|   | 
Details
   web
Records
Author Reyntjens, P.; Van de Put, M.; Vandenberghe, W.G.; Sorée, B.
Title Ultrascaled graphene-capped interconnects : a quantum mechanical study Type P1 Proceeding
Year 2023 Publication Proceedings of the IEEE ... International Interconnect Technology Conference T2 – IEEE International Interconnect Technology Conference (IITC) / IEEE, Materials for Advanced Metallization Conference (MAM), MAY 22-25, 2023, Dresden, Germany Abbreviated Journal
Volume Issue Pages 1-3
Keywords P1 Proceeding; Condensed Matter Theory (CMT)
Abstract In this theoretical study, we assess the impact of a graphene capping layer on the resistivity of defective, extremely scaled interconnects. We investigate the effect of graphene capping on the electronic transport in ultrascaled interconnects, in the presence of grain boundary defects in the metal layer. We compare the results obtained using our quantum mechanical model to a simple parallel-conductor model and find that the parallel-conductor model does not capture the effect of the graphene cap correctly. At 0.5 nm metal thickness, the parallel-conductor model underestimates the conductivity by 3.0% to 4.0% for single-sided and double sided graphene capping, respectively.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001027381700006 Publication Date 2023-06-24
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 979-83-503-1097-9 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:198343 Serial 8949
Permanent link to this record
 

 
Author Smith, G.J.; Diomede, P.; Gibson, A.R.; Doyle, S.J.; Guerra, V.; Kushner, M.J.; Gans, T.; Dedrick, J.P.
Title Low-pressure inductively coupled plasmas in hydrogen : impact of gas heating on the spatial distribution of atomic hydrogen and vibrationally excited states Type A1 Journal article
Year 2024 Publication Plasma sources science and technology Abbreviated Journal
Volume 33 Issue 2 Pages 025002-25020
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Non-equilibrium inductively coupled plasmas (ICPs) operating in hydrogen are of significant interest for applications including large-area materials processing. Increasing control of spatial gas heating, which drives the formation of neutral species density gradients and the rate of gas-temperature-dependent reactions, is critical. In this study, we use 2D fluid-kinetic simulations with the Hybrid Plasma Equipment Model to investigate the spatially resolved production of atomic hydrogen in a low-pressure planar ICP operating in pure hydrogen (10-20 Pa or 0.075-0.15 Torr, 300 W). The reaction set incorporates self-consistent calculation of the spatially resolved gas temperature and 14 vibrationally excited states. We find that the formation of neutral-gas density gradients, which result from spatially non-uniform electrical power deposition at constant pressure, can drive significant variations in the vibrational distribution function and density of atomic hydrogen when gas heating is spatially resolved. This highlights the significance of spatial gas heating on the production of reactive species in relatively high-power-density plasma processing sources.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001154851700001 Publication Date 2024-01-15
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0963-0252 ISBN Additional Links UA library record; WoS full record
Impact Factor 3.8 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 3.8; 2024 IF: 3.302
Call Number UA @ admin @ c:irua:203866 Serial 9054
Permanent link to this record
 

 
Author Linek, J.; Wyszynski, M.; Müller, B.; Korinski, D.; Milošević, M.V.; Kleiner, R.; Koelle, D.
Title On the coupling of magnetic moments to superconducting quantum interference devices Type A1 Journal article
Year 2024 Publication Superconductor science and technology Abbreviated Journal
Volume 37 Issue 2 Pages 025010-25012
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate the coupling factor phi( mu) that quantifies the magnetic flux phi per magnetic moment mu of a point-like magnetic dipole that couples to a superconducting quantum interference device (SQUID). Representing the dipole by a tiny current-carrying (Amperian) loop, the reciprocity of mutual inductances of SQUID and Amperian loop provides an elegant way of calculating phi(mu)(r,e(mu)) vs. position r and orientation e(mu) of the dipole anywhere in space from the magnetic field B-J(r) produced by a supercurrent circulating in the SQUID loop. We use numerical simulations based on London and Ginzburg-Landau theory to calculate phi (mu) from the supercurrent density distributions in various superconducting loop geometries. We treat the far-field regime ( r greater than or similar to a= inner size of the SQUID loop) with the dipole placed on (oriented along) the symmetry axis of circular or square shaped loops. We compare expressions for phi (mu) from simple filamentary loop models with simulation results for loops with finite width w (outer size A > alpha), thickness d and London penetration depth lambda(L )and show that for thin ( d << alpha ) and narrow (w < alpha) loops the introduction of an effective loop size a(eff) in the filamentary loop-model expressions results in good agreement with simulations. For a dipole placed right in the center of the loop, simulations provide an expression phi(mu)(a,A,d,lambda(L)) that covers a wide parameter range. In the near-field regime (dipole centered at small distance z above one SQUID arm) only coupling to a single strip representing the SQUID arm has to be considered. For this case, we compare simulations with an analytical expression derived for a homogeneous current density distribution, which yields excellent agreement for lambda(L)>w,d . Moreover, we analyze the improvement of phi(mu) provided by the introduction of a narrow constriction in the SQUID arm below the magnetic dipole.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001145725500001 Publication Date 2024-01-04
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048 ISBN Additional Links UA library record; WoS full record
Impact Factor 3.6 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 3.6; 2024 IF: 2.878
Call Number UA @ admin @ c:irua:202759 Serial 9067
Permanent link to this record
 

 
Author Zhou, S.; Zhang, C.; Xu, W.; Zhang, J.; Xiao, Y.; Ding, L.; Wen, H.; Cheng, X.; Hu, C.; Li, H.; Li, X.; Peeters, F.M.
Title Observation of temperature induced phase transitions in TiO superconducting thin film via infrared measurement Type A1 Journal article
Year 2024 Publication Infrared physics and technology Abbreviated Journal
Volume 137 Issue Pages 105160-105169
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In contrast to conventional polycrystalline titanium oxide (TiO), it was found recently that the superconducting transition temperature Tc can be significantly enhanced from about 2 K to 7.4 K in cubic TiO thin films grown epitaxially on alpha-Al2O3 substrates. This kind of TiO film is also expected to have distinctive optoelectronic properties, which are still not very clear up to now. Herein, by using infrared (IR) reflection measurement we investigate the temperature-dependent optoelectronic response of a cubic TiO thin film, in which temperature induced phase transitions are observed. The semiconductor-, metallic- and semiconductor-like electronic phases of this superconducting film are found in the temperature regimes from 10 to 110 K, 110 to 220 K and above 220 K, respectively. The results obtained optically are consistent with those measured by transport experiment. Furthermore, based on an improved reflection model developed here, we extract the complex optical conductivity of the cubic TiO thin film. We are able to approximately determine the characteristic parameters (e.g., effective electron mass, carrier density, scattering time, etc.) for different electronic phases by fitting the optical conductivity with the modified Lorentz formula. These results not only deepen our understanding of the fundamental physics for cubic TiO thin films but also may find applications in optoelectronic devices based on superconductors.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001170490200001 Publication Date 2024-01-21
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1350-4495 ISBN Additional Links UA library record; WoS full record
Impact Factor 3.3 Times cited Open Access
Notes Approved Most recent IF: 3.3; 2024 IF: 1.713
Call Number UA @ admin @ c:irua:204853 Serial 9162
Permanent link to this record
 

