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Author Vladimirova, N.V.; Frolov, A.S.; Sanchez-Barriga, J.; Clark, O.J.; Matsui, F.; Usachov, D.Y.; Muntwiler, M.; Callaert, C.; Hadermann, J.; Neudachina, V.S.; Tamm, M.E.; Yashina, L.V.
Title Occupancy of lattice positions probed by X-ray photoelectron diffraction : a case study of tetradymite topological insulators Type A1 Journal article
Year 2023 Publication Surfaces and interfaces Abbreviated Journal
Volume 36 Issue Pages 102516-10
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Occupancy of different structural positions in a crystal lattice often seems to play a key role in material prop-erties. Several experimental techniques have been developed to uncover this issue, all of them being mostly bulk sensitive. However, many materials including topological insulators (TIs), which are among the most intriguing modern materials, are intended to be used in devices as thin films, for which the sublattice occupancy may differ from the bulk. One of the possible approaches to occupancy analysis is X-ray Photoelectron Diffraction (XPD), a structural method in surface science with chemical sensitivity. We applied this method in a case study of Sb2(Te1-xSex)3 mixed crystals, which belong to prototypical TIs. We used high-angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) as a reference method to verify our analysis. We revealed that the XPD data for vacuum cleaved bulk crystals are in excellent agreement with the reference ones. Also, we demonstrate that the anion occupancy near a naturally formed surface can be rather different from that of the bulk. The present results are relevant for a wide range of compositions where the system remains a topological phase, as we ultimately show by probing the transiently occupied topological surface state above the Fermi level by ultrafast photoemission.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000901694900001 Publication Date (up) 2022-11-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2468-0230 ISBN Additional Links UA library record; WoS full record
Impact Factor 6.2 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 6.2; 2023 IF: NA
Call Number UA @ admin @ c:irua:193502 Serial 7327
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Author Morsdorf, L.; Kashiwar, A.; Kübel, C.; Tasan, C.C.
Title Carbon segregation and cementite precipitation at grain boundaries in quenched and tempered lath martensite Type A1 Journal article
Year 2023 Publication Materials science and engineering: part A: structural materials: properties, microstructure and processing Abbreviated Journal
Volume 862 Issue Pages 144369-21
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Tempering is widely applied to make carbon atoms beneficially rearrange in high strength steel microstructures after quenching; though the nano-scale interaction of carbon atoms with crystallographic defects is hard to experimentally observe. To improve, we investigate the redistribution of carbon atoms along martensite grain boundaries in a quenched and tempered low carbon steel. We observe the tempering-induced microstructural evolution by in-situ heating in a transmission electron microscope (TEM) and by compositional analysis through atom probe tomography (APT). Probe volumes for APT originate from a single martensite packet but in different tempering conditions, which is achieved via a sequential lift-out with in-between tempering treatments. The complementary use of TEM and APT provides crystallographic as well as chemical information on carbon segregation and subsequent carbide precipitation at martensite grain boundaries. The results show that the amount of carbon segregation to martensite grain boundaries is influenced by the boundary type, e.g. low-angle lath or high-angle block boundaries. Also, the growth behavior of cementite precipitates from grain boundary nucleation sites into neighboring martensite grains differs at low- and high-angle grain boundaries. This is due to the crystallographic constraints arising from the semi-coherent orientation relationship between cementite and adjacent martensite. We also show that slower quenching stabilizes thin retained austenite films between martensite grains because of enhanced carbon segregation during cooling. Finally, we demonstrate the effect of carbon redistribution along martensite grain boundaries on the mechanical properties. Here, we compare micro-scale Vickers hardness results from boundary-containing probe volumes to nanoindentation results from pure bulk martensite (boundary-free) probe volumes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000905165700001 Publication Date (up) 2022-12-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-5093 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.4 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 6.4; 2023 IF: 3.094
Call Number UA @ admin @ c:irua:192279 Serial 7285
Permanent link to this record
 
 
Author Wang, J.; Zhang, K.; Kavak, S.; Bals, S.; Meynen, V.
Title Modifying the Stöber Process: Is the Organic Solvent Indispensable? Type A1 Journal Article
Year 2022 Publication Chemistry-A European Journal Abbreviated Journal Chem-Eur J
Volume Issue Pages
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract The Stöber method is one of the most important and fundamental processes for the synthesis of inorganic (nano)materials but has the drawback of using a large amount of organic solvent. Herein, ethanol was used as an example to explore if the organic solvent in a typical Stöber method can be omitted. It was found that ethanol increases the particle size of the obtained silica spheres and aids the formation of uniform silica particles rather than forming a gel. Nevertheless, the results indicated that an organic solvent in the initial synthesis mixture is not indispensable. An initially immiscible synthesis method was discovered, which can replace the organic solvent-based Stöber method to successfully synthesize silica particles with the same size ranges as the original Stöber process without addition of organic solvents. Moreover, this process can be of further value for the extension to synthesis processes of other materials based on the Stöber process.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000898283500001 Publication Date (up) 2022-12-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0947-6539 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.3 Times cited 3 Open Access OpenAccess
Notes The authors are grateful to Alexander Vansant and Dr. Steven Mullens of VITO for their contributions to the DLS measurements in this paper. J.W acknowledges the State Scholarship funded by the China Scholarship Council (201806060123). K.Z acknowledges the EASiCHEM project funded by the Flemish Strategic Basic Research Program of the Catalisti cluster and Flanders Innovation & Entrepreneurship (HBC.2018.0484). S.K acknowledges the Flemish Fund for Scientific Research (FWO Flanders) through a PhD research grant (1181122N). Approved Most recent IF: 4.3
Call Number EMAT @ emat @c:irua:191646 Serial 7233
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Author Martin, É.; Gossuin, Y.; Bals, S.; Kavak, S.; Vuong, Q.L.
Title Monte Carlo simulations of the magnetic behaviour of iron oxide nanoparticle ensembles: taking size dispersion, particle anisotropy, and dipolar interactions into account Type A1 Journal article
Year 2022 Publication European physical journal : B : condensed matter and complex systems Abbreviated Journal Eur Phys J B
Volume 95 Issue 12 Pages 201
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In this work, the magnetic properties of superparamagnetic iron oxide nanoparticles (SPIONs) submitted to an external magnetic field are studied using a Metropolis algorithm. The influence on the M(B) curves of the size distribution of the nanoparticles, of uniaxial anisotropy, and of dipolar interaction between the cores are examined, as well as the influence of drying the samples under a zero or non-zero magnetic field. It is shown that the anisotropy impacts the shape of the magnetization curves, which then deviate from a pure Langevin behaviour, whereas the dipolar interaction has no influence on the curves at 300 K for small particles (with a radius of 3 nm). The fitting of the magnetization curves of particles with magnetic anisotropy to a Langevin model (including a size distribution of the particles) can then lead to erroneous values of the distribution parameters. The simulation results are qualitatively compared to experimental results obtained for iron oxide nanoparticles (with a 3.21 nm median radius).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000901937400001 Publication Date (up) 2022-12-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6028 ISBN Additional Links UA library record; WoS full record
Impact Factor 1.6 Times cited Open Access OpenAccess
Notes The authors would like to thank Sophie Laurent from the University of Mons for the access to the Dynamic Light Scattering equipment. Computational resources have been provided by the Consortium des Equipements de Calcul Intensif (C ´ ECI), funded by the ´ Fonds de la Recherche Scientifique de Belgique (F.R.S.- FNRS) under Grant No. 2.5020.11 and by the Walloon Region. Approved Most recent IF: 1.6
Call Number EMAT @ emat @c:irua:192706 Serial 7232
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Author Panzic, I.; Mandic, V.; Mangalam, J.; Rath, T.; Radovanovic-Peric, F.; Gaboardi, M.; De Coen, B.; Bals, S.; Schrenker, N.
Title In-situ structural degradation study of quadruple-cation perovskite solar cells with nanostructured charge transfer layer Type A1 Journal article
Year 2023 Publication Ceramics international Abbreviated Journal
Volume 49 Issue 14b Pages 24475-24486
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We investigated the structural stability of perovskite solar cells (PSCs) in n-i-p configuration comprising a rubidium-caesium-methylammonium-formamidinium (Rb-Cs-MA-FA) lead iodide/bromide perovskite absorber, interfaced with nanostructured ZnO-nanorod (NR) or mesostructured (MS) TiO2 electron transfer layers (ETL). An in-situ setup was established comprising synchrotron grazing incidence diffraction (GID) and Raman spectroscopy as a function of temperature under ambient and isothermal conditions; measurements of current-voltage (IV) characteristics and electron microscopic investigations were conducted discretely.The aging of the solar cells was performed at ambient conditions or at elevated temperatures directly in the in -situ measurement setup. The diffraction depth profiling results point to different degradation rates for different ETLs; moreover, electron microscopy and atomic force microscopy, as well as energy dispersive spectroscopy clarified surface conditions in terms of the extent of the degradation. Scanning transmission electron microscopy of lamellas, derived by dual beam microscopy, revealed that the origin of the degradation lay in the ETL/ absorber interface. For the case of the nanostructured zincite, the perovskite absorber contained many voids, leading to the conclusion that the investigated quadruple perovskite absorber showed limited compatibility with ZnO NR ETL due to a higher number of defects. Morphological defects promoted the absorber degradation and nullified the advantages initially achieved by nanostructuring. The exchange of the ZnO NR ETL with MS TiO2 improved the stability parameters of the absorber layer.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001021057200001 Publication Date (up) 2022-12-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0272-8842; 1873-3956 ISBN Additional Links UA library record; WoS full record
Impact Factor 5.2 Times cited Open Access OpenAccess
Notes This work has been funded by the projects PZS-2019-02-1555 PV-WALL in Research Cooperability Program of the Croatian Science Foundation funded by the European Union from the European Social Fund under the Operational Programme Efficient Human Resources 2014-2020 (perovskite solar cells) , UIP-2019-04-2367 SLIPPERY SLOPE of the Croatian Science Foundation (nanostructured titania and zincite constituents) , KK.01.2.1.02.0316 “ The development of the technical solution for energy saving using VIS -transparent or semi-transparent and IR-reflective thin-films” by the European Regional Development Fund (ERDF) (characterisation of thin-films) , 20190571 and 20190516 at Elettra Synchrotron, ICM-2019-13220 in Ernst Mach program of the OeAD-GmbH, and E210900588 in the EUSMI program. The group of prof Gregor Trimmel of the ICTM, NAWI Graz, the beam- line scientists of the MCX beamline of the Elettra synchrotron, and FIB- STEM researchers of the Faculty of Science, University of Antwerp, are gratefully acknowledged for collaboration and instrument access. The financial sustenance of the University of Zagreb is gratefully acknowledged. Approved Most recent IF: 5.2; 2023 IF: 2.986
Call Number UA @ admin @ c:irua:197806 Serial 8885
Permanent link to this record
 
