|
Records |
|
Author |
Wu, S.; Luo, X.; Turner, S.; Peng, H.; Lin, W.; Ding, J.; David, A.; Wang, B.; Van Tendeloo, G.; Wang, J.; Wu, T.; |
|
Title |
Nonvolatile resistive switching in Pt/LaAlO3/SrTiO3 heterostructures |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Physical review X |
Abbreviated Journal |
Phys Rev X |
|
Volume |
3 |
Issue |
4 |
Pages |
041027-14 |
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
Abstract |
Resistive switching heterojunctions, which are promising for nonvolatile memory applications, usually share a capacitorlike metal-oxide-metal configuration. Here, we report on the nonvolatile resistive switching in Pt/LaAlO3/SrTiO3 heterostructures, where the conducting layer near the LaAlO3/SrTiO3 interface serves as the unconventional bottom electrode although both oxides are band insulators. Interestingly, the switching between low-resistance and high-resistance states is accompanied by reversible transitions between tunneling and Ohmic characteristics in the current transport perpendicular to the planes of the heterojunctions. We propose that the observed resistive switching is likely caused by the electric-field-induced drift of charged oxygen vacancies across the LaAlO3/SrTiO3 interface and the creation of defect-induced gap states within the ultrathin LaAlO3 layer. These metal-oxide-oxide heterojunctions with atomically smooth interfaces and defect-controlled transport provide a platform for the development of nonvolatile oxide nanoelectronics that integrate logic and memory devices. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
College Park, Md |
Editor |
|
|
Language |
|
Wos |
000328862400001 |
Publication Date |
2013-12-17 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2160-3308; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
12.789 |
Times cited |
77 |
Open Access |
|
|
Notes |
FWO;FP7;IFOX; Countatoms; Hercules |
Approved |
Most recent IF: 12.789; 2013 IF: 8.463 |
|
Call Number |
UA @ lucian @ c:irua:112524 |
Serial |
2365 |
Permanent link to this record |
|
|
|
|
Author |
Petrovic, M.D.; Peeters, F.M.; Chaves, A.; Farias, G.A. |
|
Title |
Conductance maps of quantum rings due to a local potential perturbation |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
|
Volume |
25 |
Issue |
49 |
Pages |
495301-495309 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
We performed a numerical simulation of the dynamics of a Gaussian shaped wavepacket inside a small sized quantum ring, smoothly connected to two leads and exposed to a perturbing potential of a biased atomic force microscope tip. Using the Landauer formalism, we calculated conductance maps of this system in the case of single and two subband transport. We explain the main features in the conductance maps as due to the AFM tip influence on the wavepacket phase and amplitude. In the presence of an external magnetic field, the tip modifies the phi(0) periodic Aharonov-Bohm oscillation pattern into a phi(0)/2 periodic Al'tshuler-Aronov-Spivak oscillation pattern. Our results in the case of multiband transport suggest tip selectivity to higher subbands, making them more observable in the total |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
London |
Editor |
|
|
Language |
|
Wos |
000327181400002 |
Publication Date |
2013-11-01 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
2.649 |
Times cited |
12 |
Open Access |
|
|
Notes |
; This work was supported by the Methusalem programme of the Flemish government, the CNPq-FWO bilateral programme and PNPD and FUNCAP/PRONEX grants. ; |
Approved |
Most recent IF: 2.649; 2013 IF: 2.223 |
|
Call Number |
UA @ lucian @ c:irua:112694 |
Serial |
478 |
Permanent link to this record |
|
|
|
|
Author |
Shariat, M.; Hosseini, S.I.; Shokri, B.; Neyts, E.C. |
|
Title |
Plasma enhanced growth of single walled carbon nanotubes at low temperature : a reactive molecular dynamics simulation |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
|
Volume |
65 |
Issue |
|
Pages |
269-276 |
|
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
Abstract |
Low-temperature growth of carbon nanotubes (CNTs) has been claimed to provide a route towards chiral-selective growth, enabling a host of applications. In this contribution, we employ reactive molecular dynamics simulations to demonstrate how plasma-based deposition allows such low-temperature growth. We first show how ion bombardment during the growth affects the carbon dissolution and precipitation process. We then continue to demonstrate how a narrow ion energy window allows CNT growth at 500 K. Finally, we also show how CNTs in contrast cannot be grown in thermal CVD at this low temperature, but only at high temperature, in agreement with experimental data. (C) 2013 Elsevier Ltd. All rights reserved. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
|
Language |
|
Wos |
000326773200031 |
Publication Date |
2013-08-23 |
|
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 |
21 |
Open Access |
|
|
Notes |
|
Approved |
Most recent IF: 6.337; 2013 IF: 6.160 |
|
Call Number |
UA @ lucian @ c:irua:112697 |
Serial |
2635 |
Permanent link to this record |
|
|
|
|
Author |
Monico, L.; Rosi, F.; Miliani, C.; Daveri, A.; Brunetti, B.G. |
|
Title |
Non-invasive identification of metal-oxalate complexes on polychrome artwork surfaces by reflection mid-infrared spectroscopy |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Spectrochimica acta: part A: molecular and biomolecular spectroscopy |
Abbreviated Journal |
|
|
Volume |
116 |
Issue |
|
Pages |
270-280 |
|
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
|
Abstract |
In this work a reflection mid-infrared spectroscopy study of twelve metal-oxalate complexes, of interest in art conservation science as alteration compounds, was performed. Spectra of the reference materials highlighted the presence of derivative-like and/or inverted features for the fundamental vibrational modes as result of the main contribution from the surface component of the reflected light. In order to provide insights in the interpretation of theses spectral distortions, reflection spectra were compared with conventional transmission ones. The Kramers-Kronig (KK) algorithm, employed to correct for the surface reflection distortions, worked properly only for the derivative-like bands. Therefore, to pay attention to the use of this algorithm when interpreting the reflection spectra is recommended. The outcome of this investigation was exploited to discriminate among different oxalates on thirteen polychrome art-works analyzed in situ by reflection mid-infrared spectroscopy. The visualization of the v(s)(CO) modes (1400-1200 cm(-1)) and low wavenumber bands (below 900 cm(-1)) in the raw reflection profiles allowed Ca, Cu and Zn oxalates to be identified. Further information about the speciation of different hydration forms of calcium oxalates were obtained by using the KK transform. The work proves reflection mid-infrared spectroscopy to be a reliable and sensitive spectro-analytical method for identifying and mapping different metal-oxalate alteration compounds on the surface of artworks, thus providing conservation scientists with a non-invasive tool to obtain information on the state of conservation and causes of alteration of artworks. (C) 2013 Elsevier B.V. All rights reserved. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000326207900035 |
