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Author Verbruggen, S.W.; Ribbens, S.; Tytgat, T.; Hauchecorne, B.; Smits, M.; Meynen, V.; Cool, P.; Martens, J.A.; Lenaerts, S.
  Title The benefit of glass bead supports for efficient gas phase photocatalysis : case study of a commercial and a synthesised photocatalyst Type A1 Journal article
  Year (up) 2011 Publication Chemical engineering journal Abbreviated Journal Chem Eng J
  Volume 174 Issue 1 Pages 318-325
  Keywords A1 Journal article; Engineering sciences. Technology; Laboratory of adsorption and catalysis (LADCA); Sustainable Energy, Air and Water Technology (DuEL)
  Abstract In the field of photocatalytic air purification, the immobilisation of catalyst particles on support surfaces without loss of photon efficiency is an important challenge. Therefore, an immobilisation method involving a one-step suspension coating of pre-synthesised photocatalysts on glass beads was applied. The various benefits are exemplified in the gas phase photodegradation of ethylene. Coating of glass beads is easy, fast, cheap and offers a more efficient alternative to bulk catalyst pellets. Furthermore, this coating procedure allows to use porous, pre-synthesised catalysts to their full potential, as the surface area and morphology of the initial powder is barely altered after coating, in strong contrast to pelletising. With this technique it became possible to study the gas phase photocatalytic activity of commercial titanium dioxide, trititanate nanotubes and mixed phase anatase/trititanate nanotubes in a packed bed reactor towards the degradation of ethylene without changing the catalyst properties. Coating of glass beads with the photocatalyst revealed the superior activity of the as-prepared nanotubes, compared to TiO2 Aerolyst® 7710 in gaseous phase.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000296950300041 Publication Date 2011-09-17
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1385-8947; 1873-3212 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 6.216 Times cited 39 Open Access
  Notes ; The author wishes to acknowledge the Research Foundation of Flanders (FWO) for the financial support. Evonik is greatly thanked for supplying the TiO<INF>2</ INF> Aerolyst (R) 7710 pellets. ; Approved Most recent IF: 6.216; 2011 IF: 3.461
  Call Number UA @ admin @ c:irua:93364 Serial 5929
Permanent link to this record
 

 
Author Jammaer, J.; Aprile, C.; Verbruggen, S.W.; Lenaerts, S.; Pescarmona, P.P.; Martens, J.A.
  Title A non-aqueous synthesis of TiO2SiO2 composites in supercritical CO2 for the photodegradation of pollutants Type A1 Journal article
  Year (up) 2011 Publication Chemsuschem Abbreviated Journal Chemsuschem
  Volume 4 Issue 10 Pages 1457-1463
  Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
  Abstract Titania/silica composites with different Ti/Si ratios are synthesized via a nonconventional synthesis route. The synthesis involves non-aqueous reaction of metal alkoxides and formic acid at 75 °C in supercritical carbon dioxide. The as-prepared composite materials contain nanometer-sized anatase crystallites and amorphous silica. Large specific surface areas are obtained. The composites are evaluated in the photocatalytic degradation of phenol in aqueous medium, and in the elimination of acetaldehyde from air. The highest photocatalytic activity in both processes is achieved with a composite containing 40 wt % TiO2.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000296497400010 Publication Date 2011-05-20
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1864-5631 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 7.226 Times cited 15 Open Access
  Notes ; The authors acknowledge sponsorship from CECAT and Methusalem (long-term financing of the Flemish government). We thank Dr. E. Gobechiya for assistance with XRD measurements and A. Lemaire for assistance with mercury porosimetry measurements. ; Approved Most recent IF: 7.226; 2011 IF: 6.827
  Call Number UA @ admin @ c:irua:93363 Serial 5973
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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 (up) 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume 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 Narayanan, V.; Lommens, P.; De Buysser, K.; Vanpoucke, D.E.P.; Huehne, R.; Molina, L.; Van Tendeloo, G.; van der Voort, P.; Van Driessche, I.
