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Author |
Neek-Amal, M.; Peeters, F.M.; Grigorieva, I.V.; Geim, A.K. |
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Title |
Commensurability Effects in Viscosity of Nanoconfined Water |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
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Volume |
10 |
Issue |
10 |
Pages |
3685-3692 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The rate of water flow through hydrophobic nanocapillaries is greatly enhanced as compared to that expected from macroscopic hydrodynamics. This phenomenon is usually described in terms of a relatively large slip length, which is in turn defined by such microscopic properties as the friction between water and capillary surfaces and the viscosity of water. We show that the viscosity of water and, therefore, its flow rate are profoundly affected by the layered structure of confined water if the capillary size becomes less than 2 nm. To this end, we study the structure and dynamics of water confined between two parallel graphene layers using equilibrium molecular dynamics simulations. We find that the shear viscosity is not only greatly enhanced for subnanometer capillaries, but also exhibits large oscillations that originate from commensurability between the capillary size and the size of water molecules. Such oscillating behavior of viscosity and, consequently, the slip length should be taken into account in designing and studying graphene-based and similar membranes for desalination and filtration. |
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Address |
School of Physics and Astronomy, University of Manchester , Manchester M13 9PL, United Kingdom |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000372855400073 |
Publication Date |
2016-02-16 |
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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 |
1936-0851 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.942 |
Times cited |
160 |
Open Access |
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Notes |
; M.N.A. was support by Shahid Rajaee Teacher Training University under contract number 29605. ; |
Approved |
Most recent IF: 13.942 |
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Call Number |
c:irua:133237 |
Serial |
4012 |
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Permanent link to this record |
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Author |
Ghosh, S.; Gaspari, R.; Bertoni, G.; Spadaro, M.C.; Prato, M.; Turner, S.; Cavalli, A.; Manna, L.; Brescia, R. |
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Title |
Pyramid-Shaped Wurtzite CdSe Nanocrystals with Inverted Polarity |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
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Volume |
9 |
Issue |
9 |
Pages |
8537-8546 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
We report on pyramid-shaped wurtzite cadmium selenide (CdSe) nanocrystals (NCs), synthesized by hot injection in the presence of chloride ions as shape-directing agents, exhibiting reversed crystal polarity compared to former reports. Advanced transmission electron microscopy (TEM) techniques (image-corrected high-resolution TEM with exit wave reconstruction and probe-corrected high-angle annular dark field-scanning TEM) unequivocally indicate that the triangular base of the pyramids is the polar (0001) facet and their apex points toward the [0001] direction. Density functional theory calculations, based on a simple model of binding of Cl(-) ions to surface Cd atoms, support the experimentally evident higher thermodynamic stability of the (0001) facet over the (0001) one conferred by Cl(-) ions. The relative stability of the two polar facets of wurtzite CdSe is reversed compared to previous experimental and computational studies on Cd chalcogenide NCs, in which no Cl-based chemicals were deliberately used in the synthesis or no Cl(-) ions were considered in the binding models. Self-assembly of these pyramids in a peculiar clover-like geometry, triggered by the addition of oleic acid, suggests that the basal (polar) facet has a density and perhaps type of ligands significantly different from the other three facets, since the pyramids interact with each other exclusively via their lateral facets. A superstructure, however with no long-range order, is observed for clovers with their (0001) facets roughly facing each other. The CdSe pyramids were also exploited as seeds for CdS pods growth, and the peculiar shape of the derived branched nanostructures clearly arises from the inverted polarity of the seeds. |
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Address |
Department of Nanochemistry, Istituto Italiano di Tecnologia (IIT) , via Morego 30, I-16163 Genova, Italy |
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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 |
000360323300085 |
Publication Date |
2015-07-23 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1936-0851;1936-086X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.942 |
Times cited |
16 |
Open Access |
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Notes |
PMID:26203791 |
Approved |
Most recent IF: 13.942; 2015 IF: 12.881 |
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Call Number |
c:irua:127807 |
Serial |
3956 |
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Permanent link to this record |
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Author |
Zeng, Y.-J.; Gauquelin, N.; Li, D.-Y.; Ruan, S.-C.; He, H.-P.; Egoavil, R.; Ye, Z.-Z.; Verbeeck, J.; Hadermann, J.; Van Bael, M.J.; Van Haesendonck, C. |
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Title |
Co-Rich ZnCoO Nanoparticles Embedded in Wurtzite Zn1-xCoxO Thin Films: Possible Origin of Superconductivity |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
ACS applied materials and interfaces |
Abbreviated Journal |
Acs Appl Mater Inter |
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Volume |
7 |
Issue |
7 |
Pages |
22166-22171 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Co-rich ZnCoO nanoparticles embedded in wurtzite Zn0.7Co0.3O thin films are grown by pulsed laser deposition on a Si substrate. Local superconductivity with an onset Tc at 5.9 K is demonstrated in the hybrid system. The unexpected superconductivity probably results from Co(3+) in the Co-rich ZnCoO nanoparticles or from the interface between the Co-rich nanoparticles and the Zn0.7Co0.3O matrix. |
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Address |
Solid State Physics and Magnetism Section, KU Leuven , Celestijnenlaan 200 D, BE-3001 Leuven, Belgium |
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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 |
000363001500007 |
Publication Date |
2015-09-21 |
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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 |
1944-8244;1944-8252; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.504 |
Times cited |
13 |
Open Access |
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Notes |
This work has been supported by the Research Foundation − Flanders (FWO, Belgium) as well as by the Flemish Concerted Research Action program (BOF KU Leuven, GOA/14/007). N. G. and J. V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. The Qu-Ant-EM microscope was partly funded by the Flemish Hercules Foundation. The work at Shenzhen University was supported by National Natural Science Foundation of China under Grant No. 61275144 and Natural Science Foundation of SZU. Y.-J. Z. acknowledges funding under grant No. SKL2015-12 from the State Key Laboratory of Silicon Materials; ECASJO_; |
Approved |
Most recent IF: 7.504; 2015 IF: 6.723 |
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Call Number |
c:irua:129195 c:irua:129195UA @ admin @ c:irua:129195 |
Serial |
3949 |
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Permanent link to this record |
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Author |
Mayer, M.; Scarabelli, L.; March, K.; Altantzis, T.; Tebbe, M.; Kociak, M.; Bals, S.; Garcia de Abajo, F.J.; Fery, A.; Liz-Marzan, L.M. |
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Title |
Controlled Living Nanowire Growth: Precise Control over the Morphology and Optical Properties of AgAuAg Bimetallic Nanowires |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
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Volume |
15 |
Issue |
15 |
Pages |
5427-5437 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Inspired by the concept of living polymerization reaction, we are able to produce silver-gold-silver nanowires with a precise control over their total length and plasmonic properties by establishing a constant silver deposition rate on the tips of penta-twinned gold nanorods used as seed cores. Consequently, the length of the wires increases linearly in time. Starting with approximately 210 nm x 32 nm gold cores, we produce nanowire lengths up to several microns in a highly controlled manner, with a small self-limited increase in thickness of approximately 4 nm, corresponding to aspect ratios above 100, whereas the low polydispersity of the product allows us to detect up to nine distinguishable plasmonic resonances in a single colloidal solution. We analyze the spatial distribution and the nature of the plasmons by electron energy loss spectroscopy and obtain excellent agreement between measurements and electromagnetic simulations, clearly demonstrating that the presence of the gold core plays a marginal role, except for relatively short wires or high-energy modes. |
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Corporate Author |
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Publisher |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000359613700087 |
Publication Date |
2015-07-03 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1530-6984;1530-6992; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.712 |
Times cited |
117 |
Open Access |
OpenAccess |
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Notes |
