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Author Rusakov, D.; Abakumov, A.M.; Yamaura, K.; Belik, A.A.; Van Tendeloo, G.; Takayama-Muromachi, E.
  Title Structural evolution of the BiFeO3-LaFeO3 system Type A1 Journal article
  Year 2011 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 23 Issue 2 Pages 285-292
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The (1 − x)BiFeO3−xLaFeO3 system has been investigated and characterized by room-temperature and high-temperature laboratory and synchrotron powder X-ray diffraction, electron diffraction, high-resolution transmission electron microscopy, differential scanning calorimetry, and magnetization measurements. At room temperature, the ferroelectric R3c phase is observed for 0.0 ≤ x ≤ 0.10. The PbZrO3-related √2ap × 2√2ap × 4ap superstructure (where ap is the parameter of the cubic perovskite subcell) is observed for Bi0.82La0.18FeO3, while an incommensurately modulated phase is formed for 0.19 ≤ x ≤ 0.30 with the √2ap × 2ap × √2ap basic unit cell. The GdFeO3-type phase with space group Pnma (√2ap × 2ap × √2ap) is stable at 0.50 ≤ x ≤ 1. Bi0.82La0.18FeO3 has no detectable homogeneity range (space group Pnam, a = 5.6004(1) Å, b = 11.2493(3) Å, c = 15.6179(3) Å). The incommensurately modulated Bi0.75La0.25FeO3 structure was solved from synchrotron X-ray powder diffraction data (Imma(00γ)s00 superspace group, a = 5.5956(1) Å, b = 7.8171(1) Å, c = 5.62055(8) Å, q = 0.4855(4)c*, RP = 0.023, RwP = 0.033). In this structure, cooperative displacements of the Bi and O atoms occur, which order within the (AO) (where A = Bi, La) layers, resulting in an antipolar structure. Local fluctuations of the intralayer antipolar ordering are compensated by an interaction with the neighboring (AO) layers. A coupling of the antipolar displacements with the cooperative tilting distortion of the perovskite octahedral framework is proposed as the origin of the incommensurability. All the phases transform to the GdFeO3-type structure at high temperatures. Bi0.82La0.18FeO3 shows an intermediate PbZrO3-type phase with √2ap × 2√2ap × 2ap (space group Pbam; a = 5.6154(2) Å, b = 11.2710(4) Å, and c = 7.8248(2) Å at 570 K). The compounds in the compositional range of 0.18 ≤ x ≤ 0.95 are canted antiferromagnets.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000286160800021 Publication Date 2010-12-23
  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 133 Open Access
  Notes Approved Most recent IF: 9.466; 2011 IF: 7.286
  Call Number UA @ lucian @ c:irua:88650 Serial 3236
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Author Eckert, M.; Mortet, V.; Zhang, L.; Neyts, E.; Verbeeck, J.; Haenen, ken; Bogaerts, A.
  Title Theoretical investigation of grain size tuning during prolonged bias-enhanced nucleation Type A1 Journal article
  Year 2011 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 23 Issue 6 Pages 1414-1423
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract In this paper, the effects of prolonged bias-enhanced nucleation (prolonged BEN) on the growth mechanisms of diamond are investigated by molecular dynamics (MD) and combined MD-Metropolis Monte Carlo (MD-MMC) simulations. First, cumulative impacts of CxHy+ and Hx+ on an a-C:H/nanodiamond composite were simulated; second, nonconsecutive impacts of the dominant ions were simulated in order to understand the observed phenomena in more detail. As stated in the existing literature, the growth of diamond structures during prolonged BEN is a process that takes place below the surface of the growing film. The investigation of the penetration behavior of CxHy+ and Hx+ species shows that the carbon-containing ions remain trapped within this amorphous phase where they dominate mechanisms like precipitation of sp3 carbon clusters. The H+ ions, however, penetrate into the crystalline phase at high bias voltages (>100 V), destroying the perfect diamond structure. The experimentally measured reduction of grain sizes at high bias voltage, reported in the literature, might thus be related to penetrating H+ ions. Furthermore, the CxHy+ ions are found to be the most efficient sputtering agents, preventing the build up of defective material.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000288291400011 Publication Date 2011-02-23
  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 9 Open Access
  Notes Iwt; Fwo; Esteem 026019; Iap Approved Most recent IF: 9.466; 2011 IF: 7.286
  Call Number UA @ lucian @ c:irua:87642 Serial 3605
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Author Idrissi, H.; Wang, B.; Colla, M.S.; Raskin, J.P.; Schryvers, D.; Pardoen, T.
  Title Ultrahigh strain hardening in thin palladium films with nanoscale twins Type A1 Journal article
  Year 2011 Publication Advanced materials Abbreviated Journal Adv Mater
  Volume (up) 23 Issue 18 Pages 2119-2122
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Nanocrystalline Pd thin films containing coherent growth twin boundaries are deformed using on-chip nanomechanical testing. A large work-hardening capacity is measured. The origin of the observed behavior is unraveled using transmission electron microscopy and shows specific dislocations and twin boundaries interactions. The results indicate the potential for large strength and ductility balance enhancement in Pd films, as needed in membranes for H technologies.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Weinheim Editor
  Language Wos 000291164200013 Publication Date 2011-04-04
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0935-9648; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 19.791 Times cited 57 Open Access
  Notes Iap Approved Most recent IF: 19.791; 2011 IF: 13.877
  Call Number UA @ lucian @ c:irua:90103 Serial 3794
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Author Kazakov, S.M.; Abakumov, A.M.; Perz-Mato, J.M.; Ovchinnikov, A.V.; Roslova, M.V.; Boltalin, A.I.; Morozov, I.V.; Antipov, E.V.; Van Tendeloo, G.
  Title Uniform patterns of Fe-vacancy ordering in the Kx(Fe,Co)2-ySe2 superconductors Type A1 Journal article
  Year 2011 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 23 Issue 19 Pages 4311-4316
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The Fe-vacancy ordering patterns in the superconducting KxFe2ySe2 and nonsuperconducting Kx(Fe,Co)2ySe2 samples have been investigated by electron diffraction and high angle annular dark field scanning transmission electron microscopy. The Fe-vacancy ordering occurs in the ab plane of the parent ThCr2Si2-type structure, demonstrating two types of patterns. Superstructure I retains the tetragonal symmetry and can be described with the aI = bI = as√5 (as is the unit cell parameter of the parent ThCr2Si2-type structure) supercell and I4/m space group. Superstructure II reduces the symmetry to orthorhombic with the aII = as√2, bII = 2as√2 supercell and the Ibam space group. This type of superstructure is observed for the first time in KxFe2ySe2. The Fe-vacancy ordering is inhomogeneous: the disordered areas interleave with the superstructures I and II in the same crystallite. The observed superstructures represent the compositionally dependent uniform ordering patterns of two species (the Fe atoms and vacancies) on a square lattice. More complex uniform ordered configurations, including compositional stripes, can be predicted for different chemical compositions of the KxFe2ySe2 (0 < y < 0.5) solid solutions.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000295487800005 Publication Date 2011-09-13
  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 20 Open Access
  Notes Approved Most recent IF: 9.466; 2011 IF: 7.286
  Call Number UA @ lucian @ c:irua:92805 Serial 3810
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Author Van Tendeloo, G.; Bals, S.; Van Aert, S.; Verbeeck, J.; van Dyck, D.
