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Author (up) Wang, L.; Wen, D.-Q.; Zhang, Q.-Z.; Song, Y.-H.; Zhang, Y.-R.; Wang, Y.-N.
Title Disruption of self-organized striated structure induced by secondary electron emission in capacitive oxygen discharges Type A1 Journal article
Year 2019 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 28 Issue 5 Pages 055007
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Self-organized striated structure has been observed experimentally and numerically in CF4 plasmas in radio-frequency capacitively coupled plasmas recently (Liu et al 2016 Phys. Rev. Lett. 116 255002). In this work, the striated structure is investigated in a capacitively coupled oxygen discharge with the introduction of the effect from the secondary electron emission, based on a particle-in-cell/Monte Carlo collision model. As we know, the transport of positive and negative ions plays a key role in the formation of striations in electronegative gases, for which, the electronegativity needs to be large enough. As the secondary electron emission increases, electrons in the sheaths gradually contribute more ionization to the discharge. Meanwhile, the increase of the electron density, especially in the plasma bulk, leads to an increased electrical conductivity and a reduced bulk electric field, which would shield the ions' mobility. These changes result in enlarged striation gaps. And then, with more emitted electrons, obvious disruption of the striations is observed accompanied with a transition of electron heating mode. Due to the weakened field, the impact ionization in the plasma bulk is attenuated, compared with the enhanced ionization caused by secondary electrons. This would lead to the electron heating mode transition from striated (STR) mode to gamma-mode. Besides, our investigation further reveals that gamma-mode is more likely to dominate the discharge under high gas pressures or driving voltages.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000467827800001 Publication Date 2019-04-09
Series Editor 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 2 Open Access Not_Open_Access: Available from 13.05.2020
Notes Approved Most recent IF: 3.302
Call Number UA @ admin @ c:irua:160365 Serial 5270
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Author (up) Wang, Y.-L.; Glatz, A.; Kimmel, G.J.; Aranson, I.S.; Thoutam, L.R.; Xiao, Z.-L.; Berdiyorov, G.R.; Peeters, F.M.; Crabtree, G.W.; Kwok, W.-K.
Title Parallel magnetic field suppresses dissipation in superconducting nanostrips Type A1 Journal article
Year 2017 Publication America Abbreviated Journal P Natl Acad Sci Usa
Volume 114 Issue 48 Pages E10274-E10280
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract <script type='text/javascript'>document.write(unpmarked('The motion of Abrikosov vortices in type-II superconductors results in a finite resistance in the presence of an applied electric current. Elimination or reduction of the resistance via immobilization of vortices is the \u0022holy grail\u0022 of superconductivity research. Common wisdom dictates that an increase in the magnetic field escalates the loss of energy since the number of vortices increases. Here we show that this is no longer true if the magnetic field and the current are applied parallel to each other. Our experimental studies on the resistive behavior of a superconducting Mo0.79Ge0.21 nanostrip reveal the emergence of a dissipative state with increasing magnetic field, followed by a pronounced resistance drop, signifying a reentrance to the superconducting state. Large-scale simulations of the 3D time-dependent Ginzburg-Landau model indicate that the intermediate resistive state is due to an unwinding of twisted vortices. When the magnetic field increases, this instability is suppressed due to a better accommodation of the vortex lattice to the pinning configuration. Our findings show that magnetic field and geometrical confinement can suppress the dissipation induced by vortex motion and thus radically improve the performance of superconducting materials.'));
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Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000416891600007 Publication Date 2017-11-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0027-8424; 1091-6490 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.661 Times cited 18 Open Access
Notes ; This work was supported by the US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division. The simulation was supported by the Scientific Discovery through Advanced Computing program funded by US DOE, Office of Science, Advanced Scientific Computing Research and Basic Energy Science, Division of Materials Science and Engineering. L.R.T. and Z.-L.X. acknowledge support through National Science Foundation Grant DMR-1407175. Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the DOE, Office of Science, Office of Basic Energy Sciences, under Contract DE-AC02-06CH11357. ; Approved Most recent IF: 9.661
Call Number UA @ lucian @ c:irua:147697 Serial 4889
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Author (up) Wang, Y.-T.; Wu, S.-M.; Luo, G.-Q.; Tian, G.; Wang, L.-Y.; Xiao, S.-T.; Wu, J.-X.; Wu, A.; Wu, K.-J.; Lenaerts, S.; Yang, X.-Y.
Title A core-shell confined Pd@TS-1 @meso-SiO2 catalyst and its synergy effect on styrene oxidation Type A1 Journal article
Year 2023 Publication Applied catalysis : A : general Abbreviated Journal
Volume 650 Issue Pages 119016-6
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Dual active sites from acidic zeolite and Pd are not only capable of catalyzing multiple type of reactions, but could also generate unique functions owing to the synergy between metals and acidic sites. However, there are only a few reports on the investigation of the synergy of acid/Pd dual sites in TS-1. Herein, TS-1 confined Pd catalyst with mesoporous silica shell (Pd@TS-1 @meso-SiO2) has been successfully synthesized and its synergy effect contributes to the enhanced conversion rate (19.2%) and selectivity (74.7%) on styrene oxidation. The interaction between Pd and TS-1 has been investigated by EPR and 1H NMR techniques, the experimental measurements show an obvious change in the signal distribution of weakly acidic terminal hydroxyls and hydrogen-bonding silanols. The schematic illustration of selective styrene oxidation in the model of Pd@TS-1 @meso-SiO2 is proposed to clarify the synergistic effect on styrene oxidation between TS-1 and Pd nanoparticles at an atomic-/nanoscale.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001015700000001 Publication Date 2022-12-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0926-860x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.5 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 5.5; 2023 IF: 4.339
Call Number UA @ admin @ c:irua:197805 Serial 8826
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Author (up) Wang, Y.; Belén Serrano, A.; Sentosun, K.; Bals, S.; Liz-Marzán, L.M.