 
Author Xiao, H.; Wen, H.; Xu, W.; Cheng, Y.; Zhang, J.; Cheng, X.; Xiao, Y.; Ding, L.; Li, H.; He, B.; Peeters, F.M.
Title Terahertz magneto-optical properties of Nitrogen-doped diamond Type A1 Journal article
Year 2024 Publication Infrared physics and technology Abbreviated Journal
Volume 138 Issue Pages 105237-105239
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Nitrogen-doped diamond (N-D) is one of the most important carbon-based electronic and optical materials. Here we study the terahertz (THz) magneto-optical (MO) properties of N-D grown by microwave plasma-enhanced chemical vapor deposition. The optical microscope, SEM, XRD, Raman spectrum, FTIR spectroscopy and XPS are used for the characterization of N-D samples. Applying THz time-domain spectroscopy (TDS), in combination with the polarization test and the presence of magnetic field in Faraday geometry, THz MO transmissions through N-D are measured from 0 to 8 T at 80 K. The complex right- and left-handed circular transmission coefficients and MO conductivities for N-D are obtained accordingly. Through fitting the experimental results with theoretical formulas of the dielectric constant and MO conductivities for an electron gas, we are able to determine magneto-optically the key electronic parameters of N-D, such as the static dielectric constant epsilon b, the electron density ne, the electronic relaxation time tau, the electronic localization factor alpha and, particularly, the effective electron mass m* obtained under non-resonant condition. The dependence of these parameters upon magnetic field is examined and analyzed. We find that the MO conductivities of N-D can be described rightly by the MO Drude-Smith formulas developed by us previously. It is shown that N-doping and the presence of the magnetic field can lead towards the larger epsilon b and heavier m* in diamond, while ne/tau/alpha in N-D decreases/increases/decreases with increasing magnetic field. The results obtained from this work are benefit to us in gaining an in-depth understanding of the electronic and optoelectronic properties of N-D.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001200173100001 Publication Date 2024-02-15
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1350-4495 ISBN Additional Links UA library record; WoS full record
Impact Factor 3.3 Times cited Open Access
Notes Approved Most recent IF: 3.3; 2024 IF: 1.713
Call Number UA @ admin @ c:irua:205523 Serial 9178
Permanent link to this record
 

 
Author Van Tendeloo, L.; Wangermez, W.; Kurttepeli, M.; de Blochouse, B.; Bals, S.; Van Tendeloo, G.; Martens, J.A.; Maes, A.; Kirschhock, C.E.A.; Breynaert, E.
Title Chabazite : stable cation-exchanger in hyper alkaline concrete pore water Type A1 Journal article
Year 2015 Publication Environmental science and technology Abbreviated Journal Environ Sci Technol
Volume 49 Issue 49 Pages 2358-2365
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract To avoid impact on the environment, facilities for permanent disposal of hazardous waste adopt multibarrier design schemes. As the primary barrier very often consists of cement-based materials, two distinct aspects are essential for the selection of suitable complementary barriers: (1) selective sorption of the contaminants in the repository and (2) long-term chemical stability in hyperalkaline concrete-derived media. A multidisciplinary approach combining experimental strategies from environmental chemistry and materials science is therefore essential to provide a reliable assessment of potential candidate materials. Chabazite is typically synthesized in 1 M KOH solutions but also crystallizes in simulated young cement pore water, a pH 13 aqueous solution mainly containing K+ and Na+ cations. Its formation and stability in this medium was evaluated as a function of temperature (60 and 85 °C) over a timeframe of more than 2 years and was also asessed from a mechanistic point of view. Chabazite demonstrates excellent cation-exchange properties in simulated young cement pore water. Comparison of its Cs+ cation exchange properties at pH 8 and pH 13 unexpectedly demonstrated an increase of the KD with increasing pH. The combined results identify chabazite as a valid candidate for inclusion in engineered barriers for concrete-based waste disposal.
Address
Corporate Author Thesis
Publisher Place of Publication Easton, Pa Editor
Language Wos 000349806400047 Publication Date 2015-01-08
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0013-936X;1520-5851; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.198 Times cited 13 Open Access OpenAccess
Notes This work was supported by long-term structural funding by the Flemish Government (Methusalem) and by ONDRAF/ NIRAS, the Belgian Agency for Radioactive Waste and Fissile Materials, as part of the program on surface disposal of Belgian Category A waste. The Belgian government is acknowledged for financing the interuniversity poles of attraction (IAP-PAI). G.V.T. and S.B. acknowledge financial support from European Research Council (ERC Advanced Grant no. 24691-COUNTATOMS, ERC Starting Grant no. 335078-COLOURATOMS).; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); Approved Most recent IF: 6.198; 2015 IF: 5.330
Call Number c:irua:127695 Serial 307
Permanent link to this record
 

 
Author Molina, L.; Egoavil, R.; Turner, S.; Thersleff, T.; Verbeeck, J.; Holzapfel, B.; Eibl, O.; Van Tendeloo, G.
Title Interlayer structure in YBCO-coated conductors prepared by chemical solution deposition Type A1 Journal article
Year 2013 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 26 Issue 7 Pages 075016-75018
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The functionality of YBa2Cu3O7−δ (YBCO)-coated conductor technology depends on the reliability and microstructural properties of a given tape or wire architecture. Particularly, the interface to the metal tape is of interest since it determines the adhesion, mechanical stability of the film and thermal contact of the film to the substrate. A trifluoroacetate (TFA)metal organic deposition (MOD) prepared YBCO film deposited on a chemical solution-derived buffer layer architecture based on CeO2/La2Zr2O7 and grown on a flexible Ni5 at.%W substrate with a {100}⟨001⟩ biaxial texture was investigated. The YBCO film had a thickness was 440 nm and a jc of 1.02 MA cm−2 was determined at 77 K and zero external field. We present a sub-nanoscale analysis of a fully processed solution-derived YBCO-coated conductor by aberration-corrected scanning transmission electron microscopy (STEM) combined with electron energy-loss spectroscopy (EELS). For the first time, structural and chemical analysis of the valence has been carried out on the sub-nm scale. Intermixing of Ni, La, Ce, O and Ba takes place at these interfaces and gives rise to nanometer-sized interlayers which are a by-product of the sequential annealing process. Two distinct interfacial regions were analyzed in detail: (i) the YBCO/CeO2/La2Zr2O7 region (10 nm interlayer) and (ii) the La2Zr2O7/Ni5 at.%W substrate interface region (20 nm NiO). This is of particular significance for the functionality of these YBCO-coated conductor architectures grown by chemical solution deposition.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000319973800024 Publication Date 2013-05-28
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 11 Open Access
Notes vortex; Countatoms; Fwo; Esteem2; esteem2jra2; esteem2jra3 ECASJO_; Approved Most recent IF: 2.878; 2013 IF: 2.796
Call Number UA @ lucian @ c:irua:108704UA @ admin @ c:irua:108704 Serial 1698
Permanent link to this record
 

