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Author Koblischka, M.R.; Winter, M.; Das, P.; Koblischka-Veneva, A.; Muralidhar, M.; Wolf, T.; Babu, N.H.; Turner, S.; Van Tendeloo, G.; Hartmann, U.
Title Observation of nanostripes and -clusters in (Nd, EuGd)Ba2Cu3Ox superconductors Type A1 Journal article
Year 2009 Publication Physica: C : superconductivity Abbreviated Journal Physica C
Volume 469 Issue 4 Pages 168-176
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Nanostripes are observed in melt-textured and single-crystalline samples of the ternary light rare earth (LRE)-compound (Nd0.33Eu0.33Gd0.33)Ba2Cu3Ox (NEG) by means of atomic force microscopy, scanning tunnelling microscopy at ambient conditions, combined with transmission electron microscopy and electron backscatter diffraction. This enables the observation of several important features: The nanostripes are formed by chains of nanoclusters, representing the LRE/Ba substitution. The dimensions of the nanostripes are similar for both types of NEG samples. The periodicity of the nanostripes is found to range between 40 and 60 nm; the shape of the nanoclusters is elliptic with a major axis length between 300 and 500 nm and a minor axis length of about 30150 nm. The stripes are filling effectively the space in between the twin boundaries. Concerning the flux pinning, the nanoclusters are the important pinning sites, not the nanostripes themselves.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000264657100008 Publication Date 2009-01-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-4534; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.404 Times cited 6 Open Access
Notes Approved Most recent IF: 1.404; 2009 IF: 0.723
Call Number UA @ lucian @ c:irua:76403 Serial 2418
Permanent link to this record
 
 
Author Tirry, W.; Schryvers, D.
Title Linking a completely three-dimensional nanostrain to a structural transformation eigenstrain Type A1 Journal article
Year 2009 Publication Nature materials Abbreviated Journal Nat Mater
Volume 8 Issue 9 Pages 752-757
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) NiTi is one of the most popular shape-memory alloys, a phenomenon resulting from a martensitic transformation. Commercial NiTi-based alloys are often thermally treated to contain Ni4Ti3 precipitates. The presence of these precipitates can introduce an extra transformation step related to the so-called R-phase. It is believed that the strain field surrounding the precipitates, caused by the matrixprecipitate lattice mismatch, lies at the origin of this intermediate transformation step. Atomic-resolution transmission electron microscopy in combination with geometrical phase analysis is used to measure the elastic strain field surrounding these precipitates. By combining measurements from two different crystallographic directions, the three-dimensional strain matrix is determined from two-dimensional measurements. Comparison of the measured strain matrix to the eigenstrain of the R-phase shows that both are very similar and that the introduction of the R-phase might indeed compensate the elastic strain introduced by the precipitate.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000269215500022 Publication Date 2009-06-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1476-1122;1476-4660; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 39.737 Times cited 53 Open Access
Notes Multimat Approved Most recent IF: 39.737; 2009 IF: 29.504
Call Number UA @ lucian @ c:irua:77657 Serial 1822
Permanent link to this record
 
 
Author van der Snickt, G.; Dik, J.; Cotte, M.; Janssens, K.; Jaroszewicz, J.; de Nolf, W.; Groenewegen, J.; van der Loeff, L.
Title Characterization of a degraded cadmium yellow (CdS) pigment in an oil painting by means of synchrotron radiation based X-ray techniques Type A1 Journal article
Year 2009 Publication Analytical chemistry Abbreviated Journal Anal Chem
Volume 81 Issue 7 Pages 2600-2610
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (up) On several paintings of James Ensor (1860−1949), a gradual fading of originally bright yellow areas, painted with the pigment cadmium yellow (CdS), is observed. Additionally, in some areas exposed to light, the formation of small white-colored globules on top of the original paint surface is observed. In this paper the chemical transformation leading to the color change and to the formation of the globules is elucidated. Microscopic X-ray absorption near-edge spectroscopy (ì-XANES) experiments show that sulfur, originally present in sulfidic form (S2−), is oxidized during the transformation to the sulfate form (S6+). Upon formation (at or immediately below the surface), the highly soluble cadmium sulfate is assumed to be transported to the surface in solution and reprecipitates there, forming the whitish globules. The presence of cadmium sulfate (CdSO4·2H2O) and ammonium cadmium sulfate [(NH4)2Cd(SO4)2] at the surface is confirmed by microscopic X-ray diffraction measurements, where the latter salt is suspected to result from a secondary reaction of cadmium sulfate with ammonia. Measurements performed on cross sections reveal that the oxidation front has penetrated into the yellow paint down to ca. 1−2 ìm. The morphology and elemental distribution of the paint and degradation product were examined by means of scanning electron microscopy equipped with an energy-dispersive spectrometer (SEM-EDS) and synchrotron radiation based micro-X-ray fluorescence spectrometry (SR ì-XRF). In addition, ultraviolet-induced visible fluorescence photography (UIVFP) revealed itself to be a straightforward technique for documenting the occurrence of this specific kind of degradation on a macroscale by painting conservators.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000264759400025 Publication Date 2009-03-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.32 Times cited 91 Open Access
Notes Approved Most recent IF: 6.32; 2009 IF: 5.214
Call Number UA @ admin @ c:irua:76415 Serial 5501
Permanent link to this record
 
 
Author Xu, W.; Peeters, F.M.; Lu, T.C.
Title Dependence of resistivity on electron density and temperature in graphene Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue 7 Pages 073403,1-073403,4
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) 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
Permanent link to this record
 
