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Author Werner, R.; Raisch, C.; Leca, V.; Ion, V.; Bals, S.; Van Tendeloo, G.; Chasse, T.; Kleiner, R.; Koelle, D.
Title Transport, magnetic, and structural properties of La0.7Ce0.3MnO3 thin films: evidence for hole-doping Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue (up) 5 Pages 054416,1-054416,8
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Cerium-doped manganite thin films were grown epitaxially by pulsed laser deposition at 720 °C and oxygen pressure pO2=125 Pa and were subjected to different annealing steps. According to x-ray diffraction (XRD) data, the formation of CeO2 as a secondary phase could be avoided for pO28 Pa. However, transmission electron microscopy shows the presence of CeO2 nanoclusters even in those films which appear to be single phase in XRD. With O2 annealing, the metal-to-insulator transition temperature increases, while the saturation magnetization decreases and stays well below the theoretical value for electron-doped La0.7Ce0.3MnO3 with mixed Mn3+/Mn2+ valences. The same trend is observed with decreasing film thickness from 100 to 20 nm, indicating a higher oxygen content for thinner films. Hall measurements on a film which shows a metal-to-insulator transition clearly reveal holes as dominating charge carriers. Combining data from x-ray photoemission spectroscopy, for determination of the oxygen content, and x-ray absorption spectroscopy (XAS), for determination of the hole concentration and cation valences, we find that with increasing oxygen content the hole concentration increases and Mn valences are shifted from 2+ to 4+. The dominating Mn valences in the films are Mn3+ and Mn4+, and only a small amount of Mn2+ ions can be observed by XAS. Mn2+ and Ce4+ XAS signals obtained in surface-sensitive total electron yield mode are strongly reduced in the bulk-sensitive fluorescence mode, which indicates hole-doping in the bulk for those films which do show a metal-to-insulator transition.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000263815400057 Publication Date 2009-02-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 25 Open Access
Notes Esteem 026019; Fwo Approved Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:76221 Serial 3725
Permanent link to this record
 
 
Author Bending, S.J.; Neal, J.S.; Milošević, M.V.; Potenza, A.; san Emeterio, L.; Marrows, C.H.
Title Vortex-antivortex 'molecular crystals' in hybrid ferromagnet/superconductor structures Type A1 Journal article
Year 2009 Publication Journal of physics : conference series Abbreviated Journal
Volume 150 Issue (up) 5 Pages 052019
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We have used high resolution Hall probe microscopy to image vortex-antivortex (V-AV) 'molecules' induced in superconducting Pb films by the stray fields from square arrays of ferromagnetic Co/Pt dots. We have directly observed spontaneous V-AV pairs and studied how they interact with added 'free' (anti)fluxons in an applied magnetic field. We observe a rich variety of subtle phenomena arising from competing symmetries in our system which can either drive added antivortices to join AV shells around nanomagnets or stabilise the translationally symmetric AV lattice between the dots. Added vortices annihilate AV shells, leading eventually to a stable 'nulling' state with no free fluxons, which should exhibit a strongly (field-)enhanced critical current. At higher densities we actually observe vortex shells around the magnets, stabilised by the asymmetric anti-pinning potential. Our experimental findings are in good agreement with Ginzburg-Landau calculations.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos Publication Date 2009-04-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1742-6588;1742-6596; ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:106136 Serial 3855
Permanent link to this record
 
 
Author Connolly, M.R.; Milošević, M.V.; Bending, S.J.; Clem, J.R.; Tamegai, T.
Title Vortex 'puddles' and magic vortex numbers in mesoscopic superconducting disks Type A1 Journal article
Year 2009 Publication Journal of physics : conference series Abbreviated Journal
Volume 150 Issue (up) 5 Pages 052039
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The magnetic properties of a superconducting disk change dramatically when its dimensions become mesoscopic. Unlike large disks, where the screening currents induced by an applied magnetic field are strong enough to force vortices to accumulate in a 'puddle' at the centre, in a mesoscopic disk the interaction between one of these vortices and the edge currents can be comparable to the intervortex repulsion, resulting in a destruction of the ordered triangular vortex lattice structure at the centre. Vortices instead form clusters which adopt polygonal and shell-like structures which exhibit magic number states similar to those of charged particles in a confining potential, and electrons in artificial atoms. We have fabricated mesoscopic high temperature superconducting Bi2Sr2CaCu2O8+δ disks and investigated their magnetic properties using magneto-optical imaging (MOI) and high resolution scanning Hall probe microscopy (SHPM). The temperature dependence of the vortex penetration field measured using MOI is in excellent agreement with models of the thermal excitation of pancake vortices over edge barriers. The growth of the central vortex puddle has been directly imaged using SHPM and magic vortex numbers showing higher stability have been correlated with abrupt jumps in the measured local magnetisation curves.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos Publication Date 2009-04-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1742-6588;1742-6596; ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:106137 Serial 3881
Permanent link to this record
 
