-D.; Zhi, R.; Xu, Y.-Y.; Tao, Z.-W.; Sang, X.; Cheng, Y.-B.; Van Tendeloo, G.; Hu, Z.-Y.; Su, B.-L.
Title Atomically deciphering the phase segregation in mixed halide perovskite Type A1 Journal article
Year 2024 Publication Advanced functional materials Abbreviated Journal
Volume Issue Pages 1-10
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Mixed-halide perovskites show promising applications in tandem solar cells owing to their adjustable bandgap. One major obstacle to their commercialization is halide phase segregation, which results in large open-circuit voltage deficiency and J-V hysteresis. However, the ambiguous interplay between structural origin and phase segregation often results in aimless and unspecific optimization strategies for the device's performance and stability. An atomic scale is directly figured out the abundant Ruddlesden-Popper anti-phase boundaries (RP-APBs) within a CsPbIBr2 polycrystalline film and revealed that phase segregation predominantly occurs at RP-APB-enriched interfaces due to the defect-mediated lattice strain. By compensating their structural lead halide, such RP-APBs are eliminated, and the decreasing of strain can be observed, resulting in the suppression of halide phase segregation. The present work provides the deciphering to precisely regulate the perovskite atomic structure for achieving photo-stable mixed halide wide-bandgap perovskites of high-efficiency tandem solar cell commercial applications. The phase segregation in mixed halide perovskite film predominantly occurs at Ruddlesden-Popper anti-phase boundaries (RP-APBs)-enriched interfaces due to the defect-mediated lattice strain. The RP-APBs defects can be eliminated by compensating for their structural lead halide deficiency, resulting in the suppression of halide phase segregation. image
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001200673300001 Publication Date (down) 2024-04-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301x ISBN Additional Links UA library record; WoS full record
Impact Factor 19 Times cited Open Access
Notes Approved Most recent IF: 19; 2024 IF: 12.124
Call Number UA @ admin @ c:irua:205509 Serial 9134
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Author Esteban, D.A.; Chamocho, E.G.; Carretero González, J.; Urones Garrote, E.; Otero Díaz, L.C.; Brande, D.Á.
Title Enhancing Electrochemical Properties of Walnut Shell Activated Carbon with Embedded MnO Clusters for Supercapacitor Applications Type A1 Journal Article
Year 2024 Publication Batteries & Supercaps Abbreviated Journal Batteries &amp; Supercaps
Volume Issue Pages
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract Activated carbon (AC) materials from renewable sources are widely used in electrochemical applications due to their well‐known high surface area. However, their application as electrode material in double‐layer electrochemical devices may be limited due to their relatively low electrical conductivity and lightweight. To overcome these limitations, the incorporation of pseudocapacitance metal oxide nanoparticles is an optimum approach. These nanoparticles can provide a second energy storage mechanism to the composite, mitigating the loss of surface area associated with their incorporation. As a result, the composite material is endowed with increased conductivity and higher density, making it more suitable for practical implementation in real devices. In this study, we have incorporated a fine dispersion of 1 % of MnO clusters into a highly porous activated carbon synthesized from walnut shells (WAC). The high‐resolution electron microscopy studies, combined with their related analytical techniques, allow us to determine the presence of the cluster within the matrix carbon precisely. The resulting MnO@WAC composite demonstrated significantly improved capacitive behavior compared with the WAC material, with increased volumetric capacitance and higher charge retention at higher current densities. The composite‘s electrochemical performance suggests its potential as a promising electrode material for supercapacitors, addressing drawbacks associated with traditional AC materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001198179300001 Publication Date (down) 2024-04-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2566-6223 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Grants PID2020-112848RB-C21 funded by MCIN/AEI/ 10.13039/501100011033 and by the European Union PRTR funding through projects are acknowledged. Access to the ICTS- CNME for TEM is also acknowledged. Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:205463 Serial 9119
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Author Ignatova, K.; Vlasov, E.; Seddon, S.D.; Gauquelin, N.; Verbeeck, J.; Wermeille, D.; Bals, S.; Hase, T.P.A.; Arnalds, U.B.
