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Records |
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Author |
Lepoittevin, C.; Hadermann, J.; Malo, S.; Pérez, O.; Van Tendeloo, G.; Hervieu, M. |
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Title |
Two variants of the 1/2[110]p(203)p crystallographic shear structures: the phasoid Sr0.61Pb0.18(Fe0.75Mn0.25)O2.29 |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
48 |
Issue |
17 |
Pages |
8257-8262 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
For the composition (Sr0.61Pb0.18)(Fe0.75Mn0.25)O2.29, a new modulated crystallographic shear structure, related to perovskite, has been synthesized and structurally characterized by transmission electron microscopy. The structure can be described using a monoclinic supercell with cell parameters am = 27.595(2) Å, bm = 3.8786(2) Å, cm = 13.3453(9) Å, and βm = 100.126(5)°, refined from powder X-ray diffraction data. The incommensurate crystallographic shear phases require an alternative approach using the superspace formalism. This allows a unified description of the incommensurate phases from a monoclinically distorted perovskite unit cell and a modulation wave vector. The structure deduced from the high-resolution transmission electron microscopy and high-angle annular dark-field−scanning transmission electron microscopy images is that of a 1/2[110]p(203)p crystallographic shear structure. The structure follows the concept of a phasoid, with two coexisting variants with the same unit cell. The difference is situated at the translational interface, with the local formation of double (phase 2) or single (phase 1) tunnels, where the Pb cations are likely located. |
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Corporate Author |
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Thesis |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos  |
000269313500032 |
Publication Date |
2009-07-24 |
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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 |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.857 |
Times cited |
11 |
Open Access |
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Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.857; 2009 IF: 4.657 |
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Call Number |
UA @ lucian @ c:irua:78482 |
Serial |
3786 |
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Author |
Zhang, H.; Yang, J.-H.; Shpanchenko, R.V.; Abakumov, A.M.; Hadermann, J.; Clérac, R.; Dikarev, E.V. |
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Title |
New class of single-source precursors for the synthesis of main group-transition metal oxides: heterobimetallic Pb-Mn \beta-diketonates |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
48 |
Issue |
17 |
Pages |
8480-8488 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Heterometallic lead−manganese â-diketonates have been isolated in pure form by several synthetic methods that include solid-state and solution techniques. Two compounds with different Pb/Mn ratios, PbMn2(hfac)6 (1) and PbMn(hfac)4 (2) (hfac = hexafluoroacetylacetonate), can be obtained in quantitative yield by using different starting materials. Single crystal X-ray investigation revealed that the solid-state structure of 1 contains trinuclear molecules in which lead metal center is sandwiched between two [Mn(hfac)3] units, while 2 consists of infinite chains of alternating [Pb(hfac)2] and [Mn(hfac)2] fragments. The heterometallic structures are held together by strong Lewis acid−base interactions between metal atoms and diketonate ligands acting in chelating-bridging fashion. Spectroscopic investigation confirmed the retention of heterometallic structures in solutions of non-coordinating solvents as well as upon sublimation-deposition procedure. Thermal decomposition of heterometallic diketonates has been systematically investigated in a wide range of temperatures and annealing times. For the first time, it has been shown that thermal decomposition of heterometallic diketonates results in mixed-metal oxides, while both the structure of precursors and the thermolysis conditions have a significant influence on the nature of the resulting oxides. Five different Pb−Mn oxides have been detected by X-ray powder diffraction when studying the decomposition of 1 and 2 in the temperature range 500−800 °C. The phase that has been previously reported as Pb0.43MnO2.18 was synthesized in the pure form by decomposition of 1, and crystallographically characterized. The orthorhombic unit cell parameters of this oxide, obtained by electron diffraction technique, have been subsequently refined using X-ray powder diffraction data. Besides that, a previously unknown lead−manganese oxide has been obtained at low temperature decomposition and short annealing times. The parameters of its monoclinically distorted unit cell have been determined. The EDX analysis revealed that this compound has a Pb/Mn ratio close to 1:4 and contains no appreciable amount of fluorine. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000269313500056 |
Publication Date |
2009-08-04 |
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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 |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
28 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.857; 2009 IF: 4.657 |
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Call Number |
UA @ lucian @ c:irua:78486 |
Serial |
2308 |
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Author |
Berdiyorov, G.R.; Yu, S.H.; Xiao, Z.L.; Peeters, F.M.; Hua, J.; Imre, A.; Kwok, W.K. |
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Title |
Effect of sample geometry on the phase boundary of a mesoscopic superconducting loop |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
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Volume |
80 |
Issue |
6 |
Pages |
064511,1-064511,6 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We studied the effect of sample geometry on the evolution of the superconducting state in nanoscale Nb circular and square loops by transport measurements. A multistage resistive transition with temperature is found for both samples, which is related to the effect of contact leads made from the same superconducting material. The H-T phase diagrams close to Tc0 show clear periodic oscillations on top of a parabolic background, i.e., Little-Parks effect. However, the amplitude of the oscillations decreases faster in the circular loop compared to the one in the square sample. Numerical simulations are conducted within the nonlinear Ginzburg-Landau theory to show the effect of sample geometry on the nucleation of superconductivity in superconducting loop structures. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000269638800067 |
