Records |
Author |
Ramaneti, R.; Sankaran, K.J.; Korneychuk, S.; Yeh, C.J.; Degutis, G.; Leou, K.C.; Verbeeck, J.; Van Bael, M.K.; Lin, I.N.; Haenen, K. |
Title |
Vertically aligned diamond-graphite hybrid nanorod arrays with superior field electron emission properties |
Type |
A1 Journal article |
Year |
2017 |
Publication |
APL materials |
Abbreviated Journal |
Apl Mater |
Volume |
5 |
Issue |
6 |
Pages |
066102 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
A “patterned-seeding technique” in combination with a “nanodiamond masked reactive ion etching process” is demonstrated for fabricating vertically aligned diamond-graphite hybrid (DGH) nanorod arrays. The DGH nanorod arrays possess superior field electron emission (FEE) behavior with a low turn-on field, long lifetime stability, and large field enhancement factor. Such an enhanced FEE is attributed to the nanocomposite nature of theDGHnanorods, which contain sp(2)-graphitic phases in the boundaries of nano-sized diamond grains. The simplicity in the nanorod fabrication process renders the DGH nanorods of greater potential for the applications as cathodes in field emission displays and microplasma display devices. (C) 2017 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000404623000002 |
Publication Date |
2017-06-08 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2166-532x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.335 |
Times cited |
16 |
Open Access |
|
Notes |
The authors would like to thank the Methusalem “NANO” network for financial support and Mr. B. Ruttens and Professor Jan D'Haen for technical and experimental assistance. K.J. Sankaran is a Postdoctoral Fellow of the Research Foundation-Flanders (FWO). |
Approved |
Most recent IF: 4.335 |
Call Number |
UA @ admin @ c:irua:152633 |
Serial |
5369 |
Permanent link to this record |
|
|
|
Author |
Do, M.T.; Gauquelin, N.; Nguyen, M.D.; Blom, F.; Verbeeck, J.; Koster, G.; Houwman, E.P.; Rijnders, G. |
Title |
Interface degradation and field screening mechanism behind bipolar-cycling fatigue in ferroelectric capacitors |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Apl Materials |
Abbreviated Journal |
Apl Mater |
Volume |
9 |
Issue |
2 |
Pages |
021113 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Polarization fatigue, i.e., the loss of polarization of ferroelectric capacitors upon field cycling, has been widely discussed as an interface related effect. However, mechanism(s) behind the development of fatigue have not been fully identified. Here, we study the fatigue mechanisms in Pt/PbZr0.52Ti0.48O3/SrRuO3 (Pt/PZT/SRO) capacitors in which all layers are fabricated by pulsed laser deposition without breaking the vacuum. With scanning transmission electron microscopy, we observed that in the fatigued capacitor, the Pt/PZT interface becomes structurally degraded, forming a 5 nm-10 nm thick non-ferroelectric layer of crystalline ZrO2 and diffused Pt grains. We then found that the fatigued capacitors can regain the full initial polarization switching if the externally applied field is increased to at least 10 times the switching field of the pristine capacitor. These findings suggest that polarization fatigue is driven by a two-step mechanism. First, the transient depolarization field that repeatedly appears during the domain switching under field cycling causes decomposition of the metal/ferroelectric interface, resulting in a non-ferroelectric degraded layer. Second, this interfacial non-ferroelectric layer screens the external applied field causing an increase in the coercive field beyond the usually applied maximum field and consequently suppresses the polarization switching in the cycled capacitor. Our work clearly confirms the key role of the electrode/ferroelectric interface in the endurance of ferroelectric-based devices. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000630052100006 |
Publication Date |
2021-02-09 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2166-532x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.335 |
Times cited |
5 |
Open Access |
OpenAccess |
Notes |
This work was supported by the Nederlandse Organisatie voor Wetenschappelijk Onderzoek through Grant No. F62.3.15559. The Qu-Ant-EM microscope and the direct electron detector were partly funded by the Hercules fund from the Flemish Government. N.G. and J.V. acknowledge funding from the GOA project “Solarpaint” of the University of Antwerp. This work has also received funding from the European Union's Horizon 2020 research and innovation program under Grant No. 823717-ESTEEM3. We acknowledge D. Chezganov for his useful insights. |
Approved |
Most recent IF: 4.335 |
Call Number |
UA @ admin @ c:irua:177663 |
Serial |
6783 |
Permanent link to this record |
|
|
|
Author |
Leusink, D.P.; Coneri, F.; Hoek, M.; Turner, S.; Idrissi, H.; Van Tendeloo, G.; Hilgenkamp, H. |
Title |
Thin films of the spin ice compound Ho2Ti2O7 |
Type |
A1 Journal article |
Year |
2014 |
Publication |
APL materials |
Abbreviated Journal |
Apl Mater |
Volume |
2 |
Issue |
3 |
Pages |
032101-32107 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The pyrochlore compounds Ho2Ti2O7 and Dy2Ti2O7 show an exotic form of magnetism called the spin ice state, resulting from the interplay between geometrical frustration and ferromagnetic coupling. A fascinating feature of this state is the appearance of magnetic monopoles as emergent excitations above the degenerate ground state. Over the past years, strong effort has been devoted to the investigation of these monopoles and other properties of the spin ice state in bulk crystals. Here, we report the fabrication of Ho2Ti2O7 thin films using pulsed laser deposition on yttria-stabilized ZrO2 substrates. We investigated the structural properties of these films by X-ray diffraction, scanning transmission electron microscopy, and atomic force microscopy, and the magnetic properties by vibrating sample magnetometry at 2 K. The films not only show a high crystalline quality, but also exhibit the hallmarks of a spin ice: a pronounced magnetic anisotropy and an intermediate plateau in the magnetization along the [111] crystal direction. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000334220300002 |
Publication Date |
2014-03-04 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2166-532X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.335 |
Times cited |
18 |
Open Access |
|
Notes |
The authors acknowledge support from the Dutch FOM and NWO foundations and from the European Union under the Framework 7 program under a contract from an Integrated Infrastructure Initiative (Reference 312483 ESTEEM2). G.V.T. acknowledges the ERC Grant N246791- COUNTATOMS. S.T. gratefully acknowledges financial support from the Fund for Scientific Research Flanders (FWO). H.I. acknowledges the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs under Contract No. P7/21. The microscope used in this study was partially financed by the Hercules Foundation of the Flemish Government. The authors acknowledge fruitful interactions with A. Brinkman, M. G. Blamire, M. Egilmez, F. J. G. Roesthuis, J. N. Beukers, C. G. Molenaar, M. Veldhorst, and X. Renshaw Wang; esteem2_ta |
Approved |
Most recent IF: 4.335; 2014 IF: NA |
Call Number |
UA @ lucian @ c:irua:115555 |
Serial |
3641 |
Permanent link to this record |
|
|
|
Author |
Blandy, J.N.; Abakumov, A.M.; Christensen, K.E.; Hadermann, J.; Adamson, P.; Cassidy, S.J.; Ramos, S.; Free, D.G.; Cohen, H.; Woodruff, D.N.; Thompson, A.L.; Clarke, S.J.; |
Title |
Soft chemical control of the crystal and magnetic structure of a layered mixed valent manganite oxide sulfide |
Type |
A1 Journal article |
Year |
2015 |
Publication |
