| Records |
| Author |
Carrillo-Nuñez, H.; Magnus, W.; Peeters, F.M. |
| Title |
A simplified quantum mechanical model for nanowire transistors based on non-linear variational calculus |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
| Volume |
108 |
Issue |
6 |
Pages |
063708,1-063708,8 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
A simplified quantum mechanical model is developed to investigate quantum transport features such as the electron concentration and the current flowing through a silicon nanowire metal-oxide-semiconductor field-effect transistor (MOSFET). In particular, the electron concentration is extracted from a self-consistent solution of the Schrödinger and Poisson equations as well as the ballistic Boltzmann equation which have been solved by exploiting a nonlinear variational principle within the framework of the generalized local density approximation. A suitable action functional has been minimized and details of the implementation and its numerical minimization are given. The current density and its related current-voltage characteristics are calculated from the one-dimensional ballistic steady-state Boltzmann transport equation which is solved analytically by using the method of characteristic curves. The straightforward implementation, the computational speed and the good qualitative behavior of the transport characteristics observed in our approach make it a promising simulation method for modeling quantum transport in nanowire MOSFETs. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos  |
000282646400067 |
Publication Date |
2010-09-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0021-8979; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.068 |
Times cited |
7 |
Open Access |
|
| Notes |
; This work was supported by Flemish Science Foundation (FWO-VI) and the Interuniversity Attraction Poles, Belgium State, Belgium Science Policy, and IMEC. ; |
Approved |
Most recent IF: 2.068; 2010 IF: 2.079 |
| Call Number |
UA @ lucian @ c:irua:84943 |
Serial |
3006 |
| Permanent link to this record |
| |
|
| |
| Author |
Hernández-Nieves, A.D.; Partoens, B.; Peeters, F.M. |
| Title |
Electronic and magnetic properties of superlattices of graphene/graphane nanoribbons with different edge hydrogenation |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
16 |
Pages |
165412-165412,9 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Zigzag graphene nanoribbons patterned on graphane are studied using spin-polarized ab initio calculations. We found that the electronic and magnetic properties of the graphene/graphane superlattice strongly depends on the degree of hydrogenation at the interfaces between the two materials. When both zigzag interfaces are fully hydrogenated, the superlattice behaves like a freestanding zigzag graphene nanoribbon, and the magnetic ground state is antiferromagnetic. When one of the interfaces is half hydrogenated, the magnetic ground state becomes ferromagnetic, and the system is very close to being a half metal with possible spintronics applications whereas the magnetic ground state of the superlattice with both interfaces half hydrogenated is again antiferromagnetic. In this last case, both edges of the graphane nanoribbon also contribute to the total magnetization of the system. All the spin-polarized ground states are semiconducting, independent of the degree of hydrogenation of the interfaces. The ab initio results are supplemented by a simple tight-binding analysis that captures the main qualitative features. Our ab initio results show that patterned hydrogenation of graphene is a promising way to obtain stable graphene nanoribbons with interesting technological applications. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000282569500011 |
Publication Date |
2010-10-07 |
| 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 |
46 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-VI), the Belgian Science Policy (IAP), and the collaborative project FWO-MINCyT (FW/08/01). A. D. H. acknowledges also support from ANPCyT (under Grant No. PICT2008-2236) ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:85030 |
Serial |
996 |
| Permanent link to this record |
| |
|
| |
| Author |
Bencs, L.; Ravindra, K.; de Hoog, J.; Spolnik, Z.; Bleux, N.; Berghmans, P.; Deutsch, F.; Roekens, E.; Van Grieken, R. |
| Title |
Appraisal of measurement methods, chemical composition and sources of fine atmospheric particles over six different areas of Northern Belgium |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Environmental pollution |
Abbreviated Journal |
|
| Volume |
158 |
Issue |
11 |
Pages |
3421-3430 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Daily and seasonal variation in the total elemental, organic carbon (OC) and elemental carbon (EC) content and mass of PM2.5 were studied at industrial, urban, suburban and agricultural/rural areas. Continuous (optical Dustscan, standard tapered element oscillating micro-balance (TEOM), TEOM with filter dynamics measurement system), semi-continuous (Partisol filter-sampling) and non-continuous (Dekati-impactor sampling and gravimetry) methods of PM2.5 mass monitoring were critically evaluated. The average elemental fraction accounted for 26% of the PM2.5 mass measured by gravimetry. Metals, like K, Mn, Fe, Cu, Zn and Pb were strongly inter-correlated, also frequently with non-metallic elements (P, S, Cl and/or Br) and EC/OC. A high OC/EC ratio (29) was generally observed. The total carbon content of PM2.5 ranged between 3 and 77% (averages: 1232%), peaking near industrial/heavy trafficked sites. Principal component analysis identified heavy oil burning, ferrous/non-ferrous industry and vehicular emissions as the main sources of metal pollution. This work compares various aerosol monitoring methods to characterize PM2.5 over six locations of different anthropogenic activities over Northern Belgium. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000282563200009 |
Publication Date |
2010-08-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0269-7491; 1873-6424 |
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:84237 |
Serial |
7488 |
| Permanent link to this record |
| |
|
| |
| Author |
Van Aert, S.; Chen, J.H.; van Dyck, D. |
| Title |
Linear versus non-linear structural information limit in high-resolution transmission electron microscopy |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
110 |
Issue |
11 |
Pages |
1404-1410 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
