Records |
Author |
de Sousa, G.O.; da Costa, D.R.; Chaves, A.; Farias, G.A.; Peeters, F.M. |
Title |
Unusual quantum confined Stark effect and Aharonov-Bohm oscillations in semiconductor quantum rings with anisotropic effective masses |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
95 |
Issue |
95 |
Pages |
205414 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The effects of external electric and magnetic fields on the energy spectrum of quantum rings made out of a bidimensional semiconductor material with anisotropic band structures are investigated within the effective-mass model. The interplay between the effective-mass anisotropy and the radial confinement leads to wave functions that are strongly localized at two diametrically opposite regions where the kinetic energy is lowest due to the highest effective mass. We show that this quantum phenomenon has clear consequences on the behavior of the energy states in the presence of applied in-plane electric fields and out-of-plane magnetic fields. In the former, the quantum confined Stark effect is observed with either linear or quadratic shifts, depending on the direction of the applied field. As for the latter, the usual Aharonov-Bohm oscillations are not observed for a circularly symmetric confining potential, however they can be reinstated if an elliptic ring with an appropriate aspect ratio is chosen. |
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 |
000401230600007 |
Publication Date |
2017-05-12 |
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 |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
19 |
Open Access |
|
Notes |
; This work was financially supported by CNPq under the PRONEX/FUNCAP grants, CAPES Foundation, the Flemish Science Foundation (FWO-Vl), and the Brazilian Program Science Without Borders (CsF). ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:143746 |
Serial |
4610 |
Permanent link to this record |
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|
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Author |
Zhang, L.; Lin, B.-C.; Wu, Y.-F.; Wu, H.; Huang, T.-W.; Chang, C.-R.; Ke, X.; Kurttepeli, M.; Tendeloo, G.V.; Xu, J.; Yu, D.; Liao, Z.-M. |
Title |
Electronic Coupling between Graphene and Topological Insulator Induced Anomalous Magnetotransport Properties |
Type |
A1 Journal article |
Year |
2017 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
Volume |
11 |
Issue |
11 |
Pages |
6277-6285 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
It has been theoretically proposed that the spin textures of surface states in a topological insulator can be directly transferred to graphene by means of the proximity effect, which is very important for realizing the two-dimensional topological insulator based on graphene. Here we report the anomalous magnetotransport properties of graphene-topological insulator Bi2Se3 heterojunctions, which are sensitive to the electronic coupling between graphene and the topological surface state. The coupling between the p_z orbitals of graphene and the p orbitals of the surface states on the Bi2Se3 bottom surface can be enhanced by applying a perpendicular negative magnetic field, resulting in a giant negative magnetoresistance at the Dirac point up to about -91%. Obvious resistances dip in the transfer curve at the Dirac point is also observed in the hybrid devices, which is consistent with theoretical predictions of the distorted Dirac bands with nontrivial spin textures inherited from the Bi2Se3 surface states. |
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 |
000404808000110 |
Publication Date |
2017-05-10 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1936-0851 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
13.942 |
Times cited |
12 |
Open Access |
OpenAccess |
Notes |
; This work was supported by National Key Research and Development Program of China (Nos. 2016YFA0300802, 2013CB934600) and NSFC (No. 11234001). ; |
Approved |
Most recent IF: 13.942 |
Call Number |
EMAT @ emat @ c:irua:143192 |
Serial |
4569 |
Permanent link to this record |
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Author |
Volodin, A.; Van Haesendonck, C.; Leenaerts, O.; Partoens, B.; Peeters, F.M. |
Title |
Stress dependence of the suspended graphene work function : vacuum Kelvin probe force microscopy and density functional theory |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
110 |
Issue |
19 |
Pages |
193101 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We report on work function measurements on graphene, which is exfoliated over a predefined array of wells in silicon oxide, by Kelvin probe force microscopy operating in a vacuum. The obtained graphene sealed microchambers can support large pressure differences, providing controllable stretching of the nearly impermeable graphene membranes. These measurements allow detecting variations of the work function induced by the mechanical stresses in the suspended graphene where the work function varies linearly with the strain and changes by 62 +/- 2 meV for 1 percent of strain. Our related ab initio calculations result in a work function variation that is a factor of 1.4 larger than the experimental value. The limited discrepancy between the theory and the experiment can be accounted for by a charge transfer from the unstrained to the strained graphene regions. Published by AIP Publishing. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000402319200036 |
Publication Date |
2017-05-08 |
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 |
0003-6951; 1077-3118 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
8 |
Open Access |
|
Notes |
; The authors wish to thank A. Klekachev (IMEC Leuven, Belgium) for the fabrication of the samples. This work was supported by the Science Foundation-Flanders (FWO, Belgium). The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Hercules Foundation and the Flemish Government-Department EWI. The Hercules Foundation also funded the scanning probe microscopy equipment. ; |
Approved |
Most recent IF: 3.411 |
Call Number |
UA @ lucian @ c:irua:144279 |
Serial |
4690 |
Permanent link to this record |
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Author |
Kleibert, A.; Balan, A.; Yanes, R.; Derlet, P.M.; Vaz, C.A.F.; Timm, M.; Fraile Rodríguez, A.; Béché, A.; Verbeeck, J.; Dhaka, R.S.; Radovic, M.; Nowak, U.; Nolting, F. |
Title |
Direct observation of enhanced magnetism in individual size- and shape-selected 3d transition metal nanoparticles |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
95 |
Issue |
95 |
Pages |
195404 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Magnetic nanoparticles are critical building blocks for future technologies ranging from nanomedicine to spintronics. Many related applications require nanoparticles with tailored magnetic properties. However, despite significant efforts undertaken towards this goal, a broad and poorly understood dispersion of magnetic properties is reported, even within monodisperse samples of the canonical ferromagnetic 3d transition metals. We address this issue by investigating the magnetism of a large number of size- and shape-selected, individual nanoparticles of Fe, Co, and Ni using a unique set of complementary characterization techniques. At room temperature, only superparamagnetic behavior is observed in our experiments for all Ni nanoparticles within the investigated sizes, which range from 8 to 20 nm. However, Fe and Co nanoparticles can exist in two distinct magnetic states at any size in this range: (i) a superparamagnetic state, as expected from the bulk and surface anisotropies known for the respective materials and as observed for Ni, and (ii) a state with unexpected stable magnetization at room temperature. This striking state is assigned to significant modifications of the magnetic properties arising from metastable lattice defects in the core of the nanoparticles, as concluded by calculations and atomic structural characterization. Also related with the structural defects, we find that the magnetic state of Fe and Co nanoparticles can be tuned by thermal treatment enabling one to tailor their magnetic properties for applications. This paper demonstrates the importance of complementary single particle investigations for a better understanding of nanoparticle magnetism and for full exploration of their potential for applications. |