Publication Date |
2009-08-17 |
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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 |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
21 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
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Call Number |
UA @ lucian @ c:irua:78292 |
Serial |
833 |
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Author |
Zha, G.-Q.; Chen, Y.; Peeters, F.M.; Zhou, S.-P. |
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Title |
Impurity-induced modulations of orders in d-wave superconductors |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
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Volume |
80 |
Issue |
6 |
Pages |
064518,1-064518,5 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
By using a model Hamiltonian with competing antiferromagnetic (AFM) and d-wave superconductivity orders, the impurity-induced structures of orders in d-wave superconductors is investigated. We find that the transition between one-dimensional stripe and two-dimensional checkerboardlike modulation around a single nonmagnetic impurity can take place as the strength of the AFM interaction U or the impurity scattering strength V0 is varied. It is also found that the impurity-induced stripe can first transit to checkerboardlike modulation and then disappears with increasing the next-nearest-neighbor hopping strength |t|. Phase diagrams of V0 versus U and |t| for various modulations of the spin order are presented. In addition, the quantum interference effect on the modulations of orders due to two strong nonmagnetic impurities is briefly examined, and the checkerboardlike and quasistripe patterns can occur depending on the sites where two impurities are placed. |
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Corporate Author |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000269638800074 |
Publication Date |
2009-09-01 |
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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 |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
3 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
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Call Number |
UA @ lucian @ c:irua:78293 |
Serial |
1572 |
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Author |
Pourghaderi, M.A.; Magnus, W.; Sorée, B.; Meuris, M.; de Meyer, K.; Heyns, M. |
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Title |
Tunneling-lifetime model for metal-oxide-semiconductor structures |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
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Volume |
80 |
Issue |
8 |
Pages |
085315,1-085315,10 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
In this paper we investigate the basic physics of charge carriers (electrons) leaking out of the inversion layer of a metal-oxide-semiconductor capacitor with a biased gate. In particular, we treat the gate leakage current as resulting from two combined processes: (1) the time-dependent decay of electron wave packets representing the inversion-layer charge and (2) the local generation of new electrons replacing those that have leaked away. As a result, the gate current simply emerges as the ratio of the total charge in the inversion layer to the tunneling lifetime. The latter is extracted from the quantum dynamics of the decaying wave packets, while the generation rate is incorporated as a phenomenological source term in the continuity equation. Not only do the gate currents calculated with this model agree very well with experiment, the model also provides an onset to solve the paradox of the current-free bound states representing the resonances of the Schrödinger equation that governs the fully coupled metal-oxide-semiconductor system. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000269639300076 |
Publication Date |
2009-08-21 |
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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 |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
2 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
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Call Number |
UA @ lucian @ c:irua:78294 |
Serial |
3763 |
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Author |
Dominiczak, M.; Ruyter, A.; Limelette, P.; Monot-Laffez, I.; Giovannelli, F.; Rossell, M.D.; Van Tendeloo, G. |
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Title |
Effects of nanocracks on the magnetic and electrical properties of La0.8Sr0.2MnO3 single crystals |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Solid state communications |
Abbreviated Journal |
Solid State Commun |
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Volume |
149 |
Issue |
37/38 |
Pages |
1543-1548 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
An investigation of the physical properties of La0.8Sr0.2MnO3 single crystals grown by the molten zone technique is realized close to the metal-to-insulator transition temperature (TMI). In this paper, we review the effect of the structural defects through magnetotransport and local magnetic microstructures. From electron microscopy observations, some nanocrack defects (i.e. defects at a nanometer scale) were found, essentially in the center part of the single crystals. At room temperature, magnetic force microscopy measurements have shown that the absence of defects allowed a magnetic ordering of the domains at the crystal edge, which is the best-crystallized region. In addition, the magnetization loops have permitted us to verify that the crystal was ferromagnetically weaker in the center. On analyzing the electrical resistivity data, we observed in the linear current regime a sensitive variation of the resistivity due to defects, by comparing the center and the edge of the material at TMI. Additionally, at strong current, non-linearity phenomena have been supposed to be related to local heating. Finally, we discuss the structural disorder effect on the relaxation of the ferromagnetic domains. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000269679500012 |
Publication Date |
2009-06-09 |
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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 |