 
Author Steiner, R.E.; Barshick, C.M.; Bogaerts, A.
Title Glow discharge optical spectroscopy and mass spectrometry Type H1 Book chapter
Year 2009 Publication Abbreviated Journal
Volume Issue Pages 1-28
Keywords H1 Book chapter; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) Optical (atomic absorption spectroscopy, AAS; atomic emission spectroscopy, AES; atomic fluorescence spectroscopy, AFS; and optogalvanic spectroscopy) and mass spectrometric (magnetic sector, quadrupolemass analyzer, QMA; quadrupole ion trap, QIT; Fourier transform ion cyclotron resonance, FTICR; and time-of-flight, TOF) instrumentation are well suited for coupling to the glow discharge (GD). The GD is a relatively simple device. A potential gradient (5001500 V) is applied between an anode and a cathode. In most cases, the sample is also the cathode. A noble gas (e.g. Ar, Ne, and Xe) is introduced into the discharge region before power initiation. When a potential is applied, electrons are accelerated toward the anode. As these electrons accelerate, they collide with gas atoms. A fraction of these collisions are of sufficient energy to remove an electron from a support gas atom, forming an ion. These ions are, in turn, accelerated toward the cathode. These ions impinge on the surface of the cathode, sputtering sample atoms from the surface. Sputtered atoms that do not redeposit on the surface diffuse into the excitation/ionization regions of the plasma where they can undergo excitation and/or ionization via a number of collisional processes. GD sources offer a number of distinct advantages that make them well suited for specific types of analyses. These sources afford direct analysis of solid samples, thus minimizing the sample preparation required for analysis. The nature of the plasma also provides mutually exclusive atomization and excitation processes that help to minimize the matrix effects that plague so many other elemental techniques. Unfortunately, the GD source functions optimally in a dry environment, making analysis of solutions more difficult. These sources also suffer from difficulties associated with analyzing nonconductingsamples. In this article, first, the principles of operation of the GD plasma are reviewed, with an emphasis on how those principles relate to optical spectroscopy and mass spectrometry. Basic applications of the GD techniques are considered next. These include bulk analysis, surface analysis, and the analysis of solution samples. The requirements necessary to obtain optical information are addressed following the analytical applications. This section focuses on the instrumentation needed to make optical measurements using the GD as an atomization/excitation source. Finally, mass spectrometric instrumentation and interfaces are addressed as they pertain to the use of a GD plasma as an ion source. GDsources provide analytically useful gas-phase species from solid samples. These sources can be interfaced with avariety of spectroscopic and spectrometric instruments for both quantitative and qualitative analysis.
Address
Corporate Author Thesis
Publisher Wiley Place of Publication Chichester Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 0471976709 Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:78169 Serial 1352
Permanent link to this record
 
 
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 7 Pages 799-800
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) 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
Permanent link to this record
 
 
Author van Dijk, J.; Kroesen, G.M.W.; Bogaerts, A.
Title Plasma modelling and numerical simulation Type Editorial
Year 2009 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 42 Issue 19 Pages 190301,1-190301,14
Keywords Editorial; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) Plasma modelling is an exciting subject in which virtually all physical disciplines are represented. Plasma models combine the electromagnetic, statistical and fluid dynamical theories that have their roots in the 19th century with the modern insights concerning the structure of matter that were developed throughout the 20th century. The present cluster issue consists of 20 invited contributions, which are representative of the state of the art in plasma modelling and numerical simulation. These contributions provide an in-depth discussion of the major theories and modelling and simulation strategies, and their applications to contemporary plasma-based technologies. In this editorial review, we introduce and complement those papers by providing a bird's eye perspective on plasma modelling and discussing the historical context in which it has surfaced.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000269993100001 Publication Date 2009-09-19
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 64 Open Access
Notes Approved Most recent IF: 2.588; 2009 IF: 2.083
Call Number UA @ lucian @ c:irua:78166 Serial 2637
Permanent link to this record
 
 
Author Vandevoorde, D.; Pamplona, M.; Schalm, O.; Vanhellemont, Y.; Cnudde, V.; Verhaeven, E.
Title Contact sponge method : performance of a promising tool for measuring the initial water absorption Type A1 Journal article
Year 2009 Publication Journal of cultural heritage Abbreviated Journal
Volume 10 Issue 1 Pages 41-47
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (up) Porous limestone and mortar are able to absorb large quantities of water. This phenomenon will accelerate the deterioration of the material. In such cases, the material might be treated with a hydrophobic product, which creates a superficial layer that hampers the penetration of water. In order to decide if such a treatment should be applied or not, the water absorbing behaviour of the material should be measured. With the same measuring technique the efficiency of the hydrophobic barrier can be evaluated. Moreover, it allows the monitoring of such barriers as a function of time. At the same time, the water absorption of porous stone material is an indication of the degree of deterioration and its sensitivity to future deterioration. Up to now, two different measuring techniques exist, but one can only be used in laboratory and the other, which can be operated in laboratory as well as in situ, is not always reliable for in situ analyses. This article proposes an alternative method: the contact sponge method. This recently developed method was tested on non-treated porous stone materials in a laboratory environment in order to evaluate its performance in comparison with the two existing methods.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000264831900005 Publication Date 2009-03-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1296-2074 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:115023 Serial 7728
Permanent link to this record
 
