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Records |
Links |
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Author |
Moshnyaga, V.; Damaschke, B.; Shapoval, O.; Belenchuk, A.; Faupel, J.; Lebedev, O.I.; Verbeeck, J.; Van Tendeloo, G.; Mücksch, M.; Tsurkan, V.; Tidecks, R.; Samwer, K. |
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Title |
Structural phase transition at the percolation threshold in epitaxial (La0.7Ca0.3MnO3)1-x:(MgO)x nanocomposite films |
Type |
A1 Journal article |
| |
Year |
2003 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
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| |
Volume |
2 |
Issue |
4 |
Pages |
247-252 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
'Colossal magnetoresistance' in perovskite manganites such as La0.7Ca0.3MnO3 (LCMO), is caused by the interplay of ferro-paramagnetic, metal-insulator and structural phase transitions. Moreover, different electronic phases can coexist on a very fine scale resulting in percolative electron transport. Here we report on (LCMO)(1-x):(MgO)(x) (0 < x less than or equal to 0.8) epitaxial nano-composite films in which the structure and magnetotransport properties of the manganite nanoclusters can be tuned by the tensile stress originating from the MgO second phase. With increasing x, the lattice of LCMO was found to expand, yielding a bulk tensile strain. The largest colossal magnetoresistance of 10(5)% was observed at the percolation threshold in the conductivity at x(c) approximate to 0.3, which is coupled to a structural phase transition from orthorhombic (0 < x less than or equal to 0.1) to rhombohedral R (3) over barc structure (0.33 less than or equal to x less than or equal to 0.8). An increase of the Curie temperature for the R (3) over barc phase was observed. These results may provide a general method for controlling the magnetotransport properties of manganite-based composite films by appropriate choice of the second phase. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000182052700022 |
Publication Date |
2003-03-31 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1476-1122;1476-4660; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
39.737 |
Times cited |
177 |
Open Access |
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Notes |
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Approved  |
Most recent IF: 39.737; 2003 IF: 10.778 |
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| |
Call Number |
UA @ lucian @ c:irua:54855 |
Serial |
3247 |
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| Permanent link to this record |
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Author |
Liao, Z.; Huijben, M.; Zhong, Z.; Gauquelin, N.; Macke, S.; Green, R.J.; Van Aert, S.; Verbeeck, J.; Van Tendeloo, G.; Held, K.; Sawatzky, G.A.; Koster, G.; Rijnders, G. |
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| |
Title |
Controlled lateral anisotropy in correlated manganite heterostructures by interface-engineered oxygen octahedral coupling |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
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| |
Volume |
15 |
Issue |
15 |
Pages |
425-431 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Controlled in-plane rotation of the magnetic easy axis in manganite heterostructures by tailoring the interface oxygen network could allow the development of correlated oxide-based magnetic tunnelling junctions with non-collinear magnetization, with possible practical applications as miniaturized high-switching-speed magnetic random access memory (MRAM) devices. Here, we demonstrate how to manipulate magnetic and electronic anisotropic properties in manganite heterostructures by engineering the oxygen network on the unit-cell level. The strong oxygen octahedral coupling is found to transfer the octahedral rotation, present in the NdGaO3 (NGO) substrate, to the La2/3Sr1/3MnO3 (LSMO) film in the interface region. This causes an unexpected realignment of the magnetic easy axis along the short axis of the LSMO unit cell as well as the presence of a giant anisotropic transport in these ultrathin LSMO films. As a result we possess control of the lateral magnetic and electronic anisotropies by atomic-scale design of the oxygen octahedral rotation. |
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Address |
MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, 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 |
000372591700017 |
Publication Date |
2016-03-07 |
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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 |
1476-1122 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
39.737 |
Times cited |
273 |
Open Access |
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| |
Notes |
We would like to acknowledge Dr. Evert Houwman for stimulated discussion. M.H., G.K. and G.R. acknowledge funding from DESCO program of the Dutch Foundation for Fundamental Research on Matter (FOM) with financial support from the Netherlands Organization for Scientific Research (NWO). This work was funded by the European Union Council under the 7th Framework Program (FP7) grant nr NMP3-LA-2010- 246102 IFOX. J.V. and S.V.A. acknowledges funding from FWO project G.0044.13N and G. 0368.15N. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. N.G. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. N.G., S.V.A., J.V. and G.V.T. acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative (Reference No. 312483-ESTEEM2). The Canadian work was supported by NSERC and the Max Planck-UBC Centre for Quantum Materials. Some experiments for this work were performed at the Canadian Light Source, which is funded by the Canada Foundation for Innovation, NSERC, the National Research Council of Canada, the Canadian Institutes of Health Research, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan. Z.Z. acknowledges funding from the SFB ViCoM (Austrian Science Fund project ID F4103- N13), and Calculations have been done on the Vienna Scientific Cluster (VSC).; esteem2jra2; esteem2jra3 ECASJO_; |
Approved |
Most recent IF: 39.737 |
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| |
Call Number |
c:irua:133190 c:irua:133190UA @ admin @ c:irua:133190 |
Serial |
4041 |
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| Permanent link to this record |
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Author |
Geuchies, J.J.; van Overbeek, C.; Evers, W.H.; Goris, B.; de Backer, A.; Gantapara, A.P.; Rabouw, F.T.; Hilhorst, J.; Peters, J.L.; Konovalov, O.; Petukhov, A.V.; Dijkstra, M.; Siebbeles, L.D.A.; van Aert, S.; Bals, S.; Vanmaekelbergh, D. |
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Title |
In situ study of the formation mechanism of two-dimensional superlattices from PbSe nanocrystals |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
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| |
Volume |
15 |
Issue |
15 |
Pages |
1248-1254 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Oriented attachment of PbSe nanocubes can result in the formation of two-dimensional (2D) superstructures with long-range nanoscale and atomic order. This questions the applicability of classic models in which the superlattice grows by first forming a nucleus, followed by sequential irreversible attachment of nanocrystals, as one misaligned attachment would disrupt the 2D order beyond repair. Here, we demonstrate the formation mechanism of 2D PbSe superstructures with square geometry by using in situ grazing-incidence X-ray scattering (small angle and wide angle), ex situ electron microscopy, and Monte Carlo simulations. We observed nanocrystal adsorption at the liquid/gas interface, followed by the formation of a hexagonal nanocrystal monolayer. The hexagonal geometry transforms gradually through a pseudo-hexagonal phase into a phase with square order, driven by attractive interactions between the {100} planes perpendicular to the liquid substrate, which maximize facet-to-facet overlap. The nanocrystals then attach atomically via a necking process, resulting in 2D square superlattices. |
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Address |
Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3584 CC 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 |
000389104400011 |
Publication Date |
2016-09-05 |
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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 |
1476-1122 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
39.737 |
Times cited |
182 |
Open Access |
OpenAccess |
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| |
Notes |
This research is part of the programme ‘Designing Dirac Carriers in semiconductor honeycomb superlattices (DDC13),’ which is supported by the Foundation for Fundamental Research on Matter (FOM), which is part of the Dutch Research Council (NWO). J.J.G. acknowledges funding from the Debye and ESRF Graduate Programs. The authors gratefully acknowledge funding from the Research Foundation Flanders (G.036915 G.037413 and funding of postdoctoral grants to B.G. and A.d.B). S.B. acknowledges the European Research Council, ERC grant No 335078—Colouratom. The authors gratefully acknowledge I. Swart and M. van Huis for fruitful discussions. We acknowledge funding from NWO-CW TOPPUNT ‘Superficial Superstructures’. The X-ray scattering measurements were performed at the ID10 beamline at ESRF under proposal numbers SC-4125 and SC-3786. The authors thank G. L. Destri and F. Zontone for their support during the experiments.; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 39.737 |
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| |
Call Number |
EMAT @ emat @ c:irua:136165 |
Serial |
4289 |
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| Permanent link to this record |
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Author |
Pearce, P.E.; Perez, A.J.; Rousse, G.; Saubanère, M.; Batuk, D.; Foix, D.; McCalla, E.; Abakumov, A.M.; Van Tendeloo, G.; Doublet, M.-L.; Tarascon, J.-M. |
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Title |
Evidence for anionic redox activity in a tridimensional-ordered Li-rich positive electrode β-Li2IrO3 |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
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| |
Volume |
16 |
Issue |
5 |
Pages |
