Records |
Author |
Wu, X.; Ding, J.; Cui, W.; Lin, W.; Xue, Z.; Yang, Z.; Liu, J.; Nie, X.; Zhu, W.; Van Tendeloo, G.; Sang, X. |
Title |
Enhanced electrical properties of Bi2-xSbxTe3 nanoflake thin films through interface engineering |
Type |
A1 Journal article |
Year |
2024 |
Publication |
Energy & environment materials |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
e12755-8 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The structure-property relationship at interfaces is difficult to probe for thermoelectric materials with a complex interfacial microstructure. Designing thermoelectric materials with a simple, structurally-uniform interface provides a facile way to understand how these interfaces influence the transport properties. Here, we synthesized Bi2-xSbxTe3 (x = 0, 0.1, 0.2, 0.4) nanoflakes using a hydrothermal method, and prepared Bi2-xSbxTe3 thin films with predominantly (0001) interfaces by stacking the nanoflakes through spin coating. The influence of the annealing temperature and Sb content on the (0001) interface structure was systematically investigated at atomic scale using aberration-corrected scanning transmission electron microscopy. Annealing and Sb doping facilitate atom diffusion and migration between adjacent nanoflakes along the (0001) interface. As such it enhances interfacial connectivity and improves the electrical transport properties. Interfac reactions create new interfaces that increase the scattering and the Seebeck coefficient. Due to the simultaneous optimization of electrical conductivity and Seebeck coefficient, the maximum power factor of the Bi1.8Sb0.2Te3 nanoflake films reaches 1.72 mW m(-1) K-2, which is 43% higher than that of a pure Bi2Te3 thin film. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
001204495900001 |
Publication Date |
2024-04-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
|
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:205438 |
Serial |
9148 |
Permanent link to this record |
|
|
|
Author |
Vlasov, E. |
Title |
Exploiting secondary electrons in transmission electron microscopy for 3D characterization of nanoparticle morphologies |
Type |
Doctoral thesis |
Year |
2024 |
Publication |
|
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
x, 118 p. |
Keywords |
Doctoral thesis; Electron microscopy for materials research (EMAT) |
Abstract |
Electron tomography (ET) is an indispensable tool for determining the three-dimensional (3D) structure of nanomaterials in (scanning) transmission electron microscopy ((S)TEM). ET enables 3D characterization of a variety of nanomaterials across different fields, including life sciences, chemistry, solid-state physics, and materials science down to atomic resolution. However, the acquisition of a conventional tilt series for ET is a time-consuming process and thus cannot capture fast transformations of materials in realistic conditions. Moreover, only a limited number of nanoparticles (NPs) can be investigated, hampering a general understanding of the average properties of the material. Therefore, alternative characterization techniques that allow for high-resolution characterization of the surface structure without the need to acquire a full tilt series in ET are required which would enable a more time-efficient investigation with better statistical value. In the first part of this work, an alternative technique for the characterization of the morphology of NPs to improve the throughput and temporal resolution of ET is presented. The proposed technique exploits surface-sensitive secondary electron (SE) imaging in STEM employed using a modification of electron beam-induced current (EBIC) setup. The time- and dose efficiency of SEEBIC are tested in comparison with ET and superior spatial resolution is shown compared to conventional scanning electron microscopy. Finally, contrast artefacts arising in SEEBIC images are described, and their origin is discussed. The second part of my thesis focuses on real applications of the proposed technique and introduces a high-throughput methodology that combines images acquired by SEEBIC with quantitative image analysis to retrieve information about the helicity of gold nanorods. It shows that SEEBIC imaging overcomes the limitation of ET providing a general understanding of the connection between structure and chiroptical properties. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