APL materials |
Abbreviated Journal |
Apl Mater |
Volume |
3 |
Issue |
3 |
Pages |
041520 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Oxidative deintercalation of copper ions from the sulfide layers of the layered mixed-valent manganite oxide sulfide Sr2MnO2Cu1.5S2 results in control of the copper-vacancy modulated superstructure and the ordered arrangement of magnetic moments carried by the manganese ions. This soft chemistry enables control of the structures and properties of these complex materials which complement mixed-valent perovskite and perovskite-related transition metal oxides. (C) 2015 Author(s). |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000353828400027 |
Publication Date |
2015-04-21 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2166-532X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.335 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.335; 2015 IF: NA |
Call Number |
c:irua:126021 |
Serial |
3049 |
Permanent link to this record |
|
|
|
Author |
Hoek, M.; Coneri, F.; Poccia, N.; Renshaw Wang, X.; Ke, X.; Van Tendeloo, G.; Hilgenkamp, H. |
Title |
Strain accommodation through facet matching in La1.85Sr0.15CuO4/Nd1.85Ce0.15CuO4 ramp-edge junctions |
Type |
A1 Journal article |
Year |
2015 |
Publication |
APL materials |
Abbreviated Journal |
Apl Mater |
Volume |
3 |
Issue |
3 |
Pages |
086101 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Scanning nano-focused X-ray diffraction and high-angle annular dark-field scanning transmission electron microscopy are used to investigate the crystal structure of ramp-edge junctions between superconducting electron-doped Nd1.85Ce0.15CuO4 and superconducting hole-doped La1.85Sr0.15CuO4 thin films, the latter being the top layer. On the ramp, a new growth mode of La1.85Sr0.15CuO4 with a 3.3° tilt of the c-axis is found. We explain the tilt by developing a strain accommodation model that relies on facet matching, dictated by the ramp angle, indicating that a coherent domain boundary is formed at the interface. The possible implications of this growth mode for the creation of artificial domains in morphotropic materials are discussed. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000360656800009 |
Publication Date |
2015-08-03 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2166-532X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.335 |
Times cited |
4 |
Open Access |
|
Notes |
312483 Esteem2; 246791 Countatoms; esteem2_jra2 |
Approved |
Most recent IF: 4.335; 2015 IF: NA |
Call Number |
c:irua:127690 c:irua:127690 |
Serial |
3163 |
Permanent link to this record |
|
|
|
Author |
Van Aelst, J.; Philippaerts, A.; Turner, S.; Van Tendeloo, G.; Jacobs, P.; Sels, B. |
Title |
Heterogeneous conjugation of vegetable oil with alkaline treated highly dispersed Ru/USY catalysts |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
Volume |
526 |
Issue |
526 |
Pages |
172-182 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Heterogeneous metal catalysts enable the direct conjugation of linoleic acid tails in vegetable oil to their conjugated linoleic acid (CIA) isomers. CIA-enriched oils are useful as renewable feedstock for the chemical industry and as nutraceutical. Up to now, a solvent-free process for conjugated oils without significant formation of undesired hydrogenation products was not existing. This work shows the design of Ru/USY catalysts able to directly conjugate highly unsaturated vegetable oils such as safflower oil in absence of solvent and hydrogen. Key is fast molecular transport of the bulky reagent and reactive product triglycerides in the zeolite crystal. A two-step zeolite post-synthetic treatment (with NH4OH and acetate salt) was applied to create the necessary mesoporosity. More open zeolite structures allow for a faster conjugation reaction, while securing a fast removal of the reactive conjugated triglycerides, otherwise rapidly deactivating through fouling and pore blockage by polymers. The best Ru/USY catalyst in this contribution is capable of producing exceptionally high yields of conjugated oils, containing up to almost 30 wt% conjugated fatty acid tails in safflower oil, at an initial production rate of 328 g(CLA) mL(-1) h(-1) per gram metal catalyst. (C) 2016 Elsevier B.V. All rights reserved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000384865600021 |
Publication Date |
2016-09-03 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0926-860x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.339 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.339 |
Call Number |
UA @ lucian @ c:irua:137242 |
Serial |
4383 |
Permanent link to this record |
|
|
|
Author |
van der Graaf, W.N.P.; Tempelman, C.H.L.; Hendriks, F.C.; Ruiz-Martinez, J.; Bals, S.; Weckhuysen, B.M.; Pidko, E.A.; Hensen, E.J.M. |
Title |
Deactivation of Sn-Beta during carbohydrate conversion |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
Volume |
564 |
Issue |
564 |
Pages |
113-122 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The deactivation of Sn-Beta zeolite catalyst during retro-aldolization and isomerization of glucose is investigated. Confocal fluorescence microscopy reveals that retro-aldolization of glucose in CH3OH at 160 degrees C is accompanied with the build-up of insoluble oligomeric deposits in the micropores, resulting in a rapid catalyst deactivation. These deposits accumulate predominantly in the outer regions of the zeolite crystals, which points to mass transport limitations. Glucose isomerization in water is not only accompanied by the formation of insoluble deposits in the micropores, but also by the structural degradation of the zeolite due to desilication and destannation. Enhanced and sustained catalytic performance can be achieved by using ethanol/water mixtures as the reaction solvent instead of water. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000443669800012 |
Publication Date |
2018-07-21 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0926-860x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.339 |
Times cited |
25 |
Open Access |
OpenAccess |
Notes |
; This work was performed in the framework of the CatchBio programme and the Joint Scientific Thematic Research Programme funded by the The Netherlands Organization for Scientific Research (NWO) and the Chinese Ministry of Science and Technology. J.R.M. acknowledges the Dutch Science Foundation (NWO) for his personal VENI grant. ; |
Approved |
Most recent IF: 4.339 |
Call Number |
UA @ lucian @ c:irua:153715UA @ admin @ c:irua:153715 |
Serial |
5088 |
Permanent link to this record |
|
|
|
Author |
Zhao, Q.; Lorenz, H.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Rameshan, C.; Klötzer, B.; Konzett, J.; Penner, S. |
Title |
Catalytic characterization of pure SnO2 and GeO2 in methanol steam reforming |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
Volume |
375 |
Issue |
2 |
Pages |
