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Records |
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Author |
van Dyck, D.; Van Aert, S.; Croitoru, M. |
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Title |
Atomic resolution electron tomography: a dream? |
Type |
A1 Journal article |
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Year |
2006 |
Publication |
International journal of materials research |
Abbreviated Journal |
Int J Mater Res |
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Volume |
97 |
Issue |
7 |
Pages |
872-879 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Vision lab |
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Wos |
000239916700003 |
Publication Date |
2013-12-09 |
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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 |
1862-5282;2195-8556; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
0.681 |
Times cited |
6 |
Open Access |
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Notes |
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Approved |
Most recent IF: 0.681; 2006 IF: NA |
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Call Number |
UA @ lucian @ c:irua:60965 |
Serial |
176 |
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Permanent link to this record |
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Author |
van Dyck, D.; Lobato, I.; Chen, F.-R.; Kisielowski, C. |
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Title |
Do you believe that atoms stay in place when you observe them in HREM? |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Micron |
Abbreviated Journal |
Micron |
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Volume |
68 |
Issue |
68 |
Pages |
158-163 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
Recent advancements in aberration-corrected electron microscopy allow for an evaluation of unexpectedly large atom displacements beyond a resolution limit of similar to 0.5 angstrom, which are found to be dose-rate dependent in high resolution images. In this paper we outline a consistent description of the electron scattering process, which explains these unexpected phenomena. Our approach links thermal diffuse scattering to electron beam-induced object excitation and relaxation processes, which strongly contribute to the image formation process. The effect can provide an explanation for the well-known contrast mismatch (“Stobbs factor”) between image calculations and experiments. (C) 2014 Elsevier Ltd. All rights reserved. |
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Place of Publication |
Oxford |
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Wos |
000348016500023 |
Publication Date |
2014-09-16 |
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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 |
0968-4328; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.98 |
Times cited |
11 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1.98; 2015 IF: 1.988 |
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Call Number |
c:irua:123802 |
Serial |
745 |
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Permanent link to this record |
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Author |
van Dyck, D.; Croitoru, M.D. |
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Title |
Statistical method for thickness measurement of amorphous objects |
Type |
A1 Journal article |
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Year |
2007 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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Volume |
90 |
Issue |
24 |
Pages |
241911-241913 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
The authors propose a nondestructive method for the determination of the thickness of an amorphous sample. This method is based on the statistics of the phase of the electron exit wave function, which depend on the number of atoms traversed by the incident electron which itself is a function of the thickness of the object. The accuracy of this method has been checked numerically by the multislice method and compared with that based on the mean inner potential. (c) 2007 American Institute of Physics. |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
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Wos |
000247305400033 |
Publication Date |
2007-06-14 |
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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 |
0003-6951; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.411 |
Times cited |
4 |
Open Access |
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Notes |
Fwo |
Approved |
Most recent IF: 3.411; 2007 IF: 3.596 |
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Call Number |
UA @ lucian @ c:irua:102671 |
Serial |
3158 |
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Permanent link to this record |
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Author |
Van Duppen, B.; Vasilopoulos, P.; Peeters, F.M. |
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Title |
Spin and valley polarization of plasmons in silicene due to external fields |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
3 |
Pages |
035142 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The electronic properties of the two-dimensional material silicene are strongly influenced by the application of a perpendicular electric field E-z and of an exchange field M due to adatoms positioned on the surface or a ferromagnetic substrate. Within the random phase approximation, we investigate how electron-electron interactions are affected by these fields and present analytical and numerical results for the dispersion of plasmons, their lifetime, and their oscillator strength. We find that the combination of the fields E-z and M brings a spin and valley texture to the particle-hole excitation spectrum and allows the formation of spin-and valley-polarized plasmons. When the Fermi level lies in the gap of one spin in one valley, the intraband region of the corresponding spectrum disappears. For zero E-z and finite M the spin symmetry is broken and spin polarization is possible. The lifetime and oscillator strength of the plasmons are shown to depend strongly on the number of spin and valley type electrons that form the electron-hole pairs. |
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Wos |
000339974700001 |
Publication Date |
2014-07-30 |
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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 |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
49 |
Open Access |
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Notes |
; This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro-GRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-Vl) by an aspirant grant to B.V.D., the Methusalem Foundation of the Flemish Government, and by the Canadian NSERC Grant No. OGP0121756. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:118776 |
Serial |
3080 |
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Permanent link to this record |
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Author |
Van Duppen, B.; Tomadin, A.; Grigorenko, A.N.; Polini, M. |
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Title |
Current-induced birefringent absorption and non-reciprocal plasmons in graphene |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
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Volume |
3 |
Issue |
3 |
Pages |
015011 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We present extensive calculations of the optical and plasmonic properties of a graphene sheet carrying a dc current. By calculating analytically the density-density response function of current-carrying states at finite temperature, we demonstrate that an applied dc current modifies the Pauli blocking mechanism and that absorption acquires a birefringent character with respect to the angle between the in-plane light polarization and current flow. Employing the random phase approximation at finite temperature, we show that graphene plasmons display a degree of non-reciprocity and collimation that can be tuned with the applied current. We discuss the possibility to measure these effects. |
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Corporate Author |
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Wos |
000373936300031 |
Publication Date |
2016-02-23 |
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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 |
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Series Issue |
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Edition |
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ISSN |
2053-1583 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.937 |
Times cited |
5 |
Open Access |
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Notes |
This work was supported by the EC under the Graphene Flagship program (contract no. CNECT- ICT-604391) and MIUR through the program ‘Pro- getti Premiali 2012’ – Project ‘ABNANOTECH’. B.V. D. wishes to thank the Scuola Normale Superiore (Pisa, Italy) for the kind hospitality while this work was carried out and Research Foundation Flanders (FWO- Vl) for a PhD Fellowship. |
Approved |
Most recent IF: 6.937 |
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Call Number |
c:irua:131900 c:irua:131900 |
Serial |
4017 |
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Permanent link to this record |
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Author |
Van Duppen, B.; Sena, S.H.R.; Peeters, F.M. |
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Title |
Multiband tunneling in trilayer graphene |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
87 |
Issue |
19 |
Pages |
195439-10 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The electronic tunneling properties of the two stable forms of trilayer graphene (TLG), rhombohedral ABC and Bernal ABA, are examined for p-n and p-n-p junctions as realized by using a single gate (SG) or a double gate (DG). For the rhombohedral form, due to the chirality of the electrons, the Klein paradox is found at normal incidence for SG devices, while at high-energy interband scattering between additional propagation modes can occur. The electrons in Bernal ABA TLG can have a monolayer- or bilayer-like character when incident on a SG device. Using a DG, however, both propagation modes will couple by breaking the mirror symmetry of the system, which induces intermode scattering and resonances that depend on the width of the DG p-n-p junction. For ABC TLG the DG opens up a band gap which suppresses Klein tunneling. The DG induces also an unexpected asymmetry in the tunneling angle for single-valley electrons. |
