Records |
Author |
Gorbanev, Y.; Engelmann, Y.; van’t Veer, K.; Vlasov, E.; Ndayirinde, C.; Yi, Y.; Bals, S.; Bogaerts, A. |
Title |
Al2O3-Supported Transition Metals for Plasma-Catalytic NH3 Synthesis in a DBD Plasma: Metal Activity and Insights into Mechanisms |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Catalysts |
Abbreviated Journal |
Catalysts |
Volume |
11 |
Issue |
10 |
Pages |
1230 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Movement Antwerp (MOVANT) |
Abstract |
N2 fixation into NH3 is one of the main processes in the chemical industry. Plasma catalysis is among the environmentally friendly alternatives to the industrial energy-intensive Haber-Bosch process. However, many questions remain open, such as the applicability of the conventional catalytic knowledge to plasma. In this work, we studied the performance of Al2O3-supported Fe, Ru, Co and Cu catalysts in plasma-catalytic NH3 synthesis in a DBD reactor. We investigated the effects of different active metals, and different ratios of the feed gas components, on the concentration and production rate of NH3, and the energy consumption of the plasma system. The results show that the trend of the metal activity (common for thermal catalysis) does not appear in the case of plasma catalysis: here, all metals exhibited similar performance. These findings are in good agreement with our recently published microkinetic model. This highlights the virtual independence of NH3 production on the metal catalyst material, thus validating the model and indicating the potential contribution of radical adsorption and Eley-Rideal reactions to the plasma-catalytic mechanism of NH3 synthesis. |
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Corporate Author |
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Thesis ![sorted by Thesis field, ascending order (up)](img/sort_asc.gif) |
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Place of Publication |
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Language |
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Wos |
000715656300001 |
Publication Date |
2021-10-13 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2073-4344 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.082 |
Times cited |
19 |
Open Access |
OpenAccess |
Notes |
Catalisti, Moonshot P2C ; Research Foundation – Flanders, GoF9618n ; European Research Council, 810182 SCOPE 815128 REALNANO ; sygmaSB |
Approved |
Most recent IF: 3.082 |
Call Number |
EMAT @ emat @c:irua:183279 |
Serial |
6815 |
Permanent link to this record |
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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 |
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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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Corporate Author |
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Thesis ![sorted by Thesis field, ascending order (up)](img/sort_asc.gif) |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001042486000001 |
Publication Date |
2023-03-10 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2468-0672 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
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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 |
Permanent link to this record |
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Author |
Vlasov, E.; Skorikov, A.; Sánchez-Iglesias, A.; Liz-Marzán, L.M.; Verbeeck, J.; Bals, S. |
Title |
Secondary electron induced current in scanning transmission electron microscopy: an alternative way to visualize the morphology of nanoparticles |
Type |
A1 Journal article |
Year |
2023 |
Publication |
ACS materials letters |
Abbreviated Journal |
ACS Materials Lett. |
Volume |
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Issue |
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Pages |
1916-1921 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Electron tomography (ET) is a powerful tool to determine the three-dimensional (3D) structure of nanomaterials in a transmission electron microscope. However, the acquisition of a conventional tilt series for ET is a time-consuming process and can therefore not provide 3D structural information in a time-efficient manner. Here, we propose surface-sensitive secondary electron (SE) imaging as an alternative to ET for the investigation of the morphology of nanomaterials. We use the SE electron beam induced current (SEEBIC) technique that maps the electrical current arising from holes generated by the emission of SEs from the sample. SEEBIC imaging can provide valuable information on the sample morphology with high spatial resolution and significantly shorter throughput times compared with ET. In addition, we discuss the contrast formation mechanisms that aid in the interpretation of SEEBIC data. |
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Corporate Author |
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Thesis ![sorted by Thesis field, ascending order (up)](img/sort_asc.gif) |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001006191600001 |
Publication Date |
2023-06-12 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2639-4979 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
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Times cited |
1 |
Open Access |
OpenAccess |
Notes |
The funding for this project was provided by European Research Council (ERC Consolidator Grant 815128, REALNANO). J.V. acknowledges the eBEAM project, which is supported by the European Union’s Horizon 2020 research and innovation program under grant agreement no. 101017720 (FET-Proactive EBEAM). L.M.L.-M. acknowledges funding from MCIN/AEI/10.13039/501100011033 (grant # PID2020-117779RB-I00). |
Approved |
Most recent IF: NA |
