Records |
Author |
De Meulenaere, P.; Mommaert, C.; Van Tendeloo, G. |
Title |
Short-range order in phase segregation systems |
Type |
A1 Journal article |
Year |
1997 |
Publication |
Solid state communications |
Abbreviated Journal |
Solid State Commun |
Volume |
102 |
Issue |
9 |
Pages |
687-690 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Spin systems on an f.c.c.-lattice which exhibit phase segregation are studied by means of Monte Carlo simulations. Short-range order, both above and below the segregation temperature, is observed. Experimental evidence for short range order in Ti-V is provided by electron diffraction. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
A1997WX40300011 |
Publication Date |
2003-05-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0038-1098; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
1.554 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.554; 1997 IF: 1.323 |
Call Number |
UA @ lucian @ c:irua:21429 |
Serial |
2997 |
Permanent link to this record |
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|
|
Author |
Tsirlin, A.A.; Abakumov, A.M.; Ritter, C.; Henry, P.F.; Janson, O.; Rosner, H. |
Title |
Short-range order of Br and three-dimensional magnetism in (CuBr)LaNb2O7 |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
85 |
Issue |
21 |
Pages |
214427 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We present a comprehensive study of the crystal structure, magnetic structure, and microscopic magnetic model of (CuBr)LaNb2O7, the Br analog of the spin-gap quantum magnet (CuCl) LaNb2O7. Despite similar crystal structures and spin lattices, the magnetic behavior and even peculiarities of the atomic arrangement in the Cl and Br compounds are very different. The high- resolution x-ray and neutron data reveal a split position of Br atoms in (CuBr) LaNb2O7. This splitting originates from two possible configurations developed by [CuBr] zigzag ribbons. While the Br atoms are locally ordered in the ab plane, their arrangement along the c direction remains partially disordered. The predominant and energetically more favorable configuration features an additional doubling of the c lattice parameter that was not observed in (CuCl) LaNb2O7. (CuBr) LaNb2O7 undergoes long-range antiferromagnetic ordering at T-N = 32 K, which is nearly 70% of the leading exchange coupling J4 similar or equal to 48 K. The Br compound does not show any experimental signatures of low-dimensional magnetism because the underlying spin lattice is three-dimensional. The coupling along the c direction is comparable to the couplings in the ab plane, even though the shortest Cu-Cu distance along c (11.69 angstrom) is three times larger than nearest-neighbor distances in the ab plane (3.55 angstrom). The stripe antiferromagnetic long-range order featuring columns of parallel spins in the ab plane and antiparallel spins along c is verified experimentally and confirmed by the microscopic analysis. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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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 |
000305557600002 |
Publication Date |
2012-06-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:100289 |
Serial |
2998 |
Permanent link to this record |
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|
|
Author |
Szafran, B.; Peeters, F.M. |
Title |
Signatures of lateral coupling of double quantum dots in the exciton photoluminescence spectrum |
Type |
A1 Journal article |
Year |
2007 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
76 |
Issue |
|
Pages |
195442,1-9 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
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Wos |
000251326800147 |
Publication Date |
2007-11-28 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
29 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2007 IF: 3.172 |
Call Number |
UA @ lucian @ c:irua:69663 |
Serial |
2999 |
Permanent link to this record |
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|
Author |
Hermans, I.; Breynaert, E.; Poelman, H.; de Gryse, R.; Liang, D.; Van Tendeloo, G.; Maes, A.; Peeters, J.; Jacobs, P. |
Title |
Silica-supported chromium oxide: colloids as building blocks |
Type |
A1 Journal article |
Year |
2007 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
Volume |
9 |
Issue |
39 |
Pages |
5382-5386 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
Language |
|
Wos |
000249925500022 |
Publication Date |
2007-10-03 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1463-9076;1463-9084; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.123 |
Times cited |
8 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.123; 2007 IF: 3.343 |
Call Number |
UA @ lucian @ c:irua:66752 |
Serial |
3000 |
Permanent link to this record |
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|
Author |
Bogaerts, A.; Gijbels, R. |
Title |
Similarities and differences between direct current and radio-frequency glow discharges: a mathematical simulation |
Type |
A1 Journal article |
Year |
2000 |
Publication |
Journal of analytical atomic spectrometry |
Abbreviated Journal |
J Anal Atom Spectrom |
Volume |
15 |
Issue |
|
Pages |
1191-1201 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000089141900019 |
Publication Date |
2002-07-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0267-9477;1364-5544; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.379 |
Times cited |
25 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.379; 2000 IF: 3.488 |
Call Number |
UA @ lucian @ c:irua:34076 |
Serial |
3001 |
Permanent link to this record |
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|
Author |
Zhang, X.F.; Zhang, X.B.; Bernaerts, D.; Van Tendeloo, G.; Amelinckx, S.; van Landuyt, J.; Werner, H. |
Title |
A simple preparation method for air-sensitive specimens for transmission electron microscopy demonstrated by Rb6C60 |
Type |
A1 Journal article |
Year |
1994 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
55 |
Issue |
|
Pages |
25-30 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
In this paper a particularly simple but efficient method is presented by which samples of alkali-doped C-60 materials or other air-sensitive materials can be prepared and transferred into a transmission electron microscope for direct observations and investigations. Flexible, transparent glove bags are used which are filled to a slight overpressure with dry nitrogen. Under this protective atmosphere, the air-sensitive sample is mounted in the specimen holder and inserted in the vacuum of the electron microscope. Rb6C60 which is prepared and transferred into the microscope in this way has been investigated by transmission electron microscopy (TEM). The results confirm the bcc structure and especially the location of the rubidium atoms. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
