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Author 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 (down) 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 Liang, Y.-S.; Liu, Y.-X.; Zhang, Y.-R.; Wang, Y.-N.
Title Investigation of voltage effect on reaction mechanisms in capacitively coupled N-2 discharges Type A1 Journal article
Year 2020 Publication Journal Of Applied Physics Abbreviated Journal J Appl Phys
Volume 127 Issue 13 Pages 133301
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A systematic investigation of voltage effect on the plasma parameters, especially the species densities and chemical reaction mechanisms, in the capacitive N-2 discharges is performed by employing a two-dimensional self-consistent fluid model. The validity of the numerical model is first demonstrated by the qualitative agreement of the calculated and experimental results. Then, the densities, production mechanisms, and loss mechanisms of species from simulation are examined at various voltages. It is found that all the species densities increase monotonically with the voltage, whereas their spatial profiles at lower voltages are quite different from those at higher voltages. The electrons and Nthorn 2 ions are mainly generated by the electron impact ionization of N-2 gas, while the Nthorn ions, whose density is one or two orders of magnitude lower, are mostly formed by the ionization of N atoms. The electron impact dissociation of N-2 gas dominates the generation of N atoms, which are mostly destroyed for the Nthorn ion production. As for the excited N-2 levels, the level conversion processes play a very important role in their production and depletion mechanisms, except for the electron impact excitation of the ground state N-2 molecules. Published under license by AIP Publishing.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000524256700001 Publication Date 2020-04-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; 1089-7550 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (down) 3.2 Times cited Open Access
Notes ; This work was financially supported by the National Natural Science Foundation of China (NNSFC) (Grant Nos. 11805089 and 11875101), the Natural Science Foundation of Liaoning Province, China (Grant No. 2019-BS-127), the Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, China (Grant No. KF1804), and the China Scholarship Council. ; Approved Most recent IF: 3.2; 2020 IF: 2.068
Call Number UA @ admin @ c:irua:168558 Serial 6555
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Author Tian, F.; Wang, Y.; Sandhu, H.S.; Gielis, J.; Shi, P.
Title Comparison of seed morphology of two ginkgo cultivars Type A1 Journal article
Year 2020 Publication Journal Of Forestry Research Abbreviated Journal J Forestry Res
Volume 31 Issue 3 Pages 751-758
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Ginkgo biloba L. is a precious relic tree species with important economic value. Seeds, as a vital reproductive organ of plants, can be used to distinguish cultivars of the species. We chose 400 seeds from two cultivars of ginkgo (Fozhi and Maling; 200 seeds for each cultivar) as the study material and used the Gielis equation to fit the projected shape of these seeds. The coefficients of variation (CV) in root mean squared errors (RMSE) obtained from the fitted data were used to compare the level of inter-cultivar variations in seed shape. We also used the covariance analysis to compare the allometric relationships between seed weights and projected areas of these two cultivars. The Gielis equation fitted well the seed shapes of two ginkgo cultivars. The lower CV in RMSE of cultivar Fozhi than Maling indicated a less symmetrical seed shape in the latter than the former. The bootstrap percentile method showed that the seed shape differences between the two cultivars were significant. However, there was no significant difference in the exponents between the seed weights and the projected areas of these two cultivars. Overall, the significant differences in shapes between the seeds of two ginkgo cultivars were well explained by the Gielis equation; this model can be further extended to compare morphological differences in other ginkgo cultivars, and even for plant seeds or animal eggs that have similar oval shapes.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000529367600005 Publication Date 2018-07-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1007-662x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (down) 3 Times cited 3 Open Access
Notes ; ; Approved Most recent IF: 3; 2020 IF: 0.774
Call Number UA @ admin @ c:irua:154987 Serial 6474
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Author 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 (down) 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 Mei, H.; Xu, W.; Wang, C.; Yuan, H.; Zhang, C.; Ding, L.; Zhang, J.; Deng, C.; Wang, Y.; Peeters, F.M.
Title Terahertz magneto-optical properties of bi- and tri-layer graphene Type A1 Journal article
Year 2018 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 30 Issue 17 Pages 175701
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Magneto-optical (MO) properties of bi- and tri-layer graphene are investigated utilizing terahertz time-domain spectroscopy (THz TDS) in the presence of a strong magnetic field at room-temperature. In the Faraday configuration and applying optical polarization measurements, we measure the real and imaginary parts of the longitudinal and transverse MO conductivities of different graphene samples. The obtained experimental data fits very well with the classical MO Drude formula. Thus, we are able to obtain the key sample and material parameters of bi- and tri-layer graphene, such as the electron effective mass, the electronic relaxation time and the electron density. It is found that in high magnetic fields the electronic relaxation time tau for bi- and tri-layer graphene increases with magnetic field B roughly in a form tau similar to B-2. Most importantly, we obtain the electron effective mass for bi- and tri-layer graphene at room-temperature under non-resonant conditions. This work shows how the advanced THz MO techniques can be applied for the investigation into fundamental physics properties of atomically thin 2D electronic systems.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000429329500001 Publication Date 2018-03-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (down) 2.649 Times cited 11 Open Access
Notes ; This work was supported by the National Natural Science Foundation of China (11574319, 11304317, 11304272), the Ministry of Science and Technology of China (2011YQ130018), the Center of Science and Technology of Hefei Academy of Science, the Department of Science and Technology of Yunnan Province, and by the Chinese Academy of Sciences. ; Approved Most recent IF: 2.649
Call Number UA @ lucian @ c:irua:150715UA @ admin @ c:irua:150715 Serial 4983
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Author 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 (down) 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
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Author Zhang, Y.-R.; Xu, X.; Bogaerts, A.; Wang, Y.-N.
Title Fluid simulation of the phase-shift effect in hydrogen capacitively coupled plasmas: 2 : radial uniformity of the plasma characteristics 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 015203-015203,13
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A two-dimensional fluid model, including the full set of Maxwell equations, has been developed and applied to investigate the effect of a phase shift between two power sources on the radial uniformity of several plasma characteristics in a hydrogen capacitively coupled plasma. This study was carried out at various frequencies in the range 13.56200 MHz. When the frequency is low, at 13.56 MHz, the plasma density is characterized by an off-axis peak when both power sources are in-phase (phgr = 0), and the best radial uniformity is obtained at phgr = π. This trend can be explained because the radial nonuniformity caused by the electrostatic edge effect can be effectively suppressed by the phase-shift effect at a phase difference equal to π. When the frequency rises to 60 MHz, the plasma density profiles shift smoothly from edge-peaked over uniform to centre-peaked as the phase difference increases, due to the pronounced standing-wave effect, and the best radial uniformity is reached at phgr = 0.3π. At a frequency of 100 MHz, a similar behaviour is observed, except that the maximum of the plasma density moves again towards the radial edge at the reverse-phase case (phgr = π), because of the dominant skin effect. When the frequency is 200 MHz, the bulk plasma density increases significantly with increasing phase-shift values, and a better uniformity is obtained at phgr = 0.4π. This is because the density in the centre increases faster than at the radial edge as the phase difference rises, due to the increasing power deposition Pz in the centre and the decreasing power density Pr at the radial edge. As the phase difference increases to π, the maximum near the radial edge becomes obvious again. This is because the skin effect has a predominant influence on the plasma density under this condition, resulting in a high density at the radial edge. Moreover, the axial ion flux increases monotonically with phase difference, and exhibits similar profiles to the plasma density. The calculation results illustrate that the radial uniformity of the various plasma characteristics is strongly dependent on the applied frequency and the phase shift between both power sources, which is important to realize, for controlling the uniformity of the plasma etch and deposition processes.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000298290000012 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 (down) 2.588 Times cited 15 Open Access
Notes Approved Most recent IF: 2.588; 2012 IF: 2.528
Call Number UA @ lucian @ c:irua:92852 Serial 1231
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Author 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 (down) 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
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Author Mao, M.; Wang, Y.N.; Bogaerts, A.
Title Numerical study of the plasma chemistry in inductively coupled SF6 and SF6/AR plasmas used for deep silicon etching applications Type A1 Journal article
Year 2011 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 44 Issue 43 Pages 435202,1-435202,15
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A hybrid model, called the hybrid plasma equipment model, was used to study inductively coupled SF6 plasmas used for Si etching applications. The plasma properties such as number densities of electrons, positive and negative ions, and neutrals are calculated under typical etching conditions. The electron kinetics is analysed by means of the electron energy probability function. The plasma chemistry taking place in pure SF6 and in an Ar/SF6 mixture is also discussed, and finally the effect of the argon fraction on the plasma properties is investigated.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000296591100004 Publication Date 2011-10-13
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 (down) 2.588 Times cited 20 Open Access
Notes Approved Most recent IF: 2.588; 2011 IF: 2.544
Call Number UA @ lucian @ c:irua:91754 Serial 2409
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Author 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 (down) 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
Permanent link to this record
 
