Records |
Author |
Yang, M.; Orekhov, A.; Hu, Z.-Y.; Feng, M.; Jin, S.; Sha, G.; Li, K.; Samaee, V.; Song, M.; Du, Y.; Van Tendeloo, G.; Schryvers, D. |
Title |
Shearing and rotation of β'' and β' precipitates in an Al-Mg-Si alloy under tensile deformation : in-situ and ex-situ studies |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Acta Materialia |
Abbreviated Journal |
Acta Mater |
Volume |
220 |
Issue |
|
Pages |
117310 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The interaction between dislocations and nano-precipitates during deformation directly influences hardening response of precipitation-strengthening metals such as Al-Mg-Si alloys. However, how coherent and semi-coherent nano-precipitates accommodate external deformation applied to an Al alloy remains to be elucidated. In-situ tensile experiments in a transmission electron microscope (TEM) were conducted to study the dynamic process of dislocations cutting through coherent needle-like beta '' precipitates with diameters of 3 similar to 8 nm. Comprehensive investigations using in-situ, ex-situ TEM and atom probe tomography uncovered that beta '' precipitates were firstly sheared into small fragments, and then the rotation of the fragments, via sliding along precipitate/matrix interfaces, destroyed their initially coherent interface with the Al matrix. In contrast, semi-coherent beta' precipitates with sizes similar to beta '' were more difficult to be fragmented and accumulation of dislocations at the interface increased interface misfit between beta' and the Al matrix. Consequently, beta' precipitates could basically maintain their needle-like shape after the tensile deformation. This research gains new insights into the interaction between nano-precipitates and dislocations. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
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Wos |
000705535300005 |
Publication Date |
2021-09-12 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.301 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 5.301 |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
UA @ admin @ c:irua:182528 |
Serial |
6884 |
Permanent link to this record |
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|
|
Author |
Vervaet, B.A.; Nast, C.C.; Jayasumana, C.; Schreurs, G.; Roels, F.; Herath, C.; Kojc, N.; Samaee, V.; Rodrigo, S.; Gowrishankar, R. |
Title |
Chronic interstitial nephritis in agricultural communities : a toxin-induced proximal tubular nephropathy |
Type |
A1 Journal article |
Year |
2020 |
Publication |
European Medical Journal : Nephrology |
Abbreviated Journal |
|
Volume |
8 |
Issue |
1 |
Pages |
40-42 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Pathophysiology |
Abstract |
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Corporate Author |
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Thesis |
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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 |
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Publication Date |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
ISSN |
2053-4248 |
ISBN |
|
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
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Open Access |
|
Notes |
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Approved |
Most recent IF: NA |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
UA @ admin @ c:irua:180862 |
Serial |
6858 |
Permanent link to this record |
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|
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Author |
Akamine, H.; Mitsuhara, M.; Nishida, M.; Samaee, V.; Schryvers, D.; Tsukamoto, G.; Kunieda, T.; Fujii, H. |
Title |
Precipitation behaviors in Ti-2.3 Wt Pct Cu alloy during isothermal and two-step aging |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Metallurgical And Materials Transactions A-Physical Metallurgy And Materials Science |
Abbreviated Journal |
Metall Mater Trans A |
Volume |
52 |
Issue |
|
Pages |
2760-2772 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Time evolution of precipitates related to age-hardening in Ti-2.3 wt pct Cu alloys was investigated by electron microscopy. In isothermal aging at 723 K, the hardness increases continuously owing to precipitation strengthening, whereas in two-step aging where the aging temperature is switched from 673 K to 873 K after 100 hours, the hardness is found to drastically drop after the aging temperature switches. In isothermal aging, metastable and stable precipitates are independently nucleated, whereas characteristic V-shaped clusters of precipitates are observed during the two-step aging. It is revealed by atomic-scale observations that the V-shaped clusters are composed of metastable and stable precipitates and each type of precipitate has a different orientation relationship with the alpha phase: (10 (3) over bar)//(0001)(alpha) and [0 (1) over bar0]//respectively. The drop in hardness during two-step aging can be explained by a synergistic effect of decreased precipitation strengthening and solid solution strengthening. (C) The Minerals, Metals & Materials Society and ASM International 2021 |