|
Publication Date |
2024-06-17 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
|
ISBN |
|
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:204905 |
Serial |
9149 |
Permanent link to this record |
|
|
|
Author |
Xu, H.; Li, H.; Gauquelin, N.; Chen, X.; Wu, W.-F.; Zhao, Y.; Si, L.; Tian, D.; Li, L.; Gan, Y.; Qi, S.; Li, M.; Hu, F.; Sun, J.; Jannis, D.; Yu, P.; Chen, G.; Zhong, Z.; Radovic, M.; Verbeeck, J.; Chen, Y.; Shen, B. |
Title |
Giant tunability of Rashba splitting at cation-exchanged polar oxide interfaces by selective orbital hybridization |
Type |
A1 Journal article |
Year |
2024 |
Publication |
Advanced materials |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The 2D electron gas (2DEG) at oxide interfaces exhibits extraordinary properties, such as 2D superconductivity and ferromagnetism, coupled to strongly correlated electrons in narrow d-bands. In particular, 2DEGs in KTaO3 (KTO) with 5d t2g orbitals exhibit larger atomic spin-orbit coupling and crystal-facet-dependent superconductivity absent for 3d 2DEGs in SrTiO3 (STO). Herein, by tracing the interfacial chemistry, weak anti-localization magneto-transport behavior, and electronic structures of (001), (110), and (111) KTO 2DEGs, unambiguously cation exchange across KTO interfaces is discovered. Therefore, the origin of the 2DEGs at KTO-based interfaces is dramatically different from the electronic reconstruction observed at STO interfaces. More importantly, as the interface polarization grows with the higher order planes in the KTO case, the Rashba spin splitting becomes maximal for the superconducting (111) interfaces approximately twice that of the (001) interface. The larger Rashba spin splitting couples strongly to the asymmetric chiral texture of the orbital angular moment, and results mainly from the enhanced inter-orbital hopping of the t2g bands and more localized wave functions. This finding has profound implications for the search for topological superconductors, as well as the realization of efficient spin-charge interconversion for low-power spin-orbitronics based on (110) and (111) KTO interfaces. An unambiguous cation exchange is discovered across the interfaces of (001), (110), and (111) KTaO3 2D electron gases fabricated at room temperature. Remarkably, the (111) interfaces with the highest superconducting transition temperature also turn out to show the strongest electron-phonon interaction and the largest Rashba spin splitting. image |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
001219658400001 |
Publication Date |
2024-03-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
0935-9648 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
29.4 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 29.4; 2024 IF: 19.791 |
Call Number |
UA @ admin @ c:irua:206037 |
Serial |
9152 |
Permanent link to this record |
|
|
|
Author |
Bampouli, A.; Goris, Q.; Hussain, M.N.; Louisnard, O.; Stefanidis, G.D.; Van Gerven, T. |
Title |
Importance of design and operating parameters in a sonication system for viscous solutions : effects of input power, horn tip diameter and reactor capacity |
Type |
A1 Journal article |
Year |
2024 |
Publication |
Chemical engineering and processing |
Abbreviated Journal |
|
Volume |
198 |
Issue |
|
Pages |
109715-12 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
This study investigates the distribution of ultrasound (US) energy in a batch system for solutions with viscosity ranging from 1 to approximately 3000 mPas. Sonication was performed using horn type configurations operating at 20-30 kHz and rated power capacity of 50 or 200 W. Two different tip diameters (3 or 7 mm) and two insertion depths (35 or 25 mm) within vessels of different sizes ( approximate to 60 or 130 ml) were utilized. Additionally, a special conical tip design was employed. For each experimental setup, the calorimetric efficiency was estimated, the cavitationally active regions were visualized using the sonochemiluminescence (SCL) method and bubble cluster formation inside the vessel was macroscopically observed using a high speed camera (HSC). In the viscosity range tested, the calorimetry