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Author Schouteden, K.; Amin-Ahmadi, B.; Li, Z.; Muzychenko, D.; Schryvers, D.; Van Haesendonck, C.
Title Electronically decoupled stacking fault tetrahedra embedded in Au(111) films Type A1 Journal article
Year 2016 Publication Nature communications Abbreviated Journal Nat Commun
Volume 7 Issue 7 Pages 14001
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Stacking faults are known as defective structures in crystalline materials that typically lower the structural quality of the material. Here, we show that a particular type of defects, i.e., stacking fault tetrahedra (SFTs), exhibits quantized, particle-in-a-box electronic behaviour, revealing a potential synthetic route to decoupled nanoparticles in metal films. We report on the electronic properties of SFTs that exist in Au(111) films, as evidenced by scanning tunnelling microscopy and confirmed by transmission electron microscopy. We find that the SFTs reveal a remarkable decoupling from their metal surroundings, leading to pronounced energy level quantization effects within the SFTs. The electronic behaviour of the SFTs can be described well by the particle-in-a-box model. Our findings demonstrate that controlled preparation of SFTs may offer an alternative way to achieve well decoupled nanoparticles of high crystalline quality in metal thin films without the need of thin insulating layers.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000390367700001 Publication Date 2016-12-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited (up) 7 Open Access
Notes The research in Leuven has been supported by the Research Foundation – Flanders (FWO, Belgium), and by the Flemish Concerted Research Action program (BOF KU Leuven, Project No. GOA/14/007). Z.L. acknowledges the support from the China Scholarship Council (No. 2011624021) and from Internal Funds KU Leuven. K.S. acknowledges additional support from the FWO. The research in Moscow has been supported by grants of the Russian Foundation for Basic Research (RFBR). Approved Most recent IF: 12.124
Call Number EMAT @ emat @ c:irua:138983 Serial 4336
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Author Fatima; Oguz, I.C.; Çakir, D.; Hossain, S.; Mohottige, R.; Gulseren, O.; Oncel, N.
Title On the structural and electronic properties of Ir-silicide nanowires on Si(001) surface Type A1 Journal article
Year 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 120 Issue 120 Pages 095303
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Iridium (Ir) modified Silicon (Si) (001) surface is studied with Scanning Tunneling Microscopy/Spectroscopy (STM/STS) and Density Functional Theory (DFT). A model for Ir-silicide nanowires based on STM images and ab-initio calculations is proposed. According to our model, the Ir adatom is on the top of the substrate dimer row and directly binds to the dimer atoms. I-V curves measured at 77K shows that the nanowires are metallic. DFT calculations confirm strong metallic nature of the nanowires. Published by AIP Publishing.
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Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000383978100030 Publication Date 2016-09-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; 1089-7550 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited (up) 7 Open Access
Notes ; We gratefully acknowledge the NSF (Grant No. DMR-1306101) for financial support. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. ; Approved Most recent IF: 2.068
Call Number UA @ lucian @ c:irua:137132 Serial 4359
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Author Eleftheriadis, G.K.; Filippousi, M.; Tsachouridou, V.; Darda, M.-A.; Sygellou, L.; Kontopoulou, I.; Bouropoulos, N.; Steriotis, T.; Charalambopoulou, G.; Vizirianakis, I.S.; Van Tendeloo, G.; Fatouros, D.G.
Title Evaluation of mesoporous carbon aerogels as carriers of the non-steroidal anti-inflammatory drug ibuprofen Type A1 Journal article
Year 2016 Publication International journal of pharmaceutics Abbreviated Journal Int J Pharmaceut
Volume 515 Issue 515 Pages 262-270
Keywords A1 Journal article; Pharmacology. Therapy; Electron microscopy for materials research (EMAT)
Abstract Towards the development of novel drug carriers for oral delivery of poorly soluble drugs mesoporous aerogel carbons (CAs), namely CA10 and CA20 with different pore sizes (10 and 20 nm, respectively), were evaluated. The non-steroidal anti-inflammatory lipophilic compound ibuprofen was incorporated via passive loading. The drug loaded carbon aerogels were systemically investigated by means of High-Resolution Transmission Electron Microscopy (HR-TEM), Nitrogen physisorption studies, X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC), X-ray photon electron spectroscopy (XPS) and zeta-potential studies. In vitro release studies were performed in simulated intestinal fluids reflecting both fasted (FaSSIF) and fed (FeSSIF) state conditions. Cytotoxicity studies were conducted with human intestinal cells (Caco-2). Drug was in an amorphous state in the pores of the carbon carrier as shown from the physicochemical characterization studies. The results showed marked differences in the release profiles for ibuprofen from the two aerogels in the media tested whereas in vitro toxicity profiles appear to be compatible with potential therapeutic applications at low concentrations. (C) 2016 Elsevier B.V. All rights reserved.
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Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000389150700024 Publication Date 2016-10-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0378-5173 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.649 Times cited (up) 7 Open Access
Notes Approved Most recent IF: 3.649
Call Number UA @ lucian @ c:irua:140231 Serial 4441
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Author Rahemi, V.; Sarmadian, N.; Anaf, W.; Janssens, K.; Lamoen, D.; Partoens, B.; De Wael, K.
Title Unique opto-electronic structure and photo reduction properties of sulfur doped lead chromates explaining their instability in paintings Type A1 Journal article
Year 2017 Publication Analytical chemistry Abbreviated Journal Anal Chem
Volume 89 Issue 89 Pages 3326-3334
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Chrome yellow refers to a group of synthetic inorganic pigments that became popular as an artists material from the second quarter of the 19th century. The color of the pigment, in which the chromate ion acts as a chromophore, is related to its chemical composition (PbCr1-xSxO4, with 0≤x≤0.8) and crystalline structure (monoclinic/orthorhombic). Their shades range from the yellow-orange to the paler yellow tones with increasing sulfate amount. These pigments show remarkable signs of degradation after limited time periods. Pure PbCrO4 (crocoite in its natural form) has a deep yellow color and is relatively stable, while the co-precipitate with lead sulfate (PbCr1-xSxO4) has a paler shade and seems to degrade faster. This degradation is assumed to be related to the reduction of Cr(VI) to Cr(III). We show that on increasing the sulfur(S)-content in chrome yellow, the band gap increases. Typically, when increasing the band gap, one might assume that a decrease in photo activity is the result. However, the photo activity relative to the Cr content, and thus Cr reduction, of sulfur-rich PbCr1-xSxO4 is found to be much higher compared to the sulfur-poor or non-doped lead chromates. This discrepancy can be explained by the evolution of the crystal and electronic structure as function of the sulfur content: first-principles density functional theory calculations show that both the absorption coefficient and reflection coefficients of the lead chromates change as a result of the sulfate doping in such a way that the generation of electron-hole pairs under illumination relative to the total Cr content increases. These changes in the material properties explain why paler shade yellow colors of this pigment are more prone to discoloration. The electronic structure calculations also demonstrate that lead chromate and its co-precipitates are p-type semiconductors, which explains the observed reduction reaction. As understanding this phenomenon is valuable in the field of cultural heritage, this study is the first joint action of photo-electrochemical measurements and first-principles calculations to approve the higher tendency of sulfur-rich lead chromates to darken.
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Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000397478300015 Publication Date 2017-02-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-2700 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.32 Times cited (up) 7 Open Access OpenAccess
Notes ; The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government, department EWI. The BOF-GOA action SOLARPAINT of the University of Antwerp Research Council is acknowledged for financial support. W.A. acknowledges support from BELSPO project S2-ART. Dr. L. Monico and Dr. C. Miliani (ISTM, Perugia) are gratefully acknowledged for helpful discussions and for providing some of the initial batches of the materials studied. ; Approved Most recent IF: 6.32
Call Number UA @ lucian @ c:irua:140886 Serial 4451
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Author Fernández Becerra, V.; Milošević, M.V.
Title Multichiral ground states in mesoscopic p-wave superconductors Type A1 Journal article
Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 94 Issue 94 Pages 184517
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using Ginzburg-Landau formalism, we investigate the effect of confinement on the ground state of mesoscopic chiral p-wave superconductors in the absence of magnetic field. We reveal stable multichiral states with domain walls separating the regions with different chiralities, as well as monochiral states with spontaneous currents flowing along the edges. We show that multichiral states can exhibit identifying signatures in the spatial profile of the magnetic field if those are not screened by edge currents in the case of strong confinement. Such magnetic detection of domain walls in topological superconductors can serve as long-sought evidence of broken time-reversal symmetry. Furthermore, when applying electric current to mesoscopic p-wave samples, we found a hysteretic behavior in the current-voltage characteristic that distinguishes states with and without domain walls, thereby providing another useful hallmark for indirect confirmation of chiral p-wave superconductivity.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000388816700001 Publication Date 2016-11-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9950;2469-9969; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited (up) 7 Open Access
Notes ; This work was supported by the Research Foundation-Flanders (FWO-Vlaanderen), the COST-EU action MP1201, and the MultiSuper network. ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:139241 Serial 4456
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Author Heshmati-Moulai, A.; Simchi, H.; Esmaeilzadeh, M.; Peeters, F.M.
Title Phase transition and spin-resolved transport in MoS2 nanoribbons Type A1 Journal article
Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 94 Issue 94 Pages 235424
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The electronic structure and transport properties of monolayer MoS2 are studied using a tight-binding approach coupled with the nonequilibrium Green's function method. A zigzag nanoribbon of MoS2 is conducting due to the intersection of the edge states with the Fermi level that is located within the bulk gap. We show that applying a transverse electric field results in the disappearance of this intersection and turns the material into a semiconductor. By increasing the electric field the band gap undergoes a two stage linear increase after which it decreases and ultimately closes. It is shown that in the presence of a uniform exchange field, this electric field tuning of the gap can be exploited to open low energy domains where only one of the spin states contributes to the electronic conductance. This introduces possibilities in designing spin filters for spintronic applications.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000394546100005 Publication Date 2016-12-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9950;2469-9969; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited (up) 7 Open Access
Notes ; ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:141978 Serial 4557
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Author Petrovic, M.D.; Milovanović, S.P.; Peeters, F.M.
Title Scanning gate microscopy of magnetic focusing in graphene devices : quantum versus classical simulation Type A1 Journal article
Year 2017 Publication Nanotechnology Abbreviated Journal Nanotechnology
Volume 28 Issue 28 Pages 185202
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract We compare classical versus quantum electron transport in recently investigated magnetic focusing devices (Bhandari et al 2016 Nano Lett. 16 1690) exposed to the perturbing potential of a scanning gate microscope (SGM). Using the Landauer-Buttiker formalism for a multi-terminal device, we calculate resistance maps that are obtained as the SGM tip is scanned over the sample. There are three unique regimes in which the scanning tip can operate (focusing, repelling, and mixed regime) which are investigated. Tip interacts mostly with electrons with cyclotron trajectories passing directly underneath it, leaving a trail of modified current density behind it. Other (indirect) trajectories become relevant when the tip is placed near the edges of the sample, and current is scattered between the tip and the edge. We point out that, in contrast to SGM experiments on gapped semiconductors, the STM tip can induce a pn junction in graphene, which improves contrast and resolution in SGM. We also discuss possible explanations for spatial asymmetry of experimentally measured resistance maps, and connect it with specific configurations of the measuring probes.
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Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000399273800001 Publication Date 2017-03-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0957-4484 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.44 Times cited (up) 7 Open Access
Notes ; This work was supported by the Methusalem program of the Flemish government. ; Approved Most recent IF: 3.44
Call Number UA @ lucian @ c:irua:143639 Serial 4607
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Author Van Eynde, E.; Hu, Z.-Y.; Tytgat, T.; Verbruggen, S.W.; Watte, J.; Van Tendeloo, G.; Van Driessche, I.; Blust, R.; Lenaerts, S.
Title Diatom silica-titania photocatalysts for air purification by bio-accumulation of different titanium sources Type A1 Journal article
Year 2016 Publication Environmental science : nano Abbreviated Journal Environ Sci-Nano
Volume 3 Issue 5 Pages 1052-1061
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL)
Abstract We present a green, biological production route for silica-titania photocatalysts using diatom microalgae. Diatoms are single-celled, eukaryotic microalgae (2-2000 mu m) that self-assemble soluble silicon (Si(OH)(4)) into intricate silica cell walls, called frustules. These diatom frustules are formed under ambient conditions and consist of hydrated silica with specific 3D morphologies and micro-meso or macroporosity. A remarkable characteristic of diatoms is their ability to bioaccumulate soluble titanium from cell culture medium and incorporate them into their nanostructured silica cell wall. Controlled cultivation of the diatom Pinnularia sp. on soluble titanium in a batch process resulted in the biological immobilisation of titanium dioxide in the porous 3D architecture of the frustules. Six different titanium sources are tested. The silica-titania frustules were isolated by treating the harvested Pinnularia cells with nitric acid (65%) or by high temperature treatment. Thermal annealing converted the amorphous titania into crystalline titania. The produced silica-titania material is evaluated towards photocatalytic activity for acetaldehyde (C2H4O) abatement. Frustules cultivated with TiBaldH showed the highest photocatalytic performance. Comparison of the photocatalytic activity with P25 reveals that P25 has a 4 fold higher photocatalytic activity, but when photocatalytic activity is normalized for titania content, the frustules show double activity. Further material characterization (morphology, crystallinity, surface area and elemental distribution) of the TiBaldH silica-titania frustules provides additional insight into their structure-activity relationship. These natural biosilicatitania materials have excellent properties for photocatalytic purposes, including high surface area (108 m(2) g(-1)) and good porosity, and show reliable immobilization of TiO2 in the ordered structure of the diatom frustule.
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Publisher Royal Society of Chemistry Place of Publication Cambridge Editor
Language Wos 000385257900011 Publication Date 2016-07-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2051-8153; 2051-8161 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.047 Times cited (up) 7 Open Access
Notes ; ; Approved Most recent IF: 6.047
Call Number UA @ lucian @ c:irua:144751 Serial 4644
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Author Bartolome, E.; Cayado, P.; Solano, E.; Mocuta, C.; Ricart, S.; Mundet, B.; Coll, M.; Gazquez, J.; Meledin, A.; Van Tendeloo, G.; Valvidares, S.M.; Herrero-Martin, J.; Gargiani, P.; Pellegrin, E.; Magen, C.; Puig, T.; Obradors, X.
Title Hybrid YBa2Cu3O7 superconducting-ferromagnetic nanocomposite thin films prepared from colloidal chemical solutions Type A1 Journal article
Year 2017 Publication Advanced Electronic Materials Abbreviated Journal Adv Electron Mater
Volume 3 Issue 7 Pages 1700037
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract High T-c superconductor-ferromagnetic heterostructures constitute an appealing playground to study the interplay between flux vortices and magnetic moments. Here, the capability of a solution-derived route to grow hybrid YBa2Cu3O7-ferromagnetic nanocomposite epitaxial thin films from preformed spinel ferrite (MFe2O4, M = Mn, Co) nanoparticles (NPs) is explored. The characterization, performed using a combination of structural and magnetic techniques, reveals the complexity of the resulting nanocomposites. Results show that during the YBCO growth process, most of the NPs evolve to ferromagnetic double-perovskite (DP) phases (YBaCu2-x-yFexCoyO5/YBaCoFeO5), while a residual fraction of preformed ferrite NPs may remain in the YBCO matrix. Magnetometry cycles reflect the presence of ferromagnetic structures associated to the DPs embedded in the superconducting films. In addition, a superparamagnetic signal that may be associated with a diluted system of ferromagnetic clusters around complex defects has been detected, as previously observed in standard YBCO films and nanocomposites. The hybrid nanocomposites described in this work will allow studying several fundamental issues like the nucleation of superconductivity and the mechanisms of magnetic vortex pinning in superconducting/ferromagnetic heterostructures.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000405205300010 Publication Date 2017-05-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2199-160x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.193 Times cited (up) 7 Open Access Not_Open_Access
Notes ; The authors acknowledge financial support from Spanish Ministry of Economy and Competitiveness through the “Severo Ochoa” Programme for Centres of Excellence in R& D (SEV-2015-0496), CONSOLIDER Excellence Network (MAT2015-68994-REDC), COACHSUPENERGY project (MAT2014-51778-C21-R, cofinanced by the European Regional Development Fund), and from the Catalan Government with 2014-SGR753 and Xarmae. Some of the electron microscopy work has also been conducted in the Laboratorio de Microscopias Avanzadas (LMA) at Instituto de Nanociencia de Aragcn (INA) at the University of Zaragoza. Part of the electron microscopy work in EMAT group ( University of Antwerp) was performed within the framework of the EUROTAPES project (FP7-NMP. 2011.2.2-1 Grant No. 280432), funded by the European Union. Work at INA-LMA was supported by NanoAraCat. Research at UCM (J.S.) was supported by the ERC starting Investigator Award, Grant No. 239739 STEMOX and Juan de la Cierva Program JCI2011-09428 (MICINN-Spain). The XMCD experiments were performed at the BOREAS beamline of the ALBA Synchrotron Light Facility with the collaboration of ALBA staff. The authors would like to thank SOLEIL synchrotron for allocating beamtime and the DiffAbs beamline staff for help during the experiments. ; Approved Most recent IF: 4.193
Call Number UA @ lucian @ c:irua:144852 Serial 4719
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Author Ramakers, M.; Medrano, J.A.; Trenchev, G.; Gallucci, F.; Bogaerts, A.
Title Revealing the arc dynamics in a gliding arc plasmatron: a better insight to improve CO2conversion Type A1 Journal article
Year 2017 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 26 Issue 12 Pages 125002