Title Stabilization and encapsulation of gold nanostars mediated by dithiols Type A1 Journal article
Year 2015 Publication Small Abbreviated Journal Small
Volume 11 Issue 11 Pages 4314-4320
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Surface chemistry plays a pivotal role in regulating the morphology of nanoparticles, maintaining colloidal stability, and mediating the interaction with target analytes toward practical applications such as surface-enhanced Raman scattering (SERS)-based sensing and imaging. The use of a binary ligand mixture composed of 1,4-benzenedithiol (BDT) and hexadecyltrimethylammonium chloride (CTAC) to provide gold nanostars with long-term stability is reported. This is despite BDT being a bifunctional ligand, which usually leads to bridging and loss of colloidal stability. It is found however that neither BDT nor CTAC alone are able to provide sufficient colloidal and chemical stability. BDT-coated Au nanostars are additionally used as seeds to direct the encapsulation with a gold outer shell, leading to the formation of unusual nanostructures including semishell-coated gold nanostars, which are characterized by high-resolution electron microscopy and electron tomography. Finally, BDT is exploited as a probe to reveal the enhanced local electric fields in the different nanostructures, showing that the semishell configuration provides significantly high SERS signals as compared to other coreshell configurations obtained during seeded growth, including full shells.
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Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000360852900009 Publication Date 2015-06-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1613-6810; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.643 Times cited 36 Open Access OpenAccess
Notes 267867 Plasmaquo; 335078 Colouratom; 262348 Esmi; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); Approved Most recent IF: 8.643; 2015 IF: 8.368
Call Number c:irua:127571 Serial 3136
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Author (up) Wang, Y.; Chen, Y.; Harding, J.; He, H.; Bogaerts, A.; Tu, X.
Title Catalyst-free single-step plasma reforming of CH4 and CO2 to higher value oxygenates under ambient conditions Type A1 Journal article
Year 2022 Publication Chemical Engineering Journal Abbreviated Journal Chem Eng J
Volume 450 Issue Pages 137860
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Direct conversion of CH4 and CO2 to liquid fuels and chemicals under mild conditions is appealing for biogas conversion and utilization but challenging due to the inert nature of both gases. Herein, we report a promising plasma process for the catalyst-free single-step conversion of CH4 and CO2 into higher value oxygenates (i.e., methanol, acetic acid, ethanol, and acetone) at ambient pressure and room temperature using a water-cooled dielectric barrier discharge (DBD) reactor, with methanol being the main liquid product. The distribution of liquid products could be tailored by tuning the discharge power, reaction temperature and residence time. Lower discharge powers (10–15 W) and reaction temperatures (5–20 ◦ C) were favourable for the production of liquid products, achieving the highest methanol selectivity of 43% at 5 ◦ C and 15 W. A higher discharge power and reaction temperature, on the other hand, produced more gaseous products, particularly H2 (up to 26% selec­tivity) and CO (up to 33% selectivity). In addition, varying these process parameters (discharge power, reaction temperature and residence time) resulted in a simultaneous change in key discharge properties, such as mean electron energy (Ee), electron density (ne) and specific energy input (SEI), all of which are essential determiners of plasma chemical reactions. According to the results of artificial neural network (ANN) models, the relative importance of these process parameters and key discharge indicators on reaction performance follows the order: discharge power > reaction temperature > residence time, and SEI > ne > Ee, respectively. This work provides new insights into the contributions and tuning mechanism of multiple parameters for optimizing the reaction performance (e.g., liquid production) in the plasma gas conversion process.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000830813300004 Publication Date 0000-00-00
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 15.1 Times cited Open Access OpenAccess
Notes This project received funding from the European Union’s Horizon 2020 research and innovation program under the Marie SklodowskaCurie grant agreement No. 813393. Approved Most recent IF: 15.1
Call Number PLASMANT @ plasmant @c:irua:189502 Serial 7100
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Author (up) Wang, Y.; Sentosun, K.; Li, A.; Coronado-Puchau, M.; Sánchez-Iglesias, A.; Li, S.; Su, X.; Bals, S.; Liz-Marzán, L.M.
Title Engineering Structural Diversity in Gold Nanocrystals by Ligand-Mediated Interface Control Type A1 Journal article
Year 2015 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 27 Issue 27 Pages 8032-8040
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Surface and interface control is fundamentally important for crystal growth engineering, catalysis, surface enhanced spectroscopies, and self-assembly, among other processes and applications. Understanding the role of ligands in regulating surface properties of plasmonic metal nanocrystals during growth has received considerable attention. However, the underlying mechanisms and the diverse functionalities of ligands are yet to be fully addressed. In this contribution,

we report a systematic study of ligand-mediated interface control in seeded growth of gold nanocrystals, leading to diverse and exotic nanostructures with an improved surface enhanced Raman scattering (SERS) activity. Three dimensional transmission electron microscopy (3D TEM) revealed an intriguing gold shell growth process mediated by the bifunctional ligand 1,4-benzenedithiol (BDT), which leads to a unique crystal growth mechanism as compared to other ligands, and subsequently to the concept of interfacial energy control mechanism. Volmer-Weber growth mode was proposed to be responsible for BDT-mediated seeded growth, favoring the strongest interfacial energy and generating an asymmetric island growth pathway with internal crevices/gaps. This additionally favors incorporation of BDT at the plasmonic nanogaps, thereby generating strong SERS activity with a maximum efficiency for a core-semishell configuration obtained along seeded growth. Numerical modeling was used to explain this observation. Interestingly, the same strategy can be used to engineer the structural diversity of this system, by using gold nanoparticle seeds with various sizes and shapes, and varying the [Au3+]/[Au0] ratio. This rendered a series of diverse and exotic plasmonic nanohybrids such as semishell-coated gold nanorods, with embedded Raman-active tags and Janus surface with distinct surface functionalities.