 
Author Delville, R.; James, R.D.; Salman, U.; Finel, A.; Schryvers, D.
Title Transmission electron microscopy study of low-hysteresis shape memory alloys Type P1 Proceeding
Year 2009 Publication Abbreviated Journal
Volume Issue Pages 02005,1-02005,7
Keywords P1 Proceeding; Electron microscopy for materials research (EMAT)
Abstract (up) Recent findings have linked low hysteresis in shape memory alloys with phase compatibility between austenite and martensite. In order to investigate the evolution of microstructure as the phase compatibility increases and the hysteresis is reduced, transmission electron microscopy was used to study the alloy system Ti50Ni50-xPdx where the composition is systemically tuned to approach perfect compatibility. Changes in morphology, twinning density and twinning modes are reported along with special microstructures occurring when the compatibility is achieved. In addition, the interface between austenite and a single variant of martensite was studied by high-resolution and conventional electron microscopy. The atomically sharp, defect free, low energy configuration of the interface suggests that it plays an important role in the lowering of hysteresis. Finally, dynamical modeling of the martensitic transformation using the phase-field micro-elasticity model within the geometrically linear theory succeeded in reproducing the change in microstructure as the compatibility condition is satisfied. Latest results on the extension of these findings in other Ni-Ti based ternary/quaternary systems are also reported.
Address
Corporate Author Thesis
Publisher Edp Place of Publication Coutaboeuf Editor
Language Wos 000274582300009 Publication Date 2009-08-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 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:81951 Serial 3716
Permanent link to this record
 
 
Author van den Broek, W.; Verbeeck, J.; Schryvers, D.; de Backer, S.; Scheunders, P.
Title Tomographic spectroscopic imaging; an experimental proof of concept Type A1 Journal article
Year 2009 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 109 Issue 4 Pages 296-303
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract (up) Recording the electron energy loss spectroscopy data cube with a series of energy filtered images is a dose inefficient process because the energy slit blocks most of the electrons. When recording the data cube by scanning an electron probe over the sample, perfect dose efficiency is attained; but due to the low current in nanoprobes, this often is slower, with a smaller field of view. In W. Van den Broek et al. [Ultramicroscopy, 106 (2006) 269], we proposed a new method to record the data cube, which is more dose efficient than an energy filtered series. It produces a set of projections of the data cube and then tomographically reconstructs it. In this article, we demonstrate these projections in practice, we present a simple geometrical model that allows for quantification of the projection angles and we present the first successful experimental reconstruction, all on a standard post-column instrument.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000265345400003 Publication Date 2008-12-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 1 Open Access
Notes Esteem 026019 Approved Most recent IF: 2.843; 2009 IF: 2.067
Call Number UA @ lucian @ c:irua:77271 Serial 3671
Permanent link to this record
 
 
Author Darchuk, L.; Stefaniak, E.A.; Vázquez, C.; Palacios, O.M.; Worobiec, A.; Van Grieken, R.
Title Composition of pigments on human bones found in excavations in Argentina studied with micro-Raman spectrometry and scanning electron microscopy Type A1 Journal article
Year 2009 Publication e-Preservation Science Abbreviated Journal
Volume 6 Issue Pages 112-117
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP)
Abstract (up) Results on analysis of prehistoric pigments from excavations and pigments on coloured child bones from North Patagonia, Argentina, are reported. To analyze their composition we used two micro-analytical techniques: micro- Raman spectrometry (MRS) and scanning electron microscopy coupled with X-ray micro-analysis (SEM/EDX). Most investigated excavated pigments show red or yellow ochres consistent with reddish or yellow minerals, such as á- and ã-goethite, haematite, erdite, haapalaite and jarosite. Raman spectra show also evidence of calcium oxalate monohydrate and calcite indicating lichen activity. Pigments covering human bones were identified as hematite and magnetite. This study allows us to infer that pigments found in excavation were employed for burial ceremonies, even though distances between excavated pigment archaeological site and buried remains are quite far, more than 50 km in a straight line.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1854-3928 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:78469 Serial 7712
Permanent link to this record
 
 
Author Stefaniak, E.A.; Alsecz, A.; Frost, R.; Máthé, Z.; Sajó, I.E.; Török, S.; Worobiec, A.; Van Grieken, R.
Title Combined SEM/EDX and micro-Raman spectroscopy analysis of uranium minerals from a former uranium mine Type A1 Journal article
Year 2009 Publication Journal of hazardous materials Abbreviated Journal
Volume 168 Issue 1 Pages 416-423
Keywords A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (up) Samples of the secondary uranium minerals collected in the abandoned uranium mine at Pecs (Hungary) were investigated by two micro-techniques: scanning electron microscopy (SEM/EDX) and micro-Raman spectroscopy (MRS). They were applied to locate U-rich particles and identify the chemical form and oxidation state of the uranium compounds. The most abundant mineral was a K and/or Na uranyl sulphate (zippeite group). U(VI) was also present in the form showing intensive Raman scattering at 860 cm−1 which can be attributed to uranium trioxide. This research has shown the successful application of micro-Raman spectroscopy for the identification of uranyl mineral species on the level of individual particles.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000267567600060 Publication Date 2009-02-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3894 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:77032 Serial 7681
Permanent link to this record
 
 
Author Connolly, M.R.; Milošević, M.V.; Bending, S.J.; Clem, J.R.; Tamegai, T.
Title Continuum vs. discrete flux behaviour in large mesoscopic Bi2Sr2CaCu2O8+\delta disks Type A1 Journal article
Year 2009 Publication Europhysics letters Abbreviated Journal Epl-Europhys Lett
Volume 85 Issue 1 Pages 17008,1-17008,6
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Scanning Hall probe and local Hall magnetometry measurements have been used to investigate flux distributions in large mesoscopic superconducting disks with sizes that lie near the crossover between the bulk and mesoscopic vortex regimes. Results obtained by directly mapping the magnetic induction profiles of the disks at different applied fields can be quite successfully fitted to analytic models which assume a continuous distribution of flux in the sample. At low fields, however, we do observe clear signatures of the underlying discrete vortex structure and can resolve the characteristic mesoscopic compression of vortex clusters in increasing magnetic fields. Even at higher fields, where single-vortex resolution is lost, we are still able to track configurational changes in the vortex patterns, since competing vortex orders impose unmistakable signatures on “local” magnetisation curves as a function of the applied field. Our observations are in excellent agreement with molecular-dynamics numerical simulations which lead us to a natural definition of the lengthscale for the crossover between discrete and continuum behaviours in our system.
Address
Corporate Author Thesis
Publisher Place of Publication Paris Editor
Language Wos 000263692500029 Publication Date 2009-01-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0295-5075;1286-4854; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.957 Times cited 17 Open Access
Notes Approved Most recent IF: 1.957; 2009 IF: 2.893
Call Number UA @ lucian @ c:irua:76306 Serial 495
Permanent link to this record
 