188-195 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Structural changes of a variety of different SnO, SnO2 and GeO2 catalysts upon reduction in hydrogen were correlated with associated catalytic changes in methanol steam reforming. Studied systems include SnO, SnO2 and GeO2 thin film model catalysts prepared by vapour phase deposition and growth on polycrystalline NaCl surfaces and, for comparison, the corresponding pure oxide powder catalysts. Reduction of both the SnO2 thin film and powder at around 673 K in 1 bar hydrogen leads to a substantial reduction of the bulk structure and yields a mixture of SnO2 and metallic β-Sn. On the powder catalyst this transformation is fully reversible upon oxidation in 1 bar O2 at 673 K. Strongly reduced thin films, however, can only be re-transformed to SnO2 if the reduction temperature did not exceed 573 K. For GeO2, the situation is more complex due to its polymorphism. Whereas the tetragonal phase is structurally stable during reduction, oxidation or catalytic reaction, a small part of the hexagonal phase is always transformed into the tetragonal at 673 K independent of the gas phase used. SnO2 is highly active and CO2 selective in methanol steam reforming, but the initial high activity drops considerably upon reduction between 373 and 573 K and almost complete catalyst deactivation is observed after reduction at 673 K, which is associated with the parallel formation of β-Sn. In close correlation to the structural results, the catalytic activity and selectivity can be restored upon an oxidative catalyst regeneration at 673 K. Tetragonal GeO2 exhibits only a small activity and no pronounced selectivity to either CO or CO2, at least after reduction. In its fully oxidized state release of surface/lattice oxygen results in a non-catalytic formation of CO2 by oxidation of CO originating from catalytic dehydrogenation. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000275580600002 |
Publication Date |
2010-01-15 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0926-860X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.339 |
Times cited |
20 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.339; 2010 IF: 3.384 |
Call Number |
UA @ lucian @ c:irua:81741 |
Serial |
292 |
Permanent link to this record |
|
|
|
Author |
Lorenz, H.; Zhao, Q.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Kloetzer, B.; Rameshan, C.; Pfaller, K. |
Title |
Origin of different deactivation of Pd/SnO2 and Pd/GeO2 catalysts in methanol dehydrogenation and reforming: a comparative study |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
Volume |
381 |
Issue |
1/2 |
Pages |
242-252 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Pd particles supported on SnO2 and GeO2 have been structurally investigated by X-ray diffraction, (High-Resolution) transmission and scanning electron microscopy after different reductive treatments to monitor the eventual formation of bimetallic phases and catalytically tested in methanol dehydrogenation/ reforming. For both oxides this included a thin film sample with well-defined Pd particles and a powder catalyst prepared by incipient wetness impregnation. The hexagonal and the tetragonal polymorph were studied for powder GeO2. Pd2Ge formation was observed on all GeO2-supported catalysts, strongly depending on the specific sample used. Reduction of the thin film at 573K resulted in full transformation into the bimetallic state. The partial solubility of hexagonal GeO2 in water and its thermal structural instability yielded Pd2Ge formation at 473 K, at the cost of a structurally inhomogeneous support and Ge metal formation at higher reduction temperatures. Pd on tetragonal GeO2 entered a state of strong metalsupport interaction after reduction at 573673 K, resulting in coalescing Pd2Ge particles on a sintered and re-crystallized support, apparently partially covering the bimetallic particles and decreasing the catalytic activity. Pd2Ge on amorphous thin film and hexagonal GeO2 converted methanol primarily via dehydrogenation to CO and H2. At 573 K, formation of Pd2Sn and also PdSn occurred on the Pd/SnO2 thin film. Pd3Sn2 (and to some extent Pd2Sn) were predominantly obtained on the respective powder catalyst. Strong deactivation with increasing reduction temperature was observed, likely not based on the classical strong metalsupport interaction effect, but rather on a combination of missing active structural ensembles on Sn-enriched bimetallic phases and the formation of metallic -Sn. Correlations to Pd and its bimetallics supported on ZnO, Ga2O3 and In2O3 were also discussed. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000279100700029 |
Publication Date |
2010-04-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0926-860X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.339 |
Times cited |
14 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.339; 2010 IF: 3.384 |
Call Number |
UA @ lucian @ c:irua:83927 |
Serial |
2522 |
Permanent link to this record |
|
|
|
Author |
Lorenz, H.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Klötzer, B.; Rameshan, C.; Pfaller, K.; Penner, S. |
Title |
Pd-In2O3 interaction due to reduction in hydrogen: consequences for methanol steam reforming |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
Volume |
374 |
Issue |
1/2 |
Pages |
180-188 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Two different Pd/In2O3 samples including a thin film model catalyst with well-defined Pd particles grown on NaCl(0 0 1) supports and a powder catalyst prepared by an impregnation technique are examined by electron microscopy, X-ray diffraction and catalytic measurements in methanol steam reforming in order to correlate the formation of different oxide-supported bimetallic PdIn phases with catalytic activity and selectivity. A PdIn shell around the Pd particles is observed on the thin film catalyst after embedding the Pd particles in In2O3 at 300 K, likely because alloying to PdIn and oxidation to In2O3 are competing processes. Increased PdIn bimetallic formation is observed up to 573 K reduction temperature until at 623 K the film stability limit in hydrogen is reached. Oxidative treatments at 573 K lead to decomposition of PdIn and to the formation of an In2O3 shell covering the Pd particles, which irreversibly changes the activity and selectivity pattern to clean In2O3. PdIn and Pd2In3 phases are obtained on the powder catalyst after reduction at 573 K and 673 K, respectively. Only CO2-selective methanol steam reforming is observed in the reduction temperature range between 473 K and 573 K. After reduction at 673 K encapsulation of the bimetallic particles by crystalline In2O3 suppresses CO2 formation and only activity and selectivity of clean In2O3 are measured. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000274869900023 |
Publication Date |
2009-12-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0926-860X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.339 |
Times cited |
55 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.339; 2010 IF: 3.384 |
Call Number |
UA @ lucian @ c:irua:81801 |
Serial |
3553 |
Permanent link to this record |
|
|
|
Author |
Geukens, I.; Vermoortele, F.; Meledina, M.; Turner, S.; Van Tendeloo, G.; De Vos, D.E. |
Title |
Ag nanoparticles on mixed Al2O3-Ga2O3 supports as catalysts for the N-alkylation of amines with alcohols |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
Volume |
469 |
Issue |
|
Pages |
373-379 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The combination of AgNO3 with NaH results in Ag nanoparticles that can selectively perform alcohol aminations under mild reaction conditions (110 °C). NaH not only serves as a reducing agent for the Ag salt, but also activates the alcohol for dehydrogenation to the corresponding ketone/aldehyde. The stability of the particles can be improved by immobilizing them onto mixed Al2O3Ga2O3 supports; the combination of Ga and Al provides materials with stronger Lewis acidic sites compared to pure alumina or gallium oxide supports. This leads to catalysts with enhanced activities, without the necessity of adding external Lewis acids. Detailed TEM characterization also reveals a close interaction between the Ag NPs and the gallium oxide phase. The obtained catalysts are recyclable and show activity for the alcohol amination using a variety of aliphatic and aromatic amines under mild conditions. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000329266500045 |
