Records |
Author |
Wendelen, W.; Mueller, B.Y.; Autrique, D.; Rethfeld, B.; Bogaerts, A. |
Title |
Space charge corrected electron emission from an aluminum surface under non-equilibrium conditions |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
Volume |
111 |
Issue |
11 |
Pages |
113110 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
A theoretical study has been conducted of ultrashort pulsed laser induced electron emission from an aluminum surface. Electron emission fluxes retrieved from the commonly employed Fowler-DuBridge theory were compared to fluxes based on a laser-induced non-equilibrium electron distribution. As a result, the two-and three-photon photoelectron emission parameters for the Fowler-DuBridge theory have been approximated. We observe that at regimes where photoemission is important, laser-induced electron emission evolves in a more smooth manner than predicted by the Fowler-DuBridge theory. The importance of the actual electron distribution decreases at higher laser fluences, whereas the contribution of thermionic emission increases. Furthermore, the influence of a space charge effect on electron emission was evaluated by a one dimensional particle-in-cell model. Depending on the fluences, the space charge reduces the electron emission by several orders of magnitude. The influence of the electron emission flux profiles on the effective electron emission was found to be negligible. However, a non-equilibrium electron velocity distribution increases the effective electron emission significantly. Our results show that it is essential to consider the non-equilibrium electron distribution as well as the space charge effect for the description of laser-induced photoemission. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729071] |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000305401400043 |
Publication Date |
2012-06-14 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-8979; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.068 |
Times cited |
30 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.068; 2012 IF: 2.210 |
Call Number |
UA @ lucian @ c:irua:100300 |
Serial |
3057 |
Permanent link to this record |
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|
|
Author |
Teodoru, S.; Kusano, Y.; Bogaerts, A. |
Title |
The effect of O2 in a humid O2/N2/NOx gas mixture on NOx and N2O remediation by an atmospheric pressure dielectric barrier discharge |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Plasma processes and polymers |
Abbreviated Journal |
Plasma Process Polym |
Volume |
9 |
Issue |
7 |
Pages |
652-689 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
A numerical model for NxOy remediation in humid air plasma produced with a dielectric barrier discharge at atmospheric pressure is presented. Special emphasis is given to NO2 and N2O reduction with the decrease of O2 content in the feedstock gas. A detailed reaction mechanism including electronic and ionic processes, as well as the contribution of radicals and excited atomic/molecular species is proposed. The temporal evolution of the densities of NO, NO2 and N2O species, and some other by-products, is analyzed, and the major pathways for the NxOy remediation are discussed for one pulse. Subsequently, simulations are presented for a multi-pulses case, where three O2 contents are tested for optimization of the remediation process. It is found that when the gas mixture O2/N2/H2O/NOx has no initial O2 content, the best NOx and N2O remediation is achieved. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000306279500005 |
Publication Date |
2012-03-14 |
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 |
24 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.846; 2012 IF: 3.730 |
Call Number |
UA @ lucian @ c:irua:100920 |
Serial |
842 |
Permanent link to this record |
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|
|
Author |
Yusupov, M.; Saraiva, M.; Depla, D.; Bogaerts, A. |
Title |
Sputter deposition of MgxAlyOz thin films in a dual-magnetron device : a multi-species Monte Carlo model |
Type |
A1 Journal article |
Year |
2012 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
Volume |
14 |
Issue |
7 |
Pages |
073043 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
A multi-species Monte Carlo (MC) model, combined with an analytical surface model, has been developed in order to investigate the general plasma processes occurring during the sputter deposition of complex oxide films in a dual-magnetron sputter deposition system. The important plasma species, such as electrons, Ar+ ions, fast Ar atoms and sputtered metal atoms (i.e. Mg and Al atoms) are described with the so-called multi-species MC model, whereas the deposition of MgxAlyOz films is treated by an analytical surface model. Targetsubstrate distances for both magnetrons in the dual-magnetron setup are varied for the purpose of growing stoichiometric complex oxide thin films. The metal atoms are sputtered from pure metallic targets, whereas the oxygen flux is only directed toward the substrate and is high enough to obtain fully oxidized thin films but low enough to avoid target poisoning. The calculations correspond to typical experimental conditions applied to grow these complex oxide films. In this paper, some calculation results are shown, such as the densities of various plasma species, their fluxes toward the targets and substrate, the deposition rates, as well as the film stoichiometry. Moreover, some results of the combined model are compared with experimental observations. Note that this is the first complete model, which can be applied for large and complicated magnetron reactor geometries, such as dual-magnetron configurations. With this model, we are able to describe all important plasma species as well as the deposition process. It can also be used to predict film stoichiometries of complex oxide films on the substrate. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000307072500003 |
Publication Date |
2012-07-21 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1367-2630; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.786 |
Times cited |
2 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.786; 2012 IF: 4.063 |
Call Number |
UA @ lucian @ c:irua:100100 |
Serial |
3111 |
Permanent link to this record |
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|
|
Author |
Mortet, V.; Zhang, L.; Eckert, M.; D'Haen, J.; Soltani, A.; Moreau, M.; Troadec, D.; Neyts, E.; De Jaeger, J.C.; Verbeeck, J.; Bogaerts, A.; Van Tendeloo, G.; Haenen, K.; Wagner, P. |
Title |
