Records |
Author |
Smeulders, G.; Meynen, V.; van Baelen, G.; Mertens, M.; Lebedev, O.I.; Van Tendeloo, G.; Maes, B.U.W.; Cool, P. |
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. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
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Place of Publication |
Cambridge |
Editor |
|
Language |
|
Wos |
000265919300024 |
Publication Date |
2009-03-17 |
Series Editor |
|
Series Title |
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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 |
Bogaerts, A.; Bultinck, E.; Eckert, M.; Georgieva, V.; Mao, M.; Neyts, E.; Schwaederlé, L. |
Title |
Computer modeling of plasmas and plasma-surface interactions |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Plasma processes and polymers |
Abbreviated Journal |
Plasma Process Polym |
Volume |
6 |
Issue |
5 |
Pages |
295-307 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this paper, an overview is given of different modeling approaches used for describing gas discharge plasmas, as well as plasma-surface interactions. A fluid model is illustrated for describing the detailed plasma chemistry in capacitively coupled rf discharges. The strengths and limitations of Monte Carlo simulations and of a particle-in-cell-Monte Carlo collisions model are explained for a magnetron discharge, whereas the capabilities of a hybrid Monte Carlo-fluid approach are illustrated for a direct current glow discharge used for spectrochemical analysis of materials. Finally, some examples of molecular dynamics simulations, for the purpose of plasma-deposition, are given. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000266471800003 |
Publication Date |
2009-04-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1612-8850;1612-8869; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.846 |
Times cited |
18 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.846; 2009 IF: 4.037 |
Call Number |
UA @ lucian @ c:irua:76833 |
Serial |
461 |
Permanent link to this record |
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|
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Author |
Lepoittevin, C.; Malo, S.; Nguyen, N.; Hebert, S.; Van Tendeloo, G.; Hervieu, M. |
Title |
A layered iron-rich 2234-type with a mixed valence of iron: the ferrimagnetic Tl-doped Fe2(Sr2-\varepsilonTl\varepsilon)Sr3Fe4O14.65 |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
20 |
Issue |
20 |
Pages |
6468-6476 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A new Tl-doped strontium ferrite Fe2(Sr2-Tl)Sr3Fe4O14.65, with an original structure, has been synthesized and structurally characterized by powder X-ray diffraction and transmission electron microscopy. The TGA and Mssbauer studies evidence a mixed valence of iron. The structure exhibits a commensurate modulation, with a F-type subcell a ≈ b ≈ 5.4 Å (≈ ap√2), c ≈ 42 Å with a modulation vector q = αa* with α = 0.4. The supercell parameters have been refined as a= 27.1101(8) Å, b= 5.5187(2) Å and c= 42.0513(9) Å, in the space group Fmmm. The electron diffraction and electron microscopy data of this novel ferrite show that it can be described as a FeTl-2234-type structure corresponding to the intergrowth of a quadruple perovskite slice [(SrFeO2.8)4], with a complex rock salt related slice [Fe2(Sr2-Tl)O3.4]∞, built up of one double iron layer [Fe2O2.4] sandwiched between two [SrO] layers. The HRTEM images show that the oxygen atoms and vacancies are randomly distributed in the perovskite layers while the HAADF STEM images evidence the absence of Tl segregation in the matrix. Fe2(Sr2-Tl)Sr3Fe4O14.65 exhibits a very large value of χ (11emu/mol) at 5 K, which remains large at 400 K; the M(H) loop presents a shape characteristic of ferrimagnetism, with a large coercive field of 0.3 T. The value of magnetization saturates at 400 K at 0.68 μB/Fe. At 10 K, the value of magnetization reaches a maximum of 2 μB/Fe. The resistivity presents a semiconducting-like behavior, with ρ 800 Ω·cm at 300 K. |
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 |
|
Language |
|
Wos |
000260254400030 |
Publication Date |
2008-09-25 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
8 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 9.466; 2008 IF: 5.046 |
Call Number |
UA @ lucian @ c:irua:76671 |
Serial |
1804 |
Permanent link to this record |
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|
|
Author |
Nowak, M.P.; Szafran, B.; Peeters, F.M. |
Title |
Manipulation of two-electron states by the electric field in stacked self-assembled dots |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
20 |
Issue |
39 |
Pages |
395225,1-395225,14 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
A pair of electrons in vertically stacked self-assembled quantum dots is studied and the singlettriplet energy splitting is calculated in an external electric field using the configuration-interaction method. We show that for double quantum dots the dependence of the singlet energy levels on the electric field involves multiple avoided crossings of three energy levels. The exchange interaction, i.e., the energy difference of the lowest triplet and lowest singlet states, can be tuned by an electric field in a wide range of several tens of meV. For electric fields exceeding a threshold value the exchange interaction becomes a linear function of the field when the two electrons in the singlet state start to occupy the same dot. We also consider non-symmetric confinement, non-perfectly aligned dots, in horizontal as well as vertical field orientation. In a stack of three vertically coupled dots the depth of the confinement in the central dot can be used to enhance the exchange interaction. For a deeper central dot the dependence of the exchange interaction on the electric field is anomalousit initially decreases when the field is applied in both directions parallel and antiparallel to the axis of the stack. Such a behavior is never observed for a pair of quantum dots. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000259034200032 |