0038-1098; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.554 |
Times cited |
3 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1.554; 2009 IF: 1.837 |
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Call Number |
UA @ lucian @ c:irua:78289 |
Serial |
868 |
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Author |
Pourghaderi, M.A.; Magnus, W.; Sorée, B.; Meuris, M.; de Meyer, K.; Heyns, M. |
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Title |
Ballistic current in metal-oxide-semiconductor field-effect transistors: the role of device topology |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
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Volume |
106 |
Issue |
5 |
Pages |
053702,1-053702,8 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
In this study we investigate the effect of device topology on the ballistic current in n-channel metal-oxide-semiconductor field-effect transistors. Comparison of the nanoscale planar and double-gate devices reveals that, down to a certain thickness of the double gate film, the ballistic current flowing in the double gate device is twice as large compared to its planar counterpart. On the other hand, further thinning of the film beyond this threshold is found to change noticeably the confinement and transport characteristics, which are strongly depending on the film material and the surface orientation. For double gate Ge and Si devices there exists a critical film thickness below which the transverse gate field is no longer effectively screened by the inversion layer electron gas and mutual inversion of the two gates is turned on. In the case of GaAs and other similar IIIV compounds, a decrease in the film thickness may drastically change the occupation of the L-valleys and therefore amend the transport properties. The simulation results show that, in both cases, the ballistic current and the transconductance are considerably enhanced. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000269850300052 |
Publication Date |
2009-09-03 |
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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 |
0021-8979; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.068 |
Times cited |
3 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.068; 2009 IF: 2.072 |
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Call Number |
UA @ lucian @ c:irua:79744 |
Serial |
214 |
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| Permanent link to this record |
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Author |
Zhang, Z.Z.; Wu, Z.H.; Chang, K.; Peeters, F.M. |
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Title |
Resonant tunneling through S- and U-shaped graphene nanoribbons |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
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Volume |
20 |
Issue |
41 |
Pages |
415203,1-415203,7 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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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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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 |
000269930100007 |
Publication Date |
2009-09-17 |
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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 |
0957-4484;1361-6528; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.44 |
Times cited |
32 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.44; 2009 IF: 3.137 |
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Call Number |
UA @ lucian @ c:irua:79311 |
Serial |
2893 |
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Author |
van Dijk, J.; Kroesen, G.M.W.; Bogaerts, A. |
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Title |
Plasma modelling and numerical simulation |
Type |
Editorial |
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Year |
2009 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
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Volume |
42 |
Issue |
19 |
Pages |
190301,1-190301,14 |
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Keywords |
Editorial; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Plasma modelling is an exciting subject in which virtually all physical disciplines are represented. Plasma models combine the electromagnetic, statistical and fluid dynamical theories that have their roots in the 19th century with the modern insights concerning the structure of matter that were developed throughout the 20th century. The present cluster issue consists of 20 invited contributions, which are representative of the state of the art in plasma modelling and numerical simulation. These contributions provide an in-depth discussion of the major theories and modelling and simulation strategies, and their applications to contemporary plasma-based technologies. In this editorial review, we introduce and complement those papers by providing a bird's eye perspective on plasma modelling and discussing the historical context in which it has surfaced. |
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Corporate Author |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000269993100001 |
Publication Date |
2009-09-19 |
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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 |
0022-3727;1361-6463; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.588 |
Times cited |
64 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.588; 2009 IF: 2.083 |
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Call Number |
UA @ lucian @ c:irua:78166 |
Serial |
2637 |
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Author |
Denecke, M.A.; Brendebach, B.; de Nolf, W.; Falkenberg, G.; Janssens, K.; Simon, R. |
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Title |
Spatially resolved micro-X-ray fluorescence and micro-X-ray absorption fine structure study of a fractured granite bore core following a radiotracer experiment |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Spectrochimica acta: part B : atomic spectroscopy |
Abbreviated Journal |
Spectrochim Acta B |
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Volume |
64 |
Issue |
8 |
Pages |