Publication Date |
2013-07-12 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
1386-1425 |
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:112701 |
Serial |
8313 |
Permanent link to this record |
|
|
|
|
Author |
Krstajić, P.M.; Van Duppen, B.; Peeters, F.M. |
|
Title |
Plasmons and their interaction with electrons in trilayer graphene |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
Volume |
88 |
Issue |
19 |
Pages |
195423 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
The interaction between electrons and plasmons in trilayer graphene is investigated within the Overhauser approach resulting in the “plasmaron” quasiparticle. This interaction is cast into a field theoretical problem, and its effect on the energy spectrum is calculated using improved Wigner-Brillouin perturbation theory. The plasmaron spectrum is shifted with respect to the bare electron spectrum by ΔE(k)∼150−200meV for ABC stacked trilayer graphene and for ABA trilayer graphene by ΔE(k)∼30−150 meV[ ΔE(k) ∼1 −5meV] for the hyperbolic (linear) part of the spectrum. The shift in general increases with the electron concentration and electron momentum. The dispersion of plasmarons is more pronounced in ABC stacked than in ABA stacked trilayer graphene, because of the different energy band structure and their different plasmon dispersion. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000327239200003 |
Publication Date |
2013-11-21 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
1098-0121 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
10 |
Open Access |
|
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), by the ESF-EuroGRAPHENE project CON-GRAN, and by the Serbian Ministry of Education and Science, within the Project No. TR 32008. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
|
Call Number |
CMT @ cmt @ c:irua:112702 |
Serial |
4489 |
Permanent link to this record |
|
|
|
|
Author |
Čukarić, N.A.; Tadić, M.Z.; Partoens, B.; Peeters, F.M. |
|
Title |
30-band k\cdot p model of electron and hole states in silicon quantum wells |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
Volume |
88 |
Issue |
20 |
Pages |
205306 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
We modeled the electron and hole states in Si/SiO2 quantum wells within a basis of standing waves using the 30-band k . p theory. The hard-wall confinement potential is assumed, and the influence of the peculiar band structure of bulk silicon on the quantum-well sub-bands is explored. Numerous spurious solutions in the conduction-band and valence-band energy spectra are found and are identified to be of two types: (1) spurious states which have large contributions of the bulk solutions with large wave vectors (the high-k spurious solutions) and (2) states which originate mainly from the spurious valley outside the Brillouin zone (the extravalley spurious solutions). An algorithm to remove all those nonphysical solutions from the electron and hole energy spectra is proposed. Furthermore, slow and oscillatory convergence of the hole energy levels with the number of basis functions is found and is explained by the peculiar band mixing and the confinement in the considered quantum well. We discovered that assuming the hard-wall potential leads to numerical instability of the hole states computation. Nonetheless, allowing the envelope functions to exponentially decay in a barrier of finite height is found to improve the accuracy of the computed hole states. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000327161500007 |
Publication Date |
2013-11-20 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
10 |
Open Access |
|
|
Notes |
; This work was supported by the Ministry of Education, Science, and Technological Development of Serbia, the Belgian Science Policy (IAP), the Flemish fund for Scientific Research (FWO-Vl), and the Methusalem programme of the Flemish government. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
|
Call Number |
UA @ lucian @ c:irua:112704 |
Serial |
18 |
Permanent link to this record |
|
|
|
|
Author |
Marikutsa, A.V.; Rumyantseva, M.N.; Frolov, D.D.; Morozov, I.V.; Boltalin, A.I.; Fedorova, A.A.; Petukhov, I.A.; Yashina, L.V.; Konstantinova, E.A.; Sadovskaya, E.M.; Abakumov, A.M.; Zubavichus, Y.V.; Gaskov, A.M.; |
|
Title |
Role of PdOx and RuOy clusters in oxygen exchange between nanocrystalline tin dioxide and the gas phase |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
|
Volume |
117 |
Issue |
45 |
Pages |
23858-23867 |
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
Abstract |
The effect of palladium- and ruthenium-based clusters on nanocrystalline tin dioxide interaction with oxygen was studied by temperature-programmed oxygen isotopic exchange with mass-spectrometry detection. The modification of aqueous sol-gel prepared SnO2 by palladium and, to a larger extent, by ruthenium, increases surface oxygen concentration on the materials. The revealed effects on oxygen exchange-lowering the threshold temperature, separation of surface oxygen contribution to the process, increase of heteroexchange rate and oxygen diffusion coefficient, decrease of activation energies of exchange and diffusion-were more intensive for Ru-modified SnO2 than in the case of SnO2/Pd. The superior promoting activity of ruthenium on tin dioxide interaction with oxygen was interpreted by favoring the dissociative O-2 adsorption and increasing the oxygen mobility, taking into account the structure and chemical composition of the modifier clusters. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
|
Language |
|
Wos |
000327110500046 |
Publication Date |
2013-10-04 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
4.536 |
Times cited |
20 |
Open Access |
|
|
Notes |
|
Approved |
Most recent IF: 4.536; 2013 IF: 4.835 |
|
Call Number |
UA @ lucian @ c:irua:112706 |
Serial |
2924 |
Permanent link to this record |
|
|
|
|
Author |
Park, K.; De Beule, C.; Partoens, B. |
|
Title |
The ageing effect in topological insulators : evolution of the surface electronic structure of Bi2Se3 upon K adsorption |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
|
Volume |
15 |
Issue |
|
Pages |
113031-16 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
Topological insulators (TIs) have attracted a lot of interest in recent years due to their topologically protected surface states, as well as exotic proximity-induced phenomena and device applications for TI heterostructures. Since the first experimental studies of TIs, angle-resolved photoemission spectra (ARPES) showed that the electronic structure of the topological surface states significantly changes as a function of time after cleavage. The origin and underlying mechanism of this ageing effect are still under debate, despite its importance. Here we investigate the evolution of the surface Dirac cone for Bi2Se3 films upon asymmetric potassium (K) adsorption, using density-functional theory and a tight-binding model. We find that the K adatoms induce short-ranged downward band bending within 2-3 nm from the surface, due to charge transfer from the adatoms to the TI. These findings are in contrast to earlier proposals in the literature, that propose a long-ranged downward band bending up to 15 nm from the surface. Furthermore, as the charge transfer increases, we find that a new Dirac cone, localized slightly deeper into the TI than the original one, appears at the K-adsorbed surface, originating from strong Rashba-split conduction-band states. Our results suggest possible reinterpretations of experiments because the new Dirac cone might have been observed in ARPES measurements instead of the original one that appears immediately after cleavage. Our findings are consistent with ARPES data and provide insight into building TI-heterostructure devices by varying the band-bending potential or film thickness. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