Title Phase coexistence induced surface roughness in V2O3/Ni magnetic heterostructures Type A1 Journal Article
Year 2024 Publication APL Materials Abbreviated Journal
Volume 12 Issue 4 Pages
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract We present an investigation of the microstructure changes in V2O3 as it goes through its inherent structural phase transition. Using V2O3 films with a well-defined crystal structure deposited by reactive magnetron sputtering on r-plane Al2O3 substrates, we study the phase coexistence region and its impact on the surface roughness of the films and the magnetic properties of overlying Ni magnetic layers in V2O3/Ni hybrid magnetic heterostructures. The simultaneous presence of two phases in V2O3 during its structural phase transition was identified with high resolution x-ray diffraction and led to an increase in surface roughness observed using x-ray reflectivity. The roughness reaches its maximum at the midpoint of the transition. In V2O3/Ni hybrid heterostructures, we find a concomitant increase in the coercivity of the magnetic layer correlated with the increased roughness of the V2O3 surface. The chemical homogeneity of the V2O3 is confirmed through transmission electron microscopy analysis. High-angle annular dark field imaging and electron energy loss spectroscopy reveal an atomically flat interface between Al2O3 and V2O3, as well as a sharp interface between V2O3 and Ni.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001202661800003 Publication Date (down) 2024-04-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2166-532X ISBN Additional Links UA library record; WoS full record
Impact Factor 6.1 Times cited Open Access
Notes This work was supported by the funding from the University of Iceland Research Fund, the Icelandic Research Fund Grant No. 207111. Instrumentation funding from the Icelandic Infrastructure Fund is acknowledged. This work was based on experiments per- formed at the BM28 (XMaS) beamline at the European Synchrotron Radiation Facility, Grenoble, France. XMaS is a National Research Facility funded by the UK EPSRC and managed by the Universi- ties of Liverpool and Warwick. This project has received funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 823717—ESTEEM3. Approved Most recent IF: 6.1; 2024 IF: 4.335
Call Number EMAT @ emat @c:irua:205569 Serial 9120
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Author Leinders, G.; Grendal, O.G.; Arts, I.; Bes, R.; Prozheev, I.; Orlat, S.; Fitch, A.; Kvashnina, K.; Verwerft, M.
Title Refinement of the uranium dispersion corrections from anomalous diffraction Type A1 Journal Article
Year 2024 Publication Journal of Applied Crystallography Abbreviated Journal J Appl Cryst
Volume 57 Issue 2 Pages 284-295
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract The evolution of the uranium chemical state in uranium compounds, principally in the oxides, is of concern in the context of nuclear fuel degradation under storage and repository conditions, and in accident scenarios. The U–O system shows complicated phase relations between single-valence uranium dioxide (UO<sub>2</sub>) and different mixed-valence compounds (<italic>e.g.</italic>U<sub>4</sub>O<sub>9</sub>, U<sub>3</sub>O<sub>7</sub>and U<sub>3</sub>O<sub>8</sub>). To try resolving the electronic structure associated with unique atomic positions, a combined application of diffraction and spectroscopic techniques, such as diffraction anomalous fine structure (DAFS), can be considered. Reported here is the application of two newly developed routines for assessing a DAFS data set, with the aim of refining the uranium X-ray dispersion corrections. High-resolution anomalous diffraction data were acquired from polycrystalline powder samples of UO<sub>2</sub>(containing tetravalent uranium) and potassium uranate (KUO<sub>3</sub>, containing pentavalent uranium) using synchrotron radiation in the vicinity of the U<italic>L</italic><sub>3</sub>edge (17.17 keV). Both routines are based on an iterative refinement of the dispersion corrections, but they differ in either using the intensity of a selection of reflections or doing a full-pattern (Rietveld method) refinement. The uranium dispersion corrections obtained using either method are in excellent agreement with each other, and they show in great detail the chemical shifts and differences in fine structure expected for tetravalent and pentavalent uranium. This approach may open new possibilities for the assessment of other, more complicated, materials such as mixed-valence compounds. Additionally, the DAFS methodology can offer a significant resource optimization because each data set contains both structural (diffraction) and chemical (spectroscopy) information, which can avoid the requirement to use multiple experimental stations at synchrotron sources.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001208800100008 Publication Date (down) 2024-04-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1600-5767 ISBN Additional Links UA library record; WoS full record
Impact Factor 6.1 Times cited Open Access
Notes FPS Economy, SF-CORMOD; Approved Most recent IF: 6.1; 2024 IF: 2.495
Call Number EMAT @ emat @c:irua:206011 Serial 9127
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Author Lelouche, S.N.K.; Lemir, I.; Biglione, C.; Craig, T.; Bals, S.; Horcajada, P.
Title AuNP/MIL-88B-NH₂ nanocomposite for the valorization of nitroarene by green catalytic hydrogenation Type A1 Journal article
Year 2024 Publication Chemistry: a European journal Abbreviated Journal
Volume Issue Pages 1-10
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The efficiency of a catalytic process is assessed based on conversion, yield, and time effectiveness. However, these parameters are insufficient for evaluating environmentally sustainable research. As the world is urged to shift towards green catalysis, additional factors such as reaction media, raw material availability, sustainability, waste minimization and catalyst biosafety, need to be considered to accurately determine the efficacy and sustainability of the process. By combining the high porosity and versatility of metal organic frameworks (MOFs) and the activity of gold nanoparticles (AuNPs), efficient, cyclable and biosafe composite catalysts can be achieved. Thus, a composite based on AuNPs and the nanometric flexible porous iron(III) aminoterephthalate MIL-88B-NH2 was successfully synthesized and fully characterized. This nanocomposite was tested as catalyst in the reduction of nitroarenes, which were identified as anthropogenic water pollutants, reaching cyclable high conversion rates at short times for different nitroarenes. Both synthesis and catalytic reactions were performed using green conditions, and even further tested in a time-optimizing one-pot synthesis and catalysis experiment. The sustainability and environmental impact of the catalytic conditions were assessed by green metrics. Thus, this study provides an easily implementable synthesis, and efficient catalysis, while minimizing the environmental and health impact of the process.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001204094600001 Publication Date (down) 2024-03-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0947-6539 ISBN Additional Links UA library record; WoS full record
Impact Factor 4.3 Times cited Open Access
Notes Approved Most recent IF: 4.3; 2024 IF: 5.317
Call Number UA @ admin @ c:irua:205426 Serial 9135
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Author Xu, H.; Li, H.; Gauquelin, N.; Chen, X.; Wu, W.-F.; Zhao, Y.; Si, L.; Tian, D.; Li, L.; Gan, Y.; Qi, S.; Li, M.; Hu, F.; Sun, J.; Jannis, D.; Yu, P.; Chen, G.; Zhong, Z.; Radovic, M.; Verbeeck, J.; Chen, Y.; Shen, B.
