| Records |
Author  |
Ludu, A.; Van Deun, J.; Milošević, M.V.; Cuyt, A.; Peeters, F.M. |
| Title |
Analytic treatment of vortex states in cylindrical superconductors in applied axial magnetic field |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Journal of mathematical physics |
Abbreviated Journal |
J Math Phys |
| Volume |
51 |
Issue |
8 |
Pages |
082903,1-082903,29 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We solve the linear GinzburgLandau (GL) equation in the presence of a uniform magnetic field with cylindrical symmetry and we find analytic expressions for the eigenfunctions in terms of the confluent hypergeometric functions. The discrete spectrum results from an implicit equation associated to the boundary conditions and it is resolved in analytic form using the continued fractions formalism. We study the dependence of the spectrum and the eigenfunctions on the sample size and the surface conditions for solid and hollow cylindrical superconductors. Finally, the solutions of the nonlinear GL formalism are constructed as expansions in the linear GL eigenfunction basis and selected by minimization of the free energy. We present examples of vortex states and their energies for different samples in enhancing/suppressing superconductivity surroundings. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000281905000026 |
Publication Date |
2010-08-23 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0022-2488; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.077 |
Times cited |
10 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 1.077; 2010 IF: 1.291 |
| Call Number |
UA @ lucian @ c:irua:84880 |
Serial |
106 |
| Permanent link to this record |
| |
|
| |
| Author |
Ludu, A.; Milošević, M.V.; Peeters, F.M. |
| Title |
Vortex states in axially symmetric superconductors in applied magnetic field |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Sn – 0378-4754 |
Abbreviated Journal |
Math Comput Simulat |
| Volume |
82 |
Issue |
7 |
Pages |
1258-1270 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We solve analytically the linearized Ginzburg-Landau (GL) equation in the presence of an uniform magnetic field with cylindrical boundary conditions. The solution of the non-linear GL equation is provided as an expansion in the basis of linearized solutions. We present examples of the resulting vortex structure for a solid and perforated superconducting cylinder. (C) 2012 IMACS. Published by Elsevier B.V. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000303097000009 |
Publication Date |
2012-02-11 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0378-4754; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.218 |
Times cited |
1 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 1.218; 2012 IF: 0.836 |
| Call Number |
UA @ lucian @ c:irua:98300 |
Serial |
3887 |
| Permanent link to this record |
| |
|
| |
| Author |
Ludu, A. |
| Title |
Fiber bundle description of flow and nonlinear hydrodynamics on circles |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Journal of nonlinear mathematical physics |
Abbreviated Journal |
J Nonlinear Math Phy |
| Volume |
15 |
Issue |
|
Pages |
157-170 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We introduce a differential geometry description of the path lines, stream lines and particles contours in hydrodynamics. We present a generalized form of a Korteweg-de Vries type of equation for the exterior of a circle. Nonlinearities from the boundary conditions, surface tension and the Euler equations are taken into account, but the flow is considered inviscid and irrotational. For the circular case we describe the traveling waves shapes, solitons and the particles trajectories. |
| 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 |
000263517200012 |
Publication Date |
2008-09-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1402-9251;1776-0852; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
0.986 |
Times cited |
1 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 0.986; 2008 IF: 0.760 |
| Call Number |
UA @ lucian @ c:irua:94603 |
Serial |
1189 |
| Permanent link to this record |
| |
|
| |
| Author |
Lucena, D.; Tkachenko, D.V.; Nelissen, K.; Misko, V.R.; Ferreira, W.P.; Farias, G.A.; Peeters, F.M. |
| Title |
Transition from single-file to two-dimensional diffusion of interacting particles in a quasi-one-dimensional channel |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Physical review : E : statistical, nonlinear, and soft matter physics |
Abbreviated Journal |
Phys Rev E |
| Volume |
85 |
Issue |
3:1 |
Pages |
031147-031147,12 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Diffusive properties of a monodisperse system of interacting particles confined to a quasi-one-dimensional channel are studied using molecular dynamics simulations. We calculate numerically the mean-squared displacement (MSD) and investigate the influence of the width of the channel (or the strength of the confinement potential) on diffusion in finite-size channels of different shapes (i.e., straight and circular). The transition from single-file diffusion to the two-dimensional diffusion regime is investigated. This transition [ regarding the calculation of the scaling exponent (alpha) of the MSD <Delta x(2)(t)> proportional to t(alpha)] as a function of the width of the channel is shown to change depending on the channel's confinement profile. In particular, the transition can be either smooth (i.e., for a parabolic confinement potential) or rather sharp (i.e., for a hard-wall potential), as distinct from infinite channels where this transition is abrupt. This result can be explained by qualitatively different distributions of the particle density for the different confinement potentials. |
| Address |
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| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
Woodbury (NY) |
Editor |
|
| Language |
|
Wos |
000302117900003 |
Publication Date |
2012-03-29 |
| 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 |
38 |
Open Access |
|
| Notes |
; This work was supported by CNPq, FUNCAP (Pronex grant), the “Odysseus” program of the Flemish Government, the Flemish Science Foundation (FWO-Vl), the bilateral program between Flanders and Brazil, and the collaborative program CNPq-FWO-Vl. ; |
Approved |
Most recent IF: 2.366; 2012 IF: 2.313 |
| Call Number |
UA @ lucian @ c:irua:97784 |
Serial |
3699 |
| Permanent link to this record |
| |
|
| |
| 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 |
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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 |
| |
|
| |
| Author |
Lucena, D.; Ferreira, W.P.; Munarin, F.F.; Farias, G.A.; Peeters, F.M. |
| Title |
Tunable diffusion of magnetic particles in a quasi-one-dimensional channel |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : E : statistical, nonlinear, and soft matter physics |
Abbreviated Journal |
Phys Rev E |
| Volume |
87 |
Issue |
1 |
Pages |