A1994PE30800005 |
Publication Date |
2002-10-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.436 |
Times cited |
2 |
Open Access |
|
Notes |
|
Approved |
CHEMISTRY, PHYSICAL 77/144 Q3 # MATHEMATICS, INTERDISCIPLINARY 19/101 Q1 # PHYSICS, ATOMIC, MOLECULAR & CHEMICAL 17/35 Q2 # |
Call Number |
UA @ lucian @ c:irua:10007 |
Serial |
3002 |
Permanent link to this record |
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|
Author |
Quintana, M.; Grzelczak, M.; Spyrou, K.; Calvaresi, M.; Bals, S.; Kooi, B.; Van Tendeloo, G.; Rudolf, P.; Zerbetto, F.; Prato, M. |
Title |
A simple road for the transformation of few-layer graphene into MWNTs |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
Volume |
134 |
Issue |
32 |
Pages |
13310-13315 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We report the direct formation of multiwalled carbon nanotubes (MWNT) by ultrasonication of graphite in dimethylformamide (DMF) upon addition of ferrocene aldehyde (Fc-CHO). The tubular structures appear exclusively at the edges of graphene layers and contain Fe clusters. Pc in conjunction with benzyl aldehyde, or other Fc derivatives, does not induce formation of NT. Higher amounts of Fc-CHO added to the dispersion do not increase significantly MWNT formation. Increasing the temperature reduces the amount of formation of MWNTs and shows the key role of ultrasound-induced cavitation energy. It is concluded that Fc-CHO first reduces the concentration of radical reactive species that slice graphene into small moieties, localizes itself at the edges of graphene, templates the rolling up of a sheet to form a nanoscroll, where it remains trapped, and finally accepts and donates unpaired electron to the graphene edges and converts the less stable scroll into a MWNT. This new methodology matches the long held notion that CNTs are rolled up graphene layers. The proposed mechanism is general and will lead to control the production of carbon nanostructures by simple ultrasonication treatments. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000307487200034 |
Publication Date |
2012-05-08 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0002-7863;1520-5126; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
13.858 |
Times cited |
56 |
Open Access |
|
Notes |
This work was supported by the University of Trieste, the Italian Ministry of Education MIUR (cofin Prot. 20085M27SS), the European Union through the ERC grant No. 246791 – COUNTATOMS, the grant agreement for an Integrated Infrastructure Initiative N. 262348 ESMI, and the “Graphene-based electronics” research program of the Foundation for Fundamental Research on Matter (FOM). |
Approved |
Most recent IF: 13.858; 2012 IF: 10.677 |
Call Number |
UA @ lucian @ c:irua:101109 |
Serial |
3003 |
Permanent link to this record |
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|
|
Author |
Saniz, R.; Xu, Y.; Matsubara, M.; Amini, M.N.; Dixit, H.; Lamoen, D.; Partoens, B. |
Title |
A simplified approach to the band gap correction of defect formation energies : Al, Ga, and In-doped ZnO |
Type |
A1 Journal article |
Year |
2013 |
Publication |
The journal of physics and chemistry of solids |
Abbreviated Journal |
J Phys Chem Solids |
Volume |
74 |
Issue |
1 |
Pages |
45-50 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
Abstract |
The calculation of defect levels in semiconductors within a density functional theory approach suffers greatly from the band gap problem. We propose a band gap correction scheme that is based on the separation of energy differences in electron addition and relaxation energies. We show that it can predict defect levels with a reasonable accuracy, particularly in the case of defects with conduction band character, and yet is simple and computationally economical. We apply this method to ZnO doped with group III elements (Al, Ga, In). As expected from experiment, the results indicate that Zn substitutional doping is preferred over interstitial doping in Al, Ga, and In-doped ZnO, under both zinc-rich and oxygen-rich conditions. Further, all three dopants act as shallow donors, with the +1 charge state having the most advantageous formation energy. Also, doping effects on the electronic structure of ZnO are sufficiently mild so as to affect little the fundamental band gap and lowest conduction bands dispersion, which secures their n-type transparent conducting behavior. A comparison with the extrapolation method based on LDA+U calculations and with the HeydScuseriaErnzerhof hybrid functional (HSE) shows the reliability of the proposed scheme in predicting the thermodynamic transition levels in shallow donor systems. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000311062500009 |
Publication Date |
2012-08-10 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-3697; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.059 |
Times cited |
36 |
Open Access |
|
Notes |
Fwo; Bof-Nio |
Approved |
Most recent IF: 2.059; 2013 IF: 1.594 |
Call Number |
UA @ lucian @ c:irua:101782 |
Serial |
3004 |
Permanent link to this record |
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|
|
Author |
Zarenia, M.; Pereira, J.M.; Chaves, A.; Peeters, F.M.; Farias, G.A. |
Title |
Simplified model for the energy levels of quantum rings in single layer and bilayer graphene |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
81 |
Issue |
4 |
Pages |
045431,1-045431,9 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Within a minimal model, we present analytical expressions for the eigenstates and eigenvalues of carriers confined in quantum rings in monolayer and bilayer graphene. The calculations were performed in the context of the continuum model by solving the Dirac equation for a zero width ring geometry, i.e., by freezing out the carrier radial motion. We include the effect of an external magnetic field and show the appearance of Aharonov-Bohm oscillations and of a nonzero gap in the spectrum. Our minimal model gives insight on the energy spectrum of graphene-based quantum rings and models different aspects of finite width rings. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
|
Editor |
|
Language |
|
Wos |
000277186000010 |
Publication Date |
2010-01-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
76 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the Bilateral program between Flanders and Brazil, and the Brazilian Council for Research (CNPq). ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
Call Number |
UA @ lucian @ c:irua:82866 |