580-586 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Lithium-ion battery cathode materials have relied on cationic redox reactions until the recent discovery of anionic redox activity in Li-rich layered compounds which enables capacities as high as 300 mAh g(-1). In the quest for new high-capacity electrodes with anionic redox, a still unanswered question was remaining regarding the importance of the structural dimensionality. The present manuscript provides an answer. We herein report on a beta-Li2IrO3 phase which, in spite of having the Ir arranged in a tridimensional (3D) framework instead of the typical two-dimensional (2D) layers seen in other Li-rich oxides, can reversibly exchange 2.5 e(-) per Ir, the highest value ever reported for any insertion reaction involving d-metals. We show that such a large activity results from joint reversible cationic (Mn+) and anionic (O-2)(n-) redox processes, the latter being visualized via complementary transmission electron microscopy and neutron diffraction experiments, and confirmed by density functional theory calculations. Moreover, beta-Li2IrO3 presents a good cycling behaviour while showing neither cationic migration nor shearing of atomic layers as seen in 2D-layered Li-rich materials. Remarkably, the anionic redox process occurs jointly with the oxidation of Ir4+ at potentials as low as 3.4 V versus Li+/Li-0, as equivalently observed in the layered alpha-Li2IrO3 polymorph. Theoretical calculations elucidate the electrochemical similarities and differences of the 3D versus 2D polymorphs in terms of structural, electronic and mechanical descriptors. Our findings free the structural dimensionality constraint and broaden the possibilities in designing high-energy-density electrodes for the next generation of Li-ion batteries. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000400004200018 |
Publication Date |
2017-02-27 |
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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 |
1476-1122 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
39.737 |
Times cited |
|
Open Access |
Not_Open_Access |
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Notes |
The authors thank Q. Jacquet for fruitful discussions and V. Pomjakushin for his valuable help in neutron diffraction experiments. This work is based on experiments performed at the Swiss Spallation Neutron Source SINQ, Paul Scherrer Institute, Villigen, Switzerland. Use of the 11-BM mail service of the APS at Argonne National Laboratory was supported by the US Department of Energy under contract No. DE-AC02-06CH11357 and is greatly acknowledged. J.-M.T. acknowledges funding from the European Research Council (ERC) (FP/2014)/ERC Grant-Project 670116-ARPEMA. E.M. acknowledges financial support from the Fonds de Recherche du Quebec-Nature et Technologies. |
Approved |
Most recent IF: 39.737 |
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| |
Call Number |
EMAT @ emat @c:irua:147502 |
Serial |
4773 |
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| Permanent link to this record |
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Author |
Talgorn, E.; Gao, Y.; Aerts, M.; Kunneman, L.T.; Schins, J.M.; Savenije, T.J.; van Huis, M.A.; van der Zant, H.S.J.; Houtepen, A.J.; Siebbeles, L.D.A. |
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Title |
Unity quantum yield of photogenerated charges and band-like transport in quantum-dot solids |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Nature nanotechnology |
Abbreviated Journal |
Nat Nanotechnol |
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Volume |
6 |
Issue |
11 |
Pages |
733-739 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Solid films of colloidal quantum dots show promise in the manufacture of photodetectors and solar cells. These devices require high yields of photogenerated charges and high carrier mobilities, which are difficult to achieve in quantum-dot films owing to a strong electronhole interaction and quantum confinement. Here, we show that the quantum yield of photogenerated charges in strongly coupled PbSe quantum-dot films is unity over a large temperature range. At high photoexcitation density, a transition takes place from hopping between localized states to band-like transport. These strongly coupled quantum-dot films have electrical properties that approach those of crystalline bulk semiconductors, while retaining the size tunability and cheap processing properties of colloidal quantum dots. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000296737300012 |
Publication Date |
2011-09-25 |
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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 |
1748-3387;1748-3395; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
38.986 |
Times cited |
129 |
Open Access |
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Notes |
|
Approved |
Most recent IF: 38.986; 2011 IF: 27.270 |
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Call Number |
UA @ lucian @ c:irua:93296 |
Serial |
3813 |
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| Permanent link to this record |
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Author |
Godefroo, S.; Hayne, M.; Jivanescu, M.; Stesmans, A.; Zacharias, M.; Lebedev, O.I.; Van Tendeloo, G.; Moshchalkov, V.V. |
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Title |
Classification and control of the origin of photoluminescence from Si nanocrystals |
Type |
A1 Journal article |
| |
Year |
2008 |
Publication |
Nature nanotechnology |
Abbreviated Journal |
Nat Nanotechnol |
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| |
Volume |
3 |
Issue |
3 |
Pages |
174-178 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Silicon dominates the electronics industry, but its poor optical properties mean that III-V compound semiconductors are preferred for photonics applications. Photoluminescence at visible wavelengths was observed from porous Si at room temperature in 1990, but the origin of these photons (do they arise from highly localized defect states or quantum confinement effects?) has been the subject of intense debate ever since. Attention has subsequently shifted from porous Si to Si nanocrystals, but the same fundamental question about the origin of the photoluminescence has remained. Here we show, based on measurements in high magnetic fields, that defects are the dominant source of light from Si nanocrystals. Moreover, we show that it is possible to control the origin of the photoluminescence in a single sample: passivation with hydrogen removes the defects, resulting in photoluminescence from quantum-confined states, but subsequent ultraviolet illumination reintroduces the defects, making them the origin of the light again. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000254743600017 |
Publication Date |
2008-03-02 |
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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 |
|
Series Issue |
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Edition |
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| |
ISSN |
1748-3387;1748-3395; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
38.986 |
Times cited |
426 |
Open Access |
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| |
Notes |
Fwo |
Approved |
Most recent IF: 38.986; 2008 IF: 20.571 |
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Call Number |
UA @ lucian @ c:irua:102630 |
Serial |
373 |
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| Permanent link to this record |
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Author |
Yang, S.; An, H.; Arnouts, S.; Wang, H.; Yu, X.; de Ruiter, J.; Bals, S.; Altantzis, T.; Weckhuysen, B.M.; van der Stam, W. |
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Title |
Halide-guided active site exposure in bismuth electrocatalysts for selective CO₂ conversion into formic acid |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Nature Catalysis |
Abbreviated Journal |
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| |
Volume |
6 |
Issue |
9 |
Pages |
796-806 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) |
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Abstract |
It remains a challenge to identify the active sites of bismuth catalysts in the electrochemical CO2 reduction reaction. Here we show through in situ characterization that the activation of bismuth oxyhalide electrocatalysts to metallic bismuth is guided by the halides. In situ X-ray diffraction results show that bromide promotes the selective exposure of planar bismuth surfaces, whereas chloride and iodide result in more disordered active sites. Furthermore, we find that bromide-activated bismuth catalysts outperform the chloride and iodide counterparts, achieving high current density (>100 mA cm(-2)) and formic acid selectivity (>90%), suggesting that planar bismuth surfaces are more active for the electrochemical CO2 reduction reaction. In addition, in situ X-ray absorption spectroscopy measurements reveal that the reconstruction proceeds rapidly in chloride-activated bismuth and gradually when bromide is present, facilitating the formation of ordered planar surfaces. These findings show the pivotal role of halogens on selective facet exposure in activated bismuth-based electrocatalysts during the electrochemical CO2 reduction reaction. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001050367400001 |
Publication Date |
2023-08-17 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
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| |
ISSN |
2520-1158 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
37.8 |
Times cited |
13 |
Open Access |
OpenAccess |
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| |
Notes |
B.M.W. acknowledges support from the Strategic UU-TU/e Alliance project 'Joint Centre for Chemergy Research' as well as from the Netherlands Center for Multiscale Catalytic Energy Conversion (MCEC), an NWO gravitation programme funded by the Ministry of Education, Culture and Science of the government of the Netherlands. S.B. acknowledges support from the European Research Council (ERC Consolidator Grant #815128 REALNANO). S.A. and T.A. acknowledge funding from the University of Antwerp Research fund (BOF). We also thank J. Wijten, J. Janssens and T. Prins (all from the Inorganic Chemistry and Catalysis group, Utrecht University) for helpful technical support. S. Deelen (Faculty of Science, Utrecht University) and L. Wu (Inorganic Chemistry and Catalysis group, Utrecht University) are acknowledged for the design of the in situ XRD cell. We also acknowledge B. Detlefs, P. Glatzel and V. Paidi (ESRF) for the support during the HERFD-XANES measurements on the ID26 beamline of the ESRF. |