012307-12309 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The diffusion of a system of ferromagnetic dipoles confined in a quasi-one-dimensional parabolic trap is studied using Brownian dynamics simulations. We show that the dynamics of the system is tunable by an in-plane external homogeneous magnetic field. For a strong applied magnetic field, we find that the mobility of the system, the exponent of diffusion, and the crossover time among different diffusion regimes can be tuned by the orientation of the magnetic field. For weak magnetic fields, the exponent of diffusion in the subdiffusive regime is independent of the orientation of the external field. DOI: 10.1103/PhysRevE.87.012307 |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
American Institute of Physics |
Place of Publication |
Woodbury (NY) |
Editor |
|
| Language |
|
Wos |
000314152300005 |
Publication Date |
2013-01-15 |
| 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 |
11 |
Open Access |
|
| Notes |
; This work was supported by CNPq, CAPES, FUNCAP (Pronex grant), the Flemish Science Foundation (FWO-Vl), the bilateral program between Flanders and Brazil, the collaborative program CNPq – FWO-Vl, and the Brazilian program Science Without Borders (CsF). Discussions with V. R. Misko are gratefully acknowledged. ; |
Approved |
Most recent IF: 2.366; 2013 IF: 2.326 |
| Call Number |
UA @ lucian @ c:irua:110089 |
Serial |
3739 |
| Permanent link to this record |
| |
|
| |
| Author |
Lubyshev, D.; Fastenau, J.M.; Fang, X.-M.; Wu, Y.; Doss, C.; Snyder, A.; Liu, W.K.; Lamb, M.S.M.; Bals, S.; Song, C. |
| Title |
Comparison of As- and P-based metamorphic buffers for high performance InP heterojunction bipolar transistor and high electron mobility transistor applications |
Type |
A1 Journal article |
| Year |
2004 |
Publication |
Journal of vacuum science & technology. B. Microelectronics and nanometer structures. Processing, measurement and phenomena |
Abbreviated Journal |
|
| Volume |
22 |
Issue |
3 |
Pages |
1565-1569 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Metamorphic buffers (M-buffers) consisting of graded InAlAs or bulk InP were employed for the production of InP-based epiwafers on GaAs substrates by molecular-beam epitaxy. The graded InAlAs is the standard for production metamorphic high electron mobility transistors (M-HEMTs), while the bulk InP offers superior thermal properties for higher current density circuits. The surface morphology and crystal structure of the two M-buffers showed different relaxation mechanisms. The graded InAlAs gave a cross-hatched pattern with nearly full relaxation and very effective dislocation filtering, while the bulk InP had a uniform isotropic surface with dislocations propagating further up towards the active layers. Both types of M-buffers had atomic force microscopy root-mean-square roughness values around 2030 Å. The Hall transport properties of high electron mobility transistors (HEMTs) grown on the InAlAs M-buffer, and a baseline HEMT grown lattice matched on InP, both had room-temperature mobilities >10 000 cm2/V s, while the M-HEMT on the InP M-buffer showed a decrease to 9000 cm2/V s. Similarly, the dc parameters of a double heterojunction bipolar transistor (DHBT) grown on the InAlAs M-buffer were much closer to the baseline heterojunction bipolar transistor than a DHBT grown on the InP M-buffer. A high breakdown voltage of 11.3 V was achieved on an M-DHBT with the InAlAs M-buffer. We speculate that the degradation in device characteristics on the InP M-buffer was related to the incomplete dislocation filtering. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Woodbury, N.Y. |
Editor |
|
| Language |
|
Wos |
000222481400141 |
Publication Date |
2004-07-08 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0734-211X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
25 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:87596 |
Serial |
427 |
| Permanent link to this record |
| |
|
| |
| Author |
Lubk, A.; Vogel, K.; Wolf, D.; Krehl, J.; Röder, F.; Clark, L.; Guzzinati, G.; Verbeeck, J. |
| Title |
Fundamentals of Focal Series Inline Electron Holography |
Type |
H1 Book chapter |
| Year |
2016 |
Publication |
Advances in imaging and electron physics
T2 – Advances in imaging and electron physics / Hawkes, P.W. [edit.] |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
105-147 |
| Keywords |
H1 Book chapter; Electron microscopy for materials research (EMAT) |
| Abstract |
|
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
Elsevier BV |
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
|
Publication Date |
2016-09-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1076-5670; http://id.crossref.org/isbn/9780128048115 |
ISBN |
9780128048115 |
Additional Links |
UA library record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
L.C., G.G., and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant no. 278510 VORTEX. A.L., K.V., J. K., D.W., and F.R. acknowledge funding from the DIP of the Deutsche Forschungsgesellschaft.; ECASJO_; |
Approved |
Most recent IF: NA |
| Call Number |
EMAT @ emat @ c:irua:140097UA @ admin @ c:irua:140097 |
Serial |
4419 |
| Permanent link to this record |
| |
|
| |
| Author |
Lubk, A.; Javon, E.; Cherkashin, N.; Reboh, S.; Gatel, C.; Hytch, M. |
| Title |
Dynamic scattering theory for dark-field electron holography of 3D strain fields |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
136 |
Issue |
|
Pages |
42-49 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Dark-held electron holography maps strain in crystal lattices into reconstructed phases over large fields of view. Here we investigate the details of the lattice strain-reconstructed phase relationship by applying dynamic scattering theory both analytically and numerically. We develop efficient analytic linear projection rules for 3D strain fields, facilitating a straight-forward calculation of reconstructed phases from 3D strained materials. They are used in the following to quantify the influence of various experimental parameters like strain magnitude, specimen thickness, excitation error and surface relaxation. (C) 2013 Elsevier B.V. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000327884700006 |
Publication Date |
2013-07-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
18 |
Open Access |
|
| Notes |
European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative (Reference312483 – ESTEEM2); esteem2_jra4 |
Approved |
Most recent IF: 2.843; 2014 IF: 2.436 |
| Call Number |
UA @ lucian @ c:irua:112836 |
Serial |
766 |
| Permanent link to this record |
| |
|
| |
| Author |
Lubk, A.; Guzzinati, G.; Börrnert, F.; Verbeeck, J. |
| Title |
Transport of intensity phase retrieval of arbitrary wave fields including vortices |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
| Volume |
111 |
Issue |
17 |
Pages |
173902-173905 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The phase problem can be considered as one of the cornerstones of quantum mechanics intimately connected to the detection process and the uncertainty relation. The latter impose fundamental limits on the manifold phase reconstruction schemes invented to date, in particular, at small magnitudes of the quantum wave. Here, we show that a rigorous solution of the transport of intensity reconstruction (TIE) scheme in terms of a linear elliptic partial differential equation for the phase provides reconstructions even in the presence of wave zeros if particular boundary conditions are given. We furthermore discuss how partial coherence hampers phase reconstruction and show that a modified version of the TIE reconstructs the curl-free current density at arbitrary (in)coherence. Our results open the way for TIE-based phase retrieval of arbitrary wave fields, eventually containing zeros such as phase vortices. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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| Language |