Title Giant tunability of Rashba splitting at cation-exchanged polar oxide interfaces by selective orbital hybridization Type A1 Journal article
Year 2024 Publication Advanced materials Abbreviated Journal
Volume Issue Pages
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The 2D electron gas (2DEG) at oxide interfaces exhibits extraordinary properties, such as 2D superconductivity and ferromagnetism, coupled to strongly correlated electrons in narrow d-bands. In particular, 2DEGs in KTaO3 (KTO) with 5d t2g orbitals exhibit larger atomic spin-orbit coupling and crystal-facet-dependent superconductivity absent for 3d 2DEGs in SrTiO3 (STO). Herein, by tracing the interfacial chemistry, weak anti-localization magneto-transport behavior, and electronic structures of (001), (110), and (111) KTO 2DEGs, unambiguously cation exchange across KTO interfaces is discovered. Therefore, the origin of the 2DEGs at KTO-based interfaces is dramatically different from the electronic reconstruction observed at STO interfaces. More importantly, as the interface polarization grows with the higher order planes in the KTO case, the Rashba spin splitting becomes maximal for the superconducting (111) interfaces approximately twice that of the (001) interface. The larger Rashba spin splitting couples strongly to the asymmetric chiral texture of the orbital angular moment, and results mainly from the enhanced inter-orbital hopping of the t2g bands and more localized wave functions. This finding has profound implications for the search for topological superconductors, as well as the realization of efficient spin-charge interconversion for low-power spin-orbitronics based on (110) and (111) KTO interfaces. An unambiguous cation exchange is discovered across the interfaces of (001), (110), and (111) KTaO3 2D electron gases fabricated at room temperature. Remarkably, the (111) interfaces with the highest superconducting transition temperature also turn out to show the strongest electron-phonon interaction and the largest Rashba spin splitting. image
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001219658400001 Publication Date (down) 2024-03-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648 ISBN Additional Links UA library record; WoS full record
Impact Factor 29.4 Times cited Open Access
Notes Approved Most recent IF: 29.4; 2024 IF: 19.791
Call Number UA @ admin @ c:irua:206037 Serial 9152
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Author Ni, S.; Houwman, E.; Gauquelin, N.; Chezganov, D.; Van Aert, S.; Verbeeck, J.; Rijnders, G.; Koster, G.
Title Stabilizing perovskite Pb(Mg0.33Nb0.67)O3-PbTiO3 thin films by fast deposition and tensile mismatched growth template Type A1 Journal article
Year 2024 Publication ACS applied materials and interfaces Abbreviated Journal
Volume 16 Issue 10 Pages 12744-12753
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Because of its low hysteresis, high dielectric constant, and strong piezoelectric response, Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMN-PT) thin films have attracted considerable attention for the application in PiezoMEMS, field-effect transistors, and energy harvesting and storage devices. However, it remains a great challenge to fabricate phase-pure, pyrochlore-free PMN-PT thin films. In this study, we demonstrate that a high deposition rate, combined with a tensile mismatched template layer can stabilize the perovskite phase of PMN-PT films and prevent the nucleation of passive pyrochlore phases. We observed that an accelerated deposition rate promoted mixing of the B-site cation and facilitated relaxation of the compressively strained PMN-PT on the SrTiO3 (STO) substrate in the initial growth layer, which apparently suppressed the initial formation of pyrochlore phases. By employing La-doped-BaSnO3 (LBSO) as the tensile mismatched buffer layer, 750 nm thick phase-pure perovskite PMN-PT films were synthesized. The resulting PMN-PT films exhibited excellent crystalline quality close to that of the STO substrate.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001176343700001 Publication Date (down) 2024-02-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1944-8244 ISBN Additional Links UA library record; WoS full record
Impact Factor 9.5 Times cited Open Access
Notes We would like to acknowledge the Netherlands Organization for Scientific Research (NWO) for the financial support of this work. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 823717-ESTEEM3. Approved Most recent IF: 9.5; 2024 IF: 7.504
Call Number UA @ admin @ c:irua:204754 Serial 9174
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Author Arisnabarreta, N.; Hao, Y.; Jin, E.; Salame, A.; Muellen, K.; Robert, M.; Lazzaroni, R.; Van Aert, S.; Mali, K.S.; De Feyter, S.