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Wos |
000319281700004 |
Publication Date |
2013-05-23 |
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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 |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
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Notes |
; This work was supported by the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-VI) by an aspirant research grant to B. Van Duppen and the Methusalem Programme of the Flemish Government. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
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Call Number |
UA @ lucian @ c:irua:108998 |
Serial |
2216 |
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Permanent link to this record |
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Author |
Van Duppen, B.; Peeters, F.M. |
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Title |
Four-band tunneling in bilayer graphene |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
87 |
Issue |
20 |
Pages |
205427-10 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The conductance, the transmission, and the reflection probabilities through rectangular potential barriers and p-n junctions are obtained for bilayer graphene taking into account the four bands of the energy spectrum. We have evaluated the importance of the skew hopping parameters gamma(3) and gamma(4) to these properties and show that for energies E > gamma(1)/100 their effect is negligible. For high energies two modes of propagation exist and we investigate scattering between these modes. For perpendicular incidence both propagation modes are decoupled, and scattering between them is forbidden. This extends the concept of pseudospin as defined within the two-band approximation to a four-band model and corresponds to the (anti) symmetry of the wave functions under in-plane mirroring. New transmission resonances are found that appear as sharp peaks in the conductance which are absent in the two-band approximation. The application of an interlayer bias to the system (1) breaks the pseudospin structure, (2) opens a band gap that results in a distinct feature of suppressed transmission in the conductance, and (3) breaks the angular symmetry with respect to normal incidence in the transmission and reflection. |
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Wos |
000319282000002 |
Publication Date |
2013-05-21 |
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Series Editor |
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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 |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
37 |
Open Access |
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Notes |
; This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro-GRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-Vl) by an aspirant research grant to B. Van Duppen and the Methusalem Programme of the Flemish Government. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
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Call Number |
UA @ lucian @ c:irua:109001 |
Serial |
1269 |
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Permanent link to this record |
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Author |
Van Duppen, B.; Peeters, F.M. |
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Title |
Klein paradox for a pn junction in multilayer graphene |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Europhysics letters |
Abbreviated Journal |
Epl-Europhys Lett |
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Volume |
102 |
Issue |
2 |
Pages |
27001-27005 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Charge carriers in single and multilayered graphene systems behave as chiral particles due to the particular lattice symmetry of the crystal. We show that the interplay between the meta-material properties of graphene multilayers and the pseudospinorial properties of the charge carriers result in the occurrence of Klein and anti-Klein tunneling for rhombohedral stacked multilayers. We derive an algebraic formula predicting the angles at which these phenomena occur and support this with numerical calculations for systems up to four layers. We present a decomposition of an arbitrarily stacked multilayer into pseudospin doublets that have the same properties as rhombohedral systems with a lower number of layers. Copyright (C) EPLA, 2013 |
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Corporate Author |
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Place of Publication |
Paris |
Editor |
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Wos |
000319617700017 |
Publication Date |
2013-05-02 |
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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 |
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Series Issue |
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Edition |
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ISSN |
0295-5075;1286-4854; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.957 |
Times cited |
17 |
Open Access |
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Notes |
; We thank S. GILLIS for valuable discussions. This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro-GRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-Vl) by an aspirant research grant to B. Van Duppen and the Methusalem Programme of the Flemish Government. ; |
Approved |
Most recent IF: 1.957; 2013 IF: 2.269 |
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Call Number |
UA @ lucian @ c:irua:109665 |
Serial |
1763 |
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Permanent link to this record |
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Author |
Van Duppen, B.; Peeters, F.M. |
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Title |
Thermodynamic properties of the electron gas in multilayer graphene in the presence of a perpendicular magnetic field |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
88 |
Issue |
24 |
Pages |
245429-7 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The thermodynamic properties of the electron gas in multilayer graphene depend strongly on the number of layers and the type of stacking. Here we analyze how those properties change when we vary the number of layers for rhombohedral stacked multilayer graphene and compare our results with those from a conventional two-dimensional electron gas. We show that the highly degenerate zero-energy Landau level which is partly filled with electrons and partly with holes has a strong influence on the values of the different thermodynamic quantities. |
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Wos |
000328686900006 |
Publication Date |
2014-01-09 |
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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 |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
2 |
Open Access |
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Notes |
; The authors would like to thank C. De Beule for enlightening discussions. This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro-GRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-Vl) by an aspirant research grant to B.V.D., and the Methusalem Program of the Flemish Government. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
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Call Number |
UA @ lucian @ c:irua:113700 |
Serial |
3635 |
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Permanent link to this record |
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Author |
van Duijn, F.; Osca, J.; Sorée, B. |
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Title |
Skyrmion elongation, duplication, and rotation by spin-transfer torque under spatially varying spin current |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
104 |
Issue |
9 |
Pages |
094426 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The effect of the spatially varying spin current on a skyrmion is numerically investigated. It is shown that an inhomogeneous current density induces an elongation of the skyrmion. This elongation can be controlled using current pulses of different strength and duration. Long current pulses lead to a splitting that forms two replicas of the initial skyrmion while for short pulses the elongated skyrmion relaxes back to its initial circular state through rotation in the MHz-GHz frequency range. The frequency is dependent on the strength of the damping coefficient. |
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Wos |
000704236000002 |
Publication Date |
2021-09-21 |
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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 |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:182467 |
Serial |
7018 |
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Permanent link to this record |
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Author |
Van Dijck, J.G.; Mampuys, P.; Ching, H.Y.V.; Krishnan, D.; Baert, K.; Hauffman, T.; Verbeeck, J.; Van Doorslaer, S.; Maes, B.U.W.; Dorbec, M.; Buekenhoudt, A.; Meynen, V. |
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Title |
Synthesis – properties correlation and the unexpected role of the titania support on the Grignard surface modification |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Applied Surface Science |
Abbreviated Journal |
Appl Surf Sci |
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Volume |
527 |
Issue |
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Pages |
146851-17 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA); Organic synthesis (ORSY); Applied Electrochemistry & Catalysis (ELCAT) |
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Abstract |
While the impact of reaction conditions on surface modification with Grignard reactants has been studied for silica supports, such information is absent for metal oxides like titania. Differences between modified titania and silica are observed, making it paramount to explore the reaction mechanism. A detailed study on the impact of the reaction conditions is reported, with a focus on the chain length of the alkyl Grignard reactant, its concentration, the reaction time and temperature, and the type of titania support. While the increase in the chain length reduces the amount of organic groups on the surface, the concentration, time and temperature show little/no influence on the modification degree. However, the type of titania support used and the percentage of amorphous phase present has a significant impact on the amount of grafted groups. Even though the temperature and concentration show no clear impact on the modification degree, they can cause changes in the surface hydroxyl population, which are thus not linked to the modification degree. Furthermore, the titania support is reduced during functionalization. This reduction dependents on the reaction temperature, the titania support and the chain length of the Grignard reactant. Similarly, this reduction is not linked to the modification degree. |
