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Author Kosimov, D.P.; Dzhurakhalov, A.A.; Peeters, F.M.
Title Carbon clusters: from ring structures to nanographene Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 81 Issue 19 Pages 195414,1-195414,12
Keywords A1 Journal article; Condensed Matter Theory (CMT); Integrated Molecular Plant Physiology Research (IMPRES); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The lowest-energy configurations of Cn(n≤55) clusters are obtained using the energy-minimization technique with the conjugate gradient method where a modified Brenner potential is invoked to describe the carbon and hydrocarbon interaction. We found that the ground-state configuration consists of a single ring for small number of C atoms and multiring structures are found with increasing n, which can be in planar, bowl-like or caplike form. Contrary to previous predictions, the binding energy Eb does not show even-odd oscillations and only small jumps are found in the Eb(n) curve as a consequence of specific types of edges or equivalently the number of secondary atoms. We found that hydrogenation of the edge atoms may change the ground-state configuration of the nanocluster. In both cases we determined the magic clusters. Special attention is paid to trigonal and hexagonal shaped carbon clusters and to clusters having a graphenelike configuration. Trigonal clusters are never the ground state while hexagonal-shaped clusters are only the ground state when they have zigzag edges.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000278142000103 Publication Date 2010-05-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 55 Open Access
Notes ; This work was supported by the Belgian Science Policy (IAP) and the Flemish Science Foundation (FWO-V1). ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:83385 Serial 278
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Author Ao, Z.M.; Peeters, F.M.
Title High-capacity hydrogen storage in Al-adsorbed graphene Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 81 Issue 20 Pages 205406,1-205406,7
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A high-capacity hydrogen storage mediumAl-adsorbed grapheneis proposed based on density-functional theory calculations. We find that a graphene layer with Al adsorbed on both sides can store hydrogen up to 13.79 wt % with average adsorption energy −0.193 eV/H2. Its hydrogen storage capacity is in excess of 6 wt %, surpassing U. S. Department of Energy (DOEs) target. Based on the binding-energy criterion and molecular-dynamics calculations, we find that hydrogen storage can be recycled at near ambient conditions. This high-capacity hydrogen storage is due to the adsorbed Al atoms that act as bridges to link the electron clouds of the H2 molecules and the graphene layer. As a consequence, a two-layer arrangement of H2 molecules is formed on each side of the Al-adsorbed graphene layer. The H2 concentration in the hydrogen storage medium can be measured by the change in the conductivity of the graphene layer.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000278144500082 Publication Date 2010-05-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 219 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO) and the Belgian Science Policy (IAP). ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:83386 Serial 1422
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Author Rosenberg, E.; De Santis, F.; Kontozova-Deutsch, V.; Odlyha, M.; Van Grieken, R.; Vichi, F.
Title Measuring gaseous and particulate pollutants: instruments and instrumental problems Type H2 Book chapter
Year 2010 Publication Abbreviated Journal
Volume Issue Pages 115-146 T2 - Basic environmental mechanisms: affec
Keywords H2 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-88-404-4334-8 Additional Links (up) UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:83559 Serial 8213
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Author Nistor, S.V.; Stefan, M.; Nistor, L.C.; Goovaerts, E.; Van Tendeloo, G.
Title Incorporation and localization of substitutional Mn2+ ions in cubic ZnS quantum dots Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 81 Issue 3 Pages 035336,1-035336,6
Keywords A1 Journal article; Nanostructured and organic optical and electronic materials (NANOrOPT); Electron microscopy for materials research (EMAT)
Abstract Multifrequency electron paramagnetic resonance (EPR) and high resolution transmission electron microscopy (HRTEM) investigations were performed on small (2 nm) cubic ZnS nanocrystals (quantum dotsQDs) doped with 0.2% mol Mn2+, self-assembled into a mesoporous structure. The EPR data analysis shows that the substitutional Mn2+ ions are localized at Zn2+ sites subjected to a local axial lattice distortion, resulting in the observed zero-field-splitting parameter |D|=41×10−4 cm−1. The local distortion is attributed to the presence in the second shell of ligands of a stacking fault or twin, which alters the normal stacking sequence of the cubic structure. The HRTEM results confirm the presence of such extended planar defects in a large percentage of the investigated QDs, which makes possible the proposed substitutional Mn2+ impurity ions localization model. Based on these results it is suggested that the high doping levels of Mn2+ ions observed in cubic ZnS and possible in other II-VI semiconductor QDs prepared at low temperatures can be explained by the assistance of the extended lattice defects in the impurities incorporation.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000277970900007 Publication Date 2010-01-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 55 Open Access
Notes Fwo Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:83649 Serial 1597
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Author Schattschneider, P.; Ennen, I.; Stoger-Pollach, M.; Verbeeck, J.
Title Circular dichroism in the electron microscope: progress and applications (invited) Type A1 Journal article
Year 2010 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 107 Issue 9 Pages 09d311,1-09d311,6
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract According to theory, x-ray magnetic circular dichroism in a synchrotron is equivalent to energy loss magnetic chiral dichroism (EMCD) in a transmission electron microscope (TEM). After a synopsis of the development of EMCD, the theoretical background is reviewed and recent results are presented, focusing on the study of magnetic nanoparticles for ferrofluids and Heusler alloys for spintronic devices. Simulated maps of the dichroic strength as a function of atom position in the crystal allow evaluating the influence of specimen thickness and sample tilt on the experimental EMCD signal. Finally, the possibility of direct observation of chiral electronic transitions with atomic resolution in a TEM is discussed.