Publication Date |
2013-10-10 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0926-860X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.339 |
Times cited |
24 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.339; 2014 IF: 3.942 |
Call Number |
UA @ lucian @ c:irua:111095 |
Serial |
83 |
Permanent link to this record |
|
|
|
Author |
Barhoum, A.; Van Assche, G.; Rahier, H.; Fleisch, M.; Bals, S.; Delplancked, M.-P.; Leroux, F.; Bahnemann, D. |
Title |
Sol-gel hot injection synthesis of ZnO nanoparticles into a porous silica matrix and reaction mechanism |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Materials & design |
Abbreviated Journal |
Mater Design |
Volume |
119 |
Issue |
119 |
Pages |
270-276 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Despite the enormous interest in the properties and applications of porous silica matrix, only a few attempts have been reported to deposit metal and metal oxide nanoparticles (NPs) inside the porous silica matrix. We report a simple approach (i.e. sol-gel hot injection) for insitu synthesis of ZnO NPs inside a porous silica matrix. Control of the Zn:Si molar ratio, reaction temperature, pH value, and annealing temperature permits formation of ZnO NPs (<= 10 nm) inside a porous silica particles, without additives or organic solvents. Results revealed that a solid state reaction inside the ZnO/SiO2 nanocomposites occurs with increasing the annealing temperature. The reaction of ZnO NPs with SiO2 matrix was insignificant up to approximately 500 degrees C. However, ZnO NPs react strongly with the silica matrix when the nanocomposites are annealed at temperatures above 700 degrees C. Extensive annealing of the ZnO/SiO2 nanocomposite at 900 degrees C yields 3D structures made of 500 nm rod-like, 5-7 pm tube-like and 35 pm needle-like Zn2SiO4 crystals. A possible mechanism for forming ZnO NPs inside porous silica matrix and phase transformation of the ZnO/SiO2 nanocomposites into 3D architectures of Zn2SiO4 are carefully discussed. (C) 2017 Elsevier Ltd. All rights reserved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000397360000030 |
Publication Date |
2017-01-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0264-1275 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.364 |
Times cited |
43 |
Open Access |
Not_Open_Access |
Notes |
; A.B. would like to thank FWO – Research Foundation Flanders (grant no. V450315N) and the Strategic Initiative Materials in Flanders (SBO-project no. 130529 – INSITU) for financial support. TEM and TEM-EDX analyses were performed by Dr. F. Leroux (EMAT, Universiteit Antwerpen). XRD and DSC measurements were performed by T. Segato (4MAT, Universite Libre de Bruxelles). Notes: the authors declare no competing for financial interest. ; |
Approved |
Most recent IF: 4.364 |
Call Number |
UA @ lucian @ c:irua:142394UA @ admin @ c:irua:142394 |
Serial |
4689 |
Permanent link to this record |
|
|
|
Author |
Radi, A.; Khalil-Allafi, J.; Etminanfar, M.R.; Pourbabak, S.; Schryvers, D.; Amin-Ahmadi, B. |
Title |
Influence of stress aging process on variants of nano-N4Ti3precipitates and martensitic transformation temperatures in NiTi shape memory alloy |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Materials & design |
Abbreviated Journal |
Mater Design |
Volume |
262 |
Issue |
262 |
Pages |
74-81 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
In this study, the effect of a stress aging process on the microstructure and martensitic phase transformation of NiTi shape memory alloy has been investigated. NiTi samples were aged at 450 degrees C for 1 h and 5 h under different levels of external tensile stress of 15, 60 and 150 MPa. Transmission electron microscopy (TEM) was used to characterize different variants and morphology of precipitates. The results show that application of all stress levels restricts the formation of precipitates variants in the microstructure after I h stress aging process. However, all variants can be detected by prolonging aging time to 5 h at 15 MPa stress level and the variants formation is again restricted by increasing the stress level. Moreover, the stress aging process resulted in changing the shape of precipitates in comparison with that of the stress-free aged samples. Coffee-bean shaped morphologies were detected for precipitates in all stress levels. According to the Differential Scanning Calorimetry (DSC) results, the martensite start temperature (M-s) on cooling shifts to higher temperatures with increasing the tensile stress during the aging process. This can be related to the change ofaustenite to martensite interface energy due to the different volume fractions and variants of precipitates. (c) 2018 Elsevier Ltd. All rights reserved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
|
Publication Date |
2018-01-04 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0264-1275 |
ISBN |
|
Additional Links |
UA library record; ; WoS full record; WoS citing articles |
Impact Factor |
4.364 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 4.364 |
Call Number |
UA @ lucian @ c:irua:149854 |
Serial |
4938 |
Permanent link to this record |
|
|
|
Author |
Miotti Bettanini, A.; Ding, L.; Mithieux, J.-D.; Parrens, C.; Idrissi, H.; Schryvers, D.; Delannay, L.; Pardoen, T.; Jacques, P.J. |
Title |
Influence of M23C6 dissolution on the kinetics of ferrite to austenite transformation in Fe-11Cr-0.06C stainless steel |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Materials & design |
Abbreviated Journal |
Mater Design |
Volume |
162 |
Issue |
|
Pages |
362-374 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The design of high-strength martensitic stainless steels requires an accurate control over the stability of undesired phases, like carbides and ferrite, which can hamper strength and ductility. Here, the ferrite to austenite transformation in Fe-11Cr-0.06C has been studied with a combined experimental-modelling approach. Experimental observations of the austenization process indicate that austenite growth proceeds in multiple steps, each one characterized by a different transformation rate. DICTRA based modelling reveals that the dissolution of the M23C6 Cr-rich carbides leads to Cr partitioning between austenite and parent phases, which controls the rate of transformation through (i) a soft-impingement effect and (ii) consequent stabilization of the ferrite, which remains untransformed inside chromium-enriched-zones even after prolonged austenization stage. Slow heating rate and smaller initial particle sizes allow the design of ferrite-free microstructure. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000454128400036 |
Publication Date |
2018-12-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0264-1275 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.364 |
Times cited |
3 |
Open Access |
OpenAccess |
Notes |
The authors thank Professor Anne-Francoise Gourgues-Lorenzon and Helene Godin, Ecole Nationale Superiore des Mines de Paris (MINES ParisTech) for their fruitful discussions. AMB thanks Stijn Van den broek (Universiteit Antwerpen) for the skillful preparation of TEM samples with FIB. The financial support of CBMM (Companhia Brasileira de Metalurgia e Mineracao) is gratefully acknowledged. L. Delannay is mandated by the FNRS-Belgium. Computational resources have been provided by the supercomputing facilities of the UCLouvain (CISM/UCL) and the Consortium des Equipements de Calcul Intensif en Federation Wallonie Bruxelles (CÉCI) funded by the Fond de la Recherche Scientifique de Belgique (F.R.S.-FNRS) under convention 2.5020.11.; Cbmm; F.r.s.-fnrs, 2.5020.11 ; |
Approved |
Most recent IF: 4.364 |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:156721 |
