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Author |
van der Stam, W.; Gradmann, S.; Altantzis, T.; Ke, X.; Baldus, M.; Bals, S.; de Mello Donega, C. |
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Title |
Shape Control of Colloidal Cu2-x S Polyhedral Nanocrystals by Tuning the Nucleation Rates |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
28 |
Issue |
28 |
Pages |
6705-6715 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Synthesis protocols for colloidal nanocrystals (NCs) with narrow size and shape distributions are of particular interest for the successful implementation of these nanocrystals into devices. Moreover, the preparation of NCs with well-defined crystal phases is of key importance. In this work, we show that Sn(IV)-thiolate complexes formed in situ strongly influence the nucleation and growth rates of colloidal Cu2-x S polyhedral NCs, thereby dictating their final size, shape, and crystal structure. This allowed us to successfully synthesize hexagonal bifrustums and hexagonal bipyramid NCs with low-chalcocite crystal structure, and hexagonal nanoplatelets with various thicknesses and aspect ratios with the djurleite crystal structure, by solely varying the concentration of Sn(IV)-additives (namely, SnBr4) in the reaction medium. Solution and solid-state 119Sn NMR measurements show that SnBr4 is converted in situ to Sn(IV)-thiolate complexes, which increase the Cu2-x S nucleation barrier without affecting the precursor conversion rates. This influences both the nucleation and growth rates in a concentration-dependent fashion and leads to a better separation between nucleation and growth. Our approach of tuning the nucleation and growth rates with in situ-generated Sn-thiolate complexes might have a more general impact due to the availability of various metal-thiolate complexes, possibly resulting in polyhedral NCs of a wide variety of metal-sulfide compositions. |
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Address |
Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University , P.O. Box 80000, 3508 TA Utrecht, The Netherlands |
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English |
Wos |
000384399000037 |
Publication Date |
2016-09-02 |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
0897-4756 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
27 |
Open Access |
OpenAccess |
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Notes |
W.v.d.S. and C.d.M.D. acknowledge financial support from the division of Chemical Sciences (CW) of The Netherlands Organization for Scientific Research (NWO) under grant number ECHO.712.012.001. M.B. also gratefully acknowledges NWO for funding the NMR infrastructure (Middle Groot program, grant number 700.58.102). S.B. acknowledges financial support from the European Research Council (ERC Starting Grant # 335078-COLOURATOMS).; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); |
Approved |
Most recent IF: 9.466 |
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Call Number |
EMAT @ emat @ c:irua:135928 |
Serial |
4285 |
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Permanent link to this record |
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Author |
Wang, W.; Berthelot, A.; Kolev, S.; Tu, X.; Bogaerts, A. |
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Title |
CO2 conversion in a gliding arc plasma: 1D cylindrical discharge model |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
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Volume |
25 |
Issue |
25 |
Pages |
065012 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
CO 2 conversion by a gliding arc plasma is gaining increasing interest, but the underlying mechanisms for an energy-efficient process are still far from understood. Indeed, the chemical complexity of the non-equilibrium plasma poses a challenge for plasma modeling due to the huge computational load. In this paper, a one-dimensional (1D) gliding arc model is developed in a cylindrical frame, with a detailed non-equilibrium CO 2 plasma chemistry set, including the CO 2 vibrational kinetics up to the dissociation limit. The model solves a set of time- dependent continuity equations based on the chemical reactions, as well as the electron energy balance equation, and it assumes quasi-neutrality in the plasma. The loss of plasma species and heat due to convection by the transverse gas flow is accounted for by using a characteristic frequency of convective cooling, which depends on the gliding arc radius, the relative velocity of the gas flow with respect to the arc and on the arc elongation rate. The calculated values for plasma density and plasma temperature within this work are comparable with experimental data on gliding arc plasma reactors in the literature. Our calculation results indicate that excitation to the vibrational levels promotes efficient dissociation in the gliding arc, and this is consistent with experimental investigations of the gliding arc based CO 2 conversion in the literature. Additionally, the dissociation of CO 2 through collisions with O atoms has the largest contribution to CO 2 splitting under the conditions studied. In addition to the above results, we also demonstrate that lumping the CO 2 vibrational states can bring a significant reduction of the computational load. The latter opens up the way for 2D or 3D models with an accurate description of the CO 2 vibrational kinetics. |
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Wos |
000386605100002 |
Publication Date |
2016-10-18 |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
1361-6595 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.302 |
Times cited |
3 |
Open Access |
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Notes |
This research was supported by the European Marie Skłodowska-Curie Individual Fellowship ‘GlidArc’ within Horizon2020 (Grant No. 657304) and by the FWO project (grant G.0383.16N). The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. |
Approved |
Most recent IF: 3.302 |
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Call Number |
PLASMANT @ plasmant @ c:irua:135990 |
Serial |
4286 |
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Permanent link to this record |
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Author |
Perez, A.J.; Batuk, D.; Saubanère, M.; Rousse, G.; Foix, D.; Mc Calla, E.; J. Berg, E.; Dugas, R.; van den Bos, K. H. W.; Doublet, M.-L.; Gonbeau, D.; Abakumov, A.M.; Van Tendeloo, G.; Tarascon, J.-M. |
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Title |
Strong oxygen participation in the redox governing the structural and electrochemical properties of Na-rich layered oxide Na2IrO3 |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
28 |
Issue |
28 |
Pages |
8278-8288 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The recent revival of the Na-ion battery concept has prompted intense activities in the search for new Na-based layered oxide positive electrodes. The largest capacity to date was obtained for a Na-deficient layered oxide that relies on cationic redox processes only. To go beyond this limit, we decided to chemically manipulate these Na-based layered compounds in a way to trigger the participation of the anionic network. We herein report the electrochemical properties of a Na-rich phase Na2IrO3, which can reversibly cycle 1.5 Na+ per formula unit while not suffering from oxygen release nor cationic migrations. Such large capacities, as deduced by complementary XPS, X-ray/neutron diffraction and transmission electron microscopy measurements, arise from cumulative cationic and anionic redox processes occurring simultaneously at potentials as low as 3.0 V. The inability to remove more than 1.5 Na+ is rooted in the formation of an O1-type phase having highly stabilized Na sites as confirmed by DFT calculations, which could rationalize as well the competing metal/oxygen redox processes in Na2IrO3. This work will help to define the most fertile directions in the search for novel high energy Na-rich materials based on more sustainable elements than Ir. |
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Wos |
000388914500021 |
Publication Date |
2016-10-17 |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
0897-4756 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
45 |
Open Access |
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Notes |
The authors thank Montse Casas-Cabanas and Marine Reynaud for discussions about the FAULTS program, Sandra Van Aert for her great help in guiding us towards the use of the statistical parameter estimation method for establishing the O-O histogram, and Thomas Hansen and Vladimir Pomjakushin for their precious help in neutron diffraction experiments. This work is based on experiments performed at the Swiss spallation neutron source SINQ, Paul Scherrer Institute, Villigen, Switzerland, and at Institut Laue Langevin, Grenoble, France. Use of the 11-BM mail service of the APS at Argonne National Laboratory was supported by the U.S. department of Energy under contract No. DE-AC02-06CH11357 and is greatly acknowledged. |
Approved |
Most recent IF: 9.466 |
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Call Number |
EMAT @ emat @ c:irua:135994 |
Serial |
4287 |