Publication Date |
2008-09-05 |
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 |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.649; 2008 IF: 1.900 |
Call Number |
UA @ lucian @ c:irua:76592 |
Serial |
1940 |
Permanent link to this record |
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|
|
Author |
Zhao, H.-W.; Zha, G.-Q.; Zhou, S.-P.; Peeters, F.M. |
Title |
Long-range Coulomb repulsion effect on a charged vortex in high-temperature superconductors with competing d-wave and antiferromagnetic orders |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
78 |
Issue |
6 |
Pages |
064505,1-064505,5 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Vortex charges in high-temperature superconductor (HTS) are studied by solving the Bogoliubovde Gennes equations based on a model Hamiltonian with antiferromagnetic (AF) and d-wave orders in the presence of the long-range Coulomb repulsion. For a sufficient strength of the AF order, the negative vortex charge is found. A sign change between negative and positive may occur by tuning the long-range Coulomb repulsion strength or the doping parameter. Recent NMR experiments are hopefully understood. We show that the charged vortex can induce a spin-orbit coupling that is important for superconductors with a short coherence length and a large value of the energy gap over the Fermi-level ratio. Fractional flux quanta are possible for HTS. |
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 |
000259264900084 |
Publication Date |
2008-08-06 |
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 |
12 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2008 IF: 3.322 |
Call Number |
UA @ lucian @ c:irua:76553 |
Serial |
1837 |
Permanent link to this record |
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|
|
Author |
Schweigert, I.V.; Alexandrov, A.L.; Ariskin, D.A.; Peeters, F.M.; Stefanović, I.; Kovačević, E.; Berndt, J.; Winter, J. |
Title |
Effect of transport of growing nanoparticles on capacitively coupled rf discharge dynamics |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics |
Abbreviated Journal |
Phys Rev E |
Volume |
78 |
Issue |
2 |
Pages |
026410,1-026410,6 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We present experimental and numerical studies of the properties of a capacitively coupled 13.56 MHz discharge in a mixture of Ar and C2H2 with growing nanosize particles. It is found that at the initial stage of the growth, nanoparticles are accumulated near the sheath-plasma boundaries, where the ionization by electrons is maximal. The nanoparticles suppress the ionization due to the absorbing fast electrons and stimulate a quick change of the plasma parameters followed by a transition between different modes of discharge operation. At that moment the peaked distribution of the dust particles transforms into a flat one. |
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 |
000259263700071 |
Publication Date |
2008-08-20 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1539-3755;1550-2376; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.366 |
Times cited |
36 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.366; 2008 IF: 2.508 |
Call Number |
UA @ lucian @ c:irua:76552 |
Serial |
851 |
Permanent link to this record |
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|
|
Author |
Shanenko, A.A.; Croitoru, M.D.; Peeters, F.M. |
Title |
Superconducting nanofilms: Andreev-type states induced by quantum confinement |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
78 |
Issue |
5 |
Pages |
054505,1-054505,8 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT) |
Abstract |
Quantum confinement of the transverse electron motion is the major effect governing the superconducting properties of high-quality metallic nanofilms, leading to a nonuniform transverse distribution of the superconducting condensate. In this case the order parameter can exhibit significant local enhancements due to these quantum-size effects and, consequently, quasiparticles have lower energies when they avoid the local enhancements of the pair condensate. Such excitations can be considered as new Andreev-type quasiparticles but now induced by quantum confinement. By numerically solving the Bogoliubovde Gennes equations and using Anderson's approximate solution to these equations, we: (a) formulate a criterion for such new Andreev-type states (NATS) and (b) study their effect on the superconducting characteristics in metallic nanofilms. We also argue that nanofilms made of low-carrier-density materials, e.g., of superconducting semiconductors, can be a more optimal choice for the observations of NATS and other quantum-size superconducting effects. |
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 |
000259368200109 |
Publication Date |
2008-08-11 |
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 |
14 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2008 IF: 3.322 |
Call Number |
UA @ lucian @ c:irua:76526 |
Serial |
3356 |
Permanent link to this record |
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|
|
Author |
Doria, M.M.; Brandt, E.H.; Peeters, F.M. |
Title |
Magnetization of a superconducting film in a perpendicular magnetic field |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
78 |
Issue |
5 |
Pages |
0544047,1-054407,7 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