  Title Advanced electron microscopy for advanced materials Type A1 Journal article
  Year 2012 Publication Advanced materials Abbreviated Journal Adv Mater
  Volume (up) 24 Issue 42 Pages 5655-5675
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Vision lab
  Abstract The idea of this Review is to introduce newly developed possibilities of advanced electron microscopy to the materials science community. Over the last decade, electron microscopy has evolved into a full analytical tool, able to provide atomic scale information on the position, nature, and even the valency atoms. This information is classically obtained in two dimensions (2D), but can now also be obtained in 3D. We show examples of applications in the field of nanoparticles and interfaces.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Weinheim Editor
  Language Wos 000310602200001 Publication Date 2012-08-21
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0935-9648; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 19.791 Times cited 107 Open Access
  Notes This work was supported by funding from the European Research Council under the 7th Framework Program (FP7), ERC grant No 246791 – COUNTATOMS. J.V. Acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. The authors gratefully acknowledge funding from the Research Foundation Flanders (FWO, Belgium). The Qu-Ant-EM microscope was partly funded by the Hercules Fund from the Flemish Government. We thank Rafal Dunin-Borkowski for providing Figure 5d. The authors would like to thank the colleagues who have contributed to this work over the years, including K.J. Batenburg, R. Erni, B. Goris, F. Leroux, H. Lichte, A. Lubk, B. Partoens, M. D. Rossell, P. Schattschneider, B. Schoeters, D. Schryvers, H. Tan, H. Tian, S. Turner, M. van Huis. ECASJO_; Approved Most recent IF: 19.791; 2012 IF: 14.829
  Call Number UA @ lucian @ c:irua:100470UA @ admin @ c:irua:100470 Serial 70
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Author Casavola, M.; van Huis, M.A.; Bals, S.; Lambert, K.; Hens, Z.; Vanmaekelbergh, D.
  Title Anisotropic cation exchange in PbSe/CdSe core/shell nanocrystals of different geometry Type A1 Journal article
  Year 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 24 Issue 2 Pages 294-302
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract We present a study of Cd2+-for-Pb2+ exchange in PbSe nanocrystals (NCs) with cube, star, and rod shapes. Prolonged temperature-activated cation exchange results in PbSe/CdSe heterostructured nanocrystals (HNCs) that preserve their specific overall shape, whereas the PbSe core is strongly faceted with dominance of {111} facets. Hence, cation exchange proceeds while the Se anion lattice is preserved, and well-defined {111}/{111} PbSe/CdSe interfaces develop. Interestingly, by quenching the reaction at different stages of the cation exchange new structures have been isolated, such as coreshell nanorods, CdSe rods that contain one or two separated PbSe dots and fully zinc blende CdSe nanorods. The crystallographically anisotropic cation exchange has been characterized by a combined HRTEM/HAADF-STEM study of heterointerface evolution over reaction time and temperature. Strikingly, Pb and Cd are only intermixed at the PbSe/CdSe interface. We propose a plausible model for the cation exchange based on a layer-by-layer replacement of Pb2+ by Cd2+ enabled by a vacancy-assisted cation migration mechanism.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000299367500008 Publication Date 2011-11-17
  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 136 Open Access
  Notes Esteem 026019 Approved Most recent IF: 9.466; 2012 IF: 8.238
  Call Number UA @ lucian @ c:irua:94211 Serial 124
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Author Turner, S.; Verbeeck, J.; Ramezanipour, F.; Greedan, J.E.; Van Tendeloo, G.; Botton, G.A.
  Title Atomic resolution coordination mapping in Ca2FeCoO5 brownmillerite by spatially resolved electron energy-loss spectroscopy Type A1 Journal article
  Year 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 24 Issue 10 Pages 1904-1909
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Using a combination of high-angle annular dark field scanning transmission electron microscopy and atomically resolved electron energy-loss spectroscopy at high energy resolution in an aberration-corrected electron microscope, we demonstrate the capability of coordination mapping in complex oxides. Brownmillerite compound Ca2FeCoO5, consisting of repetitive octahedral and tetrahedral coordination layers with Fe and Co in a fixed 3+ valency, is selected to demonstrate the principle of atomic resolution coordination mapping. Analysis of the Co-L2,3 and the Fe-L2,3 edges shows small variations in the fine structure that can be specifically attributed to Co/Fe in tetrahedral or in octahedral coordination. Using internal reference spectra, we show that the coordination of the Fe and Co atoms in the compound can be mapped at atomic resolution.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000304237500024 Publication Date 2012-04-25
  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 33 Open Access
  Notes A.M. Abakumov is thanked for fruitful discussions. S.T. gratefully acknowledges the Fund for Scientific Research Flanders (FWO). J.E.G. and GAB. acknowledge the support of the NSERC of Canada through Discovery Grants. The Canadian Centre for Electron Microscopy is a National Facility supported by NSERC and McMaster University and was funded by the Canada Foundation for Innovation and the Ontario Government. Part of this work was supported by funding from the European Research Council under the FP7, ERC Grant N 246791 COUNTATOMS and ERC Starting Grant N 278510 VORTEX. The EMAT microscope is partially funded by the Hercules fund of the Flemish Government. ECASJO_; Approved Most recent IF: 9.466; 2012 IF: 8.238
  Call Number UA @ lucian @ c:irua:98379UA @ admin @ c:irua:98379 Serial 175
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Author Adamson, P.; Hadermann, J.; Smura, C.F.; Rutt, O.J.; Hyett, G.; Free, D.G.; Clarke, S.J.