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Permanent link to this record |
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Author |
van den Bos, K.H.W.; Krause, F.F.; Béché, A.; Verbeeck, J.; Rosenauer, A.; Van Aert, S. |
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Title |
Locating light and heavy atomic column positions with picometer precision using ISTEM |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
172 |
Issue |
172 |
Pages |
75-81 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Recently, imaging scanning transmission electron microscopy (ISTEM) has been proposed as a promising new technique combining the advantages of conventional TEM (CTEM) and STEM [1]. The ability to visualize light and heavy elements together makes it a particularly interesting new, spatially incoherent imaging mode. Here, we evaluate this technique in term of precision with which atomic column locations can be measured. By using statistical parameter estimation theory, we will show that these locations can be accurately measured with a precision in the picometer range. Furthermore, a quantitative comparison is made with HAADF STEM imaging to investigate the advantages of ISTEM. |
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Wos |
000390600200009 |
Publication Date |
2016-10-09 |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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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 |
8 |
Open Access |
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Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0368.15N, G.0369.15N), and by a Ph.D. grant to K.H.W. van den Bos. The research leading to these results has received funding from the Deutsche Forschungsgemeinschaft under Contract No. RO 2057/4-2 and the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2. We thank Prof. G. Koster from the University of Twente for kindly providing us with the PbTiO3 test sample. |
Approved |
Most recent IF: 2.843 |
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Call Number |
EMAT @ emat @ c:irua:136109UA @ admin @ c:irua:136109 |
Serial |
4288 |
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Permanent link to this record |
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Author |
Geuchies, J.J.; van Overbeek, C.; Evers, W.H.; Goris, B.; de Backer, A.; Gantapara, A.P.; Rabouw, F.T.; Hilhorst, J.; Peters, J.L.; Konovalov, O.; Petukhov, A.V.; Dijkstra, M.; Siebbeles, L.D.A.; van Aert, S.; Bals, S.; Vanmaekelbergh, D. |
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Title |
In situ study of the formation mechanism of two-dimensional superlattices from PbSe nanocrystals |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
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Volume |
15 |
Issue |
15 |
Pages |
1248-1254 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Oriented attachment of PbSe nanocubes can result in the formation of two-dimensional (2D) superstructures with long-range nanoscale and atomic order. This questions the applicability of classic models in which the superlattice grows by first forming a nucleus, followed by sequential irreversible attachment of nanocrystals, as one misaligned attachment would disrupt the 2D order beyond repair. Here, we demonstrate the formation mechanism of 2D PbSe superstructures with square geometry by using in situ grazing-incidence X-ray scattering (small angle and wide angle), ex situ electron microscopy, and Monte Carlo simulations. We observed nanocrystal adsorption at the liquid/gas interface, followed by the formation of a hexagonal nanocrystal monolayer. The hexagonal geometry transforms gradually through a pseudo-hexagonal phase into a phase with square order, driven by attractive interactions between the {100} planes perpendicular to the liquid substrate, which maximize facet-to-facet overlap. The nanocrystals then attach atomically via a necking process, resulting in 2D square superlattices. |
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Address |
Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3584 CC Utrecht, The Netherlands |
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English |
Wos |
000389104400011 |
Publication Date |
2016-09-05 |
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Abbreviated Series Title |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
1476-1122 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
39.737 |
Times cited |
182 |
Open Access |
OpenAccess |
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Notes |
This research is part of the programme ‘Designing Dirac Carriers in semiconductor honeycomb superlattices (DDC13),’ which is supported by the Foundation for Fundamental Research on Matter (FOM), which is part of the Dutch Research Council (NWO). J.J.G. acknowledges funding from the Debye and ESRF Graduate Programs. The authors gratefully acknowledge funding from the Research Foundation Flanders (G.036915 G.037413 and funding of postdoctoral grants to B.G. and A.d.B). S.B. acknowledges the European Research Council, ERC grant No 335078—Colouratom. The authors gratefully acknowledge I. Swart and M. van Huis for fruitful discussions. We acknowledge funding from NWO-CW TOPPUNT ‘Superficial Superstructures’. The X-ray scattering measurements were performed at the ID10 beamline at ESRF under proposal numbers SC-4125 and SC-3786. The authors thank G. L. Destri and F. Zontone for their support during the experiments.; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 39.737 |
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Call Number |
EMAT @ emat @ c:irua:136165 |
Serial |
4289 |
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Permanent link to this record |
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Author |
Aghaei, M.; Lindner, H.; Bogaerts, A. |
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Title |
Ion Clouds in the Inductively Coupled Plasma Torch: A Closer Look through Computations |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
88 |
Issue |
88 |
Pages |
8005-8018 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
We have computationally investigated the introduction of copper elemental particles in an inductively coupled plasma torch connected to a sampling cone, including for the first time the ionization of the sample. The sample is inserted as liquid particles, which are followed inside the entire torch, i.e., from the injector inlet up to the ionization and reaching the sampler. The spatial position of the ion clouds inside the torch as well as detailed information on the copper species fluxes at the position of the sampler orifice and the exhausts of the torch are provided. The effect of on- and off-axis injection is studied. We clearly show that the ion clouds of on-axis injected material are located closer to the sampler with less radial diffusion. This guarantees a higher transport efficiency through the sampler cone. Moreover, our model reveals the optimum ranges of applied power and flow rates, which ensure the proper position of ion clouds inside the torch, i.e., close enough to the sampler to increase the fraction that can enter the mass spectrometer and with minimum loss of material toward the exhausts as well as a sufficiently high plasma temperature for efficient ionization. |
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Address |
Research Group PLASMANT, Chemistry Department, University of Antwerp , Universiteitsplein 1, 2610 Antwerp, Belgium |
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English |
Wos |
000381654800020 |
Publication Date |
2016-07-26 |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
0003-2700 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
9 |
Open Access |
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Notes |
The authors gratefully acknowledge financial support from the Fonds voor Wetenschappelijk Onderzoek (FWO), Grant Number 6713. The computational work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI), and the UA. |
Approved |
Most recent IF: 6.32 |
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Call Number |
PLASMANT @ plasmant @ c:irua:135644 |
Serial |
4293 |
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Permanent link to this record |
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Author |
Huygh, S.; Bogaerts, A.; Neyts, E.C. |
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Title |
How Oxygen Vacancies Activate CO2 Dissociation on TiO2 Anatase (001) |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
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Volume |
120 |
Issue |
120 |
Pages |
21659-21669 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
The adsorption, dissociation, and diffusion of CO2 on the anatase (001) surface was studied using DFT by means of the generalized gradient approximation using the Perdew−Burcke−Ernzerhof (PBE)-functional and applying corrections for long-range dispersion interactions. Different stable adsorption configurations were identified for the fully oxidized surface. The most stable adsorption configuration is the monodentated carbonate-like structure. Small energy barriers were identified for the conversion of a physisorbed to a chemisorbed configuration.