Serial |
3005 |
Permanent link to this record |
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|
|
Author |
Carrillo-Nuñez, H.; Magnus, W.; Peeters, F.M. |
Title |
A simplified quantum mechanical model for nanowire transistors based on non-linear variational calculus |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
Volume |
108 |
Issue |
6 |
Pages |
063708,1-063708,8 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
A simplified quantum mechanical model is developed to investigate quantum transport features such as the electron concentration and the current flowing through a silicon nanowire metal-oxide-semiconductor field-effect transistor (MOSFET). In particular, the electron concentration is extracted from a self-consistent solution of the Schrödinger and Poisson equations as well as the ballistic Boltzmann equation which have been solved by exploiting a nonlinear variational principle within the framework of the generalized local density approximation. A suitable action functional has been minimized and details of the implementation and its numerical minimization are given. The current density and its related current-voltage characteristics are calculated from the one-dimensional ballistic steady-state Boltzmann transport equation which is solved analytically by using the method of characteristic curves. The straightforward implementation, the computational speed and the good qualitative behavior of the transport characteristics observed in our approach make it a promising simulation method for modeling quantum transport in nanowire MOSFETs. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000282646400067 |
Publication Date |
2010-09-22 |
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 |
7 |
Open Access |
|
Notes |
; This work was supported by Flemish Science Foundation (FWO-VI) and the Interuniversity Attraction Poles, Belgium State, Belgium Science Policy, and IMEC. ; |
Approved |
Most recent IF: 2.068; 2010 IF: 2.079 |
Call Number |
UA @ lucian @ c:irua:84943 |
Serial |
3006 |
Permanent link to this record |
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|
Author |
de Witte, H.; Conard, T.; Vandervorst, W.; Gijbels, R. |
Title |
SIMS analysis of oxynitrides: evidence for nitrogen diffusion induced by oxygen flooding |
Type |
A1 Journal article |
Year |
2000 |
Publication |
Surface and interface analysis |
Abbreviated Journal |
Surf Interface Anal |
Volume |
29 |
Issue |
|
Pages |
761-765 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000165476500006 |
Publication Date |
2002-08-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0142-2421;1096-9918; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.132 |
Times cited |
4 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.132; 2000 IF: 1.215 |
Call Number |
UA @ lucian @ c:irua:34072 |
Serial |
3007 |
Permanent link to this record |
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|
|
Author |
Lindner, H.; Murtazin, A.; Groh, S.; Niemax, K.; Bogaerts, A. |
Title |
Simulation and experimental studies on plasma temperature, flow velocity, and injector diameter effects for an inductively coupled plasma |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
83 |
Issue |
24 |
Pages |
9260-9266 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
An inductively coupled plasma (ICP) is analyzed by means of experiments and numerical simulation. Important plasma properties are analyzed, namely, the effective temperature inside the central channel and the mean flow velocity inside the plasma. Furthermore, the effect of torches with different injector diameters is studied by the model. The temperature inside the central channel is determined from the end-on collected line-to-background ratio in dependence of the injector gas flow rates. Within the limits of 3% deviation, the results of the simulation and the experiments are in good agreement in the range of flow rates relevant for the analysis of relatively large droplets, i.e., 50 μm. The deviation increases for higher gas flow rates but stays below 6% for all flow rates studied. The velocity of the gas inside the coil region was determined by side-on analyte emission measurements with single monodisperse droplet introduction and by the analysis of the injector gas path lines in the simulation. In the downstream region significantly higher velocities were found than in the upstream region in both the simulation and the experiment. The quantitative values show good agreement in the downstream region. In the upstream region, deviations were found in the absolute values which can be attributed to the flow conditions in that region and because the methods used for velocity determination are not fully consistent. Eddy structures are found in the simulated flow lines. These affect strongly the way taken by the path lines of the injector gas and they can explain the very long analytical signals found in the experiments at low flow rates. Simulations were performed for different injector diameters in order to find conditions where good analyte transport and optimum signals can be expected. The results clearly show the existence of a transition flow rate which marks the lower limit for effective analyte transport conditions through the plasma. A rule-of-thumb equation was extracted from the results from which the transition flow rate can be estimated for different injector diameters and different injector gas compositions. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000297946900013 |
Publication Date |
2011-07-29 |
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 |
34 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 2011 IF: 5.856 |
Call Number |
UA @ lucian @ c:irua:94001 |
Serial |
3009 |
Permanent link to this record |
|
|
|
Author |
Tinck, S.; Boullart, W.; Bogaerts, A. |
Title |
Simulation of an Ar/Cl2 inductively coupled plasma: study of the effect of bias, power and pressure and comparison with experiments |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
Volume |
41 |
Issue |
6 |
Pages |
065207,1-14 |