A widely used performance criterion in high-resolution transmission electron microscopy (HRTEM) is the information limit. It corresponds to the inverse of the maximum spatial object frequency that is linearly transmitted with sufficient intensity from the exit plane of the object to the image plane and is limited due to partial temporal coherence. In practice, the information limit is often measured from a diffractogram or from Young's fringes assuming a weak phase object scattering beyond the inverse of the information limit. However, for an aberration corrected electron microscope, with an information limit in the sub-angstrom range, weak phase objects are no longer applicable since they do not scatter sufficiently in this range. Therefore, one relies on more strongly scattering objects such as crystals of heavy atoms observed along a low index zone axis. In that case, dynamical scattering becomes important such that the non-linear and linear interaction may be equally important. The non-linear interaction may then set the experimental cut-off frequency observed in a diffractogram. The goal of this paper is to quantify both the linear and the non-linear information transfer in terms of closed form analytical expressions. Whereas the cut-off frequency set by the linear transfer can be directly related with the attainable resolution, information from the non-linear transfer can only be extracted using quantitative, model-based methods. In contrast to the historic definition of the information limit depending on microscope parameters only, the expressions derived in this paper explicitly incorporate their dependence on the structure parameters as well. In order to emphasize this dependence and to distinguish from the usual information limit, the expressions derived for the inverse cut-off frequencies will be referred to as the linear and non-linear structural information limit. The present findings confirm the well-known result that partial temporal coherence has different effects on the transfer of the linear and non-linear terms, such that the non-linear imaging contributions are damped less than the linear imaging contributions at high spatial frequencies. This will be important when coherent aberrations such as spherical aberration and defocus are reduced. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000282562100008 |
Publication Date |
2010-07-15 |
| 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 |
6 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2010 IF: 2.063 |
| Call Number |
UA @ lucian @ c:irua:83689 |
Serial |
1821 |
| Permanent link to this record |
| |
|
| |
| Author |
Zha, G.-Q.; Covaci, L.; Zhou, S.-P.; Peeters, F.M. |
| Title |
Proximity-induced pseudogap in mesoscopic superconductor/normal-metal bilayers |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
14 |
Pages |
140502-140502,4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Recent scanning tunneling microscopy (STM) measurements of the proximity effect in Au/La2−xSrxCuO4 and La1.55Sr0.45CuO4/La2−xSrxCuO4 bilayers showed a proximity-induced pseudogap [O. Yuli, I. Asulin, Y. Kalcheim, G. Koren, and O. Millo, Phys. Rev. Lett. 103, 197003 (2009)]. We describe the proximity effect in mesoscopic superconductor/normal-metal bilayers by using the Bogoliubov-de Gennes equations for a tight-binding Hamiltonian with competing antiferromagnetic and d-wave superconductivity orders. The temperature-dependent local density of states is calculated as a function of the distance from the interface. Bound state due to both d-wave and spin-density wave gaps are formed in the normal metal for energies less than the respective gaps. If there is a mismatch between the Fermi velocities in the two layers we observe that these states will shift in energy when spin-density wave order is present, thus inducing a minigap at finite energy. We conclude that the STM measurement in the proximity structures is able to distinguish between the two scenarios proposed for the pseudogap (competing or precursor to superconductivity). |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000282507200002 |
Publication Date |
2010-10-05 |
| 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 |
7 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), by Belgian Science Policy (IAP), by National Natural Science Foundation of China under Grants No. 10904089 and No. 60971053, by the Research Fund of Higher Education of China under Grant No. 20093108120005, by Shanghai Leading Academic Discipline project under Grant No. S30105, by Science and Technology Committee of Shanghai Municipal under Grant No. 09JC1406000, by Shanghai Municipal Education Committee under Grants No. shu-08053 and No. 10zz63, and by Innovation Funds of Shanghai University. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:85028 |
Serial |
2735 |
| Permanent link to this record |
| |
|
| |
| Author |
Burriel, M.; Casa-Cabanas, M.; Zapata, J.; Tan, H.; Verbeeck, J.; Solis, C.; Roqueta, J.; Skinner, S.J.; Kilner, J.A.; Van Tendeloo, G.; Santiso, J. |
| Title |
Influence of the microstructure on the high-temperature transport properties of GdBaCo2O5.5+\delta epitaxial films |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
| Volume |
22 |
Issue |
19 |
Pages |
5512-5520 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Epitaxial thin films of GdBaCo2O5.5+δ (GBCO) grown by pulsed laser deposition have been studied as a function of deposition conditions. The variation in film structure, domain orientation, and microstructure upon deviations in the cation composition have been correlated with the charge transport properties of the films. The epitaxial GBCO films mainly consist of single- and double-perovskite regions that are oriented in different directions depending on the deposition temperature. Additionally, cobalt depletion induces the formation of a high density of stacking defects in the films, consisting of supplementary GdO planes along the c-axis of the material. The presence of such defects progressively reduces the electrical conductivity. The films closer to the stoichiometric composition have shown p-type electronic conductivity at high pO2 with values as high as 800 S/cm at 330 °C in 1 atm O2, and with a pO2 power dependence with an exponent as low as 1/25, consistent with the behavior reported for bulk GBCO. These values place GBCO thin films as a very promising material to be applied as cathodes in intermediate temperature solid oxide fuel cells. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000282471000013 |
Publication Date |
2010-09-20 |
| 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 |
17 |
Open Access |
|
| Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 9.466; 2010 IF: 6.400 |
| Call Number |
UA @ lucian @ c:irua:85412UA @ admin @ c:irua:85412 |
Serial |
1648 |
| Permanent link to this record |
| |
|
| |
| Author |
Idrissi, H.; Renard, K.; Schryvers, D.; Jacques, P.J. |
| Title |
On the relationship between the twin internal structure and the work-hardening rate of TWIP steels |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Scripta materialia |
Abbreviated Journal |
Scripta Mater |
| Volume |
63 |
Issue |
10 |
Pages |
961-964 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