With large thin superconducting films in a perpendicular magnetic field, the usual definition and calculation of the magnetization M via currents or as the difference of two fields fail, since the spatially averaged magnetic field in the film coincides with the uniform applied field and the demagnetization factor is unity. The definition of M as field-derivative of the free energy, however, still works in this limit. We generalize the virial theorem, previously derived for infinite bulk superconductors, to infinitely extended films of arbitrary thickness. An expression for M is obtained that indeed reproduces the M computed from the field derivative of the free energy. |
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 |
000259368200063 |
Publication Date |
2008-08-08 |
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 |
12 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2008 IF: 3.322 |
Call Number |
UA @ lucian @ c:irua:76525 |
Serial |
1895 |
Permanent link to this record |
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|
|
Author |
Alexandrov, A.L.; Schweigert, I.V.; Peeters, F.M. |
Title |
A non-Maxwellian kinetic approach for charging of dust particles in discharge plasmas |
Type |
A1 Journal article |
Year |
2008 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
Volume |
10 |
Issue |
|
Pages |
093025,1-093025,12 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Nanoparticle charging in a capacitively coupled radio frequency discharge in argon is studied using a particle in cell Monte Carlo collisions method. The plasma parameters and dust potential were calculated self-consistently for different unmovable dust profiles. A new method for definition of the dust floating potential is proposed, based on the information about electron and ion energy distribution functions, obtained during the kinetic simulations. This approach provides an accurate balance of the electron and ion currents on the dust particle surface and allows us to precisely calculate the dust floating potential. A comparison of the obtained floating potentials with the results of the traditional orbital motion limit (OML) theory shows that in the presence of the ion resonant charge exchange collisions, even when the OML approximation is valid, its results are correct only in the region of a weak electric field, where the ion drift velocity is much smaller than the thermal one. With increasing ion drift velocity, the absolute value of the calculated dust potential becomes significantly smaller than the theory predicts. This is explained by a non-Maxwellian shape of the ion energy distribution function for the case of fast ion drift. |
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 |
|
Language |
|
Wos |
000259615700004 |
Publication Date |
2008-09-24 |
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 |
19 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.786; 2008 IF: 3.440 |
Call Number |
UA @ lucian @ c:irua:76519 |
Serial |
2348 |
Permanent link to this record |
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Author |
Das, P.; Koblischka, M.R.; Turner, S.; Van Tendeloo, G.; Wolf, T.; Jirsa, M.; Hartmann, U. |
Title |
Direct observation of nanometer-scale pinning sites in (Nd0.33Eu0.20Gd0.47)Ba2Cu3O7-\delta single crystals |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Europhysics letters |
Abbreviated Journal |
Epl-Europhys Lett |
Volume |
83 |
Issue |
3 |
Pages |
37005,1-37005,4 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We report on the observation of self-organized stripe-like structures on the as-grown surface and in the bulk of (Nd,Eu,Gd)Ba2Cu3Oy single crystals. The periodicity of the stripes on the surface lies between 500800 nm. These are possibly the growth steps of the crystal. Transmission electron microscopy investigations revealed stripes of periodicity in the range of 2040 nm in the bulk. From electron back scattered diffraction investigations, no crystallographic misorientation due to the nanostripes has been found. Scanning tunneling spectroscopic experiments revealed nonsuperconducting regions, running along twin directions, which presumably constitute strong pinning sites. |
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 |
000259022600032 |
Publication Date |
2008-07-18 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0295-5075;1286-4854; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.957 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.957; 2008 IF: 2.203 |
Call Number |
UA @ lucian @ c:irua:76496 |
Serial |
719 |
Permanent link to this record |
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Author |
Bittencourt, C.; Hecq, M.; Felten, A.; Pireaux, J.J.; Ghijsen, J.; Felicissimo, M.P.; Rudolf, P.; Drube, W.; Ke, X.; Van Tendeloo, G. |
Title |
Platinumcarbon nanotube interaction |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Chemical physics letters |
Abbreviated Journal |
Chem Phys Lett |
Volume |
462 |
Issue |
4/6 |
Pages |
260-264 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The interaction between evaporated Pt and pristine or oxygen-plasma-treated multiwall carbon nanotubes (CNTs) is investigated. Pt is found to nucleate at defect sites, whether initially present or introduced by oxygen plasma treatment. The plasma treatment induces a uniform dispersion of Pt nanoparticles at the CNT surface. The absence of additional features in the C 1s core level spectrum indicates that no mixed PtC phase is formed. The formation of COPt bonds at the cluster-CNT interface is suggested to reduce the electronic interaction between Pt nanoparticles and the CNT surface. |
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 |
|
Language |
|
Wos |
000258830900025 |
Publication Date |
2008-07-30 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0009-2614; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.815 |
Times cited |
62 |
Open Access |
|
Notes |
Pai |
Approved |
Most recent IF: 1.815; 2008 IF: 2.169 |
Call Number |
UA @ lucian @ c:irua:76489 |
Serial |
2652 |
Permanent link to this record |
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Author |