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Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000277834300276 Publication Date 2010-05-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 28 Open Access
Notes Esteem Approved Most recent IF: 2.068; 2010 IF: 2.079
Call Number UA @ lucian @ c:irua:83653UA @ admin @ c:irua:83653 Serial 361
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Author Milošević, M.V.; Peeters, F.M.
Title Vortex manipulation in a superconducting matrix with view on applications Type A1 Journal article
Year 2010 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 96 Issue 19 Pages 192501,1-192501,3
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We show how a single flux quantum can be effectively manipulated in a superconducting film with a matrix of blind holes. Such a sample can serve as a basic memory element, where the position of the vortex in a k×l matrix of pinning sites defines the desired combination of n bits of information (2n = k×l). Vortex placement is achieved by strategically applied current and the resulting position is read out via generated voltage between metallic contacts on the sample. Such a device can also act as a controllable source of a nanoengineered local magnetic field for, e.g., spintronics applications.
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Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000277756400040 Publication Date 2010-05-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 14 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the ESF-NES and ESF-AQDJJ networks. ; Approved Most recent IF: 3.411; 2010 IF: 3.841
Call Number UA @ lucian @ c:irua:83657 Serial 3869
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Author Napierala, C.; Lepoittevin, C.; Edely, M.; Sauques, L.; Giovanelli, F.; Laffez, P.; Van Tendeloo, G.
Title Moderate pressure synthesis of rare earth nickelate with metal-insulator transition using polymeric precursors Type A1 Journal article
Year 2010 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume 183 Issue 7 Pages 1663-1669
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Rare earth nickelates exhibit a reversible metalsemiconductor phase transition that is, in the infrared range, responsible for a thermo-optical contrast. The state of the art synthesis of these compounds usually requires high oxygen pressure to stabilize Ni in the oxidation state 3+. In this work, using polymeric precursor associated with moderate pressure annealing, we show that it is possible to obtain fully oxidized rare earth nickelate with metalinsulator transition. Using thermogravimetric analysis, X-ray diffraction and transmission electronic microscopy we compare different samples synthesized at different oxygen pressures and demonstrate their structural similarity. Thermo-optical properties were measured, in the infrared range, using reflectance measurements and confirmed the metalinsulator transition at 60 °C in both samples.TEM observations lead to the conclusion that the structure commonly obtained at 175 bar is perfectly observed in the 20 bar sample without major structural defects. The two samples exhibit a thermochromic behavior and thermo-optical properties of the two samples are equivalent.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000279711200028 Publication Date 2010-05-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 3 Open Access
Notes Approved Most recent IF: 2.299; 2010 IF: 2.261
Call Number UA @ lucian @ c:irua:83679 Serial 2156
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Author Barreca, D.; Gasparotto, A.; Lebedev, O.I.; Maccato, C.; Pozza, A.; Tondello, E.; Turner, S.; Van Tendeloo, G.
Title Controlled vapor-phase synthesis of cobalt oxide nanomaterials with tuned composition and spatial organization Type A1 Journal article
Year 2010 Publication CrystEngComm Abbreviated Journal Crystengcomm
Volume 12 Issue 7 Pages 2185-2197
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000279627700040 Publication Date 2010-03-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1466-8033; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.474 Times cited 85 Open Access
Notes Approved Most recent IF: 3.474; 2010 IF: 4.006
Call Number UA @ lucian @ c:irua:83686 Serial 503
Permanent link to this record
 
 
Author Van Aert, S.; Chen, J.H.; van Dyck, D.
Title Linear versus non-linear structural information limit in high-resolution transmission electron microscopy Type A1 Journal article
Year 2010 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 110 Issue 11 Pages 1404-1410
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract A widely used performance criterion in high-resolution transmission electron microscopy (HRTEM) is the information limit. It corresponds to the inverse of the maximum spatial object frequency that is linearly transmitted with sufficient intensity from the exit plane of the object to the image plane and is limited due to partial temporal coherence. In practice, the information limit is often measured from a diffractogram or from Young's fringes assuming a weak phase object scattering beyond the inverse of the information limit. However, for an aberration corrected electron microscope, with an information limit in the sub-angstrom range, weak phase objects are no longer applicable since they do not scatter sufficiently in this range. Therefore, one relies on more strongly scattering objects such as crystals of heavy atoms observed along a low index zone axis. In that case, dynamical scattering becomes important such that the non-linear and linear interaction may be equally important. The non-linear interaction may then set the experimental cut-off frequency observed in a diffractogram. The goal of this paper is to quantify both the linear and the non-linear information transfer in terms of closed form analytical expressions. Whereas the cut-off frequency set by the linear transfer can be directly related with the attainable resolution, information from the non-linear transfer can only be extracted using quantitative, model-based methods. In contrast to the historic definition of the information limit depending on microscope parameters only, the expressions derived in this paper explicitly incorporate their dependence on the structure parameters as well. In order to emphasize this dependence and to distinguish from the usual information limit, the expressions derived for the inverse cut-off frequencies will be referred to as the linear and non-linear structural information limit. The present findings confirm the well-known result that partial temporal coherence has different effects on the transfer of the linear and non-linear terms, such that the non-linear imaging contributions are damped less than the linear imaging contributions at high spatial frequencies. This will be important when coherent aberrations such as spherical aberration and defocus are reduced.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000282562100008 Publication Date 2010-07-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 6 Open Access
Notes Fwo Approved Most recent IF: 2.843; 2010 IF: 2.063
Call Number UA @ lucian @ c:irua:83689 Serial 1821
Permanent link to this record
 
 
Author van den Broek, W.; Van Aert, S.; van Dyck, D.