results showed that the efficiency and continuous operation of the device depend on both the rated power and the horn tip diameter. The ratio between electrical and calorimetric power input remained consistently around 40 to 50% across the different configurations for water, but for the 123.2 mPas solution exhibited significant variation ranging from 40 to 85%. Moreover, the power density in the smaller reactor was found to be nearly double compared to the larger one. The SCL analysis showed multiple cavitationally active zones in all setups, and the zones intensity decreased considerably with increase of the solutions viscosity. The results for the cone tip were not conclusive, but can be used as the basis for further investigation. The current research highlights the importance of thoroughly understanding the impact of each design parameter, and of establishing characterization methodologies to assist in the future development of scaled-up, commercial applications. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
001218630800001 |
Publication Date |
2024-02-21 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
0255-2701 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
4.3 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.3; 2024 IF: 2.234 |
Call Number |
UA @ admin @ c:irua:206003 |
Serial |
9154 |
Permanent link to this record |
|
|
|
Author |
Wang, G.; Xie, C.; Wang, H.; Li, Q.; Xia, F.; Zeng, W.; Peng, H.; Van Tendeloo, G.; Tan, G.; Tian, J.; Wu, J. |
Title |
Mitigated oxygen loss in lithium-rich manganese-based cathode enabled by strong Zr-O affinity |
Type |
A1 Journal article |
Year |
2024 |
Publication |
Advanced functional materials |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
2313672 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Oxygen loss is a serious problem of lithium-rich layered oxide (LLO) cathodes, as the high capacity of LLO relies on reversible oxygen redox. Oxygen release can occur at the surface leading to the formation of spinel or rock salt structures. Also, the lattice oxygen will usually become unstable after long cycling, which remains a major roadblock in the application of LLO. Here, it is shown that Zr doping is an effective strategy to retain lattice oxygen in LLO due to the high affinity between Zr and O. A simple sol-gel method is used to dope Zr4+ into the LLOs to adjust the local electronic structure and inhibit the diffusion of oxygen anions to the surface during cycling. Compared with untreated LLOs, LLO-Zr cathodes exhibit a higher cycling stability, with 94% capacity retention after 100 cycles at 0.4 C, up to 223 mAh g-1 at 1 C, and 88% capacity retention after 300 cycles. Theoretical calculations show that due to the strong Zr-O covalent bonding, the formation energy of oxygen vacancies has effectively increased and the loss of lattice oxygen under high voltage can be suppressed. This study provides a simple method for developing high-capacity and cyclability Li-rich cathode materials for lithium-ion batteries. Oxygen release can occur at the cathode surface leading to the formation of spinel or rock salt structures. Here, it is shown that Zr doping is an effective strategy to retain lattice oxygen in lithium-rich layered oxides (LLO) due to the high affinity between Zr and O. LLO-Zr exhibit higher cycling stability, with 88% capacity retention after 300 cycles at 1 C. image |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
001159843800001 |
Publication Date |
2024-02-10 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
1616-301x |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
19 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 19; 2024 IF: 12.124 |
Call Number |
UA @ admin @ c:irua:203812 |
Serial |
9161 |
Permanent link to this record |
|
|
|
Author |
Coulombier, M.; Baral, P.; Orekhov, A.; Dohmen, R.; Raskin, J.P.; Pardoen, T.; Cordier, P.; Idrissi, H. |
Title |
On-chip very low strain rate rheology of amorphous olivine films |
Type |
A1 Journal article |
Year |
2024 |
Publication |
Acta materialia |
Abbreviated Journal |
|
Volume |
266 |
Issue |
|
Pages |