  Title Aqueous CSD approach for the growth of novel, lattice-tuned LaxCe1-xO\delta epitaxial layers Type A1 Journal article
  Year (up) 2012 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem
  Volume 22 Issue 17 Pages 8476-8483
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Lanthanumcerium oxide (LCO) films were deposited on Ni-5%W substrates by chemical solution deposition (CSD) from water-based precursors. LCO films containing different ratios of lanthanum and cerium ions (from CeO2 to La2Ce2O7) were prepared. The composition of the layers was optimized towards the formation of LCO buffer layers, lattice-matched with the superconducting YBa2Cu3Oy layer, useful for the development of coated conductors. Single, crack-free LCO layers with a thickness of up to 140 nm could be obtained in a single deposition step. The crystallinity and microstructure of these lattice-matched LCO layers were studied by X-ray diffraction techniques, RHEED and SEM. We find that only layers with thickness below 100 nm show a crystalline top surface although both thick and thin layers show good biaxial texture in XRD. On the most promising layers, AFM and (S)TEM were performed to further evaluate their morphology. The overall surface roughness varies between 3.9 and 7.5 nm, while the layers appear much more dense than the frequently used La2Zr2O7 (LZO) systems, showing much smaller nanovoids (12 nm) than the latter system. Their effective buffer layer action was studied using XPS. The thin LCO layers supported the growth of superconducting YBCO deposited using PLD methods.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Cambridge Editor
  Language Wos 000302367500044 Publication Date 2012-03-20
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0959-9428;1364-5501; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor Times cited 24 Open Access
  Notes Iap Approved Most recent IF: NA
  Call Number UA @ lucian @ c:irua:96960 Serial 148
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Author Palgrave, R.G.; Borisov, P.; Dyer, M.S.; McMitchell, S.R.C.; Darling, G.R.; Claridge, J.B.; Batuk, M.; Tan, H.; Tian, H.; Verbeeck, J.; Hadermann, J.; Rosseinsky, M.J.;
  Title Artificial construction of the layered Ruddlesden-Popper manganite La2Sr2Mn3O10 by reflection high energy electron diffraction monitored pulsed laser deposition Type A1 Journal article
  Year (up) 2012 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
  Volume 134 Issue 18 Pages 7700-7714
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Pulsed laser deposition has been used to artificially construct the n = 3 Ruddlesden Popper structure La2Sr2Mn3O10 in epitaxial thin film form by sequentially layering La1-xSrxMnO3 and SrO unit cells aided by in situ reflection high energy electron diffraction monitoring. The interval deposition technique was used to promote two-dimensional SrO growth. X-ray diffraction and cross-sectional transmission electron microscopy indicated that the trilayer structure had been formed. A site ordering was found to differ from that expected thermodynamically, with the smaller Sr2+ predominantly on the R site due to kinetic trapping of the deposited cation sequence. A dependence of the out-of-plane lattice parameter on growth pressure was interpreted as changing the oxygen content of the films. Magnetic and transport measurements on fully oxygenated films indicated a frustrated magnetic ground state characterized as a spin glass-like magnetic phase with the glass temperature T-g approximate to 34 K. The magnetic frustration has a clear in-plane (ab) magnetic anisotropy, which is maintained up to temperatures of 150 K. Density functional theory calculations suggest competing antiferromagnetic and ferromagnetic long-range orders, which are proposed as the origin of the low-temperature glassy state.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000303696200029 Publication Date 2012-03-30
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 13.858 Times cited 27 Open Access
  Notes Fwo; Esteem 026019 Approved Most recent IF: 13.858; 2012 IF: 10.677
  Call Number UA @ lucian @ c:irua:98947UA @ admin @ c:irua:98947 Serial 153
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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 (up) 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume 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 Marikutsa, A.; Krivetskiy, V.; Yashina, L.; Rumyantseva, M.; Konstantinova, E.; Ponzoni, A.; Comini, E.; Abakumov, A.; Gaskov, A.
  Title Catalytic impact of RuOx clusters to high ammonia sensitivity of tin dioxide Type A1 Journal article
  Year (up) 2012 Publication Sensors and actuators : B : chemical T2 – 25th Eurosensors Conference, SEP 04-07, 2011, Athens, GREECE Abbreviated Journal Sensor Actuat B-Chem
  Volume 175 Issue Pages 186-193
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract A comparative study of NH3-sensing performance of blank and modified nanocrystal line SnO2 was performed. Tin dioxide modified by ruthenium displayed the highest ammonia sensitivity with a maximum signal at 200 degrees C. The modifier was shown by XPS and EPR to occur in a mixed valence state of oxidized ruthenium distributed between the surface and bulk of tin dioxide nanocrystals. RuOx clustering on SnO2 surface was detected by means of electron microscopy assisted EDX-mapping. The effect of RuOx on tin dioxide interaction with ammonia was studied by temperature-programmed NH3 desorption, simultaneous Kelvin probe and DC-resistance measurements, EPR spectroscopy and analyses of the gas-solid interaction products. The modifier was shown to promote the materials reactivity to NH3 due to the catalytic activity of RuOx. The interaction with ammonia resulted in dipoles formation on the oxide surface along with reducing the grains net surface charge, established from the electron affinity increase and resistance decrease during NH3 exposure. The RuOx-catalyzed gas-solid interaction was deduced to proceed deeper than in the case of non-modified SnO2 and to yield nitrogen oxides (e.g. NO2), as was suggested by the oxidative character of gaseous products of NH3 interaction with RuOx-modified tin dioxide at 200 degrees C. (C) 2012 Elsevier B.V. All rights reserved.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lausanne Editor
  Language Wos 000312358700033 Publication Date 2012-06-19
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0925-4005; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 5.401 Times cited 20 Open Access
  Notes Approved Most recent IF: 5.401; 2012 IF: 3.535
  Call Number UA @ lucian @ c:irua:105985 Serial 293
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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 (up) 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume 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 de Oliveira, E.L.; Albuquerque, E.L.; de Sousa, J.S.; Farias, G.A.; Peeters, F.M.