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 Ar/Cl(2) inductively coupled plasmas used for the etching of Si. The effects of substrate bias, source power and gas pressure on the plasma characteristics and on the fluxes and energies of plasma species bombarding the substrate were observed. A comparison with experimentally measured etch rates was made to investigate how the etch process is influenced and which plasma species mainly account for the etch process. First, the general plasma characteristics are investigated at the following operating conditions: 10% Ar 90% Cl(2) gas mixture, 5mTorr total gas pressure, 100 sccm gas flow rate, 250W source power, -200V dc bias at the substrate electrode and an operating frequency of 13.56MHz applied to the coil and to the substrate electrode. Subsequently, the pressure is varied from 5 to 80mTorr, the substrate bias from -100 to -300V and the source power from 250 to 1000W. Increasing the total gas pressure results in a decrease of the etch rate and a less anisotropic flux to the substrate due to more collisions of the ions in the sheath. Increasing the substrate bias has an effect on the energy of the ions bombarding the substrate and to a lesser extent on the magnitude of the ion flux. When source power is increased, it was found that, not the energy, but the magnitude of the ion flux is increased. The etch rate was more influenced by a variation of the substrate bias than by a variation of the source power, at these operating conditions. These results suggest that the etch process is mainly affected by the energy of the ions bombarding the substrate and the magnitude of the ion flux, and to a lesser extent by the magnitude of the radical flux. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000254153900022 |
Publication Date |
2008-02-27 |
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 |
0022-3727;1361-6463; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.588 |
Times cited |
31 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.588; 2008 IF: 2.104 |
Call Number |
UA @ lucian @ c:irua:67019 |
Serial |
3010 |
Permanent link to this record |
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|
|
Author |
Liu, Y.H.; Chen, Z.Y.; Huang, F.; Yu, M.Y.; Wang, L.; Bogaerts, A. |
Title |
Simulation of disk- and band-like voids in dusty plasma systems |
Type |
A1 Journal article |
Year |
2006 |
Publication |
Physics of plasmas |
Abbreviated Journal |
Phys Plasmas |
Volume |
13 |
Issue |
|
Pages |
052110,1-6 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
Woodbury, N.Y. |
Editor |
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Language |
|
Wos |
000237943000011 |
Publication Date |
2006-05-12 |
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 |
20 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.115; 2006 IF: 2.258 |
Call Number |
UA @ lucian @ c:irua:57858 |
Serial |
3011 |
Permanent link to this record |
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Author |
Rubino, S.; Schattschneider, P.; Rusz, J.; Verbeeck, J.; Leifer, K. |
Title |
Simulation of magnetic circular dichroism in the electron microscope |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
Volume |
43 |
Issue |
47 |
Pages |
474005,1-474005,11 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
As electron energy-loss spectroscopy (EELS) and x-ray absorption spectroscopy (XAS) probe the same transitions from coreshell states to unoccupied states above the Fermi energy, it should always be possible to apply the two techniques to the same physical phenomena, such as magnetic dichroism, and obtain the same information. Indeed, the similarity in the expression of the electron and x-ray cross-sections had been already exploited to prove the equivalence of x-ray magnetic linear dichroism and anisotropy in EELS, by noting that the polarization vector of a photon plays the same role as the momentum transfer in electron scattering. Recently, the same was proven true for x-ray magnetic circular dichroism (XMCD) by establishing a new TEM technique called EMCD (electron energy-loss magnetic chiral dichroism) (Schattschneider P et al 2006 Nature 441 4868), which makes use of special electron scattering conditions to force the absorption of a circularly polarized virtual photon. The intrinsic advantage of EMCD over XMCD is the high spatial resolution of electron microscopes, which are readily available. Among the particular obstacles in EMCD that do not exist for synchrotron radiation, is the notoriously low signal and the very particular scattering conditions necessary to observe a chiral dichroic signal. In spite of that, impressive progress has been made in recent years. The signal strength could be considerably increased, and some innovations such as using a convergent beam have been introduced. EMCD has evolved into several techniques, which make full use of the versatility of the TEM and energy filtering, spectroscopy or STEM conditions (Rubino S 2007 Magnetic circular dichroism in the transmission electron microscope PhD Thesis Vienna University of Technology, Vienna, Austria). |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000284099700006 |
Publication Date |
2010-11-12 |
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 |
0022-3727;1361-6463; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.588 |
Times cited |
13 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.588; 2010 IF: 2.109 |
Call Number |
UA @ lucian @ c:irua:85808UA @ admin @ c:irua:85808 |
Serial |
3012 |
Permanent link to this record |
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|
|
Author |
Tinck, S.; Bogaerts, A.; Shamiryan, D. |
Title |
Simultaneous etching and deposition processes during the etching of silicon with a Cl2/O2/Ar inductively coupled plasma |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Plasma processes and polymers |
Abbreviated Journal |
Plasma Process Polym |
Volume |
8 |
Issue |
6 |
Pages |
490-499 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this article, surface processes occurring during the etching of Si with a Cl2/O2/Ar plasma are investigated by means of experiments and modeling. Cl2-based plasmas are commonly used to etch silicon, while a small fraction of O2 is added to protect the sidewalls from lateral etching during the shallow trench isolation process. When the oxygen fraction exceeds a critical value, the wafer surface process changes from an etching regime to a deposition regime, drastically reducing the etch rate. This effect is commonly referred to as the etch stop phenomenon. To gain better understanding of this mechanism, the oxygen fraction is varied in the gas mixture and special attention is paid to the effects of oxygen and of the redeposition of non-volatile etched species on the overall etch/deposition process. It is found that, when the O2 flow is increased, the etch process changes from successful etching to the formation of a rough surface, and eventually to the actual growth of an oxide layer which completely blocks the etching of the underlying Si. The size of this etch stop island was found to increase as a function of oxygen flow, while its thickness was dependent on the amount of Si etched. This suggests that the growth of the oxide layer mainly depends on the redeposition of non-volatile etch products. The abrupt change in the etch rate as a function of oxygen fraction was not found back in the oxygen content of the plasma, suggesting the competitive nature between oxidation and chlorination at the wafer. Finally, the wafer and reactor wall compositions were investigated by modeling and it was found that the surface rapidly consisted mainly of SiO2 when the O2 flow was increased above about 15 sccm. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