These would greatly enrich the plasmonic nanostructure toolbox for various studies and applications such as anisotropic nanocrystal engineering, SERS, and high-resolution Raman bioimaging or nanoantenna devices.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000366223200023 Publication Date 2015-10-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 18 Open Access OpenAccess
Notes The authors thank Bart Goris for his help with electron tomography. This work was funded by the European Commission (Grant #310445-2, SAVVY). The authors acknowledge financial support from European Research Council (ERC Advanced Grant # 267867- PLASMAQUO, ERC Starting Grant #335078-COLOURATOMS). The authors also appreciate financial support from the European Union under the Seventh Framework Program (Integrated Infrastructure Initiative N. 262348 European Soft Matter Infrastructure, ESMI). Wang Y. and Su X. would like to acknowledge the Agency for Science, Technology and Research (A*STAR), Singapore, for the financial support under the Grant JCO 14302FG096. M. C.-P. acknowledges an FPU scholarship from the Spanish Ministry of Education, Culture and Sports.; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); Approved Most recent IF: 9.466; 2015 IF: 8.354
Call Number c:irua:129598 c:irua:129598 Serial 3972
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Author (up) Wang, Y.; Sztranyovszky, Z.; Zilli, A.; Albrecht, W.; Bals, S.; Borri, P.; Langbein, W.
Title Quantitatively linking morphology and optical response of individual silver nanohedra Type A1 Journal article
Year 2022 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 14 Issue 30 Pages 11028-11037
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The optical response of metal nanoparticles is governed by plasmonic resonances, which are dictated by the particle morphology. A thorough understanding of the link between morphology and optical response requires quantitatively measuring optical and structural properties of the same particle. Here we present such a study, correlating electron tomography and optical micro-spectroscopy. The optical measurements determine the scattering and absorption cross-section spectra in absolute units, and electron tomography determines the 3D morphology. Numerical simulations of the spectra for the individual particle geometry, and the specific optical set-up used, allow for a quantitative comparison including the cross-section magnitude. Silver nanoparticles produced by photochemically driven colloidal synthesis, including decahedra, tetrahedra and bi-tetrahedra are investigated. A mismatch of measured and simulated spectra is found in some cases when assuming pure silver particles, which is explained by the presence of a few atomic layers of tarnish on the surface, not evident in electron tomography. The presented method tightens the link between particle morphology and optical response, supporting the predictive design of plasmonic nanomaterials.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000828704000001 Publication Date 2022-07-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364; 2040-3372 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited 1 Open Access OpenAccess
Notes Z.S. acknowledges the UK Engineering and Physical Sciences Research Council (EPSRC) for his Ph.D. studentship award (grant EP/R513003/1). Y.W. acknowledges Iwan Moreels (University of Ghent) for training in nanoparticle synthesis. Y.W. acknowledges the Biotechnology and Biological Sciences Research Council (BBSRC) for his Ph.D. studentship award (grant BB/L015889/1). This work was supported by the UK EPSRC (grants EP/I005072/1 and EP/M028313/1), and by the European Commission (EUSMI E191000350). W.A. acknowledges an Individual Fellowship from the Marie Skodowska-Curie actions (MSCA) under the EU's Horizon 2020 program (Grant 797153, SOPMEN). We thank Lukas Payne and Iestyn Pope for contributions to the development of the hardware and software used for the optical measurements. Approved Most recent IF: 6.7
Call Number UA @ admin @ c:irua:189578 Serial 7092
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Author (up) Wang, Y.; Yu, M.Y.; Chen, Z.Y.
Title Coherent relativistic wake wave of a charged object moving steadily in a plasma Type A1 Journal article
Year 2011 Publication Physica scripta Abbreviated Journal Phys Scripta
Volume 84 Issue 2 Pages 025501,1-025501,5
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Nonlinear electron plasma waves driven by a finite-charged particle pulse or rigid object moving at relativistic speeds are investigated. Quasi-stationary smooth and spiky wake waves comoving with the object are found. Localized soliton-like solutions are also shown to exist. Relativistic effects tend to prevent their formation because of the electron mass increase. The application of the very-large-amplitude wake density waves as a source of ultrahigh-energy cosmic-ray events is discussed.
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Corporate Author Thesis
Publisher Place of Publication Stockholm Editor
Language Wos 000294727900017 Publication Date 2011-07-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-8949;1402-4896; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.28 Times cited 5 Open Access
Notes Approved Most recent IF: 1.28; 2011 IF: 1.204
Call Number UA @ lucian @ c:irua:92435 Serial 381
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Author (up) Wang, Y.; Yuan, Y.; Liao, X.; Van Tendeloo, G.; Zhao, Y.; Sun, C.
Title Chip-based in situ TEM investigation of structural thermal instability in aged layered cathode Type A1 Journal article
Year 2023 Publication Nanoscale Advances Abbreviated Journal
Volume 5 Issue 16 Pages 4182-4190
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Thermally induced oxygen release is an intrinsic structural instability in layered cathodes, which causes thermal runaway issues and becomes increasingly critical with the continuous improvement in energy density. Furthermore, thermal runaway events always occur in electrochemically aged cathodes, where the coupling of the thermal and electrochemical effect remains elusive. Herein, we report the anomalous segregation of cobalt metal in an aged LiCoO2 cathode, which is attributed to the local exposure of the high-energy (100) surface of LiCoO2 and weak interface Co-O dangling bonds significantly promoting the diffusion of Co. The presence of the LCO-Co interface severely aggregated the oxygen release in the form of dramatic Co growth. A unique particle-to-particle oxygen release pathway was also found, starting from the isolated high reduction areas induced by the cycling heterogeneity. This study provides atomistic insight into the robust coupling between the intrinsic structural instability and electrochemical cycling.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001030149900001 Publication Date 2023-07-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2516-0230 ISBN Additional Links UA library record; WoS full record
Impact Factor 4.7 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.7; 2023 IF: NA
Call Number UA @ admin @ c:irua:198281 Serial 8841
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Author (up) Wang, Y.J.; Jiang, Z.X.; McCombe, B.D.; Peeters, F.M.; Wu, X.G.; Hai, G.Q.; Eusfis, T.J.; Schaff, W.