Grain size tuning of nanocrystalline chemical vapor deposited diamond by continuous electrical bias growth : experimental and theoretical study |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physica status solidi : A : applications and materials science |
Abbreviated Journal |
Phys Status Solidi A |
Volume |
209 |
Issue |
9 |
Pages |
1675-1682 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this work, a detailed structural and spectroscopic study of nanocrystalline diamond (NCD) thin films grown by a continuous bias assisted CVD growth technique is reported. This technique allows the tuning of grain size and phase purity in the deposited material. The crystalline properties of the films are characterized by SEM, TEM, EELS, and Raman spectroscopy. A clear improvement of the crystalline structure of the nanograined diamond film is observed for low negative bias voltages, while high bias voltages lead to thin films consisting of diamond grains of only ∼10 nm nanometer in size, showing remarkable similarities with so-called ultrananocrystalline diamond. These layers arecharacterized by an increasing amount of sp2-bonded carbon content of the matrix in which the diamond grains are embedded. Classical molecular dynamics simulations support the observed experimental data, giving insight in the underlying mechanism for the observed increase in deposition rate with bias voltage. Furthermore, a high atomic concentration of hydrogen has been determined in these films. Finally, Raman scattering analyses confirm that the Raman line observed at ∼1150 cm−1 cannot be attributed to trans-poly-acetylene, which continues to be reported in literature, reassigning it to a deformation mode of CHx bonds in NCD. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000308942100009 |
Publication Date |
2012-09-04 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1862-6300; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.775 |
Times cited |
31 |
Open Access |
|
Notes |
M.E. and E.N. acknowledge financial support from, respectively, the Institute for Promotion of Innovation through Science and Technology in Flanders (IWT), and the Research Foundation-Flanders (FWO). J.V. gratefully acknowledges financial support from the GOA project “XANES meets ELNES” of the research fund of the University of Antwerp. Calculation support was provided by the University of Antwerp through the core facility CALCUA. G.V.T. acknowledges the ERC grant COUNTATOMS. The work was also financially supported by the joint UAUHasseltMethusalem “NANO” network, the Research Programs G.0068.07 and G.0555.10N of the Research Foundation-Flanders (FWO), the IAP-P6/42 project “Quantum Effects in Clusters and Nanowires”, and by the EU FP7 through the Integrated Infrastructure Initiative “ESMI” (No. 262348), the Marie Curie ITN “MATCON” (PITN-GA-2009-238201), and the Collaborative Project “DINAMO” (No. 245122). |
Approved |
Most recent IF: 1.775; 2012 IF: 1.469 |
Call Number |
UA @ lucian @ c:irua:101516UA @ admin @ c:irua:101516 |
Serial |
1364 |
Permanent link to this record |
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|
|
Author |
Liu, Y.-X.; Zhang, Q.-Z.; Liu, J.; Song, Y.-H.; Bogaerts, A.; Wang, Y.-N. |
Title |
Effect of bulk electric field reversal on the bounce resonance heating in dual-frequency capacitively coupled electronegative plasmas |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
101 |
Issue |
11 |
Pages |
114101 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The electron bounce resonance heating (BRH) in dual-frequency capacitively coupled plasmas operated in oxygen and argon has been studied by different experimental methods. In comparison with the electropositive argon discharge, the BRH in an electronegative discharge occurs at larger electrode gaps. Kinetic particle simulations reveal that in the oxygen discharge, the bulk electric field becomes quite strong and is out of phase with the sheath field. Therefore, it retards the resonant electrons when traversing the bulk, resulting in a suppressed BRH. This effect becomes more pronounced at lower high-frequency power, when the discharge mode changes from electropositive to electronegative. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000309329300094 |
Publication Date |
2012-09-10 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
26 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.411; 2012 IF: 3.794 |
Call Number |
UA @ lucian @ c:irua:100637 |
Serial |
802 |
Permanent link to this record |
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|
|
Author |
Somers, W.; Bogaerts, A.; van Duin, A.C.T.; Neyts, E.C. |
Title |
Plasma species interacting with nickel surfaces : toward an atomic scale understanding of plasma-catalysis |
Type |
A1 Journal article |
Year |
2012 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
Volume |
116 |
Issue |
39 |
Pages |
20958-20965 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The adsorption probability and reaction behavior of CHx plasma species on various nickel catalyst surfaces is investigated by means of reactive molecular dynamics (MD) simulations using the ReaxFF potential. Such catalysts are used in the reforming of hydrocarbons and in the growth of carbon nanotubes, and further insight in the underlying mechanisms of these processes is needed to increase their applicability. Single and consecutive impacts of CHx radicals (x={1,2,3}) were performed on four different Ni surfaces, at a temperature of 400 K. The adsorption probability is shown to be related to the number of free electrons, i.e. a higher number leads to more adsorptions, and the steric hindrance caused by the hydrogen atoms bonded to the impacting CHx species. Furthermore, some of the CH bonds break after adsorption, which generally leads to diffusion of the hydrogen atom over the surface. Additionally, these adsorbed H-atoms can be used in reactions to form new molecules, such as CH4 and C2Hx, although this is dependent on the precise morphology of the surface. New molecules are also formed by subtraction of H-atoms from adsorbed radicals, leading to occasional formation of H2 and C2Hx molecules. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000309375700040 |
Publication Date |
2012-09-10 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.536 |
Times cited |
37 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.536; 2012 IF: 4.814 |
Call Number |
UA @ lucian @ c:irua:101522 |
Serial |
2640 |
Permanent link to this record |
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|
|
Author |
Yusupov, M.; Neyts, E.C.; Khalilov, U.; Snoeckx, R.; van Duin, A.C.T.; Bogaerts, A. |