 
Author Cayado, P.; De Keukeleere, K.; Garzón, A.; Perez-Mirabet, L.; Meledin, A.; De Roo, J.; Vallés, F.; Mundet, B.; Rijckaert, H.; Pollefeyt, G.; Coll, M.; Ricart, S.; Palau, A.; Gázquez, J.; Ros, J.; Van Tendeloo, G.; Van Driessche, I.; Puig, T.; Obradors, X.
Title Epitaxial YBa2Cu3O7−xnanocomposite thin films from colloidal solutions Type A1 Journal article
Year 2015 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 28 Issue 28 Pages 124007
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A methodology of general validity to prepare epitaxial nanocomposite films based on the use of colloidal solutions containing different crystalline preformed oxide nanoparticles ( ex situ nanocomposites) is reported. The trifluoroacetate (TFA) metal–organic chemical solution deposition route is used with alcoholic solvents to grow epitaxial YBa 2 Cu 3 O 7 (YBCO) films. For this reason stabilizing oxide nanoparticles in polar solvents is a challenging goal. We have used scalable nanoparticle synthetic methodologies such as thermal and microwave-assisted solvothermal techniques to prepare CeO 2 and ZrO 2 nanoparticles. We show that stable and homogeneous colloidal solutions with these nanoparticles can be reached using benzyl alcohol, triethyleneglycol, nonanoic acid, trifluoroacetic acid or decanoic acid as protecting ligands, thereby allowing subsequent mixing with alcoholic TFA solutions. An elaborate YBCO film growth analysis of these nanocomposites allows the identification of the different relevant growth phenomena, e.g. nanoparticles pushing towards the film surface, nanoparticle reactivity, coarsening and nanoparticle accumulation at the substrate interface. Upon mitigation of these effects, YBCO nanocomposite films with high self-field critical currents ( J c ∼ 3–4 MA cm −2 at 77 K) were reached, indicating no current limitation effects associated with epitaxy perturbation, while smoothed magnetic field dependences of the critical currents at high magnetic fields and decreased effective anisotropic pinning behavior confirm the effectiveness of the novel developed approach to enhance vortex pinning. In conclusion, a novel low cost solution-derived route to high current nanocomposite superconducting films and coated conductors has been developed with very promising features.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000366288100009 Publication Date 2015-11-16
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 32 Open Access
Notes All authors acknowledge the EU (EU-FP7 NMP-LA-2012-280432 EUROTAPES project). ICMAB acknowledges MINECO (MAT2014-51778-C2-1-R) and Generalitat de Catalunya (2014SGR 753 and Xarmae). UGhent acknowledges the Special Research Fund (BOF), the Research Foundation Flanders (FWO) and the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT). TEM microscopy work was conducted in the Catalan Institute of Nanoscience and Nanotechnology (ICN2). The authors acknowledge the ICN2 Electron Microscopy Division for offering access to their instruments and expertise. Part of the STEM microscopy work was conducted in 'Laboratorio de Microscopias Avanzadas' at the Instituto de Nanociencia de Aragon—Universidad de Zaragoza. The authors acknowledge the LMA-INA for offering access to their instruments and expertise. JG and MC also acknowledge the Ramon y Cajal program (RYC-2012-11709 and RYC-2013-12448 respectively). Approved Most recent IF: 2.878; 2015 IF: 2.325
Call Number c:irua:129593 Serial 3966
Permanent link to this record
 

 
Author Kolev, S.; Bogaerts, A.
Title Similarities and differences between gliding glow and gliding arc discharges Type A1 Journal article
Year 2015 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 24 Issue 24 Pages 065023
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this work we have analyzed the properties of a gliding dc discharge in argon at atmospheric pressure. Despite the usual designation of these discharges as ‘gliding arc discharges’, it was found previously that they operate in two different regimes—glow and arc. Here we analyze the differences in both regimes by means of two dimensional fluid modeling. In order to address different aspects of the discharge operation, we use two models—Cartesian and axisymmetric in a cylindrical coordinate system. The obtained results show that the two types of discharges produce a similar plasma column for a similar discharge current. However, the different mechanisms of plasma channel attachment to the cathode could produce certain differences in the plasma parameters (i.e. arc elongation), and this can affect gas treatments applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000368117100028 Publication Date 2015-11-26
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0963-0252;1361-6595; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited 12 Open Access
Notes This work is financially supported by the Methusalem financing and by the IAP/7 (Inter-university Attraction Pole) program ‘Physical Chemistry of Plasma-Surface Interactions’ from the Belgian Federal Office for Science Policy (BELSPO). The work was carried out in part using the Turing HPC infrastructure of the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the Universiteit Antwerpen Approved Most recent IF: 3.302; 2015 IF: 3.591
Call Number c:irua:129214 Serial 3952
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 (up) 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 Lamas, J.S.; Leroy, W.P.; Lu, Y.-G.; Verbeeck, J.; Van Tendeloo, G.; Depla, D.
Title Using the macroscopic scale to predict the nano-scale behavior of YSZ thin films Type A1 Journal article
Year 2014 Publication Surface and coatings technology Abbreviated Journal Surf Coat Tech
Volume 238 Issue Pages 45-50
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In this work, Yttria-stabilized zirconia (YSZ) thin films were deposited using dual reactive magnetron sputtering. By varying the deposition conditions, the film morphology and texture of the thin films are tuned and biaxial alignment is obtained. Studying the crystallographic and microstructural properties of the YSZ thin films, a tilted columnar growth was identified. This tilt is shown to be dependent on the compositional gradient of the sample. The variation of composition within a single YSZ column measured via STEM-EDX is demonstrated to be equal to the macroscopic variation on a full YSZ sample when deposited under the same deposition parameters. A simple stress model was developed to predict the tilt of the growing columns. The results indicate that this model not only determines the column bending of the growing film but also confirms that a macroscopic approach is sufficient to determine the compositional gradient in a single column of the YSZ thin films. (C) 2013 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Lausanne Editor
Language Wos 000331028200005 Publication Date 2013-10-29
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0257-8972; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.589 Times cited 8 Open Access
Notes 246791 Countatoms; 278510 Vortex;Nmp3-La-2010-246102 Ifox; 312483 Esteem2; esteem2jra3 ECASJO; Approved Most recent IF: 2.589; 2014 IF: 1.998
Call Number UA @ lucian @ c:irua:115765 Serial 3827
Permanent link to this record
 

 
Author Shanenko, A.A.; Aguiar, J.A.; Vagov, A.; Croitoru, M.D.; Milošević, M.V.
Title Atomically flat superconducting nanofilms: multiband properties and mean-field theory Type A1 Journal article
Year 2015 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 28 Issue 28 Pages 054001
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Recent progress in materials synthesis enabled fabrication of superconducting atomically flat single-crystalline metallic nanofilms with thicknesses down to a few monolayers. Interest in such nano-thin systems is attracted by the dimensional 3D-2D crossover in their coherent properties which occurs with decreasing the film thickness. The first fundamental aspect of this crossover is dictated by the Mermin-Wagner-Hohenberg theorem and concerns frustration of the long-range order due to superconductive fluctuations and the possibility to track its impact with an unprecedented level of control. The second important aspect is related to the Fabri-Perot modes of the electronic motion strongly bound in the direction perpendicular to the nanofilm. The formation of such modes results in a pronounced multiband structure that changes with the nanofilm thickness and affects both the mean-field behavior and superconductive fluctuations. Though the subject is very rich in physics, it is scarcely investigated to date. The main obstacle is that there are no manageable models to study a complex magnetic response in this case. Full microscopic consideration is rather time consuming, if practicable at all, while the standard Ginzburg-Landau theory is not applicable. In the present work we review the main achievements in the subject to date, and construct and justify an efficient multiband mean-field formalism which allows for numerical and even analytical treatment of nano-thin superconductors in applied magnetic fields.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000353015700005 Publication Date 2015-03-19
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 23 Open Access
Notes This work was supported by the Brazilian agencies CNPq (grants 307552/2012-8 and 141911/2012-3) and FACEPE (APQ-0589-1.05/08). AAS acknowledges fruitful discussions with A Perali and D Neilson during his stay in the University of Camerino and is thankful for partial support of his visit by the University of Camerino under the project FAR 'Control and enhancement of superconductivity by engineering materials at the nanoscale'. MDC acknowledges the support from the Back to Belgium Grant of the federal Science Policy (BELSPO). Approved Most recent IF: 2.878; 2015 IF: 2.325
Call Number c:irua:132501 Serial 3944
Permanent link to this record
 