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Wos |
000564205300003 |
Publication Date |
2020-06-03 |
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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 |
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Series Issue |
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Edition |
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ISSN |
0169-4332 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.7 |
Times cited |
5 |
Open Access |
OpenAccess |
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Notes |
; The FWO (Fonds Wetenschappelijk Onderzoek) is gratefully acknowledged for the VITO-FWO grant of fellow Jeroen G. Van Dijck (11W9416N) and the financial support granted in project GO12712N. The E.U. is acknowledged for H.Y. Vincent Ching's H2020-MSCA-IF (grant number 792946, iSPY). Dileep Krishnan and Johan Verbeeck acknowledge funding from GOA project “solarpaint” of the University of Antwerp. ; |
Approved |
Most recent IF: 6.7; 2020 IF: 3.387 |
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Call Number |
UA @ admin @ c:irua:169722 |
Serial |
6712 |
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Permanent link to this record |
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Author |
van der Torren, A.J.H.; Liao, Z.; Xu, C.; Gauquelin, N.; Yin, C.; Aarts, J.; van der Molen, S.J. |
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Title |
Formation of a conducting LaAlO3/SrTiO3 interface studied by low-energy electron reflection during growth |
Type |
A1 Journal Article |
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Year |
2017 |
Publication |
Physical Review Materials |
Abbreviated Journal |
Phys. Rev. Materials |
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Volume |
1 |
Issue |
7 |
Pages |
075001 |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
The two-dimensional electron gas occurring between the band insulators SrTiO 3 and LaAlO 3 continues to attract considerable interest, due to the possibility of dynamic control over the carrier density, and the ensuing phenomena such as magnetism and superconductivity. The formation of this conducting interface is sensitive to the growth conditions, but despite numerous investigations, there are still questions about the details of the physics involved. In particular, not much is known about the electronic structure of the growing LaAlO 3 layer at the growth temperature (around 800 ◦ C) in oxygen (pressure around 5 × 10 −5 mbar), since analysis techniques at these conditions are not readily available. We developed a pulsed laser deposition system inside a low-energy electron microscope in order to study this issue. The setup allows for layer-by-layer growth control and in-situ measurements of the angle-dependent electron reflection intensity, which can be used as a fingerprint of the electronic structure of the surface layers during growth. By using different substrate terminations and growth conditions we observe two families of reflectivity maps, which we can connect either to samples with an AlO 2 -rich surface and a conducting interface; or to samples with a LaO-rich surface and an insulating interface. Our observations emphasize that substrate termination and stoichiometry determine the electronic structure of the growing layer, and thereby the conductance of the interface. |
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Thesis |
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Place of Publication |
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Wos |
000418770200003 |
Publication Date |
2017-12-06 |
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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 |
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Series Issue |
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Edition |
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ISSN |
2475-9953 |
ISBN |
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Additional Links |
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Impact Factor |
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Times cited |
2 |
Open Access |
Not_Open_Access |
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Notes |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek; Fonds Wetenschappelijk Onderzoek, G.0044.13N ; European Cooperation in Science and Technology, MP 1308 ; We want to acknowledge Ruud Tromp, Daniel Gee- len, Johannes Jobst, Regina Dittmann, Gert Jan Koster, Guus Rijnders and Jo Verbeek for discussions and ad- vice and Ruud van Egmond and Marcel Hesselberth for technical assistance. This work was supported by the Netherlands Organization for Scientific Research (NWO) by means of an ”NWO Groot” grant and by the Leiden- Delft Consortium NanoFront. The work is part of the re- search programmes NWOnano and DESCO, which are fi- nanced by NWO. N.G. acknowledges funding through the GOA project “Solarpaint” of the University of Antwerp and from the FWO project G.0044.13N (Charge order- ing). The microscope used in this work was partly funded by the Hercules Fund from the Flemish Government. We would also like to acknowledge networking support by the COST Action MP 1308 (COST TO-BE). |
Approved |
Most recent IF: NA |
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Call Number |
EMAT @ emat @ |
Serial |
4903 |
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Permanent link to this record |
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Author |
van der Stam, W.; Gradmann, S.; Altantzis, T.; Ke, X.; Baldus, M.; Bals, S.; de Mello Donega, C. |
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Title |
Shape Control of Colloidal Cu2-x S Polyhedral Nanocrystals by Tuning the Nucleation Rates |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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|
Volume |
28 |
Issue |
28 |
Pages |
6705-6715 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Synthesis protocols for colloidal nanocrystals (NCs) with narrow size and shape distributions are of particular interest for the successful implementation of these nanocrystals into devices. Moreover, the preparation of NCs with well-defined crystal phases is of key importance. In this work, we show that Sn(IV)-thiolate complexes formed in situ strongly influence the nucleation and growth rates of colloidal Cu2-x S polyhedral NCs, thereby dictating their final size, shape, and crystal structure. This allowed us to successfully synthesize hexagonal bifrustums and hexagonal bipyramid NCs with low-chalcocite crystal structure, and hexagonal nanoplatelets with various thicknesses and aspect ratios with the djurleite crystal structure, by solely varying the concentration of Sn(IV)-additives (namely, SnBr4) in the reaction medium. Solution and solid-state 119Sn NMR measurements show that SnBr4 is converted in situ to Sn(IV)-thiolate complexes, which increase the Cu2-x S nucleation barrier without affecting the precursor conversion rates. This influences both the nucleation and growth rates in a concentration-dependent fashion and leads to a better separation between nucleation and growth. Our approach of tuning the nucleation and growth rates with in situ-generated Sn-thiolate complexes might have a more general impact due to the availability of various metal-thiolate complexes, possibly resulting in polyhedral NCs of a wide variety of metal-sulfide compositions. |
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Address |
Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University , P.O. Box 80000, 3508 TA Utrecht, The Netherlands |
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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 |
English |
Wos |
000384399000037 |
Publication Date |
2016-09-02 |
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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 |
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Series Issue |
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Edition |
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ISSN |
0897-4756 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
27 |
Open Access |
OpenAccess |
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Notes |
W.v.d.S. and C.d.M.D. acknowledge financial support from the division of Chemical Sciences (CW) of The Netherlands Organization for Scientific Research (NWO) under grant number ECHO.712.012.001. M.B. also gratefully acknowledges NWO for funding the NMR infrastructure (Middle Groot program, grant number 700.58.102). S.B. acknowledges financial support from the European Research Council (ERC Starting Grant # 335078-COLOURATOMS).; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); |
Approved |
Most recent IF: 9.466 |
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Call Number |
EMAT @ emat @ c:irua:135928 |
Serial |
4285 |
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Permanent link to this record |
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Author |
van der Stam, W.; Geuchies, J.J.; Altantzis, T.; van den Bos, K.H.W.; Meeldijk, J.D.; Van Aert, S.; Bals, S.; Vanmaekelbergh, D.; de Mello Donega, C. |
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Title |
Highly Emissive Divalent-Ion-Doped Colloidal CsPb1–xMxBr3Perovskite Nanocrystals through Cation Exchange |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
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Volume |
139 |
Issue |
139 |
Pages |
4087-4097 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Colloidal CsPbX3 (X = Br, Cl, and I) perovskite nanocrystals (NCs) have emerged as promising phosphors and solar cell materials due to their remarkable optoelectronic properties. These properties can be tailored by not only controlling the size and shape of the NCs but also postsynthetic composition tuning through topotactic
