| Home | << 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 >> [101–200] |
|
| Records | |||||
|---|---|---|---|---|---|
| Author | Müller, E.; Kruse, P.; Gerthsen, D.; Schowalter, M.; Rosenauer, A.; Lamoen, D.; Kling, R. | ||||
| Title | Measurement of the mean inner potential of ZnO nanorods by transmission electron holography | Type | A1 Journal article | ||
| Year | 2005 | Publication | Microscopy of Semiconducting Materials | Abbreviated Journal | |
| Volume | 107 | Issue | Pages | 303-306 | |
| Keywords | A1 Journal article; Electron Microscopy for Materials Science (EMAT) | ||||
| Abstract | |||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Berlin | Editor | ||
| Language | Wos | Publication Date | 0000-00-00 | ||
| Series Editor | Series Title  |
SPRINGER PROCEEDINGS IN PHYSICS | Abbreviated Series Title | ||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0930-8989 | ISBN | Additional Links | UA library record; WoS full record; | |
| Impact Factor | Times cited | Open Access | |||
| Notes | Approved | Most recent IF: NA | |||
| Call Number | UA @ lucian @ c:irua:72914 | Serial | 1962 | ||
| Permanent link to this record | |||||
| Author | Engelmann, Y.; Bogaerts, A.; Neyts, E.C. | ||||
| Title | Thermodynamics at the nanoscale : phase diagrams of nickel-carbon nanoclusters and equilibrium constants for face transitions | Type | A1 Journal article | ||
| Year | 2014 | Publication | Nanoscale | Abbreviated Journal | Nanoscale |
| Volume | 6 | Issue | Pages | 11981-11987 | |
| Keywords | A1 Journal article; PLASMANT | ||||
| Abstract | Using reactive molecular dynamics simulations, the melting behavior of nickelcarbon nanoclusters is examined. The phase diagrams of icosahedral and Wulff polyhedron clusters are determined using both the Lindemann index and the potential energy. Formulae are derived for calculating the equilibrium constants and the solid and liquid fractions during a phase transition, allowing more rational determination of the melting temperature with respect to the arbitrary Lindemann value. These results give more insight into the properties of nickelcarbon nanoclusters in general and can specifically be very useful for a better understanding of the synthesis of carbon nanotubes using the catalytic chemical vapor deposition method. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Cambridge | Editor | ||
| Language | Wos | 000343000800049 | Publication Date | 2014-07-24 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2040-3364;2040-3372; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 7.367 | Times cited | 20 | Open Access | |
| Notes | Approved | Most recent IF: 7.367; 2014 IF: 7.394 | |||
| Call Number | UA @ lucian @ c:irua:119408 | Serial | 3636 | ||
| Permanent link to this record | |||||
| Author | Milošević, M.V.; Perali, A. | ||||
| Title | Emergent phenomena in multicomponent superconductivity: an introduction to the focus issue | Type | A1 Journal article | ||
| Year | 2015 | Publication | Superconductor Science & Technology | Abbreviated Journal | Supercond Sci Tech |
| Volume | 28 | Issue | 28 | Pages | 060201 |
| Keywords | A1 Journal article; CMT | ||||
| Abstract | |||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000354110200001 | Publication Date | 2015-04-24 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0953-2048;1361-6668; | ISBN | Additional Links | ||
| Impact Factor | 2.878 | Times cited | 41 | Open Access | |
| Notes | ; ; | Approved | Most recent IF: 2.878; 2015 IF: 2.325 | ||
| Call Number | UA @ lucian @ | Serial | 3945 | ||
| Permanent link to this record | |||||
| Author | Roose, D.; Leroux, F.; De Vocht, N.; Guglielmetti, C.; Pintelon, I.; Adriaensen, D.; Ponsaerts, P.; Van der Linden, A.; Bals, S. | ||||
| Title | Multimodal imaging of micron-sized iron oxide particles following in vitro and in vivo uptake by stem cells: down to the nanometer scale | Type | A1 Journal article | ||
| Year | 2014 | Publication | Contrast Media & Molecular Imaging | Abbreviated Journal | Contrast Media Mol I |
| Volume | 9 | Issue | 6 | Pages | 400-408 |
| Keywords | A1 Journal article; Electron Microscopy for Materials Science (EMAT); | ||||
| Abstract | In this study, the interaction between cells and micron-sized paramagnetic iron oxide (MPIO) particles was investigated by characterizing MPIO in their original state, and after cellular uptake in vitro as well as in vivo. Moreover, MPIO in the olfactory bulb were studied 9 months after injection. Using various imaging techniques, cell-MPIO interactions were investigated with increasing spatial resolution. Live cell confocal microscopy demonstrated that MPIO co-localize with lysosomes after in vitro cellular uptake. In more detail, a membrane surrounding the MPIO was observed by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Following MPIO uptake in vivo, the same cell-MPIO interaction was observed by HAADF-STEM in the subventricular zone at 1 week and in the olfactory bulb at 9 months after MPIO injection. These findings provide proof for the current hypothesis that MPIO are internalized by the cell through endocytosis. The results also show MPIO are not biodegradable, even after 9 months in the brain. Moreover, they show the possibility of HAADF-STEM generating information on the labeled cell as well as on the MPIO. In summary, the methodology presented here provides a systematic route to investigate the interaction between cells and nanoparticles from the micrometer level down to the nanometer level and beyond. | ||||
| Address | EMAT, University of Antwerp, Antwerp, Belgium; Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium; Laboratory of Experimental Hematology, University of Antwerp, Antwerp, Belgium | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | English | Wos | 000346172100002 | Publication Date | 2014-04-22 |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1555-4309; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.307 | Times cited | 8 | Open Access | Not_Open_Access |
| Notes | IAP-PAI; 262348 ESMI; Hercules Type 1: AUHA 09/001 and AUHA 11/01 | Approved | Most recent IF: 3.307; 2014 IF: 2.923 | ||
| Call Number | UA @ lucian @ | Serial | 3938 | ||
| Permanent link to this record | |||||
| Author | Kozák, T.; Vlček, J. | ||||
| Title | A parametric model for reactive high-power impulse magnetron sputtering of films | Type | A1 Journal article | ||
| Year | 2016 | Publication | Journal Of Physics D-Applied Physics | Abbreviated Journal | J Phys D Appl Phys |
| Volume | 49 | Issue | 49 | Pages | 055202 |
| Keywords | A1 Journal article; Electron Microscopy for Materials Science (EMAT); | ||||