 
Author Molina-Luna, L.; Duerrschnabel, M.; Turner, S.; Erbe, M.; Martinez, G.T.; Van Aert, S.; Holzapfel, B.; Van Tendeloo, G.
Title Atomic and electronic structures of BaHfO3-doped TFA-MOD-derived YBa2Cu3O7−δthin films Type A1 Journal article
Year 2015 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 28 Issue 28 Pages 115009
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Tailoring the properties of oxide-based nanocomposites is of great importance for a wide range of materials relevant for energy technology. YBa2Cu3O7−δ (YBCO) superconducting thin films containing nanosized BaHfO3 (BHO) particles yield a significant improvement of the magnetic flux pinning properties and a reduced anisotropy of the critical current density. These films were prepared by chemical solution deposition (CSD) on (100) SrTiO3 (STO) substrates yielding critical current densities up to 3.6 MA cm−2 at 77 K and self-field. Transport in-field J c measurements demonstrated a high pinning force maximum of around 6 GN/m3 for a sample annealed at T = 760 °C that has a doping of 12 mol% of BHO. This sample was investigated by scanning transmission electron microscopy (STEM) in combination with electron energy-loss spectroscopy (EELS) yielding strain and spectral maps. Spherical BHO nanoparticles of 15 nm in size were found in the matrix, whereas the particles at the interface were flat. A 2 nm diffusion layer containing Ti was found at the YBCO (BHO)/STO interface. Local lattice deformation mapping at the atomic scale revealed crystal defects induced by the presence of both sorts of BHO nanoparticles, which can act as pinning centers for magnetic flux lines. Two types of local lattice defects were identified and imaged: (i) misfit edge dislocations and (ii) Ba-Cu-Cu-Ba stacking faults (Y-248 intergrowths). The local electronic structure and charge transfer were probed by high energy resolution monochromated electron energy-loss spectroscopy. This technique made it possible to distinguish superconducting from non-superconducting areas in nanocomposite samples with atomic resolution in real space, allowing the identification of local pinning sites on the order of the coherence length of YBCO (~1.5 nm) and the determination of 0.25 nm dislocation cores.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000366193000018 Publication Date 2015-09-25
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 4 Open Access
Notes The authors thank financial support from the European Union under the Framework 6 program as a contract for an Integrated Infrastructure Initiative (References No. 026019 ESTEEM) and by the EUFP6 Research Project “NanoEngineered Superconductors for Power Applications” NESPA no. MRTN-CT-2006-035619. This work was supported by funding from the European Research Council under the Seventh Framework Programme (FP7). L.M.L, S.T. and G.V.T acknowledge ERC grant N°246791 – COUNTATOMS and funding under a contract for an Integrated Infrastructure Initiative, Reference No. 312483- ESTEEM2, as well as the EC project EUROTAPES. G.T.M. and S.V.A acknowledge financial support from the Fund for Scientific Research-Flanders (Reference G.0064.10N and G.0393.11N). M.D. acknowledges financial support from the LOEWE research cluster RESPONSE (Hessen, Germany). M.E. has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement n° NMP-LA-2012-280432.; esteem2jra2; esteem2jra3 Approved Most recent IF: 2.878; 2015 IF: 2.325
Call Number c:irua:129199 c:irua:129199 Serial 3942
Permanent link to this record
 

 
Author Erbe, M.; Hänisch, J.; Hühne, R.; Freudenberg, T.; Kirchner, A.; Molina-Luna, L.; Damm, C.; Van Tendeloo, G.; Kaskel, S.; Schultz, L.; Holzapfel, B.
Title BaHfO3artificial pinning centres in TFA-MOD-derived YBCO and GdBCO thin films Type A1 Journal article
Year 2015 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 28 Issue 28 Pages 114002
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Chemical solution deposition (CSD) is a promising way to realize REBa2Cu3O7−x (REBCO;RE = rare earth (here Y, Gd))-coated conductors with high performance in applied magnetic fields. However, the preparation process contains numerous parameters which need to be tuned to achieve high-quality films. Therefore, we investigated the growth of REBCO thin films containing nanometre-scale BaHfO3 (BHO) particles as pinning centres for magnetic flux lines, with emphasis on the influence of crystallization temperature and substrate on the microstructure and superconductivity. Conductivity, microscopy and x-ray investigations show an enhanced performance of BHO nano-composites in comparison to pristine REBCO. Further, those measurements reveal the superiority of GdBCO to YBCO—e.g. by inductive critical current densities, Jc, at self-field and 77 K. YBCO is outperformed by more than 1 MA cm−2 with Jc values of up to 5.0 MA cm−2 for 265 nm thick layers of GdBCO(BHO) on lanthanum aluminate. Transport in-field Jc measurements demonstrate high pinning force maxima of around 4 GN m−3 for YBCO(BHO) and GdBCO(BHO). However, the irreversibility fields are appreciably higher for GdBCO. The critical temperature was not significantly reduced upon BHO addition to both YBCO and GdBCO, indicating a low tendency for Hf diffusion into the REBCO matrix. Angular-dependent Jc measurements show a reduction of the anisotropy in the same order of magnitude for both REBCO compounds. Theoretical models suggest that more than one sort of pinning centre is active in all CSD films.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000366193000003 Publication Date 2015-09-25
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 36 Open Access
Notes Experimental work was mainly done at IFW Dresden. We thank Juliane Scheiter and Dr Jens Ingolf Mönch of IFW Dresden for technical assistance. The research leading to these results received funding from EUROTAPES, a collaborative project funded by the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement no. NMP-LA-2012-280 432. L Molina-Luna and G Van Tendeloo acknowledge funding from the European Research Council (ERC grant nr. 24 691-COUNTATOMS). Approved Most recent IF: 2.878; 2015 IF: 2.325
Call Number c:irua:129200 Serial 3941
Permanent link to this record
 

 
Author Van Laer, K.; Bogaerts, A.
Title Fluid modelling of a packed bed dielectric barrier discharge plasma reactor Type A1 Journal article
Year 2016 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 25 Issue 25 Pages 015002
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A packed bed dielectric barrier discharge plasma reactor is computationally studied with a fluid model. Two different complementary axisymmetric 2D geometries are used to mimic the intrinsic 3D problem. It is found that a packing enhances the electric field strength and electron temperature at the contact points of the dielectric material due to polarization of the beads by the applied potential. As a result, these contact points prove to be of direct importance to initiate the plasma. At low applied potential, the discharge stays at the contact points, and shows the properties of a Townsend discharge. When a high enough potential is applied, the plasma will be able to travel through the gaps in between the beads from wall to wall, forming a kind of glow discharge. Therefore, the inclusion of a so-called ‘channel of voids’ is indispensable in any type of packed bed modelling.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000370974800009 Publication Date 2015-12-01
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0963-0252 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited 50 Open Access
Notes The authors gratefully thank St Kolev for the many interesting discussions and the useful advise in setting up the models. This research was carried out in the framework of the network on Physical Chemistry of Plasma-Surface Interactions— Interuniversity Attraction Poles, phase VII (http://psi-iap7.ulb. ac.be/), and supported by the Belgian Science Policy Office (BELSPO). K Van Laer is indebted to the Institute for the Promotion of Innovation by Science and Technology in Flanders (IWT Flanders) for financial support. Approved Most recent IF: 3.302
Call Number c:irua:129802 Serial 3982
Permanent link to this record
 