FeMnC and FeMnSiAl TWIP steels deformed under the same conditions exhibit different work-hardening rates. The present study investigates the microstructure of plastically deformed FeMnC and FeMnSiAl samples, particularly the internal structure of the mechanically generated twins and their topology at the grain scale. Twins in the FeMnC steel are finer and full of sessile dislocations, rendering this material distinctly stronger with an improved work-hardening rate. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000282461800003 |
Publication Date |
2010-07-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1359-6462; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.747 |
Times cited |
145 |
Open Access |
|
| Notes |
Iap |
Approved |
Most recent IF: 3.747; 2010 IF: 2.820 |
| Call Number |
UA @ lucian @ c:irua:84472 |
Serial |
2452 |
| Permanent link to this record |
| |
|
| |
| Author |
Berdiyorov, G.R.; Milošević, M.V.; Peeters, F.M. |
| Title |
Dynamics of kinematic vortices in a mesoscopic superconducting loop |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
| Volume |
470 |
Issue |
19 |
Pages |
946-948 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using the time-dependent GinzburgLandau formalism, we study the dynamic properties of a submicron superconducting loop in applied current and in presence of a perpendicular magnetic field. The resistive state of the sample is caused by the motion of kinematic vortexantivortex pairs. Vortices and antivortices move in opposite directions to each other, perpendicularly to the applied drive, and the periodic creation and annihilation of such pairs results in periodic oscillations of the voltage across the sample. The dynamics of these kinematic pairs is strongly influenced by the applied magnetic field, which for high fields leads to the flow of just vortices. Kinematic vortices can be temporarily pinned inside the loop with observable trace in the voltage vs. time characteristics. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000282454400061 |
Publication Date |
2010-03-08 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.404 |
Times cited |
9 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 1.404; 2010 IF: 1.415 |
| Call Number |
UA @ lucian @ c:irua:85039 |
Serial |
777 |
| Permanent link to this record |
| |
|
| |
| Author |
Misko, V.R.; Lin, N.S.; Peeters, F.M. |
| Title |
Unconventional dynamics of vortex shells in mesoscopic superconducting corbino disks |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
| Volume |
470 |
Issue |
19 |
Pages |
939-941 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The dynamics of vortex matter in mesoscopic superconducting Corbino disk is strongly influenced by the discrete vortex structure arranged in shells. While in previous works the vortex dynamics has been studied in large (macroscopic) and in very small mesoscopic disks (containing only few shells), in the intermediate-size regime it is much more complex and unusual, due to: (i) the competition between the vortexvortex interaction and confinement and (ii) (in)commensurability among the vortex shells. We found that the interplay between these effects can result in a very unusual vortex dynamical behavior: (i) unconventional angular melting (i.e., propagating from the boundary, where the shear stress is minimum, towards the center) and (ii) unconventional dynamics of shells (i.e., the inversion of shell velocities with respect to the gradient driving force). This unusual behavior is found for different number of shells. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000282454400059 |
Publication Date |
2010-03-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.404 |
Times cited |
3 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 1.404; 2010 IF: 1.415 |
| Call Number |
UA @ lucian @ c:irua:85036 |
Serial |
3799 |
| Permanent link to this record |
| |
|
| |
| Author |
Romaguera, A.R. de C.; Doria, M.M.; Peeters, F.M. |
| Title |
Vortex patterns in a superconducting-ferromagnetic rod |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
| Volume |
470 |
Issue |
19 |
Pages |
871-873 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
A superconducting rod with a magnetic moment on top develops vortices obtained here through 3D calculations of the GinzburgLandau theory. The inhomogeneity of the applied field brings new properties to the vortex patterns that vary according to the rod thickness. We find that for thin rods (disks) the vortex patterns are similar to those obtained in presence of a homogeneous magnetic field instead because they consist of giant vortex states. For thick rods novel patterns are obtained as vortices are curve lines in space that exit through the lateral surface. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000282454400039 |
Publication Date |
2010-03-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.404 |
Times cited |
1 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 1.404; 2010 IF: 1.415 |
| Call Number |
UA @ lucian @ c:irua:85035 |
Serial |
3878 |
| Permanent link to this record |
| |
|
| |
| Author |
Milošević, M.V.; Geurts, R. |
| Title |
The Ginzburg-Landau theory in application |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
| Volume |
470 |
Issue |
19 |
Pages |
791-795 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
A numerical approach to GinzburgLandau (GL) theory is demonstrated and we review its applications to several examples of current interest in the research on superconductivity. This analysis also shows the applicability of the two-dimensional approach to thin superconductors and the re-defined effective GL parameter κ. For two-gap superconductors, the conveniently written GL equations directly show that the magnetic behavior of the sample depends not just on the GL parameter of two bands, but also on the ratio of respective coherence lengths. |
| Address |
|
| Corporate Author |
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Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000282454400020 |
Publication Date |
2010-02-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.404 |
Times cited |
66 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 1.404; 2010 IF: 1.415 |
| Call Number |
UA @ lucian @ c:irua:85033 |
Serial |
3583 |
| Permanent link to this record |
| |
|
| |
| Author |
Silhanek, A.V.; Kramer, R.G.B.; van de Vondel, J.; Moshchalkov, V.V.; Milošević, M.V.; Berdiyorov, G.R.; Peeters, F.M.; Luccas, R.F.; Puig, T. |
| Title |
Freezing vortex rivers |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
| Volume |
470 |
Issue |
19 |
Pages |
726-729 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We demonstrate experimentally and theoretically that the dissipative state at high current densities of superconducting samples with a periodic array of holes consist of flux rivers resulting from a short range attractive interaction between vortices. This dynamically induced vortexvortex attraction results from the migration of quasiparticles out of the vortex core. We have directly visualized the formation of vortex chains by scanning Hall microscopy after freezing the dynamic state by a field cooling procedure at constant bias current. Similar experiments carried out in a sample without holes show no hint of flux river formation. |
