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Author Dong, H.M.; Xu, W.; Peeters, F.M.
Title High-field transport properties of graphene Type A1 Journal article
Year 2011 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 110 Issue 6 Pages 063704,1-063704,6
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We present a theoretical investigation on the transport properties of graphene in the presence of high dc driving fields. Considering electron interactions with impurities and acoustic and optical phonons in graphene, we employ the momentum- and energy-balance equations derived from the Boltzmann equation to self-consistently evaluate the drift velocity and temperature of electrons in graphene in the linear and nonlinear response regimes. We find that the current-voltage relation exhibits distinctly nonlinear behavior, especially in the high electric field regime. Under the action of high-fields the large source-drain (sd) current density can be achieved and the current saturation in graphene is incomplete with increasing the sd voltage Vsd up to 3 V. Moreover, for high fields, Vsd>0.1 V, the heating of electrons in graphene occurs. It is shown that the sd current and electron temperature are sensitive to electron density and lattice temperature in the graphene device. This study is relevant to the application of graphene as high-field nano-electronic devices such as graphene field-effect transistors.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000295619300059 Publication Date 2011-09-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 17 Open Access
Notes ; This work was supported by the National Natural Science Foundation of China (Grant No. 10974206) and the Department of Science and Technology of Yunnan Province. ; Approved Most recent IF: 2.068; 2011 IF: 2.168
Call Number UA @ lucian @ c:irua:93614 Serial 1433
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Author Liu, Y.; Cheng, F.; Li, X.J.; Peeters, F.M.; Chang, K.
Title Tuning of anisotropy in two-electron quantum dots by spin-orbit interactions Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 99 Issue 3 Pages 032102,1-032102,3
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate the influence of the spin-orbit interactions (SOIs) on the electron distribution and the optical absorption of a two-electron quantum dot. It is shown that the interplay between the SOIs makes the two-electron quantum dot behave like two laterally coupled quantum dots and the anisotropic distribution can be rotated from [110] to [11®0] by reversing the direction of the perpendicular electric field and detect it through the optical absorption spectrum.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000293679000026 Publication Date 2011-07-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 8 Open Access
Notes ; This work was supported by NSFC Grants No. 16760525405, 10874175 and 11004017 and the Belgian Science Policy 168(IAP). ; Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number UA @ lucian @ c:irua:92473 Serial 3749
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Author Houssa, M.; Scalise, E.; Sankaran, K.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A.
Title Electronic properties of hydrogenated silicene and germanene Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 98 Issue 22 Pages 223107
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The electronic properties of hydrogenated silicene and germanene, so called silicane and germanane, respectively, are investigated using first-principles calculations based on density functional theory. Two different atomic configurations are found to be stable and energetically degenerate. Upon the adsorption of hydrogen, an energy gap opens in silicene and germanene. Their energy gaps are next computed using the HSE hybrid functional as well as the G(0)W(0) many-body perturbation method. These materials are found to be wide band-gap semiconductors, the type of gap in silicane (direct or indirect) depending on its atomic configuration. Germanane is predicted to be a direct-gap material, independent of its atomic configuration, with an average energy gap of about 3.2 eV, this material thus being potentially interesting for optoelectronic applications in the blue/violet spectral range. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3595682]
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000291405700057 Publication Date 2011-06-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 63 Open Access
Notes Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number UA @ lucian @ c:irua:105586 Serial 1003
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Author Vandenberghe, W.; Sorée, B.; Magnus, W.; Fischetti, M.V.
Title Generalized phonon-assisted Zener tunneling in indirect semiconductors with non-uniform electric fields : a rigorous approach Type A1 Journal article
Year 2011 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 109 Issue 12 Pages 124503-124503,12
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A general framework to calculate the Zener current in an indirect semiconductor with an externally applied potential is provided. Assuming a parabolic valence and conduction band dispersion, the semiconductor is in equilibrium in the presence of the external field as long as the electron-phonon interaction is absent. The linear response to the electron-phonon interaction results in a non-equilibrium system. The Zener tunneling current is calculated from the number of electrons making the transition from valence to conduction band per unit time. A convenient expression based on the single particle spectral functions is provided, enabling the evaluation of the Zener tunneling current under any three-dimensional potential profile. For a one-dimensional potential profile an analytical expression is obtained for the current in a bulk semiconductor, a semiconductor under uniform field, and a semiconductor under a non-uniform field using the WKB (Wentzel-Kramers-Brillouin) approximation. The obtained results agree with the Kane result in the low field limit. A numerical example for abrupt p-n diodes with different doping concentrations is given, from which it can be seen that the uniform field model is a better approximation than the WKB model, but a direct numerical treatment is required for low bias conditions.
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Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000292331200134 Publication Date 2011-06-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 41 Open Access
Notes ; William Vandenberghe gratefully acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). ; Approved Most recent IF: 2.068; 2011 IF: 2.168
Call Number UA @ lucian @ c:irua:90808 Serial 1325
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Author Scalise, E.; Houssa, M.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A.
Title Structural and vibrational properties of amorphous GeO2 from first-principles Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 98 Issue 20 Pages 202110,1-202110,3
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The structural and vibrational properties of amorphous germanium oxide (a-GeO<sub>2</sub>) are investigated using first-principles calculations based on density functional theory. We first generate an a-GeO<sub>2</sub> structure by first-principles molecular dynamics and analyze its structural properties. The vibrational spectra is then calculated within a density-functional approach. Both static and dynamic properties are in good agreement with experimental data. We next generate defects in our structure (oxygen vacancies with several density and charge states) and consider the most stable atomic configurations, focusing on the vibrational features of threefold coordinated O and divalent Ge centers.
