Records |
Author |
Wang, Y.J.; Nickel, H.A.; McCombe, B.D.; Peeters, F.M.; Shi, J.M.; Hai, G.Q.; Wu, X.G.; Eustis, T.J.; Schaff, W. |
Title |
Resonant magnetopolaron effects due to interface phonons in GaAs/AlGaAs multiple quantum well structures |
Type |
A1 Journal article |
Year |
1997 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
79 |
Issue |
|
Pages |
3226-3229 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
A1997YC78200033 |
Publication Date |
0000-00-00 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
36 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 8.462; 1997 IF: 6.140 |
Call Number |
UA @ lucian @ c:irua:19278 |
Serial |
2889 |
Permanent link to this record |
|
|
|
Author |
Wang, Y.J.; Nickel, H.A.; McCombe, B.D.; Peeters, F.M.; Hai, G.Q.; Shi, J.M.; Devreese, J.T.; Wu, X.G. |
Title |
Resonant magnetopolaron effects in GaAs/AlGaAs MQWs at high magnetic fields |
Type |
P3 Proceeding |
Year |
1997 |
Publication |
|
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
797-800 |
Keywords |
P3 Proceeding; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
World Scientific |
Place of Publication |
Singapore |
Editor |
|
Language |
|
Wos |
|
Publication Date |
0000-00-00 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
|
ISBN |
|
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:19305 |
Serial |
2890 |
Permanent link to this record |
|
|
|
Author |
Wang, Y.; Chen, Y.; Harding, J.; He, H.; Bogaerts, A.; Tu, X. |
Title |
Catalyst-free single-step plasma reforming of CH4 and CO2 to higher value oxygenates under ambient conditions |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Chemical Engineering Journal |
Abbreviated Journal |
Chem Eng J |
Volume |
450 |
Issue |
|
Pages |
137860 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Direct conversion of CH4 and CO2 to liquid fuels and chemicals under mild conditions is appealing for biogas conversion and utilization but challenging due to the inert nature of both gases. Herein, we report a promising plasma process for the catalyst-free single-step conversion of CH4 and CO2 into higher value oxygenates (i.e., methanol, acetic acid, ethanol, and acetone) at ambient pressure and room temperature using a water-cooled dielectric barrier discharge (DBD) reactor, with methanol being the main liquid product. The distribution of liquid products could be tailored by tuning the discharge power, reaction temperature and residence time. Lower discharge powers (10–15 W) and reaction temperatures (5–20 ◦ C) were favourable for the production of liquid products, achieving the highest methanol selectivity of 43% at 5 ◦ C and 15 W. A higher discharge power and reaction temperature, on the other hand, produced more gaseous products, particularly H2 (up to 26% selectivity) and CO (up to 33% selectivity). In addition, varying these process parameters (discharge power, reaction temperature and residence time) resulted in a simultaneous change in key discharge properties, such as mean electron energy (Ee), electron density (ne) and specific energy input (SEI), all of which are essential determiners of plasma chemical reactions. According to the results of artificial neural network (ANN) models, the relative importance of these process parameters and key discharge indicators on reaction performance follows the order: discharge power > reaction temperature > residence time, and SEI > ne > Ee, respectively. This work provides new insights into the contributions and tuning mechanism of multiple parameters for optimizing the reaction performance (e.g., liquid production) in the plasma gas conversion process. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000830813300004 |
Publication Date |
0000-00-00 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1385-8947 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
15.1 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
This project received funding from the European Union’s Horizon 2020 research and innovation program under the Marie SklodowskaCurie grant agreement No. 813393. |
Approved |
Most recent IF: 15.1 |
Call Number |
PLASMANT @ plasmant @c:irua:189502 |
Serial |
7100 |
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 |
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 |
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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 |
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 |
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 |
Wu, X.G.; Peeters, F.M.; Wang, Y.J.; McCombe, B.D. |
Title |
Blocking of the polaron effect and spin-split cyclotron resonance in a two-dimensional electron gas |
Type |
A1 Journal article |
Year |
2000 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
84 |
Issue |
|
Pages |
4934-4937 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000087114400038 |
Publication Date |
2002-07-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
15 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 8.462; 2000 IF: 6.462 |
Call Number |
UA @ lucian @ c:irua:28517 |
Serial |
245 |
Permanent link to this record |
|
|
|
Author |
Hai, G.Q.; Peeters, F.M.; Studart, N.; Wang, Y.J.; McCombe, B.D. |
Title |
Interface effects on magnetopolarons in GaAs/AlxGa1-xAs quantum wells at high magnetic fields |
Type |
A1 Journal article |
Year |
1998 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
58 |
Issue |
|
Pages |
7822-7829 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000076130500055 |
Publication Date |
2002-07-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
8 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 1998 IF: NA |
Call Number |
UA @ lucian @ c:irua:24161 |
Serial |
1693 |
Permanent link to this record |
|
|
|
Author |
Wang, Y.J.; Leem, Y.A.; McCombe, B.D.; Wu, X.G.; Peeters, F.M.; Jones, E.D.; Reno, J.R.; Lee, X.Y.; Jiang, H.W. |
Title |
Strong three-level resonant magnetopolaron effect due to the intersubband coupling in heavily modulation-doped GaAs/AlxGa1-xAs single quantum wells at high magnetic-fields |
Type |
A1 Journal article |
Year |
2001 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
Volume |
64 |
Issue |
16 |
Pages |
