|
Records |
Links |
|
Author |
Gao, C.; Hofer, C.; Jannis, D.; Béché, A.; Verbeeck, J.; Pennycook, T.J. |
|
|
Title |
Overcoming contrast reversals in focused probe ptychography of thick materials: An optimal pipeline for efficiently determining local atomic structure in materials science |
Type |
A1 Journal article |
|
Year |
2022 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
|
|
Volume |
121 |
Issue |
8 |
Pages |
081906 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Ptychography provides highly efficient imaging in scanning transmission electron microscopy (STEM), but questions have remained over its applicability to strongly scattering samples such as those most commonly seen in materials science. Although contrast reversals can appear in ptychographic phase images as the projected potentials of the sample increase, we show here how these can be easily overcome by a small amount of defocus. The amount of defocus is small enough that it not only can exist naturally when focusing using the annular dark field (ADF) signal but can also be adjusted post acquisition. The ptychographic images of strongly scattering materials are clearer at finite doses than other STEM techniques and can better reveal light atomic columns within heavy lattices. In addition, data for ptychography can now be collected simultaneously with the fastest of ADF scans. This combination of sensitivity and interpretability presents an ideal workflow for materials science. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000844403300006 |
Publication Date |
2022-08-22 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0003-6951 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4 |
Times cited |
9 |
Open Access |
OpenAccess |
|
|
Notes |
European Research Council, 802123-HDEM ; HORIZON EUROPE European Research Council, 823717-ESTEEM3 ; Fonds Wetenschappelijk Onderzoek, G042920N ; Fonds Wetenschappelijk Onderzoek, G042820N ; Horizon 2020 Framework Programme, 101017720 ; Fonds Wetenschappelijk Onderzoek, G013122N ; esteem3reported; esteem3jra |
Approved |
Most recent IF: 4 |
|
|
Call Number |
EMAT @ emat @c:irua:190670 |
Serial |
7120 |
|
Permanent link to this record |
|
|
|
|
Author |
Jannis, D.; Müller-Caspary, K.; Béché, A.; Verbeeck, J. |
|
|
Title |
Coincidence Detection of EELS and EDX Spectral Events in the Electron Microscope |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Applied Sciences-Basel |
Abbreviated Journal |
Appl Sci-Basel |
|
|
Volume |
11 |
Issue |
19 |
Pages |
9058 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Recent advances in the development of electron and X-ray detectors have opened up the possibility to detect single events from which its time of arrival can be determined with nanosecond resolution. This allows observing time correlations between electrons and X-rays in the transmission electron microscope. In this work, a novel setup is described which measures individual events using a silicon drift detector and digital pulse processor for the X-rays and a Timepix3 detector for the electrons. This setup enables recording time correlation between both event streams while at the same time preserving the complete conventional electron energy loss (EELS) and energy dispersive X-ray (EDX) signal. We show that the added coincidence information improves the sensitivity for detecting trace elements in a matrix as compared to conventional EELS and EDX. Furthermore, the method allows the determination of the collection efficiencies without the use of a reference sample and can subtract the background signal for EELS and EDX without any prior knowledge of the background shape and without pre-edge fitting region. We discuss limitations in time resolution arising due to specificities of the silicon drift detector and discuss ways to further improve this aspect. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000710160300001 |
Publication Date |
2021-09-28 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2076-3417 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
1.679 |
Times cited |
9 |
Open Access |
OpenAccess |
|
|
Notes |
Fonds Wetenschappelijk Onderzoek, G042920 ; Horizon 2020 Framework Programme, 101017720 ; Helmholtz-Fonds, VH-NG-1317 ; |
Approved |
Most recent IF: 1.679 |
|
|
Call Number |
EMAT @ emat @c:irua:183336 |
Serial |
6821 |
|
Permanent link to this record |
|
|
|
|
Author |
Hamid, I.; Jalali, H.; Peeters, F.M.; Neek-Amal, M. |
|
|
Title |
Abnormal in-plane permittivity and ferroelectricity of confined water : from sub-nanometer channels to bulk |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Journal Of Chemical Physics |
Abbreviated Journal |
J Chem Phys |
|
|
Volume |
154 |
Issue |
11 |
Pages |
114503 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Dielectric properties of nano-confined water are important in several areas of science, i.e., it is relevant in the dielectric double layer that exists in practically all heterogeneous fluid-based systems. Molecular dynamics simulations are used to predict the in-plane dielectric properties of confined water in planar channels of width ranging from sub-nanometer to bulk. Because of suppressed rotational degrees of freedom near the confining walls, the dipole of the water molecules tends to be aligned parallel to the walls, which results in a strongly enhanced in-plane dielectric constant (epsilon (parallel to)) reaching values of about 120 for channels with height 8 angstrom < h < 10 angstrom. With the increase in the width of the channel, we predict that epsilon (parallel to) decreases nonlinearly and reaches the bulk value for h > 70 angstrom. A stratified continuum model is proposed that reproduces the h > 10 angstrom dependence of epsilon (parallel to). For sub-nanometer height channels, abnormal behavior of epsilon (parallel to) is found with two orders of magnitude reduction of epsilon (parallel to) around h similar to 7.5 angstrom, which is attributed to the formation of a particular ice phase that exhibits long-time (similar to mu s) stable ferroelectricity. This is of particular importance for the understanding of the influence of confined water on the functioning of biological systems. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000629831900001 |
Publication Date |
2021-03-17 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0021-9606 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.965 |
Times cited |
9 |
Open Access |
OpenAccess |
|
|
Notes |
|
Approved |
Most recent IF: 2.965 |
|
|
Call Number |
UA @ admin @ c:irua:177579 |
Serial |
6967 |
|
Permanent link to this record |
|
|
|
|
Author |
Renero-Lecuna, C.; Herrero, A.; Jimenez de Aberasturi, D.; Martínez-Flórez, M.; Valiente, R.; Mychinko, M.; Bals, S.; Liz-Marzán, L.M. |
|
|
Title |
Nd3+-Doped Lanthanum Oxychloride Nanocrystals as Nanothermometers |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
|
|
Volume |
125 |
Issue |
36 |
Pages |
19887-19896 |
|
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
The development of optical nanothermometers operating in the near-infrared (NIR) is of high relevance toward temperature measurements in biological systems. We propose herein the use of Nd3+-doped lanthanum oxychloride nanocrystals as an efficient system with intense photoluminescence under NIR irradiation in the first biological transparency window and emission in the second biological window with excellent emission stability over time under 808 nm excitation, regardless of Nd3+ concentration, which can be considered as a particular strength of our system. Additionally, surface passivation through overgrowth of an inert LaOCl shell around optically active LaOCl/Nd3+ cores was found to further enhance the photoluminescence intensity and also the lifetime of the 1066 nm, 4F3/2 to 4I11/2 transition, without affecting its (ratiometric) sensitivity toward temperature changes. As required for biological applications, we show that the obtained (initially hydrophobic) nanocrystals can be readily transferred into aqueous solvents with high, long-term stability, through either ligand exchange or encapsulation with an amphiphilic polymer. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000697335100031 |
Publication Date |
2021-09-16 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1932-7447 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4.536 |
Times cited |
9 |
Open Access |
OpenAccess |
|
|
Notes |
The authors thank the financial support of the European Research Council (ERC-AdG-2017 787510, ERC-CoG-2019 815128) and of the European Commission (EUSMI, Grant 731019). This work was performed under the Maria de Maeztu Units of Excellence Program from the Spanish State Research Agency−Grant MDM-2017−0720. Realnano; sygmaSB |
Approved |
Most recent IF: 4.536 |
|
|
Call Number |