 
Author de Maeyer-Worobiec, A.; Dekov, V.M.; Laane, R.W.P.M.; Van Grieken, R.
Title EPXMA survey of shelf sediments (Southern Bight, North Sea): a glance beyond the XRD-invisible Type A1 Journal article
Year 2009 Publication Microchemical journal Abbreviated Journal
Volume 91 Issue 1 Pages 21-31
Keywords A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (up) Shelf sediments of the southern North Sea, were studied with a microanalytical [electron probe X-ray microanalysis (EPXMA)] and two bulk [X-ray diffraction (XRD) and X-ray fluorescence (XRF)] techniques. The investigation proved that the promptness of the microanalytical method is combined with a reasonable analytical reliability. XRD studies of such a type of sediments with monotonous mineral composition are not able to provide mineralogical information beyond the main well-crystalline minerals and the mineralogical quantitative characteristic of the sediment based on XRD estimations are incorrect. The EPXMA mineralogical interpretations are based on the statistical evaluation of a huge data set (thousands of mineral particles) and provide a rather correct quantitative determination of the main minerals. The comparative EPXMAXRF study revealed that the Al, Si, K, Ca, Fe and to some extent Ti contents estimated by EPXMA are fairly reliable. In this respect the accuracy of the EPXMA-based mineral identification of the pure silicates, pure aluminosilicates, and Al-, Ca-, Fe- and Ti-containing minerals with simple composition is very high. Mg-calcite, augite and apatite determinations are assessed to be correct. The supposed accuracy of the clay mineral determinations is slightly lower (7080%) than that of the other main minerals due to the complex and varying composition of the clays. The identification of XRD-invisible accessory minerals and quantification of their presence in the sediments is an essential advantage of the EPXMA, which makes it a useful approach in tracing the origin of the sediments, the pathways of their transport and the geochemical processes they have undergone. However, the EPXMA has several flaws, which need to be solved in the future sediment investigations: (1) calibration with natural standards is needed in order to provide a higher accuracy of the mineral determinations; (2) any EPXMA study of sediments needs to be secured with XRF examinations of selected samples since EPXMA gives only semi-quantitative information about the abundance of the elements; (3) ultra-thin window EPXMA of low-Z elements has to be used since some of them (O, C) are always present in the main sediment components: silicates, aluminosilicates, carbonates and metal oxyhydroxides; (4) the interpretations of the clay fraction have to be supported with detailed XRD investigations of selected samples, while the mineralogy of the silt and sand fractions needs to be backed up with optical microscopy studies. The information from different analytical techniques (EPXMA with XRFXRD-optical microscopy of selected samples) combined with the knowledge about the most possible minerals in a given environment, would give the most reliable results in studying mineralogical composition of shelf sediments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000262963300006 Publication Date 2008-07-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0026-265x; 0026-265x 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:71604 Serial 7933
Permanent link to this record
 
 
Author Bharathy, M.; Gemmill, W.R.; Fox, A.H.; Darriet, J.; Smith, M.D.; Hadermann, J.; Remy, M.S.; zur Loye, H.-C.
Title Synthesis and magnetic properties of rare earth ruthenates, Ln5Ru2O12 (Ln=Pr, Nd, SmTb) Type A1 Journal article
Year 2009 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume 182 Issue 5 Pages 1164-1170
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Single crystals of Ln5Ru2O12 (Ln=Pr, Nd, SmTb) were grown out of either NaOH or KOH fluxes in sealed silver tubes. The crystals of all the phases were observed to be twinned as confirmed by TEM studies. The series crystallize in the C2/m monoclinic system with lattice parameters, a=12.4049(4)12.7621(6) Å, b=5.8414(2)5.9488(3) Å, c=7.3489(2)7.6424(4) Å, β=107.425(3)107.432(2)° and Z=2. The crystal structure is isotypic with the defect/disorder model of Ln5Re2O12 (Ln = Y, Gd) and consists of one dimensional edge shared RuO6 octahedral chains separated by a two dimensional LnOx polyhedral framework. Magnetic measurements indicate paramagnetic and antiferromagnetic behavior for Ln=Nd, SmGd and Ln=Tb, respectively.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000265893700027 Publication Date 2009-02-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 4 Open Access
Notes Approved Most recent IF: 2.299; 2009 IF: 2.340
Call Number UA @ lucian @ c:irua:77052 Serial 3433
Permanent link to this record
 
 
Author Turner, S.; Lebedev, O.I.; Shenderova, O.; Vlasov, I.I.; Verbeeck, J.; Van Tendeloo, G.
Title Determination of size, morphology, and nitrogen impurity location in treated detonation nanodiamond by transmission electron microscopy Type A1 Journal article
Year 2009 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
Volume 19 Issue 13 Pages 2116-2124
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Size, morphology, and nitrogen impurity location, all of which are all thought to be related to the luminescent properties of detonation nanodiamonds, are determined in several detonation nanodiamond samples using a combination of transmission electron microscopy techniques. Results obtained from annealed and cleaned detonation nanodiamond samples are compared to results from conventionally purified detonation nanodiamond. Detailed electron energy loss spectroscopy combined with model-based quantification provides direct evidence for the sp3 like embedding of nitrogen impurities into the diamond cores of all the studied nanodiamond samples. Simultaneously, the structure and morphology of the cleaned detonation nanodiamond particles are studied using high resolution transmission electron microscopy. The results show that the size and morphology of detonation nanodiamonds can be modified by temperature treatment and that by applying a special cleaning procedure after temperature treatment, nanodiamond particles with clean facets almost free from sp2 carbon can be prepared. These clean facets are clear evidence that nanodiamond cores are not necessarily in coexistence with a graphitic shell of non-diamond carbon.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000268297800012 Publication Date 2009-05-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301X;1616-3028; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 100 Open Access
Notes Esteem 026019 Approved Most recent IF: 12.124; 2009 IF: 6.990
Call Number UA @ lucian @ c:irua:78261UA @ admin @ c:irua:78261 Serial 674
Permanent link to this record
 