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 |
000400665300002 |
Publication Date |
2017-05-05 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
21 |
Open Access |
OpenAccess |
Notes |
We thank A. Weber, R. Schelldorfer, and J. Krbanjevic (Paul Scherrer Institut) for technical assistance. This paper was supported by the Swiss Nanoscience Institute, University of Basel. A.F.R. acknowledges support from the MICIIN “Ramón y Cajal” Programme. A.B. and J.V. acknowledge funding from the European Union under the European Research Council (ERC) Starting Grant No. 278510 VORTEX and under a contract for Integrated Infrastructure Initiative ESTEEM2 No. 312483. R.Y. and U.N. thank the Deutsche Forschungsgemeinschaft for financial support via Sonderforschungsbereich 1214. Part of this work was performed at the Surface/Interface: Microscopy (SIM) beamline of the Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland. |
Approved |
Most recent IF: 3.836 |
Call Number |
EMAT @ emat @ c:irua:143634UA @ admin @ c:irua:143634 |
Serial |
4575 |
Permanent link to this record |
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Author |
Clauwaert, P.; Muys, M.; Alloul, A.; De Paepe, J.; Luther, A.; Sun, X.; Ilgrande, C.; Christiaens, M.E.R.; Hu, X.; Zhang, D.; Lindeboom, R.E.F.; Sas, B.; Rabaey, K.; Boon, N.; Ronsse, F.; Geelen, D.; Vlaeminck, S.E. |
Title |
Nitrogen cycling in bioregenerative life support systems : challenges for waste refinery and food production processes |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Progress in aerospace sciences |
Abbreviated Journal |
|
Volume |
91 |
Issue |
|
Pages |
87-98 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
Abstract |
In order to sustain human life in an isolated environment, an efficient conversion of wasted nutrients to food might become mandatory. This is particularly the case for space missions where resupply from earth or in-situ resource utilization is not possible or desirable. A combination of different technologies is needed to allow full recycling of e.g. nitrogenous compounds in space. In this review, an overview is given of the different essential processes and technologies that enable closure of the nitrogen cycle in Bioregenerative Life Support Systems (BLSS). Firstly, a set of biological and physicochemical refinery stages ensures efficient conversion of waste products into the building blocks, followed by the production of food with a range of biological methods. For each technology, bottlenecks are identified. Furthermore, challenges and outlooks are presented at the integrated system level. Space adaptation and integration deserve key attention to enable the recovery of nitrogen for the production of nutritional food in space, but also in closed loop systems on earth. |
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 |
000404699800005 |
Publication Date |
2017-05-04 |
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 |
|
Edition |
|
ISSN |
0376-0421; 1873-1724 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:148996 |
Serial |
8310 |
Permanent link to this record |
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Author |
De Cocker, P.; Bessiere, Y.; Hernandez-Raquet, G.; Dubos, S.; Mercade, M.; Sun, X.Y.; Mozo, I.; Barillon, B.; Gaval, G.; Caligaris, M.; Martin Ruel, S.; Vlaeminck, S.E.; Sperandio, M. |
Title |
Short and long term effect of decreasing temperature on anammox activity and enrichment in mainstream granular sludge process |
Type |
P1 Proceeding |
Year |
2017 |
Publication |
|
Abbreviated Journal |
|
Volume |
4 |
Issue |
|
Pages |
50-54
T2 - Frontiers International Conference on W |
Keywords |
P1 Proceeding; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
Abstract |
This study investigates the impact of lower temperature on short term and long term (down to 10 degrees C) on a completely anoxic anammox granular sludge process. This is the first time granular sludge Anammox is operated in pure anoxic condition in SBR and at low temperature. Conversion performance, kinetic parameters, sludge characteristics and microbial community were analyzed. |
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 |
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Publication Date |
2017-05-04 |
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 |
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ISBN |
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Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:151120 |
Serial |
8519 |
Permanent link to this record |
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|
Author |
De Cocker, P.; Bessiere, Y.; Hernandez-Raquet, G.; Dubos, S.; Mercade, M.; Sun, X.Y.; Mozo, I.; Barillon, B.; Gaval, G.; Caligaris, M.; Ruel, S.M.; Vlaeminck, S.E.; Sperandio, M. |
Title |
Short and long term effect of decreasing temperature on anammox activity and enrichment in mainstream granular sludge process |
Type |
P1 Proceeding |
Year |
2017 |
Publication |
Frontiers In Wastewater Treatment And Modelling, Ficwtm 2017 |
Abbreviated Journal |
|
Volume |
4 |
Issue |
|
Pages |
50-54
T2 - Frontiers International Conference on W |
Keywords |
P1 Proceeding; Sustainable Energy, Air and Water Technology (DuEL) |
Abstract |
This study investigates the impact of lower temperature on short term and long term (down to 10 degrees C) on a completely anoxic anammox granular sludge process. This is the first time granular sludge Anammox is operated in pure anoxic condition in SBR and at low temperature. Conversion performance, kinetic parameters, sludge characteristics and microbial community were analyzed. |
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 |
000430181700008 |
Publication Date |
2017-05-04 |
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 |
978-3-319-58421-8; 978-3-319-58420-1; 978-3-319-58420-1 |
ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
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Approved |
no |
Call Number |
UA @ admin @ c:irua:151640 |
Serial |
8520 |
Permanent link to this record |
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Author |
Grieb, T.; Krause, F.F.; Mahr, C.; Zillmann, D.; Müller-Caspary, K.; Schowalter, M.; Rosenauer, A. |
Title |
Optimization of NBED simulations for disc-detection measurements |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
181 |
Issue |
|
Pages |
50-60 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Nano-beam electron diffraction (NBED) is a method which can be applied to measure lattice strain and polarisation fields in strained layer heterostructures and transistors. To investigate precision, accuracy and spatial resolution of such measurements in dependence of properties of the specimen as well as electron optical parameters, simulations of NBED patterns are required which allow to predict the result of common disc-detection algorithms. In this paper we demonstrate by focusing on the detection of the central disc in crystalline silicon that such simulations require to take several experimental characteristics into account in order to obtain results which are comparable to those from experimental NBED patterns. These experimental characteristics are the background intensity, the presence of Poisson noise caused by electron statistics and blurring caused by inelastic scattering and by the transfer quality of the microscope camera. By means of these optimized simulations, different effects of specimen properties on disc detection – such as strain, surface morphology and compositional changes on the nanometer scale – are investigated and discussed in the context of misinterpretation in experimental NBED evaluations. It is shown that changes in surface morphology and chemical composition lead to measured shifts of the central disc in the NBED pattern of tens to hundreds of grad. These shifts are of the same order of magnitude or even larger than shifts that could be caused by an electric polarisation field in the range of MV/cm. (C) 2017 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 |