L.M.L.-M. acknowledges funding from the European Research Council Advanced Grant PLASMAQUO (No. 267867) and from the Spanish MINECO (grant MAT2013-46101-R). S.B. acknowledges funding from ERC Starting Grant COLOURATOMS (335078). The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreements 312483 (ESTEEM2) and 262348 (ESMI). M.M., M.T., and A.F. acknowledge funding from the European Research Council starting grant METAMECH (No 306686). M.T. was supported by the Elite Network Bavaria in the frame of the Elite Study Program “Macromolecular Science” and funded via a grant for Ph.D. candidates according to Bavarian elite promotion law (BayEFG). F.J.G.deA. acknowledges funding from the Spanish MINECO (grant MAT2014-59096-P).; esteem2jra3; esteem2jra4; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); |
Approved |
Most recent IF: 12.712; 2015 IF: 13.592 |
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Call Number |
c:irua:129687 c:irua:129687 |
Serial |
3975 |
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Permanent link to this record |
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Author |
Gonzalez-Rubio, G.; Gonzalez-Izquierdo, J.; Banares, L.; Tardajos, G.; Rivera, A.; Altantzis, T.; Bals, S.; Pena-Rodriguez, O.; Guerrero-Martinez, A.; Liz-Marzan, L.M. |
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Title |
Femtosecond Laser-Controlled Tip-to-Tip Assembly and Welding of Gold Nanorods |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
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Volume |
15 |
Issue |
15 |
Pages |
8282-8288 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Directed assembly of gold nanorods through the use of dithiolated molecular linkers is one of the most efficient methodologies for the morphologically controlled tip-to-tip assembly of this type of anisotropic nanocrystals. However, in a direct analogy to molecular polymerization synthesis, this process is characterized by difficulties in chain-growth control over nanoparticle oligomers. In particular, it is nearly impossible to favor the formation of one type of oligomer, making the methodology hard to use for actual applications in nanoplasmonics. We propose here a light-controlled synthetic procedure that allows obtaining selected plasmonic oligomers in high yield and with reaction times in the scale of minutes by irradiation with low fluence near-infrared (NIR) femtosecond laser pulses. Selective inhibition of the formation of gold nanorod n-mers (trimers) with a longitudinal localized surface plasmon in resonance with a 800 nm Ti:sapphire laser, allowed efficient trapping of the (n – 1)-mers (dimers) by hot spot mediated photothermal decomposition of the interparticle molecular linkers. Laser irradiation at higher energies produced near-field enhancement at the interparticle gaps, which is large enough to melt gold nanorod tips, offering a new pathway toward tip-to-tip welding of gold nanorod oligomers with a plasmonic response at the NIR. Thorough optical and electron microscopy characterization indicates that plasmonic oligomers can be selectively trapped and welded, which has been analyzed in terms of a model that predicts with reasonable accuracy the relative concentrations of the main plasmonic species. |
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Address |
Ikerbasque, Basque Foundation for Science , 48013 Bilbao, Spain |
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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 |
000366339600075 |
Publication Date |
2015-11-09 |
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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 |
1530-6984;1530-6992; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.712 |
Times cited |
101 |
Open Access |
OpenAccess |
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Notes |
This work has been funded by the Spanish MINECO (MAT2012-38541, MAT2013-46101-R, MAT2014-59678-R and CTQ2012-37404-C02-01). A.G.-M. and G.G.-R., respectively, acknowledge receipt of Ramón y Cajal and FPI Fellowships from the Spanish MINECO. O.P.-R. is grateful with Moncloa Campus of International Excellence (UCMUPM) for the PICATA postdoctoral fellowship. The facilities provided by the Center for Ultrafast Lasers at Complutense University of Madrid are gratefully acknowledged. S.B. acknowledges funding from the European Research Council under the Seventh Framework Program (FP7), ERC Grant 335078 COLOURATOMS.; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); |
Approved |
Most recent IF: 12.712; 2015 IF: 13.592 |
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Call Number |
c:irua:129686 |
Serial |
3976 |
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Permanent link to this record |
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Author |
Zanaga, D.; Bleichrodt, F.; Altantzis, T.; Winckelmans, N.; Palenstijn, W.J.; Sijbers, J.; de Nijs, B.; van Huis, M.A.; Sanchez-Iglesias, A.; Liz-Marzan, L.M.; van Blaaderen, A.; Joost Batenburg, K.; Bals, S.; Van Tendeloo, G. |
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Title |
Quantitative 3D analysis of huge nanoparticle assemblies |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
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Volume |
8 |
Issue |
8 |
Pages |
292-299 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
Nanoparticle assemblies can be investigated in 3 dimensions using electron tomography. However, it is not straightforward to obtain quantitative information such as the number of particles or their relative position. This becomes particularly difficult when the number of particles increases. We propose a novel approach in which prior information on the shape of the individual particles is exploited. It improves the quality of the reconstruction of these complex assemblies significantly. Moreover, this quantitative Sparse Sphere Reconstruction approach yields directly the number of particles and their position as an output of the reconstruction technique, enabling a detailed 3D analysis of assemblies with as many as 10 000 particles. The approach can also be used to reconstruct objects based on a very limited number of projections, which opens up possibilities to investigate beam sensitive assemblies where previous reconstructions with the available electron tomography techniques failed. |
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Address |
EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium. sara.bals@uantwerpen.be |
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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 |
000366911700028 |
Publication Date |
2015-11-19 |
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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 |
2040-3364 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.367 |
Times cited |
34 |
Open Access |
OpenAccess |
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Notes |
The authors acknowledge financial support from European Research Council (ERC Starting Grant # 335078-COLOURATOMS, ERC Advanced Grant # 291667 HierarSACol and ERC Advanced Grant 267867 – PLASMAQUO), the European Union under the FP7 (Integrated Infrastructure Initiative N. 262348 European Soft Matter Infrastructure, ESMI and N. 312483 ESTEEM2), and from the Netherlands Organisation for Scientific Research (NWO), project number 639.072.005 and NWO CW 700.57.026. Networking support was provided by COST Action MP1207.; esteem2jra4; ECASSara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 7.367 |
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Call Number |
c:irua:131062 c:irua:131062 |
Serial |
3979 |
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Permanent link to this record |
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Author |
Jelić, Ž.L.; Milošević, M.V.; Van de Vondel, J.; Silhanek, A.V. |
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Title |
Stroboscopic phenomena in superconductors with dynamic pinning landscape |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
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Volume |
5 |
Issue |
5 |
Pages |
14604 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Introducing artificial pinning centers is a well established strategy to trap quantum vortices and increase the maximal magnetic field and applied electric current that a superconductor can sustain without dissipation. In case of spatially periodic pinning, a clear enhancement of the superconducting critical current arises when commensurability between the vortex configurations and the pinning landscape occurs. With recent achievements in (ultrafast) optics and nanoengineered plasmonics it has become possible to exploit the interaction of light with superconductivity, and create not only spatially periodic imprints on the superconducting condensate, but also temporally periodic ones. Here we show that in the latter case, temporal matching phenomena develop, caused by stroboscopic commensurability between the characteristic frequency of the vortex motion under applied current and the frequency of the dynamic pinning. The matching resonances persist in a broad parameter space, including magnetic field, driving current, or material purity, giving rise to unusual features such as externally variable resistance/impedance and Shapiro steps in current-voltage characteristics. All features are tunable by the frequency of the dynamic pinning landscape. These findings open further exploration avenues for using flashing, spatially engineered, and/or mobile excitations on superconductors, permitting us to achieve advanced functionalities. |
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Address |
Departement de Physique, Universite de Liege, Allee du 6-Aout 17, B-4000 Liege, Belgium |
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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 |
000362082500001 |
Publication Date |
2015-10-01 |
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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 |
2045-2322 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.259 |
Times cited |
29 |
Open Access |
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Notes |
Acknowledgements: This work was supported by the Methusalem Funding of the Flemish Government, the Research Foundation-Flanders (FWO) and the COST Action MP1201. The work of Ž.L.J. and A.V.S. was partially supported by “Mandat d’Impulsion Scientifique” of the F.R.S.-FNRS. |