  Title Competing magnetic structures and the evolution of copper ion/vacancy ordering with composition in the manganite oxide chalcogenides Sr2MnO2Cu1.5(S1-xSex)2 Type A1 Journal article
  Year 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 24 Issue 14 Pages 2802-2816
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The series Sr2MnO2Cu1.5(S1-xSex)(2) (0 <= x <= 1) contains mixed-valent Mn ions (Mn2+/Mn3+) in MnO2 sheets which are separated by copper-deficient antifluorite-type Cu(2-delta)Ch(2) layers with delta similar to 0.5. The compounds crystallize in the structure type first described for Sr2Mn3Sb2O2 and are described in the I4/mmm space group at ambient temperatures. Below about 250 K, ordering between Cu+ ions and tetrahedral vacancies occurs which is long-range and close to complete in the sulfide-containing end member of the series Sr2MnO2Cu1.5S2 but which occurs over shorter length scales as the selenide content increases. The superstructure is an orthorhombic 2 root 2a x root 2a x c expansion in Ibam of the room temperature cell. For x > 0.3 there are no superstructure reflections evident in the X-ray or neutron diffraction patterns, and the I4/mmm description is valid for the average structure at all temperatures. However, in the pure selenide end member, Sr2MnO2Cu1.5Se2, diffuse scattering in electron diffractograms and modulation in high resolution lattice image profiles may arise from short-range Cu/vacancy order. All members of the series exhibit long-range magnetic order. In the sulfide-rich end member and in compounds with x < 0.1 in the formula Sr2MnO2Cu1.5(S1-xSex)(2), which show well developed superstructures due to long-range Cu/vacancy order, the magnetic structure has a (1/4 1/4 0) propagation vector in which ferromagnetic zigzag chains of Mn moments in the MnO2 sheets are coupled antiferromagnetically in an arrangement described as the CE-type magnetic structure and found in many mixed-valent perovskite and Ruddlesden-Popper type oxide manganites. In these cases the magnetic cell is an a x 2b x c expansion of the low temperature Ibam structural cell. For x >= 0.2 in the formula Sr2MnO2Cu1.5(S1-xSex)(2) the magnetic structure has a (0 0 0) propagation vector and is similar to the A-type structure, also commonly adopted by some perovskite-related manganites, in which the Mn moments in the MnO2 sheets are coupled ferromagnetically and long-range antiferromagnetic order results from antiferromagnetic coupling between planes. In the region of the transition between the two different structural and magnetic long-range ordering schemes (0.1 < x < 0.2) the two magnetic structures coexist in the same sample. The evolution of the competition between magnetic ordering schemes and the length scale of the structural order with composition in Sr2MnO2Cu1.5(S1-xSex)(2) suggest that the changes in magnetic and structural order are related consequences of the introduction of chemical disorder.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000306674200024 Publication Date 2012-06-20
  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 11 Open Access
  Notes Esteem 026019 Approved Most recent IF: 9.466; 2012 IF: 8.238
  Call Number UA @ lucian @ c:irua:100839 Serial 435
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Author Hadermann, J.; Abakumov, A.; Van Rompaey, S.; Perkisas, T.; Filinchuk, Y.; Van Tendeloo, G.
  Title Crystal structure of a lightweight borohydride from submicrometer crystallites by precession electron diffraction Type A1 Journal article
  Year 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 24 Issue 17 Pages 3401-3405
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract We demonstrate that precession electron diffraction at low-dose conditions can be successfully applied for structure analysis of extremely electron-beam-sensitive materials. Using LiBH4 as a test material, complete structural information, including the location of the H atoms, was obtained from submicrometer-sized crystallites. This demonstrates for the first time that, where conventional transmission electron microscopy techniques fail, quantitative precession electron diffraction can provide structural information from submicrometer particles of such extremely electron-beam-sensitive materials as complex lightweight hydrides. We expect the precession electron diffraction technique to be a useful tool for nanoscale investigations of thermally unstable lightweight hydrogen-storage materials.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000308833400012 Publication Date 2012-08-01
  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 17 Open Access
  Notes Approved Most recent IF: 9.466; 2012 IF: 8.238
  Call Number UA @ lucian @ c:irua:101845 Serial 567
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Author Van Aert, S.; Turner, S.; Delville, R.; Schryvers, D.; Van Tendeloo, G.; Salje, E.K.H.
  Title Direct observation of ferrielectricity at ferroelastic domain boundaries in CaTiO3 by electron microscopy Type A1 Journal article
  Year 2012 Publication Advanced materials Abbreviated Journal Adv Mater
  Volume (up) 24 Issue 4 Pages 523-527
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract High-resolution aberration-corrected transmission electron microscopy aided by statistical parameter estimation theory is used to quantify localized displacements at a (110) twin boundary in orthorhombic CaTiO3. The displacements are 36 pm for the Ti atoms and confined to a thin layer. This is the first direct observation of the generation of ferroelectricity by interfaces inside this material which opens the door for domain boundary engineering.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Weinheim Editor
  Language Wos 000299156400011 Publication Date 2011-12-24
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0935-9648; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 19.791 Times cited 150 Open Access
  Notes Fwo Approved Most recent IF: 19.791; 2012 IF: 14.829
  Call Number UA @ lucian @ c:irua:94110 Serial 717
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Author Carraro, G.; Maccato, C.; Gasparotto, A.; Montini, T.; Turner, S.; Lebedev, O.I.; Gombac, V.; Adami, G.; Van Tendeloo, G.; Barreca, D.; Fornasiero, P.;
  Title Enhanced hydrogen production by photoreforming of renewable oxygenates through nanostructured Fe2O3 polymorphs Type A1 Journal article
  Year 2014 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
  Volume (up) 24 Issue 3 Pages 372-378
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Sunlight-driven hydrogen production via photoreforming of aqueous solutions containing renewable compounds is an attractive option for sustainable energy generation with reduced carbon footprint. Nevertheless, the absence of photocatalysts combining high efficiency and stability upon solar light activation has up to date strongly hindered the development of this technology. Herein, two scarcely investigated iron(III) oxide polymorphs, β- and ε-Fe2O3, possessing a remarkable activity in sunlight-activated H2 generation from aqueous solutions of renewable oxygenates (i.e., ethanol, glycerol, glucose) are reported. For β-Fe2O3 and ε-Fe2O3, H2 production rates up to 225 and 125 mmol h−1 m−2 are obtained, with significantly superior performances with respect to the commonly investigated α-Fe2O3.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Weinheim Editor
  Language Wos 000332832500011 Publication Date 2013-10-08
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1616-301X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 12.124 Times cited 95 Open Access
  Notes Countatoms; Hercules; Fwo Approved Most recent IF: 12.124; 2014 IF: 11.805
  Call Number UA @ lucian @ c:irua:113090 Serial 1051
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Author Dachraoui, W.; Hadermann, J.; Abakumov, A.M.; Tsirlin, A.A.; Batuk, D.; Glazyrin, K.; McCammon, C.; Dubrovinsky, L.; Van Tendeloo, G.