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A gliding arc plasmatron (GAP) is very promising for CO2 conversion into value-added chemicals, but to further improve this important application, a better understanding of the arc behavior is indispensable. Therefore, we study here for the first time the dynamic arc behavior of the GAP by means of a high-speed camera, for different reactor configurations and in a wide range of operating conditions. This allows us to provide a complete image of the behavior of the gliding arc. More specifically, the arc body shape, diameter, movement and rotation speed are analyzed and discussed. Clearly, the arc movement and shape relies on a number of factors, such as gas turbulence, outlet diameter, electrode surface, gas contraction and buoyance force. Furthermore, we also compare the experimentally measured arc movement to a state-of-the-art 3D-plasma model, which predicts the plasma movement and rotation speed with very good accuracy, to gain further insight in the underlying mechanisms. Finally, we correlate the arc dynamics with the CO2 conversion and energy efficiency, at exactly the same conditions, to explain the effect of these parameters on the CO2 conversion process. This work is important for understanding and optimizing the GAP for CO2 conversion.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000414675000001 Publication Date 2017-11-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1361-6595 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited (up) 7 Open Access OpenAccess
Notes This work was supported by the Belgian Federal Office for Science Policy (BELSPO) and the Fund for Scientific Research Flanders (FWO; grant numbers G.0383.16N and 11U5316N). Approved Most recent IF: 3.302
Call Number PLASMANT @ plasmant @c:irua:147023 Serial 4761
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Author Morozov, V.A.; Batuk, D.; Batuk, M.; Basovich, O.M.; Khaikina, E.G.; Deyneko, D.V.; Lazoryak, B.I.; Leonidov, I.I.; Abakumov, A.M.; Hadermann, J.
Title Luminescence Property Upgrading via the Structure and Cation Changing in AgxEu(2–x)/3WO4and AgxGd(2–x)/3–0.3Eu0.3WO4 Type A1 Journal article
Year 2017 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 29 Issue 20 Pages 8811-8823
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The creation and ordering of A-cation vacancies and the effect of cation substitutions in the scheelite-type framework are investigated as a factor for controlling the scheelite-type structure and luminescence properties. AgxEu3+(2−x)/3□(1−2x)/3WO4 and AgxGd(2−x)/3−0.3Eu3+0.3□(1−2x)/3WO4 (x = 0.5−0) scheelite-type phases were synthesized by a solid state method, and their structures were investigated using a combination of transmission electron microscopy techniques and powder synchrotron X-ray diffraction. Transmission electron microscopy also revealed the (3 + 1)D incommensurately modulated character of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.286, 0.2) phases. The crystal structures of the scheelite-based AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286, 0.2) red phosphors have been refined from high resolution synchrotron powder X-ray diffraction data. The luminescence properties of all phases under near-ultraviolet (n-UV) light have been investigated. The excitation spectra of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286,0.2) phosphors show the strongest absorption at 395 nm, which matches well with the commercially available n-UV-emitting GaN-based LED chip. The excitation spectra of the Eu2/3□1/3WO4 and Gd0.367Eu0.30□1/3WO4 phases exhibit the highest contribution of the charge transfer band at 250 nm and thus the most efficient energy transfer mechanism between the host and the luminescent ion as compared to direct excitation. The emission spectra of all samples indicate an intense red emission due to the 5D0 → 7F2 transition of Eu3+. Concentration dependence of the 5D0 → 7F2 emission for AgxEu(2−x)/3□(1−2x)/3WO4 samples differs from the same dependence for the earlier studied NaxEu3+(2−x)/3□(1−2x)/3MoO4 (0 ≤ x ≤ 0.5) phases. The intensity of the 5D0 → 7F2 emission is reduced almost 7 times with decreasing x from 0.5 to 0, but it practically does not change in the range from x = 0.286 to x = 0.200. The emission spectra of Gd-containing samples show a completely different trend as compared to only Eu-containing samples. The Eu3+ emission under excitation of Eu3+(5L6) level (λex = 395 nm) increases more than 2.5 times with the increasing Gd3+ concentration from 0.2 (x = 0.5) to 0.3 (x = 0.2) in the AgxGd(2−x)/3−0.3Eu3+0.3□(1−2x)/3WO4, after which it remains almost constant for higher Gd3+ concentrations.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000413884900028 Publication Date 2017-10-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited (up) 7 Open Access Not_Open_Access
Notes This research was supported by FWO (project G039211N), Flanders Research Foundation. V.A.M. is grateful for financial support of the Russian Foundation for Basic Research (Grant 15-03-07741). E.G.K. and O.M.B. are grateful for financial support of the Russian Foundation for Basic Research (Grants 13-03-01020 and 16-03-00510). D.V.D. is grateful for financial support of the Russian Foundation for Basic Research (Grant 16-33-00197) and the Foundation of the President of the Russian Federation (Grant MK-7926.2016.5.). We are grateful to the ESRF for granting the beamtime. Experimental support of Andy Fitch at the ID31 beamline of ESRF is kindly acknowledged. Approved Most recent IF: 9.466
Call Number EMAT @ emat @c:irua:147241 Serial 4768
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Author Tsirlin, A.A.; Rousochatzakis, I.; Filimonov, D.; Batuk, D.; Frontzek, M.; Abakumov, A.M.
Title Spin-reorientation transitions in the Cairo pentagonal magnet Bi4Fe5O13F Type A1 Journal article
Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 96 Issue 9 Pages 094420
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We show that interlayer spins play a dual role in the Cairo pentagonal magnet Bi4Fe5O13F, on one hand mediating the three-dimensional magnetic order, and on the other driving spin-reorientation transitions both within and between the planes. The corresponding sequence of magnetic orders unraveled by neutron diffraction and Mossbauer spectroscopy features two orthogonal magnetic structures described by opposite local vector chiralities, and an intermediate, partly disordered phase with nearly collinear spins. A similar collinear phase has been predicted theoretically to be stabilized by quantum fluctuations, but Bi4Fe5O13F is very far from the relevant parameter regime. While the observed in-plane reorientation cannot be explained by any standard frustration mechanism, our ab initio band-structure calculations reveal strong single-ion anisotropy of the interlayer Fe3+ spins that turns out to be instrumental in controlling the local vector chirality and the associated interlayer order.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000411161700002 Publication Date 2017-09-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited (up) 7 Open Access OpenAccess
Notes We are grateful to J.-M. Perez-Mato and Dmitry Khalyavin for valuable discussions on the magnetic structures and symmetries. D.F. and A.A. are grateful to the Russian Science Foundation (Grant No. 14-13-00680) for support. A.T. was supported by the Federal Ministry for Education and Research through the Sofja Kovalevskaya Award of the Alexander von Humboldt Foundation. This work is based on experiments performed at the Swiss spallation neutron source SINQ, Paul Scherrer Institut, Villigen, Switzerland. Approved Most recent IF: 3.836
Call Number EMAT @ emat @c:irua:146748 Serial 4774
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Author Zografos, O.; Manfrini, M.; Vaysset, A.; Sorée, B.; Ciubotaru, F.; Adelmann, C.; Lauwereins, R.; Raghavan, P.; Radu, I.P.
Title Exchange-driven magnetic logic Type A1 Journal article
Year 2017 Publication Scientific reports Abbreviated Journal Sci Rep-Uk
Volume 7 Issue Pages 12154
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Direct exchange interaction allows spins to be magnetically ordered. Additionally, it can be an efficient manipulation pathway for low-powered spintronic logic devices. We present a novel logic scheme driven by exchange between two distinct regions in a composite magnetic layer containing a bistable canted magnetization configuration. By applying a magnetic field pulse to the input region, the magnetization state is propagated to the output via spin-to-spin interaction in which the output state is given by the magnetization orientation of the output region. The dependence of this scheme with input field conditions is extensively studied through a wide range of micromagnetic simulations. These results allow different logic operating modes to be extracted from the simulation results, and majority logic is successfully demonstrated.
Address
Corporate Author Thesis
Publisher Nature Publishing Group Place of Publication London Editor
Language Wos 000411434900020 Publication Date 2017-09-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2045-2322 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.259 Times cited (up) 7 Open Access
Notes ; ; Approved Most recent IF: 4.259
Call Number UA @ lucian @ c:irua:146742 Serial 4784
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Author Zhang, L.-F.; Flammia, L.; Covaci, L.; Perali, A.; Milošević, M.V.
Title Multifaceted impact of a surface step on superconductivity in atomically thin films Type A1 Journal article
Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 96 Issue 10 Pages 104509
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Recent experiments show that an atomic step on the surface of atomically thin metallic films can strongly affect electronic transport. Here we reveal multiple and versatile effects that such a surface step can have on superconductivity in ultrathin films. By solving the Bogoliubov-de Gennes equations self-consistently in this regime, where quantum confinement dominates the emergent physics, we show that the electronic structure is profoundly modified on the two sides of the step, as is the spatial distribution of the superconducting order parameter and its dependence on temperature and electronic gating. Furthermore, the surface step changes nontrivially the transport properties both in the proximity-induced superconducting pair correlations and the Josephson effect, depending on the step height. These results offer a new route to tailor superconducting circuits and design atomically thin heterojunctions made of one same material.
Address
Corporate Author Thesis
Publisher American Physical Society Place of Publication New York, N.Y Editor
Language Wos 000411076000012 Publication Date 2017-09-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited (up) 7 Open Access
Notes ; This work was supported by the Research Foundation Flanders (FWO-Vlaanderen), the Special Research Funds of the University of Antwerp (TOPBOF project) and the Italian MIUR through the PRIN 2015 program (Contract No. 2015C5SEJJ001). ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:146750 Serial 4790
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Author Yusupov, M.; Yan, D.; Cordeiro, R.M.; Bogaerts, A.
Title Atomic scale simulation of H2O2permeation through aquaporin: toward the understanding of plasma cancer treatment Type A1 Journal article
Year 2018 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 51 Issue 12 Pages 125401
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Experiments have demonstrated the potential selective anticancer capacity of cold atmospheric plasmas (CAPs), but the underlying mechanisms remain unclear. Using computer simulations, we try to shed light on the mechanism of selectivity, based on aquaporins (AQPs), i.e. transmembrane protein channels transferring external H 2 O 2 and other reactive oxygen species, created e.g. by CAPs, to the cell interior. Specifically, we perform molecular dynamics simulations for the permeation of H 2 O 2 through AQP1 (one of the members of the AQP family) and the palmitoyl-oleoyl-phosphatidylcholine (POPC) phospholipid bilayer (PLB). The free energy barrier of H 2 O 2 across AQP1 is lower than for the POPC PLB, while the permeability coefficient, calculated using the free energy and diffusion rate profiles, is two orders of magnitude higher. This indicates that the delivery of H 2 O 2 into the cell interior should be through AQP. Our study gives a better insight into the role of AQPs in the selectivity of CAPs for treating cancer cells.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000426378100001 Publication Date 2018-02-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited (up) 7 Open Access OpenAccess
Notes MY gratefully acknowledges financial support from the Research Foundation—Flanders (FWO) via Grant No. 1200216N and a travel grant to George Washington University (GWU). 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 Super- computer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UA. Work at GWU was supported by the National Science Foundation, grant 1465061. RMC thanks FAPESP and CNPq for finan- cial support (Grant Nos. 2012/50680-5 and 459270/2014-1, respectively). Approved Most recent IF: 2.588
Call Number PLASMANT @ plasmant @c:irua:149382 Serial 4811
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Author Grieb, T.; Tewes, M.; Schowalter, M.; Müller-Caspary, K.; Krause, F.F.; Mehrtens, T.; Hartmann, J.-M.; Rosenauer, A.
Title Quantitative HAADF STEM of SiGe in presence of amorphous surface layers from FIB preparation Type A1 Journal article
Year 2018 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 184 Issue B Pages 29-36
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract <script type='text/javascript'>document.write(unpmarked('The chemical composition of four Si1-xGex layers grown on silicon was determined from quantitative scanning transmission electron microscopy (STEM). The chemical analysis was performed by a comparison of the high-angle annular dark field (HAADF) intensity with multislice simulations. It could be shown that amorphous surface layers originating from the preparation process by focused-ion beam (FIB) at 30 kV have a strong influence on the quantification: the local specimen thickness is overestimated by approximately a factor of two, and the germanium concentration is substantially underestimated. By means of simulations, the effect of amorphous surface layers on the HAADF intensity of crystalline silicon and germanium is investigated. Based on these simulations, a method is developed to analyze the experimental HAADF-STEM images by taking the influence of the amorphous layers into account which is done by a reduction of the intensities by multiplication with a constant factor. This suggested modified HAADF analysis gives germanium concentrations which are in agreement with the nominal values. The same TEM lamella was treated with low-voltage ion milling which removed the amorphous surface layers completely. The results from subsequent quantitative HAADF analyses are in agreement with the nominal concentrations which validates the applicability of the used frozen-lattice based multislice simulations to describe the HAADF scattering of Si1-xGex in STEM. (C) 2017 Elsevier B.V. All rights reserved.'));
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000417779800004 Publication Date 2017-10-14
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 (up) 7 Open Access Not_Open_Access
Notes ; This work was supported by the German Research Foundation (DFG) under Contract No. RO2057/11-1. ; Approved Most recent IF: 2.843
Call Number UA @ lucian @ c:irua:148500 Serial 4893
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Author Wu, J.; Zhang, L.; Xin, X.; Zhang, Y.; Wang, H.; Sun, A.; Cheng, Y.; Chen, X.; Xu, G.
Title Electrorheological fluids with high shear stress based on wrinkly tin titanyl oxalate Type A1 Journal article
Year 2018 Publication ACS applied materials and interfaces Abbreviated Journal Acs Appl Mater Inter
Volume 10 Issue 7 Pages 6785-6792
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Electrorheological (ER) fluids are considered as a type of smart fluids because their rheological characteristics can be altered through an electric field. The discovery of giant ER effect revived the researchers' interest in the ER technological area. However, the poor stability including the insufficient dynamic shear stress, the large leakage current density, and the sedimentation tendency still hinders their practical applications. Herein, we report a facile and scalable coprecipitation method for synthesizing surfactant-free tin titanyl oxalate (TTO) particles with tremella-like wrinkly microstructure (W-TTO). The W-TTO-based ER fluids exhibit enhanced ER activity compared to that of the pristine TTO because of the improved wettability between W-TTO and the silicone oil. In addition, the static yield stress and leakage current of W-TTO ER fluids also show a fine time stability during the 30 day tests. More importantly, the dynamic shear stress of W-TTO ER fluids can remain stable throughout the shear rate range, which is valuable for their use in engineering applications. The results in this work provided a promising strategy to solving the long-standing problem of ER fluid stability. Moreover, this convenient route of synthesis may be considered a green approach for the mass production of giant ER materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000426143900081 Publication Date 2018-02-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1944-8244 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.504 Times cited (up) 7 Open Access OpenAccess
Notes ; The work was supported by the National Natural Science Foundation of China (Grant 21573267, 11674335), the Youth Innovation Promotion Association CAS (2013196), and the Program for Ningbo Municipal Science and Technology Innovative Research Team (2015B11002, 2016B10005). ; Approved Most recent IF: 7.504
Call Number UA @ lucian @ c:irua:149911 Serial 4931
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Author Wang, W.; Berthelot, A.; Zhang, Q.; Bogaerts, A.
Title Modelling of plasma-based dry reforming: how do uncertainties in the input data affect the calculation results? Type A1 Journal article
Year 2018 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 51 Issue 20 Pages 204003
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract One of the main issues in plasma chemistry modeling is that the cross sections and rate coefficients are subject to uncertainties, which yields uncertainties in the modeling results and hence hinders the predictive capabilities. In this paper, we reveal the impact of these uncertainties on the model predictions of plasma-based dry reforming in a dielectric barrier discharge. For this purpose, we performed a detailed uncertainty analysis and sensitivity study. 2000 different combinations of rate coefficients, based on the uncertainty from a log-normal distribution, are used to predict the uncertainties in the model output. The uncertainties in the electron density and electron temperature are around 11% and 8% at the maximum of the power deposition for a 70% confidence level. Still, this can have a major effect on the electron impact rates and hence on the calculated conversions of CO2 and CH4, as well as on the selectivities of CO and H2. For the CO2 and CH4 conversion, we obtain uncertainties of 24% and 33%, respectively. For the CO and H2 selectivity, the corresponding uncertainties are 28% and 14%, respectively. We also identify which reactions contribute most to the uncertainty in the model predictions. In order to improve the accuracy and reliability of plasma chemistry models, we recommend using only verified rate coefficients, and we point out the need for dedicated verification experiments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000430960600003 Publication Date 2018-04-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited (up) 7 Open Access OpenAccess
Notes We acknowledge financial support from the Fund for Scientific Research Flanders (FWO) (Grant No. G.0383.16N) and the TOP-BOF project of the University of Antwerp. The calculations were carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Centre VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. Approved Most recent IF: 2.588
Call Number PLASMANT @ plasmant @c:irua:151292 Serial 4958
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Author Flammia, L.; Zhang, L.-F.; Covaci, L.; Perali, A.; Milošević, M.V.
Title Superconducting nanoribbon with a constriction : a quantum-confined Josephson junction Type A1 Journal article
Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 97 Issue 13 Pages 134514
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Extended defects are known to strongly affect nanoscale superconductors. Here, we report the properties of superconducting nanoribbons with a constriction formed between two adjacent step edges by solving the Bogoliubov-de Gennes equations self-consistently in the regime where quantum confinement is important. Since the quantum resonances of the superconducting gap in the constricted area are different from the rest of the nanoribbon, such constriction forms a quantum-confined S-S'-S Josephson junction, with a broadly tunable performance depending on the length and width of the constriction with respect to the nanoribbon, and possible gating. These findings provide an intriguing approach to further tailor superconducting quantum devices where Josephson effect is of use.
Address
Corporate Author Thesis
Publisher American Physical Society Place of Publication New York, N.Y Editor
Language Wos 000430161500004 Publication Date 2018-04-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited (up) 7 Open Access
Notes ; This work was supported by the Research Foundation Flanders (FWO-Vlaanderen), the Special Research Funds of the University of Antwerp (TOPBOF), the Italian MIUR through the PRIN 2015 program (Contract No. 2015C5SEJJ001), the MultiSuper network, and the EU-COST NANOCOHYBRI action CA16218. ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:150754UA @ admin @ c:irua:150754 Serial 4980
Permanent link to this record
 