Zhao, H.J.; Misko, V.R.; Peeters, F.M.; Dubonos, G.; Oboznov, V.; Grigorieva, I.V. |
Title |
Vortex configurations in mesoscopic superconducting triangles: finite-size and shape effects |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Europhysics letters |
Abbreviated Journal |
Epl-Europhys Lett |
Volume |
83 |
Issue |
1 |
Pages |
17008,1-17008,6 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Triangular-shaped mesoscopic superconductors are consistent with the symmetry of the Abrikosov vortex lattice resulting in a high stability of vortex patterns for commensurate vorticities. However, for non-commensurate vorticities, vortex configurations in triangles are not compatible with the sample shape. Here we present the first direct observation of vortex configurations in ìm-sized niobium triangles using the Bitter decoration technique, and we analyze the vortex states in triangles by analytically solving the London equations and performing molecular-dynamics simulations. We found that filling rules with increasing vorticity can be formulated for triangles in a similar way as for mesoscopic disks where vortices form shells. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Paris |
Editor |
|
Language |
|
Wos |
000259020300030 |
Publication Date |
2008-06-17 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0295-5075;1286-4854; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.957 |
Times cited |
29 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.957; 2008 IF: 2.203 |
Call Number |
UA @ lucian @ c:irua:76488 |
Serial |
3863 |
Permanent link to this record |
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|
|
Author |
Felten, A.; Ghijsen, J.; Pireaux, J.-J.; Whelan, C.M.; Liang, D.; Van Tendeloo, G.; Bittencourt, C. |
Title |
Photoemission study of CF4 rf-plasma treated multi-wall carbon nanotubes |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
Volume |
46 |
Issue |
10 |
Pages |
1271-1275 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Multi-wall carbon nanotubes (MWCNTs) were exposed to a CF4 rf-plasma. X-ray photoelectron spectroscopy analysis shows that the treatment effectively grafts fluorine atoms onto the MWCNTs. The fluorine atomic concentration and the nature of the CF bond (semi-ionic or covalent) can be tuned by varying the exposure time. Ultraviolet photoelectron spectroscopy analysis confirms that the valence electronic states are altered by the grafting of fluorine atoms. Characterization with high-resolution transmission electron microscopy reveals that while the plasma treatment does not induce significant etching impact on the CNT-surface, it does increase the number of active sites for gold cluster formation. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
Language |
|
Wos |
000258987500001 |
Publication Date |
2008-05-16 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0008-6223; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.337 |
Times cited |
21 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.337; 2008 IF: 4.373 |
Call Number |
UA @ lucian @ c:irua:76481 |
Serial |
2612 |
Permanent link to this record |
|
|
|
Author |
Martens, T.; Brok, W.J.M.; van Dijk, J.; Bogaerts, A. |
Title |
On the regime transitions during the formation of an atmospheric pressure dielectric barrier glow discharge |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
Volume |
42 |
Issue |
12 |
Pages |
122002,1-122002,5 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The atmospheric pressure dielectric barrier discharge in helium is a pulsed discharge in nature. If during the electrical current pulse a glow discharge is reached, then this pulse will last only a few microseconds in operating periods of sinusoidal voltage with lengths of about 10 to 100 µs. In this paper we demonstrate that right before a glow discharge is reached, the discharge very closely resembles the commonly assumed Townsend discharge structure, but actually contains some significant differing features and hence should not be considered as a Townsend discharge. In order to clarify this, we present calculation results of high time and space resolution of the pulse formation. The results indicate that indeed a maximum of ionization is formed at the anode, but that the level of ionization remains high and that the electric field at that time is significantly disturbed. Our results also show where this intermediate structure comes from. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000266639300002 |
Publication Date |
2009-05-22 |
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 |
21 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.588; 2009 IF: 2.083 |
Call Number |
UA @ lucian @ c:irua:76458 |
Serial |
2450 |
Permanent link to this record |
|
|
|
Author |
Burriel, M.; Santiso, J.; Rossell, M.D.; Van Tendeloo, G.; Figueras, A.; Garcia, G. |
Title |
Enhancing total conductivity of La2NiO4+\delta epitaxial thin films by reducing thickness |
Type |
A1 Journal article |
Year |
2008 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
Volume |
112 |
Issue |
29 |
Pages |
10982-10987 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
High quality epitaxial c axis oriented La2NiO4+ä thin films have been prepared by the pulsed injection metal organic chemical vapor deposition technique on different substrates. High-resolution electron microscopy/transmission electron microscopy has been used to confirm the high crystalline quality of the deposited films. The c-parameter evolution has been studied by XRD as a function of time and gas atmosphere. The high temperature transport properties along the basal a−b plane of epitaxial La2NiO4+ä films have been measured, and the total conductivity of the layers has been found to increase as the thickness is reduced. Layers of 50 nm and thinner have shown a maximum conductivity larger than that measured for single-crystals, in particular, the 33 nm thick films with a conductivity of 475 S/cm in oxygen correspond to the highest value measured to date for this material. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000257724100057 |