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Thesis |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000644823000001 |
Publication Date |
2021-04-27 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1073-5623 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
1.874 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 1.874 |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
UA @ admin @ c:irua:178222 |
Serial |
6786 |
Permanent link to this record |
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|
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Author |
Van Cauwenbergh, P.; Samaee, V.; Thijs, L.; Nejezchlebova, J.; Sedlak, P.; Ivekovic, A.; Schryvers, D.; Van Hooreweder, B.; Vanmeensel, K. |
Title |
Unravelling the multi-scale structure-property relationship of laser powder bed fusion processed and heat-treated AlSi10Mg |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Scientific Reports |
Abbreviated Journal |
Sci Rep-Uk |
Volume |
11 |
Issue |
1 |
Pages |
6423 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Tailoring heat treatments for Laser Powder Bed Fusion (LPBF) processed materials is critical to ensure superior and repeatable material properties for high-end applications. This tailoring requires in-depth understanding of the LPBF-processed material. Therefore, the current study aims at unravelling the threefold interrelationship between the process (LPBF and heat treatment), the microstructure at different scales (macro-, meso-, micro-, and nano-scale), and the macroscopic material properties of AlSi10Mg. A similar solidification trajectory applies at different length scales when comparing the solidification of AlSi10Mg, ranging from mould-casting to rapid solidification (LPBF). The similarity in solidification trajectories triggers the reason why the Brody-Flemings cellular microsegregation solidification model could predict the cellular morphology of the LPBF as-printed microstructure. Where rapid solidification occurs at a much finer scale, the LPBF microstructure exhibits a significant grain refinement and a high degree of silicon (Si) supersaturation. This study has identified the grain refinement and Si supersaturation as critical assets of the as-printed microstructure, playing a vital role in achieving superior mechanical and thermal properties during heat treatment. Next, an electrical conductivity model could accurately predict the Si solute concentration in LPBF-processed and heat-treated AlSi10Mg and allows understanding the microstructural evolution during heat treatment. The LPBF-processed and heat-treated AlSi10Mg conditions (as-built (AB), direct-aged (DA), stress-relieved (SR), preheated (PH)) show an interesting range of superior mechanical properties (tensile strength: 300-450 MPa, elongation: 4-13%) compared to the mould-cast T6 reference condition. |
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Corporate Author |
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Thesis |
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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 |
000632047000003 |
Publication Date |
2021-03-19 |
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 |
|
Edition |
|
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.259 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 4.259 |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
UA @ admin @ c:irua:177634 |
Serial |
6791 |
Permanent link to this record |
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|
|
Author |
Samaee, V.; Dupraz, M.; Pardoen, T.; VAn Swygenhoven, H.; Schryvers, D.; Idrissi, H. |
Title |
Deciphering the interactions between single arm dislocation sources and coherent twin boundary in nickel bi-crystal |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat Commun |
Volume |
12 |
Issue |
1 |
Pages |