 
Author Jia, W.-Z.; Zhang, Q.-Z.; Wang, X.-F.; Song, Y.-H.; Zhang, Y.-Y.; Wang, Y.-N.
Title Effect of dust particle size on the plasma characteristics in a radio frequency capacitively coupled silane plasma Type A1 Journal article
Year 2019 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 52 Issue 1 Pages 015206
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Compared with dust-free plasmas, the existence of dust particles in plasmas may greatly influence the plasma properties. such as the plasma density, electron temperature, sheath properties, electron energy distribution function (EEDF) as well as the heating mechanism. In this work, a 1D hybrid fluid/MC model has been developed to investigate the interaction between dust and plasma in a low-pressure silane discharge sustained in a radio frequency capacitively coupled plasma, in which we assume spherical dust particles with a given radius are generated by taking the sum of the production rate of Si2H4- and Si2H5- as the nucleation rate. From our simulation, the plasma may experience definite perturbation by dust particles with a certain radius (more than 50nm) with an increase in electron temperature first, which further induces a rapid rise in the positive and negative ion densities. Then, the densities begin to decline due to the gradual lack of sufficient seed electrons. In addition, as the dust radius increases, the high energy tails of the EEDFs will be enhanced for discharge maintenance, accompanied by a decline in the population of low-energy electrons in comparison with those of pristine plasma. Furthermore, an obvious bulk heating is observed apart from the a-mode and local field reversal heating. This may contribute to the enhanced bulk electric field (also called the drift field) as a result of electron depletion via the dust. In addition, large-sized dust particles that accumulate near the sheaths tend to form two stable density peaks with their positions largely influenced by the time-averaged sheath thickness. A detailed study of the effects of the external parameters, including pressure, voltage and frequency, on the spatial distribution of dust particles is also conducted.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000448423800002 Publication Date 2018-10-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (down) 2.588 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 2.588
Call Number UA @ admin @ c:irua:155361 Serial 5271
Permanent link to this record
 