Title Single-layered imine-linked porphyrin-based two-dimensional covalent organic frameworks targeting CO₂ reduction Type A1 Journal article
Year 2024 Publication Advanced energy materials Abbreviated Journal
Volume Issue Pages
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The reduction of carbon dioxide (CO2) using porphyrin-containing 2D covalent organic frameworks (2D-COFs) catalysts is widely explored nowadays. While these framework materials are normally fabricated as powders followed by their uncontrolled surface heterogenization or directly grown as thin films (thickness >200 nm), very little is known about the performance of substrate-supported single-layered (approximate to 0.5 nm thickness) 2D-COFs films (s2D-COFs) due to its highly challenging synthesis and characterization protocols. In this work, a fast and straightforward fabrication method of porphyrin-containing s2D-COFs is demonstrated, which allows their extensive high-resolution visualization via scanning tunneling microscopy (STM) in liquid conditions with the support of STM simulations. The as-prepared single-layered film is then employed as a cathode for the electrochemical reduction of CO2. Fe porphyrin-containing s2D-COF@graphite used as a single-layered heterogeneous catalyst provided moderate-to-high carbon monoxide selectivity (82%) and partial CO current density (5.1 mA cm(-2)). This work establishes the value of using single-layered films as heterogene ous catalysts and demonstrates the possibility of achieving high performance in CO2 reduction even with extremely low catalyst loadings.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001177577200001 Publication Date (down) 2024-02-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1614-6832; 1614-6840 ISBN Additional Links UA library record; WoS full record
Impact Factor 27.8 Times cited Open Access
Notes N.A. acknowledges a postdoctoral fellowship from the Research Foundation- Flanders (FWO) via grant 12ZS623N. S.D.F. acknowledges support from FWO (G0A4120N, G0H2122N, G0A5U24N), KU Leuven Internal Funds (grants C14/18/06, C14/19/079, C14/23/090), European Union under the Horizon Europe grant 101046231 (FantastiCOF), and M-ERA.NET via FWO (G0K9822N). S.D.F., K.M., Y.H., R.L., and S.V.A. were thankful to the FWO and FNRS for the financial support through the EOS program (grant 30489208, 40007495). Research in Mons was also supported by the Belgian National Fund for Scientific Research (FRS-FNRS) within the Consortium des Équipements de Calcul Intensif- CÉCI, and by the Walloon Region (ZENOBE and LUCIA Tier-1 supercomputers). E.J. appreciated the support from the Alexander von Humboldt Foundation, the Max Planck Society, the FLAG-ERA Grant OPERA by DFG 437130745, the National Natural Science Foundation of China (22288101), and the 111 Project (B17020). Partial financial support to M.R. from the Institut Universitaire de France (IUF) was warmly thanked. Approved Most recent IF: 27.8; 2024 IF: 16.721
Call Number UA @ admin @ c:irua:204856 Serial 9172
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Author Grünewald, L.; Chezganov, D.; De Meyer, R.; Orekhov, A.; Van Aert, S.; Bogaerts, A.; Bals, S.; Verbeeck, J.
Title In Situ Plasma Studies Using a Direct Current Microplasma in a Scanning Electron Microscope Type A1 Journal Article
Year 2024 Publication Advanced Materials Technologies Abbreviated Journal Adv Materials Technologies
Volume Issue Pages
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract Microplasmas can be used for a wide range of technological applications and to improve the understanding of fundamental physics. Scanning electron microscopy, on the other hand, provides insights into the sample morphology and chemistry of materials from the mm‐ down to the nm‐scale. Combining both would provide direct insight into plasma‐sample interactions in real‐time and at high spatial resolution. Up till now, very few attempts in this direction have been made, and significant challenges remain. This work presents a stable direct current glow discharge microplasma setup built inside a scanning electron microscope. The experimental setup is capable of real‐time in situ imaging of the sample evolution during plasma operation and it demonstrates localized sputtering and sample oxidation. Further, the experimental parameters such as varying gas mixtures, electrode polarity, and field strength are explored and experimental<italic>V</italic>–<italic>I</italic>curves under various conditions are provided. These results demonstrate the capabilities of this setup in potential investigations of plasma physics, plasma‐surface interactions, and materials science and its practical applications. The presented setup shows the potential to have several technological applications, for example, to locally modify the sample surface (e.g., local oxidation and ion implantation for nanotechnology applications) on the µm‐scale.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001168639900001 Publication Date (down) 2024-02-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2365-709X ISBN Additional Links UA library record; WoS full record
Impact Factor 6.8 Times cited Open Access OpenAccess
Notes L.G., S.B., and J.V. acknowledge support from the iBOF-21-085 PERsist research fund. D.C., S.V.A., and J.V. acknowledge funding from a TOPBOF project of the University of Antwerp (FFB 170366). R.D.M., A.B., and J.V. acknowledge funding from the Methusalem project of the University of Antwerp (FFB 15001A, FFB 15001C). A.O. and J.V. acknowledge funding from the Research Foundation Flanders (FWO, Belgium) project SBO S000121N. Approved Most recent IF: 6.8; 2024 IF: NA
Call Number EMAT @ emat @c:irua:204363 Serial 8995
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Author Bampouli, A.; Goris, Q.; Hussain, M.N.; Louisnard, O.; Stefanidis, G.D.; Van Gerven, T.