| Abstract | We present a time-dependent parametric model for reactive HiPIMS deposition of films. Specific features of HiPIMS discharges and a possible increase in the density of the reactive gas in front of the reactive gas inlets placed between the target and the substrate are considered in the model. The model makes it possible to calculate the compound fractions in two target layers and in one substrate layer, and the deposition rate of films at fixed partial pressures of the reactive and inert gas. A simplified relation for the deposition rate of films prepared using a reactive HiPIMS is presented. We used the model to simulate controlled reactive HiPIMS depositions of stoichiometric ZrO2 films, which were recently carried out in our laboratories with two different configurations of the O2 inlets in front of the sputtered target. The repetition frequency was 500 Hz at the deposition-averaged target power densities of 5 Wcm−2 and 50 Wcm−2 with a pulse-averaged target power density up to 2 kWcm−2. The pulse durations were 50 μs and 200 μs. Our model calculations show that the to-substrate O2 inlet provides systematically lower compound fractions in the target surface layer and higher compound fractions in the substrate surface layer, compared with the to-target O2 inlet. The low compound fractions in the target surface layer (being approximately 10% at the depositionaveraged target power density of 50 Wcm−2 and the pulse duration of 200 μs) result in high deposition rates of the films produced, which are in agreement with experimental values. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000368944100016 | Publication Date | 2015-12-16 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0022-3727 | ISBN | Additional Links | ||
| Impact Factor | 2.588 | Times cited | 25 | Open Access | |
| Notes | This work was supported by the Czech Science Foundation under Project No. GA14–03875S | Approved | Most recent IF: 2.588 | ||
| Call Number | PLASMANT @ plasmant @ | Serial | 3994 | ||
| Permanent link to this record | |||||
| Author | Covaci, L.; Berciu, M. | ||||
| Title | Survival of the Dirac points in rippled graphene | Type | A1 Journal article | ||
| Year | 2008 | Publication | Physical Review Letters | Abbreviated Journal | Phys Rev Lett |
| Volume | 100 | Issue | 25 | Pages | 256405 |
| Keywords | A1 Journal article; Electron Microscopy for Materials Science (EMAT); | ||||
| Abstract | We study the effects of the rippling of a graphene sheet on quasiparticle dispersion. This is achieved using a generalization to the honeycomb lattice of the momentum average approximation, which is accurate for all coupling strengths and at all energies. We show that even though the position of the Dirac points may move and the Fermi speed can be renormalized significantly, quasiparticles with very long lifetimes survive near the Dirac points even for very strong couplings. | ||||
| Address | Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada, V6T 1Z1 | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | English | Wos | 000257230500047 | Publication Date | 2008-06-26 |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0031-9007 | ISBN | Additional Links | ||
| Impact Factor | 8.462 | Times cited | 15 | Open Access | |
| Notes | Approved | Most recent IF: 8.462; 2008 IF: 7.180 | |||
| Call Number | UA @ lucian @ | Serial | 4010 | ||
| Permanent link to this record | |||||
| Author | Zanaga, D.; Altantzis, T.; Sanctorum, J.; Freitag, B.; Bals, S. | ||||
| Title | An alternative approach for ζ-factor measurement using pure element nanoparticles | Type | A1 Journal article | ||
| Year | 2016 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 164 | Issue | 164 | Pages | 11-16 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | It is very challenging to measure the chemical composition of hetero nanostructures in a reliable and quantitative manner. Here, we propose a novel and straightforward approach that can be used to quantify energy dispersive X-ray spectra acquired in a transmission electron microscope. Our method is based on a combination of electron tomography and the so-called ζ-factor technique. We will demonstrate the reliability of our approach as well as its applicability by investigating Au-Ag and Au-Pt hetero nanostructures. Given its simplicity, we expect that the method could become a new standard in the field of chemical characterization using electron microscopy. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000373526200002 | Publication Date | 2016-03-10 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 2.843 | Times cited | 19 | Open Access | OpenAccess |
| Notes | The authors acknowledge financial support from the European Research Council (ERC Starting Grant # 335078-COLOURATOMS) and the European Union under the FP7 (Integrated Infrastructure Initiative N. 312483 – ESTEEM2). The authors would also like to thank Luis M. Liz-Marzán, Ana Sánchez-Iglesias, Stefanos Mourdikoudis and Cristina Fernández-López for sample provision and useful discussions.; esteem2jra4; ECASSara; (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); | Approved | Most recent IF: 2.843 | ||
| Call Number | EMAT @ emat @ | Serial | 4019 | ||
| Permanent link to this record | |||||
| Author | Covaci, L.; Marsiglio, F. | ||||
| Title | Proximity effect and Josephson current in clean strong/weak/strong superconducting trilayers | Type | A1 Journal article | ||
| Year | 2006 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 73 | Issue | 1 | Pages | 014503 |
| Keywords | A1 Journal article | ||||
| Abstract | Recent measurements of the Josephson critical current through LSCO/LCO/LSCO thin films showed an unusually large proximity effect. Using the Bogoliubov-de Gennes equations for a tight-binding Hamiltonian we describe the proximity effect in weak links between a superconductor with critical temperature T-c and one with critical temperature T-c('), where T-c > T-c('). The weak link (N-') is therefore a superconductor above its own critical temperature and the superconducting regions are considered to have either s-wave or d-wave symmetry. We note that the proximity effect is enhanced due to the presence of superconducting correlations in the weak link. The dc Josephson current is calculated, and we obtain a nonzero value for temperatures greater than T-c(') for sizes of the weak links that can be almost an order of magnitude greater than the conventional coherence length. Considering pockets of superconductivity in the N-' layer, we show that this can lead to an even larger effect on the Josephson critical current by effectively shortening the weak link. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000235009000103 | Publication Date | 2006-01-03 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1098-0121 | ISBN | Additional Links | ||
| Impact Factor | 3.836 | Times cited | 31 | Open Access | |
| Notes | Approved | Most recent IF: 3.836; 2006 IF: 3.107 | |||
| Call Number | UA @ lucian @ | Serial | 4427 | ||
| Permanent link to this record | |||||
| Author | Kirilenko, D.A.; Brunkov, P.N. | ||||
| Title | Measuring the height-to-height correlation function of corrugation in suspended graphene | Type | A1 Journal article | ||
| Year | 2016 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
| Volume | 165 | Issue | 165 | Pages | 1-7 |
| Keywords | A1 Journal article; Electron Microscopy for Materials Science (EMAT); | ||||