 
Author Müller, M.; Turner, S.; Lebedev, O.I.; Wang, Y.; Van Tendeloo, G.; Fischer, R.A.
Title Au@MOF-5 and Au/Mox@MOF-5 (M = Zn, Ti; x = 1, 2) : preparation and microstructural characterisation Type A1 Journal article
Year 2011 Publication European journal of inorganic chemistry Abbreviated Journal Eur J Inorg Chem
Volume Issue 12 Pages 1876-1887
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The Zn-carboxylate-based porous coordination polymer MOF-5 [Zn4O(bdc)3] and the metal oxide loaded materials ZnO@MOF-5 and TiO2@MOF-5 were loaded in a second step with the precursor [ClAuCO] to yield intermediate materials denoted as [ClAuCO]@MOF-5, [ClAuCO]/ZnO@MOF-5 and [ClAuCO]/TiO2@MOF-5. These composites were decomposed to Au@MOF-5, Au/ZnO@MOF-5 and Au/TiO2@MOF-5 under hydrogen at 100 °C. The nanoparticle-loaded hybrid materials were characterised by powder X-ray diffraction (PXRD), IR spectroscopy, X-ray photoelectron spectroscopy (XPS) and N2 sorption measurements, which reveal an intact MOF-5 structure that maintains a high specific surface area. For Au@MOF-5, crystalline Au nanoparticles were distributed over the MOF matrix in a homogeneous fashion with a size of ca. 13 nm, evidenced by high resolution transmission electron microscopy. In the case of Au/ZnO@MOF-5, the Au and metal oxide particles of a few nm in size were coexistent in a given volume of the MOF-5 matrix and were not separated in different crystalline MOF particles. For the TiO2 loaded materials the oxide is preferentially located near the outer surface of the MOF particles, leading to an increase of larger exterior Au particles in comparison to very small interior Au particles as observed for the other materials. Au@MOF-5, Au/ZnO@MOF-5 and Au/TiO2@MOF-5 were tested in liquid-phase oxidation of alcohols. Preliminary results show a high activity for the Au loaded materials in this reaction. This observation is attributed to the microstructure of the composites with very small Au particles distributed homogeneously over the MOF matrix.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000289644300004 Publication Date 2011-03-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-1948; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (down) 2.444 Times cited 75 Open Access
Notes Fwo; Esteem 026019 Approved Most recent IF: 2.444; 2011 IF: 3.049
Call Number UA @ lucian @ c:irua:88644 Serial 205
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Author 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 (down) 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
Permanent link to this record
 