Title High-field cyclotron resonance and electron-phonon interaction in modulation-doped multiple quantum well structures Type A1 Journal article
Year 1998 Publication Physica: B : condensed matter Abbreviated Journal Physica B
Volume 256/258 Issue Pages 215-219
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000077775900059 Publication Date 2002-07-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-4526; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.386 Times cited 5 Open Access
Notes Approved Most recent IF: 1.386; 1998 IF: 0.619
Call Number UA @ lucian @ c:irua:24179 Serial 1427
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Author (up) Wang, Y.J.; Leem, Y.A.; McCombe, B.D.; Wu, X.G.; Peeters, F.M.; Jones, E.; Reno, J.; Lee, X.Y.; Jiang, H.W.
Title Strong resonant intersubband magnetopolaron effect in heavily modulation-doped GaAs/AlGaAs single quantum wells at high magnetic fields Type A1 Journal article
Year 2000 Publication Physica. E: Low-dimensional systems and nanostructures Abbreviated Journal Physica E
Volume 6 Issue Pages 195-200
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher North-Holland Place of Publication Amsterdam Editor
Language Wos 000085770600048 Publication Date 2002-07-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1386-9477; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.221 Times cited 2 Open Access
Notes Approved Most recent IF: 2.221; 2000 IF: 0.878
Call Number UA @ lucian @ c:irua:28526 Serial 3183
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Author (up) Wang, Y.J.; Leem, Y.A.; McCombe, B.D.; Wu, X.G.; Peeters, F.M.; Jones, E.D.; Reno, J.R.; Lee, X.Y.; Jiang, H.W.
Title Strong three-level resonant magnetopolaron effect due to the intersubband coupling in heavily modulation-doped GaAs/AlxGa1-xAs single quantum wells at high magnetic-fields Type A1 Journal article
Year 2001 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 64 Issue 16 Pages 161303
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Electron cyclotron resonance CR) measurements have been carried out in magnetic fields up to 32 T to study electron-phonon interaction in two heavily modulation-delta -doped GaAs/Al0.3Ga0.7As single-quantum-well samples. No measurable resonant magnetopolaron effects were observed in either sample in the region of the GaAs longitudinal optical (LO) phonons. However, when the CR frequency is above LO phonon frequency, omega (LO)=E-LO/(h) over bar, at high magnetic fields (B>27 T), electron CR exhibits a strong avoided-level-crossing splitting for both samples at frequencies close to (omega (LO)+ (E-2-E-1)1 (h) over bar, where E-2, and E-1 are the energies of the bottoms of the second and the first subbands, respectively. The energy separation between the two branches is large with the minimum separation of 40 cm(-1) occurring at around 30.5 T. A detailed theoretical analysis, which includes a self-consistent calculation of the band structure and the effects of electron-phonon interaction on the CR, shows that this type of splitting is due to a three-level resonance between the second Landau level of the first electron subband and the lowest Landau level of the second subband plus one GaAs LO phonon. The absence of occupation effects in the final states and weak screening or this three-level process yields large energy separation even in the presence of high electron densities. Excellent agreement between the theory and the experimental results is obtained.
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Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000171866400009 Publication Date 2002-07-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 7 Open Access
Notes Approved Most recent IF: 3.836; 2001 IF: NA
Call Number UA @ lucian @ c:irua:37278 Serial 3184
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Author (up) Wang, Y.J.; Nichel, H.A.; McCombe, B.D.; Peeters, F.M.; Shi, J.M.; Hai, G.Q.; Wu, X.G.; Eustis, T.J.; Schaff, W.
Title Resonant magnetopolaron effect in GaAs/AlGaAs multiple quantum well structures Type A1 Journal article
Year 1998 Publication Physica. E: Low-dimensional systems and nanostructures Abbreviated Journal Physica E
Volume 2 Issue Pages 161-165
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher North-Holland Place of Publication Amsterdam Editor
Language Wos 000075383500034 Publication Date 2002-07-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1386-9477; ISBN Additional Links UA library record; WoS full record
Impact Factor 2.221 Times cited Open Access
Notes Approved Most recent IF: 2.221; 1998 IF: NA
Call Number UA @ lucian @ c:irua:24185 Serial 2888
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Author (up) Wang, Y.J.; Nickel, H.A.; McCombe, B.D.; Peeters, F.M.; Hai, G.Q.; Shi, J.M.; Devreese, J.T.; Wu, X.G.
Title Resonant magnetopolaron effects in GaAs/AlGaAs MQWs at high magnetic fields Type P3 Proceeding
Year 1997 Publication Abbreviated Journal
Volume Issue Pages 797-800
Keywords P3 Proceeding; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Abstract
Address
Corporate Author Thesis
Publisher World Scientific Place of Publication Singapore Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:19305 Serial 2890
Permanent link to this record
 
 
Author (up) Wang, Y.J.; Nickel, H.A.; McCombe, B.D.; Peeters, F.M.; Shi, J.M.; Hai, G.Q.; Wu, X.G.; Eustis, T.J.; Schaff, W.
Title Resonant magnetopolaron effects due to interface phonons in GaAs/AlGaAs multiple quantum well structures Type A1 Journal article
Year 1997 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 79 Issue Pages 3226-3229
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos A1997YC78200033 Publication Date 0000-00-00
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 36 Open Access
Notes Approved Most recent IF: 8.462; 1997 IF: 6.140
Call Number UA @ lucian @ c:irua:19278 Serial 2889
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Author (up) Wang, Z.; Wang, Y.B.; Yin, J.; Tovari, E.; Yang, Y.; Lin, L.; Holwill, M.; Birkbeck, J.; Perello, D.J.; Xu, S.; Zultak, J.; Gorbachev, R.V.; Kretinin, A.V.; Taniguchi, T.; Watanabe, K.; Morozov, S.V.; Andelkovic, M.; Milovanović, S.P.; Covaci, L.; Peeters, F.M.; Mishchenko, A.; Geim, A.K.; Novoselov, K.S.; Fal'ko, V.I.; Knothe, A.; Woods, C.R.