Serial |
5161 |
Permanent link to this record |
|
|
|
Author |
Montero-Sistiaga, M.L.; Pourbabak, S.; Van Humbeeck, J.; Schryvers, D.; Vanmeensel, K. |
Title |
Microstructure and mechanical properties of Hastelloy X produced by HP-SLM (high power selective laser melting) |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Materials & design |
Abbreviated Journal |
Mater Design |
Volume |
165 |
Issue |
|
Pages |
107598 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
In order to increase the production rate during selective laser melting (SLM), a high power laser with a large beam diameter is used to build fully dense Hastelloy X parts. Compared to SLM with a low power and small diameter beam, the productivity was increased from 6 mm3/s to 16 mm3/s, i.e. 2.6 times faster. Besides the productivity benefit, the influence of the use of a high power laser on the rapid solidification microstructure and concomitant material properties is highlighted. The current paper compares the microstructure and tensile properties of Hastelloy X built with low and high power lasers. The use of a high power laser results in wider and shallower melt pools inducing an enhanced morphological and crystallographic texture along the building direction (BD). In addition, the increased heat input results in coarser sub-grains or high density dislocation walls for samples processed with a high power laser. Additionally, the influence of hot isostatic pressing (HIP) as a post-processing technique was evaluated. After HIP, the tensile fracture strain increased as compared to the strain in the as-built state and helped in obtaining competitive mechanical properties as compared to conventionally processed Hastelloy X parts. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000458259300020 |
Publication Date |
2019-01-09 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0264-1275 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.364 |
Times cited |
15 |
Open Access |
OpenAccess |
Notes |
This research was supported by the ENGIE Research and Technology Division. The authors acknowledge ENGIE Research and Technology Division for the use of the SLM280HL machine. S.P. likes to thank the Flemish Science Foundation FWO for financial support under Project G.0366.15N. |
Approved |
Most recent IF: 4.364 |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:157469 |
Serial |
5176 |
Permanent link to this record |
|
|
|
Author |
Zhang, L.; Batuk, D.; Chen, G.; Tarascon, J.-M. |
Title |
Electrochemically activated MnO as a cathode material for sodium-ion batteries |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Electrochemistry communications |
Abbreviated Journal |
Electrochem Commun |
Volume |
77 |
Issue |
|
Pages |
81-84 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Besides classical electrode materials pertaining to Li-ion batteries, recent interest has been devoted to pairs of active redox composites having a redox center and an intercalant source. Taking advantage of the NaPFG salt decomposition above 4.2 V. we extrapolate this concept to the electrochemical in situ preparation of F-based MnO composite electrodes for Na-ion batteries. Such electrodes exhibit a reversible discharge capacity of 145 mAh g(-1) at room temperature. The amorphization of pristine MnO electrode after activation is attributed to the electrochemical grinding effect caused by substantial atomic migration and lattice strain build-up upon cycling. (C) 2017 Elsevier B.V. All rights reserved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000399510400019 |
Publication Date |
2017-02-28 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1388-2481 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.396 |
Times cited |
8 |
Open Access |
OpenAccess |
Notes |
; This work was partially supported by the Hong Kong Research Grants Council under the General Research Fund Project #611213. L.Z. thanks the HKUST for his Postgraduate Studentship. ; |
Approved |
Most recent IF: 4.396 |
Call Number |
UA @ lucian @ c:irua:143648 |
Serial |
4650 |
Permanent link to this record |
|
|
|
Author |
Ustarroz, J.; Gupta, U.; Hubin, A.; Bals, S.; Terryn, H. |
Title |
Electrodeposition of Ag nanoparticles onto carbon coated TEM grids : a direct approach to study early stages of nucleation |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Electrochemistry communications |
Abbreviated Journal |
Electrochem Commun |
Volume |
12 |
Issue |
12 |
Pages |
1706-1709 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
An innovative experimental approach to study the electrodeposition of small nanoparticles and the early stages of electrochemical nucleation and growth is presented. Carbon coated gold TEM grids are used as substrates for the electrodeposition of silver nanoparticles so that electrochemical data, FESEM, HAADFSTEM and HRTEM data can be acquired from the same sample without the need to remove the particles from the substrate. It is shown that the real distribution of nanoparticles cannot be resolved by FESEM whereas HAADFSTEM analysis confirms that a distribution of small nanoparticles (d ≈ 12 nm) coexist with large nanoparticles corresponding to a bimodal size distribution. Besides, particles grown under the same conditions have been found to present different structures such as monocrystals, polycrystals or aggregates of smaller particles. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000285904700010 |
Publication Date |
2010-10-09 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1388-2481; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.396 |
Times cited |
52 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 4.396; 2010 IF: 4.287 |
Call Number |
UA @ lucian @ c:irua:87612 |
Serial |
900 |
Permanent link to this record |
|
|
|
Author |
Canossa, S.; Gonzalez-Nelson, A.; Shupletsov, L.; Carmen Martin, M.; Van der Veen, M.A. |
Title |
Overcoming Crystallinity Limitations of Aluminium Metal-Organic Frameworks by Oxalic Acid Modulated Synthesis |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Chemistry-A European Journal |
Abbreviated Journal |
Chem-Eur J |
Volume |
26 |
Issue |
16 |
Pages |
3564-3570 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A modulated synthesis approach based on the chelating properties of oxalic acid (H2C2O4) is presented as a robust and versatile method to achieve highly crystalline Al‐based metal‐organic frameworks. A comparative study on this method and the already established modulation by hydrofluoric acid was conducted using MIL‐53 as test system. The superior performance of oxalic acid modulation in terms of crystallinity and absence of undesired impurities is explained by assessing the coordination modes of the two modulators and the structural features of the product. The validity of our approach was confirmed for a diverse set of Al‐MOFs, namely X‐MIL‐53 (X=OH, CH3O, Br, NO2), CAU‐10, MIL‐69, and Al(OH)ndc (ndc=1,4‐naphtalenedicarboxylate), highlighting the potential benefits of extending the use of this modulator to other coordination materials. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000517650300001 |
Publication Date |
2020-03-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0947-6539 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.3 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
The Elettra Synchrotron facility (CNR Trieste, Basovizza, Italy) is acknowledged for granting beamtime at the single-crystal diffraction beamline XRD1 (Proposal ID 20185483) and the beamline staff is gratefully thanked for the precious assistance. This work was funded by the European Research Council (grant number 759 212) within the Horizon 2020 Framework Programme (H2020-EU.1.1). The work by A.G.-N. forms part of the research programme of DPI, NEWPOL project 731.015.506. |