 
Author van der Linden, V.; Cosyns, P.; Schalm, O.; Cagno, S.; Nys, K.; Janssens, K.; Nowak, A.; Wagner, B.; Bulska, E.
Title Deeply coloured and black glass in the Northern provinces of the Roman Empire : differences and similarities in chemical composition before and after AD 150 Type A1 Journal article
Year 2009 Publication Archaeometry Abbreviated Journal Archaeometry
Volume 51 Issue (up) 5 Pages 822-844
Keywords A1 Journal article; History; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract In this work we attempt to elucidate the chronological and geographical origin of deeply coloured and black glass dating between 100 bc and ad 300 on the basis of their major and trace element compositions. Samples from the western and eastern parts of the Roman Empire were analysed. Analytical data were obtained by means of a scanning electron microscope – energy-dispersive system (SEM-EDS, 63 samples analysed) and laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS, 41 samples analysed). Among the glass fragments analysed, dark brown, dark purple and dark green hues could be distinguished. Only among the dark green fragments could a clear compositional distinction be observed between fragments dated to the periods before and after ad 150. In the early samples (first century bc to first century ad), iron, responsible for the green hue, was introduced by using impure sand containing relatively high amounts of Ti. In contrast, a Ti-poor source of iron was employed, containing Sb, Co and Pb in trace quantities, in order to obtain the dark green colour in the later glass samples. The analytical results obtained by combining SEM-EDS and LA-ICP-MS are therefore consistent with a differentiation of glassmaking recipes, detectable in glass composition, occurring in the period around ad 150.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000269728600009 Publication Date 2008-11-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-813x; 1475-4754 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.47 Times cited 39 Open Access
Notes Approved Most recent IF: 1.47; 2009 IF: 1.355
Call Number UA @ admin @ c:irua:94510 Serial 5568
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Author Avetisyan, A.A.; Ghazaryan, A.V.; Djotyan, A.P.; Kirakosyan, A.A.; Moulopoulos, K.
Title Magnetoexcitons in semiconductor quantum rings with complicated (Kane's) dispersion law Type A1 Journal article
Year 2009 Publication Acta physica Polonica: A: general physics, solid state physics, applied physics T2 – 4th Workshop on Quantum Chaos and Localisation Phenomena, MAY 22-24, 2009, Polish Acad Sci, Ctr Theoret Phys, Inst Phys, Polish Acad Sci, Ctr Theoret Phys, Inst Phys, War Abbreviated Journal
Volume 116 Issue (up) 5 Pages 826-828
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The influence of the nonparabolicity of charge carriers dispersion law (Kane's dispersion) on a magnetoexciton energy spectrum in InSb quantum rings is theoretically investigated The analytical expression for the energy spectrum of exciton in a narrow-gap semiconductor nanoring in a magnetic field is obtained. The Aharonov – Bohm oscillations in the energy of excited states are studied.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000273091200015 Publication Date 2016-02-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0587-4246 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:172293 Serial 8193
Permanent link to this record
 
 
Author Baltas, H.; Čevik, U.
Title Variation of K X-ray fluorescence cross-sections of Cu, Y and Ba in YBa2Cu3O7-\delta superconductor Type A1 Journal article
Year 2009 Publication Solid state communications Abbreviated Journal
Volume 149 Issue (up) 5/6 Pages 231-235
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract K X-ray fluorescence cross-sections of Cu, Y and Ba elements were measured in CuO, Y(2)O(3), BaCO(3) Compounds and YBa(2)Cu(3)O(7-delta) superconductor samples (nonreacted agent, calcined and sintered states). A superconductor sample of YBa(2)Cu(3)O(7-delta) was prepared by using a solid-state reaction technique. The samples were excited by gamma rays of energy 59.5 keV from a (241)Am radioisotope source. The Cu, Y and Ba K X-ray intensities counted with a Si(Li) detector were measured in different solid-state conditions. The obtained values of K X-ray fluorescence cross-section were compared with the theoretical values of pure Cu, Y and Ba elements. We found that the K X-ray fluorescence cross-section of Cu, Y and Ba in YBa(2)Cu(3)O(7-delta) sample is changed in different solid-state conditions, depending on the mixture (nonreacted agent), calcined and sintered states. (c) 2008 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000262795900013 Publication Date 2008-11-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0038-1098 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:94568 Serial 8735
Permanent link to this record
 