Title |
Atomic-scale simulations of reactive oxygen plasma species interacting with bacterial cell walls |
Type |
A1 Journal article |
Year |
2012 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
Volume |
14 |
Issue |
9 |
Pages |
093043 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In recent years there has been growing interest in the use of low-temperature atmospheric pressure plasmas for biomedical applications. Currently, however, there is very little fundamental knowledge regarding the relevant interaction mechanisms of plasma species with living cells. In this paper, we investigate the interaction of important plasma species, such as O3, O2 and O atoms, with bacterial peptidoglycan (or murein) by means of reactive molecular dynamics simulations. Specifically, we use the peptidoglycan structure to model the gram-positive bacterium Staphylococcus aureus murein. Peptidoglycan is the outer protective barrier in bacteria and can therefore interact directly with plasma species. Our results demonstrate that among the species mentioned above, O3 molecules and especially O atoms can break important bonds of the peptidoglycan structure (i.e. CO, CN and CC bonds), which subsequently leads to the destruction of the bacterial cell wall. This study is important for gaining a fundamental insight into the chemical damaging mechanisms of the bacterial peptidoglycan structure on the atomic scale. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000309393400001 |
Publication Date |
2012-09-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1367-2630; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.786 |
Times cited |
47 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.786; 2012 IF: 4.063 |
Call Number |
UA @ lucian @ c:irua:101014 |
Serial |
189 |
Permanent link to this record |
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Author |
Aerts, R.; Tu, X.; De Bie, C.; Whitehead, J.C.; Bogaerts, A. |
Title |
An investigation into the dominant reactions for ethylene destruction in non-thermal atmospheric plasmas |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Plasma processes and polymers |
Abbreviated Journal |
Plasma Process Polym |
Volume |
9 |
Issue |
10 |
Pages |
994-1000 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
A crucial step, which is still not well understood in the destruction of volatile organic compounds (VOCs) with low temperature plasmas, is the initiation of the process. Here, we present a kinetic model for the destruction of ethylene in low temperature plasmas that allows us to calculate the relative importance of all plasma species and their related reactions. Modifying the ethylene concentration and/or the SED had a major impact on the relative importance of the radicals (i.e., mainly atomic oxygen) and the metastable nitrogen (i.e., more specifically N2(equation image)) in the destruction process. Our results show that the direct destruction by electron impact reactions for ethylene can be neglected; however, we can certainly not neglect the influence of N2(equation image)). |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000309750300008 |
Publication Date |
2012-07-30 |
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 |
46 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.846; 2012 IF: 3.730 |
Call Number |
UA @ lucian @ c:irua:101765 |
Serial |
1727 |
Permanent link to this record |
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|
|
Author |
Aerts, R.; Martens, T.; Bogaerts, A. |
Title |
Influence of vibrational states on CO2 splitting by dielectric barrier discharges |
Type |
A1 Journal article |
Year |
2012 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
Volume |
116 |
Issue |
44 |
Pages |
23257-23273 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this paper, the splitting of CO2 in a pulsed plasma system, such as a dielectric barrier discharge (DBD), is evaluated from a chemical point of view by means of numerical modeling. For this purpose, a chemical reaction set of CO2 in an atmospheric pressure plasma is developed, including the vibrational states of CO2, O2, and CO. The simulated pulses are matched to the conditions of a filament (or microdischarge) and repeated with intervals of 1 μs. The influence of vibrationally excited CO2 as well as other neutral species, ions, and electrons on the CO2 splitting is discussed. Our calculations predict that the electrons have the largest contribution to the CO2 splitting at the conditions under study, by electron impact dissociation. The contribution of vibrationally excited CO2 levels in the splitting of CO2 is found be 6.4%, when only considering one microdischarge pulse and its afterglow, but it can be much higher for consecutive discharge pulses, as is typical for a filamentary DBD, when the interpulse time is short enough and accumulation effects in the vibrationally excited CO2 densities can occur. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
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Language |
|
Wos |
000310769300012 |
Publication Date |
2012-10-19 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.536 |
Times cited |
112 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.536; 2012 IF: 4.814 |
Call Number |
UA @ lucian @ c:irua:101764 |
Serial |
1659 |
Permanent link to this record |
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|
|
Author |
Aghaei, M.; Lindner, H.; Bogaerts, A. |
Title |
Optimization of operating parameters for inductively coupled plasma mass spectrometry : a computational study |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Spectrochimica acta: part B : atomic spectroscopy |
Abbreviated Journal |
Spectrochim Acta B |
Volume |
76 |
Issue |
|
Pages |
56-64 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
An inductively coupled plasma, connected to a mass spectrometer interface, is computationally investigated. The effect of pressure behind the sampler, injector gas flow rate, auxiliary gas flow rate, and applied power is studied. There seems to be an optimum range of injector gas flow rate for each setup which guaranties the presence and also a proper length of the central channel in the torch. Moreover, our modeling results show that for any specific purpose, it is possible to control that either only the central gas flow passes through the sampler orifice or that it is accompanied by the auxiliary gas flow. It was also found that depending on geometry, the variation of outgoing gas flow rate is much less than the variation of the injector gas flow rate and this causes a slightly higher pressure inside the torch. The general effect of increasing the applied power is a rise in the plasma temperature, which results in a higher ionization in the coil region. However, the negative effect is reducing the length of the cool central channel which is important to transfer the sample substances to the sampler. Using a proper applied power can enhance the efficiency of the system. Indeed, by changing the gas path lines, the power can control which flow (i.e., only from injector gas or also from the auxiliary gas) goes to the sampler orifice. Finally, as also reported from experiments in literature, the pressure behind the sampler has no dramatic effect on the plasma characteristics. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
