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Author Lu, J.; Bartholomeeusen, E.; Sels, B.F.; Schryvers, D.
Title Internal architecture of coffin-shaped ZSM-5 zeolite crystals with hourglass contrast unravelled by focused ion beam-assisted transmission electron microscopy: INTERNAL ARCHITECTURE OF COFFIN-SHAPED Type A1 Journal article
Year 2017 Publication Journal of microscopy Abbreviated Journal J Microsc-Oxford
Volume 265 Issue 265 Pages 27-33
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Optical microscopy, focused ion beam and transmission electron microscopy are combined to study the internal architecture in a coffin-shaped ZSM-5 crystal showing an hourglass contrast in optical microscopy. Based on parallel lamellas from different positions in the crystal, the orientation relationships between the intergrowth components of the crystal are studied and the internal architecture and growth mechanism are illustrated. The crystal is found to contain two pyramid-like components aside from a central component. Both pyramid-like components are rotated by 90 degrees along the common c-axis and with respect to the central component while the interfaces between the components show local zig-zag feature, the latter indicating variations in relative growth velocity of the two components. The pyramid-like intergrowth components are larger and come closer to one another in the middle of the crystal than at the edges, but they do not connect. A model of multisite nucleation and growth of 90 degrees intergrowth components is proposed.
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Publisher Place of Publication Editor
Language Wos (up) 000392487400004 Publication Date 2016-08-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2720 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.692 Times cited 4 Open Access OpenAccess
Notes Fonds Wetenschappelijk Onderzoek, G.0603.10N ; Approved Most recent IF: 1.692
Call Number EMAT @ emat @ c:irua:141015 Serial 4437
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Author Rozova, M.G.; Grigoriev, V.V.; Tyablikov, O.A.; Filimonov, D.S.; Zakharov, K.V.; Volkova, O.S.; Vasiliev, A.N.; Antipov, E.V.; Abakumov, A.M.
Title Doping of Bi4Fe5O13F with pentagonal Cairo lattice with Cr and Mn: Synthesis, structure and magnetic properties Type A1 Journal article
Year 2017 Publication Materials research bulletin Abbreviated Journal Mater Res Bull
Volume 87 Issue 87 Pages 54-60
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The substitution of Cr3+ and Mn3+ for Fe3+ in the Bi4Fe6O13F oxyfluoride featuring the magnetically frustrated pentagonal Cairo lattice is reported. Bi4Fe4.1Cr0.9O13F and BiFe4.2Mn0.8O13F have been prepared using a solid state reaction in inert atmosphere. Their crystal structures were studied with transmission electron microscopy, powder X-ray diffraction and Fe-57 Mossbauer spectroscopy (S.G. P4(2)/mbc, a = 8.27836(2)angstrom, c = 18.00330(9) angstrom, R-F = 0.031 (Bi4Fe4.1Cr0.9O13F)), a= 8.29535(3)angstrom, c= 18.0060(1)angstrom, R-F = 0.027 (Bi4Fe4.1Cr0.9O13F)). The structures are formed by infinite rutile-like chains of the edge sharing BO6 octahedra (B transition metal cations) linked by the Fe2O7 groups of two corner-sharing tetrahedra. The"voids in thus formed framework are occupied by the Bi4F tetrahedra. The Fe-57 Mossbauer spectroscopy reveals that Cr3+ and Mn3+ replace Fe3+. exclusively at the octahedral positions. The Mn- and Cr-doped compounds demonstrate antiferromagnetic ordering below T-N =165 K and 120 K, respectively. (C) 2016 Elsevier Ltd. All rights reserved.
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Publisher Place of Publication New York, N.Y. Editor
Language Wos (up) 000392681800009 Publication Date 2016-11-17
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 2.446 Times cited 1 Open Access Not_Open_Access
Notes ; The work has been supported by the Russian Science Foundation (grant 14-13-00680). ; Approved Most recent IF: 2.446
Call Number UA @ lucian @ c:irua:141535 Serial 4498
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Author Conings, B.; Babayigit, A.; Klug, M. T.; Bai, S.; Gauquelin, N.; Sakai, N.; Wang, J. T.-W.; Verbeeck, J.; Boyen, H.-G.
Title A Universal Deposition Protocol for Planar Heterojunction Solar Cells with High Efficiency Based on Hybrid Lead Halide Perovskite Families Type A1 Journal article
Year 2016 Publication Advanced materials Abbreviated Journal Adv Mater
Volume 28 Issue 28 Pages 10701-10709
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract A robust and expedient gas quenching method is developed for the solution deposition of hybrid perovskite thin films. The method offers a reliable standard practice for the fabrication of a non-exhaustive variety of perovskites exhibiting excellent film morphology and commensurate high performance in both regular and inverted structured solar cell architectures.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000392728200014 Publication Date 2016-10-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1521-4095 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 19.791 Times cited 95 Open Access
Notes This work was financially supported by BOF (Hasselt University) and the Research Fund Flanders (FWO). B.C. is a postdoctoral research fellow of the FWO. A.B. is financially supported by Imec and FWO. M.T.K. acknowledges funding from the EPSRC project EP/M024881/1 “Organic-inorganic Perovskite Hybrid Tandem Solar Cells”. S.B. is a VINNMER Fellow and Marie Skłodowska-Curie Fellow. J.V. and N.G. acknowledge funding from GOA project “Solarpaint” of the University of Antwerp and FWO project G.0044.13N “Charge ordering”. The Qu-Ant-EM microscope used for this study was partly funded by the Hercules fund from the Flemish Government. N.G. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. The authors thank Johnny Baccus and Jan Mertens for technical support.; ECASJO_; Approved Most recent IF: 19.791; 2016 IF: NA
Call Number EMAT @ emat @ c:irua:138597 Serial 4318
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Author Van Tendeloo, L.; Wangermez, W.; Vandekerkhove, A.; Willhammar, T.; Bals, S.; Maes, A.; Martens, J.A.; Kirschhock, C.E.A.; Breynaert, E.
Title Postsynthetic high-alumina zeolite crystal engineering in organic free hyper-alkaline media Type A1 Journal article
Year 2017 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 29 Issue 29 Pages 629-638
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Postsynthetic modification of high -alumina zeolites in hyper alkaline media can be tailored toward alteration of framework topology, crystal size and morphology, or desired Si/A1 ratio. FAU, EMT, MAZ, KFI, HEU, and LTA starting materials were treated with 1.2 M MOH (M = Na, K, RE, or Cs), leading to systematic ordered porosity or fully transformed frameworks with new topology and adjustable Si/Al ratio. In addition to the versatility of this tool for zeolite crystal engineering, these alterations improve understanding of the crystal chemistry. Such knowledge can guide further development in zeolite crystal engineering. Postsynthetic alteration also provides insight on the long-term stability of aluminosilicate zeolites that are used as a sorption sink in concrete -based waste disposal facilities in harsh alkaline conditions.
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Publisher American Chemical Society Place of Publication Washington, D.C Editor
Language Wos (up) 000392891700021 Publication Date 2016-12-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 16 Open Access OpenAccess
Notes ; This work was supported by long-term structural funding by the Flemish Government (Methusalem grant of Prof. J. Martens) and by ONDRAF/NIRAS, the Belgian Agency for Radioactive Waste and Fissile Materials, as part of the program on surface disposal of Belgian Category A waste. The Belgian government is acknowledged for financing the interuniversity poles of attraction (IAP-PAI). S.B. acknowledges financial support from European Research Council (ERC Advanced Grant No. 24691-COUNTATOMS, ERC Starting Grant No. 335078-COLOURATOMS). ; Ecas_Sara Approved Most recent IF: 9.466
Call Number UA @ lucian @ c:irua:152674UA @ admin @ c:irua:152674 Serial 5145
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Author Samaeeaghmiyoni, V.; Idrissi, H.; Groten, J.; Schwaiger, R.; Schryvers, D.