Approved |
Most recent IF: 4.259; 2015 IF: 5.578 |
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Call Number |
c:irua:129807 c:irua:129807 |
Serial |
3980 |
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Permanent link to this record |
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Author |
Neyts, E.C.; Ostrikov, K.K.; Sunkara, M.K.; Bogaerts, A. |
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Title |
Plasma Catalysis: Synergistic Effects at the Nanoscale |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Chemical reviews |
Abbreviated Journal |
Chem Rev |
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Volume |
115 |
Issue |
115 |
Pages |
13408-13446 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Thermal-catalytic gas processing is integral to many current industrial processes. Ever-increasing demands on conversion and energy efficiencies are a strong driving force for the development of alternative approaches. Similarly, synthesis of several functional materials (such as nanowires and nanotubes) demands special processing conditions. Plasma catalysis provides such an alternative, where the catalytic process is complemented by the use of plasmas that activate the source gas. This combination is often observed to result in a synergy between plasma and catalyst. This Review introduces the current state-of-the-art in plasma catalysis, including numerous examples where plasma catalysis has demonstrated its benefits or shows future potential, including CO2 conversion, hydrocarbon reforming, synthesis of nanomaterials, ammonia production, and abatement of toxic waste gases. The underlying mechanisms governing these applications, as resulting from the interaction between the plasma and the catalyst, render the process highly complex, and little is known about the factors leading to the often-observed synergy. This Review critically examines the catalytic mechanisms relevant to each specific application. |
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Address |
Department of Chemistry, Research Group PLASMANT, Universiteit Antwerpen , Universiteitsplein 1, 2610 Wilrijk-Antwerp, Belgium |
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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 |
000367563000006 |
Publication Date |
2015-11-30 |
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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 |
0009-2665 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
47.928 |
Times cited |
204 |
Open Access |
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Notes |
ECN and AB gratefully acknowledge financial support from the Fund of Scientific Research Flanders (FWO), Belgium, Grant Number G.0217.14N. KO acknowledges partial support by the Australian Research Council and CSIRO’s OCE Science Leaders Program. MKS acknowledges partial support from US National Science Foundation through grants DMS 1125909 and EPSCoR 1355448 and also PhD students Babajide Ajayi, Apolo Nambo and Maria Carreon for their help. |
Approved |
Most recent IF: 47.928; 2015 IF: 46.568 |
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Call Number |
c:irua:130001 |
Serial |
3993 |
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Permanent link to this record |
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Author |
Paria Sena, R.; Babaryk, A.A.; Khainakov, S.; Garcia-Granda, S.; Slobodyanik, N.S.; Van Tendeloo, G.; Abakumov, A.M.; Hadermann, J. |
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Title |
A pseudo-tetragonal tungsten bronze superstructure: a combined solution of the crystal structure of K6.4(Nb,Ta)36.3O94 with advanced transmission electron microscopy and neutron diffraction |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
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Volume |
45 |
Issue |
45 |
Pages |
973-979 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The crystal structure of the K6.4Nb28.2Ta8.1O94 pseudo-tetragonal tungsten bronze-type oxide was determined using a combination of X-ray powder diffraction, neutron diffraction and transmission electron microscopy techniques, including electron diffraction, high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), annular bright field STEM (ABF-STEM) and energy-dispersive X-ray compositional mapping (STEM-EDX). The compound crystallizes in the space group Pbam with unit cell parameters a = 37.468(9) A, b = 12.493(3) A, c = 3.95333(15) A. The structure consists of corner sharing (Nb,Ta)O6 octahedra forming trigonal, tetragonal and pentagonal tunnels. All tetragonal tunnels are occupied by K(+) ions, while 1/3 of the pentagonal tunnels are preferentially occupied by Nb(5+)/Ta(5+) and 2/3 are occupied by K(+) in a regular pattern. A fractional substitution of K(+) in the pentagonal tunnels by Nb(5+)/Ta(5+) is suggested by the analysis of the HAADF-STEM images. In contrast to similar structures, such as K2Nb8O21, also parts of the trigonal tunnels are fractionally occupied by K(+) cations. |
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Address |
Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp, Belgium. joke.hadermann@uantwerpen.be babaryk@univ.kiev.ua |
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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 |
000367614700018 |
Publication Date |
2015-11-23 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1477-9226 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4.029 |
Times cited |
6 |
Open Access |
|
|
|
Notes |
We thank Dr E. Suard and Dr O. Fabello for assistance in collecting the neutron diffraction data. R.P.S. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant No. 246791-COUNTATOMS. The titan microscope was partly funded by the Hercules fund from the Flemish Government. The authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483-ESTEEM2. AAB acknowledges the JSPDS ICDD Grant-in-Aid program (12-02).; esteem2jra1; esteem2jra2 |
Approved |
Most recent IF: 4.029 |
|
|
Call Number |
c:irua:130408 c:irua:130408 |
Serial |
3998 |
|
Permanent link to this record |
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Author |
Filez, M.; Redekop, E.A.; Galvita, V.V.; Poelman, H.; Meledina, M.; Turner, S.; Van Tendeloo, G.; Bell, A.T.; Marin, G.B. |
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Title |
The role of hydrogen during Pt-Ga nanocatalyst formation |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
|
Volume |
18 |
Issue |
18 |
Pages |
3234-3243 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Hydrogen plays an essential role during the in situ assembly of tailored catalytic materials, and serves as key ingredient in multifarious chemical reactions promoted by these catalysts. Despite intensive debate for several decades, the existence and nature of hydrogen-involved mechanisms – such as hydrogen-spillover, surface migration – have not been unambiguously proven and elucidated up to date. Here, Pt-Ga alloy formation is used as a probe reaction to study the behavior and atomic transport of H and Ga, starting from Pt nanoparticles on hydrotalcite-derived Mg(Ga)(Al)Ox supports. In situ XANES spectroscopy, time-resolved TAP kinetic experiments, HAADF-STEM imaging and EDX mapping are combined to probe Pt, Ga and H in a series of H2 reduction experiments up to 650 degrees C. Mg(Ga)(Al)Ox by itself dissociates hydrogen, but these dissociated hydrogen species do not induce significant reduction of Ga3+ cations in the support. Only in the presence of Pt, partial reduction of Ga3+ into Gadelta+ is observed, suggesting that different reaction mechanisms dominate for Pt- and Mg(Ga)(Al)Ox-dissociated hydrogen species. This partial reduction of Ga3+ is made possible by Pt-dissociated H species which spillover onto non-reducible Mg(Al)Ox or partially reducible Mg(Ga)(Al)Ox and undergo long-range transport over the support surface. Moderately mobile Gadelta+Ox migrates towards Pt clusters, where Gadelta+ is only fully reduced to Ga0 on condition of immediate stabilization inside Pt-Ga alloyed nanoparticles. |
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Address |
Laboratory for Chemical Technology (LCT), Ghent University, Technologiepark 914, B-9052 Ghent, Belgium. hilde.poelman@ugent.be |
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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 |
000369506000106 |
Publication Date |
2016-01-04 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1463-9076 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
4.123 |
Times cited |
10 |
Open Access |
|
|
|
Notes |
This work was supported by the Fund for Scientific Research Flanders (FWO: G.0209.11), the ‘Long Term Structural Methusalem Funding by the Flemish Government’, the IAP 7/05 Interuniversity Attraction Poles Programme – Belgian State – Belgian Science Policy, and the Fund for Scientific Research Flanders (FWO-Vlaanderen) in supplying financing of beam time at the DUBBLE beam line of the ESRF and travel costs and a postdoctoral fellowship for S.T. The authors acknowledge the assistance from D. Banerjee (XAS campaign 26-01-979) at DUBBLE. E. A. Redekop acknowledges the Marie Curie International Incoming Fellowship granted by the European Commission (Grant Agreement No. 301703). The authors also express their gratitude to V. Bliznuk for acquisition of the TEM images. |
Approved |
Most recent IF: 4.123 |
|
|
Call Number |
c:irua:132315 |
Serial |
4000 |
|
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 |
|
|
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 |
|
Series Issue |
|
Edition |
|
|
|
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 |
Covaci, L.; Berciu, M. |
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Title |
Survival of the Dirac points in rippled graphene |
Type |
A1 Journal article |
|
Year |
2008 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys Rev Lett |
|
|
Volume |
100 |
Issue |
25 |
Pages |
256405 |
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Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
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Abstract |