Approved |
Most recent IF: 37.8; 2023 IF: NA |
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Call Number |
UA @ admin @ c:irua:199190 |
Serial |
8877 |
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| Permanent link to this record |
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Author |
Guttmann, P.; Bittencourt, C.; Rehbein, S.; Umek, P.; Ke, X.; Van Tendeloo, G.; Ewels, C.P.; Schneider, G. |
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Title |
Nanoscale spectroscopy with polarized X-rays by NEXAFS-TXM |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Nature photonics |
Abbreviated Journal |
Nat Photonics |
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| |
Volume |
6 |
Issue |
1 |
Pages |
25-29 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Near-edge X-ray absorption spectroscopy (NEXAFS)1 is an essential analytical tool in material science. Combining NEXAFS with scanning transmission X-ray microscopy (STXM) adds spatial resolution and the possibility to study individual nanostructures2, 3. Here, we describe a full-field transmission X-ray microscope (TXM) that generates high-resolution, large-area NEXAFS data with a collection rate two orders of magnitude faster than is possible with STXM. The TXM optical design combines a spectral resolution of E/ΔE = 1 × 104 with a spatial resolution of 25 nm in a field of view of 1520 µm and a data acquisition time of ~1 s. As an example, we present image stacks and polarization-dependent NEXAFS spectra from individual anisotropic sodium and protonated titanate nanoribbons. Our NEXAFS-TXM technique has the advantage that one image stack visualizes a large number of nanostructures and therefore already contains statistical information. This new high-resolution NEXAFS-TXM technique opens the way to advanced nanoscale science studies. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000298416200011 |
Publication Date |
2011-11-25 |
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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 |
|
Series Issue |
|
Edition |
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| |
ISSN |
1749-4885;1749-4893; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
37.852 |
Times cited |
76 |
Open Access |
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|
| |
Notes |
|
Approved |
Most recent IF: 37.852; 2012 IF: 27.254 |
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| |
Call Number |
UA @ lucian @ c:irua:94198 |
Serial |
2272 |
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| Permanent link to this record |
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Author |
Parastaev, A.; Muravev, V.; Osta, E.H.; Kimpel, T.F.; Simons, J.F.M.; van Hoof, A.J.F.; Uslamin, E.; Zhang, L.; Struijs, J.J.C.; Burueva, D.B.; Pokochueva, E.V.; Kovtunov, K.V.; Koptyug, I.V.; Villar-Garcia, I.J.; Escudero, C.; Altantzis, T.; Liu, P.; Béché, A.; Bals, S.; Kosinov, N.; Hensen, E.J.M. |
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Title |
Breaking structure sensitivity in CO2 hydrogenation by tuning metal–oxide interfaces in supported cobalt nanoparticles |
Type |
A1 Journal article |
| |
Year |
2022 |
Publication |
Nature Catalysis |
Abbreviated Journal |
Nat Catal |
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| |
Volume |
5 |
Issue |
11 |
Pages |
1051-1060 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) |
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| |
Abstract |
A high dispersion of the active metal phase of transition metals on oxide supports is important when designing efficient heterogeneous catalysts. Besides nanoparticles, clusters and even single metal atoms can be attractive for a wide range of reactions. However, many industrially relevant catalytic transformations suffer from structure sensitivity, where reducing the size of the metal particles below a certain size substantially lowers catalytic performance. A case in point is the low activity of small cobalt nanoparticles in the hydrogenation of CO and CO2. Here we show how engineering of catalytic sites at the metal–oxide interface in cerium oxide–zirconium dioxide (ceria–zirconia)-supported cobalt can overcome this structure sensitivity. Few-atom cobalt clusters dispersed on 3 nm cobalt(II)-oxide particles stabilized by ceria–zirconia yielded a highly active CO2 methanation catalyst with a specific activity higher than that of larger particles under the same conditions. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000884939300006 |
Publication Date |
2022-11-17 |
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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 |
|
Edition |
|
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| |
ISSN |
2520-1158 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
37.8 |
Times cited |
32 |
Open Access |
OpenAccess |
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Notes |
This research was supported by the Applied and Engineering Sciences division of the Netherlands Organization for Scientific Research through the Alliander (now Qirion) Perspective program on Plasma Conversion of CO2. We acknowledge Diamond Light Source for time on beamline B18 under proposal SP20715-1. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3. S.B. acknowledges support from the European Research Council (ERC Consolidator Grant #815128 REALNANO) and T.A. acknowledges funding from the University of Antwerp Research fund (BOF). A.B. received funding from the European Union under grant agreement No 823717 – ESTEEM3. The authors acknowledge funding through the Hercules grant (FWO, University of Antwerp) I003218N “Infrastructure for imaging nanoscale processes in gas/vapour or liquid environments”. I.V.K., D.B.B., and E.V.P. acknowledge the Russian Ministry of Science and Higher Education (contract 075-15-2021-580) for financial support of parahydrogen-based studies. Experiments using synchrotron radiation XPS were performed at the CIRCE beamline at ALBA Synchrotron with the collaboration of ALBA staff. F. Oropeza Palacio and Rim C.J. van de Poll are acknowledged for the help with RPES measurements.; esteem3reported; esteem3jra |
Approved |
Most recent IF: 37.8 |
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| |
Call Number |
EMAT @ emat @c:irua:192068 |
Serial |
7230 |
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| Permanent link to this record |
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| |
|
Author |
McCalla, E.; Abakumov, A.M.; Saubanere, M.; Foix, D.; Berg, E.J.; Rousse, G.; Doublet, M.-L.; Gonbeau, D.; Novak, P.; Van Tendeloo, G.; Dominko, R.; Tarascon, J.-M. |
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| |
Title |
Visualization of O-O peroxo-like dimers in high-capacity layered oxides for Li-ion batteries |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Science |
Abbreviated Journal |
Science |
|
| |
Volume |
350 |
Issue |
350 |
Pages |
1516-1521 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Lithium-ion (Li-ion) batteries that rely on cationic redox reactions are the primary energy source for portable electronics. One pathway toward greater energy density is through the use of Li-rich layered oxides. The capacity of this class of materials (>270 milliampere hours per gram) has been shown to be nested in anionic redox reactions, which are thought to form peroxo-like species. However, the oxygen-oxygen (O-O) bonding pattern has not been observed in previous studies, nor has there been a satisfactory explanation for the irreversible changes that occur during first delithiation. By using Li2IrO3 as a model compound, we visualize the O-O dimers via transmission electron microscopy and neutron diffraction. Our findings establish the fundamental relation between the anionic redox process and the evolution of the O-O bonding in layered oxides. |
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Address |
College de France, Chimie du Solide et de l'Energie, FRE 3677, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05, France. ALISTORE-European Research Institute, FR CNRS 3104, 80039 Amiens, France. Reseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, France. Sorbonne Universites-UPMC Univ Paris 06, 4 Place Jussieu, F-75005 Paris, France. jean-marie.tarascon@college-de-france.fr |
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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 |
000366591100056 |
Publication Date |
2015-12-17 |
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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 |
0036-8075 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
37.205 |
Times cited |
281 |
Open Access |
|
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| |
Notes |
E.M. thanks the Fonds de Recherche du Québec–Nature et Technologies and ALISTORE–European Research Institute for funding this work, as well as the European community I3 networks for funding the neutron scattering research trip. This work was also funded by the Slovenian Research Agency research program P2-0148. This work is partially based on experiments performed at the Institut Laue Langevin. We thank J. Rodriguez-Carvajal for help with neutron scattering experiments and for fruitful discussions. We also thank M. T. Sougrati for performing the Sn-Mössbauer measurements. Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract no. DE-AC02- 06CH11357. M.S. and M.-L.D. acknowledge high-performance computational resources from GENCI-CCRT/CINES (grant cmm6691). J.-M.T. acknowledges funding from the European Research Council (ERC) (FP/2014-2020)/ERC Grant-Project670116-ARPEMA. |
Approved |
Most recent IF: 37.205; 2015 IF: 33.611 |
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| |
Call Number |
c:irua:130202 |
Serial |
4005 |
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| Permanent link to this record |
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Author |
Boneschanscher, M.P.; Evers, W.H.; Geuchies, J.J.; Altantzis, T.; Goris, B.; Rabouw, F.T.; van Rossum, S.A.P.; van der Zant, H.S.J.; Siebbeles, L.D.A.; Van Tendeloo, G.; Swart, I.; Hilhorst, J.; Petukhov, A.V.; Bals, S.; Vanmaekelbergh, D.; |