 
Author Gao, M.; Zhang, Y.; Wang, H.; Guo, B.; Zhang, Q.; Bogaerts, A.
Title Mode Transition of Filaments in Packed-Bed Dielectric Barrier Discharges Type A1 Journal article
Year 2018 Publication Catalysts Abbreviated Journal Catalysts
Volume 8 Issue 6 Pages 248
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We investigated the mode transition from volume to surface discharge in a packed bed dielectric barrier discharge reactor by a two-dimensional particle-in-cell/Monte Carlo collision method. The calculations are performed at atmospheric pressure for various driving voltages and for gas mixtures with different N2 and O2 compositions. Our results reveal that both a change of the driving voltage and gas mixture can induce mode transition. Upon increasing voltage, a mode transition from hybrid (volume+surface) discharge to pure surface discharge occurs, because the charged species can escape much more easily to the beads and charge the bead surface due to the strong electric field at high driving voltage. This significant surface charging will further enhance the tangential component of the electric field along the dielectric bead surface, yielding surface ionization waves (SIWs). The SIWs will give rise to a high concentration of reactive species on the surface, and thus possibly enhance the surface activity of the beads, which might be of interest for plasma catalysis. Indeed, electron impact excitation and ionization mainly take place near the bead surface. In addition, the propagation speed of SIWs becomes faster with increasing N2 content in the gas mixture, and slower with increasing O2 content, due to the loss of electrons by attachment to O2

