Records |
Author |
Zelaya, E.; Schryvers, D.; Tolley, A.; Fitchner, P.F.P. |
Title |
Cavity nucleation and growth in Cu-Zn-Al irradiated with Cu+ ions at different temperatures |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Intermetallics |
Abbreviated Journal |
Intermetallics |
Volume |
18 |
Issue |
4 |
Pages |
493-498 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The effects of high dose ion irradiation in β CuZnAl were investigated between room temperature and 150 °C. Single crystal samples with surface normal close to [001]β were irradiated with 300 keV Cu+ ions. Microstructural changes were characterized using transmission electron microscopy. Irradiation induced cavities located on the surface exposed to the irradiation were observed. The morphology, size and density distribution of these cavities were analyzed as a function of different irradiation conditions. The shape and location of the cavities with respect to the irradiation surface were not affected by irradiation temperature or irradiation dose. Instead, the cavity size distribution showed a bi-modal shape for a dose of 15 dpa, regardless of irradiation temperature. For a dose of 30 dpa the bi-modal distribution was only observed after room temperature irradiation. The diffusion effects of vacancies produced by irradiation are analyzed in shape memory CuZnAl alloys, which main characteristic is the diffusionless martensitic transformation. Particularly, the cavity size distributions were analyzed in terms of nucleation, growth and coalescence. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Chicago, Ill. |
Editor |
|
Language |
|
Wos |
000276058200014 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-10-17 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0966-9795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.14 |
Times cited |
1 |
Open Access |
|
Notes |
Iaea |
Approved |
Most recent IF: 3.14; 2010 IF: 2.335 |
Call Number |
UA @ lucian @ c:irua:80924 |
Serial |
302 |
Permanent link to this record |
|
|
|
Author |
Zha, G.-Q.; Milošević, M.V.; Zhou, S.-P.; Peeters, F.M. |
Title |
Magnetic flux periodicity in mesoscopic d-wave symmetric and asymmetric superconducting loops |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
80 |
Issue |
14 |
Pages |
144501,1-144501,5 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The magnetic flux dependence of energy and supercurrent in mesoscopic d-wave symmetric and asymmetric superconducting loops is investigated by numerically solving the Bogoliubov-de Gennes equations self-consistently. For square loops, we find an hc/e-flux periodicity in energy and supercurrent and demonstrate that the flux periodicity is sensitive to the hole size and the superconducting pairing strength as well as temperature. The hc/2e-periodic behavior can be restored almost entirely when we displace the central hole sufficiently out of the center of the sample. In rectangular loops, the discrete current-carrying low-energy spectrum can exist for an odd winding number of the order parameter. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000271351500085 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-10-15 |
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 |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ c:irua:79994 |
Serial |
1879 |
Permanent link to this record |
|
|
|
Author |
Verlooy, P.L.H.; Robeyns, K.; van Meervelt, L.; Lebedev, O.I.; Van Tendeloo, G.; Martens, J.A.; Kirschhock, C.E.A. |
Title |
Synthesis and characterization of the new cyclosilicate hydrate (hexamethyleneimine)4.[Si8O16(OH)4].12H2O |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Microporous and mesoporous materials: zeolites, clays, carbons and related materials |
Abbreviated Journal |
Micropor Mesopor Mat |
Volume |
130 |
Issue |
1/3 |
Pages |
14-20 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A new cyclosilicate hydrate with composition (C6H14N)4·[Si8O16(OH)4]·12H2O was crystallized and the structure determined by single-crystal X-ray diffraction. The structure, described by the tetragonal space group I41/a, with unit cell dimensions of a = 39.2150(2) Å and c = 14.1553(2) Å, contains columns of hydrogen-bonded cubic octamer silicate anions. The space between silicate columns holds hydrogen-bonded water and protonated hexamethyleneimine molecules compensating the negative charge of the silicate. The crystal water can be removed resulting in a rearrangement of the columns into orthorhombic symmetry. Removal of the organic moiety causes amorphisation. Flash evacuation results in a new microporous material with pore volumes typical of a zeolite. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000275702600003 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-10-14 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1387-1811; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.615 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.615; 2010 IF: 3.220 |
Call Number |
UA @ lucian @ c:irua:82448 |
Serial |
3418 |
Permanent link to this record |
|
|
|
Author |
Földi, P.; Benedict, M.G.; Kalman, O.; Peeters, F.M. |
Title |
Quantum rings with time-dependent spin-orbit coupling: Spintronic Rabi oscillations and conductance properties |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
80 |
Issue |
16 |
Pages |
165303,1-165303,10 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The strength of the (Rashba-type) spin-orbit coupling in mesoscopic semiconductor rings can be tuned with external gate voltages. Here we consider the case of a periodically changing spin-orbit interaction strength in time as induced by sinusoidal voltages. In a closed one dimensional quantum ring with weak spin-orbit coupling, Rabi oscillations are shown to appear. We find that the time evolution of initially localized wave packets exhibits a series of collapse and revival phenomena. Partial revivalsthat are typical in nonlinear systemsare shown to correspond to superpositions of states localized at different spatial positions along the ring. These spintronic Schrödinger-cat states appear periodically, and similarly to their counterparts in other physical systems, they are found to be sensitive to disturbances caused by the environment. The time-dependent spin transport problem, when leads are attached to the ring, is also solved. We show that the sideband currents induced by the oscillating spin-orbit interaction strength can become the dominant output channel, even in the presence of moderate thermal fluctuations and random scattering events. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000271352100078 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-10-12 |