119693-12 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Recent observations made by the authors revealed the activation of stress induced amorphization and sliding at grain boundary in olivine [1], a mechanism which is expected to play a pivotal role in the viscosity drop at the lithosphere-asthenosphere boundary and the brittle -ductile transition in the lithospheric mantle. However, there is a lack of information in the literature regarding the intrinsic mechanical properties and the elementary deformation mechanisms of this material, especially at time scales relevant for geodynamics. In the present work, amorphous olivine films were obtained by pulsed laser deposition (PLD). The mechanical response including the rate dependent behavior are investigated using a tension -on -chip (TOC) method developed at UCLouvain allowing to perform creep/relaxation tests on thin films at extremely low strain rates. In the present work, strain rate down to 10-12 s- 1 was reached which is unique. High strain rate sensitivity of 0.054 is observed together with the activation of relaxation at the very early stage of deformation. Furthermore, digital image correlation (DIC), used for the first time on films deformed by TOC, reveals local strain heterogeneities. The relationship between such heterogeneities, the high strain rate sensitivity and the effect of the electron beam in the scanning electron microscope is discussed and compared to the literature. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
001170513400001 |
Publication Date |
2024-01-17 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
9.4 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 9.4; 2024 IF: 5.301 |
Call Number |
UA @ admin @ c:irua:204864 |
Serial |
9163 |
Permanent link to this record |
|
|
|
Author |
Joy, R.M.; Pobedinskas, P.; Bourgeois, E.; Chakraborty, T.; Goerlitz, J.; Herrmann, D.; Noel, C.; Heupel, J.; Jannis, D.; Gauquelin, N.; D'Haen, J.; Verbeeck, J.; Popov, C.; Houssiau, L.; Becher, C.; Nesladek, M.; Haenen, K. |
Title |
Photoluminescence of germanium-vacancy centers in nanocrystalline diamond films : implications for quantum sensing applications |
Type |
A1 Journal article |
Year |
2024 |
Publication |
ACS applied nano materials |
Abbreviated Journal |
|
Volume |
7 |
Issue |
4 |
Pages |
3873-3884 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Point defects in diamond, promising candidates for nanoscale pressure- and temperature-sensing applications, are potentially scalable in polycrystalline diamond fabricated using the microwave plasma-enhanced chemical vapor deposition (MW PE CVD) technique. However, this approach introduces residual stress in the diamond films, leading to variations in the characteristic zero phonon line (ZPL) of the point defect in diamond. Here, we report the effect of residual stress on germanium-vacancy (GeV) centers in MW PE CVD nanocrystalline diamond (NCD) films fabricated using single crystal Ge as the substrate and solid dopant source. GeV ensemble formation indicated by the zero phonon line (ZPL) at similar to 602 nm is confirmed by room temperature (RT) photoluminescence (PL) measurements. PL mapping results show spatial nonuniformity in GeV formation along with other defects, including silicon-vacancy centers in the diamond films. The residual stress in NCD results in shifts in the PL peak positions. By estimating a stress shift coefficient of (2.9 +/- 0.9) nm/GPa, the GeV PL peak position in the NCD film is determined to be between 598.7 and 603.2 nm. A larger ground state splitting due to the strain on a GeV-incorporated NCD pillar at a low temperature (10 K) is also reported. We also report the observation of intense ZPLs at RT that in some cases could be related to low Ge concentration and the surrounding crystalline environment. In addition, we also observe thicker microcrystalline diamond (MCD) films delaminate from the Ge substrate due to film residual stress and graphitic phase at the diamond/Ge substrate interface (confirmed by electron energy loss spectroscopy). Using this approach, a free-standing color center incorporated MCD film with dimensions up to 1 x 1 cm(2) is fabricated. Qualitative analysis using time-of-flight secondary ion mass spectroscopy reveals the presence of impurities, including Ge and silicon, in the MCD film. Our experimental results will provide insights into the scalability of GeV fabrication using the MW PE CVD technique and effectively implement NCD-based nanoscale-sensing applications. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
