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Records |
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Author |
Tian, H.; Schryvers, D.; Shabalovskaya, S.; van Humbeeck, J. |
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Title |
TEM study of the mechanism of Ni ion release from Nitinol wires with original oxides |
Type |
P1 Proceeding |
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Year |
2009 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
05027,1-05027,6 |
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Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT) |
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Abstract |
The surface of commercial Nitinol wires with original oxides and a thickness in the 30-190 nm range was investigated by different state of art TEM techniques. The oxide surface layer was identified as a combination of TiO and TiO2 depending on the processing of the wire. Between the core of the wires and the oxidized surface, an interfacial Ni3Ti nanolayer was observed while Ni nanoparticles are found inside the original oxide. The particle sizes, their distribution in the surface and the Ti-O stoichiometry were deduced from the analysis of the obtained data. Molecular dynamics calculations performed for evaluation of the stability of Ni particles relative to the atomic state revealed that a pure Ni particle has a lower energy than free Ni atoms inside the TiO2 lattice. The obtained results are discussed with respect to surface stability and Ni release in the human body. |
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Publisher |
Edp |
Place of Publication |
Coutaboeuf |
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Wos |
000274582300092 |
Publication Date |
2009-08-31 |
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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; WoS citing articles |
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Impact Factor |
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Times cited |
1 |
Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:81954 |
Serial |
3493 |
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Permanent link to this record |
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Author |
Delville, R.; James, R.D.; Salman, U.; Finel, A.; Schryvers, D. |
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Title |
Transmission electron microscopy study of low-hysteresis shape memory alloys |
Type |
P1 Proceeding |
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Year |
2009 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
02005,1-02005,7 |
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Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT) |
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Abstract |
Recent findings have linked low hysteresis in shape memory alloys with phase compatibility between austenite and martensite. In order to investigate the evolution of microstructure as the phase compatibility increases and the hysteresis is reduced, transmission electron microscopy was used to study the alloy system Ti50Ni50-xPdx where the composition is systemically tuned to approach perfect compatibility. Changes in morphology, twinning density and twinning modes are reported along with special microstructures occurring when the compatibility is achieved. In addition, the interface between austenite and a single variant of martensite was studied by high-resolution and conventional electron microscopy. The atomically sharp, defect free, low energy configuration of the interface suggests that it plays an important role in the lowering of hysteresis. Finally, dynamical modeling of the martensitic transformation using the phase-field micro-elasticity model within the geometrically linear theory succeeded in reproducing the change in microstructure as the compatibility condition is satisfied. Latest results on the extension of these findings in other Ni-Ti based ternary/quaternary systems are also reported. |
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Publisher |
Edp |
Place of Publication |
Coutaboeuf |
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Wos |
000274582300009 |
Publication Date |
2009-08-31 |
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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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ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
3 |
Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:81951 |
Serial |
3716 |
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Permanent link to this record |
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Author |
Schowalter, M.; Rosenauer, A.; Titantah, J.T.; Lamoen, D. |
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Title |
Computation and parametrization of the temperature dependence of Debye-Waller factors for group IV, III-V and II-VI semiconductors |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Acta crystallographica: section A: foundations of crystallography |
Abbreviated Journal |
Acta Crystallogr A |
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Volume |
65 |
Issue |
1 |
Pages |
5-17 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
We calculated the temperature dependence of the Debye-Waller factors for a variety of group IV, III-V and II-VI semiconductors from 0.1 to 1000 K. The approach used to fit the temperature dependence is described and resulting fit parameters are tabulated for each material. The Debye-Waller factors are deduced from generalized phonon densities of states which were derived from first principles using the WIEN2k and the ABINIT codes. |
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Publisher |
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Place of Publication |
Copenhagen |
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Wos |
000261799500002 |
Publication Date |
2008-11-05 |
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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 |
0108-7673; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.725 |
Times cited |
51 |
Open Access |
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Notes |
Fwo G.0425.05; Esteem 026019 |
Approved |
Most recent IF: 5.725; 2009 IF: 49.926 |
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Call Number |
UA @ lucian @ c:irua:72918 |
Serial |
453 |
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Permanent link to this record |
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Author |
Schowalter, M.; Rosenauer, A.; Titantah, J.T.; Lamoen, D. |
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Title |
Temperature-dependent Debye-Waller factors for semiconductors with the wurtzite-type structure |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Acta crystallographica: section A: foundations of crystallography |
Abbreviated Journal |
Acta Crystallogr A |
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Volume |
65 |
Issue |
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Pages |
227-231 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
We computed Debye-Waller factors in the temperature range from 0.1 to 1000 K for AlN, GaN, InN, ZnO and CdO with the wurtzite-type structure. The Debye-Waller factors were derived from phonon densities of states obtained from Hellmann-Feynman forces computed within the density-functional-theory formalism. The temperature dependences of the Debye-Waller factors were fitted and fit parameters are given. |