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 |
26 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ c:irua:80002 |
Serial |
2784 |
Permanent link to this record |
|
|
|
Author |
Chen, Y.; Croitoru, M.D.; Shanenko, A.A.; Peeters, F.M. |
Title |
Superconducting nanowires: quantum confinement and spatially dependent Hartree-Fock potential |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
21 |
Issue |
43 |
Pages |
435701,1-435701,7 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
Abstract |
It is well known that, in bulk, the solution of the Bogoliubovde Gennes equations is the same whether or not the HartreeFock term is included. Here the HartreeFock potential is position independent and so gives the same contribution to both the single-electron energies and the Fermi level (the chemical potential). Thus, the single-electron energies measured from the Fermi level (they control the solution) stay the same. This is not the case for nanostructured superconductors, where quantum confinement breaks the translational symmetry and results in a position-dependent HartreeFock potential. In this case its contribution to the single-electron energies depends on the relevant quantum numbers. We numerically solved the Bogoliubovde Gennes equations with the HartreeFock term for a clean superconducting nanocylinder and found a shift of the curve representing the thickness-dependent oscillations of the critical superconducting temperature to larger diameters. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000270642700012 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-10-09 |
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 |
|
Approved |
Most recent IF: 2.649; 2009 IF: 1.964 |
Call Number |
UA @ lucian @ c:irua:79162 |
Serial |
3360 |
Permanent link to this record |
|
|
|
Author |
Martens, T.; Mihailova, D.; van Dijk, J.; Bogaerts, A. |
Title |
Theoretical characterization of an atmospheric pressure glow discharge used for analytical spectrometry |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
81 |
Issue |
21 |
Pages |
9096-9108 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
We have investigated the plasma processes in an atmospheric pressure glow discharge (APGD) in He used for analytical spectrometry by means of fluid and Monte Carlo (MC) simulations. Typical results include the potential and electric field distributions in the plasma, the density profiles of the various plasma species throughout the discharge, the mean electron energy, as well as the rates of the various collision processes in the plasma, and the relative importance of the different production and loss rates for the various species. The similarities and differences with low-pressure glow discharges are discussed. The main differences are a very small cathode dark space region and a large positive column as well as the dominant role of molecular ions. Some characteristic features of the APGD, such as the occurrence of the different spatial zones in the discharge, are illustrated, with links to experimental observations. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000276191900062 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-10-08 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700;1520-6882; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
15 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 2009 IF: 5.214 |
Call Number |
UA @ lucian @ c:irua:79554 |
Serial |
3604 |
Permanent link to this record |
|
|
|
Author |
Bultinck, E.; Bogaerts, A. |
Title |
Particle-in-cell/Monte Carlo collisions treatment of an Ar/O2 magnetron discharge used for the reactive sputter deposition of TiOx films |
Type |
A1 Journal article |
Year |
2009 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
Volume |
11 |
Issue |
|
Pages |
103010-103010,24 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The physical processes in an Ar/O2 magnetron discharge used for the reactive sputter deposition of TiOx thin films were simulated with a 2d3v particle-in-cell/Monte Carlo collisions (PIC/MCC) model. The plasma species taken into account are electrons, Ar+ ions, fast Arf atoms, metastable Arm* atoms, Ti+ ions, Ti atoms, O+ ions, O2+ ions, O− ions and O atoms. This model accounts for plasmatarget interactions, such as secondary electron emission and target sputtering, and the effects of target poisoning. Furthermore, the deposition process is described by an analytical surface model. The influence of the O2/Ar gas ratio on the plasma potential and on the species densities and fluxes is investigated. Among others, it is shown that a higher O2 pressure causes the region of positive plasma potential and the O− density to be more spread, and the latter to decrease. On the other hand, the deposition rates of Ti and O are not much affected by the O2/Ar proportion. Indeed, the predicted stoichiometry of the deposited TiOx film approaches x=2 for nearly all the investigated O2/Ar proportions. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000270820900001 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-10-06 |
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 |
24 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.786; 2009 IF: 3.312 |
Call Number |
UA @ lucian @ c:irua:78326 |
Serial |
2559 |
Permanent link to this record |
|
|
|
Author |
Castelano, L.K.; Hai, G.Q.; Partoens, B.; Peeters, F.M. |
Title |
Artificial molecular quantum rings under magnetic field influence |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
Volume |
106 |
Issue |
7 |
Pages |
073702,1-073702,8 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The ground states of a few electrons confined in two vertically coupled quantum rings in the presence of an external magnetic field are studied systematically within the current spin-density functional theory. Electron-electron interactions combined with inter-ring tunneling affect the electronic structure and the persistent current. For small values of the external magnetic field, we recover the zero magnetic field molecular quantum ring ground state configurations. Increasing the magnetic field many angular momentum, spin, and isospin transitions are predicted to occur in the ground state. We show that these transitions follow certain rules, which are governed by the parity of the number of electrons, the single-particle picture, Hunds rules, and many-body effects. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000270915600047 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-10-03 |