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Language |
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Wos |
000411170800006 |
Publication Date |
2017-05-03 |
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 |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
6 |
Open Access |
Not_Open_Access |
Notes |
; This work was supported by the German Research Foundation (DFG) under Contract No. R02057/11-1, R02057/4-2 and MU3660/1-1. ; |
Approved |
Most recent IF: 2.843 |
Call Number |
UA @ lucian @ c:irua:146725 |
Serial |
4792 |
Permanent link to this record |
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Author |
Longo, R.; Ferrarotti, M.; Garcia Sánchez, C.; Derudi, M.; Parente, A. |
Title |
Advanced turbulence models and boundary conditions for flows around different configurations of ground-mounted buildings |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of wind engineering and industrial aerodynamics |
Abbreviated Journal |
J Wind Eng Ind Aerod |
Volume |
167 |
Issue |
|
Pages |
160-182 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
When dealing with Atmospheric Boundary Layer (ABL) simulations, commercial computational fluid dynamics (CFD) acquires a strategic resonance. Thanks to its good compromise between accuracy of results and calculation time, RANS still represents a valid alternative to more resource-demanding methods. However, focusing on the models' performances in urban studies, LES generally outmatches RANS results, even if the former is at least one order of magnitude more expensive. Consequently, the present work aims to propose a variety of approaches meant to solve some of the major problems linked to RANS simulations and to further improve its accuracy in typical urban contexts. All of these models are capable of switching from an undisturbed flux formulation to a disturbed one through a local deviation or a marker function. For undisturbed flows, a comprehensive approach is adopted, solving the issue of the erroneous stream-wise gradients affecting the turbulent profiles. Around obstacles, Non-Linear Eddy-Viscosity closures are adopted, due to their prominent capability in capturing the anisotropy of turbulence. The purpose of this work is then to propose a new Building Influence Area concept and to offer more affordable alternatives to LES simulations without sacrificing a good grade of accuracy. |
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 |
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Language |
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Wos |
000405766600013 |
Publication Date |
2017-05-02 |
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 |
0167-6105 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.049 |
Times cited |
9 |
Open Access |
Not_Open_Access |
Notes |
; ; |
Approved |
Most recent IF: 2.049 |
Call Number |
UA @ lucian @ c:irua:145191 |
Serial |
4713 |
Permanent link to this record |
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Author |
Ata, I.; Ben Dkhil, S.; Pfannmoeller, M.; Bals, S.; Duche, D.; Simon, J.-J.; Koganezawa, T.; Yoshimoto, N.; Videlot-Ackermann, C.; Margeat, O.; Ackermann, J.; Baeuerle, P. |
Title |
The influence of branched alkyl side chains in A-D-A oligothiophenes on the photovoltaic performance and morphology of solution-processed bulk-heterojunction solar cells |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Organic chemistry frontiers : an international journal of organic chemistry |
Abbreviated Journal |
Org Chem Front |
Volume |
4 |
Issue |
4 |
Pages |
1561-1573 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Besides providing sufficient solubility, branched alkyl chains also affect the film-forming and packing properties of organic semiconductors. In order to avoid steric hindrance as it is present in wide-spread alkyl chains comprising a branching point position at the C2-position, i.e., 2-ethylhexyl, the branching point can be moved away from the pi-conjugated backbone. In this report, we study the influence of the modification of the branching point position from the C2-position in 2-hexyldecylamine (1) to the C4-position in 4-hexyldecylamine (2) connected to the central dithieno[3,2-b: 2', 3'-d] pyrrole (DTP) moiety in a well-studied A-D-A oligothiophene on the optoelectronic properties and photovoltaic performance in solution- processed bulk heterojunction solar cells (BHJSCs) with [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as the acceptor material. Post-treatment of the photoactive layers is performed via solvent vapor annealing (SVA) in order to improve the film microstructure of the bulk heterojunction. The time evolution of nanoscale morphological changes is followed by combining scanning transmission electron microscopy with low-energy-loss spectroscopic imaging (STEM-SI), solid-state absorption spectroscopy, and two-dimensional grazing incidence X-ray diffraction (2D-GIXRD). Our results show an improvement of the photovoltaic performance that is dependent on the branching point position in the donor oligomer. Optical spacers are utilized to increase light absorption inside the co-oligomer 2-based BHJSCs leading to increased power conversion efficiencies (PCEs) of 8.2% when compared to the corresponding co-oligomer 1-based devices. A STEM-SI analysis of the respective device cross-sections of active layers containing 1 and 2 as donor materials indeed reveals significant differences in their respective active layer morphologies. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
RSC Publishing |
Place of Publication |
London |
Editor |
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Language |
|
Wos |
000406374800013 |
Publication Date |
2017-05-02 |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2052-4129 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.955 |
Times cited |
24 |
Open Access |
OpenAccess |
Notes |
; We acknowledge financial support by the European Commission under the project “SUNFLOWER” (FP7-ICT-2011-7, grant number: 287594) and S.B. acknowledges the ERC Starting Grant Colouratoms (335078). ; |
Approved |
Most recent IF: 4.955 |
Call Number |
UA @ lucian @ c:irua:145176UA @ admin @ c:irua:145176 |
Serial |
4727 |
Permanent link to this record |
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|
Author |
Smolin, S.Y.; Choquette, A.K.; Wilks, R.G.; Gauquelin, N.; Félix, R.; Gerlach, D.; Ueda, S.; Krick, A.L.; Verbeeck, J.; Bär, M.; Baxter, J.B.; May, S.J. |
Title |
Energy Level Alignment and Cation Charge States at the LaFeO3/LaMnO3(001) Heterointerface |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Advanced Materials Interfaces |
Abbreviated Journal |
Adv Mater Interfaces |
Volume |
4 |
Issue |
4 |
Pages |
1700183 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The electronic properties of LaFeO 3 /LaMnO 3 epitaxial heterojunctions are investigated to determine the valence and conduction band offsets and the nominal Mn and Fe valence states at the interface. Studying a systematic series of (LaFeO 3 ) n /(LaMnO 3 ) m bilayers (m ≈ 50) epitaxially grown in the (001) orientation using molecular beam epitaxy, layer-resolved electron energy loss spectroscopy reveals a lack of significant interfacial charge transfer, with a nominal 3+ valence state observed for both Mn and Fe across the interface. Through a combination of variable angle spectroscopic ellipsometry and hard X-ray photoelectron spectroscopy, type I energy level alignments are obtained at the LaFeO 3 /LaMnO 3 interface with positive valence and conduction band offsets of (1.20 ± 0.07) eV and (0.5–0.7 ± 0.3) eV, respectively, with minimal band bending. Variable temperature resistivity measurements reveal that the bilayers remain insulating and that the presence of the heterojunction does not result in a conducting interface. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
|
Language |
|
Wos |
000406068400011 |
Publication Date |
2017-04-26 |
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 |
4.279 |
Times cited |
14 |
Open Access |
Not_Open_Access |
Notes |