CO2 dissociation is found to be unfeasible on the stoichiometric surface. The introduction of oxygen vacancy defects gives rise to new highly stable adsorption configurations with a stronger activation of the C−O bonds. This leads to the possibility of exothermic dissociation of CO2 with barriers up to 22.2 kcal/mol,
corresponding to chemical lifetimes of less than 4 s at 300 K. These reactions cause a CO molecule to be formed, which will easily desorb, and the reduced surface to become oxidized. It is clear that oxygen vacancy defects play a key role in the catalytic activity of an anatase (001) surface. Oxygen vacancies play an important role in the dissociation of CO2 on the anatase (001) surface, and will play a significant role in complex problems, such as the catalytic conversion of CO2 to value-added chemicals. |
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Wos |
000384626800055 |
Publication Date |
2016-09-02 |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
1932-7447 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.536 |
Times cited |
49 |
Open Access |
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Notes |
Stijn Huygh is funded as an aspirant of the Research Foundation Flanders (FWO, project number 11C0115N). This work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI), and the UAntwerpen. |
Approved |
Most recent IF: 4.536 |
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Call Number |
PLASMANT @ plasmant @ c:irua:136164 |
Serial |
4291 |
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Permanent link to this record |
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Author |
Liu, Y.; Claes, N.; Trepka, B.; Bals, S.; Lang, P.R. |
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Title |
A combined 3D and 2D light scattering study on aqueous colloidal model systems with tunable interactions |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Soft matter |
Abbreviated Journal |
Soft Matter |
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Volume |
12 |
Issue |
12 |
Pages |
8485-8494 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In this article we report on the synthesis and characterization of a system of colloidal spheres suspended in an aqueous solvent which can be refractive index-matched, thus allowing for investigations of the particle near-wall dynamics by evanescent wave dynamic light scattering at concentrations up to the isotropic to ordered transition and beyond. The particles are synthesized by copolymerization of a fluorinated acrylic ester monomer with a polyethylene-glycol (PEG) oligomer by surfactant free emulsion polymerization. Static and dynamic light scattering experiments in combination with cryo transmission electron microscopy reveal that the particles have a core shell structure with a significant enrichment of the PEG chains on the particles surface. In index-matching DMSO/water suspensions the particles arrange in an ordered phase at volume fraction above 7%, if no additional electrolyte is present. The near-wall dynamics at low volume fraction are quantitatively described by the combination of electrostatic repulsion and hydrodynamic interaction between the particles and the wall. At volume fractions close to the isotropic to ordered transition, the near-wall dynamics are more complex and qualitatively reminiscent of the behaviour which was observed in hard sphere suspensions at high concentrations. |
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Address |
Forschugszentrum Julich, Institute of Complex Systems ICS-3, Julich, Germany. p.lang@fz-juelich.de and Heinrich-Heine Universitat, Dusseldorf, Germany |
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Language |
English |
Wos |
000386247100004 |
Publication Date |
2016-08-22 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
1744-683X |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.889 |
Times cited |
2 |
Open Access |
OpenAccess |
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Notes |
The authors thank Prof. J. K. G. Dhont and the ICS-3 group for useful discussions and support. YL would like to thank the Marie Sklodowska Curie Initial Training Network SOMATAI under the EU Grant Agreement No. 316866 for financial support. BT contributed to this work during an internship at Forschungszentrum Ju¨lich supported by the International Helmholtz Research School of Biophysics and Soft Matter (IHRS BioSoft), which is gratefully acknowledged. SB and NC acknowledge financial support from the European Research Council (ERC Starting Grant No. 335078-COLOURATOMS).; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 3.889 |
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Call Number |
EMAT @ emat @ c:irua:136166 |
Serial |
4292 |
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Permanent link to this record |
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Author |
Schouteden, K.; Govaerts, K.; Debehets, J.; Thupakula, U.; Chen, T.; Li, Z.; Netsou, A.; Song, F.; Lamoen, D.; Van Haesendonck, C.; Partoens, B.; Park, K. |
![goto web page url](http://nano.uantwerpen.be/nanorefs/img/www.gif)
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Title |
Annealing-Induced Bi Bilayer on Bi2Te3 Investigated via Quasi-Particle-Interference Mapping |
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 |
8778-8787 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
Topological insulators (TIs) are renowned for their exotic topological surface states (TSSs) that reside in the top atomic layers, and hence, detailed knowledge of the surface top atomic layers is of utmost importance. Here we present the remarkable morphology changes of Bi2Te3 surfaces, which have been freshly cleaved in air, upon subsequent systematic annealing in ultrahigh vacuum and the resulting effects on the local and area-averaging electronic properties of the surface states, which are investigated by combining scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), and Auger electron spectroscopy (AES) experiments with density functional theory (DFT) calculations. Our findings demonstrate that the annealing induces the formation of a Bi bilayer atop the Bi2Te3 surface. The adlayer results in n-type doping, and the atomic defects act as scattering centers of the TSS electrons. We also investigated the annealing-induced Bi bilayer surface on Bi2Te3 via voltage-dependent quasi-particle-interference (QPI) mapping of the surface local density of states and via comparison with the calculated constant-energy contours and QPI patterns. We observed closed hexagonal patterns in the Fourier transform of real-space QPI maps with secondary outer spikes. DFT calculations attribute these complex QPI patterns to the appearance of a “second” cone due to the surface charge transfer between the Bi bilayer and the Bi2Te3. Annealing in ultrahigh vacuum offers a facile route for tuning of the topological properties and may yield similar results for other topological materials. |
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Address |
Department of Physics, Virginia Tech , Blacksburg, Virginia 24061, United States |
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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 |
000384399300073 |
Publication Date |
2016-09-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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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 |
15 |
Open Access |
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Notes |
The research in Leuven and Antwerp was supported by the Research FoundationFlanders (FWO, Belgium). The research in Leuven received additional support from the Flemish Concerted Research Action Program (BOF KULeuven, Project GOA/14/007) and the KULeuven Project GOA “Fundamental Challenges in Semiconductor Research”. Z.L. acknowledges the support from the China Scholarship Council (2011624021) and from KU Leuven Internal Funds (PDM). K.S. and J.D. acknowledge additional support from the FWO. T.C. and F.S. acknowledge the financial support of the National Key Projects for Basic Research of China (Grants 2013CB922103 and 2011CB922103), the National NaturalScience Foundation of China (Grant s 91421109, 11134005,11522432, and 11274003), the Natural Science Foundation ofJiangsu Province (Grant BK20130054), and the FundamentalResearch Funds for the Central Universities. K.P. wassupported by the U.S. National Science Foundation (DMR-1206354) and San Diego Supercomputer Center (SDSC)Comet and Gordon (DMR060009N). |
Approved |
Most recent IF: 13.942 |
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Call Number |
EMAT @ emat @ c:irua:136269 |
Serial |
4294 |
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Permanent link to this record |
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Author |
Meledin, A.; Turner, S.; Cayado, P.; Mundet, B.; Solano, E.; Ricart, S.; Ros, J.; Puig, T.; Obradors, X.; Van Tendeloo, G. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Unique nanostructural features in Fe, Mn-doped YBCO thin films |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
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|
Volume |
29 |
Issue |
29 |
Pages |
125009 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
An attempt to grow a thin epitaxial composite film of YBa2Cu3O7−δ (YBCO) with spinel MnFe2O4 (MFO) nanoparticles on a LAO substrate using the CSD approach resulted in a decomposition of the spinel and various doping modes of YBCO with the Fe and Mn cations. These nanostructural effects lead to a lowering of T c and a slight J c increase in field. Using a combination of advanced transmission electron microscopy (TEM) techniques such as atomic resolution high-angle annular dark field scanning TEM, energy dispersive x-ray spectroscopy and electron energy-loss spectroscopy we have been able to decipher and characterize the effects of the Fe and Mn doping on the film architecture. The YBaCuFeO5 anion-deficient double perovskite phase was detected in the form of 3D inclusions as well as epitaxially grown lamellas within the YBCO matrix. These nano-inclusions play a positive role as pinning centers responsible for the J c/J sf (H) dependency smoothening at high magnetic fields in the YBCO-MFO films with respect to the pristine YBCO films. |
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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 |
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Wos |
000387680100001 |
Publication Date |
2016-10-31 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
0953-2048 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.878 |
Times cited |
6 |
Open Access |
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Notes |
The authors gratefully acknowledge Prof. Dr. A. Abakumov and Dr. J. Gazquez for discussions and corrections. Part of this work was performed within the framework of the EUROTAPES project (FP7-NMP.2011.2.2-1 Grant no. 280432), funded by the European Union. ICMAB research was financed by the Ministry of Economy and Competitiveness, and FEDER funds under the projects MAT2011-28874-C02-01, MAT2014-51778-C2-1-R, ENE2014-56109-C3-3-R and Consolider Nanoselect CSD2007-00041, and by Generalitat de Catalunya (2009 SGR 770, 2015 SGR 753 and Xarmae). ICMAB acknowledges support from Severo Ochoa Program (MINECO, Grant SEV-2015-0496). |
Approved |