|
Wos |
000326148400006 |
Publication Date |
2013-10-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| 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 |
40 |
Open Access |
|
| Notes |
Esteem2; Vortex; esteem2ta ECASJO; |
Approved |
Most recent IF: 8.462; 2013 IF: 7.728 |
| Call Number |
UA @ lucian @ c:irua:111093 |
Serial |
3726 |
| Permanent link to this record |
| |
|
| |
| Author |
Lubk, A.; Clark, L.; Guzzinati, G.; Verbeeck, J. |
| Title |
Topological analysis of paraxially scattered electron vortex beams |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : A : atomic, molecular and optical physics |
Abbreviated Journal |
Phys Rev A |
| Volume |
87 |
Issue |
3 |
Pages |
033834-33838 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We investigate topological aspects of subnanometer electron vortex beams upon elastic propagation through atomic scattering potentials. Two main aspects can be distinguished: (i) significantly reduced delocalization compared to a similar nonvortex beam if the beam centers on an atomic column and (ii) site symmetry dependent splitting of higher-order vortex beams. Furthermore, the results provide insight into the complex vortex line fabric within the elastically scattered wave containing characteristic vortex loops predominantly attached to atomic columns and characteristic twists of vortex lines around atomic columns. DOI: 10.1103/PhysRevA.87.033834 |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
| Language |
|
Wos |
000316790600011 |
Publication Date |
2013-03-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1050-2947;1094-1622; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.925 |
Times cited |
26 |
Open Access |
|
| Notes |
Countatoms; Vortex; Esteem2; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 2.925; 2013 IF: 2.991 |
| Call Number |
UA @ lucian @ c:irua:108496 |
Serial |
3673 |
| Permanent link to this record |
| |
|
| |
| Author |
Lubk, A.; Béché, A.; Verbeeck, J. |
| Title |
Electron Microscopy of Probability Currents at Atomic Resolution |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
| Volume |
115 |
Issue |
115 |
Pages |
176101 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Atomic resolution transmission electron microscopy records the spatially resolved scattered electron density to infer positions, density, and species of atoms. These data are indispensable for studying the relation between structure and properties in solids. Here, we show how this signal can be augmented by the lateral probability current of the scattered electrons in the object plane at similar resolutions and fields of view. The currents are reconstructed from a series of three atomic resolution TEM images recorded under a slight difference of perpendicular line foci. The technique does not rely on the coherence of the electron beam and can be used to reveal electric, magnetic, and strain fields with incoherent electron beams as well as correlations in inelastic transitions, such as electron magnetic chiral dichroism. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000363023700011 |
Publication Date |
2015-10-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| 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 |
12 |
Open Access |
|
| Notes |
J. V. and A. B. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX. The Qu-Ant- EM microscope was partly funded by the Hercules fund from the Flemish Government. All authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483- ESTEEM2. J. V. acknowledges funding from the FWO under Project No. G.0044.13N.; esteem2jra2; esteem2jra3 ECASJO_; |
Approved |
Most recent IF: 8.462; 2015 IF: 7.512 |
| Call Number |
c:irua:129190 c:irua:129190UA @ admin @ c:irua:129190 |
Serial |
3954 |
| Permanent link to this record |
| |
|
| |
| Author |
Lu, Y.; Liu, Y.-X.; He, L.; Wang, L.-Y.; Liu, X.-L.; Liu, J.-W.; Li, Y.-Z.; Tian, G.; Zhao, H.; Yang, X.-H.; Liu, J.; Janiak, C.; Lenaerts, S.; Yang, X.-Y.; Su, B.-L. |
| Title |
Interfacial co-existence of oxygen and titanium vacancies in nanostructured TiO₂ for enhancement of carrier transport |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
| Volume |
12 |
Issue |
15 |
Pages |
8364-8370 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
The interfacial co-existence of oxygen and metal vacancies in metal oxide semiconductors and their highly efficient carrier transport have rarely been reported. This work reports on the co-existence of oxygen and titanium vacancies at the interface between TiO2 and rGO via a simple two-step calcination treatment. Experimental measurements show that the oxygen and titanium vacancies are formed under 550 degrees C/Ar and 350 degrees C/air calcination conditions, respectively. These oxygen and titanium vacancies significantly enhance the transport of interfacial carriers, and thus greatly improve the photocurrent performances, the apparent quantum yield, and photocatalysis such as photocatalytic H-2 production from water-splitting, photocatalytic CO2 reduction and photo-electrochemical anticorrosion of metals. A new “interfacial co-existence of oxygen and titanium vacancies” phenomenon, and its characteristics and mechanism are proposed at the atomic-/nanoscale to clarify the generation of oxygen and titanium vacancies as well as the interfacial carrier transport. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000529201500029 |
Publication Date |
2020-02-26 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2040-3364 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.7 |
Times cited |
4 |
Open Access |
|
| Notes |
; This work was supported by the National Natural Science Foundation of China (51861135313, U1663225, U1662134, and 51472190), the International Science & Technology Cooperation Program of China (2015DFE52870), the Program for Changjiang Scholars and Innovative Research Team in University (IRT_15R52), the Fundamental Research Funds for the Central Universities (19lgpy113 and 19lgzd16), the Jilin Province Science and Technology Development Plan (20180101208JC) and the Hubei Provincial Natural Science Foundation of China (2016CFA033). ; |
Approved |
Most recent IF: 6.7; 2020 IF: 7.367 |
| Call Number |
UA @ admin @ c:irua:169578 |
Serial |
6550 |
| Permanent link to this record |
| |
|
| |
| Author |
Lu, Y.; Liu, X.-L.; He, L.; Zhang, Y.-X.; Hu, Z.-Y.; Tian, G.; Cheng, X.; Wu, S.-M.; Li, Y.-Z.; Yang, X.-H.; Wang, L.-Y.; Liu, J.-W.; Janiak, C.; Chang, G.-G.; Li, W.-H.; Van Tendeloo, G.; Yang, X.-Y.; Su, B.-L. |
| Title |
Spatial heterojunction in nanostructured TiO₂ and its cascade effect for efficient photocatalysis |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Nano Letters |
Abbreviated Journal |
Nano Lett |
| Volume |
20 |
Issue |
5 |
Pages |
3122-3129 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