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Title |
Long-range orientation and atomic attachment of nanocrystals in 2D honeycomb superlattices |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Science |
Abbreviated Journal |
Science |
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| |
Volume |
344 |
Issue |
6190 |
Pages |
1377-1380 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Oriented attachment of synthetic semiconductor nanocrystals is emerging as a route for obtaining new semiconductors that can have Dirac-type electronic bands like graphene, but also strong spin-orbit coupling. The two-dimensional assembly geometry will require both atomic coherence and long-range periodicity of the superlattices. We show how the interfacial self-assembly and oriented attachment of nanocrystals results in two-dimensional (2D) metal chalcogenide semiconductors with a honeycomb superlattice. We present an extensive atomic and nanoscale characterization of these systems using direct imaging and wave scattering methods. The honeycomb superlattices are atomically coherent, and have an octahedral symmetry that is buckled; the nanocrystals occupy two parallel planes. Considerable necking and large-scale atomic motion occurred during the attachment process. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000337531700035 |
Publication Date |
2014-05-30 |
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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 |
0036-8075;1095-9203; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
37.205 |
Times cited |
304 |
Open Access |
OpenAccess |
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| |
Notes |
Fwo; 262348 Esmi; 246791 Countatoms; 335078 Colouratom; ECAS_Sara; (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); |
Approved |
Most recent IF: 37.205; 2014 IF: 33.611 |
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| |
Call Number |
UA @ lucian @ c:irua:117095 |
Serial |
1840 |
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| Permanent link to this record |
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Author |
Udayabhaskararao, T.; Altantzis, T.; Houben, L.; Coronado-Puchau, M.; Langer, J.; Popovitz-Biro, R.; Liz-Marzán, L.M.; Vuković, L.; Král, P.; Bals, S.; Klajn, R. |
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Title |
Tunable porous nanoallotropes prepared by post-assembly etching of binary nanoparticle superlattices |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Science |
Abbreviated Journal |
Science |
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| |
Volume |
358 |
Issue |
358 |
Pages |
514-518 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Self-assembly of inorganic nanoparticles has been used to prepare hundreds of different colloidal crystals, but almost invariably with the restriction that the particles must be densely packed. Here,we show that non–close-packed nanoparticle arrays can be fabricated through the selective removal of one of two components comprising binary nanoparticle superlattices. First, a variety of binary nanoparticle superlattices were prepared at the liquid-air interface, including several arrangements that were previously unknown. Molecular dynamics simulations revealed the particular role of the liquid in templating the formation of superlattices not achievable through self-assembly in bulk solution. Second, upon stabilization, all of these binary superlattices could be transformed into distinct “nanoallotropes”—nanoporous materials having the same chemical composition but differing in their nanoscale architectures. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000413757500043 |
Publication Date |
2017-10-27 |
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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 |
0036-8075 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
37.205 |
Times cited |
113 |
Open Access |
OpenAccess |
|
| |
Notes |
This work was supported by the European Research Council (grants 336080 CONFINEDCHEM to R.K. and 335078 COLOURATOM to S.B.), the Rothschild Caesarea Foundation (R.K.), the NSF (Division of Materials Research, grant 1506886) (P.K.), the European Commission (grant EUSMI 731019 to L.M.L.-M. and S.B.), and the startup funding from the University of Texas at El Paso (L.V.). L.M.L.-M. acknowledges funding from the Spanish Ministerio de Economía y Competitividad (grant MAT2013- 46101-R). T.A. acknowledges funding from the Research Foundation Flanders (FWO, Belgium) through a postdoctoral grant. The computer support was provided by the Texas Advanced Computing Center. All data are reported in the main text and supplementary materials. ECAS_Sara (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); |
Approved |
Most recent IF: 37.205 |
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Call Number |
EMAT @ emat @c:irua:147242UA @ admin @ c:irua:147242 |
Serial |
4770 |
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| Permanent link to this record |
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Author |
Poppe, R.; Roth, N.; Neder, R.B.; Palatinus, L.; Iversen, B.B.; Hadermann, J. |
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Title |
Refining short-range order parameters from the three-dimensional diffuse scattering in single-crystal electron diffraction data |
Type |
A1 Journal article |
| |
Year |
2024 |
Publication |
IUCrJ |
Abbreviated Journal |
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| |
Volume |
11 |
Issue |
1 |
Pages |
82-91 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Our study compares short-range order parameters refined from the diffuse scattering in single-crystal X-ray and single-crystal electron diffraction data. Nb0.84CoSb was chosen as a reference material. The correlations between neighbouring vacancies and the displacements of Sb and Co atoms were refined from the diffuse scattering using a Monte Carlo refinement in DISCUS. The difference between the Sb and Co displacements refined from the diffuse scattering and the Sb and Co displacements refined from the Bragg reflections in single-crystal X-ray diffraction data is 0.012 (7) angstrom for the refinement on diffuse scattering in single-crystal X-ray diffraction data and 0.03 (2) angstrom for the refinement on the diffuse scattering in single-crystal electron diffraction data. As electron diffraction requires much smaller crystals than X-ray diffraction, this opens up the possibility of refining short-range order parameters in many technologically relevant materials for which no crystals large enough for single-crystal X-ray diffraction are available. |
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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 |
001168018300012 |
Publication Date |
2023-12-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
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| |
ISSN |
2052-2525 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
3.9 |
Times cited |
|
Open Access |
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Notes |
|
Approved |
Most recent IF: 3.9; 2024 IF: 5.793 |
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Call Number |
UA @ admin @ c:irua:205513 |
Serial |
9170 |
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| Permanent link to this record |
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Author |
Bian, G.; Ageeva, O.; Roddatis, V.; Li, C.; Pennycook, T.J.; Habler, G.; Abart, R. |
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Title |
Crystal structure controls on oriented primary magnetite micro-inclusions in plagioclase From oceanic gabbro |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Journal of petrology |
Abbreviated Journal |
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| |
Volume |
64 |
Issue |
3 |
Pages |
egad008-18 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Oriented needle-, lath- and plate-shaped magnetite micro-inclusions in rock forming plagioclase from mafic intrusive rocks, were investigated using correlated optical microscopy and scanning transmission electron microscopy. The magnetite micro-inclusions were analysed on cuts parallel and perpendicular to the inclusion-elongation directions. The crystal structures of the two phases are in direct contact along the interfaces. The shape, shape orientation and crystallographic orientation relationships between the magnetite micro-inclusions and the plagioclase host appear to be controlled by the tendency of the system to optimise lattice match along the interfaces. The elongation direction of the inclusions ensures good match between prominent oxygen layers in the magnetite and plagioclase crystal structures across the interfaces bounding the inclusions parallel to their elongation direction. In cross-section, additional modes of lattice match, such as the commensurate impingement of magnetite and plagioclase lattice planes along the interfaces, the parallel alignment of the interfaces to low-index lattice planes of magnetite or plagioclase, or the parallel alignment to low index lattice planes of both phases are observed, which appear to control the selection of interface facets, as well as the shape and crystallographic orientation relationships between magnetite micro-inclusions and plagioclase host. The systematics of the inclusion cross-sectional shapes and crystallographic orientation relationships indicate recrystallisation of magnetite with potential implications for natural remanent magnetisation of magnetite-bearing plagioclase grains. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001010636400007 |
Publication Date |
2023-01-28 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0022-3530 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
3.9 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
|
Approved |
Most recent IF: 3.9; 2023 IF: 3.28 |
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| |
Call Number |
UA @ admin @ c:irua:195160 |
Serial |
7292 |
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| Permanent link to this record |
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Author |
Ulu Okudur, F.; Batuk, M.; Hadermann, J.; Safari, M.; De Sloovere, D.; Kumar Mylavarapu, S.; Joos, B.; D'Haen, J.; Van Bael, M.K.; Hardy, A. |
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Title |
Solution-gel-based surface modification of LiNi0.5Mn1.5O4-δ with amorphous Li-Ti-O coating |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