001164609600001 |
Publication Date |
2024-02-15 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
2574-0970 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
5.9 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 5.9; 2024 IF: NA |
Call Number |
UA @ admin @ c:irua:204826 |
Serial |
9164 |
Permanent link to this record |
|
|
|
Author |
Lu, Q. |
Title |
Precipitation behavior and heat resistance properties of Al-Cu-Mg-Ag-(Si) alloy |
Type |
Doctoral thesis |
Year |
2024 |
Publication |
|
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
VIII, 212 p. |
Keywords |
Doctoral thesis; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
With the rapid increase in the speed of new-generation aerospace vehicles, conventional heat-resistant aluminum alloys cannot meet the long-term service of the equipment. Therefore, the development of new high-strength heat-resistant aluminum alloys is of great strategic for the sustainable and high-quality development of industries. Al-Cu-Mg-Ag alloy is an age-hardenable heat-resistant aluminum alloy and has high strength and heat resistance. The addition of alloying elements such as Si and Sc to Al-Cu-Mg-Ag alloy introduces a competitive relationship among the σ-Al5Cu6Mg2, θ′-Al2Cu, and Ω phases. Therefore, a systematic investigation of precipitation behavior and heat resistance of Al-Cu-Mg-Ag-(Si) is essential for guiding the design of high-strength heat-resistant aluminum alloys. Combined characterization testing methods such as scanning electron microscopy, transmission electron microscopy, atom probe tomography, microhardness testing, and tensile testing with simulation calculation methods such as calculation of phase diagram, first-principles calculations, and Ab initio molecular dynamics, the effects of heat treatment processes and element content on the precipitation behavior, mechanical properties, and heat resistance of Al-Cu-Mg-Ag-(Si) alloys were systematically investigated. Furthermore, a multiple interface segregation structure was constructed at the θ′/Al interface, and a new Al-Cu-Mg-Ag-Si-Sc alloy with synergistically improved strength and heat resistance was developed. The main conclusions are as follows: (1) Based on the Kampmann-Wagner-Numerical theory, the relationship between the coarsening rate of the Ω phase and the aging process was analyzed, revealing for the first time that the critical size of Ω phase ( ) under thermal exposure temperature was the key factor determining the coarsening rate of Ω phase during long time thermal exposure heat treatment. After artificial ageing, when the size of Ω phase was smaller than the critical size , the dissolution of smaller Ω phase leaded to a rapid decrease in the number density of Ω phases, thereby reducing the heat resistance of the alloy. When the size of Ω phase was greater than or equal to the critical size , the coarsening rate of Ω phase was consistent, but a larger initial size would result in a larger final size after long-term thermal exposure. Therefore, the closer the size of Ω phase in the alloy is to the critical size under heat exposure temperature, the better the heat resistance of the alloy. (2) A concept of constructing a multiple interface segregation structure at the precipitate/matrix interface was proposed, and based on this concept, a multiple interface segregation structure containing the C/L-AlMgSiCu interfacial phase, newly discovered χ-AgMg interfacial phase, and Sc segregation layer was successfully constructed at the θ′/Al interface. The existence of the multiple interface segregation structure ensured that the designed Al-Cu-Mg-Ag-Si-Sc alloy maintains a yield strength of 400 MPa after thermal exposure at 200 C for 100 h, with a strength retention rate of 97%, creating a new record for the synergistic improvement of strength and heat resistance in aluminum alloys. In addition, combining transmission electron microscopy ex-situ/in-situ characterization with first-principles calculations, it is shown that the χ-AgMg interface phase will be destroyed due to the diffusion of the outer Ag layer during thermal exposure, and gradually dissolve into the matrix, but it