Title Quantitative in-situ TEM nanotensile testing of single crystal Ni facilitated by a new sample preparation approach Type A1 Journal article
Year 2017 Publication Micron Abbreviated Journal Micron
Volume 94 Issue 94 Pages 66-73
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Twin-jet electro-polishing and Focused Ion Beam (FIB) were combined to produce small size Nickel single crystal specimens for quantitative in-situ nanotensile experiments in the transmission electron microscope. The combination of these techniques allows producing samples with nearly defect-free zones in the centre in contrast to conventional FIB-prepared samples. Since TEM investigations can be performed on the electro-polished samples prior to in-situ TEM straining, specimens with desired crystallographic orientation and initial microstructure can be prepared. The present results reveal a dislocation nucleation controlled plasticity, in which small loops induced by FIB near the edges of the samples play a central role.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000393247300008 Publication Date 2016-12-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0968-4328 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.98 Times cited 11 Open Access OpenAccess
Notes This research has been performed with the financial support of the Belgian Science Policy (Belspo) under the framework of the interuniversity attraction poles program, IAP7/21. Financial support from the Flemish (FWO) and German Research Foundation (DFG) through the European M-ERA.NET project “FaSS” (Fatigue Simulation near Surfaces) under the grant numbers GA.014.13N and SCHW855/5-1, respectively, is gratefully acknowledged. V. Samaeeaghmiyoni also acknowledges the FWO research project G012012N “Understanding nanocrystalline mechanical behaviour from structural investigations”. H. Idrissi is currently mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). Approved Most recent IF: 1.98
Call Number EMAT @ emat @ c:irua:139515 Serial 4341
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Author Niu, H.; Pitcher, M.J.; Corkett, A.J.; Ling, S.; Mandal, P.; Zanella, M.; Dawson, K.; Stamenov, P.; Batuk, D.; Abakumov, A.M.; Bull, C.L.; Smith, R.I.; Murray, C.A.; Day, S.J.; Slater, B.; Cora, F.; Claridge, J.B.; Rosseinsky, M.J.
Title Room Temperature Magnetically Ordered Polar Corundum GaFeO3 Displaying Magnetoelectric Coupling Type A1 Journal article
Year 2017 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
Volume 139 Issue 4 Pages 1520-1531
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The polar corundum structure type offers a route to new room temperature multiferroic materials, as the partial LiNbO3-type cation ordering that breaks inversion symmetry may be combined with long-range magnetic ordering of high spin d(5) cations above room temperature in the AFeO(3) system. We report the synthesis of a polar corundum GaFeO3 by a high-pressure, high-temperature route and demonstrate that its polarity arises from partial LiNbO3 -type cation ordering by complementary use of neutron, X-ray, and electron diffraction methods. In situ neutron diffraction shows that the polar corundum forms directly from AlFeO3-type GaFeO3 under the synthesis conditions. The A(3+)/Fe3+ cations are shown to be more ordered in polar corundum GaFeO3 than in isostructural ScFeO3. This is explained by DFT calculations which indicate that the extent of ordering is dependent on the configurational entropy available to each system at the very different synthesis temperatures required to form their corundum structures. Polar corundum GaFeO3 exhibits weak ferromagnetism at room temperature that arises from its Fe2O3-like magnetic ordering, which persists to a temperature of 408 K. We demonstrate that the polarity and magnetization are coupled in this system with a measured linear magnetoelectric coupling coefficient of 0.057 ps/m. Such coupling is a prerequisite for potential applications of polar corundum materials in multiferroic/magnetoelectric devices.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000393355600034 Publication Date 2016-12-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-7863 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.858 Times cited 12 Open Access OpenAccess
Notes This work was funded by the EPSRC under EP/N004884. We thank the STFC for provision of beam time at ISIS and Diamond Light Source. We thank the Materials Chemistry Consortium (EPSRC, EP/L000202) for access to computer time on the ARCHER UK National Supercomputing Service (http://www.archer.ac.uk). A.M.A. is grateful to the Russian Science Foundation (Grant 14-13-00680) for financial support. MJ.R is a Royal Society Research Professor. We wish to thank Dr. Ming Li (University of Nottingham, UK) for helpful discussion and advice. Original data is available at the University of Liverpool's DataCat repository at DOI: 10.17638/datacat.liverpool.ac.uk/235. The supporting crystallographic information file may also be obtained from FIZ Karlsruhe, 76344 Eggenstein-Leopoldshafen, Germany (e-mail: crysdata@fiz-karlsruhe.de), on quoting the deposition number CSD-432419. Approved Most recent IF: 13.858
Call Number EMAT @ emat @c:irua:147507 Serial 4777
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Author Belik, A.A.; Morozov, V.A.; Deyneko, D.V.; Savon, A.E.; Baryshnikova, O.V.; Zhukovskaya, E.S.; Dorbakov, N.G.; Katsuya, Y.; Tanaka, M.; Stefanovich, S.Y.; Hadermann, J.; Lazoryak, B.I.
Title Antiferroelectric properties and site occupations ofR3+ cations in Ca8MgR(PO4)7 luminescent host materials Type A1 Journal article
Year 2017 Publication Journal of alloys and compounds Abbreviated Journal
Volume 699 Issue Pages 928-937
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Ca8MgR(PO4)(7) = La, Pr, Nd, Sm-Lu, and Y) phosphates with a beta-Ca-3(PO4)(2) related structure were prepared by a standard solid-state method in air. Second-harmonic generation, differential scanning calorimetry, and dielectric measurements led to the conclusion that all Ca8MgR(PO4)(7) are centrosymmetric and go to another centrosymmetric phase in the course of a first-order antiferroelectric phase transition well above room temperature (RT). High-temperature electron diffraction showed that the symmetry changes from R (3) over barc to R (3) over barm during the phase transition. Structures of Ca8MgR(PO4)(7) at RT were refined by the Rietveld method in centrosymmetric space group R (3) over barc. Mg2+ cations occupy the M5 site; the occupancy of the M1 site by R3+ cations increases monotonically from 0.0389 for R = La to 0.1667 for R = Er-Lu, whereas the occupancy of the M3 site by R3+ cations decreases monotonically from 0.1278 for R = La to 0 for R = Er-Lu. In the case of R = Er-Lu, the M3 site is occupied only by Ca2+ cations. P1O(4) tetrahedra and cations at the M3 site are disordered in the R (3) over barc structure of Ca8MgEu(PO4)(7). Using synchrotron X-ray powder diffraction, we found that annealing conditions do not significantly affect the distribution of Ca2+ and Eu3+ cations between the structure positions of Ca8MgEu(PO4)(7). Luminescent properties of CasMgEu(PO4)(7) powder samples were investigated under near-ultraviolet (n-UV) light. Excitation spectra of CasMgEu(PO4)(7) show the strongest absorption at about 395 nm that matches with commercially available n-UV-emitting GaN-based LED chips. Emission spectra show an intense red emission due to the D-5(0) -> F-7(2) transition of Eu3+. (C) 2016 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000393727500129 Publication Date 2016-12-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-8388 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:152665 Serial 7464
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Author Heidari, H.; Rivero, G.; Idrissi, H.; Ramachandran, D.; Cakir, S.; Egoavil, R.; Kurttepeli, M.; Crabbé, A.C.; Hauffman, T.; Terryn, H.; Du Prez, F.; Schryvers, D.
Title Melamine–Formaldehyde Microcapsules: Micro- and Nanostructural Characterization with Electron Microscopy Type A1 Journal article
Year 2016 Publication Microscopy and microanalysis Abbreviated Journal Microsc Microanal
Volume 22 Issue 22 Pages 1222-1232
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A systematic study has been carried out to compare the surface morphology, shell thickness, mechanical properties, and binding behavior of melamine–formaldehyde microcapsules of 5–30 μm diameter size with various amounts of core content by using scanning and transmission electron microscopy including electron tomography, in situ nanomechanical tensile testing, and electron energy-loss spectroscopy. It is found that porosities are present on the outside surface of the capsule shell, but not on the inner surface of the shell. Nanomechanical tensile tests on the capsule shells reveal that Young’s modulus of the shell material is higher than that of bulk melamine–formaldehyde and that the shells exhibit a larger fracture strain compared with the bulk. Core-loss elemental analysis of microcapsules embedded in epoxy indicates that during the curing process, the microcapsule-matrix interface remains uniform and the epoxy matrix penetrates into the surface micro-porosities of the capsule shells.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000393853100011 Publication Date 2016-12-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.891 Times cited 2 Open Access
Notes This work was supported by SIM vzw, Technologiepark 935, BE-9052 Zwijnaarde, Belgium, within the InterPoCo project of the H-INT-S horizontal program. The authors are also thankful to Stijn Van den Broeck and Dr. Frederic Leroux for help in sample preparation and to S. Bals and J. Verbeeck for valuable discussions. H.I. acknowledges the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs, under Contract No. P7/21. Approved Most recent IF: 1.891
Call Number EMAT @ emat @ c:irua:138980 Serial 4333
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Author Zalfani, M.; Hu, Z.-Y.; Yu, W.-B.; Mahdouani, M.; Bourguig, R.; Wu, M.; Li, Y.; Van Tendeloo, G.; Djoued, Y.; Su, B.-L.