791-795 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Spatially resolved X-ray absorption and fluorescence investigation with a micrometer-scale resolution on actinide-containing samples provide information necessary for safety assessment of nuclear waste disposal. In this paper one example of such an experiment is presented. This example entails neptunium speciation in a fractured granite bore core from the Swedish Äspö Hard Rock Laboratory following a radiotracer experiment using µ-XAFS and µ-XRF. In order to probe micro-volumes below the surface in the granite samples and thereby avoid potential changes in the Np speciation during cutting of the bore core, a confocal irradiationdetection geometry is employed. µ-XAFS results for a selected granite bore core cross section with ~ 3 nmol Np/g reveal that Np, originally introduced as Np(V) in the tracer cocktail, is present in the granite in its reduced Np(IV) form. The Np(IV) is often present as particles, tens of µm in size. Elemental distribution maps show the tracer Np to be located in fissures and permeable channels not larger than 100 µm. The Np distribution appears often correlated with Zn also present in some fissures. We observe small granite fissures containing Fe (presumably Fe(II)), where we do not detect any Np. It is feasible that inflowing Np(V) has a shorter residence time in large fractures, while in the smaller fissures migration is slower, leading to longer residence times, i.e., reaction times, where it is reduced to less soluble Np(IV) and becomes thereby immobilized. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000269995300013 |
Publication Date |
2009-06-10 |
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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 |
0584-8547; 0038-6987 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.241 |
Times cited |
21 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.241; 2009 IF: 2.719 |
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Call Number |
UA @ admin @ c:irua:79740 |
Serial |
5837 |
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| Permanent link to this record |
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Author |
Schalm, O.; van der Linden, V.; Frederickx, P.; Luyten, S.; van der Snickt, G.; Caen, J.; Schryvers, D.; Janssens, K.; Cornelis, E.; van Dyck, D.; Schreiner, M. |
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Title |
Enamels in stained glass windows: preparation, chemical composition, microstructure and causes of deterioration |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Spectrochimica acta: part B : atomic spectroscopy |
Abbreviated Journal |
Spectrochim Acta B |
|
| |
Volume |
64 |
Issue |
8 |
Pages |
812-820 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Vision lab |
|
| |
Abstract |
Stained glass windows incorporating dark blue and purple enamel paint layers are in some cases subject to severe degradation while others from the same period survived the ravages of time. A series of dark blue, greenblue and purple enamel glass paints from the same region (Northwestern Europe) and from the same period (16early 20th centuries) has been studied by means of a combination of microscopic X-ray fluorescence analysis, electron probe micro analysis and transmission electron microscopy with the aim of better understanding the causes of the degradation. The chemical composition of the enamels diverges from the average chemical composition of window glass. Some of the compositions appear to be unstable, for example those with a high concentration of K2O and a low content of CaO and PbO. In other cases, the deterioration of the paint layers was caused by the less than optimal vitrification of the enamel during the firing process. Recipes and chemical compositions indicate that glassmakers of the 1617th century had full control over the color of the enamel glass paints they made. They mainly used three types of coloring agents, based on Co (dark blue), Mn (purple) and Cu (light-blue or greenblue) as coloring elements. Bluepurple enamel paints were obtained by mixing two different coloring agents. The coloring agent for redpurple enamel, introduced during the 19th century, was colloidal gold embedded in grains of lead glass. |
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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 |
Oxford |
Editor |
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| |
Language |
|
Wos |
000269995300018 |
Publication Date |
2009-06-19 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0584-8547; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.241 |
Times cited |
28 |
Open Access |
|
|
| |
Notes |
Iuap Vi/6; Fwo; Goa |
Approved |
Most recent IF: 3.241; 2009 IF: 2.719 |
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| |
Call Number |
UA @ lucian @ c:irua:79647 |
Serial |
1035 |
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| Permanent link to this record |
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| |
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Author |
Van Aert, S.; Verbeeck, J.; Erni, R.; Bals, S.; Luysberg, M.; van Dyck, D.; Van Tendeloo, G. |
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| |
Title |
Quantitative atomic resolution mapping using high-angle annular dark field scanning transmission electron microscopy |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
| |
Volume |
109 |
Issue |
10 |
Pages |
1236-1244 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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| |
Abstract |
A model-based method is proposed to relatively quantify the chemical composition of atomic columns using high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) images. The method is based on a quantification of the total intensity of the scattered electrons for the individual atomic columns using statistical parameter estimation theory. In order to apply this theory, a model is required describing the image contrast of the HAADF STEM images. Therefore, a simple, effective incoherent model has been assumed which takes the probe intensity profile into account. The scattered intensities can then be estimated by fitting this model to an experimental HAADF STEM image. These estimates are used as a performance measure to distinguish between different atomic column types and to identify the nature of unknown columns with good accuracy and precision using statistical hypothesis testing. The reliability of the method is supported by means of simulated HAADF STEM images as well as a combination of experimental images and electron energy-loss spectra. It is experimentally shown that statistically meaningful information on the composition of individual columns can be obtained even if the difference in averaged atomic number Z is only 3. Using this method, quantitative mapping at atomic resolution using HAADF STEM images only has become possible without the need of simultaneously recorded electron energy loss spectra. |