Language |
|
Wos |
000311008600008 |
Publication Date |
2012-06-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0584-8547; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.241 |
Times cited |
18 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.241; 2012 IF: 3.141 |
Call Number |
UA @ lucian @ c:irua:101356 |
Serial |
2488 |
Permanent link to this record |
|
|
|
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 |
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 |
Bogaerts, A.; Aerts, R.; Snoeckx, R.; Somers, W.; Van Gaens, W.; Yusupov, M.; Neyts, E. |
Title |
Modeling of plasma and plasma-surface interactions for medical, environmental and nano applications |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
Volume |
399 |
Issue |
|
Pages |
012011 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this paper, an overview is given of modeling investigations carried out in our research group for a better understanding of plasmas used for medical, environmental and nano applications. The focus is both on modeling the plasma chemistry and the plasma-surface interactions. The plasma chemistry provides the densities and fluxes of the important plasma species. This information can be used as input when modeling the plasma-surface interactions. The combination of plasma simulations and plasma – surface interaction simulations provides a more comprehensive understanding of the underlying processes for these applications. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000312261700011 |
Publication Date |
2012-11-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1742-6588;1742-6596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
7 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:104727 |
Serial |
2130 |
Permanent link to this record |
|
|
|
Author |
Khalilov, U.; Pourtois, G.; Bogaerts, A.; van Duin, A.C.T.; Neyts, E.C. |
Title |
Reactive molecular dynamics simulations on SiO2-coated ultra-small Si-nanowires |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
5 |
Issue |
2 |
Pages |
719-725 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The application of coreshell SiSiO2 nanowires as nanoelectronic devices strongly depends on their structure, which is difficult to tune precisely. In this work, we investigate the formation of the coreshell nanowires at the atomic scale, by reactive molecular dynamics simulations. The occurrence of two temperature-dependent oxidation mechanisms of ultra-small diameter Si-NWs is demonstrated. We found that control over the Si-core radius and the SiOx (x ≤ 2) oxide shell is possible by tuning the growth temperature and the initial Si-NW diameter. Two different structures were obtained, i.e., ultrathin SiO2 silica nanowires at high temperature and Si core|ultrathin SiO2 silica nanowires at low temperature. The transition temperature is found to linearly decrease with the nanowire curvature. Finally, the interfacial stress is found to be responsible for self-limiting oxidation, depending on both the initial Si-NW radius and the oxide growth temperature. These novel insights allow us to gain control over the exact morphology and structure of the wires, as is needed for their application in nanoelectronics. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
Language |
|
Wos |
000313426200036 |
Publication Date |
2012-11-16 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2040-3364;2040-3372; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.367 |
Times cited |
17 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 7.367; 2013 IF: 6.739 |
Call Number |
UA @ lucian @ c:irua:102584 |
Serial |
2824 |
Permanent link to this record |
|
|
|
Author |
Bings, N.H.; Bogaerts, A.; Broekaert, J.A.C. |
Title |
Atomic spectroscopy |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
85 |
Issue |
2 |
Pages |
670-704 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000313668400013 |
Publication Date |
2012-11-07 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700;1520-6882; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
29 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 2013 IF: 5.825 |
Call Number |
UA @ lucian @ c:irua:104719 |
Serial |
190 |
Permanent link to this record |
|
|
|
Author |
Neyts, E.C.; Ostrikov, K.; Han, Z.J.; Kumar, S.; van Duin, A.C.T.; Bogaerts, A. |
Title |
Defect healing and enhanced nucleation of carbon nanotubes by low-energy ion bombardment |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
110 |
Issue |
6 |
Pages |
065501-65505 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Structural defects inevitably appear during the nucleation event that determines the structure and properties of single-walled carbon nanotubes. By combining ion bombardment experiments with atomistic simulations we reveal that ion bombardment in a suitable energy range allows these defects to be healed resulting in an enhanced nucleation of the carbon nanotube cap. The enhanced growth of the nanotube cap is explained by a nonthermal ion-induced graphene network restructuring mechanism. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000314687300022 |
Publication Date |
2013-02-07 |
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 |
50 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 8.462; 2013 IF: 7.728 |
Call Number |
UA @ lucian @ c:irua:105306 |
Serial |
616 |
Permanent link to this record |
|
|
|
Author |
Zhao, S.-X.; Gao, F.; Wang, Y.-N.; Bogaerts, A. |
Title |
Gas ratio effects on the Si etch rate and profile uniformity in an inductively coupled Ar/CF4 plasma |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
Volume |
22 |
Issue |
1 |
Pages |