Title BiVO4/3DOM TiO2 nanocomposites: Effect of BiVO4 as highly efficient visible light sensitizer for highly improved visible light photocatalytic activity in the degradation of dye pollutants Type A1 Journal article
Year 2016 Publication Applied Catalysis B-Environmental Abbreviated Journal Appl Catal B-Environ
Volume 205 Issue 205 Pages 121-132
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A series of BiVO4/3DOM TiO2 nanocomposites have been synthesized and their photocatalytic activity was investigated under visible light irradiation using the RhB dye as model pollutant molecule in an aqueous solution. The effect of the amount of BiVO4 as visible light sensitizer on the photocatalytic activity of BiVO4/3DOM TiO2 nanocomposites was highlighted. The heterostructured composite system leads to much higher photocatalytic efficiencies than bare 3DOM TiO2 and BiVO4 nanoparticles. As the proportion of BiVO4 in BiVO4/3DOM TiO2 nanocomposites increases from 0.04 to 0.6, the photocatalytic performance of the BiVO4/3DOM TiO2 nanocomposites increases and then decreases after reaching a maximum at 0.2. This improvement in photocatalytic perfomance is related to 1) the interfacial electron transfer efficiency between the coupled materials, 2) the 3DOM TiO2 inverse opal structure with interconnected pores providing an easy mass transfer of the reactant molecules and high accessibility to the active sites and large surface area and 3) the effect of light sensitizer of BiVO4. Intensive studies on structural, textural, optical and surface properties reveal that the electronic interactions between BiVO4 and TiO2 lead to an improved charge separation of the coupled BiVO4/TiO2 system. The photogenerated charge carrier densities increase with increasing the BiVO4 content, which acts as visible light sensitizer to the TiO2 and is responsible for the enhancement in the rate of photocatalytic degradation. However, the photocatalytic activity is reduced when the BiVO4 amount is much higher than that of 3DOM TiO2. Two reasons could account for this behavior. First, with increasing BiVO4 content, the photogenerated electron/hole pairs are accumulated at the surface of the BiVO4 nanoparticles and the recombination rate increases as shown by the PL results. Second, decreasing the amount of 3DOM TiO2 in the nanocomposite decreases the surface area as shown by the BET results. Moreover, the poor adsorptive properties of the BiVO4 photocatalyst also affect the photocatalytic performance, in particular at higher BiVO4 content. The present work demonstrates that BiVO4/3DOM TiO2 is a very promising heterojunction system for visible light photocatalytic applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000393931000013 Publication Date 2016-12-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0926-3373 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.446 Times cited 52 Open Access OpenAccess
Notes Z. Y. Hu and G. Van Tendeloo acknowledge support from the EC Framework 7 program ESTEEM2 (Reference 312483). Approved Most recent IF: 9.446
Call Number EMAT @ emat @ Serial 4323
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Author Zalfani, M.; Hu, Z.-Y.; Yu, W.-B.; Mahdouani, M.; Bourguiga, R.; Wu, M.; Li, Y.; Van Tendeloo, G.; Djoued, Y.; Su, B.-L.
Title BiVo4/3DOM TiO2 nanocomposites : effect of BiVO4 as highly efficient visible light sensitizer for highly improved visible light photocatalytic activity in the degradation of dye pollutants Type A1 Journal article
Year 2017 Publication Applied catalysis : B : environmental Abbreviated Journal Appl Catal B-Environ
Volume 205 Issue 205 Pages 121-132
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A series of BiVO4/3DOM TiO2 nanocomposites have been synthesized and their photocatalytic activity was investigated under visible light irradiation using the RhB dye as model pollutant molecule in an aqueous solution. The effect of the amount of BiVO4 as visible light sensitizer on the photocatalytic activity of BiVO4/3DOM TiO2 nanocomposites was highlighted. The heterostructured composite system leads to much higher photocatalytic efficiencies than bare 3DOM TiO2 and BiVO4 nanoparticles. As the proportion of BiVO4 in BiVO4/3DOM TiO2 nanocomposites increases from 0.04 to 0.6, the photocatalytic performance of the BiVO4/3DOM TiO2 nanocomposites increases and then decreases after reaching a maximum at 0.2. This improvement in photocatalytic perfomance is related to 1) the interfacial electron transfer efficiency between the coupled materials, 2) the 3DOM TiO2 inverse opal structure with interconnected pores providing an easy mass transfer of the reactant molecules and high accessibility to the active sites and large surface area and 3) the effect of light sensitizer of BiVO4. Intensive studies on structural, textural, optical and surface properties reveal that the electronic interactions between BiVO4 and TiO2 lead to an improved charge separation of the coupled BiVO4/TiO2 system. The photogenerated charge carrier densities increase with increasing the BiVO4 content, which acts as visible light sensitizer to the TiO2 and is responsible for the enhancement in the rate of photocatalytic degradation. However, the photocatalytic activity is reduced when the BiVO4 amount is much higher than that of 3DOM TiO2. Two reasons could account for this behavior. First, with increasing BiVO4 content, the photogenerated electron/hole pairs are accumulated at the surface of the BiVO4 nanoparticles and the recombination rate increases as shown by the PL results. Second, decreasing the amount of 3DOM TiO2 in the nanocomposite decreases the surface area as shown by the BET results. Moreover, the poor adsorptive properties of the BiVO4 photocatalyst also affect the photocatalytic performance, in particular at higher BiVO4 content. The present work demonstrates that BiVO4/3DOM TiO2 is a very promising heterojunction system for visible light photocatalytic applications.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos (up) 000393931000013 Publication Date 2016-12-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0926-3373 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.446 Times cited 52 Open Access OpenAccess
Notes ; This work was realized with the financial support of Chinese Ministry of Education in a framework of the Changjiang Scholar Innovative Research Team Program (IRT_15R52). B. L. Su acknowledges the Chinese Central Government for an “Expert of the State” position in the Program of the “Thousand Talents” and a Clare Hall Life Member, University of Cambridge. Y. Li acknowledges Hubei Provincial Department of Education for the “Chutian Scholar” program. This work is also supported by PhD Programs Foundation (20120143120019) of Chinese Ministry of Education, the Wuhan Youth Chenguang Program of Science and Technology (2013070104010003), Hubei Provincial Natural Science Foundation (2014CFB160, 2015CFB516), the National Science Foundation for Young Scholars of China (No. 51502225) and Self-determined and Innovative Research Funds of the SKLWUT (2015-ZD-7). MZ thanks the scholarship support from the Laboratory of Inorganic Materials Chemistry ay the University of Namur. Z. Y. Hu and G. Van Tendeloo acknowledge support from the EC Framework 7 program ESTEEM2 (Reference 312483). This research used resources of the Electron Microscopy Service located at the University of Namur. This Service is member of the “Plateforme Technologique Morphologie – Imagerie”. The XPS analyses were made in the LISE, Department of Physics of University of Namur thanks to Dr. P. Louette. XRD measurements, UV-vis and photoluminescent spectroscopic analyses and N<INF>2</ INF> adsorption-desorption measurements were made with the facility of the “Plateforme Technologique Physico-Chimique”. ; Approved Most recent IF: 9.446
Call Number UA @ lucian @ c:irua:138601 Serial 4405
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Author Jany, B.R.; Gauquelin, N.; Willhammar, T.; Nikiel, M.; van den Bos, K.H.W.; Janas, A.; Szajna, K.; Verbeeck, J.; Van Aert, S.; Van Tendeloo, G.; Krok, F.
Title Controlled growth of hexagonal gold nanostructures during thermally induced self-assembling on Ge(001) surface Type A1 Journal article
Year 2017 Publication Scientific reports Abbreviated Journal Sci Rep-Uk
Volume 7 Issue 7 Pages 42420
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Nano-sized gold has become an important material in various fields of science and technology, where control over the size and crystallography is desired to tailor the functionality. Gold crystallizes in the face-centered cubic (fcc) phase, and its hexagonal closed packed (hcp) structure is a very unusual and rare phase. Stable Au hcp phase has been reported to form in nanoparticles at the tips of some Ge nanowires. It has also recently been synthesized in the form of thin graphene-supported sheets which are unstable under electron beam irradiation. Here, we show that stable hcp Au 3D nanostructures with well-defined crystallographic orientation and size can be systematically created in a process of thermally induced self-assembly of thin Au layer on Ge(001) monocrystal. The Au hcp crystallite is present in each Au nanostructure and has been characterized by different electron microscopy techniques. We report that a careful heat treatment above the eutectic melting temperature and a controlled cooling is required to form the hcp phase of Au on a Ge single crystal. This new method gives scientific prospects to obtain stable Au hcp phase for future applications in a rather simple manner as well as redefine the phase diagram of Gold with Germanium.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000393940700001 Publication Date 2017-02-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2045-2322 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.259 Times cited 25 Open Access OpenAccess
Notes The authors gratefully acknowledge the financial support from the Polish National Science Center, grant no. DEC-2012/07/B/ST5/00906. N.G., G.V.T. and J.V. acknowledge the European Union (EU) Council under the 7th Framework Program (FP7) ERC Starting Grant 278510 VORTEX for support. The Research Foundation Flanders is acknowledged through project fundings (G.0374.13N, G.0368.15N, G.0369.15N) and for a Ph.D. research grant to K.H.W.v.d.B. The microscope was partly funded by the Hercules Fund from the Flemish Government. T.W. acknowledges the Swedish Research Council for an international postdoc grant. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483–ESTEEM2 (Integrated Infrastructure Initiative–I3). Part of the research was carried out with equipment purchased with financial support from the European Regional Development Fund in the framework of the Polish Innovation Economy Operational Program (Contract No. POIG.02.01.00-12-023/08). Approved Most recent IF: 4.259
Call Number EMAT @ emat @ c:irua:140846UA @ admin @ c:irua:140846 Serial 4423
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Author van der Rest, A.; Idrissi, H.; Henry, F.; Favache, A.; Schryvers, D.; Proost, J.; Raskin, J.-P.; Van Overmeere, Q.; Pardoen, T.