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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 |
Amsterdam |
Editor |
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| |
Language |
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Wos |
000270015200004 |
Publication Date |
2009-05-28 |
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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 |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.843 |
Times cited |
166 |
Open Access |
|
|
| |
Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
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| |
Call Number |
UA @ lucian @ c:irua:78585UA @ admin @ c:irua:78585 |
Serial |
2748 |
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| Permanent link to this record |
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| |
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Author |
Dhong, H.M.; Zhang, J.; Peeters, F.M.; Xu, W. |
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| |
Title |
Optical conductance and transmission in bilayer graphene |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
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| |
Volume |
106 |
Issue |
4 |
Pages |
043103,1-043103,6 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
We present a theoretical study of the optoelectronic properties of bilayer graphene. The optical conductance and transmission coefficient are calculated using the energy-balance equation derived from a Boltzmann equation for an air/graphene/dielectric-wafer system. For short wavelengths (<0.2 µm), we obtain the universal optical conductance =e2/(2). Interestingly, there exists an optical absorption window in the wavelength range 10100 µm, which is induced by different transition energies required for inter- and intra-band optical absorptions in the presence of the MossBurstein effect. As a result, the position and width of this absorption window depend sensitively on temperature, carrier density, and sample mobility of the system. These results are relevant for applications of recently developed graphene devices in advanced optoelectronics such as the infrared photodetectors. |
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| |
Address |
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| |
Corporate Author |
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Thesis |
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| |
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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| |
Language |
|
Wos |
000270083800004 |
Publication Date |
2009-08-20 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0021-8979; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.068 |
Times cited |
11 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 2.068; 2009 IF: 2.072 |
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| |
Call Number |
UA @ lucian @ c:irua:79315 |
Serial |
2472 |
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| Permanent link to this record |
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| |
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Author |
Abakumov, A.M.; King, G.; Laurinavichute, V.K.; Rozova, M.G.; Woodward, P.M.; Antipov, E.V. |
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| |
Title |
The crystal structure of \alpha-K3AIF6: elpasolites and double perovskites with broken corner-sharing connectivity of the octahedral framework |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
|
| |
Volume |
48 |
Issue |
19 |
Pages |
9336-9344 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
The crystal structure of α-K3AlF6 was solved and refined from a combination of powder X-ray and neutron diffraction data (a = 18.8385(3)Å, c = 33.9644(6)Å, S.G. I41/a, Z = 80, RP(X-ray) = 0.037, RP(neutron) = 0.053). The crystal structure is of the A2BB′X6 elpasolite type with the a = b ≈ ae√5, c = 4ae superstructure (ae, parameter of the elpasolite subcell) and rock-salt-type ordering of the K and Al cations over the B and B′ positions, respectively. The remarkable feature of α-K3AlF6 is a rotation of 2/5 of the AlF6 octahedra by π/4 around one of the crystal axes of the elpasolite subcell, coinciding with the 4-fold symmetry axes of the AlF6 octahedra. The rotation of the AlF6 octahedra replaces the corner-sharing between the K and Al polyhedra by edge-sharing, resulting in an increase of coordination numbers of the K cations at the B positions up to 7 and 8. Due to significant deformations of the K polyhedra, the corner-sharing connectivity of the octahedral elpasolite framework is broken and the rotations of the AlF6 octahedra do not have a cooperative character. Elpasolites and double perovskites with similar structural organization are discussed. The difference in ionic radii of the B and B′ cations as well as the tolerance factor are proposed to be the parameters governing the formation of elpasolites and double perovskites with broken corner-sharing connectivity of the octahedral framework. |
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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 |
Easton, Pa |
Editor |
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| |
Language |
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Wos |
000270091000039 |
Publication Date |
2009-09-03 |
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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 |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.857 |
Times cited |
20 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 4.857; 2009 IF: 4.657 |
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| |
Call Number |
UA @ lucian @ c:irua:79733 |
Serial |
568 |
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| Permanent link to this record |
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Author |
Szafran, B.; Poniedziałek, M.R.; Peeters, F.M. |
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| |
Title |
Violation of Onsager symmetry for a ballistic channel Coulomb coupled to a quantum ring |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Europhysics letters |
Abbreviated Journal |
Epl-Europhys Lett |
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| |
Volume |
87 |
Issue |
4 |
Pages |
47002,1-47002,6 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