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Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000290812100038 Publication Date 2011-05-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 226 Open Access
Notes Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number UA @ lucian @ c:irua:90222 Serial 3202
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Author Hezareh, T.; Razavi, F.S.; Kremer, R.K.; Habermeier, H.-U.; Lebedev, O.I.; Kirilenko, D.; Van Tendeloo, G.
Title Effect of PbZr0.52Ti0.48O3 thin layer on structure, electronic and magnetic properties of La0.65Sr0.35MnO3 and La0.65Ca0.30MnO3 thin-films Type A1 Journal article
Year 2011 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 109 Issue 11 Pages 113707,1-113707,8
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Epitaxial thin film heterostructures of high dielectric PbZr<sub>1-x</sub>Ti<sub>x</sub>O<sub>3</sub> (PZT) and La<sub>1-x</sub>A<sub>x</sub>MnO<sub>3</sub> (A-divalent alkaline earth metals such as Sr (LSMO) and Ca (LCMO)) were grown on SrTiO<sub>3</sub> substrates and their structure, temperature dependence of electrical resistivity, and magnetization were investigated as a function of the thickness of the LSMO(LCMO) layer. The microstructures of the samples were analyzed by TEM. By applying an electric field across the PZT layer, we applied a ferrodistortive pressure on the manganite layer and studied the correlations between lattice distortion and electric transport and magnetic properties of the CMR materials.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000292214700069 Publication Date 2011-06-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 4 Open Access
Notes Approved Most recent IF: 2.068; 2011 IF: 2.168
Call Number UA @ lucian @ c:irua:90964 Serial 843
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Author Wu, Z.; Peeters, F.M.; Chang, K.
Title Spin and momentum filtering of electrons on the surface of a topological insulator Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 98 Issue 16 Pages 162101,1-162101,3
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate theoretically the transport properties of Dirac fermions on the surface of a three-dimensional topological insulator. Dirac electrons can be totally reflected in front of a magnetic/electric p-n junction. For a p-n-p structure, multiple total internal reflections at the interfaces result in the bound states in the channel, which behaves like an electronic waveguide. This p-n-p like structure exhibits spin and momentum filtering features and could be used as a spin and/or charge diode.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000289842700032 Publication Date 2011-04-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 33 Open Access
Notes ; ; Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number UA @ lucian @ c:irua:89971 Serial 3076
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Author Yusupov, M.; Bultinck, E.; Depla, D.; Bogaerts, A.
Title Elucidating the asymmetric behavior of the discharge in a dual magnetron sputter deposition system Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 98 Issue 13 Pages 131502-131502,3
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A magnetron discharge is characterized by drifts of the charged particles guiding center, caused by the magnetic field, in contrast to unmagnetized discharges. Because of these drifts, a pronounced asymmetry of the discharge can be observed in a dual magnetron setup. In this work, it is found that the shape of the discharge in a dual magnetron configuration depends on the magnetic field configuration. In a closed configuration, strong drifts were observed in one preferential direction, whereas in a mirror configuration the deflection of the discharge was not so pronounced. Our calculations confirm experimental observations.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000289153600017 Publication Date 2011-04-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 4 Open Access
Notes Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number UA @ lucian @ c:irua:87867 Serial 1026
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Author Vandenberghe, W.G.; Sorée, B.; Magnus, W.; Groeseneken, G.; Fischetti, M.V.
Title Impact of field-induced quantum confinement in tunneling field-effect devices Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 98 Issue 14 Pages 143503,1-143503,3
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Being the working principle of a tunnel field-effect transistor, band-to-band tunneling is given a rigorous quantum mechanical treatment to incorporate confinement effects, multiple electron and hole valleys, and interactions with phonons. The model reveals that the strong band bending near the gate dielectric, required to create short tunnel paths, results in quantization of the energy bands. Comparison with semiclassical models reveals a big shift in the onset of tunneling. The effective mass difference of the distinct valleys is found to reduce the subthreshold swing steepness.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000289297800074 Publication Date 2011-04-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 76 Open Access
Notes ; The authors acknowledge Anne Verhulst for useful discussions. William Vandenberghe gratefully acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). This work was supported by IMEC's Industrial Affiliation Program. ; Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number UA @ lucian @ c:irua:89297 Serial 1559
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Author Wouters, J.; Lebedev, O.I.; Van Tendeloo, G.; Yamada, H.; Sato, N.; Vanacken, J.; Moshchalkov, V.V.; Verbiest, T.; Valev, V.K.
Title Preparing polymer films doped with magnetic nanoparticles by spin-coating and melt-processing can induce an in-plane magnetic anisotropy Type A1 Journal article
Year 2011 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 109 Issue 7 Pages 076105-076105,3
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Faraday rotation has been used to investigate a series of polymer films doped with magnetic iron oxide nanoparticles. The films have been prepared by spin-coating and melt-processing. In each case, upon varying the angle of optical incidence on the films, an in-plane magnetic anisotropy is observed. The effect of such an anisotropy on the Faraday rotation as a function of the angle of optical incidence is verified by comparison with magnetically poled films. These results demonstrate that care should be taken upon analyzing the magnetic behavior of such films on account of the sample preparation techniques themselves being able to affect the magnetization.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000289949000166 Publication Date 2011-04-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 10 Open Access
Notes Fwo; Iap; Iwt Approved Most recent IF: 2.068; 2011 IF: 2.168
Call Number UA @ lucian @ c:irua:89917 Serial 2709
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Author Si, X.-J.; Zhao, S.-X.; Xu, X.; Bogaerts, A.; Wang, Y.-N.