 
Author Skorikov, A.; Batenburg, K.J.; Bals, S.
Title Analysis of 3D elemental distribution in nanomaterials : towards higher throughput and dose efficiency Type A1 Journal article
Year 2023 Publication Journal of microscopy Abbreviated Journal
Volume 289 Issue 3 Pages 157-163
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Many advanced nanomaterials rely on carefully designed morphology and elemental distribution to achieve their functionalities. Among the few experimental techniques that can directly visualise the 3D elemental distribution on the nanoscale are approaches based on electron tomography in combination with energy-dispersive X-ray spectroscopy (EDXS) and electron energy loss spectroscopy (EELS). Unfortunately, these highly informative methods are severely limited by the fundamentally low signal-to-noise ratio, which makes long experimental times and high electron irradiation doses necessary to obtain reliable 3D reconstructions. Addressing these limitations has been the major research question for the development of these techniques in recent years. This short review outlines the latest progress on the methods to reduce experimental time and electron irradiation dose requirements for 3D elemental distribution analysis and gives an outlook on the development of this field in the near future.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000910532600001 Publication Date (up) 2022-12-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2720 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2 Times cited 2 Open Access OpenAccess
Notes ERC Consolidator Grant, Grant/Award Number: 815128 Approved Most recent IF: 2; 2023 IF: 1.692
Call Number UA @ admin @ c:irua:193428 Serial 7281
Permanent link to this record
 
 
Author Zhang, Z.; Lobato, I.; De Backer, A.; Van Aert, S.; Nellist, P.
Title Fast generation of calculated ADF-EDX scattering cross-sections under channelling conditions Type A1 Journal article
Year 2023 Publication Ultramicroscopy Abbreviated Journal
Volume 246 Issue Pages 113671
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Advanced materials often consist of multiple elements which are arranged in a complicated structure. Quantitative scanning transmission electron microscopy is useful to determine the composition and thickness of nanostructures at the atomic scale. However, significant difficulties remain to quantify mixed columns by comparing the resulting atomic resolution images and spectroscopy data with multislice simulations where dynamic scattering needs to be taken into account. The combination of the computationally intensive nature of these simulations and the enormous amount of possible mixed column configurations for a given composition indeed severely hamper the quantification process. To overcome these challenges, we here report the development of an incoherent non-linear method for the fast prediction of ADF-EDX scattering cross-sections of mixed columns under channelling conditions. We first explain the origin of the ADF and EDX incoherence from scattering physics suggesting a linear dependence between those two signals in the case of a high-angle ADF detector. Taking EDX as a perfect incoherent reference mode, we quantitatively examine the ADF longitudinal incoherence under different microscope conditions using multislice simulations. Based on incoherent imaging, the atomic lensing model previously developed for ADF is now expanded to EDX, which yields ADF-EDX scattering cross-section predictions in good agreement with multislice simulations for mixed columns in a core–shell nanoparticle and a high entropy alloy. The fast and accurate prediction of ADF-EDX scattering cross-sections opens up new opportunities to explore the wide range of ordering possibilities of heterogeneous materials with multiple elements.
Address
Corporate Author Zezhong Zhang Thesis
Publisher Place of Publication Editor
Language Wos 000995063900001 Publication Date (up) 2022-12-28
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 European Research Council 770887 PICOMETRICS; Fonds Wetenschappelijk Onderzoek No.G.0502.18N; Horizon 2020, 770887 ; Horizon 2020 Framework Programme; European Research Council, 823717 ESTEEM3 ; esteem3reported; esteem3JRa Approved Most recent IF: 2.2; 2023 IF: 2.843
Call Number EMAT @ emat @c:irua:195890 Serial 7251
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Author Posokhova, S.M.M.; Morozov, V.A.; Deyneko, D.V.V.; Redkin, B.S.S.; Spassky, D.A.A.; Nagirnyi, V.; Belik, A.A.A.; Hadermann, J.; Pavlova, E.T.T.; Lazoryak, B.I.I.
Title K₅Eu(MoO₄)₄ red phosphor for solid state lighting applications, prepared by different techniques Type A1 Journal article
Year 2023 Publication CrystEngComm Abbreviated Journal Crystengcomm
Volume 25 Issue 5 Pages 835-847
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The influence of preparation techniques on the structure and luminescent properties of K5Eu(MoO4)(4) (KEMO) was investigated. KEMO phosphors were synthesized by three different techniques: solid state and sol-gel (sg) methods as well as the Czochralski (CZ) crystal growth technique. Laboratory powder X-ray diffraction (PXRD) studies revealed that all KEMO samples had a structure analogous to that of other high temperature alpha-K5R(MoO4)(4) palmierite-type phases (space group (SG) R3m). Contrary to laboratory PXRD data, electron diffraction revealed that the KEMO crystal grown by the CZ technique had a (3 + 1)D incommensurately modulated structure (super space group (SSG) C2/m(0 beta 0)00) with the modulation vector q = 0.689b*. A detailed analysis of electron diffraction patterns has shown formation of three twin domains rotated along the c axis of the R-subcell at 60 degrees with respect to each other. Synchrotron XRD patterns showed additional ultra-wide reflexes in addition to reflections of the R-subcell of the palmierite. However, the insufficient number of reflections, their low intensity and large width in the synchrotron X-ray diffraction patterns made it impossible to refine the structure as incommensurately modulated C2/m(0 beta 0)00. An average structure was refined in the C2/m space group with random distribution of K1 and Eu1 in [M1A(2)O(8)]-layers of the palmierite-type structure. The dependence of luminescent properties on utilized synthesis techniques was studied. The emission spectra of all samples exhibit intense red emission originating from the D-5(0) -> F-7(2) Eu3+ transition. The integrated intensity of the emission from the Eu3+ 5D0 term was found to be the highest in the crystal grown by the CZ technique. The quantum yield measured for KEMO crystals demonstrates a very high value of 66.5%. This fact confirms that KEMO crystals are exceptionally attractive for applications as a near-UV converting red phosphor for LEDs.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000912021300001 Publication Date (up) 2023-01-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1466-8033 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.1 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 3.1; 2023 IF: 3.474
Call Number UA @ admin @ c:irua:194320 Serial 7317
Permanent link to this record
 
