| Records |
| 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 |
|
Thesis |
|
| 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 |
| |
|
| |
| Author |
Turner, S.; Lebedev, O.I.; Schroeder, F.; Fischer, R.A.; Van Tendeloo, G. |
| Title |
Direct imaging of loaded metal-organic framework materials (metal@MOF-5) |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
| Volume |
20 |
Issue |
17 |
Pages |
5622-5627 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We illustrate the potential of advanced transmission electron microscopy for the characterization of a new class of soft porous materials: metal@Zn4O(bdc)3 (metal@MOF-5; bdc = 1,4-benzenedicarboxylate). By combining several electron microscopy techniques (transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), electron diffraction (ED), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and electron tomography) and by carefully reducing the electron dose to avoid beam damage, it is possible to simultaneously characterize the MOF-5 framework material and the loaded metal nanoparticles. We also demonstrate that electron tomography can be used to accurately determine the position and distribution of the particles within the MOF-5 framework. To demonstrate the implementation of these microscopy techniques and what kind of results can be expected, measurements on gas-phase-loaded metal−organic framework materials Ru@MOF-5 and Pd@MOF-5 are presented. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000258941400021 |
Publication Date |
2008-08-07 |
| 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 |
112 |
Open Access |
|
| Notes |
Esteem 026019 |
Approved |
Most recent IF: 9.466; 2008 IF: 5.046 |
| Call Number |
UA @ lucian @ c:irua:76595 |
Serial |
714 |
| Permanent link to this record |
| |
|
| |
| Author |
Major, L.; Tirry, W.; Van Tendeloo, G. |
| Title |
Microstructure and defect characterization at interfaces in TiN/CrN multilayer coatings |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Surface and coatings technology |
Abbreviated Journal |
Surf Coat Tech |
| Volume |
202 |
Issue |
24 |
Pages |
6075-6080 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Microstructures of TiN/CrN multilayer coatings deposited on austenite steel (Cr Ni 18 8) by pulsed laser deposition (PLD) are characterized using transmission electron microscopy while their mechanical properties were assessed in a ball-on-disk test. All coatings have the same total thickness of about 1 ìm. The individual layers show a highly defective columnar structure, which is characterized by conventional electron microscopy (TEM) as well as by high resolution TEM. These techniques, combined with measurements of the local chemical composition through EDS prove that PLD allows to produce fully separated CrN and TiN layers. The friction, and consequently the wear, are lowered by increasing the total number of layers in the coating. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Lausanne |
Editor |
|
| Language |
|
Wos |
000260267100042 |
Publication Date |
2008-07-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0257-8972; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.589 |
Times cited |
23 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.589; 2008 IF: 1.860 |
| Call Number |
UA @ lucian @ c:irua:76614 |
Serial |
2049 |
| Permanent link to this record |
| |
|
| |
| 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 |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000260254400030 |
Publication Date |
2008-09-25 |
| 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 |
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 |
| |
|
| |
| 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 |
|
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 |
| |
|
| |
| 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 |
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| Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
| Language |
|
Wos |
000265919300024 |
Publication Date |
2009-03-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0959-9428;1364-5501; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
20 |
Open Access |
|
| Notes |
Fwo; Iwt |
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:76844 |
Serial |
2810 |
| Permanent link to this record |
| |
|
| |
| Author |
Milošević, M.M.; Tadić, M.; Peeters, F.M. |
| Title |
Effects of lateral asymmetry on electronic structure of strained semiconductor nanorings in a magnetic field |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
| Volume |
19 |
Issue |
45 |
Pages |
|
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The influence of lateral asymmetry on the electronic structure and optical transitions in elliptical strained InAs nanorings is analyzed in the presence of a perpendicular magnetic field. Two-dimensional rings are assumed to have elliptical inner and outer boundaries oriented in mutually orthogonal directions. The influence of the eccentricity of the ring on the energy levels is analyzed. For large eccentricity of the ring, we do not find any AharonovBohm effect, in contrast to circular rings. Rather, the single-particle states of the electrons and the holes are localized as in two laterally coupled quantum dots formed in the lobes of the nanoring. Our work indicates that the control of shape is important for the existence of the AharonovBohm effect in semiconductor nanorings. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000259922000016 |
Publication Date |
2008-10-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0957-4484;1361-6528; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.44 |