|
Language |
|
Wos |
000326876100006 |
Publication Date |
2013-11-13 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
1367-2630; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.786 |
Times cited |
45 |
Open Access |
|
|
Notes |
; KP was supported by National Science Foundation grant numbers DMR-0804665 and DMR-1206354 and SDSC Trestles under DMR060009N. CDB was supported by the Research Foundation Flanders (FWO). ; |
Approved |
Most recent IF: 3.786; 2013 IF: 3.671 |
|
Call Number |
UA @ lucian @ c:irua:112707 |
Serial |
84 |
Permanent link to this record |
|
|
|
|
Author |
Skaltsas, T.; Ke, X.; Bittencourt, C.; Tagmatarchis, N. |
|
Title |
Ultrasonication induces oxygenated species and defects onto exfoliated graphene |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
|
Volume |
117 |
Issue |
44 |
Pages |
23272-23278 |
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
Abstract |
The effect of ultrasonication parameters, such as time and power applied, to exfoliate graphite in o-dichlorobenzene (o-DCB) and N-methyl-1,2-pyrrolidone (NMP) was examined. It was found that the concentration of graphene was higher in o-DCB, while its dispersibility was increased when sonication was applied for a longer period and/or at higher power. However, spectroscopic examination by X-ray photoelectron spectroscopy (XPS) revealed that ultrasonication causes defects and induces oxygen functional groups in the form of carboxylic acids and ethers/epoxides onto the graphene lattice. Additional proof for the latter arose from Raman, IR, and thermogravimetry studies. The carboxylic acids and ethers/epoxides onto exfoliated graphene were derived from air during ultrasonication and found independent of the solvent used for the exfoliation and the power and/or time ultrasonication applied. Quantitative evaluation of the amount of oxygenated species present on exfoliated graphene as performed by high-resolution XPS revealed that the relative oxygen percentage was higher when exfoliation was performed in NMP. Finally, the sonication time and/or power affected the oxygen content on exfoliated graphene, since extended ultrasonication resulted in a decrease in the oxygen content on exfoliated graphene, with a simultaneous increase of defected sp(3) carbon atoms. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
|
Language |
|
Wos |
000326845400090 |
Publication Date |
2013-10-03 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
4.536 |
Times cited |
65 |
Open Access |
|
|
Notes |
|
Approved |
Most recent IF: 4.536; 2013 IF: 4.835 |
|
Call Number |
UA @ lucian @ c:irua:112710 |
Serial |
3797 |
Permanent link to this record |
|
|
|
|
Author |
Badalyan, S.M.; Matos-Abiague, A.; Fabian, J.; Vignale, G.; Peeters, F.M. |
|
Title |
Spin-orbit-interaction induced singularity of the charge density relaxation propagator |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
Volume |
88 |
Issue |
19 |
Pages |
195402-195405 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
The charge density relaxation propagator of a two-dimensional electron system, which is the slope of the imaginary part of the polarization function, exhibits singularities for bosonic momenta having the order of the spin-orbit momentum and depending on the momentum orientation. We have provided an intuitive understanding for this nonanalytic behavior in terms of the interchirality subband electronic transitions, induced by the combined action of Bychkov-Rashba (BR) and Dresselhaus (D) spin-orbit coupling. It is shown that the regular behavior of the relaxation propagator is recovered in the presence of only one BR or D spin-orbit field or for spin-orbit interaction with equal BR and D coupling strengths. This creates a new possibility to influence carrier relaxation properties by means of an applied electric field. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000326820200005 |
Publication Date |
2013-11-07 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
2 |
Open Access |
|
|
Notes |
; We acknowledge support from the Methusalem program of the Flemish government and the Flemish Science Foundation (FWO-Vl), DFG SFB Grant 689, and NSF Grant DMR-1104788 (G.V.). ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
|
Call Number |
UA @ lucian @ c:irua:112711 |
Serial |
3093 |
Permanent link to this record |
|
|
|
|
Author |
Shakouri, K.; Badalyan, S.M.; Peeters, F.M. |
|
Title |
Helical liquid of snake states |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
Volume |
88 |
Issue |
19 |
Pages |
195404-195405 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
We derive an exact solution to the problem of spin snake states induced in a nonhomogeneous magnetic field by a combined action of the Rashba spin-orbit and Zeeman fields. The electron spin behavior as a function of the cyclotron orbit center position and an external homogeneous magnetic field was obtained. It is shown that in an antisymmetric magnetic field the electron spin in the snake states has only an in-plane projection, perpendicular to the magnetic interface, which vanishes at large positive momenta. Applying an external homogeneous magnetic field adds a finite out-of-plane spin component and simultaneously gaps out the spectral branches, which results in regular beating patterns of the spin current components. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000326820200007 |
Publication Date |
2013-11-07 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
3 |
Open Access |
|
|
Notes |
; This work was supported by the Methusalem program of the Flemish government and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
|
Call Number |
UA @ lucian @ c:irua:112712 |
Serial |
1416 |
Permanent link to this record |
|
|
|
|
Author |
Retuerto, M.; Li, M.R.; Ignatov, A.; Croft, M.; Ramanujachary, K.V.; Chi, S.; Hodges, J.P.; Dachraoui, W.; Hadermann, J.; Tran, T.T.; Halasyamani, P.S.; Grams, C.P.; Hemberger, J.; Greenblatt, M.; |
|
Title |
Polar and magnetic layered A-site and rock salt B-site-ordered NaLnFeWO6 (Ln = La, Nd) perovskites |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
|
Volume |
52 |
Issue |
21 |
Pages |
12482-12491 |
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
Abstract |