 
Author Mulder, J.T.; Meijer, M.S.; van Blaaderen, J.J.; du Fosse, I.; Jenkinson, K.; Bals, S.; Manna, L.; Houtepen, A.J.
Title Understanding and preventing photoluminescence quenching to achieve unity photoluminescence quantum yield in Yb:YLF nanocrystals Type A1 Journal article
Year 2023 Publication ACS applied materials and interfaces Abbreviated Journal
Volume 15 Issue 2 Pages 3274-3286
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Ytterbium-doped LiYF4 (Yb:YLF) is a commonly used material for laser applications, as a photon upconversion medium, and for optical refrigeration. As nanocrystals (NCs), the material is also of interest for biological and physical applications. Unfortunately, as with most phosphors, with the reduction in size comes a large reduction of the photoluminescence quantum yield (PLQY), which is typically associated with an increase in surface-related PL quenching. Here, we report the synthesis of bipyramidal Yb:YLF NCs with a short axis of similar to 60 nm. We systematically study and remove all sources of PL quenching in these NCs. By chemically removing all traces of water from the reaction mixture, we obtain NCs that exhibit a near-unity PLQY for an Yb3+ concentration below 20%. At higher Yb3+ concentrations, efficient concentration quenching occurs. The surface PL quenching is mitigated by growing an undoped YLF shell around the NC core, resulting in near-unity PLQY values even for fully Yb3+-based LiYbF4 cores. This unambiguously shows that the only remaining quenching sites in core-only Yb:YLF NCs reside on the surface and that concentration quenching is due to energy transfer to the surface. Monte Carlo simulations can reproduce the concentration dependence of the PLQY. Surprisingly, Fo''rster resonance energy transfer does not give satisfactory agreement with the experimental data, whereas nearest-neighbor energy transfer does. This work demonstrates that Yb3+-based nanophosphors can be synthesized with a quality close to that of bulk single crystals. The high Yb3+ concentration in the LiYbF4/LiYF4 core/shell nanocrystals increases the weak Yb3+ absorption, making these materials highly promising for fundamental studies and increasing their effectiveness in bioapplications and optical refrigeration.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000912997300001 Publication Date (up) 2023-01-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1944-8244 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.5 Times cited 3 Open Access OpenAccess
Notes This project has received funding from the European Union's Horizon 2020 research and innovation program under Grant Agreement No. 766900 (Testing the Large-Scale Limit of Quantum Mechanics). A.J.H. and I.d.F. further acknowledge the European Research Council Horizon 2020 ERC Grant Agreement No. 678004 (Doping on Demand) for financial support. The authors thank Freddy Rabouw and Andries Meijerink (Utrecht University) for very fruitful discussions and extremely useful advice. The author s thank Jos Thieme for his help with the laser setups used . The authors furthermore thank Niranjan Saikumar for proofreading the manuscript. Approved Most recent IF: 9.5; 2023 IF: 7.504
Call Number UA @ admin @ c:irua:194317 Serial 7348
Permanent link to this record
 
 
Author Chowdhury, M.S.; Rösch, E.L.; Esteban, D.A.; Janssen, K.-J.; Wolgast, F.; Ludwig, F.; Schilling, M.; Bals, S.; Viereck, T.; Lak, A.
Title Decoupling the Characteristics of Magnetic Nanoparticles for Ultrahigh Sensitivity Type A1 Journal article
Year 2023 Publication Nano letters Abbreviated Journal
Volume 23 Issue 1 Pages 58-65
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Immunoassays exploiting magnetization dynamics of magnetic nanoparticles are highly promising for mix-and-measure, quantitative, and point-of-care diagnostics. However, how single-core magnetic nanoparticles can be employed to reduce particle concentration and concomitantly maximize assay sensitivity is not fully understood. Here, we design monodisperse Néel and Brownian relaxing magnetic nanocubes (MNCs) of different sizes and compositions. We provide insights into how to decouple physical properties of these MNCs to achieve ultrahigh sensitivity. We find that tri-component-based Zn0.06 Co0.80Fe2.14 O4 particles, with out-of-phase to initial magnetic susceptibility χ /χ ratio of 0.47 out of 0.50 for magnetically blocked ideal particles, show the ultrahigh magnetic sensitivity by providing rich magnetic particle spectroscopy (MPS) harmonics spectrum despite bearing lower saturation magnetization than di-component Zn0.1Fe2.9O4 having high saturation magnetization. The Zn0.06Co0.80Fe2.14O4 MNCs, coated with catechol-based polyethylene glycol ligands, measured by our benchtop MPS show three orders of magnitude better particle LOD than that of commercial nanoparticles of comparable size.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000907816300001 Publication Date (up) 2023-01-11
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 10.8 Times cited 1 Open Access OpenAccess
Notes Deutsche Forschungsgemeinschaft, DFG RTG 1952 ; Joachim Herz Stiftung; H2020 Research Infrastructures, 823717 ; Approved Most recent IF: 10.8; 2023 IF: 12.712
Call Number EMAT @ emat @c:irua:193406 Serial 7248
Permanent link to this record
 