The authors thank Dmytro Nykypanchuk for assistance with the near- infrared ellipsometry measurement of the LaMnO 3 film. S.Y.S., A.K.C., J.B.B, and S.J.M. acknowledge funding from the National Science Foundation under grant number ECCS-1201957. S.Y.S. acknowledges additional funding from the German Academic Exchange Service (DAAD) through the Research Internships in Science and Engineering (RISE) professional program 2015 ID 5708457. A.L.K. was funded by the National Science Foundation under grant number DMR-1151649. J.V. and N.G. acknowledge funding through the GOA project “Solarpaint” of the University of Antwerp and from the FWO project G.0044.13N (Charge ordering). The microscope used in this work was partly funded by the Hercules Fund from the Flemish Government. Ellipsometry measurements of the LaMnO 3 film were carried out at the Center for Functional Nanomaterials, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-ACO2-98CH10886. S.U. would like to thank the staff of HiSOR, Hiroshima University, and JAEA/Spring-8 for the development of HAXPES at BL15XU of SPring-8. The HAXPES measurements were performed with approval of NIMS Synchrotron X-ray Station (Proposal No. 2015B4601), and were partly supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. The authors also thank HZB for the allocation of synchrotron radiation beamtime for HAXPES/XANES measurements. R.G.W., R.F, and M.B. are grateful to the Impuls- und Vernetzungsfonds of the Helmholtz Association (VH-NG-423).; National Science Foundation, ECCS-1201957 DMR-1151649 ; Deutscher Akademischer Austauschdienst, 2015 ID 5708457 ; GOA project; Fonds Wetenschappelijk Onderzoek, G.0044.13N ; Flemish Government; U.S. Department of Energy, DE-ACO2-98CH10886 ; Vernetzungsfonds of the Helmholtz Association, VH-NG-423 ; |
Approved |
Most recent IF: 4.279 |
Call Number |
EMAT @ emat @ c:irua:142346UA @ admin @ c:irua:142346 |
Serial |
4553 |
Permanent link to this record |
|
|
|
Author |
Ranjbar, S.; Hadipour, A.; Vermang, B.; Batuk, M.; Hadermann, J.; Garud, S.; Sahayaraj, S.; Meuris, M.; Brammertz, G.; da Cunha, A.F.; Poortmans, J. |
Title |
P-N Junction Passivation in Kesterite Solar Cells by Use of Solution-Processed TiO2 Layer |
Type |
A1 Journal article |
Year |
2017 |
Publication |
IEEE journal of photovoltaics |
Abbreviated Journal |
Ieee J Photovolt |
Volume |
7 |
Issue |
7 |
Pages |
1130-1135 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
In this work, we used a solution-processed TiO2 layer between Cu2ZnSnSe4 and CdS buffer layer to reduce the recombination at the p–n junction. Introducing the TiO2 layer showed a positive impact on VOC but fill factor and efficiency decreased. Using a KCN treatment, we could create openings in the TiO2 layer, as confirmed by transmission electron microscopy measurements. Formation of these openings in the TiO2 layer led to the improvement of the short-circuit current, fill factor, and the efficiency of the modified solar cells. |
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 |
000404258900026 |
Publication Date |
2017-04-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2156-3381 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.712 |
Times cited |
2 |
Open Access |
OpenAccess |
Notes |
This work was supported in part by the European Union’s Horizon 2020 research and innovation program under Grant 640868, in part by the Flemish government, Department Economy, Science and Innovation, in part by the FEDER funds through the COMPETE 2020 Programme, and in part by the National Funds through FCT – Portuguese Foundation for Science and Technology under the project UID/CTM/50025/2013. The work of S. Ranjbar was supported by the Portuguese Science and Technology Foundation through Ph.D. grant SFRH/BD/78409/2011. The work of B. Vermang was supported by the Flemish Research Foundation FWO (mandate 12O4215N). |
Approved |
Most recent IF: 3.712 |
Call Number |
EMAT @ emat @ c:irua:143986 |
Serial |
4583 |
Permanent link to this record |
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|
Author |
da Costa, D.R.; Chaves, A.; Farias, G.A.; Peeters, F.M. |
Title |
Valley filtering in graphene due to substrate-induced mass potential |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
|
Volume |
29 |
Issue |
21 |
Pages |
215502 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The interaction of monolayer graphene with specific substrates may break its sublattice symmetry and results in unidirectional chiral states with opposite group velocities in the different Dirac cones (Zarenia et al 2012 Phys. Rev. B 86 085451). Taking advantage of this feature, we propose a valley filter based on a transversal mass kink for low energy electrons in graphene, which is obtained by assuming a defect region in the substrate that provides a change in the sign of the substrate-induced mass and thus creates a non-biased channel, perpendicular to the kink, for electron motion. By solving the time-dependent Schrodinger equation for the tight-binding Hamiltonian, we investigate the time evolution of a Gaussian wave packet propagating through such a system and obtain the transport properties of this graphene-based substrate-induced quantum point contact. Our results demonstrate that efficient valley filtering can be obtained, provided: (i) the electron energy is sufficiently low, i.e. with electrons belonging mostly to the lowest sub-band of the channel, and (ii) the channel length (width) is sufficiently long (narrow). Moreover, even though the transmission probabilities for each valley are significantly affected by impurities and defects in the channel region, the valley polarization in this system is shown to be robust against their presence. |
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 |
000400092700002 |
Publication Date |
2017-04-24 |
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 |
|
Edition |
|
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
15 |
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:152636 |
Serial |
8730 |
Permanent link to this record |
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|
Author |
Chin, C.-M.; Sena, R.P.; Hunter, E.C.; Hadermann, J.; Battle, P.D. |
Title |
Interplay of structural chemistry and magnetism in perovskites : a study of CaLn2Ni2WO9: Ln=La, Pr, Nd |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
251 |
Issue |
|
Pages |
224-232 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Polycrystalline samples of CaLn(2)Ni(2)WO(9) (Ln=La, Pr, Nd) have been synthesized and characterised by a combination of X-ray and neutron diffraction, electron microscopy and magnetometry. Each composition adopts a perovskite-like structure with a similar to 5.50, b similar to 5.56, c similar to 7.78 angstrom beta similar to 90.1 degrees in space group P2(1)/n. Of the two crystallographically distinct six-coordinate sites, one is occupied entirely (Ln=Pr) or predominantly (Ln=La, Nd) by Ni2+ and the other by Ni2+ and W6+ in a ratio of approximately 1:2. None of the compounds shows long-range magnetic order at 5 K. The magnetometry data show that the magnetic moments of the Ni2+ cations form a spin glass below 30 K in each case. The Pr3+ moments in CaPr2Ni2WO9 also freeze but the Nd3+ moments in CaNd2Ni2WO9 do not. This behaviour is contrasted with that observed in other (A,A')B2B'O-9 perovskites. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000402581200030 |
Publication Date |
2017-04-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-4596 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
5 |
Open Access |
OpenAccess |
Notes |
; We thank EPSRC for funding through grant EP/M0189541. CMC thanks the Croucher Foundation and Oxford University for a graduate scholarship. We are grateful to Ivan da Silva who provided experimental assistance at ISIS and to Maria Batuk for help with the STEM-EDX analysis. ; |
Approved |
Most recent IF: 2.299 |
Call Number |
UA @ lucian @ c:irua:144179 |
Serial |
4664 |
Permanent link to this record |
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Author |
Mirzakhani, M.; Zarenia, M.; Vasilopoulos, P.; Peeters, F.M. |
Title |
Electrostatically confined trilayer graphene quantum dots |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
|
Volume |
95 |
Issue |
15 |
Pages |