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 |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.068; 2009 IF: 2.072 |
Call Number |
UA @ lucian @ c:irua:86926 |
Serial |
155 |
Permanent link to this record |
|
|
|
Author |
Masir, M.R.; Vasilopoulos, P.; Peeters, F.M. |
Title |
Magnetic Kronig-Penney model for Dirac electrons in single-layer graphene |
Type |
A1 Journal article |
Year |
2009 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
Volume |
11 |
Issue |
|
Pages |
095009,1-095009,21 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
he properties of Dirac electrons in a magnetic superlattice (SL) on graphene consisting of very high and thin (δ-function) barriers are investigated. We obtain the energy spectrum analytically and study the transmission through a finite number of barriers. The results are contrasted with those for electrons described by the Schrödinger equation. In addition, a collimation of an incident beam of electrons is obtained along the direction perpendicular to that of the SL. We also highlight an analogy with optical media in which the refractive index varies in space. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000270513500008 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-10-01 |
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 |
89 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.786; 2009 IF: 3.312 |
Call Number |
UA @ lucian @ c:irua:79241 |
Serial |
1884 |
Permanent link to this record |
|
|
|
Author |
Nguten, N.T.T.; Peeters, F.M. |
Title |
Many-body effects in the cyclotron resonance of a magnetic dot |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
80 |
Issue |
11 |
Pages |
115335,1-115335,9 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Intraband cyclotron resonance (CR) transitions of a two-electron quantum dot containing a single magnetic ion is investigated for different Coulomb interaction strengths and different positions of the magnetic ion. In contrast to the usual parabolic quantum dots where CR is independent of the number of electrons, we found here that due to the presence of the magnetic ion Kohn's theorem no longer holds and CR is different for systems with different number of electrons and different effective electron-electron Coulomb interaction strength. Many-body effects result in shifts in the transition energies and change the number of CR lines. The position of the magnetic ion inside the quantum dot affects the structure of the CR spectrum by changing the position and the number of crossings and anticrossings in the transition energies and oscillator strengths. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000270383200110 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-30 |
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 |
6 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ c:irua:79228 |
Serial |
1941 |
Permanent link to this record |
|
|
|
Author |
Colomer, J.-F.; Marega, R.; Traboulsi, H.; Meneghetti, M.; Van Tendeloo, G.; Bonifazi, D. |
Title |
Microwave-assisted bromination of double-walled carbon nanotubes |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
21 |
Issue |
20 |
Pages |
4747-4749 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000270807800001 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-28 |
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 |
46 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 9.466; 2009 IF: 5.368 |
Call Number |
UA @ lucian @ c:irua:94504 |
Serial |
2080 |
Permanent link to this record |
|
|
|
Author |
Magnus, W.; Brosens, F.; Sorée, B. |
Title |
Modeling drive currents and leakage currents : a dynamic approach |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of computational electronics |
Abbreviated Journal |
J Comput Electron |
Volume |
8 |
Issue |
3/4 |
Pages |
307-323 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
Abstract |
The dynamics of electrons and holes propagating through the nano-scaled channels of modern semiconductor devices can be seen as a widespread manifestation of non-equilibrium statistical physics and its ruling principles. In this respect both the devices that are pushing conventional CMOS technology towards the final frontiers of Moores law and the upcoming set of alternative, novel nanostructures grounded on entirely new concepts and working principles, provide an almost unlimited playground for assessing physical models and numerical techniques emerging from classical and quantum mechanical non-equilibrium theory. In this paper we revisit the Boltzmann as well as the WignerBoltzmann equation which offers a valuable platform to study transport of charge carriers taking part in drive currents. We focus on a numerical procedure that regained attention recently as an alternative tool to solve the time-dependent Boltzmann equation for inhomogeneous systems, such as the channel regions of field-effect transistors, and we discuss its extension to the WignerBoltzmann equation. Furthermore, we pay attention to the calculation of tunneling leakage currents. The latter typically occurs in nano-scaled transistors when part of the carrier distribution sustaining the drive current is found to tunnel into the gate due the presence of an ultra-thin insulating barrier separating the gate from the channel region. In particular, we discuss the paradox related to the very existence of leakage currents established by electrons occupying quasi-bound states, while the (real) wave functions of the latter cannot carry net currents. Finally, we describe a simple model to resolve the paradox as well as to estimate gate currents provided the local carrier generation rates largely exceed the tunneling rates. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
S.l. |
Editor |
|
Language |
|
Wos |
000208236100009 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-28 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1569-8025;1572-8137; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.526 |
Times cited |
4 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.526; 2009 IF: NA |
Call Number |
UA @ lucian @ c:irua:89503 |