Weinheim |
Editor |
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Language |
|
Wos |
000292116800003 |
Publication Date |
2011-03-29 |
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 |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.846; 2011 IF: 2.468 |
Call Number |
UA @ lucian @ c:irua:90926 |
Serial |
3014 |
Permanent link to this record |
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|
Author |
Helm, M.; Hilber, W.; Strasser, G.; de Meester, R.; Peeters, F.M.; Wacker, A. |
Title |
Simultaneous investigation of vertical transport and intersubband absorption in a superlattice: continuum Wannier-Strak ladders and next-nearest neighbor tunneling |
Type |
A1 Journal article |
Year |
1999 |
Publication |
Physica: B : condensed matter |
Abbreviated Journal |
Physica B |
Volume |
272 |
Issue |
|
Pages |
194-197 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000084375600055 |
Publication Date |
2002-07-25 |
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 |
0921-4526; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.386 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.386; 1999 IF: 0.725 |
Call Number |
UA @ lucian @ c:irua:28509 |
Serial |
3015 |
Permanent link to this record |
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Author |
Janssens, K.L.; Partoens, B.; Peeters, F.M. |
Title |
Single and coupled type II quantum dots in magnetic and electric fields |
Type |
A1 Journal article |
Year |
2002 |
Publication |
Physicalia magazine |
Abbreviated Journal |
|
Volume |
24 |
Issue |
|
Pages |
211 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
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Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
Gent |
Editor |
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Language |
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Wos |
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Publication Date |
0000-00-00 |
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 |
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Edition |
|
ISSN |
0770-0520 |
ISBN |
|
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:62456 |
Serial |
3016 |
Permanent link to this record |
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|
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Author |
Janssens, K.L.; Partoens, B.; Peeters, F.M. |
Title |
Single and vertically coupled type-II quantum dots in a perpendicular magnetic field: exciton ground-state properties |
Type |
A1 Journal article |
Year |
2002 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
66 |
Issue |
7 |
Pages |
075314,1-9 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000177969800106 |
Publication Date |
2002-10-01 |
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 |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
38 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2002 IF: NA |
Call Number |
UA @ lucian @ c:irua:62430 |
Serial |
3017 |
Permanent link to this record |
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Author |
Titantah, J.T.; Pierleoni, C.; Ryckaert, J.-P. |
Title |
Single chain elasticity and thermoelasticity of polyethylene |
Type |
A1 Journal article |
Year |
2002 |
Publication |
The journal of chemical physics |
Abbreviated Journal |
J Chem Phys |
Volume |
117 |
Issue |
19 |
Pages |
9028-9036 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Single-chain elasticity of polyethylene at theta point up to 90% of stretching with respect to its contour length is computed by Monte Carlo simulation of an atomistic model in continuous space. The elasticity law together with the free-energy and the internal energy variations with stretching are found to be very well represented by the wormlike chain model up to 65% of the chain elongation, provided the persistence length is treated as a temperature-dependent parameter. Beyond this value of elongation simple ideal chain models are not able to describe the Monte Carlo data in a thermodynamic consistent way. This study reinforces the use of the wormlike chain model to interpret experimental data on the elasticity of synthetic polymers in the finite extensibility regime, provided the chain is not yet in its fully stretched regime. Specific solvent effects on the elasticity law and the partition between energetic and entropic contributions to single chain elasticity are investigated. (C) 2002 American Institute of Physics. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000178934700046 |
Publication Date |
2002-10-31 |
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 |
0021-9606; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.965 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.965; 2002 IF: 2.998 |
Call Number |
UA @ lucian @ c:irua:103862 |
Serial |
3018 |
Permanent link to this record |
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|
Author |
Lucena, D.; Galván Moya, J.E.; Ferreira, W.P.; Peeters, F.M. |
Title |
Single-file and normal diffusion of magnetic colloids in modulated channels |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Physical review : E : statistical, nonlinear, and soft matter physics |
Abbreviated Journal |
Phys Rev E |
Volume |
89 |
Issue |
3 |
Pages |
032306-32309 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Diffusive properties of interacting magnetic dipoles confined in a parabolic narrow channel and in the presence of a periodic modulated (corrugated) potential along the unconfined direction are studied using Brownian dynamics simulations. We compare our simulation results with the analytical result for the effective diffusion coefficient of a single particle by Festa and d'Agliano [Physica A 90, 229 (1978)] and show the importance of interparticle interaction on the diffusion process. We present results for the diffusion of magnetic dipoles as a function of linear density, strength of the periodic modulation and commensurability factor. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
American Institute of Physics |
Place of Publication |
Woodbury (NY) |
Editor |
|
Language |
|
Wos |
000333646400005 |
Publication Date |
2014-03-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1539-3755;1550-2376; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.366 |
Times cited |