  Title Configuration-interaction excitonic absorption in small Si/Ge and Ge/Si core/shell nanocrystals Type A1 Journal article
  Year (up) 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 116 Issue 7 Pages 4399-4407
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
  Abstract The excitonic properties of Si(core)/Ge(shell) and Ge(core)/Si(shell) nanocrystals (NC's) with diameters of similar to 1.9 nm are investigated using a combination density functional ab initio method to obtain the single particle wave functions and a configuration interaction method to compute the exciton fine structure and absorption coefficient. These core/shell structures exhibit type II confinement, which is more pronounced for the Si/Ge NC as a consequence of strain. The absorption coefficients of these NC's exhibit a single dominant peak, which has a much larger oscillator strength than the multipeaks found for pure Si and Ge NC's. The exciton lifetime in Si, Ge, and Ge/Si shows a small i:emperature dependence in the range 10-300 K, whereas in Si/Ge, the exciton lifetime decreases more than an order of magnitude in the same temperature range.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000301156500007 Publication Date 2012-01-04
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.536 Times cited 44 Open Access
  Notes ; The authors acknowledge financial support from CNPq and the bilateral program between Flanders and Brazil and the Belgian Science Foundation (IAP). ; Approved Most recent IF: 4.536; 2012 IF: 4.814
  Call Number UA @ lucian @ c:irua:113045 Serial 482
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Author Wee, L.H.; Wiktor, C.; Turner, S.; Vanderlinden, W.; Janssens, N.; Bajpe, S.R.; Houthoofd, K.; Van Tendeloo, G.; De Feyter, S.; Kirschhock, C.E.A.; Martens, J.A.;
  Title Copper benzene tricarboxylate metal-organic framework with wide permanent mesopores stabilized by keggin polyoxometallate ions Type A1 Journal article
  Year (up) 2012 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
  Volume 134 Issue 26 Pages 10911-10919
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Porous solids with organized multiple porosity are of scientific and technological importance for broadening the application range from traditional areas of catalysis and adsorption/separation to drug release and biomedical imaging. Synthesis of crystalline porous materials offering a network of uniform micro- and mesopores remains a major scientific challenge. One strategy is based on variation of synthesis parameters of microporous networks, such as, for example, zeolites or metal organic frameworks (MOFs). Here, we show the rational development of an hierarchical variant of the microporous cubic Cu-3(BTC)(2) (BTC = 1,3,5-benzenetricarboxylate) HKUST-1 MOF having strictly repetitive S inn wide mesopores separated by uniform microporous walls in a single crystal structure. This new material coined COK-15 (COK = Centrum voor Oppervlaktechemie en Katalyse) was synthesized via a dual-templating approach. Stability was enhanced by Keggin type phosphotungstate (HPW) systematically occluded in the cavities constituting the walls between the mesopores.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000305863900037 Publication Date 2012-06-06
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 13.858 Times cited 83 Open Access
  Notes Iap; Fwo Approved Most recent IF: 13.858; 2012 IF: 10.677
  Call Number UA @ lucian @ c:irua:100330 Serial 514
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Author Nagy, N.V.; Van Doorslaer, S.; Szabó-Plánka, T.; Van Rompaey, S.; Hamza, A.; Fülöp, F.; Tóth, G.K.; Rockenbauer, A.
  Title Copper(II)-binding ability of stereoisomeric cis- and trans-2-aminocyclohexanecarboxylic acidl-phenylalanine dipeptides : a combined CW/pulsed EPR and DFT study Type A1 Journal article
  Year (up) 2012 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
  Volume 51 Issue 3 Pages 1386-1399
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract With the aim of an improved understanding of the metal-complexation properties of alicyclic β-amino acid stereoisomers, and their peptides, the complex equilibria and modes of coordination with copper(II) of l-phenylalanine (F) derivatives of cis/trans-2-aminocyclohexanecarboxylic acid (c/tACHC), i.e. the dipeptides F-c/tACHC and c/tACHC-F, were investigated by a combination of CW and pulsed EPR methods. For the interpretation of the experimental data, DFT quantum-chemical calculations were carried out. Simulation of a pH-dependent series of room-temperature CW-EPR spectra revealed the presence of EPR-active complexes ([Cu(aqua)]2+, [CuL]+, [CuLH1], [CuLH2]−, and [CuL2H1]−), and an EPR-inactive species ([Cu2L2H3]−) in aqueous solutions for all studied cases. [CuLH]2+ was included in the equilibrium model for the c/tACHC-Fcopper(II) systems, and [CuL2], together with two coordination isomers of [CuL2H1]−, were also identified in the F-tACHCcopper(II) system. Comparison of the complexation properties of the diastereomeric ligand pair F-(1S,2R)-ACHC and F-(1R,2S)-ACHC did not reveal significant differences. Considerably lower formation constants were obtained for the trans than for the cis isomers for both the F-c/tACHC and the c/tACHC-F pairs in the case of [CuLH1] involving tridentate coordination by the amino, the deprotonated peptide, and the carboxylate groups. A detailed structural analysis by pulsed EPR methods and DFT calculations indicated that there was no significant destabilization for the complexes of the trans isomers. The lower stability of their complexes was explained by the limitation that only the conformer with donor groups in equatorialequatorial ring positions can bind to copper(II), whereas both equatorial-axial conformers of the cis isomers are capable of binding. From a consideration of the proton couplings obtained with X-band 1H HYSCORE, 2H exchange experiments, and DFT, the thermodynamically most stable cyclohexane ring conformer was assigned for all four [CuLH1] complexes. For the F-cACHC case, the conformer did not match the most stable conformer of the free ligand.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Easton, Pa Editor
  Language Wos 000300474700029 Publication Date 2012-01-06
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.857 Times cited 18 Open Access
  Notes Approved Most recent IF: 4.857; 2012 IF: 4.593
  Call Number UA @ lucian @ c:irua:96729 Serial 515
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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 (up) 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume 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
Permanent link to this record
 

 
Author Neyts, E.C.; Thijsse, B.J.; Mees, M.J.; Bal, K.M.; Pourtois, G.