| Abstract | Nanocorrugation of 2D crystals is an important phenomenon since it affects their electronic and mechanical properties. The corrugation may have various sources; one of them is flexural phonons that, in particular, are responsible for the thermal conductivity of graphene. A study of corrugation of just the suspended graphene can reveal much of valuable information on the physics of this complicated phenomenon. At the same time, the suspended crystal nanorelief can hardly be measured directly because of high flexibility of the 2D crystal. Moreover, the relief portion related to rapid out-of-plane oscillations (flexural phonons) is also inaccessible by such measurements. Here we present a technique for measuring the Fourier components of the height-height correlation function H(q) of suspended graphene which includes the effect of flexural phonons. The technique is based on the analysis of electron diffraction patterns. The H(q) is measured in the range of wavevectors q approximately 0.4-4.5nm(-1). At the upper limit of this range H(q) does follow the T/kappaq(4) law. So, we measured the value of suspended graphene bending rigidity kappa=1.2+/-0.4eV at ambient temperature T approximately 300K. At intermediate wave vectors, H(q) follows a slightly weaker exponent than theoretically predicted q(-3.15) but is closer to the results of the molecular dynamics simulation. At low wave vectors, the dependence becomes even weaker, which may be a sign of influence of charge carriers on the dynamics of undulations longer than 10nm. The technique presented can be used for studying physics of flexural phonons in other 2D materials. | ||||
| Address | Ioffe Institute, Politekhnicheskaya ul. 26, 194021 St-Petersburg, Russia; ITMO University, Kronverksky pr. 49, 197101 St. Petersburg, Russia | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | English | Wos | 000375946200001 | Publication Date | 2016-03-28 |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0304-3991 | ISBN | Additional Links | ||
| Impact Factor | 2.843 | Times cited | 3 | Open Access | |
| Notes | D.K. thanks the RFBR (Grant no. 16-32-60165) for the partial support of this research. The work was carried out in part at the Joint Research Center “Material Science and Characterization in Advanced Technologies” (St-Petersburg, Russia) under the financial support from the Ministry of Education and Science of the Russian Federation (Agreement 14.621.21.0007, 04.12.2014, id RFMEFI62114X0007, the use of the Jeol JEM-2100F microscope) and at EMAT, Universiteit Antwerpen (Antwerpen, Belgium), (the use of the FEI Tecnai G2 microscope). | Approved | Most recent IF: 2.843 | ||
| Call Number | EMAT @ emat @ | Serial | 4124 | ||
| Permanent link to this record | |||||
| Author | Bogaerts, A. | ||||
| Title | Glow discharge optical spectroscopy and mass spectrometry | Type | A1 Journal article | ||
| Year | 2016 | Publication | Abbreviated Journal | ||
| Volume | Issue | Pages | |||
| Keywords | A1 Journal article; PLASMANT | ||||
| Abstract | Atomic Spectroscopy Optical (atomic absorption spectroscopy, AAS; atomic emission spectroscopy, AES; atomic fluorescence spectroscopy, AFS; and optogalvanic spectroscopy) and mass spectrometric (magnetic sector, quadrupole mass analyzer, QMA; quadrupole ion trap, QIT; Fourier transform ion cyclotron resonance, FTICR; and time-of-flight, TOF) instrumentation are well suited for coupling to the glow discharge (GD). The GD is a relatively simple device. A potential gradient (500–1500 V) is applied between an anode and a cathode. In most cases, the sample is also the cathode. A noble gas (mostly Ar) is introduced into the discharge region before power initiation. When a potential is applied, electrons are accelerated toward the anode. As these electrons accelerate, they collide with gas atoms. A fraction of these collisions are of sufficient energy to remove an electron from a support gas atom, forming an ion. These ions are, in turn, accelerated toward the cathode. These ions impinge on the surface of the cathode, sputtering sample atoms from the surface. Sputtered atoms that do not redeposit on the surface diffuse into the excitation/ionization regions of the plasma where they can undergo excitation and/or ionization via a number of collisional processes, and the photons or ions created in this way can be detected with optical emission spectroscopy or mass spectrometry. GD sources offer a number of distinct advantages that make them well suited for specific types of analyses. These sources afford direct analysis of solid samples, thus minimizing the sample preparation required for analysis. The nature of the plasma also provides mutually exclusive atomization and excitation processes that help to minimize the matrix effects that plague so many other elemental techniques. In recent years, there is also increasing interest for using GD sources for liquid and gas analyses. In this article, first, the principles of operation of the GD plasma are reviewed, with an emphasis on how those principles relate to optical spectroscopy and mass spectrometry. Basic applications of the GD techniques are considered next. These include bulk analysis, surface analysis, and the analysis of solution and gaseous samples. The requirements necessary to obtain optical information are addressed following the analytical applications. This article focuses on the instrumentation needed to make optical measurements using the GD as an atomization/excitation source. Finally, mass spectrometric instrumentation and interfaces are addressed as they pertain to the use of a GD plasma as an ion source. GD sources provide analytically useful gas-phase species from solid samples. These sources can be interfaced with a variety of spectroscopic and spectrometric instruments for both quantitative and qualitative analyses. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | Publication Date | 2006-09-11 | ||
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | ISBN | Additional Links | |||
| Impact Factor | Times cited | Open Access | |||
| Notes | Approved | Most recent IF: NA | |||
| Call Number | PLASMANT @ plasmant @ | Serial | 4282 | ||
| Permanent link to this record | |||||
| Author | Zhang, F.; Inokoshi, M.; Batuk, M.; Hadermann, J.; Naert, I.; Van Meerbeek, B.; Vleugels, J. | ||||
| Title | Strength, toughness and aging stability of highly-translucent Y-TZP ceramics for dental restorations | Type | A1 Journal article | ||
| Year | 2016 | Publication | Dental Materials | Abbreviated Journal | Dent Mater |
| Volume | 32 | Issue | 32 | Pages | e327-e337 |
| Keywords | A1 Journal article; Electron Microscopy for Materials Science (EMAT); | ||||
| 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. | ||||
| Address | KU Leuven, Department of Materials Engineering, Kasteelpark Arenberg 44, Belgium | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | English | Wos | 000389516400003 | Publication Date | 2016-10-06 |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0109-5641 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 4.07 | Times cited | Open Access | ||
| 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 | ||
| Call Number | EMAT @ emat @ c:irua:136821 | Serial | 4313 | ||
| Permanent link to this record | |||||