anion exchange. In contrast, property control by cation exchange is still underdeveloped for colloidal CsPbX3 NCs. Here, we present a method that allows partial cation exchange in colloidal CsPbBr3 NCs, whereby Pb2+ is exchanged for several isovalent cations, resulting in doped CsPb1−xMxBr3 NCs (M= Sn2+, Cd2+, and Zn2+; 0 < x ≤ 0.1), with preservation of the original NC shape. The size of the parent NCs is also preserved in the product NCs, apart from a small (few
%) contraction of the unit cells upon incorporation of the guest cations. The partial Pb2+ for M2+ exchange leads to a blue-shift of the optical spectra, while maintaining the high photoluminescence quantum yields (>50%), sharp absorption features, and narrow emission of the parent CsPbBr3 NCs. The blue-shift in the optical spectra is attributed to the lattice contraction that accompanies the Pb2+ for M2+ cation exchange and is observed to scale linearly with the lattice contraction. This work opens up new possibilities to engineer the properties of halide perovskite NCs, which to date are demonstrated to be the only known
system where cation and anion exchange reactions can be sequentially combined while preserving the original NC shape, resulting in compositionally diverse perovskite NCs. |
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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 |
000397477700027 |
Publication Date |
2017-03-10 |
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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 |
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Series Issue |
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Edition |
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ISSN |
0002-7863 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.858 |
Times cited |
535 |
Open Access |
OpenAccess |
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Notes |
W.v.d.S. and C.d.M.D. acknowledge financial support from the division of Chemical Sciences (CW) of The Netherlands Organization for Scientific Research (NWO) under grant number ECHO.712.012.001. J.J.G. and D.V. acknowledge financial support from the Debye Graduate program. S.B. acknowledges financial support from the European Research Council (ERC Starting Grant # 335078-COLOURATOMS). K.H.W.v.d.B., S.B., S.V.A. and T.A. acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0368.15N, G.0369.15N), a Ph.D. grant to K.H.W.v.d.B, and a postdoctoral research grant to T.A. (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ECAS_Sara |
Approved |
Most recent IF: 13.858 |
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Call Number |
EMAT @ emat @ c:irua:141754UA @ admin @ c:irua:141754 |
Serial |
4482 |
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Permanent link to this record |
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Author |
van der Stam, W.; Bladt, E.; Rabouw, F.T.; Bals, S.; de Mello Donega, C. |
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Title |
Near-Infrared Emitting CuInSe/CuInS Dot Core/Rod Shell Heteronanorods by Sequential Cation Exchange |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
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Volume |
9 |
Issue |
9 |
Pages |
11430-11438 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The direct synthesis of heteronanocrystals (HNCs) combining different ternary semiconductors is challenging and has not yet been successful. Here, we report a sequential topotactic cation exchange (CE) pathway that yields CuInSe2/CuInS2 dot core/rod shell nanorods with near-infrared luminescence. In our approach, the Cu+ extraction rate is coupled to the In3+ incorporation rate by the use of a stoichiometric trioctylphosphine-InCl3 complex, which fulfills the roles of both In-source and Cu-extracting agent. In this way, Cu+ ions can be extracted by trioctylphosphine ligands only when the In-P bond is broken. This results in readily available In3+ ions at the same surface site from which the Cu+ is extracted, making the process a direct place exchange reaction and shifting the overall energy balance in favor of the CE. Consequently, controlled cation exchange can occur even in large and anisotropic heterostructured nanocrystals with preservation of the size, shape, and heterostructuring of the template NCs into the product NCs. The cation exchange is self-limited, stopping when the ternary core/shell CuInSe2/CuInS2 composition is reached. The method is very versatile, successfully yielding a variety of luminescent CuInX2 (X = S, Se, and Te) quantum dots, nanorods, and HNCs, by using Cd-chalcogenide NCs and HNCs as templates. The approach reported here thus opens up routes toward materials with unprecedented properties, which would otherwise remain inaccessible. |
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Address |
Debye Institute for Nanomaterials Science, Utrecht University , P.O. Box 80000, 3508 TA Utrecht, The Netherlands |
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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 |
English |
Wos |
000365464800094 |
Publication Date |
2015-10-09 |
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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 |
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Series Issue |
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Edition |
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ISSN |
1936-0851;1936-086X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.942 |
Times cited |
88 |
Open Access |
OpenAccess |
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Notes |
The authors thank Gang Wang for XRD measurements and Eline Hutter for providing CdSe/CdS NRs. W.v.d.S. and C.d.M.D. acknowledge financial support from the division of Chemical Sciences (CW) of The Netherlands Organization for Scientific Research (NWO) under grant number ECHO.712.012.001. This work was supported by the European Research Council (ERC Starting Grant #335078 Colouratom). E.B. gratefully acknowledges financial support by the Flemish Fund for Scientific Research (FWO Vlaanderen).; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); |
Approved |
Most recent IF: 13.942; 2015 IF: 12.881 |
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Call Number |
c:irua:129184 |
Serial |
3948 |
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Permanent link to this record |
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Author |
van der Stam, W.; Berends, A.C.; Rabouw, F.T.; Willhammar, T.; Ke, X.; Meeldijk, J.D.; Bals, S.; de Donega, C.M. |
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Title |
Luminescent CuInS2 quantum dots by partial cation exchange in Cu2-xS nanocrystals |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
27 |
Issue |
27 |
Pages |
621-628 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Here, we show successful partial cation exchange reactions in Cu2-xS nanocrystals (NCs) yielding luminescent CuInS2 (CIS) NCs. Our approach of mild reaction conditions ensures slow Cu extraction rates, which results in a balance with the slow In incorporation rate. With this method, we obtain CIS NCs with photoluminescence (PL) far in the near-infrared (NIR), which cannot be directly synthesized by currently available synthesis protocols. We discuss the factors that favor partial, self-limited cation exchange from Cu2-xS to CIS NCs, rather than complete cation exchange to In2S3. The product CIS NCs have the wurtzite crystal structure, which is understood in terms of conservation of the hexagonal close packing of the anionic sublattice of the parent NCs into the product NCs. These results are an important step toward the design of CIS NCs with sizes and shapes that are not attainable by direct synthesis protocols and may thus impact a number of potential applications. |
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Corporate Author |
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Publisher |
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Place of Publication |
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Wos |
000348618400028 |
Publication Date |
2014-12-29 |
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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 |
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Series Issue |
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Edition |
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ISSN |
0897-4756;1520-5002; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
119 |
Open Access |
OpenAccess |
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Notes |
335078 Colouratom; 262348 Esmi; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); |
Approved |
Most recent IF: 9.466; 2015 IF: 8.354 |
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Call Number |
c:irua:125291 |
Serial |
1858 |
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Permanent link to this record |
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Author |
van der Stam, W.; Akkerman, Q.A.; Ke, X.; van Huis, M.A.; Bals, S.; de Donega, C.M. |
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Title |
Solution-processable ultrathin size- and shape-controlled colloidal Cu2-xS nanosheets |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
27 |
Issue |
27 |
Pages |
283-291 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Ultrathin two-dimensional (2D) nanosheets (NSs) possess extraordinary properties that are attractive for both fundamental studies and technological devices. Solution-based bottom-up methods are emerging as promising routes to produce free-standing NSs, but the synthesis of colloidal NSs with well-defined size and shape has remained a major challenge. In this work, we report a novel method that yields 2 nm thick colloidal Cu2-xS NSs with well-defined shape (triangular or hexagonal) and size (100 nm to 3 mu m). The key feature of our approach is the use of a synergistic interaction between halides (Br or Cl) and copper-thiolate metal-organic frameworks to create a template that imposes 2D constraints on the Cu-catalyzed C-S thermolysis, resulting in nucleation and growth of colloidal 2D Cu2-xS NSs. Moreover, the NS composition can be postsynthetically tailored by exploiting topotactic cation exchange reactions. This is illustrated by converting the Cu2-xS NSs into ZnS and CdS NSs while preserving their size and shape. The method presented here thus holds great promise as a route to solution-processable compositionally diverse ultrathin colloidal NSs with well-defined shape and size. |
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Wos |
000348085300036 |
Publication Date |
2014-12-04 |