 
Author Vijayakumar, J.; Savchenko, T.M.; Bracher, D.M.; Lumbeeck, G.; Béché, A.; Verbeeck, J.; Vajda, Š.; Nolting, F.; Vaz, Ca.f.; Kleibert, A.
Title Absence of a pressure gap and atomistic mechanism of the oxidation of pure Co nanoparticles Type A1 Journal article
Year 2023 Publication Nature communications Abbreviated Journal Nat Commun
Volume 14 Issue 1 Pages 174
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Understanding chemical reactivity and magnetism of 3<italic>d</italic>transition metal nanoparticles is of fundamental interest for applications in fields ranging from spintronics to catalysis. Here, we present an atomistic picture of the early stage of the oxidation mechanism and its impact on the magnetism of Co nanoparticles. Our experiments reveal a two-step process characterized by (i) the initial formation of small CoO crystallites across the nanoparticle surface, until their coalescence leads to structural completion of the oxide shell passivating the metallic core; (ii) progressive conversion of the CoO shell to Co<sub>3</sub>O<sub>4</sub>and void formation due to the nanoscale Kirkendall effect. The Co nanoparticles remain highly reactive toward oxygen during phase (i), demonstrating the absence of a pressure gap whereby a low reactivity at low pressures is postulated. Our results provide an important benchmark for the development of theoretical models for the chemical reactivity in catalysis and magnetism during metal oxidation at the nanoscale.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000955726400021 Publication Date (up) 2023-01-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 16.6 Times cited 1 Open Access OpenAccess
Notes Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, 200021160186 2002153540 ; EC | Horizon 2020 Framework Programme, 810310 823717 ; University of Basel | Swiss Nanoscience Institute, P1502 ; This work is funded by Swiss National Foundation (SNF) (Grants. No 200021160186 and 2002153540) and the Swiss Nanoscience Institut (SNI) (Grant No. SNI P1502). S.V. acknowledges support from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 810310, which corresponds to the J. Heyrovsky Chair project (“ERA Chair at J. Heyrovský Institute of Physical Chemistry AS CR – The institutional approach towards ERA”). The funders had no role in the preparation of the article. Part of this work was performed at the Surface/Interface: Microscopy (SIM) beamline of the Swiss Light Source (SLS), Paul Scherrer Institut, Villigen, Switzerland. We kindly acknowledge Anja Weber and Elisabeth Müller from PSI for their help in fabricating the sample markers. A.B. and J. Verbeeck received funding from the European Union’s Horizon 2020 Research Infrastructure – Integrating Activities for Advanced Communities under grant agreement No. 823717 – ESTEEM3 reported Approved Most recent IF: 16.6; 2023 IF: 12.124
Call Number EMAT @ emat @c:irua:196738 Serial 8804
Permanent link to this record
 
 
Author Friedrich, T.; Yu, C.-P.; Verbeeck, J.; Van Aert, S.
Title Phase object reconstruction for 4D-STEM using deep learning Type A1 Journal article
Year 2023 Publication Microscopy and microanalysis Abbreviated Journal
Volume 29 Issue 1 Pages 395-407
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In this study, we explore the possibility to use deep learning for the reconstruction of phase images from 4D scanning transmission electron microscopy (4D-STEM) data. The process can be divided into two main steps. First, the complex electron wave function is recovered for a convergent beam electron diffraction pattern (CBED) using a convolutional neural network (CNN). Subsequently, a corresponding patch of the phase object is recovered using the phase object approximation. Repeating this for each scan position in a 4D-STEM dataset and combining the patches by complex summation yields the full-phase object. Each patch is recovered from a kernel of 3x3 adjacent CBEDs only, which eliminates common, large memory requirements and enables live processing during an experiment. The machine learning pipeline, data generation, and the reconstruction algorithm are presented. We demonstrate that the CNN can retrieve phase information beyond the aperture angle, enabling super-resolution imaging. The image contrast formation is evaluated showing a dependence on the thickness and atomic column type. Columns containing light and heavy elements can be imaged simultaneously and are distinguishable. The combination of super-resolution, good noise robustness, and intuitive image contrast characteristics makes the approach unique among live imaging methods in 4D-STEM.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001033590800038 Publication Date (up) 2023-01-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.8 Times cited 1 Open Access OpenAccess
Notes We acknowledge funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement no. 770887 PICOMETRICS) and funding from the European Union's Horizon 2020 research and innovation program under grant agreement No. 823717 ESTEEM3. J.V. and S.V.A acknowledge funding from the University of Antwerp through a TOP BOF project. The direct electron detector (Merlin, Medipix3, Quantum Detectors) was funded by the Hercules fund from the Flemish Government. This work was supported by the FWO and FNRS within the 2Dto3D project of the EOS program (grant number 30489208). Approved Most recent IF: 2.8; 2023 IF: 1.891
Call Number UA @ admin @ c:irua:198221 Serial 8912
Permanent link to this record
 
 
Author Marchetti, A.; Gori, A.; Ferretti, A.M.; Esteban, D.A.; Bals, S.; Pigliacelli, C.; Metrangolo, P.
Title Templated Out‐of‐Equilibrium Self‐Assembly of Branched Au Nanoshells Type A1 Journal article
Year 2023 Publication Small Abbreviated Journal
Volume Issue Pages 2206712
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Out-of-equilibrium self-assembly of metal nanoparticles (NPs) has been devised using different types of strategies and fuels, but the achievement of finite 3D structures with a controlled morphology through this assembly mode is still rare. Here we used a spherical peptide-gold superstructure (PAuSS) as a template to control the out-of-equilibrium self-assembly of Au NPs, obtaining a transient 3D branched Au-nanoshell (BAuNS) stabilized by sodium dodecyl sulphate (SDS). The BAuNS dismantled upon concentration gradient equilibration over time in the solution, leading to NPs disassembly. Notably, BAuNS assembly and disassembly favoured temporary interparticle plasmonic coupling, leading to a remarkable oscillation of their optical properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000914725800001 Publication Date (up) 2023-01-17
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 13.3 Times cited 1 Open Access OpenAccess
Notes European Research Council, ERC‐2017‐PoC MINIRES 789815 ERC‐2012‐StG_20111012 FOLDHALO 307108 815128 ; Approved Most recent IF: 13.3; 2023 IF: 8.643
Call Number EMAT @ emat @c:irua:194299 Serial 7247
Permanent link to this record
 
 
Author Bhatia, H.; Martin, C.; Keshavarz, M.; Dovgaliuk, I.; Schrenker, N.J.; Ottesen, M.; Qiu, W.; Fron, E.; Bremholm, M.; Van de Vondel, J.; Bals, S.; Roeffaers, M.B.J.; Hofkens, J.; Debroye, E.
Title Deciphering the role of water in promoting the optoelectronic performance of surface-engineered lead halide perovskite nanocrystals Type A1 Journal article
Year 2023 Publication ACS applied materials and interfaces Abbreviated Journal
Volume 15 Issue 5 Pages 7294-7307
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Lead halide perovskites are promising candidates for applicability is limited by their structural instability toward moisture. Although a deliberate addition of water to the precursor solution has recently been shown to improve the crystallinity and optical properties of perovskites, the corresponding thin films still do not exhibit a near-unity quantum yield. Herein, we report that the direct addition of a minute amount of water to post-treated substantially enhances the stability while achieving a 95% photoluminescence quantum yield in a NC thin film. We unveil the mechanism of how moisture assists in the formation of an additional NH4Br component. Alongside, we demonstrate the crucial role of moisture in assisting localized etching of the perovskite crystal, facilitating the partial incorporation of NH4+, which is key for improved performance under ambient conditions. Finally, as a proof-of-concept, the application of post-treated and watertreated perovskites is tested in LEDs, with the latter exhibiting a superior performance, offering opportunities toward commercial application in moisture-stable optoelectronics.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000931729400001 Publication Date (up) 2023-01-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1944-8244 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.5 Times cited 3 Open Access Not_Open_Access
Notes H.B. would like to express her sincere gratitude to Dr. Peter Erk (formerly BASF SE, Germany) for very insightful discussions. The authors acknowledge financial support from the Research Foundation-Flanders (FWO grant numbers S002019N, 1514220N, G.0B39.15, G.0B49.15, G098319N, and ZW15_09-GOH6316) , the KU Leuven Research Fund (C14/19/079, iBOF-21-085 PERSIST, and STG/21/010) , the Flemish government through long-term structural funding Methusalem (CASAS2, Meth/15/04) , the Hercules Founda-tion (HER/11/14) , and the ERC through the Marie Curie ITN iSwitch Ph.D. fellowship to H.B. (grant number 642196) . C.M. acknowledges the financial support from grants PID2021-128761OA-C22 funded by MCIN/AEI/10.13039/501100011033 by the ?European Union? and SBPLY/21/180501/000127 funded by JCCM and by the EU through Fondo Europeo de Desarollo Regional? (FEDER) . Martin Bremholm and Martin Ottesen acknowledge funding from the Danish Council for Independent Research, Natural Sciences, under the Sapere Aude program (grant no. 7027-00077B) and VILLUM FONDEN through the Centre of Excellence for Dirac Materials (grant no. 11744) . Affiliation with the Center for Integrated Materials Research (iMAT) at Aarhus University is gratefully acknowledged.-N.J.S. acknowledges financial support from the research foundation Flanders (FWO) through a postdoctoral fellowship (FWO grant no. 1238622N) . S.B. acknowledges financial support from the European Commission by the ERC Consolidator grant REALNANO (no. 815128) . Approved Most recent IF: 9.5; 2023 IF: 7.504
Call Number UA @ admin @ c:irua:195375 Serial 7293
Permanent link to this record
 