Title A model based reconstruction technique for depth sectioning with scanning transmission electron microscopy Type A1 Journal article
Year 2010 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 110 Issue 5 Pages 548-554
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract Depth sectioning in high angular annular dark field scanning transmission electron microscopy is considered a candidate for three-dimensional characterization on the atomic scale. However at present the depth resolution is still far from the atomic level, due to strong limitations in the opening angle of the beam. In this paper we introduce a new, parameter based tomographic reconstruction algorithm that allows to make maximal use of the prior knowledge about the constituent atom types and the microscope settings, so as to retrieve the atomic positions and push the resolution to the atomic level in all three dimensions.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000279065700022 Publication Date 2009-09-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 16 Open Access
Notes Fwo Approved Most recent IF: 2.843; 2010 IF: 2.063
Call Number UA @ lucian @ c:irua:83690 Serial 2104
Permanent link to this record
 
 
Author Wang, A.; Chen, F.R.; Van Aert, S.; van Dyck, D.
Title Direct structure inversion from exit waves: part 1: theory and simulations Type A1 Journal article
Year 2010 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 110 Issue 5 Pages 527-534
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract In order to interpret the amplitude and phase of the exit wave in terms of mass and position of the atoms, one has to invert the dynamic scattering of the electrons in the object so as to obtain a starting structure which can then be used as a seed for further quantitative structure refinement. This is especially challenging in case of a zone axis condition when the interaction of the electrons with the atom column is very strong. Based on the channelling theory we will show that the channelling map not only yields a circle on the Argand plot but also a circular defocus curve for every column. The former gives the number of atoms in each column, while the latter provides the defocus value for each column, which reveals the surface roughness at the exit plane with single atom sensitivity.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000279065700019 Publication Date 2009-12-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 25 Open Access
Notes Fwo Approved Most recent IF: 2.843; 2010 IF: 2.063
Call Number UA @ lucian @ c:irua:83691 Serial 723
Permanent link to this record
 
 
Author Eckert, M.; Neyts, E.; Bogaerts, A.
Title Differences between ultrananocrystalline and nanocrystalline diamond growth: theoretical investigation of CxHy species at diamond step edges Type A1 Journal article
Year 2010 Publication Crystal growth & design Abbreviated Journal Cryst Growth Des
Volume 10 Issue 9 Pages 4123-4134
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The behavior of hydrocarbon species at step edges of diamond terraces is investigated by means of combined molecular dynamics−Metropolis Monte Carlo simulations. The results show that the formation of ballas-like diamond films (like UNCD) and well-faceted diamond films (like NCD) can be related to the gas phase concentrations of CxHy in a new manner: Species that have high concentrations above the growing UNCD films suppress the extension of step edges through defect formation. The species that are present above the growing NCD film, however, enhance the extension of diamond terraces, which is believed to result in well-faceted diamond films. Furthermore, it is shown that, during UNCD growth, CxHy species with x ≥ 2 play an important role, in contrast to the currently adopted CVD diamond growth mechanism. Finally, the probabilities for the extension of the diamond (100) terrace are much higher than those for the diamond (111) terrace, which is in full agreement with the experimental observation that diamond (100) facets are more favored than diamond (111) facets during CVD diamond growth.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000281353900042 Publication Date 2010-08-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1528-7483;1528-7505; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 4.055 Times cited 11 Open Access
Notes Approved Most recent IF: 4.055; 2010 IF: 4.390
Call Number UA @ lucian @ c:irua:83696 Serial 694
Permanent link to this record
 
 
Author Neek-Amal, M.; Peeters, F.M.
Title Linear reduction of stiffness and vibration frequencies in defected circular monolayer graphene Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 81 Issue 23 Pages 11
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000279336000001 Publication Date 2010-06-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 44 Open Access
Notes ; Financial support was provided by the Hungarian Research Foundation (Contracts No. OTKA K68312, No. K77771, No. K73361, and No. F68726). ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:83857 Serial 1820
Permanent link to this record
 
 
Author Ferreira, W.P.; Farias, G.A.; Peeters, F.M.