| Address |
|
| Corporate Author |
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Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000282454400004 |
Publication Date |
2010-03-08 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.404 |
Times cited |
4 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 1.404; 2010 IF: 1.415 |
| Call Number |
UA @ lucian @ c:irua:85032 |
Serial |
1278 |
| Permanent link to this record |
| |
|
| |
| Author |
Khalil-Allafi, J.; Amin-Ahmadi, B. |
| Title |
Multiple-step martensitic transformations in the Ni51Ti49 single crystal |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Journal of materials science |
Abbreviated Journal |
J Mater Sci |
| Volume |
45 |
Issue |
23 |
Pages |
6440-6445 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Multiple-step martensitic transformations of an aged Ni51Ti49 single crystal using calorimetric method were investigated. Results show that for short aging times (1045 min) multiple-step martensitic transformations on cooling occur in two steps. Applying intermediate aging times (1.254 h) results in three steps and long aging times (more than 8 h) lead to two-step martensitic transformations again. This behavior has not been recognized in NiTi single crystals in literatures. It can be related to the heterogeneity of composition and stress fields around Ni4Ti3 precipitates. |
| Address |
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| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000282429400021 |
Publication Date |
2010-06-30 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0022-2461;1573-4803; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.599 |
Times cited |
5 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.599; 2010 IF: 1.859 |
| Call Number |
UA @ lucian @ c:irua:122046 |
Serial |
2231 |
| Permanent link to this record |
| |
|
| |
| Author |
Vazquez, C.; Martin Palacios, O.; Darchuk, L.; Marco Parra, L.-M. |
| Title |
Compositional study of prehistoric pigments (Carriqueo rock shelter, Argentina) by synchrotron radiation X-ray diffraction |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Powder diffraction |
Abbreviated Journal |
|
| Volume |
25 |
Issue |
3 |
Pages |
264-269 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
In this work synchrotron radiation X-ray diffraction technique was successfully applied for the analysis of pigments found in excavation at Carriqueo rock shelter, Neuquen, Argentina. The pigment samples of orange, red, and brown shades were collected from different levels of this archaeological site and compared with a suspected source of provenance (La Oficina creek). X-ray diffraction patterns of several yellowish, reddish, and red pigments showed the presence of haematite, goethite, kaolinite, and quartz. The majority of Carriqueo collected samples belonged to the same group of the suspected source, having haematite and quartz as main crystalline phases. The results indicate that the raw material from La Oficina is the source of most of the pigments found at Carriqueo. The present work helps us to understand the strategy of supplying raw materials by human groups in the North Patagonia region. (C) 2010 International Centre for Diffraction Data. [DOI: 10.1154/1.3478884] |
| 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 |
000282386500009 |
Publication Date |
2010-09-15 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0885-7156 |
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:95582 |
Serial |
7717 |
| Permanent link to this record |
| |
|
| |
| Author |
Peelaers, H.; Partoens, B.; Peeters, F.M. |
| Title |
Electronic and dynamical properties of Si/Ge core-shell nanowires |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
11 |
Pages |
113411-113411,4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Full ab initio techniques are applied to study the electronic and dynamical properties of free standing, hydrogen-passivated Si/Ge core-shell nanowires oriented along the [110] direction. All studied wires exhibit a direct band gap and are found to be structurally stable. The different contributions of the core and shell atoms to the phonon spectra are identified. The acoustic phonon velocities and the frequencies of some typical optical modes are compared with those of pure Si and Ge nanowires. These depend either on the concentration or on the type of core material. Optical modes are hardened and longitudinal acoustic velocities are softened with decreasing wire diameter. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000282270000001 |
Publication Date |
2010-09-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and NOI-BOF (University of Antwerp). ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:85421 |
Serial |
995 |
| Permanent link to this record |
| |
|
| |
| Author |
Shanenko, A.A.; Croitoru, M.D.; Vagov, A.; Peeters, F.M. |
| Title |
Giant drop in the Bardeen-Cooper-Schrieffer coherence length induced by quantum size effects in superconducting nanowires |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
10 |
Pages |
104524-104524,6 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The BCS coherence length in low-dimensional superconductors is dramatically modified by quantum-size effects. In particular, for nanowires made of conventional superconducting materials, we show that the longitudinal zero-temperature coherence length exhibits width-dependent drops by 23 orders of magnitude each time when the bottom of one of single-electron subbands formed due to the transverse quantization of electron motion is situated in a close vicinity to the Fermi level. This phenomenon has strong similarities to the well-known BCS-BEC (Bose-Einstein condensation) crossover in ultracold fermionic condensates but with an important exception: it is driven by the transverse quantization of the electron motion rather than by the externally controlled strength of the fermion-fermion interaction. |
| Address |
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| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000282269600005 |
Publication Date |
2010-09-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
29 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the ESF-network: INSTANS. M. D. C. acknowledges support from the Alexander von Humboldt Foundation. A. A. S. thanks R. G. Mints, W. V. Pogosov, D. Y. Vodolazov, A. Perali, and A. Bianconi for fruitful discussions. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:85419 |
Serial |
1337 |
| Permanent link to this record |
| |
|
| |
| Author |