962 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The introduction of a well-controlled population of coherent twin boundaries (CTBs) is an attractive route to improve the strength ductility product in face centered cubic (FCC) metals. However, the elementary mechanisms controlling the interaction between single arm dislocation sources (SASs), often present in nanotwinned FCC metals, and CTB are still not well understood. Here, quantitative in-situ transmission electron microscopy (TEM) observations of these mechanisms under tensile loading are performed on submicron Ni bi-crystal. We report that the absorption of curved screw dislocations at the CTB leads to the formation of constriction nodes connecting pairs of twinning dislocations at the CTB plane in agreement with large scale 3D atomistic simulations. The coordinated motion of the twinning dislocation pairs due to the presence of the nodes leads to a unique CTB sliding mechanism, which plays an important role in initiating the fracture process at a CTB ledge. TEM observations of the interactions between non-screw dislocations and the CTB highlight the importance of the synergy between the repulsive force of the CTB and the back stress from SASs when the interactions occur in small volumes. Interactions of dislocations with coherent twin boundaries contribute to strength and ductility in metals, but investigating the interaction mechanisms is challenging. Here the authors unravel these mechanisms through quantitative in-situ transmission electron microscopy observations in nickel bi-crystal samples under tensile loading. |
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Corporate Author |
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Thesis |
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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 |
000620142700024 |
Publication Date |
2021-02-11 |
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 |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 12.124 |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
UA @ admin @ c:irua:176680 |
Serial |
6722 |
Permanent link to this record |
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Author |
Cao, S.; Zeng, C.Y.; Li, Y.Y.; Yao, X.; Ma, X.; Samaee, V.; Schryvers, D.; Zhang, X.P. |
Title |
Quantitative FIB/SEM three-dimensional characterization of a unique Ni₄Ti₃ network in a porous Ni50.8Ti49.2 alloy undergoing a two-step martensitic transformation |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Materials Characterization |
Abbreviated Journal |
Mater Charact |
Volume |
169 |
Issue |
|
Pages |
110595 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The three-dimensional (3D) nanostructure of Ni4Ti3 precipitates in a porous Ni50.8Ti49.2 alloy has been re-constructed by “Slice-and-View” in a Focused Ion Beam/Scanning Electron Microscope (FIB/SEM). The 3D configuration of these precipitates forming a network structure in the B2 austenite matrix has been characterized via 3D visualization and quantitative analysis including volume fraction, skeleton, degree of anisotropy and local thickness. It is found that dense Ni4Ti3 precipitates occupy 54% of the volume in the B2 austenite matrix. Parallel Ni4Ti3 precipitates grow alongside the surface of a micro-pore, yielding an asymmetric structure, while nano voids do not seem to affect the growth of Ni4Ti3 precipitates. The small average local thickness of the precipitates around 60 nm allows their coherency with the matrix, and further induces the R-phase transformation in the matrix. On the other hand, the B2 matrix exhibits a winding and narrow structure with a skeleton of 18.20 mm and a thickness similar to the precipitates. This discontinuous matrix segmented by the Ni4Ti3 network and pores is responsible for the gradual transformation by stalling the martensite propagation. |
Address |
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Corporate Author |
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Thesis |
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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 |
000584353100001 |
Publication Date |
2020-08-27 |
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 |
|
ISSN |
1044-5803 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.7 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
; This work was supported by the National Natural Science Foundation of China under Grant Nos. 51401081 and 51571092, the Natural Science Foundation of Guangdong Province through Key Project under Grant No. 2018B0303110012 and General Project under Grant No. 2017A030313323, and China Scholarship Council (CSC). ; |
Approved |
Most recent IF: 4.7; 2020 IF: 2.714 |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
UA @ admin @ c:irua:173547 |
Serial |
6590 |
Permanent link to this record |
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|
Author |
Idrissi, H.; Samaee, V.; Lumbeeck, G.; van der Werf, T.; Pardoen, T.; Schryvers, D.; Cordier, P. |
Title |
Supporting data for “In situ Quantitative Tensile Tests on Antigorite in a Transmission Electron Microscope” |
Type |
Dataset |
Year |
2019 |
Publication |
|
Abbreviated Journal |
|
Volume |
|
Issue |
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Pages |
|
Keywords |
Dataset; Electron microscopy for materials research (EMAT) |
Abstract |