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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 |
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Series Issue |
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Edition |
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ISSN |
0897-4756;1520-5002; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
68 |
Open Access |
OpenAccess |
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Notes |
335078 Colouratom; 246791 Countatoms; 312483 Esteem2; esteem2ta; ECASSara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); |
Approved |
Most recent IF: 9.466; 2015 IF: 8.354 |
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Call Number |
c:irua:123865 c:irua:123865 |
Serial |
3052 |
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Permanent link to this record |
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Author |
van der Snickt, G.; Schalm, O.; Caen, J.; Janssens, K.; Schreiner, M. |
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Title |
Blue enamel on sixteenth- and seventeenth-century window glass : deterioration, microstructure, composition and preparation |
Type |
A1 Journal article |
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Year |
2006 |
Publication |
Studies in conservation |
Abbreviated Journal |
Stud Conserv |
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Volume |
51 |
Issue |
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Pages |
212-222 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
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Wos |
000241941100006 |
Publication Date |
2014-01-09 |
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Series Editor |
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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 |
0039-3630; 2047-0584 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
0.578 |
Times cited |
8 |
Open Access |
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Notes |
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Approved |
Most recent IF: 0.578; 2006 IF: 0.609 |
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Call Number |
UA @ admin @ c:irua:60712 |
Serial |
5492 |
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Permanent link to this record |
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Author |
van der Snickt, G.; Miliani, C.; Janssens, K.; Brunetti, B.G.; Romani, A.; Rosi, F.; Walter, P.; Castaing, J.; de Nolf, W.; Klaassen, L.; Labarque, I.; Wittermann, R. |
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Title |
Material analyses of “Christ with singing and music-making Angels”, a late 15th-C panel painting attributed to Hans Memling and assistants : part 1 : non-invasive in situ investigations |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Journal of analytical atomic spectrometry |
Abbreviated Journal |
J Anal Atom Spectrom |
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Volume |
26 |
Issue |
11 |
Pages |
2216-2229 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
In cultural heritage science, compositional data is traditionally obtained from works of art through the analysis of samples by means of various bench-top instruments (scanning electron microscope, Raman spectrometer, etc.). Alternatively, the object can be transported to a laboratory where it may be examined, usually by spectroscopic methods working in reflection mode. However, this paper describes how a complementary set of mobile and portable instruments was deployed in situ to gain a comprehensive view on the materials and related ageing compounds of an (almost) unmovable 15th-C polyptych, prior to and in preparation of the extraction of a limited number of samples. In line with the methodological approach discussed, PXRF was first employed as an efficient screening tool. The ensuing elemental data was supplemented by more specific information on both organic as inorganic materials supplied by reflection near- and mid-FTIR spectroscopy and fluorimetry. In completion, a limited number of diffraction patterns were collected with a mobile XRD instrument in order to identify the constituent crystalline phases in pigments, grounding materials and degradation products. In this way, it could be demonstrated how a rich array of colours was obtained by means of a limited palette of pigments: lead white, lead tin yellow, azurite, natural ultramarine, bone black, vermillion, madder lake, and a green copper-organo complex were detected and situated on the panels. Remarkably, next to chalk also gypsum was found in the ground layer(s) of this Western European easel painting. The relatively large surface of the background was covered with gold leaf; the analyses seem to point towards the labour-intensive water gilding technique. The versatility of this combination of analytical techniques was further illustrated by the accurate characterisation of degradation products affecting the readability and conservation of the painting: the overall presence of a calcium oxalate-based film of variable thickness was established. Nevertheless, further analysis of cross-sectioned samples was considered desirable in order to study the stratigraphy, to gain direct access to altered and sub-imposed layers and to allow highly detailed analysis of micrometric degradation products by state-of-the art techniques (i.e. synchrotron radiation). |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000296021800010 |
Publication Date |
2011-09-23 |
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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 |
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Series Issue |
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Edition |
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ISSN |
0267-9477 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.379 |
Times cited |
32 |
Open Access |
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Notes |
; This research was supported by the Interuniversity Attraction Poles Programme – Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0103.04, G.0689.06 and G.0704.08. The staff of the Royal Museum of Fine Arts Antwerp is acknowledged for this pleasant cooperation and the authorisation for the publication of the images in this article. Therefore, a word of gratitude to Paul Huvenne, Yolande Deckers, Stef Antonissen and Gwen Borms. In addition, the authors would like to thank the MOLAB's team operators Chiari Anselmi and Federica Presciutti. MOLAB analyses have been carried out through the support of the EU within the 6th Framework Programme (Contract Eu-ARTECH, RII3-CT-2004-506171). ; |
Approved |
Most recent IF: 3.379; 2011 IF: 3.220 |
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Call Number |
UA @ admin @ c:irua:93680 |
Serial |
5705 |
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Permanent link to this record |
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Author |
van der Snickt, G.; Martins, A.; Delaney, J.; Janssens, K.; Zeibel, J.; Duffy, M.; McGlinchey, C.; Van Driel, B.; Dik, J. |
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Title |
Exploring a hidden painting below the surface of Rene Magritte's Le Portrait |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Applied spectroscopy |
Abbreviated Journal |
Appl Spectrosc |
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Volume |
70 |
Issue |
1 |
Pages |
57-67 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Two state-of-the-art methods for non-invasive visualization of subsurface (or overpainted) pictorial layers present in painted works of art are employed to study Le portrait, painted by Belgian artist Rene Magritte in 1935. X-ray radiography, a commonly used method for the nondestructive inspection of paintings, had revealed the presence of an underlying figurative composition, part of an earlier Magritte painting entitled La pose enchantee (1927) which originally depicted two full length nude female figures with exaggerated facial features. On the one hand, macroscopic X-ray fluorescence analysis (MA-XRF), a method capable of providing information on the distribution of the key chemical elements present in many artists' pigments, was employed. The ability of the X-rays to penetrate the upper layer of paint enabled the imaging of the facial features of the female figure and provided information on Magritte's palette for both surface and hidden composition. On the other hand, visible and near infrared hyperspectral imaging spectroscopies in transmission mode were also used, especially in the area of the table cloth in order to look through the upper representation and reveal the pictorial layer(s) below. MA-XRF provided elemental information on the pigment distributions in both the final painting and the prior whereas the transmission mode provided information related to preparatory sketches as well as revealing differences between the paints used in both compositions. These results illustrate very well the manner in which the two imaging methods complement each other, both in the sense of providing different types of information on the nature and presence of paint components/pigments and in the sense of being optimally suited to easily penetrate through different types of overpaint. |
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Wos |
000368604500007 |
Publication Date |
2016-01-27 |
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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 |
0003-7028 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.529 |
Times cited |
13 |
Open Access |
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Notes |
; GvdS and KJ acknowledge the support of the Fund Inbev-Baillet Latour. JKD acknowledges support from the Andrew Mellon Foundation and the National Science Foundation. BvD and JD acknowledge support from The Netherlands Organisation for Scientific Research (NWO). ; |
Approved |
Most recent IF: 1.529 |
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Call Number |
UA @ admin @ c:irua:131544 |
Serial |
5620 |
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Permanent link to this record |
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Author |
van der Snickt, G.; Legrand, S.; Slama, I.; Van Zuien, E.; Gruber, G.; Van der Stighelen, K.; Klaassen, L.; Oberthaler, E.; Janssens, K. |
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Title |
In situ macro X-ray fluorescence (MA-XRF) scanning as a non-invasive tool to probe for subsurface modifications in paintings by PP Rubens |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Microchemical journal |