Title Fluid simulations of frequency effects on nonlinear harmonics in inductively coupled plasma Type A1 Journal article
Year 2011 Publication Physics of plasmas Abbreviated Journal Phys Plasmas
Volume 18 Issue 3 Pages 033504-033504,9
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A fluid model is self-consistently established to investigate the harmonic effects in an inductively coupled plasma, where the electromagnetic field is solved by the finite difference time domain technique. The spatiotemporal distribution of harmonic current density, harmonic potential, and other plasma quantities, such as radio frequency power deposition, plasma density, and electron temperature, have been investigated. Distinct differences in current density have been observed when calculated with and without Lorentz force, which indicates that the nonlinear Lorentz force plays an important role in the harmonic effects, especially at low frequencies. Moreover, the even harmonics are larger than the odd harmonics both in the current density and the potential. Finally, the dependence of various plasma quantities with and without the Lorentz force on various driving frequencies is also examined. It is shown that the deposited power density decreases and the depth of penetration increases slightly because of the Lorentz force. The electron density increases distinctly while the electron temperature remains almost the same when the Lorentz force is taken into account.
Address
Corporate Author Thesis
Publisher Place of Publication Woodbury, N.Y. Editor
Language Wos 000289151900073 Publication Date 2011-03-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1070-664X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.115 Times cited 7 Open Access
Notes Approved Most recent IF: 2.115; 2011 IF: 2.147
Call Number UA @ lucian @ c:irua:87876 Serial 1233
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Author Peelaers, H.; Hernández-Nieves, A.D.; Leenaerts, O.; Partoens, B.; Peeters, F.M.
Title Vibrational properties of graphene fluoride and graphane Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 98 Issue 5 Pages 051914
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The vibrational properties of graphene fluoride and graphane are studied using ab initio calculations. We find that both sp(3) bonded derivatives of graphene have different phonon dispersion relations and phonon densities of states as expected from the different masses associated with the attached atoms of fluorine and hydrogen, respectively. These differences manifest themselves in the predicted temperature behavior of the constant-volume specific heat of both compounds. (C) 2011 American Institute of Physics. [doi:10.1063/1.3551712]
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000286988400027 Publication Date 2011-02-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 66 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-V1), the Belgian Science Policy (IAP), and the collaborative project FWO-MINCyT (Contract No. FW /08/01). A.D.H.-N. is also supported by ANPCyT (under Grant No. PICT2008-2236) ; Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number UA @ lucian @ c:irua:105604 Serial 3844
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Author Paul, M.; Kufer, D.; Müller, A.; Brück, S.; Goering, E.; Kamp, M.; Verbeeck, J.; Tian, H.; Van Tendeloo, G.; Ingle, N.J.C.; Sing, M.; Claessen, R.
Title Fe3O4/ZnO : a high-quality magnetic oxide-semiconductor heterostructure by reactive deposition Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 98 Issue 1 Pages 012512,1-012512,3
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We demonstrate the epitaxial growth of Fe<sub>3</sub>O<sub>4</sub> films on ZnO by a simple reactive deposition procedure using molecular oxygen as an oxidizing agent. X-ray photoelectron spectroscopy results evidence that the iron-oxide surface is nearly stoichiometric magnetite. X-ray diffraction results indicate monocrystalline epitaxy and almost complete structural relaxation. Scanning transmission electron micrographs reveal that the microstructure consists of domains which are separated by antiphase boundaries or twin boundaries. The magnetite films show rather slow magnetization behavior in comparison with bulk crystals probably due to reduced magnetization at antiphase boundaries in small applied fields.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000286009800055 Publication Date 2011-01-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 27 Open Access
Notes The authors acknowledge financial support by DFG through Forschergruppe FOR 1162. Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number UA @ lucian @ c:irua:88653 Serial 3532
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Author Turner, S.; Lazar, S.; Freitag, B.; Egoavil, R.; Verbeeck, J.; Put, S.; Strauven, Y.; Van Tendeloo, G.
Title High resolution mapping of surface reduction in ceria nanoparticles Type A1 Journal article
Year 2011 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 3 Issue 8 Pages 3385-3390
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Surface reduction of ceria nano octahedra with predominant {111} and {100} type surfaces is studied using a combination of aberration-corrected Transmission Electron Microscopy (TEM) and spatially resolved electron energy-loss spectroscopy (EELS) at high energy resolution and atomic spatial resolution. The valency of cerium ions at the surface of the nanoparticles is mapped using the fine structure of the Ce M4,5 edge as a fingerprint. The valency of the surface cerium ions is found to change from 4+ to 3+ owing to oxygen deficiency (vacancies) close to the surface. The thickness of this Ce3+ shell is measured using atomic-resolution Scanning Transmission Electron Microscopy (STEM)-EELS mapping over a {111} surface (the predominant facet for this ceria morphology), {111} type surface island steps and {100} terminating planes. For the {111} facets and for {111} surface islands, the reduction shell is found to extend over a single fully reduced surface plane and 12 underlying mixed valency planes. For the {100} facets the reduction shell extends over a larger area of 56 oxygen vacancy-rich planes. This finding provides a plausible explanation for the higher catalytic activity of the {100} surface facets in ceria.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000293521700057 Publication Date 2011-06-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364;2040-3372; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 127 Open Access
Notes Fwo Approved Most recent IF: 7.367; 2011 IF: 5.914
Call Number UA @ lucian @ c:irua:90361UA @ admin @ c:irua:90361 Serial 1458
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Author Esken, D.; Noei, H.; Wang, Y.; Wiktor, C.; Turner, S.; Van Tendeloo, G.; Fischer, R.A.