Call Number |
EMAT @ emat @c:irua:197004 |
Serial |
8795 |
Permanent link to this record |
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Author |
Ndayirinde, C.; Gorbanev, Y.; Ciocarlan, R.-G.; De Meyer, R.; Smets, A.; Vlasov, E.; Bals, S.; Cool, P.; Bogaerts, A. |
Title |
Plasma-catalytic ammonia synthesis : packed catalysts act as plasma modifiers |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Catalysis today |
Abbreviated Journal |
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Volume |
419 |
Issue |
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Pages |
114156-12 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
We studied the plasma-catalytic production of NH3 from H2 and N2 in a dielectric barrier discharge plasma reactor using five different Co-based catalysts supported on Al2O3, namely Co/Al2O3, CoCe/Al2O3, CoLa/Al2O3, CoCeLa/Al2O3 and CoCeMg/Al2O3. The catalysts were characterized via several techniques, including SEM-EDX, and their performance was compared. The best performing catalyst was found to be CoLa/Al2O3, but the dif-ferences in NH3 concentration, energy consumption and production rate between the different catalysts were limited under the same conditions (i.e. feed gas, flow rate and ratio, and applied power). At the same time, the plasma properties, such as the plasma power and current profile, varied significantly depending on the catalyst. Taken together, these findings suggest that in the production of NH3 by plasma catalysis, our catalysts act as plasma modifiers, i.e., they change the discharge properties and hence the gas phase plasma chemistry. Importantly, this effect dominates over the direct catalytic effect (as e.g. in thermal catalysis) defined by the chemistry on the catalyst surface. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, ascending order (up)](img/sort_asc.gif) |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000987221300001 |
Publication Date |
2023-04-10 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0920-5861 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.3 |
Times cited |
3 |
Open Access |
OpenAccess |
Notes |
This research was supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 810182 – SCOPE ERC Synergy project) and the Methusalem project of the University of Antwerp. We also gratefully acknowledge the NH3-TPD analysis performed by Sander Bossier. |
Approved |
Most recent IF: 5.3; 2023 IF: 4.636 |
Call Number |
UA @ admin @ c:irua:197268 |
Serial |
8917 |
Permanent link to this record |
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Author |
Ignatova, K.; Vlasov, E.; Seddon, S.D.; Gauquelin, N.; Verbeeck, J.; Wermeille, D.; Bals, S.; Hase, T.P.A.; Arnalds, U.B. |
Title |
Phase coexistence induced surface roughness in V2O3/Ni magnetic heterostructures |
Type |
A1 Journal Article |
Year |
2024 |
Publication |
APL Materials |
Abbreviated Journal |
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Volume |
12 |
Issue |
4 |
Pages |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
Abstract |
We present an investigation of the microstructure changes in V2O3 as it goes through its inherent structural phase transition. Using V2O3 films with a well-defined crystal structure deposited by reactive magnetron sputtering on r-plane Al2O3 substrates, we study the phase coexistence region and its impact on the surface roughness of the films and the magnetic properties of overlying Ni magnetic layers in V2O3/Ni hybrid magnetic heterostructures. The simultaneous presence of two phases in V2O3 during its structural phase transition was identified with high resolution x-ray diffraction and led to an increase in surface roughness observed using x-ray reflectivity. The roughness reaches its maximum at the midpoint of the transition. In V2O3/Ni hybrid heterostructures, we find a concomitant increase in the coercivity of the magnetic layer correlated with the increased roughness of the V2O3 surface. The chemical homogeneity of the V2O3 is confirmed through transmission electron microscopy analysis. High-angle annular dark field imaging and electron energy loss spectroscopy reveal an atomically flat interface between Al2O3 and V2O3, as well as a sharp interface between V2O3 and Ni. |
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Corporate Author |
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Thesis ![sorted by Thesis field, ascending order (up)](img/sort_asc.gif) |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001202661800003 |
Publication Date |
2024-04-01 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2166-532X |
ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
6.1 |
Times cited |
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Open Access |
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Notes |
This work was supported by the funding from the University of Iceland Research Fund, the Icelandic Research Fund Grant No. 207111. Instrumentation funding from the Icelandic Infrastructure Fund is acknowledged. This work was based on experiments per- formed at the BM28 (XMaS) beamline at the European Synchrotron Radiation Facility, Grenoble, France. XMaS is a National Research Facility funded by the UK EPSRC and managed by the Universi- ties of Liverpool and Warwick. This project has received funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 823717—ESTEEM3. |
Approved |
Most recent IF: 6.1; 2024 IF: 4.335 |
Call Number |
EMAT @ emat @c:irua:205569 |
Serial |
9120 |
Permanent link to this record |
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Author |
Vlasov, E.; Heyvaert, W.; Ni, B.; Van Gordon, K.; Girod, R.; Verbeeck, J.; Liz-Marzán, L.M.; Bals, S. |
Title |
High-Throughput Morphological Chirality Quantification of Twisted and Wrinkled Gold Nanorods |
Type |
A1 Journal Article |
Year |