Title Mechanical behavior of ultrathin sputter deposited porous amorphous Al2O3 films Type A1 Journal article
Year 2017 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 125 Issue 125 Pages 27-37
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The determination of the mechanical properties of porous amorphous Al2O3 thin films is essential to address reliability issues in wear-resistant, optical and electronic coating applications. Testing the mechanical properties of Al2O3 films thinner than 200 nm is challenging, and the link between the mechanical behavior and the microstructure of such films is largely unknown. Herein, we report on the elastic and viscoplastic mechanical properties of amorphous Al2O3 thin films synthesized by reactive magnetron sputtering using a combination of internal stress, nanoindentation, and on-chip uniaxial tensile testing, together with mechanical homogenization models to separate the effect of porosity from intrinsic variations of the response of the sound material. The porosity is made of voids with 2e30 nm diameter. The Young's modulus and hardness of the films decrease by a factor of two when the deposition pressure increases from 1.2 to 8 mTorr. The contribution of porosity was found to be small, and a change in the atomic structure of the amorphous Al2O3 matrix is hypothesized to be the main contributing factor. The activation volume associated to the viscoplastic deformation mechanism is around 100 Å3. Differences in the atomic structure of the films could not be revealed by electron diffraction, pointing to a minute effect of atomic arrangement on the elastic properties.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000394201500003 Publication Date 2016-12-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6454 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.301 Times cited 5 Open Access OpenAccess
Notes This work has been funded by the Belgian Science Policy through the IAP 7/21 project. The support of the ‘Fonds Belge pour la Recherche dans l’Industrie et l’Agriculture (FRIA)’ for A.v.d.R. is also gratefully acknowledged, as well as the support of FNRS through the grant PDR T.0122.13 “Mecano”. Approved Most recent IF: 5.301
Call Number EMAT @ emat @ c:irua:138990 Serial 4330
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Author Suffian, I.F.B.M.; Wang, J.T.-W.; Hodgins, N.O.; Klippstein, R.; Garcia-Maya, M.; Brown, P.; Nishimura, Y.; Heidari, H.; Bals, S.; Sosabowski, J.K.; Ogino, C.; Kondo, A.; Al-Jamal, K.T.
Title Engineering hepatitis B virus core particles for targeting HER2 receptors in vitro and in vivo Type A1 Journal article
Year 2017 Publication Biomaterials Abbreviated Journal Biomaterials
Volume 120 Issue 120 Pages 126-138
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Hepatitis B Virus core (HBc) particles have been studied for their potential as drug delivery vehicles for cancer therapy. HBc particles are hollow nano-particles of 30-34 nm diameter and 7 nm thick envelopes, consisting of 180-240 units of 21 kDa core monomers. They have the capacity to assemble/dis-assemble in a controlled manner allowing encapsulation of various drugs and other biomolecules. Moreover, other functional motifs, i.e. receptors, receptor binding sequences, peptides and proteins can be expressed. This study focuses on the development of genetically modified HBc particles to specifically recognise and target human epidermal growth factor receptor-2 (HER2)-expressing cancer cells, in vitro and in vivo, for future cancer therapy. The non-specific binding capacity of wild type HBc particles was reduced by genetic deletion of the sequence encoding arginine-rich domains. A specific HER2-targeting was achieved by expressing the ZHER2 affibodies on the HBc particles surface. In vitro studies showed specific uptake of ZHER2-AHBc particles in HER2 expressing cancer cells. In vivo studies confirmed positive uptake of ZHER2-ABBc particles in HER2-expressing tumours, compared to non-targeted AHBc particles in intraperitoneal tumour-bearing mice models. The present results highlight the potential of these nanocarriers in targeting HER2-positive metastatic abdominal cancer following intra-peritoneal administration. (C) 2016 The Authors. Published by Elsevier Ltd.
Address
Corporate Author Thesis
Publisher Place of Publication Guildford Editor
Language Wos (up) 000394398900012 Publication Date 2016-12-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0142-9612 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.402 Times cited 20 Open Access OpenAccess
Notes ; The authors would like to thank Dr. Rafael T. M. de Rosales (King's College London) for useful discussion on the radiolabelling technique and Mr William Luckhurst (King's College London) on the technical help of AFM measurements. IFBMS would like to thank Public Service Department, Government of Malaysia for the Excellence Student Programme studentship. We acknowledge funding from Biotechnology and Biological Sciences Research Council (BBSRC; (BB/J008656/1)) and the EU FP7-ITN Marie-Curie Network programme RADDEL (290023). NH is a recipient of Graduate School King's Health Partner's scholarship. RIC is a Marie Curie Fellow. S.B. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 335078 COLOURATOMS, and the Integrated Infrastructure Initiative No. 262348 European Soft Matter Infrastructure, ESMI. The authors declare that they have no competing interests. ; ecas_Sara Approved Most recent IF: 8.402
Call Number UA @ lucian @ c:irua:141984UA @ admin @ c:irua:141984 Serial 4654
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Author Matsubara, M.; Saniz, R.; Partoens, B.; Lamoen, D.
Title Doping anatase TiO2with group V-b and VI-b transition metal atoms: a hybrid functional first-principles study Type A1 Journal article
Year 2017 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 19 Issue 19 Pages 1945-1952
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract We investigate the role of transition metal atoms of group V-b (V, Nb, Ta) and VI-b (Cr, Mo, W) as n- or p-type dopants in anatase TiO$2$ using thermodynamic

principles and density functional theory with the Heyd-Scuseria-Ernzerhof HSE06 hybrid functional. The HSE06 functional provides a realistic value for the band gap, which ensures a correct classification of dopants as shallow or deep donors or acceptors. Defect formation energies and thermodynamic transition levels are calculated taking into account the constraints imposed by the stability of TiO$
2$ and the solubility limit of the impurities.

Nb, Ta, W and Mo are identified as shallow donors. Although W provides two electrons, Nb and Ta show a considerable lower formation energy, in particular under O-poor conditions. Mo donates in principle one electron, but under specific conditions can turn into a double donor. V impurities are deep donors and Cr

shows up as an amphoteric defect, thereby acting as an electron trapping center in n-type TiO$_2$ especially under O-rich conditions. A comparison with the available experimental data yields excellent agreement.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000394426400027 Publication Date 2016-12-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 19 Open Access OpenAccess
Notes We gratefully acknowledge financial support from the IWTVlaanderenthrough projects G.0191.08 and G.0150.13, and the BOF-NOI of the University of Antwerp. This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center VSC, which is funded by the Hercules foundation. M. M. acknowledges financial support from the GOA project ‘‘XANES meets ELNES’’ of the University of Antwerp. Approved Most recent IF: 4.123
Call Number EMAT @ emat @ c:irua:140835 Serial 4421
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Author Ben Dkhil, S.; Pfannmöller, M.; Ata, I.; Duche, D.; Gaceur, M.; Koganezawa, T.; Yoshimoto, N.; Simon, J.-J.; Escoubas, L.; Videlot-Ackermann, C.; Margeat, O.; Bals, S.; Bauerle, P.; Ackermann, J.