EMAT @ emat @c:irua:181671 |
Serial |
6831 |
|
Permanent link to this record |
|
|
|
|
Author |
Sánchez-Iglesias, A.; Zhuo, X.; Albrecht, W.; Bals, S.; Liz-Marzán, L.M. |
|
|
Title |
Tuning Size and Seed Position in Small Silver Nanorods |
Type |
A1 Journal article |
|
Year |
2020 |
Publication |
ACS materials letters |
Abbreviated Journal |
ACS Materials Lett. |
|
|
Volume |
2 |
Issue |
9 |
Pages |
1246-1250 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
|
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000571390700022 |
Publication Date |
2020-09-08 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2639-4979 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
9 |
Open Access |
OpenAccess |
|
|
Notes |
Financial support is acknowledged from the European Commission under the Horizon 2020 Programme, by means of Grant Agreement No. 731019 (EUSMI), the ERC Consolidator Grant (No. 815128) (REALNANO), and the ERC Advanced Grant (No. 787510) (4DbioSERS). W.A. acknowledges an Individual Fellowship from the Marie Sklodowska-Curie actions (MSCA), under the EU’s Horizon 2020 program (Grant 797153, SOPMEN). This work was performed under the Maria de Maeztu Units of Excellence Program from the Spanish State Research Agency (Grant No. MDM-2017-0720).; sygma |
Approved |
Most recent IF: NA |
|
|
Call Number |
EMAT @ emat @c:irua:171980 |
Serial |
6439 |
|
Permanent link to this record |
|
|
|
|
Author |
Fatermans, J.; den Dekker, Aj.; Müller-Caspary, K.; Gauquelin, N.; Verbeeck, J.; Van Aert, S. |
|
|
Title |
Atom column detection from simultaneously acquired ABF and ADF STEM images |
Type |
A1 Journal article |
|
Year |
2020 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
|
Volume |
219 |
Issue |
|
Pages |
113046 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
|
|
Abstract |
In electron microscopy, the maximum a posteriori (MAP) probability rule has been introduced as a tool to determine the most probable atomic structure from high-resolution annular dark-field (ADF) scanning transmission electron microscopy (STEM) images exhibiting low contrast-to-noise ratio (CNR). Besides ADF imaging, STEM can also be applied in the annular bright-field (ABF) regime. The ABF STEM mode allows to directly visualize light-element atomic columns in the presence of heavy columns. Typically, light-element nanomaterials are sensitive to the electron beam, limiting the incoming electron dose in order to avoid beam damage and leading to images exhibiting low CNR. Therefore, it is of interest to apply the MAP probability rule not only to ADF STEM images, but to ABF STEM images as well. In this work, the methodology of the MAP rule, which combines statistical parameter estimation theory and model-order selection, is extended to be applied to simultaneously acquired ABF and ADF STEM images. For this, an extension of the commonly used parametric models in STEM is proposed. Hereby, the effect of specimen tilt has been taken into account, since small tilts from the crystal zone axis affect, especially, ABF STEM intensities. Using simulations as well as experimental data, it is shown that the proposed methodology can be successfully used to detect light elements in the presence of heavy elements. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000594768500005 |
Publication Date |
2020-06-01 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.2 |
Times cited |
9 |
Open Access |
OpenAccess |
|
|
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (No. W.O.010.16N, No. G.0368.15N, No. G.0502.18N, EOS 30489208). This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 770887). The authors acknowledge funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 823717 – ESTEEM3. The direct electron detector (Medipix3, Quantum Detectors) was funded by the Hercules fund from the Flemish Government. K. M. C. acknowledges funding from the Initiative and Network Fund of the Helmholtz Association (Germany) under contract VH-NG-1317. The authors thank Mark Huijben from the University of Twente (Enschede, The Netherlands) for providing the LiMn2O4 sample used in section 4.2 of this study. N. G., J. V., and S. V. A. acknowledge funding from the University of Antwerp through the Concerted Research Actions (GOA) project Solarpaint and the TOP project. |
Approved |
Most recent IF: 2.2; 2020 IF: 2.843 |
|
|
Call Number |
EMAT @ emat @c:irua:169706 |
Serial |
6373 |
|
Permanent link to this record |
|
|
|
|
Author |
Biscop,; Lin,; Boxem,; Loenhout,; Backer,; Deben,; Dewilde,; Smits,; Bogaerts, |
|
|
Title |
Influence of Cell Type and Culture Medium on Determining Cancer Selectivity of Cold Atmospheric Plasma Treatment |
Type |
A1 Journal article |
|
Year |
2019 |
Publication |
Cancers |
Abbreviated Journal |
Cancers |
|
|
Volume |
11 |
Issue |
9 |
Pages |
1287 |
|
|
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE) |
|
|
Abstract |
Increasing the selectivity of cancer treatments is attractive, as it has the potential to reduce side-effects of therapy. Cold atmospheric plasma (CAP) is a novel cancer treatment that disrupts the intracellular oxidative balance. Several reports claim CAP treatment to be selective, but retrospective analysis of these studies revealed discrepancies in several biological factors and culturing methods. Before CAP can be conclusively stated as a selective cancer treatment, the importance of these factors must be investigated. In this study, we evaluated the influence of the cell type, cancer type, and cell culture medium on direct and indirect CAP treatment. Comparison of cancerous cells with their non-cancerous counterparts was performed under standardized conditions to determine selectivity of treatment. Analysis of seven human cell lines (cancerous: A549, U87, A375, and Malme-3M; non-cancerous: BEAS-2B, HA, and HEMa) and five different cell culture media (DMEM, RPMI1640, AM, BEGM, and DCBM) revealed that the tested parameters strongly influence indirect CAP treatment, while direct treatment was less affected. Taken together, the results of our study demonstrate that cell type, cancer type, and culturing medium must be taken into account before selectivity of CAP treatment can be claimed and overlooking these parameters can easily result in inaccurate conclusions of selectivity. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000489719000072 |
Publication Date |
2019-09-01 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2072-6694 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
9 |
Open Access |
|
|
|
Notes |
the Research Foundation Flanders, 12S9218N – ; Universiteit Antwerpen, – ; |
Approved |
Most recent IF: NA |
|
|
Call Number |
PLASMANT @ plasmant @c:irua:162097 |
Serial |
5360 |
|
Permanent link to this record |
|
|
|
|
Author |
de Aquino, B.R.H.; Ghorbanfekr-Kalashami, H.; Neek-Amal, M.; Peeters, F.M. |
|
|
Title |
Ionized water confined in graphene nanochannels |
Type |
A1 Journal article |
|
Year |
2019 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
|
Volume |
21 |
Issue |
18 |
Pages |
9285-9295 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
|
Abstract |
When confined between graphene layers, water behaves differently from the bulk and exhibits unusual properties such as fast water flow and ordering into a crystal. The hydrogen-bonded network is affected by the limited space and by the characteristics of the confining walls. The presence of an extraordinary number of hydronium and hydroxide ions in narrow channels has the following effects: (i) they affect water permeation through the channel, (ii) they may interact with functional groups on the graphene oxide surface and on the edges, and (iii) they change the thermochemistry of water, which are fundamentally important to understand, especially when confined water is subjected to an external electric field. Here we study the physical properties of water when confined between two graphene sheets and containing hydronium and hydroxide. We found that: (i) there is a disruption in the solvation structure of the ions, which is also affected by the layered structure of confined water, (ii) hydronium and hydroxide occupy specific regions inside the nanochannel, with a prevalence of hydronium (hydroxide) ions at the edges (interior), and (iii) ions recombine more slowly in confined systems than in bulk water, with the recombination process depending on the channel height and commensurability between the size of the molecules and the nanochannel height – a decay of 20% (40%) in the number of ions in 8 ps is observed for a channel height of h = 7 angstrom (bulk water). Our work reveals distinctive properties of water confined in a nanocapillary in the presence of additional hydronium and hydroxide ions. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000472922500028 |