Most recent IF: 2.878 |
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|
Call Number |
EMAT @ emat @ c:irua:136444 |
Serial |
4295 |
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Permanent link to this record |
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Author |
Kolchina, L. M.; Lyskov, N.V.; Kuznetsov, A.N.; Kazakov, S.M.; Galin, M.Z.; Meledin, A.; Abakumov, A.M.; Bredikhin, S.I.; Mazo, G.N.; Antipov, E.V. |
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Title |
Evaluation of Ce-doped Pr2CuO4for potential application as a cathode material for solid oxide fuel cells |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
RSC advances |
Abbreviated Journal |
Rsc Adv |
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Volume |
6 |
Issue |
6 |
Pages |
101029-101037 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Pr2−xCexCuO4 (x = 0.05; 0.1; 0.15) samples were synthesized and systematically characterized towards application as a cathode material for solid oxide fuel cells (SOFCs). High-temperature electrical conductivity, thermal expansion, and electrocatalytic activity in the oxygen reduction reaction (ORR) were examined. The electrical conductivity of Pr2−xCexCuO4 oxides demonstrates semiconducting behavior up to 900 °C. Small Ce-doping (2.5 at%) allows an increase in electrical conductivity from 100 to 130 S cm−1 in air at 500–800 °C. DFT calculations revealed that the density of states directly below the Fermi level, comprised mainly of Cu 3d and O 2p states, is significantly affected by atoms in rare earth positions, which might give an indication of a correlation between calculated electronic structures and measured conducting properties. Ce-doping in Pr2−xCexCuO4 slightly increases TEC from 11.9 × 10−6 K−1 for x = 0 to 14.2 × 10−6 K−1 for x = 0.15. Substitution of 2.5% of Pr atoms in Pr2CuO4 by Ce is effective to enhance the electrochemical performance of the material as a SOFC cathode in the ORR (ASR of Pr1.95Ce0.05CuO4 electrode applied on Ce0.9Gd0.1O1.95 electrolyte is 0.39 Ω cm2 at 750 °C in air). The peak power density achieved for the electrolyte-supported fuel cell with the Pr1.95Ce0.05CuO4 cathode is 150 mW cm−2 at 800 °C |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000387427700044 |
Publication Date |
2016-10-19 |
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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 ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
2046-2069 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.108 |
Times cited |
7 |
Open Access |
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|
Notes |
his work was partially supported by Russian Foundation for Basic Research (grant no. 153820247), Skolkovo Institute of Science and Technology (Center of electrochemical energy), and MSUdevelopment Program up to 2020. K.L.M. is grateful to Haldor Topsøe A/S for the financial support. |
Approved |
Most recent IF: 3.108 |
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Call Number |
EMAT @ emat @ c:irua:136441 |
Serial |
4296 |
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Permanent link to this record |
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Author |
Evans, J.E.; Friedrich, H.; |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Advanced tomography techniques for inorganic, organic, and biological materials |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
MRS bulletin |
Abbreviated Journal |
Mrs Bull |
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Volume |
41 |
Issue |
41 |
Pages |
516-521 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Three-dimensional (3D) tomography using electrons and x-rays has pushed and expanded our understanding of the micro-and nanoscale spatial organization of inorganic, organic, and biological materials. While a significant impact on the field of materials science has already been realized from tomography applications, new advanced methods are quickly expanding the versatility of this approach to better link structure, composition, and function of complex 3D assemblies across multiple scales. In this article, we highlight several frontiers where new developments in tomography are empowering new science across biology, chemistry, and physics. The five articles that appear in this issue of MRS Bulletin describe some of these latest developments in detail, including analytical electron tomography, atomic resolution electron tomography, advanced recording schemes in scanning transmission electron microscopy (STEM) tomography, cryo-STEM tomography of whole cells, and multiscale correlative tomography. |
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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 |
Pittsburgh, Pa |
Editor |
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Language |
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Wos |
000382508100011 |
Publication Date |
2016-07-07 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
0883-7694 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.199 |
Times cited |
12 |
Open Access |
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Notes |
J.E.E. acknowledges support from the Department of Energy's Office of Biological and Environmental Research Mesoscale to Molecules Project #66382. |
Approved |
Most recent IF: 5.199 |
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Call Number |
UA @ lucian @ c:irua:135689 |
Serial |
4297 |
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Permanent link to this record |
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Author |
Bals, S.; Goris, B.; de Backer, A.; Van Aert, S.; Van Tendeloo, G. |
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Title |
Atomic resolution electron tomography |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
MRS bulletin |
Abbreviated Journal |
Mrs Bull |
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Volume |
41 |
Issue |
41 |
Pages |
525-530 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Over the last two decades, three-dimensional (3D) imaging by transmission electron microscopy or “electron tomography” has evolved into a powerful tool to investigate a variety of nanomaterials in different fields, such as life sciences, chemistry, solid-state physics, and materials science. Most of these results were obtained with nanometer-scale resolution, but different approaches have recently pushed the resolution to the atomic level. Such information is a prerequisite to understand the specific relationship between the atomic structure and the physicochemical properties of (nano) materials. We provide an overview of the latest progress in the field of atomic-resolution electron tomography. Different imaging and reconstruction approaches are presented, and state-of-the-art results are discussed. This article demonstrates the power and importance of electron tomography with atomic-scale resolution. |
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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 |
Pittsburgh, Pa |
Editor |
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Language |
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Wos |
000382508100012 |
Publication Date |
2016-07-07 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
0883-7694 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.199 |
Times cited |
19 |
Open Access |
OpenAccess |
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Notes |
; The authors gratefully acknowledge funding from the Research Foundation Flanders (G.0381.16N, G.036915, G.0374.13, and funding of postdoctoral grants to B.G. and A.D.B.). S.B. acknowledges the European Research Council, ERC Grant Number 335078-Colouratom. The research leading to these results received funding from the European Union Seventh Framework Program under Grant Agreements 312483 (ESTEEM2). The authors would like to thank the colleagues who have contributed to this work, including K.J. Batenburg, J. De Beenhouwer, R. Erni, M.D. Rossell, W. Van den Broek, L. Liz-Marzan, E. Carbo-Argibay, S. Gomez-Grana, P. Lievens, M. Van Bael, B. Partoens, B. Schoeters, and J. Sijbers. ; ecas_sara |
Approved |
Most recent IF: 5.199 |
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Call Number |
UA @ lucian @ c:irua:135690 |
Serial |
4299 |
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Permanent link to this record |
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Author |
Callewaert, V.; Saniz, R.; Barbiellini, B.; Partoens, B. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Surface states and positron annihilation spectroscopy: results and prospects from a first-principles approach |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
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Volume |
791 |
Issue |
791 |
Pages |
012036 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The trapping of positrons at the surface of a material can be exploited to study quite selectively the surface properties of the latter by means of positron annihilation spectroscopy techniques. To support these, it is desirable to be able to theoretically predict the existence of such positronic surface states and to describe their annihilation characteristics with core or valence surface electrons in a reliable way. Here, we build on the well-developed first-principles techniques for the study of positrons in bulk solids as well as on previous models for surfaces, and investigate two schemes that can improve the theoretical description of the interaction of positrons with surfaces. One is based on supplementing the local-density correlation potential with the corrugated image potential at the surface, and the other is based on the weighted-density approximation to correlation. We discuss our results for topological insulators, graphene layers, and quantum dots, with emphasis on the information that can be directly related to experiment. We also discuss some open theoretical problems that should be addressed by future research. |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000400610500036 |
Publication Date |
2017-02-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
1742-6588 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
|
Times cited |
1 |
Open Access |
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Notes |
We acknowledge financial support from FWO-Vlaanderen (projects G.0150.13 and G.0224.14N). This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), funded by the Hercules foundation and the Flemish Government (EWI Department). The work at Northeastern University was supported by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences grant number DE-FG02-07ER46352 (core research), and benefited from Northeastern University’s Advanced Scientific Computation Center (ASCC), the NERSC supercomputing center through DOE grant number DE-AC02- 05CH11231, and support (applications to layered materials) from the DOE EFRC: Center for the Computational Design of Functional Layered Materials (CCDM) under DE-SC0012575. |
Approved |
Most recent IF: NA |
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Call Number |
CMT @ cmt @ c:irua:140847 |
Serial |
4425 |
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Permanent link to this record |
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Author |
Berdiyorov, G.R.; Bahlouli, H.; Peeters, F.M. |
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Title |