 
Author 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 (down) 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
Permanent link to this record
 
 
Author Zhang, Y.-R.; Xu, X.; Zhao, S.-X.; Bogaerts, A.; Wang, Y.-N.
Title Comparison of electrostatic and electromagnetic simulations for very high frequency plasmas Type A1 Journal article
Year 2010 Publication Physics of plasmas Abbreviated Journal Phys Plasmas
Volume 17 Issue 11 Pages 113512-113512,11
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 developed to investigate an argon capacitively coupled plasma, focusing on the electromagnetic effects on the discharge characteristics at various discharge conditions. The results indicate that there exist distinct differences in plasma characteristics calculated with the so-called electrostatic model (i.e., without taking into account the electromagnetic effects) and the electromagnetic model (which includes the electromagnetic effects), especially at very high frequencies. Indeed, when the excitation source is in the high frequency regime and the electromagnetic effects are taken into account, the plasma density increases significantly and meanwhile the ionization rate evolves to a very different distribution when the electromagnetic effects are dominant. Furthermore, the dependence of the plasma characteristics on the voltage and pressure is also investigated, at constant frequency. It is observed that when the voltage is low, the difference between these two models becomes more obvious than at higher voltages. As the pressure increases, the plasma density profiles obtained from the electromagnetic model smoothly shift from edge-peaked over uniform to a broad maximum in the center. In addition, the edge effect becomes less pronounced with increasing frequency and pressure, and the skin effect rather than the standing-wave effect becomes dominant when the voltage is high.
Address
Corporate Author Thesis
Publisher Place of Publication Woodbury, N.Y. Editor
Language Wos 000285486500105 Publication Date 2010-11-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1070-664X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (down) 2.115 Times cited 30 Open Access
Notes Approved Most recent IF: 2.115; 2010 IF: 2.320
Call Number UA @ lucian @ c:irua:84763 Serial 429
Permanent link to this record
 