molecules. Indeed, the negative O-2 ion density produced by electron impact attachment is much higher than the electron and positive O+2 ion density. The different ionization rates between N2 and O2 gases will create different amounts of electrons and ions on the dielectric bead surface, which might also have effects in plasma catalysis.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000436128600027 Publication Date 2018-06-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2073-4344 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.082 Times cited (up) 7 Open Access OpenAccess
Notes The authors are very grateful to Wei Jiang for the useful discussions on the particle-incell/ Monte-Carlo collision model. Approved Most recent IF: 3.082
Call Number PLASMANT @ plasmant @c:irua:152171 Serial 4991
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Author Yusupov, M.; Lackmann, J.-W.; Razzokov, J.; Kumar, S.; Stapelmann, K.; Bogaerts, A.
Title Impact of plasma oxidation on structural features of human epidermal growth factor Type A1 Journal article
Year 2018 Publication Plasma processes and polymers Abbreviated Journal Plasma Process Polym
Volume 15 Issue 8 Pages 1800022
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We perform computer simulations supported by experiments to investigate the oxidation of an important signaling protein, that is, human epidermal growth factor (hEGF), caused by cold atmospheric plasma (CAP) treatment. Specifically, we study the conformational changes of hEGF with different degrees of oxidation, to mimic short and long CAP treatment times. Our results indicate that the oxidized structures become more flexible, due to their conformational changes and breakage of the disulfide bonds, especially at higher oxidation degrees. MM/GBSA calculations reveal that an increasing oxidation level leads to a lower binding free energy of hEGF with its receptor. These results help to understand the fundamentals of the use of CAP for wound healing versus cancer treatment at short and longer treatment times.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000441895700004 Publication Date 2018-05-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1612-8850 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.846 Times cited (up) 7 Open Access Not_Open_Access
Notes Fonds Wetenschappelijk Onderzoek, 1200216N ; Bundesministerium für Bildung und Forschung, 03Z22DN12 ; Approved Most recent IF: 2.846
Call Number PLASMANT @ plasmant @c:irua:152815 Serial 5008
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Author de de Meux, A.J.; Pourtois, G.; Genoe, J.; Heremans, P.
Title Defects in amorphous semiconductors : the case of amorphous indium gallium zinc oxide Type A1 Journal article
Year 2018 Publication Physical review applied Abbreviated Journal Phys Rev Appl
Volume 9 Issue 9 Pages 054039
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Based on a rational classification of defects in amorphous materials, we propose a simplified model to describe intrinsic defects and hydrogen impurities in amorphous indium gallium zinc oxide (a-IGZO). The proposed approach consists of organizing defects into two categories: point defects, generating structural anomalies such as metal-metal or oxygen-oxygen bonds, and defects emerging from changes in the material stoichiometry, such as vacancies and interstitial atoms. Based on first-principles simulations, it is argued that the defects originating from the second group always act as perfect donors or perfect acceptors. This classification simplifies and rationalizes the nature of defects in amorphous phases. In a-IGZO, the most important point defects are metal-metal bonds (or small metal clusters) and peroxides (O-O single bonds). Electrons are captured by metal-metal bonds and released by the formation of peroxides. The presence of hydrogen can lead to two additional types of defects: metal-hydrogen defects, acting as acceptors, and oxygen-hydrogen defects, acting as donors. The impact of these defects is linked to different instabilities observed in a-IGZO. Specifically, the diffusion of hydrogen and oxygen is connected to positive-and negative-bias stresses, while negative-bias illumination stress originates from the formation of peroxides.
Address
Corporate Author Thesis
Publisher American Physical Society Place of Publication College Park, Md Editor
Language Wos 000433070900003 Publication Date 2018-05-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2331-7019 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.808 Times cited (up) 7 Open Access OpenAccess
Notes Approved Most recent IF: 4.808
Call Number UA @ lucian @ c:irua:151497 Serial 5019
Permanent link to this record
 