Effect of substitutional impurities on the electronic transport properties of graphene |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Physica. E: Low-dimensional systems and nanostructures |
Abbreviated Journal |
Physica E |
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Volume |
84 |
Issue |
84 |
Pages |
22-26 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Density-functional theory in combination with the nonequilibrium Green's function formalism is used to study the effect of substitutional doping on the electronic transport properties of hydrogen passivated zig-zag graphene nanoribbon devices. B, N and Si atoms are used to substitute carbon atoms located at the center or at the edge of the sample. We found that Si -doping results in better electronic transport as compared to the other substitutions. The transmission spectrum also depends on the location of the substitutional dopants: for single atom doping the largest transmission is obtained for edge substitutions, whereas substitutions in the middle of the sample give larger transmission for double carbon substitutions. The obtained results are explained in terms of electron localization in the system due to the presence of impurities. (C) 2016 Elsevier B.V. All rights reserved. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
North-Holland |
Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000382489600004 |
Publication Date |
2016-05-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
1386-9477 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.221 |
Times cited |
17 |
Open Access |
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Notes |
; H.B. and F.M.P. acknowledge the support from King Fahd University of Petroleum and Minerals, Saudi Arabia, under research group project RG1329-1 and RG1329-2. G.R.B. acknowledges fruitful discussions with Dr. M.E. Madjet from Qatar Environment and Energy Research Institute. ; |
Approved |
Most recent IF: 2.221 |
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Call Number |
UA @ lucian @ c:irua:135699 |
Serial |
4301 |
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Permanent link to this record |
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Author |
Geboes, B.; Ustarroz, J.; Sentosun, K.; Vanrompay, H.; Hubin, A.; Bals, S.; Breugelmans, T. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Electrochemical behavior of electrodeposited nanoporous Pt catalysts for the oxygen reduction reaction |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
ACS catalysis |
Abbreviated Journal |
Acs Catal |
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Volume |
6 |
Issue |
6 |
Pages |
5856-5864 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) |
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Abstract |
Nanoporous Pt based nanoparticles (NP's) are promising fuel cell catalysts due to their high surface area and increased electrocatalytic activity toward the ORR In this work a direct double-pulse electrodeposition procedure at room temperature is applied to obtain dendritic Pt structures (89 nm diameter) with a high level of porosity (ca. 25%) and nanopores of 2 nm protruding until the center of the NP's. The particle morphology is characterized using aberration corrected high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and electron tomography (ET) combined with field emission scanning electron microscopy (FESEM) and macroscopic electrochemical measurements to assess their activity and stability toward the ORR. Macroscopic determination of the active surface area through hydrogen UPD measurements in combination with FESEM and ET showed that a considerable amount of the active sites inside the pores of the low overpotential NP's were accessible to oxygen species. As a result of this accessibility, up to a 9-fold enhancement of the Pt mass corrected ORR activity at 0.85 V vs RHE was observed at the highly porous structures. After successive potential cycling upward to 1.5 V vs RHE in a deaerated HClO4 solution a negative shift of 71 mV in half-wave potential occurred. This decrease in ORR activity could be correlated to the partial collapse of the nanopores, visible in both the EASA values and 3D ET reconstructions. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000382714000025 |
Publication Date |
2016-07-18 |
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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 ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
2155-5435 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
10.614 |
Times cited |
48 |
Open Access |
OpenAccess |
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Notes |
; The Quanta 250 FEG microscope of the Electron Microscopy for Material Science group at the University of Antwerp was funded by the Hercules foundation of the Flemish Government. The authors acknowledge financial support from the Fonds Wetenschappelijk Onderzoek in Flanders (FWOAL708). S.B. acknowledges financial support from the European Research Council (ERC Starting Grant # 335078-COLOURATOMS). J.U. acknowledges funding from the Fonds Wetenschappelijk Onderzoek in Flanders (FWO, postdoctoral grant 12I7816N). ; ecas_Sara |
Approved |
Most recent IF: 10.614 |
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Call Number |
UA @ lucian @ c:irua:135703 |
Serial |
4302 |
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Permanent link to this record |
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Author |
Zhang, L.; Fernández Becerra, V.; Covaci, L.; Milošević, M.V. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Electronic properties of emergent topological defects in chiral p-wave superconductivity |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
94 |
Issue |
94 |
Pages |
024520 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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|
Abstract |
Chiral p-wave superconductors in applied magnetic field can exhibit more complex topological defects than just conventional superconducting vortices, due to the two-component order parameter (OP) and the broken time-reversal symmetry. We investigate the electronic properties of those exotic states, some of which contain clusters of one-component vortices in chiral components of the OP and/or exhibit skyrmionic character in the relative OP space, all obtained as a self-consistent solution of the microscopic Bogoliubov-de Gennes equations. We reveal the link between the local density of states (LDOS) of the novel topological states and the behavior of the chiral domain wall between the OP components, enabling direct identification of those states in scanning tunneling microscopy. For example, a skyrmion always contains a closed chiral domain wall, which is found to be mapped exactly by zero-bias peaks in LDOS. Moreover, the LDOS exhibits electron-hole asymmetry, which is different from the LDOS of conventional vortex states with same vorticity. Finally, we present the magnetic field and temperature dependence of the properties of a skyrmion, indicating that this topological defect can be surprisingly large in size, and can be pinned by an artificially indented nonsuperconducting closed path in the sample. These features are expected to facilitate the experimental observation of skyrmionic states, thereby enabling experimental verification of chirality in emerging superconducting materials. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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Language |
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Wos |
000381479500002 |
Publication Date |
2016-07-26 |
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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 |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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|
ISSN |
2469-9969 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
27 |
Open Access |
|
|
|
Notes |
; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO). ; |
Approved |
Most recent IF: 3.836 |
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|
Call Number |
UA @ lucian @ c:irua:135742 |
Serial |
4303 |
|
Permanent link to this record |
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Author |
Klimin, S.N.; Tempere, J.; Verhelst, N.; Milošević, M.V. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Finite-temperature vortices in a rotating Fermi gas |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review A |
Abbreviated Journal |
Phys Rev A |
|
|
Volume |
94 |
Issue |
94 |
Pages |
023620 |
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|
Keywords |
A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT) |
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|
Abstract |
Vortices and vortex arrays have been used as a hallmark of superfluidity in rotated, ultracold Fermi gases. These superfluids can be described in terms of an effective field theory for a macroscopic wave function representing the field of condensed pairs, analogous to the Ginzburg-Landau theory for superconductors. Here we establish how rotation modifies this effective field theory, by rederiving it starting from the action of Fermi gas in the rotating frame of reference. The rotation leads to the appearance of an effective vector potential, and the coupling strength of this vector potential to the macroscopic wave function depends on the interaction strength between the fermions, due to a renormalization of the pair effective mass in the effective field theory. The mass renormalization derived here is in agreement with results of functional renormalization-group theory. In the extreme Bose-Einstein condensate regime, the pair effective mass tends to twice the fermion mass, in agreement with the physical picture of a weakly interacting Bose gas of molecular pairs. Then we use our macroscopic-wave-function description to study vortices and the critical rotation frequencies to form them. Equilibrium vortex state diagrams are derived and they are in good agreement with available results of the Bogoliubov-de Gennes theory and with experimental data. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Physical Society |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
|
Wos |
000381473100001 |
Publication Date |
2016-08-16 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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|
ISSN |
2469-9934 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
2.925 |
Times cited |
6 |
Open Access |
|
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|
Notes |
; We are grateful to G. C. Strinati and H. Warringa for valuable discussions. This research was supported by the Flemish Research Foundation Projects No. G.0115.12N, No. G.0119.12N, No. G.0122.12N, and No. G.0429.15N, by the Scientific Research Network of the Flemish Research Foundation, Grant No. WO.033.09N, and by the Research Fund of the University of Antwerp. ; |
Approved |
Most recent IF: 2.925 |
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|
Call Number |
UA @ lucian @ c:irua:135686 |
Serial |
4304 |
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Permanent link to this record |
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Author |
Mikhailova, D.; Karakulina, O.M.; Batuk, D.; Hadermann, J.; Abakumov, A.M.; Herklotz, M.; Tsirlin, A.A.; Oswald, S.; Giebeler, L.; Schmidt, M.; Eckert, J.; Knapp, M.; Ehrenberg, H. |