 
Author Si, X.-J.; Zhao, S.-X.; Xu, X.; Bogaerts, A.; Wang, Y.-N.
Title Fluid simulations of frequency effects on nonlinear harmonics in inductively coupled plasma Type A1 Journal article
Year 2011 Publication Physics of plasmas Abbreviated Journal Phys Plasmas
Volume 18 Issue 3 Pages 033504-033504,9
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A fluid model is self-consistently established to investigate the harmonic effects in an inductively coupled plasma, where the electromagnetic field is solved by the finite difference time domain technique. The spatiotemporal distribution of harmonic current density, harmonic potential, and other plasma quantities, such as radio frequency power deposition, plasma density, and electron temperature, have been investigated. Distinct differences in current density have been observed when calculated with and without Lorentz force, which indicates that the nonlinear Lorentz force plays an important role in the harmonic effects, especially at low frequencies. Moreover, the even harmonics are larger than the odd harmonics both in the current density and the potential. Finally, the dependence of various plasma quantities with and without the Lorentz force on various driving frequencies is also examined. It is shown that the deposited power density decreases and the depth of penetration increases slightly because of the Lorentz force. The electron density increases distinctly while the electron temperature remains almost the same when the Lorentz force is taken into account.
Address
Corporate Author Thesis
Publisher Place of Publication Woodbury, N.Y. Editor
Language Wos 000289151900073 Publication Date 2011-03-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1070-664X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (down) 2.115 Times cited 7 Open Access
Notes Approved Most recent IF: 2.115; 2011 IF: 2.147
Call Number UA @ lucian @ c:irua:87876 Serial 1233
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Author Sun, J.-Y.; Wen, D.-Q.; Zhang, Q.-Z.; Liu, Y.-X.; Wang, Y.-N.
Title The effects of electron surface interactions in geometrically symmetric capacitive RF plasmas in the presence of different electrode surface materials Type A1 Journal article
Year 2019 Publication Physics of plasmas Abbreviated Journal Phys Plasmas
Volume 26 Issue 6 Pages 063505
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Particle-in-cell/Monte Carlo collision (PIC/MCC) simulations are performed to investigate the asymmetric secondary electron emission (SEE) effects when electrons strike two different material electrodes in low pressure capacitively coupled plasmas (CCPs). To describe the electron-surface interactions, a realistic model, considering the primary electron impact energy and angle, as well as the corresponding surface property-dependent secondary electron yields, is employed in PIC/MCC simulations. In this model, three kinds of electrons emitted from the surface are considered: (i) elastically reflected electrons, (ii) inelastically backscattered electrons, and (iii) electron induced secondary electrons (SEs, i.e., delta-electrons). Here, we examined the effects of electron-surface interactions on the ionization dynamics and plasma characteristics of an argon discharge. The discharge is driven by a voltage source of 13.56MHz with amplitudes in the range of 200-2000V. The grounded electrode material is copper (Cu) for all cases, while the powered electrode material is either Cu or silicon dioxide (SiO2). The simulations reveal that the electron impact-induced SEE is an essential process at low pressures, especially at high voltages. Different electrode materials result in an asymmetric response of SEE. Depending on the instantaneous local sheath potential and the phase of the SEE, these SEs either are reflected by the opposite sheath or strike the electrode surface, where they can induce delta-electrons upon their residual energies. It is shown that highly energetic delta-electrons contribute significantly to the ionization rate and a self-bias forms when the powered electrode material is assumed to be made of SiO2. Complex dynamics is observed due to the multiple electron-surface interaction processes and asymmetric yields of SEs in CCPs.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000474440600043 Publication Date 2019-06-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1070-664x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (down) 2.115 Times cited 1 Open Access
Notes Approved Most recent IF: 2.115
Call Number UA @ admin @ c:irua:161353 Serial 6327
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Author Liang, Y.-S.; Xue, C.; Zhang, Y.-R.; Wang, Y.-N.
Title Investigation of active species in low-pressure capacitively coupled N-2/Ar plasmas Type A1 Journal article
Year 2021 Publication Physics Of Plasmas Abbreviated Journal Phys Plasmas
Volume 28 Issue 1 Pages 013510
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this paper, a self-consistent fluid model is developed focusing on the plasma parameters in capacitively coupled 20% N 2-80% Ar discharges. Measurements of ion density are performed with the help of a floating double probe, and the emission intensities from Ar(4p) and N 2 ( B ) transitions are detected by an optical emission spectroscopy to estimate their relative densities. The consistency between the numerical and experimental results confirms the reliability of the simulation. Then the plasma characteristics, specifically the reaction mechanisms of active species, are analyzed under various voltages. The increasing voltage leads to a monotonous increase in species density, whereas a less homogeneous radial distribution is observed at a higher voltage. Due to the high concentration of Ar gas, Ar + becomes the main ion, followed by the N 2 +</mml:msubsup> ion. Besides the electron impact ionization of neutrals, the charge transfer processes of Ar +/ N 2 and N 2 +</mml:msubsup>/Ar are found to have an impact on the ionic species. The results indicate that adopting the lower charge transfer reaction rate coefficients weakens the Ar + ion density and yields a higher N 2 +</mml:msubsup> ion density. However, the effect on the species spatial distributions and other species densities is limited. As for the excited-state species, the electron impact excitation of background gases remains overwhelming in the formation of Ar(4p), N 2 ( B ), and N 2 ( a ' ), whereas the <mml:msub> N 2 ( A ) molecules are mainly formed by the decay of <mml:msub> N 2 ( B ). In addition, the dissociation of <mml:msub> N 2 collided by excited-state Ar atoms dominates the N generation, which are mostly depleted to produce N + ions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000629931300002 Publication Date 2021-01-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1070-664x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (down) 2.115 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 2.115
Call Number UA @ admin @ c:irua:177669 Serial 6767
Permanent link to this record
 