A highly efficient photoenergy conversion is strongly dependent on the cumulative cascade efficiency of the photogenerated carriers. Spatial heterojunctions are critical to directed charge transfer and, thus, attractive but still a challenge. Here, a spatially ternary titanium-defected TiO2@carbon quantum dots@reduced graphene oxide (denoted as V-Ti@CQDs@rGO) in one system is shown to demonstrate a cascade effect of charges and significant performances regarding the photocurrent, the apparent quantum yield, and photocatalysis such as H-2 production from water splitting and CO2 reduction. A key aspect in the construction is the technologically irrational junction of Ti-vacancies and nanocarbons for the spatially inside-out heterojunction. The new “spatial heterojunctions” concept, characteristics, mechanism, and extension are proposed at an atomic- nanoscale to clarify the generation of rational heterojunctions as well as the cascade electron transfer. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000535255300024 |
Publication Date |
2020-04-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1530-6984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
10.8 |
Times cited |
5 |
Open Access |
Not_Open_Access |
| Notes |
; This work was supported by the joint National Natural Science Foundation of China-Deutsche Forschungsgemeinschaft (NSFC-DFG) project (NSFC grant 51861135313, DFG JA466/39-1), Fundamental Research Funds for the Central Universities (19lgpy113, 19lgzd16), Program for Changjiang Scholars and Innovative Research Team in University (IRT_15R52) and Jilin Province Science and Technology Development Plan (20180101208JC). ; |
Approved |
Most recent IF: 10.8; 2020 IF: 12.712 |
| Call Number |
UA @ admin @ c:irua:170263 |
Serial |
6608 |
| Permanent link to this record |
| |
|
| |
| Author |
Lu, Y.; Cheng, X.; Tian, G.; Zhao, H.; He, L.; Hu, J.; Wu, S.-M.; Dong, Y.; Chang, G.-G.; Lenaerts, S.; Siffert, S.; Van Tendeloo, G.; Li, Z.-F.; Xu, L.-L.; Yang, X.-Y.; Su, B.-L. |
| Title |
Hierarchical CdS/m-TiO 2 /G ternary photocatalyst for highly active visible light-induced hydrogen production from water splitting with high stability |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Nano energy |
Abbreviated Journal |
Nano Energy |
| Volume |
47 |
Issue |
|
Pages |
8-17 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
Hierarchical semiconductors are the most important photocatalysts, especially for visible light-induced hydrogen production from water splitting. We demonstrate herein a hierarchical electrostatic assembly approach to hierarchical CdS/m-TiO2/G ternary photocatalyst, which exhibits high photoactivity and excellent photostability (more than twice the activity of pure CdS while 82% of initial photoactivity remained after 15 recycles during 80 h irradiation). The ternary nanojunction effect of the photocatalyst has been investigated from orbitals hybrid, bonding energy to atom-stress distortion and nano-interface fusion. And a coherent separation mechanism of charge carriers in the ternary system has been proposed at an atomic/nanoscale. This work offers a promising way to inhibit the photocorrosion of CdS and, more importantly, provide new insights for the design of ternary nanostructured photocatalysts with an ideal heterojunction. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000430057000002 |
Publication Date |
2018-02-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2211-2855 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
12.343 |
Times cited |
58 |
Open Access |
Not_Open_Access |
| Notes |
This work supported by National Key R&D Program of China (2017YFC1103800), Program for Changjiang Scholars and Innovative Research Team in University (IRT_15R52), National Natural Science Foundation of China (U1663225, U1662134, 51472190, 51611530672, 21711530705, 51503166, 51602236, 21706199), International Science & Technology Cooperation Program of China (2015DFE52870), Natural Science Foundation of Hubei Province (2016CFA033, 2017CFB487), Open 22 Project Program of State Key Laboratory of Petroleum Pollution Control (PPC2016007) CNPC Research Institute of Safety and Environmental Technology., China Postdoctoral Science Foundation (2016M592400), Fundamental Research Funds for the Central Universities (WUT: 2017IVB012). |
Approved |
Most recent IF: 12.343 |
| Call Number |
EMAT @ lucian @c:irua:150720 |
Serial |
4925 |
| Permanent link to this record |
| |
|
| |
| Author |
Lu, Y.-G.; Verbeeck, J.; Turner, S.; Hardy, A.; Janssens, S.D.; De Dobbelaere, C.; Wagner, P.; Van Bael, M.K.; Van Tendeloo, G. |
| Title |
Analytical TEM study of CVD diamond growth on TiO2 sol-gel layers |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Diamond and related materials |
Abbreviated Journal |
Diam Relat Mater |
| Volume |
23 |
Issue |
|
Pages |
93-99 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The early growth stages of chemical vapor deposition (CVD) diamond on a solgel TiO2 film with buried ultra dispersed diamond seeds (UDD) have been studied. In order to investigate the diamond growth mechanism and understand the role of the TiO2 layer in the growth process, high resolution transmission electron microscopy (HRTEM), energy-filtered TEM and electron energy loss spectroscopy (EELS) techniques were applied to cross sectional diamond film samples. We find evidence for the formation of TiC crystallites inside the TiO2 layer at different diamond growth stages. However, there is no evidence that diamond nucleation starts from these crystallites. Carbon diffusion into the TiO2 layer and the chemical bonding state of carbon (sp2/sp3) were both extensively investigated. We provide evidence that carbon diffuses through the TiO2 layer and that the diamond seeds partially convert to amorphous carbon during growth. This carbon diffusion and diamond to amorphous carbon conversion make the seed areas below the TiO2 layer grow and bend the TiO2 layer upwards to form the nucleation center of the diamond film. In some of the protuberances a core of diamond seed remains, covered by amorphous carbon. It is however unlikely that the remaining seeds are still active during the growth process. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000302887600017 |
Publication Date |
2012-01-26 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0925-9635; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.561 |
Times cited |
16 |
Open Access |
|
| Notes |
Iap; Esteem 026019; Fwo |
Approved |
Most recent IF: 2.561; 2012 IF: 1.709 |
| Call Number |
UA @ lucian @ c:irua:95037UA @ admin @ c:irua:95037 |
Serial |
111 |
| Permanent link to this record |
| |
|
| |
| Author |
Lu, Y.-G.; Turner, S.; Verbeeck, J.; Janssens, S.D.; Wagner, P.; Haenen, K.; Van Tendeloo, G. |
| Title |
Direct visualization of boron dopant distribution and coordination in individual chemical vapor deposition nanocrystalline B-doped diamond grains |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
101 |
Issue |
4 |
Pages |