Publication Date |
2008-06-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.536 |
Times cited |
35 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.536; 2008 IF: 3.396 |
Call Number |
UA @ lucian @ c:irua:76440 |
Serial |
1067 |
Permanent link to this record |
|
|
|
Author |
Caignaert, V.; Abakumov, A.M.; Pelloquin, D.; Pralong, V.; Maignan, A.; Van Tendeloo, G.; Raveau, B. |
Title |
A new mixed-valence ferrite with a cubic structure, YBaFe4O7: spin-glass-like behavior |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
21 |
Issue |
6 |
Pages |
1116-1122 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A new mixed-valence ferrite, YBaFe4O7, has been synthesized. Its unique cubic structure, with a = 8.9595(2) Å, is closely related to that of the hexagonal 114 oxides YBaCo4O7 and CaBaFe4O7. It consists of corner-sharing FeO4 tetrahedra, forming triangular and kagome layers parallel to (111)C. In fact, the YBaFe4O7 and CaBaFe4O7 structures can be described as two different ccc and chch close packings of [BaO3]∞ and [O4]∞ layers, respectively, whose tetrahedral cavities are occupied by Fe2+/Fe3+ cations. The local structure of YBaFe4O7 is characterized by a large amount of stacking faults originating from the presence of hexagonal layers in the ccc cubic close-packed YBaFe4O7 structure. In this way, they belong to the large family of spinels and hexagonal ferrites studied for their magnetic properties. Differently from all the ferrites and especially from CaBaFe4O7, which are ferrimagnetic, YBaFe4O7 is an insulating spin glass with Tg = 50 K. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000264310900019 |
Publication Date |
2009-02-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
39 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 9.466; 2009 IF: 5.368 |
Call Number |
UA @ lucian @ c:irua:76432 |
Serial |
2325 |
Permanent link to this record |
|
|
|
Author |
Lepoittevin, C.; Malo, S.; Van Tendeloo, G.; Hervieu, M. |
Title |
Synthesis and structural mechanisms of the 2201-type ferrites and polytypes: Fe2(Sr2-xAx)FeO6.5-\delta/2 (A = Ba, La, Tl, Pb and Bi) |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Solid state sciences |
Abbreviated Journal |
Solid State Sci |
Volume |
11 |
Issue |
3 |
Pages |
595-607 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The Fe2(Sr2 − xAx)FeO6.5 − ä/2 systems have been investigated, by doping the iron rich 2201-type parent structure with Ba2+, La3+ and 5d10 post-transition cations. The syntheses have been carried out up to the limit of the 2201-type solid solutions, in order to test the role of the double iron layer Fe2O2.5 − ä/2. The localisation of the charge carriers in these compounds is consistent with their strong antiferro-magnetism. The investigation was then carried out in the transition part of the diagram up to the formation of stable phases. The study of structural mechanisms was carried using high resolution electron microscopy (transmission and scanning transmission), electron diffraction and energy dispersive spectroscopy. Different non-stoichiometry mechanisms are observed, depending on the electronic structure and chemical properties of the doping elements. The specific behavior of the modulated double iron layer is discussed. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000264644800001 |
Publication Date |
2008-12-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1293-2558; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.811 |
Times cited |
3 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 1.811; 2009 IF: 1.675 |
Call Number |
UA @ lucian @ c:irua:76416 |
Serial |
3437 |
Permanent link to this record |
|
|
|
Author |
van der Snickt, G.; Dik, J.; Cotte, M.; Janssens, K.; Jaroszewicz, J.; de Nolf, W.; Groenewegen, J.; van der Loeff, L. |
Title |
Characterization of a degraded cadmium yellow (CdS) pigment in an oil painting by means of synchrotron radiation based X-ray techniques |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
81 |
Issue |
7 |
Pages |
2600-2610 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
On several paintings of James Ensor (1860−1949), a gradual fading of originally bright yellow areas, painted with the pigment cadmium yellow (CdS), is observed. Additionally, in some areas exposed to light, the formation of small white-colored globules on top of the original paint surface is observed. In this paper the chemical transformation leading to the color change and to the formation of the globules is elucidated. Microscopic X-ray absorption near-edge spectroscopy (ì-XANES) experiments show that sulfur, originally present in sulfidic form (S2−), is oxidized during the transformation to the sulfate form (S6+). Upon formation (at or immediately below the surface), the highly soluble cadmium sulfate is assumed to be transported to the surface in solution and reprecipitates there, forming the whitish globules. The presence of cadmium sulfate (CdSO4·2H2O) and ammonium cadmium sulfate [(NH4)2Cd(SO4)2] at the surface is confirmed by microscopic X-ray diffraction measurements, where the latter salt is suspected to result from a secondary reaction of cadmium sulfate with ammonia. Measurements performed on cross sections reveal that the oxidation front has penetrated into the yellow paint down to ca. 1−2 ìm. The morphology and elemental distribution of the paint and degradation product were examined by means of scanning electron microscopy equipped with an energy-dispersive spectrometer (SEM-EDS) and synchrotron radiation based micro-X-ray fluorescence spectrometry (SR ì-XRF). In addition, ultraviolet-induced visible fluorescence photography (UIVFP) revealed itself to be a straightforward technique for documenting the occurrence of this specific kind of degradation on a macroscale by painting conservators. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000264759400025 |