Hadermann, J.; Abakumov, A.M.; Perkisas, T.; d' Hondt, H.; Tan, H.; Verbeeck, J.; Filonenko, V.P.; Antipov, E.V.; Van Tendeloo, G. |
| Title |
New perovskite-based manganite Pb2Mn2O5 |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
| Volume |
183 |
Issue |
183 |
Pages |
2190-2195 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
A new perovskite based compound Pb2Mn2O5 has been synthesized using a high pressure high temperature technique. The structure model of Pb2Mn2O5 is proposed based on electron diffraction, high angle annular dark field scanning transmission electron microscopy and high resolution transmission electron microscopy. The compound crystallizes in an orthorhombic unit cell with parameters a=5.736(1)Å≈√2a p p p (a p the parameter of the perovskite subcell) and space group Pnma. The Pb2Mn2O5 structure consists of quasi two-dimensional perovskite blocks separated by 1/2[110] p (1̄01) p crystallographic shear planes. The blocks are connected to each other by chains of edge-sharing MnO5 distorted tetragonal pyramids. The chains of MnO5 pyramids and the MnO6 octahedra of the perovskite blocks delimit six-sided tunnels accommodating double chains of Pb atoms. The tunnels and pyramidal chains adopt two mirror-related configurations (left L and right R) and layers consisting of chains and tunnels of the same configuration alternate in the structure according to an -LRLR-sequence. The sequence is sometimes locally violated by the appearance of -LL- or -RR-fragments. A scheme is proposed with a JahnTeller distortion of the MnO6 octahedra with two long and two short bonds lying in the ac plane, along two perpendicular orientations within this plane, forming a d-type pattern. |
| Address |
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| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000282139600041 |
Publication Date |
2010-07-25 |
| 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 |
8 |
Open Access |
|
| Notes |
Fwo; Bof; Esteem 026019 |
Approved |
Most recent IF: 2.299; 2010 IF: 2.261 |
| Call Number |
UA @ lucian @ c:irua:85472UA @ admin @ c:irua:85472 |
Serial |
2332 |
| Permanent link to this record |
| |
|
| |
| Author |
Wu, Z.; Peeters, F.M.; Chang, K. |
| Title |
Electron tunneling through double magnetic barriers on the surface of a topological insulator |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
11 |
Pages |
115211-115211,7 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We study electron tunneling through a planar magnetic and electric barrier on the surface of a three-dimensional topological insulator. For the double barrier structures, we find (i) a directional-dependent tunneling which is sensitive to the magnetic field configuration and the electric gate voltage, (ii) a spin rotation controlled by the magnetic field and the gate voltage, (iii) many Fabry-Pérot resonances in the transmission determined by the distance between the two barriers, and (iv) the electrostatic potential can enhance the difference in the transmission between the two magnetization configurations, and consequently lead to a giant magnetoresistance. Points (i), (iii), and (iv) are alike with that in graphene stemming from the same linear-dispersion relations. |
| Address |
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| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000282125700002 |
Publication Date |
2010-09-27 |
| 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 |
65 |
Open Access |
|
| Notes |
; This work was supported by the NSF of China, the Flemish Science Foundation (FWO-Vl), and the Belgian Science Policy. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:85420 |
Serial |
990 |
| Permanent link to this record |
| |
|
| |
| Author |
Tsvyashchenko, A.V.; Nikolaev, A.V.; Velichkov, A.I.; Salamatin, A.V.; Fomicheva, L.N.; Ryasny, G.K.; Sorokin, A.A.; Kochetov, O.I.; Budzynski, M.; Michel, K.H. |
| Title |
Lowering of the spatial symmetry at the gamma ->alpha phase transition in cerium |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
9 |
Pages |
1-4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using time-differential perturbed angular correlation spectroscopy we have measured the electric field gradient (EFG) at 111Cd probe nuclei in solid Ce in a pressure range up to 8 GPa. Covering various allotropic phases of Ce, we find that the value of the EFG in the cubic α phase is almost four times larger than in the cubic γ phase and close to values in the noncubic phases α′ and α″. These results together with the differences in time modulation of the spectra are interpreted as evidence for quadrupolar electronic charge-density ordering and symmetry lowering at the γ→α transition while the lattice remains face-centered cubic |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000282004400001 |
Publication Date |
2010-09-16 |
| 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 |
11 |
Open Access |
|
| Notes |
; This work is supported by the Program of the Presidium of the Russian Academy of Sciences “Physics of Strongly Compressed Matter.” We are grateful to S. M. Stishov, B. Verberck, A. N. Grum-Grzhimailo, V. B. Brudanin and G. Heger for support of this work and discussion of the results. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:85464 |
Serial |
1854 |
| Permanent link to this record |
| |
|
| |
| Author |
Harlay, J.; Borges, A.V.; van der Zee, C.; Delille, B.; Godoi, R.H.M.; Schiettecatte, L.-S.; Roevros, N.; Aerts, K.; Lapernat, P.-E.; Rebreanu, L.; Groom, S.; Daro, M.-H.; Van Grieken, R.; Chou, L. |
| Title |
Biogeochemical study of a coccolithophore bloom in the northern Bay of Biscay (NE Atlantic Ocean) in June 2004 |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Progress in oceanography |
Abbreviated Journal |
|
| Volume |
86 |
Issue |
3/4 |
Pages |
317-336 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
The present paper synthesizes data obtained during a multidisciplinary cruise carried out in June 2004 at the continental margin of the northern Bay of Biscay. The data-set allows to describe the different stages of a coccolithophore bloom dominated by Emiliania huxleyi. The cruise was carried out after the main spring phytoplankton bloom that started in mid-April and peaked in mid-May. Consequently, low phosphate (PO4 < 0.2 μM) and silicate (DSi < 2.0 μM) concentrations, low partial pressure of carbon dioxide (pCO2) and high calcite saturation degree in surface waters combined with thermal stratification, probably favoured the blooming of coccolithophores. During the period of the year our cruise was carried out, internal tides induce enhanced vertical mixing at the continental shelf break leading to the injection of inorganic nutrients to surface waters that probably trigger the bloom. The bloom developed as the water-column stratified and as the water mass was advected over the continental shelf, following the general residual circulation in the area. The most