![goto web page url](http://nano.uantwerpen.be/nanorefs/img/www.gif)
![find record details (via OpenURL) openurl](img/xref.gif)
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Title |
Layered-to-Tunnel Structure Transformation and Oxygen Redox Chemistry in LiRhO2upon Li Extraction and Insertion |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
|
|
Volume |
55 |
Issue |
55 |
Pages |
7079-7089 |
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|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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|
Abstract |
Layered Li(M,Li)O2 (where M is a transition metal) ordered rock-salt-type structures are used in advanced metal-ion batteries as one of the best hosts for the reversible intercalation of Li ions. Besides the conventional redox reaction involving oxidation/reduction of the M cation upon Li extraction/insertion, creating oxygen-located holes because of the partial oxygen oxidation increases capacity while maintaining the oxidized oxygen species in the lattice through high covalency of the M–O bonding. Typical degradation mechanism of the Li(M,Li)O2 electrodes involves partially irreversible M cation migration toward the Li positions, resulting in gradual capacity/voltage fade. Here, using LiRhO2 as a model system (isostructural and isoelectronic to LiCoO2), for the first time, we demonstrate an intimate coupling between the oxygen redox and M cation migration. A formation of the oxidized oxygen species upon electrochemical Li extraction coincides with transformation of the layered Li1–xRhO2 structure into the γ-MnO2-type rutile–ramsdellite intergrowth LiyRh3O6 structure with rutile-like [1 × 1] channels along with bigger ramsdellite-like [2 × 1] tunnels through massive and concerted Rh migration toward the empty positions in the Li layers. The oxidized oxygen dimers with the O–O distances as short as 2.26 Å are stabilized in this structure via the local Rh–O configuration reminiscent to that in the μ-peroxo-μ-hydroxo Rh complexes. The LiyRh3O6 structure is remarkably stable upon electrochemical cycling illustrating that proper structural implementation of the oxidized oxygen species can open a pathway toward deliberate employment of the anion redox chemistry in high-capacity/high-voltage positive electrodes for metal-ion batteries. Upon chemical or electrochemical oxidation, layered LiRhO2 shows a unique structural transformation that involves both cation migration and oxidation of oxygen resulting in a stable tunnel-like rutile−ramsdellite intergrowth LiyRh3O6 structure. This structure demonstrates excellent performance with the steady and reversible capacity of ∼200 mAh/g. The stability of LiyRh3O6 is rooted in the accommodation of partially oxidized oxygen species through the formation of short O−O distances that are compatible with the connectivity of RhO6 octahedra. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000380181400035 |
Publication Date |
2016-07-18 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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|
ISSN |
0020-1669 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4.857 |
Times cited |
12 |
Open Access |
|
|
|
Notes |
Bundesministerium fur Bildung und Forschung, 03SF0477B ; Fonds Wetenschappelijk Onderzoek, G040116N ; |
Approved |
Most recent IF: 4.857 |
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|
Call Number |
EMAT @ emat @ c:irua:140848 |
Serial |
4424 |
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Permanent link to this record |
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Author |
Jany, B.R.; Gauquelin, N.; Willhammar, T.; Nikiel, M.; van den Bos, K.H.W.; Janas, A.; Szajna, K.; Verbeeck, J.; Van Aert, S.; Van Tendeloo, G.; Krok, F. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Controlled growth of hexagonal gold nanostructures during thermally induced self-assembling on Ge(001) surface |
Type |
A1 Journal article |
|
Year |
2017 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
|
|
Volume |
7 |
Issue |
7 |
Pages |
42420 |
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|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Nano-sized gold has become an important material in various fields of science and technology, where control over the size and crystallography is desired to tailor the functionality. Gold crystallizes in the face-centered cubic (fcc) phase, and its hexagonal closed packed (hcp) structure is a very unusual and rare phase. Stable Au hcp phase has been reported to form in nanoparticles at the tips of some Ge nanowires. It has also recently been synthesized in the form of thin graphene-supported sheets which are unstable under electron beam irradiation. Here, we show that stable hcp Au 3D nanostructures with well-defined crystallographic orientation and size can be systematically created in a process of thermally induced self-assembly of thin Au layer on Ge(001) monocrystal. The Au hcp crystallite is present in each Au nanostructure and has been characterized by different electron microscopy techniques. We report that a careful heat treatment above the eutectic melting temperature and a controlled cooling is required to form the hcp phase of Au on a Ge single crystal. This new method gives scientific prospects to obtain stable Au hcp phase for future applications in a rather simple manner as well as redefine the phase diagram of Gold with Germanium. |
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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 |
|
Wos |
000393940700001 |
Publication Date |
2017-02-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.259 |
Times cited |
25 |
Open Access |
OpenAccess |
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Notes |
The authors gratefully acknowledge the financial support from the Polish National Science Center, grant no. DEC-2012/07/B/ST5/00906. N.G., G.V.T. and J.V. acknowledge the European Union (EU) Council under the 7th Framework Program (FP7) ERC Starting Grant 278510 VORTEX for support. The Research Foundation Flanders is acknowledged through project fundings (G.0374.13N, G.0368.15N, G.0369.15N) and for a Ph.D. research grant to K.H.W.v.d.B. The microscope was partly funded by the Hercules Fund from the Flemish Government. T.W. acknowledges the Swedish Research Council for an international postdoc grant. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483–ESTEEM2 (Integrated Infrastructure Initiative–I3). Part of the research was carried out with equipment purchased with financial support from the European Regional Development Fund in the framework of the Polish Innovation Economy Operational Program (Contract No. POIG.02.01.00-12-023/08). |
Approved |
Most recent IF: 4.259 |
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Call Number |
EMAT @ emat @ c:irua:140846UA @ admin @ c:irua:140846 |
Serial |
4423 |
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Permanent link to this record |
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Author |
Callini, E.; Aguey-Zinsou, K.F.; Ahuja, R.; Ares, J.R.; Bals, S.; Biliškov, N.; Chakraborty, S.; Charalambopoulou, G.; Chaudhary, A.L.; Cuevas, F.; Dam, B.; de Jongh, P.; Dornheim, M.; Filinchuk, Y.; Grbović Novaković, J.; Hirscher, M.; Jensen, T.R.; Jensen, P.B.; Novaković, N.; Lai, Q.; Leardini, F.; Gattia, D.M.; Pasquini, L.; Steriotis, T.; Turner, S.; Vegge, T.; Züttel, A.; Montone, A. |
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Title |
Nanostructured materials for solid-state hydrogen storage : a review of the achievement of COST Action MP1103 |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
International journal of hydrogen energy
T2 – E-MRS Fall Meeting / Symposium C on Hydrogen Storage in Solids -, Materials, Systems and Aplication Trends, SEP 15-18, 2015, Warsaw, POLAND |
Abbreviated Journal |
Int J Hydrogen Energ |
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Volume |
41 |
Issue |
41 |
Pages |
14404-14428 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
In the framework of the European Cooperation in Science and Technology (COST) Action MP1103 Nanostructured Materials for Solid-State Hydrogen Storage were synthesized, characterized and modeled. This Action dealt with the state of the art of energy storage and set up a competitive and coordinated network capable to define new and unexplored ways for Solid State Hydrogen Storage by innovative and interdisciplinary research within the European Research Area. An important number of new compounds have been synthesized: metal hydrides, complex hydrides, metal halide ammines and amidoboranes. Tuning the structure from bulk to thin film, nanoparticles and nanoconfined composites improved the hydrogen sorption properties and opened the perspective to new technological applications. Direct imaging of the hydrogenation reactions and in situ measurements under operando conditions have been carried out in these studies. Computational screening methods allowed the prediction of suitable compounds for hydrogen storage and the modeling of the hydrogen sorption reactions on mono-, bi-, and three-dimensional systems. This manuscript presents a review of the main achievements of this Action. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
Pergamon-elsevier science ltd |
Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000381950800051 |
Publication Date |
2016-05-08 |
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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 |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
0360-3199 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
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Impact Factor |
3.582 |
Times cited |
89 |
Open Access |
Not_Open_Access |
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|
Notes |
All the authors greatly thank the COST Action MP1103 for financial support. |
Approved |
Most recent IF: 3.582 |
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|
Call Number |
UA @ lucian @ c:irua:135723 |
Serial |
4307 |
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Permanent link to this record |
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Author |
Berends, A.C.; Rabouw, F.T.; Spoor, F.C.M.; Bladt, E.; Grozema, F.C.; Houtepen, A.J.; Siebbeles, L.D.A.; de Donega, C.M. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Radiative and nonradiative recombination in CuInS2 nanocrystals and CuInS2-based core/shell nanocrystals |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
The journal of physical chemistry letters |
Abbreviated Journal |
J Phys Chem Lett |
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Volume |
7 |
Issue |
7 |
Pages |
3503-3509 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Luminescent copper indium sulfide (CIS) nanocrystals are a potential solution to the toxicity issues associated with Cd- and Pb-based nanocrystals. However, the development of high-quality CIS nanocrystals has been complicated by insufficient knowledge of the electronic structure and of the factors that lead to luminescence quenching. Here we investigate the exciton decay pathways in CIS nanocrystals using time resolved photoluminescence and transient absorption spectroscopy. Core-only CIS nanocrystals with low quantum yield are compared to core/shell nanocrystals (CIS/ZnS and CIS/CdS) with higher quantum yield. Our measurements support the model of photoluminescence by radiative recombination of a conduction band electron with a localized hole. Moreover, we find that photoluminescence quenching in low-quantum-yield nanocrystals involves initially uncoupled decay pathways for the electron and hole. The electron decay pathway determines whether the exciton recombines radiatively or nonradiatively. The development of high-quality CIS nanocrystals should therefore focus on the elimination of electron traps. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Chemical Society |