Publication Date |
2009-03-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
91 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 2009 IF: 5.214 |
Call Number |
UA @ admin @ c:irua:76415 |
Serial |
5501 |
Permanent link to this record |
|
|
|
Author |
Tomecka, D.M.; Kamieniarz, G.; Partoens, B.; Peeters, F.M. |
Title |
Ground state configurations and melting of two-dimensional non-uniformly charged classical clusters |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
21 |
Issue |
15 |
Pages |
155301,1-155301,7 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We consider classical two-dimensional (2D) Coulomb clusters consisting of two species containing five particles with charge q1 and five with charge q2, respectively. Using Monte Carlo and molecular dynamics (MD) simulations, we investigated the ground state configurations as well as radial and angular displacements of particles as a function of temperature and their dependence on the ratio q = q2/q1. We found new configurations and a new multi-step melting behavior for q sufficiently different from the uniform charge limit q = 1. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000264708600007 |
Publication Date |
2009-03-18 |
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 |
2 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.649; 2009 IF: 1.964 |
Call Number |
UA @ lucian @ c:irua:76412 |
Serial |
1384 |
Permanent link to this record |
|
|
|
Author |
Li, B.; Partoens, B.; Peeters, F.M.; Magnus, W. |
Title |
Dielectric mismatch effect on coupled impurity states in a freestanding nanowire |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Microelectronics journal |
Abbreviated Journal |
Microelectron J |
Volume |
40 |
Issue |
3 |
Pages |
446-448 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We studied the coupled impurity states in a freestanding semiconductor nanowire (NW), within the effective mass approximation and including the effect of the dielectric mismatch, by using finite element method. Bonding and anti-bonding states are found and their energies converge with increasing distance di between the two impurities. The dependence of the binding energy on the wire radius R and the distance di between the two impurities is investigated, and we compare it with the result of a freestanding NW that contains a single impurity. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Luton |
Editor |
|
Language |
|
Wos |
000264694700017 |
Publication Date |
2008-07-30 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0026-2692; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.163 |
Times cited |
4 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.163; 2009 IF: 0.778 |
Call Number |
UA @ lucian @ c:irua:76410 |
Serial |
690 |
Permanent link to this record |
|
|
|
Author |
Koblischka, M.R.; Winter, M.; Das, P.; Koblischka-Veneva, A.; Muralidhar, M.; Wolf, T.; Babu, N.H.; Turner, S.; Van Tendeloo, G.; Hartmann, U. |
Title |
Observation of nanostripes and -clusters in (Nd, EuGd)Ba2Cu3Ox superconductors |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
Volume |
469 |
Issue |
4 |
Pages |
168-176 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Nanostripes are observed in melt-textured and single-crystalline samples of the ternary light rare earth (LRE)-compound (Nd0.33Eu0.33Gd0.33)Ba2Cu3Ox (NEG) by means of atomic force microscopy, scanning tunnelling microscopy at ambient conditions, combined with transmission electron microscopy and electron backscatter diffraction. This enables the observation of several important features: The nanostripes are formed by chains of nanoclusters, representing the LRE/Ba substitution. The dimensions of the nanostripes are similar for both types of NEG samples. The periodicity of the nanostripes is found to range between 40 and 60 nm; the shape of the nanoclusters is elliptic with a major axis length between 300 and 500 nm and a minor axis length of about 30150 nm. The stripes are filling effectively the space in between the twin boundaries. Concerning the flux pinning, the nanoclusters are the important pinning sites, not the nanostripes themselves. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000264657100008 |
Publication Date |
2009-01-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0921-4534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.404 |
Times cited |
6 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.404; 2009 IF: 0.723 |
Call Number |
UA @ lucian @ c:irua:76403 |
Serial |
2418 |
Permanent link to this record |
|
|
|
Author |
Doenen, M.; Zhang, L.; Erni, R.; Williams, O.A.; Hardy, A.; van Bael, M.K.; Wagner, P.; Haenen, K.; Nesladek, M.; Van Tendeloo, G. |
Title |
Diamond nucleation by carbon transport from buried nanodiamond TiO2 sol-gel composites |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
Volume |
21 |
Issue |
6 |
Pages |
670-673 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000263492000007 |
Publication Date |
2008-12-02 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0935-9648;1521-4095; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
19.791 |
Times cited |
20 |
Open Access |
|
Notes |
Fwo; Iap-P6/42; Esteem 026019 |
Approved |
Most recent IF: 19.791; 2009 IF: NA |
Call Number |
UA @ lucian @ c:irua:76329 |
Serial |
688 |
Permanent link to this record |
|
|
|
Author |
Kalina, R.; Szafran, B.; Bednarek, S.; Peeters, F.M. |
Title |
Magnetic-field asymmetry of electron wave packet transmission in bent channels capacitively coupled to a metal gate |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
102 |
Issue |
6 |
Pages |