015017-15018 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this work, a hybrid model is used to investigate the effect of different gas ratios on the Si etching and polymer film deposition characteristics in an Ar/CF4 inductively coupled plasma. The influence of the surface processes on the bulk plasma properties is studied, and also the spatial characteristics of important gas phase and etched species. The densities of F and CF2 decrease when the surface module is included in the simulations, due to the species consumption caused by etching and polymer deposition. The influence of the surface processes on the bulk plasma depends on the Ar/CF4 gas ratio. The deposited polymer becomes thicker at high CF4 content because of more abundant CFx radicals. As a result of the competition between the polymer thickness and the F flux, the etch rate first increases and then decreases upon increasing the CF4 content. The electron properties, more specifically the electron density profile, affect the Si etch characteristics substantially by determining the radical density and flux profiles. In fact, the radial profile of the etch rate is more uniform at low CF4 content since the electron density has a smooth distribution. At high CF4 content, the etch rate is less uniform with a minimum halfway along the wafer radius, because the electron density distribution is more localized. Therefore, our calculations predict that it is better to work at relatively high Ar/CF4 gas ratios, in order to obtain high etch rate and good profile uniformity for etch applications. This, in fact, corresponds to the typical experimental etch conditions in Ar/CF4 gas mixtures as found in the literature, where Ar is typically present at a much higher concentration than CF4. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
Institute of Physics |
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000314966300022 |
Publication Date |
2012-12-20 |
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 |
11 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.302; 2013 IF: 3.056 |
Call Number |
UA @ lucian @ c:irua:102583 |
Serial |
1320 |
Permanent link to this record |
|
|
|
Author |
Snoeckx, R.; Aerts, R.; Tu, X.; Bogaerts, A. |
Title |
Plasma-based dry reforming : a computational study ranging from the nanoseconds to seconds time scale |
Type |
A1 Journal article |
Year |
2013 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
Volume |
117 |
Issue |
10 |
Pages |
4957-4970 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
We present a computational study for the conversion of CH4 and CO2 into value-added chemicals, i.e., the so-called dry reforming of methane, in a dielectric barrier discharge reactor. A zero-dimensional chemical kinetics model is applied to study the plasma chemistry in a 1:1 CH4/CO2 mixture. The calculations are first performed for one microdischarge pulse and its afterglow, to study in detail the chemical pathways of the conversion. Subsequently, long time-scale simulations are carried out, corresponding to real residence times in the plasma, assuming a large number of consecutive microdischarge pulses, to mimic the conditions of the filamentary discharge regime in a dielectric barrier discharge (DBD) reactor. The conversion of CH4 and CO2 as well as the selectivity of the formed products and the energy cost and energy efficiency of the process are calculated and compared to experiments for a range of different powers and gas flows, and reasonable agreement is reached. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000316308400010 |
Publication Date |
2013-02-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.536 |
Times cited |
118 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.536; 2013 IF: 4.835 |
Call Number |
UA @ lucian @ c:irua:106516 |
Serial |
2628 |
Permanent link to this record |
|
|
|
Author |
Yusupov, M.; Bogaerts, A.; Huygh, S.; Snoeckx, R.; van Duin, A.C.T.; Neyts, E.C. |
Title |
Plasma-induced destruction of bacterial cell wall components : a reactive molecular dynamics simulation |
Type |
A1 Journal article |
Year |
2013 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
Volume |
117 |
Issue |
11 |
Pages |
5993-5998 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Nonthermal atmospheric pressure plasmas are gaining increasing attention for biomedical applications. However, very little fundamental information on the interaction mechanisms between the plasma species and biological cells is currently available. We investigate the interaction of important plasma species, such as OH, H2O2, O, O3, as well as O2 and H2O, with bacterial peptidoglycan by means of reactive molecular dynamics simulations, aiming for a better understanding of plasma disinfection. Our results show that OH, O, O3, and H2O2 can break structurally important bonds of peptidoglycan (i.e., CO, CN, or CC bonds), which consequently leads to the destruction of the bacterial cell wall. The mechanisms behind these breakups are, however, dependent on the impinging plasma species, and this also determines the effectiveness of the cell wall destruction. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000316773000056 |
Publication Date |
2013-02-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.536 |
Times cited |
59 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.536; 2013 IF: 4.835 |
Call Number |
UA @ lucian @ c:irua:107154 |
Serial |
2636 |
Permanent link to this record |
|
|
|
Author |
Neyts, E.C.; Bogaerts, A. |
Title |
Modeling the growth of SWNTs and graphene on the atomic scale |
Type |
A1 Journal article |
Year |
2012 |
Publication |
ECS transactions |
Abbreviated Journal |
|
Volume |
45 |
Issue |
4 |
Pages |
73-78 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The possibility of application of nanomaterials is determined by our ability to control the properties of the materials, which are ultimately determined by their structure and hence their growth processes. We employ hybrid molecular dynamics / Monte Carlo (MD/MC) simulations to explore the growth of SWNTs and graphene on nickel as a catalyst, with the specific goal of unraveling the growth mechanisms. While the general observations are in agreement with the literature, we find a number of interesting phenomena to be operative which are crucial for the growth, and which are not accessible by MD simulations alone due to the associated time scale. Specifically, we observe metal mediated healing and restructuring processes to take place, reorganizing the carbon network during the initial nucleation step. In the case of carbon nanotube growth, this leads to the growth of tubes with a determinable chirality. In the case of graphene formation, we find that graphene is only formed at temperatures above 700 K. These results are of importance for understanding the growth mechanisms of these carbon nanomaterials on the fundamental level. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