155434 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Electrically gating of trilayer graphene (TLG) opens a band gap offering the possibility to electrically engineer TLG quantum dots. We study the energy levels of such quantum dots and investigate their dependence on a perpendicular magnetic field B and different types of stacking of the graphene layers. The dots are modeled as circular and confined by a truncated parabolic potential which can be realized by nanostructured gates or position-dependent doping. The energy spectra exhibit the intervalley symmetry E-K(e) (m) = -E (h)(K') (m) for the electron (e) and hole (h) states, where m is the angular momentum quantum number and K and K' label the two valleys. The electron and hole spectra for B = 0 are twofold degenerate due to the intervalley symmetry E-K (m) = E-K' [-(m + 1)]. For both ABC [alpha = 1.5 (1.2) for large (small) R] and ABA (alpha = 1) stackings, the lowest-energy levels show approximately a R-alpha dependence on the dot radius R in contrast with the 1/R-3 one for ABC-stacked dots with infinite-mass boundary. As functions of the field B, the oscillator strengths for dipole-allowed transitions differ drastically for the two types of stackings. |
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 |
000399797200003 |
Publication Date |
2017-04-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
6 |
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:152652 |
Serial |
7878 |
Permanent link to this record |
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Author |
Ben Hafsia, A.; Hendrickx, M.; Batuk, M.; Khitouni, M.; Hadermann, J.; Greneche, J.-M.; Rammeh, N. |
Title |
Crystal structure study of manganese and titanium substituted BaLaFe2O6-δ |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
251 |
Issue |
251 |
Pages |
186-193 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Barium lanthanum ferrite and four Mn/Ti substituted materials were synthesized by the sol-gel method. The crystal structure of the materials was studied by a combination of X-ray powder diffraction, electron diffraction, scanning transmission electron microscopy and 57Fe Mössbauer spectrometry. BaLaFe2O6-δ has a cubic perovskite structure and Ba0.7La1.3FeMnO6-δ is distorted perovskite with the R-3c symmetry, both from electron diffraction and X-ray powder diffraction. However, according to transmission electron microscopy, the crystals of BaLaFeTiO6-δ, BaLaFeTi0.5Mn0.5O6-δ, and BaLaFe0.5Ti0.5MnO6-δ consist of nanodomains with different symmetries (Pm3m next to R-3c due to octahedral tilts), whereas the bulk X-ray powder diffraction patterns for these compounds correspond to the simple cubic structure. 57Fe Mössbauer spectrometry confirms that all materials contain high spin state Fe3+ ions which are strongly influenced by the chemical disorder
resulting from various cationic environments. |
Address |
|
Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
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Editor |
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Language |
|
Wos |
000402581200024 |
Publication Date |
2017-04-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-4596 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
This study has been supported by the Tunisian Ministry of Higher Education and Scientific Research and by the University of Antwerp BOF Grant 33024 funding scheme. |
Approved |
Most recent IF: 2.299 |
Call Number |
EMAT @ emat @ c:irua:143988 |
Serial |
4582 |
Permanent link to this record |
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|
Author |
Shayeganfar, F.; Vasu, K.S.; Nair, R.R.; Peeters, F.M.; Neek-Amal, M. |
Title |
Monolayer alkali and transition-metal monoxides : MgO, CaO, MnO, and NiO |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
|
Volume |
95 |
Issue |
14 |
Pages |
144109 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Two-dimensional crystals with strong interactions between layers has attracted increasing attention in recent years in a variety of fields. In particular, the growth of a single layer of oxide materials (e.g., MgO, CaO, NiO, and MnO) over metallic substrates were found to display different physical properties than their bulk. In this study, we report on the physical properties of a single layer of metallic oxide materials and compare their properties with their bulk and other two-dimensional (2D) crystals. We found that the planar structure of metallic monoxides are unstable whereas the buckled structures are thermodynamically stable. Also, the 2D-MnO and NiO exhibit different magnetic (ferromagnetic) and optical properties than their bulk, whereas band-gap energy and linear stiffness are found to be decreasing from NiO to MgO. Our findings provide insight into oxide thin-film technology applications. |
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 |
000399792400001 |
Publication Date |
2017-04-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
21 |
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:152654 |
Serial |
8278 |
Permanent link to this record |
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|
|
Author |
Tavkhelidze, I.; Caratelli, D.; Gielis, J.; Ricci, P.E.; Rogava, M.; Transirico, M. |
Title |
On a geometric model of bodies with “complex” configuration and some movements |
Type |
H1 Book chapter |
Year |
2017 |
Publication |
|
Abbreviated Journal |
|
Volume |
2 |
Issue |
|
Pages |
129-158
T2 - Modeling in mathematics : proceedings |
Keywords |
H1 Book chapter; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
Abstract |
Aim of this chapter is analytical representation of one wide class of geometric figures (lines, surfaces and bodies) and their complicated displacements. The accurate estimation of physical characteristics (such as volume, surface area, length, or other specific parameters) relevant to human organs is of fundamental importance in medicine. One central idea of this article is, in this respect, to provide a general methodology for the evaluation, as a function of time, of the volume and center of gravity featured by moving of one class of bodies used of describe different human organs. |
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 |
000442076400010 |
Publication Date |
2017-04-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
|
ISBN |
978-94-6239-260-1; 978-94-6239-261-8; 2543-0300; 978-94-6239-260-1 |
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:144552 |
Serial |
8326 |
Permanent link to this record |
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Author |
Zebrowski, D.P.; Peeters, F.M.; Szafran, B. |
Title |
Driven spin transitions in fluorinated single- and bilayer-graphene quantum dots |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Semiconductor science and technology |
Abbreviated Journal |
Semicond Sci Tech |
Volume |
32 |
Issue |
6 |
Pages |
065016 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Spin transitions driven by a periodically varying electric potential in dilute fluorinated graphene quantum dots are investigated. Flakes of monolayer graphene as well as electrostatic electron traps induced in bilayer graphene are considered. The stationary states obtained within the tight-binding approach are used as the basis for description of the system dynamics. The dilute fluorination of the top layer lifts the valley degeneracy of the confined states and attenuates the orbital magnetic dipole moments due to current circulation within the flake. The spin-orbit coupling introduced by the surface deformation of the top layer induced by the adatoms allows the spin flips to be driven by the AC electric field. For the bilayer quantum dots the spin flip times is substantially shorter than the spin relaxation. Dynamical effects including many-photon and multilevel transitions are also discussed. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000402405800007 |
Publication Date |
2017-04-19 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0268-1242 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
2.305 |
Times cited |
|
Open Access |
|
Notes |
; This work was supported by the National Science Centre according to decision DEC-2013/11/B/ST3/03837 and by the Flemish Science Foundation (FWO-VL). ; |