  Title Local oxygen-vacancy ordering and twinned octahedral tilting pattern in the Bi0.81Pb0.19FeO2.905 cubic perovskite Type A1 Journal article
  Year 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 24 Issue 7 Pages 1378-1385
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The structure of Bi0.81Pb0.19FeO2.905 was investigated on different length scales using a combination of electron diffraction, high-resolution scanning transmission electron microscopy, synchrotron X-ray powder diffraction, and Mössbauer spectroscopy. In the 80300 K temperature range, the average crystal structure of Bi0.81Pb0.19FeO2.905 is a cubic Pm3̅m perovskite with a = 3.95368(3) Å at T = 300 K. The (Pb2+, Bi3+) cations and O2 anions are randomly displaced along the 110 cubic directions, indicating the steric activity of the lone pair on the Pb2+ and Bi3+ cations and a tilting distortion of the perovskite framework. The charge imbalance induced by the heterovalent Bi3+ → Pb2+ substitution is compensated by the formation of oxygen vacancies preserving the trivalent state of the Fe cations. On a short scale, oxygen vacancies are located in anion-deficient (FeO1.25) layers that are approximately 6 perovskite unit cells apart and transform every sixth layer of the FeO6 octahedra into a layer with a 1:1 mixture of corner-sharing FeO4 tetrahedra and FeO5 tetragonal pyramids. The anion-deficient layers act as twin planes for the octahedral tilting pattern of adjacent perovskite blocks. They effectively randomize the octahedral tilting and prevent the cooperative distortion of the perovskite framework. The disorder in the anion sublattice impedes cooperative interactions of the local dipoles induced by the off-center displacements of the Pb and Bi cations. Magnetic susceptibility measurements evidence the antiferromagnetic ordering in Bi0.81Pb0.19FeO2.905 at low temperatures.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000302487500018 Publication Date 2012-03-13
  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 27 Open Access
  Notes Approved Most recent IF: 9.466; 2012 IF: 8.238
  Call Number UA @ lucian @ c:irua:97389 Serial 1829
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Author Wang, J.T.W.; Cabana, L.; Bourgognon, M.; Kafa, H.; Protti, A.; Venner, K.; Shah, A.M.; Sosabowski, J.K.; Mather, S.J.; Roig, A.; Ke, X.; Van Tendeloo, G.; de Rosales, R.T.M.; Tobias, G.; Al-Jamal, K.T.
  Title Magnetically decorated multiwalled carbon nanotubes as dual MRI and SPECT contrast agents Type A1 Journal article
  Year 2014 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
  Volume (up) 24 Issue 13 Pages 1880-1894
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Carbon nanotubes (CNTs) are one of the most promising nanomaterials to be used in biomedicine for drug/gene delivery as well as biomedical imaging. This study develops radio-labeled, iron oxide-decorated multiwalled CNTs (MWNTs) as dual magnetic resonance (MR) and single photon emission computed tomography (SPECT) contrast agents. Hybrids containing different amounts of iron oxide are synthesized by in situ generation. Physicochemical characterisations reveal the presence of superparamagnetic iron oxide nanoparticles (SPION) granted the magnetic properties of the hybrids. Further comprehensive examinations including high resolution transmission electron microscopy (HRTEM), fast Fourier transform simulations, X-ray diffraction, and X-ray photoelectron spectroscopy assure the conformation of prepared SPION as γ-Fe2O3. High r2 relaxivities are obtained in both phantom and in vivo MRI compared to the clinically approved SPION Endorem. The hybrids are successfully radio labeled with technetium-99m through a functionalized bisphosphonate and enable SPECT/CT imaging and γ-scintigraphy to quantitatively analyze the biodistribution in mice. No abnormality is found by histological examination and the presence of SPION and MWNT are identified by Perls stain and Neutral Red stain, respectively. TEM images of liver and spleen tissues show the co-localization of SPION and MWNTs within the same intracellular vesicles, indicating the in vivo stability of the hybrids after intravenous injection. The results demonstrate the capability of the present SPIONMWNT hybrids as dual MRI and SPECT contrast agents for in vivo use.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Weinheim Editor
  Language Wos 000333674100007 Publication Date 2013-11-19
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1616-301X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 12.124 Times cited 50 Open Access
  Notes Countatoms; Fp7; Esteem2; esteem2_ta Approved Most recent IF: 12.124; 2014 IF: 11.805
  Call Number UA @ lucian @ c:irua:111589 Serial 1891
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Author Angelomé, P.C.; Heidari Mezerji, H.; Goris, B.; Pastoriza-Santos, I.; Pérez-Juste, J.; Bals, S.; Liz-Marzán, L.M.
  Title Seedless synthesis of single crystalline Au nanoparticles with unusual shapes and tunable LSPR in the near-IR Type A1 Journal article
  Year 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 24 Issue 7 Pages 1393-1399
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The plasmonic properties of metal nanoparticles have acquired great importance because of their potential applications in very diverse fields. Metal nanoparticles with localized surface plasmon resonances (LSPR) in the near-infrared (NIR, 7501300 nm) are of particular interest because tissues, blood, and water display low absorption in this spectral range, thus facilitating biomedical applications. Cetyltrimethylammonium chloride (CTAC) was used to induce the seedless formation of highly anisotropic, twisted single crystalline Au nanoparticles in a single step. The LSPR of the obtained particles can be tuned from 600 nm up to 1400 nm by simply changing the reaction temperature or the reagents concentrations. The tunability of the LSPR is closely associated with significant changes in the final particle morphology, which was studied by advanced electron microscopy techniques (3D Tomography and HAADF-STEM). Kinetic experiments were carried out to establish the growth mechanism, suggesting that slow kinetics together with the complexation of the gold salt precursor to CTAC are key factors favoring the formation of these anisotropic particles.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000302487500020 Publication Date 2012-03-16
  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 42 Open Access
  Notes Fwo Approved Most recent IF: 9.466; 2012 IF: 8.238
  Call Number UA @ lucian @ c:irua:97388 Serial 2959
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Author Khaletskaya, K.; Turner, S.; Tu, M.; Wannapaiboon, S.; Schneemann, A.; Meyer, R.; Ludwig, A.; Van Tendeloo, G.; Fischer, R.A.