Title ZnO@ZIF-8 : stabilization of quantum confined ZnO nanoparticles by a zinc methylimidazolate framework and their surface structural characterization probed by CO2 adsorption Type A1 Journal article
Year 2011 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem
Volume 21 Issue 16 Pages 5907-5915
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The microporous and activated zeolitic imidazolate framework (Zn(MeIM)2; MeIM = imidazolate-2-methyl; ZIF-8) was loaded with the MOCVD precursor diethyl zinc [Zn(C2H5)2]. Exposure of ZIF-8 to the vapour of the volatile organometallic molecule resulted in the formation of the inclusion compound [Zn(C2H5)2]0.38@ZIF-8 revealing two precursor molecules per cavity. In a second step the obtained material was treated with oxygen (5 vol% in argon) at various temperatures (oxidative annealing) to achieve the composite material ZnO0.35@ZIF-8. The new material was characterized with powder XRD, FT-IR, UV-vis, solid state NMR, elemental analysis, N2 sorption measurements, and transmission electron microscopy. The data give evidence for the presence of nano-sized ZnO particles stabilized by ZIF-8 showing a blue-shift of the UV-vis absorption caused by quantum size effect (QSE). The surface structure and reactivity of embedded ZnO nanoparticles were characterized via carbon dioxide adsorption at different temperatures monitored by ultra-high vacuum FTIR techniques. It was found that the surface of ZnO nanoparticles is dominated by polar OZnO and ZnZnO facets as well as by defect sites, which all exhibit high reactivity towards CO2 activation forming various adsorbed carbonate and chemisorbed CO2δ− species.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000289260000012 Publication Date 2011-03-19
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 76 Open Access
Notes Esteem 026019 Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:88641 Serial 3936
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Author Janssens, K.
Title Synchrotron radiation in art and archaeology Type Editorial
Year 2011 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
Volume 26 Issue 5 Pages 883-884
Keywords Editorial; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000289731900001 Publication Date 2011-04-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.379 Times cited 5 Open Access
Notes ; ; Approved Most recent IF: 3.379; 2011 IF: 3.220
Call Number UA @ admin @ c:irua:89918 Serial 5864
Permanent link to this record
 
 
Author Cagno, S.; Nuyts, G.; Bugani, S.; De Vis, K.; Schalm, O.; Caen, J.; Helfen, L.; Cotte, M.; Reischig, P.; Janssens, K.
Title Evaluation of manganese-bodies removal in historical stained glass windows via SR-\mu-XANES/XRF and SR-\mu-CT Type A1 Journal article
Year 2011 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
Volume 26 Issue 12 Pages 2442-2451
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract The speed and effectiveness of a conservation treatment used for stained glass windows have been investigated. Dark-coloured Mn-rich stains can be found in the alteration layer of ancient glass artefacts and cause the surface to turn brown/black: this phenomenon is known as Mn-browning or Mn-staining. While in glass manganese is present in the +II or +III oxidation states, in the Mn-rich bodies, manganese is in a higher oxidation state (+IV). In restoration practice, mildly reducing solutions are employed to eliminate the dark colour and restore the clear appearance of the glass. In this paper the effectiveness and side effects of the use of hydroxylamine hydrochloride for this purpose are assessed. Archaeological fragments of stained glass windows, dated to the 14th century and originating from Sidney Sussex College, Cambridge (UK), were examined by means of synchrotron radiation (SR) based microscopic X-ray Absorption Near-Edge Spectroscopy (μ-XANES) and microscopic X-Ray Fluorescence (μ-XRF) and with high resolution computed absorption tomography (μ-CT) before, during and after the treatment. The monitoring of the glass fragments during the treatment allows us to better understand the manner in which the process unfolds and its kinetics. The results obtained reveal that the hydroxylamine hydrochloride treatment is effective, but also that it has a number of unwanted side effects. These findings are useful for optimizing the time and other modalities of the Mn-reducing treatment as well as minimizing its unwanted results.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000297030400009 Publication Date 2011-10-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.379 Times cited 17 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 GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. Special thanks to Ms Leonie Seliger, head of the stained-glass conservation studio (The Cathedral Studios-The Chapter of Canterbury Cathedral) for the supply of the archaeological samples. The authors gratefully acknowledge ESRF for granting beamtime (proposal EC-602). ; Approved Most recent IF: 3.379; 2011 IF: 3.220
Call Number UA @ admin @ c:irua:93848 Serial 5613
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Author Rouchon, V.; Pellizzi, E.; Duranton, M.; Vanmeert, F.; Janssens, K.