The determination of the mechanical properties of serpentinites is essential towards the understanding of the mechanics of faulting and subduction. Here, we present the first in situ tensile tests on antigorite in a transmission electron microscope. A push-to-pull deformation device is used to perform quantitative tensile tests, during which force and displacement are measured, while the microstructure is imaged with the microscope. The experiments have been performed at room temperature on beams prepared by focused ion beam. The specimens are not single crystals despite their small sizes. Orientation mapping indicated that some grains were well-oriented for plastic slip. However, no dislocation activity has been observed even though engineering tensile stress went up to 700 MPa. We show also that antigorite does not exhibit an pure elastic-brittle behaviour since, despite the presence of defects, the specimens underwent plastic deformation and did not fail within the elastic regime. Instead, we observe that strain localizes at grain boundaries. All observations concur to show that under our experimental conditions, grain boundary sliding is the dominant deformation mechanism. This study sheds a new light on the mechanical properties of antigorite and calls for further studies on the structure and properties of grain boundaries in antigorite and more generally in phyllosilicates. |
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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 |
no |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
UA @ admin @ c:irua:169107 |
Serial |
6891 |
Permanent link to this record |
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Author |
Sandfeld, S.; Samaee, V.; Idrissi, H.; Groten, J.; Pardoen, T.; Schwaiger, R.; Schryvers, D. |
Title |
Datasets for the analysis of dislocations at grain boundaries and during vein formation in cyclically deformed Ni micropillars |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Data in Brief |
Abbreviated Journal |
|
Volume |
27 |
Issue |
27 |
Pages |
104724 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The dataset together with the corresponding Python scripts and Jupyter notebooks presented in this article are supplementary data for the work presented in Samaee et al., 2019 [1]. The data itself consists of two parts: the simulation data that was used in [1] to analyze the effect of a particular grain boundary on curved dislocations and the precession electron diffraction (PED) strain maps together with post-processed data for analyzing details of the observed dislocation vein structures. Additionally, the complete stress tensor components, which are not shown in [1], have also been included. The data sets are accompanied by Python code explaining the file formats and showing how to post-process the data. (c) 2019 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). |
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Place of Publication |
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Language |
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Wos |
000501988200181 |
Publication Date |
2019-11-03 |
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 |
2352-3409 |
ISBN |
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Additional Links |
UA library record; WoS full 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 ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
UA @ admin @ c:irua:165092 |
Serial |
6292 |
Permanent link to this record |
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Author |
Vervaet, B.A.; Nast, C.C.; Jayasumana, C.; Schreurs, G.; Roels, F.; Herath, C.; Kojc, N.; Samaee, V.; Rodrigo, S.; Gowrishankar, S.; Mousson, C.; Dassanayake, R.; Orantes, C.M.; Vuiblet, V.; Rigothier, C.; d' Haese, P.C.; de Broe, M.E. |
Title |
Chronic interstitial nephritis in agricultural communities is a toxin induced proximal tubular nephropathy |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Kidney international |
Abbreviated Journal |
Kidney Int |
Volume |
97 |
Issue |
97 |
Pages |
350-369 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory Experimental Medicine and Pediatrics (LEMP); Pathophysiology |
Abstract |
Almost 30 years after the detection of chronic interstitial nephritis in agricultural communities (CINAC) its etiology remains unknown. To help define this we examined 34 renal biopsies from Sri Lanka, El Salvador, India and France of patients with chronic kidney disease 2-3 and diagnosed with CINAC by light and electron microscopy. In addition to known histopathology, we identified a unique constellation of proximal tubular cell findings including large dysmorphic lysosomes with a light-medium electron-dense matrix containing dispersed dark electron-dense non-membrane bound “aggregates”. These aggregates associated with varying degrees of cellular/tubular atrophy, apparent cell fragment shedding and no-weak proximal tubular cell proliferative capacity. Identical lysosomal