Serial |
2110 |
Permanent link to this record |
|
|
|
Author |
Falkenberg, G.; Fleissner, G.E.; Fleissner, G.U.E.; Schuchardt, K.; Kühbacher, M.; Chalmin, E.; Janssens, K. |
Title |
High resolution micro-XRF maps of iron oxides inside sensory dendrites of putative avian magnetoreceptors |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
Volume |
186 |
Issue |
1 |
Pages |
012084-3 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Iron mineral containing sensory dendrites in the inner lining of the upper beak of homing pigeons [1] and various bird species [2] are the first candidate structures for an avian magnetic field receptor. A new concept of magnetoreception [3, 4] is based on detailed ultra-structural optical and electron microscopy analyses in combination with synchrotron radiation microscopic X-ray fluorescence analysis (micro-XRF) and microscopic X-ray absorption near edge structures (micro-XANES). Several behavioral experiments [5, 6] and first mathematical simulations [6] affirm our avian magnetoreceptor model. The iron minerals inside the dendrites are housed in three different subcellular compartments (bullets, platelets, vesicles), which could be clearly resolved and identified by electron microscopy on ultrathin sections [1, 3]. Micro-XRF and micro-XANES data obtained at HASYLAB beamline L added information about the elemental distribution and Fe speciation [3], but are averaged over the complete dendrite due to limited spatial resolution. Here we present recently performed micro-XRF maps with sub-micrometer resolution (ESRF ID21), which reveal for the first time subcellular structural information from almost bulk-like dendrite sample material. Due to the thickness of 30 μm the microarchitecture of the dendrites can be considered as undisturbed and artefacts introduced by sectioning might be widely reduced. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000282023900084 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1742-6588; 1742-6596 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
2 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:111317 |
Serial |
5642 |
Permanent link to this record |
|
|
|
Author |
Peelaers, H.; Partoens, B.; Peeters, F.M. |
Title |
Phonons in Ge nanowires |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
95 |
Issue |
12 |
Pages |
122110,1-122110,3 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The phonon spectra of thin freestanding, hydrogen passivated, Ge nanowires are calculated by ab initio techniques. The effect of confinement on the phonon modes as caused by the small diameters of the wires is investigated. Confinement causes a hardening of the optical modes and a softening of the longitudinal acoustic modes. The stability of the nanowires, undoped or doped with B or P atoms, is investigated using the obtained phonon spectra. All considered wires were stable, except for highly doped, very thin nanowires. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000270243800035 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
12 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.411; 2009 IF: 3.554 |
Call Number |
UA @ lucian @ c:irua:79307 |
Serial |
2606 |
Permanent link to this record |
|
|
|
Author |
Chaves, A.; Farias, G.A.; Peeters, F.M.; Szafran, B. |
Title |
Wave packet dynamics in semiconductor quantum rings of finite width |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
80 |
Issue |
12 |
Pages |
125331,1-125331,14 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The time evolution of a wave packet injected into a semiconductor quantum ring is investigated in order to obtain the transmission and reflection probabilities. Within the effective-mass approximation, the time-dependent Schrödinger equation is solved for a system with nonzero width of the ring and leads and finite potential-barrier heights, where we include smooth lead-ring connections. In the absence of a magnetic field, an analysis of the projection of the wave function over the different subband states shows that when the injected wave packet is within a single subband, the junction can scatter this wave packet into different subbands but remarkably at the second junction the wave packet is scattered back into the subband state of the incoming wave packet. If a magnetic field is applied perpendicularly to the ring plane, transmission and reflection probabilities exhibit Aharonov-Bohm (AB) oscillations and the outgoing electrons may end up in different subband states from those of the incoming electrons. Localized impurities, placed in the ring arms, influence the AB oscillation period and amplitude. For a single impurity or potential barrier of sufficiently strong strength, the period of the AB oscillations is halved while for two impurities localized in diametrically opposite points of the ring, the original AB period is recovered. A theoretical investigation of the confined states and time evolution of wave packets in T wires is also made, where a comparison between this system and the lead-ring junction is drawn. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000270383300098 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-25 |
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 |
40 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ c:irua:79231 |
Serial |
3906 |
Permanent link to this record |
|
|
|
Author |
Doğan, F.; Covaci, L.; Kim, W.; Marsiglio, F. |
Title |
Emerging nonequilibrium bound state in spin-current–local-spin scattering |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
Volume |
80 |
Issue |
10 |
Pages |
104434 |
Keywords |
A1 Journal article |
Abstract |
Magnetization reversal is a well-studied problem with obvious applicability in computer hard drives. One can accomplish a magnetization reversal in at least one of two ways: application of a magnetic field or through a spin current. The latter is more amenable to a fully quantum-mechanical analysis. We formulate and solve the problem whereby a spin current interacts with a ferromagnetic Heisenberg spin chain, to eventually reverse the magnetization of the chain. Spin flips are accomplished through both elastic and inelastic scattering. A consequence of the inelastic-scattering channel, when it is no longer energetically possible, is the occurrence of a nonequilibrium bound state, which is an emergent property of the coupled local plus itinerant spin system. For certain definite parameter values the itinerant spin lingers near the local spins for some time, before eventually leaking out as an outwardly diffusing state. This phenomenon results in spin-flip dynamics and filtering properties for this type of system. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000270383100077 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121 |