 
Author Yang, X.-Y.; Li, Y.; Van Tendeloo, G.; Xiao, F.-S.; Su, B.-L.
Title One-pot synthesis of catalytically stable and active nanoreactors: encapsulation of size-controlled nanoparticles within a hierarchically macroporous core@ordered mesoporous shell system Type A1 Journal article
Year 2009 Publication Advanced materials Abbreviated Journal Adv Mater
Volume 21 Issue 13 Pages 1368-1372
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Size-controlled, catalytically active nanoparticles are successfully encapsulated in a one-pot synthesis to form novel hierarchical macroporous core@mesoporous shell structures, where macroporous cores are connected by uniform and ordered mesoporous channels. Most importantly, the encapsulated nanoparticles can be used as nanoreactors, with high activities and excellent long-term recycling stability.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000265432700011 Publication Date 2009-01-14
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 61 Open Access
Notes Iap Approved Most recent IF: 19.791; 2009 IF: NA
Call Number UA @ lucian @ c:irua:77316 Serial 2466
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Author Denecke, M.A.; Brendebach, B.; de Nolf, W.; Falkenberg, G.; Janssens, K.; Simon, R.
Title Spatially resolved micro-X-ray fluorescence and micro-X-ray absorption fine structure study of a fractured granite bore core following a radiotracer experiment Type A1 Journal article
Year 2009 Publication Spectrochimica acta: part B : atomic spectroscopy Abbreviated Journal Spectrochim Acta B
Volume 64 Issue 8 Pages 791-795
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (up) Spatially resolved X-ray absorption and fluorescence investigation with a micrometer-scale resolution on actinide-containing samples provide information necessary for safety assessment of nuclear waste disposal. In this paper one example of such an experiment is presented. This example entails neptunium speciation in a fractured granite bore core from the Swedish Äspö Hard Rock Laboratory following a radiotracer experiment using µ-XAFS and µ-XRF. In order to probe micro-volumes below the surface in the granite samples and thereby avoid potential changes in the Np speciation during cutting of the bore core, a confocal irradiationdetection geometry is employed. µ-XAFS results for a selected granite bore core cross section with ~ 3 nmol Np/g reveal that Np, originally introduced as Np(V) in the tracer cocktail, is present in the granite in its reduced Np(IV) form. The Np(IV) is often present as particles, tens of µm in size. Elemental distribution maps show the tracer Np to be located in fissures and permeable channels not larger than 100 µm. The Np distribution appears often correlated with Zn also present in some fissures. We observe small granite fissures containing Fe (presumably Fe(II)), where we do not detect any Np. It is feasible that inflowing Np(V) has a shorter residence time in large fractures, while in the smaller fissures migration is slower, leading to longer residence times, i.e., reaction times, where it is reduced to less soluble Np(IV) and becomes thereby immobilized.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000269995300013 Publication Date 2009-06-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0584-8547; 0038-6987 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.241 Times cited 21 Open Access
Notes Approved Most recent IF: 3.241; 2009 IF: 2.719
Call Number UA @ admin @ c:irua:79740 Serial 5837
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Author Schalm, O.; van der Linden, V.; Frederickx, P.; Luyten, S.; van der Snickt, G.; Caen, J.; Schryvers, D.; Janssens, K.; Cornelis, E.; van Dyck, D.; Schreiner, M.
Title Enamels in stained glass windows: preparation, chemical composition, microstructure and causes of deterioration Type A1 Journal article
Year 2009 Publication Spectrochimica acta: part B : atomic spectroscopy Abbreviated Journal Spectrochim Acta B
Volume 64 Issue 8 Pages 812-820
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Vision lab
Abstract (up) Stained glass windows incorporating dark blue and purple enamel paint layers are in some cases subject to severe degradation while others from the same period survived the ravages of time. A series of dark blue, greenblue and purple enamel glass paints from the same region (Northwestern Europe) and from the same period (16early 20th centuries) has been studied by means of a combination of microscopic X-ray fluorescence analysis, electron probe micro analysis and transmission electron microscopy with the aim of better understanding the causes of the degradation. The chemical composition of the enamels diverges from the average chemical composition of window glass. Some of the compositions appear to be unstable, for example those with a high concentration of K2O and a low content of CaO and PbO. In other cases, the deterioration of the paint layers was caused by the less than optimal vitrification of the enamel during the firing process. Recipes and chemical compositions indicate that glassmakers of the 1617th century had full control over the color of the enamel glass paints they made. They mainly used three types of coloring agents, based on Co (dark blue), Mn (purple) and Cu (light-blue or greenblue) as coloring elements. Bluepurple enamel paints were obtained by mixing two different coloring agents. The coloring agent for redpurple enamel, introduced during the 19th century, was colloidal gold embedded in grains of lead glass.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000269995300018 Publication Date 2009-06-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0584-8547; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.241 Times cited 28 Open Access
Notes Iuap Vi/6; Fwo; Goa Approved Most recent IF: 3.241; 2009 IF: 2.719
Call Number UA @ lucian @ c:irua:79647 Serial 1035
Permanent link to this record
 