We study the effects of the rippling of a graphene sheet on quasiparticle dispersion. This is achieved using a generalization to the honeycomb lattice of the momentum average approximation, which is accurate for all coupling strengths and at all energies. We show that even though the position of the Dirac points may move and the Fermi speed can be renormalized significantly, quasiparticles with very long lifetimes survive near the Dirac points even for very strong couplings. |
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Address |
Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada, V6T 1Z1 |
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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 |
000257230500047 |
Publication Date |
2008-06-26 |
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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 |
0031-9007 |
ISBN |
|
Additional Links |
|
|
|
Impact Factor |
8.462 |
Times cited |
15 |
Open Access |
|
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|
Notes |
|
Approved |
Most recent IF: 8.462; 2008 IF: 7.180 |
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Call Number |
UA @ lucian @ |
Serial |
4010 |
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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 |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
|
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 |
|
|
|
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 |
Albrecht, W.; Deng, T.-S.; Goris, B.; van Huis, M.A.; Bals, S.; van Blaaderen, A. |
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Title |
Single Particle Deformation and Analysis of Silica-Coated Gold Nanorods before and after Femtosecond Laser Pulse Excitation |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
|
|
Volume |
16 |
Issue |
16 |
Pages |
1818-1825 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
We performed single particle deformation experiments on silica-coated gold nanorods under femtosecond (fs) illumination. Changes in the particle shape were analyzed by electron microscopy and associated changes in the plasmon resonance by electron energy loss spectroscopy. Silica-coated rods were found to be more stable compared to uncoated rods but could still be deformed via an intermediate bullet-like shape for silica shell thicknesses of 14 nm. Changes in the size ratio of the rods after fs-illumination resulted in blue-shifting of the longitudinal plasmon resonances. Two-dimensional spatial mapping of the plasmon resonances revealed that the flat side of the bullet-like particles showed a less pronounced longitudinal plasmonic electric field enhancement. These findings were confirmed by finite-difference time-domain (FDTD) simulations. Furthermore, at higher laser fluences size reduction of the particles was found as well as for particles that were not completely deformed yet. |
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Address |
Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University , Princetonplein 5, 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 |
000371946300045 |
Publication Date |
2016-02-12 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1530-6984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
12.712 |
Times cited |
55 |
Open Access |
OpenAccess |
|
|
Notes |
We thank Dr. Nicolas Gauquelin for his assistance during the EELS measurements and Thomas Atlantzis for the high-resolution images of the gold clusters. We furthermore thank Ernest van der Wee for the simulation of the confocal point spread functions. The authors acknowledge financial support from the European Research Council under the European Unions Seventh Framework Programme (FP-2007-2013)/ERC Advanced Grant Agreement #291667 HierarSACol and the Foundation of Fundamental Research on Matter (FOM), which is part of the Netherlands Organisation for Scientific Research (NWO). The authors furthermore acknowledge financial support from European Research Council (ERC Starting Grant #335078-COLOURATOMS). The authors also appreciate financial support from the European Union under the Seventh Framework Program (Integrated Infrastructure Initiative N. 262348 European Soft Matter Infrastructure, ESMI). This work was supported by the Flemish Fund for Scientific Research (FWO Vlaanderen) through a postdoctoral research grant to B.G.; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); |
Approved |
Most recent IF: 12.712 |
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|
Call Number |
c:irua:131924 c:irua:131924 |
Serial |
4016 |
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Permanent link to this record |
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Author |
Yang, Z.; Altantzis, T.; Zanaga, D.; Bals, S.; Van Tendeloo, G.; Pileni, M.-P. |
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Title |
Supracrystalline Colloidal Eggs: Epitaxial Growth and Freestanding Three-Dimensional Supracrystals in Nanoscaled Colloidosomes |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
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|
Volume |
138 |
Issue |
138 |
Pages |
3493-3500 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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|
Abstract |
The concept of template-confined chemical reactions allows the synthesis of complex molecules that would hardly be producible through conventional method. This idea was developed to produce high quality nanocrystals more than 20 years ago. However, template-mediated assembly of colloidal nanocrystals is still at an elementary level, not only because of the limited templates suitable for colloidal assemblies, but also because of the poor control over the assembly of nanocrystals within a confined space. Here, we report the design of a new system called “supracrystalline colloidal eggs” formed by controlled assembly of nanocrystals into complex colloidal supracrystals through superlattice-matched epitaxial overgrowth along the existing colloidosomes. Then, with this concept, we extend the supracrystalline growth to lattice-mismatched binary nanocrystal superlattices, in order to reach anisotropic superlattice growths, yielding freestanding binary nanocrystal supracrystals that could not be produced previously. |
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Address |
CEA/IRAMIS , CEA Saclay F-91191 Gif-sur-Yvette, France |
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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 |
000372477700034 |
Publication Date |
2016-02-24 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0002-7863 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
13.858 |
Times cited |
57 |
Open Access |
OpenAccess |
|
|
Notes |
The research leading to these results has been supported by an Advanced Grant of the European Research Council under Grant 267129. The authors appreciate financial support by the European Union under the Framework 7 program under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2). The authors thank Dr. P. A. Albouy for the SAXS measurement.; esteem2_ta |
Approved |
Most recent IF: 13.858 |
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|
Call Number |
c:irua:131923 c:irua:131923 |
Serial |
4018 |
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Permanent link to this record |
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Author |
Milovanovic, S.P.; Peeters, F.M. |
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Title |
Characterization of the size and position of electron-hole puddles at a graphene p-n junction |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
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Volume |
27 |
Issue |
27 |
Pages |
105203 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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|
Abstract |
The effect of an electron-hole puddle on the electrical transport when governed by snake states in a bipolar graphene structure is investigated. Using numerical simulations we show that information on the size and position of the electron-hole puddle can be obtained using the dependence of the conductance on magnetic field and electron density of the gated region. The presence of the scatterer disrupts snake state transport which alters the conduction pattern. We obtain a simple analytical formula that connects the position of the electron-hole puddle with features observed in the conductance. The size of the electron-hole puddle is estimated from the magnetic field and gate potential that maximizes the effect of the puddle on the electrical transport. |
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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 |
English |
Wos |
000369849200003 |
Publication Date |
2016-02-11 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0957-4484 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.44 |
Times cited |
3 |
Open Access |
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|
|
Notes |
This work was supported by the Flemish Science Foundation (FWO-Vl) and the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN. We acknowledge interesting correspondence with Thiti Taychatanapat. |
Approved |
Most recent IF: 3.44 |
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|
Call Number |
c:irua:131907 |
Serial |
4025 |
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Permanent link to this record |
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Author |
Martens, K.; Jeong, J.W.; Aetukuri, N.; Rettner, C.; Shukla, N.; Freeman, E.; Esfahani, D.N.; Peeters, F.M.; Topuria, T.; Rice, P.M.; Volodin, A.; Douhard, B.; Vandervorst, W.; Samant, M.G.; Datta, S.; Parkin, S.S.P. |
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Title |
Field Effect and Strongly Localized Carriers in the Metal-Insulator Transition Material VO(2) |
Type |
A1 Journal article |
|
Year |
2015 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
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Volume |
115 |
Issue |
115 |
Pages |