Title Time evolution studies of dithieno[3,2-b:2 ',3 '-d] pyrrole-based A-D-A oligothiophene bulk heterojunctions during solvent vapor annealing towards optimization of photocurrent generation Type A1 Journal article
Year 2017 Publication Journal of materials chemistry A : materials for energy and sustainability Abbreviated Journal J Mater Chem A
Volume 5 Issue 5 Pages 1005-1013
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Solvent vapor annealing (SVA) is one of the main techniques to improve the morphology of bulk heterojunction solar cells using oligomeric donors. In this report, we study time evolution of nanoscale morphological changes in bulk heterojunctions based on a well-studied dithienopyrrole-based A-D-A oligothiophene (dithieno[3,2-b: 2',3'-d] pyrrole named here 1) blended with [6,6]-phenyl-C-71-butyric acid methyl ester (PC71BM) to increase photocurrent density by combining scanning transmission electron microscopy and low-energy-loss spectroscopy. Our results show that SVA transforms the morphology of 1 : PC71BM blends by a three-stage mechanism: highly intermixed phases evolve into nanostructured bilayers that correspond to an optimal blend morphology. Additional SVA leads to completely phaseseparated micrometer-sized domains. Optical spacers were used to increase light absorption inside optimized 1 : PC71BM blends leading to solar cells of 7.74% efficiency but a moderate photocurrent density of 12.3 mA cm (-2). Quantum efficiency analyses reveal that photocurrent density is mainly limited by losses inside the donor phase. Indeed, optimized 1 : PC71BM blends consist of large donor-enriched domains not optimal for exciton to photocurrent conversion. Shorter SVA times lead to smaller domains; however they are embedded in large mixed phases suggesting that introduction of stronger molecular packing may help us to better balance phase separation and domain size enabling more efficient bulk heterojunction solar cells.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos (up) 000394430800018 Publication Date 2016-11-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2050-7488; 2050-7496 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.867 Times cited 19 Open Access Not_Open_Access
Notes ; We acknowledge financial support by the French Fond Unique Interministeriel (FUI) under the project “SFUMATO” (Grant number: F1110019V/201308815) as well as by the European Commission under the Project “SUNFLOWER” (FP7-ICT-2011-7, Grant number: 287594). The synchrotron radiation experiments were performed at BL19B2 in SPring-8 with the approval of Japan Synchrotron Radiation Research Institute (JASRI) (Proposal No. 2016A1568). We further acknowledge financial support via ERC Starting Grant Colouratoms (335078). ; Approved Most recent IF: 8.867
Call Number UA @ lucian @ c:irua:142602UA @ admin @ c:irua:142602 Serial 4695
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Author Sieger, M.; Pahlke, P.; Lao, M.; Eisterer, M.; Meledin, A.; Van Tendeloo, G.; Ottolinger, R.; Haenisch, J.; Holzapfel, B.; Usoskin, A.; Kursumovic, A.; MacManus-Driscoll, J.L.; Stafford, B.H.; Bauer, M.; Nielsch, K.; Schultz, L.; Huehne, R.
Title Tailoring microstructure and superconducting properties in thick BaHfO3 and Ba2YNb/Ta)O-6 doped YBCO films on technical templates Type A1 Journal article
Year 2017 Publication IEEE transactions on applied superconductivity Abbreviated Journal
Volume 27 Issue 4 Pages 6601407
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The current transport capability of YBa2Cu3O7-x(YBCO) based coated conductors (CCs) is mainly limited by two features: the grain boundaries of the used textured template, which are transferred into the superconducting film through the buffer layers, and the ability to pin magnetic flux lines by incorporation of defined defects in the crystal lattice. By adjusting the deposition conditions, it is possible to tailor the pinning landscape in doped YBCO in order to meet specific working conditions (T, B) for CC applications. To study these effects, we deposited YBCO layers with a thickness of about 1-2 mu m using pulsed laser deposition on buffered rolling-assisted biaxially textured Ni-W substrates as well as on metal tapes having either an ion-beam-texturedYSZbuffer or an MgO layer textured by inclined substrate deposition. BaHfO3 and the mixed double-perovskite Ba2Y(Nb/Ta)O-6 were incorporated as artificial pinning centers in these YBCO layers. X-ray diffraction confirmed the epitaxial growth of the superconductor on these templates as well as the biaxially oriented incorporation of the secondary phase additions in the YBCO matrix. A critical current density J(c) of more than 2 MA/cm(2) was achieved at 77 K in self-field for 1-2 mu m thick films. Detailed TEM (transmission electron microscopy) studies revealed that the structure of the secondary phase can be tuned, forming c-axis aligned nanocolumns, ab-oriented platelets, or a combination of both. Transport measurements show that the J(c) anisotropy in magnetic fields is reduced by doping and the peak in the J(c) (theta) curves can be correlated to the microstructural features.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos (up) 000394588100001 Publication Date 2016-12-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1051-8223 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 12 Open Access OpenAccess
Notes ; This work was supported by EUROTAPES, a collaborative project funded by the European Commission's Seventh Framework Program (FP7/2007-2013) under Grant Agreement no. 280432. ; Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:141961 Serial 4693
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Author Lander, L.; Rousse, G.; Batuk, D.; Colin, C.V.; Dalla Corte, D.A.; Tarascon, J.-M.
Title Synthesis, structure, and electrochemical properties of k-based sulfates K2M2(SO4)3) with M = Fe and Cu Type A1 Journal article
Year 2017 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
Volume 56 Issue 4 Pages 2013-2021
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Stabilizing new host structures through potassium extraction from K-based polyanionic materials has been proven to be an interesting approach to develop new Li+/Na+ insertion materials. Pursuing the same trend, we here report the feasibility of preparing langbeinite “Fe-2(SO4)(3)” via electrochemical and chemical oxidation of K2Fe2(SO4)(3). Additionally, we succeeded in stabilizing a new K2Cu2(SO4)(3) phase via a solid-state synthesis approach. This novel compound crystallizes in a complex orthorhombic structure that differs from that of langbeinite as deduced from synchrotron X-ray and neutron powder diffraction. Electrochemically, the performance of this new phase is limited, which we explain in terms of sluggish diffusion kinetics. We further show that K2Cu2(SO4)(3) decomposes into K2Cu3O(SO4)(3) on heating, and we report for the first time the synthesis of fedotovite K2Cu3O(SO4)(3). Finally, the fundamental attractiveness of these S = 1/2 systems for physicists is examined by neutron magnetic diffraction, which reveals the absence of a long-range ordering of Cu2+ magnetic moments down to 1.5 K.
Address
Corporate Author Thesis
Publisher Place of Publication Easton, Pa Editor
Language Wos (up) 000394736600027 Publication Date 2017-01-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-1669 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.857 Times cited 13 Open Access Not_Open_Access
Notes ; We thank Matthieu Courty for performing TGA/DSC measurements. Use of the 11-BM mail service of the APS at Argonne National Laboratory was supported by the U.S. Department of Energy under Contract DE-AC02-06CH11357 and is acknowledged. The French CRG D1B is acknowledged for allocating neutron beamtime. L.L. thanks the ANR “Hipolite” for the Ph.D. funding. ; Approved Most recent IF: 4.857
Call Number UA @ lucian @ c:irua:142531 Serial 4692
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Author Pourbabak, S.; Wang, X.; Van Dyck, D.; Verlinden, B.; Schryvers, D.
Title Ni cluster formation in low temperature annealed Ni50.6Ti49.4 Type A1 Journal article
Year 2017 Publication Functional materials letters Abbreviated Journal Funct Mater Lett
Volume 10 Issue 10 Pages 1740005
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract Various low temperature treatments of Ni50.6Ti49.4 have shown an unexpected effect on the martensitic start temperature. Periodic diffuse intensity distributions in reciprocal space indicate the formation of short pure Ni strings along the <111> directions in the B2 ordered lattice, precursing the formation of Ni4Ti3 precipitates formed at higher annealing temperatures.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000395164100006 Publication Date 2017-01-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1793-6047 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.234 Times cited 4 Open Access Not_Open_Access
Notes The authors like to thank the Flemish Science Foundation FWO for financial support under project G.0366.15N “Influence of nano- and microstructural features and defects in fine-grained Ni-Ti on the thermal and mechanical reversibility of the martensitic transformation and the shape memory and superelastic behavior”. We are also very grateful to Prof. Dr. Jan Van Humbeeck for initiating this work, for his continuous support and inspiring discussions. Approved Most recent IF: 1.234
Call Number EMAT @ emat @ c:irua:142545 Serial 4619
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Author Mikhailova, D.; Kuratieva, N.N.; Utsumi, Y.; Tsirlin, A.A.; Abakumov, A.M.; Schmidt, M.; Oswald, S.; Fuess, H.; Ehrenberg, H.