 
Author Bian, G.; Ageeva, O.; Roddatis, V.; Li, C.; Pennycook, T.J.; Habler, G.; Abart, R.
Title Crystal structure controls on oriented primary magnetite micro-inclusions in plagioclase From oceanic gabbro Type A1 Journal article
Year 2023 Publication Journal of petrology Abbreviated Journal
Volume 64 Issue 3 Pages egad008-18
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Oriented needle-, lath- and plate-shaped magnetite micro-inclusions in rock forming plagioclase from mafic intrusive rocks, were investigated using correlated optical microscopy and scanning transmission electron microscopy. The magnetite micro-inclusions were analysed on cuts parallel and perpendicular to the inclusion-elongation directions. The crystal structures of the two phases are in direct contact along the interfaces. The shape, shape orientation and crystallographic orientation relationships between the magnetite micro-inclusions and the plagioclase host appear to be controlled by the tendency of the system to optimise lattice match along the interfaces. The elongation direction of the inclusions ensures good match between prominent oxygen layers in the magnetite and plagioclase crystal structures across the interfaces bounding the inclusions parallel to their elongation direction. In cross-section, additional modes of lattice match, such as the commensurate impingement of magnetite and plagioclase lattice planes along the interfaces, the parallel alignment of the interfaces to low-index lattice planes of magnetite or plagioclase, or the parallel alignment to low index lattice planes of both phases are observed, which appear to control the selection of interface facets, as well as the shape and crystallographic orientation relationships between magnetite micro-inclusions and plagioclase host. The systematics of the inclusion cross-sectional shapes and crystallographic orientation relationships indicate recrystallisation of magnetite with potential implications for natural remanent magnetisation of magnetite-bearing plagioclase grains.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001010636400007 Publication Date (up) 2023-01-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3530 ISBN Additional Links UA library record; WoS full record
Impact Factor 3.9 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 3.9; 2023 IF: 3.28
Call Number UA @ admin @ c:irua:195160 Serial 7292
Permanent link to this record
 
 
Author Cui, W.; Lin, W.; Lu, W.; Liu, C.; Gao, Z.; Ma, H.; Zhao, W.; Van Tendeloo, G.; Zhao, W.; Zhang, Q.; Sang, X.
Title Direct observation of cation diffusion driven surface reconstruction at van der Waals gaps Type A1 Journal article
Year 2023 Publication Nature communications Abbreviated Journal
Volume 14 Issue 1 Pages 554-10
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Weak interlayer van der Waals (vdW) bonding has significant impact on the surface/interface structure, electronic properties, and transport properties of vdW layered materials. Unraveling the complex atomistic dynamics and structural evolution at vdW surfaces is therefore critical for the design and synthesis of the next-generation vdW layered materials. Here, we show that Ge/Bi cation diffusion along the vdW gap in layered GeBi2Te4 (GBT) can be directly observed using in situ heating scanning transmission electron microscopy (STEM). The cation concentration variation during diffusion was correlated with the local Te-6 octahedron distortion based on a quantitative analysis of the atomic column intensity and position in time-elapsed STEM images. The in-plane cation diffusion leads to out-of-plane surface etching through complex structural evolutions involving the formation and propagation of a non-centrosymmetric GeTe2 triple layer surface reconstruction on fresh vdW surfaces, and GBT subsurface reconstruction from a septuple layer to a quintuple layer. Our results provide atomistic insight into the cation diffusion and surface reconstruction in vdW layered materials. Weak interlayer van der Waals (vdW) bonding has significant impact on the structure and properties of vdW layered materials. Here authors use in-situ aberration-corrected ADF-STEM for an atomistic insight into the cation diffusion in the vdW gaps and the etching of vdW surfaces at high temperatures.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001076227200001 Publication Date (up) 2023-02-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 16.6 Times cited Open Access
Notes Approved Most recent IF: 16.6; 2023 IF: 12.124
Call Number UA @ admin @ c:irua:201342 Serial 9021
Permanent link to this record
 
 
Author Benedet, M.; Andrea Rizzi, G.; Gasparotto, A.; Gauquelin, N.; Orekhov, A.; Verbeeck, J.; Maccato, C.; Barreca, D.
Title Functionalization of graphitic carbon nitride systems by cobalt and cobalt-iron oxides boosts solar water oxidation performances Type A1 Journal article
Year 2023 Publication Applied surface science Abbreviated Journal
Volume 618 Issue Pages 156652
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The ever-increasing energy demand from the world population has made the intensive use of fossil fuels an overarching threat to global environment and human health. An appealing alternative is offered by sunlight-assisted photoelectrochemical water splitting to yield carbon-free hydrogen fuel, but kinetic limitations associated to the oxygen evolution reaction (OER) render the development of cost-effective, eco-friendly and stable electrocatalysts an imperative issue. In the present work, OER catalysts based on graphitic carbon nitride (g-C3N4) were deposited on conducting glass substrates by a simple decantation procedure, followed by functionalization with low amounts of nanostructured CoO and CoFe2O4 by radio frequency (RF)-sputtering, and final annealing under inert atmosphere. A combination of advanced characterization tools was used to investigate the interplay between material features and electrochemical performances. The obtained results highlighted the formation of a p-n junction for the g-C3N4-CoO system, whereas a Z-scheme junction accounted for the remarkable performance enhancement yielded by g-C3N4-CoFe2O4. The intimate contact between the system components also afforded an improved electrocatalyst stability in comparison to various bare and functionalized g-C3N4-based systems. These findings emphasize the importance of tailoring g-C3N4 chemico-physical properties through the dispersion of complementary catalysts to fully exploit its applicative potential.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000950654300001 Publication Date (up) 2023-02-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited 11 Open Access OpenAccess
Notes The authors gratefully acknowledge financial support from CNR (Progetti di Ricerca @CNR – avviso 2020 – ASSIST), Padova University (P-DiSC#04BIRD2020-UNIPD EUREKA, DOR 2020–2022), AMGA Foundation (NYMPHEA project), INSTM Consortium (INSTM21PDGASPAROTTO – NANOMAT, INSTM21PDBARMAC – ATENA) and the European Union's Horizon 2020 research and innovation program under grant agreement No 823717 – ESTEEM3. The FWO-Hercules fund G0H4316N 'Direct electron detector for soft matter TEM' is also acknowledged. Many thanks are due to Prof. Luca Gavioli (Università Cattolica del Sacro Cuore, Brescia, Italy) and Dr. Riccardo Lorenzin (Department of Chemical Sciences, Padova University, Italy) for their invaluable technical support.; esteem3reported; esteem3TA Approved Most recent IF: 6.7; 2023 IF: 3.387
Call Number EMAT @ emat @c:irua:196150 Serial 7376
Permanent link to this record
 