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Place of Publication |
Copenhagen |
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Wos |
000264927100006 |
Publication Date |
2009-03-12 |
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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 |
0108-7673; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.725 |
Times cited |
23 |
Open Access |
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Notes |
Fwo G.0425.05; Esteem 026019 |
Approved |
Most recent IF: 5.725; 2009 IF: 49.926 |
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Call Number |
UA @ lucian @ c:irua:74565 |
Serial |
3497 |
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Permanent link to this record |
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Author |
Steiner, R.E.; Barshick, C.M.; Bogaerts, A. |
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Title |
Glow discharge optical spectroscopy and mass spectrometry |
Type |
H1 Book chapter |
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Year |
2009 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
1-28 |
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Keywords |
H1 Book chapter; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Optical (atomic absorption spectroscopy, AAS; atomic emission spectroscopy, AES; atomic fluorescence spectroscopy, AFS; and optogalvanic spectroscopy) and mass spectrometric (magnetic sector, quadrupolemass analyzer, QMA; quadrupole ion trap, QIT; Fourier transform ion cyclotron resonance, FTICR; and time-of-flight, TOF) instrumentation are well suited for coupling to the glow discharge (GD). The GD is a relatively simple device. A potential gradient (5001500 V) is applied between an anode and a cathode. In most cases, the sample is also the cathode. A noble gas (e.g. Ar, Ne, and Xe) is introduced into the discharge region before power initiation. When a potential is applied, electrons are accelerated toward the anode. As these electrons accelerate, they collide with gas atoms. A fraction of these collisions are of sufficient energy to remove an electron from a support gas atom, forming an ion. These ions are, in turn, accelerated toward the cathode. These ions impinge on the surface of the cathode, sputtering sample atoms from the surface. Sputtered atoms that do not redeposit on the surface diffuse into the excitation/ionization regions of the plasma where they can undergo excitation and/or ionization via a number of collisional processes. GD sources offer a number of distinct advantages that make them well suited for specific types of analyses. These sources afford direct analysis of solid samples, thus minimizing the sample preparation required for analysis. The nature of the plasma also provides mutually exclusive atomization and excitation processes that help to minimize the matrix effects that plague so many other elemental techniques. Unfortunately, the GD source functions optimally in a dry environment, making analysis of solutions more difficult. These sources also suffer from difficulties associated with analyzing nonconductingsamples. In this article, first, the principles of operation of the GD plasma are reviewed, with an emphasis on how those principles relate to optical spectroscopy and mass spectrometry. Basic applications of the GD techniques are considered next. These include bulk analysis, surface analysis, and the analysis of solution samples. The requirements necessary to obtain optical information are addressed following the analytical applications. This section focuses on the instrumentation needed to make optical measurements using the GD as an atomization/excitation source. Finally, mass spectrometric instrumentation and interfaces are addressed as they pertain to the use of a GD plasma as an ion source. GDsources provide analytically useful gas-phase species from solid samples. These sources can be interfaced with avariety of spectroscopic and spectrometric instruments for both quantitative and qualitative analysis. |
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Thesis |
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Publisher |
Wiley |
Place of Publication |
Chichester |
Editor |
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Wos |
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Publication Date |
0000-00-00 |
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Series Editor |
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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 |
0471976709 |
Additional Links |
UA library record |
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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 |
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Call Number |
UA @ lucian @ c:irua:78169 |
Serial |
1352 |
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Permanent link to this record |
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Author |
Van Aert, S.; Verbeeck, J.; Bals, S.; Erni, R.; van Dyck, D.; Van Tendeloo, G. |
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Title |
Atomic resolution mapping using quantitative high-angle annular dark field scanning transmission electron microscopy |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Microscopy and microanalysis |
Abbreviated Journal |
Microsc Microanal |
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Volume |
15 |
Issue |
S:2 |
Pages |
464-465 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge, Mass. |
Editor |
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Language |
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Wos |
000208119100230 |
Publication Date |
2009-07-27 |
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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 |
1431-9276;1435-8115; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.891 |
Times cited |
1 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1.891; 2009 IF: 3.035 |
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Call Number |
UA @ lucian @ c:irua:96555UA @ admin @ c:irua:96555 |
Serial |
178 |
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Permanent link to this record |
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Author |
Bach, D.; Schneider, R.; Gerthsen, D.; Verbeeck, J.; Sigle, W. |
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Title |
EELS of niobium and stoichiometric niobium-oxide phases: part 1: plasmon and Near-edges fine structure |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Microscopy and microanalysis |
Abbreviated Journal |
Microsc Microanal |
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Volume |
15 |
Issue |
6 |
Pages |
505-523 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A comprehensive electron energy-loss spectroscopy study of niobium (Nb) and stable Nb-oxide phases (NbO, NbO2, Nb2O5) was carried out. In this work (Part I), the plasmons and energy-loss near-edge structures (ELNES) of all relevant Nb edges (Nb-N2,3, Nb-M4,5, Nb-M2,3, Nb-M1, and Nb-L2,3) up to energy losses of about 2600 eV and the O-K edge are analyzed with respect to achieving characteristic fingerprints of Nb in different formal oxidation states (0 for metallic Nb, +2 for NbO, +4 for NbO2, and +5 for Nb2O5). Chemical shifts of the Nb-N2,3, Nb-M4,5, Nb-M2,3, and Nb-L2,3 edges are extracted from the spectra that amount to about 4 eV as the oxidation state increases from 0 for Nb to +5 for Nb2O5. Four different microscopes, including a 200 keV ZEISS Libra with monochromator, were used. The corresponding wide range of experimental parameters with respect to the primary electron energy, convergence, and collection semi-angles as well as energy resolution allows an assessment of the influence of the experimental setup on the ELNES of the different edges. Finally, the intensity of the Nb-L2,3 white-line edges is correlated with niobium 4d-state occupancy in the different reference materials. |