041907 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The boron dopant distribution in individual heavily boron-doped nanocrystalline diamond film grains, with sizes ranging from 100 to 350nm in diameter, has been studied using a combination of high resolution annular dark field scanning transmission electron microscopy and spatially resolved electron energy-loss spectroscopy. Using these tools, the boron distribution and local boron coordination have been determined. Quantification results reveal embedding of B dopants in the diamond lattice, and a preferential enrichment of boron at defective areas and twin boundaries. Coordination mapping reveals a distinct difference in coordination of the B dopants in “pristine” diamond areas and in defective regions. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4738885] |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000306944700030 |
Publication Date |
2012-07-25 |
| 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 |
59 |
Open Access |
|
| Notes |
This work was performed within the framework of an IAP P6/42 project of the Belgian government. The authors acknowledge financial support from the Fund for Scientific Research Flanders (FWO) under Contract No. G.0568.10N. The authors acknowledge support from the European Union under a Contract from an Integrated Infrastructure Initiative (Reference 262348 ESMI), the Marie Curie ITN “MATCON” (PITN-GA-2009-238201), and the Collaborative Project “DINAMO” (No. 245122). G.V.T. and J.V. acknowledge the ERC Grant N246791-COUNTATOMS and ERC Starting Grant 278510 VORTEX. S.T. gratefully acknowledges financial support from the FWO. The microscope used in this study was partially financed by the Hercules Foundation of the Flemish Government. ECASJO_; |
Approved |
Most recent IF: 3.411; 2012 IF: 3.794 |
| Call Number |
UA @ lucian @ c:irua:100468UA @ admin @ c:irua:100468 |
Serial |
726 |
| Permanent link to this record |
| |
|
| |
| Author |
Lu, Y.-G.; Turner, S.; Verbeeck, J.; Janssens, S.D.; Haenen, K.; Van Tendeloo, G. |
| Title |
Local bond length variations in boron-doped nanocrystalline diamond measured by spatially resolved electron energy-loss spectroscopy |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
103 |
Issue |
3 |
Pages |
032105-5 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Variations in local bond length and coordination in boron-doped nanocrystalline diamond (NCD) films have been studied through changes in the fine structure of boron and carbon K-edges in electron energy-loss spectra, acquired in a scanning transmission electron microscope. The presence of high concentrations of B in pristine diamond regions and enrichment of B at defects in single NCD grains is demonstrated. Local bond length variations are evidenced through an energy shift of the carbon 1s → σ* edge at B-rich defective regions within single diamond grains, indicating an expansion of the diamond bond length at sites with local high B content. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000322146300049 |
Publication Date |
2013-07-17 |
| 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 |
15 |
Open Access |
|
| Notes |
Iap P6/42; Fwo G056810n; 262348 Esmi; 246791 Countatoms; 278510 Vortex; Fwo ECASJO_; |
Approved |
Most recent IF: 3.411; 2013 IF: 3.515 |
| Call Number |
UA @ lucian @ c:irua:109210UA @ admin @ c:irua:109210 |
Serial |
1824 |
| Permanent link to this record |
| |
|
| |
| Author |
Lu, Y.-G.; Turner, S.; Ekimov, E.A.; Verbeeck, J.; Van Tendeloo, G. |
| Title |
Boron-rich inclusions and boron distribution in HPHT polycrystalline superconducting diamond |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
| Volume |
86 |
Issue |
86 |
Pages |
156-162 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Polycrystalline boron-doped superconducting diamond, synthesized at high pressure and high temperature (HPHT) via a reaction of a single piece of crystalline boron with monolithic graphite, has been investigated by analytical transmission electron microscopy. The local boron distribution and boron environment have been studied by a combination of (scanning) transmission electron microscopy ((S)TEM) and spatially resolved electron energy-loss spectroscopy (EELS). High resolution TEM imaging and EELS elemental mapping have established, for the first time, the presence of largely crystalline diamond-diamond grain boundaries within the material and have evidenced the presence of substitutional boron dopants within individual diamond grains. Confirmation of the presence of substitutional B dopants has been obtained through comparison of acquired boron K-edge EELS fine structures with known references. This confirmation is important to understand the origin of superconductivity in polycrystalline B-doped diamond. In addition to the substitutional boron doping, boron-rich inclusions and triple-points, both amorphous and crystalline, with chemical compositions close to boron carbide B4C, are evidenced. (C) 2015 Elsevier Ltd. All rights reserved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000352922700019 |
Publication Date |
2015-01-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0008-6223; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.337 |
Times cited |
20 |
Open Access |
|
| Notes |
FWO; 246791 COUNTATOMS; 278510 VORTEX; Hercules ECASJO_; |
Approved |
Most recent IF: 6.337; 2015 IF: 6.196 |
| Call Number |
c:irua:125994UA @ admin @ c:irua:125994 |
Serial |
250 |
| Permanent link to this record |
| |
|
| |
| Author |
Lu, Y. |
| Title |
Electron energy-loss spectroscopy (EELS) characterization of diamond and related materials |
Type |
Doctoral thesis |
| Year |
2013 |
Publication |
|
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
|
| Keywords |
Doctoral thesis; Electron microscopy for materials research (EMAT) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Antwerpen |
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:111231 |
Serial |
932 |
| Permanent link to this record |
| |
|
| |
| Author |
Lu, X.P.; Bruggeman, P.J.; Reuter, S.; Naidis, G.; Bogaerts, A.; Laroussi, M.; Keidar, M.; Robert, E.; Pouvesle, J.-M.; Liu, D.W.; Ostrikov, K.(K.) |
| Title |
Grand challenges in low temperature plasmas |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Frontiers in physics |
Abbreviated Journal |
|
| Volume |
10 |
Issue |
|
Pages |
1040658-12 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
Low temperature plasmas (LTPs) enable to create a highly reactive environment at near ambient temperatures due to the energetic electrons with typical kinetic energies in the range of 1 to 10 eV (1 eV = 11600K), which are being used in applications ranging from plasma etching of electronic chips and additive manufacturing to plasma-assisted combustion. LTPs are at the core of many advanced technologies. Without LTPs, many of the conveniences of modern society would simply not exist. New applications of LTPs are continuously being proposed. Researchers are facing many grand challenges before these new applications can be translated to practice. In this paper, we will discuss the challenges being faced in the field of LTPs, in particular for atmospheric pressure plasmas, with a focus on health, energy and sustainability. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000878212000001 |
Publication Date |
2022-10-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2296-424x |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
3.1 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 3.1 |
| Call Number |
UA @ admin @ c:irua:192173 |
Serial |
7267 |