 
Author Batenburg, K.J.; Bals, S.; Sijbers, J.; Kübel, C.; Midgley, P.A.; Hernandez, J.C.; Kaiser, U.; Encina, E.R.; Coronado, E.A.; Van Tendeloo, G.
Title 3D imaging of nanomaterials by discrete tomography Type A1 Journal article
Year 2009 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 109 Issue (up) 6 Pages 730-740
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract The field of discrete tomography focuses on the reconstruction of samples that consist of only a few different materials. Ideally, a three-dimensional (3D) reconstruction of such a sample should contain only one grey level for each of the compositions in the sample. By exploiting this property in the reconstruction algorithm, either the quality of the reconstruction can be improved significantly, or the number of required projection images can be reduced. The discrete reconstruction typically contains fewer artifacts and does not have to be segmented, as it already contains one grey level for each composition. Recently, a new algorithm, called discrete algebraic reconstruction technique (DART), has been proposed that can be used effectively on experimental electron tomography datasets. In this paper, we propose discrete tomography as a general reconstruction method for electron tomography in materials science. We describe the basic principles of DART and show that it can be applied successfully to three different types of samples, consisting of embedded ErSi2 nanocrystals, a carbon nanotube grown from a catalyst particle and a single gold nanoparticle, respectively.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000265816400005 Publication Date 2009-02-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 220 Open Access
Notes Fwo; Esteem 026019 Approved Most recent IF: 2.843; 2009 IF: 2.067
Call Number UA @ lucian @ c:irua:74665 c:irua:74665 Serial 12
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Author Doenen, M.; Zhang, L.; Erni, R.; Williams, O.A.; Hardy, A.; van Bael, M.K.; Wagner, P.; Haenen, K.; Nesladek, M.; Van Tendeloo, G.
Title Diamond nucleation by carbon transport from buried nanodiamond TiO2 sol-gel composites Type A1 Journal article
Year 2009 Publication Advanced materials Abbreviated Journal Adv Mater
Volume 21 Issue (up) 6 Pages 670-673
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000263492000007 Publication Date 2008-12-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648;1521-4095; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 19.791 Times cited 20 Open Access
Notes Fwo; Iap-P6/42; Esteem 026019 Approved Most recent IF: 19.791; 2009 IF: NA
Call Number UA @ lucian @ c:irua:76329 Serial 688
Permanent link to this record
 
 
Author Bach, D.; Schneider, R.; Gerthsen, D.; Verbeeck, J.; Sigle, W.
Title EELS of niobium and stoichiometric niobium-oxide phases: part 1: plasmon and Near-edges fine structure Type A1 Journal article
Year 2009 Publication Microscopy and microanalysis Abbreviated Journal Microsc Microanal
Volume 15 Issue (up) 6 Pages 505-523
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A comprehensive electron energy-loss spectroscopy study of niobium (Nb) and stable Nb-oxide phases (NbO, NbO2, Nb2O5) was carried out. In this work (Part I), the plasmons and energy-loss near-edge structures (ELNES) of all relevant Nb edges (Nb-N2,3, Nb-M4,5, Nb-M2,3, Nb-M1, and Nb-L2,3) up to energy losses of about 2600 eV and the O-K edge are analyzed with respect to achieving characteristic fingerprints of Nb in different formal oxidation states (0 for metallic Nb, +2 for NbO, +4 for NbO2, and +5 for Nb2O5). Chemical shifts of the Nb-N2,3, Nb-M4,5, Nb-M2,3, and Nb-L2,3 edges are extracted from the spectra that amount to about 4 eV as the oxidation state increases from 0 for Nb to +5 for Nb2O5. Four different microscopes, including a 200 keV ZEISS Libra with monochromator, were used. The corresponding wide range of experimental parameters with respect to the primary electron energy, convergence, and collection semi-angles as well as energy resolution allows an assessment of the influence of the experimental setup on the ELNES of the different edges. Finally, the intensity of the Nb-L2,3 white-line edges is correlated with niobium 4d-state occupancy in the different reference materials.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge, Mass. Editor
Language Wos 000272433200005 Publication Date 2009-10-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276;1435-8115; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.891 Times cited 55 Open Access
Notes Approved Most recent IF: 1.891; 2009 IF: 3.035
Call Number UA @ lucian @ c:irua:80320UA @ admin @ c:irua:80320 Serial 790
Permanent link to this record
 
 
Author Berdiyorov, G.R.; Yu, S.H.; Xiao, Z.L.; Peeters, F.M.; Hua, J.; Imre, A.; Kwok, W.K.
Title Effect of sample geometry on the phase boundary of a mesoscopic superconducting loop Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue (up) 6 Pages 064511,1-064511,6
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We studied the effect of sample geometry on the evolution of the superconducting state in nanoscale Nb circular and square loops by transport measurements. A multistage resistive transition with temperature is found for both samples, which is related to the effect of contact leads made from the same superconducting material. The H-T phase diagrams close to Tc0 show clear periodic oscillations on top of a parabolic background, i.e., Little-Parks effect. However, the amplitude of the oscillations decreases faster in the circular loop compared to the one in the square sample. Numerical simulations are conducted within the nonlinear Ginzburg-Landau theory to show the effect of sample geometry on the nucleation of superconductivity in superconducting loop structures.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000269638800067 Publication Date 2009-08-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 21 Open Access
Notes Approved Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:78292 Serial 833
Permanent link to this record
 
 
Author Zha, G.-Q.; Chen, Y.; Peeters, F.M.; Zhou, S.-P.
Title Impurity-induced modulations of orders in d-wave superconductors Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue (up) 6 Pages 064518,1-064518,5
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract By using a model Hamiltonian with competing antiferromagnetic (AFM) and d-wave superconductivity orders, the impurity-induced structures of orders in d-wave superconductors is investigated. We find that the transition between one-dimensional stripe and two-dimensional checkerboardlike modulation around a single nonmagnetic impurity can take place as the strength of the AFM interaction U or the impurity scattering strength V0 is varied. It is also found that the impurity-induced stripe can first transit to checkerboardlike modulation and then disappears with increasing the next-nearest-neighbor hopping strength |t|. Phase diagrams of V0 versus U and |t| for various modulations of the spin order are presented. In addition, the quantum interference effect on the modulations of orders due to two strong nonmagnetic impurities is briefly examined, and the checkerboardlike and quasistripe patterns can occur depending on the sites where two impurities are placed.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000269638800074 Publication Date 2009-09-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 3 Open Access
Notes Approved Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:78293 Serial 1572
Permanent link to this record
 