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Corporate Author |
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Thesis |
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Place of Publication |
Cambridge, Mass. |
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Language |
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Wos |
000272433200005 |
Publication Date |
2009-10-27 |
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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 |
1431-9276;1435-8115; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.891 |
Times cited |
55 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1.891; 2009 IF: 3.035 |
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Call Number |
UA @ lucian @ c:irua:80320UA @ admin @ c:irua:80320 |
Serial |
790 |
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Permanent link to this record |
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Author |
Tian, H.; Schryvers, D.; Shabalovskaya, S.; van Humbeeck, J. |
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Title |
Microstructure of surface and subsurface layers of a Ni-Ti shape memory microwire |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Microscopy and microanalysis |
Abbreviated Journal |
Microsc Microanal |
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Volume |
15 |
Issue |
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Pages |
62-70 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The microstructure of a 55 Êm diameter, cold-worked Ni-Ti microwire is investigated by different transmission electron microscopy techniques. The surface consists of a few hundred nanometer thick oxide layer composed of TiO and TiO2 with a small fraction of inhomogeneously distributed Ni. The interior of the wire has a core-shell structure with primarily B2 grains in the 1 Êm thick shell, and heavily twinned B19 martensite in the core. This core-shell structure can be explained by a concentration gradient of the alloying elements resulting in a structure separation due to the strong temperature dependence of the martensitic start temperature. Moreover, in between the B2 part of the metallic core-shell and the oxide layer, a Ni3Ti interfacial layer is detected. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge, Mass. |
Editor |
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Language |
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Wos |
000262912700009 |
Publication Date |
2009-01-15 |
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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 |
1431-9276;1435-8115; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.891 |
Times cited |
15 |
Open Access |
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Notes |
FWO G.0465.05; Multimat |
Approved |
Most recent IF: 1.891; 2009 IF: 3.035 |
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Call Number |
UA @ lucian @ c:irua:72319 |
Serial |
2074 |
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Permanent link to this record |
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Author |
Van Tendeloo, G.; Hadermann, J.; Abakumov, A.M.; Antipov, E.V. |
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Title |
Advanced electron microscopy and its possibilities to solve complex structures: application to transition metal oxides |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Journal of materials chemistry |
Abbreviated Journal |
J Mater Chem |
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Volume |
19 |
Issue |
18 |
Pages |
2660-2670 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Design and optimization of materials properties can only be performed through a thorough knowledge of the structure of the compound. In this feature article we illustrate the possibilities of advanced electron microscopy in materials science and solid state chemistry. The different techniques are briefly discussed and several examples are given where the structures of complex oxides, often with a modulated structure, have been solved using electron microscopy. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
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Language |
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Wos |
000265740600002 |
Publication Date |
2009-02-04 |
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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 |
0959-9428;1364-5501; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
9 |
Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:77065 |
Serial |
68 |
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Permanent link to this record |
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Author |
Hamelet, S.; Gibot, P.; Casas-Cabanas, M.; Bonnin, D.; Grey, C.P.; Cabana, J.; Leriche, J.B.; Rodriguez-Carvajal, J.; Courty, M.; Levasseur, S.; Carlach, P.; Van Thournout, M.; Tarascon, J.M.; Masquelier, C.; |
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Title |
The effects of moderate thermal treatments under air on LiFePO4-based nano powders |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Journal of materials chemistry |
Abbreviated Journal |
J Mater Chem |
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Volume |
19 |
Issue |
23 |
Pages |
3979-3991 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The thermal behavior under air of LiFePO(4)-based powders was investigated through the combination of several techniques such as temperature-controlled X-ray diffraction, thermogravimetric analysis and Mossbauer and NMR spectroscopies. The reactivity with air at moderate temperatures depends on the particle size and leads to progressive displacement of Fe from the core structure yielding nano-size Fe(2)O(3) and highly defective, oxidized Li(x)Fe(y)PO(4) compositions whose unit-cell volume decreases dramatically when the temperature is raised between 400 and 600 K. The novel LiFePO(4)-like compositions display new electrochemical reactivity when used as positive electrodes in Li batteries. Several redox phenomena between 3.4 V and 2.7 V vs. Li were discovered and followed by in-situ X-ray diffraction, which revealed two distinct solid solution domains associated with highly anisotropic variations of the unit-cell constants. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
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Language |
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Wos |
000266615800024 |
Publication Date |
2009-05-05 |
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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 |
0959-9428;1364-5501; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
93 |
Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:94582 |
Serial |
867 |
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Permanent link to this record |
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Author |
Esken, D.; Zhang, X.; Lebedev, O.I.; Schröder, F.; Fischer, R.A. |
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Title |