| Permanent link to this record |
| |
|
| |
| Author |
Lu, W.; Cui, W.; Zhao, W.; Lin, W.; Liu, C.; Van Tendeloo, G.; Sang, X.; Zhao, W.; Zhang, Q. |
| Title |
In situ atomistic insight into magnetic metal diffusion across Bi0.5Sb1.5Te3 quintuple layers |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Advanced Materials Interfaces |
Abbreviated Journal |
Adv Mater Interfaces |
| Volume |
|
Issue |
|
Pages |
2102161 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Diffusion and occupancy of magnetic atoms in van der Waals (VDW) layered materials have significant impact on applications such as energy storage, thermoelectrics, catalysis, and topological phenomena. However, due to the weak VDW bonding, most research focus on in-plane diffusion within the VDW gap, while out-of-plane diffusion has rarely been reported. Here, to investigate out-of-plane diffusion in VDW-layered Bi2Te3-based alloys, a Ni/Bi0.5Sb1.5Te3 heterointerface is synthesized by depositing magnetic Ni metal on a mechanically exfoliated Bi0.5Sb1.5Te3 (0001) substrate. Diffusion of Ni atoms across the Bi0.5Sb1.5Te3 quintuple layers is directly observed at elevated temperatures using spherical-aberration-corrected scanning transmission electron microscopy (STEM). Density functional theory calculations demonstrate that the diffusion energy barrier of Ni atoms is only 0.31-0.45 eV when they diffuse through Te-3(Bi, Sb)(3) octahedron chains. Atomic-resolution in situ STEM reveals that the distortion of the Te-3(Bi, Sb)(3) octahedron, induced by the Ni occupancy, drives the formation of coherent NiM (M = Bi, Sb, Te) at the heterointerfaces. This work can lead to new strategies to design novel thermoelectric and topological materials by introducing magnetic dopants to VDW-layered materials. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000751742300001 |
Publication Date |
2022-02-07 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2196-7350 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
5.4 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 5.4 |
| Call Number |
UA @ admin @ c:irua:186421 |
Serial |
6960 |
| Permanent link to this record |
| |
|
| |
| Author |
Lu, Q. |
| Title |
Precipitation behavior and heat resistance properties of Al-Cu-Mg-Ag-(Si) alloy |
Type |
Doctoral thesis |
| Year |
2024 |
Publication |
|
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
VIII, 212 p. |
| Keywords |
Doctoral thesis; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
With the rapid increase in the speed of new-generation aerospace vehicles, conventional heat-resistant aluminum alloys cannot meet the long-term service of the equipment. Therefore, the development of new high-strength heat-resistant aluminum alloys is of great strategic for the sustainable and high-quality development of industries. Al-Cu-Mg-Ag alloy is an age-hardenable heat-resistant aluminum alloy and has high strength and heat resistance. The addition of alloying elements such as Si and Sc to Al-Cu-Mg-Ag alloy introduces a competitive relationship among the σ-Al5Cu6Mg2, θ′-Al2Cu, and Ω phases. Therefore, a systematic investigation of precipitation behavior and heat resistance of Al-Cu-Mg-Ag-(Si) is essential for guiding the design of high-strength heat-resistant aluminum alloys. Combined characterization testing methods such as scanning electron microscopy, transmission electron microscopy, atom probe tomography, microhardness testing, and tensile testing with simulation calculation methods such as calculation of phase diagram, first-principles calculations, and Ab initio molecular dynamics, the effects of heat treatment processes and element content on the precipitation behavior, mechanical properties, and heat resistance of Al-Cu-Mg-Ag-(Si) alloys were systematically investigated. Furthermore, a multiple interface segregation structure was constructed at the θ′/Al interface, and a new Al-Cu-Mg-Ag-Si-Sc alloy with synergistically improved strength and heat resistance was developed. The main conclusions are as follows: (1) Based on the Kampmann-Wagner-Numerical theory, the relationship between the coarsening rate of the Ω phase and the aging process was analyzed, revealing for the first time that the critical size of Ω phase ( ) under thermal exposure temperature was the key factor determining the coarsening rate of Ω phase during long time thermal exposure heat treatment. After artificial ageing, when the size of Ω phase was smaller than the critical size , the dissolution of smaller Ω phase leaded to a rapid decrease in the number density of Ω phases, thereby reducing the heat resistance of the alloy. When the size of Ω phase was greater than or equal to the critical size , the coarsening rate of Ω phase was consistent, but a larger initial size would result in a larger final size after long-term thermal exposure. Therefore, the closer the size of Ω phase in the alloy is to the critical size under heat exposure temperature, the better the heat resistance of the alloy. (2) A concept of constructing a multiple interface segregation structure at the precipitate/matrix interface was proposed, and based on this concept, a multiple interface segregation structure containing the C/L-AlMgSiCu interfacial phase, newly discovered χ-AgMg interfacial phase, and Sc segregation layer was successfully constructed at the θ′/Al interface. The existence of the multiple interface segregation structure ensured that the designed Al-Cu-Mg-Ag-Si-Sc alloy maintains a yield strength of 400 MPa after thermal exposure at 200 C for 100 h, with a strength retention rate of 97%, creating a new record for the synergistic improvement of strength and heat resistance in aluminum alloys. In addition, combining transmission electron microscopy ex-situ/in-situ characterization with first-principles calculations, it is shown that the χ-AgMg interface phase will be destroyed due to the diffusion of the outer Ag layer during thermal exposure, and gradually dissolve into the matrix, but it can still delay the coarsening behavior of θ′-Al2Cu phase. (3) The criteria for determining whether Ω phase can precipitate are updated in Al-Cu-Mg-Ag-Si alloys with low Mg/Si ratio based on phase diagram thermodynamic calculations and multi-scale structural characterization. When W(Mg)/W(Si) > 1.4 and X(Ag)/X(Mgexcess) > 1, Ω phase can precipitate in Al-Cu-Mg-Ag-Si alloys, where X(Mgexcess) represents the atomic percentage of residual Mg elements after the formation of the AlMgSiCu quaternary precipitate phase C/L phase in the supersaturated solid solution, and the W(Mg) is the mass fraction of Mg in the supersaturated solid solution before artificial ageing. (4) The effects of alloy element content on precipitation behavior and heat resistance of Al-Cu-Mg-Ag-Si alloys were systematically analyzed. Critical conditions for the precipitation of σ-Al5Cu6Mg2 and Ω phase in Al-Cu-Mg-Ag-Si alloys are revealed. Based on calculation of phase diagram results, the conditions for precipitating σ-Al5Cu6Mg2 phase in the alloy are: ① W(Mg)/W(Si) > 1.8; ② W(Cu) > 2.7W(Mg) – 5W(Si). When W(Mg)/W(Si) < 1.8, the alloy is mainly precipitated with C/L/Q′-AlMgSiCu. When W(Cu) < 2.7W(Mg) – 5W(Si), the alloy will generate GPB zone. In addition, W(Ag)/W(Si) > 4 is the critical condition which the Ω phase