lesions, identifiable by electron microscopy, were observed in 9% of renal transplant implantation biopsies, but were more prevalent in six month (50%) and 12 month (67%) protocol biopsies and in indication biopsies (76%) of calcineurin inhibitor treated transplant patients. The phenotype was also found associated with nephrotoxic drugs (lomustine, clomiphene, lithium, cocaine) and in some patients with light chain tubulopathy, all conditions that can be directly or indirectly linked to calcineurin pathway inhibition or modulation. One hundred biopsies of normal kidneys, drug/toxin induced nephropathies, and overt proteinuric patients of different etiologies to some extent could demonstrate the light microscopic proximal tubular cell changes, but rarely the electron microscopic lysosomal features. Rats treated with the calcineurin inhibitor cyclosporine for four weeks developed similar proximal tubular cell lysosomal alterations, which were absent in a dehydration group. Overall, the finding of an identical proximal tubular cell (lysosomal) lesion in CINAC and calcineurin inhibitor nephrotoxicity in different geographic regions suggests a common paradigm where CINAC patients undergo a tubulotoxic mechanism similar to calcineurin inhibitor nephrotoxicity. |
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Corporate Author |
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Place of Publication |
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Wos |
000508449300020 |
Publication Date |
2019-11-23 |
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 |
|
ISSN |
0085-2538; 1523-1755 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.395 |
Times cited |
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Open Access |
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Notes |
|
Approved |
Most recent IF: 8.395 |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
UA @ admin @ c:irua:164305c:irua:166544 |
Serial |
5384 |
Permanent link to this record |
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Author |
Samaee, V. |
Title |
In-situ transmission electron microscopic nanomechanical investigations of Ni |
Type |
Doctoral thesis |
Year |
2018 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
|
Pages |
172 p. |
Keywords |
Doctoral thesis; Electron microscopy for materials research (EMAT) |
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Abbreviated Series Title |
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Edition |
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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 |
no |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
UA @ admin @ c:irua:156143 |
Serial |
8075 |
Permanent link to this record |
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Author |
Pourbabak, S.; Orekhov, A.; Samaee, V.; Verlinden, B.; Van Humbeeck, J.; Schryvers, D. |
Title |
In-Situ TEM Stress Induced Martensitic Transformation in Ni50.8Ti49.2 Microwires |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Shape memory and superelasticity |
Abbreviated Journal |
Shap. Mem. Superelasticity |
Volume |
5 |
Issue |
2 |
Pages |
154-162 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
In-situ transmission electron microscopy tensile straining is used to study the stress induced martensitic transformation in Ni50.8Ti49.2. Two microwire samples with different heat treatment are investigated from which one single crystal and three polycrystalline TEM specimens, the latter with micro- and nano-size grains, have been produced. The measured Young’s modulus for all TEM specimens is around 70 GPa, considerably higher than the averaged 55 GPa of the original microwire sample. The height of the superelastic stress plateau shows an inverse relationship with the specimen thickness for the polycrystalline specimens. Martensite starts nucleating within the elastic region of the stress–strain curve and on the edges of the specimens while also grain boundaries act as nucleation sites in the polycrystalline specimens. When a martensite plate reaches a grain boundary in the polycrystalline specimen, it initiates the transformation in the neighboring grain at the other side of the grain boundary. In later stages martensite plates coalesce at higher loads in the stress plateau. In highly strained specimens, residual martensite remains after release. |
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Publisher |
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Place of Publication |
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Wos |
000472940200002 |
Publication Date |
2019-05-20 |
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 |
2199-384X |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
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Times cited |
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Open Access |