Title A two-component mixture of charged particles confined in a channel: melting Type A1 Journal article
Year 2010 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 22 Issue 28 Pages 11
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The melting of a binary system of charged particles confined in a quasi-one-dimensional parabolic channel is studied through Monte Carlo simulations. At zero temperature the particles are ordered in parallel chains. The melting is anisotropic and different melting temperatures are obtained according to the spatial direction, and the different kinds of particles present in the system. Melting is very different for the single-, two- and four-chain configurations. A temperature induced structural phase transition is found between two different four-chain ordered states which is absent in the mono-disperse system. In the mixed regime, where the two kinds of particles are only slightly different, melting is almost isotropic and a thermally induced homogeneous distribution of the distinct kinds of charges is observed.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000279257300023 Publication Date 2010-06-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 10 Open Access
Notes ; This work was supported by CNPq, the Flemish Science Foundation (FWO-V1) and the bilateral program between Flanders and Brazil. ; Approved Most recent IF: 2.649; 2010 IF: 2.332
Call Number UA @ lucian @ c:irua:83862 Serial 3771
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Author King, G.; Abakumov, A.M.; Hadermann, J.; Alekseeva, A.M.; Rozova, M.G.; Perkisas, T.; Woodward, P.M.; Van Tendeloo, G.; Antipov, E.V.
Title Crystal structure and phase transitions in Sr3WO6 Type A1 Journal article
Year 2010 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
Volume 49 Issue 13 Pages 6058-6065
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The crystal structures of the beta and gamma polymorphs of Sr3WO6 and the gamma <->beta phase transition have been investigated using electron diffraction, synchrotron X-ray powder diffraction, and neutron powder diffraction. The gamma-Sr3WO6 polymorph is stable above T-c approximate to 470 K and adopts a monoclinically distorted double perovskite A(2)BB'O-6= Sr2SrWO6 structure (space group Cc, a = 10.2363(1)angstrom, b= 17.9007(1)angstrom, c= 11.9717(1)angstrom, beta=125.585(1)degrees at T= 1373 K, Z=12, corresponding to a = a(p)+1/2b(p) – 1/2c(p), b =3/2b(p) + 3/2c(p), c =-b(p) + c(p), a(p),b(p), c(p), lattice vectors of the parent Fm (3) over barm double perovskite structure). Upon cooling it undergoes a continuous phase transition into the triclinically distorted beta-Sr3WO6 phase (space group Cl, a = 10.09497(3)angstrom, b = 17.64748(5)angstrom, c = 11.81400(3)angstrom, alpha = 89.5470(2)degrees, beta= 125.4529(2)degrees, gamma =90.2889(2)degrees at T= 300 K). Both crystal structures of Sr3WO6 belong to a family of double perovskites with broken corner sharing connectivity of the octahedral framework. A remarkable feature of the gamma-Sr3WO6 structure is a non-cooperative rotation of the WO6 octahedra. One third of the WO6 octahedra are rotated by 45 about either the bp or the cp axis of the parent double perovskite structure. As a result, the WO6 octahedra do not share corners but instead share edges with the coordination polyhedra of the Sr cations at the B positions increasing their coordination number from 6 to 7 or 8. The crystal structure of the beta-phase is very close to the structure of the gamma-phase; decreasing symmetry upon the gamma ->beta transformation occurs because of unequal octahedral rotation angles about the bp and cp axes and increasing distortions of the WO6 octahedra.
Address
Corporate Author Thesis
Publisher Place of Publication Easton, Pa Editor
Language Wos 000279211500036 Publication Date 2010-06-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-1669;1520-510X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 4.857 Times cited 18 Open Access
Notes Approved Most recent IF: 4.857; 2010 IF: 4.326
Call Number UA @ lucian @ c:irua:83877 Serial 562
Permanent link to this record
 
 
Author Li, Y.; Tan, H.; Lebedev, O.; Verbeeck, J.; Biermans, E.; Van Tendeloo, G.; Su, B.-L.
Title Insight into the growth of multiple branched MnOOH nanorods Type A1 Journal article
Year 2010 Publication Crystal growth & design Abbreviated Journal Cryst Growth Des
Volume 10 Issue 7 Pages 2969-2976
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Multiple branched manganese oxide hydroxide (MnOOH) nanorods prepared by a hydrothermal process were extensively studied by transmission electron microscopy (TEM). A model of the branch formation is proposed together with a study of the interface structure. The sword-like tip plays a crucial role for the nanorods to form different shapes. Importantly, the branching occurs at an angle of around either 57 degrees or 123 degrees. Specifically, a (111) twin plane can only be formed at the interface with a 123 degrees angle. The interfaces formed with a 57 degrees angle usually contain edge dislocations. Electron energy loss spectroscopy (EELS) demonstrates that the whole crystal has a uniform chemical composition. Interestingly, an epitaxial growth of Mn3O4 at the radial surface was also observed under electron beam irradiation; this is because of the rough purification of the products. The proposed mechanism is expected to shed light on the branched/dendrite nanostructure growth and to provide opportunities for further novel nanomaterial structure growth and design.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000279422700027 Publication Date 2010-06-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1528-7483;1528-7505; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 4.055 Times cited 41 Open Access
Notes Fwo; Esteem 026019 Approved Most recent IF: 4.055; 2010 IF: 4.390
Call Number UA @ lucian @ c:irua:83886UA @ admin @ c:irua:83886 Serial 1672
Permanent link to this record
 
 
Author Janssens, K.; de Nolf, W.; van der Snickt, G.; Vincze, L.; Vekemans, B.; Terzano, R.; Brenker, F.E.