developed phase of the bloom was sampled in a remote sensed high reflectance (HR) patch over the continental shelf that was characterized by low chlorophyll-a (Chl-a) concentration in surface waters (<1.0 μg L−1), high particulate inorganic carbon (PIC) concentration (not, vert, similar8 μmol L−1) and coccolithophore abundance up to 57 × 106 cells L−1. Transparent exopolymer particles (TEP) concentrations ranged between 15 and 75 μg C L−1 and carbon content of TEP represented up to 26% of the particulate organic carbon (POC; maximum concentration of 15.5 μmol L−1 in the upper 40 m). Integrated primary production (PP) ranged between 210 and 680 mg C m−2 d−1 and integrated calcification (CAL) ranged between 14 and 140 mg C m−2 d−1, within the range of PP and CAL values previously reported during coccolithophore blooms in open and shelf waters of the North Atlantic Ocean. Bacterial protein production (BPP) measurements in surface waters (0.30.7 μg C L−1 h−1) were much higher than those reported during early phases of coccolithophore blooms in natural conditions, but similar to those during peak and declining coocolithophorid blooms reported in mesocosms. Total alkalinity anomalies with respect to conservative mixing (ΔTA) down to −49 μmol kg−1 are consistent with the occurrence of biogenic precipitation of calcite, while pCO2 remained 15107 μatm lower than atmospheric equilibrium (372 μatm). The correlation between ΔTA and pCO2 suggested that pCO2 increased in part due to calcification, but this increase was insufficient to overcome the background under-saturation of CO2. This is related to the biogeochemical history of the water masses due to net carbon fixation by the successive phytoplankton blooms in the area prior to the cruise, hence, the investigated area remained a sink for atmospheric CO2 despite calcification. |
| 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 |
|
| Language |
|
Wos |
000281937800001 |
Publication Date |
2010-04-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0079-6611 |
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:84236 |
Serial |
7560 |
| Permanent link to this record |
| |
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| |
| Author |
Ludu, A.; Van Deun, J.; Milošević, M.V.; Cuyt, A.; Peeters, F.M. |
| Title |
Analytic treatment of vortex states in cylindrical superconductors in applied axial magnetic field |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Journal of mathematical physics |
Abbreviated Journal |
J Math Phys |
| Volume |
51 |
Issue |
8 |
Pages |
082903,1-082903,29 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We solve the linear GinzburgLandau (GL) equation in the presence of a uniform magnetic field with cylindrical symmetry and we find analytic expressions for the eigenfunctions in terms of the confluent hypergeometric functions. The discrete spectrum results from an implicit equation associated to the boundary conditions and it is resolved in analytic form using the continued fractions formalism. We study the dependence of the spectrum and the eigenfunctions on the sample size and the surface conditions for solid and hollow cylindrical superconductors. Finally, the solutions of the nonlinear GL formalism are constructed as expansions in the linear GL eigenfunction basis and selected by minimization of the free energy. We present examples of vortex states and their energies for different samples in enhancing/suppressing superconductivity surroundings. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000281905000026 |
Publication Date |
2010-08-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0022-2488; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.077 |
Times cited |
10 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 1.077; 2010 IF: 1.291 |
| Call Number |
UA @ lucian @ c:irua:84880 |
Serial |
106 |
| Permanent link to this record |
| |
|
| |
| Author |
Khaydarov, R.T.; Beisinbaeva, H.B.; Sabitov, M.M.; Kalal, M.; Berdiyorov, G.R. |
| Title |
Conditions defining the mechanisms of the formation of light gas ions in multicomponent laser-produced plasmas |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Nuclear fusion |
Abbreviated Journal |
Nucl Fusion |
| Volume |
50 |
Issue |
10 |
Pages |
105007,1-105007,4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using the mass-spectrometric method we study the charge, energy and spatial characteristics of ions in multicomponent plasma, generated under the action of Nd : YAG laser radiation on the surface of solid targets. We focus on the effect of the entry form of light gas atoms on the parameters of ions in such laser-produced plasmas. We found that the presence of light gas atoms considerably affects the parameters (e.g. the intensity and the charge multiplicity) of the heavier ions. |
| Address |
|
| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Vienna |
Editor |
|
| Language |
|
Wos |
000281859300008 |
Publication Date |
2010-08-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0029-5515;1741-4326; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.307 |
Times cited |
1 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 3.307; 2010 IF: 3.303 |
| Call Number |
UA @ lucian @ c:irua:84876 |
Serial |
476 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Tian, H.; Schattschneider, P. |
| Title |
Production and application of electron vortex beams |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Nature |
Abbreviated Journal |
Nature |
| Volume |
467 |
Issue |
7313 |
Pages |
301-304 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Vortex beams (also known as beams with a phase singularity) consist of spiralling wavefronts that give rise to angular momentum around the propagation direction. Vortex photon beams are widely used in applications such as optical tweezers to manipulate micrometre-sized particles and in micro-motors to provide angular momentum1, 2, improving channel capacity in optical3 and radio-wave4 information transfer, astrophysics5 and so on6. Very recently, an experimental realization of vortex beams formed of electrons was demonstrated7. Here we describe the creation of vortex electron beams, making use of a versatile holographic reconstruction technique in a transmission electron microscope. This technique is a reproducible method of creating vortex electron beams in a conventional electron microscope. We demonstrate how they may be used in electron energy-loss spectroscopy to detect the magnetic state of materials and describe their properties. Our results show that electron vortex beams hold promise for new applications, in particular for analysing and manipulating nanomaterials, and can be easily produced. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000281824900033 |
Publication Date |
2010-09-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0028-0836;1476-4687; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
40.137 |