Not_Open_Access |
Notes |
Saeid Pourbabak likes to thank the Flemish Science Foundation FWO for financial support under Project G.0366.15N. This work was also made possible through the AUHA13009 Grant “TopSPIN for TEM nanostatistics” of the Flemish HERCULES foundation. |
Approved |
Most recent IF: NA |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
EMAT @ emat @UA @ admin @ c:irua:159989 |
Serial |
5177 |
Permanent link to this record |
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|
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Author |
Idrissi, H.; Samaee, V.; Lumbeeck, G.; Werf, T.; Pardoen, T.; Schryvers, D.; Cordier, P. |
Title |
In Situ Quantitative Tensile Testing of Antigorite in a Transmission Electron Microscope |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Journal Of Geophysical Research-Solid Earth |
Abbreviated Journal |
J Geophys Res-Sol Ea |
Volume |
125 |
Issue |
3 |
Pages |
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The determination of the mechanical properties of serpentinites is essential toward the understanding of the mechanics of faulting and subduction. Here we present the first in situ tensile tests on antigorite in a transmission electron microscope. A push‐to‐pull deformation device is used to perform quantitative tensile tests, during which force and displacement are measured, while the evolving microstructure is imaged with the microscope. The experiments have been performed at room temperature on 2 × 1 × 0.2 μm3 beams prepared by focused ion beam. The specimens are not single crystals despite their small sizes. Orientation mapping indicated that several grains were well oriented for plastic slip. However, no dislocation activity has been observed even though the engineering tensile stress went up to 700 MPa. We show also that antigorite does not exhibit a purely elastic‐brittle behavior since, despite the presence of defects, the specimens accumulate permanent deformation and did not fail within the elastic regime. Instead, we observe that strain localizes at grain boundaries. All observations concur to show that under these experimental conditions, grain boundary sliding is the dominant deformation mechanism. This study sheds a new light on the mechanical properties of antigorite and calls for further studies on the structure and properties of grain boundaries in antigorite and more generally in phyllosilicates. |
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Wos |
000530895800023 |
Publication Date |
2020-02-20 |
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Series Issue |
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Edition |
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ISSN |
2169-9313 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.9 |
Times cited |
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Open Access |
OpenAccess |
Notes |
We thank S. Guillot for having kindly provided us with the two antigorite samples investigated in this study. We acknowledge funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program under Grant Agreement 787198—TimeMan. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR‐FNRS). We acknowledge fruitful discussions with A. Baronnet. We thank J. Gasc and an anonymous reviewer for their critical comments. Data (movies of the three in situ deformation experiments) can be downloaded (from https://doi.org/10.5281/zenodo.3583135). |
Approved |
Most recent IF: 3.9; 2020 IF: 3.35 |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
EMAT @ emat @c:irua:167594 |
Serial |
6355 |
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Author |
Samaee, V.; Sandfeld, S.; Idrissi, H.; Groten, J.; Pardoen, T.; Schwaiger, R.; Schryvers, D. |
Title |
Dislocation structures and the role of grain boundaries in cyclically deformed Ni micropillars |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Materials Science And Engineering A-Structural Materials Properties Microstructure And Processing |
Abbreviated Journal |
Mat Sci Eng A-Struct |
Volume |
769 |
Issue |
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Pages |
138295 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Transmission electron microscopy and finite element-based dislocation simulations were combined to study the development of dislocation microstructures after cyclic deformation of single crystal and bicrystal Ni micropillars oriented for multi-slip. A direct correlation between large accumulation of plastic strain and the presence of dislocation cell walls in the single crystal micropillars was observed, while the presence of the grain boundary hampered the formation of wall-like structures in agreement with a smaller accumulated plastic strain. Automated crystallographic orientation and nanostrain mapping using transmission electron microscopy revealed the presence of lattice heterogeneities associated to the cell walls including long range elastic strain fields. By combining the nanostrain mapping with an inverse modelling approach, information about dislocation density, line orientation and Burgers vector direction was derived, which is not accessible otherwise in such dense dislocation structures. Simulations showed that the image forces associated with the grain boundary in this specific bicrystal configuration have only a minor influence on dislocation behavior. Thus, the reduced occurrence of “mature” cell walls in the bicrystal can be attributed to the available volume, which is too small to accommodate cell structures. |