Electrochemical Society |
Place of Publication |
Pennington |
Editor |
|
Language |
|
Wos |
000316890000008 |
Publication Date |
2012-04-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1938-6737;1938-5862; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
2 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:108535 |
Serial |
2144 |
Permanent link to this record |
|
|
|
Author |
Van Laer, K.; Tinck, S.; Samara, V.; de Marneffe, J.F.; Bogaerts, A. |
Title |
Etching of low-k materials for microelectronics applications by means of a N2/H2 plasma : modeling and experimental investigation |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
Volume |
22 |
Issue |
2 |
Pages |
025011-25019 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this paper, we investigate the etch process of so-called low-k organic material by means of a N2/H2 capacitively coupled plasma, as applied in the micro-electronics industry for the manufacturing of computer chips. In recent years, such an organic material has emerged as a possible alternative for replacing bulk SiO2 as a dielectric material in the back-end-of-line, because of the smaller parasitic capacity between adjacent conducting lines, and thus a faster propagation of the electrical signals throughout the chip. Numerical simulations with a hybrid plasma model, using an extensive plasma and surface chemistry set, as well as experiments are performed, focusing on the plasma properties as well as the actual etching process, to obtain a better insight into the underlying mechanisms. Furthermore, the effects of gas pressure, applied power and gas composition are investigated to try to optimize the etch process. In general, the plasma density reaches a maximum near the wafer edge due to the so-called 'edge effect'. As a result, the etch rate is not uniform but will also reach its maximum near the wafer edge. The pressure seems not to have a big effect. A higher power increases the etch rate, but the uniformity becomes (slightly) worse. The gas mixing ratio has no significant effect on the etch process, except when a pure H2 or N2 plasma is used, illustrating the synergistic effects of a N2/H2 plasma. In fact, our calculations reveal that the N2/H2 plasma entails an ion-enhanced etch process. The simulation results are in reasonable agreement with the experimental values. The microscopic etch profile shows the desired anisotropic shape under all conditions under study. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
Institute of Physics |
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000317275400013 |
Publication Date |
2013-03-18 |
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 |
13 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.302; 2013 IF: 3.056 |
Call Number |
UA @ lucian @ c:irua:106654 |
Serial |
1084 |
Permanent link to this record |
|
|
|
Author |
Liu, Y.-X.; Zhang, Q.-Z.; Liu, L.; Song, Y.-H.; Bogaerts, A.; Wang, Y.-N. |
Title |
Electron bounce resonance heating in dual-frequency capacitively coupled oxygen discharges |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
Volume |
22 |
Issue |
2 |
Pages |
025012-11 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The electron bounce resonance heating (BRH) in dual-frequency capacitively coupled plasmas operated in oxygen is studied by different experimental methods and a particle-in-cell/Monte Carlo collision (PIC/MCC) simulation, and compared with the electropositive argon discharge. In comparison with argon, the experimental results show that in an oxygen discharge the resonance peaks in positive-ion density and light intensity tend to occur at larger electrode gaps. Moreover, at electrode gaps L > 2.5 cm, the positive-ion (and electron) density and the light emission drop monotonically in the oxygen discharge upon increasing L, whereas they rise (after an initial drop) in the argon case. At resonance gap the electronegativity reaches its maximum due to the BRH. All these experimental observations are explained by PIC/MCC simulations, which show that in the oxygen discharge the bulk electric field becomes quite strong and is out of phase with the sheath field. Therefore, it retards the resonance electrons when traversing the bulk, resulting in a suppressed BRH. Both experiment and simulation results show that this effect becomes more pronounced at lower high-frequency power, when the discharge mode changes from electropositive to electronegative. In a pure oxygen discharge, the BRH is suppressed with increasing pressure and almost diminishes at 12 Pa. Finally, the driving frequency significantly affects the BRH, because it determines the phase relation between bulk electric field and sheath electric field. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
Institute of Physics |
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000317275400014 |
Publication Date |
2013-03-18 |
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 |
20 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.302; 2013 IF: 3.056 |
Call Number |
UA @ lucian @ c:irua:106534 |
Serial |
911 |
Permanent link to this record |
|
|
|
Author |
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 |
Permanent link to this record |
|
|
|
Author |
Neyts, E.C.; Bogaerts, A. |
Title |
Combining molecular dynamics with Monte Carlo simulations : implementations and applications |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Theoretical chemistry accounts : theory, computation, and modeling |
Abbreviated Journal |
Theor Chem Acc |
Volume |
132 |
Issue |
2 |
Pages |
1320-12 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this contribution, we present an overview of the various techniques for combining atomistic molecular dynamics with Monte Carlo simulations, mainly in the context of condensed matter systems, as well as a brief summary of the main accelerated dynamics techniques. Special attention is given to the force bias Monte Carlo technique and its combination with molecular dynamics, in view of promising recent developments, including a definable timescale. Various examples of the application of combined molecular dynamics / Monte Carlo simulations are given, in order to demonstrate the enhanced simulation efficiency with respect to either pure molecular dynamics or Monte Carlo. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000318294700010 |
Publication Date |
2012-12-19 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1432-881X;1432-2234; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.89 |