Times cited |
11 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.44; 2008 IF: 3.446 |
| Call Number |
UA @ lucian @ c:irua:76874 |
Serial |
865 |
| Permanent link to this record |
| |
|
| |
| Author |
Bencs, L.; Ravindra, K.; de Hoog, J.; Rasoazanany, E.O.; Deutsch, F.; Bleux, N.; Berghmans, P.; Roekens, E.; Krata, A.; Van Grieken, R. |
| Title |
Mass and ionic composition of atmospheric fine particles over Belgium and their relation with gaseous air pollutants |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Journal of environmental monitoring |
Abbreviated Journal |
|
| Volume |
10 |
Issue |
10 |
Pages |
1148-1157 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Mass, major ionic components (MICs) of PM2.5, and related gaseous pollutants (SO2, NOx, NH3, HNO2, and HNO3) were monitored over six locations of different anthropogenic influence (industrial, urban, suburban, and rural) in Belgium. SO42-, NO3-, NH4+, and Na+ were the primary ions of PM2.5 with averages diurnal concentrations ranging from 0.44.5, 0.37.6, 0.94.9, and 0.41.2 µg m-3, respectively. MICs formed 39% of PM2.5 on an average, but it could reach up to 8098%. The SO2, NO, NO2, HNO2, and HNO3 levels showed high seasonal and site-specific fluctuations. The NH3 levels were similar over all the sites (26 µg m-3), indicating its relation to the evenly distributed animal husbandry activities. The sulfur and nitrogen oxidation ratios for PM2.5 point towards a low-to-moderate formation of secondary sulfate and nitrate aerosols over five cities/towns, but their fairly intensive formation over the rural Wingene. Cluster analysis revealed the association of three groups of compounds in PM2.5: (i) NH4NO3, KNO3; (ii) Na2SO4; and (iii) MgCl2, CaCl2, MgF2, CaF2, corresponding to anthropogenic, sea-salt, and mixed (sea-salt + anthropogenic) aerosols, respectively. The neutralization and cation-to-anion ratios indicate that MICs of PM2.5 appeared mostly as (NH4)2SO4 and NH4NO3 salts. Sea-salt input was maximal during winter reaching up to 12% of PM2.5. The overall average Cl-loss for sea-salt particles of PM2.5 at the six sites varied between 69 and 96% with an average of 87%. Principal component analysis revealed vehicular emission, coal/wood burning and animal farming as the dominating sources for the ionic components of PM2.5. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000259890100005 |
Publication Date |
2008-10-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1464-0325; 1464-0333 |
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:76876 |
Serial |
8206 |
| Permanent link to this record |
| |
|
| |
| Author |
Lindner, H.; Autrique, D.; Garcia, C.C.; Niemax, K.; Bogaerts, A. |
| Title |
Optimized transport setup for high repetition rate pulse-separated analysis in laser ablation-inductively coupled plasma mass spectrometry |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
81 |
Issue |
11 |
Pages |
4241-4248 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
An optimized laser ablation setup, proposed for high repetition rate inductively coupled plasma mass spectrometry (ICPMS) analyses such as 2D imaging or depth profiling, is presented. For such applications, the particle washout time needs to be as short as possible to allow high laser pulse frequencies for reduced analysis time. Therefore, it is desirable to have an ablation setup that operates as a laminar flow reactor (LFR). A top-down strategy was applied that resulted in the present design. In the first step, a previously applied ablation setup was analyzed on the basis of computational fluid dynamics (CFD) results presented by D. Autrique et al. (Spectrochim. Acta, B 2008, 63, 257−270). By means of CFD simulations, the design was modified in such a way that it operated in the LFR regime. Experimental results demonstrate that the current design can indeed be regarded as an LFR. Furthermore, the operation under LFR conditions allowed some insight into the initial radial concentration distribution if the experimental ICPMS signal and analytical expressions are taken into account. Recommendations for a modified setup for more resilient spatial distributions are given. With the present setup, a washout time of 140 ms has been achieved for a 3% signal area criterion. Therefore, 7 Hz repetition rates can be applied with the present setup. Using elementary formulas of the analytical model, an upper bound for the washout times for similar setups can be predicted. The authors believe that the presented setup geometry comes close to the achievable limit for reliable short washout times. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000266601800014 |
Publication Date |
2009-04-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-2700;1520-6882; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.32 |
Times cited |
18 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 6.32; 2009 IF: 5.214 |
| Call Number |
UA @ lucian @ c:irua:76935 |
Serial |
2492 |
| Permanent link to this record |
| |
|
| |
| Author |
Yang, W.; Nelissen, K.; Kong, M.; Zeng, Z.; Peeters, F.M. |
| Title |
Structure of binary colloidal systems confined in a quasi-one-dimensional channel |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics |
Abbreviated Journal |
Phys Rev E |
| Volume |
79 |
Issue |
4 |
Pages |