2024 |
Publication |
ACS Nano |
Abbreviated Journal |
ACS Nano |
Volume |
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Issue |
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Pages |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
Abstract |
Chirality in gold nanostructures offers an exciting opportunity to tune their differential optical response to left- and right-handed circularly polarized light, as well as their interactions with biomolecules and living matter. However, tuning and understanding such interactions demands quantification of the structural features that are responsible for the chiral behavior. Electron tomography (ET) enables structural characterization at the single-particle level and has been used to quantify the helicity of complex chiral nanorods. However, the technique is time-consuming and consequently lacks statistical value. To address this issue, we introduce herein a high-throughput methodology that combines images acquired by secondary electron-based electron beam-induced current (SEEBIC) with quantitative image analysis. As a result, the geometric chirality of hundreds of nanoparticles can be quantified in less than 1 h. When combining the drastic gain in data collection efficiency of SEEBIC with a limited number of ET data sets, a better understanding of how the chiral structure of individual chiral nanoparticles translates into the ensemble chiroptical response can be reached. |
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Corporate Author |
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Thesis ![sorted by Thesis field, ascending order (up)](img/sort_asc.gif) |
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Publisher |
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Place of Publication |
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Language |
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Wos |
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Publication Date |
2024-04-26 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1936-0851 |
ISBN |
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Additional Links |
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Impact Factor |
17.1 |
Times cited |
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Open Access |
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Notes |
The authors acknowledge financial support by the European Research Council (ERC CoG No. 815128 REALNANO to S.B.) and from MCIN/AEI/10.13039/501100011033 (Grant PID2020-117779RB-I00 to L.M.L.-M and FPI Fellowship PRE2021-097588 to K.V.G.). Funded by the European Union under Project 101131111 − DELIGHT, JV acknowledges the eBEAM project supported by the European Union’s Horizon 2020 research and innovation program FETPROACT-EIC-07- 2020: emerging paradigms and communities. |
Approved |
Most recent IF: 17.1; 2024 IF: 13.942 |
Call Number |
EMAT @ emat @ |
Serial |
9121 |
Permanent link to this record |
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Author |
Vlasov, E. |
Title |
Exploiting secondary electrons in transmission electron microscopy for 3D characterization of nanoparticle morphologies |
Type |
Doctoral thesis |
Year |
2024 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
x, 118 p. |
Keywords |
Doctoral thesis; Electron microscopy for materials research (EMAT) |
Abstract |
Electron tomography (ET) is an indispensable tool for determining the three-dimensional (3D) structure of nanomaterials in (scanning) transmission electron microscopy ((S)TEM). ET enables 3D characterization of a variety of nanomaterials across different fields, including life sciences, chemistry, solid-state physics, and materials science down to atomic resolution. However, the acquisition of a conventional tilt series for ET is a time-consuming process and thus cannot capture fast transformations of materials in realistic conditions. Moreover, only a limited number of nanoparticles (NPs) can be investigated, hampering a general understanding of the average properties of the material. Therefore, alternative characterization techniques that allow for high-resolution characterization of the surface structure without the need to acquire a full tilt series in ET are required which would enable a more time-efficient investigation with better statistical value. In the first part of this work, an alternative technique for the characterization of the morphology of NPs to improve the throughput and temporal resolution of ET is presented. The proposed technique exploits surface-sensitive secondary electron (SE) imaging in STEM employed using a modification of electron beam-induced current (EBIC) setup. The time- and dose efficiency of SEEBIC are tested in comparison with ET and superior spatial resolution is shown compared to conventional scanning electron microscopy. Finally, contrast artefacts arising in SEEBIC images are described, and their origin is discussed. The second part of my thesis focuses on real applications of the proposed technique and introduces a high-throughput methodology that combines images acquired by SEEBIC with quantitative image analysis to retrieve information about the helicity of gold nanorods. It shows that SEEBIC imaging overcomes the limitation of ET providing a general understanding of the connection between structure and chiroptical properties. |
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Wos |
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Publication Date |
2024-06-17 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
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ISBN |
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Additional Links |
UA library record |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:204905 |
Serial |
9149 |
Permanent link to this record |