 
Author Kalina, R.; Szafran, B.; Bednarek, S.; Peeters, F.M.
Title Magnetic-field asymmetry of electron wave packet transmission in bent channels capacitively coupled to a metal gate Type A1 Journal article
Year 2009 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 102 Issue (up) 6 Pages 066807,1-066807,4
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study the electron wave packet moving through a bent channel. We demonstrate that the packet transmission probability becomes an asymmetric function of the magnetic field when the electron packet is capacitively coupled to a metal plate. The coupling occurs through a nonlinear potential which translates a different kinetics of the transport for opposite magnetic-field orientations into a different potential felt by the scattered electron.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000263389500056 Publication Date 2009-02-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007;1079-7114; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.462 Times cited 14 Open Access
Notes Approved Most recent IF: 8.462; 2009 IF: 7.328
Call Number UA @ lucian @ c:irua:76315 Serial 1867
Permanent link to this record
 
 
Author Ariskin, D.A.; Schweigert, I.V.; Alexandrov, A.L.; Bogaerts, A.; Peeters, F.M.
Title Modeling of chemical processes in the low pressure capacitive radio frequency discharges in a mixture of Ar/C2H2 Type A1 Journal article
Year 2009 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 105 Issue (up) 6 Pages 063305,1-063305,9
Keywords A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We study the properties of a capacitive 13.56 MHz discharge with a mixture of Ar/C<sub>2</sub>H<sub>2</sub> taking into account the plasmochemistry and growth of heavy hydrocarbons. A hybrid model was developed to combine the kinetic description for electron motion and the fluid approach for negative and positive ion transports and plasmochemical processes. A significant change in plasma parameters related to injection of 5.8% portion of acetylene in argon was observed and analyzed. We found that the electronegativity of the mixture is about 30%. The densities of negatively and positively charged heavy hydrocarbons are sufficiently large to be precursors for the formation of nanoparticles in the discharge volume.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000264774000059 Publication Date 2009-03-26
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 21 Open Access
Notes Approved Most recent IF: 2.068; 2009 IF: 2.072
Call Number UA @ lucian @ c:irua:74496 Serial 2121
Permanent link to this record
 
 
Author Caignaert, V.; Abakumov, A.M.; Pelloquin, D.; Pralong, V.; Maignan, A.; Van Tendeloo, G.; Raveau, B.
Title A new mixed-valence ferrite with a cubic structure, YBaFe4O7: spin-glass-like behavior Type A1 Journal article
Year 2009 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 21 Issue (up) 6 Pages 1116-1122
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A new mixed-valence ferrite, YBaFe4O7, has been synthesized. Its unique cubic structure, with a = 8.9595(2) Å, is closely related to that of the hexagonal 114 oxides YBaCo4O7 and CaBaFe4O7. It consists of corner-sharing FeO4 tetrahedra, forming triangular and kagome layers parallel to (111)C. In fact, the YBaFe4O7 and CaBaFe4O7 structures can be described as two different ccc and chch close packings of [BaO3]∞ and [O4]∞ layers, respectively, whose tetrahedral cavities are occupied by Fe2+/Fe3+ cations. The local structure of YBaFe4O7 is characterized by a large amount of stacking faults originating from the presence of hexagonal layers in the ccc cubic close-packed YBaFe4O7 structure. In this way, they belong to the large family of spinels and hexagonal ferrites studied for their magnetic properties. Differently from all the ferrites and especially from CaBaFe4O7, which are ferrimagnetic, YBaFe4O7 is an insulating spin glass with Tg = 50 K.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000264310900019 Publication Date 2009-02-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 39 Open Access
Notes Esteem 026019 Approved Most recent IF: 9.466; 2009 IF: 5.368
Call Number UA @ lucian @ c:irua:76432 Serial 2325
Permanent link to this record
 
 
Author Suarez-Martinez, I.; Bittencourt, C.; Ke, X.; Felten, A.; Pireaux, J.J.; Ghijsen, J.; Drube, W.; Van Tendeloo, G.; Ewels, C.P.
Title Probing the interaction between gold nanoparticles and oxygen functionalized carbon nanotubes Type A1 Journal article
Year 2009 Publication Carbon Abbreviated Journal Carbon
Volume 47 Issue (up) 6 Pages 1549-1554
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The interaction between evaporated gold and pristine or oxygen plasma treated multi-walled carbon nanotubes (MWCNTs) is investigated. Experimental and theoretical results indicate that gold nucleation occurs at defect sites, whether initially present or introduced by oxygen plasma treatment. Uniform gold cluster dispersion is observed on plasma treated carbon nanotubes (CNTs) and associated with the presence of uniformly dispersed oxidized vacancy centres on the CNT surface.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000265518700018 Publication Date 2009-02-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-6223; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.337 Times cited 38 Open Access
Notes Pai Approved Most recent IF: 6.337; 2009 IF: 4.504
Call Number UA @ lucian @ c:irua:77267 Serial 2717
Permanent link to this record
 