Publication Date |
2019-03-22 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4.123 |
Times cited |
9 |
Open Access |
|
|
|
Notes |
; This work was supported by the Fund for Scientific Research Flanders (FWO-Vl) and the Methusalem programe. ; |
Approved |
Most recent IF: 4.123 |
|
|
Call Number |
UA @ admin @ c:irua:161377 |
Serial |
5419 |
|
Permanent link to this record |
|
|
|
|
Author |
Van der Donck, M.; Peeters, F.M. |
|
|
Title |
Spectrum of exciton states in monolayer transition metal dichalcogenides : angular momentum and Landau levels |
Type |
A1 Journal article |
|
Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
99 |
Issue |
11 |
Pages |
115439 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
A four-band exciton Hamiltonian is constructed starting from the single-particle Dirac Hamiltonian for charge carriers in monolayer transition metal dichalcogenides (TMDs). The angular part of the exciton wave function can be separated from the radial part, in the case of zero center of mass momentum excitons, by exploiting the eigenstates of the total exciton angular momentum operator with which the Hamiltonian commutes. We explain why this approach fails for excitons with finite center of mass momentum or in the presence of a perpendicular magnetic field and present an approximation to resolve this issue. We calculate the (binding) energy and average interparticle distance of different excited exciton states in different TMDs and compare these with results available in the literature. Remarkably, we find that the intervalley exciton ground state in the -/+ K valley has angular momentum j = +/- 1, which is due to the pseudospin of the separate particles. The exciton mass and the exciton Landau levels are calculated and we find that the degeneracy of exciton states with opposite relative angular momentum is altered by a magnetic field. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000462896400004 |
Publication Date |
2019-03-28 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
|
|
|
Notes |
; This work was supported by the Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for MVDD and by the FLAG-ERA project TRANS-2D-TMD. ; |
Approved |
Most recent IF: 3.836 |
|
|
Call Number |
UA @ admin @ c:irua:159406 |
Serial |
5230 |
|
Permanent link to this record |
|
|
|
|
Author |
Yagmurcukardes, M. |
|
|
Title |
Monolayer fluoro-InSe : formation of a thin monolayer via fluorination of InSe |
Type |
A1 Journal article |
|
Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
100 |
Issue |
2 |
Pages |
024108 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
By performing density functional theory-based first-principles calculations, the formation of a thin monolayer structure, namely InSeF, via fluorination of monolayer InSe is predicted. It is shown that strong interaction of F and In atoms leads to the detachment of In-Se layers in monolayer InSe and 1T-like monolayer InSeF structure is formed. Monolayer InSeF is found to be dynamically stable in terms of its phonon band dispersions. In addition, its Raman spectrum is shown to exhibit totally distinctive features as compared to monolayer InSe. The electronic band dispersions reveal that monolayer InSeF is a direct gap semiconductor whose valence and conduction band edges reside at the Gamma point. Moreover, the orientation-dependent linear elastic properties of monolayer InSeF are investigated in terms of the in-plane stiffness and Poisson ratio. It is found that monolayer InSeF displays strong in-plane anisotropy in elastic constants and it is slightly softer material as compared to monolayer InSe. Overall, it is proposed that a thin, direct gap semiconducting monolayer InSeF can be formed by full fluorination of monolayer InSe as a new member of the two-dimensional family. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000477885700003 |
Publication Date |
2019-07-29 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
|
|
|
Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). This work is supported by the Flemish Science Foundation (FWO-Vl) by a postdoctoral fellowship (M.Y.). ; |
Approved |
Most recent IF: 3.836 |
|
|
Call Number |
UA @ admin @ c:irua:161891 |
Serial |
5423 |
|
Permanent link to this record |
|
|
|
|
Author |
Ben Dkhil, S.; Pfannmöller, M.; Schroeder, R.R.; Alkarsifi, R.; Gaceur, M.; Koentges, W.; Heidari, H.; Bals, S.; Margeat, O.; Ackermann, J.; Videlot-Ackermann, C. |
|
|
Title |
Interplay of interfacial layers and blend composition to reduce thermal degradation of polymer solar cells at high temperature |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
ACS applied materials and interfaces |
Abbreviated Journal |
Acs Appl Mater Inter |
|
|
Volume |
10 |
Issue |
10 |
Pages |
3874-3884 |
|
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
The thermal stability of printed polymer solar cells at elevated temperatures needs to be improved to achieve high-throughput fabrication including annealing steps as well as long-term stability. During device processing, thermal annealing impacts both the organic photoactive layer, and the two interfacial layers make detailed studies of degradation mechanism delicate. A recently identified thermally stable poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b'-dithiopherie-2,6-diyl] [3-fluoro-2-[(2-ethylhexyl) carbonyl] thieno [3,4-b]thiophenediyl]] : [6,6]-phenyl- C-71-butyric acid methyl ester (PTB7:PC70BM) blend as photoactive layer in combination with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate as hole extraction layer is used here to focus on the impact of electron extraction layer (EEL) on the thermal stability of solar cells. Solar cells processed with densely packed ZnO nanoparticle layers still show 92% of the initial efficiency after constant annealing during 1 day at 140 degrees C, whereas partially covering ZnO layers as well as an evaporated calcium layer leads to performance losses of up to 30%. This demonstrates that the nature and morphology of EELs highly influence the thermal stability of the device. We extend our study to thermally unstable PTB7:[6,6]-phenyl-C-61-butyric acid methyl ester (PC60BM) blends to highlight the impact of ZnO on the device degradation during annealing. Importantly, only 12% loss in photocurrent density is observed after annealing at 140 degrees C during 1 day when using closely packed ZnO. This is in stark contrast to literature and addressed here to the use of a stable double-sided confinement during thermal annealing. The underlying mechanism of the inhibition of photocurrent losses is revealed by electron microscopy imaging and spatially resolved spectroscopy. We found that the double-sided confinement suppresses extensive fullerene diffusion during the annealing step, but with still an increase in size and distance of the enriched donor and acceptor domains inside the photoactive layer by an average factor of 5. The later result in combination with comparably small photocurrent density losses indicates the existence of an efficient transport of minority charge carriers inside the donor and acceptor enriched phases in PTB7:PC60BM blends. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000424728800082 |
Publication Date |
2018-01-12 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1944-8244 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
7.504 |
Times cited |
9 |
Open Access |
OpenAccess |
|
|
Notes |
; We acknowledge the financial support by the French Fond Unique Interministeriel (FUI) under the project “SFUMATO” (grant number: F1110019V/201308815) as well as by the European Commission under the Project “SUNFLOWER” (FP7-ICT-2011-7-contract number: 287594). M.P. and R.R.S. acknowledge support by the HeiKA (Heidelberg Karlsruhe Research Partnership) FunTech-3D materials science program. ; |
Approved |
Most recent IF: 7.504 |
|
|
Call Number |
UA @ lucian @ c:irua:149309UA @ admin @ c:irua:149309 |
Serial |
4939 |
|
Permanent link to this record |
|
|
|
|
Author |
Abdullah, H.M.; Van der Donck, M.; Bahlouli, H.; Peeters, F.M.; Van Duppen, B. |
|
|
Title |
Graphene quantum blisters : a tunable system to confine charge carriers |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
|
|
Volume |
112 |
Issue |
21 |
Pages |