Title Composite super-moiré lattices in double-aligned graphene heterostructures = Composite super-moire lattices in double-aligned graphene heterostructures Type A1 Journal article
Year 2019 Publication Science Advances Abbreviated Journal
Volume 5 Issue 12 Pages eaay8897
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract When two-dimensional (2D) atomic crystals are brought into close proximity to form a van der Waals heterostructure, neighbouring crystals may influence each other's properties. Of particular interest is when the two crystals closely match and a moire pattern forms, resulting in modified electronic and excitonic spectra, crystal reconstruction, and more. Thus, moire patterns are a viable tool for controlling the properties of 2D materials. However, the difference in periodicity of the two crystals limits the reconstruction and, thus, is a barrier to the low-energy regime. Here, we present a route to spectrum reconstruction at all energies. By using graphene which is aligned to two hexagonal boron nitride layers, one can make electrons scatter in the differential moire pattern which results in spectral changes at arbitrarily low energies. Further, we demonstrate that the strength of this potential relies crucially on the atomic reconstruction of graphene within the differential moire super cell.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000505069600089 Publication Date 2019-12-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2375-2548 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 49 Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:165754 Serial 6289
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Author (up) Wen, D.-Q.; Zhang, Q.-Z.; Jiang, W.; Song, U.-H.; Bogaerts, A.; Wang, Y.-N.
Title Phase modulation in pulsed dual-frequency capacitively coupled plasmas Type A1 Journal article
Year 2014 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 115 Issue 23 Pages 233303
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Particle-in-cell/Monte Carlo collision simulations, coupled with an external circuit, are used to investigate the behavior of pulsed dual-frequency (DF) capacitively coupled plasmas (CCPs). It is found that the phase shift θ between the high (or low) frequency source and the pulse modulation has a great influence on the ion density and the ionization rate. By pulsing the high frequency source, the time-averaged ion density shows a maximum when θ = 90∘. The time-averaged ion energy distribution functions (IEDFs) at the driven electrode, however, keep almost unchanged, illustrating the potential of pulsed DF-CCP for independent control of ion density (and flux) and ion energy. A detailed investigation of the temporal evolution of the plasma characteristics indicates that several high frequency harmonics can be excited at the initial stage of a pulse period by tuning the phase shift θ, and this gives rise to strong sheath oscillations, and therefore high ionization rates. For comparison, the pulsing of the low frequency source is also studied. In this case, the ion density changes slightly as a function of time, and the time-averaged ion density shows the same trend as in the HF modulation for different phase shifts θ. Moreover, the time-averaged IEDFs at the driven electrode can be modulated, showing the potential to reduce the maximum ion bombardment energy.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000338106000008 Publication Date 2014-06-23
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 8 Open Access
Notes Approved Most recent IF: 2.068; 2014 IF: 2.183
Call Number UA @ lucian @ c:irua:117415 Serial 2585
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Author (up) Wu, X.G.; Peeters, F.M.; Wang, Y.J.; McCombe, B.D.
Title Blocking of the polaron effect and spin-split cyclotron resonance in a two-dimensional electron gas Type A1 Journal article
Year 2000 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 84 Issue Pages 4934-4937
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000087114400038 Publication Date 2002-07-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007;1079-7114; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.462 Times cited 15 Open Access
Notes Approved Most recent IF: 8.462; 2000 IF: 6.462
Call Number UA @ lucian @ c:irua:28517 Serial 245
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Author (up) Xiao, S.; Lu, Y.; Xiao, B.-Y.; Wu, L.; Song, J.-P.; Xiao, Y.-X.; Wu, S.-M.; Hu, J.; Wang, Y.; Chang, G.-G.; Tian, G.; Lenaerts, S.; Janiak, C.; Yang, X.-Y.; Su, B.-L.
Title Hierarchically dual-mesoporous TiO2 microspheres for enhanced photocatalytic properties and lithium storage Type A1 Journal article
Year 2018 Publication Chemistry: a European journal Abbreviated Journal Chem-Eur J
Volume 24 Issue 50 Pages 13246-13252
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Hierarchically dual‐mesoporous TiO2 microspheres have been synthesized via a solvothermal process in the presence of 1‐butyl‐3‐methylmidazolium tetrafluoroborate ([BMIm][BF4]) and diethylenetriamine (DETA) as co‐templates. Secondary mesostructured defects in the hierarchical TiO2 microspheres produce the oxygen vacancies, which not only significantly enhance the photocatalytic activity on degrading methyl blue (over 1.7 times to P25) and acetone (over 2.9 times of P25), but which also are beneficial for lithium storage. Moreover, we propose a mechanism to obtain a better understanding of the role of dual mesoporosity of TiO2 microspheres for enhancing the molecular diffusion, ion transportation and electron transformation.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000443804100025 Publication Date 2018-06-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0947-6539 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.317 Times cited 6 Open Access
Notes ; This work is supported by the National Key R&D Program of China (2017YFC1103800), the Program for Changjiang Scholars and Innovative Research Team in University (IRT 15R52), the National Natural Science Foundation of China (U1662134, U1663225, 51472190, 51611530672, 51503166, 21706199, 21711530705), the International Science & Technology Cooperation Program of China (2015DFE52870), the Natural Science Foundation of Hubei Province (2016CFA033, 2017CFB487), the Open Project Program of State Key Laboratory of Petroleum Pollution Control (PPC2016007), and the CNPC Research Institute of Safety and Environmental Technology. ; Approved Most recent IF: 5.317
Call Number UA @ admin @ c:irua:151812 Serial 5957
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Author (up) Xiaoyan, S.; Zhang, Y.-R.; Wang, Y.-N.; He, J.-X.