We investigate a scattering of electron which is injected individually into an empty ballistic channel containing a cavity that is Coulomb coupled to a quantum ring charged with a single electron. We solve the time-dependent Schrödinger equation for the electron pair with an exact account for the electron-electron correlation. Absorption of energy and angular momentum by the quantum ring is not an even function of the external magnetic field. As a consequence we find that the electron backscattering probability is asymmetric in the magnetic field and thus violates Onsager symmetry. |
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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 |
Paris |
Editor |
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| |
Language |
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Wos |
000270146400017 |
Publication Date |
2009-09-02 |
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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 |
|
Series Issue |
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Edition |
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| |
ISSN |
0295-5075;1286-4854; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
1.957 |
Times cited |
4 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 1.957; 2009 IF: 2.893 |
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| |
Call Number |
UA @ lucian @ c:irua:79734 |
Serial |
3847 |
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| Permanent link to this record |
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Author |
Neira, I.S.; Kolen'ko, Y.V.; Lebedev, O.I.; Van Tendeloo, G.; Gupta, H.S.; Matsushita, N.; Yoshimura, M.; Guitian, F. |
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| |
Title |
Rational synthesis of a nanocrystalline calcium phosphate cement exhibiting rapid conversion to hydroxyapatite |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Materials science and engineering: part C: biomimetic materials |
Abbreviated Journal |
Mat Sci Eng C-Mater |
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| |
Volume |
29 |
Issue |
7 |
Pages |
2124-2132 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
The rational synthesis, comprehensive characterization, and mechanical and micromechanical properties of a calcium phosphate cement are presented. Hydroxyapatite cement biomaterial was synthesized from reactive sub-micrometer-sized dicalcium phosphate dihydrate and tetracalcium phosphate via a dissolution-precipitation reaction using water as the liquid phase. As a result nanostructured, Ca-deficient and carbonated B-type hydroxyapatite is formed. The cement shows good processibility, sets in 22 ± 2 min and entirely transforms to the end product after 6 h of setting reaction, one of the highest conversion rates among previously reported for calcium phosphate cements based on dicalcium and tetracalcium phosphates. The combination of all elucidated physical-chemical traits leads to an essential bioactivity and biocompatibility of the cement, as revealed by in vitro acellular simulated body fluid and cell culture studies. The compressive strength of the produced cement biomaterial was established to be 25 ± 3 MPa. Furthermore, nanoindentation tests were performed directly on the cement to probe its local elasticity and plasticity at sub-micrometer/micrometer level. The measured elastic modulus and hardness were established to be Es = 23 ± 3.5 and H = 0.7 ± 0.2 GPa, respectively. These values are in close agreement with those reported in literature for trabecular and cortical bones, reflecting good elastic and plastic coherence between synthesized cement biomaterial and human bones. |
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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 |
Lausanne |
Editor |
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| |
Language |
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Wos |
000270159200008 |
Publication Date |
2009-04-20 |
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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 |
|
Series Issue |
|
Edition |
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| |
ISSN |
0928-4931; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.164 |
Times cited |
18 |
Open Access |
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| |
Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.164; 2009 IF: NA |
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| |
Call Number |
UA @ lucian @ c:irua:79312 |
Serial |
2812 |
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| Permanent link to this record |
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Author |
Peelaers, H.; Partoens, B.; Peeters, F.M. |
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| |
Title |
Phonons in Ge nanowires |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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| |
Volume |
95 |
Issue |
12 |
Pages |
122110,1-122110,3 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
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. |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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| |
Language |
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Wos |
000270243800035 |
Publication Date |
2009-09-25 |
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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 |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.411 |
Times cited |
12 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 3.411; 2009 IF: 3.554 |
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| |
Call Number |
UA @ lucian @ c:irua:79307 |
Serial |
2606 |
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| Permanent link to this record |
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Author |
Nguten, N.T.T.; Peeters, F.M. |
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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 |
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| |
Volume |
80 |
Issue |
11 |
Pages |
115335,1-115335,9 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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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. |
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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 |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000270383200110 |
Publication Date |
2009-09-30 |
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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 |
|
Series Issue |
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Edition |
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