 
Author 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 (down) 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
Permanent link to this record
 
 
Author Zhao, S.-X.; Zhang, Y.-R.; Gao, F.; Wang, Y.-N.; Bogaerts, A.
Title Bulk plasma fragmentation in a C4F8 inductively coupled plasma : a hybrid modelling study Type A1 Journal article
Year 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 117 Issue 117 Pages 243303
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A hybrid model is used to investigate the fragmentation of C4F8 inductive discharges. Indeed, the resulting reactive species are crucial for the optimization of the Si-based etching process, since they determine the mechanisms of fluorination, polymerization, and sputtering. In this paper, we present the dissociation degree, the density ratio of F vs. CxFy (i.e., fluorocarbon (fc) neutrals), the neutral vs. positive ion density ratio, details on the neutral and ion components, and fractions of various fc neutrals (or ions) in the total fc neutral (or ion) density in a C4F8 inductively coupled plasma source, as well as the effect of pressure and power on these results. To analyze the fragmentation behavior, the electron density and temperature and electron energy probability function (EEPF) are investigated. Moreover, the main electron-impact generation sources for all considered neutrals and ions are determined from the complicated C4F8 reaction set used in the model. The C4F8 plasma fragmentation is explained, taking into account many factors, such as the EEPF characteristics, the dominance of primary and secondary processes, and the thresholds of dissociation and ionization. The simulation results are compared with experiments from literature, and reasonable agreement is obtained. Some discrepancies are observed, which can probably be attributed to the simplified polymer surface kinetics assumed in the model.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000357613900009 Publication Date 2015-06-30
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 (down) 2.068 Times cited 11 Open Access
Notes Approved Most recent IF: 2.068; 2015 IF: 2.183
Call Number c:irua:126477 Serial 261
Permanent link to this record
 