5 |
Open Access |
|
Notes |
; This work was supported by CNPq, CAPES, FUNCAP (Pronex grant), the Flemish Science Foundation (FWO-Vl), the collaborative program CNPq-FWO-Vl, and the Brazilian program Science Without Borders (CsF). D. Lucena acknowledges fruitful discussions with W. A. Munoz, V. F. Becerra, E. C. Euan-Diaz, and M. R. Masir. ; |
Approved |
Most recent IF: 2.366; 2014 IF: 2.288 |
Call Number |
UA @ lucian @ c:irua:116865 |
Serial |
3020 |
Permanent link to this record |
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Author |
Ghosh, S.; Gaspari, R.; Bertoni, G.; Spadaro, M.C.; Prato, M.; Turner, S.; Cavalli, A.; Manna, L.; Brescia, R. |
Title |
Pyramid-Shaped Wurtzite CdSe Nanocrystals with Inverted Polarity |
Type |
A1 Journal article |
Year |
2015 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
Volume |
9 |
Issue |
9 |
Pages |
8537-8546 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
We report on pyramid-shaped wurtzite cadmium selenide (CdSe) nanocrystals (NCs), synthesized by hot injection in the presence of chloride ions as shape-directing agents, exhibiting reversed crystal polarity compared to former reports. Advanced transmission electron microscopy (TEM) techniques (image-corrected high-resolution TEM with exit wave reconstruction and probe-corrected high-angle annular dark field-scanning TEM) unequivocally indicate that the triangular base of the pyramids is the polar (0001) facet and their apex points toward the [0001] direction. Density functional theory calculations, based on a simple model of binding of Cl(-) ions to surface Cd atoms, support the experimentally evident higher thermodynamic stability of the (0001) facet over the (0001) one conferred by Cl(-) ions. The relative stability of the two polar facets of wurtzite CdSe is reversed compared to previous experimental and computational studies on Cd chalcogenide NCs, in which no Cl-based chemicals were deliberately used in the synthesis or no Cl(-) ions were considered in the binding models. Self-assembly of these pyramids in a peculiar clover-like geometry, triggered by the addition of oleic acid, suggests that the basal (polar) facet has a density and perhaps type of ligands significantly different from the other three facets, since the pyramids interact with each other exclusively via their lateral facets. A superstructure, however with no long-range order, is observed for clovers with their (0001) facets roughly facing each other. The CdSe pyramids were also exploited as seeds for CdS pods growth, and the peculiar shape of the derived branched nanostructures clearly arises from the inverted polarity of the seeds. |
Address |
Department of Nanochemistry, Istituto Italiano di Tecnologia (IIT) , via Morego 30, I-16163 Genova, Italy |
Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000360323300085 |
Publication Date |
2015-07-23 |
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 |
1936-0851;1936-086X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
13.942 |
Times cited |
16 |
Open Access |
|
Notes |
PMID:26203791 |
Approved |
Most recent IF: 13.942; 2015 IF: 12.881 |
Call Number |
c:irua:127807 |
Serial |
3956 |
Permanent link to this record |
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Author |
Euán-Díaz, E.C.; Misko, V.R.; Peeters, F.M.; Herrera-Velarde, S.; Castaneda-Priego, R. |
Title |
Single-file diffusion in periodic energy landscapes : the role of hydrodynamic interactions |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : E : statistical, nonlinear, and soft matter physics |
Abbreviated Journal |
Phys Rev E |
Volume |
86 |
Issue |
3Part 1 |
Pages |
031123 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We report on the dynamical properties of interacting colloids confined to one dimension and subjected to external periodic energy landscapes. We particularly focus on the influence of hydrodynamic interactions on the mean-square displacement. Using Brownian dynamics simulations, we study colloidal systems with two types of repulsive interparticle interactions, namely, Yukawa and superparamagnetic potentials. We find that in the homogeneous case, hydrodynamic interactions lead to an enhancement of the particle mobility and the mean-square displacement at long times scales as t(alpha), with alpha = 1/2 + epsilon and epsilon being a small correction. This correction, however, becomes much more important in the presence of an external field, which breaks the homogeneity of the particle distribution along the line and, therefore, promotes a richer dynamical scenario due to the hydrodynamical coupling among particles. We provide here the complete dynamical scenario in terms of the external potential parameters: amplitude and commensurability. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
American Institute of Physics |
Place of Publication |
Woodbury (NY) |
Editor |
|
Language |
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Wos |
000308873500002 |
Publication Date |
2012-09-21 |
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 |
1539-3755;1550-2376; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.366 |
Times cited |
14 |
Open Access |
|
Notes |
; This work was partially supported by the “Odysseus” Program of the Flemish Government, the Flemish Science Foundation (FWO-Vl), and PIFI 3.4-PROMEP and CONACyT (Grant Nos. 61418/2007 and 102339/2008, Ph.D. Scholarship No. 230171/ 2010). ; |
Approved |
Most recent IF: 2.366; 2012 IF: 2.313 |
Call Number |
UA @ lucian @ c:irua:101840 |
Serial |
3021 |
Permanent link to this record |
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Author |
Nelissen, K.; Misko, V.R.; Peeters, F.M. |
Title |
Single-file diffusion of interacting particles in a one-dimensional channel |
Type |
A1 Journal article |
Year |
2007 |
Publication |
Epl |
Abbreviated Journal |
Epl-Europhys Lett |
Volume |
80 |
Issue |
5 |
Pages |
56004,1-5 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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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 |
000251647900018 |
Publication Date |
2007-11-30 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0295-5075;1286-4854; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.957 |
Times cited |
48 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.957; 2007 IF: 2.206 |
Call Number |
UA @ lucian @ c:irua:67336 |
Serial |
3022 |
Permanent link to this record |
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Author |
Barbier, M.; Vasilopoulos, P.; Peeters, F.M. |
Title |
Single-layer and bilayer graphene superlattices: collimation, additional Dirac points and Dirac lines |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Philosophical transactions of the Royal Society : mathematical, physical and engineering sciences |