Pd@MOF-5: limitations of gas-phase infiltration and solution impregnation of [Zn4O(bdc)3] (MOF-5) with metalorganic palladium precursors for loading with Pd nanoparticles |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Journal of materials chemistry |
Abbreviated Journal |
J Mater Chem |
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Volume |
19 |
Issue |
9 |
Pages |
1314-1319 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The limitations of the loading of the porous metalorganic framework [Zn4O(bdc)3] (bdc = benzene-1,4-dicarboxylate; MOF-5 or IRMOF-1) with Pd nanoparticles was investigated. First, the volatile organometallic precursor [Pd(5-C5H5)(3-C3H5)] was employed to get the inclusion compound [Pd(5-C5H5)(3-C3H5)]x@MOF-5 via gas-phase infiltration at 10-3 mbar. A loading of four molecules of [Pd(5-C5H5)(3-C3H5)] per formula unit of MOF-5 (x = 4) can be reached (35 wt.% Pd). Second, the metalorganic precursor [Pd(acac)2] (acac = 2,4-pentanedionate) was used and the inclusion materials [Pd(acac)2]x@MOF-5 of different Pd loadings were obtained by incipient wetness infiltration. However, the maximum loading was lower as compared with the former case with about two precursor molecules per formula unit of MOF-5. Both loading routes are suitable for the synthesis of Pd nanoparticles inside the porous host matrix. Homogeneously distributed nanoparticles with diameter of 2.4(±0.2) nm can be achieved by photolysis of the inclusion compounds [Pd(5-C5H5)(3-C3H5)]x@MOF-5 (x 4), while the hydrogenolysis of [Pd(acac)2]x@MOF-5 (x 2) leads to a mixture of small particles inside the network (< 3 nm) and large Pd agglomerates (40 nm) on the outer surface of the MOF-5 specimens. The pure Pdx@MOF-5 materials proved to be stable under hydrogen pressure (2 bar) at 150 °C over many hours. Neither hydrogenation of the bdc linkers nor particle growth was observed. The new composite materials were characterized by 1H/13C-MAS-NMR, powder XRD, ICP-AES, FT-IR, N2 sorption measurements and high resolution TEM. Raising the Pd loading of a representative sample Pd4@MOF-5 (35 wt.% Pd) by using [Pd(5-C5H5)(3-C3H5)] as precursor in a second cycle of gas-phase infiltration and photolysis was accompanied by the collapse of the long-range crystalline order of the MOF. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
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Language |
|
Wos |
000263450300015 |
Publication Date |
2009-01-22 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0959-9428;1364-5501; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
100 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: NA |
|
|
Call Number |
UA @ lucian @ c:irua:76318 |
Serial |
2565 |
|
Permanent link to this record |
|
|
|
|
Author |
Smeulders, G.; Meynen, V.; van Baelen, G.; Mertens, M.; Lebedev, O.I.; Van Tendeloo, G.; Maes, B.U.W.; Cool, P. |
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Title |
Rapid microwave-assisted synthesis of benzene bridged periodic mesoporous organosilicas |
Type |
A1 Journal article |
|
Year |
2009 |
Publication |
Journal of materials chemistry |
Abbreviated Journal |
J Mater Chem |
|
|
Volume |
19 |
Issue |
19 |
Pages |
3042-3048 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA); Organic synthesis (ORSY) |
|
|
Abstract |
Following extended use in organic chemistry, microwave-assisted synthesis is gaining more importance in the field of inorganic chemistry, especially for the synthesis of nanoporous materials. It offers some major advantages such as a significant shortening of the synthesis time and an improved promotion of nucleation. In the research here reported, microwave technology is applied for the synthesis of benzene bridged PMOs (periodic mesoporous organosilicas). PMOs are one of the latest innovations in the field of hybrid ordered mesoporous materials and have attracted much attention because of their feasibility in electronics, catalysis, separation and sorption applications. The different synthesis steps (stirring, aging and extraction) of the classical PMO synthesis are replaced by microwave-assisted synthesis steps. The characteristics of the as-synthesized materials are evaluated by X-ray diffraction, N2-sorption, thermogravimetric analysis, scanning- and transmission electron microscopy. The microwave-assisted synthesis drastically reduces the synthesis time by more than 40 hours without any loss in structural properties, such as mesoscale and molecular ordering. The porosity of the PMO materials has even been improved by more than 25%. Moreover, the number of handling/transfer steps and amounts of chemicals and waste are drastically reduced. The study also shows that there is a clear time (1 to 3 hours) and temperature frame (373 K to 403 K) wherein synthesis of benzene bridged PMO is optimal. In conclusion, the microwave-assisted synthesis pathway allows an improved material to be obtained in a more economical way i.e. a much shorter time with fewer chemicals and less waste. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Cambridge |
Editor |
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|
|
Language |
|
Wos |
000265919300024 |
Publication Date |
2009-03-17 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0959-9428;1364-5501; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
20 |
Open Access |
|
|
|
Notes |
Fwo; Iwt |
Approved |
Most recent IF: NA |
|
|
Call Number |
UA @ lucian @ c:irua:76844 |
Serial |
2810 |
|
Permanent link to this record |
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|
Author |
Mandal, T.K.; Croft, M.; Hadermann, J.; Van Tendeloo, G.; Stephens, P.W.; Greenblatt, M. |
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|
Title |
La2MnVO6 double perovskite: a structural, magnetic and X-ray absorption investigation |
Type |
A1 Journal article |
|
Year |
2009 |
Publication |
Journal of materials chemistry |
Abbreviated Journal |
J Mater Chem |
|
|
Volume |
19 |
Issue |
25 |
Pages |
4382-4390 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
The synthesis, electron diffraction (ED), synchrotron X-ray and neutron structure, X-ray absorption spectroscopy (XAS) and magnetic property studies of La2MnVO6 double perovskite are described. Analysis of the synchrotron powder X-ray diffraction data for La2MnVO6 indicates a disordered arrangement of Mn and V at the B-site of the perovskite structure. Absence of super-lattice reflections in the ED patterns for La2MnVO6 supports the disordered cation arrangement. Room temperature time-of-flight (TOF) neutron powder diffraction (NPD) data show no evidence of cation ordering, in corroboration with the ED and synchrotron studies (orthorhombic Pnma, a = 5.6097(3), b = 7.8837(5) and c = 5.5668(3) ; 295 K, NPD). A comparison of XAS analyses of La2TVO6 with T = Ni and Co shows T2+ formal oxidation state while the T = Mn material evidences a Mn3+ admixture into a dominantly Mn2+ ground state. V-K edge measurements manifest a mirror image behavior with a V4+ state for T = Ni and Co with a V3+ admixture arising in the T = Mn material. The magnetic susceptibility data for La2MnVO6 show ferromagnetic correlations; the observed effective moment, µeff (5.72 µB) is much smaller than the calculated moment (6.16 µB) based on the spin-only formula for Mn2+ (d5, HS) /V4+ (d1), supportive of the partly oxidized Mn and reduced V scenario (Mn3+/V3+). |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
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Language |
|
Wos |
000266989800015 |
Publication Date |