Approved |
Most recent IF: 4.3; 2020 IF: 5.317 |
Call Number |
EMAT @ emat @c:irua:167706 |
Serial |
6388 |
Permanent link to this record |
|
|
|
Author |
Kaminsky, F.V.; Ryabchikov, I.D.; McCammon, C.A.; Longo, M.; Abakumov, A.M.; Turner, S.; Heidari, H. |
Title |
Oxidation potential in the Earth's lower mantle as recorded by ferropericlase inclusions in diamond |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Earth and planetary science letters |
Abbreviated Journal |
Earth Planet Sc Lett |
Volume |
417 |
Issue |
417 |
Pages |
49-56 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Ferropericlase (fPer) inclusions from kimberlitic lower-mantle diamonds recovered in the Juina area, Mato Grosso State, Brazil were analyzed with transmission electron microscopy, electron energy-loss spectroscopy and the flank method. The presence of exsolved non-stoichiometric Fe3+-enriched clusters, varying in size from 1-2 nm to 10-15 nm and comprising similar to 3.64 vol.% of fPer was established. The oxidation conditions necessary for fPer formation within the uppermost lower mantle (P = 25 GPa, T = 1960 K) vary over a wide range: Delta log f(o2) (IW) from 1.58 to 7.76 (Delta = 6.2), reaching the fayalite-magnetite-quartz (FMQ) oxygen buffer position. This agrees with the identification of carbonates and free silica among inclusions within lower-mantle Juina diamonds. On the other hand, at the base of the lower mantle Delta log f(o2) values may lie at and below the iron-wustite (IW) oxygen buffer. Hence, the variations of Delta log f(o2) values within the entire sequence of the lower mantle may reach ten logarithmic units, varying from the IW buffer to the FMQ buffer values. The similarity between lower- and upper-mantle redox conditions supports whole mantle convection, as already suggested on the basis of nitrogen and carbon isotopic compositions in lower- and upper-mantle diamonds. The mechanisms responsible for redox differentiation in the lower mantle may include subduction of oxidized crustal material, mechanical separation of metallic phase(s) and silicate-oxide mineral assemblages enriched in ferric iron, as well as transfer of fused silicate-oxide material presumably also enriched in ferric iron through the mantle. (C) 2015 Elsevier B.V. All rights reserved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000351799400006 |
Publication Date |
2015-03-05 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0012-821X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.409 |
Times cited |
23 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.409; 2015 IF: 4.734 |
Call Number |
c:irua:125451 |
Serial |
2539 |
Permanent link to this record |
|
|
|
Author |
Meledina, M.; Turner, S.; Filippousi, M.; Leus, K.; Lobato, I.; Ramachandran, R.K.; Dendooven, J.; Detavernier, C.; Van Der Voort, P.; Van Tendeloo, G. |
Title |
Direct Imaging of ALD Deposited Pt Nanoclusters inside the Giant Pores of MIL-101 |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
Volume |
33 |
Issue |
33 |
Pages |
382-387 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
MIL-101 giant-pore metal-organic framework (MOF) materials have been loaded with Pt nanoparticles using atomic layer deposition. The final structure has been investigated by aberration-corrected annular dark-field scanning transmission electron microscopy under strictly controlled low dose conditions. By combining the acquired experimental data with image simulations, the position of the small clusters within the individual pores of a metal-organic framework has been determined. The embedding of the Pt nanoparticles is confirmed by electron tomography, which shows a distinct ordering of the highly uniform Pt nanoparticles. The results show that atomic layer deposition is particularly well-suited for the deposition of individual nanoparticles inside MOF framework pores and that, upon proper regulation of the incident electron dose, annular dark-field scanning transmission electron microscopy is a powerful tool for the characterization of this type of materials at a local scale. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000379970000006 |
Publication Date |
2016-02-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.474 |
Times cited |
11 |
Open Access |
|
Notes |
S.T. and J.D. gratefully acknowledge the FWO Vlaanderen for a postdoctoral scholarship. The Titan microscope used for this investigation was partially funded by the Hercules foundation of the Flemish government. This work was supported by the Belgian IAP-PAI network. K.L. acknowledges the financial support from the Ghent University BOF postdoctoral Grant 01P06813T and UGent GOA Grant 01G00710. C.D. thanks the FWO Vlaanderen, BOF-UGent (GOA 01G01513), and the Hercules Foundation (AUGE/09/014) for financial support. |
Approved |
Most recent IF: 4.474 |
Call Number |
c:irua:131913 |
Serial |
4028 |
Permanent link to this record |
|
|
|
Author |
Zanaga, D.; Altantzis, T.; Polavarapu, L.; Liz-Marzán, L.M.; Freitag, B.; Bals, S. |
Title |
A New Method for Quantitative XEDS Tomography of Complex Heteronanostructures |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
Volume |
33 |
Issue |
33 |
Pages |
396-403 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Reliable quantification of 3D results obtained by X-ray Energy Dispersive Spectroscopy (XEDS) tomography is currently hampered by the presence of shadowing effects and poor spatial resolution. Here, we present a method that overcomes these problems by synergistically combining quantified XEDS data and High Angle Annular Dark Field – Scanning Transmission Electron Microscopy (HAADF-STEM) tomography. As a proof of principle, the approach is applied to characterize a complex Au/Ag nanorattle obtained through a galvanic replacement reaction. However, the technique we propose here is widely applicable to a broad range of nanostructures. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000379970000008 |
Publication Date |
2016-03-31 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.474 |
Times cited |
29 |
Open Access |
OpenAccess |
Notes |
The authors acknowledge financial support from European Research Council (ERC Starting Grant # 335078-COLOURATOMS, ERC Advanced Grant # 291667 HierarSACol and ERC Advanced Grant 267867 – PLASMAQUO), the European Union under the FP7 (Integrated Infrastructure Initiative N. 262348 European Soft Matter Infrastructure, ESMI and N. 312483 ESTEEM2).; esteem2jra4; ECASSara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 4.474 |
Call Number |
c:irua:132643 c:irua:132643 |
Serial |
4052 |
Permanent link to this record |
|
|
|
Author |
Varambhia, A.M.; Jones, L.; De Backer, A.; Fauske, V.T.; Van Aert, S.; Ozkaya, D.; Nellist, P.D. |
Title |
Quantifying a Heterogeneous Ru Catalyst on Carbon Black Using ADF STEM |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
Volume |
33 |
Issue |
33 |
Pages |
438-444 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Ru catalysts are part of a set of late transition metal nanocatalysts that have garnered much interest for catalytic applications such as ammonia synthesis and fuel cell production. Their performance varies greatly depending on their morphology and size, these catalysts are widely studied using electron microscopy. Using recent developments in Annular Dark Field (ADF) Scanning Transmission Electron Microscopy (STEM) quantification techniques, a rapid atom counting procedure was utilized to document the evolution of a heterogeneous Ru catalyst supported on carbon black. Areas of the catalyst were imaged for approximately 15 minutes using ADF STEM. When the Ru clusters were exposed to the electron beam, the clusters changed phase from amorphous to crystalline. To quantify the thickness of the crystalline clusters, two techniques were applied (simulation and statistical decomposition) and compared. These techniques show that stable face centredcubic crystal structures in the form of rafts, between 2 and 8 atoms thick, were formed after the initial wetting of the carbon support. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000379970000012 |