We have expanded the double perovskite family of materials with the unusual combination of layered order in the A sublattice and rock salt order over the B sublattice to compounds NaLaFeWO6 and NaNdFeWO6. The materials have been synthesized and studied by powder X-ray diffraction, neutron diffraction, electron diffraction, magnetic measurements, X-ray absorption spectroscopy, dielectric measurements, and second harmonic generation. At room temperature, the crystal structures of both compounds can be defined in the noncentrosymmetric monoclinic P2(1) space group resulting from the combination of ordering both in the A and B sublattices, the distortion of the cell due to tilting of the octahedra, and the displacement of certain cations. The magnetic studies show that both compounds are ordered antiferromagnetically below T-N approximate to 25 K for NaLaFeWO6 and at similar to 21 K for NaNdFeWO6. The magnetic structure of NaNdFeWO6 has been solved with a propagation vector k = (1/2 0 1/2) as an antiferromagnetic arrangement of Fe and Nd moments. Although the samples are potential multiferroics, the dielectric measurements do not show a ferroelectric response. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
|
Language |
|
Wos |
000326669200035 |
Publication Date |
2013-10-18 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
4.857 |
Times cited |
17 |
Open Access |
|
|
Notes |
|
Approved |
Most recent IF: 4.857; 2013 IF: 4.794 |
|
Call Number |
UA @ lucian @ c:irua:112714 |
Serial |
2656 |
Permanent link to this record |
|
|
|
|
Author |
Tan, H.; Egoavil, R.; Béché, A.; Martinez, G.T.; Van Aert, S.; Verbeeck, J.; Van Tendeloo, G.; Rotella, H.; Boullay, P.; Pautrat, A.; Prellier, W. |
|
Title |
Mapping electronic reconstruction at the metal-insulator interface in LaVO3/SrVO3 heterostructures |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
Volume |
88 |
Issue |
15 |
Pages |
155123-155126 |
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
Abstract |
A (LaVO3)6/(SrVO3)(3) superlattice is studied with a combination of sub-A resolved scanning transmission electron microscopy and monochromated electron energy-loss spectroscopy. The V oxidation state is mapped with atomic spatial resolution enabling us to investigate electronic reconstruction at the LaVO3/SrVO3 interfaces. Surprisingly, asymmetric charge distribution is found at adjacent chemically symmetric interfaces. The local structure is proposed and simulated with a double channeling calculation which agrees qualitatively with our experiment. We demonstrate that local strain asymmetry is the likely cause of the electronic asymmetry of the interfaces. The electronic reconstruction at the interfaces extends much further than the chemical composition, varying from 0.5 to 1.2 nm. This distance corresponds to the length of charge transfer previously found in the (LaVO3)./(SrVO3). metal/insulating and the (LaAlO3)./(SrTiO3). insulating/insulating interfaces. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000326087100003 |
Publication Date |
2013-10-21 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
15 |
Open Access |
|
|
Notes |
Hercules; 246791 COUNTATOMS; 278510 VORTEX; 246102 IFOX; 312483 ESTEEM2; FWO; GOA XANES meets ELNES; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
|
Call Number |
UA @ lucian @ c:irua:112733UA @ admin @ c:irua:112733 |
Serial |
1944 |
Permanent link to this record |
|
|
|
|
Author |
Damm, H.; Kelchtermans, A.; Bertha, A.; Van den Broeck, F.; Elen, K.; Martins, J.C.; Carleer, R.; D'Haen, J.; De Dobbelaere, C.; Hadermann, J.; Hardy, A.; Van Bael, M.K.; |
|
Title |
Thermal decomposition synthesis of Al-doped ZnO nanoparticles : an in-depth study |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
RSC advances |
Abbreviated Journal |
Rsc Adv |
|
Volume |
3 |
Issue |
45 |
Pages |
23745-23754 |
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
Abstract |
Al-doped ZnO nanoparticles are synthesized by means of a heating up solution based thermal decomposition method. The synthesis involves a reaction of zinc acetylacetonate hydrate, aluminium acetylacetonate and 1,2-hexadecanediol in the presence of oleic acid and oleyl amine. A proposed reaction mechanism from reagents to monomers is corroborated by analysis of the evolving gases using headspace GC-MS analysis. The Al-doped ZnO nanoparticles synthesized are dynamically stabilized by adsorbed oleate ions, after deprotonation of oleic acid by oleyl amine, as was found by NOESY proton NMR and complementary FTIR spectroscopy. Precession electron diffraction shows a simultaneous increase in lattice parameters with Al concentration. This, together with HAADF-STEM and EDX maps, indicates the incorporation of Al into the ZnO nanoparticles. By the combination of complementary characterization methods during all stages of the synthesis, it is concluded that Al is incorporated into the ZnO wurtzite lattice as a dopant. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000326395800139 |
Publication Date |
2013-10-18 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2046-2069; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.108 |
Times cited |
10 |
Open Access |
|
|
Notes |
|
Approved |
Most recent IF: 3.108; 2013 IF: 3.708 |
|
Call Number |
UA @ lucian @ c:irua:112753 |
Serial |
3627 |
Permanent link to this record |
|
|
|
|
Author |
van Winsen, F.; de Mey, Y.; Lauwers, L.; Van Passel, S.; Vancauteren, M.; Wauters, E. |
|
Title |
Cognitive mapping : a method to elucidate and present farmers' risk perception |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Agricultural Systems |
Abbreviated Journal |
Agr Syst |
|
Volume |
122 |
Issue |
|
Pages |
42-52 |
|
Keywords |
A1 Journal article |
|
Abstract |
Assumptions on the perceptions of risks, made in agricultural economics literature, are recognized to be over-simplistic. For example most studies assume that risks are independent and static, while in reality most risks are interlinked and dynamic. We propose an alternative method to identify and present risk perception, closer to the actual comprehension of risk by farmers. Grounded theory is used to investigate the perceptions of risk by farmers while avoiding prior assumptions. Main findings are: (i) farmers have difficulty to rank or score probability and impact of risks in a (semi)quantitative manner; (ii) farmers attach different meanings to risk, when the focus shifts between, uncertain event, probability or value at stake and; (iii) farmers perceive risks as being interrelated. Based on these findings, we propose that farmers' risk perception can be best understood as a network of interrelated notions of uncertain events, their effects and uncertain outcomes. Furthermore, cognitive mapping is suggested to elucidate and present these networks. We test cognitive mapping, exploring dairy farmers' risk perception, and demonstrate the appropriateness of this methodology for capturing the complexity and context of perceived risk. Advantages are: (i) the qualitative approach, (ii) the focus on interrelations and context, (iii) the applicability at farm level, (iv) the farmer-driven rather than researcher-driven perspective, and (v) the elucidation of the polyvalent use of the risk concept. Cognitive maps can be used as a communication tool, a risk management tool, and a tool to stimulate bi-directional learning amongst farmers, policy makers, researchers and extension agents. (C) 2013 Elsevier Ltd. All rights reserved. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000326910500005 |