ISBN |
|
Additional Links |
|
Impact Factor |
3.836 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ |
Serial |
4436 |
Permanent link to this record |
|
|
|
Author |
Petrović, D.; Martens, T.; van Dijk, J.; Brok, W.J.M.; Bogaerts, A. |
Title |
Fluid modelling of an atmospheric pressure dielectric barrier discharge in cylindrical geometry |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
Volume |
42 |
Issue |
20 |
Pages |
205206,1-205206,12 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
A numerical parameter study has been performed for a cylindrical atmospheric pressure dielectric barrier discharge (DBD) in helium with nitrogen impurities using a two-dimensional time-dependent fluid model. The calculated electric currents and gap voltages as a function of time for a given applied potential are presented, as well as the number densities of the various plasma species. This study shows that for the geometry under consideration the applied voltage parameters have a large impact on the electric current profiles and that the discharge current is always determined by the electron and ion conduction currents while the displacement current is nearly negligible. A relative broadening of the current profiles (compared with the duration of the half cycle of the applied voltage) with an increase in the applied frequency is obtained. Nearly sinusoidal current wave forms, usually typical for radio frequency DBDs, are observed while still operating at the frequencies of tens of kilohertz. For the setup under investigation, the Townsend mode of the DBD is observed in the entire range of applied voltage amplitudes and frequencies. It is shown that the average power density dissipated in the discharge increases with rising applied voltage and frequency. An increase in applied voltage frequency leads to an increase in the electron density and a decrease in electron energy, while increasing the voltage amplitude has the opposite effect. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000270563200028 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-24 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-3727;1361-6463; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.588 |
Times cited |
29 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.588; 2009 IF: 2.083 |
Call Number |
UA @ lucian @ c:irua:78202 |
Serial |
1228 |
Permanent link to this record |
|
|
|
Author |
di Vece, M.; Bals, S.; Lievens, P.; Van Tendeloo, G. |
Title |
Compositional changes of Pd-Au bimetallic nanoclusters upon hydrogenation |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
80 |
Issue |
12 |
Pages |
125420,1-125420,4 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Changes in the size distribution and composition of bimetallic Pd-Au nanoclusters have been observed after hydrogen exposure. This effect is caused by hydrogen-induced Ostwald ripening whereby the hydrogen reduces the binding energy of the cluster atoms leading to their detachment from the cluster. The composition changes due to a difference in mobility of the detached palladium and gold atoms on the surface. Fast palladium atoms contribute to the formation of larger nanoclusters, while the slower gold atoms are confined to the smaller nanoclusters. These transformations in the Pd-Au nanocluster size and composition set a limit for chemical reactions in which such nanoclusters are involved together with hydrogen. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000270383300121 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-23 |
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 |
28 |
Open Access |
|
Notes |
Fwo; Goa; Iap-Vi; Esteem 026019 |
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ c:irua:79232 |
Serial |
445 |
Permanent link to this record |
|
|
|
Author |
Földi, P.; Kálmán, O.; Peeters, F.M. |
Title |
Stability of spintronic devices based on quantum ring networks |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
80 |
Issue |
12 |
Pages |
125324,1-125324,9 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Transport properties in mesoscopic networks are investigated, where the strength of the (Rashba-type) spin-orbit coupling is tuned with external gate voltages. We analyze in detail to what extent the ideal behavior and functionality of some promising network-based devices are modified by random (spin-dependent) scattering events and by thermal fluctuations. It is found that although the functionality of these devices is obviously based on the quantum coherence of the transmitted electrons, there is a certain stability: moderate level of errors can be tolerated. For mesoscopic networks made of typical semiconductor materials, we found that when the energy distribution of the input carriers is narrow enough, the devices can operate close to their ideal limits even at relatively high temperature. As an example, we present results for two different networks: one that realizes a Stern-Gerlach device and another that simulates a spin quantum walker. Finally we propose a simple network that can act as a narrow band energy filter even in the presence of random scatterers. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000270383300091 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-23 |
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 |
41 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ c:irua:79230 |
Serial |
3131 |
Permanent link to this record |
|
|
|
Author |
Croitoru, M.D.; Shanenko, A.A.; Peeters, F.M. |
Title |
Superconducting nanowires: quantum-confinement effect on the critical magnetic field and supercurrent |
Type |
A1 Journal article |
Year |
2009 |
Publication |
International journal of modern physics: B: condensed matter physics, statistical physics, applied physics
T2 – 32nd International Workshop on Condensed Matter Theories, Aug 12-19, 2008, Loughborough Univ, Loughborough, England |
Abbreviated Journal |
Int J Mod Phys B |
Volume |
23 |
Issue |
20-21 |
Pages |
4257-4268 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT) |
Abstract |