Abbreviated Journal |
Microchem J |
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Volume |
138 |
Issue |
138 |
Pages |
238-245 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Within the last decade, the established synchrotron- and laboratory-based micro-XRF scanning technology inspired the development of mobile instruments that allow performing in situ experiments on paintings on a macro scale. Since the development of the first mobile scanner at the start of this decade, this chemical imaging technique has brought new insights with respect to several iconic paintings, especially in cases when standard imaging techniques such as X-Ray Radiography (XRR) or Infrared Refiectography (IRR) yielded ambiguous results. The ability of scanning MA-XRF to visualise the distribution of elements detected at and below the paint surface renders this spectrometric method particularly helpful for studying painting techniques and revealing materials that remain hidden below the paint surface. The latter aspect is especially relevant for the technical study of works by Pieter Paul Rubens (1577-1640) as this highly productive seventeenth century master is particularly renowned for the continuous application of modifications during (and even after) the entire course of the creative process. In this work, the added value of MA-XRF scanning experiments for visualising these subsurface features is exemplified by interpreting the chemical images obtained on three of Rubens' key works. Special attention is given to three types of adjustments that are particularly relevant for the technical study of Rubens' oeuvre: (1) compositional changes ('pentimenti'), exemplified by results obtained on The Portrait of Helene Fourment (ca. 1638), (2) extensions to the support ('Anstlickungen.), illustrated by imaging experiments performed on the Venus Frigida (1614) and (3) Rubens' intriguing halos around flesh tones, as found amongst others in The Incredulity of Saint Thomas (1613). The ensuing insights in the paint stratigraphy and the underlying supporting structure illustrate the potential of MA-XRF scanning for the non-invasive, comparative study of Rubens' oeuvre. The results do not only augment the understanding of the complex genesis of Rubens' works of art and his efficient painting technique, but prove valuable during conservation treatments as well, as addressed in this paper. (C) 2018 Elsevier B.V. All rights reserved. |
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Place of Publication |
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Wos |
000428103000027 |
Publication Date |
2018-01-17 |
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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 |
0026-265x; 0026-265x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.034 |
Times cited |
5 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.034 |
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Call Number |
UA @ admin @ c:irua:151564 |
Serial |
5657 |
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Permanent link to this record |
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Author |
van der Snickt, G.; Legrand, S.; Caen, J.; Vanmeert, F.; Alfeld, M.; Janssens, K. |
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Title |
Chemical imaging of stained-glass windows by means of macro X-ray fluorescence (MA-XRF) scanning |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Microchemical journal |
Abbreviated Journal |
Microchem J |
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Volume |
124 |
Issue |
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Pages |
615-622 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
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Abstract |
Since the recent development of a mobile setup, MA-XRF scanning proved a valuable tool for the non-invasive, technical study of paintings. In this work, the applicability of MA-XRF scanning for investigating stained-glass windows inside a conservation studio is assessed by analysis of a high-profile, well-studied late-mediaeval panel. Although accurate quantification of components is not feasible with this analytical imaging technique, plotting the detected intensities of K versus Ca in a scatter plot allowed distinguishing glass fragments of different compositional types within the same panel. In particular, clusters in the Ca/K correlation plot revealed the presence of two subtypes of potash glass and three subtypes of high lime low alkali glass. MA-XRF results proved consistent with previous quantitative SEM-EDX analysis on two samples and analytical-based theories on glass production in the Low Countries formulated in literature. A bi-plot of the intensities of the more energetic Rb-K versus Sr-K emission lines yielded a similar glass type differentiation and is here presented as suitable alternative in case the Ca/K signal ratio is affected by superimposed weathering crusts. Apart from identification of the chromophores responsible for the green, blue and red glass colors, contrasting the associated elemental distribution maps obtained on the exterior and interior side of the glass permitted discriminating between colored pot metal glass and multi-layered flashed glass as well. Finally, the benefit of obtaining compositional information from the entire surface, as opposed to point analysis, was illustrated by the discovery of what appears to be a green cobalt glass a feature that was previously missed on this well-studied stained-glass window, both by connoisseurs and spectroscopic sample analysis. (C) 2015 Elsevier B.V. All rights reserved. |
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Wos |
000367755600074 |
Publication Date |
2015-10-25 |
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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 |
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Series Issue |
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Edition |
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ISSN |
0026-265x; 0026-265x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.034 |
Times cited |
22 |
Open Access |
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Notes |
; The staff of the Museums of the City of Bruges, i.e. Director Till-Holger Borchert and Deputy Curator Kristel Van Audenaeren, are acknowledged for this pleasant collaboration and the authorization for the publication of the images in this article. This research was supported by the InBev-Baillet Latour fund. ; |
Approved |
Most recent IF: 3.034 |
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Call Number |
UA @ admin @ c:irua:131100 |
Serial |
5514 |
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Permanent link to this record |
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Author |
van der Snickt, G.; Janssens, K.; Schalm, O.; Aibéo, C.; Kloust, H.; Alfeld, M. |
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Title |
James Ensor's pigment use: artistic and material evolution studied by means of portable X-ray fluorescence spectrometry |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
X-ray spectrometry |
Abbreviated Journal |
X-Ray Spectrom |
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Volume |
39 |
Issue |
2 |
Pages |
103-111 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
In this paper, portable X-ray fluorescence spectrometry (PXRF) was employed as a screening tool for determining and comparing the pigment use in a large series of paintings by the Belgian artist James Ensor (1860-1949). Benefits and drawbacks of PXRF as a method, and the instrument employed, are discussed from a practical, conservation and instrumental perspective. Regardless of several restrictions due to the set-up and/or the analytical method, it appeared feasible to document the evolution with time in Ensor's use of inorganic pigments and to correlate this technical evolution with stylistic developments, Nevertheless, it became clear that a full identification of all materials present can only be done by means of the analysis of (cross-sectioned) samples. |
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Wos |
000275959400006 |
Publication Date |
2009-12-15 |
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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 |
0049-8246 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.298 |
Times cited |
25 |
Open Access |
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Notes |
; This research was supported by the Interuniversity Attraction Poles Programme – Belgian Science Policy (IUAP VI/16). The staff of the different museums and private institutions is acknowledged for rendering their assistance to this research, i.e. by making all paintings available for analysis and authorising the publication of the images in this article. Therefore, a word of gratitude to Paul Huvenne, Yolande Deckers, Herwig Todts, Stef Antonissen, Gwen Borms and Lizet Klaassen of the Koninklijk Museum voor Schone Kunsten Antwerpen (KMSKA), Luuk Van der Loeff of the Kroller-Muller Museum in Otterlo and Mireille Engel, Barbara De Jong of the Musea aan Zee (MuZee), Patricia Jaspers of the Dexia bank, Hildegard Van de Velde of the KBC bank and Frederik Leen of the Koninklijke Musea voor Schone Kunsten van Belgie (KMSKB). Special thanks to Xavier Tricot and the other members of the Ensor committee for their valuable feedback. ; |
Approved |
Most recent IF: 1.298; 2010 IF: 1.661 |
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Call Number |
UA @ admin @ c:irua:82324 |
Serial |
5680 |
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Permanent link to this record |
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Author |
van der Snickt, G.; Janssens, K.; Dik, J.; de Nolf, W.; Vanmeert, F.; Jaroszewicz, J.; Cotte, M.; Falkenberg, G.; Van der Loeff, L. |
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Title |
Combined use of synchrotron radiation based micro-X-ray fluorescence, micro-X-ray diffraction, micro-X-ray absorption near-edge, and micro-fourier transform infrared spectroscopies for revealing an alternative degradation pathway of the pigment cadmium yellow in a painting by Van Gogh |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
84 |
Issue |
23 |
Pages |