041406,1-041406,6 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The structural properties of a binary colloidal quasi-one-dimensional system confined in a narrow channel are investigated through modified Monte Carlo simulations. Two species of particles with different magnetic moment interact through a repulsive dipole-dipole force are confined in a quasi-one-dimensional channel. The impact of three decisive parameters (the density of particles, the magnetic-moment ratio, and the fraction between the two species) on the transition from disordered phase to crystal-like phases and the transitions among the different mixed phases are summarized in a phase diagram. |
| 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 |
000265941300077 |
Publication Date |
2009-04-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| 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 |
11 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.366; 2009 IF: 2.400 |
| Call Number |
UA @ lucian @ c:irua:77021 |
Serial |
3308 |
| Permanent link to this record |
| |
|
| |
| Author |
Moshnyaga, V.; Gehrke, K.; Sudheendra, L.; Belenchuk, A.; Raabe, S.; Shapoval, O.; Verbeeck, J.; Van Tendeloo, G.; Samwer, K. |
| Title |
Electrical nonlinearity in colossal magnetoresistance manganite films: relevance of correlated polarons |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
| Volume |
79 |
Issue |
13 |
Pages |
134413,1-134413,8 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The metal-insulator (MI) transition in epitaxial thin films of La0.75Ca0.25MnO3 (LCMO) is accompanied by the appearance of an intrinsic electrical nonlinearity. The latter, probed by electrical third harmonic voltage, U3, or resistance, R3=dU3/dJ, is drastically enhanced in the vicinity of the MI transition, TMI=267 K. Applied magnetic field, B=5 T, suppresses the nonlinearity, resulting in a huge nonlinear CMR3(TMI)~105%. R3 shows a peculiar low-frequency (1 kHz) dependence, R3~(-0)n, with exponent, n, changing across the MI transition from n~1,52 for TTMI to n=1 (T<TMI). The observed electrical nonlinearity in LCMO reflects the behavior of correlated polarons, the number of which dramatically enhances in the vicinity of TMI. We argued that correlated polarons, considered as electric-elastic quadrupoles, provide a nonlinear (quadratic) coupling to the electric field, yielding a third harmonic electric nonlinearity in LCMO. The reference film of La0.7Sr0.3MnO3 (LSMO), a prototypic double exchange system with second-order phase transition, is characterized as a linear metallic material in the whole range of temperatures (T=10400 K), magnetic fields (B=05 T), and frequencies (=11000 Hz). |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000265942800074 |
Publication Date |
2009-04-09 |
| 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 |
Esteem 026019 |
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
| Call Number |
UA @ lucian @ c:irua:77022UA @ admin @ c:irua:77022 |
Serial |
893 |
| Permanent link to this record |
| |
|
| |
| Author |
Tadić, M.; Peeters, F.M. |
| Title |
Excitonic properties of strained triple quantum-ring molecules |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
| Volume |
79 |
Issue |
15 |
Pages |
153305,1-153305,4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The tunneling coupling in three vertically stacked (In,Ga)As/GaAs quantum rings is investigated. With increasing inter-ring separation (d), we find that the nonuniform strain results into a crossing of the lowest-energy electron states. Strain is also responsible for an increase in the ground electron energy above the level in the single quantum ring. The ground hole energy level exhibits decrease when d decreases, which is typical for antibonding states in an unstrained structure. These effects lead to a local maximum in the dependence of the ground-state exciton energy on d. Our theoretical results compare well with recent photoluminescence measurements but deviate considerably from the calculations for flat bands in quantum-ring molecules. We conclude that the nonuniform character of the strain distribution gives rise to a peculiar exciton hybridization in self-assembled quantum-ring molecules. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000265944200018 |
Publication Date |
2009-04-21 |
| 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 |
8 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
| Call Number |
UA @ lucian @ c:irua:77024 |
Serial |
1123 |
| Permanent link to this record |
| |
|
| |
| Author |
Barbier, M.; Vasilopoulos, P.; Peeters, F.M.; Pereira, J.M. |
| Title |
Bilayer graphene with single and multiple electrostatic barriers: band structure and transmission |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
| Volume |
79 |
Issue |
15 |
Pages |
155402,1-155402,8 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We evaluate the electronic transmission and conductance in bilayer graphene through a finite number of potential barriers. Further, we evaluate the dispersion relation in a bilayer graphene superlattice with a periodic potential applied to both layers. As a model we use the tight-binding Hamiltonian in the continuum approximation. For zero bias the dispersion relation shows a finite gap for carriers with zero momentum in the direction parallel to the barriers. This is in contrast to single-layer graphene where no such gap was found. A gap also appears for a finite bias. Numerical results for the energy spectrum, conductance, and the density of states are presented and contrasted with those pertaining to single-layer graphene. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000265944200091 |
Publication Date |
2009-04-01 |
| 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 |
74 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
| Call Number |