 
Author van Laer, K.; Bogaerts, A.
Title Improving the Conversion and Energy Efficiency of Carbon Dioxide Splitting in a Zirconia-Packed Dielectric Barrier Discharge Reactor Type A1 Journal article
Year 2015 Publication Energy technology Abbreviated Journal Energy Technol-Ger
Volume 3 Issue 3 Pages 1038-1044
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The use of plasma technology for CO2 splitting is gaining increasing interest, but one of the major obstacles to date for industrial implementation is the considerable energy cost. We demonstrate that the introduction of a packing of dielectric zirconia (ZrO2) beads into a dielectric barrier discharge (DBD) plasma reactor can enhance the CO2 conversion and energy efficiency up to a factor 1.9 and 2.2, respectively, compared to that in a normal (unpacked) DBD reactor. We obtained a maximum conversion of 42 % and a maximum energy efficiency of 9.6 %. However, it is the ability of the packing to almost double both the conversion and the energy efficiency simultaneously at certain input parameters that makes it very promising. The improved conversion and energy efficiency can be explained by the higher values of the local electric field and electron energy near the contact points of the beads and the lower breakdown voltage, demonstrated by 2 D fluid modeling.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000362913600006 Publication Date 2015-08-19
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2194-4288 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.789 Times cited 59 Open Access
Notes This research was carried out in the framework of the network on Physical Chemistry of Plasma-Surface Interactions—Interuniversity Attraction Poles, phase VII (http://psiiap7.ulb.ac.be/), and supported by the Belgian Science Policy Office (BELSPO). K.V.L. is indebted to the Institute for the Promotion of Innovation by Science and Technology in Flanders (IWT Flanders) for financial support Approved Most recent IF: 2.789; 2015 IF: 2.824
Call Number c:irua:128224 Serial 3992
Permanent link to this record
 

 
Author Belov, I.; Paulussen, S.; Bogaerts, A.
Title Appearance of a conductive carbonaceous coating in a CO2dielectric barrier discharge and its influence on the electrical properties and the conversion efficiency Type A1 Journal article
Year 2016 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 25 Issue 25 Pages 015023
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract This work examines the properties of a dielectric barrier discharge (DBD) reactor, built for CO2 decomposition, by means of electrical characterization, optical emission spectroscopy and gas chromatography. The discharge, formed in an electronegative gas (such as CO2, but also O2), exhibits clearly different electrical characteristics, depending on the surface conductivity of the reactor walls. An asymmetric current waveform is observed in the metaldielectric (MD) configuration, with sparse high-current pulses in the positive half-cycle (HC) and a more uniform regime in the negative HC. This indicates that the discharge is operating in two alternating regimes with rather different properties. At high CO2 conversion regimes, a conductive coating is deposited on the dielectric. This so-called coated MD configuration yields a symmetric current waveform, with current peaks in both the positive and negative HCs. In a double-dielectric (DD) configuration, the current waveform is also symmetric, but without current peaks in both the positive and negative HC. Finally, the DD configuration with conductive coating on the inner surface of the outer dielectric, i.e. so-called coated DD, yields again an asymmetric current waveform, with current peaks in the negative HC. These different electrical characteristics are related to the presence of the conductive coating on the dielectric wall of the reactor and can be explained by an increase of the local barrier capacitance available for charge transfer. The different discharge regimes affect the CO2 conversion, more specifically, the CO2 conversion is lowest in the clean DD configuration. It is somewhat higher in the coated DD configuration, and still higher in the MD configuration. The clean and coated MD configuration, however, gave similar CO2 conversion. These results indicate that the conductivity of the dielectric reactor walls can highly promote the development of the high-amplitude discharge current pulses and subsequently the CO2 conversion.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000370974800030 Publication Date 2016-01-21
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0963-0252 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited 25 Open Access
Notes The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7-PEOPLE-2013-ITN) under Grant Agreement № 606889 (RAPID—Reactive Atmospheric Plasma processIng—eDucation network). Approved Most recent IF: 3.302
Call Number c:irua:130790 Serial 4006
Permanent link to this record
 

 
Author Ozkan, A.; Dufour, T.; Silva, T.; Britun, N.; Snyders, R.; Bogaerts, A.; Reniers, F.
Title The influence of power and frequency on the filamentary behavior of a flowing DBD—application to the splitting of CO2 Type A1 Journal article
Year 2016 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 25 Issue 25 Pages 025013
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this experimental study, a flowing dielectric barrier discharge operating at atmospheric pressure is used for the splitting of CO2 into O2 and CO. The influence of the applied frequency and plasma power on the microdischarge properties is investigated to understand their role on the CO2 conversion. Electrical measurements are carried out to explain the conversion trends and to characterize the microdischarges through their number, their lifetime,

their intensity and the induced electrical charge. Their influence on the gas and electrode temperatures is also evidenced through optical emission spectroscopy and infrared imaging. It is shown that, in our configuration, the conversion depends mostly on the charge delivered in the plasma and not on the effective plasma voltage when the applied power is modified. Similarly, at constant total current, a better conversion is observed at low frequencies, where a less filamentary discharge regime with a higher effective plasma voltage than that at a higher

frequency is obtained.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000372337900015 Publication Date 2016-02-25
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0963-0252 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited 40 Open Access
Notes The authors acknowledge financial support from the IAPVII/ 12, P7/34 (Inter-university Attraction Pole) program ‘PSI-Physical Chemistry of Plasma-Surface Interactions’, financially supported by the Belgian Federal Office for Science Policy (BELSPO). A Ozkan would like to thank the financial support given by ‘Fonds David et Alice Van Buuren’. N Britun is a postdoctoral researcher of the F.R.S.-FNRS, Belgium. Approved Most recent IF: 3.302
Call Number c:irua:131904 Serial 4021
Permanent link to this record
 

 
Author Milovanovic, S.P.; Peeters, F.M.
Title Characterization of the size and position of electron-hole puddles at a graphene p-n junction Type A1 Journal article
Year 2016 Publication Nanotechnology Abbreviated Journal Nanotechnology
Volume 27 Issue 27 Pages 105203
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract The effect of an electron-hole puddle on the electrical transport when governed by snake states in a bipolar graphene structure is investigated. Using numerical simulations we show that information on the size and position of the electron-hole puddle can be obtained using the dependence of the conductance on magnetic field and electron density of the gated region. The presence of the scatterer disrupts snake state transport which alters the conduction pattern. We obtain a simple analytical formula that connects the position of the electron-hole puddle with features observed in the conductance. The size of the electron-hole puddle is estimated from the magnetic field and gate potential that maximizes the effect of the puddle on the electrical transport.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000369849200003 Publication Date 2016-02-11
Series Editor (up) 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 3 Open Access
Notes This work was supported by the Flemish Science Foundation (FWO-Vl) and the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN. We acknowledge interesting correspondence with Thiti Taychatanapat. Approved Most recent IF: 3.44
Call Number c:irua:131907 Serial 4025
Permanent link to this record
 