 
Author Smeyers, R.; Milošević, M.V.; Covaci, L.
Title Strong gate-tunability of flat bands in bilayer graphene due to moiré encapsulation between hBN monolayers Type A1 Journal article
Year 2023 Publication Nanoscale Abbreviated Journal
Volume 15 Issue 9 Pages 4561-4569
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract When using hexagonal boron-nitride (hBN) as a substrate for graphene, the resulting moire pattern creates secondary Dirac points. By encapsulating a multilayer graphene within aligned hBN sheets the controlled moire stacking may offer even richer benefits. Using advanced tight-binding simulations on atomistically-relaxed heterostructures, here we show that the gap at the secondary Dirac point can be opened in selected moire-stacking configurations, and is independent of any additional vertical gating of the heterostructure. On the other hand, gating can broadly tune the gap at the principal Dirac point, and may thereby strongly compress the first moire mini-band in width against the moire-induced gap at the secondary Dirac point. We reveal that in hBN-encapsulated bilayer graphene this novel mechanism can lead to isolated bands flatter than 10 meV under moderate gating, hence presenting a convenient pathway towards electronically-controlled strongly-correlated states on demand.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000933052600001 Publication Date (up) 2023-02-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364; 2040-3372 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 6.7; 2023 IF: 7.367
Call Number UA @ admin @ c:irua:195249 Serial 7340
Permanent link to this record
 
 
Author Mary Joy, R.; Pobedinskas, P.; Bourgeois, E.; Chakraborty, T.; Görlitz, J.; Herrmann, D.; Noël, C.; Heupel, J.; Jannis, D.; Gauquelin, N.; D'Haen, J.; Verbeeck, J.; Popov, C.; Houssiau, L.; Becher, C.; Nesládek, M.; Haenen, K.
Title Germanium vacancy centre formation in CVD nanocrystalline diamond using a solid dopant source Type A3 Journal article
Year 2023 Publication Science talks Abbreviated Journal Science Talks
Volume 5 Issue Pages 100157
Keywords A3 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date (up) 2023-02-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2772-5693 ISBN Additional Links UA library record
Impact Factor Times cited Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:196969 Serial 8791
Permanent link to this record
 
 
Author De Backer, A.; Bals, S.; Van Aert, S.
Title A decade of atom-counting in STEM: From the first results toward reliable 3D atomic models from a single projection Type A1 Journal article
Year 2023 Publication Ultramicroscopy Abbreviated Journal
Volume Issue Pages 113702
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Quantitative structure determination is needed in order to study and understand nanomaterials at the atomic scale. Materials characterisation resulting in precise structural information is a crucial point to understand the structure–property relation of materials. Counting the number of atoms and retrieving the 3D atomic structure of nanoparticles plays an important role here. In this paper, an overview will be given of the atom-counting methodology and its applications over the past decade. The procedure to count the number of atoms will be discussed in detail and it will be shown how the performance of the method can be further improved. Furthermore, advances toward mixed element nanostructures, 3D atomic modelling based on the atom-counting results, and quantifying the nanoparticle dynamics will be highlighted.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000953765800001 Publication Date (up) 2023-02-10
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 3 Open Access OpenAccess
Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert, Grant 815128 REALNANO to S. Bals, and Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0267.18N, G.0502.18N, G.0346.21N, and EOS 30489208) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF) . The authors also thank the colleagues who have contributed to this work over the years, including T. Altantzis, E. Arslan Irmak, K.J. Batenburg, E. Bladt, A. De wael, R. Erni, C. Faes, B. Goris, L. Jones, L.M. Liz-Marzán, I. Lobato, G.T. Martinez, P.D. Nellist, M.D. Rosell, A. Rosenauer, K.H.W. van den Bos, A. Varambhia, and Z. Zhang.; esteem3reported; esteem3JRA Approved Most recent IF: 2.2; 2023 IF: 2.843
Call Number EMAT @ emat @c:irua:195896 Serial 7236
Permanent link to this record
 
 
Author Craig, T.M.; Kadu, A.A.; Batenburg, K.J.; Bals, S.
Title Real-time tilt undersampling optimization during electron tomography of beam sensitive samples using golden ratio scanning and RECAST3D Type A1 Journal article
Year 2023 Publication Nanoscale Abbreviated Journal
Volume 15 Issue 11 Pages 5391-5402
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Electron tomography is a widely used technique for 3D structural analysis of nanomaterials, but it can cause damage to samples due to high electron doses and long exposure times. To minimize such damage, researchers often reduce beam exposure by acquiring fewer projections through tilt undersampling. However, this approach can also introduce reconstruction artifacts due to insufficient sampling. Therefore, it is important to determine the optimal number of projections that minimizes both beam exposure and undersampling artifacts for accurate reconstructions of beam-sensitive samples. Current methods for determining this optimal number of projections involve acquiring and post-processing multiple reconstructions with different numbers of projections, which can be time-consuming and requires multiple samples due to sample damage. To improve this process, we propose a protocol that combines golden ratio scanning and quasi-3D reconstruction to estimate the optimal number of projections in real-time during a single acquisition. This protocol was validated using simulated and realistic nanoparticles, and was successfully applied to reconstruct two beam-sensitive metal–organic framework complexes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000937908900001 Publication Date (up) 2023-02-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited 1 Open Access OpenAccess
Notes H2020 European Research Council, 815128 ; H2020 Marie Skłodowska-Curie Actions, 860942 ; Approved Most recent IF: 6.7; 2023 IF: 7.367
Call Number EMAT @ emat @c:irua:195235 Serial 7260
Permanent link to this record
 
 
Author Yang, C.-Q.; Zhi, R.; Rothmann, M.U.; Xu, Y.-Y.; Li, L.-Q.; Hu, Z.-Y.; Pang, S.; Cheng, Y.-B.; Van Tendeloo, G.; Li, W.
Title Unveiling the intrinsic structure and intragrain defects of organic-inorganic hybrid perovskites by ultralow dose transmission electron microscopy Type A1 Journal article
Year 2023 Publication Advanced materials Abbreviated Journal
Volume Issue Pages 1-9
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Transmission electron microscopy (TEM) is a powerful tool for unveiling the structural, compositional, and electronic properties of organic-inorganic hybrid perovskites (OIHPs) at the atomic to micrometer length scales. However, the structural and compositional instability of OIHPs under electron beam radiation results in misunderstandings of the microscopic structure-property-performance relationship in OIHP devices. Here, ultralow dose TEM is utilized to identify the mechanism of the electron-beam-induced changes in OHIPs and clarify the cumulative electron dose thresholds (critical dose) of different commercially interesting state-of-the-art OIHPs, including methylammonium lead iodide (MAPbI(3)), formamidinium lead iodide (FAPbI(3)), FA(0.83)Cs(0.17)PbI(3), FA(0.15)Cs(0.85)PbI(3), and MAPb(0.5)Sn(0.5)I(3). The critical dose is related to the composition of the OIHPs, with FA(0.15)Cs(0.85)PbI(3) having the highest critical dose of approximate to 84 e angstrom(-2) and FA(0.83)Cs(0.17)PbI(3) having the lowest critical dose of approximate to 4.2 e angstrom(-2). The electron beam irradiation results in the formation of a superstructure with ordered I and FA vacancies along (c), as identified from the three major crystal axes in cubic FAPbI(3), (c), (c), and (c). The intragrain planar defects in FAPbI(3) are stable, while an obvious modification is observed in FA(0.83)Cs(0.17)PbI(3) under continuous electron beam exposure. This information can serve as a guide for ensuring a reliable understanding of the microstructure of OIHP optoelectronic devices by TEM.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000950461600001 Publication Date (up) 2023-02-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 29.4 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 29.4; 2023 IF: 19.791
Call Number UA @ admin @ c:irua:195116 Serial 7349
Permanent link to this record
 