Title Fluid simulation of the superimposed dual-frequency source effect in inductively coupled discharges Type A1 Journal article
Year 2021 Publication Physics Of Plasmas Abbreviated Journal Phys Plasmas
Volume 28 Issue 11 Pages 113504-113510
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Superimposition of dual frequencies (DFs) is one of the methods used for controlling plasma distribution in an inductively coupled plasma (ICP) source. The effects of a superimposed DF on the argon plasma characteristics have been investigated using a two-dimensional self-consistent fluid model. When both currents are fixed at 6A, the plasma density drops with decrease in one of the source frequencies due to less efficient heating and the plasma uniformity improves significantly. Moreover, for ICP operated with superimposed DFs (i.e., 4.52MHz/13.56MHz and 2.26MHz/13.56MHz), the current source exhibits the same period as the low frequency (LF) component, and the plasma density is higher than that obtained at a single frequency (i.e., 4.52 and 2.26MHz) with the same total current of 12A. However, at superimposed current frequencies of 6.78MHz/13.56MHz, the plasma density is lower than that obtained at a single frequency of 6.78MHz due to the weaker negative azimuthal electric field between two positive maxima during one period of 6.78MHz. When the superimposed DF ICP operates at 2.26 and 13.56MHz, the rapid oscillations of the induced electric field become weaker during one period of 2.26MHz as the current ratio of 2.26MHz/13.56MHz rises from 24A/7 A to 30A/1 A, and the plasma density drops with the current ratio due to weakened electron heating. The uniformity of plasma increases due to sufficient diffusion under the low-density condition.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000760326100004 Publication Date 2021-11-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1070-664x ISBN Additional Links UA library record; WoS full record
Impact Factor 2.115 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 2.115
Call Number UA @ admin @ c:irua:187245 Serial 7974
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Author (up) Yang, T.; Kong, Y.; Li, K.; Lu, Q.; Wang, Y.; Du, Y.; Schryvers, D.
Title Quasicrystalline clusters transformed from C14-MgZn₂ nanoprecipitates in Al alloys Type A1 Journal article
Year 2023 Publication Materials characterization Abbreviated Journal
Volume 199 Issue Pages 112772-112777
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Ultrafine faulty C14-MgZn2 Laves phase precipitates containing quasicrystalline clusters and demonstrating the formation of binary quasicrystalline precipitates with Penrose-like random-tiling were observed in the over-aged FCC matrix of a commercial 7N01 Al-Zn-Mg alloy, using high angle annular dark field scanning transmission electron microscopy. The evolution from C14-Laves phase to quasicrystalline clusters is illustrated, and five-fold symmetry can be found in both real and reciprocal spaces. Our findings reveal the possibility of quasicrystalline formation from Laves phase in a highly plastic metal matrix like Al and demonstrate the structural relationship between Laves phase and quasicrystals.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000954788800001 Publication Date 2023-03-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.7 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 4.7; 2023 IF: 2.714
Call Number UA @ admin @ c:irua:196106 Serial 8446
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Author (up) Yuan, Y.; Wu, F.-J.; Xiao, S.-T.; Wang, Y.-T.; Yin, Z.-W.; Van Tendeloo, G.; Chang, G.-G.; Tian, G.; Hu, Z.-Y.; Wu, S.-M.; Yang, X.-Y.
Title Hierarchical zeolites containing embedded Cd0.2Zn0.8S as a photocatalyst for hydrogen production from seawater Type A1 Journal article
Year 2023 Publication Chemical communications Abbreviated Journal
Volume 59 Issue 47 Pages 7275-7278
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Uncovering an efficient and stable photocatalytic system for seawater splitting is a highly desirable but challenging goal. Herein, Cd0.2Zn0.8S@Silicalite-1 (CZS@S-1) composites, in which CZS is embedded in the hierarchical zeolite S-1, were prepared and show remarkably high activity, stability and salt resistance in seawater.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000994367000001 Publication Date 2023-05-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-7345; 1364-548x ISBN Additional Links UA library record; WoS full record
Impact Factor 4.9 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.9; 2023 IF: 6.319
Call Number UA @ admin @ c:irua:197291 Serial 8878
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Author (up) Zhang, Q.-Z.; Liu, Y.-X.; Jiang, W.; Bogaerts, A.; Wang, Y.-N.
Title Heating mechanism in direct current superposed single-frequency and dual-frequency capacitively coupled plasmas Type A1 Journal article
Year 2013 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 22 Issue 2 Pages 025014-25018
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this work particle-in-cell/Monte Carlo collision simulations are performed to study the heating mechanism and plasma characteristics in direct current (dc) superposed radio-frequency (RF) capacitively coupled plasmas, operated both in single-frequency (SF) and dual-frequency (DF) regimes. An RF (60/2 MHz) source is applied on the bottom electrode to sustain the discharge, and a dc source is fixed on the top electrode. The heating mechanism appears to be very different in dc superposed SF and DF discharges. When only a single source of 60 MHz is applied, the plasma bulk region is reduced by the dc source, thus the ionization rate and hence the electron density decrease with rising dc voltage. However, when a DF source of 60 and 2 MHz is applied, the electron density can increase upon addition of a dc voltage, depending on the gap length and applied dc voltage. This is explained from the spatiotemporal ionization rates in the DF discharge. In fact, a completely different behavior is observed for the ionization rate in the two half-periods of the LF source. In the first LF half-period, the situation resembles the dc superposed SF discharge, and the reduced plasma bulk region due to the negative dc bias results in a very small effective discharge area and a low ionization rate. On the other hand, in the second half-period, the negative dc bias is to some extent counteracted by the LF voltage, and the sheath close to the dc electrode becomes particularly thin. Consequently, the amplitude of the high-frequency sheath oscillations at the top electrode is largely enhanced, while the LF sheath at the bottom electrode is in its expanding phase and can thus well confine the high-energy electrons. Therefore, the ionization rate increases considerably in this second LF half-period. Furthermore, in addition to the comparison between SF and DF discharges and the effect of gap length and dc voltage, the effect of secondary electrons is examined.
Address
Corporate Author Thesis
Publisher Institute of Physics Place of Publication Bristol Editor
Language Wos 000317275400016 Publication Date 2013-03-28
Series Editor 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 9 Open Access
Notes Approved Most recent IF: 3.302; 2013 IF: 3.056
Call Number UA @ lucian @ c:irua:106877 Serial 1413
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Author (up) Zhang, Q.-Z.; Wang, Y.-N.; Bogaerts, A.