 
Author Filez, M.; Redekop, E.A.; Poelman, H.; Galvita, V.V.; Meledina, M.; Turner, S.; Van Tendeloo, G.; Detavernier, C.; Marin, G.B.
Title One-pot synthesis of Pt catalysts based on layered double hydroxides: an application in propane dehydrogenation Type A1 Journal article
Year 2016 Publication Catalysis science & technology Abbreviated Journal Catal Sci Technol
Volume 6 Issue 6 Pages 1863-1869
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Simple methods for producing noble metal catalysts with well-defined active sites and improved performance are highly desired in the chemical industry. However, the development of such methods still presents a formidable synthetic challenge. Here, we demonstrate a one-pot synthesis route for the controlled production of bimetallic Pt–In catalysts based on the single-step formation of Mg,Al,Pt,In-containing layered double hydroxides (LDHs). Besides their simple synthesis, these Pt–In catalysts exhibit superior propane dehydrogenation activity compared to their multi-step synthesized analogs. The presented material serves as a showcase for the one-pot synthesis of a broader class of LDH-derived mono- and multimetallic Pt catalysts. The compositional flexibility provided by LDH materials can pave the way towards highperforming Pt-based catalysts with tunable physicochemical properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000372172800031 Publication Date 2015-10-23
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2044-4753 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.773 Times cited 12 Open Access
Notes This work was supported by the Fund for Scientific Research Flanders (FWO: G.0209.11), the ‘Long Term Structural Methusalem Funding by the Flemish Government’, the IAP 7/05 Interuniversity Attraction Poles Programme – Belgian State – Belgian Science Policy, and the Fund for Scientific Research Flanders (FWO-Vlaanderen) by supplying financing of beam time at the DUBBLE beamline of the ESRF and travel costs and a post-doctoral fellowship for S. T. The authors acknowledge the assistance from the DUBBLE (XAS campaign 26-01-979) and SuperXAS staff (Proposal 20131191). E. A. Redekop acknowledges the Marie Curie International Incoming Fellowship granted by the European Commission (Grant Agreement No. 301703). The authors also express their gratitude to O. Janssens for performing ex situ XRD characterization. Approved Most recent IF: 5.773
Call Number c:irua:133167 Serial 4057
Permanent link to this record
 

 
Author Trenchev, G.; Kolev, S.; Bogaerts, A.
Title A 3D model of a reverse vortex flow gliding arc reactor Type A1 Journal article
Year 2016 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 25 Issue 25 Pages 035014
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this computational study, a gliding arc plasma reactor with a reverse-vortex flow stabilization is modelled for the first time by a fluid plasma description. The plasma reactor operates with argon gas at atmospheric pressure. The gas flow is simulated using the k-ε Reynolds-averaged Navier–Stokes turbulent model. A quasi-neutral fluid plasma model is used for computing the plasma properties. The plasma arc movement in the reactor is observed, and the results for the gas flow, electrical characteristics, plasma density, electron temperature, and gas temperature are analyzed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000376557400022 Publication Date 2016-04-09
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0963-0252 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited 20 Open Access
Notes This research was carried out in the framework of the network on Physical Chemistry of Plasma–Surface Interactions— Interuniversity Attraction Poles, phase VII (http://psi-iap7.ulb. ac.be/), and supported by the Belgian Science Policy Office (BELSPO), and it was also funded by the Fund for Scientific Research Flanders (FWO). Grant number: 11U5316N. Approved Most recent IF: 3.302
Call Number c:irua:132888 c:irua:132888 Serial 4063
Permanent link to this record
 

 
Author Ozkan, A.; Dufour, T.; Bogaerts, A.; Reniers, F.
Title How do the barrier thickness and dielectric material influence the filamentary mode and CO2conversion in a flowing DBD? Type A1 Journal article
Year 2016 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 25 Issue 25 Pages 045016
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Dielectric barrier discharges (DBDs) are commonly used to generate cold plasmas at

atmospheric pressure. Whatever their configuration (tubular or planar), the presence of a dielectric barrier is mandatory to prevent too much charge build up in the plasma and the formation of a thermal arc. In this article, the role of the barrier thickness (2.0, 2.4 and 2.8 mm) and of the kind of dielectric material (alumina, mullite, pyrex, quartz) is investigated on the filamentary behavior in the plasma and on the CO2 conversion in a tubular flowing DBD, by means of mass spectrometry measurements correlated with electrical characterization and IR imaging. Increasing the barrier thickness decreases the capacitance, while preserving the electrical charge. As a result, the voltage over the dielectric increases and a larger number of microdischarges is generated, which enhances the CO2 conversion. Furthermore, changing the dielectric material of the barrier, while keeping the same geometry and dimensions, also affects the CO2 conversion. The highest CO2 conversion and energy efficiency are obtained for quartz and alumina, thus not following the trend of the relative permittivity. From the

electrical characterization, we clearly demonstrate that the most important parameters are the somewhat higher effective plasma voltage (yielding a somewhat higher electric field and electron energy in the plasma) for quartz, as well as the higher plasma current (and thus larger electron density) and the larger number of microdischarge filaments (mainly for alumina, but also for quartz). The latter could be correlated to the higher surface roughness for alumina and to the higher voltage over the dielectric for quartz.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000380380200030 Publication Date 2016-06-30
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0963-0252 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited 24 Open Access
Notes The authors acknowledge financial support from the IAPVII/ 12, P7/34 (Inter-university Attraction Pole) program ‘PSI-Physical Chemistry of Plasma-Surface Interactions’, financially supported by the Belgian Federal Office for Science Policy (BELSPO). A. Ozkan would like to thank the financial support given by ‘Fonds David et Alice Van Buuren’. Approved Most recent IF: 3.302
Call Number c:irua:134396 Serial 4100
Permanent link to this record
 

 
Author Berthelot, A.; Bogaerts, A.
Title Modeling of plasma-based CO2conversion: lumping of the vibrational levels Type A1 Journal article
Year 2016 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 25 Issue 25 Pages 045022
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Although CO2 conversion by plasma technology is gaining increasing interest, the

underlying mechanisms for an energy-efficient process are still far from understood. In this work, a reduced non-equilibrium CO2 plasma chemistry set, based on level lumping of the vibrational levels, is proposed and the reliability of this level-lumping method is tested by a self-consistent zero-dimensional code. A severe reduction of the number of equations to be solved is achieved, which is crucial to be able to model non-equilibrium CO2 plasmas by 2-dimensional models. Typical conditions of pressure and power used in a microwave plasma for CO2 conversion are investigated. Several different sets, using different numbers of lumped groups, are considered. The lumped models with 1, 2 or 3 groups are able to reproduce the gas temperature, electron density and electron temperature profiles, as calculated by the full model treating all individual excited levels, in the entire pressure range investigated. Furthermore, a 3-groups model is also able to reproduce the shape of the vibrational distribution function (VDF) and gives the most reliable prediction of the CO2 conversion. A strong influence of the vibrational excitation on the plasma characteristics is observed. Finally, the limitations of the lumped-levels method are discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000380380200036 Publication Date 2016-07-08
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0963-0252 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited 33 Open Access
Notes This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 606889 and it was also carried out in the framework of the network on Physical Chemistry of Plasma-Surface Interactions—Interuniversity Attraction Poles, phase VII (PSI-IAP7) supported by the Belgian Science Policy Office (BELSPO). The computational work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UA. Approved Most recent IF: 3.302
Call Number c:irua:134397 Serial 4101
Permanent link to this record
 