Times cited |
626 |
Open Access |
|
| Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 40.137; 2010 IF: 36.104 |
| Call Number |
UA @ lucian @ c:irua:84878UA @ admin @ c:irua:84878 |
Serial |
2720 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Heuvel, W.; Tikhomirov, V.K.; Kirilenko, D.; Schildermans, N.; Chibotaru, L.F.; Vanacken, J.; Gredin, P.; Mortier, M.; Van Tendeloo, G.; Moshchalkov, V.V. |
| Title |
Ultralow blocking temperature and breakdown of the giant spin model in Er3+-doped nanoparticles |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
9 |
Pages |
094421-094421,8 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The magnetization of luminescent Er3+-doped PbF2 nanoparticles (formula Er0.3Pb0.7F2.3) has been studied. Despite the high concentration of the doping Er3+ ions and relatively large size (8 nm) of these nanoparticles we have found no deviation between field-cooled and zero-field-cooled magnetization curves down to T=0.35 K, which points out an ultralow blocking temperature for the reversal of magnetization. We also have found strongly deviating magnetization curves M(H/T) for different temperatures T. These results altogether show that the investigated nanoparticles are not superparamagnetic, but rather each Er3+ ion in these nanoparticles is found in a paramagnetic state down to very low temperatures, which implies the breakdown of the Néel-Brown giant spin model in the case of these nanoparticles. Calculations of magnetization within a paramagnetic model of noninteracting Er3+ ions completely support this conclusion. Due to the ultralow blocking temperature, these nanoparticles have a potential for magnetic field-induced nanoscale refrigeration with an option of their optical localization and temperature control. |
| 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 |
000281773300005 |
Publication Date |
2010-09-13 |
| 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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
11 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:85423 |
Serial |
3796 |
| Permanent link to this record |
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| |
| Author |
Masir, M.R.; Vasilopoulos, P.; Peeters, F.M. |
| Title |
Fabry-Pérot resonances in graphene microstructures: influence of a magnetic field |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
11 |
Pages |
115417-115417,12 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Fabry-Pérot resonances in the transmission through single and double, graphene-based barriers (of height V) and wells are investigated and their dependence on an applied perpendicular magnetic field. For rectangular barriers the conductance decreases with increasing magnetic field while the resonances weaken (become more pronounced) with increasing magnetic field for EF<V (EF>V). The position of the resonances exhibit a linear shift with magnetic field which move to lower (higher) energy for EF<V (EF>V). Compared to semielliptic- or Gaussian-shaped barriers they show a smaller number of resonances in the absence of a magnetic field and an overall lower conductance but the resonant structure is more pronounced. The conductance of asymmetric double barriers show two major regions of resonances while the symmetric ones show one, that of three asymmetric barriers three, and so on. |
| 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 |
000281723100007 |
Publication Date |
2010-09-10 |
| 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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
74 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP) and the Canadian NSERC under Grant No. OGP0121756. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:84871 |
Serial |
1167 |
| Permanent link to this record |
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| |
| Author |
Verleysen, E.; Bender, H.; Richard, O.; Schryvers, D.; Vandervorst, W. |
| Title |
Characterization of nickel silicides using EELS-based methods |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Journal of microscopy |
Abbreviated Journal |
J Microsc-Oxford |
| Volume |
240 |
Issue |
1 |
Pages |
75-82 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The characterization of Ni-silicides using electron energy loss spectroscopy (EELS) based methods is discussed. A series of Ni-silicide phases is examined: Ni3Si, Ni31Si12, Ni2Si, NiSi and NiSi2. The composition of these phases is determined by quantitative core-loss EELS. A study of the low loss part of the EELS spectrum shows that both the energy and the shape of the plasmon peak are characteristic for each phase. Examination of the Ni-L edge energy loss near edge structure (ELNES) shows that the ratio and the sum of the L2 and L3 white line intensities are also characteristic for each phase. The sum of the white line intensities is used to determine the trend in electron occupation of the 3d states of the phases. The dependence of the plasmon energy on the electron occupation of the 3d states is demonstrated. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Oxford |
Editor |
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| Language |
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Wos |
000281715400009 |
Publication Date |
2010-05-20 |
| 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 |
0022-2720; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.692 |
Times cited |
11 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.692; 2010 IF: 1.872 |
| Call Number |
UA @ lucian @ c:irua:84879 |
Serial |
329 |
| Permanent link to this record |
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| Author |
Gorlé, C.; van Beeck, J.; Rambaud, P. |
| Title |
Dispersion in the wake of a rectangular building : validation of two Reynolds-averaged Navier-Stokes modelling approaches |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Boundary-layer meteorology |
Abbreviated Journal |
Bound-Lay Meteorol |
| Volume |
137 |
Issue |
1 |
Pages |
115-133 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
When modelling the turbulent dispersion of a passive tracer using Reynolds-averaged Navier-Stokes (RANS) simulations, two different approaches can be used. The first consists of solving a transport equation for a scalar, where the governing parameters are the mean velocity field and the turbulent diffusion coefficient, given by the ratio of the turbulent viscosity and the turbulent Schmidt number Sc (t) . The second approach uses a Lagrangian particle tracking algorithm, where the governing parameters are the mean velocity and the fluctuating velocity field, which is determined from the turbulence kinetic energy and the Lagrangian time T (L) . A comparison between the two approaches and wind-tunnel data for the dispersion in the wake of a rectangular building immersed in a neutral atmospheric boundary layer (ABL) is presented. Particular attention was paid to the influence of turbulence model parameters on the flow and concentration field. In addition, an approach to estimate Sc (t) and T (L) based on the calculated flow field is proposed. The results show that applying modified turbulence model constants to enable correct modelling of the ABL improves the prediction for the velocity and concentration fields when the modification is restricted to the region for which it was derived. The difference between simulated and measured concentrations is smaller than 25% or the uncertainty of the data on 76% of the points when solving the transport equation for a scalar with the proposed formulation for Sc (t) , and on 69% of the points when using the Lagrangian particle tracking with the proposed formulation for T (L) . |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Dordrecht |