  Title Establishing uniform acceptance in force biased Monte Carlo simulations Type A1 Journal article
  Year (up) 2012 Publication Journal of chemical theory and computation Abbreviated Journal J Chem Theory Comput
  Volume 8 Issue 6 Pages 1865-1869
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract Uniform acceptance force biased Monte Carlo (UFMC) simulations have previously been shown to be a powerful tool to simulate atomic scale processes, enabling one to follow the dynamical path during the simulation. In this contribution, we present a simple proof to demonstrate that this uniform acceptance still complies with the condition of detailed balance, on the condition that the characteristic parameter lambda = 1/2 and that the maximum allowed step size is chosen to be sufficiently small. Furthermore, the relation to Metropolis Monte Carlo (MMC) is also established, and it is shown that UFMC reduces to MMC by choosing the characteristic parameter lambda = 0 [Rao, M. et al. Mol. Phys. 1979, 37, 1773]. Finally, a simple example compares the UFMC and MMC methods.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000305092400002 Publication Date 2012-05-16
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1549-9618;1549-9626; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 5.245 Times cited 20 Open Access
  Notes Approved Most recent IF: 5.245; 2012 IF: 5.389
  Call Number UA @ lucian @ c:irua:99090 Serial 1082
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Author Hadermann, J.; Abakumov, A.M.; Tsirlin, A.A.; Rozova, M.G.; Sarakinou, E.; Antipov, E.V.
  Title Expanding the Ruddlesden-Popper manganite family : the n=3 La3.2Ba0.8Mn3O10 Member Type A1 Journal article
  Year (up) 2012 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
  Volume 51 Issue 21 Pages 11487-11492
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract La3.2Ba0.8Mn3O10, a representative of the rare n = 3 members of the Ruddlesden-Popper manganites A(n+1)Mn(n)O(3n+1), was synthesized in an evacuated sealed silica tube. Its crystal structure was refined from a combination of powder X-ray diffraction (PXD) and precession electron diffraction (PED) data, with the rotations of the MnO6 octahedra described within the symmetry-adapted mode approach (space group Cccm, a = 29.068(1) angstrom, b = 5.5504(5) angstrom, c = 5.5412(5) angstrom; PXD RF = 0.053, RP = 0.026; PED RF = 0.248). The perovskite block in La3.2Ba0.8Mn3O10 features an octahedral tilting distortion with out-of-phase rotations of the Mn06 octahedra according to the (Phi,Phi,0)(Phi,Phi,0) mode, observed for the first time in the n = 3 Ruddlesden-Popper structures. The Mn06 octahedra demonstrate a noticeable deformation with the elongation of two apical Mn-O bonds due to the Jahn-Teller effect in the Mn3+ cations. The relationships between the octahedral tilting distortion, the ionic radii of the cations at the A- and B-positions, and the mismatch between the perovslcite and rock-salt blocks of the Ruddlesden-Popper structure are discussed. At low temperatures, La3.2Ba0.8Mn3O10 reveals a sizable remnant magnetization of about 1.3 mu(B)/Mn at 2K, and shows signatures of spin freezing below 150 K.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Easton, Pa Editor
  Language Wos 000313220200036 Publication Date 2012-10-17
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.857 Times cited 2 Open Access
  Notes Approved Most recent IF: 4.857; 2012 IF: 4.593
  Call Number UA @ lucian @ c:irua:110121 Serial 1133
Permanent link to this record
 

 
Author Sivek, J.; Leenaerts, O.; Partoens, B.; Peeters, F.M.
  Title First-principles investigation of bilayer fluorographene Type A1 Journal article
  Year (up) 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 116 Issue 36 Pages 19240-19245
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
  Abstract Ab initio calculations within the density functional theory formalism are performed to investigate the stability and electronic properties of fluorinated bilayer graphene (bilayer fluorographene). A comparison is made to previously investigated graphane, bilayer graphane, and fluorographene. Bilayer fluorographene is found to be a much more stable material than bilayer graphane. Its electronic band structure is similar to that of monolayer fluorographene, but its electronic band gap is significantly larger (about 1 eV). We also calculate the effective masses around the Gamma-point for fluorographene and bilayer fluorographene and find that they are isotropic, in contrast to earlier reports. Furthermore, it is found that bilayer fluorographene is almost as strong as graphene, as its 2D Young's modulus is approximately 300 N m(-1).
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000308631300022 Publication Date 2012-08-21
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.536 Times cited 39 Open Access
  Notes ; This work is supported by the ESF-Eurocores program EuroGRAPHENE (project CONERAN) and the Flemish Science Foundation (FWO-V1). ; Approved Most recent IF: 4.536; 2012 IF: 4.814
  Call Number UA @ lucian @ c:irua:101842 Serial 1211
Permanent link to this record
 

 
Author Maignan, A.; Martin, C.; Singh, K.; Simon, C.; Lebedev, O.I.; Turner, S.
  Title From spin induced ferroelectricity to dipolar glasses : spinel chromites and mixed delafossites Type A1 Journal article
  Year (up) 2012 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
  Volume 195 Issue Pages 41-49
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Magnetoelectric multiferroics showing coupling between polarization and magnetic order are attracting much attention. For instance, they could be used in memory devices. Metal-transition oxides are provided several examples of inorganic magnetoelectric multiferroics. In the present short review, spinel and delafossite chromites are described. For the former, an electric polarization is evidenced in the ferrimagnetic state for ACr2O4 polycrystalline samples (A=Ni, Fe, Co). The presence of a JahnTeller cation such as Ni2+ at the A site is shown to yield larger polarization values. In the delafossites, substitution by V3+ at the Cr or Fe site in CuCrO2 (CuFeO2) suppresses the complex antiferromagnetic structure at the benefit of a spin glass state. The presence of cation disorder, probed by transmission electron microscopy, favors relaxor-like ferroelectricity. The results on the ferroelectricity of ferrimagnets and insulating spin glasses demonstrate that, in this research field, transition-metal oxides are worth to be studied.