  Title Self-directed localization of ZIF-8 thin film formation by conversion of ZnO nanolayers Type A1 Journal article
  Year 2014 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
  Volume (up) 24 Issue 30 Pages 4804-4811
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Control of localized metal-organic framework (MOF) thin film formation is a challenge. Zeolitic imidazolate frameworks (ZIFs) are an important sub-class of MOFs based on transition metals and imidazolate linkers. Continuous coatings of intergrown ZIF crystals require high rates of heterogeneous nucleation. In this work, substrates coated with zinc oxide layers are used, obtained by atomic layer deposition (ALD) or by magnetron sputtering, to provide the Zn2+ ions required for nucleation and localized growth of ZIF-8 films ([Zn(mim)(2)]; Hmim = 2-methylimidazolate). The obtained ZIF-8 films reveal the expected microporosity, as deduced from methanol adsorption studies using an environmentally controlled quartz crystal microbalance (QCM) and comparison with bulk ZIF-8 reference data. The concept is transferable to other MOFs, and is applied to the formation of [Al(OH)(1,4-ndc)](n) (ndc = naphtalenedicarboxylate) thin films derived from Al2O3 nanolayers.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Weinheim Editor
  Language Wos 000340549900010 Publication Date 2014-05-07
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1616-301X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 12.124 Times cited 77 Open Access
  Notes 312483 Esteem2; Fwo; esteem2_ta Approved Most recent IF: 12.124; 2014 IF: 11.805
  Call Number UA @ lucian @ c:irua:119215 Serial 2975
Permanent link to this record
 

 
Author Khalilov, U.; Pourtois, G.; van Duin, A.C.T.; Neyts, E.C.
  Title Self-limiting oxidation in small-diameter Si nanowires Type A1 Journal article
  Year 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 24 Issue 11 Pages 2141-2147
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract Recently, core shell silicon nanowires (Si-NWs) have been envisaged to be used for field-effect transistors and photovoltaic applications. In spite of the constant downsizing of such devices, the formation of ultrasmall diameter core shell Si-NWs currently remains entirely unexplored. We report here on the modeling of the formation of such core shell Si-NWs using a dry thermal oxidation of 2 nm diameter (100) Si nanowires at 300 and 1273 K, by means of reactive molecular dynamics simulations using the ReaxFF potential. Two different oxidation mechanisms are discussed, namely a self-limiting process that occurs at low temperature (300 K), resulting in a Si core I ultrathin SiO2 silica shell nanowire, and a complete oxidation process that takes place at a higher temperature (1273 K), resulting in the formation of an ultrathin SiO2 silica nanowire. The oxidation kinetics of both cases and the resulting structures are analyzed in detail. Our results demonstrate that precise control over the Si-core radius of such NWs and the SiOx (x <= 2.0) oxide shell is possible by controlling the growth temperature used during the oxidation process.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000305092600021 Publication Date 2012-05-18
  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 45 Open Access
  Notes Approved Most recent IF: 9.466; 2012 IF: 8.238
  Call Number UA @ lucian @ c:irua:99079 Serial 2976
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Author Dixon, E.; Hadermann, J.; Hayward, M.A.
  Title Structures and magnetism of La1-xSrxMnO3-(0.5+x)/2 (0.67\leq x\leq1) phases Type A1 Journal article
  Year 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 24 Issue 8 Pages 1486-1495
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Topotactic reduction of La1-xSrxMnO3 (0.67 <= x <= 1) phases with sodium hydride yields a series of isoelectronic materials of composition La1-xSrxMnO3-(0.5+x)/2. Lanthanum rich members of the series (0.67 <= x <= 0.83) adopt anion deficient perovskite structures with a 6-layer -OTOOT'O- stacking sequence of sheets of octahedra/square-based pyramids (O) and sheets of tetrahedra (T). The strontium rich members of the series (0.83 <= x <= 1) incorporate “step defects” into this 6-layer structure in which the OTOOT'O stacking sequence is converted into either OOTOOT' or TOOT'OO at a defect plane which runs perpendicular to the [201] lattice plane. The step defects appear to provide a mechanism to relieve lattice strain and accommodate additional anion deficiency in phases with x > 0.83. Magnetization and neutron diffraction data indicate La1-xSrxMnO3-(0.5+x)/2 phases adopt antiferromagnetically ordered states at low-temperature in which the ordered arrangement of magnetic spins is incommensurate with the crystallographic lattice.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000303092300011 Publication Date 2012-03-28
  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 13 Open Access
  Notes Esteem 026019 Approved Most recent IF: 9.466; 2012 IF: 8.238
  Call Number UA @ lucian @ c:irua:98253 Serial 3318
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Author Spyrou, K.; Potsi, G.; Diamanti, E.K.; Ke, X.; Serestatidou, E.; Verginadis, I.I.; Velalopoulou, A.P.; Evangelou, A.M.; Deligiannakis, Y.; Van Tendeloo, G.; Gournis, D.; Rudolf, P.;
  Title Towards Novel Multifunctional Pillared Nanostructures: Effective Intercalation of Adamantylamine in Graphene Oxide and Smectite Clays Type A1 Journal article
  Year 2014 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
  Volume (up) 24 Issue 37 Pages 5841-5850
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Multifunctional pillared materials are synthesized by the intercalation of cage-shaped adamantylamine (ADMA) molecules into the interlayer space of graphite oxide (GO) and aluminosilicate clays. The physicochemical and structural properties of these hybrids, determined by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Raman and X-ray photoemission (XPS) spectroscopies and transmission electron microscopy (TEM) show that they can serve as tunable hydrophobic/hydrophilic and stereospecific nanotemplates. Thus, in ADMA-pillared clay hybrids, the phyllomorphous clay provides a hydrophilic nanoenvironment where the local hydrophobicity is modulated by the presence of ADMA moieties. On the other hand, in the ADMA-GO hybrid, both the aromatic rings of GO sheets and the ADMA molecules define a hydrophobic nanoenvironment where sp(3)-oxo moieties (epoxy, hydroxyl and carboxyl groups), present on GO, modulate hydrophilicity. As test applications, these pillared nanostructures are capable of selective/stereospecific trapping of small chlorophenols or can act as cytotoxic agents.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Weinheim Editor
  Language Wos 000342794500008 Publication Date 2014-07-19
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1616-301X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 12.124 Times cited 19 Open Access
  Notes Approved Most recent IF: 12.124; 2014 IF: 11.805
  Call Number UA @ lucian @ c:irua:121085 Serial 3686
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Author Dendooven, J.; Goris, B.; Devloo-Casier, K.; Levrau, E.; Biermans, E.; Baklanov, M.R.; Ludwig, K.F.; van der Voort, P.; Bals, S.; Detavernier, C.
  Title Tuning the pore size of ink-bottle mesopores by atomic layer deposition Type A1 Journal article
  Year 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 24 Issue 11 Pages 1992-1994
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000305092600002 Publication Date 2012-05-03
  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 52 Open Access
  Notes Fwo Approved Most recent IF: 9.466; 2012 IF: 8.238
  Call Number UA @ lucian @ c:irua:99078 Serial 3760
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Author Abakumov, A.M.; Erni, R.; Tsirlin, A.A.; Rossell, M.D.; Batuk, D.; Nénert, G.; Van Tendeloo, G.