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Wos |
000500373800018 |
Publication Date |
2019-08-21 |
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Series Issue |
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Edition |
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ISSN |
0921-5093 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.4 |
Times cited |
1 |
Open Access |
OpenAccess |
Notes |
Financial support from the Flemish (FWO) and German Research Foundation (DFG) through the European M-ERA.NET project “FaSS” (Fatigue Simulation near Surfaces) under the grant numbers GA.014.13 N,SCHW855/5-1, and SA2292/2-1 is gratefully acknowledged. V.S. acknowledges the FWO research project G012012 N “Understanding nanocrystalline mechanical behaviour from structural investigations”. H.I. is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). S.S. acknowledges financial support from the European Research Council through the ERC Grant Agreement No. 759419 (MuDiLingo – A Multiscale Dislocation Language for Data- Driven Materials Science). |
Approved |
Most recent IF: 6.4; 2020 IF: 3.094 |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
EMAT @ emat @c:irua:163475 |
Serial |
5371 |
Permanent link to this record |
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Author |
Samaee, V.; Gatti, R.; Devincre, B.; Pardoen, T.; Schryvers, D.; Idrissi, H. |
Title |
Dislocation driven nanosample plasticity: new insights from quantitative in-situ TEM tensile testing |
Type |
A1 Journal Article |
Year |
2018 |
Publication |
Scientific Reports |
Abbreviated Journal |
Sci Rep-Uk |
Volume |
8 |
Issue |
1 |
Pages |
12012 |
Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
Abstract |
Intrinsic dislocation mechanisms in the vicinity of free surfaces of an almost FIB damage-free single crystal Ni sample have been quantitatively investigated owing to a novel sample preparation method combining twin-jet electro-polishing, in-situ TEM heating and FIB. The results reveal that the small-scale plasticity is mainly controlled by the conversion of few tangled dislocations, still present after heating, into stable single arm sources (SASs) as well as by the successive operation of these sources. Strain hardening resulting from the operation of an individual SAS is reported and attributed to the decrease of the length of the source. Moreover, the impact of the shortening of the dislocation source on the intermittent plastic flow, characteristic of SASs, is discussed. These findings provide essential information for the understanding of the regime of ‘dislocation source’ controlled plasticity and the related mechanical size effect. |
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Wos |
000460200900001 |
Publication Date |
2018-08-07 |
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Edition |
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ISSN |
2045-2322 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.259 |
Times cited |
9 |
Open Access |
Not_Open_Access |
Notes |
Financial support from the Flemish (FWO) and German Research Foundation (DFG) through the European M-ERA.NET project “FaSS” (Fatigue Simulation near Surfaces) under the grant numbers GA.014.13 N and SCHW855/5-1, respectively, is gratefully acknowledged. V. Samaee also acknowledges the FWO research project G012012N “Understanding nanocrystalline mechanical behaviour from structural investigations”. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). Dr. Ruth Schwaiger is acknowledged for providing the Ni foils used to prepare the in-situ TEM tensile specimens. |
Approved |
Most recent IF: 4.259 |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
EMAT @ emat @c:irua:155772 |
Serial |
5136 |
Permanent link to this record |
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Author |
Lumbeeck, G.; Idrissi, H.; Amin-Ahmadi, B.; Favache, A.; Delmelle, R.; Samaee, V.; Proost, J.; Pardoen, T.; Schryvers, D. |
Title |
Effect of hydriding induced defects on the small-scale plasticity mechanisms in nanocrystalline palladium thin films |
Type |
A1 Journal Article |
Year |
2018 |
Publication |
Journal Of Applied Physics |