We study the effect of electron confinement on the superconducting-to-normal phase transition driven by a magnetic field and/or on the current-carrying state of the superconducting condensate in nanowires. Our investigation is based on a self-consistent numerical solution of the Bogoliubov-de Gennes equations. We show that in a parallel magnetic field and/or in the presence of supercurrent the transition from superconducting to normal phase occurs as a cascade of discontinuous jumps in the superconducting order parameter for diameters D < 10 divided by 15 nm at T = 0. The critical magnetic field exhibits quantum-size oscillations with pronounced resonant enhancements. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
World scientific |
Place of Publication |
Singapore |
Editor |
|
Language |
|
Wos |
000274525500026 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0217-9792;1793-6578; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
0.736 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 0.736; 2009 IF: 0.408 |
Call Number |
UA @ lucian @ c:irua:95673 |
Serial |
3362 |
Permanent link to this record |
|
|
|
Author |
van den Broek, W.; Van Aert, S.; van Dyck, D. |
Title |
A model based reconstruction technique for depth sectioning with scanning transmission electron microscopy |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
110 |
Issue |
5 |
Pages |
548-554 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
Depth sectioning in high angular annular dark field scanning transmission electron microscopy is considered a candidate for three-dimensional characterization on the atomic scale. However at present the depth resolution is still far from the atomic level, due to strong limitations in the opening angle of the beam. In this paper we introduce a new, parameter based tomographic reconstruction algorithm that allows to make maximal use of the prior knowledge about the constituent atom types and the microscope settings, so as to retrieve the atomic positions and push the resolution to the atomic level in all three dimensions. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000279065700022 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-21 |
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 |
16 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2010 IF: 2.063 |
Call Number |
UA @ lucian @ c:irua:83690 |
Serial |
2104 |
Permanent link to this record |
|
|
|
Author |
van der Linden, V.; Van de Casteele, E.; Thomas, M.S.; de Vos, A.; Janssen, E.; Janssens, K. |
Title |
Analysis of micro computed tomography images; a look inside historic enamelled metal objects |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Applied physics A : materials science & processing |
Abbreviated Journal |
Appl Phys A-Mater |
Volume |
98 |
Issue |
2 |
Pages |
385-392 |
Keywords |
A1 Journal article; Vision lab; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
In this study the usefulness of micro-Computed Tomography (µ-CT) for the in-depth analysis of enamelled metal objects was tested. Usually investigations of enamelled metal artefacts are restricted to non-destructive surface analysis or analysis of cross sections after destructive sampling. Radiography, a commonly used technique in the field of cultural heritage studies, is limited to providing two-dimensional information about a three-dimensional object (Lang and Middleton, Radiography of Cultural Material, pp. 6061, Elsevier-Butterworth-Heinemann, Amsterdam-Stoneham-London, 2005). Obtaining virtual slices and information about the internal structure of these objects was made possible by CT analysis. With this technique the underlying metal work was studied without removing the decorative enamel layer. Moreover visible defects such as cracks were measured in both width and depth and as of yet invisible defects and weaker areas are visualised. All these features are of great interest to restorers and conservators as they allow a view inside these objects without so much as touching them. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000272158200018 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-21 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0947-8396 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.455 |
Times cited |
3 |
Open Access |
|
Notes |
; This research was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “Atom” (Research Fund University of Antwerp, Belgium), FWO (Brussels, Belgium) projects nos. G.0177.03, G.0103.04 and G.0689.06. ; |
Approved |
Most recent IF: 1.455; 2010 IF: 1.765 |
Call Number |
UA @ admin @ c:irua:80421 |
Serial |
5469 |
Permanent link to this record |
|
|
|
Author |
Bogaerts, A.; Bultinck, E.; Kolev, I.; Schwaederlé, L.; van Aeken, K.; Buyle, G.; Depla, D. |
Title |
Computer modelling of magnetron discharges |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
Volume |
42 |
Issue |
19 |
Pages |
194018,1-194018,12 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this paper, some modelling approaches to describe direct current (dc) magnetron discharges developed in our research groups will be presented, including an analytical model, Monte Carlo simulations for the electrons and for the sputtered atoms, a hybrid Monte Carlo-fluid model and particle-in-cell-Monte Carlo collision simulations. The strengths and limitations of the various modelling approaches will be explained, and some characteristic simulation results will be illustrated. Furthermore, some other simulation methods related to the magnetron device will be briefly explained, more specifically for calculating the magnetic field distribution inside the discharge, and for describing the (reactive) sputtering. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000269993100020 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-19 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-3727;1361-6463; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.588 |
Times cited |
32 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.588; 2009 IF: 2.083 |
Call Number |
UA @ lucian @ c:irua:78168 |
Serial |
462 |
Permanent link to this record |
|
|
|
Author |
Nikolaev, A.V.; Michel, K.H. |
Title |
Elusive s-f intrasite interactions and double exchange in solids: ferromagnetic versus nonmagnetic ground state |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of experimental and theoretical physics |
Abbreviated Journal |
J Exp Theor Phys+ |
Volume |
109 |
Issue |
2 |
Pages |
286-292 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