Times cited |
27 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.89; 2013 IF: 2.143 |
Call Number |
UA @ lucian @ c:irua:104725 |
Serial |
404 |
Permanent link to this record |
|
|
|
Author |
Zhang, S.; Van Gaens, W.; van Gessel, B.; Hofmann, S.; van Veldhuizen, E.; Bogaerts, A.; Bruggeman, P. |
Title |
Spatially resolved ozone densities and gas temperatures in a time modulated RF driven atmospheric pressure plasma jet : an analysis of the production and destruction mechanisms |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
Volume |
46 |
Issue |
20 |
Pages |
205202-205212 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this work, a time modulated RF driven DBD-like atmospheric pressure plasma jet in Ar + 2%O2, operating at a time averaged power of 6.5 W is investigated. Spatially resolved ozone densities and gas temperatures are obtained by UV absorption and Rayleigh scattering, respectively. Significant gas heating in the core of the plasma up to 700 K is found and at the position of this increased gas temperature a depletion of the ozone density is found. The production and destruction reactions of O3 in the jet effluent as a function of the distance from the nozzle are obtained from a zero-dimensional chemical kinetics model in plug flow mode which considers relevant air chemistry due to air entrainment in the jet fluent. A comparison of the measurements and the models show that the depletion of O3 in the core of the plasma is mainly caused by an enhanced destruction of O3 due to a large atomic oxygen density. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000318546100008 |
Publication Date |
2013-05-02 |
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 |
74 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.588; 2013 IF: 2.521 |
Call Number |
UA @ lucian @ c:irua:107840 |
Serial |
3067 |
Permanent link to this record |
|
|
|
Author |
Khalilov, U.; Pourtois, G.; Huygh, S.; van Duin, A.C.T.; Neyts, E.C.; Bogaerts, A. |
Title |
New mechanism for oxidation of native silicon oxide |
Type |
A1 Journal article |
Year |
2013 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
Volume |
117 |
Issue |
19 |
Pages |
9819-9825 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Continued miniaturization of metal-oxide-semiconductor field-effect transistors (MOSFETs) requires an ever-decreasing thickness of the gate oxide. The structure of ultrathin silicon oxide films, however, critically depends on the oxidation mechanism. Using reactive atomistic simulations, we here demonstrate how the oxidation mechanism in hyperthermal oxidation of such structures may be controlled by the oxidation temperature and the oxidant energy. Specifically, we study the interaction of hyperthermal oxygen with energies of 15 eV with thin SiOx (x ≤ 2) films with a native oxide thickness of about 10 Å. We analyze the oxygen penetration depth probability and compare with results of the hyperthermal oxidation of a bare Si(100){2 × 1} (c-Si) surface. The temperature-dependent oxidation mechanisms are discussed in detail. Our results demonstrate that, at low (i.e., room) temperature, the penetrated oxygen mostly resides in the oxide region rather than at the SiOx|c-Si interface. However, at higher temperatures, starting at around 700 K, oxygen atoms are found to penetrate and to diffuse through the oxide layer followed by reaction at the c-Si boundary. We demonstrate that hyperthermal oxidation resembles thermal oxidation, which can be described by the DealGrove model at high temperatures. Furthermore, defect creation mechanisms that occur during the oxidation process are also analyzed. This study is useful for the fabrication of ultrathin silicon oxide gate oxides for metal-oxide-semiconductor devices as it links parameters that can be straightforwardly controlled in experiment (oxygen temperature, velocity) with the silicon oxide structure. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000319649100032 |
Publication Date |
2013-04-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.536 |
Times cited |
24 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.536; 2013 IF: 4.835 |
Call Number |
UA @ lucian @ c:irua:107989 |
Serial |
2321 |
Permanent link to this record |
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|
|
Author |
Somers, W.; Bogaerts, A.; van Duin, A.C.T.; Huygh, S.; Bal, K.M.; Neyts, E.C. |
Title |
Temperature influence on the reactivity of plasma species on a nickel catalyst surface : an atomic scale study |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Catalysis today |
Abbreviated Journal |
Catal Today |
Volume |
211 |
Issue |
|
Pages |
131-136 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In recent years, the potential use of hydrogen as a clean energy source has gained considerable attention. Especially H2 formation by Ni-catalyzed reforming of methane at elevated temperatures is an attractive process. However, a more fundamental knowledge at the atomic level is needed for a full comprehension of the reactions at the catalyst surface. In this contribution, we therefore investigate the H2 formation after CHx impacts on a Ni(1 1 1) surface in the temperature range 4001600 K, by means of reactive molecular dynamics (MD) simulations using the ReaxFF potential. While some H2 formation is already observed at the lower temperatures, substantial H2 formation is only obtained at elevated temperatures of 1400 K and above. At 1600 K, the H2 molecules are even the most frequently formed species. In direct correlation with the increasing dehydrogenation at elevated temperatures, an increased surface-to-subsurface C-diffusivity is observed as well. This study highlights the major importance of the temperature on the H2 formation. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000320697800020 |
Publication Date |
2013-03-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0920-5861; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.636 |
Times cited |
27 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.636; 2013 IF: 3.309 |
Call Number |
UA @ lucian @ c:irua:108675 |
Serial |
3500 |
Permanent link to this record |
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|
|
Author |
Aerts, R.; Tu, X.; Van Gaens, W.; Whitehead, J.C.; Bogaerts, A. |
Title |
Gas purification by nonthermal plasma : a case study of ethylene |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Environmental science and technology |
Abbreviated Journal |
Environ Sci Technol |
Volume |
47 |
Issue |
12 |
Pages |