Abbreviated Journal |
J Appl Phys |
Volume |
124 |
Issue |
22 |
Pages |
225105 |
Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
Abstract |
Nanoindentation tests performed on nanocrystalline palladium films subjected to hydriding/dehydriding cycles demonstrate a significant softening when compared to the as-received material. The origin of this softening is unraveled by combining in situ TEM nanomechanical testing with automated crystal orientation mapping in TEM and high resolution TEM. The softening is attributed to the presence of a high density of stacking faults and of Shockley partial dislocations after hydrogen loading. The hydrogen induced defects affect the elementary plasticity mechanisms and the mechanical response by acting as preferential sites for twinning/detwinning during deformation. These results are analyzed and compared to previous experimental and simulation works in the literature. This study provides new insights into the effect of hydrogen on the atomistic deformation and cracking mechanisms as well as on the mechanical properties of nanocrystalline thin films and membranes. |
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Wos |
000453254000025 |
Publication Date |
2018-12-14 |
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ISSN |
0021-8979 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.068 |
Times cited |
2 |
Open Access |
Not_Open_Access |
Notes |
This work was supported by the Hercules Foundation under Grant No. AUHA13009, the Flemish Research Fund (FWO) under Grant No. G.0365.15N, and the Flemish Strategic Initiative for Materials (SIM) under the project InterPoCo. Dr. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). We would like to thank Dr. Hadi Pirgazi from UGent for his technical support to process the ACOM data in the OIM Analysis software. |
Approved |
Most recent IF: 2.068 |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
EMAT @ emat @c:irua:155742 |
Serial |
5135 |
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Author |
Guzzinati, G.; Altantzis, T.; Batuk, M.; De Backer, A.; Lumbeeck, G.; Samaee, V.; Batuk, D.; Idrissi, H.; Hadermann, J.; Van Aert, S.; Schryvers, D.; Verbeeck, J.; Bals, S. |
Title |
Recent Advances in Transmission Electron Microscopy for Materials Science at the EMAT Lab of the University of Antwerp |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Materials |
Abbreviated Journal |
Materials |
Volume |
11 |
Issue |
11 |
Pages |
1304 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The rapid progress in materials science that enables the design of materials down to the nanoscale also demands characterization techniques able to analyze the materials down to the same scale, such as transmission electron microscopy. As Belgium’s foremost electron microscopy group, among the largest in the world, EMAT is continuously contributing to the development of TEM techniques, such as high-resolution imaging, diffraction, electron tomography, and spectroscopies, with an emphasis on quantification and reproducibility, as well as employing TEM methodology at the highest level to solve real-world materials science problems. The lab’s recent contributions are presented here together with specific case studies in order to highlight the usefulness of TEM to the advancement of materials science. |
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Wos |
000444112800041 |
Publication Date |
2018-07-28 |
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ISSN |
1996-1944 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.654 |
Times cited |
15 |
Open Access |
OpenAccess |
Notes |
Fonds Wetenschappelijk Onderzoek, G.0502.18N, G.0267.18N, G.0120.12N, G.0365.15N, G.0934.17N, S.0100.18N AUHA13009 ; European Research Council, COLOURATOM 335078 ; Universiteit Antwerpen, GOA Solarpaint ; G. Guzzinati, T. Altantzis and A. De Backer have been supported by postdoctoral fellowship grants from the Research Foundation Flanders (FWO). Funding was also received from the European Research Council (starting grant no. COLOURATOM 335078), the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 770887), the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0502.18N, G.0267.18N, G.0120.12N, G.0365.15N, G.0934.17N, S.0100.18N, G.0401.16N) and from the University of Antwerp through GOA project Solarpaint. Funding for the TopSPIN precession system under grant AUHA13009, as well as for the Qu-Ant-EM microscope, is acknowledged from the HERCULES Foundation. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (F.R.S.-FNRS). (ROMEO:green; preprint:; postprint:can ; pdfversion:can); saraecas; ECAS_Sara; |
Approved |
Most recent IF: 2.654 |
Call Number ![sorted by Call Number field, descending order (down)](img/sort_desc.gif) |
EMAT @ emat @c:irua:153737UA @ admin @ c:irua:153737 |
Serial |
5064 |
Permanent link to this record |