UA @ lucian @ c:irua:77025 |
Serial |
235 |
| Permanent link to this record |
| |
|
| |
| Author |
Masir, M.R.; Matulis, A.; Peeters, F.M. |
| Title |
Quasibound states of Schrödinger and Dirac electrons in a magnetic quantum dot |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
| Volume |
79 |
Issue |
15 |
Pages |
155451,1-155451,8 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The properties of a two-dimensional electron are investigated in the presence of a circular step magnetic-field profile. Both electrons with parabolic dispersion as well as Dirac electrons with linear dispersion are studied. We found that in such a magnetic quantum dot no electrons can be confined. Nevertheless close to the Landau levels quasibound states can exist with a rather long lifetime. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000265944200140 |
Publication Date |
2009-04-30 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
55 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
| Call Number |
UA @ lucian @ c:irua:77026 |
Serial |
2800 |
| Permanent link to this record |
| |
|
| |
| Author |
Slachmuylders, A.F.; Partoens, B.; Magnus, W.; Peeters, F.M. |
| Title |
Neutral shallow donors near a metallic interface |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Microelectronics journal |
Abbreviated Journal |
Microelectron J |
| Volume |
40 |
Issue |
4/5 |
Pages |
753-755 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The effect of a metallic gate on the bound states of a shallow donor located near the gate is studied. We calculate the energy spectrum as a function of the distance between the metallic gate and the donor and find an anti-crossing behavior in the energy levels for certain distances. We show how a transverse electric field can tune the average position of the electron with respect to the metallic gate and the impurity. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Luton |
Editor |
|
| Language |
|
Wos |
000265870200024 |
Publication Date |
2009-02-04 |
| 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 |
1 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.163; 2009 IF: 0.778 |
| Call Number |
UA @ lucian @ c:irua:77029 |
Serial |
2296 |
| Permanent link to this record |
| |
|
| |
| Author |
Leenaerts, O.; Partoens, B.; Peeters, F.M. |
| Title |
Adsorption of small molecules on graphene |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Microelectronics journal |
Abbreviated Journal |
Microelectron J |
| Volume |
40 |
Issue |
4/5 |
Pages |
860-862 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We investigate the adsorption process of small molecules on graphene through first-principles calculations and show the presence of two main charge transfer mechanisms. Which mechanism is the dominant one depends on the magnetic properties of the adsorbing molecules. We explain these mechanisms through the density of states of the system and the molecular orbitals of the adsorbates, and demonstrate the possible difficulties in calculating the charge transfer from first principles between a graphene sheet and a molecule. Our results are in good agreement with experiment. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Luton |
Editor |
|
| Language |
|
Wos |
000265870200058 |
Publication Date |
2008-12-26 |
| 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 |
116 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.163; 2009 IF: 0.778 |
| Call Number |
UA @ lucian @ c:irua:77030 |
Serial |
65 |
| Permanent link to this record |
| |
|
| |
| Author |
Stefaniak, E.A.; Alsecz, A.; Frost, R.; Máthé, Z.; Sajó, I.E.; Török, S.; Worobiec, A.; Van Grieken, R. |
| Title |
Combined SEM/EDX and micro-Raman spectroscopy analysis of uranium minerals from a former uranium mine |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of hazardous materials |
Abbreviated Journal |
|
| Volume |
168 |
Issue |
1 |
Pages |
416-423 |
| Keywords |
A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Samples of the secondary uranium minerals collected in the abandoned uranium mine at Pecs (Hungary) were investigated by two micro-techniques: scanning electron microscopy (SEM/EDX) and micro-Raman spectroscopy (MRS). They were applied to locate U-rich particles and identify the chemical form and oxidation state of the uranium compounds. The most abundant mineral was a K and/or Na uranyl sulphate (zippeite group). U(VI) was also present in the form showing intensive Raman scattering at 860 cm−1 which can be attributed to uranium trioxide. This research has shown the successful application of micro-Raman spectroscopy for the identification of uranyl mineral species on the level of individual particles. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000267567600060 |
Publication Date |
2009-02-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3894 |
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:77032 |
Serial |
7681 |
| Permanent link to this record |
| |
|
| |
| Author |
Bharathy, M.; Gemmill, W.R.; Fox, A.H.; Darriet, J.; Smith, M.D.; Hadermann, J.; Remy, M.S.; zur Loye, H.-C. |
| Title |
Synthesis and magnetic properties of rare earth ruthenates, Ln5Ru2O12 (Ln=Pr, Nd, SmTb) |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
| Volume |
182 |
Issue |
5 |
Pages |