 
Author Bittencourt, C.; van Lier, G.; Ke, X.; Suarez-Martinez, I.; Felten, A.; Ghijsen, J.; Van Tendeloo, G.; Ewels, C.O.
Title Spectroscopy and defect identification for fluorinated carbon nanotubes Type A1 Journal article
Year 2009 Publication ChemPhysChem : a European journal of chemical physics and physical chemistry Abbreviated Journal Chemphyschem
Volume 10 Issue (up) 6 Pages 920-925
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Multi-wall carbon nanotubes (MWCNTs) were exposed to a CF4 radio-frequency (rf) plasma. High-resolution photoelectron spectroscopy shows that the treatment effectively grafts fluorine atoms onto the MWCNTs, altering the valence electronic states. Fluorine surface concentration can be tuned by varying the exposure time. Evaporation of gold onto MWCNTs is used to mark active site formation. High-resolution transmission electron microscopy coupled with density functional theory (DFT) modelling is used to characterise the surface defects formed, indicating that the plasma treatment does not etch the tube surface. We suggest that this combination of theory and microscopy of thermally evaporated gold atoms onto the CNT surface may be a powerful approach to characterise both surface defect density as well as defect type.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000265469200011 Publication Date 2009-03-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1439-4235;1439-7641; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.075 Times cited 14 Open Access
Notes Iuap; Fwo Approved Most recent IF: 3.075; 2009 IF: 3.453
Call Number UA @ lucian @ c:irua:77315 Serial 3073
Permanent link to this record
 
 
Author Georgieva, V.; Saraiva, M.; Jehanathan, N.; Lebelev, O.I.; Depla, D.; Bogaerts, A.
Title Sputter-deposited Mg-Al-O thin films: linking molecular dynamics simulations to experiments Type A1 Journal article
Year 2009 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 42 Issue (up) 6 Pages 065107,1-065107,8
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Using a molecular dynamics model the crystallinity of MgxAlyOz thin films with a variation in the stoichiometry of the thin film is studied at operating conditions similar to the experimental operating conditions of a dual magnetron sputter deposition system. The films are deposited on a crystalline or amorphous substrate. The Mg metal content in the film ranged from 100% (i.e. MgO film) to 0% (i.e. Al2O3 film). The radial distribution function and density of the films are calculated. The results are compared with x-ray diffraction and transmission electron microscopy analyses of experimentally deposited thin films by the dual magnetron reactive sputtering process. Both simulation and experimental results show that the structure of the MgAlO film varies from crystalline to amorphous when the Mg concentration decreases. It seems that the crystalline MgAlO films have a MgO structure with Al atoms in between.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000263824200024 Publication Date 2009-03-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727;1361-6463; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited 37 Open Access
Notes Iwt Approved Most recent IF: 2.588; 2009 IF: 2.083
Call Number UA @ lucian @ c:irua:73246 Serial 3110
Permanent link to this record
 