Title Importance of design and operating parameters in a sonication system for viscous solutions : effects of input power, horn tip diameter and reactor capacity Type A1 Journal article
Year 2024 Publication Chemical engineering and processing Abbreviated Journal
Volume 198 Issue Pages 109715-12
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract This study investigates the distribution of ultrasound (US) energy in a batch system for solutions with viscosity ranging from 1 to approximately 3000 mPas. Sonication was performed using horn type configurations operating at 20-30 kHz and rated power capacity of 50 or 200 W. Two different tip diameters (3 or 7 mm) and two insertion depths (35 or 25 mm) within vessels of different sizes ( approximate to 60 or 130 ml) were utilized. Additionally, a special conical tip design was employed. For each experimental setup, the calorimetric efficiency was estimated, the cavitationally active regions were visualized using the sonochemiluminescence (SCL) method and bubble cluster formation inside the vessel was macroscopically observed using a high speed camera (HSC). In the viscosity range tested, the calorimetry results showed that the efficiency and continuous operation of the device depend on both the rated power and the horn tip diameter. The ratio between electrical and calorimetric power input remained consistently around 40 to 50% across the different configurations for water, but for the 123.2 mPas solution exhibited significant variation ranging from 40 to 85%. Moreover, the power density in the smaller reactor was found to be nearly double compared to the larger one. The SCL analysis showed multiple cavitationally active zones in all setups, and the zones intensity decreased considerably with increase of the solutions viscosity. The results for the cone tip were not conclusive, but can be used as the basis for further investigation. The current research highlights the importance of thoroughly understanding the impact of each design parameter, and of establishing characterization methodologies to assist in the future development of scaled-up, commercial applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001218630800001 Publication Date (down) 2024-02-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0255-2701 ISBN Additional Links UA library record; WoS full record
Impact Factor 4.3 Times cited Open Access
Notes Approved Most recent IF: 4.3; 2024 IF: 2.234
Call Number UA @ admin @ c:irua:206003 Serial 9154
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Author Vandemeulebroucke, D.; Batuk, M.; Hajizadeh, A.; Wastiaux, M.; Roussel, P.; Hadermann, J.
Title Incommensurate Modulations and Perovskite Growth in LaxSr2–xMnO4−δAffecting Solid Oxide Fuel Cell Conductivity Type A1 Journal Article
Year 2024 Publication Chemistry of Materials Abbreviated Journal Chem. Mater.
Volume Issue Pages
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract Ruddlesden-Popper La????Sr2−????MnO4−???? materials are interesting symmetric solid oxide

fuel cell electrodes due to their good redox stability, mixed ionic and electronic conducting behavior and thermal expansion that matches well with common electrolytes. In reducing environments – as at a solid oxide fuel cell anode – the x = 0.5 member, i.e. La0.5Sr1.5MnO4−????, has a much higher total conductivity than compounds with a different La/Sr ratio, although all those compositions have the same K2NiF4-type I4/mmm structure. The origin for this conductivity difference is not yet known in literature. Now, a combination of in-situ and ex-situ 3D electron diffraction, high-resolution imaging, energy-dispersive X-ray analysis and electron energy-loss spectroscopy uncovered clear differences between x=0.25 and x=0.5 in the pristine structure, as well as in the transformations upon high-temperature reduction. In La0.5Sr1.5MnO4−????, Ruddlesden-Popper n=2 layer defects and an amorphous surface layer are present, but not in La0.25Sr1.75MnO4−????. After annealing at 700°C in 5% H2/Ar, La0.25Sr1.75MnO4−???? transforms to a tetragonal 2D incommensurately modulated structure with modulation vectors ⃗????1 = 0.2848(1) · (⃗????* +⃗????*) and ⃗????2 =0.2848(1) · (⃗????* – ⃗????*), whereas La0.5Sr1.5MnO4−???? only partially transforms to an orthorhombic 1D incommensurately modulated structure,

with ⃗???? = 0.318(2) · ⃗????*. Perovskite domains grow at the crystal edge at 700°C in 5%

H2 or vacuum, due to the higher La concentration on the surface compared to the bulk, which leads to a different thermodynamic equilibrium. Since it is known that a lower degree of oxygen vacancy ordering and a higher amount of perovskite blocks enhance oxygen mobility, those differences in defect structure and structural transformation upon reduction, might all contribute to the higher conductivity of La0.5Sr1.5MnO4−???? in solid oxide fuel cell anode conditions compared to other La/Sr ratios.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 001174840900001 Publication Date (down) 2024-02-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record
Impact Factor 8.6 Times cited Open Access Not_Open_Access
Notes Universiteit Antwerpen, BOF TOP 38689 ; Fonds Wetenschappelijk Onderzoek, I003218N ; European Commission NanED, 956099 ; Approved Most recent IF: 8.6; 2024 IF: 9.466
Call Number EMAT @ emat @c:irua:204354 Serial 8997
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Author Şentürk, D.G.; De Backer, A.; Van Aert, S.