From the theory of many-electron states in atoms, we know that there exists a strong Coulomb repulsion, which results in the electronic term structure of atoms and is responsible for Hunds rules. By expanding the Coulomb on-site repulsion into a multipolar series, we derive this interaction and show that it is also present in solids as a correlation effect, which means that the interaction requires a multideterminant version of the Hartree-Fock method. Of particular interest is the case where this interaction couples states of localized ( f) and delocalized ( s) electrons. We show that the interaction is bilinear in the creation/annihilation operators for localized electrons and bilinear in the operators for conduction electrons. To study the coupling, we consider a simple model in the framework of an effective limited configuration interaction method with one localized f-electron and one itinerant s-electron per crystal site. The on-site multipole interaction between the f- and s-electrons is explicitly taken into account. It is shown that depending on the low-lying excitation spectrum imposed by the crystal electric field, the model can lead not only to ferromagnetism but also to a nonmagnetic state. The model is relevant for solids with localized and itinerant electron states. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Woodbury, N.Y. |
Editor |
|
Language |
|
Wos |
000270506500014 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1063-7761;1090-6509; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.196 |
Times cited |
3 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.196; 2009 IF: 0.871 |
Call Number |
UA @ lucian @ c:irua:79163 |
Serial |
1027 |
Permanent link to this record |
|
|
|
Author |
Mao, D.; Lookman, R.; van de Weghe, H.; Weltens, R.; Vanermen, G.; de Brucker, N.; Diels, L. |
Title |
Combining HPLC-GCXGC, GCXGC/ToF-MS, and selected ecotoxicity assays for detailed monitoring of petroleum hydrocarbon degradation in soil and leaching water |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Environmental science and technology |
Abbreviated Journal |
|
Volume |
43 |
Issue |
20 |
Pages |
7651-7657 |
Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
Abstract |
HPLC-GCXGC/FID (high-performance liquid chromatography followed by comprehensive two-dimensional gas chromatography with flame-ionization detection) and GCXGC/ToF-MS (comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry) were used to study the biodegradation of petroleum hydrocarbons in soil microcosms during 20 weeks. Two soils were studied: one spiked with fresh diesel and one field sample containing weathered diesel-like oil. Nutrient amended and unamended samples were included. Total petroleum hydrocarbon (TPH) levels in spiked soil decreased from 15000 to 7500 mg/kg d.m. and from 12000 to 4000 mg/kg d.m. in the field soil. Linear alkanes and aromatic hydrocarbons were better biodegradable (>60% degraded) than iso-alkanes; cycloalkanes were least degradable (<40%). Aromatic hydrocarbons up to three rings showed better degradability than n-alkanes. GCXGC/ToF-MS analysis of leaching water showed that initially various oxygenated hydrocarbons were produced. Compound peaks seemed to move up and rightward in the GCXGC chromatograms, indicating that more polar and heavier compounds were formed as biodegradation proceeded. Nutrient amendment can increase TPH removal rates, but had adverse effects on ecotoxicity and leaching potential in our experiment. This was explained by observed shifts in the soil microbial community. Ecotoxicity assays showed that residual TPH still inhibited cress (Lepidium sativum) seed germination, but the leaching water was no longer toxic toward luminescent bacteria (Vibrio fischeri). |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000270594900014 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0013-936x; 1520-5851 |
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:79168 |
Serial |
7683 |
Permanent link to this record |
|
|
|
Author |
Zhang, Z.Z.; Wu, Z.H.; Chang, K.; Peeters, F.M. |
Title |
Resonant tunneling through S- and U-shaped graphene nanoribbons |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
Volume |
20 |
Issue |
41 |
Pages |
415203,1-415203,7 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We theoretically investigate resonant tunneling through S- and U-shaped nanostructured graphene nanoribbons. A rich structure of resonant tunneling peaks is found emanating from different quasi-bound states in the middle region. The tunneling current can be turned on and off by varying the Fermi energy. Tunability of resonant tunneling is realized by changing the width of the left and/or right leads and without the use of any external gates. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000269930100007 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-17 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0957-4484;1361-6528; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.44 |
Times cited |
32 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.44; 2009 IF: 3.137 |
Call Number |
UA @ lucian @ c:irua:79311 |
Serial |
2893 |
Permanent link to this record |
|
|
|
Author |
Bultinck, E.; Mahieu, S.; Depla, D.; Bogaerts, A. |
Title |
Particle-in-cell/Monte Carlo collisions model for the reactive sputter deposition of nitride layers |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Plasma processes and polymers |
Abbreviated Journal |
Plasma Process Polym |
Volume |
6 |
Issue |
S:1 |
Pages |
S784-S788 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
A 2d3v Particle-in-cell/Monte Carlo collisions (PIC/MCC) model was constructed for an Ar/N2 reactive gas mixture in a magnetron discharge. A titanium target was used, in order to study the sputter deposition of a TiNx thin film. Cathode currents and voltages were calculated self-consistently and compared with experiments. Also, ion fluxes to the cathode were calculated, which cause sputtering of the target. The sputtered atom fluxes from the target, and to the substrate were calculated, in order to visualize the deposition of the TiNx film. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000272302900149 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-16 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1612-8850; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.846 |
Times cited |