| Author | Zalfani, M.; Hu, Z.-Y.; Yu, W.-B.; Mahdouani, M.; Bourguig, R.; Wu, M.; Li, Y.; Van Tendeloo, G.; Djoued, Y.; Su, B.-L. | ||||
| Title | BiVO4/3DOM TiO2 nanocomposites: Effect of BiVO4 as highly efficient visible light sensitizer for highly improved visible light photocatalytic activity in the degradation of dye pollutants | Type | A1 Journal article | ||
| Year | 2016 | Publication | Applied Catalysis B-Environmental | Abbreviated Journal | Appl Catal B-Environ |
| Volume | 205 | Issue | 205 | Pages | 121-132 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | A series of BiVO4/3DOM TiO2 nanocomposites have been synthesized and their photocatalytic activity was investigated under visible light irradiation using the RhB dye as model pollutant molecule in an aqueous solution. The effect of the amount of BiVO4 as visible light sensitizer on the photocatalytic activity of BiVO4/3DOM TiO2 nanocomposites was highlighted. The heterostructured composite system leads to much higher photocatalytic efficiencies than bare 3DOM TiO2 and BiVO4 nanoparticles. As the proportion of BiVO4 in BiVO4/3DOM TiO2 nanocomposites increases from 0.04 to 0.6, the photocatalytic performance of the BiVO4/3DOM TiO2 nanocomposites increases and then decreases after reaching a maximum at 0.2. This improvement in photocatalytic perfomance is related to 1) the interfacial electron transfer efficiency between the coupled materials, 2) the 3DOM TiO2 inverse opal structure with interconnected pores providing an easy mass transfer of the reactant molecules and high accessibility to the active sites and large surface area and 3) the effect of light sensitizer of BiVO4. Intensive studies on structural, textural, optical and surface properties reveal that the electronic interactions between BiVO4 and TiO2 lead to an improved charge separation of the coupled BiVO4/TiO2 system. The photogenerated charge carrier densities increase with increasing the BiVO4 content, which acts as visible light sensitizer to the TiO2 and is responsible for the enhancement in the rate of photocatalytic degradation. However, the photocatalytic activity is reduced when the BiVO4 amount is much higher than that of 3DOM TiO2. Two reasons could account for this behavior. First, with increasing BiVO4 content, the photogenerated electron/hole pairs are accumulated at the surface of the BiVO4 nanoparticles and the recombination rate increases as shown by the PL results. Second, decreasing the amount of 3DOM TiO2 in the nanocomposite decreases the surface area as shown by the BET results. Moreover, the poor adsorptive properties of the BiVO4 photocatalyst also affect the photocatalytic performance, in particular at higher BiVO4 content. The present work demonstrates that BiVO4/3DOM TiO2 is a very promising heterojunction system for visible light photocatalytic applications. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000393931000013 | Publication Date | 2016-12-08 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0926-3373 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 9.446 | Times cited | 52 | Open Access | OpenAccess |
| Notes | Z. Y. Hu and G. Van Tendeloo acknowledge support from the EC Framework 7 program ESTEEM2 (Reference 312483). | Approved | Most recent IF: 9.446 | ||
| Call Number | EMAT @ emat @ | Serial | 4323 | ||
| Permanent link to this record | |||||
| Author | Schalm, O.; Crabbé, A.; Storme, P.; Wiesinger, R.; Gambirasi, A.; Grieten, E.; Tack, P.; Bauters, S.; Kleber, C.; Favaro, M.; Schryvers, D.; Vincze, L.; Terryn, H.; Patelli, A. | ||||
| Title | The corrosion process of sterling silver exposed to a Na2S solution: monitoring and characterizing the complex surface evolution using a multi-analytical approach | Type | A1 Journal article | ||
| Year | 2016 | Publication | Applied Physics A-Materials Science & Processing | Abbreviated Journal | Appl Phys A-Mater |
| Volume | 122 | Issue | 122 | Pages | 903 |
| Keywords | A1 Journal article; Electron Microscopy for Materials Science (EMAT); | ||||
| Abstract | Many historical ‘silver’ objects are composed of sterling silver, a silver alloy containing small amounts of copper. Besides the dramatic impact of copper on the corrosion process, the chemical composition of the corrosion layer evolves continuously. The evolution of the surface during the exposure to a Na2S solution was monitored by means of visual observation at macroscopic level, chemical analysis at microscopic level and analysis at the nanoscopic level. The corrosion process starts with the preferential oxidation of copper, forming mixtures of oxides and sulphides while voids are being created beneath the corrosion layer. Only at a later stage, the silver below the corrosion layer is consumed. This results in the formation of jalpaite and at a later stage of acanthite. The acanthite is found inside the corrosion layer at the boundaries of jalpaite grains and as individual grains between the jalpaite grains but also as a thin film on top of the corrosion layer. The corrosion process could be described as a sequence of 5 subsequent surface states with transitions between these states. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000384753800033 | Publication Date | 2016-09-20 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0947-8396 | ISBN | Additional Links | ||
| Impact Factor | 1.455 | Times cited | 9 | Open Access | |
| Notes | The authors are grateful for the financial support by the EU-FP7 Grant PANNA No. 282998 and for the opportunity to perform SR-XPS measurements at the NanoESCA beamline of the Elettra storage ring, under the approval of the advisory Committee (Proposal No. 20135164), as well as the opportunity to perform XANES measurements at the DUBBLE beamline of the ESRF storage ring (Proposal No. 26-01-990). The authors are grateful for the financial support by the STIMPRO Project FFB150215 of the University of Antwerp. Pieter Tack is funded by a Ph.D. Grant of the Agency for Innovation by Science and Technology (IWT). We would also like to thank Peter Van den Haute for the XRD measurements that were performed at the University of Ghent. | Approved | Most recent IF: 1.455 | ||
| Call Number | EMAT @ emat @ | Serial | 4331 | ||
| Permanent link to this record | |||||
| Author | Doğan, F.; Covaci, L.; Kim, W.; Marsiglio, F. | ||||
| Title | Emerging nonequilibrium bound state in spin-current–local-spin scattering | Type | A1 Journal article | ||
| Year | 2009 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 80 | Issue | 10 | Pages | 104434 |
| Keywords | A1 Journal article | ||||
| Abstract | Magnetization reversal is a well-studied problem with obvious applicability in computer hard drives. One can accomplish a magnetization reversal in at least one of two ways: application of a magnetic field or through a spin current. The latter is more amenable to a fully quantum-mechanical analysis. We formulate and solve the problem whereby a spin current interacts with a ferromagnetic Heisenberg spin chain, to eventually reverse the magnetization of the chain. Spin flips are accomplished through both elastic and inelastic scattering. A consequence of the inelastic-scattering channel, when it is no longer energetically possible, is the occurrence of a nonequilibrium bound state, which is an emergent property of the coupled local plus itinerant spin system. For certain definite parameter values the itinerant spin lingers near the local spins for some time, before eventually leaking out as an outwardly diffusing state. This phenomenon results in spin-flip dynamics and filtering properties for this type of system. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000270383100077 | Publication Date | 2009-09-25 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1098-0121 | ISBN | Additional Links | ||