Title Heating mode transition in a hybrid direct current/dual-frequency capacitively coupled CF4 discharge Type A1 Journal article
Year 2014 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 115 Issue 22 Pages 223302-223306
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Computer simulations based on the particle-in-cell/Monte Carlo collision method are performed to study the plasma characteristics and especially the transition in electron heating mechanisms in a hybrid direct current (dc)/dual-frequency (DF) capacitively coupled CF 4 discharge. When applying a superposed dc voltage, the plasma density first increases, then decreases, and finally increases again, which is in good agreement with experiments. This trend can be explained by the transition between the four main heating modes, i.e., DF coupling, dc and DF coupling, dc source dominant heating, and secondary electron dominant heating.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000337891800006 Publication Date 2014-06-11
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 9 Open Access
Notes Approved Most recent IF: 2.068; 2014 IF: 2.183
Call Number UA @ lucian @ c:irua:117347 Serial 1414
Permanent link to this record
 
 
Author (up) Zhang, Q.-Z.; Zhao, S.-X.; Jiang, W.; Wang, Y.-N.
Title Separate control between geometrical and electrical asymmetry effects in capacitively coupled plasmas Type A1 Journal article
Year 2012 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 45 Issue 30 Pages 305203
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Both geometrical and electrical asymmetry effects in capacitive argon discharges are investigated using a two-dimensional particle-in-cell coupled with Monte Carlo collision model. When changing the ratio of the top and bottom electrode surface areas and the phase shift between the two applied harmonics, the induced self-bias was found to develop separately. By adjusting the ratio between the high and low harmonic amplitudes, the electrical asymmetry effect at a fixed phase shift can be substantially optimized. However, the self-bias caused by the geometrical asymmetry hardly changed. Moreover, the separate control of these two asymmetry effects can also be demonstrated from their power absorption profiles. Both the axial and radial plasma density distributions can be modulated by the electrical asymmetry effect.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000306475200007 Publication Date 2012-07-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727;1361-6463; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited 20 Open Access
Notes Approved Most recent IF: 2.588; 2012 IF: 2.528
Call Number UA @ lucian @ c:irua:100751 Serial 2984
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Author (up) Zhang, Q.‐Z.; Zhang, L.; Yang, D.‐Z.; Schulze, J.; Wang, Y.‐N.; Bogaerts, A.
Title Positive and negative streamer propagation in volume dielectric barrier discharges with planar and porous electrodes Type A1 Journal article
Year 2021 Publication Plasma Processes And Polymers Abbreviated Journal Plasma Process Polym
Volume 18 Issue 4 Pages 2000234
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The spatiotemporal dynamics of volume and surface positive and negative streamers in a pintoplate volume dielectric barrier discharge is investigated in this study. The discharge characteristics are found to be completely different for positive and negative streamers. First, the spatial propagation of a positive streamer is found to rely on electron avalanches caused by photo-electrons in front of the streamer head, whereas this is not the case for negative streamers. Second, our simulations reveal an interesting phenomenon of floating positive surface discharges, which develop when a positive streamer reaches a dielectric wall and which explain the experimentally observed branching characteristics. Third, we report for the first time, the interactions between a positive streamer and dielectric pores, in which both the pore diameter and depth affect the evolution of a positive streamer.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000617876700001 Publication Date 2021-02-17
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 Open Access OpenAccess
Notes Dalian University of Technology, DUT19RC(3)045 ; National Natural Science Foundation of China, 12020101005 ; Deutsche Forschungsgemeinschaft, SFB 1316 project A5 ; Universiteit Antwerpen, TOP‐BOF ; The authors acknowledge financial support from the TOP-BOF project of the University of Antwerp. This study was carried out in part using the Turing HPC infrastructure at 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 University of Antwerp. Funding by the German Research Foundation (DFG) in the frame of the Collaborative Research Center SFB 1316, project A5, National Natural Science Foundation of China (No. 12020101005), and the Scientific Research Foundation from Dalian University of Technology (DUT19RC(3)045) is also acknowledged. Approved Most recent IF: 2.846
Call Number PLASMANT @ plasmant @c:irua:176565 Serial 6744
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Author (up) Zhang, Y.-R.; Bogaerts, A.; Wang, Y.-N.
Title Fluid simulation of the phase-shift effect in Ar/CF4 capacitively coupled plasmas Type A1 Journal article
Year 2012 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 45 Issue 48 Pages 485204
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A two-dimensional self-consistent fluid model combined with the full set of Maxwell equations is employed to investigate an Ar/CF4 capacitively coupled plasma, focusing on the phase-shift effect on the plasma characteristics at various frequencies and gas mixture ratios. When the discharge is sustained by a single frequency at 13.56 MHz in an Ar/CF4 mixture with a ratio of 0.9/0.1, no obvious difference is detected between the electron densities obtained in the so-called electrostatic model (with only the static electric fields taken into account) and the electromagnetic model (which includes the electromagnetic effects). However, as the frequency increases to 60 and 100 MHz, the difference becomes distinct, due to the significant influence of the electromagnetic effects. The phase-shift effect on the plasma radial uniformity has also been investigated in a dual frequency discharge, i.e. when the top driven source is switched on with a phase difference phiv ranging from 0 to π, in the frequency range 13.56100 MHz. At low concentration of CF4 (10%), Ar+ ions are the major positive ions in the entire range of frequencies. When the frequency is low, i.e. 13.56 MHz, the Ar+ density exhibits an off-axis peak at phiv = 0 due to the edge effect, and a better uniformity caused by the phase-shift modulation is obtained at phiv = π. At 60 MHz, the Ar+ density varies from edge-peaked at phiv = 0 to uniform (i.e. at phiv = 0.53π), and finally at phiv = π, a broad maximum is observed at the centre due to the standing-wave effect. As the frequency increases to 100 MHz, the best radial uniformity is reached at 0.25π, and the maximum moves again towards the radial wall in the reverse-phase case (phiv = π) due to the dominant skin effect. When the frequency is fixed at 100 MHz, the phase-shift control shows a different behaviour at a high concentration of CF4. For instance, the ${\rm CF}_3
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000311148300011 Publication Date 2012-11-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727;1361-6463; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited 8 Open Access
Notes Approved Most recent IF: 2.588; 2012 IF: 2.528
Call Number UA @ lucian @ c:irua:101754 Serial 1232
Permanent link to this record
 
 
Author (up) Zhang, Y.-R.; Gao, F.; Li, X.-C.; Bogaerts, A.; Wang, Y.-N.