Abbreviated Journal |
Philos T R Soc A |
Volume |
368 |
Issue |
1932 |
Pages |
5499-5524 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We review the energy spectrum and transport properties of several types of one-dimensional superlattices (SLs) on single-layer and bilayer graphene. In single-layer graphene, for certain SL parameters an electron beam incident on an SL is highly collimated. On the other hand, there are extra Dirac points generated for other SL parameters. Using rectangular barriers allows us to find analytical expressions for the location of new Dirac points in the spectrum and for the renormalization of the electron velocities. The influence of these extra Dirac points on the conductivity is investigated. In the limit of δ-function barriers, the transmission T through and conductance G of a finite number of barriers as well as the energy spectra of SLs are periodic functions of the dimensionless strength P of the barriers, Graphic, with vF the Fermi velocity. For a KronigPenney SL with alternating sign of the height of the barriers, the Dirac point becomes a Dirac line for P = π/2+nπ with n an integer. In bilayer graphene, with an appropriate bias applied to the barriers and wells, we show that several new types of SLs are produced and two of them are similar to type I and type II semiconductor SLs. Similar to single-layer graphene SLs, extra Dirac points are found in bilayer graphene SLs. Non-ballistic transport is also considered. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000283660000011 |
Publication Date |
2010-11-01 |
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 |
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Edition |
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ISSN |
1364-503X;1471-2962; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.97 |
Times cited |
64 |
Open Access |
|
Notes |
; This work was supported by IMEC, the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP) and the Canadian NSERC through grant no. OGP0121756. ; |
Approved |
Most recent IF: 2.97; 2010 IF: 2.459 |
Call Number |
UA @ lucian @ c:irua:85597 |
Serial |
3023 |
Permanent link to this record |
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Author |
Nourbakhsh, A.; Cantoro, M.; Klekachev, A.V.; Pourtois, G.; Vosch, T.; Hofkens, J.; van der Veen, M.H.; Heyns, M.M.; de Gendt, S.; Sels, B.F. |
Title |
Single layer vs bilayer graphene : a comparative study of the effects of oxygen plasma treatment on their electronic and optical properties |
Type |
A1 Journal article |
Year |
2011 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
Volume |
115 |
Issue |
33 |
Pages |
16619-16624 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
This contribution presents the effects of a mild O2 plasma treatment on the structural, optical, and electrical properties of single-layer (SLG) and bilayer graphene (BLG). Unexpectedly, we observe only photoluminescence in the SLG parts of a graphene flake composed of regions of various thickness upon O2 plasma treatment, whereas the BLG and few-layer graphene (FLG) parts remain optically unchanged. Confirmed with X-ray photoelectron spectroscopy (XPS) that O2 plasma induces epoxide and hydroxyl-like groups in graphene, density functional theory (DFT) calculations are carried out on representative epoxidized and hydroxylated SLG and BLG models to predict density of states (DOS) and band structures. Sufficiently oxidized SLG shows a bandgap and thus loss of semimetallic behavior, while oxidized BLG maintains its semimetallic behavior even at high oxygen density in agreement with the results of the photoluminescence spectroscopy (PL) experiments. DFT calculations confirm that the Fermi velocity in epoxidized BLG is remarkably comparable with that of pristine SLG, pointing to a similarity of electronic band structure. The similarity is also experimentally demonstrated by the electrical characterization of a plasma-treated BLG-FET. As expected from the electronegative oxygen adatoms in the graphene, epoxidized BLG presents conductive features typical of hole doping. Moreover, the electrical characteristics suggest band structures closely related to that of epoxidized graphene while deviating from that of hydroxylated graphene. Finally, upon O2 plasma treatment of BLG, the four-component 2D peak around 2700 cm1 in the Raman spectrum evolves into a single Lorentzian line, very like the 2D peak of pristine SLG. Summarizing, the data in this contribution recommend that a controlled O2 plasma treatment, which is compatible with CMOS process flow in contrast to wet chemical oxidation methods, provides an efficient and valuable technique to exploit the transport properties of the bottom layer of BLG. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000294077000047 |
Publication Date |
2011-06-24 |
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 |
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Edition |
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ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.536 |
Times cited |
46 |
Open Access |
|
Notes |
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Approved |
Most recent IF: 4.536; 2011 IF: 4.805 |
Call Number |
UA @ lucian @ c:irua:91715 |
Serial |
3024 |
Permanent link to this record |
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Author |
Ding, F.; Li, B.; Akopian, N.; Perinetti, U.; Chen, Y.H.; Peeters, F.M.; Rastelli, A.; Zwiller, V.; Schmidt, O.G. |
Title |
Single neutral excitons confined in AsBr3 in situ etched InGaAs quantum rings |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Journal of nanoelectronics and optoelectronics |
Abbreviated Journal |
J Nanoelectron Optoe |
Volume |
6 |
Issue |
1 |
Pages |
51-57 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
We observe the evolution of single self-assembled semiconductor quantum dots into quantum rings during AsBr3 in situ etching. The direct three-dimensional imaging of In(Ga)As nanostructures embedded in GaAs matrix is demonstrated by selective wet chemical etching combined with atomic force microscopy. Single neutral excitons confined in these quantum rings are studied by magneto-photoluminescence. Oscillations in the exciton radiative recombination energy and in the emission intensity are observed under an applied magnetic field. Further, we demonstrate that the period of the oscillations can be tuned by a gate potential that modifies the exciton confinement. The experimental results, combined with calculations, indicate that the exciton Aharonov-Bohm effect may account for the observed effects. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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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 |