can still delay the coarsening behavior of θ′-Al2Cu phase. (3) The criteria for determining whether Ω phase can precipitate are updated in Al-Cu-Mg-Ag-Si alloys with low Mg/Si ratio based on phase diagram thermodynamic calculations and multi-scale structural characterization. When W(Mg)/W(Si) > 1.4 and X(Ag)/X(Mgexcess) > 1, Ω phase can precipitate in Al-Cu-Mg-Ag-Si alloys, where X(Mgexcess) represents the atomic percentage of residual Mg elements after the formation of the AlMgSiCu quaternary precipitate phase C/L phase in the supersaturated solid solution, and the W(Mg) is the mass fraction of Mg in the supersaturated solid solution before artificial ageing. (4) The effects of alloy element content on precipitation behavior and heat resistance of Al-Cu-Mg-Ag-Si alloys were systematically analyzed. Critical conditions for the precipitation of σ-Al5Cu6Mg2 and Ω phase in Al-Cu-Mg-Ag-Si alloys are revealed. Based on calculation of phase diagram results, the conditions for precipitating σ-Al5Cu6Mg2 phase in the alloy are: ① W(Mg)/W(Si) > 1.8; ② W(Cu) > 2.7W(Mg) – 5W(Si). When W(Mg)/W(Si) < 1.8, the alloy is mainly precipitated with C/L/Q′-AlMgSiCu. When W(Cu) < 2.7W(Mg) – 5W(Si), the alloy will generate GPB zone. In addition, W(Ag)/W(Si) > 4 is the critical condition which the Ω phase can the main precipitates in Al-Cu-Mg-Ag-Si alloys. Furthermore, the correlation between precipitate types and heat resistance was summarized, showing that Al-Cu-Mg-Ag-(Si) alloys with Ω phase as the main strengthening phase are more suitable for the preparation of structures with short service time but high temperature, while Al-Cu-Mg-Ag-(Si) alloys with low Mg content and multiple segregation structures are more suitable for structures requiring long-term service at medium to high temperatures. This study, for the first time, combines calculation of phase diagram with multi-scale microstructure characterization, systematically unraveling the effects of element content on precipitation behavior, strength, and heat resistance of Al-Cu-Mg-Ag-(Si) alloys. In addition, a concept of constructing a multiple interface segregation structure at the precipitate/matrix interface was proposed to synergistically improve alloy strength and heat resistance. This work provides theoretical guidance for optimizing the composition and processing of Al-Cu-Mg-Ag-(Si) alloy and regulating the microstructure. Furthermore, it also offers new ideas and theoretical guidance for the development of novel high-strength heat-resistant alloys in other systems. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
|
Publication Date |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
|
ISBN |
|
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:206180 |
Serial |
9167 |
Permanent link to this record |
|
|
|
Author |
Poppe, R.; Roth, N.; Neder, R.B.; Palatinus, L.; Iversen, B.B.; Hadermann, J. |
Title |
Refining short-range order parameters from the three-dimensional diffuse scattering in single-crystal electron diffraction data |
Type |
A1 Journal article |
Year |
2024 |
Publication |
IUCrJ |
Abbreviated Journal |
|
Volume |
11 |
Issue |
1 |
Pages |
82-91 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Our study compares short-range order parameters refined from the diffuse scattering in single-crystal X-ray and single-crystal electron diffraction data. Nb0.84CoSb was chosen as a reference material. The correlations between neighbouring vacancies and the displacements of Sb and Co atoms were refined from the diffuse scattering using a Monte Carlo refinement in DISCUS. The difference between the Sb and Co displacements refined from the diffuse scattering and the Sb and Co displacements refined from the Bragg reflections in single-crystal X-ray diffraction data is 0.012 (7) angstrom for the refinement on diffuse scattering in single-crystal X-ray diffraction data and 0.03 (2) angstrom for the refinement on the diffuse scattering in single-crystal electron diffraction data. As electron diffraction requires much smaller crystals than X-ray diffraction, this opens up the possibility of refining short-range order parameters in many technologically relevant materials for which no crystals large enough for single-crystal X-ray diffraction are available. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