1164-1170 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Single crystals of Ln5Ru2O12 (Ln=Pr, Nd, SmTb) were grown out of either NaOH or KOH fluxes in sealed silver tubes. The crystals of all the phases were observed to be twinned as confirmed by TEM studies. The series crystallize in the C2/m monoclinic system with lattice parameters, a=12.4049(4)12.7621(6) Å, b=5.8414(2)5.9488(3) Å, c=7.3489(2)7.6424(4) Å, β=107.425(3)107.432(2)° and Z=2. The crystal structure is isotypic with the defect/disorder model of Ln5Re2O12 (Ln = Y, Gd) and consists of one dimensional edge shared RuO6 octahedral chains separated by a two dimensional LnOx polyhedral framework. Magnetic measurements indicate paramagnetic and antiferromagnetic behavior for Ln=Nd, SmGd and Ln=Tb, respectively. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000265893700027 |
Publication Date |
2009-02-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0022-4596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.299 |
Times cited |
4 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.299; 2009 IF: 2.340 |
| Call Number |
UA @ lucian @ c:irua:77052 |
Serial |
3433 |
| Permanent link to this record |
| |
|
| |
| Author |
Barreca, D.; Gasparotto, A.; Maccato, C.; Tondello, E.; Lebedev, O.I.; Van Tendeloo, G. |
| Title |
CVD of copper oxides from a \beta-diketonate diamine precursor: tailoring the nano-organization |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Crystal growth & design |
Abbreviated Journal |
Cryst Growth Des |
| Volume |
9 |
Issue |
5 |
Pages |
2470-2480 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
A copper(II) hexafluoroacetylacetonate (1,1,1,5,5,5-hexafluoro-2,4-pentanedionate, hfa) adduct with N,N,N¡ä,N¡ä-tetramethylethylenediamine (TMEDA) [Cu(hfa)2¡¤TMEDA] is used for the first time as precursor for the chemical vapor deposition (CVD) of copper oxide nanosystems. The syntheses are carried out under both O2 and O2+H2O reaction atmospheres on Si(100) substrates, at temperatures ranging between 250 and 550 ¡ãC. Subsequently, the interrelations between the preparative conditions and the system composition, nanostructure, and morphology are elucidated by means of complementary analytical techniques [Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron and X-ray excited auger electron spectroscopies (XPS and XE-AES), glancing incidence X-ray diffraction (GIXRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM)]. The obtained data revealed a gradual transformation from Cu2O, to Cu2O + CuO, to CuO nanosystems upon increasing the deposition temperature from 250 to 550 ¡ãC under both growth atmospheres. Such a phenomenon was accompanied by a progressive morphological evolution from continuous films to 1D hyperbranched nanostructures. Water vapor introduction in the deposition environment enabled to lower the deposition temperature and resulted in a higher aggregate interconnection, attributed to a higher density of nucleation centers. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000265892200066 |
Publication Date |
2009-05-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1528-7483;1528-7505; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.055 |
Times cited |
60 |
Open Access |
|
| Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.055; 2009 IF: 4.162 |
| Call Number |
UA @ lucian @ c:irua:77053 |
Serial |
597 |
| Permanent link to this record |
| |
|
| |
| Author |
Dubourdieu, C.; Rauwel, E.; Roussel, H.; Ducroquet, F.; Hollaender, B.; Rossell, M.; Van Tendeloo, G.; Lhostis, S.; Rushworth, S. |
| Title |
Addition of yttrium into HfO2 films: microstructure and electrical properties |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of vacuum science and technology: A: vacuum surfaces and films |
Abbreviated Journal |
J Vac Sci Technol A |
| Volume |
27 |
Issue |
3 |
Pages |
503-514 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The cubic phase of HfO2 was stabilized by addition of yttrium in thin films grown on Si/SiO2 by metal-organic chemical vapor deposition. The cubic phase was obtained for contents of 6.5 at. % Y or higher at a temperature as low as 470 °C. The complete compositional range (from 1.5 to 99.5 at. % Y) was investigated. The crystalline structure of HfO2 was determined from x-ray diffraction, electron diffraction, and attenuated total-reflection infrared spectroscopy. For cubic films, the continuous increase in the lattice parameter indicates the formation of a solid-solution HfO2Y2O3. As shown by x-ray photoelectron spectroscopy, yttrium silicate is formed at the interface with silicon; the interfacial layer thickness increases with increasing yttrium content and increasing film thickness. The dependence of the intrinsic relative permittivity r as a function of Y content was determined. It exhibits a maximum of ~30 for ~8.8 at. % Y. The cubic phase is stable upon postdeposition high-temperature annealing at 900 °C under NH3. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000265739100016 |
Publication Date |
2009-05-02 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0734-2101; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.374 |
Times cited |
29 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.374; 2009 IF: 1.297 |
| Call Number |
UA @ lucian @ c:irua:77054 |
Serial |
58 |
| Permanent link to this record |
| |
|
| |
| Author |
Hadermann, J.; Abakumov, A.M.; Van Rompaey, S.; Mankevich, A.S.; Korsakov, I.E. |
| Title |
Comment on ALaMn2O6-y (A = K, Rb): novel ferromagnetic manganites exhibiting negative giant magnetoresistance |
Type |
Editorial |
| Year |
2009 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
| Volume |
21 |
Issue |
9 |
Pages |
2000-2001 |
| Keywords |
Editorial; Electron microscopy for materials research (EMAT) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000265781000036 |
Publication Date |
2009-04-14 |
| 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 |