Approved |
Most recent IF: 2.305 |
Call Number |
UA @ lucian @ c:irua:144238 |
Serial |
4646 |
Permanent link to this record |
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|
Author |
Guzzinati, G.; Béché, A.; Lourenço-Martins, H.; Martin, J.; Kociak, M.; Verbeeck, J. |
Title |
Probing the symmetry of the potential of localized surface plasmon resonances with phase-shaped electron beams |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
8 |
Issue |
8 |
Pages |
14999 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Plasmonics, the science and technology of the interaction of light with metallic objects, is fundamentally changing the way we can detect, generate and manipulate light. Although the field is progressing swiftly, thanks to the availability of nanoscale manufacturing and analysis methods, fundamental properties such as the plasmonic excitations’ symmetries cannot be accessed directly, leading to a partial, sometimes incorrect, understanding of their properties. Here we overcome this limitation by deliberately shaping the wave function of an electron beam to match a plasmonic excitations’ symmetry in a modified transmission electron microscope. We show experimentally and theoretically that this offers selective detection of specific plasmon modes within metallic nanoparticles, while excluding modes with other symmetries. This method resembles the widespread use of polarized light for the selective excitation of plasmon modes with the advantage of locally probing the response of individual plasmonic objects and a far wider range of symmetry selection criteria. |
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 |
000399084300001 |
Publication Date |
2017-04-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
84 |
Open Access |
OpenAccess |
Notes |
; We thank F.J. Garcia de Abajo and D.M. Ugarte for interesting and fruitful discussion. This work was supported by funding from the European Research Council under the 7th Framework Program (FP7) ERC Starting Grant 278510 VORTEX. Financial support from the European Union under the Framework 7 program under a contract for an Integrated Infrastructure Initiative (Reference number 312483 ESTEEM2) is also gratefully acknowledged. Aluminum nanostructures were fabricated using the Nanomat nanofabrication facility. ; |
Approved |
Most recent IF: 12.124 |
Call Number |
EMAT @ emat @ c:irua:142205UA @ admin @ c:irua:142205 |
Serial |
4548 |
Permanent link to this record |
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|
Author |
Houben, K.; Couet, S.; Trekels, M.; Menendez, E.; Peissker, T.; Seo, J.W.; Hu, M.Y.; Zhao, J.Y.; Alp, E.E.; Roelants, S.; Partoens, B.; Milošević, M.V.; Peeters, F.M.; Bessas, D.; Brown, S.A.; Vantomme, A.; Temst, K.; Van Bael, M.J. |
Title |
Lattice dynamics in Sn nanoislands and cluster-assembled films |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
95 |
Issue |
15 |
Pages |
155413 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
To unravel the effects of phonon confinement, the influence of size and morphology on the atomic vibrations is investigated in Sn nanoislands and cluster-assembled films. Nuclear resonant inelastic x-ray scattering is used to probe the phonon densities of states of the Sn nanostructures which show significant broadening of the features compared to bulk phonon behavior. Supported by ab initio calculations, the broadening is attributed to phonon scattering and can be described within the damped harmonic oscillator model. Contrary to the expectations based on previous research, the appearance of high-energy modes above the cutoff energy is not observed. From the thermodynamic properties extracted from the phonon densities of states, it was found that grain boundary Sn atoms are bound by weaker forces than bulk Sn atoms. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
Language |
|
Wos |
000401762400008 |
Publication Date |
2017-04-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
5 |
Open Access |
|
Notes |
; This work was supported by the Research Foundation-Flanders (FWO) and the Concerted Research Action (GOA/14/007). The authors acknowledge Hercules stichting (Projects No. AKUL/13/19 and No. AKUL/13/25). K.H. and S.C. thank the FWO for financial support. T.P. acknowledges the IWT for financial support. S.R., M.V.M., and B.P. acknowledge TOPBOF funding of the University of Antwerp Research Fund. J.W.S. acknowledges Hercules Stichting (Project No. AKUL/13/19). The authors want to thank R. Lieten for help with the XRD measurements and T. Picot for fruitful discussions. The authors gratefully acknowledge R. Ruffer and A. I. Chumakov for fruitful discussions and the European Synchrotron Radiation Facility for the measurement of the SnO<INF>2</INF> powder at the Nuclear Resonance beamline (ID-18). This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:144305 |
Serial |
4667 |
Permanent link to this record |
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|
Author |
De Decker, J.; Folens, K.; De Clercq, J.; Meledina, M.; Van Tendeloo, G.; Du Laing, G.; Van Der Voort, P. |
Title |
Ship-in-a-bottle CMPO in MIL-101(Cr) for selective uranium recovery from aqueous streams through adsorption |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of hazardous materials |
Abbreviated Journal |
J Hazard Mater |
Volume |
335 |
Issue |
|
Pages |
1-9 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Mesoporous MIL-101(Cr) is used as host for a ship-in-a-bottle type adsorbent for selective U(VI) recovery from aqueous environments. The acid-resistant cage-type MOF is built in-situ around N,N-Diisobutyl-2-(octylphenylphosphoryl)acetamide (CMPO), a sterically demanding ligand with high U(VI) affinity. This one-step procedure yields an adsorbent which is an ideal compromise between homogeneous and heterogeneous systems, where the ligand can act freely within the pores of MIL-101, without leaching, while the adsorbent is easy separable and reusable. The adsorbent was characterized by XRD, FTIR spectroscopy, nitrogen adsorption, XRF, ADF-STEM and EDX, to confirm and quantify the successful encapsulation of the CMPO in MIL-101, and the preservation of the host. Adsorption experiments with a central focus on U(VI) recovery were performed. Very high selectivity for U(VI) was observed, while competitive metal adsorption (rare earths, transition metals...) was almost negligible. The adsorption capacity was calculated at 5.32 mg U/g (pH 3) and 27.99 mg U/g (pH 4), by fitting equilibrium data to the Langmuir model. Adsorption kinetics correlated to the pseudo-second-order model, where more than 95% of maximum uptake is achieved within 375 min. The adsorbed U(VI) is easily recovered by desorption in 0.1 M HNO3. Three adsorption/desorption cycles were performed. (C) 2017 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 |
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Language |
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Wos |
000402948600001 |
Publication Date |
2017-04-09 |
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 |
0304-3894 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.065 |
Times cited |
35 |
Open Access |
OpenAccess |
Notes |
; The authors acknowledge the AUGent/UGent for financial support, Grant Number DEF12/AOP/008 fund IV1. ; |
Approved |
Most recent IF: 6.065 |
Call Number |
UA @ lucian @ c:irua:144153 |
Serial |
4685 |
Permanent link to this record |
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Author |
Li, L.; Leenaerts, O.; Kong, X.; Chen, X.; Zhao, M.; Peeters, F.M. |
Title |
Gallium bismuth halide GaBi-X2 (X = I, Br, Cl) monolayers with distorted hexagonal framework: Novel room-temperature quantum spin Hall insulators |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nano Research |
Abbreviated Journal |
Nano Res |
Volume |
10 |
Issue |
10 |
Pages |