213101 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Due to Klein tunneling, electrostatic confinement of electrons in graphene is not possible. This hinders the use of graphene for quantum dot applications. Only through quasi-bound states with finite lifetime has one achieved to confine charge carriers. Here, we propose that bilayer graphene with a local region of decoupled graphene layers is able to generate bound states under the application of an electrostatic gate. The discrete energy levels in such a quantum blister correspond to localized electron and hole states in the top and bottom layers. We find that this layer localization and the energy spectrum itself are tunable by a global electrostatic gate and that the latter also coincides with the electronic modes in a graphene disk. Curiously, states with energy close to the continuum exist primarily in the classically forbidden region outside the domain defining the blister. The results are robust against variations in size and shape of the blister which shows that it is a versatile system to achieve tunable electrostatic confinement in graphene. Published by AIP Publishing. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
|
|
Language |
|
Wos |
000433140900025 |
Publication Date |
2018-05-22 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0003-6951; 1077-3118 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.411 |
Times cited |
9 |
Open Access |
|
|
|
Notes |
; H.M.A. and H.B. acknowledge the Saudi Center for Theoretical Physics (SCTP) for their generous support and the support of KFUPM under physics research group Project Nos. RG1502-1 and RG1502-2. This work was supported by the Flemish Science Foundation (FWO-Vl) by a post-doctoral fellowship (B.V.D.) and a doctoral fellowship (M.V.d.D.). ; |
Approved |
Most recent IF: 3.411 |
|
|
Call Number |
UA @ lucian @ c:irua:151505UA @ admin @ c:irua:151505 |
Serial |
5027 |
|
Permanent link to this record |
|
|
|
|
Author |
Deshmukh, S.; Sankaran, K.J.; Srinivasu, K.; Korneychuk, S.; Banerjee, D.; Barman, A.; Bhattacharya, G.; Phase, D.M.; Gupta, M.; Verbeeck, J.; Leou, K.C.; Lin, I.N.; Haenen, K.; Roy, S.S. |
|
|
Title |
Local probing of the enhanced field electron emission of vertically aligned nitrogen-doped diamond nanorods and their plasma illumination properties |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Diamond and related materials |
Abbreviated Journal |
Diam Relat Mater |
|
|
Volume |
83 |
Issue |
83 |
Pages |
118-125 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
A detailed conductive atomic force microscopic investigation is carried out to directly image the electron emission behavior for nitrogen-doped diamond nanorods (N-DNRs). Localized emission measurements illustrate uniform distribution of high-density electron emission sites from N-DNRs. Emission sites coupled to nano graphitic phases at the grain boundaries facilitate electron transport and thereby enhance field electron emission from N-DNRs, resulting in a device operation at low turn-on fields of 6.23 V/mu m, a high current density of 1.94 mA/cm(2) (at an applied field of 11.8 V/mu m) and a large field enhancement factor of 3320 with a long lifetime stability of 980 min. Moreover, using N-DNRs as cathodes, a microplasma device that can ignite a plasma at a low threshold field of 390 V/mm achieving a high plasma illumination current density of 3.95 mA/cm2 at an applied voltage of 550 V and a plasma life-time stability for a duration of 433 min was demonstrated. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
|
|
Language |
|
Wos |
000430767200017 |
Publication Date |
2018-02-07 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0925-9635 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.561 |
Times cited |
9 |
Open Access |
Not_Open_Access |
|
|
Notes |
; S. Deshmulch, D. Banerjee and G. Bhattacharya are indebted to Shiv Nadar University for providing Ph.D. scholarships. K.J. Sankaran and K. Haenen like to thank the financial support of the Research Foundation Flanders (FWO) via Research Grant 12I8416N and Research Project 1519817N, and the Methusalem “NANO” network. K.J. Sankaran is a Postdoctoral Fellow of the Research Foundation-Flanders (FWO). The Qu-Ant-EM microscope used for the TEM experiments was partly funded by the Hercules fund from the Flemish Government. S. Korneychuk and J. Verbeeck acknowledge funding from GOA project “Solarpaint” of the University of Antwerp. ; |
Approved |
Most recent IF: 2.561 |
|
|
Call Number |
UA @ lucian @ c:irua:151609UA @ admin @ c:irua:151609 |
Serial |
5030 |
|
Permanent link to this record |
|
|
|
|
Author |
Hofman, J.; Samson, R.; Joosen, S.; Blust, R.; Lenaerts, S. |
|
|
Title |
Cyclist exposure to black carbon, ultrafine particles and heavy metals : an experimental study along two commuting routes near Antwerp, Belgium |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Environmental research |
Abbreviated Journal |
|
|
|
Volume |
164 |
Issue |
164 |
Pages |
530-538 |
|
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
|
|
Abstract |
Urban environments typically exhibit large atmospheric pollution variation, in both space and time. In contrast to traditional monitoring networks suffering from a limited spatial coverage, mobile platforms enable personalized high-resolution monitoring, providing valuable insights into personal atmospheric pollution exposure, and the identification of potential pollution hotspots. This study evaluated personal cyclist exposure to UFPs, BC and heavy metals whilst commuting near Antwerp, Belgium, by performing mobile measurements with wearable black carbon (BC) and ultrafine particle (UFP) instruments. Loaded micro-aethalometer filterstrips were chemically analysed and the inhaled pollutant dose determined from the exhibited heart rate. Considerable spatial pollutant variation was observed along the travelled routes, with distinct contributions from spatial factors (e.g. traffic intersections, urban park and market) and temporary events. On average 300% higher BC, 20% higher UFP and changing elemental concentrations are observed along the road traffic route (RT), when compared to the bicycle highway route (BH). Although the overall background pollution determines a large portion of the experienced personal exposure (in this case 53% for BC and 40% for UFP), cyclists can influence their personal atmospheric pollution exposure, by selecting less exposed commuting routes. Our results, hereby, strengthen the body of evidence in favour of further policy investments in isolated bicycle infrastructure. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000431387100063 |
Publication Date |
2018-04-06 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
|
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
9 |
Open Access |
|
|
|
Notes |
; The authors would like to acknowledge the Flanders Environment Agency (VMM) for granting access to the 42R817 monitoring station and provision of telemetric pollutant and meteorological data. The corresponding author acknowledges the Research Foundation Flanders (FWO) for his postdoctoral research grant (12I4816N). ; |
Approved |
Most recent IF: NA |
|
|
Call Number |
UA @ admin @ c:irua:150540 |
Serial |
5939 |
|
Permanent link to this record |
|
|
|
|
Author |
Hai, G.-Q.; Candido, L.; Brito, B.G.A.; Peeters, F.M. |
|
|
Title |
Electron pairing: from metastable electron pair to bipolaron |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Journal of physics communications |
Abbreviated Journal |
|
|
|
Volume |
2 |
Issue |
3 |
Pages |
Unsp 035017 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Starting from the shell structure in atoms and the significant correlation within electron pairs, we distinguish the exchange-correlation effects between two electrons of opposite spins occupying the same orbital from the average correlation among many electrons in a crystal. In the periodic potential of the crystal with lattice constant larger than the effective Bohr radius of the valence electrons, these correlated electron pairs can form a metastable energy band above the corresponding single-electron band separated by an energy gap. In order to determine if these metastable electron pairs can be stabilized, we calculate the many-electron exchange-correlation renormalization and the polaron correction to the two-band system with single electrons and electron pairs. We find that the electron-phonon interaction is essential to counterbalance the Coulomb repulsion and to stabilize the electron pairs. The interplay of the electron-electron and electron-phonon interactions, manifested in the exchange-correlation energies, polaron effects, and screening, is responsible for the formation of electron pairs (bipolarons) that are located on the Fermi surface of the single-electron band. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
|
|
|
Language |
|
Wos |
000434996900022 |
Publication Date |
2018-02-13 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2399-6528 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
9 |
Open Access |
|
|
|
Notes |
; This work was supported by the Brazilian agencies FAPESP and CNPq. GQH would like to thank Prof. Bangfen Zhu for his invaluable support and expert advice. ; |
Approved |
Most recent IF: NA |
|
|
Call Number |