Title Combining XANES, ICP-AES, and SEM/EDS for the study of phytate chelating treatments used on iron gall ink damaged manuscripts Type A1 Journal article
Year 2011 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
Volume 26 Issue 12 Pages 2434-2441
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Many historical documents written with iron gall inks are endangered by the corrosive effects of these inks. In this work, a combination of complementary analytical methods was used for the first time in order to study the phytate process which is used in conservation studios to stabilize damaged manuscripts. This process consists of an antioxidant treatment performed by means of a calcium phytate (CP) solution, followed by a deacidification treatment performed with a calcium carbonate (CC) solution. The antioxidant treatment capitalizes on the properties of myo-inositol hexaphosphoric acid (phytic acid) that inhibits iron through chelation. In order to use relatively low acidic solutions, the pH of the CP solution is increased up to values between 5 and 6, which is in the range of the CP precipitation threshold. This study was performed on laboratory samples made of paper impregnated with iron gall ink and artificially aged in climatic chambers. It aims to investigate how the CP precipitate impacts the efficiency of the treatment. Side effects, such as elemental losses and deposits, were measured by means of several analytical techniques (FeK Edge XANES, SEM/EDS, and ICP-AES). These measurements were crosschecked with a ready to use colour spot test made of bathophenanthroline impregnated paper. It appeared that the CP treatment should necessarily be followed by the deacidification treatment in order to achieve long term stability. The precipitation of CP in the treating solution does finally not impact the efficiency of the treatment despite the fact that it should theoretically lower the availability of phytate to chelate iron. A scenario is proposed to explain this point.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000297030400008 Publication Date 2011-10-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.379 Times cited 10 Open Access
Notes ; This research was funded by SOLEIL (proposals 20060396 and 20080761) and was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. We are thankful to the paper conservator students of the Institut National du Patrimoine who were involved in some of the sample preparations, and to Dr Dominique Thiaudiere and Dr Solenn Reguer for their assistance and help during the experiments performed at SOLEIL beamline “DIFFABS”. ; Approved Most recent IF: 3.379; 2011 IF: 3.220
Call Number UA @ admin @ c:irua:93845 Serial 5527
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Author van der Snickt, G.; Miliani, C.; Janssens, K.; Brunetti, B.G.; Romani, A.; Rosi, F.; Walter, P.; Castaing, J.; de Nolf, W.; Klaassen, L.; Labarque, I.; Wittermann, R.
Title Material analyses of “Christ with singing and music-making Angels”, a late 15th-C panel painting attributed to Hans Memling and assistants : part 1 : non-invasive in situ investigations Type A1 Journal article
Year 2011 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
Volume 26 Issue 11 Pages 2216-2229
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract In cultural heritage science, compositional data is traditionally obtained from works of art through the analysis of samples by means of various bench-top instruments (scanning electron microscope, Raman spectrometer, etc.). Alternatively, the object can be transported to a laboratory where it may be examined, usually by spectroscopic methods working in reflection mode. However, this paper describes how a complementary set of mobile and portable instruments was deployed in situ to gain a comprehensive view on the materials and related ageing compounds of an (almost) unmovable 15th-C polyptych, prior to and in preparation of the extraction of a limited number of samples. In line with the methodological approach discussed, PXRF was first employed as an efficient screening tool. The ensuing elemental data was supplemented by more specific information on both organic as inorganic materials supplied by reflection near- and mid-FTIR spectroscopy and fluorimetry. In completion, a limited number of diffraction patterns were collected with a mobile XRD instrument in order to identify the constituent crystalline phases in pigments, grounding materials and degradation products. In this way, it could be demonstrated how a rich array of colours was obtained by means of a limited palette of pigments: lead white, lead tin yellow, azurite, natural ultramarine, bone black, vermillion, madder lake, and a green copper-organo complex were detected and situated on the panels. Remarkably, next to chalk also gypsum was found in the ground layer(s) of this Western European easel painting. The relatively large surface of the background was covered with gold leaf; the analyses seem to point towards the labour-intensive water gilding technique. The versatility of this combination of analytical techniques was further illustrated by the accurate characterisation of degradation products affecting the readability and conservation of the painting: the overall presence of a calcium oxalate-based film of variable thickness was established. Nevertheless, further analysis of cross-sectioned samples was considered desirable in order to study the stratigraphy, to gain direct access to altered and sub-imposed layers and to allow highly detailed analysis of micrometric degradation products by state-of-the art techniques (i.e. synchrotron radiation).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000296021800010 Publication Date 2011-09-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.379 Times cited 32 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 GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0103.04, G.0689.06 and G.0704.08. The staff of the Royal Museum of Fine Arts Antwerp is acknowledged for this pleasant cooperation and the authorisation for the publication of the images in this article. Therefore, a word of gratitude to Paul Huvenne, Yolande Deckers, Stef Antonissen and Gwen Borms. In addition, the authors would like to thank the MOLAB's team operators Chiari Anselmi and Federica Presciutti. MOLAB analyses have been carried out through the support of the EU within the 6th Framework Programme (Contract Eu-ARTECH, RII3-CT-2004-506171). ; Approved Most recent IF: 3.379; 2011 IF: 3.220
Call Number UA @ admin @ c:irua:93680 Serial 5705
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Author Jochems, P.; Satyawali, Y.; Diels, L.; Dejonghe, W.