  Title Frustrated octahedral tilting distortion in the incommensurately modulated Li3xNd2/3-xTiO3 perovskites Type A1 Journal article
  Year 2013 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 25 Issue 13 Pages 2670-2683
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Perovskite-structured titanates with layered A-site ordering form remarkably complex superstructures. Using transmission electron microscopy, synchrotron X-ray and neutron powder diffraction, and ab initio structure relaxation, we present the structural solution of the incommensurately modulated Li3xNd2/3xTiO3 perovskites (x = 0.05, superspace group Pmmm(α1,1/2,0)000(1/2,β2 0)000, a = 3.831048(5) Å, b = 3.827977(4) Å, c = 7.724356(8) Å, q1 = 0.45131(8)a* + 1/2b*, q2 = 1/2a* + 0.41923(4)b*). In contrast to earlier conjectures on the nanoscale compositional phase separation in these materials, all peculiarities of the superstructure can be understood in terms of displacive modulations related to an intricate octahedral tilting pattern. It involves fragmenting the pattern of the out-of-phase tilted TiO6 octahedra around the a- and b-axes into antiphase domains, superimposed on the pattern of domains with either pronounced or suppressed in-phase tilt component around the c-axis. The octahedral tilting competes with the second order JahnTeller distortion of the TiO6 octahedra. This competition is considered as the primary driving force for the modulated structure. The A cations are suspected to play a role in this modulation affecting it mainly through the tolerance factor and the size variance. The reported crystal structure calls for a revision of the structure models proposed for the family of layered A-site ordered perovskites exhibiting a similar type of modulated structure.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000321809700015 Publication Date 2013-06-04
  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 23 Open Access
  Notes Countatoms Approved Most recent IF: 9.466; 2013 IF: 8.535
  Call Number UA @ lucian @ c:irua:109216 Serial 1292
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Author Verbeeck, J.; Tian, H.; Van Tendeloo, G.
  Title How to manipulate nanoparticles with an electron beam? Type A1 Journal article
  Year 2013 Publication Advanced materials Abbreviated Journal Adv Mater
  Volume (up) 25 Issue 8 Pages 1114-1117
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract
  Address
  Corporate Author Thesis
  Publisher Place of Publication Weinheim Editor
  Language Wos 000315102600003 Publication Date 2012-11-26
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0935-9648; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 19.791 Times cited 75 Open Access
  Notes FWO; VORTEX; Countatoms ECASJO_; Approved Most recent IF: 19.791; 2013 IF: 15.409
  Call Number UA @ lucian @ c:irua:105287UA @ admin @ c:irua:105287 Serial 1494
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Author Morozov, V.A.; Bertha, A.; Meert, K.W.; Van Rompaey, S.; Batuk, D.; Martinez, G.T.; Van Aert, S.; Smet, P.F.; Raskina, M.V.; Poelman, D.; Abakumov, A.M.; Hadermann, J.;
  Title Incommensurate modulation and luminescence in the CaGd2(1-x)Eu2x(MoO4)4(1-y)(WO)4y (0\leq x\leq1, 0\leq y\leq1) red phosphors Type A1 Journal article
  Year 2013 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 25 Issue 21 Pages 4387-4395
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Scheelite related compounds (A',A '') [(B',B '')O-4], with B', B '' = W and/or Mo are promising new light-emitting materials for photonic applications, including phosphor converted LEDs (light-emitting diodes). In this paper, the creation and ordering of A-cation vacancies and the effect of cation substitutions in the scheelite-type framework are investigated as a factor for controlling the scheelite-type structure and luminescent properties. CaGd2(1-x)Eu2x(MoO4)(4(1-y))(WO4)(4y) (0 <= x <= 1, 0 <= y <= 1) solid solutions with scheelite-type structure were synthesized by a solid state method, and their structures were investigated using a combination of transmission electron microscopy techniques and powder X-ray diffraction. Within this series all complex molybdenum oxides have (3 + 2)D incommensurately modulated structures with superspace group I4(1)/a(alpha,beta,0)00(-beta,alpha,0)00, while the structures of all tungstates are (3 + 1)D incommensurately modulated with superspace group I2/b(alpha beta 0)00. In both cases the modulation arises because of cation-vacancy ordering at the A site. The prominent structural motif is formed by columns of A-site vacancies running along the c-axis. These vacant columns occur in rows of two or three aligned along the [110] direction of the scheelite subcell. The replacement of the smaller Gd3+ by the larger Eu3+ at the A-sublattice does not affect the nature of the incommensurate modulation, but an increasing replacement of Mo6+ by W6+ switches the modulation from (3 + 2)D to (3 + 1)D regime. Thus, these solid solutions can be considered as a model system where the incommensurate modulation can be monitored as a function of cation nature while the number of cation vacancies at the A sites remain constant upon the isovalent cation replacement. All compounds' luminescent properties were measured, and the optical properties were related to the structural properties of the materials. CaGd2(1-x)(MoO4)(4(1-y))(WO4)(4y) phosphors emit intense red light dominated by the D-5(0)-F-7(2) transition at 612 nm, along with other transitions from the D-5(1) and D-5(0) excited states. The intensity of the 5D0-7F2 transition reaches a maximum at x = 0.5 for y = 0 and 1.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000327045000030 Publication Date 2013-09-24
  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 63 Open Access
  Notes Approved Most recent IF: 9.466; 2013 IF: 8.535
  Call Number UA @ lucian @ c:irua:112776 Serial 1594
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Author Li, Y.J.; Wang, J.J.; Ye, J.C.; Ke, X.X.; Gou, G.Y.; Wei, Y.; Xue, F.; Wang, J.; Wang, C.S.; Peng, R.C.; Deng, X.L.; Yang, Y.; Ren, X.B.; Chen, L.Q.; Nan, C.W.; Zhang, J.X.;
  Title Mechanical switching of nanoscale multiferroic phase boundaries Type A1 Journal article
  Year 2015 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
  Volume (up) 25 Issue 25 Pages 3405-3413
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Tuning the lattice degree of freedom in nanoscale functional crystals is critical to exploit the emerging functionalities such as piezoelectricity, shape-memory effect, or piezomagnetism, which are attributed to the intrinsic lattice-polar or lattice-spin coupling. Here it is reported that a mechanical probe can be a dynamic tool to switch the ferroic orders at the nanoscale multiferroic phase boundaries in BiFeO3 with a phase mixture, where the material can be reversibly transformed between the soft tetragonal-like and the hard rhombohedral-like structures. The microscopic origin of the nonvolatile mechanical switching of the multiferroic phase boundaries, coupled with a reversible 180 degrees rotation of the in-plane ferroelectric polarization, is the nanoscale pressure-induced elastic deformation and reconstruction of the spontaneous strain gradient across the multiferroic phase boundaries. The reversible control of the room-temperature multiple ferroic orders using a pure mechanical stimulus may bring us a new pathway to achieve the potential energy conversion and sensing applications.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Weinheim Editor
  Language Wos 000355992600017 Publication Date 2015-04-20
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1616-301X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 12.124 Times cited 23 Open Access
  Notes Approved Most recent IF: 12.124; 2015 IF: 11.805
  Call Number c:irua:126430 Serial 1976
Permanent link to this record
 

 
Author Afanasov, I.M.; Van Tendeloo, G.; Mateev, A.T.