UA @ lucian @ c:irua:152079UA @ admin @ c:irua:152079 |
Serial |
5022 |
|
Permanent link to this record |
|
|
|
|
Author |
Godet, M.; Vergès-Belmin, V.; Gauquelin, N.; Saheb, M.; Monnier, J.; Leroy, E.; Bourgon, J.; Verbeeck, J.; Andraud, C. |
|
|
Title |
Nanoscale investigation by TEM and STEM-EELS of the laser induced yellowing |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Micron |
Abbreviated Journal |
Micron |
|
|
Volume |
115 |
Issue |
|
Pages |
25-31 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Nd-YAG QS laser cleaning of soiled stone at 1064 nm can sometimes result in a more yellow appearance compared to other cleaning techniques. Especially in France, this yellowing effect is still considered as a major aesthetic issue by the architects and conservators. One explanation states that the yellowing is linked to the formation of iron-rich nanophase(s) through the laser beam interaction with black crusts that would re-deposit on the cleaned substrate after irradiation. To characterize these nanophases, a model crust containing hematite was elaborated and laser irradiated using a Nd-YAG QS laser. The color of the sample shifted instantaneously from red to a bright yellow and numerous particles were ablated in a visible smoke. Transmission electron microscopy (TEM) was used to examine the morphology and the crystallinity of the neo-formed compounds, both on the surface of the samples and in the ablated materials. In addition, an investigation of the chemical and structural properties of the nanophases was conducted by X-ray dispersive energy (EDX) and electron energy loss (EELS) spectroscopies. It was found that both the surface of the sample and the ablated materials are covered by crystallized nano-spheres and nano-residues, all containing iron and oxygen, sometimes along with calcium and sulfur. In particular an interfacial area containing the four elements was evidenced between some nanostructures and the substrate. Magnetite Fe3O4 was also identified at the nanoscale. This study demonstrates that the laser yellowing of a model crust is linked to the presence of iron-rich nanophases including CaxFeySzOδ nanostructures and magnetite Fe3O4 at the surface after irradiation. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000449125600004 |
Publication Date |
2018-08-18 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0968-4328 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
1.98 |
Times cited |
9 |
Open Access |
Not_Open_Access: Available from 19.08.2020
|
|
|
Notes |
The authors wish to thank Valérie Lalanne for the sample preparation for TEM and Stijn Van den Broeck for the FIB cut elaboration. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative–I3). |
Approved |
Most recent IF: 1.98 |
|
|
Call Number |
EMAT @ emat @c:irua:154356UA @ admin @ c:irua:154356 |
Serial |
5056 |
|
Permanent link to this record |
|
|
|
|
Author |
Song, H.-D.; Wu, Y.-F.; Yang, X.; Ren, Z.; Ke, X.; Kurttepeli, M.; Tendeloo, G.V.; Liu, D.; Wu, H.-C.; Yan, B.; Wu, X.; Duan, C.-G.; Han, G.; Liao, Z.-M.; Yu, D. |
|
|
Title |
Asymmetric Modulation on Exchange Field in a Graphene/BiFeO3Heterostructure by External Magnetic Field |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
|
|
Volume |
18 |
Issue |
4 |
Pages |
2435-2441 |
|
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Graphene, having all atoms on its surface, is favorable to extend the functions by introducing the spin–orbit coupling and magnetism through proximity effect. Here, we report the tunable interfacial exchange field produced by proximity coupling in graphene/BiFeO3 heterostructures. The exchange field has a notable dependence with external magnetic field, and it is much larger under negative magnetic field than that under positive magnetic field. For negative external magnetic field, interfacial exchange coupling gives rise to evident spin splitting for N ≠ 0 Landau levels and a quantum Hall metal state for N = 0 Landau level. Our findings suggest graphene/BiFeO3 heterostructures are promising for spintronics. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000430155900034 |
Publication Date |
2018-04-11 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1530-6984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
12.712 |
Times cited |
9 |
Open Access |
Not_Open_Access |
|
|
Notes |
This work was supported by National Key Research and Development Program of China (No. 2016YFA0300802) and NSFC (Nos. 11774004 and 11604004). Ministry of Science and Technology of the People's Republic of China, 2016YFA0300802 ; National Natural Science Foundation of China, 11604004 11774004 ; |
Approved |
Most recent IF: 12.712 |
|
|
Call Number |
EMAT @ lucian @c:irua:150794 |
Serial |
4923 |
|
Permanent link to this record |
|
|
|
|
Author |
Rizzo, F.; Augieri, A.; Kursumovic, A.; Bianchetti, M.; Opherden, L.; Sieger, M.; Huehne, R.; Haenisch, J.; Meledin, A.; Van Tendeloo, G.; MacManus-Driscoll, J.L.; Celentano, G. |
|
|
Title |
Pushing the limits of applicability of REBCO coated conductor films through fine chemical tuning and nanoengineering of inclusions |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
|
|
Volume |
10 |
Issue |
17 |
Pages |
8187-8195 |
|
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
An outstanding current carrying performance (namely critical current density, J(c)) over a broad temperature range of 10-77 K for magnetic fields up to 12 T is reported for films of YBa2Cu3O7-x with Ba2Y(Nb,Ta)O-6 inclusion pinning centres (YBCO-BYNTO) and thicknesses in the range of 220-500 nm. J(c) values of 10 MA cm(-2) were measured at 30 K – 5 T and 10 K – 9 T with a corresponding maximum of the pinning force density at 10 K close to 1 TN m(-3). The system is very flexible regarding properties and microstructure tuning, and the growth window for achieving a particular microstructure is wide, which is very important for industrial processing. Hence, the dependence of J(c) on the magnetic field angle was readily controlled by fine tuning the pinning microstructure. Transmission electron microscopy (TEM) analysis highlighted that higher growth rates induce more splayed and denser BYNTO nanocolumns with a matching field as high as 5.2 T. Correspondingly, a strong peak at the B||c-axis is noticed when the density of vortices is lower than the nanocolumn density. YBCO-BYNTO is a very robust and reproducible composite system for high-current coated conductors over an extended range of magnetic fields and temperatures. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
|
|
Language |
|
Wos |
000432261400037 |
Publication Date |
2018-03-26 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2040-3364 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
7.367 |
Times cited |
9 |
Open Access |
OpenAccess |
|
|
Notes |
; This work was partially financially supported by EUROTAPES, a collaborative project funded by the European Commission's Seventh Framework Program (FP7/ 2007-2013) under Grant Agreement No. 280432. This work has been partially carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under grant agreement no. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. ; |
Approved |
Most recent IF: 7.367 |
|
|
Call Number |
UA @ lucian @ c:irua:151520 |
Serial |
5038 |
|
Permanent link to this record |
|
|
|
|
Author |
Mayer, J.A.; Offermans, T.; Chrapa, M.; Pfannmöller, M.; Bals, S.; Ferrini, R.; Nisato, G. |
|
|
Title |
Optical enhancement of a printed organic tandem solar cell using diffractive nanostructures |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Optics express |
Abbreviated Journal |
Opt Express |
|
|
Volume |
26 |
Issue |
26 |
Pages |
A240 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Solution processable organic tandem solar cells offer a promising approach to achieve cost-effective, lightweight and flexible photovoltaics. In order to further enhance the efficiency of optimized organic tandem cells, diffractive light-management nanostructures were designed for an optimal redistribution of the light as function of both wavelength and propagation angles in both sub-cells. As the fabrication of these optical structures is compatible with roll-to-roll production techniques such as hot-embossing or UV NIL imprinting, they present an optimal cost-effective solution for printed photovoltaics. Tandem cells with power conversion efficiencies of 8-10% were fabricated in the ambient atmosphere by doctor blade coating, selected to approximate the conditions during roll-to-roll manufacturing. Application of the light management structure onto an 8.7% efficient encapsulated tandem cell boosted the conversion efficiency of the cell to 9.5%. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000427900400003 |
Publication Date |