Title Recent trends in quantitative aspects of microscopic X-ray fluorescence analysis Type A1 Journal article
Year 2010 Publication Trends in analytical chemistry Abbreviated Journal Trac-Trend Anal Chem
Volume 29 Issue 6 Pages 464-478
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000279235000014 Publication Date 2010-03-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0165-9936 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 8.442 Times cited 48 Open Access
Notes ; This research was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16). The text also presents results of FWO (Brussels, Belgium) projects nr. G.0704.08 and G.0179.09 and from the UA-BOF GOA programme. ; Approved Most recent IF: 8.442; 2010 IF: 6.602
Call Number UA @ admin @ c:irua:83903 Serial 5806
Permanent link to this record
 
 
Author Ao, Z.M.; Peeters, F.M.
Title Electric field: A catalyst for hydrogenation of graphene Type A1 Journal article
Year 2010 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 96 Issue 25 Pages 3
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Due to the importance of hydrogenation of graphene for several applications, we present an alternative approach to hydrogenate graphene based on density functional theory calculations. We find that a negative perpendicular electric field F can act as a catalyst to reduce the energy barrier for molecular H<sub>2</sub> dissociative adsorption on graphene. Increasing -F above 0.02 a.u. (1 a.u.=5.14×10<sup>11</sup> V/m), this hydrogenation process occurs smoothly without any potential barrier.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000279168100052 Publication Date 2010-06-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 88 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP). ; Approved Most recent IF: 3.411; 2010 IF: 3.841
Call Number UA @ lucian @ c:irua:83924 Serial 881
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Author Lorenz, H.; Zhao, Q.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Kloetzer, B.; Rameshan, C.; Pfaller, K.
Title Origin of different deactivation of Pd/SnO2 and Pd/GeO2 catalysts in methanol dehydrogenation and reforming: a comparative study Type A1 Journal article
Year 2010 Publication Applied catalysis : A : general Abbreviated Journal Appl Catal A-Gen
Volume 381 Issue 1/2 Pages 242-252
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Pd particles supported on SnO2 and GeO2 have been structurally investigated by X-ray diffraction, (High-Resolution) transmission and scanning electron microscopy after different reductive treatments to monitor the eventual formation of bimetallic phases and catalytically tested in methanol dehydrogenation/ reforming. For both oxides this included a thin film sample with well-defined Pd particles and a powder catalyst prepared by incipient wetness impregnation. The hexagonal and the tetragonal polymorph were studied for powder GeO2. Pd2Ge formation was observed on all GeO2-supported catalysts, strongly depending on the specific sample used. Reduction of the thin film at 573K resulted in full transformation into the bimetallic state. The partial solubility of hexagonal GeO2 in water and its thermal structural instability yielded Pd2Ge formation at 473 K, at the cost of a structurally inhomogeneous support and Ge metal formation at higher reduction temperatures. Pd on tetragonal GeO2 entered a state of strong metalsupport interaction after reduction at 573673 K, resulting in coalescing Pd2Ge particles on a sintered and re-crystallized support, apparently partially covering the bimetallic particles and decreasing the catalytic activity. Pd2Ge on amorphous thin film and hexagonal GeO2 converted methanol primarily via dehydrogenation to CO and H2. At 573 K, formation of Pd2Sn and also PdSn occurred on the Pd/SnO2 thin film. Pd3Sn2 (and to some extent Pd2Sn) were predominantly obtained on the respective powder catalyst. Strong deactivation with increasing reduction temperature was observed, likely not based on the classical strong metalsupport interaction effect, but rather on a combination of missing active structural ensembles on Sn-enriched bimetallic phases and the formation of metallic -Sn. Correlations to Pd and its bimetallics supported on ZnO, Ga2O3 and In2O3 were also discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000279100700029 Publication Date 2010-04-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0926-860X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 4.339 Times cited 14 Open Access
Notes Esteem 026019 Approved Most recent IF: 4.339; 2010 IF: 3.384
Call Number UA @ lucian @ c:irua:83927 Serial 2522
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Author Geurts, R.; Milošević, M.V.; Peeters, F.M.
Title Vortex matter in mesoscopic two-gap superconducting disks: influence of Josephson and magnetic coupling Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 81 Issue 21 Pages 15
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000278846600001 Publication Date 2010-06-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 89 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vlaanderen), the Belgian Science Policy (IAP), the ESF “Nanoscience and Engineering in Superconductivity” (NES) program, and the ESF “Arrays of Quantum Dots and Josephson Junctions” network. ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:83933 Serial 3872
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Author Cotte, M.; Susini, J.; Dik, J.; Janssens, K.