161303 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Electron cyclotron resonance CR) measurements have been carried out in magnetic fields up to 32 T to study electron-phonon interaction in two heavily modulation-delta -doped GaAs/Al0.3Ga0.7As single-quantum-well samples. No measurable resonant magnetopolaron effects were observed in either sample in the region of the GaAs longitudinal optical (LO) phonons. However, when the CR frequency is above LO phonon frequency, omega (LO)=E-LO/(h) over bar, at high magnetic fields (B>27 T), electron CR exhibits a strong avoided-level-crossing splitting for both samples at frequencies close to (omega (LO)+ (E-2-E-1)1 (h) over bar, where E-2, and E-1 are the energies of the bottoms of the second and the first subbands, respectively. The energy separation between the two branches is large with the minimum separation of 40 cm(-1) occurring at around 30.5 T. A detailed theoretical analysis, which includes a self-consistent calculation of the band structure and the effects of electron-phonon interaction on the CR, shows that this type of splitting is due to a three-level resonance between the second Landau level of the first electron subband and the lowest Landau level of the second subband plus one GaAs LO phonon. The absence of occupation effects in the final states and weak screening or this three-level process yields large energy separation even in the presence of high electron densities. Excellent agreement between the theory and the experimental results is obtained. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000171866400009 |
Publication Date |
2002-07-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
7 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2001 IF: NA |
Call Number |
UA @ lucian @ c:irua:37278 |
Serial |
3184 |
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 |
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 |
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 |
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 |
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 |
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 |
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Corporate Author |
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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 |
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 |
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|
|
Author |
Canioni, R.; Roch-Marchal, C.; Sécheresse, F.; Horcajada, P.; Serre, C.; Hardi-Dan, M.; Férey, G.; Grenèche, J.-M.; Lefebvre, F.; Chang, J.-S.; Hwang, Y.-K.; Lebedev, O.; Turner, S.; Van Tendeloo, G. |
Title |
Stable polyoxometalate insertion within the mesoporous metal organic framework MIL-100(Fe) |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Journal of materials chemistry |
Abbreviated Journal |
J Mater Chem |
Volume |
21 |
Issue |
4 |
Pages |
1226-1233 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Successful encapsulation of polyoxometalate (POM) within the framework of a mesoporous iron trimesate MIL-100(Fe) sample has been achieved by direct hydrothermal synthesis in the absence of fluorine. XRPD, 31P MAS NMR, IR, EELS, TEM and 57Fe Mössbauer spectrometry corroborate the insertion of POM within the cavities of the MOF. The experimental Mo/Fe ratio is 0.95, in agreement with the maximum theoretical amount of POM loaded within the pores of MIL-100(Fe), based on steric hindrance considerations. The POM-MIL-100(Fe) sample exhibits a pore volume of 0.373 cm3 g−1 and a BET surface area close to 1000 m2 g−1, indicating that small gas molecules can easily diffuse inside the cavities despite the presence of heavy phosphomolybdates. These latter contribute to the decrease in the overall surface area, due to the increase in molar weight, by 65%. Moreover, the resulting Keggin containing MIL-100(Fe) solid is stable in aqueous solution with no POM leaching even after more than 2 months. In addition, no exchange of the Keggin anions by tetrabutylammonium perchlorate in organic media has been observed. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
Language |
|
Wos |
000286110400042 |
Publication Date |
2010-11-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0959-9428;1364-5501; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
158 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:88642 |
Serial |
3145 |
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 |
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 |
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 |
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 |
Permanent link to this record |
|
|
|
Author |
Esken, D.; Noei, H.; Wang, Y.; Wiktor, C.; Turner, S.; Van Tendeloo, G.; Fischer, R.A. |
Title |
ZnO@ZIF-8 : stabilization of quantum confined ZnO nanoparticles by a zinc methylimidazolate framework and their surface structural characterization probed by CO2 adsorption |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Journal of materials chemistry |
Abbreviated Journal |
J Mater Chem |
Volume |
21 |
Issue |
16 |
Pages |
5907-5915 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The microporous and activated zeolitic imidazolate framework (Zn(MeIM)2; MeIM = imidazolate-2-methyl; ZIF-8) was loaded with the MOCVD precursor diethyl zinc [Zn(C2H5)2]. Exposure of ZIF-8 to the vapour of the volatile organometallic molecule resulted in the formation of the inclusion compound [Zn(C2H5)2]0.38@ZIF-8 revealing two precursor molecules per cavity. In a second step the obtained material was treated with oxygen (5 vol% in argon) at various temperatures (oxidative annealing) to achieve the composite material ZnO0.35@ZIF-8. The new material was characterized with powder XRD, FT-IR, UV-vis, solid state NMR, elemental analysis, N2 sorption measurements, and transmission electron microscopy. The data give evidence for the presence of nano-sized ZnO particles stabilized by ZIF-8 showing a blue-shift of the UV-vis absorption caused by quantum size effect (QSE). The surface structure and reactivity of embedded ZnO nanoparticles were characterized via carbon dioxide adsorption at different temperatures monitored by ultra-high vacuum FTIR techniques. It was found that the surface of ZnO nanoparticles is dominated by polar OZnO and ZnZnO facets as well as by defect sites, which all exhibit high reactivity towards CO2 activation forming various adsorbed carbonate and chemisorbed CO2δ− species. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
Language |
|
Wos |
000289260000012 |
Publication Date |
2011-03-19 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0959-9428;1364-5501; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
76 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:88641 |
Serial |
3936 |
Permanent link to this record |
|
|
|
Author |
Wang, Y.; Yu, M.Y.; Chen, Z.Y. |