2 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.846; 2009 IF: 4.037 |
Call Number |
UA @ lucian @ c:irua:79364 |
Serial |
2558 |
Permanent link to this record |
|
|
|
Author |
Bugani, S.; Modugno, F.; Lucejko, J.J.; Giachi, G.; Cagno, S.; Cloetens, P.; Janssens, K.; Morselli, L. |
Title |
Study on the impregnation of archaeological waterlogged wood with consolidation treatments using synchrotron radiation microtomography |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Analytical and bioanalytical chemistry |
Abbreviated Journal |
Anal Bioanal Chem |
Volume |
395 |
Issue |
7 |
Pages |
1977-1985 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
In favourable conditions of low temperature and low oxygen concentration, archaeological waterlogged wooden artefacts, such as shipwrecks, can survive with a good state of preservation. Nevertheless, anaerobic bacteria can considerably degrade waterlogged wooden objects with a significant loss in polysaccharidic components. Due to these decay processes, wood porosity and water content increase under ageing. In such conditions, the conservation treatments of archaeological wooden artefacts often involve the replacement of water with substances which fill the cavities and help to prevent collapse and stress during drying. The treatments are very often expensive and technically difficult, and their effectiveness very much depends on the chemical and physical characteristics of the substances used for impregnation. Also important are the degree of cavity-filling, penetration depth and distribution in the structure of the wood. In this study, the distribution in wood cavities of some mixtures based on polyethylene glycols and colophony, used for the conservation of waterlogged archaeological wood, was investigated using synchrotron radiation X-ray computed microtomography (SR-A mu CT). This non-destructive imaging technique was useful for the study of the degraded waterlogged wood and enabled us to visualise the morphology of the wood and the distribution of the materials used in the wood treatments. The study has shown how deposition is strictly related to the dimension of the wooden cavities. The work is currently proceeding with the comparison of synchrotron observations with the data of the solutions viscosity and with those of the properties imparted to the wood by the treatments. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000272017000005 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-16 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1618-2642 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.431 |
Times cited |
30 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.431; 2009 IF: 3.480 |
Call Number |
UA @ admin @ c:irua:94493 |
Serial |
5853 |
Permanent link to this record |
|
|
|
Author |
Worobiec, A.; Potgieter-Vermaak, S.; Brooker, A.; Darchuk, L.; Stefaniak, E.; Van Grieken, R. |
Title |
Interfaced SEM/EDX and micro-Raman spectrometry for characterisation of heterogeneous environmental particles: fundamental and practical challenges |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Microchemical journal |
Abbreviated Journal |
|
Volume |
94 |
Issue |
1 |
Pages |
65-72 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP) |
Abstract |
The molecular character of atmospheric particulate matter is of prime importance when interpreting air pollution trends and its subsequent influence on environmental monitoring and preventative conservation. The known methods of estimating the molecular composition normally involve elemental analysis of particles (both as bulk and computer controlled analyses of single particles) with subsequent multivariate analyses to clusterise the elements in groups of elements that are closely related to each other. With this approach one can at best suggest associations. Evidently the application of molecular spectroscopy in addition to elemental concentration profiles would provide intimate information regarding the nature of the particles and consequently their fate. This paper gives an overview of research performed in our laboratory and describes the optimisation of experimental parameters to use scanning electron microscopy with energy-dispersive X-ray detection (SEM/EDX) or electron probe X-ray microanalysis (EPXMA) in parallel with micro-Raman Spectrometry (MRS) to investigate single environmental particles. The challenges associated with the two stand-alone techniques are revealed and consequently those posed with an interfaced approach are discussed. Preliminary results, of an initial investigation of the SEM/EDX interfaced with MRS to ultra-fine heterogeneous environmental particles, are given. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000273238800011 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-10 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0026-265x; 0026-265x |
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:79801 |
Serial |
8114 |
Permanent link to this record |
|
|
|
Author |
Saraiva, M.; Chen, H.; Leroy, W.P.; Mahieu, S.; Jehanathan, N.; Lebedev, O.; Georgieva, V.; Persoons, R.; Depla, D. |
Title |
Influence of Al content on the properties of MgO grown by reactive magnetron sputtering |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Plasma processes and polymers |
Abbreviated Journal |
Plasma Process Polym |
Volume |
6 |
Issue |
S:1 |
Pages |
S751-S754 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In the present work, reactive magnetron sputtering in DC mode was used to grow complex oxide thin films, starting from two separate pure metal targets. A series of coatings was produced with a stoichiometry of the film ranging from MgO, over MgxAlyOz to Al2O3. The surface energy, crystallinity, hardness, refractive index, and surface roughness were investigated. A relationship between all properties studied and the Mg content of the samples was found. A critical compositional region for the Mg-Al-O system where all properties exhibit a change was noticed. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000272302900144 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2009-09-08 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1612-8850; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.846 |
Times cited |
13 |
Open Access |
|
Notes |
Iwt |
Approved |
Most recent IF: 2.846; 2009 IF: 4.037 |
Call Number |
UA @ lucian @ c:irua:79363 |
Serial |
1613 |
Permanent link to this record |