RSC advances |
Abbreviated Journal |
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| |
Volume |
13 |
Issue |
47 |
Pages |
33146-33158 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
LNMO (LiNi0.5Mn1.5O4-delta) is a high-energy density positive electrode material for lithium ion batteries. Unfortunately, it suffers from capacity loss and impedance rise during cycling due to electrolyte oxidation and electrode/electrolyte interface instabilities at high operating voltages. Here, a solution-gel synthesis route was used to coat 0.5-2.5 mu m LNMO particles with amorphous Li-Ti-O (LTO) for improved Li conduction, surface structural stability and cyclability. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) analysis coupled with energy dispersive X-ray (EDX) showed Ti-rich amorphous coatings/islands or Ti-rich spinel layers on many of the LTO-modified LNMO facets, with a thickness varying from about 1 to 10 nm. The surface modification in the form of amorphous islands was mostly possible on high-energy crystal facets. Physicochemical observations were used to propose a molecular mechanism for the surface modification, combining insights from metalorganic chemistry with the crystallographic properties of LNMO. The improvements in functional properties were investigated in half cells. The cell impedance increased faster for the bare LNMO compared to amorphous LTO modified LNMO, resulting in R-ct values as high as 1247 Omega (after 1000 cycles) for bare LNMO, against 216 Omega for the modified material. At 10C, the modified material boosted a 15% increase in average discharge capacity. The improvements in electrochemical performance were attributed to the increase in electrochemically active surface area, as well as to improved HF-scavenging, resulting in the formation of protective byproducts, generating a more stable interface during prolonged cycling. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001102666700001 |
Publication Date |
2023-11-09 |
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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 |
2046-2069 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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Impact Factor |
3.9 |
Times cited |
|
Open Access |
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Notes |
|
Approved |
Most recent IF: 3.9; 2023 IF: 3.108 |
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Call Number |
UA @ admin @ c:irua:202091 |
Serial |
9096 |
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| Permanent link to this record |
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Author |
Dinger, J.; Friedrich, T.; Reimann, T.; Toepfer, J. |
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Title |
NiMn₂O₄ revisited : temperature-dependent cation distribution from in situ neutron diffraction and thermopower studies |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Journal of the American Ceramic Society |
Abbreviated Journal |
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| |
Volume |
106 |
Issue |
3 |
Pages |
1834-1847 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The cation distribution of the negative temperature coefficient (NTC) thermistor spinel NiMn2O4 was studied in the temperature range from 55 to 900 degrees C, using a combined in situ neutron diffraction and thermopower study. Rietveld refinements of in situ neutron diffraction data reveal a temperature dependence of the degree of inversion with an inversion parameter of 0.70(1) at 900 degrees C and 0.87(1) at 55 degrees C. Thermopower measurements were evaluated using a modified Heikes formula, and the [Mn4+]/[Mn3+] ratio on octahedral sites of the spinel structure was calculated considering spin and orbital degeneracy. The inversion degree and disproportionation parameter, determined independently as function of temperature, were used to calculate the cation distribution of NiMn2O4 in the whole temperature range. At high temperature, within the stability range of the spinel, the cation distribution is characterized by a moderate degree of inversion with a concentration of NiB2+${\mathrm{Ni}}\mathrm{B}< |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000880360600001 |
Publication Date |
2022-10-21 |
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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 |
0002-7820 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
3.9 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
|
Approved |
Most recent IF: 3.9; 2023 IF: 2.841 |
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| |
Call Number |
UA @ admin @ c:irua:192087 |
Serial |
7326 |
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| Permanent link to this record |
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Author |
Idrissi, H.; Samaee, V.; Lumbeeck, G.; Werf, T.; Pardoen, T.; Schryvers, D.; Cordier, P. |
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Title |
In Situ Quantitative Tensile Testing of Antigorite in a Transmission Electron Microscope |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Journal Of Geophysical Research-Solid Earth |
Abbreviated Journal |
J Geophys Res-Sol Ea |
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Volume |
125 |
Issue |
3 |
Pages |
|
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The determination of the mechanical properties of serpentinites is essential toward the understanding of the mechanics of faulting and subduction. Here we present the first in situ tensile tests on antigorite in a transmission electron microscope. A push‐to‐pull deformation device is used to perform quantitative tensile tests, during which force and displacement are measured, while the evolving microstructure is imaged with the microscope. The experiments have been performed at room temperature on 2 × 1 × 0.2 μm3 beams prepared by focused ion beam. The specimens are not single crystals despite their small sizes. Orientation mapping indicated that several grains were well oriented for plastic slip. However, no dislocation activity has been observed even though the engineering tensile stress went up to 700 MPa. We show also that antigorite does not exhibit a purely elastic‐brittle behavior since, despite the presence of defects, the specimens accumulate permanent deformation and did not fail within the elastic regime. Instead, we observe that strain localizes at grain boundaries. All observations concur to show that under these experimental conditions, grain boundary sliding is the dominant deformation mechanism. This study sheds a new light on the mechanical properties of antigorite and calls for further studies on the structure and properties of grain boundaries in antigorite and more generally in phyllosilicates. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000530895800023 |
Publication Date |
2020-02-20 |
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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 |
2169-9313 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.9 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
We thank S. Guillot for having kindly provided us with the two antigorite samples investigated in this study. We acknowledge funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program under Grant Agreement 787198—TimeMan. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR‐FNRS). We acknowledge fruitful discussions with A. Baronnet. We thank J. Gasc and an anonymous reviewer for their critical comments. Data (movies of the three in situ deformation experiments) can be downloaded (from https://doi.org/10.5281/zenodo.3583135). |
Approved |
Most recent IF: 3.9; 2020 IF: 3.35 |
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Call Number |
EMAT @ emat @c:irua:167594 |
Serial |
6355 |
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Author |
Jovanović, Z.; Gauquelin, N.; Koster, G.; Rubio-Zuazo, J.; Ghosez, P.; Verbeeck, J.; Suvorov, D.; Spreitzer, M. |
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Title |
Simultaneous heteroepitaxial growth of SrO (001) and SrO (111) during strontium-assisted deoxidation of the Si (001) surface |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Rsc Advances |
Abbreviated Journal |
Rsc Adv |
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Volume |
10 |
Issue |
52 |
Pages |
31261-31270 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Epitaxial integration of transition-metal oxides with silicon brings a variety of functional properties to the well-established platform of electronic components. In this process, deoxidation and passivation of the silicon surface are one of the most important steps, which in our study were controlled by an ultra-thin layer of SrO and monitored by using transmission electron microscopy (TEM), electron energy-loss spectroscopy (EELS), synchrotron X-ray diffraction (XRD) and reflection high energy electron diffraction (RHEED) methods. Results revealed that an insufficient amount of SrO leads to uneven deoxidation of the silicon surface<italic>i.e.</italic>formation of pits and islands, whereas the composition of the as-formed heterostructure gradually changes from strontium silicide at the interface with silicon, to strontium silicate and SrO in the topmost layer. Epitaxial ordering of SrO, occurring simultaneously with silicon deoxidation, was observed. RHEED analysis has identified that SrO is epitaxially aligned with the (001) Si substrate both with SrO (001) and SrO (111) out-of-plane directions. This observation was discussed from the point of view of SrO desorption, SrO-induced deoxidation of the Si (001) surface and other interfacial reactions as well as structural ordering of deposited SrO. Results of the study present an important milestone in understanding subsequent epitaxial integration of functional oxides with silicon using SrO. |
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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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Wos |
000566579400025 |
Publication Date |
2020-08-24 |
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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 |
2046-2069 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.9 |
Times cited |
1 |
Open Access |
OpenAccess |
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Notes |