  Address
  Corporate Author Thesis
  Publisher Place of Publication London Editor
  Language Wos 000309783600006 Publication Date 2012-02-09
  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 27 Open Access
  Notes Fwo Approved Most recent IF: 2.299; 2012 IF: 2.040
  Call Number UA @ lucian @ c:irua:101219 Serial 1286
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Author Navío, C.; Vallejos, S.; Stoycheva, T.; Llobet, E.; Correig, X.; Snyders, R.; Blackman, C.; Umek, P.; Ke, X.; Van Tendeloo, G.; Bittencourt, C.;
  Title Gold clusters on WO3 nanoneedles grown via AACVD : XPS and TEM studies Type A1 Journal article
  Year (up) 2012 Publication Materials chemistry and physics Abbreviated Journal Mater Chem Phys
  Volume 134 Issue 2/3 Pages 809-813
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract We have prepared tungsten oxide films decorated with gold particles on Si substrates by aerosol assisted chemical vapor deposition (AACVD) and characterized them using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). SEM shows that the films are composed of needle-like structures and TEM shows that both the needles and the gold particles are crystalline. XPS indicates the presence of oxygen vacancies, i.e. the films are WO3−x, and hence the deposited material is composed of semiconducting nanostructures and that the interaction between the gold particles and the WO3 needles surface is weak. The synthesis of semiconducting tungsten oxide nanostructures decorated with metal particles represents an important step towards the development of sensing devices with optimal properties.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lausanne Editor
  Language Wos 000305918200038 Publication Date 2012-04-30
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0254-0584; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.084 Times cited 52 Open Access
  Notes Iap Approved Most recent IF: 2.084; 2012 IF: 2.072
  Call Number UA @ lucian @ c:irua:97705 Serial 1356
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Author Retuerto, M.; Li, M.R.; Go, Y.B.; Ignatov, A.; Croft, M.; Ramanujachary, K.V.; Herber, R.H.; Nowik, I.; Hodges, J.P.; Dachraoui, W.; Hadermann, J.; Greenblatt, M.;
  Title High magnetic ordering temperature in the perovskites Sr4-xLaxFe3ReO12 (x=0.0, 1.0, 2.0) Type A1 Journal article
  Year (up) 2012 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
  Volume 194 Issue Pages 48-58
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract A series of perovskites Sr4−xLaxFe3ReO12 (x=0.0, 1.0, 2.0) has been prepared by wet chemistry methods. The structure analyses by powder X-ray and neutron diffraction and electron microscopy show that these compounds adopt simple perovskite structures without cation ordering over the B sites: tetragonal (I4/mcm) for x=0.0 and 1.0 and orthorhombic (Pbmn) for x=2.0. The oxidation states of the cations in the compound with x=0.0 appear to be Fe3+/4+ and Re7+ and decrease for both with La substitution as evidenced by X-ray absorption spectroscopy. All the compounds are antiferromagnetically ordered above room temperature, as demonstrated by Mössbauer spectroscopy and the magnetic structures, which were determined by powder neutron diffraction. The substitution of Sr by La strongly affects the magnetic properties with an increase of TN up to ∼750 K.
  Address
  Corporate Author Thesis
  Publisher Place of Publication London Editor
  Language Wos 000308896400009 Publication Date 2012-07-02
  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 9 Open Access
  Notes Approved Most recent IF: 2.299; 2012 IF: 2.040
  Call Number UA @ lucian @ c:irua:101220 Serial 1435
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Author Khalilov, U.; Pourtois, G.; van Duin, A.C.T.; Neyts, E.C.
  Title Hyperthermal oxidation of Si(100)2x1 surfaces : effect of growth temperature Type A1 Journal article
  Year (up) 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 116 Issue 15 Pages 8649-8656
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract Using reactive molecular dynamics simulations based on the ReaxFF potential, we studied the growth mechanism of ultrathin silica (SiO2) layers during hyperthermal oxidation as a function of temperature in the range 100-1300 K. Oxidation of Si(100){2 x 1} surfaces by both atomic and molecular oxygen was investigated for hyperthermal impact energies in the range of 1 to 5 eV. Two different growth mechanisms are found, corresponding to a low temperature oxidation and a high temperature one. The transition temperature between these mechanisms is estimated to be about 700 K. Also, the initial step of the Si oxidation process is analyzed in detail. Where possible, we validated our results with experimental and ab initio data, and good agreement was obtained. This study is important for the fabrication of silica-based devices in the micro- and nanoelectronics industry and, more specifically, for the fabrication of metal oxide semiconductor devices.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000302924900035 Publication Date 2012-03-26
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.536 Times cited 32 Open Access
  Notes Approved Most recent IF: 4.536; 2012 IF: 4.814
  Call Number UA @ lucian @ c:irua:98259 Serial 1542
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Author Aerts, R.; Martens, T.; Bogaerts, A.