 
Author Michel, K.H.; Verberck, B.
Title Theoretical phonon dispersions in monolayers and multilayers of hexagonal boron-nitride Type A1 Journal article
Year 2009 Publication Physica status solidi: B: basic research Abbreviated Journal Phys Status Solidi B
Volume 246 Issue 11/12 Pages 2802-2805
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Starting from an empirical force constant model of valence interactions and calculating by Ewald's method the electrostatic force constants, we derive the dynamical matrix for a monolayer and for multilayer systems of hexagonal boron nitride (h-BN). Solution of the secular problem leads to the corresponding phonon dispersion relations. The interplay between valence forces and Coulomb forces is discussed. A comparison with previous results on graphene and graphene multilayers is made. Our spectra on the h-BN monolayer are rather similar to previous ab initio theory results. Comparison is also made with Raman and infrared experimental results.
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos 000272904100091 Publication Date 2009-11-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-1972; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.674 Times cited 10 Open Access
Notes Approved Most recent IF: 1.674; 2009 IF: 1.150
Call Number UA @ lucian @ c:irua:80673 Serial 3609
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Author Michel, K.H.; Verberck, B.
Title Theory of elastic and piezoelectric effects in two-dimensional hexagonal boron nitride Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 22 Pages 224301,1-224301,10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Starting from an empirical force constant model of valence interactions and calculating by Ewalds method the ion-ion force constants, we derive the dynamical matrix for a monolayer crystal of hexagonal boron nitride (h-BN). The phonon dispersion relations are calculated. The interplay between valence and Coulomb forces is discussed. It is shown by analytical methods that the longitudinal and the transverse optical (LO and TO) phonon branches for in-plane motion are degenerate at the Γ point of the Brillouin zone. Away from Γ, the LO branch exhibits pronounced overbending. It is found that the nonanalytic Coulomb contribution to the dynamical matrix causes a linear increase of the LO branch with increasing wave vector starting at Γ. This effect is general for two-dimensional (2D) ionic crystals. Performing a long-wavelength expansion of the dynamical matrix, we use Borns perturbation method to calculate the elastic constants (tension coefficients). Since the crystal is noncentrosymmetric, internal displacements due to relative shifts between the two sublattices (B and N) contribute to the elastic constants. These internal displacements are responsible for piezoelectric and dielectric phenomena. The piezoelectric stress constant and the dielectric susceptibility of 2D h-BN are calculated.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000273228500045 Publication Date 2009-12-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 96 Open Access
Notes Approved Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:80576 Serial 3616
Permanent link to this record
 
 
Author Tirry, W.; Schryvers, D.
Title 3D strain fields surrounding Ni4Ti3: direct measurement and correlation with the R-phase Type P1 Proceeding
Year 2009 Publication Abbreviated Journal
Volume Issue Pages 02032,1-02032,6
Keywords P1 Proceeding; Electron microscopy for materials research (EMAT)
Abstract (up) Strain fields introduced by coherent Ni4Ti3 precipitates in austenitic Ni-Ti are believed to be a possible origin of why the R-phase transformation is introduced as an extra step before transforming to the B19'. The presence of this strain field was already confirmed in the past by conventional transmission electron microscopy (TEM) techniques and measured quantitatively by high resolution TEM (HRTEM). This time the geometrical phase method is applied on HRTEM micrographs to measure the full 3D strain tensor of the strain fields. Since each atomic resolution micrograph only results in a 2D measurement of the strain, observations in two different zone orientations are combined to retrieve the 3 x 3 strain tensor. In this work observations in a [1-1 1](B2) and [1 0-1](B2) zone orientation are used and this in case of precipitates with a diameter of around 50nm. In a next step the measured strain tensor is compared to the calculated eigenstrain of the R-phase in reference to the B2 matrix. This comparison shows that the introduced strain is very similar to the eigenstrain of one R-phase variant. Since for both structures, Ni4Ti3 and R-phase, four orientation variants are possible, each variant of the R-phase is thus able to accommodate the strain field of one of the Ni4Ti3 variants.
Address
Corporate Author Thesis
Publisher Edp Place of Publication Coutaboeuf Editor
Language Wos 000274582300036 Publication Date 2009-08-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:81953 Serial 17
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Author Vast, L.; Carpentier, L.; Lallemand, F.; Colomer, J.-F.; Van Tendeloo, G.; Fonseca, A.; Nagy, J.B.; Mekhalif, Z.; Delhalle, J.
Title Multiwalled carbon nanotubes functionalized with 7-octenyltrichlorosilane and n-octyltrichlorosilane: dispersion in Sylgard®184 silicone and Youngs modulus Type A1 Journal article
Year 2009 Publication Journal of materials science Abbreviated Journal J Mater Sci
Volume 44 Issue 13 Pages 3476-3482
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Sylgard®184/multiwalled carbon nanotube (MWNT) composites have been prepared by in situ polymerization using purified and functionalized multiwalled carbon nanotubes (f-MWNTs) as fillers. Surface modification of the MWNTs has been carried out by silanization with 7-octenyltrichlorosilane (7OTCS) and n-octyltrichlorosilane (nOTCS). The modification and dispersion of the carbon nanotubes in composites were characterized by X-ray photoelectron spectroscopy (XPS), transmission electron spectroscopy (TEM), and high-resolution transmission electron spectroscopy (HRTEM). Youngs modulus results were derived from indentation testing. It is shown that the terminal-vinyl group of 7OTCS molecules plays an essential role for both the dispersion of the f-MWNTs in the composite and its mechanical properties. At loading as low as 0.2 wt%, the Youngs modulus is shown to increase up to 50%. This is interpreted as resulting from a combination of the good compatibility in the forming silicone matrix of the MWNTs coated with a siloxane network, on the one hand, and the covalent links created between the terminal-vinyl groups and the host matrix in formation, on the other hand.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000267153200022 Publication Date 2009-04-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2461;1573-4803; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.599 Times cited 16 Open Access
Notes Iuap Approved Most recent IF: 2.599; 2009 IF: 1.471
Call Number UA @ lucian @ c:irua:77844 Serial 2245
Permanent link to this record
 