Title Enzyme immobilization on/in polymeric membranes : status, challenges and perspectives in biocatalytic membrane reactors (BMRs) Type A1 Journal article
Year 2011 Publication Green chemistry : cutting-edge research for a greener sustainable future Abbreviated Journal
Volume 13 Issue 7 Pages 1609-1623
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Immobilization of enzymes is beneficial in terms of improving the process economics by enabling enzyme re-use and enhancing overall productivity and robustness. Increasingly, membranes are thought to be good supports for enzyme immobilization. These resulting biocatalytic membranes are integrated in reactors known as biocatalytic membrane reactors (BMRs) which enable the integration of biocatalysis and separation. Often the available commercial membranes require modifications to make them suitable for enzyme immobilization. Different immobilization techniques can be used on such suitable membranes, but no general rules exist for making a choice between them. Despite the advantages of BMR application, there are some issues which need to be addressed in order to achieve up-scaling of such systems. In this review, the different aspects of enzyme immobilization on membranes are discussed to show the complexity of this interdisciplinary technology. In addition, the existing issues which require further investigation are highlighted.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000292450600002 Publication Date 2011-05-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9262; 1463-9270 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:89567 Serial 7930
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Author Zeng, Y.I.; Menghini, M.; Li, D.Y.; Lin, S.S.; Ye, Z.Z.; Hadermann, J.; Moorkens, T.; Seo, J.W.; Locquet, J.-P.; van Haesendonck, C.
Title Unexpected optical response of single ZnO nanowires probed using controllable electrical contacts Type A1 Journal article
Year 2011 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 13 Issue 15 Pages 6931-6935
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Relying on combined electron-beam lithography and lift-off methods Au/Ti bilayer electrical contacts were attached to individual ZnO nanowires (NWs) that were grown by a vapor phase deposition method. Reliable Schottky-type as well as ohmic contacts were obtained depending on whether or not an ion milling process was used. The response of the ZnO NWs to ultraviolet light was found to be sensitive to the type of contacts. The intrinsic electronic properties of the ZnO NWs were studied in a field-effect transistor configuration. The transfer characteristics, including gate threshold voltage, hysteresis and operational mode, were demonstrated to unexpectedly respond to visible light. The origin of this effect could be accounted for by the presence of point defects in the ZnO NWs.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000288951000019 Publication Date 2011-03-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 7 Open Access
Notes Approved Most recent IF: 4.123; 2011 IF: 3.573
Call Number UA @ lucian @ c:irua:89378 Serial 3807
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Author Quintana, M.; Montellano, A.; Esau del Rio Castillo, A.; Van Tendeloo, G.; Bittencourt, C.; Prato, M.
Title Selective organic functionalization of graphene bulk or graphene edges Type A1 Journal article
Year 2011 Publication Chemical communications Abbreviated Journal Chem Commun
Volume 47 Issue 33 Pages 9330-9332
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Graphene sheets have been functionalized with a PAMAM dendron, finding that graphene can be efficiently functionalized all over the surface, or only at the edges, depending on the reactions used in the functionalization process.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000293648200010 Publication Date 2011-07-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-7345;1364-548X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.319 Times cited 84 Open Access
Notes Approved Most recent IF: 6.319; 2011 IF: 6.169
Call Number UA @ lucian @ c:irua:91892 Serial 2968
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Author Yan, L.; Niu, H.J.; Duong, G.V.; Suchomel, M.R.; Bacsa, J.; Chalker, P.R.; Hadermann, J.; Van Tendeloo, G.; Rosseinsky, M.J.
Title Cation ordering within the perovskite block of a six-layer Ruddlesden-Popper oxide from layer-by-layer growth artificial interfaces in complex unit cells Type A1 Journal article
Year 2011 Publication Chemical science Abbreviated Journal Chem Sci
Volume 2 Issue 2 Pages 261-272
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The (AO)(ABO3)n Ruddlesden-Popper structure is an archetypal complex oxide consisting of two distinct structural units, an (AO) rock salt layer separating an n-octahedra thick perovskite block. Conventional high-temperature oxide synthesis methods cannot access members with n > 3, but low-temperature layer-by-layer thin film methods allow the preparation of materials with thicker perovskite blocks, exploiting high surface mobility and lattice matching with the substrate. This paper describes the growth of an n = 6 member CaO[(CSMO)2(LCMO)2 (CSMO)2] in which the six unit cell perovskite block is sub-divided into two central La0.67Ca0.33MnO3 (LCMO) and two terminal Ca0.85Sm0.15MnO3 (CSMO) layers to allow stabilization of the rock salt layer and variation of the transition metal charge.
Address
Corporate Author Thesis
Publisher Royal Society of Chemistry Place of Publication Cambridge Editor
Language Wos 000286327600010 Publication Date 2010-11-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-6520;2041-6539; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.668 Times cited 16 Open Access
Notes Approved Most recent IF: 8.668; 2011 IF: 7.525
Call Number UA @ lucian @ c:irua:88652 Serial 300
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Author Yang, T.; Perkisas, T.; Hadermann, J.; Croft, M.; Ignatov, A.; Van Tendeloo, G.; Greenblatt, M.