2009-04-24 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0959-9428;1364-5501; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
10 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: NA |
|
|
Call Number |
UA @ lucian @ c:irua:77367 |
Serial |
3540 |
|
Permanent link to this record |
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Author |
Berdiyorov, G.R.; Milošević, M.V.; Peeters, F.M. |
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Title |
Composite vortex ordering in superconducting films with arrays of blind holes |
Type |
A1 Journal article |
|
Year |
2009 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
|
|
Volume |
11 |
Issue |
|
Pages |
013025,1-013025,20 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
The pinning properties of a superconducting thin film with a square array of blind holes are studied using the nonlinear GinzburgLandau theory. Although blind holes provide a weaker pinning potential than holes (also called antidots), several novel vortex structures are predicted for different size and thickness of the blind holes. Orientational dimer and trimer vortex states as well as concentric vortex shells can nucleate in the blind holes. In addition, we predict the stabilization of giant vortices that may be located both in the pinning centers and/or at the interstitial sites, as well as the combination of giant vortices with sets of individual vortices. For large blind holes, local vortex shell structures inside the blind holes may transfer their symmetry to interstitial vortices as well. The subtle interplay of shell formation and traditional Abrikosov vortex lattices inside the blind holes is also studied for different numbers of trapped vortices. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
|
Wos |
000262932600002 |
Publication Date |
2009-01-21 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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|
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 |
33 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 3.786; 2009 IF: 3.312 |
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|
Call Number |
UA @ lucian @ c:irua:75987 |
Serial |
441 |
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Permanent link to this record |
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Author |
Kerner, C.; Hackens, B.; Golubović, D.S.; Poli, S.; Faniel, S.; Magnus, W.; Schoenmaker, W.; Bayot, V.; Maes, H. |
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Title |
Control and readout of current-induced magnetic flux quantization in a superconducting transformer |
Type |
A1 Journal article |
|
Year |
2009 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
|
|
Volume |
22 |
Issue |
2 |
Pages |
025001,1-025001,4 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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|
Abstract |
We demonstrate a simple and robust method for inducing and detecting changes of magnetic flux quantization in the absence of an externally applied magnetic field. In our device, an isolated ring is interconnected with two access loops via permalloy cores, forming a superconducting transformer. By applying and tuning a direct current at the first access loop, the number of flux quanta trapped in the isolated ring is modified without the aid of an external field. The flux state of the isolated ring is simply detected by recording the evolution of the critical current of the second access loop. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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|
Language |
|
Wos |
000262786000003 |
Publication Date |
2008-12-24 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0953-2048;1361-6668; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.878 |
Times cited |
2 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 2.878; 2009 IF: 2.694 |
|
|
Call Number |
UA @ lucian @ c:irua:76001 |
Serial |
497 |
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Permanent link to this record |
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Author |
Wang, M.; Chang, K.; Wang, L.G.; Dai, N.; Peeters, F.M. |
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Title |
Crystallographic plane tuning of charge and spin transport in semiconductor quantum wires |
Type |
A1 Journal article |
|
Year |
2009 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
|
|
Volume |
20 |
Issue |
36 |
Pages |
365202,1-365202,8 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We investigate theoretically the charge and spin transport in quantum wires grown along different crystallographic planes in the presence of the Rashba spinorbit interaction (RSOI) and the Dresselhaus spinorbit interaction (DSOI). We find that changing the crystallographic planes leads to a variation of the anisotropy of the conductance due to a different interplay between the RSOI and DSOI, since the DSOI is induced by bulk inversion asymmetry, which is determined by crystallographic plane. This interplay depends sensitively on the crystallographic planes, and consequently leads to the anisotropic charge and spin transport in quantum wires embedded in different crystallographic planes. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000269077000003 |
Publication Date |
2009-08-19 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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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 |
14 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 3.44; 2009 IF: 3.137 |
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|
Call Number |
UA @ lucian @ c:irua:78933 |
Serial |
588 |
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Permanent link to this record |
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Author |
Misko, V.R.; Zhao, H.J.; Peeters, F.M.; Oboznov, V.; Dubonos, S.V.; Grigorieva, I.V. |
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Title |
Formation of vortex shells in mesoscopic superconducting squares |
Type |
A1 Journal article |
|
Year |
2009 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
|
|
Volume |
22 |
Issue |
3 |
Pages |
034001,1-034001,8 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We study vortex configurations in mesoscopic superconducting squares. Our theoretical approach is based on the analytical solution of the London equation using the Green's function method. The potential energy landscape found is then used in Langevin-type molecular-dynamics simulations to obtain stable vortex configurations. We show that the filling rules for vortices in squares with increasing applied magnetic field can be formulated, although in a different manner than in disks, in terms of the formation of vortex 'shells'. We discuss metastable states and the stability of the vortex configurations found with respect to variations of the material parameters and deformations of the shape of the sample. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
|
Wos |
000263564500002 |
Publication Date |
2009-01-29 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0953-2048;1361-6668; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.878 |
Times cited |
14 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 2.878; 2009 IF: 2.694 |
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|
Call Number |
UA @ lucian @ c:irua:76312 |
Serial |
1267 |
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Permanent link to this record |
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Author |
Engbarth, M.; Milošević, M.V.; Bending, S.J.; Nasirpouri, F. |