Publication Date |
2013-09-12 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
0308-521x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
2.571 |
Times cited |
27 |
Open Access |
|
|
Notes |
; We would like to acknowledge the Agency for Innovation by Science and Technology of the Flemish Government (IWT) for funding this research. Furthermore we would like to thank the anonymous reviewers for their valuable input. ; |
Approved |
Most recent IF: 2.571; 2013 IF: 2.453 |
|
Call Number |
UA @ admin @ c:irua:112765 |
Serial |
6168 |
Permanent link to this record |
|
|
|
|
Author |
Baken, S.; Sjostedt, C.; Gustafsson, J.P.; Seuntjens, P.; Desmet, N.; De Schutter, J.; Smolders, E. |
|
Title |
Characterisation of hydrous ferric oxides derived from iron-rich groundwaters and their contribution to the suspended sediment of streams |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Applied geochemistry |
Abbreviated Journal |
|
|
Volume |
39 |
Issue |
|
Pages |
59-68 |
|
Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
|
Abstract |
When Fe(II) bearing groundwaters surface in streams, particulate authigenic Fe-rich material is produced by oxidation. Such freshly precipitated Fe minerals may be transported as suspended sediment and have a profound impact on the fate of trace metals and nutrients in rivers. The objective of this study was to monitor changes in mineralogy and composition of authigenic material from its source to streams of increasing order. Groundwaters, surface waters, and suspended sediment in streams of different order were sampled in the Kleine Nete catchment (Belgium), a lowland with Fe-rich groundwaters (3.5-53.8 mg Fe/L; pH 6.3-6.9). Fresh authigenic material (>0.45 mu m) was produced by oxidising filtered (<0.45 mu m) groundwater and surface water. This material contained, on average, 44% Fe, and smaller concentrations of C, P, and Ca. Iron EXAFS (Extended X-ray Absorption Fine Structure) spectroscopy showed that the Fe was present as poorly crystalline hydrous ferric oxides with a structure similar to that of ferrihydrite. The Fe concentration in the suspended sediment samples decreased to 36-40% (stream order 2), and further to 18-26% (stream order 4 and 5). Conversely, the concentrations of organic C, Ca, Si, and trace metals increased with increasing stream order, suggesting mixing of authigenic material with suspended sediment from a different source. The Fe speciation in the suspended sediment was similar to that in fresh authigenic material, but more Fe-Fe interactions were observed, i.e. it was increasingly hydrolysed, suggesting ageing reactions. The suspended sediment in the streams of order 4 and 5 is estimated to contain between 31% and 59% of authigenic material, but more data are needed to refine this estimate. The authigenic material is an important sink for P in these streams which may alleviate the eutrophication risk in this catchment. (C) 2013 Elsevier Ltd. All rights reserved. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000327488700007 |
Publication Date |
2013-10-05 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
0883-2927 |
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:112769 |
Serial |
7595 |
Permanent link to this record |
|
|
|
|
Author |
Rodríguez-Fernández, D.; Altantzis, T.; Heidari, H.; Bals, S.; Liz-Marzan, L.M. |
|
Title |
A protecting group approach toward synthesis of Au-silica Janus nanostars |
Type |
A1 Journal article |
|
Year |
2014 |
Publication |
Chemical communications |
Abbreviated Journal |
Chem Commun |
|
Volume |
50 |
Issue |
1 |
Pages |
79-81 |
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
Abstract |
The concept of protecting groups, widely used in organic chemistry, has been applied for the synthesis of Au-silica Janus stars, in which gold branches protrude from one half of Au-silica Janus spheres. This configuration opens up new possibilities to apply the plasmonic properties of gold nanostars, as well as a variety of chemical functionalizations on the silica component. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
London |
Editor |
|
|
Language |
|
Wos |
000327606000017 |
Publication Date |
2013-10-22 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
1359-7345;1364-548X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
6.319 |
Times cited |
26 |
Open Access |
OpenAccess |
|
Notes |
262348 Esmi; 335078 Colouratom; 267867 Plasmaquo; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 6.319; 2014 IF: 6.834 |
|
Call Number |
UA @ lucian @ c:irua:112774 |
Serial |
2732 |
Permanent link to this record |
|
|
|
|
Author |
Shariat, M.; Shokri, B.; Neyts, E.C. |
|
Title |
On the low-temperature growth mechanism of single walled carbon nanotubes in plasma enhanced chemical vapor deposition |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Chemical physics letters |
Abbreviated Journal |
Chem Phys Lett |
|
Volume |
590 |
Issue |
|
Pages |
131-135 |
|
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
Abstract |
Despite significant progress in single walled carbon nanotube (SWCNT) production by plasma enhanced chemical vapor deposition (PECVD), the growth mechanism in this method is not clearly understood. We employ reactive molecular dynamics simulations to investigate how plasma-based deposition allows growth at low temperature. We first investigate the SWCNT growth mechanism at low and high temperatures under conditions similar to thermal CVD and PECVD. We then show how ion bombardment during the nucleation stage increases the carbon solubility in the catalyst at low temperature. Finally, we demonstrate how moderate energy ions sputter amorphous carbon allowing for SWCNT growth at 500 K. (C) 2013 Elsevier B. V. All rights reserved. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
|
Language |
|
Wos |
000327721000024 |
Publication Date |
2013-10-27 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
0009-2614; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
1.815 |
Times cited |
14 |
Open Access |
|
|
Notes |
|
Approved |
Most recent IF: 1.815; 2013 IF: 1.991 |
|
Call Number |
UA @ lucian @ c:irua:112775 |
Serial |
2439 |
Permanent link to this record |
|
|
|
|
Author |
Morozov, V.A.; Bertha, A.; Meert, K.W.; Van Rompaey, S.; Batuk, D.; Martinez, G.T.; Van Aert, S.; Smet, P.F.; Raskina, M.V.; Poelman, D.; Abakumov, A.M.; Hadermann, J.; |
|
Title |
Incommensurate modulation and luminescence in the CaGd2(1-x)Eu2x(MoO4)4(1-y)(WO)4y (0\leq x\leq1, 0\leq y\leq1) red phosphors |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
|
Volume |
25 |
Issue |
21 |
Pages |
4387-4395 |
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
Abstract |