Title Synchrotron-based X-ray absorption spectroscopy for art conservation: looking back and looking forward Type A1 Journal article
Year 2010 Publication Accounts of chemical research Abbreviated Journal Accounts Chem Res
Volume 43 Issue 6 Pages 705-714
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract A variety of analytical techniques augmented by the use of synchrotron radiation (SR), such as X-ray fluorescence (SR-XRF) and X-ray diffraction (SR-XRD), are now readily available, and they differ little, conceptually, from their common laboratory counterparts. Because of numerous advantages afforded by SR-based techniques over benchtop versions, however, SR methods have become popular with archaeologists, art historians, curators, and other researchers in the field of cultural heritage (CH). Although the CH community now commonly uses both SR-XRF and SR-XRD, the use of synchrotron-based X-ray absorption spectroscopy (SR-XAS) techniques remains marginal, mostly because CH specialists rarely interact with SR physicists. In this Account, we examine the basic principles and capabilities of XAS techniques in art preservation. XAS techniques offer a combination of features particularly well-suited for the chemical analysis of works of art. The methods are noninvasive, have low detection limits, afford high lateral resolution, and provide exceptional chemical sensitivity. These characteristics are highly desirable for the chemical characterization of precious, heterogeneous, and complex materials. In particular, the chemical mapping capability, with high spatial resolution that provides information about local composition and chemical states, even for trace elements, is a unique asset. The chemistry involved in both the objects history (that is, during fabrication) and future (that is, during preservation and restoration treatments) can be addressed by XAS. On the one hand, many studies seek to explain optical effects occurring in historical glasses or ceramics by probing the molecular environment of relevant chromophores. Hence, XAS can provide insight into craft skills that were mastered years, decades, or centuries ago but were lost over the course of time. On the other hand, XAS can also be used to characterize unwanted reactions, which are then considered alteration phenomena and can dramatically alter the objects original visual properties. In such cases, the bulk elemental composition is usually unchanged. Hence, monitoring oxidation state (or, more generally, other chemical modifications) can be of great importance. Recent applications of XAS in art conservation are reviewed and new trends are discussed, highlighting the value (and future possibilities) of XAS, which remains, given its potential, underutilized in the CH community.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000278842500003 Publication Date 2010-01-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0001-4842 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 20.268 Times cited 74 Open Access
Notes ; ; Approved Most recent IF: 20.268; 2010 IF: 21.852
Call Number UA @ admin @ c:irua:83982 Serial 5861
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Author Janssens, K.; Dik, J.; Cotte, M.; Susini, J.
Title Photon-based techniques for nondestructive subsurface analysis of painted cultural heritage artifacts Type A1 Journal article
Year 2010 Publication Accounts of chemical research Abbreviated Journal Accounts Chem Res
Volume 43 Issue 6 Pages 814-825
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Often, just micrometers below a paintings surface lies a wealth of information, both with Old Masters such as Peter Paul Rubens and Rembrandt van Rijn and with more recent artists of great renown such as Vincent Van Gogh and James Ensor. Subsurface layers may include underdrawing, underpainting, and alterations, and in a growing number of cases conservators have discovered abandoned compositions on paintings, illustrating artists practice of reusing a canvas or panel. The standard methods for studying the inner structure of cultural heritage (CH) artifacts are infrared reflectography and X-ray radiography, techniques that are optionally complemented with the microscopic analysis of cross-sectioned samples. These methods have limitations, but recently, a number of fundamentally new approaches for fully imaging the buildup of hidden paint layers and other complex three-dimensional (3D) substructures have been put into practice. In this Account, we discuss these developments and their recent practical application with CH artifacts. We begin with a tabular summary of 14 IR- and X-ray-based imaging methods and then continue with a discussion of each technique, illustrating CH applications with specific case studies. X-ray-based tomographic and laminographic techniques can be used to generate 3D renditions of artifacts of varying dimensions. These methods are proving invaluable for exploring inner structures, identifying the conservation state, and postulating the original manufacturing technology of metallic and other sculptures. In the analysis of paint layers, terahertz time-domain spectroscopy (THz-TDS) can highlight interfaces between layers in a stratigraphic buildup, whereas macrosopic scanning X-ray fluorescence (MA-XRF) has been employed to measure the distribution of pigments within these layers. This combination of innovative methods provides topographic and color information about the micrometer depth scale, allowing us to look into paintings in an entirely new manner. Over the past five years, several new variants of traditional IR- and X-ray-based imaging methods have been implemented by conservators and museums, and the first reports have begun to emerge in the primary research literature. Applying these state-of-the-art techniques in a complementary fashion affords a more comprehensive view of paintings and other artworks.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000278842500013 Publication Date 2010-05-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0001-4842 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 20.268 Times cited 78 Open Access
Notes ; This research was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16). The text also presents results of FWO (Brussels, Belgium) projects nr. G.0704.08 and G.0179.09 and from the UA-BOF GOA programme. ; Approved Most recent IF: 20.268; 2010 IF: 21.852
Call Number UA @ admin @ c:irua:83983 Serial 5772
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Author Tsirlin, A.A.; Abakumov, A.M.; Van Tendeloo, G.; Rosner, H.
Title Interplay of atomic displacement in the quantum magnet (CuCI)LaNb2O7 Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue 5 Pages 054107,1-054107,12
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We report on the crystal structure of the quantum magnet CuClLaNb2O7 that was controversially described with respect to its structural organization and magnetic behavior. Using high-resolution synchrotron powder x-ray diffraction, electron diffraction, transmission electron microscopy, and band-structure calculations, we solve the room-temperature structure of this compound -CuClLaNb2O7 and find two high-temperature polymorphs. The -CuClLaNb2O7 phase, stable above 640 K, is tetragonal with asub=3.889 Å, csub =11.738 Å, and the space group P4/mmm. In the -CuClLaNb2O7 structure, the Cu and Cl atoms are randomly displaced from the special positions along the 100 directions. The phase asub2asubcsub, space group Pbmm and the phase 2asub2asubcsub, space group Pbam are stable between 640 K and 500 K and below 500 K, respectively. The structural changes at 500 and 640 K are identified as order-disorder phase transitions. The displacement of the Cl atoms is frozen upon the → transformation while a cooperative tilting of the NbO6 octahedra in the phase further eliminates the disorder of the Cu atoms. The low-temperature -CuClLaNb2O7 structure thus combines the two types of the atomic displacements that interfere due to the bonding between the Cu atoms and the apical oxygens of the NbO6 octahedra. The precise structural information resolves the controversy between the previous computation-based models and provides the long-sought input for understanding CuClLaNb2O7 and related compounds with unusual magnetic properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000280849400001 Publication Date 2010-08-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 13 Open Access
Notes Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:83991 Serial 1706
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Author Ding, F.; Akopian, N.; Li, B.; Perinetti, U.; Govorov, A.; Peeters, F.M.; Bufon, C.C.; Deneke, C.; Chen, Y.H.; Rastelli, A.; Schmidt, O.G.; Zwiller, V.