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Title |
Geometry-guided flux behaviour in superconducting Pb microcrystals |
Type |
A1 Journal article |
|
Year |
2009 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
|
|
Volume |
150 |
Issue |
5 |
Pages |
052048 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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|
Abstract |
Electrochemistry offers highly flexible routes to fabrication of a wide variety of mesostructures, including three-dimensional (3D) crystallites, thin films and nanowires. Using this method we have grown various 3D superconducting Pb mesostructures with vastly different morphologies. We present here results on a truncated(half)-icosahedron with a hexagonal base and a tripod structure with a triangular base. Using Hall probe magnetometry we have obtained magnetisation curves for these structures at several temperatures and see evidence of geometry-driven flux entry and exit as well as flux trapping caused by specific sample geometries. We also observe behaviour that we interpret in terms of the formation of giant vortices, bearing in mind that bulk Pb is a type-I superconducting material. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
|
Publication Date |
2009-04-01 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1742-6588;1742-6596; |
ISBN |
|
Additional Links |
UA library record |
|
|
Impact Factor |
|
Times cited |
1 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: NA |
|
|
Call Number |
UA @ lucian @ c:irua:106138 |
Serial |
1332 |
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Permanent link to this record |
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Author |
Masir, M.R.; Vasilopoulos, P.; Peeters, F.M. |
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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 |
|
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Volume |
11 |
Issue |
|
Pages |
095009,1-095009,21 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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|
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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Bristol |
Editor |
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Language |
|
Wos |
000270513500008 |
Publication Date |
2009-10-01 |
|
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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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 |
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Permanent link to this record |
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Author |
Bultinck, E.; Bogaerts, A. |
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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 |
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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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000270820900001 |
Publication Date |
2009-10-06 |
|
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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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 |
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Permanent link to this record |
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Author |
Bultinck, E.; Mahieu, S.; Depla, D.; Bogaerts, A. |
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Title |
Reactive sputter deposition of TiNx films, simulated with a particle-in-cell/Monte Carlo collisions model |
Type |
A1 Journal article |
|
Year |
2009 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
|
|
Volume |
11 |
Issue |
|
Pages |
023039,1-023039,24 |
|
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
|
Abstract |
The physical processes in an Ar/N2 magnetron discharge used for the reactive sputter deposition of TiNx thin films were simulated with a 2d3v particle-in-cell/Monte Carlo collisions (PIC/MCC) model. Cathode currents and voltages were calculated self-consistently and compared with experiments. Also, ion fractions were calculated and validated with mass spectrometric measurements. With this PIC/MCC model, the influence of N2/Ar gas ratio on the particle densities and fluxes was investigated, taking into account the effect of the poisoned state of the target. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
|
Wos |
000263744100001 |
Publication Date |
2009-02-26 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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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 |
23 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 3.786; 2009 IF: 3.312 |
|
|
Call Number |
UA @ lucian @ c:irua:73150 |
Serial |
2825 |
|
Permanent link to this record |
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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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
|
Wos |
000269930100007 |
Publication Date |
2009-09-17 |
|
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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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 |
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Permanent link to this record |
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Author |
Magnus, W.; Brosens, F.; Sorée, B. |
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Title |
Time dependent transport in 1D micro- and nanostructures: solving the Boltzmann and Wigner-Boltzmann equations |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
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Volume |
193 |
Issue |
1 |
Pages |
012004,1-012004,4 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
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Abstract |
For many decades the Boltzmann distribution function has been used to calculate the non-equilibrium properties of mobile particles undergoing the combined action of various scattering mechanisms and externally applied force fields. When the latter give rise to the occurrence of inhomogeneous potential profiles across the region through which the particles are moving, the numerical solution of the Boltzmann equation becomes a highly complicated task. In this work we highlight a particular algorithm that can be used to solve the time dependent Boltzmann equation as well as its quantum mechanical extension, the WignerBoltzmann equation. As an illustration, we show the calculated distribution function describing electrons propagating under the action of both a uniform and a pronouncedly non-uniform electric field. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000277100400004 |
Publication Date |
2009-11-17 |
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Series Editor |
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Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1742-6596; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
2 |
Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:82861 |
Serial |
3667 |
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Permanent link to this record |
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Author |
Bending, S.J.; Neal, J.S.; Milošević, M.V.; Potenza, A.; san Emeterio, L.; Marrows, C.H. |
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Title |
Vortex-antivortex 'molecular crystals' in hybrid ferromagnet/superconductor structures |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
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Volume |
150 |
Issue |