Publication Date |
2016-06-17 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.474 |
Times cited |
4 |
Open Access |
|
Notes |
The authors would like to thank the EPSRC and Johnson Matthey for funding this work as part of a CASE-Award studentship. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative–I3). We would like to thank Brian Theobald and Jonathan Sharman from JMTC for provision of the samples The authors gratefully acknowledge the Research Foundation Flanders (FWO, Belgium) for funding and for a postdoctoral grant to ADB. The microscope used was funded by the INFRASTRUKTUR Grant 197405 (NORTEM) program of the Research Council of Norway.; esteem2_jra2 |
Approved |
Most recent IF: 4.474 |
Call Number |
c:irua:134036 c:irua:134036 |
Serial |
4086 |
Permanent link to this record |
|
|
|
Author |
Liz-Marzan, L.; Bals, S. |
Title |
Advanced particle characterization techniques |
Type |
Editorial |
Year |
2016 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
Volume |
33 |
Issue |
33 |
Pages |
350-351 |
Keywords |
Editorial; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
Wiley-v c h verlag gmbh |
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000379970000001 |
Publication Date |
2016-07-14 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
4.474 |
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
; ; |
Approved |
Most recent IF: 4.474 |
Call Number |
UA @ lucian @ c:irua:134957 |
Serial |
4136 |
Permanent link to this record |
|
|
|
Author |
Chinchilla, L.E.; Olmos, C.; Kurttepeli, M.; Bals, S.; Van Tendeloo, G.; Villa, A.; Prati, L.; Blanco, G.; Calvino, J.J.; Chen, X.; Hungría, A.B. |
Title |
Combined macroscopic, nanoscopic, and atomic-scale characterization of gold-ruthenium bimetallic catalysts for octanol oxidation |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
Volume |
33 |
Issue |
33 |
Pages |
419-437 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
A series of gold-ruthenium bimetallic catalysts of increasing Au:Ru molar ratios supported on a Ce0.62Zr0.38O2 mixed oxide are prepared and their structural and chemical features characterized by a combination of macroscopic and atomic-scale techniques based on scanning transmission electron microscopy. The influence of the temperature of the final reduction treatment used as activation step (350-700 degrees C range) is also investigated. The preparation method used allows catalysts to be successfully prepared where a major fraction of the metal nanoparticles is in the size range below 5 nm. The structural complexities characteristic of this type of catalysts are evidenced, as well as the capabilities and limitations of both the macroscopic and microscopic techniques in the characterization of the system of metal nanoparticles. A positive influence of the addition of Ru on both the resistance against sintering and the catalytic performance of the starting supported Au catalyst is evidenced. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000379970000011 |
Publication Date |
2016-05-24 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.474 |
Times cited |
7 |
Open Access |
OpenAccess |
Notes |
; This work was supported by the Ministry of Science and Innovation of Spain/ FEDER Program of the EU (Project Nos.: MAT 2013-40823-R and CSD2009-00013), ESTEEM2 (FP7-INFRASTUCTURE-2012-1-312493), Junta de Andalucia (FQM334 and FQM110 and Project: FQM3994). S.B. acknowledges the European Research Council, ERC grant No. 335078 – Colouratom. M.K. is grateful to the Fund for Scientific Research Flanders. X.C. thanks the Ramon y Cajal Program. ; ecas_sara |
Approved |
Most recent IF: 4.474 |
Call Number |
UA @ lucian @ c:irua:134958 |
Serial |
4150 |
Permanent link to this record |
|
|
|
Author |
Amini, M.N.; Altantzis, T.; Lobato, I.; Grzelczak, M.; Sánchez-Iglesias, A.; Van Aert, S.; Liz-Marzán, L.M.; Partoens, B.; Bals, S.; Neyts, E.C. |
Title |
Understanding the Effect of Iodide Ions on the Morphology of Gold Nanorods |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
Volume |
35 |
Issue |
35 |
Pages |
1800051 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The presence of iodide ions during the growth of gold nanorods strongly affects the shape of the final products, which is proposed to be due to selective iodide adsorption on certain crystallographic facets. Therefore, a detailed structural and morphological characterization of the starting rods is crucial toward understanding this effect. Electron tomography is used to determine the crystallographic indices of the lateral facets of gold nanorods, as well as those present at the tips. Based on this information, density functional theory calculations are used to determine the surface and interface energies of the observed facets and provide insight into the relationship between the amount of iodide ions in the growth solution and the final morphology of anisotropic gold nanoparticles. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000441893400002 |
Publication Date |
2018-06-10 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.474 |
Times cited |
6 |
Open Access |
OpenAccess |
Notes |
This work was supported by the European Research Council (grant 335078 COLOURATOM to S.B.). T.A., S.V.A. S.B. and E.C.N., acknowledge funding from the Research Foundation Flanders (FWO, Belgium), through project funding (G.0218.14N and G.0369.15N) and a postdoctoral grant to T.A. L.M.L.-M. and M.G. acknowledge funding from the Spanish Ministerio de Economía y Competitividad (grant MAT2013-46101-R). Mozhgan N. Amini and Thomas Altantzis contributed equally to this work. (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); ecas_sara |
Approved |
Most recent IF: 4.474 |
Call Number |
EMAT @ emat @c:irua:152998UA @ admin @ c:irua:152998 |
Serial |
5010 |
Permanent link to this record |
|
|
|
Author |
Zhang, Y.; Bals, S.; Van Tendeloo, G. |
Title |
Understanding CeO2-Based Nanostructures through Advanced Electron Microscopy in 2D and 3D |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
Volume |
36 |
Issue |
36 |
Pages |
1800287 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Engineering morphology and size of CeO2-based nanostructures on a (sub)nanometer scale will greatly influence their performance; this is because of their high oxygen storage capacity and unique redox properties, which allow faster switching of the oxidation state between Ce4+ and Ce3+. Although tremendous research has been carried out on the shapecontrolled synthesis of CeO2, the characterization of these nanostructures at the atomic scale remains a major challenge and the origin of debate. The rapid developments of aberration-corrected transmission electron microscopy (AC-TEM) have pushed the resolution below 1 Å, both in TEM and in scanning transmission electron microscopy (STEM) mode. At present, not only morphology and structure, but also composition and electronic structure can be analyzed at an atomic scale, even in 3D. This review summarizes recent significant achievements using TEM/ STEM and associated spectroscopic techniques to study CeO2-based nanostructures and related catalytic phenomena. Recent results have shed light on the understanding of the different mechanisms. The potential and limitations, including future needs of various techniques, are discussed with recommendations to facilitate further developments of new and highly efficient CeO2-based nanostructures. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000455414600012 |