Editor |
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| Language |
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Wos |
000281712500006 |
Publication Date |
2010-06-30 |
| 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 |
0006-8314;1573-1472; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.573 |
Times cited |
16 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.573; 2010 IF: 1.879 |
| Call Number |
UA @ lucian @ c:irua:95570 |
Serial |
736 |
| Permanent link to this record |
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| Author |
Meilikhov, M.; Yusenko, K.; Esken, D.; Turner, S.; Van Tendeloo, G.; Fischer, R.A. |
| Title |
Metals@MOFs – loading MOFs with metal nanoparticles for hybrid functions |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
European journal of inorganic chemistry |
Abbreviated Journal |
Eur J Inorg Chem |
| Volume |
2010 |
Issue |
24 |
Pages |
3701-3714 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Metalorganic frameworks (MOFs) as well as porous coordination polymers (PCPs) are porous, organicinorganic hybrid solids with zeolite-like structures and properties. Due to their extraordinarily high surface area and well defined pore structure MOFs can be used for the stabilization of metal nanoparticles with adjustable size. The embedded metal nanoparticles are still accessible for other reagents due to the high porosity of the MOF systems. This fact makes metal@MOF systems especially interesting for heterogeneous catalysis, gas storage and chemical sensing. This review compiles the cases of metal nanoparticles supported by or embedded into MOFs reported so far and the main aspects and problems associated with these novel nanocomposite systems. The determination of the dispersion and the location of the particles at the MOF support, the control of the loading degree and its effect on the catalytic activity of the system are discussed as well as the partial degradation of the MOF structure upon particle formation. Examples of the introduction of stabilizing groups into the MOF network that direct the loading and can influence the size and shape of the embedded particles are still rare and point into the possible direction of future investigations. Finally, the formation of bimetallic nanoparticles, which are stabilized and supported by a MOF network, will also be reviewed. |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Weinheim |
Editor |
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| Language |
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Wos |
000281684300001 |
Publication Date |
2010-07-09 |
| 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 |
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| ISSN |
1434-1948; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.444 |
Times cited |
366 |
Open Access |
|
| Notes |
Esteem 026019 |
Approved |
Most recent IF: 2.444; 2010 IF: 2.910 |
| Call Number |
UA @ lucian @ c:irua:85495 |
Serial |
2014 |
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| Author |
Gehrke, K.; Moshnyaga, V.; Samwer, K.; Lebedev, O.I.; Verbeeck, J.; Kirilenko, D.; Van Tendeloo, G. |
| Title |
Interface controlled electronic variations in correlated heterostructures |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
11 |
Pages |
113101,1-113101,4 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
An interface modification of (LaCa)MnO3-BaTiO3 superlattices was found to massively influence magnetic and magnetotransport properties. Moreover it determines the crystal structure of the manganite layers, changing it from orthorhombic (Pnma) for the conventional superlattice (cSL), to rhombohedral (R3̅ c) for the modified one (mSL). While the cSL shows extremely nonlinear ac transport, the mSL is an electrically homogeneous material. The observations go beyond an oversimplified picture of dead interface layers and evidence the importance of electronic correlations at perovskite interfaces. |
| 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 |
000281643200001 |
Publication Date |
2010-09-07 |
| 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 |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
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| Notes |
This work was supported by DFG via SFB 602, TPA2. |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:84249UA @ admin @ c:irua:84249 |
Serial |
1691 |
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| Author |
Payette, C.; Austing, D.G.; Yu, G.; Gupta, J.A.; Nair, S.V.; Partoens, B.; Amaha, S.; Tarucha, S. |
| Title |
Branch current behavior at two level anti-crossings in vertical quantum dot single-particle spectra |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
AIP conference proceedings |
Abbreviated Journal |
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| Volume |
1199 |
Issue |
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Pages |
271-272 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We study single-electron-elastic-resonant-tunneling through two weakly coupled vertical quantum dots and investigate the branch current behavior at anti-crossings between two single-particle energy levels in the constituent dot spectra that are induced to approach each other by application of an out-of-dot-plane magnetic field. We observe both the familiar case of monotonic transfer of the resonant current strengths between the two branches as well as the less familiar case of concurrent enhancement and suppression (ideally complete cancellation) of the resonant current in the two branches. These two situations can be explained in terms of a simple coherent tunneling model. ©2009 American Institute of Physics |
| 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 |
Editor |
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| Language |
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Wos |
000281590800127 |
Publication Date |
2010-01-15 |
| 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; WoS full record |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:86923 |
Serial |
254 |
| Permanent link to this record |