 
Author Ozkan, A.; Dufour, T.; Silva, T.; Britun, N.; Snyders, R.; Reniers, F.; Bogaerts, A.
Title DBD in burst mode: solution for more efficient CO2conversion? Type A1 Journal article
Year 2016 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 25 Issue 25 Pages 055005
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract CO2 conversion into value-added products has gained significant interest over the few last years, as the greenhouse gas concentrations constantly increase due to anthropogenic activities. Here we report on experiments for CO2 conversion by means of a cold atmospheric plasma using a cylindrical flowing dielectric barrier discharge (DBD) reactor. A detailed comparison of this DBD ignited in a so-called burst mode (i.e. where an AC voltage is applied during a limited amount of time) and pure AC mode is carried out to evaluate their effect on the conversion of CO2 as well as on the energy efficiency. Decreasing the duty cycle in the burst mode from 100% (i.e. corresponding to pure AC mode) to 40% leads to a rise in the

conversion from 16–26% and to a rise in the energy efficiency from 15 to 23%. Based on a detailed electrical analysis, we show that the conversion correlates with the features of the microfilaments. Moreover, the root-mean-square voltage in the burst mode remains constant as a function of the process time for the duty cycles <70%, while a higher duty cycle or the usual pure AC mode leads to a clear voltage decay by more than 500 V, over approximately 90 s, before reaching a steady state regime. The higher plasma voltage in the burst mode yields a higher electric field. This causes the increasing the electron energy, and therefore their

involvement in the CO2 dissociation process, which is an additional explanation for the higher CO2 conversion and energy efficiency in the burst mode.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000403945500005 Publication Date 2016-08-02
Series Editor (up) 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 17 Open Access
Notes The authors acknowledge financial support from the IAPVII/ 12, P7/34 (Inter-university Attraction Pole) program ‘PSI-Physical Chemistry of Plasma-Surface Interactions’, financially supported by the Belgian Federal Office for Science Policy (BELSPO). A. Ozkan would also like to thank financial support given by ‘Fonds David et Alice Van Buuren’. Approved Most recent IF: 3.302
Call Number c:irua:134841 Serial 4107
Permanent link to this record
 

 
Author Bogaerts, A.; Wang, W.; Berthelot, A.; Guerra, V.
Title Modeling plasma-based CO2conversion: crucial role of the dissociation cross section Type A1 Journal article
Year 2016 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 25 Issue 25 Pages 055016
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Plasma-based CO2 conversion is gaining increasing interest worldwide. A large research effort is devoted to improving the energy efficiency. For this purpose, it is very important to understand the underlying mechanisms of the CO2 conversion. The latter can be obtained by computer modeling, describing in detail the behavior of the various plasma species and all relevant chemical processes. However, the accuracy of the modeling results critically depends on the accuracy of the assumed input data, like cross sections. This is especially true for the cross section of electron impact dissociation, as the latter process is believed

to proceed through electron impact excitation, but it is not clear from the literature which excitation channels effectively lead to dissociation. Therefore, the present paper discusses the effect of different electron impact dissociation cross sections reported in the literature on the calculated CO2 conversion, for a dielectric barrier discharge (DBD) and a microwave (MW) plasma. Comparison is made to experimental data for the DBD case, to elucidate which cross section might be the most realistic. This comparison reveals that the cross sections proposed

by Itikawa and by Polak and Slovetsky both seem to underestimate the CO2 conversion. The cross sections recommended by Phelps with thresholds of 7 eV and 10.5 eV yield a CO2 conversion only slightly lower than the experimental data, but the sum of both cross sections overestimates the values, indicating that these cross sections represent dissociation, but most probably also include other (pure excitation) channels. Our calculations indicate that the choice of the electron impact dissociation cross section is crucial for the DBD, where this process is the dominant mechanism for CO2 conversion. In the MW plasma, it is only significant at pressures up to 100 mbar, while it is of minor importance for higher pressures, when dissociation proceeds mainly through collisions of CO2 with heavy particles.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000384030600001 Publication Date 2016-08-31
Series Editor (up) 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 57 Open Access
Notes The authors would like to thank R Snoeckx and S Heijkers for the interesting discussions. This research was supported by the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 606889, the European Marie Skłodowska-Curie Individual Fellowship project ‘GlidArc’ within Horizon2020, the FWO project (grant G.0383.16N), and the Network on Physical Chemistry of Plasma-Surface Interactions—Interuniversity Attraction Poles, phase VII (PSI-IAP7), supported by the Belgian Science Policy Office (BELSPO). The computational work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UA. VG was partially supported by the Portuguese FCT— Fundação para a Ci Approved Most recent IF: 3.302
Call Number c:irua:135070 Serial 4111
Permanent link to this record
 

 
Author Spadaro, M.C.; Luches, P.; Bertoni, G.; Grillo, V.; Turner, S.; Van Tendeloo, G.; Valeri, S.; D'Addato, S.
Title Influence of defect distribution on the reducibility of CeO2-x nanoparticles Type A1 Journal article
Year 2016 Publication Nanotechnology Abbreviated Journal Nanotechnology
Volume 27 Issue 27 Pages 425705
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Ceria nanoparticles (NPs) are fundamental in heterogeneous catalysis because of their ability to store or release oxygen depending on the ambient conditions. Their oxygen storage capacity is strictly related to the exposed planes, crystallinity, density and distribution of defects. In this work a study of ceria NPs produced with a ligand-free, physical synthesis method is presented. The NP films were grown by a magnetron sputtering based gas aggregation source and studied by high resolution- and scanning-transmission electron microscopy and x-ray photoelectron spectroscopy. In particular, the influence of the oxidation procedure on the NP reducibility has been investigated. The different reducibility has been correlated to the exposed planes, crystallinity and density and distribution of structural defects. The results obtained in this work represent a basis to obtain cerium oxide NP with desired oxygen transport properties.
Address Dipartimento FIM, Universita di Modena e Reggio Emilia, via G. Campi 213/a, I-41125 Modena, Italy. CNR-NANO, via G. Campi 213/a, I-41125 Modena, Italy
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000385483900004 Publication Date 2016-09-15
Series Editor (up) 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 11 Open Access
Notes The authors gratefully acknowledge financial support by the Italian MIUR under grant FIRB RBAP115AYN (Oxides at the nanoscale: multifunctionality and applications). The activity is performed within the COST Action CM1104 'Reducible oxide chemistry, structure and functions'. The research leading to these results has received funding also from the European Union Seventh Framework Programme under Grant Agreement 312483—ESTEEM2 (Integrated Infrastructure Initiative–I3).; esteem2_ta Approved Most recent IF: 3.44
Call Number EMAT @ emat @ c:irua:135424 Serial 4130
Permanent link to this record
 

 
Author Wang, W.; Bogaerts, A.
Title Effective ionisation coefficients and critical breakdown electric field of CO2at elevated temperature: effect of excited states and ion kinetics Type A1 Journal article
Year 2016 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 25 Issue 25 Pages 055025
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Electrical breakdown by the application of an electric field occurs more easily in hot gases than in cold gases because of the extra electron-species interactions that occur as a result of dissociation, ionization and excitation at higher temperature. This paper discusses some overlooked physics and clarifies inaccuracies in the evaluation of the effective ionization coefficients and the critical reduced breakdown electric field of CO2 at elevated temperature, considering the influence of excited states and ion kinetics. The critical reduced breakdown electric field is obtained by balancing electron generation and loss mechanisms using the electron energy distribution function (EEDF) derived from the Boltzmann transport equation under the two-term approximation. The equilibrium compositions of the hot gas mixtures are determined based on Gibbs free energy minimization considering the ground states as well as vibrationally and electronically excited states as independent species, which follow a Boltzmann distribution with a fixed excitation temperature. The interaction cross sections between electrons and the excited species, not reported previously, are properly taken into account. Furthermore, the ion kinetics, including electron–ion recombination, associative electron detachment, charge transfer and ion conversion into stable negative ion clusters, are also considered. Our results indicate that the excited species lead to a greater population of high-energy electrons at higher gas temperature and this affects the Townsend rate coefficients (i.e. of electron impact ionization and attachment), but the critical reduced breakdown electric field strength of CO2 is only affected when also properly accounting for the ion kinetics. Indeed, the latter greatly influences the effective ionization coefficients and hence the critical reduced breakdown electric field at temperatures above 1500 K. The rapid increase of the dissociative electron attachment cross-section of molecular oxygen with rising vibrational quantum number leads to a larger electron loss rate and this enhances the critical reduced breakdown electric field strength in the temperature range where the concentration of molecular oxygen is relatively high. The results obtained in this work show reasonable agreement with experimental results from literature, and are important for the evaluation of the dielectric strength of CO2 in a highly reactive environment at elevated temperature.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000385494000006 Publication Date 2016-09-22
Series Editor (up) 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 3 Open Access
Notes Skłodowska-Curie Individual Fellowship ‘GlidArc’ within Horizon2020 (Grant No.657304) and the FWO project (grant G.0383.16N). The computational work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UA. Approved Most recent IF: 3.302
Call Number PLASMANT @ plasmant @ c:irua:135515 Serial 4281
Permanent link to this record
 