 
Author Matthai, C.C.; March, N.H.; Lamoen, D.
Title Supercooled molecular liquids and the glassy phases of chemically bonded N, P, As, Si and Ge Type A1 Journal article
Year 2009 Publication Physics and chemistry of liquids Abbreviated Journal Phys Chem Liq
Volume 47 Issue (up) 6 Pages 607-613
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Glassy phases which have insulating character exist for a variety of monatomic species. By contrast, until recently, it has been possible to make bulk metallic glasses (BMG) by vitrification only for multicomponent systems. After a relatively brief summary on supercooling of a few molecular liquids, we review some of the recently reported results on molecular assemblies of the series N, P, As and amorphous Si and Ge. Based on these results, we suggest that the transition metals with their directional bonding might be suitable candidates for the production of BMG by vitrification.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000273047400003 Publication Date 2009-11-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9104;1029-0451; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.145 Times cited 1 Open Access
Notes BoF Approved Most recent IF: 1.145; 2009 IF: 0.580
Call Number UA @ lucian @ c:irua:80653 Serial 3376
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Author Matulis, A.; Peeters, F.M.
Title Analogy between one-dimensional chain models and graphene Type A1 Journal article
Year 2009 Publication American journal of physics Abbreviated Journal Am J Phys
Volume 77 Issue (up) 7 Pages 595-601
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The electron and hole spectrum in single and bilayer graphene is derived from known one-dimensional models, and the relation between the spectrum and symmetry of the lattice is shown.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000266976000003 Publication Date 2009-06-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-9505; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.069 Times cited 11 Open Access
Notes Approved Most recent IF: 1.069; 2009 IF: 0.779
Call Number UA @ lucian @ c:irua:77381 Serial 97
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Author Castelano, L.K.; Hai, G.Q.; Partoens, B.; Peeters, F.M.
Title Artificial molecular quantum rings under magnetic field influence Type A1 Journal article
Year 2009 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 106 Issue (up) 7 Pages 073702,1-073702,8
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The ground states of a few electrons confined in two vertically coupled quantum rings in the presence of an external magnetic field are studied systematically within the current spin-density functional theory. Electron-electron interactions combined with inter-ring tunneling affect the electronic structure and the persistent current. For small values of the external magnetic field, we recover the zero magnetic field molecular quantum ring ground state configurations. Increasing the magnetic field many angular momentum, spin, and isospin transitions are predicted to occur in the ground state. We show that these transitions follow certain rules, which are governed by the parity of the number of electrons, the single-particle picture, Hunds rules, and many-body effects.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000270915600047 Publication Date 2009-10-03
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 5 Open Access
Notes Approved Most recent IF: 2.068; 2009 IF: 2.072
Call Number UA @ lucian @ c:irua:86926 Serial 155
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Author Brosens, F.; Magnus, W.
Title Carrier transport in nanodevices: revisiting the Boltzmann and Wigner distribution functions Type A1 Journal article
Year 2009 Publication Physica status solidi: B: basic research Abbreviated Journal Phys Status Solidi B
Volume 246 Issue (up) 7 Pages 1656-1661
Keywords A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Abstract In principle, transport of charged carriers in nanometer sized solid-state devices can be fully characterized once the non-equilibrium distribution function describing the carrier ensemble is known. In this light, we have revisited the Boltzmann and the Wigner distribution functions and the framework in which they emerge from the classical respectively quantum mechanical Liouville equation. We have assessed the method of the characteristic curves as a potential workhorse to solve the time dependent Boltzmann equation for carriers propagating through spatially non-uniform systems, such as nanodevices. In order to validate the proposed solution strategy, we numerically solve the Boltzmann equation for a one-dimensional conductor mimicking the basic features of a biased low-dimensional transistor operating in the on-state. Finally, we propose a computational scheme capable of extending the benefits of the above mentioned solution strategy when it comes to solve the Wigner-Liouville equation.
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos 000268659100033 Publication Date 2009-04-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-1972;1521-3951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.674 Times cited 8 Open Access
Notes Approved Most recent IF: 1.674; 2009 IF: 1.150
Call Number UA @ lucian @ c:irua:77953 Serial 284
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Author Xu, W.; Peeters, F.M.; Lu, T.C.
Title Dependence of resistivity on electron density and temperature in graphene Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue (up) 7 Pages 073403,1-073403,4
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract On the basis of the momentum-balance equation derived from the Boltzmann equation in which electron interactions with impurities and acoustic and optic phonons are included, we examine the dependence of the resistivity in graphene on temperature and electron density. Simple analytical expressions for the different contributions to the resistivity are obtained. Our results reproduce recent experimental findings and we are able to understand the different temperature dependence of the resistivity for low and high density samples.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000263815800013 Publication Date 2009-02-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 31 Open Access
Notes Approved Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:76222 Serial 642
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Author Vlasov, I.I.; Barnard, A.S.; Ralchenko, V.G.; Lebedev, O.I.; Kanzyuba, M.V.; Saveliev, A.V.; Konov, V.I.; Goovaerts, E.
Title Nanodiamond photoemitters based on strong narrow-band luminescence from silicon-vacancy defects Type A1 Journal article
Year 2009 Publication Advanced materials Abbreviated Journal Adv Mater
Volume 21 Issue (up) 7 Pages 808-812
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Nanostructured and organic optical and electronic materials (NANOrOPT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000263737800012 Publication Date 2008-12-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648;1521-4095; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 19.791 Times cited 98 Open Access