Title Composition-dependent charge transfer and phase separation in the V1-xRexO2 solid solution Type A1 Journal article
Year 2017 Publication Journal of the Chemical Society : Dalton transactions Abbreviated Journal
Volume 46 Issue 5 Pages 1606-1617
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The substitution of vanadium in vanadium dioxide VO2 influences the critical temperatures of structural and metal-to-insulator transitions in different ways depending on the valence of the dopant. Rhenium adopts valence states between + 4 and + 7 in an octahedral oxygen surrounding and is particularly interesting in this context. Structural investigation of V1-xRexO2 solid solutions (0.01 <= x <= 0.30) between 80 and 1200 K using synchrotron X-ray powder diffraction revealed only two polymorphs that resemble VO2: the low-temperature monoclinic MoO2-type form (space group P2(1)/c), and the tetragonal rutile-like form (space group P4(2)/mnm). However, for compositions with 0.03 < x <= 0.15 a phase separation in the solid solution was observed below 1000 K upon cooling down from 1200 K, giving rise to two isostructural phases with slightly different lattice parameters. This is reflected in the appearance of two metal-toinsulator transition temperatures detected by magnetization and specific heat measurements. Comprehensive X-ray photoelectron spectroscopy studies showed that an increased amount of Re leads to a change in the Re valence state from solely Re6+ at a low doping level (<= 3 at% Re) via mixed-valence states Re4+/Re6+ for at least 0.03 < x <= 0.10, up to nearly pure Re4+ in V0.70Re0.30O2. Thus, compositions V1-xRexO2 with only one valence state of Re in the material (Re6+ or Re4+) can be obtained as a single phase, while intermediate compositions are subjected to a phase separation, presumably due to different valence states of Re.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos (up) 000395442700030 Publication Date 2016-12-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0300-9246; 1477-9226; 1472-7773 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.029 Times cited 1 Open Access Not_Open_Access
Notes ; The authors are indebted to Dr G. Auffermann (Max Planck Institute for Chemical Physics of Solids, Dresden, Germany) for performing the ICP-OES analyses. This research has received a partial funding from the BMBF, project grant number 03SF0477B (DESIREE). AT acknowledges financial support from Federal Ministry for Education and Research under Sofja Kovalevksaya Award of Alexander von Humboldt Foundation. AMA is grateful to the Russian Science Foundation (grant 14-13-00680) for financial support. ; Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:142580 Serial 4642
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Author Tarasov, A.; Hu, Z.-Y.; Meledina, M.; Trusov, G.; Goodilin, E.; Van Tendeloo, G.; Dobrovolsky, Y.
Title One-Step Microheterogeneous Formation of Rutile@Anatase Core–Shell Nanostructured Microspheres Discovered by Precise Phase Mapping Type A1 Journal article
Year 2017 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 121 Issue 121 Pages 4443-4450
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Nanostructured core−shell microspheres with a rough rutile core and a thin anatase shell are synthesized via a one-step heterogeneous templated hydrolysis process of TiCl4 vapor on the aerosol water−air interface. The rutile-in-anatase core−shell structure has been evidenced by different electron microscopy techniques, including electron energy-loss spectroscopy and 3D electron tomography. A new mechanism for the formation of a crystalline rutile core inside the anatase shell is proposed based on a statistical evaluation of a large number of electron microscopy data. We found that the control over the TiCl4 vapor pressure, the ratio between TiCl4 and H2O aerosol, and the reaction conditions plays a crucial role in the formation of the core−shell morphology and increases the yield of nanostructured microspheres.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000395616200038 Publication Date 2017-03-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 4 Open Access OpenAccess
Notes Z.-Y.H., M. M., and G.V.T. acknowledge support from the the EC Framework 7 program ESTEEM2 (Reference 312483). Approved Most recent IF: 4.536
Call Number EMAT @ emat @ c:irua:141720 Serial 4472
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Author Abeysinghe, D.; Smith, M.D.; Yeon, J.; Tran, T.T.; Sena, R.P.; Hadermann, J.; Halasyamani, P.S.; zur Loye, H.-C.
Title Crystal growth and structure analysis of Ce-18-W-10-O-57 : a complex oxide containing tungsten in an unusual trigonal prismatic coordination environment Type A1 Journal article
Year 2017 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
Volume 56 Issue 5 Pages 2566-2575
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The noncentrosymmetric tungstate oxide, Ce18W10O57) was synthesized for the first time as high-quality single crystals via the molten chloride flux method and structurally characterized by single-crystal X-ray diffraction. The compound is a structural analogue to the previously reported La18W10O57, which crystallizes in the hexagonal space group P (6) over bar 2c. The +3 oxidation state of cerium in Ce18W10O57 was achieved via the in situ reduction of Ce(IV) to Ce(III) using Zn metal. The structure consists of both isolated and face-shared WO6 octahedra and, surprisingly, isolated WO6 trigonal prisms. A careful analysis of the packing arrangement in the structure makes it possible to explain the unusual structural architecture of Ce18W10O57, which is described in detail. The temperature-dependent magnetic susceptibility of Ce18W10O57 indicates that the cerium(III) f(1) cations do not order magnetically and exhibit simple paramagnetic behavior. The SHG efficiency of Ln(18)W(10)O(57) (Ln = La, Ce) was measured as a function of particle size, and both compounds were found to be SHG active with efficiency approximately equal to that of alpha-SiO2.
Address
Corporate Author Thesis
Publisher Place of Publication Easton, Pa Editor
Language Wos (up) 000395847300026 Publication Date 2017-02-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-1669 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.857 Times cited 9 Open Access Not_Open_Access
Notes ; Financial support for this work was provided by the National Science Foundation under DMR-1301757 and is gratefully acknowledged. T.T.T. and P.S.H. thank the Welch Foundation (Grant E-1457) and NSF-DMR-1503573. ; Approved Most recent IF: 4.857
Call Number UA @ lucian @ c:irua:142449 Serial 4643
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Author Kurttepeli, M.; Deng, S.; Mattelaer, F.; Cott, D.J.; Vereecken, P.; Dendooven, J.; Detavernier, C.; Bals, S.
Title Heterogeneous TiO2/V2O5/Carbon Nanotube Electrodes for Lithium-Ion Batteries Type A1 Journal article
Year 2017 Publication ACS applied materials and interfaces Abbreviated Journal Acs Appl Mater Inter
Volume 9 Issue 9 Pages 8055-8064
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Vanadium pentoxide (V2O5) is proposed and investigated as a cathode material for lithium-ion (Li-ion) batteries. However, the dissolution of V2O5 during the charge/discharge remains as an issue at the V2O5–electrolyte interface. In this work, we present a heterogeneous nanostructure with carbon nanotubes supported V2O5/titanium dioxide (TiO2) multilayers as electrodes for thin-film Li-ion batteries. Atomic layer deposition of V2O5 on carbon nanotubes provides enhanced Li storage capacity and high rate performance. An additional TiO2 layer leads to increased morphological stability and in return higher electrochemical cycling performance of V2O5/carbon nanotubes. The physical and chemical properties of TiO2/V2O5/carbon nanotubes are characterized by cyclic voltammetry and charge/discharge measurements as well as electron microscopy. The detailed mechanism of the protective TiO2 layer to improve the electrochemical cycling stability of the V2O5 is unveiled.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000396186000021 Publication Date 2017-03-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1944-8244 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.504 Times cited 28 Open Access OpenAccess
Notes European Research Council, 239865 335078 ; Fonds Wetenschappelijk Onderzoek; Agentschap voor Innovatie door Wetenschap en Technologie, 18142 ; Bijzonder Onderzoeksfonds, GOA – 01G01513 ; This research was funded by the Flemish research foundation FWO-Vlaanderen, by the European Research Council (Starting Grant No. 239865 and No. 335078), by IWT-Flanders (SBO project IWT 18142 “SoS-Lion”) and by the Special Research Fund BOF of Ghent University (GOA – 01G01513); colouratoms (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ECAS_Sara Approved Most recent IF: 7.504
Call Number EMAT @ emat @ c:irua:142446UA @ admin @ c:irua:142446 Serial 4572
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Author Conings, B.; Bretschneider, S.A.; Babayigit, A.; Gauquelin, N.; Cardinaletti, I.; Manca, J.V.; Verbeeck, J.; Snaith, H.J.; Boyen, H.-G.
Title Structure-property relations of methylamine vapor treated hybrid perovskite CH3NH3PbI3 films and solar cells Type A1 Journal article
Year 2017 Publication ACS applied materials and interfaces Abbreviated Journal Acs Appl Mater Inter
Volume 9 Issue 9 Pages 8092-8099
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The power conversion efficiency of halide perovskite solar cells is heavily dependent on the perovskite layer being sufficiently smooth and pinhole-free. It has been shown that these features can be obtained even when starting out from rough and discontinuous perovskite film, by briefly exposing it to methylamine (MA) vapor. The exact underlying physical mechanisms of this phenomenon are, however, still unclear. By investigating smooth, MA treated films, based on very rough and discontinuous reference films of methylammonium triiode (MAPbI3), considering their morphology, crystalline features, local conductive properties, and charge carrier lifetime, we unravel the relation between their characteristic physical qualities and their performance in corresponding solar cells. We discover that the extensive improvement in photovoltaic performance upon MA treatment is a consequence of the induced morphological enhancement of the perovskite layer, together with improved electron injection into TiO2, which in fact compensates for an otherwise compromised bulk electronic quality, simultaneously caused by the MA treatment.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000396186000025 Publication Date 2017-02-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1944-8244 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.504 Times cited 43 Open Access OpenAccess
Notes This work was financially supported by BOF (Hasselt University) and the Research Fund Flanders (FWO). B.C. is a postdoctoral research fellow of the FWO. A.B. is financially supported by FWO and Imec. J.V. and N.G. acknowledge funding from GOA project “Solarpaint” of the University of Antwerp and FWO project G.0044.13N “Charge ordering”. The Qu-Ant-EM microscope used for this study was partly funded by the Hercules fund from the Flemish Government. The authors thank Tim Vangerven for Urbach energy determination, and Johnny Baccus and Jan Mertens for technical support. Approved Most recent IF: 7.504
Call Number EMAT @ emat @ c:irua:140849 Serial 4422
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Author Ben Dkhil, S.; Pfannmöller, M.; Saba, M.I.; Gaceur, M.; Heidari, H.; Videlot-Ackermann, C.; Margeat, O.; Guerrero, A.; Bisquert, J.; Garcia-Belmonte, G.; Mattoni, A.; Bals, S.; Ackermann, J.