 
Author Cao, S.; Tirry, W.; van den Broek, W.; Schryvers, D.
Title Optimization of a FIB/SEM slice-and-view study of the 3D distribution of Ni4Ti3 precipitates in NiTi Type A1 Journal article
Year 2009 Publication Journal of microscopy Abbreviated Journal J Microsc-Oxford
Volume 233 Issue 1 Pages 61-68
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract (up) The 3D morphology and distribution of lenticular Ni4Ti3 precipitates in the austenitic B2 matrix of a binary Ni51Ti49 alloy has been investigated by a slice-and-view procedure in a dual-beam focused ion beam/scanning electron microscope system. Due to the weak contrast of the precipitates, proper imaging conditions need to be selected first to allow for semi-automated image treatment. Knowledgeable imaging is further needed to ensure that all variants of the precipitates are observed with equal probability, regardless of sample orientation. Finally, a volume ratio of 10.2% for the Ni4Ti3 precipitates could be calculated, summed over all variants, which yields a net composition of Ni50.27Ti49.73 for the matrix, leading to an increase of 125 degrees for the martensitic start temperature. Also, the expected relative orientation of the different variants of the precipitates could be confirmed.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000262511900008 Publication Date 2009-01-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2720;1365-2818; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.692 Times cited 22 Open Access
Notes Multimat Fwo; G0465.05 Approved Most recent IF: 1.692; 2009 IF: 1.612
Call Number UA @ lucian @ c:irua:76026 Serial 2486
Permanent link to this record
 
 
Author Damla, N.; Čevik, U.; Kobya, A.I.; Celik, A.; Van Grieken, R.; Kobya, Y.
Title Characterization of gas concrete materials used in buildings of Turkey Type A1 Journal article
Year 2009 Publication Journal of hazardous materials Abbreviated Journal
Volume 168 Issue 2/3 Pages 681-687
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (up) The activity concentration of 226Ra, 232Th and 40K in gas concrete samples collected from different suppliers and some provinces in Turkey were measured using gamma-ray spectrometry. Knowledge of radioactivity in gas concrete used in building materials enables one to assess any possible radiological risks to human health. The mean activity concentrations observed in the gas concrete samples were 82.0, 28.2 and 383.9 Bq kg−1 for 226Ra, 232Th and 40K, respectively. The radium equivalent activity, external and internal hazard indices as well as terrestrial absorbed dose and annual effective dose rate was calculated. The results indicate that the radium equivalent activity values of gas concrete samples are lower than the limit of 370 Bq kg−1, equivalent to a gamma-dose of 1.5 mSv y−1. Moreover, mass attenuation coefficients were measured in some gas concrete samples. It was found that the mass attenuation coefficients decreased with increasing photon energies. Also, chemical compositions and structural analysis (XRD and SEM) of the gas concrete samples were investigated.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000268200700014 Publication Date 2009-02-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3894 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:77256 Serial 7621
Permanent link to this record
 
 
Author Hadermann, J.; Abakumov, A.M.; Adkin, J.J.; Hayward, M.A.
Title Topotactic reduction as a route to new close-packed anion deficient perovskites: structure and magnetism of 4H-BaMnO2+x Type A1 Journal article
Year 2009 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
Volume 131 Issue 30 Pages 10598-10604
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) The anion-deficient perovskite 4H-BaMnO2+x has been obtained by a topotactic reduction, with LiH, of the hexagonal perovskite 4H-BaMnO3−x. The crystal structure of 4H-BaMnO2+x was solved using electron diffraction and X-ray powder diffraction and further refined using neutron powder diffraction (S.G. Pnma, a = 10.375(2) Å, b = 9.466(2) Å, c = 11.276(3) Å, at 373 K). The orthorhombic superstructure arises from the ordering of oxygen vacancies within a 4H (chch) stacking of close packed c-type BaO2.5 and h-type BaO1.5 layers. The ordering of the oxygen vacancies transforms the Mn2O9 units of face-sharing MnO6 octahedra into Mn2O7 (two corner-sharing tetrahedra) and Mn2O6 (two edge-sharing tetrahedra) groups. The Mn2O7 and Mn2O6 groups are linked by corner-sharing into a three-dimensional framework. The structures of the BaO2.5 and BaO1.5 layers are different from those observed previously in anion-deficient perovskites providing a new type of order pattern of oxygen atoms and vacancies in close packed structures. Magnetization measurements and neutron diffraction data reveal 4H-BaMnO2+x adopts an antiferromagnetically ordered state below TN ≈ 350 K.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000268644400056 Publication Date 2009-07-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.858 Times cited 25 Open Access
Notes Approved Most recent IF: 13.858; 2009 IF: 8.580
Call Number UA @ lucian @ c:irua:77928 Serial 3681
Permanent link to this record
 