Publication Date |
2018-10-24 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.474 |
Times cited |
22 |
Open Access |
OpenAccess |
Notes |
Y.Z. acknowledges financial support from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska- Curie grant agreement no. 665501 through a FWO [PEGASUS]2 Marie Skłodowska-Curie fellowship (12U4917N). S.B. acknowledges funding from the European Research Council, ERC grant no. 335078-Colouratom. ; ecas_sara |
Approved |
Most recent IF: 4.474 |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:156391 |
Serial |
5151 |
Permanent link to this record |
|
|
|
Author |
Vanrompay, H.; Béché, A.; Verbeeck, J.; Bals, S. |
Title |
Experimental Evaluation of Undersampling Schemes for Electron Tomography of Nanoparticles |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
Volume |
36 |
Issue |
36 |
Pages |
1900096 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
One of the emerging challenges in the field of 3D characterization of nanoparticles by electron tomography is to avoid degradation and deformation of the samples during the acquisition of a tilt series. In order to reduce the required electron dose, various undersampling approaches have been proposed. These methods include lowering the number of 2D projection images, reducing the probe current during the acquisition, and scanning a smaller number of pixels in the 2D images. A comparison is made between these approaches based on tilt series acquired for a gold nanoparticle. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000477679400014 |
Publication Date |
2019-05-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.474 |
Times cited |
12 |
Open Access |
Not_Open_Access |
Notes |
H.V. acknowledges financial support by the Research Foundation Flanders (FWO Grant No. 1S32617N). A.B. and J.V. acknowledge FWO project 6093417N “Compressed sensing enabling low dose imaging in STEM.” The authors thank G. González-Rubio, A. Sánchez-Iglesias, and L.M. Liz-Marzán for provision of the samples. |
Approved |
Most recent IF: 4.474 |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:159986 |
Serial |
5175 |
Permanent link to this record |
|
|
|
Author |
Altantzis, T.; Goris, B.; Sánchez-Iglesias, A.; Grzelczak, M.; Liz-Marzán, L.M.; Bals, S. |
Title |
Quantitative structure determination of large three-dimensional nanoparticle assemblies |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
Volume |
30 |
Issue |
1 |
Pages |
84-88 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Thumbnail image of graphical abstract To investigate nanoassemblies in three dimensions, electron tomography is an important tool. For large nanoassemblies, it is not straightforward to obtain quantitative results in three dimensions. An optimized acquisition technique, incoherent bright field scanning transmission electron microscopy, is combined with an advanced 3D reconstruction algorithm. The approach is applied to quantitatively analyze large nanoassemblies in three dimensions. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000310806000008 |
Publication Date |
2012-11-07 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0934-0866; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.474 |
Times cited |
23 |
Open Access |
|
Notes |
Goa; Fwo; 267867 Plasmaquo; 262348 Esmi |
Approved |
Most recent IF: 4.474; 2013 IF: 0.537 |
Call Number |
UA @ lucian @ c:irua:101776 |
Serial |
2763 |
Permanent link to this record |
|
|
|
Author |
Shenderova, O.; Hens, S.; Vlasov, I.; Turner, S.; Lu, Y.-G.; Van Tendeloo, G.; Schrand, A.; Burikov, S.A.; Dolenko, T.A. |
Title |
Carbon-dot-decorated nanodiamonds |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
Volume |
31 |
Issue |
5 |
Pages |
580-590 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The synthesis of a new class of fluorescent carbon nanomaterials, carbon-dot-decorated nanodiamonds (CDD-ND), is reported. These CDD-NDs are produced by specific acid treatment of detonation soot, forming tiny rounded sp2 carbon species (carbon dots), 12 atomic layers thick and 12 nm in size, covalently attached to the surface of the detonation diamond nanoparticles. A combination of nanodiamonds bonded with a graphitic phase as a starting material and the application of graphite intercalated acids for oxidation of the graphitic carbon is necessary for the successful production of CDD-ND. The CDD-ND photoluminescence (PL) is stable, 20 times more intense than the intrinsic PL of well-purified NDs and can be tailored by changing the oxidation process parameters. Carbon-dot-decorated DNDs are shown to be excellent probes for bioimaging applications and inexpensive additives for PL nanocomposites. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000335518900008 |
Publication Date |
2014-01-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0934-0866; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.474 |
Times cited |
30 |
Open Access |
|
Notes |
Fwo; 262348 Esmi; 246791 Countatoms |
Approved |
Most recent IF: 4.474; 2014 IF: 3.081 |
Call Number |
UA @ lucian @ c:irua:117332 |
Serial |
280 |
Permanent link to this record |
|
|
|
Author |
Sentosun, K.; Sanz Ortiz, M.N.; Batenburg, K.J.; Liz-Marzán, L.M.; Bals, S. |
Title |
Combination of HAADF-STEM and ADF-STEM Tomography for Core-Shell Hybrid Materials |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
Volume |
32 |
Issue |
32 |
Pages |
1063-1067 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
Characterization of core-shell type nanoparticles in 3D by transmission electron microscopy (TEM) can be very challenging. Especially when both heavy and light elements co-exist within the same nanostructure, artefacts in the 3D reconstruction are often present. A representative example would be a particle comprising an anisotropic metallic (Au) nanoparticle coated with a (mesoporous) silica shell. To obtain a reliable 3D characterization of such an object, we propose a dose-efficient strategy to simultaneously acquire high angle annular dark field scanning TEM and annular dark field tilt series for tomography. The 3D reconstruction is further improved by applying an advanced masking and interpolation approach to the acquired data. This new methodology enables us to obtain high quality reconstructions from which also quantitative information can be extracted. This approach is broadly applicable to investigate hybrid core-shell materials. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000368446800003 |
Publication Date |
2015-10-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0934-0866; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.474 |
Times cited |
13 |
Open Access |
OpenAccess |
Notes |
S.B. acknowledges financial support from European Research Council (ERC) (ERC Starting Grant #335078-COLOURATOM). L.M. acknowledges funding from the EU, Grant# 310651-2 Self-Assembly in Confined Space (SACS). K.J.B acknowledges financial support from the Netherlands Organisation for Scientific Research (NWO), project number 639.072.005 and NWO CW 700.57.026. Networking support was provided by COST Action MP1207. The authors acknowledge the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative, Reference No. 312483-ESTEEM2 for financial support.; esteem2jra4; ECASSara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 4.474; 2015 IF: 3.081 |
Call Number |
c:irua:129590 c:irua:129590 |
Serial |
3967 |
Permanent link to this record |