| Impact Factor | 3.836 | Times cited | Open Access | ||
| Notes | Approved | Most recent IF: 3.836; 2009 IF: 3.475 | |||
| Call Number | UA @ lucian @ | Serial | 4436 | ||
| Permanent link to this record | |||||
| Author | Goodvin, G.L.; Covaci, L.; Berciu, M. | ||||
| Title | Holstein polarons near surfaces | Type | A1 Journal article | ||
| Year | 2009 | Publication | Physical Review Letters | Abbreviated Journal | Phys Rev Lett |
| Volume | 103 | Issue | 17 | Pages | 176402 |
| Keywords | A1 Journal article | ||||
| Abstract | We study the effects of a nearby surface on the spectral weight of a Holstein polaron, using the inhomogeneous momentum average approximation which is accurate over the entire range of electron-phonon (e-ph) coupling strengths. The broken translational symmetry is taken into account exactly. We find that the e-ph coupling gives rise to a large additional surface potential, with strong retardation effects, which may bind surface states even when they are not normally expected. The surface, therefore, has a significant effect and bulk properties are recovered only very far away from it. These results demonstrate that interpretation in terms of bulk quantities of spectroscopic data sensitive only to a few surface layers is not always appropriate. | ||||
| Address | Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1 | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | English | Wos | 000271164500042 | Publication Date | 2009-10-22 |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0031-9007 | ISBN | Additional Links | ||
| Impact Factor | 8.462 | Times cited | 8 | Open Access | |
| Notes | Approved | Most recent IF: 8.462; 2009 IF: 7.328 | |||
| Call Number | UA @ lucian @ | Serial | 4435 | ||
| Permanent link to this record | |||||
| Author | Kim, W.; Covaci, L.; Marsiglio, F. | ||||
| Title | Impurity scattering of wave packets on a lattice | Type | A1 Journal article | ||
| Year | 2006 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 74 | Issue | 20 | Pages | 205120 |
| Keywords | A1 Journal article | ||||
| Abstract | Quantum transport in a lattice is distinct from its counterpart in continuum media. Even a free wave packet travels differently in a lattice than in the continuum. We describe quantum scattering in a one-dimensional lattice and illustrate characteristics of quantum transport such as resonant transmission. In particular we examine the transport characteristics of a random trimer model. We demonstrate the real-time propagation of a wave packet and its phase shift due to impurity configurations. Spin-flip scattering is also taken into account in a spin-chain system. We show how individual spins in the chain evolve as a result of a spin-flip interaction between an incoming electron and a spin chain. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000242409400030 | Publication Date | 2006-11-27 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1098-0121 | ISBN | Additional Links | ||
| Impact Factor | 3.836 | Times cited | 14 | Open Access | |
| Notes | Approved | Most recent IF: 3.836; 2006 IF: 3.107 | |||
| Call Number | UA @ lucian @ | Serial | 4428 | ||
| Permanent link to this record | |||||
| Author | Kim, W.; Covaci, L.; Marsiglio, F. | ||||
| Title | Hidden symmetries of electronic transport in a disordered one-dimensional lattice | Type | A1 Journal article | ||
| Year | 2006 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 73 | Issue | 19 | Pages | 195109 |
| Keywords | A1 Journal article | ||||
| Abstract | Correlated, or extended, impurities play an important role in the transport properties of dirty metals. Here, we examine, in the framework of a tight-binding lattice, the transmission of a single electron through an array of correlated impurities. In particular we show that particles transmit through an impurity array in identical fashion, regardless of the direction of traversal. The demonstration of this fact is straightforward in the continuum limit, but requires a detailed proof for the discrete lattice. We also briefly demonstrate and discuss the time evolution of these scattering states, to delineate regions (in time and space) where the aforementioned symmetry is violated. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000237950400042 | Publication Date | 2006-05-11 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1098-0121 | ISBN | Additional Links | ||
| Impact Factor | 3.836 | Times cited | 5 | Open Access | |
| Notes | Approved | Most recent IF: 3.836; 2006 IF: 3.107 | |||
| Call Number | UA @ lucian @ | Serial | 4429 | ||
| Permanent link to this record | |||||
| Author | Kim, W.; Covaci, L.; Dogan, F.; Marsiglio, F. | ||||
| Title | Quantum mechanics of spin transfer in coupled electron-spin chains | Type | A1 Journal article | ||
| Year | 2007 | Publication | Epl | Abbreviated Journal | Epl-Europhys Lett |
| Volume | 79 | Issue | 6 | Pages | 67004 |
| Keywords | A1 Journal article | ||||
| Abstract | The manner in which spin-polarized electrons interact with a magnetized thin film is currently described by a semi-classical approach. This in turn provides our present understanding of the spin transfer, or spin torque phenomenon. However, spin is an intrinsically quantum-mechanical quantity. Here, we make the first strides towards a fully quantum-mechanical description of spin transfer through spin currents interacting with a Heisenberg-coupled spin chain. Because of quantum entanglement, this requires a formalism based on the density matrix approach. Our description illustrates how individual spins in the chain time-evolve as a result of spin transfer. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000250409500023 | Publication Date | 2007-08-24 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0295-5075 | ISBN | Additional Links | ||
| Impact Factor | 1.957 | Times cited | 3 | Open Access | |
| Notes | Approved | Most recent IF: 1.957; 2007 IF: 2.206 | |||
| Call Number | UA @ lucian @ | Serial | 4430 | ||
| Permanent link to this record | |||||
| Author | Covaci, L.; Berciu, M. | ||||
| Title | Holstein polaron: The effect of coupling to multiple-phonon modes | Type | A1 Journal article | ||
| Year | 2007 | Publication | Epl | Abbreviated Journal | Epl-Europhys Lett |
| Volume | 80 | Issue | 6 | Pages | 67001 |
| Keywords | A1 Journal article | ||||