 
Author Wang, W.; Berthelot, A.; Kolev, S.; Tu, X.; Bogaerts, A.
Title CO2 conversion in a gliding arc plasma: 1D cylindrical discharge model Type A1 Journal article
Year 2016 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 25 Issue 25 Pages 065012
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract CO 2 conversion by a gliding arc plasma is gaining increasing interest, but the underlying mechanisms for an energy-efficient process are still far from understood. Indeed, the chemical complexity of the non-equilibrium plasma poses a challenge for plasma modeling due to the huge computational load. In this paper, a one-dimensional (1D) gliding arc model is developed in a cylindrical frame, with a detailed non-equilibrium CO 2 plasma chemistry set, including the CO 2 vibrational kinetics up to the dissociation limit. The model solves a set of time- dependent continuity equations based on the chemical reactions, as well as the electron energy balance equation, and it assumes quasi-neutrality in the plasma. The loss of plasma species and heat due to convection by the transverse gas flow is accounted for by using a characteristic frequency of convective cooling, which depends on the gliding arc radius, the relative velocity of the gas flow with respect to the arc and on the arc elongation rate. The calculated values for plasma density and plasma temperature within this work are comparable with experimental data on gliding arc plasma reactors in the literature. Our calculation results indicate that excitation to the vibrational levels promotes efficient dissociation in the gliding arc, and this is consistent with experimental investigations of the gliding arc based CO 2 conversion in the literature. Additionally, the dissociation of CO 2 through collisions with O atoms has the largest contribution to CO 2 splitting under the conditions studied. In addition to the above results, we also demonstrate that lumping the CO 2 vibrational states can bring a significant reduction of the computational load. The latter opens up the way for 2D or 3D models with an accurate description of the CO 2 vibrational kinetics.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000386605100002 Publication Date 2016-10-18
Series Editor (up) 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 3 Open Access
Notes This research was supported by the European Marie Skłodowska-Curie Individual Fellowship ‘GlidArc’ within Horizon2020 (Grant No. 657304) and by the FWO project (grant G.0383.16N). The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. Approved Most recent IF: 3.302
Call Number PLASMANT @ plasmant @ c:irua:135990 Serial 4286
Permanent link to this record
 

 
Author Meledin, A.; Turner, S.; Cayado, P.; Mundet, B.; Solano, E.; Ricart, S.; Ros, J.; Puig, T.; Obradors, X.; Van Tendeloo, G.
Title Unique nanostructural features in Fe, Mn-doped YBCO thin films Type A1 Journal article
Year 2016 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 29 Issue 29 Pages 125009
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract An attempt to grow a thin epitaxial composite film of YBa2Cu3O7−δ (YBCO) with spinel MnFe2O4 (MFO) nanoparticles on a LAO substrate using the CSD approach resulted in a decomposition of the spinel and various doping modes of YBCO with the Fe and Mn cations. These nanostructural effects lead to a lowering of T c and a slight J c increase in field. Using a combination of advanced transmission electron microscopy (TEM) techniques such as atomic resolution high-angle annular dark field scanning TEM, energy dispersive x-ray spectroscopy and electron energy-loss spectroscopy we have been able to decipher and characterize the effects of the Fe and Mn doping on the film architecture. The YBaCuFeO5 anion-deficient double perovskite phase was detected in the form of 3D inclusions as well as epitaxially grown lamellas within the YBCO matrix. These nano-inclusions play a positive role as pinning centers responsible for the J c/J sf (H) dependency smoothening at high magnetic fields in the YBCO-MFO films with respect to the pristine YBCO films.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000387680100001 Publication Date 2016-10-31
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 6 Open Access
Notes The authors gratefully acknowledge Prof. Dr. A. Abakumov and Dr. J. Gazquez for discussions and corrections. Part of this work was performed within the framework of the EUROTAPES project (FP7-NMP.2011.2.2-1 Grant no. 280432), funded by the European Union. ICMAB research was financed by the Ministry of Economy and Competitiveness, and FEDER funds under the projects MAT2011-28874-C02-01, MAT2014-51778-C2-1-R, ENE2014-56109-C3-3-R and Consolider Nanoselect CSD2007-00041, and by Generalitat de Catalunya (2009 SGR 770, 2015 SGR 753 and Xarmae). ICMAB acknowledges support from Severo Ochoa Program (MINECO, Grant SEV-2015-0496). Approved Most recent IF: 2.878
Call Number EMAT @ emat @ c:irua:136444 Serial 4295
Permanent link to this record
 

 
Author Chizhov, A.S.; Rumyantseva, M.N.; Vasiliev, R.B.; Filatova, D.G.; Drozdov, K.A.; Krylov, I.V.; Marchevsky, A.V.; Karakulina, O.M.; Abakumov, A.M.; Gaskov, A.M.
Title Visible light activation of room temperature NO2 gas sensors based on ZnO, SnO2 and In2O3 sensitized with CdSe quantum dots Type A1 Journal article
Year 2016 Publication Thin solid films : an international journal on the science and technology of thin and thick films Abbreviated Journal Thin Solid Films
Volume 618 Issue 618 Pages 253-262
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract This work reports the analysis of visible light activation of room temperature NO2 gas sensitivity of metal oxide semiconductors (MOS): blank and CdSe quantum dots (QDs) sensitized nanocrystallinematrixes ZnO, SnO2 and In2O3. Nanocrystalline metal oxides (MOx) ZnO, SnO2, In2O3 were synthesized by the precipitation method. Colloidal CdSe QDs were obtained by high temperature colloidal synthesis. Sensitization was effectuated by direct adsorption of CdSe QDs stabilized with oleic acid on MOx surface. The role of illumination consists in generation of electrons, which can be transferred into MOx conduction band, and holes that can recombine with the electrons previously trapped by the chemisorbed acceptor species and thus activate desorption of analyte molecules. Under green light illumination for blank SnO2 and In2O3 matrixes the indirect consequential mechanism for the generation of holes is proposed. Anothermechanismis realized in the presence of CdSe QDs. In this case the electron-hole pair is generated in the CdSe quantum dot. Sensor measurements demonstrated that synthesizedmaterials can be used for NO2 detection under visible (green) light illumination at room temperature without any thermal heating.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000389164400005 Publication Date 2016-09-18
Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0040-6090 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.879 Times cited 19 Open Access
Notes The work was financially supported by Russian Foundation for Basic Research grant no. 15-03-03026. Approved Most recent IF: 1.879
Call Number EMAT @ emat @ c:irua:138598 Serial 4321
Permanent link to this record