2018-02-26 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1094-4087 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.307 |
Times cited |
9 |
Open Access |
OpenAccess |
|
|
Notes |
; FP7 European collaborative project SUNFLOWER (FP7-ICT-2011-7, grant number 287594); German Federal Ministry of Education and Research (BMBF) (03xEK3504, project TAURUS); FP7 European project ESTEEM2 (grant number 312483); HEiKA centre FunTECH-3D. ; |
Approved |
Most recent IF: 3.307 |
|
|
Call Number |
UA @ lucian @ c:irua:150839UA @ admin @ c:irua:150839 |
Serial |
4975 |
|
Permanent link to this record |
|
|
|
|
Author |
Wang, W.; Van Duppen, B.; Van der Donck, M.; Peeters, F.M. |
|
|
Title |
Magnetopolaron effect on shallow-impurity states in the presence of magnetic and intense terahertz laser fields in the Faraday configuration |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
97 |
Issue |
6 |
Pages |
064108 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
The magnetopolaron effect on shallow-impurity states in semiconductors is investigated when subjected simultaneously to a magnetic field and an intense terahertz laser field within the Faraday configuration. We use a time-dependent nonperturbative theory to describe electron interactions. The externally applied fields are exactly included via a laser-dressed interaction potential. Through a variational approach we evaluate the binding energy of the shallow-impurity states. We find that the interaction strength of the laser-dressed Coulomb potential can not only be enhanced but also weakened by varying the two external fields. In this way, the binding energy can be tuned by the external fields and red-or blue-shifted with respect to the static binding energy. In the nonresonant polaron region, a magnetopolaron correction that includes the effects of photon process is observed. In the resonant polaron region, moreover, the resonant magnetopolaron effect accompanied by the emission and absorption of a single photon is distinctly observed. This can be modulated to be far away from the reststrahlen band. The intriguing findings of this paper can be observed experimentally and, in turn, provide a way to measure the strength of the electron-phonon interaction. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
|
|
Language |
|
Wos |
000426041900004 |
Publication Date |
2018-02-26 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
|
|
|
Notes |
; This work was supported by the National Natural Science Foundation of China (Grants No. 11404214 and No. 11455015) and the China Scholarship Council (CSC), Anhui Provincial Natural Science Foundation (Grant No. 1408085QA13), Key Projects of Anhui Provincial Department of Education (Grants No. KJ2017A406 and No. KJ2017A401). B.V.D. was financially supported by the Research Science Foundation-Flanders (FWO-Vl) through a postdoctoral fellowship and M.V.d.D. was financially supported by the Research Science Foundation-Flanders (FWO-Vl) through a doctoral fellowship. ; |
Approved |
Most recent IF: 3.836 |
|
|
Call Number |
UA @ lucian @ c:irua:149906UA @ admin @ c:irua:149906 |
Serial |
4942 |
|
Permanent link to this record |
|
|
|
|
Author |
Zhang, S.-H.; Yang, W.; Peeters, F.M. |
|
|
Title |
Veselago focusing of anisotropic massless Dirac fermions |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
97 |
Issue |
20 |
Pages |
205437 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Massless Dirac fermions (MDFs) emerge as quasiparticles in various novel materials such as graphene and topological insulators, and they exhibit several intriguing properties, of which Veselago focusing is an outstanding example with a lot of possible applications. However, up to now Veselago focusing merely occurred in p-n junction devices based on the isotropic MDF, which lacks the tunability needed for realistic applications. Here, motivated by the emergence of novel Dirac materials, we investigate the propagation behaviors of anisotropic MDFs in such a p-n junction structure. By projecting the Hamiltonian of the anisotropic MDF to that of the isotropic MDF and deriving an exact analytical expression for the propagator, precise Veselago focusing is demonstrated without the need for mirror symmetry of the electron source and its focusing image. We show a tunable focusing position that can be used in a device to probe masked atom-scale defects. This study provides an innovative concept to realize Veselago focusing relevant for potential applications, and it paves the way for the design of novel electron optics devices by exploiting the anisotropic MDF. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
|
|
Language |
|
Wos |
000433026700005 |
Publication Date |
2018-05-22 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
|
|
|
Notes |
; This work was supported by the National Key R&D Program of China (Grant No. 2017YFA0303400), the NSFC (Grants No. 11504018 and No. 11774021), the MOST of China (Grant No. 2014CB848700), and the NSFC program for “Scientific Research Center” (Grant No. U1530401). Support by the bilateral project (FWO-MOST) is gratefully acknowledged. S.H.Z. is also supported by “the Fundamental Research Funds for the Central Universities (ZY1824).” We acknowledge the computational support from the Beijing Computational Science Research Center (CSRC). ; |
Approved |
Most recent IF: 3.836 |
|
|
Call Number |
UA @ lucian @ c:irua:151501UA @ admin @ c:irua:151501 |
Serial |
5047 |
|
Permanent link to this record |
|
|
|
|
Author |
Mulkers, J.; Hals, K.M.D.; Leliaert, J.; Milošević, M.V.; Van Waeyenberge, B.; Everschor-Sitte, K. |
|
|
Title |
Effect of boundary-induced chirality on magnetic textures in thin films |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
98 |
Issue |
6 |
Pages |
064429 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
In the quest for miniaturizing magnetic devices, the effects of boundaries and surfaces become increasingly important. Here we show how the recently predicted boundary-induced Dzyaloshinskii-Moriya interaction (DMI) affects the magnetization of ferromagnetic films with a C-infinity v symmetry and a perpendicular magnetic anisotropy. For an otherwise uniformly magnetized film, we find a surface twist when the magnetization in the bulk is canted by an in-plane external field. This twist at the surfaces caused by the boundary-induced DMI differs from the common canting caused by internal DMI observed at the edges of a chiral magnet. Furthermore, we find that the surface twist due to the boundary-induced DMI strongly affects the width of the domain wall at the surfaces. We also find that the skyrmion radius increases in the depth of the film, with the average size of the skyrmion increasing with boundary-induced DMI. This increase suggests that the boundary-induced DMI contributes to the stability of the skyrmion. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
|
|
Language |
|
Wos |
000443394600004 |
Publication Date |
2018-08-31 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
|
|
|
Notes |
; The authors thank Matthias Sitte and Andre Thiaville for fruitful discussions. This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vlaanderen) through Project No. G098917N and the German Research Foundation (DFG) under the Project No. EV 196/2-1. J.L. is supported by the Ghent University Special Research Fund with a BOF postdoctoral fellowship. ; |
Approved |
Most recent IF: 3.836 |
|
|
Call Number |
UA @ lucian @ c:irua:153706UA @ admin @ c:irua:153706 |
Serial |
5093 |
|
Permanent link to this record |
|
|
|
|
Author |
Ulu Okudur, F.; D'Haen, J.; Vranken, T.; De Sloovere, D.; Verheijen, M.; Karakulina, O.M.; Abakumov, A.M.; Hadermann, J.; Van Bael, M.K.; Hardy, A. |
|
|
Title |
Ti surface doping of LiNi0.5Mn1.5O4−δpositive electrodes for lithium ion batteries |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
RSC advances |
Abbreviated Journal |
Rsc Adv |
|
|
Volume |
8 |
Issue |
13 |
Pages |
7287-7300 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
The particle surface of LiNi0.5Mn1.5O4−δ (LNMO), a Li-ion battery cathode material, has been modified by Ti cation doping through a hydrolysis–condensation reaction followed by annealing in oxygen. The effect of different annealing temperatures (500–850 °C) on the Ti distribution and electrochemical performance of the surface modified LNMO was investigated. Ti cations diffuse from the preformed amorphous ‘TiOx’ layer into the LNMO surface during annealing at 500 °C. This results in a 2–4 nm thick Ti-rich spinel surface having lower Mn and Ni content compared to the core of the LNMO particles, which was observed with scanning transmission electron microscopy coupled with compositional EDX mapping. An increase in the annealing temperature promotes the formation of a Ti bulk doped LiNi(0.5−w)Mn(1.5+w)−tTitO4 phase and Ti-rich LiNi0.5Mn1.5−yTiyO4 segregates above 750 °C. Fourier-transform infrared spectrometry indicates increasing Ni–Mn ordering with annealing temperature, for both bare and surface modified LNMO. Ti surface modified LNMO annealed at 500 °C shows a superior cyclic stability, coulombic efficiency and rate performance compared to bare LNMO annealed at 500 °C when cycled at 3.4–4.9 V vs. Li/Li+. The improvements are probably due to suppressed Ni and Mn dissolution with Ti surface doping. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000425508900064 |