Title Element specific atom counting for heterogeneous nanostructures: Combining multiple ADF STEM images for simultaneous thickness and composition determination Type A1 Journal Article
Year 2024 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 259 Issue Pages 113941
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract In this paper, a methodology is presented to count the number of atoms in heterogeneous nanoparticles based on the combination of multiple annular dark field scanning transmission electron microscopy (ADF STEM) images. The different non-overlapping annular detector collection regions are selected based on the principles of optimal statistical experiment design for the atom-counting problem. To count the number of atoms, the total intensities of scattered electrons for each atomic column, the so-called scattering cross-sections, are simultaneously compared with simulated library values for the different detector regions by minimising the squared differences. The performance of the method is evaluated for simulated Ni@Pt and Au@Ag core-shell nanoparticles. Our approach turns out to be a dose efficient alternative for the investigation of beam-sensitive heterogeneous materials as compared to the combination of ADF STEM and energy dispersive X-ray spectroscopy.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date (down) 2024-02-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record
Impact Factor 2.2 Times cited Open Access OpenAccess
Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0346.21N, GOA7723N, and EOS 40007495) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF). Approved Most recent IF: 2.2; 2024 IF: 2.843
Call Number EMAT @ emat @c:irua:204353 Serial 8996
Permanent link to this record
 

 
Author Kashiwar, A.; Arseenko, M.; Simar, A.; Idrissi, H.
Title On the role of microstructural defects on precipitation, damage, and healing behavior in a novel Al-0.5Mg2Si alloy Type A1 Journal article
Year 2024 Publication Materials & design Abbreviated Journal
Volume 239 Issue Pages 112765-112769
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract A recently developed healable Al-Mg2Si designed by the programmed damage and repair (PDR) strategy is studied considering the role microstructural defects play on precipitation, damage, and healing. The alloy incorporates sacrificial Mg2Si particles that precipitate after friction stir processing (FSP). They act as damage localization sites and are healable based on the solid-state diffusion of Al-matrix. A combination of different transmission electron microscopy (TEM) imaging techniques enabled the visualization and quantification of various crystallographic defects and the spatial distribution of Mg2Si precipitates. Intragrain nucleation is found to be the dominant mechanism for precipitation during FSP whereas grain boundaries and subgrain boundaries mainly lead to coarsening of the precipitates. The statistical and spatial analyses of the damaged particles have shown particle fracture as the dominant damage mechanism which is strongly dependent on the size and aspect ratio of the particles whereas the damage was not found to depend on the location of the precipitates within the matrix. The damaged particles are associated with dislocations accumulated around them. The interplay of these dislocations is directly visualized during healing based on in situ TEM heating which revealed recovery in the matrix as an operative mechanism during the diffusion healing of the PDR alloy.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001194110200001 Publication Date (down) 2024-02-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0264-1275; 1873-4197 ISBN Additional Links UA library record; WoS full record
Impact Factor 8.4 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 8.4; 2024 IF: 4.364
Call Number UA @ admin @ c:irua:203298 Serial 9068
Permanent link to this record
 

 
Author Joy, R.M.; Pobedinskas, P.; Bourgeois, E.; Chakraborty, T.; Goerlitz, J.; Herrmann, D.; Noel, C.; Heupel, J.; Jannis, D.; Gauquelin, N.; D'Haen, J.; Verbeeck, J.; Popov, C.; Houssiau, L.; Becher, C.; Nesladek, M.; Haenen, K.
Title Photoluminescence of germanium-vacancy centers in nanocrystalline diamond films : implications for quantum sensing applications Type A1 Journal article
Year 2024 Publication ACS applied nano materials Abbreviated Journal
Volume 7 Issue 4 Pages 3873-3884
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Point defects in diamond, promising candidates for nanoscale pressure- and temperature-sensing applications, are potentially scalable in polycrystalline diamond fabricated using the microwave plasma-enhanced chemical vapor deposition (MW PE CVD) technique. However, this approach introduces residual stress in the diamond films, leading to variations in the characteristic zero phonon line (ZPL) of the point defect in diamond. Here, we report the effect of residual stress on germanium-vacancy (GeV) centers in MW PE CVD nanocrystalline diamond (NCD) films fabricated using single crystal Ge as the substrate and solid dopant source. GeV ensemble formation indicated by the zero phonon line (ZPL) at similar to 602 nm is confirmed by room temperature (RT) photoluminescence (PL) measurements. PL mapping results show spatial nonuniformity in GeV formation along with other defects, including silicon-vacancy centers in the diamond films. The residual stress in NCD results in shifts in the PL peak positions. By estimating a stress shift coefficient of (2.9 +/- 0.9) nm/GPa, the GeV PL peak position in the NCD film is determined to be between 598.7 and 603.2 nm. A larger ground state splitting due to the strain on a GeV-incorporated NCD pillar at a low temperature (10 K) is also reported. We also report the observation of intense ZPLs at RT that in some cases could be related to low Ge concentration and the surrounding crystalline environment. In addition, we also observe thicker microcrystalline diamond (MCD) films delaminate from the Ge substrate due to film residual stress and graphitic phase at the diamond/Ge substrate interface (confirmed by electron energy loss spectroscopy). Using this approach, a free-standing color center incorporated MCD film with dimensions up to 1 x 1 cm(2) is fabricated. Qualitative analysis using time-of-flight secondary ion mass spectroscopy reveals the presence of impurities, including Ge and silicon, in the MCD film. Our experimental results will provide insights into the scalability of GeV fabrication using the MW PE CVD technique and effectively implement NCD-based nanoscale-sensing applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001164609600001 Publication Date (down) 2024-02-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2574-0970 ISBN Additional Links UA library record; WoS full record
Impact Factor 5.9 Times cited Open Access
Notes Approved Most recent IF: 5.9; 2024 IF: NA
Call Number UA @ admin @ c:irua:204826 Serial 9164
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Author Wang, G.; Xie, C.; Wang, H.; Li, Q.; Xia, F.; Zeng, W.; Peng, H.; Van Tendeloo, G.; Tan, G.; Tian, J.; Wu, J.