Notes Approved Most recent IF: 19.791; 2009 IF: NA
Call Number UA @ lucian @ c:irua:74513 Serial 2253
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Author Neyts, E.C.; Bogaerts, A.
Title Numerical study of the size-dependent melting mechanisms of nickel nanoclusters Type A1 Journal article
Year 2009 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 113 Issue (up) 7 Pages 2771-2776
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Molecular dynamics simulations were used to investigate the size-dependent melting mechanism of nickel nanoclusters of various sizes. The melting process was monitored by the caloric curve, the overall cluster Lindemann index, and the atomic Lindemann index. Size-dependent melting temperatures were determined, and the correct linear dependence on inverse diameter was recovered. We found that the melting mechanism gradually changes from dynamic coexistence melting to surface melting with increasing cluster size. These findings are of importance in better understanding carbon nanotube growth by catalytic chemical vapor deposition as the phase state of the catalyst nanoparticle codetermines the growth mechanism.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited Open Access
Notes Approved Most recent IF: 4.536; 2009 IF: 4.224
Call Number UA @ lucian @ c:irua:76495 Serial 2410
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Author Lamoen, D.; March, N.H.
Title Orientational disorder in some molecular solids in relation to the boson peak in glasses Type A1 Journal article
Year 2009 Publication Physics letters : A Abbreviated Journal Phys Lett A
Volume 373 Issue (up) 7 Pages 799-800
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Orientational disorder in some molecular solids is discussed in relation to the emphasis placed on transverse vibrational modes in glasses as the origin of the observed boson peak in two very recent contributions in Nature Materials. In particular, facts are here presented for (i) CH4, (ii) C60 and (iii) ethanol in their solid phases for (a) specific heat and (b) neutron scattering. The results for ethanol in particular do not fit in with the interpretation of the boson peak in terms of transverse acoustic phonons in disordered systems. Glasses will therefore have to be separated into at least two classes where the physical interpretation of the boson peak is concerned.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000263515500020 Publication Date 2009-01-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0375-9601; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.772 Times cited 3 Open Access
Notes Bof Approved Most recent IF: 1.772; 2009 IF: 2.009
Call Number UA @ lucian @ c:irua:72917 Serial 2516
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Author Neira, I.S.; Kolen'ko, Y.V.; Lebedev, O.I.; Van Tendeloo, G.; Gupta, H.S.; Matsushita, N.; Yoshimura, M.; Guitian, F.
Title Rational synthesis of a nanocrystalline calcium phosphate cement exhibiting rapid conversion to hydroxyapatite Type A1 Journal article
Year 2009 Publication Materials science and engineering: part C: biomimetic materials Abbreviated Journal Mat Sci Eng C-Mater
Volume 29 Issue (up) 7 Pages 2124-2132
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The rational synthesis, comprehensive characterization, and mechanical and micromechanical properties of a calcium phosphate cement are presented. Hydroxyapatite cement biomaterial was synthesized from reactive sub-micrometer-sized dicalcium phosphate dihydrate and tetracalcium phosphate via a dissolution-precipitation reaction using water as the liquid phase. As a result nanostructured, Ca-deficient and carbonated B-type hydroxyapatite is formed. The cement shows good processibility, sets in 22 ± 2 min and entirely transforms to the end product after 6 h of setting reaction, one of the highest conversion rates among previously reported for calcium phosphate cements based on dicalcium and tetracalcium phosphates. The combination of all elucidated physical-chemical traits leads to an essential bioactivity and biocompatibility of the cement, as revealed by in vitro acellular simulated body fluid and cell culture studies. The compressive strength of the produced cement biomaterial was established to be 25 ± 3 MPa. Furthermore, nanoindentation tests were performed directly on the cement to probe its local elasticity and plasticity at sub-micrometer/micrometer level. The measured elastic modulus and hardness were established to be Es = 23 ± 3.5 and H = 0.7 ± 0.2 GPa, respectively. These values are in close agreement with those reported in literature for trabecular and cortical bones, reflecting good elastic and plastic coherence between synthesized cement biomaterial and human bones.
Address
Corporate Author Thesis
Publisher Place of Publication Lausanne Editor
Language Wos 000270159200008 Publication Date 2009-04-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0928-4931; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.164 Times cited 18 Open Access
Notes Esteem 026019 Approved Most recent IF: 4.164; 2009 IF: NA
Call Number UA @ lucian @ c:irua:79312 Serial 2812
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Author Schattschneider, P.; Verbeeck, J.; Hamon, A.L.
Title Real space maps of atomic transitions Type A1 Journal article
Year 2009 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 109 Issue (up) 7 Pages 781-787
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Considering the rapid technical development of transmission electron microscopes, we investigate the possibility to map electronic transitions in real space on the atomic scale. To this purpose, we analyse the information carried by the scatterer's initial and final state wave functions and the role of the different atomic transition channels for the inelastic scattering cross section. It is shown that the change in the magnetic quantum number in the transition can be mapped. Two experimental set-ups are proposed, one blocking half the diffraction plane, the other one using a cylinder lens for imaging. Both methods break the conventional circular symmetry in the electron microscope making it possible to detect the handedness of electronic transitions as an asymmetry in the image intensity. This finding is of important for atomic resolution energy-loss magnetic chiral dichroism (EMCD), allowing to obtain the magnetic moments of single atoms.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000266787900002 Publication Date 2009-03-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 10 Open Access
Notes J.V. acknowledges the FWO-Vlaanderen for support (contract no. G.0147.06) and the European Union under the Framework 6 program under a contract for an Integrated Infrastructure Initiative. Reference 026019 ESTEEM. Approved Most recent IF: 2.843; 2009 IF: 2.067
Call Number UA @ lucian @ c:irua:77360UA @ admin @ c:irua:77360 Serial 2829
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Author Müller, K.; Schowalter, M.; Jansen, J.; Tsuda, K.; Titantah, J.; Lamoen, D.; Rosenauer, A.
Title Refinement of the 200 structure factor for GaAs using parallel and convergent beam electron nanodiffraction data Type A1 Journal article