Publication Date |
2018-02-13 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2046-2069 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.108 |
Times cited |
9 |
Open Access |
OpenAccess |
|
|
Notes |
This research is supported by the Research Foundation Flanders (FWO Vlaanderen, grant number G040116N). This project receives the support of the European Union, the European Regional Development Fund ERDF, Flanders Innovation & Entrepreneurship and the Province of Limburg (project 936). Greet Cuyvers and Gilles Bonneux (UHasselt) are acknowledged for the ICP-AES sample preparation and measurements. Vera Meynen and Karen Leyssens (Antwerp University, Belgium) are acknowledged for the BET measurements. Special thanks to Bart Ruttens (UHasselt) for XRD measurements and discussions on the refinements. |
Approved |
Most recent IF: 3.108 |
|
|
Call Number |
EMAT @ emat @c:irua:149513 |
Serial |
4905 |
|
Permanent link to this record |
|
|
|
|
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. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000460200900001 |
Publication Date |
2018-08-07 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2045-2322 |
ISBN |
|
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 |
EMAT @ emat @c:irua:155772 |
Serial |
5136 |
|
Permanent link to this record |
|
|
|
|
Author |
Pahlke, P.; Sieger, M.; Ottolinger, R.; Lao, M.; Eisterer, M.; Meledin, A.; Van Tendeloo, G.; Haenisch, J.; Holzapfel, B.; Schultz, L.; Nielsch, K.; Huehne, R. |
|
|
Title |
Influence of artificial pinning centers on structural and superconducting properties of thick YBCO films on ABAD-YSZ templates |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
|
|
Volume |
31 |
Issue |
4 |
Pages |
044007 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Recent efforts in the development of YBa2Cu3O7-x (YBCO) coated conductors are devoted to the increase of the critical current I-c in magnetic fields. This is typically realized by growing thicker YBCO layers as well as by the incorporation of artificial pinning centers. We studied the growth of doped YBCO layers with a thickness of up to 7 mu m using pulsed laser deposition with a growth rate of about 1.2 nm s(-1). Industrially fabricated ion-beam textured YSZ templates based on metal tapes were used as substrates for this study. The incorporation of BaHfO3 (BHO) or Ba2Y(Nb0.5Ta0.5)O-6 (BYNTO) secondary phase additions leads to a denser microstructure compared to undoped films. A purely c-axis-oriented YBCO growth is preserved up to a thickness of about 4 mu m, whereas misoriented texture components were observed in thicker films. The critical temperature is slightly reduced compared to undoped films and independent of film thickness. The critical current density J(c) of the BHO- and BYNTO-doped YBCO layers is lower at 77 K and self-field compared to pure YBCO layers; however, I-c increases up to a thickness of 5 mu m. A comparison between films with a thickness of 1.3 mu m revealed that the anisotropy of the critical current density J(c)(theta) strongly depends on the incorporated pinning centers. Whereas BHO nanorods lead to a strong B vertical bar vertical bar c-axis peak, the overall anisotropy is significantly reduced by the incorporation of BYNTO forming a mixture of short c-axis-oriented nanorods and small (a-b)-oriented platelets. As a result, the J(c) values of the doped films outperform the undoped samples at higher fields and lower temperatures for most magnetic field directions. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
|
|
Language |
|
Wos |
000442196400001 |
Publication Date |
2018-02-15 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0953-2048 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.878 |
Times cited |
9 |
Open Access |
OpenAccess |
|
|
Notes |
; The authors acknowledge financial support from EURO-TAPES, a collaborative project funded by the European Union's Seventh Framework Programme (FP7/ 2007-2013) under Grant Agreement no. 280432. We thank A Usoskin (Bruker HTS GmbH, Germany) for the provision of buffered templates, and M Bianchetti, A Kursumovic and J L Mac-Manus-Driscoll (University of Cambridge, UK) for the supply of BYNTO targets. The authors also gratefully acknowledge the technical assistance of J Scheiter, M Kuhnel, U Besold (IFW) and R Nast (KIT). ; |
Approved |
Most recent IF: 2.878 |
|
|
Call Number |
UA @ lucian @ c:irua:153775 |
Serial |
5108 |
|
Permanent link to this record |
|
|
|
|
Author |
Florea, A.; Cowen, T.; Piletsky, S.; De Wael, K. |
|
|
Title |
Polymer platforms for selective detection of cocaine in street samples adulterated with levamisole |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Talanta : the international journal of pure and applied analytical chemistry |
Abbreviated Journal |
Talanta |
|
|
Volume |
186 |
Issue |
186 |
Pages |
362-367 |
|
|
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
|
|
Abstract |
Accurate drug detection is of utmost importance for fighting against drug abuse. With a high number of cutting agents and adulterants being added to cut or mask drugs in street powders the number of false results is increasing. We demonstrate for the first time the usefulness of employing polymers readily synthesized by electrodeposition to selectively detect cocaine in the presence of the commonly used adulterant levamisole. The polymers were selected by computational modelling to exhibit high binding affinity towards cocaine and deposited directly on the surface of graphene-modified electrodes via electropolymerization. The resulting platforms allowed a distinct electrochemical signal for cocaine, which is otherwise suppressed by levamisole. Square wave voltammetry was used to quantify cocaine alone and in the presence of levamisole. The usefulness of the platforms was demonstrated in the screening of real street samples. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000435048800049 |
Publication Date |
2018-04-25 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0039-9140; 1873-3573 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4.162 |
Times cited |
9 |
Open Access |
|
|
|
Notes |
; This project has received funding from the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement no. 753223 Narcoreader. This work was also supported by IOF-SBO (UAntwerp). The authors thank Gert Nuyts for the help with SEM analyses. ; |
Approved |
Most recent IF: 4.162 |
|
|
Call Number |
UA @ admin @ c:irua:151250 |
Serial |
5777 |
|
Permanent link to this record |
|
|
|
|
Author |
Minjauw, M.M.; Solano, E.; Sree, S.P.; Asapu, R.; Van Daele, M.; Ramachandran, R.K.; Heremans, G.; Verbruggen, S.W.; Lenaerts, S.; Martens, J.A.; Detavernier, C.; Dendooven, J. |
|
|
Title |
Plasma-enhanced atomic layer deposition of silver using Ag(fod)(PEt3) and NH3-plasma |
Type |
A1 Journal article |
|
Year |
2017 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
|
|
Volume |
29 |
Issue |
17 |
Pages |
7114-7121 |
|
|
Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
|
|
Abstract |
A plasma-enhanced atomic layer deposition (ALD) process using the Ag(fod)(PEt3) precursor [(triethylphosphine)(6,6,7,7,8,8,8-heptafluoro-2,2-dimethy1-3,5-octanedionate)silver(I)] in combination with NH3-plasma is reported. The steady growth rate of the reported process (0.24 +/- 0.03 nm/cycle) was found to be 6 times larger than that of the previously reported Ag ALD process based on the same precursor in combination with H-2-plasma (0.04 +/- 0.02 nm/cycle). The ALD characteristics of the H-2-plasma and NH3-plasma processes were verified. The deposited Ag films were polycrystalline face-centered cubic Ag for both processes. The film morphology was investigated by ex situ scanning electron microscopy and grazing-incidence small-angle X-ray scattering, and it was found that films grown with the NH3-plasma process exhibit a much higher particle areal density and smaller particle sizes on oxide substrates compared to those deposited using the H-2-plasma process. This control over morphology of the deposited Ag is important for applications in catalysis and plasmonics. While films grown with the H-2-plasma process had oxygen impurities (similar to 9 atom %) in the bulk, the main impurity for the NH3-plasma process was nitrogen (similar to 7 atom %). In situ Fourier transform infrared spectroscopy experiments suggest that these nitrogen impurities are derived from NH surface groups generated during the NH3-plasma, which interact with the precursor molecules during the precursor pulse. We propose that the reaction of these surface groups with the precursor leads to additional deposition of Ag atoms during the precursor pulse compared to the H-2-plasma process, which explains the enhanced growth rate of the NH3-plasma process. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000410868600012 |