Title Mitigated oxygen loss in lithium-rich manganese-based cathode enabled by strong Zr-O affinity Type A1 Journal article
Year 2024 Publication Advanced functional materials Abbreviated Journal
Volume Issue Pages 2313672
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Oxygen loss is a serious problem of lithium-rich layered oxide (LLO) cathodes, as the high capacity of LLO relies on reversible oxygen redox. Oxygen release can occur at the surface leading to the formation of spinel or rock salt structures. Also, the lattice oxygen will usually become unstable after long cycling, which remains a major roadblock in the application of LLO. Here, it is shown that Zr doping is an effective strategy to retain lattice oxygen in LLO due to the high affinity between Zr and O. A simple sol-gel method is used to dope Zr4+ into the LLOs to adjust the local electronic structure and inhibit the diffusion of oxygen anions to the surface during cycling. Compared with untreated LLOs, LLO-Zr cathodes exhibit a higher cycling stability, with 94% capacity retention after 100 cycles at 0.4 C, up to 223 mAh g-1 at 1 C, and 88% capacity retention after 300 cycles. Theoretical calculations show that due to the strong Zr-O covalent bonding, the formation energy of oxygen vacancies has effectively increased and the loss of lattice oxygen under high voltage can be suppressed. This study provides a simple method for developing high-capacity and cyclability Li-rich cathode materials for lithium-ion batteries. Oxygen release can occur at the cathode surface leading to the formation of spinel or rock salt structures. Here, it is shown that Zr doping is an effective strategy to retain lattice oxygen in lithium-rich layered oxides (LLO) due to the high affinity between Zr and O. LLO-Zr exhibit higher cycling stability, with 88% capacity retention after 300 cycles at 1 C. image
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001159843800001 Publication Date (down) 2024-02-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301x ISBN Additional Links UA library record; WoS full record
Impact Factor 19 Times cited Open Access
Notes Approved Most recent IF: 19; 2024 IF: 12.124
Call Number UA @ admin @ c:irua:203812 Serial 9161
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Author Jorissen, B.; Covaci, L.; Partoens, B.
Title Comparative analysis of tight-binding models for transition metal dichalcogenides Type A1 Journal article
Year 2024 Publication SciPost physics core Abbreviated Journal
Volume 7 Issue 1 Pages 004-30
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract We provide a comprehensive analysis of the prominent tight-binding (TB) models for transition metal dichalcogenides (TMDs) available in the literature. We inspect the construction of these TB models, discuss their parameterization used and conduct a thorough comparison of their effectiveness in capturing important electronic properties. Based on these insights, we propose a novel TB model for TMDs designed for enhanced computational efficiency. Utilizing MoS2 as a representative case, we explain why specific models offer a more accurate description. Our primary aim is to assist researchers in choosing the most appropriate TB model for their calculations on TMDs.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001170769300001 Publication Date (down) 2024-02-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 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:202983 Serial 9012
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Author Coulombier, M.; Baral, P.; Orekhov, A.; Dohmen, R.; Raskin, J.P.; Pardoen, T.; Cordier, P.; Idrissi, H.
Title On-chip very low strain rate rheology of amorphous olivine films Type A1 Journal article
Year 2024 Publication Acta materialia Abbreviated Journal
Volume 266 Issue Pages 119693-12
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Recent observations made by the authors revealed the activation of stress induced amorphization and sliding at grain boundary in olivine [1], a mechanism which is expected to play a pivotal role in the viscosity drop at the lithosphere-asthenosphere boundary and the brittle -ductile transition in the lithospheric mantle. However, there is a lack of information in the literature regarding the intrinsic mechanical properties and the elementary deformation mechanisms of this material, especially at time scales relevant for geodynamics. In the present work, amorphous olivine films were obtained by pulsed laser deposition (PLD). The mechanical response including the rate dependent behavior are investigated using a tension -on -chip (TOC) method developed at UCLouvain allowing to perform creep/relaxation tests on thin films at extremely low strain rates. In the present work, strain rate down to 10-12 s- 1 was reached which is unique. High strain rate sensitivity of 0.054 is observed together with the activation of relaxation at the very early stage of deformation. Furthermore, digital image correlation (DIC), used for the first time on films deformed by TOC, reveals local strain heterogeneities. The relationship between such heterogeneities, the high strain rate sensitivity and the effect of the electron beam in the scanning electron microscope is discussed and compared to the literature.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001170513400001 Publication Date (down) 2024-01-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6454 ISBN Additional Links UA library record; WoS full record
Impact Factor 9.4 Times cited Open Access
Notes Approved Most recent IF: 9.4; 2024 IF: 5.301
Call Number UA @ admin @ c:irua:204864 Serial 9163
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Author Lobato, I.; Friedrich, T.; Van Aert, S.