Vlaamse regering, Hercules Fund ; Ministarstvo Prosvete, Nauke i Tehnološkog Razvoja, III 45006 ; Javna Agencija za Raziskovalno Dejavnost RS, J2-9237 P2-0091 ; Fonds Wetenschappelijk Onderzoek, G.0044.13N ; Ministerio de Ciencia, Innovación y Universidades; Universiteit Antwerpen, GOA project Solarpaint ; F.R.S.-FNRS, PDR project PROMOSPAN ; Consejo Superior de Investigaciones Cientificas; University of Liège, ARC project AIMED ; Ministry of Education, Science and Sport, M.ERA-NET project SIOX ; |
Approved |
Most recent IF: 3.9; 2020 IF: 3.108 |
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Call Number |
EMAT @ emat @c:irua:172059 |
Serial |
6416 |
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Author |
Dixit, H.; Saniz, R.; Lamoen, D.; Partoens, B. |
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Title |
Accurate pseudopotential description of the GW bandstructure of ZnO |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Computer physics communications |
Abbreviated Journal |
Comput Phys Commun |
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Volume |
182 |
Issue |
9 |
Pages |
2029-2031 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
We present the GW band structure of ZnO in its wurtzite (WZ), zincblende (ZB) and rocksalt (RS) phases at the Γ point, calculated within the GW approximation. We have used a Zn20+ pseudopotential which is essential for the adequate treatment of the exchange interaction in the self-energy. The accuracy of the pseudopotential used is also discussed. The effect of the pd hybridization on the GW corrections to the band gap is correlated by comparing the ZB and RS phase. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000292675100062 |
Publication Date |
2011-02-17 |
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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 |
0010-4655; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.936 |
Times cited |
18 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.936; 2011 IF: 3.268 |
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Call Number |
UA @ lucian @ c:irua:90761 |
Serial |
51 |
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Author |
Sébilleau, D.; Natoli, C.; Gavaza, G.M.; Zhao, H.; da Pieve, F.; Hatada, K. |
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Title |
MsSpec-1.0 : a multiple scattering package for electron spectroscopies in material science |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Computer physics communications |
Abbreviated Journal |
Comput Phys Commun |
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Volume |
182 |
Issue |
12 |
Pages |
2567-2579 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
We present a multiple scattering package to calculate the cross-section of various spectroscopies namely photoelectron diffraction (PED), Auger electron diffraction (AED), X-ray absorption (XAS), low-energy electron diffraction (LEED) and Auger photoelectron coincidence spectroscopy (APECS). This package is composed of three main codes, computing respectively the cluster, the potential and the cross-section. In the latter case, in order to cover a range of energies as wide as possible, three different algorithms are provided to perform the multiple scattering calculation: full matrix inversion, series expansion or correlation expansion of the multiple scattering matrix. Numerous other small Fortran codes or bash/csh shell scripts are also provided to perform specific tasks. The cross-section code is built by the user from a library of subroutines using a makefile. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000295769700014 |
Publication Date |
2011-07-28 |
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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 |
0010-4655; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.936 |
Times cited |
6 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.936; 2011 IF: 3.268 |
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Call Number |
UA @ lucian @ c:irua:93288 |
Serial |
2208 |
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Author |
Poppe, R.; Vandemeulebroucke, D.; Neder, R.B.; Hadermann, J. |
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Title |
Quantitative analysis of diffuse electron scattering in the lithium-ion battery cathode material Li1.2Ni0.13Mn0.54Co0.13O2 |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
IUCrJ |
Abbreviated Journal |
Iucrj |
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Volume |
9 |
Issue |
5 |
Pages |
695-704 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In contrast to perfectly periodic crystals, materials with short-range order produce diffraction patterns that contain both Bragg reflections and diffuse scattering. To understand the influence of short-range order on material properties, current research focuses increasingly on the analysis of diffuse scattering. This article verifies the possibility to refine the short-range order parameters in submicrometre-sized crystals from diffuse scattering in single-crystal electron diffraction data. The approach was demonstrated on Li<sub>1.2</sub>Ni<sub>0.13</sub>Mn<sub>0.54</sub>Co<sub>0.13</sub>O<sub>2</sub>, which is a state-of-the-art cathode material for lithium-ion batteries. The intensity distribution of the 1D diffuse scattering in the electron diffraction patterns of Li<sub>1.2</sub>Ni<sub>0.13</sub>Mn<sub>0.54</sub>Co<sub>0.13</sub>O<sub>2</sub>depends on the number of stacking faults and twins in the crystal. A model of the disorder in Li<sub>1.2</sub>Ni<sub>0.13</sub>Mn<sub>0.54</sub>Co<sub>0.13</sub>O<sub>2</sub>was developed and both the stacking fault probability and the percentage of the different twins in the crystal were refined using an evolutionary algorithm in<italic>DISCUS</italic>. The approach was applied on reciprocal space sections reconstructed from 3D electron diffraction data since they exhibit less dynamical effects compared with in-zone electron diffraction patterns. A good agreement was achieved between the calculated and the experimental intensity distribution of the diffuse scattering. The short-range order parameters in submicrometre-sized crystals can thus successfully be refined from the diffuse scattering in single-crystal electron diffraction data using an evolutionary algorithm in<italic>DISCUS</italic>. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Wos |
000852551800018 |
Publication Date |
2022-09-01 |
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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 |
2052-2525 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.9 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
The research leading to these results has received funding from the Research Foundation Flanders, G035619N G040116N ; |
Approved |
Most recent IF: 3.9 |
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Call Number |
EMAT @ emat @c:irua:190647 |
Serial |
7105 |
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Author |
Ben Abdallah, M.A.; Bacchi, A.; Parisini, A.; Canossa, S.; Bergamonti, L.; Balestri, D.; Kamoun, S. |
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Title |
Crystal structure, vibrational, electrical, optical and DFT study of C₂H₁0N₂(IO₃)₂.HIO₃ |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Journal Of Molecular Structure |
Abbreviated Journal |
J Mol Struct |
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Volume |
1215 |
Issue |
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Pages |
128254-12 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The reinvestigation of the EDA-HIO3-H2O system using a different stoichiometric ratio gives rise to a new iodate salt C2H10N2(IO3)(2 center dot)HIO3 denoted as EBIMIA. In this study, we reported the structural properties of ethylenediammonium bis iodate mono iodic acid using X-ray powder and single crystal diffraction at room temperature. The Hirshfeld and the potential energy surface analysis reveal that I center dot center dot center dot O and N-H center dot center dot center dot O are the most noticeable interactions that took place inside the crystal and contribute to the cohesion and stability of the synthesized compound. The DSC measurement shows that this iodate salt undergoes two structural phase transitions, the first occurs at T = 290 K while the second occurs at T = 363 K. However, the dielectric analysis confirms only the second transition because it lies in the studied temperature domain 338-413K. Besides, the impedance data obey a circuit model consisting of a parallel combination of a bulk resistance and CPE. The frequency dispersion of the conductivity follows Jonscher's law and the charge carrier transport may be interpreted using the correlation barrier hopping mechanism (CBH). Finally, the electronic properties and the vibrational analysis of this novel iodate salt are studied using DFT and compared to the experimental data given by the FT-IR, Raman and UV-visible spectroscopies. (C) 2020 Elsevier B.V. All rights reserved. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Wos |
000537221300012 |
Publication Date |
2020-04-16 |
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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 |
0022-2860 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
3.8 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
; The authors are grateful to Pr. Giovani Predieri, Pr. Pier Paolo Lottici, and Pr. Danilo Bersani, for their help with the vibrational measurement. Moreover, authors wish to thank, Pr. Salvatore Vantaggio and Dr. Silvio Scaravonati for their contribution in carrying out the impedance spectroscopy measurements. The authors acknowledge also the Analytical Chemistry, Cultural Heritage, Inorganic Chemistry and Crystallography Unit (SCVSA department, university of Parma, Italy) and the Tunisian Ministry of Higher Education and Scientific Research (LR11ES46) for their support. ; |
Approved |
Most recent IF: 3.8; 2020 IF: 1.753 |
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Call Number |
UA @ admin @ c:irua:170148 |
Serial |
6480 |
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Author |
Liu, Y.; Claes, N.; Trepka, B.; Bals, S.; Lang, P.R. |
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Title |
A combined 3D and 2D light scattering study on aqueous colloidal model systems with tunable interactions |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Soft matter |