4 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 9.466; 2009 IF: 5.368 |
| Call Number |
UA @ lucian @ c:irua:77055 |
Serial |
411 |
| Permanent link to this record |
| |
|
| |
| Author |
Kips, R.; Pidduck, A.J.; Houlton, M.R.; Leenaers, A.; Mace, J.D.; Marie, O.; Pointurier, F.; Stefaniak, E.A.; Taylor, P.D.P.; van den Berghe, S.; van Espen, P.; Van Grieken, R.; Wellum, R. |
| Title |
Determination of fluorine in uranium oxyfluoride particles as an indicator of particle age |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Spectrochimica acta: part B : atomic spectroscopy |
Abbreviated Journal |
|
| Volume |
64 |
Issue |
3 |
Pages |
199-207 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3) |
| Abstract |
As swipe samples from enrichment activities typically contain uranium particles with a detectable amount of fluorine, the question was raised whether the analysis of fluorine in particles could complement the information on the uranium isotope ratios. For this, uranium oxyfluoride particles were prepared from the controlled hydrolysis of uranium hexafluoride (UF6). The relative amount of fluorine was characterized by scanning electron microscopy combined with energy-dispersive X-ray spectrometry (SEM-EDX), as well as ion-microprobe secondary ion mass spectrometry (IM-SIMS). Of particular interest was the assessment of the reduction of the amount of fluorine over time, and after exposure to UV-light and high temperatures. Micro-Raman spectrometry (MRS) was applied to look for differences in molecular structure between these various sample types. Both SEM-EDX and IM-SIMS showed a general reduction of the fluorine-to-uranium ratio after 12 years of storage. The exposure to UV-light and high temperatures was found to have accelerated the loss of fluorine. A distinct peak at 865 cm− 1 Raman shift was detected for the majority of particles analyzed by MRS. For the particles that were heat-treated, the Raman spectra were similar to the spectrum of U3O8. Although often large variations were observed between particles from the same sample, the three particle measurement techniques (IM-SIMS, SEM-EDX and MRS) showed some consistent trends. They therefore appear promising in terms of the ability to place bounds on particle age, as well as shedding light on the complex processes involved in UO2F2 particle ageing. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000265755600002 |
Publication Date |
2008-12-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0584-8547; 1873-3565 |
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:77057 |
Serial |
7780 |
| Permanent link to this record |
| |
|
| |
| Author |
Van Tendeloo, G.; Hadermann, J.; Abakumov, A.M.; Antipov, E.V. |
| Title |
Advanced electron microscopy and its possibilities to solve complex structures: application to transition metal oxides |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of materials chemistry |
Abbreviated Journal |
J Mater Chem |
| Volume |
19 |
Issue |
18 |
Pages |
2660-2670 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Design and optimization of materials properties can only be performed through a thorough knowledge of the structure of the compound. In this feature article we illustrate the possibilities of advanced electron microscopy in materials science and solid state chemistry. The different techniques are briefly discussed and several examples are given where the structures of complex oxides, often with a modulated structure, have been solved using electron microscopy. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
| Language |
|
Wos |
000265740600002 |
Publication Date |
2009-02-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0959-9428;1364-5501; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
9 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:77065 |
Serial |
68 |
| Permanent link to this record |
| |
|
| |
| Author |
Beyers, E.; Biermans, E.; Ribbens, S.; de Witte, K.; Mertens, M.; Meynen, V.; Bals, S.; Van Tendeloo, G.; Vansant, E.F.; Cool, P. |
| Title |
Combined TiO2/SiO2 mesoporous photocatalysts with location and phase controllable TiO2 nanoparticles |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Applied catalysis : B : environmental |
Abbreviated Journal |
Appl Catal B-Environ |
| Volume |
88 |
Issue |
3/4 |
Pages |
515-524 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA) |
| Abstract |
Combined TiO2/SiO2 mesoporous materials were prepared by deposition of TiO2 nanoparticles synthesised via the acid-catalysed solgel method. In the first synthesis step a titania solution is prepared, by dissolving titaniumtetraisopropoxide in nitric acid. The influences of the initial titaniumtetraisopropoxide concentration and the temperature of dissolving on the final structural properties were investigated. In the second step of the synthesis, the titania nanoparticles were deposited on a silica support. Here, the influence of the temperature during deposition was studied. The depositions were carried out on two different mesoporous silica supports, SBA-15 and MCF, leading to substantial differences in the catalytic and structural properties. The samples were analysed with N2-sorption, X-ray diffraction (XRD), electron probe microanalysis (EPMA) and transmission electron microscopy (TEM) to obtain structural information, determining the amount of titania, the crystal phase and the location of the titania particles on the mesoporous material (inside or outside the mesoporous channels). The structural differences of the support strongly determine the location of the nanoparticles and the subsequent photocatalytic activity towards the degradation of rhodamine 6G in aqueous solution under UV irradiation. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000266513400032 |