Title Gate controlled Aharonov-Bohm-type oscillations from single neutral excitons in quantum rings Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue 7 Pages 8
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000280813100005 Publication Date 2010-08-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 58 Open Access
Notes ; We acknowledge L. P. Kouwenhoven and Z. G. Wang for support, L. Wang, V. Fomin, S. Kiravittaya, M. Tadic, Wen-Hao Chang, I. Sellers, A. Avetisyan, and C. Pryor for fruitful discussions and the financial support of NWO (VIDI), the CAS-MPG program, the DFG (FOR730), BMBF (Grant No. 01BM459), NSFC (Grant No. 60625402), and Flemish Science Foundation (FWO-V1). Access to the TEM of B. Rellinghaus is acknowledged. ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:83992 Serial 1321
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Author Figuerola, A.; van Huis, M.; Zanella, M.; Genovese, A.; Marras, S.; Falqui, A.; Zandbergen, H.W.; Cingolani, R.; Manna, L.
Title Epitaxial CdSe-Au nanocrystal heterostructures by thermal annealing Type A1 Journal article
Year 2010 Publication Nano letters Abbreviated Journal Nano Lett
Volume 10 Issue 8 Pages 3028-3036
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Washington Editor
Language Wos 000280728900049 Publication Date 2010-07-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1530-6984;1530-6992; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 12.712 Times cited 112 Open Access
Notes Approved Most recent IF: 12.712; 2010 IF: 12.219
Call Number UA @ lucian @ c:irua:83995 Serial 1069
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Author Yang, C.H.; Peeters, F.M.; Xu, W.
Title Landau-level broadening due to electron-impurity interaction in graphene in strong magnetic fields Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue 7 Pages 075401:1-075401:6
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The effect of electron-impurity and electron-electron interactions on the energy spectrum of electrons moving in graphene is investigated in the presence of a high magnetic field. We find that the width of the broadened Landau levels exhibits an approximate 1/B dependence near half filling for charged impurity scattering. The Landau-level width, the density of states, and the Fermi energy exhibit an oscillatory behavior as a function of magnetic field. Comparison with experiment shows that scattering with charged impurities cannot be the main scattering mechanism that determines the width of the Landau levels.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000280553700008 Publication Date 2010-08-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 38 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the National Science Foundation of China under Grant No. 10804053, the Foundation of NUIST under Grant No. S8108062001, and the Chinese Academy of Sciences and Department of Science and Technology of Yunnan Province. ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:84043 Serial 1769
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Author Bezjak, J.; Abakumov, A.M.; Recnik, A.; Krzmanc, M.M.; Jancar, B.; Suvorov, D.
Title The local structure and composition of Ba4Nb2O9-based oxycarbonates Type A1 Journal article
Year 2010 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume 183 Issue 8 Pages 1823-1828
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract X-ray powder-diffraction(XRD),high-resolutiontransmissionelectronmicroscopy(HRTEM),electron diffraction(ED),infraredspectroscopy(IR),thermogravimetry(TG)andmassspectroscopy(MS)were performedtoinvestigatethecompositionandthecrystalstructureoftetra-bariumdi-niobate(V) Ba4Nb2O9. TheTG,MSandIRstudiesrevealedthatthecompoundisahydratedoxycarbonate.Assuming that thecarbonatestoichiometricallyreplacesoxygen,thecompositionofthelow-temperature a-modification,obtainedbyslowcoolingfrom1100 1C, correspondstoBa4Nb2O8.8(CO3)0.2 0.1H2O, while thequenchedhigh-temperature g-modificationhastheBa4Nb2O8.42(CO3)0.58 0.38H2O composi- tion. The a-phase hasacompositeincommensuratelymodulatedstructureconsistingoftwomutually interacting[Ba]N and the[(Nb,)O3]N subsystems.Thecompositemodulatedcrystalstructureofthe a-phase canbedescribedwiththelatticeparameters a¼10.2688(1) A˚ , c¼2.82426(8) A˚ , q¼0.66774(2)c* and asuperspacegroup R3m(00g)0s. TheHRTEManalysisdemonstratesthenanoscale twinningofthetrigonaldomainsparalleltothe{100}crystallographicplanes.Thetwinningintroduces a one-dimensionaldisorderintothe[(Nb,)O3]N subsystem,whichresultsinanaverage P62c crystal structureofthe a-phase. Possibleplacesforthecarbonategroupinthestructurearediscussedusinga comparisonwithotherhexagonalperovskite-basedoxycarbonates.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000280620300013 Publication Date 2010-06-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 10 Open Access
Notes Approved Most recent IF: 2.299; 2010 IF: 2.261
Call Number UA @ lucian @ c:irua:84046 Serial 1830
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Author Terzano, R.; Santoro, A.; Spagnuolo, M.; Vekemans, B.; Medici, L.; Janssens, K.; Göttlicher, J.; Denecke, M.A.; Mangold, S.; Ruggiero, P.