  Title Influence of vibrational states on CO2 splitting by dielectric barrier discharges Type A1 Journal article
  Year (up) 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 116 Issue 44 Pages 23257-23273
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract In this paper, the splitting of CO2 in a pulsed plasma system, such as a dielectric barrier discharge (DBD), is evaluated from a chemical point of view by means of numerical modeling. For this purpose, a chemical reaction set of CO2 in an atmospheric pressure plasma is developed, including the vibrational states of CO2, O2, and CO. The simulated pulses are matched to the conditions of a filament (or microdischarge) and repeated with intervals of 1 μs. The influence of vibrationally excited CO2 as well as other neutral species, ions, and electrons on the CO2 splitting is discussed. Our calculations predict that the electrons have the largest contribution to the CO2 splitting at the conditions under study, by electron impact dissociation. The contribution of vibrationally excited CO2 levels in the splitting of CO2 is found be 6.4%, when only considering one microdischarge pulse and its afterglow, but it can be much higher for consecutive discharge pulses, as is typical for a filamentary DBD, when the interpulse time is short enough and accumulation effects in the vibrationally excited CO2 densities can occur.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000310769300012 Publication Date 2012-10-19
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.536 Times cited 112 Open Access
  Notes Approved Most recent IF: 4.536; 2012 IF: 4.814
  Call Number UA @ lucian @ c:irua:101764 Serial 1659
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Author Neyts, E.C.; van Duin, A.C.T.; Bogaerts, A.
  Title Insights in the plasma-assisted growth of carbon nanotubes through atomic scale simulations : effect of electric field Type A1 Journal article
  Year (up) 2012 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
  Volume 134 Issue 2 Pages 1256-1260
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract Carbon nanotubes (CNTs) are nowadays routinely grown in a thermal CVD setup. State-of-the-art plasma-enhanced CVD (PECVD) growth, however, offers advantages over thermal CVD. A lower growth temperature and the growth of aligned freestanding single-walled CNTs (SWNTs) makes the technique very attractive. The atomic scale growth mechanisms of PECVD CNT growth, however, remain currently entirely unexplored. In this contribution, we employed molecular dynamics simulations to focus on the effect of applying an electric field on the SWNT growth process, as one of the effects coming into play in PECVD. Using sufficiently strong fields results in (a) alignment of the growing SWNTs, (b) a better ordering of the carbon network, and (c) a higher growth rate relative to thermal growth rate. We suggest that these effects are due to the small charge transfer occurring in the Ni/C system. These simulations constitute the first study of PECVD growth of SWNTs on the atomic level.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000301084300086 Publication Date 2011-11-30
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 13.858 Times cited 56 Open Access
  Notes Approved Most recent IF: 13.858; 2012 IF: 10.677
  Call Number UA @ lucian @ c:irua:97163 Serial 1673
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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 (up) 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
  Volume 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 Retuerto, M.; Li, M.R.; Go, Y.B.; Ignatov, A.; Croft, M.; Ramanujachary, K.V.; Hadermann, J.; Hodges, J.P.; Herber, R.H.; Nowik, I.; Greenblatt, M.;
  Title Magnetic and structural studies of the multifunctional material SrFe0.75Mo0.25O3-\text{\textgreek{d}} Type A1 Journal article
  Year (up) 2012 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
  Volume 51 Issue 22 Pages 12273-12280
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract SrFe0.75Mo0.25O3-delta has been recently discovered as an extremely efficient electrode for intermediate temperature solid oxide fuel cells (IT-SOFCs). We have performed structural and magnetic studies to fully characterize this multifunctional material. We have observed by powder neutron diffraction (PND) and transmission electron microscopy (TEM) that its crystal symmetry is better explained with a tetragonal symmetry (I4/mcm space group) than with the previously reported orthorhombic symmetry (Pnma space group). The temperature dependent magnetic properties indicate an exceptionally high magnetic ordering temperature (T-N similar to 750 K), well above room temperature. The ordered magnetic structure at low temperature was determined by PND to be an antiferromagnetic coupling of the Fe cations. Mossbauer spectroscopy corroborated the PND results. A detailed study, with X-ray absorption spectroscopy (XAS), in agreement with the Mossbauer results, confirmed the formal oxidation states of the cations to be mixed valence Fe3+/4+ and Mo6+.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Easton, Pa Editor
  Language Wos 000311173700024 Publication Date 2012-10-26
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.857 Times cited 12 Open Access
  Notes Approved Most recent IF: 4.857; 2012 IF: 4.593
  Call Number UA @ lucian @ c:irua:105142 Serial 1862
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Author Kalidindi, S.B.; Hyunchul, O.; Hirscher, M.; Esken, D.; Wiktor, C.; Turner, S.; Van Tendeloo, G.; Fischer, R.A.