Publication Date |
2008-10-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0926-3373; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
9.446 |
Times cited |
69 |
Open Access |
|
| Notes |
Goa-Bof; Fwo |
Approved |
Most recent IF: 9.446; 2009 IF: 5.252 |
| Call Number |
UA @ lucian @ c:irua:77150 |
Serial |
403 |
| Permanent link to this record |
| |
|
| |
| Author |
Bencs, L.; Krata, A.; Horemans, B.; Buczyńska, A.J.; Dirtu, A.C.; Godoi, A.F.L.; Godoi, R.H.M.; Potgieter-Vermaak, S.; Van Grieken, R. |
| Title |
Atmospheric nitrogen fluxes at the Belgian coast: 2004-2006 |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Atmospheric environment : an international journal |
Abbreviated Journal |
|
| Volume |
43 |
Issue |
24 |
Pages |
3786-3798 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Daily and seasonal variations in dry and wet atmospheric nitrogen fluxes have been studied during four campaigns between 2004 and 2006 at a coastal site of the Southern North Sea at De Haan (Belgium) located at coordinates of 51.1723° N and 3.0369° E. Concentrations of inorganic N-compounds were determined in the gaseous phase, size-segregated aerosol (coarse, medium, and fine), and rainwater samples. Dissolved organic nitrogen (DON) was quantified in rainwater. The daily variations in N-fluxes of compounds were evaluated with air-mass backward trajectories, classified into the main air-masses arriving at the sampling site (i.e., continental, North Sea, and Atlantic/UK/Channel). The three, non-episodic campaigns showed broadly consistent fluxes, but during the late summer campaign exceptionally high episodic N-deposition was observed. The average dry and wet fluxes for non-episodic campaigns amounted to 2.6 and 4.0 mg N m−2 d−1, respectively, whereas during the episodic late summer period these fluxes were as high as 5.2 and 6.2 mg N m−2 d−1, respectively. Non-episodic seasons/campaigns experienced average aerosol fluxes of 0.91.4 mg N m−2 d−1. Generally, the contribution of aerosol NH4+ was more significant in the medium and fine particulate fractions than that of aerosol NO3−, whereas the latter contributed more in the coarse fraction, especially in continental air-masses. During the dry mid-summer campaign, the DON contributed considerably (15%) to the total N-budget. Exceptionally high episodic aerosol-N inputs have been observed for the late summer campaign, with especially high deposition rates of 3.6 and 2.9 mg N m−2 d−1 for Atlantic/UK/Channel and North Sea-continental (mixed) air-masses, respectively. During this pollution episode, the flux of NH4+ was dominating in each aerosol fraction/air-mass, except for coarse continental aerosols. High deposition of gaseous-N was also observed in this campaign with an average total N-flux of 22.5-times higher than in other campaigns. |
| Address |
|
| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000268609000015 |
Publication Date |
2009-04-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1352-2310 |
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:77255 |
Serial |
7527 |
| Permanent link to this record |
| |
|
| |
| Author |
Damla, N.; Čevik, U.; Kobya, A.I.; Celik, A.; Van Grieken, R.; Kobya, Y. |
| Title |
Characterization of gas concrete materials used in buildings of Turkey |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of hazardous materials |
Abbreviated Journal |
|
| Volume |
168 |
Issue |
2/3 |
Pages |
681-687 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
The activity concentration of 226Ra, 232Th and 40K in gas concrete samples collected from different suppliers and some provinces in Turkey were measured using gamma-ray spectrometry. Knowledge of radioactivity in gas concrete used in building materials enables one to assess any possible radiological risks to human health. The mean activity concentrations observed in the gas concrete samples were 82.0, 28.2 and 383.9 Bq kg−1 for 226Ra, 232Th and 40K, respectively. The radium equivalent activity, external and internal hazard indices as well as terrestrial absorbed dose and annual effective dose rate was calculated. The results indicate that the radium equivalent activity values of gas concrete samples are lower than the limit of 370 Bq kg−1, equivalent to a gamma-dose of 1.5 mSv y−1. Moreover, mass attenuation coefficients were measured in some gas concrete samples. It was found that the mass attenuation coefficients decreased with increasing photon energies. Also, chemical compositions and structural analysis (XRD and SEM) of the gas concrete samples were investigated. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000268200700014 |
Publication Date |
2009-02-26 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3894 |
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:77256 |
Serial |
7621 |
| Permanent link to this record |
| |
|
| |
| Author |
Nguyen, H.L.; Braun, M.; Szaloki, I.; Baeyens, W.; Van Grieken, R.; Leermakers, M. |
| Title |
Tracing the metal pollution history of the Tisza River through the analysis of a sediment depth profile |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Water, air and soil pollution |
Abbreviated Journal |
|
| Volume |
200 |
Issue |
|
Pages |
119-132 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