Title Toward high-temperature stability of PTB7-based bulk heterojunction solar cells : impact of fullerene size and solvent additive Type A1 Journal article
Year 2017 Publication Laser physics review Abbreviated Journal Adv Energy Mater
Volume 7 Issue 7 Pages 1601486
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The use of fullerene as acceptor limits the thermal stability of organic solar cells at high temperatures as their diffusion inside the donor leads to phase separation via Ostwald ripening. Here it is reported that fullerene diffusion is fully suppressed at temperatures up to 140 degrees C in bulk heterojunctions based on the benzodithiophene-based polymer (the poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b: 4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl) carbonyl]thieno[3,4-b]thiophenediyl]], (PTB7) in combination with the fullerene derivative [6,6]-phenyl-C71-butyric acid methyl ester (PC70BM). The blend stability is found independently of the presence of diiodooctane (DIO) used to optimize nanostructuration and in contrast to PTB7 blends using the smaller fullerene derivative PC70BM. The unprecedented thermal stability of PTB7: PC70BM layers is addressed to local minima in the mixing enthalpy of the blend forming stable phases that inhibit fullerene diffusion. Importantly, although the nanoscale morphology of DIO processed blends is thermally stable, corresponding devices show strong performance losses under thermal stress. Only by the use of a high temperature annealing step removing residual DIO from the device, remarkably stable high efficiency solar cells with performance losses less than 10% after a continuous annealing at 140 degrees C over 3 days are obtained. These results pave the way toward high temperature stable polymer solar cells using fullerene acceptors.
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Corporate Author Thesis
Publisher Place of Publication Place of publication unknown Editor
Language Wos (up) 000396328500009 Publication Date 2016-11-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1614-6832; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 16.721 Times cited 27 Open Access Not_Open_Access
Notes ; The authors acknowledge financial support by the French Fond Unique Interministeriel (FUI) under the project “SFUMATO” (grant number: F1110019V/ 201308815) as well as by the European Commission under the Project “SUNFLOWER” (FP7-ICT-2011-7, grant number: 287594). Generalitat Valenciana (ISIC/2012/008 Institute of Nanotechnologies for Clean Energies) is also acknowledged for providing financial support. The authors further acknowledge financial support via ERC Starting Grant Colouratoms (335078). ; Approved Most recent IF: 16.721
Call Number UA @ lucian @ c:irua:141991UA @ admin @ c:irua:141991 Serial 4697
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Author Hunter, E.C.; Battle, P.D.; Sena, R.P.; Hadermann, J.
Title Ferrimagnetism as a consequence of cation ordering in the perovskite LaSr2Cr2SbO9 Type A1 Journal article
Year 2017 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume 248 Issue Pages 96-103
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A polycrystalline sample of LaSr2Cr2SbO9 has been synthesised using a standard ceramic method and characterized by x-ray and neutron diffraction, magnetometry and electron microscopy. The perovskite-related compound crystallises in the triclinic space group I1 with unit cell parameters of a=5.5344(6) angstrom, b=5.5562(5) angstrom, c=7.8292(7) angstrom, a=89.986(12)degrees, beta=90.350(5)degrees and gamma=89.926(9)degrees at room temperature. The two crystallographically-distinct, six-coordinate cation sites are occupied by Cr3+ and Sb5+ in ratios of 0.868(2):0.132(2) and 0.462(2):0.538(2). Ac and de magnetometry revealed that LaSr2Cr2SbO9 is ferrimagnetic below 150 K with a magnetisation of similar to 1.25 mu(B) per formula unit in 50 kOe at 5 K. Neutron diffraction showed that the cations on the two sites order in a G-type arrangement with a mean Cr3+ moment of 2.17(1) mu(B) at 5 K, consistent with a magnetisation of 1.32 mu(B) per formula unit.
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Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos (up) 000396386300012 Publication Date 2017-01-31
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 14 Open Access Not_Open_Access
Notes ; Experiments at the ISIS Pulsed Neutron and Muon Source were supported by the STFC. We are grateful to I. da Silva for the assistance provided at ISIS and to the EPSRC for financial support under Grant EP/M018954/1. We also thank Diamond Light Source Ltd (EE13284) for the award of beamtime. ; Approved Most recent IF: 2.299
Call Number UA @ lucian @ c:irua:142413 Serial 4657
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Author Lepot, K.; Addad, A.; Knoll, A.H.; Wang, J.; Troadec, D.; Béché, A.; Javaux, E.J.
Title Iron minerals within specific microfossil morphospecies of the 1.88 Ga Gunflint Formation Type A1 Journal article
Year 2017 Publication Nature communications Abbreviated Journal Nat Commun
Volume 8 Issue 8 Pages 14890
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Problematic microfossils dominate the palaeontological record between the Great Oxidation Event 2.4 billion years ago (Ga) and the last Palaeoproterozoic iron formations, deposited 500–600 million years later. These fossils are often associated with iron-rich sedimentary rocks, but their affinities, metabolism, and, hence, their contributions to Earth surface oxidation and Fe deposition remain unknown. Here we show that specific microfossil populations of the 1.88 Ga Gunflint Iron Formation contain Fe-silicate and Fe-carbonate nanocrystal concentrations in cell interiors. Fe minerals are absent in/on all organically preserved cell walls. These features are consistent with in vivo intracellular Fe biomineralization, with subsequent in situ recrystallization, but contrast with known patterns of post-mortem Fe mineralization. The Gunflint populations that display relatively large cells (thick-walled spheres, filament-forming rods) and intra-microfossil Fe minerals are consistent with oxygenic photosynthesizers but not with other Fe-mineralizing microorganisms studied so far. Fe biomineralization may have protected oxygenic photosynthesizers against Fe2+ toxicity during the Palaeoproterozoic.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000397129900001 Publication Date 2017-03-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 20 Open Access OpenAccess
Notes We thank J.-P. Cullus (thin sections), G. Spronck and C. Henrist (TEM), M. Cabié and C. Dominici (FIB), S. Bernard and C. Karunakaran (STXM), F. Bourdelle and G. Ji (EELS), P. Recourt (SEM). This study was co-funded by FRFC Grant no. 2.4558.09F (E.J.J.), CNRS-INSU (K.L.), FNRS (K.L.), ERC StG ELiTE Grant no. 308074 (E.J.J.), BELSPO IAP PLANET TOPERS (E.J.J.), NASA Astrobiology Institute (A.H.K.), Conseil Régional du Nord-Pas de Calais+European Regional Development Fund+CNRS-INSU (TEM in Lille), FP7-ESMI no. 262348 (TEM at EMAT Antwerp) and ANR-15-CE31-0003-01 (M6fossils, K.L.). We thank Noah Planavsky and two anonymous reviewers for thorough reviews that helped improve the paper. Approved Most recent IF: 12.124
Call Number EMAT @ emat @ c:irua:141919 Serial 4536
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Author Tunca, B.; Lapauw, T.; Karakulina, O.M.; Batuk, M.; Cabioc’h, T.; Hadermann, J.; Delville, R.; Lambrinou, K.; Vleugels, J.
Title Synthesis of MAX Phases in the Zr-Ti-Al-C System Type A1 Journal article
Year 2017 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
Volume 56 Issue 56 Pages 3489-3498
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract This study reports on the synthesis and characterization of MAX phases in the (Zr,Ti)n+1AlCn system. The MAX phases were synthesized by reactive hot pressing and pressureless sintering in the 1350–1700 °C temperature range. The produced ceramics contained large fractions of 211 and 312 (n = 1, 2) MAX phases, while strong evidence of a 413 (n = 3) stacking was found. Moreover, (Zr,Ti)C, ZrAl2, ZrAl3, and Zr2Al3 were present as secondary phases. In general, the lattice parameters of the hexagonal 211 and 312 phases followed Vegard’s law over the complete Zr-Ti solid solution range, but the 312 phase showed a non-negligible deviation from Vegard’s law around the (Zr0.33,Ti0.67)3Al1.2C1.6 stoichiometry. High-resolution scanning transmission electron microscopy combined with X-ray diffraction demonstrated ordering of the Zr and Ti atoms in the 312 phase, whereby Zr atoms occupied preferentially the central position in the close-packed M6X octahedral layers. The same ordering was also observed in 413 stackings present within the 312 phase. The decomposition of the secondary (Zr,Ti)C phase was attributed to the miscibility gap in the ZrC-TiC system.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000397171100045 Publication Date 2017-03-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-1669 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.857 Times cited 26 Open Access OpenAccess
Notes Fonds Wetenschappelijk Onderzoek, G.0431.10N.F ; Agentschap voor Innovatie door Wetenschap en Technologie, 131081 ; European Atomic Energy Community, 604862 ; SCK-CEN Academy for Nuclear Science and Technology; Hercules Foundation, Project/Award no: AKUL/1319 Project/Award no: ZW09-09 ; Approved Most recent IF: 4.857
Call Number EMAT @ emat @ c:irua:141794 Serial 4491
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Author Barhoum, A.; Van Assche, G.; Rahier, H.; Fleisch, M.; Bals, S.; Delplancked, M.-P.; Leroux, F.; Bahnemann, D.