 
Author Daele, K.V.; Arenas‐Esteban, D.; Choukroun, D.; Hoekx, S.; Rossen, A.; Daems, N.; Pant, D.; Bals, S.; Breugelmans, T.
Title Enhanced Pomegranate‐Structured SnO2Electrocatalysts for the Electrochemical CO2Reduction to Formate Type A1 Journal article
Year 2023 Publication ChemElectroChem Abbreviated Journal
Volume Issue Pages
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract Although most state-of-the-art Sn-based electrocatalysts yield promising results in terms of selectivity and catalyst activity, their stability remains insufficient to date. Here, we demonstrate the successful application of the recently developed pomegranate-structured SnO2 (Pom. SnO2) and SnO2@C (Pom. SnO2@C) nanocomposite electrocatalysts for the efficient electrochemical conversion of CO2 to formate. With an initial selectivity of 83 and 86% towards formate and an operating potential of -0.72 V and -0.64 V vs. RHE, respectively, these pomegranate SnO2 electrocatalysts are able to compete with most of the current state-of-the-art Sn-based electrocatalysts in terms of activity and selectivity. Given the importance of electrocatalyst stability, long-term experiments (24 h) were performed and a temporary loss in selectivity for the Pom. SnO2@C electrocatalyst was largely restored to its initial selectivity upon drying and exposure to air. Of all the used (24 h) electrocatalysts, the pomegranate SnO2@C had the highest selectivity over a time period of one hour, reaching an average recovered FE of 85%, while the commercial SnO2 and bare pomegranate SnO2 electrocatalysts reached an average of 79 and 80% FE towards formate, respectively. Furthermore, the pomegranate structure of Pom. SnO2@C was largely preserved due to the presence of the heterogeneous carbon shell, which acts as a protective layer, physically inhibiting particle segregation/pulverisation and agglomeration.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000936694800001 Publication Date (up) 2023-02-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2196-0216 ISBN Additional Links UA library record; WoS full record
Impact Factor 4 Times cited Open Access OpenAccess
Notes European Regional Development Fund, E2C 2S03-019 ; Approved Most recent IF: 4; 2023 IF: 4.136
Call Number EMAT @ emat @c:irua:195228 Serial 7249
Permanent link to this record
 
 
Author Rivas-Murias, B.; Testa-Anta, M.; Skorikov, A.S.; Comesana-Hermo, M.; Bals, S.; Salgueirino, V.
Title Interfaceless exchange bias in CoFe₂O₄ nanocrystals Type A1 Journal article
Year 2023 Publication Nano letters Abbreviated Journal
Volume 23 Issue 5 Pages 1688-1695
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Oxidized cobalt ferrite nanocrystals with a modified distribution of the magnetic cations in their spinel structure give place to an unusual exchange-coupled system with a double reversal of the magnetization, exchange bias, and increased coercivity, but without the presence of a clear physical interface that delimits two well-differentiated magnetic phases. More specifically, the partial oxidation of cobalt cations and the formation of Fe vacancies at the surface region entail the formation of a cobalt-rich mixed ferrite spinel, which is strongly pinned by the ferrimagnetic background from the cobalt ferrite lattice. This particular configuration of exchange-biased magnetic behavior, involving two different magnetic phases but without the occurrence of a crystallographically coherent interface, revolu-tionizes the established concept of exchange bias phenomenology.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000940892000001 Publication Date (up) 2023-02-27
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 10.8 Times cited 4 Open Access OpenAccess
Notes M.T.-A. acknowledges financial support from the Spanish Ministerio de Ciencia e Innovaci?n under grant FJC2021- 046680-I. S.B. acknowledges funding from the European Research Council under the European Union?s Horizon 2020 research and innovation program (ERC Consolidator Grant N o 815128 REALNANO) . V.S. acknowledges the financial support from the Spanish Ministerio de Ciencia e Innovaci?n under project PID2020-119242-I00 and from the European Union under project H2020-MSCA-RISE-2019 PEPSA-MATE (project number 872233) . Approved Most recent IF: 10.8; 2023 IF: 12.712
Call Number UA @ admin @ c:irua:195186 Serial 7315
Permanent link to this record
 
 
Author Verdierre, G.; Gauquelin, N.; Jannis, D.; Birkhölzer, Y.A.; Mallik, S.; Verbeeck, J.; Bibes, M.; Koster, G.
Title Epitaxial growth of the candidate ferroelectric Rashba material SrBiO3by pulsed laser deposition Type A1 Journal article
Year 2023 Publication APL materials Abbreviated Journal
Volume 11 Issue 3 Pages 031109
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Among oxides, bismuthates have been gaining much interest due to their unique features. In addition to their superconducting properties, they show potential for applications as topological insulators and as possible spin-to-charge converters. After being first investigated in their bulk form in the 1980s, bismuthates have been successfully grown as thin films. However, most efforts have focused on BaBiO<sub>3</sub>, with SrBiO<sub>3</sub>receiving only little attention. Here, we report the growth of epitaxial films of SrBiO<sub>3</sub>on both TiO<sub>2</sub>-terminated SrTiO<sub>3</sub>and NdO-terminated NdScO<sub>3</sub>substrates by pulsed laser deposition. SrBiO<sub>3</sub>has a pseudocubic lattice constant of ∼4.25 Å and grows relaxed on NdScO<sub>3</sub>. Counter-intuitively, it grows with a slight tensile strain on SrTiO<sub>3</sub>despite a large lattice mismatch, which should induce compressive strain. High-resolution transmission electron microscopy reveals that this occurs as a consequence of structural domain matching, with blocks of 10 SrBiO<sub>3</sub>unit planes matching blocks of 11 SrTiO<sub>3</sub>unit planes. This work provides a framework for the synthesis of high quality perovskite bismuthates films and for the understanding of their interface interactions with homostructural substrates.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000953363800004 Publication Date (up) 2023-03-01
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 OpenAccess
Notes This work received support from the ERC Advanced grant (Grant No. 833973) “FRESCO” and funding from the European Union’s Horizon 2020 Research and Innovation Program under Grant Agreement No. 823717—ESTEEM3, Van Gogh travel grant, Nuffic, The Netherlands (CF No. 42582SB).; esteem3reported; esteem3TA Approved Most recent IF: 6.1; 2023 IF: 4.335
Call Number EMAT @ emat @c:irua:196135 Serial 7377
Permanent link to this record
 