The vertical profiles of 20 major and trace metals were investigated along a 180-cm-long sediment core, which was sampled at Kiss-Janosne-Holt Tisza, an oxbow lake located in the upper part of the Tisza River in Hungary. The vertical profiles showed sharp peaks at different depths, reflecting historical pollution events and unusual changes of river water characteristics. Five different groups of metals, containing metals which were strongly correlated and showing a similar behaviour, could be distinguished by factor analysis. Six areas, with variable degrees and types of contamination, were classified in the sediment core with cluster analysis. The most polluted sections were found in the upper 50-cm part (significantly contaminated by Cu, Zn, Pb, Cd and Hg) and the deeper 100120-cm part (characterised by high concentrations of metals associated with mining activities, such as Fe and Mn, as well as Cu, Zn and Pb). In recent years, important pollution events, such as the one which took place in March of 2000, were the reason for pollution of the upper sediment layers, whereas mining activities during the last century were responsible for the pollution of the deeper core sections. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000266487700012 |
Publication Date |
2008-10-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0049-6979; 1573-2932 |
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:77257 |
Serial |
8695 |
| Permanent link to this record |
| |
|
| |
| Author |
Verberck, B.; Vliegenthart, G.A.; Gompper, G. |
| Title |
Orientational ordering in solid C60 fullerene-cubane |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
The journal of chemical physics |
Abbreviated Journal |
J Chem Phys |
| Volume |
130 |
Issue |
15 |
Pages |
154510,1-154510,14 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We study the structure and phase behavior of fullerene-cubane C60·C8H8 by Monte Carlo simulation. Using a simple potential model capturing the icosahedral and cubic symmetries of its molecular constituents, we reproduce the experimentally observed phase transition from a cubic to an orthorhombic crystal lattice and the accompanying rotational freezing of the C60 molecules. We elaborate a scheme to identify the low-temperature orientations of individual molecules and to detect a pattern of orientational ordering similar to the arrangement of C60 molecules in solid C60. Our configuration of orientations supports a doubled periodicity along one of the crystal axes. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000265486300036 |
Publication Date |
2009-04-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0021-9606; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.965 |
Times cited |
8 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.965; 2009 IF: 3.093 |
| Call Number |
UA @ lucian @ c:irua:77258 |
Serial |
2519 |
| Permanent link to this record |
| |
|
| |
| Author |
Suarez-Martinez, I.; Bittencourt, C.; Ke, X.; Felten, A.; Pireaux, J.J.; Ghijsen, J.; Drube, W.; Van Tendeloo, G.; Ewels, C.P. |
| Title |
Probing the interaction between gold nanoparticles and oxygen functionalized carbon nanotubes |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
| Volume |
47 |
Issue |
6 |
Pages |
1549-1554 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The interaction between evaporated gold and pristine or oxygen plasma treated multi-walled carbon nanotubes (MWCNTs) is investigated. Experimental and theoretical results indicate that gold nucleation occurs at defect sites, whether initially present or introduced by oxygen plasma treatment. Uniform gold cluster dispersion is observed on plasma treated carbon nanotubes (CNTs) and associated with the presence of uniformly dispersed oxidized vacancy centres on the CNT surface. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000265518700018 |
Publication Date |
2009-02-11 |
| 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 |
38 |
Open Access |
|
| Notes |
Pai |
Approved |
Most recent IF: 6.337; 2009 IF: 4.504 |
| Call Number |
UA @ lucian @ c:irua:77267 |
Serial |
2717 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Broek, W.; Verbeeck, J.; Schryvers, D.; de Backer, S.; Scheunders, P. |
| Title |
Tomographic spectroscopic imaging; an experimental proof of concept |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
109 |
Issue |
4 |
Pages |
296-303 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
Recording the electron energy loss spectroscopy data cube with a series of energy filtered images is a dose inefficient process because the energy slit blocks most of the electrons. When recording the data cube by scanning an electron probe over the sample, perfect dose efficiency is attained; but due to the low current in nanoprobes, this often is slower, with a smaller field of view. In W. Van den Broek et al. [Ultramicroscopy, 106 (2006) 269], we proposed a new method to record the data cube, which is more dose efficient than an energy filtered series. It produces a set of projections of the data cube and then tomographically reconstructs it. In this article, we demonstrate these projections in practice, we present a simple geometrical model that allows for quantification of the projection angles and we present the first successful experimental reconstruction, all on a standard post-column instrument. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000265345400003 |
Publication Date |
2008-12-10 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
1 |
Open Access |
|
| Notes |
Esteem 026019 |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
| Call Number |
UA @ lucian @ c:irua:77271 |
Serial |
3671 |
| Permanent link to this record |