  Title Production and structure of exfoliated graphite/coke composites modified by ZrO2 nanoparticles Type A1 Journal article
  Year 2010 Publication New carbon materials Abbreviated Journal
  Volume (up) 25 Issue 4 Pages 255-260
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Exfoliated graphite/coke composites modified by ZrO2 nanoparticles were produced using two different techniques and characterized by means of X-ray diffraction, scanning and transmission electron microscopy. In the first, low-density exfoliated graphite/coke blocks were dipped repeatedly and alternately in ZrO(NO3)2 and NH4OH solutions and subsequently heat treated at 1200°C in nitrogen to deposit thin layers of ZrO2 nanoparticles on the free surfaces of the carbon matrix. In the second, a mixture of expandable graphite, phenol-formaldehyde resin powder, and ZrOC2O4-modified fibrous cellulose in a sealed container was submitted to thermal shock at 900 °C followed by heat treatment at 1 200 °C in nitrogen to obtain the modified composites. The ZrO2 nanoparticles formed in the second technique were incorporated into the composites in three length scales: 6-30 nm-isolated nanoparticles and small blobs, 200-1000 nm-lengthy dendrite-like structures, and thin layer adhering to the surface of the 1-40 μm long cellulose carbon fibers.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000281534800003 Publication Date 2010-09-02
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1872-5805; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor Times cited Open Access
  Notes Iap-Vi Approved Most recent IF: NA
  Call Number UA @ lucian @ c:irua:84438 Serial 2721
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Author Retuerto, M.; Emge, T.; Hadermann, J.; Stephens, P.W.; Li, M.R.; Yin, Z.P.; Croft, M.; Ignatov, A.; Zhang, S.J.; Yuan, Z.; Jin, C.; Simonson, J.W.; Aronson, M.C.; Pan, A.; Basov, D.N.; Kotliar, G.; Greenblatt, M.;
  Title Synthesis and properties of charge-ordered thallium halide perovskites, CsTl0.5+Tl0.53+X3 (X = F or Cl) : theoretical precursors for superconductivity? Type A1 Journal article
  Year 2013 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 25 Issue 20 Pages 4071-4079
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Recently, CsTlCl3 and CsTlF3 perovskites were theoretically predicted to be potential superconductors if they were optimally doped. The syntheses of these two compounds together with a complete characterization of the samples are reported. CsTlCl3 was obtained as orange crystals in two different polymorphs: a tetragonal phase (I4/m) and a cubic phase (Fm (3) over barm). CsTlF3 was formed as a light brown powder, and also as a double cubic perovskite (Fm (3) over barm). In all three CsTlX3 phases, Tl+ and Tl3+ were located in two different crystallographic positions that accommodate their different bond lengths. In CsTlCl3, some Tl vacancies were found in the Tl+ position. The charge ordering between Tl+ and Tl3+ was confirmed by X-ray absorption and Raman spectroscopy. The Raman spectroscopy of CsTlCl3 at high pressure (58 GPa) did not indicate any phase transition to a possible single Tl2+ state. However, the highly insulating material became less resistive with an increasing high pressure, while it underwent a change in its optical properties, from transparent to deeply opaque red, indicative of a decrease in the magnitude of the band gap. The theoretical design and experimental validation of the existence of CsTlF3 and CsTlCl3 cubic perovskites are the necessary first steps in confirming the theoretical prediction of superconductivity in these materials.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000326209200017 Publication Date 2013-09-18
  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 28 Open Access
  Notes Approved Most recent IF: 9.466; 2013 IF: 8.535
  Call Number UA @ lucian @ c:irua:112248 Serial 3434
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Author Pietra, F.; van Dijk-Moes, R.J.A.; Ke, X.; Bals, S.; Van Tendeloo, G.; de Mello Donega, C.; Vanmaekelbergh, D.
  Title Synthesis of highly luminescent silica-coated CdSe/CdS nanorods Type A1 Journal article
  Year 2013 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 25 Issue 17 Pages 3427-3434
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract CdSe(core)/CdS(shell) nanorods (NRs) have been extensively investigated for their unique optical properties, such as high photoluminescence (PL) quantum efficiency (QE) and polarized light emission. The incorporation of these NRs in silica (SiO2) is of high interest, since this renders them processable in polar solvents while increasing their photochemical stability, which would be beneficial for their application in LEDs and as biolabels. We report the synthesis of highly luminescent silica-coated CdSe/CdS NRs, by using the reverse micelle method. The mechanism for the encapsulation of the NRs in silica is unravelled and shown to be strongly influenced by the NR shape and its asymmetry. This is attributed to both the different morphology and the different crystallographic nature of the facets terminating the opposite tips of the NRs. These results lead to the formation of a novel class of NR architectures, whose symmetry can be controlled by tuning the degree of coverage of the silica shell. Interestingly, the encapsulation of the NRs in silica leads to a remarkable increase in their photostability, while preserving their optical properties.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000330097900004 Publication Date 2013-08-13
  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 46 Open Access
  Notes 262348 ESMI; 246791 COUNTATOMS; Hercules Approved Most recent IF: 9.466; 2013 IF: 8.535
  Call Number UA @ lucian @ c:irua:110037 Serial 3456
Permanent link to this record
 

 
Author Van Aelst, J.; Verboekend, D.; Philippaerts, A.; Nuttens, N.; Kurttepeli, M.; Gobechiya, E.; Haouas, M.; Sree, S.P.; Denayer, J.F.M.; Martens, J.A.; Kirschhock, C.E.A.; Taulelle, F.; Bals, S.; Baron, G.V.; Jacobs, P.A.; Sels, B.F.