Title Sol-gel hot injection synthesis of ZnO nanoparticles into a porous silica matrix and reaction mechanism Type A1 Journal article
Year 2017 Publication Materials & design Abbreviated Journal Mater Design
Volume 119 Issue 119 Pages 270-276
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Despite the enormous interest in the properties and applications of porous silica matrix, only a few attempts have been reported to deposit metal and metal oxide nanoparticles (NPs) inside the porous silica matrix. We report a simple approach (i.e. sol-gel hot injection) for insitu synthesis of ZnO NPs inside a porous silica matrix. Control of the Zn:Si molar ratio, reaction temperature, pH value, and annealing temperature permits formation of ZnO NPs (<= 10 nm) inside a porous silica particles, without additives or organic solvents. Results revealed that a solid state reaction inside the ZnO/SiO2 nanocomposites occurs with increasing the annealing temperature. The reaction of ZnO NPs with SiO2 matrix was insignificant up to approximately 500 degrees C. However, ZnO NPs react strongly with the silica matrix when the nanocomposites are annealed at temperatures above 700 degrees C. Extensive annealing of the ZnO/SiO2 nanocomposite at 900 degrees C yields 3D structures made of 500 nm rod-like, 5-7 pm tube-like and 35 pm needle-like Zn2SiO4 crystals. A possible mechanism for forming ZnO NPs inside porous silica matrix and phase transformation of the ZnO/SiO2 nanocomposites into 3D architectures of Zn2SiO4 are carefully discussed. (C) 2017 Elsevier Ltd. All rights reserved.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000397360000030 Publication Date 2017-01-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0264-1275 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.364 Times cited 43 Open Access Not_Open_Access
Notes ; A.B. would like to thank FWO – Research Foundation Flanders (grant no. V450315N) and the Strategic Initiative Materials in Flanders (SBO-project no. 130529 – INSITU) for financial support. TEM and TEM-EDX analyses were performed by Dr. F. Leroux (EMAT, Universiteit Antwerpen). XRD and DSC measurements were performed by T. Segato (4MAT, Universite Libre de Bruxelles). Notes: the authors declare no competing for financial interest. ; Approved Most recent IF: 4.364
Call Number UA @ lucian @ c:irua:142394UA @ admin @ c:irua:142394 Serial 4689
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Author van der Stam, W.; Geuchies, J.J.; Altantzis, T.; van den Bos, K.H.W.; Meeldijk, J.D.; Van Aert, S.; Bals, S.; Vanmaekelbergh, D.; de Mello Donega, C.
Title Highly Emissive Divalent-Ion-Doped Colloidal CsPb1–xMxBr3Perovskite Nanocrystals through Cation Exchange Type A1 Journal article
Year 2017 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
Volume 139 Issue 139 Pages 4087-4097
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Colloidal CsPbX3 (X = Br, Cl, and I) perovskite nanocrystals (NCs) have emerged as promising phosphors and solar cell materials due to their remarkable optoelectronic properties. These properties can be tailored by not only controlling the size and shape of the NCs but also postsynthetic composition tuning through topotactic

anion exchange. In contrast, property control by cation exchange is still underdeveloped for colloidal CsPbX3 NCs. Here, we present a method that allows partial cation exchange in colloidal CsPbBr3 NCs, whereby Pb2+ is exchanged for several isovalent cations, resulting in doped CsPb1−xMxBr3 NCs (M= Sn2+, Cd2+, and Zn2+; 0 < x ≤ 0.1), with preservation of the original NC shape. The size of the parent NCs is also preserved in the product NCs, apart from a small (few

%) contraction of the unit cells upon incorporation of the guest cations. The partial Pb2+ for M2+ exchange leads to a blue-shift of the optical spectra, while maintaining the high photoluminescence quantum yields (>50%), sharp absorption features, and narrow emission of the parent CsPbBr3 NCs. The blue-shift in the optical spectra is attributed to the lattice contraction that accompanies the Pb2+ for M2+ cation exchange and is observed to scale linearly with the lattice contraction. This work opens up new possibilities to engineer the properties of halide perovskite NCs, which to date are demonstrated to be the only known

system where cation and anion exchange reactions can be sequentially combined while preserving the original NC shape, resulting in compositionally diverse perovskite NCs.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000397477700027 Publication Date 2017-03-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-7863 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.858 Times cited 535 Open Access OpenAccess
Notes W.v.d.S. and C.d.M.D. acknowledge financial support from the division of Chemical Sciences (CW) of The Netherlands Organization for Scientific Research (NWO) under grant number ECHO.712.012.001. J.J.G. and D.V. acknowledge financial support from the Debye Graduate program. S.B. acknowledges financial support from the European Research Council (ERC Starting Grant # 335078-COLOURATOMS). K.H.W.v.d.B., S.B., S.V.A. and T.A. acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0368.15N, G.0369.15N), a Ph.D. grant to K.H.W.v.d.B, and a postdoctoral research grant to T.A. (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ECAS_Sara Approved Most recent IF: 13.858
Call Number EMAT @ emat @ c:irua:141754UA @ admin @ c:irua:141754 Serial 4482
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Author Rahemi, V.; Sarmadian, N.; Anaf, W.; Janssens, K.; Lamoen, D.; Partoens, B.; De Wael, K.
Title Unique opto-electronic structure and photo reduction properties of sulfur doped lead chromates explaining their instability in paintings Type A1 Journal article
Year 2017 Publication Analytical chemistry Abbreviated Journal Anal Chem
Volume 89 Issue 89 Pages 3326-3334
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Chrome yellow refers to a group of synthetic inorganic pigments that became popular as an artists material from the second quarter of the 19th century. The color of the pigment, in which the chromate ion acts as a chromophore, is related to its chemical composition (PbCr1-xSxO4, with 0≤x≤0.8) and crystalline structure (monoclinic/orthorhombic). Their shades range from the yellow-orange to the paler yellow tones with increasing sulfate amount. These pigments show remarkable signs of degradation after limited time periods. Pure PbCrO4 (crocoite in its natural form) has a deep yellow color and is relatively stable, while the co-precipitate with lead sulfate (PbCr1-xSxO4) has a paler shade and seems to degrade faster. This degradation is assumed to be related to the reduction of Cr(VI) to Cr(III). We show that on increasing the sulfur(S)-content in chrome yellow, the band gap increases. Typically, when increasing the band gap, one might assume that a decrease in photo activity is the result. However, the photo activity relative to the Cr content, and thus Cr reduction, of sulfur-rich PbCr1-xSxO4 is found to be much higher compared to the sulfur-poor or non-doped lead chromates. This discrepancy can be explained by the evolution of the crystal and electronic structure as function of the sulfur content: first-principles density functional theory calculations show that both the absorption coefficient and reflection coefficients of the lead chromates change as a result of the sulfate doping in such a way that the generation of electron-hole pairs under illumination relative to the total Cr content increases. These changes in the material properties explain why paler shade yellow colors of this pigment are more prone to discoloration. The electronic structure calculations also demonstrate that lead chromate and its co-precipitates are p-type semiconductors, which explains the observed reduction reaction. As understanding this phenomenon is valuable in the field of cultural heritage, this study is the first joint action of photo-electrochemical measurements and first-principles calculations to approve the higher tendency of sulfur-rich lead chromates to darken.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos (up) 000397478300015 Publication Date 2017-02-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-2700 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.32 Times cited 7 Open Access OpenAccess
Notes ; The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government, department EWI. The BOF-GOA action SOLARPAINT of the University of Antwerp Research Council is acknowledged for financial support. W.A. acknowledges support from BELSPO project S2-ART. Dr. L. Monico and Dr. C. Miliani (ISTM, Perugia) are gratefully acknowledged for helpful discussions and for providing some of the initial batches of the materials studied. ; Approved Most recent IF: 6.32
Call Number UA @ lucian @ c:irua:140886 Serial 4451
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