Year 2009 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 109 Issue (up) 7 Pages 802-814
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We present a new method to measure structure factors from electron spot diffraction patterns recorded under almost parallel illumination in transmission electron microscopes. Bloch wave refinement routines have been developed to refine the crystal thickness, its orientation and structure factors by comparison of experimentally recorded and calculated intensities. Our method requires a modicum of computational effort, making it suitable for contemporary personal computers. Frozen lattice and Bloch wave simulations of GaAs diffraction patterns are used to derive optimised experimental conditions. Systematic errors are estimated from the application of the method to simulated diffraction patterns and rules for the recognition of physically reasonable initial refinement conditions are derived. The method is applied to the measurement of the 200 structure factor for GaAs. We found that the influence of inelastically scattered electrons is negligible. Additionally, we measured the 200 structure factor from zero loss filtered two-dimensional convergent beam electron diffraction patterns. The precision of both methods is found to be comparable and the results agree well with each other. A deviation of more than 20% from isolated atom scattering data is observed, whereas close agreement is found with structure factors obtained from density functional theory [A. Rosenauer, M. Schowalter, F. Glas, D. Lamoen, Phys. Rev. B 72 (2005), 085326-1], which account for the redistribution of electrons due to chemical bonding via modified atomic scattering amplitudes.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000266787900005 Publication Date 2009-03-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 8 Open Access
Notes Fwo; G.0425.05; Esteem; Ant 200611271505 Approved Most recent IF: 2.843; 2009 IF: 2.067
Call Number UA @ lucian @ c:irua:77361 Serial 2856
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Author van der Snickt, G.; Dik, J.; Cotte, M.; Janssens, K.; Jaroszewicz, J.; de Nolf, W.; Groenewegen, J.; van der Loeff, L.
Title Characterization of a degraded cadmium yellow (CdS) pigment in an oil painting by means of synchrotron radiation based X-ray techniques Type A1 Journal article
Year 2009 Publication Analytical chemistry Abbreviated Journal Anal Chem
Volume 81 Issue (up) 7 Pages 2600-2610
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract On several paintings of James Ensor (1860−1949), a gradual fading of originally bright yellow areas, painted with the pigment cadmium yellow (CdS), is observed. Additionally, in some areas exposed to light, the formation of small white-colored globules on top of the original paint surface is observed. In this paper the chemical transformation leading to the color change and to the formation of the globules is elucidated. Microscopic X-ray absorption near-edge spectroscopy (ì-XANES) experiments show that sulfur, originally present in sulfidic form (S2−), is oxidized during the transformation to the sulfate form (S6+). Upon formation (at or immediately below the surface), the highly soluble cadmium sulfate is assumed to be transported to the surface in solution and reprecipitates there, forming the whitish globules. The presence of cadmium sulfate (CdSO4·2H2O) and ammonium cadmium sulfate [(NH4)2Cd(SO4)2] at the surface is confirmed by microscopic X-ray diffraction measurements, where the latter salt is suspected to result from a secondary reaction of cadmium sulfate with ammonia. Measurements performed on cross sections reveal that the oxidation front has penetrated into the yellow paint down to ca. 1−2 ìm. The morphology and elemental distribution of the paint and degradation product were examined by means of scanning electron microscopy equipped with an energy-dispersive spectrometer (SEM-EDS) and synchrotron radiation based micro-X-ray fluorescence spectrometry (SR ì-XRF). In addition, ultraviolet-induced visible fluorescence photography (UIVFP) revealed itself to be a straightforward technique for documenting the occurrence of this specific kind of degradation on a macroscale by painting conservators.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000264759400025 Publication Date 2009-03-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.32 Times cited 91 Open Access
Notes Approved Most recent IF: 6.32; 2009 IF: 5.214
Call Number UA @ admin @ c:irua:76415 Serial 5501
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Author Bugani, S.; Modugno, F.; Lucejko, J.J.; Giachi, G.; Cagno, S.; Cloetens, P.; Janssens, K.; Morselli, L.
Title Study on the impregnation of archaeological waterlogged wood with consolidation treatments using synchrotron radiation microtomography Type A1 Journal article
Year 2009 Publication Analytical and bioanalytical chemistry Abbreviated Journal Anal Bioanal Chem
Volume 395 Issue (up) 7 Pages 1977-1985
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract In favourable conditions of low temperature and low oxygen concentration, archaeological waterlogged wooden artefacts, such as shipwrecks, can survive with a good state of preservation. Nevertheless, anaerobic bacteria can considerably degrade waterlogged wooden objects with a significant loss in polysaccharidic components. Due to these decay processes, wood porosity and water content increase under ageing. In such conditions, the conservation treatments of archaeological wooden artefacts often involve the replacement of water with substances which fill the cavities and help to prevent collapse and stress during drying. The treatments are very often expensive and technically difficult, and their effectiveness very much depends on the chemical and physical characteristics of the substances used for impregnation. Also important are the degree of cavity-filling, penetration depth and distribution in the structure of the wood. In this study, the distribution in wood cavities of some mixtures based on polyethylene glycols and colophony, used for the conservation of waterlogged archaeological wood, was investigated using synchrotron radiation X-ray computed microtomography (SR-A mu CT). This non-destructive imaging technique was useful for the study of the degraded waterlogged wood and enabled us to visualise the morphology of the wood and the distribution of the materials used in the wood treatments. The study has shown how deposition is strictly related to the dimension of the wooden cavities. The work is currently proceeding with the comparison of synchrotron observations with the data of the solutions viscosity and with those of the properties imparted to the wood by the treatments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000272017000005 Publication Date 2009-09-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1618-2642 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.431 Times cited 30 Open Access
Notes Approved Most recent IF: 3.431; 2009 IF: 3.480
Call Number UA @ admin @ c:irua:94493 Serial 5853
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