Publication Date |
2017-08-09 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0897-4756 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
9.466 |
Times cited |
9 |
Open Access |
|
|
|
Notes |
; M.M.M. and J.D. acknowledge the Fonds Wetenschappelijk Onderzoek Vlaanderen (FWO Vlaanderen) for financial support through a personal research grant. We also acknowledge FWO Vlaanderen for providing project funding for this work. We are grateful to the ESRF staff for smoothly running the synchrotron and beamline facilities. We also thank Olivier Janssens for performing the SEM measurements and Stefaan Broekaert for mechanical assistance. J.A.M. acknowledges the Flemish Government for long-term structural funding (Methusalem). ; |
Approved |
Most recent IF: 9.466 |
|
|
Call Number |
UA @ admin @ c:irua:146757 |
Serial |
5983 |
|
Permanent link to this record |
|
|
|
|
Author |
Eliaerts, J.; Dardenne, P.; Meert, N.; Van Durme, F.; Samyn, N.; Janssens, K.; De Wael, K. |
|
|
Title |
Rapid classification and quantification of cocaine in seized powders with ATR-FTIR and chemometrics |
Type |
A1 Journal article |
|
Year |
2017 |
Publication |
Drug testing and analysis |
Abbreviated Journal |
Drug Test Anal |
|
|
Volume |
9 |
Issue |
10 |
Pages |
1480-1489 |
|
|
Keywords |
A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
|
|
Abstract |
Traditionally, fast screening for the presence of cocaine in unknown powders is performed by means of colour tests. The major drawbacks of these tests are subjective colour evaluation depending on the operator (50 shades of blue) and a lack of selectivity. An alternative fast screening technique is Fourier Transform InfraRed (FTIR) spectrometry. This technique provides spectra that are difficult to interpret without specialized expertise and showing a lack of sensitivity for the detection of cocaine in mixtures. To overcome these limitations, a portable FTIR spectrometer using Attenuated Total Reflectance (ATR) sampling was combined with a multivariate technique, called Support Vector Machines (SVM). Representative street drug powders (n = 482), seized during the period January 2013 to July 2015, and reference powders (n = 33) were used to build and validate a classification model (n = 515) and a quantification model (n = 378). Both models were compared with the conventional chromatographic techniques. The SVM classification model showed a high sensitivity, specificity and efficiency (99%). The SVM quantification model determined cocaine content with a root mean squared error of prediction (RMSEP) of 6% calculated over a wide working range from 4 to 99 w%. In conclusion, the developed models resulted in a clear output (cocaine detected or cocaine not detected) and a reliable estimation of the cocaine content in a wide variety of mixtures. The ATR-FTIR technique combined with SVM is a straightforward, user-friendly and fast approach for routine classification and quantification of cocaine in seized powders. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000413685200001 |
Publication Date |
2016-12-17 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1942-7603; 1942-7611 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.469 |
Times cited |
9 |
Open Access |
|
|
|
Notes |
; ; |
Approved |
Most recent IF: 3.469 |
|
|
Call Number |
UA @ admin @ c:irua:139483 |
Serial |
5799 |
|
Permanent link to this record |
|
|
|
|
Author |
Abeysinghe, D.; Smith, M.D.; Yeon, J.; Tran, T.T.; Sena, R.P.; Hadermann, J.; Halasyamani, P.S.; zur Loye, H.-C. |
|
|
Title |
Crystal growth and structure analysis of Ce-18-W-10-O-57 : a complex oxide containing tungsten in an unusual trigonal prismatic coordination environment |
Type |
A1 Journal article |
|
Year |
2017 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
|
|
Volume |
56 |
Issue |
5 |
Pages |
2566-2575 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
The noncentrosymmetric tungstate oxide, Ce18W10O57) was synthesized for the first time as high-quality single crystals via the molten chloride flux method and structurally characterized by single-crystal X-ray diffraction. The compound is a structural analogue to the previously reported La18W10O57, which crystallizes in the hexagonal space group P (6) over bar 2c. The +3 oxidation state of cerium in Ce18W10O57 was achieved via the in situ reduction of Ce(IV) to Ce(III) using Zn metal. The structure consists of both isolated and face-shared WO6 octahedra and, surprisingly, isolated WO6 trigonal prisms. A careful analysis of the packing arrangement in the structure makes it possible to explain the unusual structural architecture of Ce18W10O57, which is described in detail. The temperature-dependent magnetic susceptibility of Ce18W10O57 indicates that the cerium(III) f(1) cations do not order magnetically and exhibit simple paramagnetic behavior. The SHG efficiency of Ln(18)W(10)O(57) (Ln = La, Ce) was measured as a function of particle size, and both compounds were found to be SHG active with efficiency approximately equal to that of alpha-SiO2. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
|
|
Language |
|
Wos |
000395847300026 |
Publication Date |
2017-02-15 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0020-1669 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4.857 |
Times cited |
9 |
Open Access |
Not_Open_Access |
|
|
Notes |
; Financial support for this work was provided by the National Science Foundation under DMR-1301757 and is gratefully acknowledged. T.T.T. and P.S.H. thank the Welch Foundation (Grant E-1457) and NSF-DMR-1503573. ; |
Approved |
Most recent IF: 4.857 |
|
|
Call Number |
UA @ lucian @ c:irua:142449 |
Serial |
4643 |
|
Permanent link to this record |
|
|
|
|
Author |
Grieten, E.; Schalm, O.; Tack, P.; Bauters, S.; Storme, P.; Gauquelin, N.; Caen, J.; Patelli, A.; Vincze, L.; Schryvers, D. |
|
|
Title |
Reclaiming the image of daguerreotypes: Characterization of the corroded surface before and after atmospheric plasma treatment |
Type |
A1 Journal article |
|
Year |
2017 |
Publication |
Journal of cultural heritage |
Abbreviated Journal |
J Cult Herit |
|
|
Volume |
|
Issue |
|
Pages |
|
|
|
Keywords |
A1 Journal article; Art; History; Electron microscopy for materials research (EMAT); Antwerp Cultural Heritage Sciences (ARCHES) |
|
|
Abstract |
Technological developments such as atmospheric plasma jets for industry can be adapted for the conservation of cultural heritage. This application might offer a potential method for the removal or transformation of the corrosion on historical photographs. We focus on daguerreotypes and present an in-depth study of the induced changes by a multi-analytical approach using optical microscopy, scanning electron microscopy, different types of transmission electron microscopy and X-ray absorption fine structure. The H2-He afterglow removes S from an Ag2S or Cu2S layer which results in a nano-layer of metallic Ag or Cu on top of the deteriorated microstructure. In case the corrosion layer is composed of Cu-Ag-S compounds, our proposed setup can be used to partially remove the corrosion. These alterations of the corrosion results in an improvement in the readability of the photographic image. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000414230700007 |
Publication Date |
2017-06-16 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1296-2074 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
1.838 |
Times cited |
9 |
Open Access |
Not_Open_Access |
|
|
Notes |
The authors thank Herman Maes for the daguerreotypes used in this study. The authors also acknowledge the opportunity to perform XAFS measurements at the DUBBLE beamline of the ESRF storage ring under the approval of the advisory Committee (beam time nr. 26-01-990) and acknowledge the DUBBLE beamline staff for their support. They are also grateful for the financial support by the EU-FP7 grant PANNA no. 282998 and the STIMPRO project FFB150215 of the University of Antwerp. Pieter Tack is funded by a Ph.D. grant of the Agency for Innovation by Science and Technology (IWT). |
Approved |
Most recent IF: 1.838 |
|
|
Call Number |
EMAT @ emat @c:irua:144430 |
Serial |
4625 |
|
Permanent link to this record |