10221-10228 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Over the past years a number of studies have described the instability of the pigment cadmium yellow (CdS). In a previous paper we have shown how cadmium sulfide on paintings by James Ensor oxidizes to CdSO4 center dot H2O. The degradation process gives rise to the fading of the bright yellow color and the formation of disfiguring white crystals that are present on the paint surface in approximately 50 mu m sized globular agglomerations. Here, we study cadmium yellow in the painting “Flowers in a blue vase” by Vincent van Gogh. This painting differs from the Ensor case in the fact that (a) a varnish was superimposed onto the degraded paint surface and (b) the CdS paint area is entirely covered with an opaque crust. The latter obscures the yellow color completely and thus presents a seemingly more advanced state of degradation. Analysis of a cross-sectioned and a crushed sample by combining scanning microscopic X-ray diffraction (mu-XRD), microscopic X-ray absorption near-edge spectroscopy (mu-XANES), microscopic X-ray fluorescence (mu-XRF) based chemical state mapping and scanning microscopic Fourier transform infrared (mu-FT-IR) spectrometry allowed unravelling the complex alteration pathway. Although no crystalline CdSO4 compounds were identified on the Van Gogh paint samples, we conclude that the observed degradation was initially caused by oxidation of the original CdS pigment, similar as for the previous Ensor case. However, due to the presence of an overlying varnish containing lead-based driers and oxalate ions, secondary reactions took place. In particular, it appears that upon the photoinduced oxidation of its sulfidic counterion, the Cd2+ ions reprecipitated at the paint/varnish interface after having formed a complex with oxalate ions that themselves are considered to be degradation products of the resin and/or oil in the varnish. The SO42- anions, for their part, found a suitable reaction partner in Pb2+ ions stemming from a dissolved lead-based siccative that was added to the varnish to promote its drying. The resulting opaque anglesite compound in the varnish, in combination with the underlying CdC2O4 layer at the paint/varnish interface, account for the orange-gray crust that is disfiguring the painting on a macroscopic level. In this way, the results presented in this paper demonstrate how, through a judicious combined use of several microanalytical methods with speciation capabilities, many new insights can be obtained from two minute, but highly complex and heterogeneous paint samples. |
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Wos |
000311815300013 |
Publication Date |
2012-08-30 |
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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 |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
59 |
Open Access |
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Notes |
; This research was supported by BELSPO via the Interuniversity Attraction Poles Programme (IUAP VI/16) and the S2-ART project (SD/RI/04A) and funded by Grants from the ESRF (EC-442) and PETRA-III (I-20120312 EC). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) project nos. G.0103.04, G.0689.06, and G.0704.08. The staff of the Kroller-Muller Museum and painting conservators Margje Leeuwestein and Esther Van Duijn are acknowledged for this pleasant cooperation and the authorization for the publication of the images in this article. ; |
Approved |
Most recent IF: 6.32; 2012 IF: 5.695 |
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Call Number |
UA @ admin @ c:irua:105971 |
Serial |
5526 |
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Permanent link to this record |
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Author |
van der Snickt, G.; Dubois, H.; Sanyova, J.; Legrand, S.; Coudray, A.; Glaude, C.; Postec, M.; van Espen, P.; Janssens, K. |
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Title |
Large-area elemental imaging reveals Van Eyck's original paint layers on the Ghent altarpiece (1432), rescoping its conservation treatment |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
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Volume |
56 |
Issue |
17 |
Pages |
4797-4801 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
A combination of large-scale and micro-scale elemental imaging, yielding elemental distribution maps obtained by, respectively non-invasive macroscopic X-ray fluorescence (MA-XRF) and by secondary electron microscopy/energy dispersive X-ray analysis (SEM-EDX) and synchrotron radiation-based micro-XRF (SR m-XRF) imaging was employed to reorient and optimize the conservation strategy of van Eyck's renowned Ghent Altarpiece. By exploiting the penetrative properties of X-rays together with the elemental specificity offered by XRF, it was possible to visualize the original paint layers by van Eyck hidden below the overpainted surface and to simultaneously assess their condition. The distribution of the high-energy Pb-L and Hg-L emission lines revealed the exact location of hidden paint losses, while Fe-K maps demonstrated how and where these lacunae were filled-up using an iron-containing material. The chemical maps nourished the scholarly debate on the overpaint removal with objective, chemical arguments, leading to the decision to remove all skillfully applied overpaints, hitherto interpreted as work by van Eyck. MA-XRF was also employed for monitoring the removal of the overpaint during the treatment phase. To gather complementary information on the in-depth layer build-up, SEM-EDX and SR mu-XRF imaging was used on paint cross sections to record microscale elemental maps. |
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Wos |
000398576000019 |
Publication Date |
2017-03-23 |
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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 |
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Series Issue |
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Edition |
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ISSN |
1433-7851; 0570-0833 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
11.994 |
Times cited |
11 |
Open Access |
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Notes |
; This research was supported by the Baillet Latour fund, the Belgian Science Policy Office (Projects MO/39/011) and the Gieskes-Strijbis fund. The authors are also indebted to the BOF-GOA SOLAR Paint project of the University of Antwerp Research Council. The church wardens of the cathedral of St. Bavo and their chairman L. Collin are acknowledged for this agreeable collaboration. We also wish to thank conservators L. Depuydt, B. De Volder, F. Rosier, N. Laquiere and G. Steyaert as well as the members of the international committee. We are indebted to Prof. Em. A. Van Grevenstein-Kruse. ; |
Approved |
Most recent IF: 11.994 |
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Call Number |
UA @ admin @ c:irua:142376 |
Serial |
5688 |
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Permanent link to this record |
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Author |
van der Snickt, G.; Dooley, K.A.; Sanyova, J.; Dubois, H.; Delaney, J.K.; Gifford, E.M.; Legrand, S.; Laquiere, N.; Janssens, K. |
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Title |
Dual mode standoff imaging spectroscopy documents the painting process of the Lamb of God in the Ghent Altarpiece by J. and H. Van Eyck |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Science Advances |
Abbreviated Journal |
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Volume |
6 |
Issue |
31 |
Pages |
eabb3379 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
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Abstract |
The ongoing conservation treatment program of the Ghent Altarpiece by Hubert and Jan Van Eyck, one of the iconic paintings of the west, has revealed that the designs of the paintings were changed several times, first by the original artists, and then during later restorations. The central motif, The Lamb of God, representing Christ, plays an essential iconographic role, and its depiction is important. Because of the prevalence of lead white, it was not possible to visualize the Van Eycks' original underdrawing of the Lamb, their design changes, and the overpaint by later restorers with a single spectral imaging modality. However, by using elemental (x-ray fluorescence) and molecular (infrared reflectance) imaging spectroscopies, followed by analysis of the resulting data cubes, the necessary chemical contrast could be achieved. In this way, the two complementary modalities provided a more complete picture of the development and changes made to the Lamb. |
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Wos |
000556543100033 |
Publication Date |
2020-07-29 |
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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 |
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Series Issue |
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Edition |
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ISSN |
2375-2548 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.6 |
Times cited |
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Open Access |
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Notes |
; This research was part of the activities of the Chair on Advanced Imaging Techniques for the Arts, established by the Baillet Latour fund. In addition, it was supported by the Belgian Science Policy Office (Project MO/39/011) and the Gieskes-Strijbis fund. We are also indebted to the BOF-GOA SOLARPaint project of the University of Antwerp Research Council and to FWO (Brussels) projects G056619N and G054719N. J.K.D. and K.A.D. acknowledge support from the National Gallery of Art. ; |
Approved |
Most recent IF: 13.6; 2020 IF: NA |
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Call Number |
UA @ admin @ c:irua:171270 |
Serial |
6494 |
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Permanent link to this record |
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Author |
van der Snickt, G.; Dik, J.; Cotte, M.; Janssens, K.; Jaroszewicz, J.; de Nolf, W.; Groenewegen, J.; van der Loeff, L. |
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Title |
Characterization of a degraded cadmium yellow (CdS) pigment in an oil painting by means of synchrotron radiation based X-ray techniques |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
81 |
Issue |
7 |
Pages |
2600-2610 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