 
Author Zhao, S.-X.; Gao, F.; Wang, Y.-P.; Wang, Y.-N.; Bogaerts, A.
Title Effects of feedstock availability on the negative ion behavior in a C4F8 inductively coupled plasma Type A1 Journal article
Year 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 118 Issue 118 Pages 033301
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this paper, the negative ion behavior in a C4F8 inductively coupled plasma (ICP) is investigated using a hybrid model. The model predicts a non-monotonic variation of the total negative ion density with power at low pressure (1030 mTorr), and this trend agrees well with experiments that were carried out in many fluorocarbon (fc) ICP sources, like C2F6, CHF3, and C4F8. This behavior is explained by the availability of feedstock C4F8 gas as a source of the negative ions, as well as by the presence of low energy electrons due to vibrational excitation at low power. The maximum of the negative ion density shifts to low power values upon decreasing pressure, because of the more pronounced depletion of C4F8 molecules, and at high pressure (∼50 mTorr), the anion density continuously increases with power, which is similar to fc CCP sources. Furthermore, the negative ion composition is identified in this paper. Our work demonstrates that for a clear understanding of the negative ion behavior in radio frequency C4F8 plasma sources, one needs to take into account many factors, like the attachment characteristics, the anion composition, the spatial profiles, and the reactor configuration. Finally, a detailed comparison of our simulation results with experiments is conducted.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000358429200004 Publication Date 2015-07-20
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 (down) 2.068 Times cited 1 Open Access
Notes Approved Most recent IF: 2.068; 2015 IF: 2.183
Call Number c:irua:126735 Serial 861
Permanent link to this record
 
 
Author 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 (down) 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 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 (down) 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
Permanent link to this record
 
 
Author Ning, Y.; Zhang, X.; Wang, Y.; Sun, Y.; Shen, L.; Yang, X.; Van Tendeloo, G.
Title Bulk production of multi-wall carbon nanotube bundles on sol-gel prepared catalyst Type A1 Journal article
Year 2002 Publication Chemical physics letters Abbreviated Journal Chem Phys Lett
Volume 366 Issue 5/6 Pages 555-560
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000179484300017 Publication Date 2002-12-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0009-2614; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (down) 1.815 Times cited 41 Open Access
Notes Approved Most recent IF: 1.815; 2002 IF: 2.526
Call Number UA @ lucian @ c:irua:54776 Serial 262
Permanent link to this record
 
 
Author Li, Y.; Zhang, X.; Shen, L.; Luo, J.; Tao, X.; Liu, F.; Xu, G.; Wang, Y.; Geise, H.J.; Van Tendeloo, G.
Title Controlling the diameters in large-scale synthesis of single-walled carbon nanotubes by catalytic decomposition of CH4 Type A1 Journal article
Year 2004 Publication Chemical physics letters Abbreviated Journal Chem Phys Lett
Volume 398 Issue 1-3 Pages 276-282
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract High-quality single-walled carbon nanotubes (SWNTs) are synthesized in gram amount on Fe-Mo/MgO catalysts by catalytic decomposition of CH4 in H-2 or N-2. Raman data reveal that the as-prepared SATNTs have a diameter of about 0.74-1.29 nm. It is found that the diameter of the as-prepared SWNTs can be controlled mainly by adjusting the molar ratio of Fe-Mo versus the MgO support. Several other factors that potentially influence the growth of SWNTs have been studied in detail. The experimental results show that the nature of the catalyst determines the diameter of the as-prepared SWNTs. (C) 2004 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000224720300050 Publication Date 2004-10-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0009-2614; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (down) 1.815 Times cited 45 Open Access
Notes Approved Most recent IF: 1.815; 2004 IF: 2.438
Call Number UA @ lucian @ c:irua:103720 Serial 507
Permanent link to this record
 
 
Author Karczewski, G.; Wojtowicz, T.; Wang, Y.-J.; Wu, X.; Peeters, F.M.
Title Electron effective mass and resonant polaron effect in CdTe/CdMgTe quantum wells Type A1 Journal article
Year 2002 Publication Physica status solidi: B: basic research T2 – 10th International Conference on II-VI Compounds, SEP 09-14, 2001, BREMEN, GERMANY Abbreviated Journal Phys Status Solidi B
Volume 229 Issue 1 Pages 597-600
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Cyclotron resonance in CdTe/CdMgTe quantum wells (QWs) was studied. Due to the polaron effect the zero-field effective mass is strongly influenced by the QW width. The experimental data have been described theoretically by taking into account electron-phonon coupling and the nonparabolicity of the conduction band. The subband structure was calculated self-consistently. The best fit was obtained for an electron-phonon coupling constant alpha = 0.3 and bare electron mass of m(b) = 0.092m(0).
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos 000173806600118 Publication Date 2002-08-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-1972;1521-3951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (down) 1.674 Times cited 10 Open Access
Notes Approved Most recent IF: 1.674; 2002 IF: 0.930
Call Number UA @ lucian @ c:irua:102838 Serial 925
Permanent link to this record
 