2168-2180 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Quantum spin Hall (QSH) insulators with a large topologically nontrivial bulk gap are crucial for future applications of the QSH effect. Among these, group III-V monolayers and their halides, which have a chair structure (regular hexagonal framework), have been widely studied. Using first-principles calculations, we formulate a new structure model for the functionalized group III-V monolayers, which consist of rectangular GaBi-X-2 (X = I, Br, Cl) monolayers with a distorted hexagonal framework (DHF). These structures have a far lower energy than the GaBi-X-2 monolayers with a chair structure. Remarkably, the DHF GaBi-X-2 monolayers are all QSH insulators, which exhibit sizeable nontrivial band gaps ranging from 0.17 to 0.39 eV. The band gaps can be widely tuned by applying different spin-orbit coupling strengths, resulting in a distorted Dirac cone. |
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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 |
000401320700029 |
Publication Date |
2017-04-08 |
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 |
1998-0124 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.354 |
Times cited |
15 |
Open Access |
|
Notes |
; This work was supported by the Fonds voor Wetenschappelijk Onderzoek (FWO-Vl). The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation-Flanders (FWO) and the Flemish Government-department EWI. ; |
Approved |
Most recent IF: 7.354 |
Call Number |
UA @ lucian @ c:irua:143739 |
Serial |
4598 |
Permanent link to this record |
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Author |
Razzokov, J.; Yusupov, M.; Vanuytsel, S.; Neyts, E.C.; Bogaerts, A. |
Title |
Phosphatidylserine flip-flop induced by oxidation of the plasma membrane: a better insight by atomic scale modeling |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Plasma processes and polymers |
Abbreviated Journal |
Plasma Process Polym |
Volume |
14 |
Issue |
10 |
Pages |
1700013 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
We perform molecular dynamics simulations to study the flip-flop motion of phosphatidylserine (PS) across the plasma membrane upon increasing oxidation degree of the membrane. Our computational results show that an increase of the oxidation degree in the lipids leads to a decrease of the free energy barrier for translocation of PS through the membrane. In other words, oxidation of the lipids facilitates PS flip-flop motion across the membrane, because in native phospholipid bilayers this is only a “rare event” due to the high energy barriers for the translocation of PS. The present study provides an atomic-scale insight into the mechanisms of the PS flip-flop upon oxidation of lipids, as produced for example by cold atmospheric plasma, in living cells. |
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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 |
000413045800010 |
Publication Date |
2017-04-05 |
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 |
1612-8850 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.846 |
Times cited |
9 |
Open Access |
Not_Open_Access |
Notes |
Fonds Wetenschappelijk Onderzoek, 1200216N ; |
Approved |
Most recent IF: 2.846 |
Call Number |
PLASMANT @ plasmant @c:irua:149567 |
Serial |
4910 |
Permanent link to this record |
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Author |
Tennyson, J.; Rahimi, S.; Hill, C.; Tse, L.; Vibhakar, A.; Akello-Egwel, D.; Brown, D.B.; Dzarasova, A.; Hamilton, J.R.; Jaksch, D.; Mohr, S.; Wren-Little, K.; Bruckmeier, J.; Agarwal, A.; Bartschat, K.; Bogaerts, A.; Booth, J.-P.; Goeckner, M.J.; Hassouni, K.; Itikawa, Y.; Braams, B.J.; Krishnakumar, E.; Laricchiuta, A.; Mason, N.J.; Pandey, S.; Petrovic, Z.L.; Pu, Y.-K.; Ranjan, A.; Rauf, S.; Schulze, J.; Turner, M.M.; Ventzek, P.; Whitehead, J.C.; Yoon, J.-S. |
Title |
QDB: a new database of plasma chemistries and reactions |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
Volume |
26 |
Issue |
26 |
Pages |
055014 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
One of the most challenging and recurring problems when modeling plasmas is the lack of data on the key atomic and molecular reactions that drive plasma processes. Even when there are data for some reactions, complete and validated datasets of chemistries are rarely available. This hinders research on plasma processes and curbs development of industrial applications. The QDB project aims to address this problem by providing a platform for provision, exchange, and validation of chemistry datasets. A new data model developed for QDB is presented. QDB collates published data on both electron scattering and heavy-particle reactions. These data are formed into reaction sets, which are then validated against experimental data where possible. This process produces both complete chemistry sets and identifies key reactions that are currently unreported in the literature. Gaps in the datasets can be filled using established theoretical methods. Initial validated chemistry sets for SF6/CF4/O2 and SF6/CF4/N2/H2 are presented as examples. |
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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 |
000398394500001 |
Publication Date |
2017-04-04 |
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 |
1361-6595 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.302 |
Times cited |
18 |
Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 3.302 |
Call Number |
PLASMANT @ plasmant @ c:irua:142206 |
Serial |
4549 |
Permanent link to this record |
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Author |
Takatsu, H.; Hernandez, O.; Yoshimune, W.; Prestipino, C.; Yamamoto, T.; Tassel, C.; Kobayashi, Y.; Batuk, D.; Shibata, Y.; Abakumov, A.M.; Brown, C.M.; Kageyama, H. |
Title |
Cubic lead perovskite PbMoO3 with anomalous metallic behavior |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
|
Volume |
95 |
Issue |
15 |
Pages |
155105 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A previously unreported Pb-based perovskite PbMoO3 is obtained by high-pressure and high-temperature synthesis. This material crystallizes in the Pm3m cubic structure at room temperature, making it distinct from typical Pb-based perovskite oxides with a structural distortion. PbMoO3 exhibits a metallic behavior down to 0.1 K with an unusual T-sublinear dependence of the electrical resistivity. Moreover, a large specific heat is observed at low temperatures accompanied by a peak in C-P/T-3 around 10 K, in marked contrast to the isostructural metallic system SrMoO3. These transport and thermal properties for PbMoO3, taking into account anomalously large Pb atomic displacements detected through diffraction experiments, are attributed to a low-energy vibrational mode, associated with incoherent off-centering of lone-pair Pb2+ cations. We discuss the unusual behavior of the electrical resistivity in terms of a polaronlike conduction, mediated by the strong coupling between conduction electrons and optical phonons of the local low-energy vibrational mode. |
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Place of Publication |
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Wos |
000440605700001 |
Publication Date |
2017-04-04 |
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 |
2469-9969; 2469-9950 |
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:167288 |
Serial |
7743 |
Permanent link to this record |
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Author |
Mulkers, J.; Van Waeyenberge, B.; Milošević, M.V. |
Title |
Effects of spatially engineered Dzyaloshinskii-Moriya interaction in ferromagnetic films |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
95 |
Issue |
95 |
Pages |
144401 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The Dzyaloshinskii-Moriya interaction (DMI) is a chiral interaction that favors formation of domain walls. Recent experiments and ab initio calculations show that there are multiple ways to modify the strength of the interfacially induced DMI in thin ferromagnetic films with perpendicular magnetic anisotropy. In this paper we reveal theoretically the effects of spatially varied DMI on the magnetic state in thin films. In such heterochiral 2D structures we report several emergent phenomena, ranging from the equilibrium spin canting at the interface between regions with different DMI, over particularly strong confinement of domain walls and skyrmions within high-DMI tracks, to advanced applications such as domain tailoring nearly at will, design of magnonic waveguides, and much improved skyrmion racetrack memory. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Wos |