Title Synthesis and structure determination of ferromagnetic semiconductors LaAMnSnO6(A = Sr, Ba) Type A1 Journal article
Year 2011 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem
Volume 21 Issue 1 Pages 199-205
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract LaAMnSnO(6) (A = Sr, Ba) have been synthesized by high temperature solid-state reactions under dynamic 1% H(2)/Ar flow. Rietveld refinements on room temperature powder X-ray diffraction data indicate that LaSrMnSnO(6) crystallizes in the GdFeO(3)-structure, with space group Pnma and, combined with transmission electron microscopy, LaBaMnSnO(6) in Imma. Both space groups are common in disordered double-perovskites. The Mn(3+) and Sn(4+) ions whose valence states were confirmed by X-ray absorption spectroscopy, are completely disordered over the B-sites and the BO(6) octahedra are slightly distorted. LaAMnSnO(6) are ferromagnetic semiconductors with a T(C) = 83 K for the Sr- and 66 K for the Ba-compound. The title compounds, together with the previously reported LaCaMnSnO(6) provide an interesting example of progression from Pnma to Imma as the tolerance factor increases. An analysis of the relationship between space group and tolerance factor for the series LaAMnMO(6) (A = Ca, Sr, Ba; M = Sn, Ru) provides a better understanding of the symmetry determination for double perovskites.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000285067300025 Publication Date 2010-10-26
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 3 Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:95527 Serial 3440
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Author Canioni, R.; Roch-Marchal, C.; Sécheresse, F.; Horcajada, P.; Serre, C.; Hardi-Dan, M.; Férey, G.; Grenèche, J.-M.; Lefebvre, F.; Chang, J.-S.; Hwang, Y.-K.; Lebedev, O.; Turner, S.; Van Tendeloo, G.
Title Stable polyoxometalate insertion within the mesoporous metal organic framework MIL-100(Fe) Type A1 Journal article
Year 2011 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem
Volume 21 Issue 4 Pages 1226-1233
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Successful encapsulation of polyoxometalate (POM) within the framework of a mesoporous iron trimesate MIL-100(Fe) sample has been achieved by direct hydrothermal synthesis in the absence of fluorine. XRPD, 31P MAS NMR, IR, EELS, TEM and 57Fe Mössbauer spectrometry corroborate the insertion of POM within the cavities of the MOF. The experimental Mo/Fe ratio is 0.95, in agreement with the maximum theoretical amount of POM loaded within the pores of MIL-100(Fe), based on steric hindrance considerations. The POM-MIL-100(Fe) sample exhibits a pore volume of 0.373 cm3 g−1 and a BET surface area close to 1000 m2 g−1, indicating that small gas molecules can easily diffuse inside the cavities despite the presence of heavy phosphomolybdates. These latter contribute to the decrease in the overall surface area, due to the increase in molar weight, by 65%. Moreover, the resulting Keggin containing MIL-100(Fe) solid is stable in aqueous solution with no POM leaching even after more than 2 months. In addition, no exchange of the Keggin anions by tetrabutylammonium perchlorate in organic media has been observed.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000286110400042 Publication Date 2010-11-25
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 158 Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:88642 Serial 3145
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Author Radepont, M.; de Nolf, W.; Janssens, K.; van der Snickt, G.; Coquinot, Y.; Klaassen, L.; Cotte, M.
Title The use of microscopic X-ray diffraction for the study of HgS and its degradation products corderoite (\alpha-Hg3S2Cl2), kenhsuite (\gamma-Hg3S2Cl2) and calomel (Hg2Cl2) in historical paintings Type A1 Journal article
Year 2011 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
Volume 26 Issue 5 Pages 959-968
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Since antiquity, the red pigment mercury sulfide (α-HgS), called cinnabar in its natural form or vermilion red when synthetic, was very often used in frescoes and paintings, even if it was known to suffer occasionally from degradation. The paint hereby acquires a black or silver-grey aspect. The chemical characterization of these alteration products is rather challenging mainly because of the micrometric size and heterogeneity of the surface layers that develop and that are responsible for the color change. Methods such as electron microscopy, synchrotron-based microscopic X-ray fluorescence, microscopic X-ray absorption near edge spectroscopy, Raman microscopy and secondary ion microscopy have been previously employed to identify the (Hg- and S-) compounds present and to study their co-localization. Next to these, also microscopic X-ray diffraction (XRD) (either by making use of laboratory X-ray sources or when used at a synchrotron facility) allows the identification of the crystal phases that are present in degraded HgS paint layers. In this paper we employ these various forms of micro-XRD to analyze degraded red paint in different paintings and compare the results with other X-ray based methods. Whereas the elemental analyses of the degradation products revealed, next to mercury and sulfur, the presence of chlorine, X-ray diffraction allowed the identification, next to α-HgS, of the Hg and S-containing compound calomel (Hg2Cl2) but also of the Hg, S and Cl-containing minerals corderoite (α-Hg3S2Cl2) and kenhsuite (γ-Hg3S2Cl2). These observations are consistent with X-ray absorption spectroscopy measurements performed at the S- and Cl-edges.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000289731900011 Publication Date 2011-03-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.379 Times cited 40 Open Access
Notes ; The authors gratefully acknowledge GOA programme “XANES meets EELS'' (University of Antwerp Research Council), the IUAP VI/P16 programme ”Nacho'' (BELSPO, Brussels, Belgium) and FWO (Brussels, Belgium) projects no. G.0689.06, G.0704.08 and G017909N for financial support, the ESRF for granting beamtime under proposals no. EC442 and EC720, and Gema Martinez-Criado for practical help on ID18F. The KMSKA staff is also gratefully acknowledged for their help and interest. Javier Chillida is thanked for providing us with the Pedralbes samples. The authors are also indebted to the CHARISMA project (grant agreement 228330) for financial support. ; Approved Most recent IF: 3.379; 2011 IF: 3.220
Call Number UA @ admin @ c:irua:89927 Serial 5896
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Author Alfeld, M.; Janssens, K.; Dik, J.; de Nolf, W.; van der Snickt, G.