196401 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The intrinsic field effect, the change in surface conductance with an applied transverse electric field, of prototypal strongly correlated VO(2) has remained elusive. Here we report its measurement enabled by epitaxial VO(2) and atomic layer deposited high-kappa dielectrics. Oxygen migration, joule heating, and the linked field-induced phase transition are precluded. The field effect can be understood in terms of field-induced carriers with densities up to approximately 5x10(13) cm(-2) which are trongly localized, as shown by their low, thermally activated mobility ( approximately 1x10(-3) cm(2)/V s at 300 K). These carriers show behavior consistent with that of Holstein polarons and strongly impact the (opto)electronics of VO(2). |
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Address |
IBM Research-Almaden, San Jose, California 95120, USA |
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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 |
000364024800013 |
Publication Date |
2015-11-05 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0031-9007 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
8.462 |
Times cited |
28 |
Open Access |
|
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|
Notes |
; The authors acknowledge B. Hughes, K. Roche, L. Gao, C. Lada, J. Van Houdt, M. Heyns, J. P. Locquet, J. Delmotte, L. Krupp, L. Clark, and FWO (K. M.). S. D. and N. S. acknowledge LEAST (Low Energy Systems Technology), one of six SRC STARnet Centers, sponsored by MARCO/DARPA, for financial support. ; |
Approved |
Most recent IF: 8.462; 2015 IF: 7.512 |
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Call Number |
c:irua:129547 |
Serial |
4051 |
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Permanent link to this record |
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Author |
Ovsyannikov, S.V.; Bykov, M.; Bykova, E.; Kozlenko, D.P.; Tsirlin, A.A.; Karkin, A.E.; Shchennikov, V.V.; Kichanov, S.E.; Gou, H.; Abakumov, A.M.; Egoavil, R.; Verbeeck, J.; McCammon, C.; Dyadkin, V.; Chernyshov, D.; van Smaalen, S.; Dubrovinsky, L.S. |
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Title |
Charge-ordering transition in iron oxide Fe4O5 involving competing dimer and trimer formation |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Nature chemistry |
Abbreviated Journal |
Nat Chem |
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Volume |
8 |
Issue |
8 |
Pages |
501-508 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Phase transitions that occur in materials, driven, for instance, by changes in temperature or pressure, can dramatically change the materials' properties. Discovering new types of transitions and understanding their mechanisms is important not only from a fundamental perspective, but also for practical applications. Here we investigate a recently discovered Fe4O5 that adopts an orthorhombic CaFe3O5-type crystal structure that features linear chains of Fe ions. On cooling below approximately 150 K, Fe4O5 undergoes an unusual charge-ordering transition that involves competing dimeric and trimeric ordering within the chains of Fe ions. This transition is concurrent with a significant increase in electrical resistivity. Magnetic-susceptibility measurements and neutron diffraction establish the formation of a collinear antiferromagnetic order above room temperature and a spin canting at 85 K that gives rise to spontaneous magnetization. We discuss possible mechanisms of this transition and compare it with the trimeronic charge ordering observed in magnetite below the Verwey transition temperature. |
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Address |
Bayerisches Geoinstitut, Universitat Bayreuth, Universitatsstrasse 30, D-95447, Bayreuth, 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 |
000374534100019 |
Publication Date |
2016-04-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1755-4330 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
25.87 |
Times cited |
51 |
Open Access |
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Notes |
S.V.O. acknowledges the financial support of the Deutsche Forschungsgemeinschaft (DFG) under project OV-110/1-3. A.E.K. and V.V.S. acknowledge the support of the Russian Foundation for Basic Research (Project 14–02–00622a). H.G. acknowledges the support from the Alexander von Humboldt (AvH) Foundation and the National Natural Science Foundation of China (No. 51201148). A.M.A., R.E. and J.V. acknowledge financial support from the European Commission (EC) under the Seventh Framework Programme (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483- ESTEEM2. R.E. acknowledges support from the EC under FP7 Grant No. 246102 IFOX. A.M.A. acknowledges funding from the Russian Science Foundation (Grant No. 14-13- 00680). A.A.T. acknowledges funding and from the Federal Ministry for Education and Research through the Sofja Kovalevkaya Award of the AvH Foundation. Funding from the Fund for Scientific Research Flanders under FWO Project G.0044.13N is acknowledged. M.B. and S.v.S. acknowledge support from the DFG under Project Sm55/15-2. We acknowledge the European Synchrotron Radiation Facility for the provision of synchrotron radiation facilities.; esteem2jra2; esteem2jra3 |
Approved |
Most recent IF: 25.87 |
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Call Number |
c:irua:133593 c:irua:133593UA @ admin @ c:irua:133593 |
Serial |
4068 |
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Permanent link to this record |
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Author |
Batuk, D.; Tsirlin, A.A.; Filimonov, D.S.; Zakharov, K.V.; Volkova, O.S.; Vasiliev, A.; Hadermann, J.; Abakumov, A.M. |
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Title |
Bi(3n+1)Ti7Fe(3n-3)O(9n+11) Homologous Series: Slicing Perovskite Structure with Planar Interfaces Containing Anatase-like Chains |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
55 |
Issue |
55 |
Pages |
1245-1257 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The n = 3-6 members of a new perovskite-based homologous series Bi(3n+1)Ti7Fe(3n-3)O(9n+11) are reported. The crystal structure of the n = 3 Bi10Ti7Fe6O38 member is refined using a combination of X-ray and neutron powder diffraction data (a = 11.8511(2) A, b = 3.85076(4) A, c = 33.0722(6) A, S.G. Immm), unveiling the partially ordered distribution of Ti(4+) and Fe(3+) cations and indicating the presence of static random displacements of the Bi and O atoms. All Bi(3n+1)Ti7Fe(3n-3)O(9n+11) structures are composed of perovskite blocks separated by translational interfaces parallel to the (001)p perovskite planes. The thickness of the perovskite blocks increases with n, while the atomic arrangement at the interfaces remains the same. The interfaces comprise chains of double edge-sharing (Fe,Ti)O6 octahedra connected to the octahedra of the perovskite blocks by sharing edges and corners. This configuration shifts the adjacent perovskite blocks relative to each other over a vector (1/2)[110]p and creates S-shaped tunnels along the [010] direction. The tunnels accommodate double columns of the Bi(3+) cations, which stabilize the interfaces owing to the stereochemical activity of their lone electron pairs. The Bi(3n+1)Ti7Fe(3n-3)O(9n+11) structures can be formally considered either as intergrowths of perovskite modules and polysynthetically twinned modules of the Bi2Ti4O11 structure or as intergrowths of the 2D perovskite and 1D anatase fragments. Transmission electron microscopy (TEM) on Bi10Ti7Fe6O38 reveals that static atomic displacements of Bi and O inside the perovskite blocks are not completely random; they are cooperative, yet only short-range ordered. According to TEM, the interfaces can be laterally shifted with respect to each other over +/-1/3a, introducing an additional degree of disorder. Bi10Ti7Fe6O38 is paramagnetic in the 1.5-1000 K temperature range due to dilution of the magnetic Fe(3+) cations with nonmagnetic Ti(4+). The n = 3, 4 compounds demonstrate a high dielectric constant of 70-165 at room temperature. |
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Address |
Center for Electrochemical Energy Storage, Skolkovo Institute of Science and Technology , Nobelya str. 3, 143026 Moscow, Russia |
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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 |
000369356800031 |
Publication Date |
2016-01-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
3 |
Open Access |
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Notes |
We are grateful to the Laboratory for Neutron Scattering and Imaging of Paul Scherrer Institut (LNS PSI, Villigen, Switzerland) for granting beam time at the HRPT diffrac- tometer and to Dr. Denis Sheptyakov for the technical support during the experiment. We are also grateful to Valery Verchenko for his help with magnetization measurements. The work has been supported by the Russian Science Foundation (grant 14-13-00680). A.A.T. was partly supported by the Federal Ministry for Education and Science through a Sofja Kovalevskaya Award of Alexander von Humboldt Foundation. |
Approved |
Most recent IF: 4.857 |
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Call Number |
c:irua:132247 |
Serial |
4073 |
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Permanent link to this record |
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Author |
Batuk, D.; Batuk, M.; Tsirlin, A.A.; Hadermann, J.; Abakumov, A.M. |
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Title |
Trapping of Oxygen Vacancies at Crystallographic Shear Planes in Acceptor-Doped Pb-Based Ferroelectrics |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
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Volume |
54 |
Issue |
54 |
Pages |
14787-14790 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The defect chemistry of the ferroelectric material PbTiO3 after doping with Fe(III) acceptor ions is reported. Using advanced transmission electron microscopy and powder X-ray and neutron diffraction, we demonstrate that even at concentrations as low as circa 1.7% (material composition approximately ABO2.95), the oxygen vacancies are trapped into extended planar defects, specifically crystallographic shear planes. We investigate the evolution of these defects upon doping and unravel their detailed atomic structure using the formalism of superspace crystallography, thus unveiling their role in nonstoichiometry in the Pb-based perovskites. |