6478-6485 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The destruction of ethylene in a dielectric barrier discharge plasma is investigated by the combination of kinetic modeling and experiments, as a case study for plasma-based gas purification. The influence of the specific energy deposition on the removal efficiency and the selectivity toward CO and CO2 is studied for different concentrations of ethylene. The model allows the identication of the destruction pathway in dry and humid air. The latter is found to be mainly initiated by metastable N2 molecules, but the further destruction steps are dominated by O atoms and OH radicals. Upon increasing air humidity, the removal efficiency drops by ±15% (from 85% to 70%), but the selectivity toward CO and CO2 stays more or less constant at 60% and 22%, respectively. Beside CO and CO2, we also identified acetylene, formaldehyde, and water as byproducts of the destruction process, with concentrations of 1606 ppm, 15033 ppm, and 185 ppm in humid air (with 20% RH), respectively. Finally, we investigated the byproducts generated by the humid air discharge itself, which are the greenhouse gases O3, N2O, and the toxic gas NO2. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
Language |
|
Wos |
000320749000051 |
Publication Date |
2013-05-15 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0013-936X;1520-5851; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.198 |
Times cited |
56 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.198; 2013 IF: 5.481 |
Call Number |
UA @ lucian @ c:irua:108743 |
Serial |
1319 |
Permanent link to this record |
|
|
|
Author |
Van Gaens, W.; Bogaerts, A. |
Title |
Kinetic modelling for an atmospheric pressure argon plasma jet in humid air |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
Volume |
46 |
Issue |
27 |
Pages |
275201-275253 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
A zero-dimensional, semi-empirical model is used to describe the plasma chemistry in an argon plasma jet flowing into humid air, mimicking the experimental conditions of a setup from the Eindhoven University of Technology. The model provides species density profiles as a function of the position in the plasma jet device and effluent. A reaction chemistry set for an argon/humid air mixture is developed, which considers 84 different species and 1880 reactions. Additionally, we present a reduced chemistry set, useful for higher level computational models. Calculated species density profiles along the plasma jet are shown and the chemical pathways are explained in detail. It is demonstrated that chemically reactive H, N, O and OH radicals are formed in large quantities after the nozzle exit and H2, O2(1Δg), O3, H2O2, NO2, N2O, HNO2 and HNO3 are predominantly formed as 'long living' species. The simulations show that water clustering of positive ions is very important under these conditions. The influence of vibrational excitation on the calculated electron temperature is studied. Finally, the effect of varying gas temperature, flow speed, power density and air humidity on the chemistry is investigated. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000320854700009 |
Publication Date |
2013-06-18 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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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 |
115 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.588; 2013 IF: 2.521 |
Call Number |
UA @ lucian @ c:irua:108725 |
Serial |
1758 |
Permanent link to this record |
|
|
|
Author |
Autrique, D.; Clair, G.; L'Hermite, D.; Alexiades, V.; Bogaerts, A.; Rethfeld, B. |
Title |
The role of mass removal mechanisms in the onset of ns-laser induced plasma formation |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
Volume |
114 |
Issue |
2 |
Pages |
023301-23310 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The present study focuses on the role of mass removal mechanisms in ns-laser ablation. A copper sample is placed in argon, initially set at standard pressure and temperature. Calculations are performed for a 6 ns laser pulse with a wavelength of 532 nm and laser fluences up to 10 J/cm2. The transient behavior in and above the copper target is described by a hydrodynamic model. Transmission profiles and ablation depths are compared with experimental results and similar trends are found. Our calculations reveal an interesting self-inhibiting mechanism: volumetric mass removal in the supercritical region triggers plasma shielding and therefore stops proceeding. This self-limiting process indicates that volumetric mass removal does not necessarily result in large ablation depths. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000321761600006 |
Publication Date |
2013-07-08 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-8979; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.068 |
Times cited |
31 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.068; 2013 IF: 2.185 |
Call Number |
UA @ lucian @ c:irua:109237 |
Serial |
2915 |
Permanent link to this record |
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|
|
Author |
Neyts, E.C.; van Duin, A.C.T.; Bogaerts, A. |
Title |
Formation of single layer graphene on nickel under far-from-equilibrium high flux conditions |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
5 |
Issue |
16 |
Pages |
7250-7255 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
We investigate the theoretical possibility of single layer graphene formation on a nickel surface at different substrate temperatures under far-from-equilibrium high precursor flux conditions, employing state-of-the-art hybrid reactive molecular dynamics/uniform acceptance force bias Monte Carlo simulations. It is predicted that under these conditions, the formation of a single layer graphene-like film may proceed through a combined depositionsegregation mechanism on a nickel substrate, rather than by pure surface segregation as is typically observed for metals with high carbon solubility. At 900 K and above, nearly continuous graphene layers are obtained. These simulations suggest that single layer graphene deposition is theoretically possible on Ni under high flux conditions. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
Language |
|
Wos |
000322315600019 |
Publication Date |
2013-04-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2040-3364;2040-3372; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.367 |
Times cited |
25 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 7.367; 2013 IF: 6.739 |
Call Number |
UA @ lucian @ c:irua:109249 |
Serial |
1264 |
Permanent link to this record |