 
Author Korneychuk, S.; Partoens, B.; Guzzinati, G.; Ramaneti, R.; Derluyn, J.; Haenen, K.; Verbeeck, J.
Title Exploring possibilities of band gap measurement with off-axis EELS in TEM Type A1 Journal article
Year 2018 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 189 Issue 189 Pages 76-84
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract A technique to measure the band gap of dielectric materials with high refractive index by means of energy electron loss spectroscopy (EELS) is presented. The technique relies on the use of a circular (Bessel) aperture and suppresses Cherenkov losses and surface-guided light modes by enforcing a momentum transfer selection. The technique also strongly suppresses the elastic zero loss peak, making the acquisition, interpretation and signal to noise ratio of low loss spectra considerably better, especially for excitations in the first few eV of the EELS spectrum. Simulations of the low loss inelastic electron scattering probabilities demonstrate the beneficial influence of the Bessel aperture in this setup even for high accelerating voltages. The importance of selecting the optimal experimental convergence and collection angles is highlighted. The effect of the created off-axis acquisition conditions on the selection of the transitions from valence to conduction bands is discussed in detail on a simplified isotropic two band model. This opens the opportunity for deliberately selecting certain transitions by carefully tuning the microscope parameters. The suggested approach is experimentally demonstrated and provides good signal to noise ratio and interpretable band gap signals on reference samples of diamond, GaN and AlN while offering spatial resolution in the nm range. (C) 2018 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000432868500008 Publication Date 2018-03-29
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 (up) 7 Open Access OpenAccess
Notes ; S.K., B.P. and J.V. acknowledge funding from the “Geconcentreerde Onderzoekacties” (GOA) project “Solarpaint” of the University of Antwerp. S.K. and J.V. also acknowledge the FWO-Vlaanderen for financial support under contract G.0044.13N 'Charge ordering'. Financial support via the Methusalem “NANO” network is acknowledged. GG acknowledges support from a postdoctoral fellowship grant from the Fonds Wetenschappelijk Onderzoek-Vlaanderen (FWO). ; Approved Most recent IF: 2.843
Call Number UA @ lucian @ c:irua:151472UA @ admin @ c:irua:151472 Serial 5026
Permanent link to this record
 