 
Author Shi, R.; Choudhuri, D.; Kashiwar, A.; Dasari, S.; Wang, Y.; Banerjee, R.; Banerjee, D.
Title α phase growth and branching in titanium alloys Type A1 Journal article
Year 2021 Publication Philosophical magazine Abbreviated Journal Philos Mag
Volume Issue Pages
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The morphology and spatial distribution of alpha (α) precipitates have been mapped as a function of Mo content in Ti-Mo binary alloys employing a combinatorial approach. Heat-treatments were carried out on compositionally graded Ti-xMo samples processed using a rapid throughput laser engineered net shape (LENS) process. The composition space spans 1.5 at% to 6 at% Mo with ageing at 750°C, 650°C and 600°C following a β solution treatment. Three distinct regimes of α morphology and distribution were observed. These are colony-dominated microstructures originating from grain boundary α allotriomorphs, bundles of intragranular α laths, and homogeneously distributed individual fine-scale α laths. Branching of the α precipitates was observed in all these domains in a manner reminiscent of solid-state dendritic growth. The phenomenon is particularly apparent at low volume fractions of α. Similar features are present in a wide variety of alloy compositions. 3-dimensional features of such branched structures have been analysed. Simulation of the branching process by phase field methods incorporating anisotropy in the α/β interface energy and elasticity suggests that it can be initiated at growth ledges present at broad faces of the α laths, driven by the enhancement of the diffusion flux at these steps. The dependence of branching on various parameters such as supersaturation and diffusivity, and microstructural features like ledge height and distribution and the presence of adjacent α variants has been evaluated.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000722082700001 Publication Date 2021-11-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1478-6435 ISBN Additional Links UA library record; WoS full record
Impact Factor (down) 1.505 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 1.505
Call Number UA @ admin @ c:irua:183616 Serial 6849
Permanent link to this record
 
 
Author 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 (down) 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
Permanent link to this record
 
 
Author Liu, Y.-X.; Zhang, Y.-R.; Bogaerts, A.; Wang, Y.-N.
Title Electromagnetic effects in high-frequency large-area capacitive discharges : a review 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 020801
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In traditional capacitively coupled plasmas, the discharge can be described by an electrostatic model, in which the Poisson equation is employed to determine the electrostatic electric field. However, current plasma reactors are much larger and driven at a much higher frequency. If the excitation wavelength k in the plasma becomes comparable to the electrode radius, and the plasma skin depth d becomes comparable to the electrode spacing, the electromagnetic (EM) effects will become significant and compromise the plasma uniformity. In this regime, capacitive discharges have to be described by an EM model, i.e., the full set of Maxwells equations should be solved to address the EM effects. This paper gives an overview of the theory, simulation and experiments that have recently been carried out to understand these effects, which cause major uniformity problems in plasma processing for microelectronics and flat panel display industries. Furthermore, some methods for improving the plasma uniformity are also described and compared.
Address
Corporate Author Thesis
Publisher A v s amer inst physics Place of Publication Melville Editor
Language Wos 000355739500007 Publication Date 2015-02-12
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 (down) 1.374 Times cited 10 Open Access
Notes Approved Most recent IF: 1.374; 2015 IF: 2.322
Call Number c:irua:123541 Serial 903
Permanent link to this record
 
 
Author 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 (down) 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
Permanent link to this record