can the main precipitates in Al-Cu-Mg-Ag-Si alloys. Furthermore, the correlation between precipitate types and heat resistance was summarized, showing that Al-Cu-Mg-Ag-(Si) alloys with Ω phase as the main strengthening phase are more suitable for the preparation of structures with short service time but high temperature, while Al-Cu-Mg-Ag-(Si) alloys with low Mg content and multiple segregation structures are more suitable for structures requiring long-term service at medium to high temperatures. This study, for the first time, combines calculation of phase diagram with multi-scale microstructure characterization, systematically unraveling the effects of element content on precipitation behavior, strength, and heat resistance of Al-Cu-Mg-Ag-(Si) alloys. In addition, a concept of constructing a multiple interface segregation structure at the precipitate/matrix interface was proposed to synergistically improve alloy strength and heat resistance. This work provides theoretical guidance for optimizing the composition and processing of Al-Cu-Mg-Ag-(Si) alloy and regulating the microstructure. Furthermore, it also offers new ideas and theoretical guidance for the development of novel high-strength heat-resistant alloys in other systems. |
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Additional Links |
UA library record |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:206180 |
Serial |
9167 |
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| |
| Author |
Lu, J.B.; Shi, H.; Sedlakova-Ignacova, S.; Espinoza, R.; Kopeček, J.; Sittner, P.; Bártová, B.; Schryvers, D. |
| Title |
Microstructure and precipitates in annealed Co38Ni33Al29 ferromagnetic shape memory alloy |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Journal of alloys and compounds |
Abbreviated Journal |
J Alloy Compd |
| Volume |
572 |
Issue |
|
Pages |
5-10 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Transmission electron microscopy was performed to investigate the microstructure and precipitates in the annealed Co38Ni33Al29 ferromagnetic shape memory alloy. Apart from the dendritic secondary phase in the austenite matrix, micron-sized (up to 100 μm) fcc-based precipitates with partial γ′ L12 ordering and containing none, one or three {1 1 1}p parallel twin planes were found. The orientation relationship between the precipitates and matrix was found to be KurdjumovSachs. STEMEDX analysis indicates that twinned and non-twinned precipitates are Co-rich and Al- and Ni-deficient with respect to the matrix and with a lower Co/Al ratio for the latter. The 3D morphologies of precipitates were reconstructed with focused ion beam/scanning electron microscope dual-beam slice-and-view imaging, showing that the single {1 1 1}p plane twinned precipitates have a plate-like shape while the non-twinned precipitates are lath-like and often bent. |
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Thesis |
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Place of Publication |
Amsterdam |
Editor |
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Wos |
000319209600002 |
Publication Date |
2013-04-02 |
| 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 |
0925-8388; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.133 |
Times cited |
10 |
Open Access |
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| Notes |
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Approved |
Most recent IF: 3.133; 2013 IF: 2.726 |
| Call Number |
UA @ lucian @ c:irua:107914 |
Serial |
2058 |
| Permanent link to this record |
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| |
| Author |
Lu, J.B.; Schryvers, D. |
| Title |
Microstructure and phase composition characterization in a Co38Ni33Al29 ferromagnetic shape memory alloy |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Materials characterization |
Abbreviated Journal |
Mater Charact |
| Volume |
118 |
Issue |
118 |
Pages |
9-13 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Transmission electron microscopy was performed to investigate the microstructures of a secondary phase and its surrounding matrix in a Co38Ni33Al29 ferromagnetic shape memory alloy. The secondary phase shows a γ′ L12 structure exhibiting a dendritic morphology with enclosed B2 austenite regions while the matrix shows the L10 martensitic structure. A secondary phase-austenite-martensite sandwich structure with residual austenite ranging from several hundred nanometers to several micrometers wide is observed at the secondary phase-martensite interface due to the depletion of Co and enrichment of Al in the chemical gradient zone and the effect of the strong martensitic start temperature dependency of the element concentrations. The crystallographic orientation relationship of the secondary phase and the B2 austenite fits the Kurdjumov-Sachs relationship. |
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Thesis |
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Place of Publication |
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Editor |
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Wos |
000383292000002 |
Publication Date |
2016-05-04 |
| 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 |
1044-5803 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.714 |
Times cited |
3 |
Open Access |
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| Notes |
J.B. Lu thanks the Belgian Science Ministry (Belspo) for support of his post-doctoral research stay at EMAT. We thank S. Sedlakova-Ignacova from the Institute of Physics in Prague, Czech Republic, for providing samples. |
Approved |
Most recent IF: 2.714 |
| Call Number |
c:irua:133100 |
Serial |
4071 |
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| Author |
Lu, J.; Roeffaers, M.B.J.; Bartholomeeusen, E.; Sels, B.F.; Schryvers, D. |
| Title |
Intergrowth of components and ramps in coffin-shaped ZSM-5 zeolite crystals unraveled by focused ion beam-assisted transmission electron microscopy |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Microscopy and microanalysis |
Abbreviated Journal |
Microsc Microanal |
| Volume |
20 |
Issue |
1 |
Pages |
42-49 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Scanning electron microscopy, focused ion beam (FIB), and transmission electron microscopy are combined to study the intergrowth of 90 degrees rotational components and of ramps in coffin-shaped ZSM-5 crystals. The 90 degrees rotational boundaries with local zig-zag features between different intergrowth components are observed in the main part of crystal. Also a new kind of displacement boundary is described. At the displacement boundary there is a shift of the unit cells along the boundary without a change in orientation. Based on lamellae prepared with FIB from different positions of the ramps and crystal, the orientation relationships between ramps and the main part of the crystal are studied and the three-dimensional morphology and growth mechanism of the ramp are illustrated. |
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Place of Publication |
Cambridge, Mass. |
Editor |
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Wos |
000335378400006 |
Publication Date |
2013-11-05 |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1431-9276;1435-8115; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.891 |