Scheelite related compounds (A',A '') [(B',B '')O-4], with B', B '' = W and/or Mo are promising new light-emitting materials for photonic applications, including phosphor converted LEDs (light-emitting diodes). In this paper, the creation and ordering of A-cation vacancies and the effect of cation substitutions in the scheelite-type framework are investigated as a factor for controlling the scheelite-type structure and luminescent properties. CaGd2(1-x)Eu2x(MoO4)(4(1-y))(WO4)(4y) (0 <= x <= 1, 0 <= y <= 1) solid solutions with scheelite-type structure were synthesized by a solid state method, and their structures were investigated using a combination of transmission electron microscopy techniques and powder X-ray diffraction. Within this series all complex molybdenum oxides have (3 + 2)D incommensurately modulated structures with superspace group I4(1)/a(alpha,beta,0)00(-beta,alpha,0)00, while the structures of all tungstates are (3 + 1)D incommensurately modulated with superspace group I2/b(alpha beta 0)00. In both cases the modulation arises because of cation-vacancy ordering at the A site. The prominent structural motif is formed by columns of A-site vacancies running along the c-axis. These vacant columns occur in rows of two or three aligned along the [110] direction of the scheelite subcell. The replacement of the smaller Gd3+ by the larger Eu3+ at the A-sublattice does not affect the nature of the incommensurate modulation, but an increasing replacement of Mo6+ by W6+ switches the modulation from (3 + 2)D to (3 + 1)D regime. Thus, these solid solutions can be considered as a model system where the incommensurate modulation can be monitored as a function of cation nature while the number of cation vacancies at the A sites remain constant upon the isovalent cation replacement. All compounds' luminescent properties were measured, and the optical properties were related to the structural properties of the materials. CaGd2(1-x)(MoO4)(4(1-y))(WO4)(4y) phosphors emit intense red light dominated by the D-5(0)-F-7(2) transition at 612 nm, along with other transitions from the D-5(1) and D-5(0) excited states. The intensity of the 5D0-7F2 transition reaches a maximum at x = 0.5 for y = 0 and 1. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
|
Language |
|
Wos |
000327045000030 |
Publication Date |
2013-09-24 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
9.466 |
Times cited |
63 |
Open Access |
|
|
Notes |
|
Approved |
Most recent IF: 9.466; 2013 IF: 8.535 |
|
Call Number |
UA @ lucian @ c:irua:112776 |
Serial |
1594 |
Permanent link to this record |
|
|
|
|
Author |
Idrissi, H.; Renard, K.; Schryvers, D.; Jacques, P.J. |
|
Title |
TEM investigation of the formation mechanism of deformation twins in Fe-Mn-Si-Al TWIP steels |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Philosophical magazine |
Abbreviated Journal |
Philos Mag |
|
Volume |
93 |
Issue |
35 |
Pages |
4378-4391 |
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
Abstract |
The microstructure of a Fe-Mn-Si-Al twinning-induced plasticity (TWIP) steel exhibiting remarkable work hardening rate under uniaxial tensile deformation was investigated using transmission electron microscopy to uncover the mechanism(s) controlling the nucleation and growth of the mechanically induced twins. The results show that the stair-rod cross-slip deviation mechanism is necessary for the formation of the twins, while large extrinsic stacking faults homogenously distributed within the grains could act as preferential sources for the activation of the deviation process. The influence of such features on the thickness and strength of the twins and the resulting mechanical behaviour is discussed and compared to similar works recently performed on Fe-Mn-C TWIP steels. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000327478300005 |
Publication Date |
2013-09-12 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
1478-6435;1478-6443; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
1.505 |
Times cited |
15 |
Open Access |
|
|
Notes |
|
Approved |
Most recent IF: 1.505; 2013 IF: 1.427 |
|
Call Number |
UA @ lucian @ c:irua:112815 |
Serial |
3478 |
Permanent link to this record |
|
|
|
|
Author |
Berdiyorov, G.R.; Peeters, F.M. |
|
Title |
Influence of vacancy defects on the thermal stability of silicene: a reactive molecular dynamics study |
Type |
A1 Journal article |
|
Year |
2014 |
Publication |
RSC advances |
Abbreviated Journal |
Rsc Adv |
|
Volume |
4 |
Issue |
3 |
Pages |
1133-1137 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
The effect of vacancy defects on the structural properties and the thermal stability of free standing silicene – a buckled structure of hexagonally arranged silicon atoms – is studied using reactive molecular dynamics simulations. Pristine silicene is found to be stable up to 1500 K, above which the system transits to a three-dimensional amorphous configuration. Vacancy defects result in local structural changes in the system and considerably reduce the thermal stability of silicene: depending on the size of the vacancy defect, the critical temperature decreases by more than 30%. However, the system is still found to be stable well above room temperature within our simulation time of 500 ps. We found that the, stability of silicene can be increased by saturating the dangling bonds at the defect edges by foreign atoms (e.g., hydrogen). |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000327868400015 |
Publication Date |
2013-11-06 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2046-2069; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.108 |
Times cited |
62 |
Open Access |
|
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. The authors are grateful to Prof. Adri van Duin for his support with the ReaxFF force field. ; |
Approved |
Most recent IF: 3.108; 2014 IF: 3.840 |
|
Call Number |
UA @ lucian @ c:irua:112829 |
Serial |
1658 |
Permanent link to this record |
|
|
|
|
Author |
Wang, H.; Picot, T.; Houben, K.; Moorkens, T.; Grigg, J.; Van Haesendonck, C.; Biermans, E.; Bals, S.; Brown, S.A.; Vantomme, A.; Temst, K.; Van Bael, M.J.; |
|
Title |
The superconducting proximity effect in epitaxial Al/Pb nanocomposites |
Type |
A1 Journal article |
|
Year |
2014 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
|
Volume |
27 |
Issue |
1 |
Pages |
015008-8 |
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
Abstract |
We have investigated the superconducting properties of Pb nanoparticles with a diameter ranging from 8 to 20 nm, synthesized by Pb+ ion implantation in a crystalline Al matrix. A detailed structural characterization of the nanocomposites reveals the highly epitaxial relation between the Al crystalline matrix and the Pb nanoparticles. The Al/Pb nanocomposites display a single superconducting transition, with the critical temperature T-c increasing with the Pb content. The dependence of T-c on the Pb/Al volume ratio was compared with theoretical models of the superconducting proximity effect based on the bulk properties of Al and Pb. A very good correspondence with the strong-coupling proximity effect model was found, with an electron-phonon coupling constant in the Pb nanoparticles slightly reduced compared to bulk Pb. Our result differs from other studies on Pb nanoparticle based proximity systems where weak-coupling models were found to better describe the T-c dependence. We infer that the high interface quality resulting from the ion implantation synthesis method is a determining factor for the superconducting properties. Critical field and critical current measurements support the high quality of the nanocomposite superconducting films. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
|
Language |
|
Wos |
000328275000010 |
Publication Date |