001168018300012 |
Publication Date |
2023-12-14 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
2052-2525 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
3.9 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.9; 2024 IF: 5.793 |
Call Number |
UA @ admin @ c:irua:205513 |
Serial |
9170 |
Permanent link to this record |
|
|
|
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 |
2024-04-24 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
2198-3844 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
15.1 |
Times cited |
|
Open Access |
|
Notes |
This work was supported by the funding received by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement no. 818776- DYNAPOL, no. 770887 PICOMETRICS and no. 815128 REALNANO). The authors also acknowledge the computational resources provided by the Swiss National Supercomputing Center (CSCS), by CINECA, and the Research Foundation Flanders (FWO, Belgium) G.0346.21N. |
Approved |
Most recent IF: 15.1; 2024 IF: 9.034 |
Call Number |
UA @ admin @ c:irua:205442 |
Serial |
9171 |
Permanent link to this record |
|
|
|
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 |
2024-02-28 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
1614-6832; 1614-6840 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
27.8 |
Times cited |
|
Open Access |
|
Notes |
N.A. acknowledges a postdoctoral fellowship from the Research Foundation- Flanders (FWO) via grant 12ZS623N. S.D.F. acknowledges support from FWO (G0A4120N, G0H2122N, G0A5U24N), KU Leuven Internal Funds (grants C14/18/06, C14/19/079, C14/23/090), European Union under the Horizon Europe grant 101046231 (FantastiCOF), and M-ERA.NET via FWO (G0K9822N). S.D.F., K.M., Y.H., R.L., and S.V.A. were thankful to the FWO and FNRS for the financial support through the EOS program (grant 30489208, 40007495). Research in Mons was also supported by the Belgian National Fund for Scientific Research (FRS-FNRS) within the Consortium des Équipements de Calcul Intensif- CÉCI, and by the Walloon Region (ZENOBE and LUCIA Tier-1 supercomputers). E.J. appreciated the support from the Alexander von Humboldt Foundation, the Max Planck Society, the FLAG-ERA Grant OPERA by DFG 437130745, the National Natural Science Foundation of China (22288101), and the 111 Project (B17020). Partial financial support to M.R. from the Institut Universitaire de France (IUF) was warmly thanked. |
Approved |
Most recent IF: 27.8; 2024 IF: 16.721 |
Call Number |
UA @ admin @ c:irua:204856 |
Serial |
9172 |
Permanent link to this record |
|
|
|
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 |
2024-02-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
1944-8244 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
9.5 |
Times cited |
|
Open Access |
|
Notes |
We would like to acknowledge the Netherlands Organization for Scientific Research (NWO) for the financial support of this work. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 823717-ESTEEM3. |
Approved |
Most recent IF: 9.5; 2024 IF: 7.504 |
Call Number |
UA @ admin @ c:irua:204754 |
Serial |
9174 |
Permanent link to this record |
|
|
|
Author |
Brognara, A.; Kashiwar, A.; Jung, C.; Zhang, X.; Ahmadian, A.; Gauquelin, N.; Verbeeck, J.; Djemia, P.; Faurie, D.; Dehm, G.; Idrissi, H.; Best, J.P.; Ghidelli, M. |
Title |
Tailoring mechanical properties and shear band propagation in ZrCu metallic glass nanolaminates through chemical heterogeneities and interface density |
Type |
A1 Journal article |
Year |
2024 |
Publication |
Small Structures |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
2400011-11 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The design of high‐performance structural thin films consistently seeks to achieve a delicate equilibrium by balancing outstanding mechanical properties like yield strength, ductility, and substrate adhesion, which are often mutually exclusive. Metallic glasses (MGs) with their amorphous structure have superior strength, but usually poor ductility with catastrophic failure induced by shear bands (SBs) formation. Herein, we introduce an innovative approach by synthesizing MGs characterized by large and tunable mechanical properties, pioneering a nanoengineering design based on the control of nanoscale