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Address |
Chemistry Department, Moscow State University, 119991, Moscow (Russia). artem.abakumov@uantwerpen.be |
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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 |
000367723400031 |
Publication Date |
2015-10-21 |
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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 |
1433-7851 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
11.994 |
Times cited |
3 |
Open Access |
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Notes |
A.M.A. is grateful to the Russian Science Foundation (grant 14-13-00680). AT was funded by the Mobilitas grant MTT77 of the ESF and by the Federal Ministry for Education and Research through the Sofja Kovalevskaya Award of Alexander von Humboldt Foundation. |
Approved |
Most recent IF: 11.994; 2015 IF: 11.261 |
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Call Number |
c:irua:131104 |
Serial |
4080 |
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Permanent link to this record |
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Author |
Zheng, G.; de Marchi, S.; Lopez-Puente, V.; Sentosun, K.; Polavarapu, L.; Perez-Juste, I.; Hill, E.H.; Bals, S.; Liz-Marzan, L.M.; Pastoriza-Santos, I.; Perez-Juste, J. |
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Title |
Encapsulation of Single Plasmonic Nanoparticles within ZIF-8 and SERS Analysis of the MOF Flexibility |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Small |
Abbreviated Journal |
Small |
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Volume |
12 |
Issue |
12 |
Pages |
3935-3943 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Hybrid nanostructures composed of metal nanoparticles and metal-organic frameworks (MOFs) have recently received increasing attention toward various applications due to the combination of optical and catalytic properties of nanometals with the large internal surface area, tunable crystal porosity and unique chemical properties of MOFs. Encapsulation of metal nanoparticles of well-defined shapes into porous MOFs in a core-shell type configuration can thus lead to enhanced stability and selectivity in applications such as sensing or catalysis. In this study, the encapsulation of single noble metal nanoparticles with arbitrary shapes within zeolitic imidazolate-based metal organic frameworks (ZIF-8) is demonstrated. The synthetic strategy is based on the enhanced interaction between ZIF-8 nanocrystals and metal nanoparticle surfaces covered by quaternary ammonium surfactants. High resolution electron microscopy and tomography confirm a complete core-shell morphology. Such a well-defined morphology allowed us to study the transport of guest molecules through the ZIF-8 porous shell by means of surface-enhanced Raman scattering by the metal cores. The results demonstrate that even molecules larger than the ZIF-8 aperture and pore size may be able to diffuse through the framework and reach the metal core. |
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Address |
Departamento de Quiimica Fisica, Universidade de Vigo, 36310, Vigo, Spain |
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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 |
000383375500006 |
Publication Date |
2016-06-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1613-6810 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.643 |
Times cited |
140 |
Open Access |
OpenAccess |
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Notes |
This work was supported by the Spanish Ministerio de Economía y Competitividad (MAT2013-45168-R) and the Xunta de Galicia/FEDER (Grant No. GPC2013-006; INBIOMED-FEDER “Unha maneira de facer Europa”). L.M.L.-M. acknowledges funding from the European Union’s Seventh Framework Programme (FP7/2007-2013 under grant agreement No. 312184, SACS). S.B. acknowledges financial support from European Research Council (ERC) (ERC Starting Grant No. 335078-COLOURATOM). The authors thank Prof. Paolo Fornasiero for the nitrogen adsorption measurements. E.H.H. acknowledges the Spanish MINECO for a Juan de la Cierva fellowship. S.D.M. acknowledges the support from CsF/CNPq-Brazil fellowship.; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 8.643 |
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Call Number |
c:irua:133953 |
Serial |
4083 |
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Permanent link to this record |
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Author |
Filippousi, M.; Turner, S.; Leus, K.; Siafaka, P.I.; Tseligka, E.D.; Vandichel, M.; Nanaki, S.G.; Vizirianakis, I.S.; Bikiaris, D.N.; Van Der Voort, P.; Van Tendeloo, G. |
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Title |
Biocompatible Zr-based nanoscale MOFs coated with modified poly(epsilon-caprolactone) as anticancer drug carriers |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
International journal of pharmaceutics |
Abbreviated Journal |
Int J Pharmaceut |
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Volume |
509 |
Issue |
509 |
Pages |
208-218 |
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Keywords |
A1 Journal article; Pharmacology. Therapy; Electron microscopy for materials research (EMAT) |
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Abstract |
Nanoscale Zr-based metal organic frameworks (MOFs) UiO-66 and UiO-67 were studied as potential anticancer drug delivery vehicles. Two model drugs were used, hydrophobic paclitaxel and hydrophilic cisplatin, and were adsorbed onto/into the nano MOFs (NMOFs). The drug loaded MOFs were further encapsulated inside a modified poly(epsilon-caprolactone) with d-alpha-tocopheryl polyethylene glycol succinate polymeric matrix, in the form of microparticles, in order to prepare sustained release formulations and to reduce the drug toxicity. The drugs physical state and release rate was studied at 37 degrees C using Simulated Body Fluid. It was found that the drug release depends on the interaction between the MOFs and the drugs while the controlled release rates can be attributed to the microencapsulated formulations. The in vitro antitumor activity was assessed using HSC-3 (human oral squamous carcinoma; head and neck) and U-87 MG (human glioblastoma grade IV; astrocytoma) cancer cells. Cytotoxicity studies for both cell lines showed that the polymer coated, drug loaded MOFs exhibited better anticancer activity compared to free paclitaxel and cisplatin solutions at different concentrations. |
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Address |
EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium |
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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 |
000378949800022 |
Publication Date |
2016-05-27 |
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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 |
0378-5173 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.649 |
Times cited |
37 |
Open Access |
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Notes |
This work is performed within the framework of the IAP-P7/05. S.T. Gratefully acknowledges the Fund for Scientific Research Flanders (FWO). K.L. acknowledges the financial support from the Ghent University BOF postdoctoral grant 01P06813T and UGent GOA Grant 01G00710. |
Approved |
Most recent IF: 3.649 |
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Call Number |
c:irua:134039 |
Serial |
4088 |
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Permanent link to this record |
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Author |
Muller-Caspary, K.; Krause, F.F.; Grieb, T.; Loffler, S.; Schowalter, M.; Béché, A.; Galioit, V.; Marquardt, D.; Zweck, J.; Schattschneider, P.; Verbeeck, J.; Rosenauer, A. |
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Title |
Measurement of atomic electric fields and charge densities from average momentum transfers using scanning transmission electron microscopy |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
178 |
Issue |
178 |
Pages |
62-80 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
This study sheds light on the prerequisites, possibilities, limitations and interpretation of high-resolution differential phase contrast (DPC) imaging in scanning transmission electron microscopy (STEM). We draw particular attention to the well-established DPC technique based on segmented annular detectors and its relation to recent developments based on pixelated detectors. These employ the expectation value of the momentum transfer as a reliable measure of the angular deflection of the STEM beam induced by an electric field in the specimen. The influence of scattering and propagation of electrons within the specimen is initially discussed separately and then treated in terms of a two-state channeling theory. A detailed simulation study of GaN is presented as a function of specimen thickness and bonding. It is found that bonding effects are rather detectable implicitly, e.g., by characteristics of the momentum flux in areas between the atoms than by directly mapping electric fields and charge densities. For strontium titanate, experimental charge densities are compared with simulations and discussed with respect to experimental artifacts such as scan noise. Finally, we consider practical issues such as figures of merit for spatial and momentum resolution, minimum electron dose, and the mapping of larger-scale, built-in electric fields by virtue of data averaged over a crystal unit cell. We find that the latter is possible for crystals with an inversion center. Concerning the optimal detector design, this study indicates that a sampling of 5mrad per pixel is sufficient in typical applications, corresponding to approximately 10x10 available pixels. |
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Address |
Institut fur Festkr perphysik, Universitat Bremen, Otto-Hahn-Allee 1, 28359 Bremen, 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 |
000403862900009 |
Publication Date |
2016-05-12 |
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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 |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
93 |
Open Access |