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| |
Call Number |
UA @ lucian @ c:irua:79228 |
Serial |
1941 |
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| Permanent link to this record |
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Author |
Földi, P.; Kálmán, O.; Peeters, F.M. |
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| |
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 |
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| |
Volume |
80 |
Issue |
12 |
Pages |
125324,1-125324,9 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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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. |
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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 |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000270383300091 |
Publication Date |
2009-09-23 |
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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 |
|
Series Issue |
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Edition |
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
41 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
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| |
Call Number |
UA @ lucian @ c:irua:79230 |
Serial |
3131 |
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| Permanent link to this record |
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| |
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Author |
Chaves, A.; Farias, G.A.; Peeters, F.M.; Szafran, B. |
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| |
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 |
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| |
Volume |
80 |
Issue |
12 |
Pages |
125331,1-125331,14 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
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. |
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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 |
Lancaster, Pa |
Editor |
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| |
Language |
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Wos |
000270383300098 |
Publication Date |
2009-09-25 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
40 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
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| |
Call Number |
UA @ lucian @ c:irua:79231 |
Serial |
3906 |
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| Permanent link to this record |
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| |
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Author |
di Vece, M.; Bals, S.; Lievens, P.; Van Tendeloo, G. |
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| |
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 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
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. |
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| |
Address |
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| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
|
| |
Language |
|
Wos |
000270383300121 |
Publication Date |
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 |
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. |
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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 |
|
|
| |
Language |
|
Wos |
000270513500008 |
Publication Date |
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 |
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| Permanent link to this record |
| |
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| |
|
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 |
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| |
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. |
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| |
Address |
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| |
Corporate Author |
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Thesis |
|
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| |
Publisher |
|
Place of Publication |
London |
Editor |
|
|
| |
Language |
|
Wos |
000270563200028 |
Publication Date |
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 |
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| 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. |
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| |
Address |
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| |
Corporate Author |
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Thesis |
|
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| |
Publisher |
|
Place of Publication |
London |
Editor |
|
|
| |
Language |
|
Wos |
000270642700012 |
Publication Date |
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 |
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| Permanent link to this record |
| |
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| |
|
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 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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 |
Washington, D.C. |
Editor |
|
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| |
Language |
|
Wos |
000270807800001 |
Publication Date |
2009-09-28 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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|
| |
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 |
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| Permanent link to this record |
| |
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| |
|
Author |
Castelano, L.K.; Hai, G.Q.; Partoens, B.; Peeters, F.M. |
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| |
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 |
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| |
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. |
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| |
Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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| |
Language |
|
Wos |
000270915600047 |
Publication Date |
2009-10-03 |
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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 |
|
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 |
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| Permanent link to this record |
| |
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| |
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Author |
Goodvin, G.L.; Covaci, L.; Berciu, M. |
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| |
Title |