Title Deep convolutional neural networks to restore single-shot electron microscopy images Type A1 Journal article
Year 2024 Publication N P J Computational Materials Abbreviated Journal npj Comput Mater
Volume 10 Issue 1 Pages 10
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Advanced electron microscopy techniques, including scanning electron microscopes (SEM), scanning transmission electron microscopes (STEM), and transmission electron microscopes (TEM), have revolutionized imaging capabilities. However, achieving high-quality experimental images remains a challenge due to various distortions stemming from the instrumentation and external factors. These distortions, introduced at different stages of imaging, hinder the extraction of reliable quantitative insights. In this paper, we will discuss the main sources of distortion in TEM and S(T)EM images, develop models to describe them, and propose a method to correct these distortions using a convolutional neural network. We validate the effectiveness of our method on a range of simulated and experimental images, demonstrating its ability to significantly enhance the signal-to-noise ratio. This improvement leads to a more reliable extraction of quantitative structural information from the images. In summary, our findings offer a robust framework to enhance the quality of electron microscopy images, which in turn supports progress in structural analysis and quantification in materials science and biology.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001138183000001 Publication Date (down) 2024-01-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2057-3960 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access OpenAccess
Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S.V.A.). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G034621N, G0A7723N and EOS 40007495). S.V.A. acknowledges funding from the University of Antwerp Research Fund (BOF). The authors thank Lukas Grünewald for data acquisition and support for Fig. 7. Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:202714 Serial 8994
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Author Hofer, C.; Gao, C.; Chennit, T.; Yuan, B.; Pennycook, T.J.
Title Phase offset method of ptychographic contrast reversal correction Type A1 Journal article
Year 2024 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume Issue Pages 113922
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001164447000001 Publication Date (down) 2024-01-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record
Impact Factor 2.2 Times cited Open Access Not_Open_Access
Notes FWO, G013122N ; Horizon 2020 Framework Programme; European Research Council, 802123-HDEM ; European Research Council; Approved Most recent IF: 2.2; 2024 IF: 2.843
Call Number EMAT @ emat @c:irua:202379 Serial 8988
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Author Ding, L.; Zhao, M.; Ehlers, F.J.H.; Jia, Z.; Zhang, Z.; Weng, Y.; Schryvers, D.; Liu, Q.; Idrissi, H.
Title “Branched” structural transformation of the L12-Al3Zr phase manipulated by Cu substitution/segregation in the Al-Cu-Zr alloy system Type A1 Journal article
Year 2024 Publication Journal of materials science & technology Abbreviated Journal Journal of Materials Science & Technology
Volume 185 Issue Pages 186-206
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The effect of Cu on the evolution of the Al3Zr phase in an Al-Cu-Zr cast alloy during solution treatment at 500 °C has been thoroughly studied by combining atomic resolution high-angle annular dark-field scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy and first-principles cal- culations. The heat treatment initially produces a pure L12-Al3Zr microstructure, allowing for about 13 % Cu to be incorporated in the dispersoid. Cu incorporation increases the energy barrier for anti-phase boundary (APB) activation, thus stabilizing the L12 structure. Additional heating leads to a Cu-induced “branched”path for the L12 structural transformation, with the latter process accelerated once the first APB has been created. Cu atoms may either (i) be repelled by the APBs, promoting the transformation to a Cu-poor D023 phase, or (ii) they may segregate at one Al-Zr layer adjacent to the APB, promoting a transformation to a new thermodynamically favored phase, Al4CuZr, formed when these segregation layers are periodically arranged. Theoretical studies suggest that the branching of the L12 transformation path is linked to the speed at which an APB is created, with Cu attraction triggered by a comparatively slow process. This unexpected transformation behavior of the L12-Al3Zr phase opens a new path to understanding, and potentially regulating the Al3Zr dispersoid evolution for high temperature applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001154261100001 Publication Date (down) 2023-12-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1005-0302 ISBN Additional Links UA library record; WoS full record
Impact Factor 10.9 Times cited Open Access Not_Open_Access
Notes This work was supported by the National Key Research and Development Program (No. 2020YFA0405900), the National Natural Science Foundation of China (Grant No. 52371111 and U2141215 ), the Natural Science Foundation of Jiangsu Province (No. BE2022159 ). We are grateful to the High Performance Computing Center of Nanjing Tech University for supporting the computational resources. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR- FNRS). Approved Most recent IF: 10.9; 2024 IF: 2.764
Call Number EMAT @ emat @c:irua:202392 Serial 8981
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