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Notes |
K.M.-C. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG) under contract MU3660/1-1. This work was further supported by the DFG under contract RO2057/4-2 and O2057/11-1. J.V. and A.B. acknowledge funding from the European Research Council (ERC) under the 7th Framework Program (FP7), and ERC Starting Grant No. 278510-VORTEX. Experimental results are obtained on the Qu-Ant-EM microscope partly funded by the Hercules fund from the Flemish government. J.V. also acknowledges funding through a GOA project “Solarpaint” of the University of Antwerp. SL and PS acknowledge financial support by the Austrian Science Fund (FWF) under grants No. I543-N20 and J3732-N27. ECASJO_; |
Approved |
Most recent IF: 2.843 |
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Call Number |
c:irua:134125UA @ admin @ c:irua:134125 |
Serial |
4098 |
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Permanent link to this record |
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Author |
Altantzis, T.; Coutino-Gonzalez, E.; Baekelant, W.; Martinez, G.T.; Abakumov, A.M.; Van Tendeloo, G.; Roeffaers, M.B.J.; Bals, S.; Hofkens, J. |
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Title |
Direct Observation of Luminescent Silver Clusters Confined in Faujasite Zeolites |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
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Volume |
10 |
Issue |
10 |
Pages |
7604-7611 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
One of the ultimate goals in the study of metal clusters is the correlation between the atomic-scale organization and their physicochemical properties. However, direct observation of the atomic organization of such minuscule metal clusters is heavily hindered by radiation damage imposed by the different characterization techniques. We present direct evidence of the structural arrangement, at an atomic level, of luminescent silver species stabilized in faujasite (FAU) zeolites using aberration-corrected scanning transmission electron microscopy. Two different silver clusters were identified in Ag-FAU zeolites, a trinuclear silver species associated with green emission and a tetranuclear silver species related to yellow emission. By combining direct imaging with complementary information obtained from X-ray powder diffraction and Rietveld analysis, we were able to elucidate the main differences at an atomic scale between luminescent (heat-treated) and nonluminescent (cation-exchanged) Ag-FAU zeolites. It is expected that such insights will trigger the directed synthesis of functional metal nanocluster-zeolite composites with tailored luminescent properties. |
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Address |
RIES, Hokkaido University , N20W10, Kita-Ward Sapporo 001-0020, Japan |
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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 |
000381959100043 |
Publication Date |
2016-07-08 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1936-0851 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.942 |
Times cited |
57 |
Open Access |
OpenAccess |
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Notes |
The authors gratefully acknowledge financial support from the Belgian Federal government (Belspo through the IAP-VI/27 and IAP-VII/05 programs), the European Union’s Seventh Framework Programme (FP7/2007-2013 under grant agreement no. 310651 SACS and no. 312483-ESTEEM2), the Flemish government in the form of long-term structural funding “Methusalem” grant METH/15/04 CASAS2, the Hercules foundation (HER/11/14), the “Strategisch Initiatief Materialen” SoPPoM program, and the Fund for Scientific Research Flanders (FWO) grants G.0349.12 and G.0B39.15. S.B. acknowledges funding from ERC Starting Grant COLOURATOMS (335078). The authors thank Prof. S. Van Aert for helpful discussions, Dr. T. De Baerdemaeker for XRD measurements, Mr. B. Dieu for the preparation of graphical material, and UOP Antwerp for the kind donation of zeolite samples.; esteem2jra4; ECASSara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); |
Approved |
Most recent IF: 13.942 |
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Call Number |
c:irua:134576 c:irua:134576 |
Serial |
4102 |
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Permanent link to this record |
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Author |
Ying, J.; Hu, Z.-Y.; Yang, X.-Y.; Wei, H.; Xiao, Y.-X.; Janiak, C.; Mu, S.-C.; Tian, G.; Pan, M.; Van Tendeloo, G.; Su, B.-L. |
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Title |
High viscosity to highly dispersed PtPd bimetallic nanocrystals for enhanced catalytic activity and stability |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Chemical communications |
Abbreviated Journal |
Chem Commun |
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Volume |
52 |
Issue |
52 |
Pages |
8219-8222 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A facile high-viscosity-solvent method is presented to synthesize PtPd bimetallic nanocrystals highly dispersed in different mesostructures (2D and 3D structures), porosities (large and small pore sizes), and compositions (silica and carbon). Further, highly catalytic activity, stability and durability of the nanometals have been proven in different catalytic reactions. |
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Address |
State Key Laboratory Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122, Luoshi Road, Wuhan, 430070, China. xyyang@whut.edu.cn |
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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 |
000378715400006 |
Publication Date |
2016-05-16 |
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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 |
1359-7345 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.319 |
Times cited |
19 |
Open Access |
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Notes |
This work was supported by NFSC (51472190 and 51503166), ISTCP (2015DFE52870), PCSIRT (IRT15R52) of China, and the Integrated Infrastructure Initiative of EU (312483-ESTEEM2).; esteem2jra4 |
Approved |
Most recent IF: 6.319 |
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Call Number |
c:irua:134660 c:irua:134660 |
Serial |
4110 |
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Permanent link to this record |
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Author |
Bercx, M.; Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. |
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Title |
First-principles analysis of the spectroscopic limited maximum efficiency of photovoltaic absorber layers for CuAu-like chalcogenides and silicon |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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Volume |
18 |
Issue |
18 |
Pages |
20542-20549 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
Chalcopyrite semiconductors are of considerable interest for application as absorber layers in thin-film photovoltaic cells. When growing films of these compounds, however, they are often found to contain CuAu-like domains, a metastable phase of chalcopyrite. It has been reported that for CuInS2, the presence of the CuAu-like phase improves the short circuit current of the chalcopyrite-based photovoltaic cell. We investigate the thermodynamic stability of both phases for a selected list of I-III-VI2 materials using a first-principles density functional theory approach. For the CuIn-VI2 compounds, the difference in formation energy between the chalcopyrite and CuAu-like phase is found to be close to 2 meV per atom, indicating a high likelihood of the presence of CuAu-like domains. Next, we calculate the spectroscopic limited maximum efficiency (SLME) of the CuAu-like phase and compare the results with those of the corresponding chalcopyrite phase. We identify several candidates with a high efficiency, such as CuAu-like CuInS2, for which we obtain an SLME of 29% at a thickness of 500 nm. We observe that the SLME can have values above the Shockley-Queisser (SQ) limit, and show that this can occur because the SQ limit assumes the absorptivity to be a step function, thus overestimating the radiative recombination in the detailed balance approach. This means that it is possible to find higher theoretical efficiencies within this framework simply by calculating the J-V characteristic with an absorption spectrum. Finally, we expand our SLME analysis to indirect band gap absorbers by studying silicon, and find that the SLME quickly overestimates the reverse saturation current of indirect band gap materials, drastically lowering their calculated efficiency. |
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Address |
EMAT & CMT groups, Department of Physics, University of Antwerp, Campus Groenenborger, Groenenborgerlaan 171, 2020 Antwerp, Belgium. marnik.bercx@uantwerpen.be |
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Corporate Author |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000381428600058 |
Publication Date |
2016-07-08 |
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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 |
1463-9076 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.123 |
Times cited |
34 |
Open Access |
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Notes |
We acknowledge financial support of FWO-Vlaanderen through projects G.0150.13N and G.0216.14N and ERA-NET RUS Plus/FWO, Grant G0D6515N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO FWOVlaanderen. |
Approved |
Most recent IF: 4.123 |
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Call Number |
c:irua:135091 |
Serial |
4112 |
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Permanent link to this record |
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Author |
Sankaran, K.J.; Hoang, D.Q.; Kunuku, S.; Korneychuk, S.; Turner, S.; Pobedinskas, P.; Drijkoningen, S.; Van Bael, M.K.; D' Haen, J.; Verbeeck, J.; Leou, K.-C.; Lin, I.-N.; Haenen, K. |
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Title |
Enhanced optoelectronic performances of vertically aligned hexagonal boron nitride nanowalls-nanocrystalline diamond heterostructures |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