| Abstract | We investigate the effects of coupling to multiple-phonon modes on the properties of a Holstein polaron. To this end, we generalize the Momentum Average approximations MA((0)) and MA((1)) to deal with multiple-phonon modes. As for a single-phonon mode, these approximations are found to be numerically very efficient. They become exact for very weak or very strong couplings, and are highly accurate in the intermediate regimes, e.g. the spectral weights obey exactly the first six, respectively eight, sum rules. Our results show that the effect on ground-state properties is cumulative in nature. As a result, if the effective coupling to one mode is much larger than to all the others, this mode effectively determines the ground-state properties. However, even very weak coupling to a second phonon mode has important non-perturbational effects on the higher-energy spectrum, in particular on the dispersion and the phonon statistics of the polaron band. This has important consequences on the analysis and interpretation of data for real materials. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000251648300016 | Publication Date | 2007-11-30 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0295-5075 | ISBN | Additional Links | ||
| Impact Factor | 1.957 | Times cited | 9 | Open Access | |
| Notes | Approved | Most recent IF: 1.957; 2007 IF: 2.206 | |||
| Call Number | UA @ lucian @ | Serial | 4431 | ||
| Permanent link to this record | |||||
| Author | Marchand, D.; Covaci, L.; Berciu, M.; Franz, M. | ||||
| Title | Giant proximity effect in a phase-fluctuating superconductor | Type | A1 Journal article | ||
| Year | 2008 | Publication | Physical Review Letters | Abbreviated Journal | Phys Rev Lett |
| Volume | 101 | Issue | 9 | Pages | 097004 |
| Keywords | A1 Journal article | ||||
| Abstract | When a tunneling barrier between two superconductors is formed by a normal material that would be a superconductor in the absence of phase fluctuations, the resulting Josephson effect can undergo an enormous enhancement. We establish this novel proximity effect by a general argument as well as a numerical simulation and argue that it may underlie recent experimental observations of the giant proximity effect between two cuprate superconductors separated by a barrier made of the same material rendered normal by severe underdoping. | ||||
| Address | Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada V6T 1Z1 | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | English | Wos | 000259195800055 | Publication Date | 2008-08-28 |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0031-9007 | ISBN | Additional Links | ||
| Impact Factor | 8.462 | Times cited | 17 | Open Access | |
| Notes | Approved | Most recent IF: 8.462; 2008 IF: 7.180 | |||
| Call Number | UA @ lucian @ | Serial | 4433 | ||
| Permanent link to this record | |||||
| Author | Covaci, L.; Berciu, M. | ||||
| Title | Polaron formation in the presence of Rashba spin-orbit coupling: implications for spintronics | Type | A1 Journal article | ||
| Year | 2009 | Publication | Physical Review Letters | Abbreviated Journal | Phys Rev Lett |
| Volume | 102 | Issue | 18 | Pages | 186403 |
| Keywords | A1 Journal article | ||||
| Abstract | We study the effects of the Rashba spin-orbit coupling on polaron formation, using a suitable generalization of the momentum average approximation. While previous work on a parabolic band model found that spin-orbit coupling increases the effective mass, we show that the opposite holds for a tight-binding model, unless both the spin-orbit and the electron-phonon couplings are weak. It is thus possible to lower the effective mass of the polaron by increasing the spin-orbit coupling. We also show that when the spin-orbit coupling is large as compared to the phonon energy, the polaron retains only one of the spin-polarized bands in its coherent spectrum. This has major implications for the propagation of spin-polarized currents in such materials, and thus for spintronic applications. | ||||
| Address | Department of Physics, University of British Columbia, Vancouver, British Columbia, Canada, V6T 1Z1 | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | English | Wos | 000265948600049 | Publication Date | 2009-05-08 |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0031-9007 | ISBN | Additional Links | ||
| Impact Factor | 8.462 | Times cited | 25 | Open Access | |
| Notes | Approved | Most recent IF: 8.462; 2009 IF: 7.328 | |||
| Call Number | UA @ lucian @ | Serial | 4434 | ||
| Permanent link to this record | |||||
| Author | Colin D. Judge, Nicolas Gauquelin, Lori Walters, Mike Wright, James I. Cole, James Madden, Gianluigi A. Botton, Malcolm Griffiths | ||||
| Title | Intergranular fracture in irradiated Inconel X-750 containing very high concentrations of helium and hydrogen | Type | A1 Journal Article | ||
| Year | 2015 | Publication | Journal of Nuclear Materials | Abbreviated Journal | |
| Volume | 457 | Issue | 457 | Pages | 165-172 |
| Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
| Abstract | In recent years, it has been observed that Inconel X-750 spacers in CANDU reactors exhibits lower ductility with reduced load carrying capacity following irradiation in a reactor environment. The fracture behaviour of ex-service material was also found to be entirely intergranular at high doses. The thermalized flux spectrum in a CANDU reactor leads to transmutation of 58Ni to 59Ni. The 59Ni itself has unusually high thermal neutron reaction cross-sections of the type: (n, γ), (n, p), and (n, α). The latter two reactions, in particular, contribute to a significant enhancement of the atomic displacements in addition to creating high concentrations of hydrogen and helium within the material. Microstructural examinations by transmission electron microscopy (TEM) have confirmed the presence of helium bubbles in the matrix and aligned along grain boundaries and matrix–precipitate interfaces. Helium bubble size and density are found to be highly dependent on the irradiation temperature and material microstructure; the bubbles are larger within grain boundary precipitates. TEM specimens extracted from fracture surfaces and crack tips provide information that is consistent with crack propagation along grain boundaries due to the presence of He bubbles. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000349169100022 | Publication Date | 2014-11-01 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | ISBN | Additional Links | |||
| Impact Factor | Times cited | 29 | Open Access | ||
| Notes | Approved | Most recent IF: NA | |||
| Call Number | EMAT @ emat @ | Serial | 4540 | ||
| Permanent link to this record | |||||
| Author | Macke, S.; Radi, A.; Hamann-Borrero, J.E.; Verna, A.; Bluschke, M.; Brück, S.; Goering, E.; Sutarto, R.; He, F.; Cristiani, G.; Wu, M.; Benckiser, E.; Habermeier, H.-U.; Logvenov, G.; Gauquelin, N.; Botton, G.A; Kajdos, A.P.; Stemmer, S.; Sawatzky,G.A.; Haverkort, M.W.; Keimer, B.; Hinkov, V. | ||||
| Title | Element Specific Monolayer Depth Profiling | Type | A1 Journal Article | ||
| Year | 2014 | Publication | Advanced Materials | Abbreviated Journal | Adv Mater |
| Volume | 26 | Issue | 38 | Pages | 6554-6559 |
| Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) | ||||