  Title Catalyst design by NH4OH treatment of USY zeolite Type A1 Journal article
  Year 2015 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
  Volume (up) 25 Issue 25 Pages 7130-7144
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Hierarchical zeolites are a class of superior catalysts which couples the intrinsic zeolitic properties to enhanced accessibility and intracrystalline mass transport to and from the active sites. The design of hierarchical USY (Ultra-Stable Y) catalysts is achieved using a sustainable postsynthetic room temperature treatment with mildly alkaline NH4OH ( 0.02(M)) solutions. Starting from a commercial dealuminated USY zeolite (Si/Al = 47), a hierarchical material is obtained by selective and tuneable creation of interconnected and accessible small mesopores (2- 6 nm). In addition, the treatment immediately yields the NH4+ form without the need for additional ion exchange. After NH4OH modification, the crystal morphology is retained, whereas the microporosity and relative crystallinity are decreased. The gradual formation of dense amorphous phases throughout the crystal without significant framework atom leaching rationalizes the very high material yields (>90%). The superior catalytic performance of the developed hierarchical zeolites is demonstrated in the acid-catalyzed isomerization of alpha-pinene and the metal-catalyzed conjugation of safflower oil. Significant improvements in activity and selectivity are attained, as well as a lowered susceptibility to deactivation. The catalytic performance is intimately related to the introduced mesopores, hence enhanced mass transport capacity, and the retained intrinsic zeolitic properties.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Weinheim Editor
  Language Wos 000366503700003 Publication Date 2015-10-30
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1616-301x ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 12.124 Times cited 64 Open Access OpenAccess
  Notes ; The authors thank Dr. M. Thommes and Dr. K. Cychosz for numerous and helpful discussions on the correct evaluation of the Ar isotherms. I. Cuppens is acknowledged for ICP-AES analyses. Research was funded through a PhD grant to J.V.A. of the Agency for Innovation by Science and Technology in Flanders (IWT). D.V. and A.P. acknowledge F.W.O.-Vlaanderen (Research Foundation Flanders) for a postdoctoral fellowship. N.N. thanks the KU Leuven for financial support (FLOF). E.G., C.K., and J.M. acknowledge the long-term structural funding by the Flemish Government (Methusalem). S.B. acknowledges the European Research Council for funding under the European Union's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement No. 335078-COLOURATOMS. The authors are grateful for financial support by the Belgian government through Interuniversity Attraction Poles (IAP-PAI). They also thank Oleon NV for supplying safflower oil. ; ecas_Sara Approved Most recent IF: 12.124; 2015 IF: 11.805
  Call Number UA @ lucian @ c:irua:130214 Serial 4147
Permanent link to this record
 

 
Author Čevik, U.; Damla, N.; Van Grieken, R.; Vefa Akpinar, M.
  Title Chemical composition of building materials used in Turkey Type A1 Journal article
  Year 2011 Publication Construction and building materials Abbreviated Journal
  Volume (up) 25 Issue 4 Pages 1546-1552
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
  Abstract The main goal of this work was to determine the chemical composition of building materials used in Turkey by utilizing energy dispersive X-ray fluorescence (EDXRF) spectrometry. Gas concrete, cement, sand, bricks, roofing tiles, marble, lime and gypsum materials were selected as building materials for this research. The chemical contents and their trace concentrations of the selected samples were determined. The most abundant oxides measured were generally SiO2, Al2O3, CaO, MgO, Fe2O3, K2O and SO3 for all samples. While the main chemical component of gas concrete, cement, sand and marble samples were SiO2 and CaO, brick and roofing tile mainly consisted of SiO2 and Al2O3. CaO and SO3 were major component of lime and gypsum samples, respectively. For U and Th concentrations in the samples, activities of 226Ra and 232Th were measured by utilizing gamma spectrometry. ANOVA and Pearson correlation analyses were performed on the studied data for statistical analysis.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000287379300007 Publication Date 2010-09-22
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0950-0618 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:86448 Serial 7653
Permanent link to this record
 

 
Author Morozov, V.A.; Raskina, M.V.; Lazoryak, B.I.; Meert, K.W.; Korthout, K.; Smet, P.F.; Poelman, D.; Gauquelin, N.; Verbeeck, J.; Abakumov, A.M.; Hadermann, J.;
  Title Crystal Structure and Luminescent Properties of R2-xEux(MoO4)(3) (R = Gd, Sm) Red Phosphors Type A1 Journal article
  Year 2014 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume (up) 26 Issue 24 Pages 7124-7136
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The R-2(MoO4)(3) (R = rare earth elements) molybdates doped with Eu3+ cations are interesting red-emitting materials for display and solid-state lighting applications. The structure and luminescent properties of the R2-xEux(MoO4)(3) (R = Gd, Sm) solid solutions have been investigated as a function of chemical composition and preparation conditions. Monoclinic (alpha) and orthorhombic (beta') R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) modifications were prepared by solid-state reaction, and their structures were investigated using synchrotron powder X-ray diffraction and transmission electron microscopy. The pure orthorhombic beta'-phases could be synthesized only by quenching from high temperature to room temperature for Gd2-xEux(MoO4)(3) in the Eu3+-rich part (x > 1) and for all Sm2-xEux(MoO4)(3) solid solutions. The transformation from the alpha-phase to the beta'-phase results in a notable increase (similar to 24%) of the unit cell volume for all R2-xEux(MoO4)(3) (R = Sm, Gd) solid solutions. The luminescent properties of all R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) solid solutions were measured, and their optical properties were related to their structural properties. All R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) phosphors emit intense red light dominated by the D-5(0)-> F-7(2) transition at similar to 616 nm. However, a change in the multiplet splitting is observed when switching from the monoclinic to the orthorhombic structure, as a consequence of the change in coordination polyhedron of the luminescent ion from RO8 to RO7 for the alpha- and beta'-modification, respectively. The Gd2-xEux(MoO4)(3) solid solutions are the most efficient emitters in the range of 0 < x < 1.5, but their emission intensity is comparable to or even significantly lower than that of Sm2-xEux(MoO4)(3) for higher Eu3+ concentrations (1.5 <= x <= 1.75). Electron energy loss spectroscopy (EELS) measurements revealed the influence of the structure and element content on the number and positions of bands in the ultraviolet-visible-infrared regions of the EELS spectrum.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000347139700027 Publication Date 2014-11-27
  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 24 Open Access
  Notes Fwo G039211n; G004413n; 278510 Vortex ECASJO_; Approved Most recent IF: 9.466; 2014 IF: 8.354
  Call Number UA @ lucian @ c:irua:122829UA @ admin @ c:irua:122829 Serial 558
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Author Schryvers, D.; de Saegher, B.; van Landuyt, J.
  Title Electron microscopy and diffraction study of the composition dependency of the 3R microtwinned martensite in Ni-Al Type A1 Journal article
  Year 1991 Publication Materials research bulletin Abbreviated Journal Mater Res Bull
  Volume (up) 26 Issue Pages 57-66
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract
  Address
  Corporate Author Thesis
  Publisher Place of Publication New York, N.Y. Editor
  Language Wos A1991EU98500007 Publication Date 0000-00-00
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0025-5408 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.288 Times cited 11 Open Access
  Notes Approved no
  Call Number UA @ lucian @ c:irua:48348 Serial 943
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