2013-11-28 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
0953-2048;1361-6668; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
2.878 |
Times cited |
2 |
Open Access |
Not_Open_Access |
|
Notes |
; This work was supported by the Research Foundation-Flanders (FWO), the KU Leuven BOF Concerted Research Action programs (GOA/09/006, the KU Leuven BOF CREA/12/015 project, and GOA/14/007) and the EU FP7 program SPIRIT (227012). TP and KH are postdoctoral research fellow and doctoral fellow of the FWO. ; |
Approved |
Most recent IF: 2.878; 2014 IF: 2.325 |
|
Call Number |
UA @ lucian @ c:irua:112833 |
Serial |
3599 |
Permanent link to this record |
|
|
|
|
Author |
Berdiyorov, G.R.; Savel'ev, S.E.; Kusmartsev, F.V.; Peeters, F.M. |
|
Title |
In-phase motion of Josephson vortices in stacked SNS Josephson junctions : effect of ordered pinning |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
|
Volume |
26 |
Issue |
12 |
Pages |
125010-125016 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
The dynamics of Josephson vortices (fluxons) in artificial stacks of superconducting-normal-superconducting Josephson junctions is investigated using the anisotropic time-dependent Ginzburg-Landau theory in the presence of a square/rectangular array of pinning centers (holes). For small values of the applied drive, fluxons in different junctions move out of phase, forming a periodic triangular lattice. A rectangular lattice of moving fluxons is observed at larger currents, which is in agreement with previous theoretical predictions (Koshelev and Aranson 2000 Phys. Rev. Lett. 85 3938). This 'superradiant' flux-flow state is found to be stable in a wide region of applied current. The stability range of this ordered state is considerably larger than the one obtained for the pinning-free sample. Clear commensurability features are observed in the current-voltage characteristics of the system with pronounced peaks in the critical current at (fractional) matching fields. The effect of density and strength of the pinning centers on the stability of the rectangular fluxon lattice is discussed. Predicted synchronized motion of fluxons in the presence of ordered pinning can be detected experimentally using the rf response of the system, where enhancement of the Shapiro-like steps is expected due to the synchronization. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
|
Language |
|
Wos |
000327447200013 |
Publication Date |
2013-10-29 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
0953-2048;1361-6668; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
2.878 |
Times cited |
5 |
Open Access |
|
|
Notes |
; This work was supported by EU Marie Curie (Project No: 253057) and by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 2.878; 2013 IF: 2.796 |
|
Call Number |
UA @ lucian @ c:irua:112834 |
Serial |
1573 |
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 |
|
|
Corporate Author |
|
Thesis |
|
|
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 |
Niermann, T.; Verbeeck, J.; Lehmann, M. |
|
Title |
Creating arrays of electron vortices |
Type |
A1 Journal article |
|
Year |
2014 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
Volume |
136 |
Issue |
|
Pages |
165-170 |
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
Abstract |
We demonstrate the production of an ordered array of electron vortices making use of an electron optical setup consisting of two electrostatic biprisms. The biprism filaments are oriented nearly orthogonal with respect to each other in a transmission electron microscope. Matching the position of the filaments, we can choose to form different topological features in the electron wave. We outline the working principle of the setup and demonstrate fist experimental results. This setup partially bridges the gap between angular momentum carried by electron spin, which is intrinsic and therefore present in any position of the wave, and angular momentum carried by the vortex character of the wave, which can be extrinsic depending on the axis around which it is measured. (C) 2013 Elsevier B.V. All rights reserved. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
|
Language |
|
Wos |
000327884700021 |
Publication Date |
2013-10-15 |
|
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 |
9 |
Open Access |
|
|
Notes |
FP7; Countatoms; Vortex ECASJO_; |
Approved |
Most recent IF: 2.843; 2014 IF: 2.436 |
|
Call Number |
UA @ lucian @ c:irua:112837UA @ admin @ c:irua:112837 |
Serial |
538 |
Permanent link to this record |
|
|
|
|
Author |
Aghaei, M.; Flamigni, L.; Lindner, H.; Günther, D.; Bogaerts, A. |
|
Title |
Occurrence of gas flow rotational motion inside the ICP torch : a computational and experimental study |
Type |
A1 Journal article |
|
Year |
2014 |
Publication |
Journal of analytical atomic spectrometry |
Abbreviated Journal |
J Anal Atom Spectrom |
|
Volume |
29 |
Issue |
2 |
Pages |
249-261 |
|
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
Abstract |
An inductively coupled plasma, connected to the sampling cone of a mass spectrometer, is computationally investigated. The occurrence of rotational motion of the auxiliary and carrier gas flows is studied. The effects of operating parameters, i.e., applied power and gas flow rates, as well as geometrical parameters, i.e., sampler orifice diameter and injector inlet diameter, are investigated. Our calculations predict that at higher applied power the auxiliary and carrier gas flows inside the torch move more forward to the sampling cone, which is validated experimentally for the auxiliary gas flow, by means of an Elan 6000 ICP-MS. Furthermore, an increase of the gas flow rates can also modify the occurrence of rotational motion. This is especially true for the carrier gas flow rate, which has a more pronounced effect to reduce the backward motion than the flow rates of the auxiliary and cooling gas. Moreover, a larger sampler orifice (e.g., 2 mm instead of 1 mm) reduces the backward flow of the auxiliary gas path lines. Finally, according to our model, an injector inlet of 2 mm diameter causes more rotations in the carrier gas flow than an injector inlet diameter of 1.5 mm, which can be avoided again by changing the operating parameters. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
London |
Editor |
|
|
Language |
|
Wos |
000329934000005 |
Publication Date |
2013-11-14 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
0267-9477;1364-5544; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.379 |
Times cited |
21 |
Open Access |
|
|
Notes |
|
Approved |
Most recent IF: 3.379; 2014 IF: 3.466 |
|
Call Number |
UA @ lucian @ c:irua:112896 |
Serial |
2427 |
Permanent link to this record |
|
|
|
|
Author |
Borovinskaya, O.; Aghaei, M.; Flamigni, L.; Hattendorf, B.; Tanner, M.; Bogaerts, A.; Günther, D. |
|
Title |
Diffusion- and velocity-driven spatial separation of analytes from single droplets entering an ICP off-axis |
Type |
A1 Journal article |
|
Year |
2014 |
Publication |
Journal of analytical atomic spectrometry |
Abbreviated Journal |
J Anal Atom Spectrom |
|
Volume |
29 |
Issue |
2 |
Pages |
262-271 |
|
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
Abstract |