 
Author Martens, T.; Brok, W.J.M.; van Dijk, J.; Bogaerts, A.
Title On the regime transitions during the formation of an atmospheric pressure dielectric barrier glow discharge Type A1 Journal article
Year 2009 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 42 Issue 12 Pages 122002,1-122002,5
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) The atmospheric pressure dielectric barrier discharge in helium is a pulsed discharge in nature. If during the electrical current pulse a glow discharge is reached, then this pulse will last only a few microseconds in operating periods of sinusoidal voltage with lengths of about 10 to 100 µs. In this paper we demonstrate that right before a glow discharge is reached, the discharge very closely resembles the commonly assumed Townsend discharge structure, but actually contains some significant differing features and hence should not be considered as a Townsend discharge. In order to clarify this, we present calculation results of high time and space resolution of the pulse formation. The results indicate that indeed a maximum of ionization is formed at the anode, but that the level of ionization remains high and that the electric field at that time is significantly disturbed. Our results also show where this intermediate structure comes from.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000266639300002 Publication Date 2009-05-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727;1361-6463; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited 21 Open Access
Notes Approved Most recent IF: 2.588; 2009 IF: 2.083
Call Number UA @ lucian @ c:irua:76458 Serial 2450
Permanent link to this record
 
 
Author Horemans, B.; Krata, A.; Buczyńska, A.J.; Dirtu, A.C.; van Meel, K.; Van Grieken, R.; Bencs, L.
Title Major ionic species in size-segregated aerosols and associated gaseous pollutants at a coastal site on the Belgian North Sea Type A1 Journal article
Year 2009 Publication Journal of environmental monitoring Abbreviated Journal
Volume 11 Issue 3 Pages 670-677
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (up) The chemical composition of airborne particulate matter (PM) was studied at a coastal region near De Haan, Belgium, during a winterspring and a summer campaign in 2006. The major ionic components of size-segregated PM, i.e. NH4+, Na+, K+, Mg2+, Ca2+, Cl-, NO3-, and SO42-, and related gaseous pollutants (SO2, NO2, NH3, HNO2, and HNO3) were monitored on a daily basis. Air mass backward-trajectories aided in evaluating the origin of the diurnal pollution load. This was characterised with high levels of fine secondary inorganic aerosols (NH4+, NO3-, and non-sea-salt SO42-) for continental air masses, and sea-salts as the dominant species in coarse maritime aerosols. Seasonal variations in the level of major ionic species were explained by weather conditions and the release of dimethyl sulfide from marine regions. This species was responsible for an increased sea-salt Cl- depletion during summer (56%), causing elevated levels of HCl. Neutralisation ratios for the coarse fraction (0.60.8) suggested a depleted NH4+ level, while that for the fine fraction (1.11.3) had definitely an excess of NH4+, formed by the neutralisation of HCl. The results of factor analysis and the extent of SO2 oxidation indicated that the major ionic species originated from both local and remote sources, classifying the Belgian coastal region as a combined sourcereceptor area of air pollution.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000264098400022 Publication Date 2008-12-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1464-0325; 1464-0333 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:74341 Serial 8196
Permanent link to this record
 
 
Author Tarakina, N.V.; Zubkov, V.G.; Leonidov, I.I.; Tyutunnik, A.P.; Surat, L.L.; Hadermann, J.; Van Tendeloo, G.
Title Crystal structure of the group of optical materials Ln2MeGe4O12 (Me = Ca, Mn) Type A1 Journal article
Year 2009 Publication Zeitschrift für Kristallographie Abbreviated Journal
Volume Issue S:30 Pages 401-406
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) The crystal structure of the group of optical materials Ln2MeGe4O12, Ln = Eu, Gd, Dy-Lu, Y; Me = Ca, Mn and of the solid solution (Y1-xErx)2CaGe4O12 (x = 0 – 1), promising materials for photonics, has been studied in detail. The crystal structure of all compounds exhibit two alternating layers: one formed by Ln and Me atoms and another by cyclic [Ge4O12]8- anions.
Address
Corporate Author Thesis
Publisher Place of Publication München Editor
Language Wos 000271325700028 Publication Date 2009-08-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0930-486X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 7 Open Access
Notes Iap Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:79988 Serial 575
Permanent link to this record
 
 
Author Abakumov, A.M.; Hadermann, J.; Tsirlin, A.A.; Tan, H.; Verbeeck, J.; Zhang, H.; Dikarev, E.V.; Shpanchenko, R.V.; Antipov, E.V.
Title Original close-packed structure and magnetic properties of the Pb4Mn9O20 manganite Type A1 Journal article
Year 2009 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume 182 Issue 8 Pages 2231-2238
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) The crystal structure of the Pb4Mn9O20 compound (previously known as Pb0.43MnO2.18) was solved from powder X-ray diffraction, electron diffraction, and high resolution electron microscopy data (S.G. Pnma, a=13.8888(2) Å, b=11.2665(2) Å, c=9.9867(1) Å, RI=0.016, RP=0.047). The structure is based on a 6H (cch)2 close packing of pure oxygen h-type (O16) layers alternating with mixed c-type (Pb4O12) layers. The Mn atoms occupy octahedral interstices formed by the oxygen atoms of the close-packed layers. The MnO6 octahedra share edges within the layers, whereas the octahedra in neighboring layers are linked through corner sharing. The relationship with the closely related Pb3Mn7O15 structure is discussed. Magnetization measurements reveal a peculiar magnetic behavior with a phase transition at 52 K, a small net magnetization below the transition temperature, and a tendency towards spin freezing.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000269066400035 Publication Date 2009-06-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 5 Open Access
Notes The authors are grateful to Christoph Geibel for the help in magnetization measurements. A.Ts. acknowledges MPI CKS for hospitality and financial support during the stay. E.D. thanks the National Science Foundation (CHE-0718900) for financial support. This work was supported by the Russian Foundation of Basic Research (RFBR Grants 07-03-00664-a, 06-03-90168-a and 07-03-00890-a). The authors acknowledge financial support from the European Union under the Framework 6 program under a contract for an Integrated Infrastructure Initiative. Reference 026019 ESTEEM. Approved Most recent IF: 2.299; 2009 IF: 2.340
Call Number UA @ lucian @ c:irua:78935UA @ admin @ c:irua:78935 Serial 2529
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