Times cited |
7 |
Open Access |
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| Notes |
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Approved |
Most recent IF: 1.891; 2014 IF: 1.877 |
| Call Number |
UA @ lucian @ c:irua:117688 |
Serial |
1697 |
| Permanent link to this record |
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| Author |
Lu, J.; Martinez, G.T.; Van Aert, S.; Schryvers, D. |
| Title |
Lattice deformations in quasi-dynamic strain glass visualised and quantified by aberration corrected electron microscopy |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Physica status solidi: B: basic research |
Abbreviated Journal |
Phys Status Solidi B |
| Volume |
251 |
Issue |
10 |
Pages |
2034-2040 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Advanced transmission electron microscopy and statistical parameter estimated quantification procedures were applied to study the room temperature quasi-dynamical strain glass state in NiTi alloys. Nanosized strain pockets are visualised and the displacements of the atom columns are quantified. A comparison is made with conventional high-resolution transmission electron microscopy images of point defect induced strains in NiAl alloys. |
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Place of Publication |
Berlin |
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Wos |
000344360000009 |
Publication Date |
2014-03-31 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0370-1972; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.674 |
Times cited |
2 |
Open Access |
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| Notes |
Fwo |
Approved |
Most recent IF: 1.674; 2014 IF: 1.489 |
| Call Number |
UA @ lucian @ c:irua:120471 |
Serial |
1801 |
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| Author |
Lu, J.; Bartholomeeusen, E.; Sels, B.F.; Schryvers, D. |
| Title |
Internal architecture of coffin-shaped ZSM-5 zeolite crystals with hourglass contrast unravelled by focused ion beam-assisted transmission electron microscopy: INTERNAL ARCHITECTURE OF COFFIN-SHAPED |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Journal of microscopy |
Abbreviated Journal |
J Microsc-Oxford |
| Volume |
265 |
Issue |
265 |
Pages |
27-33 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Optical microscopy, focused ion beam and transmission electron microscopy are combined to study the internal architecture in a coffin-shaped ZSM-5 crystal showing an hourglass contrast in optical microscopy. Based on parallel lamellas from different positions in the crystal, the orientation relationships between the intergrowth components of the crystal are studied and the internal architecture and growth mechanism are illustrated. The crystal is found to contain two pyramid-like components aside from a central component. Both pyramid-like components are rotated by 90 degrees along the common c-axis and with respect to the central component while the interfaces between the components show local zig-zag feature, the latter indicating variations in relative growth velocity of the two components. The pyramid-like intergrowth components are larger and come closer to one another in the middle of the crystal than at the edges, but they do not connect. A model of multisite nucleation and growth of 90 degrees intergrowth components is proposed. |
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Place of Publication |
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Editor |
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Wos |
000392487400004 |
Publication Date |
2016-08-19 |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0022-2720 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.692 |
Times cited |
4 |
Open Access |
OpenAccess |
| Notes |
Fonds Wetenschappelijk Onderzoek, G.0603.10N ; |
Approved |
Most recent IF: 1.692 |
| Call Number |
EMAT @ emat @ c:irua:141015 |
Serial |
4437 |
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| Author |
Lu, A.K.A.; Pourtois, G.; Luisier, M.; Radu, I.P.; Houssa, M. |
| Title |
On the electrostatic control achieved in transistors based on multilayered MoS2 : a first-principles study |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Journal of applied physics |
Abbreviated Journal |
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| Volume |
121 |
Issue |
4 |
Pages |
044505 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
In this work, the electrostatic control in metal-oxide-semiconductor field-effect transistors based on MoS2 is studied, with respect to the number of MoS2 layers in the channel and to the equivalent oxide thickness of the gate dielectric, using first-principles calculations combined with a quantum transport formalism. Our simulations show that a compromise exists between the drive current and the electrostatic control on the channel. When increasing the number of MoS2 layers, a degradation of the device performances in terms of subthreshold swing and OFF currents arises due to the screening of the MoS2 layers constituting the transistor channel. Published by AIP Publishing. |
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Place of Publication |
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Wos |
000393480100030 |
Publication Date |
2017-01-26 |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0021-8979; 1089-7550 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:152673 |
Serial |
8329 |
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| Author |
Lu, A.K.A.; Pourtois, G.; Agarwal, T.; Afzalian, A.; Radu, I.P.; Houssa, M. |
| Title |
Origin of the performances degradation of two-dimensional-based metal-oxide-semiconductor field effect transistors in the sub-10 nm regime: A first-principles study |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
108 |
Issue |
4 |
Pages |
043504 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
The impact of the scaling of the channel length on the performances of metal-oxide-semiconductor field effect transistors, based on two-dimensional (2D) channel materials, is theoretically investigated, using density functional theory combined with the non-equilibrium Green's function method. It is found that the scaling of the channel length below 10nm leads to strong device performance degradations. Our simulations reveal that this degradation is essentially due to the tunneling current flowing between the source and the drain in these aggressively scaled devices. It is shown that this electron tunneling process is modulated by the effective mass of the 2D channel material, and sets the limit of the scaling in future transistor designs. (C) 2016 AIP Publishing LLC. |
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American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Wos |
000375217200061 |
Publication Date |
2016-01-26 |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0003-6951; 1077-3118 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.411 |
Times cited |
4 |
Open Access |
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| Notes |
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Approved |
Most recent IF: 3.411 |
| Call Number |
UA @ lucian @ c:irua:144750 |
Serial |
4677 |
| Permanent link to this record |