Abbreviated Journal |
Soft Matter |
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Volume |
12 |
Issue |
12 |
Pages |
8485-8494 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In this article we report on the synthesis and characterization of a system of colloidal spheres suspended in an aqueous solvent which can be refractive index-matched, thus allowing for investigations of the particle near-wall dynamics by evanescent wave dynamic light scattering at concentrations up to the isotropic to ordered transition and beyond. The particles are synthesized by copolymerization of a fluorinated acrylic ester monomer with a polyethylene-glycol (PEG) oligomer by surfactant free emulsion polymerization. Static and dynamic light scattering experiments in combination with cryo transmission electron microscopy reveal that the particles have a core shell structure with a significant enrichment of the PEG chains on the particles surface. In index-matching DMSO/water suspensions the particles arrange in an ordered phase at volume fraction above 7%, if no additional electrolyte is present. The near-wall dynamics at low volume fraction are quantitatively described by the combination of electrostatic repulsion and hydrodynamic interaction between the particles and the wall. At volume fractions close to the isotropic to ordered transition, the near-wall dynamics are more complex and qualitatively reminiscent of the behaviour which was observed in hard sphere suspensions at high concentrations. |
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Address |
Forschugszentrum Julich, Institute of Complex Systems ICS-3, Julich, Germany. p.lang@fz-juelich.de and Heinrich-Heine Universitat, Dusseldorf, Germany |
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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 |
000386247100004 |
Publication Date |
2016-08-22 |
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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 |
1744-683X |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.889 |
Times cited |
2 |
Open Access |
OpenAccess |
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Notes |
The authors thank Prof. J. K. G. Dhont and the ICS-3 group for useful discussions and support. YL would like to thank the Marie Sklodowska Curie Initial Training Network SOMATAI under the EU Grant Agreement No. 316866 for financial support. BT contributed to this work during an internship at Forschungszentrum Ju¨lich supported by the International Helmholtz Research School of Biophysics and Soft Matter (IHRS BioSoft), which is gratefully acknowledged. SB and NC acknowledge financial support from the European Research Council (ERC Starting Grant No. 335078-COLOURATOMS).; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 3.889 |
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Call Number |
EMAT @ emat @ c:irua:136166 |
Serial |
4292 |
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Author |
Semkina, A.; Abakumov, M.; Grinenko, N.; Abakumov, A.; Skorikov, A.; Mironova, E.; Davydova, G.; Majouga, A.G.; Nukolova, N.; Kabanov, A.; Chekhonin, V.; |
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Title |
Core-shell-corona doxorubicin-loaded superparamagnetic Fe3O4 nanoparticles for cancer theranostics |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Colloids and surfaces: B : biointerfaces |
Abbreviated Journal |
Colloid Surface B |
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Volume |
136 |
Issue |
136 |
Pages |
1073-1080 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Superparamagnetic iron oxide magnetic nanoparticles (MNPs) are successfully used as contrast agents in magnetic-resonance imaging. They can be easily functionalized for drug delivery functions, demonstrating great potential for both imaging and therapeutic applications. Here we developed new pH-responsive theranostic core-shell-corona nanoparticles consisting of superparamagentic Fe3O4 core that displays high T2 relaxivity, bovine serum albumin (BSA) shell that binds anticancer drug, doxorubicin (Dox) and poly(ethylene glycol) (PEG) corona that increases stability and biocompatibility. The nanoparticles were produced by adsorption of the BSA shell onto the Fe3O4 core followed by crosslinking of the protein layer and subsequent grafting of the PEG corona using monoamino-terminated PEG via carbodiimide chemistry. The hydrodynamic diameter, zeta-potential, composition and T2 relaxivity of the resulting nanoparticles were characterized using transmission electron microscopy, dynamic light scattering, thermogravimetric analysis and T2-relaxometry. Nanoparticles were shown to absorb Dox molecules, possibly through a combination of electrostatic and hydrophobic interactions. The loading capacity (LC) of the nanoparticles was 8 wt.%. The Dox loaded nanoparticles release the drug at a higher rate at pH 5.5 compared to pH 7.4 and display similar cytotoxicity against C6 and HEK293 cells as the free Dox. (C) 2015 Elsevier B.V. All rights reserved. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Wos |
000367408100131 |
Publication Date |
2015-11-10 |
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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 |
0927-7765 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.887 |
Times cited |
37 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.887; 2015 IF: 4.152 |
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Call Number |
UA @ lucian @ c:irua:131075 |
Serial |
4157 |
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Author |
Djoković, V.; Krsmanović, R.; Božanić, D.K.; McPherson, M.; Van Tendeloo, G.; Nair, P.S.; Georges, M.K.; Radhakrishnan, T. |
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Title |
Adsorption of sulfur onto a surface of silver nanoparticles stabilized with sago starch biopolymer |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Colloids and surfaces: B : biointerfaces |
Abbreviated Journal |
Colloid Surface B |
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Volume |
73 |
Issue |
1 |
Pages |
30-35 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Adsorption of sulfide ions onto a surface of starch capped silver nanoparticles upon addition of thioacetamide was investigated. UVvis absorption spectroscopy revealed that the adsorption of the sulfide ion on the surface of the silver nanoparticles induced damping as well as blue shift of the silver surface plasmon resonance band. Further increase in thioacetamide concentration led to shift of the resonance band toward higher wavelengths indicating the formation of the continuous Ag2S layer on the silver surface. Thus fabricated nanoparticles were investigated using electron microscopy techniques (TEM, HRTEM, and HAADF-STEM) and X-ray photoelectron spectroscopy (XPS), which confirmed their coreshell structure. |
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Corporate Author |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000268657500005 |
Publication Date |
2009-05-05 |
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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 |
0927-7765; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.887 |
Times cited |
41 |
Open Access |
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Notes |
Esteem 026019 |
Approved |
Most recent IF: 3.887; 2009 IF: 2.600 |
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Call Number |
UA @ lucian @ c:irua:77972 |
Serial |
66 |
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Author |
Juchtmans, R.; Béché, A.; Abakumov, A.; Batuk, M.; Verbeeck, J. |
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Title |
Using electron vortex beams to determine chirality of crystals in transmission electron microscopy |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
91 |
Issue |
91 |
Pages |
094112 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
We investigate electron vortex beams elastically scattered on chiral crystals. After deriving a general expression for the scattering amplitude of a vortex electron, we study its diffraction on point scatterers arranged on a helix. We derive a relation between the handedness of the helix and the topological charge of the electron vortex on one hand and the symmetry of the higher-order Laue zones in the diffraction pattern on the other for kinematically and dynamically scattered electrons. We then extend this to atoms arranged on a helix as found in crystals which belong to chiral space groups and propose a method to determine the handedness of such crystals by looking at the symmetry of the diffraction pattern. In contrast to alternative methods, our technique does not require multiple scattering, which makes it possible to also investigate extremely thin samples in which multiple scattering is suppressed. In order to verify the model, elastic scattering simulations are performed, and an experimental demonstration on Mn2Sb2O7 is given in which we find the sample to belong to the right-handed variant of its enantiomorphic pair. This demonstrates the usefulness of electron vortex beams to reveal the chirality of crystals in a transmission electron microscope and provides the required theoretical basis for further developments in this field. |
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Place of Publication |
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Wos |
000352017000002 |
Publication Date |
2015-03-27 |
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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 |
54 |
Open Access |
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Notes |
Fwo; 312483 Esteem2; 278510 Vortex; esteem2jra1; esteem2jra2 ECASJO_; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
c:irua:125512 c:irua:125512 |
Serial |
3825 |
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Author |
Juchtmans, R.; Verbeeck, J. |
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Title |
Orbital angular momentum in electron diffraction and its use to determine chiral crystal symmetries |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Physical review: B: condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
92 |
Issue |
92 |
Pages |
134108 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In this work we present an alternative way to look at electron diffraction in a transmission electron microscope.