 
Author Barreca, D.; Gri, F.; Gasparotto, A.; Carraro, G.; Bigiani, L.; Altantzis, T.; Žener, B.; Lavrenčič Štangar, U.; Alessi, B.; Padmanaban, D.B.; Mariotti, D.; Maccato, C.
Title Multi-functional MnO2nanomaterials for photo-activated applications by a plasma-assisted fabrication route Type A1 Journal article
Year 2019 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 11 Issue 1 Pages 98-108
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Supported MnO2-based nanomaterials were fabricated on fluorine-doped tin oxide substrates by plasma enhanced-chemical vapor deposition (PE-CVD) between 100 °C and 400 °C, starting from a fluorinated Mn(II) diamine diketonate precursor. Growth experiments yielded -MnO2 nanosystems with hierarchical morphology tuneable from dendritic structures to quasi-1D nanosystems as a function of growth temperature, whose variation enabled also a concomitant tailoring of the system fluorine content, and of the optical absorption and band gap. Preliminary photocatalytic tests were aimed at the investigation of photoinduced hydrophilic (PH) and solid phase photocatalytic (PC) performances of the present nanomaterials, as well as at the photodegradation of Plasmocorinth B azo-dye aqueous solutions. The obtained findings highlighted an attractive system photoactivity even under visible light, finely tailored by fluorine content, morphological organization and optical properties of the prepared nanostructures. The results indicate that the synthesized MnO2 nanosystems have potential applications as advanced smart materials for anti-fogging/self-cleaning end uses and water purification.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000454327500037 Publication Date 2018-10-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited (up) 7 Open Access OpenAccess
Notes Padova University DOR 2016–2017, P-DiSC #03BIRD2016-UNIPD projects, HERALD Cost Action MP1402 – 37831 and ACTION post-doc fellowship are acknowledged for financial support. T.A. acknowledges a post-doctoral grant from the Research Foundation Flanders (FWO). Thanks are also due to Prof. Sara Bals (EMAT, University of Antwerp, Belgium), Prof. Romana Cerc Korošec and to Dr. Lev Matoh (University of Ljubljana, Slovenia), and to Prof. Elza Bontempi (Brescia University, Italy). The work was also supported by EPSRC (award EP/R008841/1, EP/M024938/1). Approved Most recent IF: 7.367
Call Number EMAT @ emat @UA @ admin @ c:irua:156388 Serial 5148
Permanent link to this record
 