chemical/structural heterogeneities. This is realized through a simplified model Zr 24 Cu 76 /Zr 61 Cu 39 , fully amorphous nanocomposite with controlled nanoscale periodicity ( Λ , from 400 down to 5 nm), local chemistry, and glass–glass interfaces, while focusing in‐depth on the SB nucleation/propagation processes. The nanolaminates enable a fine control of the mechanical properties, and an onset of crack formation/percolation (>1.9 and 3.3%, respectively) far above the monolithic counterparts. Moreover, we show that SB propagation induces large chemical intermixing, enabling a brittle‐to‐ductile transition when Λ ≤ 50 nm, reaching remarkably large plastic deformation of 16% in compression and yield strength ≈2 GPa. Overall, the nanoengineered control of local heterogeneities leads to ultimate and tunable mechanical properties opening up a new approach for strong and ductile materials. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
|
Publication Date |
2024-05-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
2688-4062 |
ISBN |
|
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:205798 |
Serial |
9176 |
Permanent link to this record |
|
|
|
Author |
Debie, Y.; van Audenaerde, J.R.M.; Vandamme, T.; Croes, L.; Teuwen, L.-A.; Verbruggen, L.; Vanhoutte, G.; Marcq, E.; Verheggen, L.; Le Blon, D.; Peeters, B.; Goossens, M.; Pannus, P.; Ariën, K.K.; Anguille, S.; Janssens, A.; Prenen, H.; Smits, E.L.J.; Vulsteke, C.; Lion, E.; Peeters, M.; Van Dam, P.A. |
Title |
Humoral and cellular immune responses against SARS-CoV-2 after third dose BNT162b2 following double-dose vaccination with BNT162b2 versus ChAdOx1 in patients with cancer |
Type |
University Hospital Antwerp |
Year |
2023 |
Publication |
Clinical cancer research |
Abbreviated Journal |
|
Volume |
29 |
Issue |
3 |
Pages |
635-646 |
Keywords |
University Hospital Antwerp; A1 Journal article; Laboratory for Experimental Hematology (LEH); Center for Oncological Research (CORE) |
Abstract |
Purpose: Patients with cancer display reduced humoral responses after double-dose COVID-19 vaccination, whereas their cellular response is more comparable with that in healthy individuals. Recent studies demonstrated that a third vaccination dose boosts these immune responses, both in healthy people and patients with cancer. Because of the availability of many different COVID-19 vaccines, many people have been boosted with a different vaccine fromthe one used for double-dose vaccination. Data on such alternative vaccination schedules are scarce. This prospective study compares a third dose of BNT162b2 after double-dose BNT162b2 (homologous) versus ChAdOx1 (heterologous) vaccination in patients with cancer. Experimental Design: A total of 442 subjects (315 patients and 127 healthy) received a third dose of BNT162b2 (230 homologous vs. 212 heterologous). Vaccine-induced adverse events (AE) were captured up to 7 days after vaccination. Humoral immunity was assessed by SARS-CoV-2 anti-S1 IgG antibody levels and SARSCoV- 2 50% neutralization titers (NT50) against Wuhan and BA.1 Omicron strains. Cellular immunity was examined by analyzing CD4þ and CD8þ T-cell responses against SARS-CoV-2–specific S1 and S2 peptides. Results: Local AEs were more common after heterologous boosting. SARS-CoV-2 anti-S1 IgG antibody levels did not differ significantly between homologous and heterologous boosted subjects [GMT 1,755.90 BAU/mL (95% CI, 1,276.95–2,414.48) vs. 1,495.82 BAU/mL (95% CI, 1,131.48–1,977.46)]. However, homologous- boosted subjects show significantly higher NT50 values against BA.1 Omicron. Subjects receiving heterologous boosting demonstrated increased spike-specific CD8þ T cells, including higher IFNg and TNFa levels. Conclusions: In patients with cancer who received double-dose ChAdOx1, a third heterologous dose of BNT162b2 was able to close the gap in antibody response. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000928414200001 |
Publication Date |
2022-11-07 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
ISSN |
1078-0432; 1557-3265 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
11.5 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 11.5; 2023 IF: 9.619 |
Call Number |
UA @ admin @ c:irua:192500 |
Serial |
9207 |
Permanent link to this record |