Instead of writing the scattering amplitude in Fourier space as a set of plane waves,we use the cylindrical Fourier transform to describe the scattering amplitude in a basis of orbital angular momentum (OAM) eigenstates. We show how working in this framework can be very convenient when investigating, e.g., rotation and screw-axis symmetries. For the latter we find selection rules on the OAM coefficients that unambiguously reveal the handedness of the screw axis. Detecting the OAM coefficients of the scattering amplitude thus offers the possibility to detect the handedness of crystals without the need for dynamical simulations, the thickness of the sample, nor the exact crystal structure. We propose an experimental setup to measure the OAM components where an image of the crystal is taken after inserting a spiral phase plate in the diffraction plane and perform multislice simulations on α quartz to demonstrate how the method indeed reveals the chirality. The experimental feasibility of the technique is discussed together with its main advantages with respect to chirality determination of screw axes. The method shows how the use of a spiral phase plate can be extended from a simple phase imaging technique to a tool to measure the local OAM decomposition of an electron wave, widening the field of interest well beyond chiral space group determination. |
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Wos |
000362893100002 |
Publication Date |
2015-10-14 |
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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 |
16 |
Open Access |
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Notes |
The authors acknowledge support from the FWO (As- pirant Fonds Wetenschappelijk Onderzoek–Vlaanderen), the EU under the Seventh Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483-ESTEEM2, and ERC Starting Grant No. 278510 VORTEX; esteem2jra1; ECASJO; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
c:irua:129417 c:irua:129417UA @ admin @ c:irua:129417 |
Serial |
4089 |
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Author |
Prodi, A.; Daoud-Aladine, A.; Gozzo, F.; Schmitt, B.; Lebedev, O.; Van Tendeloo, G.; Gilioli, E.; Bolzoni, F.; Aruga-Katori, H.; Takagi, H.; Marezio, M.; Gauzzi, A.; |
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Title |
Commensurate structural modulation in the charge- and orbitally ordered phase of the quadruple perovskite (NaMn3)Mn4O12 |
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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 |
18 |
Pages |
180101 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
By means of synchrotron x-ray and electron diffraction, we studied the structural changes at the charge order transition T-CO = 176 K in the mixed-valence quadruple perovskite (NaMn3)Mn4O12. Below T-CO we find satellite peaks indicating a commensurate structural modulation with the same propagation vector q = ( 1/2,0,-1/2) of the CE magnetic structure that orders at low temperatures, similarly to the case of simple perovskites such as La0.5Ca0.5MnO3. In the present case, the modulated structure, together with the observation of a large entropy change at T-CO, gives evidence of a rare case of full Mn3+/Mn4+ charge and orbital order, consistent with the Goodenough-Kanamori model. |
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Wos |
000344915100001 |
Publication Date |
2014-11-10 |
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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 |
11 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:122097 |
Serial |
406 |
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Author |
Govaerts, K.; Park, K.; De Beule, C.; Partoens, B.; Lamoen, D. |
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Title |
Effect of Bi bilayers on the topological states of Bi2Se3 : a first-principles study |
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 |
15 |
Pages |
155124 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
Bi2Se3 is a three-dimensional topological insulator which has been extensively studied because it has a single Dirac cone on the surface, inside a relatively large bulk band gap. However, the effect of two-dimensional topological insulator Bi bilayers on the properties of Bi2Se3 and vice versa, has not been explored much. Bi bilayers are often present between the quintuple layers of Bi2Se3, since (Bi2)n(Bi2Se3)m form stable ground-state structures. Moreover, Bi2Se3 is a good substrate for growing ultrathin Bi bilayers. By first-principles techniques, we first show that there is no preferable surface termination by either Bi or Se. Next, we investigate the electronic structure of Bi bilayers on top of, or inside a Bi2Se3 slab. If the Bi bilayers are on top, we observe a charge transfer to the quintuple layers that increases the binding energy of the surface Dirac cones. The extra states, originating from the Bi bilayers, were declared to form a topological Dirac cone, but here we show that these are ordinary Rashba-split states. This result, together with the appearance of a new Dirac cone that is localized slightly deeper, might necessitate the reinterpretation of several experimental results. When the Bi bilayers are located inside the Bi2Se3 slab, they tend to split the slab into two topological insulators with clear surface states. Interface states can also be observed, but an energy gap persists because of strong coupling between the neighboring quintuple layers and the Bi bilayers. |
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Wos |
000343773200001 |
Publication Date |
2014-10-20 |
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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 |
30 |
Open Access |
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Notes |
; We gratefully acknowledge financial support from the Research Foundation – Flanders (FWO-Vlaanderen). K.G. thanks the University of Antwerp for a Ph.D. fellowship. C.D.B. is an aspirant of the Flemish Science Foundation. This work was carried out using the HPC infrastructure at the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center VSC, supported financially by the Hercules Foundation and the Flemish Government (EWI Department). K.P. was supported by U.S. National Science Foundation Grant No. DMR-1206354. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:119527 |
Serial |
800 |
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Author |
Govaerts, K.; Sluiter, M.H.F.; Partoens, B.; Lamoen, D. |
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Title |
Homologous series of layered structures in binary and ternary Bi-Sb-Te-Se systems : ab initio study |
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 |
89 |
Issue |
5 |
Pages |
054106-54109 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
In order to account explicitly for the existence of long-periodic layered structures and the strong structural relaxations in the most common binary and ternary alloys of the Bi-Sb-Te-Se system, we have developed a one-dimensional cluster expansion (CE) based on first-principles electronic structure calculations, which accounts for the Bi and Sb bilayer formation. Excellent interlayer distances are obtained with a van der Waals density functional. It is shown that a CE solely based on pair interactions is sufficient to provide an accurate description of the ground-state energies of Bi-Sb-Te-Se binary and ternary systems without making the data set of ab initio calculated structures unreasonably large. For the binary alloys A1−xQx (A=Sb, Bi; Q=Te, Se), a ternary CE yields an almost continuous series of (meta)stable structures consisting of consecutive A bilayers next to consecutive A2Q3 for 0<x<0.6. For x>0.6, the binary alloy segregates into pure Q and A2Q3. The Bi-Sb system is described by a quaternary CE and is found to be an ideal solid solution stabilized by entropic effects at T≠0 K but with an ordered structure of alternating Bi and Sb layers for x=0.5 at T=0 K. A quintuple CE is used for the ternary Bi-Sb-Te system, where stable ternary layered compounds with an arbitrary stacking of Sb2Te3, Bi2Te3, and Te-Bi-Te-Sb-Te quintuple units are found, optionally separated by mixed Bi/Sb bilayers. Electronic properties of the stable compounds were studied taking spin-orbit coupling into account. |
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Wos |
000332420900001 |
Publication Date |
2014-03-05 |
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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 |
5 |
Open Access |
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Notes |
Fwo; Hercules |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:114910 |
Serial |
1487 |
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