 
Author Gröger, S.; Ramakers, M.; Hamme, M.; Medrano, J.A.; Bibinov, N.; Gallucci, F.; Bogaerts, A.; Awakowicz, P.
Title Characterization of a nitrogen gliding arc plasmatron using optical emission spectroscopy and high-speed camera Type A1 Journal article
Year 2019 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 52 Issue 6 Pages 065201
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A gliding arc plasmatron (GAP), which is very promising for purification and gas conversion,

is characterized in nitrogen using optical emission spectroscopy and high-speed photography,

because the cross sections of electron impact excitation of N 2 are well known. The gas

temperature (of about 5500 K), the electron density (up to 1.5 × 10 15 cm −3 ) and the reduced

electric field (of about 37 Td) are determined using an absolutely calibrated intensified charge-

coupled device (ICCD) camera, equipped with an in-house made optical arrangement for

simultaneous two-wavelength diagnostics, adapted to the transient behavior of a GA channel

in turbulent gas flow. The intensities of nitrogen molecular emission bands, N 2 (C–B,0–0) as

well as N +

2 (B–X,0–0), are measured simultaneously. The electron density and the reduced

electric field are determined at a spatial resolution of 30 µm, using numerical simulation and

measured emission intensities, applying the Abel inversion of the ICCD images. The temporal

behavior of the GA plasma channel and the formation of plasma plumes are studied using a

high-speed camera. Based on the determined plasma parameters, we suggest that the plasma

plume formation is due to the magnetization of electrons in the plasma channel of the GAP by

an axial magnetic field in the plasma vortex.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000451745900001 Publication Date 2018-11-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited (up) 7 Open Access Not_Open_Access: Available from 30.11.2019
Notes The authors are very grateful to Professor Kurt Behringer for the development of the program code for simulation of emis- sion spectra of nitrogen. Approved Most recent IF: 2.588
Call Number PLASMANT @ plasmant @UA @ admin @ c:irua:155974 Serial 5141
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Author Kutukov, P.; Rumyantseva, M.; Krivetskiy, V.; Filatova, D.; Batuk, M.; Hadermann, J.; Khmelevsky, N.; Aksenenko, A.; Gaskov, A.
Title Influence of Mono- and Bimetallic PtOx, PdOx, PtPdOx Clusters on CO Sensing by SnO2 Based Gas Sensors Type A1 Journal Article
Year 2018 Publication Nanomaterials Abbreviated Journal Nanomaterials-Basel
Volume 8 Issue 11 Pages 917
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract To obtain a nanocrystalline SnO2 matrix and mono- and bimetallic nanocomposites SnO2/Pd, SnO2/Pt, and SnO2/PtPd, a flame spray pyrolysis with subsequent impregnation was used. The materials were characterized using X-ray diffraction (XRD), a single-point BET method, transmission electron microscopy (TEM), and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) with energy dispersive X-ray (EDX) mapping. The electronic state of the metals in mono- and bimetallic clusters was determined using X-ray photoelectron spectroscopy (XPS). The active surface sites were investigated using the Fourier Transform infrared spectroscopy (FTIR) and thermo-programmed reduction with hydrogen (TPR-H-2) methods. The sensor response of blank SnO2 and nanocomposites had a carbon monoxide (CO) level of 6.7 ppm and was determined in the temperature range 60-300 degrees C in dry (Relative Humidity (RH) = 0%) and humid (RH = 20%) air. The sensor properties of the mono- and bimetallic nanocomposites were analyzed on the basis of information on the electronic state, the distribution of modifiers in SnO2 matrix, and active surface centers. For SnO2/PtPd, the combined effect of the modifiers on the electrophysical properties of SnO2 explained the inversion of sensor response from n- to p-types observed in dry conditions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000451316100052 Publication Date 2018-11-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2079-4991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.553 Times cited (up) 7 Open Access Not_Open_Access
Notes This research was funded by the Russian Ministry of Education and Sciences (Agreement No. 14.613.21.0075, RFMEFI61317X0075). Approved Most recent IF: 3.553
Call Number EMAT @ emat @c:irua:155767 Serial 5139
Permanent link to this record
 