On several paintings of James Ensor (1860−1949), a gradual fading of originally bright yellow areas, painted with the pigment cadmium yellow (CdS), is observed. Additionally, in some areas exposed to light, the formation of small white-colored globules on top of the original paint surface is observed. In this paper the chemical transformation leading to the color change and to the formation of the globules is elucidated. Microscopic X-ray absorption near-edge spectroscopy (ì-XANES) experiments show that sulfur, originally present in sulfidic form (S2−), is oxidized during the transformation to the sulfate form (S6+). Upon formation (at or immediately below the surface), the highly soluble cadmium sulfate is assumed to be transported to the surface in solution and reprecipitates there, forming the whitish globules. The presence of cadmium sulfate (CdSO4·2H2O) and ammonium cadmium sulfate [(NH4)2Cd(SO4)2] at the surface is confirmed by microscopic X-ray diffraction measurements, where the latter salt is suspected to result from a secondary reaction of cadmium sulfate with ammonia. Measurements performed on cross sections reveal that the oxidation front has penetrated into the yellow paint down to ca. 1−2 ìm. The morphology and elemental distribution of the paint and degradation product were examined by means of scanning electron microscopy equipped with an energy-dispersive spectrometer (SEM-EDS) and synchrotron radiation based micro-X-ray fluorescence spectrometry (SR ì-XRF). In addition, ultraviolet-induced visible fluorescence photography (UIVFP) revealed itself to be a straightforward technique for documenting the occurrence of this specific kind of degradation on a macroscale by painting conservators. |
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Wos |
000264759400025 |
Publication Date |
2009-03-11 |
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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 |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
91 |
Open Access |
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Notes |
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Approved |
Most recent IF: 6.32; 2009 IF: 5.214 |
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Call Number |
UA @ admin @ c:irua:76415 |
Serial |
5501 |
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Permanent link to this record |
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Author |
van der Snickt, G.; de Nolf, W.; Vekemans, B.; Janssens, K. |
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Title |
μ-XRF/μ-RS vs. SR μ-XRD for pigment identification in illuminated manuscripts |
Type |
A1 Journal article |
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Year |
2008 |
Publication |
Applied physics A : materials science & processing |
Abbreviated Journal |
Appl Phys A-Mater |
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Volume |
92 |
Issue |
1 |
Pages |
59-68 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
For the non-destructive identification of pigments and colorants in works of art, in archaeological and in forensic materials, a wide range of analytical techniques can be used. Bearing in mind that every method holds particular limitations, two complementary spectroscopic techniques, namely confocal ì-Raman spectroscopy (ì-RS) and ì-X-ray fluorescence spectroscopy (ì-XRF), were joined in one instrument. The combined ì-XRF and ì-RS device, called PRAXIS unites both complementary techniques in one mobile setup, which allows ì- and in situ analysis. ì-XRF allows one to collect elemental and spatially-resolved information in a non-destructive way on major and minor constituents of a variety of materials. However, the main disadvantages of ì-XRF are the penetration depth of the X-rays and the fact that only elements and not specific molecular combinations of elements can be detected. As a result ì-XRF is often not specific enough to identify the pigments within complex mixtures. Confocal Raman microscopy (ì-RS) can offer a surplus as molecular information can be obtained from single pigment grains. However, in some cases the presence of a strong fluorescence background limits the applicability. In this paper, the concrete analytical possibilities of the combined PRAXIS device are evaluated by comparing the results on an illuminated sheet of parchment with the analytical information supplied by synchrotron radiation ì-X-ray diffraction (SR ì-XRD), a highly specific technique. |
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Wos |
000256426000008 |
Publication Date |
2008-03-19 |
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ISSN |
0947-8396 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.455 |
Times cited |
56 |
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Approved |
Most recent IF: 1.455; 2008 IF: 1.884 |
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Call Number |
UA @ admin @ c:irua:74465 |
Serial |
5695 |
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Author |
van der Sluijs, M.M.; Salzmann, B.B.V.; Arenas Esteban, D.; Li, C.; Jannis, D.; Brafine, L.C.; Laning, T.D.; Reinders, J.W.C.; Hijmans, N.S.A.; Moes, J.R.; Verbeeck, J.; Bals, S.; Vanmaekelbergh, D. |
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Title |
Study of the Mechanism and Increasing Crystallinity in the Self-Templated Growth of Ultrathin PbS Nanosheets |
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A1 Journal article |
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2023 |
Publication |
Chemistry of materials |
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A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Colloidal 2D semiconductor nanocrystals, the analogue of solid-state quantum wells, have attracted strong interest in material science and physics. Molar quantities of suspended quantum objects with spectrally pure absorption and emission can be synthesized. For the visible region, CdSe nanoplatelets with atomically precise thickness and tailorable emission have been (almost) perfected. For the near-infrared region, PbS nanosheets (NSs) hold strong promise, but the photoluminescence quantum yield is low and many questions on the crystallinity, atomic structure, intriguing rectangular shape, and formation mechanism remain to be answered. Here, we report on a detailed investigation of the PbS NSs prepared with a lead thiocyanate single source precursor. Atomically resolved HAADF-STEM imaging reveals the presence of defects and small cubic domains in the deformed orthorhombic PbS crystal lattice. Moreover, variations in thickness are observed in the NSs, but only in steps of 2 PbS monolayers. To study the reaction mechanism, a synthesis at a lower temperature allowed for the study of reaction intermediates. Specifically, we studied the evolution of pseudo-crystalline templates towards mature, crystalline PbS NSs. We propose a self-induced templating mechanism based on an oleylamine-lead-thiocyanate (OLAM-Pb-SCN) complex with two Pb-SCN units as a building block; the interactions between the long-chain ligands regulate the crystal structure and possibly the lateral dimensions. |
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Wos |
000959572100001 |
Publication Date |
2023-03-25 |
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ISSN |
0897-4756 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.6 |
Times cited |
2 |
Open Access |
OpenAccess |
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Notes |
H2020 Research Infrastructures, 731019 ; H2020 European Research Council, 692691 815128 ; Nederlandse Organisatie voor Wetenschappelijk Onderzoek, 715.016.002 ; |
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Most recent IF: 8.6; 2023 IF: 9.466 |
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EMAT @ emat @c:irua:195894 |
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7255 |
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van der Rest, A.; Idrissi, H.; Henry, F.; Favache, A.; Schryvers, D.; Proost, J.; Raskin, J.-P.; Van Overmeere, Q.; Pardoen, T. |
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Mechanical behavior of ultrathin sputter deposited porous amorphous Al2O3 films |
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A1 Journal article |
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2017 |
Publication |
Acta materialia |
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Acta Mater |
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125 |
Issue |
125 |
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27-37 |
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A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The determination of the mechanical properties of porous amorphous Al2O3 thin films is essential to address reliability issues in wear-resistant, optical and electronic coating applications. Testing the mechanical properties of Al2O3 films thinner than 200 nm is challenging, and the link between the mechanical behavior and the microstructure of such films is largely unknown. Herein, we report on the elastic and viscoplastic mechanical properties of amorphous Al2O3 thin films synthesized by reactive magnetron sputtering using a combination of internal stress, nanoindentation, and on-chip uniaxial tensile testing, together with mechanical homogenization models to separate the effect of porosity from intrinsic variations of the response of the sound material. The porosity is made of voids with 2e30 nm diameter. The Young's modulus and hardness of the films decrease by a factor of two when the deposition pressure increases from 1.2 to 8 mTorr. The contribution of porosity was found to be small, and a change in the atomic structure of the amorphous Al2O3 matrix is hypothesized to be the main contributing factor. The activation volume associated to the viscoplastic deformation mechanism is around 100 Å3. Differences in the atomic structure of the films could not be revealed by electron diffraction, pointing to a minute effect of atomic arrangement on the elastic properties. |
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000394201500003 |
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2016-12-02 |
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ISSN |
1359-6454 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
5 |
Open Access |
OpenAccess |
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Notes |
This work has been funded by the Belgian Science Policy through the IAP 7/21 project. The support of the ‘Fonds Belge pour la Recherche dans l’Industrie et l’Agriculture (FRIA)’ for A.v.d.R. is also gratefully acknowledged, as well as the support of FNRS through the grant PDR T.0122.13 “Mecano”. |
Approved |
Most recent IF: 5.301 |
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Call Number |
EMAT @ emat @ c:irua:138990 |
Serial |
4330 |
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