| Abstract | The electronic phase behavior and functionality of interfaces and surfaces in complex materials are strongly correlated to chemical composition profiles, stoichiometry and intermixing. Here a novel analysis scheme for resonant X-ray reflectivity maps is introduced to determine such profiles, which is element specific and non-destructive, and which exhibits atomic-layer resolution and a probing depth of hundreds of nanometers. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000343763200004 | Publication Date | 2014-08-08 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1521-4095 | ISBN | Additional Links | ||
| Impact Factor | 19.791 | Times cited | 34 | Open Access | |
| Notes | Approved | Most recent IF: 19.791; 2014 IF: NA | |||
| Call Number | EMAT @ emat @ | Serial | 4541 | ||
| Permanent link to this record | |||||
| Author | N. Gauquelin, D. G. Hawthorn, G. A. Sawatzky, R. X. Liang, D. A. Bonn, W. N. Hardy & G.A. Botton | ||||
| Title | Atomic scale real-space mapping of holes in YBa2Cu3O6+δ | Type | A1 Journal Article | ||
| Year | 2014 | Publication | Nature Communications | Abbreviated Journal | |
| Volume | 5 | Issue | Pages | 4275 | |
| Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
| Abstract | The high-temperature superconductor YBa2Cu3O6+δ consists of two main structural units—a bilayer of CuO2 planes that are central to superconductivity and a CuO2+δ chain layer. Although the functional role of the planes and chains has long been established, most probes integrate over both, which makes it difficult to distinguish the contribution of each. Here we use electron energy loss spectroscopy to directly resolve the plane and chain contributions to the electronic structure in YBa2Cu3O6 and YBa2Cu3O7. We directly probe the charge transfer of holes from the chains to the planes as a function of oxygen content, and show that the change in orbital occupation of Cu is large in the chain layer but modest in CuO2 planes, with holes in the planes doped primarily into the O 2p states. These results provide direct insight into the local electronic structure and charge transfers in this important high-temperature superconductor. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000340615100002 | Publication Date | 2014-07-16 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | ISBN | Additional Links | |||
| Impact Factor | Times cited | 22 | Open Access | ||
| Notes | Approved | Most recent IF: NA | |||
| Call Number | EMAT @ emat @ | Serial | 4542 | ||
| Permanent link to this record | |||||
| Author | Shuhui Sun, Gaixia Zhang, Nicolas Gauquelin, Ning Chen, Jigang Zhou, Songlan Yang, Weifeng Chen, Xiangbo Meng, Dongsheng Geng, Mohammad N. Banis, Ruying Li, Siyu Ye, Shanna Knights, Gianluigi A. Botton, Tsun-Kong Sham & Xueliang Sun | ||||
| Title | Single-atom Catalysis Using Pt/Graphene Achieved through Atomic Layer Deposition | Type | A1 Journal Article | ||
| Year | 2013 | Publication | Scientific Reports | Abbreviated Journal | |
| Volume | 3 | Issue | Pages | 1775 | |
| Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
| Abstract | Platinum-nanoparticle-based catalysts are widely used in many important chemical processes and automobile industries. Downsizing catalyst nanoparticles to single atoms is highly desirable to maximize their use efficiency, however, very challenging. Here we report a practical synthesis for isolated single Pt atoms anchored to graphene nanosheet using the atomic layer deposition (ALD) technique. ALD offers the capability of precise control of catalyst size span from single atom, subnanometer cluster to nanoparticle. The single-atom catalysts exhibit significantly improved catalytic activity (up to 10 times) over that of the state-of-the-art commercial Pt/C catalyst. X-ray absorption fine structure (XAFS) analyses reveal that the low-coordination and partially unoccupied densities of states of 5d orbital of Pt atoms are responsible for the excellent performance. This work is anticipated to form the basis for the exploration of a next generation of highly efficient single-atom catalysts for various applications. |
||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000318334300004 | Publication Date | 2013-05-03 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | ISBN | Additional Links | |||
| Impact Factor | Times cited | 345 | Open Access | ||
| Notes | Approved | Most recent IF: NA | |||
| Call Number | EMAT @ emat @ | Serial | 4543 | ||
| Permanent link to this record | |||||
| Author | N. Gauquelin, E. Benckiser, M. K. Kinyanjui, M. Wu, Y. Lu, G. Christiani, G. Logvenov, H.-U. Habermeier, U. Kaiser, B. Keimer, and G. A. Botton | ||||
| Title | Atomically resolved EELS mapping of the interfacial structure of epitaxially strained LaNiO3/LaAlO3 superlattices | Type | A1 Journal Article | ||
| Year | 2014 | Publication | Physical Review B | Abbreviated Journal | |
| Volume | 90 | Issue | Pages | 195140 | |
| Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
| Abstract | The interfacial atomic structure of a metallic LaNiO3/LaAlO3 superlattice grown on a LaSrAlO4 substrate was investigated using a combination of atomically resolved electron energy loss spectroscopy (EELS) at the Al K, Al L2,3, Sr L2,3, Ni L2,3, La M4,5, and O K edges as well as hybridization mapping of selected features of the O K-edge fine structure.We observe an additional La1−xSrxAl1−yNiyO3 layer at the substrate-superlattice interface, possibly linked to diffusion of Al and Sr into the growing film or a surface reconstruction due to Sr segregation. The roughness of the LaNiO3/LaAlO3 interfaces is found to be on average around one pseudocubic unit cell. The O K-edge EELS spectra revealed reduced spectral weight of the prepeak derived from Ni-O hybridized states in the LaNiO3 layers. We rule out oxygen nonstoichiometry of the LaNiO3 layers and discuss changes in the Ni-O hybridization due to heterostructuring as possible origin. |
||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000345467000003 | Publication Date | 2014-11-20 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | ISBN | Additional Links | |||
| Impact Factor | Times cited | 17 | Open Access | ||
| Notes | Approved | Most recent IF: NA | |||
| Call Number | EMAT @ emat @ | Serial | 4544 | ||
| Permanent link to this record | |||||
| Author | M. K. Kinyanjui, N. Gauquelin, E. Benckiser, H. –U. Habermeier, B. Keimer, U. Kaiser and G.A. Botton | ||||
| Title | Local lattice distortion and anisotropic modulation in Epitaxially Strained LaNiO3/LaAlO3 hetero-structures | Type | A1 Journal Article | ||
| Year | 2014 | Publication | Applied Physics Letters | Abbreviated Journal | |
| Volume | 104 | Issue | Pages | 221909 | |
| Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