 
Author Zarenia, M.; Hamilton, A.R.; Peeters, F.M.; Neilson, D.
Title Multiband mechanism for the sign reversal of Coulomb drag observed in double bilayer graphene heterostructures Type A1 Journal article
Year 2018 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 121 Issue 3 Pages 036601
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Coupled 2D sheets of electrons and holes are predicted to support novel quantum phases. Two experiments of Coulomb drag in electron-hole (e-h) double bilayer graphene (DBLG) have reported an unexplained and puzzling sign reversal of the drag signal. However, we show that this effect is due to the multiband character of DBLG. Our multiband Fermi liquid theory produces excellent agreement and captures the key features of the experimental drag resistance for all temperatures. This demonstrates the importance of multiband effects in DBLG: they have a strong effect not only on superfluidity, but also on the drag.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000438883600008 Publication Date 2018-07-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.462 Times cited (up) 7 Open Access
Notes ; We are grateful to Cory Dean, Emanuel Tutuc, and their research groups for discussing details of their experiments with us. This work was partially supported by the Flemish Science Foundation (FWO-Vl), the Methusalem program of the Flemish government, and the Australian Government through the Australian Research Council Centre of Excellence in Future Low-Energy Electronics Technologies (Project No. CE170100039). D. N. acknowledges support from the University of Camerino FAR project CESEMN. ; Approved Most recent IF: 8.462
Call Number UA @ lucian @ c:irua:152416UA @ admin @ c:irua:152416 Serial 5116
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Author Li, K.; Liu, J.-L.; Li, X.-S.; Lian, H.-Y.; Zhu, X.; Bogaerts, A.; Zhu, A.-M.
Title Novel power-to-syngas concept for plasma catalytic reforming coupled with water electrolysis Type A1 Journal article
Year 2018 Publication Chemical engineering journal Abbreviated Journal Chem Eng J
Volume 353 Issue Pages 297-304
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We propose a novel Power to Synthesis Gas (P2SG) approach, composed of two high-efficiency and renewable electricity-driven units, i.e., plasma catalytic reforming (PCR) and water electrolysis (WE), to produce high quality syngas from CH4, CO2 and H2O. As WE technology is already commercial, we mainly focus on the PCR unit, consisting of gliding arc plasma and Ni-based catalyst, for oxidative dry reforming of methane. An energy efficiency of 78.9% and energy cost of 1.0 kWh/Nm3 at a CH4 conversion of 99% and a CO2 conversion of 79% are obtained. Considering an energy efficiency of 80% for WE, the P2SG system yields an overall energy efficiency of 79.3% and energy cost of 1.8 kWh/Nm3. High-quality syngas is produced without the need for posttreatment units, featuring the ideal stoichiometric number of 2, with concentration of 94.6 vol%, and a desired CO2 fraction of 1.9 vol% for methanol synthesis. The PCR unit has the advantage of fast response to adapting to fluctuation of renewable electricity, avoiding local hot spots in the catalyst bed and coking, in contrast to conventional catalytic processes. Moreover, pure O2 from the WE unit is directly utilized by the PCR unit for oxidative dry reforming of methane, and thus, no air separation unit, like in conventional processes, is required. This work demonstrates the viability of the P2SG approach for large-scale energy storage of renewable electricity via electricity-to-fuel conversion.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000441527900029 Publication Date 2018-07-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1385-8947 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.216 Times cited (up) 7 Open Access OpenAccess
Notes This project is supported by the National Natural Science Foundation of China (11705019, 11475041), the Fundamental Research Funds for the Central Universities (DUT16QY49, DUT16LK16) and the Fund for Scientific Research Flanders (FWO; grant G.0383.16N). Approved Most recent IF: 6.216
Call Number PLASMANT @ plasmant @c:irua:153059 Serial 5049
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Author Saniz, R.; Sarmadian, N.; Partoens, B.; Batuk, M.; Hadermann, J.; Marikutsa, A.; Rumyantseva, M.; Gaskov, A.; Lamoen, D.
Title First-principles study of CO and OH adsorption on in-doped ZnO surfaces Type A1 Journal article
Year 2019 Publication The journal of physics and chemistry of solids Abbreviated Journal J Phys Chem Solids
Volume 132 Issue Pages 172-181
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract We present a first-principles computational study of CO and OH adsorption on non-polar ZnO (10¯10) surfaces doped with indium. The calculations were performed using a model ZnO slab. The position of the In dopants was varied from deep bulk-like layers to

the surface layers. It was established that the preferential location of the In atoms is at the surface by examining the dependence of

the defect formation energy as well as the surface energy on In location. The adsorption sites on the surface of ZnO and the energy

of adsorption of CO molecules and OH-species were determined in connection to In doping. It was found that OH has higher

bonding energy to the surface than CO. The presence of In atoms at the surface of ZnO is favorable for CO adsorption, resulting

in an elongation of the C-O bond and in charge transfer to the surface. The effect of CO and OH adsorption on the electronic

and conduction properties of surfaces was assessed. We conclude that In-doped ZnO surfaces should present a higher electronic

response upon adsorption of CO.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000472124700023 Publication Date 2019-04-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3697 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.059 Times cited (up) 7 Open Access Not_Open_Access: Available from 26.04.2021
Notes FWO-Vlaanderen, G0D6515N ; ERA.Net RUS Plus, 096 ; VSC; HPC infrastructure of the University of Antwerp; FWO-Vlaanderen; Flemish Government-department EWI; Approved Most recent IF: 2.059
Call Number EMAT @ emat @UA @ admin @ c:irua:159656 Serial 5170
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Author De Sloovere, D.; Safari, M.; Elen, K.; D'Haen, J.; Drozhzhin, O.A.; Abakumov, A.M.; Simenas, M.; Banys, J.; Bekaert, J.; Partoens, B.; Van Bael, M.K.; Hardy, A.
Title Reduced Na2+xTi4O9 composite : a durable anode for sodium-ion batteries Type A1 Journal article
Year 2018 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 30 Issue 23 Pages 8521-8527
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Sodium-ion batteries (SIBs) are potential cost-effective solutions for stationary energy storage applications. Unavailability of suitable anode materials, however, is one of the important barriers to the maturity of SIBs. Here, we report a Na2+xTi4O9/C composite as a promising anode candidate for SIBs with high capacity and cycling stability. This anode is characterized by a capacity of 124 mAh g(-1) (plus 11 mAh g(-1) contributed by carbon black), an average discharge potential of 0.9 V vs Na/Na+, a good rate capability and a high stability (89% capacity retention after 250 cycles at a rate of 1 degrees C). The mechanisms of sodium insertion/deinsertion and of the formation of Na2+xTi4O9/C are investigated with the aid of various ex/in situ characterization techniques. The in situ formed carbon is necessary for the formation of the reduced sodium titanate. This synthesis method may enable the convenient synthesis of other composites of crystalline phases with amorphous carbon.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000453489300014 Publication Date 2018-11-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited (up) 7 Open Access
Notes ; This work was supported by the FWO (Research Foundation Flanders, project G040116). O.A.D. and A.M.A. are grateful to the Russian Science Foundation for financial support (Grant 17-73-30006). The authors acknowledge Pieter Samyn for Raman spectroscopy, Fulya Ulu Okudur for preliminary TEM, Bart Ruttens for XRD, Hilde Pellaers for SEM, Tom Haeldermans for elemental analysis, and Karen Leyssen and Vera Meynen for physisorption measurements. ; Approved Most recent IF: 9.466
Call Number UA @ admin @ c:irua:156235 Serial 5227
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