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Author Teunissen, J.L.; Braeckevelt, T.; Skvortsova, I.; Guo, J.; Pradhan, B.; Debroye, E.; Roeffaers, M.B.J.; Hofkens, J.; Van Aert, S.; Bals, S.; Rogge, S.M.J.; Van Speybroeck, V.
Title Additivity of Atomic Strain Fields as a Tool to Strain-Engineering Phase-Stabilized CsPbI3Perovskites Type A1 Journal Article
Year 2023 Publication The Journal of Physical Chemistry C Abbreviated Journal J. Phys. Chem. C
Volume 127 Issue 48 Pages 23400-23411
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract CsPbI3 is a promising perovskite material for photovoltaic applications in its photoactive perovskite or black phase. However, the material degrades to a photovoltaically inactive or yellow phase at room temperature. Various mitigation strategies are currently being developed to increase the lifetime of the black phase, many of which rely on inducing strains in the material that hinder the black-to-yellow phase transition. Physical insight into how these strategies exactly induce strain as well as knowledge of the spatial extent over which these strains impact the material is crucial to optimize these approaches but is still lacking. Herein, we combine machine learning potential-based molecular dynamics simulations with our in silico strain engineering approach to accurately quantify strained large-scale atomic structures on a nanosecond time scale. To this end, we first model the strain fields introduced by atomic substitutions as they form the most elementary strain sources. We demonstrate that the magnitude of the induced strain fields decays exponentially with the distance from the strain source, following a decay rate that is largely independent of the specific substitution. Second, we show that the total strain field induced by multiple strain sources can be predicted to an excellent approximation by summing the strain fields of each individual source. Finally, through a case study, we illustrate how this additive character allows us to explain how complex strain fields, induced by spatially extended strain sources, can be predicted by adequately combining the strain fields caused by local strain sources. Hence, the strain additivity proposed here can be adopted to further our insight into the complex strain behavior in perovskites and to design strain from the atomic level onward to enhance their sought-after phase stability.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001116862000001 Publication Date (up) 2023-12-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record
Impact Factor 3.7 Times cited Open Access OpenAccess
Notes This work was supported by iBOF-21-085 PERsist (Special Research Fund of Ghent University, KU Leuven Research Fund, and the Research Fund of the University of Antwerp). S.M.J.R., T.B., and B.P. acknowledge financial support from the Research Foundation-Flanders (FWO) through two postdoctoral fellow- ships [grant nos. 12T3522N (S.M.J.R.) and 1275521N (B.P.)] and an SB-FWO fellowship [grant no. 1SC1319 (T.B.)]. E.D., M.B.J.R., and J.H. acknowledge financial support from the Research Foundation-Flanders (FWO, grant nos. G.0B39.15, G.0B49.15, G098319N, S002019N, S004322N, and ZW15_09- GOH6316). J.H. acknowledges support from the Flemish government through long-term structural funding Methusalem (CASAS2, Meth/15/04) and the MPI as an MPI fellow. S.V.A. and S.B. acknowledge financial support from the Research Foundation-Flanders (FWO, grant no. G0A7723N). S.M.J.R. and V.V.S. acknowledge funding from the Research Board of Ghent University (BOF). The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation- Flanders (FWO) and the Flemish Government�department EWI.; KU Leuven, iBOF-21-085 PERsist ; Universiteit Antwerpen, iBOF-21-085 PERsist ; Universiteit Gent, iBOF-21-085 PERsist ; Vlaamse regering, CASAS2, Meth/15/04 ; Fonds Wetenschappelijk Onderzoek, G.0B39.15 G098319N G.0B49.15 1SC1319 12T3522N ZW15 09-GOH6316 G0A7723N 1275521N S004322N S002019N ; Approved Most recent IF: 3.7; 2023 IF: 4.536
Call Number EMAT @ emat @c:irua:202124 Serial 8985
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Author Hugenschmidt, M.; Jannis, D.; Kadu, A.A.; Grünewald, L.; De Marchi, S.; Perez-Juste, J.; Verbeeck, J.; Van Aert, S.; Bals, S.
Title Low-dose 4D-STEM tomography for beam-sensitive nanocomposites Type A1 Journal article
Year 2023 Publication ACS materials letters Abbreviated Journal
Volume 6 Issue 1 Pages 165-173
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Electron tomography is essential for investigating the three-dimensional (3D) structure of nanomaterials. However, many of these materials, such as metal-organic frameworks (MOFs), are extremely sensitive to electron radiation, making it difficult to acquire a series of projection images for electron tomography without inducing electron-beam damage. Another significant challenge is the high contrast in high-angle annular dark field scanning transmission electron microscopy that can be expected for nanocomposites composed of a metal nanoparticle and an MOF. This strong contrast leads to so-called metal artifacts in the 3D reconstruction. To overcome these limitations, we here present low-dose electron tomography based on four-dimensional scanning transmission electron microscopy (4D-STEM) data sets, collected using an ultrafast and highly sensitive direct electron detector. As a proof of concept, we demonstrate the applicability of the method for an Au nanostar embedded in a ZIF-8 MOF, which is of great interest for applications in various fields, including drug delivery.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001141178500001 Publication Date (up) 2023-12-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2639-4979 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access Not_Open_Access
Notes This work was supported by the European Research Council (Grant 815128 REALNANO to S.B., Grant 770887 PICOMETRICS to S.V.A.). J.P.-J. and S.M. acknowledge financial support from the MCIN/AEI/10.13039/501100011033 (Grants No. PID2019-108954RB-I00) and EU Horizon 2020 research and innovation program under grant agreement no. 883390 (SERSing). J.V., S.B., S.V.A., and L.G. acknowledge funding from the Flemish government (iBOF-21-085 PERsist). Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:202771 Serial 9053
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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.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001138183000001 Publication Date (up) 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 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.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date (up) 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
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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.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001168639900001 Publication Date (up) 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 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 (up) 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 Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:204856 Serial 9172
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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 (up) 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 Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:204754 Serial 9174
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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 (up) 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 Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:205442 Serial 9171
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