| Abstract | Using a complementary combination of x-ray diffraction and atomically resolved imaging we investigated the lattice structure of epitaxial LaNiO3/LaAlO3 superlattices grown on a compressive-strain inducing LaSrAlO4 (001) substrate. A refinement of the structure obtained from the x-ray data revealed the monoclinic I 2/c 1 1 space group. The (Ni/Al)O6 octahedral rotation angle perpendicular to the superlattice plane is enhanced, and the one parallel to the plane is reduced with respect to the corresponding bulk values. High-angle annular dark field imaging was used to determine the lattice parameters within the superlattice unit cell. High-resolution electron microscopy images of the oxygen atoms are consistent with the x-ray results. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000337161700029 | Publication Date | 2014-06-07 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | ISBN | Additional Links | |||
| Impact Factor | Times cited | 22 | Open Access | ||
| Notes | Approved | Most recent IF: NA | |||
| Call Number | EMAT @ emat @ | Serial | 4545 | ||
| Permanent link to this record | |||||
| Author | H. Zhang, N. Gauquelin, G.A. Botton and J.Y.T. Wei | ||||
| Title | Attenuation of superconductivity in manganite/cuprate heterostructures by epitaxially induced CuO intergrowths | Type | A1 Journal Article | ||
| Year | 2013 | Publication | Applied Physics Letters | Abbreviated Journal | |
| Volume | 103 | Issue | Pages | 052606 | |
| Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
| Abstract | We examine the effect of CuO intergrowths on the superconductivity in epitaxial La 2/3 Ca 1/3 MnO 3 / YBa 2 Cu 3 O 7−δ La2/3Ca1/3MnO3/YBa2Cu3O7−δ (LCMO/YBCO) thin-film heterostructures. Scanning transmission electron microscopy on bilayer LCMO/YBCO thin films revealed double CuO-chain intergrowths which form regions with the 247 lattice structure in the YBCO layer. These nanoscale 247 regions do not appear in x-ray diffraction, but can physically account for the reduced critical temperature (Tc) of bilayer thin films relative to unilayer films with the same YBCO thickness, at least down to ∼25 nm. We attribute the CuO intergrowths to the bilayer heteroepitaxial mismatch and the Tc reduction to the generally lower Tc seen in bulk 247 samples. These epitaxially-induced CuO intergrowths provide a microstructural mechanism for the attenuation of superconductivity in LCMO/YBCO heterostructures. |
||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000322723000063 | Publication Date | 2013-08-02 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | ISBN | Additional Links | |||
| Impact Factor | Times cited | 12 | Open Access | ||
| Notes | Approved | Most recent IF: NA | |||
| Call Number | EMAT @ emat @ | Serial | 4546 | ||
| Permanent link to this record | |||||
| Author | L. Zhang, J. Kim, J. Zhang, F. Nan, N. Gauquelin, G.A. Botton, P. He, R. Bashyam, S. Knights | ||||
| Title | Ti4O7 supported Ru@Pt core–shell catalyst for CO-tolerance in PEM fuel cell hydrogen oxidation reaction | Type | A1 Journal Article | ||
| Year | 2013 | Publication | Applied Energy | Abbreviated Journal | |
| Volume | 103 | Issue | March 2013 | Pages | 507-513 |
| Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
| Abstract | A new method is developed for synthesizing Ti4O7 supported Ru@Pt core–shell catalyst (Ru@Pt/Ti4O7) through pyrolysis followed by microwave irradiation. The purpose is to improve the Ru durability of PtRu from core–shell structure and strong bonding to Ti4O7 oxide. In this method, the first step is to co-reduce the mixture of ruthenium precursor and TiO2 in a H2 reducing atmosphere under heat-treatment to obtain a Ru core on Ti4O7 support, and the second step is to create a shell of platinum via microwave irradiation. Energy dispersive X-ray spectrometry, X-ray Diffraction, High-resolution Scanning Transmission Electron Microscopy with the high-angle annular dark-field method and Electron Energy-Loss Spectroscopy are used to demonstrate that this catalyst with larger particles has a core–shell structure with a Ru core and a Pt shell. Electrochemical measurements show Ru@Pt/Ti4O7 catalyst has a higher CO-tolerance capability than that of PtRu/C alloy catalyst. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000314669500048 | Publication Date | 2012-11-11 | |
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | ISBN | Additional Links | |||
| Impact Factor | Times cited | 33 | Open Access | ||
| Notes | Approved | Most recent IF: NA | |||
| Call Number | EMAT @ emat @ | Serial | 4547 | ||
| Permanent link to this record | |||||
| Author | Wang, W.; Patil, B.; Heijkers, S.; Hessel, V.; Bogaerts, A. | ||||
| Title | Nitrogen Fixation by Gliding Arc Plasma: Better Insight by Chemical Kinetics Modelling | Type | A1 Journal Article | ||
| Year | 2017 | Publication | Chemsuschem | Abbreviated Journal | Chemsuschem |
| Volume | 10 | Issue | 10 | Pages | 2110-2110 |
| Keywords | A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
| Abstract | The conversion of atmospheric nitrogen into valuable compounds, that is, so-called nitrogen fixation, is gaining increased interest, owing to the essential role in the nitrogen cycle of the biosphere. Plasma technology, and more specifically gliding arc plasma, has great potential in this area, but little is known about the underlying mechanisms. Therefore, we developed a detailed chemical kinetics model for a pulsed-power gliding-arc reactor operating at atmospheric pressure for nitrogen oxide synthesis. Experiments are performed to validate the model and reasonable agreement is reached between the calculated and measured NO and NO2 yields and the corresponding energy efficiency for NOx formation for different N2/O2 ratios, indicating that the model can provide a realistic picture of the plasma chemistry. Therefore, we can use the model to investigate the reaction pathways for the formation and loss of NOx. The results indicate that vibrational excitation of N2 in the gliding arc contributes significantly to activating the N2 molecules, and leads to an energy efficient way of NOx production, compared to the thermal process. Based on the underlying chemistry, the model allows us to propose solutions on how to further improve the NOx formation by gliding arc technology. Although the energy efficiency of the gliding-arc-based nitrogen fixation process at the present stage is not comparable to the world-scale Haber–Bosch process, we believe our study helps us to come up with more realistic scenarios of entering a cutting-edge innovation in new business cases for the decentralised production of fertilisers for agriculture, in which lowtemperature plasma technology might play an important role. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | Publication Date | 2017-05-11 | ||
| Series Editor | Series Title |
Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1864-5631 | ISBN | Additional Links | ||
| Impact Factor | 7.226 | Times cited | Open Access | Not_Open_Access | |
| Notes | This research was supported by the European Marie Skłodowska- Curie Individual Fellowship “GlidArc” within Horizon 2020 (Grant No.657304), by the FWO project (grant G.0383.16 N) and by the EU project MAPSYN: Microwave, Acoustic and Plasma assisted SYNthesis, under the grant agreement no. CP-IP 309376 of the European Community’s Seventh Framework Program. 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: 7.226 | ||
| Call Number | PLASMANT @ plasmant @ | Serial | 4573 | ||
| Permanent link to this record | |||||