000399382100003 |
Publication Date |
2017-04-03 |
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 |
2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
60 |
Open Access |
|
Notes |
Fonds Wetenschappelijk Onderzoek, G098917N ; |
Approved |
Most recent IF: 3.836 |
Call Number |
CMT @ cmt @ c:irua:141917 |
Serial |
4534 |
Permanent link to this record |
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Author |
Kim, E.; Roosen, J.; Horckmans, L.; Spooren, J.; Broos, K.; Binnemans, K.; Vrancken, K.C.M.; Quaghebeur, M. |
Title |
Process development for hydrometallurgical recovery of valuable metals from sulfide-rich residue generated in a secondary lead smelter |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Hydrometallurgy |
Abbreviated Journal |
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Volume |
169 |
Issue |
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Pages |
589-598 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
Abstract |
Two routes were investigated to selectively recover lead and minor metals (Cu, Ni, Zn) from a sulfide-rich lead smelter residue, matte. The first route comprises a two-step leaching process that combines Fe(III)-HNO3 leaching with roasting, followed by water leaching. In the first step, the efficiency of Pb leaching was 90% at the optimum condition (L/S ratio 8, 0.5 mol.L-1 HNO3, 0.15 mol.L-1 Fe(III), 25 degrees C). In the second step, roasting at 600 degrees C followed by water leaching at 50 degrees C selectively leached Ni, Cu, and Zn while fully converting iron sulfides to oxides. One-step oxidative pressure leaching in HNO3 was investigated as an alternative to simultaneously leach Pb, Cu, Ni and Zn. At the optimal conditions (130 degrees C, 60 min, 0.3 mol.L-1 HNO3, 0.07 mol.L-1 Fe(III), L/S ratio 20), Pb, Cu, Zn and Ni leaching were 92, 60, 70 and 66%, respectively, while Fe leaching remained low (2%). The leachates obtained from both leaching routes were treated by ion-exchange adsorption with diethylenetriaminepentaacetic acid (DTPA) functionalized chitosan-silica hybrid materials to investigate the selective recovery of Cu, Zn and Ni. The adsorption order appeared to be in the same order as the corresponding stability constants for complexes between the respective metal ions and free DTPA: Ca(II) < Zn(II) < Pb (II) approximate to Ni(II) < Cu(II). This allows not only to selectively recover Cu, Zn and Ni from the leachates, but also to mutually separate them by using the functionalized resin as a stationary phase in column chromatography. To avoid adsorbent contamination, Fe(III) and Pb(II) may be removed from the leachates in a pre-treatment step. Based on these results, the investigated methods can be combined as process steps of two possible routes for the selective recovery of valuable metals from the studied secondary lead smelting residue. The two-step leaching process seems to be superior since a more concentrated solution of Cu, Ni, and Zn is produced in the 2nd leaching step with low capital cost. |
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Place of Publication |
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Language |
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Wos |
000401878200070 |
Publication Date |
2017-04-03 |
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 |
0304-386x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
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:144300 |
Serial |
8414 |
Permanent link to this record |
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Author |
Petrovic, M.D.; Peeters, F.M. |
Title |
Quantum transport in graphene Hall bars : effects of side gates |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Solid state communications |
Abbreviated Journal |
Solid State Commun |
Volume |
257 |
Issue |
257 |
Pages |
20-26 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Quantum electron transport in side-gated graphene Hall bars is investigated in the presence of quantizing external magnetic fields. The asymmetric potential of four side-gates distorts the otherwise flat bands of the relativistic Landau levels, and creates new propagating states in the Landau spectrum (i.e. snake states). The existence of these new states leads to an interesting modification of the bend and Hall resistances, with new quantizing plateaus appearing in close proximity of the Landau levels. The electron guiding in this system can be understood by studying the current density profiles of the incoming and outgoing modes. From the fact that guided electrons fully transmit without any backscattering (similarly to edge states), we are able to analytically predict the values of the quantized resistances, and they match the resistance data we obtain with our numerical (tight-binding) method. These insights in the electron guiding will be useful in predicting the resistances for other side-gate configurations, and possibly in other system geometries, as long as there is no backscattering of the guided states. |
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 |
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Wos |
000401101400005 |
Publication Date |
2017-04-02 |
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 |
0038-1098 |
ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
1.554 |
Times cited |
|
Open Access |
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Notes |
; This work was supported by the Methusalem programme of the Flemish government. One of us (F. M. Peeters) acknowledges correspondence with K. Novoselov. ; |
Approved |
Most recent IF: 1.554 |
Call Number |
UA @ lucian @ c:irua:143761 |
Serial |
4604 |
Permanent link to this record |
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Author |
Ghidelli, M.; Idrissi, H.; Gravier, S.; Blandin, J.-J.; Raskin, J.-P.; Schryvers, D.; Pardoen, T. |
Title |
Homogeneous flow and size dependent mechanical behavior in highly ductile Zr 65 Ni 35 metallic glass films |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
131 |
Issue |
131 |
Pages |
246-259 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Motivated by recent studies demonstrating a high strength – high ductility potential of nano-scale metallic glass samples, the mechanical response of freestanding Zr65Ni35 film with sub-micron thickness has been investigated by combining advanced on-chip tensile testing and electron microscopy. Large deformation up to 15% is found for specimen thicknesses below 500 nm with variations depending on specimen size and frame compliance. The deformation is homogenous until fracture, with no evidence of shear banding. The yield stress is doubled when decreasing the specimen cross-section, reaching ~3 GPa for small cross-sections. The fracture strain variation is related to both the stability of the test device and to the specimen size. The study concludes on clear disconnect between the mechanisms controlling the onset of plasticity and the fracture process. |
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Corporate Author |
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Publisher |
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Place of Publication |
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Wos |
000402343400023 |
Publication Date |
2017-03-31 |
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 |
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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 |
42 |
Open Access |
OpenAccess |
Notes |
This work has been funded by the Belgian Science Policy through the IAP 7/21 project. We acknowledge IDS-FunMat for the PhD financial support.We thank the Renatech network and the PTA (Plateforme Technologique Amont) in Grenoble (France) for TFMG deposition facilities. The WINFAB infrastructure at the UCL and the help of R. Vayrette and M. Coulombier for the on-chip tests. H. Idrissi is currently mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). |
Approved |
Most recent IF: 5.301 |
Call Number |
EMAT @ emat @ c:irua:142642 |
Serial |
4562 |
Permanent link to this record |