Place of Publication |
Washington, D.C |
Editor |
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Language |
|
Wos |
000382603300037 |
Publication Date |
2016-08-23 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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|
ISSN |
1948-7185 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
9.353 |
Times cited |
67 |
Open Access |
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|
Notes |
|
Approved |
Most recent IF: 9.353 |
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Call Number |
UA @ lucian @ c:irua:135715 |
Serial |
4308 |
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Permanent link to this record |
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Author |
Sisakht, E.T.; Fazileh, F.; Zare, M.H.; Zarenia, M.; Peeters, F.M. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Strain-induced topological phase transition in phosphorene and in phosphorene nanoribbons |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
94 |
Issue |
94 |
Pages |
085417 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using the tight-binding (TB) approximation with inclusion of the spin-orbit interaction, we predict a topological phase transition in the electronic band structure of phosphorene in the presence of axial strains. We derive a low-energy TB Hamiltonian that includes the spin-orbit interaction for bulk phosphorene. Applying a compressive biaxial in-plane strain and perpendicular tensile strain in ranges where the structure is still stable leads to a topological phase transition. We also examine the influence of strain on zigzag phosphorene nanoribbons (zPNRs) and the formation of the corresponding protected edge states when the system is in the topological phase. For zPNRs up to a width of 100 nm the energy gap is at least three orders of magnitude larger than the thermal energy at room temperature. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000381600800004 |
Publication Date |
2016-08-18 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
76 |
Open Access |
|
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|
Notes |
; This work was supported by Ministry of Science, Research and Technology, Iran. M.Z. acknowledges support as a postdoctoral fellow of the Flemish Research Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836 |
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|
Call Number |
UA @ lucian @ c:irua:135643 |
Serial |
4309 |
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Permanent link to this record |
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Author |
Tang, Y.; Hunter, E.C.; Battle, P.D.; Sena, R.P.; Hadermann, J.; Avdeev, M.; Cadogan, J.M. |
![goto web page url](http://nano.uantwerpen.be/nanorefs/img/www.gif)
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Title |
Structural chemistry and magnetic properties of the perovskite Sr3Fe2TeO9 |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
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Volume |
242 |
Issue |
242 |
Pages |
86-95 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A polycrystalline sample of perovskite-like Sr3Fe2TeO9 has been prepared in a solid-state reaction and studied by a combination of electron microscopy, Mossbauer spectroscopy, magnetometry, X-ray diffraction and neutron diffraction. The majority of the reaction product is shown to be a trigonal phase with a 2:1 ordered arrangement of Fe3+ and Te6+ cations. However, the sample is prone to nano twinning and tetragonal domains with a different pattern of cation ordering exist within many crystallites. Antiferromagnetic ordering exists in the trigonal phase at 300 K and Sr3Fe2TeO9 is thus the first example of a perovskite with 2:1 trigonal cation ordering to show long-range magnetic order. At 300 K the antiferromagnetic phase coexists with two paramagnetic phases which show spin -glass behaviour below similar to 80 K. (C) 2016 The Authors. Published by Elsevier Inc. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
London |
Editor |
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Language |
|
Wos |
000382429600012 |
Publication Date |
2016-06-29 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
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Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
|
|
|
ISSN |
0022-4596 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.299 |
Times cited |
12 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 2.299 |
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|
Call Number |
UA @ lucian @ c:irua:135682 |
Serial |
4310 |
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Permanent link to this record |
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Author |
Dabaghmanesh, S.; Neyts, E.C.; Partoens, B. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
van der Waals density functionals applied to corundum-type sesquioxides : bulk properties and adsorption of CH3 and C6H6 on (0001) surfaces |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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|
Volume |
18 |
Issue |
18 |
Pages |
23139-23146 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
van der Waals (vdW) forces play an important role in the adsorption of molecules on the surface of solids. However, the choice of the most suitable vdW functional for different systems is an essential problem which must be addressed for different systems. The lack of a systematic study on the performance of the vdW functionals in the bulk and adsorption properties of metal-oxides motivated us to examine different vdW approaches and compute the bulk and molecular adsorption properties of alpha-Cr2O3, alpha-Fe2O3, and alpha-Al2O3. For the bulk properties, we compared our results for the heat of formation, cohesive energy, lattice parameters and bond distances between the different vdW functionals and available experimental data. Next we studied the adsorption of benzene and CH3 molecules on top of different oxide surfaces. We employed different approximations to exchange and correlation within DFT, namely, the Perdew-Burke-Ernzerhof (PBE) GGA, (PBE)+U, and vdW density functionals [ DFT(vdW-DF/DF2/optPBE/optB86b/optB88)+U] as well as DFT-D2/D3(+U) methods of Grimme for the bulk calculations and optB86b-vdW(+U) and DFT-D2(+U) for the adsorption energy calculations. Our results highlight the importance of vdW interactions not only in the adsorption of molecules, but importantly also for the bulk properties. Although the vdW contribution in the adsorption of CH3 (as a chemisorption interaction) is less important compared to the adsorption of benzene (as a physisorption interaction), this contribution is not negligible. Also adsorption of benzene on ferryl/chromyl terminated surfaces shows an important chemisorption contribution in which the vdW interactions become less significant. |
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Place of Publication |
Cambridge |
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Wos |
000382109300040 |
Publication Date |
2016-07-27 |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
1463-9076; 1463-9084 |
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 |
6 |
Open Access |
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Notes |
; This work was supported by the Strategic Initiative Materials in Flanders (SIM). The computational resources and services used in this work were provided by the Vlaams Supercomputer Centrum (VSC) and the HPC infrastructure of the University of Antwerp. ; |
Approved |
Most recent IF: 4.123 |
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Call Number |
UA @ lucian @ c:irua:135701 |
Serial |
4311 |
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Permanent link to this record |
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Author |
Cassidy, S.J.; Batuk, M.; Batuk, D.; Hadermann, J.; Woodruff, D.N.; Thompson, A.L.; Clarke, S.J. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Complex Microstructure and Magnetism in Polymorphic CaFeSeO |
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 |
10714-10726 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The structural complexity of the antiferromagnetic oxide selenide CaFeSeO is described. The compound contains puckered FeSeO layers composed of FeSe2O2 tetrahedra sharing all their vertexes. Two polymorphs coexist that can be derived from an archetype BaZnSO structure by cooperative tilting of the FeSe2O2 tetrahedra. The polymorphs differ in the relative arrangement of the puckered layers of vertex-linked FeSe2O2 tetrahedra. In a noncentrosymmetric Cmc21 polymorph (a = 3.89684(2) A, b = 13.22054(8) A, c = 5.93625(2) A) the layers are related by the C-centering translation, while in a centrosymmetric Pmcn polymorph, with a similar cell metric (a = 3.89557(6) A, b = 13.2237(6) A, c = 5.9363(3) A), the layers are related by inversion. The compound shows long-range antiferromagnetic order below a Neel temperature of 159(1) K with both polymorphs showing antiferromagnetic coupling via Fe-O-Fe linkages and ferromagnetic coupling via Fe-Se-Fe linkages within the FeSeO layers. The magnetic susceptibility also shows evidence for weak ferromagnetism which is modeled in the refinements of the magnetic structure as arising from an uncompensated spin canting in the noncentrosymmetric polymorph. There is also a spin glass component to the magnetism which likely arises from the disordered regions of the structure evident in the transmission electron microscopy. |
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Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QR, United Kingdom |
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English |
Wos |
000385785700085 |
Publication Date |
2016-10-05 |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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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 |
6 |
Open Access |
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Notes |
We acknowledge the financial support of the EPSRC (Grants EP/I017844/1 and EP/M020517/1), the Leverhulme Trust (RPG-2014-221), and the Diamond Light Source (studentship support for S. J. Cassidy). We thank the ESTEEM2 network for enabling the electron microscopy investigations and the ISIS facility and the Diamond Light Source Ltd. for the award of beam time. We thank Dr. P. Manuel for assistance on WISH, Dr. R. I. Smith for assistance on GEM and POLARIS, and Dr. C. Murray and Dr. A. Baker for assistance on I11. |
Approved |
Most recent IF: 4.857 |
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Call Number |
EMAT @ emat @ c:irua:136823 |
Serial |
4312 |
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Permanent link to this record |
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Author |