Title Fluid simulation of the bias effect in inductive/capacitive discharges Type A1 Journal article
Year 2015 Publication Journal of vacuum science and technology: A: vacuum surfaces and films Abbreviated Journal J Vac Sci Technol A
Volume 33 Issue 33 Pages 061303
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Computer simulations are performed for an argon inductively coupled plasma (ICP) with a capacitive radio-frequency bias power, to investigate the bias effect on the discharge mode transition and on the plasma characteristics at various ICP currents, bias voltages, and bias frequencies. When the bias frequency is fixed at 13.56 MHz and the ICP current is low, e.g., 6A, the spatiotemporal averaged plasma density increases monotonically with bias voltage, and the bias effect is already prominent at a bias voltage of 90 V. The maximum of the ionization rate moves toward the bottom electrode, which indicates clearly the discharge mode transition in inductive/capacitive discharges. At higher ICP currents, i.e., 11 and 13 A, the plasma density decreases first and then increases with bias voltage, due to the competing mechanisms between the ion acceleration power dissipation and the capacitive power deposition. At 11 A, the bias effect is still important, but it is noticeable only at higher bias voltages. At 13 A, the ionization rate is characterized by a maximum at the reactor center near the dielectric window at all selected bias voltages, which indicates that the ICP power, instead of the bias power, plays a dominant role under this condition, and no mode transition is observed. Indeed, the ratio of the bias power to the total power is lower than 0.4 over a wide range of bias voltages, i.e., 0300V. Besides the effect of ICP current, also the effect of various bias frequencies is investigated. It is found that the modulation of the bias power to the spatiotemporal distributions of the ionization rate at 2MHz is strikingly different from the behavior observed at higher bias frequencies. Furthermore, the minimum of the plasma density appears at different bias voltages, i.e., 120V at 2MHz and 90V at 27.12 MHz.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000365503800020 Publication Date 2015-08-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0734-2101;1520-8559; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.374 Times cited 9 Open Access
Notes Approved Most recent IF: 1.374; 2015 IF: 2.322
Call Number c:irua:126824 Serial 1229
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Author (up) Zhang, Y.-R.; Tinck, S.; De Schepper, P.; Wang, Y.-N.; Bogaerts, A.
Title Modeling and experimental investigation of the plasma uniformity in CF4/O2 capacitively coupled plasmas, operating in single frequency and dual frequency regime Type A1 Journal article
Year 2015 Publication Journal of vacuum science and technology: A: vacuum surfaces and films Abbreviated Journal J Vac Sci Technol A
Volume 33 Issue 33 Pages 021310
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A two-dimensional hybrid Monte Carlofluid model, incorporating a full-wave solution of Maxwell's equations, is employed to describe the behavior of high frequency (HF) and very high frequency capacitively coupled plasmas (CCPs), operating both at single frequency (SF) and dual frequency (DF) in a CF4/O2 gas mixture. First, the authors investigate the plasma composition, and the simulations reveal that besides CF4 and O2, also COF2, CF3, and CO2 are important neutral species, and CF+3 and F− are the most important positive and negative ions. Second, by comparing the results of the model with and without taking into account the electromagnetic effects for a SF CCP, it is clear that the electromagnetic effects are important, both at 27 and 60 MHz, because they affect the absolute values of the calculation results and also (to some extent) the spatial profiles, which accordingly affects the uniformity in plasma processing. In order to improve the plasma radial uniformity, which is important for the etch process, a low frequency (LF) source is added to the discharge. Therefore, in the major part of the paper, the plasma uniformity is investigated for both SF and DF CCPs, operating at a HF of 27 and 60 MHz and a LF of 2 MHz. For this purpose, the authors measure the etch rates as a function of position on the wafer in a wide range of LF powers, and the authors compare them with the calculated fluxes toward the wafer of the plasma species playing a role in the etch process, to explain the trends in the measured etch rate profiles. It is found that at a HF of 60 MHz, the uniformity of the etch rate is effectively improved by adding a LF power of 2 MHz and 300 W, while its absolute value increases by about 50%, thus a high etch rate with a uniform distribution is observed under this condition.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000355739500026 Publication Date 2015-01-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0734-2101;1520-8559; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.374 Times cited 3 Open Access
Notes Approved Most recent IF: 1.374; 2015 IF: 2.322
Call Number c:irua:122650 Serial 2107
Permanent link to this record
 
 
Author (up) Zhang, Y.-R.; Xu, X.; Bogaerts, A.; Wang, Y.-N.
Title Fluid simulation of the phase-shift effect in hydrogen capacitively coupled plasmas: 1 : transient behaviour of electrodynamics and power deposition Type A1 Journal article
Year 2012 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 45 Issue 1 Pages 015202-015202,11
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A two-dimensional self-consistent fluid model coupled with the full set of Maxwell equations is established to investigate the phase-shift effect on the transient behaviour of electrodynamics and power deposition in a hydrogen capacitively coupled plasma. The effect has been examined at 13.56 MHz and 100 MHz, respectively, because of the different phase-shift modulation when the electromagnetic effects are dominant. The results indicate that the spatiotemporal distributions of the plasma characteristics obtained for various phase-shift cases are obviously different both in shape and especially in absolute values. Indeed, when the phase difference varies from 0 to π, there is an increase in the electron flux, thus the power deposition becomes more pronounced. At the frequency of 13.56 MHz, the axial electron flux in the bulk plasma becomes uniform along the z-axis, and the radial electron flux exhibits two peaks within one period at the reverse-phase case, whereas the oscillation is less pronounced at the in-phase case. Furthermore, in the very high frequency discharge, the radial electron flux is alternately positive and negative with four peaks during one period, and the ionization mainly occurs in the sheath region, due to the prominent power deposition there at a phase difference equal to π.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000298290000011 Publication Date 2011-12-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727;1361-6463; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited 57 Open Access
Notes Approved Most recent IF: 2.588; 2012 IF: 2.528
Call Number UA @ lucian @ c:irua:92851 Serial 1230
Permanent link to this record