 
Author Yang, T.; Kong, Y.; Li, K.; Lu, Q.; Wang, Y.; Du, Y.; Schryvers, D.
Title Quasicrystalline clusters transformed from C14-MgZn₂ nanoprecipitates in Al alloys Type A1 Journal article
Year 2023 Publication Materials characterization Abbreviated Journal
Volume 199 Issue Pages 112772-112777
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Ultrafine faulty C14-MgZn2 Laves phase precipitates containing quasicrystalline clusters and demonstrating the formation of binary quasicrystalline precipitates with Penrose-like random-tiling were observed in the over-aged FCC matrix of a commercial 7N01 Al-Zn-Mg alloy, using high angle annular dark field scanning transmission electron microscopy. The evolution from C14-Laves phase to quasicrystalline clusters is illustrated, and five-fold symmetry can be found in both real and reciprocal spaces. Our findings reveal the possibility of quasicrystalline formation from Laves phase in a highly plastic metal matrix like Al and demonstrate the structural relationship between Laves phase and quasicrystals.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000954788800001 Publication Date (up) 2023-03-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.7 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 4.7; 2023 IF: 2.714
Call Number UA @ admin @ c:irua:196106 Serial 8446
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Author Vlasov, E.; Denisov, N.; Verbeeck, J.
Title Low-cost electron detector for scanning electron microscope Type A1 Journal article
Year 2023 Publication HardwareX Abbreviated Journal HardwareX
Volume 14 Issue Pages e00413
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Electron microscopy is an indispensable tool for the characterization of (nano) materials. Electron microscopes are typically very expensive and their internal operation is often shielded from the user. This situation can provide fast and high quality results for researchers focusing on e.g. materials science if they have access to the relevant instruments. For researchers focusing on technique development, wishing to test novel setups, however, the high entry price can lead to risk aversion and deter researchers from innovating electron microscopy technology further. The closed attitude of commercial entities about how exactly the different parts of electron microscopes work, makes it even harder for newcomers in this field. Here we propose an affordable, easy-to-build electron detector for use in a scanning electron microscope (SEM). The aim of this project is to shed light on the functioning of such detectors as well as show that even a very modest design can lead to acceptable performance while providing high flexibility for experimentation and customization.
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Language Wos 001042486000001 Publication Date (up) 2023-03-10
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ISSN 2468-0672 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 1 Open Access OpenAccess
Notes The authors acknowledge the financial support of the Research Foundation Flanders (FWO, Belgium) project SBO [Grant No. S000121N]. JV acknowledges funding from the HORIZON-INFRA-2022-TECH-01-01 project IMPRESS [Grant No. 101094299]. Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:195886 Serial 7252
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Author Benedoue, S.; Benedet, M.; Gasparotto, A.; Gauquelin, N.; Orekhov, A.; Verbeeck, J.; Seraglia, R.; Pagot, G.; Rizzi, G.A.; Balzano, V.; Gavioli, L.; Noto, V.D.; Barreca, D.; Maccato, C.
Title Insights into the Photoelectrocatalytic Behavior of gCN-Based Anode Materials Supported on Ni Foams Type A1 Journal article
Year 2023 Publication Nanomaterials Abbreviated Journal Nanomaterials-Basel
Volume 13 Issue 6 Pages 1035
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Graphitic carbon nitride (gCN) is a promising n-type semiconductor widely investigated for photo-assisted water splitting, but less studied for the (photo)electrochemical degradation of aqueous organic pollutants. In these fields, attractive perspectives for advancements are offered by a proper engineering of the material properties, e.g., by depositing gCN onto conductive and porous scaffolds, tailoring its nanoscale morphology, and functionalizing it with suitable cocatalysts. The present study reports on a simple and easily controllable synthesis of gCN flakes on Ni foam substrates by electrophoretic deposition (EPD), and on their eventual decoration with Co-based cocatalysts [CoO, CoFe2O4, cobalt phosphate (CoPi)] via radio frequency (RF)-sputtering or electrodeposition. After examining the influence of processing conditions on the material characteristics, the developed systems are comparatively investigated as (photo)anodes for water splitting and photoelectrocatalysts for the degradation of a recalcitrant water pollutant [potassium hydrogen phthalate (KHP)]. The obtained results highlight that while gCN decoration with Co-based cocatalysts boosts water splitting performances, bare gCN as such is more efficient in KHP abatement, due to the occurrence of a different reaction mechanism. The related insights, provided by a multi-technique characterization, may provide valuable guidelines for the implementation of active nanomaterials in environmental remediation and sustainable solar-to-chemical energy conversion.
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Language Wos 000960297000001 Publication Date (up) 2023-03-13
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ISSN 2079-4991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.3 Times cited 3 Open Access OpenAccess
Notes The present work was financially supported by CNR (Progetti di Ricerca @CNR—avviso 2020—ASSIST), Padova University (P-DiSC#04BIRD2020-UNIPD EUREKA, DOR 2020–2022), AMGA Foundation (NYMPHEA project), INSTM Consortium (INSTM21PDGASPAROTTO—NANOMAT, INSTM21PDBARMAC—ATENA) and the European Union’s Horizon 2020 research and innovation program under grant agreement No. 823717—ESTEEM3. The FWO-Hercules fund G0H4316N ‘Direct electron detector for soft matter TEM’ is also acknowledged. Many thanks are also due to Dr. Riccardo Lorenzin for his support to experimental activities.; esteem3reported; esteem3TA Approved Most recent IF: 5.3; 2023 IF: 3.553
Call Number EMAT @ emat @c:irua:196115 Serial 7378
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Author Kante, M.V.; Weber, M.L.; Ni, S.; van den Bosch, I.C.G.; van der Minne, E.; Heymann, L.; Falling, L.J.; Gauquelin, N.; Tsvetanova, M.; Cunha, D.M.; Koster, G.; Gunkel, F.; Nemsak, S.; Hahn, H.; Estrada, L.V.; Baeumer, C.
Title A high-entropy oxide as high-activity electrocatalyst for water oxidation Type A1 Journal article
Year 2023 Publication ACS nano Abbreviated Journal
Volume 17 Issue 6 Pages 5329-5339
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract High-entropy materials are an emerging pathway in the development of high-activity (electro)catalysts because of the inherent tunability and coexistence of multiple potential active sites, which may lead to earth-abundant catalyst materials for energy-efficient electrochemical energy storage. In this report, we identify how the multication composition in high-entropy perovskite oxides (HEO) contributes to high catalytic activity for the oxygen evolution reaction (OER), i.e., the key kinetically limiting half-reaction in several electrochemical energy conversion technologies, including green hydrogen generation. We compare the activity of the (001) facet of LaCr0.2Mn0.2Fe0.2Co0.2Ni0.2O3-delta with the parent compounds (single B-site in the ABO3 perovskite). While the single B-site perovskites roughly follow the expected volcano-type activity trends, the HEO clearly outperforms all of its parent compounds with 17 to 680 times higher currents at a fixed overpotential. As all samples were grown as an epitaxial layer, our results indicate an intrinsic composition-function relationship, avoiding the effects of complex geometries or unknown surface composition. In-depth X-ray photoemission studies reveal a synergistic effect of simultaneous oxidation and reduction of different transition metal cations during the adsorption of reaction intermediates. The surprisingly high OER activity demonstrates that HEOs are a highly attractive, earth-abundant material class for high-activity OER electrocatalysts, possibly allowing the activity to be fine-tuned beyond the scaling limits of mono-or bimetallic oxides.
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Language Wos 000953440900001 Publication Date (up) 2023-03-13
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ISSN 1936-0851 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 17.1 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 17.1; 2023 IF: 13.942
Call Number UA @ admin @ c:irua:196097 Serial 7390
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Author Jain, N.; Hao, Y.; Parekh, U.; Kaltenegger, M.; Pedrazo-Tardajos, A.; Lazzaroni, R.; Resel, R.; Geerts, Y.H.; Bals, S.; Van Aert, S.
Title Exploring the effects of graphene and temperature in reducing electron beam damage: A TEM and electron diffraction-based quantitative study on Lead Phthalocyanine (PbPc) crystals Type A1 Journal article
Year 2023 Publication Micron Abbreviated Journal
Volume 169 Issue Pages 103444
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract High-resolution transmission electron microscopy (TEM) of organic crystals, such as Lead Phthalocyanine (PbPc), is very challenging since these materials are prone to electron beam damage leading to the breakdown of the crystal structure during investigation. Quantification of the damage is imperative to enable high-resolution imaging of PbPc crystals with minimum structural changes. In this work, we performed a detailed electron diffraction study to quantitatively measure degradation of PbPc crystals upon electron beam irradiation. Our study is based on the quantification of the fading intensity of the spots in the electron diffraction patterns. At various incident dose rates (e/Å2/s) and acceleration voltages, we experimentally extracted the decay rate (1/s), which directly correlates with the rate of beam damage. In this manner, a value for the critical dose (e/Å2) could be determined, which can be used as a measure to quantify beam damage. Using the same methodology, we explored the influence of cryogenic temperatures, graphene TEM substrates, and graphene encapsulation in prolonging the lifetime of the PbPc crystal structure during TEM investigation. The knowledge obtained by diffraction experiments is then translated to real space high-resolution TEM imaging of PbPc.
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Language Wos 000965998800001 Publication Date (up) 2023-03-21
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ISSN 0968-4328 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.4 Times cited 1 Open Access OpenAccess
Notes This work is supported by FWO and FNRS within the 2Dto3D network of the EOS (Excellence of Science) program (grant number 30489208) and ERC-CoGREALNANO-815128 (to Prof. Dr. Sara Bals). N.J. would like to thank Dr. Kunal S. Mali and Dr. Da Wang for useful and interesting discussions on sample preparation procedures. Approved Most recent IF: 2.4; 2023 IF: 1.98
Call Number EMAT @ emat @c:irua:196069 Serial 7379
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