Title Optimization of mobile scanning macro-XRF systems for the in situ investigation of historical paintings Type A1 Journal article
Year 2011 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
Volume 26 Issue 5 Pages 899-909
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Elemental distribution maps are of great interest in the study of historical paintings, as they allow to investigate the pigment use of the artist, to image changes made in the painting during or after its creation and in some cases to reveal discarded paintings that were later over painted. Yet a method that allows to record such maps of a broad range of elements in a fast, non-destructive and in situ manner is not yet commonly available; a dedicated mobile scanning XRF instrument might fill this gap. In this paper we present three self-built scanning macro-XRF instruments, each based on the experience gained with its precursor. These instruments are compared in terms of sensitivity and limits of detection, which includes a discussion of the use of polycapillary optics and pinhole collimators as beam defining devices. Furthermore, the imaging capabilities of the instruments are demonstrated in three exemplary cases: (parts of) historical paintings from the 15th to the 19th century are examined. These cases illustrate the value of element specific distribution maps in the study of historical paintings and allow in the case of Vincent van Gogh's Patch of Grass a direct comparison between in situ and synchrotron based scanning macro-XRF.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000289731900004 Publication Date 2011-03-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.379 Times cited 107 Open Access
Notes ; The investigation of the “Triptych of the Seven Sacraments'' was done in collaboration with Griet Steyaert, independent restorer, and Lizet Klaassen, Royal Museum of Fine Arts (Antwerp, Belgium). The investigation of ”Patch of Grass'' was realized in collaboration with Luuk van der Loeff, Kroller-Muller-Museum (Otterlo, The Netherlands). M. Alfeld is a PhD fellowship of the Research Foundation-Flanders (FWO). This research was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16) NACHO. The text also presents results of GOA "XANES meets ELNES'' (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0103.04, G.0689.06 and G.0704.08. Further, the work presented was sponsored by the Innovational Research Incentives Scheme of the Netherlands Organization for Scientific Research, NWO (proj. no. 016.118.303). ; Approved Most recent IF: 3.379; 2011 IF: 3.220
Call Number UA @ admin @ c:irua:89919 Serial 5758
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Author de Nolf, W.; Dik, J.; van der Snickt, G.; Wallert, A.; Janssens, K.
Title High energy X-ray powder diffraction for the imaging of (hidden) paintings Type A1 Journal article
Year 2011 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
Volume 26 Issue 5 Pages 910-916
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Over the past few years a number of innovative imaging techniques have been introduced for the visualization of hidden paint layers in Old Master Paintings. These include X-ray fluorescence scanning, TeraHertz imaging, optical coherence tomography and other acoustics-based forms of visualization. All of these techniques are usually a trade-off between their penetrative capability on the one side and their analytical precision in terms of spatial resolution and material identification on the other. Here, we present the first-time use of High-Energy X-ray Powder Diffraction imaging (HE-XRPD) in the study of hidden layers in paintings. As an imaging tool, it combines high-depth sensitivity with fingerprint identification of most inorganic painting materials. The potential as well as some limitations of this technique are demonstrated using model paintings as well as an authentic 16th century painting.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000289731900005 Publication Date 2011-03-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.379 Times cited 34 Open Access
Notes ; ; Approved Most recent IF: 3.379; 2011 IF: 3.220
Call Number UA @ admin @ c:irua:89922 Serial 5640
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Author Schalm, O.; Cabal, A.; van Espen, P.; Laquière, N.; Storme, P.
Title Improved radiographic methods for the investigation of paintings using laboratory and synchrotron X-ray sources Type A1 Journal article
Year 2011 Publication Journal of analytical atomic spectrometry Abbreviated Journal
Volume 26 Issue 5 Pages 1068-1077
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract It is generally known that radiographic inspection of 1517th century paintings can easily be done with a polychromatic X-ray source using a voltage between 20 kV and 40 kV in combination with classic X-ray films. Unfortunately, the spatial structure of numerous 19th and early 20th century paintings cannot be visualized with conventional radiography due to several reasons such as the use of lead white grounds or low absorbing pigments. Radiographic images are blurred or worse, they do not contain the picture of the painting. During the last decades, many technological innovations have been introduced in the field of radiography but their possibilities in cultural heritage have not been explored in full detail. In our investigation we used phosphor imaging plates, energy dispersive detectors and CCD-cameras in combination with synchrotron radiation and conventional X-ray tubes in order to improve the quality of radiographic images. Several promising techniques that could improve the quality of radiographs of paintings were identified.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000289731900023 Publication Date 2011-04-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477 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:89928 Serial 8070
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Author Simon, P.; Bogaerts, A.
Title Vibrational level population of nitrogen impurities in low-pressure argon glow discharges Type A1 Journal article
Year 2011 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
Volume 26 Issue 4 Pages 804-810
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The vibrational level populations of the electronic ground state of the nitrogen molecule have been calculated for typical glow discharge conditions in argonnitrogen mixtures with nitrogen concentrations between 0.1 and 1%. Stationary solutions of the master equations of the vibrational levels have been obtained using numerical methods. The main mechanisms responsible for the population and depopulation of the vibrational levels, and for the overall shape of the vibrational distribution function are pointed out. It has been found that vibrationvibration collisions play only a minor role and therefore the population of the vibrational levels is basically determined by the electron temperature.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000288703300012 Publication Date 2010-12-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477;1364-5544; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.379 Times cited 6 Open Access
Notes Approved Most recent IF: 3.379; 2011 IF: 3.220
Call Number UA @ lucian @ c:irua:87530 Serial 3842
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