  Title Metal@COFs : covalent organic frameworks as templates for Pd nanoparticles and hydrogen storage properties of Pd@COF-102 hybrid material Type A1 Journal article
  Year (up) 2012 Publication Chemistry: a European journal Abbreviated Journal Chem-Eur J
  Volume 18 Issue 35 Pages 10848-10856
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Three-dimensional covalent organic frameworks (COFs) have been demonstrated as a new class of templates for nanoparticles. Photodecomposition of the [Pd(eta 3-C3H5)(eta 5-C5H5)]@COF-102 inclusion compound (synthesized by a gas-phase infiltration method) led to the formation of the Pd@COF-102 hybrid material. Advanced electron microscopy techniques (including high-angle annular dark-field scanning transmission electron microscopy and electron tomography) along with other conventional characterization techniques unambiguously showed that highly monodisperse Pd nanoparticles ((2.4 +/- 0.5) nm) were evenly distributed inside the COF-102 framework. The Pd@COF-102 hybrid material is a rare example of a metal-nanoparticle-loaded porous crystalline material with a very narrow size distribution without any larger agglomerates even at high loadings (30 wt %). Two samples with moderate Pd content (3.5 and 9.5 wt %) were used to study the hydrogen storage properties of the metal-decorated COF surface. The uptakes at room temperature from these samples were higher than those of similar systems such as Pd@metalorganic frameworks (MOFs). The studies show that the H2 capacities were enhanced by a factor of 2-3 through Pd impregnation on COF-102 at room temperature and 20 bar. This remarkable enhancement is not just due to Pd hydride formation and can be mainly ascribed to hydrogenation of residual organic compounds, such as bicyclopentadiene. The significantly higher reversible hydrogen storage capacity that comes from decomposed products of the employed organometallic Pd precursor suggests that this discovery may be relevant to the discussion of the spillover phenomenon in metal/MOFs and related systems.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Weinheim Editor
  Language Wos 000307782800013 Publication Date 2012-08-08
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0947-6539; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 5.317 Times cited 88 Open Access
  Notes Fwo Approved Most recent IF: 5.317; 2012 IF: 5.831
  Call Number UA @ lucian @ c:irua:100469 Serial 2007
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Author Nayuk, R.; Zacher, D.; Schweins, R.; Wiktor, C.; Fischer, R.A.; Van Tendeloo, G.; Huber, K.
  Title Modulated formation of MOF-5 nanoparticles : a SANS analysis Type A1 Journal article
  Year (up) 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 116 Issue 10 Pages 6127-6135
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract MOF-5 nanoparticles were prepared by mixing a solution of [Zn4O(C6H5COO)(6)] with a solution of benzene-1,4-dicarboxylic acid in DMF at ambient conditions. The former species mimics as a secondary building unit (SBU), and the latter acts as linker. Mixing of the two solutions induced the formation of MOF-5 nanoparticles in dilute suspension. The applied conditions were identified as suitable for a closer investigation of the particle formation process by combined light and small angle neutron scattering (SANS). Scattering analysis revealed a significant impact of the molar ratio of the two components in the reaction mixture. Excessive use of the building unit slowed down the process. A similar effect was observed upon addition of 4n-decylbenzoic acid, which is supposed to act as a modulator. The formation mechanism leads to initial intermediates, which turn into cubelike nanoparticles with a diameter of about 60-80 nm. This initial stage is followed by an extended formation period, where nucleation proceeds over hours, leading to an increasing number of nanoparticles with the same final size of 60-80 nm.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000301509600020 Publication Date 2012-02-16
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.536 Times cited 24 Open Access
  Notes Approved Most recent IF: 4.536; 2012 IF: 4.814
  Call Number UA @ lucian @ c:irua:97789 Serial 2163
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Author Justo, Y.; Goris, B.; Sundar Kamal, J.; Geiregat, P.; Bals, S.; Hens, Z.
  Title Multiple dot-in-rod PbS/CdS heterostructures with high photoluminescence quantum yield in the near-infrared Type A1 Journal article
  Year (up) 2012 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
  Volume 134 Issue 12 Pages 5484-5487
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Pb cations in PbS quantum rods made from CdS quantum rods by successive complete cationic exchange reactions are partially re-exchanged for Cd cations. Using STEM-HAADF, we show that this leads to the formation of unique multiple dot-in-rod PbS/CdS heteronanostructures, with a photoluminescence quantum yield of 4555%. We argue that the formation of multiple dot-in-rods is related to the initial polycrystallinity of the PbS quantum rods, where each PbS crystallite transforms in a separate PbS/CdS dot-in-dot. Effective mass modeling indicates that electronic coupling between the different PbS conduction band states is feasible for the multiple dot-in-rod geometries obtained, while the hole states remain largely uncoupled.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000302489500015 Publication Date 2012-03-16
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 13.858 Times cited 41 Open Access
  Notes Fwo; Iap Approved Most recent IF: 13.858; 2012 IF: 10.677
  Call Number UA @ lucian @ c:irua:96957 Serial 2226
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Author Ustarroz, J.; Ke, X.; Hubin, A.; Bals, S.; Terryn, H.
  Title New insights into the early stages of nanoparticle electrodeposition Type A1 Journal article
  Year (up) 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 116 Issue 3 Pages 2322-2329
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Electrodeposition is an increasingly important method to synthesize supported nanoparticles, yet the early stages of electrochemical nanoparticle formation are not perfectly understood. In this paper, the early stages of silver nanoparticle electrodeposition on carbon substrates have been studied by aberration-corrected TEM, using carbon-coated TEM grids as electrochemical electrodes. In this manner we have access to as-deposited nanoparticle size distribution and structural characterization at the atomic scale combined with electrochemical measurements, which represents a breakthrough in a full understanding of the nanoparticle electrodeposition mechanisms. Whereas classical models, based upon characterization at the nanoscale, assume that electrochemical growth is only driven by direct attachment, the results reported hereafter indicate that early nanoparticle growth is mostly driven by nanocluster surface movement and aggregation. Hence, we conclude that electrochemical nulceation and growth models should be revised and that an electrochemical aggregative growth mechanism should be considered in the early stages of nanoparticle electrodeposition.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000299584400037 Publication Date 2011-12-23
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.536 Times cited 104 Open Access
  Notes Fwo Approved Most recent IF: 4.536; 2012 IF: 4.814
  Call Number UA @ lucian @ c:irua:96225 Serial 2316
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Author Khalilov, U.; Pourtois, G.; van Duin, A.C.T.; Neyts, E.C.