The reproducible temporal separation of ion signals generated from a single multi-element droplet, observed in previous studies, was investigated in detail in this work using an ICPTOFMS with high temporal resolution. It was shown that the signal peak intensities of individual elements temporally shift relative to each other only for droplets moving through the plasma off-axis. The magnitude of these shifts correlated with the vaporization temperatures of the analytes and depended on the radial position of the droplets as well as on the thermal properties and velocity profiles of the carrier gases of the ICP. The occurrence of the signal shifting was explained by a spatial separation of analytes already present in the vapor phase in the ICP from a yet unvaporized residue of the droplet. This separation is most likely driven by anisotropic diffusion of vaporized analytes towards the plasma axis and a radial velocity gradient. The proposed explanation is supported by modeling of the gas velocities inside the ICP and imaging of the atomic and ionic emissions produced from single droplets, whose patterns were sloping towards the center of the torch. The effects observed in these studies are important not only for the fundamental understanding of analyteplasma interactions but have also a direct impact on the signal intensities and stability. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
London |
Editor |
|
|
Language |
|
Wos |
000329934000006 |
Publication Date |
2013-11-02 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
0267-9477;1364-5544; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.379 |
Times cited |
18 |
Open Access |
|
|
Notes |
|
Approved |
Most recent IF: 3.379; 2014 IF: 3.466 |
|
Call Number |
UA @ lucian @ c:irua:112897 |
Serial |
697 |
Permanent link to this record |
|
|
|
|
Author |
Van Holsbeke, C.S.; Leemans, G.; Vos, W.G.; de Backer, J.W.; Vinchurkar, S.C.; Geldof, M.; Verdonck, P.R.; Parizel, P.M.; van Schil, P.E.; de Backer, W.A. |
|
Title |
Functional Respiratory Imaging as a tool to personalize respiratory treatment in subjects with unilateral diaphragmatic paralysis |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Respiratory care |
Abbreviated Journal |
Resp Care |
|
Volume |
|
Issue |
|
Pages |
1-20 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP) |
|
Abstract |
In two subjects with a unilateral diaphragmatic paralysis and complaints of dyspnea, a completely different treatment approach was chosen despite similar anatomical and physiological abnormalities. These decisions were supported by the results generated by Functional Respiratory Imaging (FRI). FRI was able to generate functional information with respect to lobar ventilation and local drug deposition. In one subject, it was found that some lobes were poorly ventilated and drug deposition simulation showed that some regions were undertreated. This subject underwent a diaphragm plication to restore the ventilation. In the other subject, it was found that all lobes were still ventilated. A conservative approach with regular follow-up was chosen to wait for spontaneous recovery of the diaphragmatic function. Both subjects improved subjectively and objectively. These cases demonstrate how novel medical imaging techniques such as FRI can be used to personalize respiratory treatment in subjects with unilateral diaphragmatic paralysis. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
Dallas, Tex. |
Editor |
|
|
Language |
|
Wos |
000349200100024 |
Publication Date |
2013-12-11 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
0020-1324;1943-3654; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
1.733 |
Times cited |
5 |
Open Access |
|
|
Notes |
; ; |
Approved |
Most recent IF: 1.733; 2013 IF: 1.840 |
|
Call Number |
UA @ lucian @ c:irua:112982 |
Serial |
1303 |
Permanent link to this record |
|
|
|
|
Author |
de Oliveira, E.L.; Albuquerque, E.L.; de Sousa, J.S.; Farias, G.A.; Peeters, F.M. |
|
Title |
Configuration-interaction excitonic absorption in small Si/Ge and Ge/Si core/shell nanocrystals |
Type |
A1 Journal article |
|
Year |
2012 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
|
Volume |
116 |
Issue |
7 |
Pages |
4399-4407 |
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
Abstract |
The excitonic properties of Si(core)/Ge(shell) and Ge(core)/Si(shell) nanocrystals (NC's) with diameters of similar to 1.9 nm are investigated using a combination density functional ab initio method to obtain the single particle wave functions and a configuration interaction method to compute the exciton fine structure and absorption coefficient. These core/shell structures exhibit type II confinement, which is more pronounced for the Si/Ge NC as a consequence of strain. The absorption coefficients of these NC's exhibit a single dominant peak, which has a much larger oscillator strength than the multipeaks found for pure Si and Ge NC's. The exciton lifetime in Si, Ge, and Ge/Si shows a small i:emperature dependence in the range 10-300 K, whereas in Si/Ge, the exciton lifetime decreases more than an order of magnitude in the same temperature range. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
|
Language |
|
Wos |
000301156500007 |
Publication Date |
2012-01-04 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
4.536 |
Times cited |
44 |
Open Access |
|
|
Notes |
; The authors acknowledge financial support from CNPq and the bilateral program between Flanders and Brazil and the Belgian Science Foundation (IAP). ; |
Approved |
Most recent IF: 4.536; 2012 IF: 4.814 |
|
Call Number |
UA @ lucian @ c:irua:113045 |
Serial |
482 |
Permanent link to this record |
|
|
|
|
Author |
Avetisyan, A.A.; Partoens, B.; Peeters, F.M. |
|
Title |
Electric field tuning of the band gap in four layers of graphene with different stacking order |
Type |
P1 Proceeding |
|
Year |
2012 |
Publication |
Proceedings of the Society of Photo-optical Instrumentation Engineers
T2 – Conference on Photonics and Micro and Nano-structured Materials, JUN 28-30, 2011, Yerevan, ARMENIA |
Abbreviated Journal |
|
|
Volume |
|
Issue |
|
Pages |
84140-84148 |
|
Keywords |
P1 Proceeding; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
Abstract |
We investigated the effect of different stacking order of the four graphene layer system on the induced band gap when positively charged top and negatively charged back gates are applied to the system. A tight-binding approach within a self-consistent Hartree approximation is used to calculate the induced charges on the different graphene layers. We show that the electric field does not open an energy gap if the multilayer graphene system contains a trilayer part with the ABA Bernal stacking. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000303856600012 |
Publication Date |
2012-01-20 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
8414 |
Series Issue |
|
Edition |
|
|
ISSN |
|
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
Impact Factor |
|
Times cited |
|
Open Access |
|
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), and the BelgianScience Policy (IAP). One of us (A.A.A.) was supported by a fellowship from the Belgian Federal Science Policy Office (BELSPO). ; |
Approved |
Most recent IF: NA |
|
Call Number |
UA @ lucian @ c:irua:113046 |
Serial |
886 |
Permanent link to this record |