Holstein polarons near surfaces |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys Rev Lett |
|
| |
Volume |
103 |
Issue |
17 |
Pages |
176402 |
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| |
Keywords |
A1 Journal article |
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| |
Abstract |
We study the effects of a nearby surface on the spectral weight of a Holstein polaron, using the inhomogeneous momentum average approximation which is accurate over the entire range of electron-phonon (e-ph) coupling strengths. The broken translational symmetry is taken into account exactly. We find that the e-ph coupling gives rise to a large additional surface potential, with strong retardation effects, which may bind surface states even when they are not normally expected. The surface, therefore, has a significant effect and bulk properties are recovered only very far away from it. These results demonstrate that interpretation in terms of bulk quantities of spectroscopic data sensitive only to a few surface layers is not always appropriate. |
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| |
Address |
Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1 |
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| |
Corporate Author |
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Thesis |
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| |
Publisher |
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Place of Publication |
|
Editor |
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| |
Language |
English |
Wos |
000271164500042 |
Publication Date |
2009-10-22 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0031-9007 |
ISBN |
|
Additional Links |
|
|
| |
Impact Factor |
8.462 |
Times cited |
8 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 8.462; 2009 IF: 7.328 |
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| |
Call Number |
UA @ lucian @ |
Serial |
4435 |
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| Permanent link to this record |
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| |
|
Author |
Salje, E.K.H.; Zhang, H.; Idrissi, H.; Schryvers, D.; Carpenter, M.A.; Moya, X.; Planes, A. |
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| |
Title |
Mechanical resonance of the austenite/martensite interface and the pinning of the martensitic microstructures by dislocations in Cu74.08Al23.13Be2.79 |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Physical review: B: condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
80 |
Issue |
13 |
Pages |
134114,1-1134114,8 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
A single crystal of Cu74.08Al23.13Be2.79 undergoes a martensitic phase transition at 246 and 232 K under heating and cooling, respectively. The phase fronts between the austenite and martensite regions of the sample are weakly mobile with a power-law resonance under external stress fields. Surprisingly, the martensite phase is elastically much harder than the austenite phase showing that interfaces between various crystallographic variants are strongly pinned and cannot be moved by external stress while the phase boundary between the austenite and martensite regions in the sample remains mobile. This unusual behavior was studied by dynamical mechanical analysis (DMA) and resonant ultrasound spectroscopy. The remnant strain, storage modulus, and internal friction were recorded simultaneously for different applied forces in DMA. With increasing forces, the remnant strain increases monotonously while the internal friction peak height shows a minimum at 300 mN. Transmission electron microscopy shows that the pinning is generated by dislocations which are inherited from the austenite phase. |
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| |
Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
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| |
Language |
|
Wos |
000271351300033 |
Publication Date |
2009-10-22 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
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 |
38 |
Open Access |
|
|
| |
Notes |
Multimat |
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
|
| |
Call Number |
UA @ lucian @ c:irua:78542 |
Serial |
1975 |
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| Permanent link to this record |
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| |
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Author |
Zha, G.-Q.; Milošević, M.V.; Zhou, S.-P.; Peeters, F.M. |
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| |
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 |
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| |
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. |
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| |
Address |
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| |
Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
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| |
Language |
|
Wos |
000271351500085 |
Publication Date |
2009-10-15 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
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 |
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| Permanent link to this record |
| |
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| |
|
Author |
Li, J.; Chang, K.; Peeters, F.M. |
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| |
Title |
Dyakonov-Perel spin relaxation in InSb/AlxIn1-xSb quantum wells |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
80 |
Issue |
15 |
Pages |
153307,1-153307,4 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
We investigate theoretically the Dyakonov-Perel spin relaxation time by solving the eight-band Kane model and Poisson equation self-consistently. Our results show distinct behavior with the single-band model due to the anomalous spin-orbit interactions in narrow band-gap semiconductors, and agree well with the experiment values reported in recent experiment [K. L. Litvinenko et al., New J. Phys. 8, 49 (2006)]. We find a strong resonant enhancement of the spin relaxation time appears for spin align along [11̅ 0] at a certain electron density at 4 K. This resonant peak is smeared out with increasing the temperature. |
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| |
Address |
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| |
Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
|
| |
Language |
|
Wos |
000271352000015 |
Publication Date |
2009-11-02 |
|
| |
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:79996 |
Serial |
760 |
|
| Permanent link to this record |