5 |
Pages |
052019 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We have used high resolution Hall probe microscopy to image vortex-antivortex (V-AV) 'molecules' induced in superconducting Pb films by the stray fields from square arrays of ferromagnetic Co/Pt dots. We have directly observed spontaneous V-AV pairs and studied how they interact with added 'free' (anti)fluxons in an applied magnetic field. We observe a rich variety of subtle phenomena arising from competing symmetries in our system which can either drive added antivortices to join AV shells around nanomagnets or stabilise the translationally symmetric AV lattice between the dots. Added vortices annihilate AV shells, leading eventually to a stable 'nulling' state with no free fluxons, which should exhibit a strongly (field-)enhanced critical current. At higher densities we actually observe vortex shells around the magnets, stabilised by the asymmetric anti-pinning potential. Our experimental findings are in good agreement with Ginzburg-Landau calculations. |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
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Publication Date |
2009-04-01 |
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Series Editor |
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Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1742-6588;1742-6596; |
ISBN |
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Additional Links |
UA library record |
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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 |
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Call Number |
UA @ lucian @ c:irua:106136 |
Serial |
3855 |
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Permanent link to this record |
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Author |
Xu, B.; Milošević, M.V.; Peeters, F.M. |
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Title |
Vortex matter in oblate mesoscopic superconductors with a hole: broken symmetry vortex states and multi-vortex entry |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
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Volume |
11 |
Issue |
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Pages |
013020,1-013020,21 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using three-dimensional (3D) numerical discretization of the GinzburgLandau (GL) equations, we investigate the superconducting state of a sphere with a piercing hole in the presence of a magnetic field. In the case of samples with central perforation, in axially applied homogeneous magnetic field, we realized unconventional vortex states of broken symmetry due to complex, 3D competing interactions, which depend on the GL parameter ê. For certain sizes of the sample, non-hysteretic multi-vortex entry and exit is predicted with the non-existence of some vorticities as stable states. In a tilted magnetic field, we studied the gradual transformation of 3D flux patterns into 1D vortex chains, where vortices align along the perforation, and the evolvement of the multi-vortex entry as well. We analyze the flux-guiding ability of the hole in a tilted field, which leads to fractional flux response in magnetization M(H) curves. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000262932500003 |
Publication Date |
2009-01-17 |
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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 |
1367-2630; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.786 |
Times cited |
8 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.786; 2009 IF: 3.312 |
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Call Number |
UA @ lucian @ c:irua:75986 |
Serial |
3873 |
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Permanent link to this record |
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Author |
Connolly, M.R.; Milošević, M.V.; Bending, S.J.; Clem, J.R.; Tamegai, T. |
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Title |
Vortex 'puddles' and magic vortex numbers in mesoscopic superconducting disks |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
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Volume |
150 |
Issue |
5 |
Pages |
052039 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The magnetic properties of a superconducting disk change dramatically when its dimensions become mesoscopic. Unlike large disks, where the screening currents induced by an applied magnetic field are strong enough to force vortices to accumulate in a 'puddle' at the centre, in a mesoscopic disk the interaction between one of these vortices and the edge currents can be comparable to the intervortex repulsion, resulting in a destruction of the ordered triangular vortex lattice structure at the centre. Vortices instead form clusters which adopt polygonal and shell-like structures which exhibit magic number states similar to those of charged particles in a confining potential, and electrons in artificial atoms. We have fabricated mesoscopic high temperature superconducting Bi2Sr2CaCu2O8+δ disks and investigated their magnetic properties using magneto-optical imaging (MOI) and high resolution scanning Hall probe microscopy (SHPM). The temperature dependence of the vortex penetration field measured using MOI is in excellent agreement with models of the thermal excitation of pancake vortices over edge barriers. The growth of the central vortex puddle has been directly imaged using SHPM and magic vortex numbers showing higher stability have been correlated with abrupt jumps in the measured local magnetisation curves. |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Wos |
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Publication Date |
2009-04-01 |
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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 |
1742-6588;1742-6596; |
ISBN |
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Additional Links |
UA library record |
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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 |
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Call Number |
UA @ lucian @ c:irua:106137 |
Serial |
3881 |
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Permanent link to this record |
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Author |
Brosens, F.; Magnus, W. |
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Title |
Carrier transport in nanodevices: revisiting the Boltzmann and Wigner distribution functions |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Physica status solidi: B: basic research |
Abbreviated Journal |
Phys Status Solidi B |
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Volume |
246 |
Issue |
7 |
Pages |
1656-1661 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
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Abstract |
In principle, transport of charged carriers in nanometer sized solid-state devices can be fully characterized once the non-equilibrium distribution function describing the carrier ensemble is known. In this light, we have revisited the Boltzmann and the Wigner distribution functions and the framework in which they emerge from the classical respectively quantum mechanical Liouville equation. We have assessed the method of the characteristic curves as a potential workhorse to solve the time dependent Boltzmann equation for carriers propagating through spatially non-uniform systems, such as nanodevices. In order to validate the proposed solution strategy, we numerically solve the Boltzmann equation for a one-dimensional conductor mimicking the basic features of a biased low-dimensional transistor operating in the on-state. Finally, we propose a computational scheme capable of extending the benefits of the above mentioned solution strategy when it comes to solve the Wigner-Liouville equation. |