Title Solving mercury (Hg) speciation in soil samples by synchrotron X-ray microspectroscopic techniques Type A1 Journal article
Year 2010 Publication Environmental pollution Abbreviated Journal Environ Pollut
Volume 158 Issue 8 Pages 2702-2709
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Direct mercury (Hg) speciation was assessed for soil samples with a Hg concentration ranging from 7 up to 240 mg kg1. Hg chemical forms were identified and quantified by sequential extractions and bulkand micro-analytical techniques exploiting synchrotron generated X-rays. In particular, microspectroscopic techniques such as m-XRF, m-XRD and m-XANES were necessary to solve bulk Hg speciation, in both soil fractions <2 mm and <2 mm. The main Hg-species found in the soil samples were metacinnabar (b-HgS), cinnabar (a-HgS), corderoite (Hg3S2Cl2), and an amorphous phase containing Hg bound to chlorine and sulfur. The amount of metacinnabar and amorphous phases increased in the fraction <2 mm. No interaction among Hg-species and soil components was observed. All the observed Hgspecies originated from the slow weathering of an inert Hg-containing waste material (K106, U.S. EPA) dumped in the area several years ago, which is changing into a relatively more dangerous source of pollution.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000280571500026 Publication Date 2010-06-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0269-7491 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 5.099 Times cited 30 Open Access
Notes ; This research was partially financed by the MIUR (COFIN 2005) project “Innovative chemical, physical, and biological methods to characterize and remediate soils polluted by heavy metals (MICROS)”. Synchrotron experiments at HASYLAB were financially supported by the European Community-Research Infrastructure Action under the FP6 “Structuring the European Research Area” Program I(Integrating Activity on Synchrotron and Free Electron Laser Science; project: contract RII3-CT-2004-506008). This research was also performed as part of the “Interuniversity Attraction Poles” (IAP6) Program financed by the Belgian government. We thank Gerald Falkenberg and Karen Rickers-Appel for their scientific and technical support in obtaining the experimental data at Beam line L (HASYLAB, DESY, Hamburg, Germany). ; Approved Most recent IF: 5.099; 2010 IF: 3.395
Call Number UA @ admin @ c:irua:84050 Serial 5835
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Author Fang, C.M.; Sluiter, M.H.F.; van Huis, M.; Ande, C.K.; Zandbergen, H.W.
Title Origin of predominance of cementite among iron carbides in steel at elevated temperature Type A1 Journal article
Year 2010 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 105 Issue 5 Pages 4
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A long-standing challenge in physics is to understand why cementite is the predominant carbide in steel. Here we show that the prevalent formation of cementite can be explained only by considering its stability at elevated temperature. A systematic highly accurate quantum mechanical study was conducted on the stability of binary iron carbides. The calculations show that all the iron carbides are unstable relative to the elemental solids, -Fe and graphite. Apart from a cubic Fe23C6 phase, the energetically most favorable carbides exhibit hexagonal close-packed Fe sublattices. Finite-temperature analysis showed that contributions from lattice vibration and anomalous Curie-Weis magnetic ordering, rather than from the conventional lattice mismatch with the matrix, are the origin of the predominance of cementite during steel fabrication processes.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000280472900008 Publication Date 2010-07-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007;1079-7114; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 8.462 Times cited 65 Open Access
Notes Approved Most recent IF: 8.462; 2010 IF: 7.622
Call Number UA @ lucian @ c:irua:84064 Serial 2526
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Author Maignan, A.; Lebedev, O.I.; Van Tendeloo, G.; Martin, C.; Hebert, S.
Title Metal to insulator transition in the n-type hollandite vanadate Pb1.6V8O16 Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue 3 Pages 035122, 1-035122,5
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The transport and magnetic measurements of polycrystalline Pb1.6V8O16 hollandite reveal a concomitant metal to insulator and antiferromagnetic transition at TMI≈140 K. A clear localization is found below TMI, evidenced by a rapid increase in the absolute value of the negative Seebeck coefficient. The structural study by x-ray and transmission electron microscopy confirms the hollandite structure and shows that no structural transition occurs at TMI, ruling out a possible charge orbital ordering. The negative Seebeck coefficient observed from 50 K up to 900 K, with values reaching S=−38 μV K−1 at 900 K, is explained by the electron doping of ∼1.4e− in the V empty t2g orbitals responsible for the bad metal resistivity (ρ900 K∼2 mΩ cm). As this S value is close to that obtained by considering only the spin and orbital degeneracies, it is expected that |S| for such vanadates will not be sensitive at high temperature to the t2g band filling
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000280366300002 Publication Date 2010-07-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 10 Open Access
Notes Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:84065 Serial 2009
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