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Volume |
6 |
Issue |
6 |
Pages |
29444 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Field electron emission (FEE) properties of vertically aligned hexagonal boron nitride nanowalls (hBNNWs) grown on Si have been markedly enhanced through the use of nitrogen doped nanocrystalline diamond (nNCD) films as an interlayer. The FEE properties of hBNNWs-nNCD heterostructures show a low turn-on field of 15.2 V/mum, a high FEE current density of 1.48 mA/cm(2) and life-time up to a period of 248 min. These values are far superior to those for hBNNWs grown on Si substrates without the nNCD interlayer, which have a turn-on field of 46.6 V/mum with 0.21 mA/cm(2) FEE current density and life-time of 27 min. Cross-sectional TEM investigation reveals that the utilization of the diamond interlayer circumvented the formation of amorphous boron nitride prior to the growth of hexagonal boron nitride. Moreover, incorporation of carbon in hBNNWs improves the conductivity of hBNNWs. Such a unique combination of materials results in efficient electron transport crossing nNCD-to-hBNNWs interface and inside the hBNNWs that results in enhanced field emission of electrons. The prospective application of these materials is manifested by plasma illumination measurements with lower threshold voltage (370 V) and longer life-time, authorizing the role of hBNNWs-nNCD heterostructures in the enhancement of electron emission. |
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Address |
IMOMEC, IMEC vzw, 3590 Diepenbeek, Belgium |
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Thesis |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000379391000001 |
Publication Date |
2016-07-12 |
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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 |
2045-2322 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.259 |
Times cited |
15 |
Open Access |
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Notes |
The authors like to thank the financial support of the Research Foundation Flanders (FWO) via Research Project G.0456.12, G0044.13N and the Methusalem “NANO” network. Kamatchi Jothiramalingam Sankaran, Stuart Turner, and Paulius Pobedinskas are Postdoctoral Fellows of the Research Foundations Flanders (FWO). |
Approved |
Most recent IF: 4.259 |
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Call Number |
c:irua:134643 c:irua:134643UA @ admin @ c:irua:134643 |
Serial |
4119 |
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Permanent link to this record |
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Author |
Turner, S.; Idrissi, H.; Sartori, A.F.; Korneychuck, S.; Lu, Y.-G.; Verbeeck, J.; Schreck, M.; Van Tendeloo, G. |
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Title |
Direct imaging of boron segregation at dislocations in B:diamond heteroepitaxial films |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
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Volume |
8 |
Issue |
8 |
Pages |
2212-2218 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
A thin film of heavily B-doped diamond has been grown epitaxially by microwave plasma chemical vapor deposition on an undoped diamond layer, on top of a Ir/YSZ/Si(001) substrate stack, to study the boron segregation and boron environment at the dislocations present in the film. The density and nature of the dislocations were investigated by conventional and weak-beam dark-field transmission electron microscopy techniques, revealing the presence of two types of dislocations: edge and mixed-type 45 degrees dislocations. The presence and distribution of B in the sample was studied using annular dark-field scanning transmission electron microscopy and spatially resolved electron energy-loss spectroscopy. Using these techniques, a segregation of B at the dislocations in the film is evidenced, which is shown to be intermittent along the dislocation. A single edge-type dislocation was selected to study the distribution of the boron surrounding the dislocation core. By imaging this defect at atomic resolution, the boron is revealed to segregate towards the tensile strain field surrounding the edge-type dislocations. An investigation of the fine structure of the B-K edge at the dislocation core shows that the boron is partially substitutionally incorporated into the diamond lattice and partially present in a lower coordination (sp(2)-like hybridization). |
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Address |
EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium. stuart.turner@uantwerpen.be |
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Corporate Author |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000368860900053 |
Publication Date |
2015-12-21 |
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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 |
2040-3364 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.367 |
Times cited |
15 |
Open Access |
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Notes |
S. T. acknowledges the fund for scien tific research Flanders (FWO) for a post-doctoral scholarship and under contract number G.0044.13N |
Approved |
Most recent IF: 7.367 |
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Call Number |
c:irua:131597UA @ admin @ c:irua:131597 |
Serial |
4121 |
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Permanent link to this record |
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Author |
Babynina, A.; Fedoruk, M.; Kuhler, P.; Meledin, A.; Doblinger, M.; Lohmueller, T. |
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Title |
Bending Gold Nanorods with Light |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
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Volume |
16 |
Issue |
16 |
Pages |
6485-6490 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
V-shaped gold nanoantennas are the functional components of plasmonic metasurfaces, which are capable of manipulating light in unprecedented ways. Designing a metasurface requires the custom arrangement of individual antennas with controlled shape and orientation. Here, we show how highly crystalline gold nanorods in solution can be bend, one-by one, into a V-shaped geometry and printed to the surface of a solid support through a combination of plasmonic heating and optical force. Significantly, we demonstrate that both the bending angle and the orientation of each rod-antenna can be adjusted independent from each other by tuning the laser intensity and polarization. This approach is applicable for the patterning of V-shaped plasmonic antennas on almost any substrate, which holds great potential for the fabrication of ultrathin optical components and devices. |
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Place of Publication |
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Language |
English |
Wos |
000385469800072 |
Publication Date |
2016-09-06 |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1530-6984 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.712 |
Times cited |
24 |
Open Access |
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Notes |
PMID:27598653 We would also like to thank Prof. Jochen Feldmann and Bernhard Bohn for fruitful discussions. |
Approved |
Most recent IF: 12.712 |
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Call Number |
c:irua:135172 |
Serial |
4122 |
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Permanent link to this record |
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Author |
Spadaro, M.C.; Luches, P.; Bertoni, G.; Grillo, V.; Turner, S.; Van Tendeloo, G.; Valeri, S.; D'Addato, S. |
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Title |
Influence of defect distribution on the reducibility of CeO2-x nanoparticles |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
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Volume |
27 |
Issue |
27 |
Pages |
425705 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Ceria nanoparticles (NPs) are fundamental in heterogeneous catalysis because of their ability to store or release oxygen depending on the ambient conditions. Their oxygen storage capacity is strictly related to the exposed planes, crystallinity, density and distribution of defects. In this work a study of ceria NPs produced with a ligand-free, physical synthesis method is presented. The NP films were grown by a magnetron sputtering based gas aggregation source and studied by high resolution- and scanning-transmission electron microscopy and x-ray photoelectron spectroscopy. In particular, the influence of the oxidation procedure on the NP reducibility has been investigated. The different reducibility has been correlated to the exposed planes, crystallinity and density and distribution of structural defects. The results obtained in this work represent a basis to obtain cerium oxide NP with desired oxygen transport properties. |
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Address |
Dipartimento FIM, Universita di Modena e Reggio Emilia, via G. Campi 213/a, I-41125 Modena, Italy. CNR-NANO, via G. Campi 213/a, I-41125 Modena, Italy |
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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 |
000385483900004 |
Publication Date |
2016-09-15 |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0957-4484 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.44 |
Times cited |
11 |
Open Access |
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Notes |
The authors gratefully acknowledge financial support by the Italian MIUR under grant FIRB RBAP115AYN (Oxides at the nanoscale: multifunctionality and applications). The activity is performed within the COST Action CM1104 'Reducible oxide chemistry, structure and functions'. The research leading to these results has received funding also from the European Union Seventh Framework Programme under Grant Agreement 312483—ESTEEM2 (Integrated Infrastructure Initiative–I3).; esteem2_ta |
Approved |
Most recent IF: 3.44 |
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Call Number |
EMAT @ emat @ c:irua:135424 |
Serial |
4130 |
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Permanent link to this record |