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Corporate Author |
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Publisher |
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Place of Publication |
Berlin |
Editor |
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Language |
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Wos |
000268659100033 |
Publication Date |
2009-04-22 |
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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 |
0370-1972;1521-3951; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.674 |
Times cited |
8 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1.674; 2009 IF: 1.150 |
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Call Number |
UA @ lucian @ c:irua:77953 |
Serial |
284 |
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Permanent link to this record |
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Author |
Austing, D.G.; Payette, C.; Nair, S.V.; Yu, G.; Gupta, J.A.; Partoens, B.; Amaha, S.; Tarucha, S. |
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Title |
Scheme for coherently quenching resonant current in a three-level quantum dot energy level mixer |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Physica status solidi: C: conferences and critical reviews |
Abbreviated Journal |
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Volume |
6 |
Issue |
4 |
Pages |
940-943 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We outline a scheme to create a dark state by three-level mixing that is potentially a useful tool for quantum coherent transport. Magnetic-field-induced intra-dot level mixing can lead to rich quantum superposition phenomena between three approaching single-particle states in a quantum dot when probed by the ground state of an adjacent weakly coupled quantum dot in the single-electron resonant tunnelling regime. The mixing relies on non-negligible anharmonicity and anisotropy in confining potentials of realistic quantum dots. Anti-crossing and transfer of strengths between resonances can be understood with a simple coherent level mixing model. Superposition can lead to the formation of a dark state by complete cancellation of an otherwise strong resonance. This is an all-electrical analogue of coherent population trapping seen in three-level-systems from quantum and atom optics. |
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Place of Publication |
Berlin |
Editor |
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Wos |
000266597600040 |
Publication Date |
2008-12-12 |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1862-6351;1610-1642; |
ISBN |
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Additional Links |
UA library record; WoS full record |
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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 |
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Call Number |
UA @ lucian @ c:irua:86927 |
Serial |
2953 |
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Permanent link to this record |
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Author |
Michel, K.H.; Verberck, B. |
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Title |
Theoretical phonon dispersions in monolayers and multilayers of hexagonal boron-nitride |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Physica status solidi: B: basic research |
Abbreviated Journal |
Phys Status Solidi B |
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Volume |
246 |
Issue |
11/12 |
Pages |
2802-2805 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Starting from an empirical force constant model of valence interactions and calculating by Ewald's method the electrostatic force constants, we derive the dynamical matrix for a monolayer and for multilayer systems of hexagonal boron nitride (h-BN). Solution of the secular problem leads to the corresponding phonon dispersion relations. The interplay between valence forces and Coulomb forces is discussed. A comparison with previous results on graphene and graphene multilayers is made. Our spectra on the h-BN monolayer are rather similar to previous ab initio theory results. Comparison is also made with Raman and infrared experimental results. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Berlin |
Editor |
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Language |
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Wos |
000272904100091 |
Publication Date |
2009-11-12 |
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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 |
0370-1972; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.674 |
Times cited |
10 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1.674; 2009 IF: 1.150 |
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Call Number |
UA @ lucian @ c:irua:80673 |
Serial |
3609 |
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Permanent link to this record |
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Author |
Batenburg, K.J.; Bals, S.; Sijbers, J.; Kübel, C.; Midgley, P.A.; Hernandez, J.C.; Kaiser, U.; Encina, E.R.; Coronado, E.A.; Van Tendeloo, G. |
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Title |
3D imaging of nanomaterials by discrete tomography |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
109 |
Issue |
6 |
Pages |
730-740 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
The field of discrete tomography focuses on the reconstruction of samples that consist of only a few different materials. Ideally, a three-dimensional (3D) reconstruction of such a sample should contain only one grey level for each of the compositions in the sample. By exploiting this property in the reconstruction algorithm, either the quality of the reconstruction can be improved significantly, or the number of required projection images can be reduced. The discrete reconstruction typically contains fewer artifacts and does not have to be segmented, as it already contains one grey level for each composition. Recently, a new algorithm, called discrete algebraic reconstruction technique (DART), has been proposed that can be used effectively on experimental electron tomography datasets. In this paper, we propose discrete tomography as a general reconstruction method for electron tomography in materials science. We describe the basic principles of DART and show that it can be applied successfully to three different types of samples, consisting of embedded ErSi2 nanocrystals, a carbon nanotube grown from a catalyst particle and a single gold nanoparticle, respectively. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000265816400005 |
Publication Date |
2009-02-01 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0304-3991; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
220 |
Open Access |
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Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
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Call Number |
UA @ lucian @ c:irua:74665 c:irua:74665 |
Serial |
12 |
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Permanent link to this record |