  Title On the c-Si\mid a-SiO2 interface in hyperthermal Si oxidation at room temperature Type A1 Journal article
  Year (up) 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 116 Issue 41 Pages 21856-21863
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract The exact structure and properties of the Si vertical bar SiO2 interface are very important in microelectronics and photovoltaic devices such as metal-oxide-semiconductor field-effect transistors (MOSFETs) and solar cells. Whereas Si vertical bar SiO2 structures are traditionally produced by thermal oxidation, hyperthermal oxidation shows a number of promising advantages. However, the Si vertical bar SiO2 interface induced in hyperthermal Si oxidation has not been properly investigated yet. Therefore, in this work, the interface morphology and interfacial stresses during hyperthermal oxidation at room temperature are studied using reactive molecular dynamics simulations based on the ReaxFF potential. Interface thickness and roughness, as well as the bond length and bond angle distributions in the interface are discussed and compared with other models developed for the interfaces induced by traditional thermal oxidation. The formation of a compressive stress is observed. This compressive stress, which at the interface amounts about 2 GPa, significantly slows down the inward silica growth. This value is close to the experimental value in the Si vertical bar SiO2 interface obtained in traditional thermal oxidation.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Washington, D.C. Editor
  Language Wos 000309902100026 Publication Date 2012-09-26
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.536 Times cited 27 Open Access
  Notes Approved Most recent IF: 4.536; 2012 IF: 4.814
  Call Number UA @ lucian @ c:irua:102167 Serial 2458
Permanent link to this record
 

 
Author Frolov, D.D.; Kotovshchikov, Y.N.; Morozov, I.V.; Boltalin, A.I.; Fedorova, A.A.; Marikutsa, A.V.; Rumyantseva, M.N.; Gaskov, A.M.; Sadovskaya, E.M.; Abakumov, A.M.
  Title Oxygen exchange on nanocrystalline tin dioxide modified by palladium Type A1 Journal article
  Year (up) 2012 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
  Volume 186 Issue Pages 1-8
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Temperature-programmed oxygen isotopic exchange study was performed on nanocrystalline tin dioxide-based materials synthesized via sol-gel route and modified by palladium. Such materials are widely used as resistive gas sensors. The experiments were carried out in a flow-reactor up to complete isotopic substitution of oxygen. Substantial rates of isotopic exchange for SnO2 were observed from about 700 K. The distribution of isotopic molecules O-16(2). (OO)-O-16-O-18 and O-18(2) corresponds to simple dioxygen heteroexchange mechanism with single lattice oxygen atom. The modification of SnO2 by Pd introduced multiple heteroexchange mechanism with preliminary O-2 dissociation on the clusters surface. Spill-over of atomic oxygen from Pd to the surface of SnO2 and fast exchange with lattice oxygen result in more than 100% increase of apparent heteroexchange rate. The exchange on SnO2/Pd was shown to be a complex process involving partial deactivation of the catalytic centers at temperature higher than 750 K. (C) 2011 Elsevier Inc. All rights reserved.
  Address
  Corporate Author Thesis
  Publisher Place of Publication London Editor
  Language Wos 000299801400001 Publication Date 2011-12-08
  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 34 Open Access
  Notes Approved Most recent IF: 2.299; 2012 IF: 2.040
  Call Number UA @ lucian @ c:irua:96202 Serial 2546
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Author Tytgat, T.; Hauchecorne, B.; Abakumov, A.M.; Smits, M.; Verbruggen, S.W.; Lenaerts, S.
  Title Photocatalytic process optimisation for ethylene oxidation Type A1 Journal article
  Year (up) 2012 Publication Chemical engineering journal Abbreviated Journal Chem Eng J
  Volume 209 Issue Pages 494-500
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL)
  Abstract When studying photocatalysis it is important to consider, beside the chemical approach, the engineering part related to process optimisation. To achieve this a fixed bed photocatalytic set-up consisting of different catalyst placings, in order to vary catalyst distribution, is studied. The use of a fixed quantity of catalyst placed packed or randomly distributed in the reactor, results in an almost double degradation for the distributed catalyst. Applying this knowledge leads to an improved performance with limited use of catalyst. A reactor only half filled with catalyst leads to higher degradation performance compared to a completely filled reactor. Taking into account this simple process optimisation by better distributing the catalyst a more sustainable photocatalytic air purification process is achieved. (C) 2012 Elsevier B.V. All rights reserved.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lausanne Editor
  Language Wos 000311190500058 Publication Date 2012-08-22
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1385-8947; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 6.216 Times cited 12 Open Access
  Notes ; We are grateful for the delivered photocatalyst by Evonik as well as for the PhD grant (T. Tytgat) given by the Institute of Innovation by Science and Technology in Flanders (IWT). ; Approved Most recent IF: 6.216; 2012 IF: 3.473
  Call Number UA @ lucian @ c:irua:105185 Serial 2609
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