066807,1-066807,4 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We study the electron wave packet moving through a bent channel. We demonstrate that the packet transmission probability becomes an asymmetric function of the magnetic field when the electron packet is capacitively coupled to a metal plate. The coupling occurs through a nonlinear potential which translates a different kinetics of the transport for opposite magnetic-field orientations into a different potential felt by the scattered electron. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000263389500056 |
Publication Date |
2009-02-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
14 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 8.462; 2009 IF: 7.328 |
Call Number |
UA @ lucian @ c:irua:76315 |
Serial |
1867 |
Permanent link to this record |
|
|
|
Author |
Misko, V.R.; Zhao, H.J.; Peeters, F.M.; Oboznov, V.; Dubonos, S.V.; Grigorieva, I.V. |
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 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000263564500002 |
Publication Date |
2009-01-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-2048;1361-6668; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.878 |
Times cited |
14 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.878; 2009 IF: 2.694 |
Call Number |
UA @ lucian @ c:irua:76312 |
Serial |
1267 |
Permanent link to this record |
|
|
|
Author |
Connolly, M.R.; Milošević, M.V.; Bending, S.J.; Clem, J.R.; Tamegai, T. |
Title |
Continuum vs. discrete flux behaviour in large mesoscopic Bi2Sr2CaCu2O8+\delta disks |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Europhysics letters |
Abbreviated Journal |
Epl-Europhys Lett |
Volume |
85 |
Issue |
1 |
Pages |
17008,1-17008,6 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Scanning Hall probe and local Hall magnetometry measurements have been used to investigate flux distributions in large mesoscopic superconducting disks with sizes that lie near the crossover between the bulk and mesoscopic vortex regimes. Results obtained by directly mapping the magnetic induction profiles of the disks at different applied fields can be quite successfully fitted to analytic models which assume a continuous distribution of flux in the sample. At low fields, however, we do observe clear signatures of the underlying discrete vortex structure and can resolve the characteristic mesoscopic compression of vortex clusters in increasing magnetic fields. Even at higher fields, where single-vortex resolution is lost, we are still able to track configurational changes in the vortex patterns, since competing vortex orders impose unmistakable signatures on “local” magnetisation curves as a function of the applied field. Our observations are in excellent agreement with molecular-dynamics numerical simulations which lead us to a natural definition of the lengthscale for the crossover between discrete and continuum behaviours in our system. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Paris |
Editor |
|
Language |
|
Wos |
000263692500029 |
Publication Date |
2009-01-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0295-5075;1286-4854; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.957 |
Times cited |
17 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.957; 2009 IF: 2.893 |
Call Number |
UA @ lucian @ c:irua:76306 |
Serial |
495 |
Permanent link to this record |
|
|
|
Author |
Li, B.; Partoens, B.; Peeters, F.M.; Magnus, W. |
Title |
Dielectric mismatch effect on coupled shallow impurity states in a semiconductor nanowire |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
79 |
Issue |
8 |
Pages |
085306,1-085306,7 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Coupled shallow impurity states in a freestanding semiconductor nanowire and in a semiconductor nanowire surrounded by a metallic gate are studied within the effective-mass approximation. Bonding and antibonding states are found due to the coupling of the two impurities, and their energy converges with increasing distance di between the two impurities. The dependences of the binding energy on the wire radius R, the distance di between the two impurities, and the impurity radial position in the nanowire are examined. |
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 |
|
Language |
|
Wos |
000263816000051 |
Publication Date |
2009-02-09 |
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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
11 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ c:irua:76223 |
Serial |
691 |
Permanent link to this record |
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|
|
Author |
Xu, W.; Peeters, F.M.; Lu, T.C. |
Title |
Dependence of resistivity on electron density and temperature in graphene |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
79 |
Issue |
7 |
Pages |
073403,1-073403,4 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
On the basis of the momentum-balance equation derived from the Boltzmann equation in which electron interactions with impurities and acoustic and optic phonons are included, we examine the dependence of the resistivity in graphene on temperature and electron density. Simple analytical expressions for the different contributions to the resistivity are obtained. Our results reproduce recent experimental findings and we are able to understand the different temperature dependence of the resistivity for low and high density samples. |
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 |
|
Language |
|
Wos |
000263815800013 |
Publication Date |
2009-02-12 |
Series Editor |
|
Series Title |
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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 |
31 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ c:irua:76222 |
Serial |
642 |
Permanent link to this record |