000290692200005 |
Publication Date |
2011-04-18 |
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 |
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Edition |
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ISSN |
1555-130X;1555-1318; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
0.497 |
Times cited |
3 |
Open Access |
|
Notes |
; We acknowledge L. P. Kouwenhoven and Z. G. Wang for support, C. C. Bof Bufon, C. Deneke, V. Fomin, A. Govorov, S. Kiravittaya, and Wen-Hao Chang for their help and discussions. We are grateful for the financial support of NWO (VIDI), the CAS-MPG programm, the DFG (FOR730), BMBF (No. 01BM459), NSFC China (60625402), and Flemish Science Foundation (FWO-V1). ; |
Approved |
Most recent IF: 0.497; 2011 IF: 0.556 |
Call Number |
UA @ lucian @ c:irua:90187 |
Serial |
3025 |
Permanent link to this record |
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Author |
Kerkhofs, S.; Leroux, F.; Allouche, L.; Mellaerts, R.; Jammaer, J.; Aerts, A.; Kirschhock, C.E.A.; Magusin, P.C.M.M.; Taulelle, F.; Bals, S.; Van Tendeloo, G.; Martens, J.A.; |
Title |
Single-step alcohol-free synthesis of coreshell nanoparticles of \gamma-casein micelles and silica |
Type |
A1 Journal article |
Year |
2014 |
Publication |
RSC advances |
Abbreviated Journal |
Rsc Adv |
Volume |
4 |
Issue |
49 |
Pages |
25650-25657 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A new, single-step protocol for wrapping individual nanosized β-casein micelles with silica is presented. This biomolecule-friendly synthesis proceeds at low protein concentration at almost neutral pH, and makes use of sodium silicate instead of the common silicon alkoxides. This way, formation of potentially protein-denaturizing alcohols can be avoided. The pH of the citrate-buffered synthesis medium is close to the isoelectric point of β-casein, which favours micelle formation. A limited amount of sodium silicate is added to the protein micelle suspension, to form a thin silica coating around the β-casein micelles. The size distribution of the resulting proteinsilica structures was characterized using DLS and SAXS, as well as 1H NMR DOSY with a dedicated pulsed-field gradient cryo-probehead to cope with the low protein concentration. The degree of silica-condensation was investigated by 29Si MAS NMR, and the nanostructure was revealed by advanced electron microscopy techniques such as ESEM and HAADF-STEM. As indicated by the combined characterization results, a silica shell of 2 nm is formed around individual β-casein micelles giving rise to separate protein coresilica shell nanoparticles of 17 nm diameter. This alcohol-free method at mild temperature and pH is potentially suited for packing protein molecules into bio-compatible silica nanocapsules for a variety of applications in biosensing, therapeutic protein delivery and biocatalysis. |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
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Language |
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Wos |
000338434500025 |
Publication Date |
2014-05-29 |
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 |
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Edition |
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ISSN |
2046-2069; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.108 |
Times cited |
3 |
Open Access |
OpenAccess |
Notes |
Fwo; 262348 Esmi; 335078 Colouratom; ECAS_Sara; (ROMEO:green; preprint:; postprint:can ; pdfversion:can); |
Approved |
Most recent IF: 3.108; 2014 IF: 3.840 |
Call Number |
UA @ lucian @ c:irua:125382 |
Serial |
3027 |
Permanent link to this record |
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Author |
Shi, H.; Frenzel, J.; Martinez, G.T.; Van Rompaey, S.; Bakulin, A.; Kulkova, A.; Van Aert, S.; Schryvers, D. |
Title |
Site occupation of Nb atoms in ternary Ni-Ti-Nb shape memory alloys |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
74 |
Issue |
|
Pages |
85-95 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Nb occupancy in the austenite B2-NiTi matrix and Ti2Ni phase in NiTiNb shape memory alloys was investigated by aberration-corrected scanning transmission electron microscopy and precession electron diffraction. In both cases, Nb atoms were found to prefer to occupy the Ti rather than Ni sites. A projector augmented wave method within density functional theory was used to calculate the atomic and electronic structures of the austenitic B2-NiTi matrix phase and the Ti2Ni precipitates both with and without addition of Nb. The obtained formation energies and analysis of structural and electronic characteristics explain the preference for Ti sites for Nb over Ni sites. |
Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000338621400009 |
Publication Date |
2014-05-08 |
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 |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.301 |
Times cited |
21 |
Open Access |
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Notes |
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Approved |
Most recent IF: 5.301; 2014 IF: 4.465 |
Call Number |
UA @ lucian @ c:irua:118334 |
Serial |
3028 |
Permanent link to this record |
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Author |
Moshnyaga, V.; Sudheendra, L.; Lebedev, O.I.; Koster, S.A.; Gehrke, K.; Shapoval, O.; Belenchuk, A.; Damaschke, B.; Van Tendeloo, G.; Samwer, K. |
Title |
A-site ordering versus electronic inhomogeneity in colossally magnetoresistive manganite films |
Type |
A1 Journal article |
Year |
2006 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
97 |
Issue |
10 |
Pages |
107205,1-4 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
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Address |
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Corporate Author |
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Thesis ![sorted by Thesis field, descending order (down)](img/sort_desc.gif) |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000240384300058 |
Publication Date |
2006-09-08 |
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 |
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Edition |
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ISSN |
0031-9007;1079-7114; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
43 |
Open Access |
|
Notes |
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Approved |
Most recent IF: 8.462; 2006 IF: 7.072 |
Call Number |
UA @ lucian @ c:irua:60786 |
Serial |
3029 |
Permanent link to this record |