Title |
Coherent relativistic wake wave of a charged object moving steadily in a plasma |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physica scripta |
Abbreviated Journal |
Phys Scripta |
Volume |
84 |
Issue |
2 |
Pages |
025501,1-025501,5 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Nonlinear electron plasma waves driven by a finite-charged particle pulse or rigid object moving at relativistic speeds are investigated. Quasi-stationary smooth and spiky wake waves comoving with the object are found. Localized soliton-like solutions are also shown to exist. Relativistic effects tend to prevent their formation because of the electron mass increase. The application of the very-large-amplitude wake density waves as a source of ultrahigh-energy cosmic-ray events is discussed. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Stockholm |
Editor |
|
Language |
|
Wos |
000294727900017 |
Publication Date |
2011-07-09 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-8949;1402-4896; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.28 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.28; 2011 IF: 1.204 |
Call Number |
UA @ lucian @ c:irua:92435 |
Serial |
381 |
Permanent link to this record |
|
|
|
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 |
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 |
Permanent link to this record |
|
|
|
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 |
2.588 |
Times cited |
57 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.588; 2012 IF: 2.528 |
Call Number |
UA @ lucian @ c:irua:92851 |
Serial |
1230 |
Permanent link to this record |
|
|
|
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 |
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 |
Permanent link to this record |
|
|
|
Author |
Zhao, S.-X.; Gao, F.; Wang, Y.-N.; Bogaerts, A. |
Title |
The effect of F2 attachment by low-energy electrons on the electron behaviour in an Ar/CF4 inductively coupled plasma |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
Volume |
21 |
Issue |
2 |
Pages |
025008-025008,13 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The electron behaviour in an Ar/CF4 inductively coupled plasma is investigated by a Langmuir probe and a hybrid model. The simulated and measured results include electron density, temperature and electron energy distribution function for different values of Ar/CF4 ratio, coil power and gas pressure. The hybrid plasma equipment model simulations show qualitative agreement with experiment. The effect of F2 electron attachment on the electron behaviour is explored by comparing two sets of data based on different F atom boundary conditions. It is demonstrated that electron attachment at F2 molecules is responsible for the depletion of low-energy electrons, causing a density decrease as well as a temperature increase when CF4 is added to an Ar plasma. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
Institute of Physics |
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000302779400022 |
Publication Date |
2012-03-12 |
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 |
23 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.302; 2012 IF: 2.515 |
Call Number |
UA @ lucian @ c:irua:96549 |
Serial |
841 |
Permanent link to this record |
|
|
|
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 |
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 |
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 |
|
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 |
|
|
|
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 |
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 |
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Corporate Author |
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Thesis |
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Publisher |
Institute of Physics |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000314966300022 |
Publication Date |
2012-12-20 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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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 |
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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 |
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Corporate Author |
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Thesis |
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Publisher |
Institute of Physics |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000317275400014 |
Publication Date |
2013-03-18 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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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 |
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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 |
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Corporate Author |
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Thesis |
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Publisher |
Institute of Physics |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000317275400016 |
Publication Date |
2013-03-28 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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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 |
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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 |
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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 |
000337891800006 |
Publication Date |
2014-06-11 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-8979;1089-7550; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.068 |
Times cited |
9 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.068; 2014 IF: 2.183 |
Call Number |
UA @ lucian @ c:irua:117347 |
Serial |
1414 |
Permanent link to this record |
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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 |
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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 |
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Language |
|
Wos |
000338106000008 |
Publication Date |
2014-06-23 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
0021-8979;1089-7550; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.068 |
Times cited |
8 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.068; 2014 IF: 2.183 |
Call Number |
UA @ lucian @ c:irua:117415 |
Serial |
2585 |
Permanent link to this record |