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|
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Author |
Afanasov, I.M.; Shornikova, O.N.; Avdeev, V.V.; Lebedev, O.I.; Van Tendeloo, G.; Matveev, A.T. |
Title |
Expanded graphite as a support for Ni/carbon composites |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
Volume |
47 |
Issue |
2 |
Pages |
513-518 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Expanded graphite decorated with nickel oxide particles (EGNiO) has been synthesized through electrochemical oxidation of natural graphite in an aqueous nickel nitrate solution followed by a heat treatment. EGNiO was used to prepare nickel/carbon composites using two techniques: (a) hydrogen reduction of nickel oxide particles loaded on the expanded graphite surface and (b) pyrolysis of coal tar pitch-impregnated EGNiO blocks. The EGNiO as well as the nickel/carbon composites have been characterized by X-ray diffraction, scanning and transmission electron microscopy, energy dispersive X-ray spectroscopy and selected area electron diffraction. |
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 |
|
Language |
|
Wos |
000262558300018 |
Publication Date |
2008-11-11 |
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 |
0008-6223; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.337 |
Times cited |
45 |
Open Access |
|
Notes |
Iap-Vi |
Approved |
Most recent IF: 6.337; 2009 IF: 4.504 |
Call Number |
UA @ lucian @ c:irua:76033 |
Serial |
1132 |
Permanent link to this record |
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|
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Author |
Nowak, D.; Florek, M.; Nowak, J.; Kwiatek, W.; Lekki, J.; Chevallier, P.; Hacura, A.; Wrzalik, R.; Ben-Nissan, B.; Van Grieken, R.; Kuczumow, A. |
Title |
Morphology and the chemical make-up of the inorganic components of black corals |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Materials science and engineering: part C: biomimetic materials |
Abbreviated Journal |
|
Volume |
29 |
Issue |
3 |
Pages |
1029-1038 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Black corals (Cnidaria, Antipatharia) from three different sources were investigated with the aim of detecting inorganic components and their morphology. In general, the skeleton of black corals was composed of the chitin fibrils admixed with peptides and the chitin presence was confirmed by the X-ray diffraction (XRD), Fourier Transformed Infrared Spectrometry (FTIR) and microRaman Microscopy, the latter giving the opportunity of tracing single fibrils and their location. The composition and concentrations of the inorganic components of the black corals were measured, using a scanning electron microprobe and micro-Particle Induced X-ray Emission (µ-PIXE). The application of such instruments enabled the estimation of the constituent distributions in a microscale. The mapping option was the most useful technique of making analyses in these studies, just to reveal the composition of chamber-like cells. Analysis of the morphology and microstructure showed that there were three distinct regions within the coral: a core and the cells encircled with adjacent interface gluing strips. The majority of the elements analyzed were selectively distributed and segregated in a striking way in mentioned distinctive zones of the skeleton and it was detected for the first time. The core area was characterized by the relatively elevated concentrations of Ca. The measurements gave extremely clear images of the distribution of particular elements in the skeletal tissue, with I, Ca, K and Fe much more concentrated in the gluing zones, while C, N, Na and Mg present in the interiors of particular skeletal cells. The distribution of some elements (Mg, Fe) and some compounds (chitin) and functional groups (SS, CI) allows differentiating the biological and mechanical functions of particular fragments of the rods. The kinds of elements and their concentrations measured were essentially in compliance with rare data available in the literature. The Raman technique gave the additional qualitative information about the structure of gluing zone and the chitin fibrils and surrounding matrix inside the cell interior. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000266520400065 |
Publication Date |
2008-09-10 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0928-4931 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:76024 |
Serial |
8284 |
Permanent link to this record |
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|
|
Author |
Peelaers, H.; Partoens, B.; Peeters, F.M. |
Title |
Phonon band structure of Si nanowires: a stability analysis |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
Volume |
9 |
Issue |
1 |
Pages |
107-111 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We present full ab initio calculations of the phonon band structure of thin Si nanowires oriented along the [110] direction. Using these phonon dispersion relations, we investigate the structural stability of these wires. We found that all studied wires were stable also when doped with either B or P, if the unit cell was taken sufficiently large along the wire axis. The evolution of the phonon dispersion relations and of the sound velocities with respect to the wire diameters is discussed. Softening is observed for acoustic modes and hardening for optical phonon modes with increasing wire diameters. |
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 |
Editor |
|
Language |
|
Wos |
000262519100020 |
Publication Date |
2008-12-03 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1530-6984;1530-6992; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.712 |
Times cited |
51 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 12.712; 2009 IF: 9.991 |
Call Number |
UA @ lucian @ c:irua:76022 |
Serial |
2601 |
Permanent link to this record |