Zhang, F.; Inokoshi, M.; Batuk, M.; Hadermann, J.; Naert, I.; Van Meerbeek, B.; Vleugels, J. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Strength, toughness and aging stability of highly-translucent Y-TZP ceramics for dental restorations |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Dental Materials |
Abbreviated Journal |
Dent Mater |
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Volume |
32 |
Issue |
32 |
Pages |
e327-e337 |
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Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
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Abstract |
OBJECTIVE: The aim was to evaluate the optical properties, mechanical properties and aging stability of yttria-stabilized zirconia with different compositions, highlighting the influence of the alumina addition, Y2O3 content and La2O3 doping on the translucency. METHODS: Five different Y-TZP zirconia powders (3 commercially available and 2 experimentally modified) were sintered under the same conditions and characterized by X-ray diffraction with Rietveld analysis and scanning electron microscopy (SEM). Translucency (n=6/group) was measured with a color meter, allowing to calculate the translucency parameter (TP) and the contrast ratio (CR). Mechanical properties were appraised with four-point bending strength (n=10), single edge V-notched beam (SEVNB) fracture toughness (n=8) and Vickers hardness (n=10). The aging stability was evaluated by measuring the tetragonal to monoclinic transformation (n=3) after accelerated hydrothermal aging in steam at 134 degrees C, and the transformation curves were fitted by the Mehl-Avrami-Johnson (MAJ) equation. Data were analyzed by one-way ANOVA, followed by Tukey's HSD test (alpha=0.05). RESULTS: Lowering the alumina content below 0.25wt.% avoided the formation of alumina particles and therefore increased the translucency of 3Y-TZP ceramics, but the hydrothermal aging stability was reduced. A higher yttria content (5mol%) introduced about 50% cubic zirconia phase and gave rise to the most translucent and aging-resistant Y-TZP ceramics, but the fracture toughness and strength were considerably sacrificed. 0.2mol% La2O3 doping of 3Y-TZP tailored the grain boundary chemistry and significantly improved the aging resistance and translucency. Although the translucency improvement by La2O3 doping was less effective than for introducing a substantial amount of cubic zirconia, this strategy was able to maintain the mechanical properties of typical 3Y-TZP ceramics. SIGNIFICANCE: Three different approaches were compared to improve the translucency of 3Y-TZP ceramics. |
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Address |
KU Leuven, Department of Materials Engineering, Kasteelpark Arenberg 44, Belgium |
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English |
Wos |
000389516400003 |
Publication Date |
2016-10-06 |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
0109-5641 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.07 |
Times cited |
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Open Access |
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Notes |
The authors acknowledge the Research Fund of KU Leu- ven under project 0T/10/052 and the Fund for Scientific Research Flanders (FWO-Vlaanderen) under grant G.0431.10N. F. Zhang thanks the Research Fund of KU Leuven for her post- doctoral fellowship (PDM/15/153). We thank M. Peumans for the translucency measurements. |
Approved |
Most recent IF: 4.07 |
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Call Number |
EMAT @ emat @ c:irua:136821 |
Serial |
4313 |
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Author |
Juchtmans, R.; Guzzinati, G.; Verbeeck, J. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Extension of Friedel's law to vortex-beam diffraction |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Physical Review A |
Abbreviated Journal |
Phys Rev A |
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Volume |
94 |
Issue |
94 |
Pages |
033858 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Friedel's law states that the modulus of the Fourier transform of real functions is centrosymmetric, while the phase is antisymmetric. As a consequence of this, elastic scattering of plane-wave photons or electrons within the first-order Born-approximation, as well as Fraunhofer diffraction on any aperture, is bound to result in centrosymmetric diffraction patterns. Friedel's law, however, does not apply for vortex beams, and centrosymmetry in general is not present in their diffraction patterns. In this work we extend Friedel's law for vortex beams by showing that the diffraction patterns of vortex beams with opposite topological charge, scattered on the same two-dimensional potential, always are centrosymmetric to one another, regardless of the symmetry of the scattering object. We verify our statement by means of numerical simulations and experimental data. Our research provides deeper understanding in vortex-beam diffraction and can be used to design new experiments to measure the topological charge of vortex beams with diffraction gratings or to study general vortex-beam diffraction. |
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Wos |
000384374500010 |
Publication Date |
2016-09-30 |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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ISSN |
2469-9926 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.925 |
Times cited |
13 |
Open Access |
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Notes |
The authors acknowledge support from the FWO (Aspirant Fonds Wetenschappelijk Onderzoek – Vlaanderen) and the EU under the Seventh Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483-ESTEEM2 and ERC Starting Grant No. 278510 VORTEX.; ECASJO_; |
Approved |
Most recent IF: 2.925 |
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Call Number |
EMAT @ emat @ c:irua:137200UA @ admin @ c:irua:137200 |
Serial |
4314 |
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Permanent link to this record |
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Author |
Gonnissen, J.; De Backer, A.; den Dekker, A.J.; Sijbers, J.; Van Aert, S. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Atom-counting in High Resolution Electron Microscopy: TEM or STEM – that's the question |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
174 |
Issue |
174 |
Pages |
112-120 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
In this work, a recently developed quantitative approach based on the principles of detection theory is used in order to determine the possibilities and limitations of High Resolution Scanning Transmission Electron Microscopy (HR STEM) and HR TEM for atom-counting. So far, HR STEM has been shown to be an appropriate imaging mode to count the number of atoms in a projected atomic column. Recently, it has been demonstrated that HR TEM, when using negative spherical aberration imaging, is suitable for atom-counting as well. The capabilities of both imaging techniques are investigated and compared using the probability of error as a criterion. It is shown that for the same incoming electron dose, HR STEM outperforms HR TEM under common practice standards, i.e. when the decision is based on the probability function of the peak intensities in HR TEM and of the scattering cross-sections in HR STEM. If the atom-counting decision is based on the joint probability function of the image pixel values, the dependence of all image pixel intensities as a function of thickness should be known accurately. Under this assumption, the probability of error may decrease significantly for atom-counting in HR TEM and may, in theory, become lower as compared to HR STEM under the predicted optimal experimental settings. However, the commonly used standard for atom-counting in HR STEM leads to a high performance and has been shown to work in practice. |
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Wos |
000403342200013 |
Publication Date |
2016-10-27 |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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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 |
2 |
Open Access |
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Notes |
The authors gratefully acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0368.15N, G.0369.15N, G.0374.13N, and WO.010.16N) and a postdoctoral grant to A. De Backer. The research leading to these results has received funding from the European Union Seventh Framework Programme [FP7/2007-2013] under Grant agreement no. 312483 (ESTEEM2). |
Approved |
Most recent IF: 2.843 |
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Call Number |
EMAT @ emat @ c:irua:137102 |
Serial |
4315 |
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Author |
Alania, M.; Altantzis, T.; De Backer, A.; Lobato, I.; Bals, S.; Van Aert, S. |
![goto web page url](http://nano.uantwerpen.be/nanorefs/img/www.gif)
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Title |
Depth sectioning combined with atom-counting in HAADF STEM to retrieve the 3D atomic structure |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
177 |
Issue |
177 |
Pages |
36-42 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Aberration correction in scanning transmission electron microscopy (STEM) has greatly improved the lateral and depth resolution. When using depth sectioning, a technique during which a series of images is recorded at different defocus values, single impurity atoms can be visualised in three dimensions. In this paper, we investigate new possibilities emerging when combining depth sectioning and precise atom-counting in order to reconstruct nanosized particles in three dimensions. Although the depth resolution does not allow one to precisely locate each atom within an atomic column, it will be shown that the depth location of an atomic column as a whole can be measured precisely. In this manner, the morphology of a nanoparticle can be reconstructed in three dimensions. This will be demonstrated using simulations and experimental data of a gold nanorod. |
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Wos |
000401219800006 |
Publication Date |
2016-11-09 |
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Abbreviated Series Title |
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Edition ![sorted by Edition field, ascending order (up)](img/sort_asc.gif) |
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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 |
13 |
Open Access |
OpenAccess |
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Notes |
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. S. Bals acknowledges funding from the European Research Council (Starting Grant No. COLOURATOMS 335078). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0369.15N and G.0368.15N) and a post-doctoral grant to A. De Backer and T. Altantzis. The authors are grateful to Professor Luis M. Liz-Marzán for providing the sample.; ECAS_Sara; (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); |
Approved |
Most recent IF: 2.843 |
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Call Number |
EMAT @ emat @ c:irua:138015UA @ admin @ c:irua:138015 |
Serial |
4316 |
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Permanent link to this record |