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| Author | Khalilov, U.; Bogaerts, A.; Neyts, E.C. | ||||
| Title | Toward the Understanding of Selective Si Nano-Oxidation by Atomic Scale Simulations | Type | A1 Journal article | ||
| Year | 2017 | Publication | Accounts of chemical research | Abbreviated Journal | Accounts Chem Res |
| Volume | 50 | Issue | 50 | Pages | 796-804 |
| Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract  |
The continuous miniaturization of nanodevices, such as transistors, solar cells, and optical fibers, requires the controlled synthesis of (ultra)thin gate oxides (<10 nm), including Si gate-oxide (SiO2) with high quality at the atomic scale. Traditional thermal growth of SiO2 on planar Si surfaces, however, does not allow one to obtain such ultrathin oxide due to either the high oxygen diffusivity at high temperature or the very low sticking ability of incident oxygen at low temperature. Two recent techniques, both operative at low (room) temperature, have been put forward to overcome these obstacles: (i) hyperthermal oxidation of planar Si surfaces and (ii) thermal or plasma-assisted oxidation of nonplanar Si surfaces, including Si nanowires (SiNWs). These nanooxidation processes are, however, often difficult to study experimentally, due to the key intermediate processes taking place on the nanosecond time scale. In this Account, these Si nano-oxidation techniques are discussed from a computational point of view and compared to both hyperthermal and thermal oxidation experiments, as well as to well-known models of thermal oxidation, including the Deal−Grove, Cabrera−Mott, and Kao models and several alternative mechanisms. In our studies, we use reactive molecular dynamics (MD) and hybrid MD/Monte Carlo simulation techniques, applying the Reax force field. The incident energy of oxygen species is chosen in the range of 1−5 eV in hyperthermal oxidation of planar Si surfaces in order to prevent energy-induced damage. It turns out that hyperthermal growth allows for two growth modes, where the ultrathin oxide thickness depends on either (1) only the kinetic energy of the incident oxygen species at a growth temperature below Ttrans = 600 K, or (2) both the incident energy and the growth temperature at a growth temperature above Ttrans. These modes are specific to such ultrathin oxides, and are not observed in traditional thermal oxidation, nor theoretically considered by already existing models. In the case of thermal or plasma-assisted oxidation of small Si nanowires, on the other hand, the thickness of the ultrathin oxide is a function of the growth temperature and the nanowire diameter. Below Ttrans, which varies with the nanowire diameter, partially oxidized SiNW are formed, whereas complete oxidation to a SiO2 nanowire occurs only above Ttrans. In both nano-oxidation processes at lower temperature (T < Ttrans), final sandwich c-Si|SiOx|a-SiO2 structures are obtained due to a competition between overcoming the energy barrier to penetrate into Si subsurface layers and the compressive stress (∼2−3 GPa) at the Si crystal/oxide interface. The overall atomic-simulation results strongly indicate that the thickness of the intermediate SiOx (x < 2) region is very limited (∼0.5 nm) and constant irrespective of oxidation parameters. Thus, control over the ultrathin SiO2 thickness with good quality is indeed possible by accurately tuning the oxidant energy, oxidation temperature and surface curvature. In general, we discuss and put in perspective these two oxidation mechanisms for obtaining controllable ultrathin gate-oxide films, offering a new route toward the fabrication of nanodevices via selective nano-oxidation. |
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000399859800016 | Publication Date | 2017-04-18 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0001-4842 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 20.268 | Times cited | 5 | Open Access | OpenAccess |
| Notes | Fonds Wetenschappelijk Onderzoek, 12M1315N ; | Approved | Most recent IF: 20.268 | ||
| Call Number | PLASMANT @ plasmant @ c:irua:142638 | Serial | 4561 | ||
| Permanent link to this record | |||||
| Author | Wang, W.; Patil, B.; Heijkers, S.; Hessel, V.; Bogaerts, A. | ||||
| Title | Nitrogen Fixation by Gliding Arc Plasma: Better Insight by Chemical Kinetics Modelling | Type | A1 Journal Article | ||
| Year | 2017 | Publication | Chemsuschem | Abbreviated Journal | Chemsuschem |
| Volume | 10 | Issue | 10 | Pages | 2110-2110 |
| Keywords | A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
| Abstract |
The conversion of atmospheric nitrogen into valuable compounds, that is, so-called nitrogen fixation, is gaining increased interest, owing to the essential role in the nitrogen cycle of the biosphere. Plasma technology, and more specifically gliding arc plasma, has great potential in this area, but little is known about the underlying mechanisms. Therefore, we developed a detailed chemical kinetics model for a pulsed-power gliding-arc reactor operating at atmospheric pressure for nitrogen oxide synthesis. Experiments are performed to validate the model and reasonable agreement is reached between the calculated and measured NO and NO2 yields and the corresponding energy efficiency for NOx formation for different N2/O2 ratios, indicating that the model can provide a realistic picture of the plasma chemistry. Therefore, we can use the model to investigate the reaction pathways for the formation and loss of NOx. The results indicate that vibrational excitation of N2 in the gliding arc contributes significantly to activating the N2 molecules, and leads to an energy efficient way of NOx production, compared to the thermal process. Based on the underlying chemistry, the model allows us to propose solutions on how to further improve the NOx formation by gliding arc technology. Although the energy efficiency of the gliding-arc-based nitrogen fixation process at the present stage is not comparable to the world-scale Haber–Bosch process, we believe our study helps us to come up with more realistic scenarios of entering a cutting-edge innovation in new business cases for the decentralised production of fertilisers for agriculture, in which lowtemperature plasma technology might play an important role. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | Publication Date | 2017-05-11 | ||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1864-5631 | ISBN | Additional Links | ||
| Impact Factor | 7.226 | Times cited | Open Access | Not_Open_Access | |
| Notes | This research was supported by the European Marie Skłodowska- Curie Individual Fellowship “GlidArc” within Horizon 2020 (Grant No.657304), by the FWO project (grant G.0383.16 N) and by the EU project MAPSYN: Microwave, Acoustic and Plasma assisted SYNthesis, under the grant agreement no. CP-IP 309376 of the European Community’s Seventh Framework Program. The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. | Approved | Most recent IF: 7.226 | ||
| Call Number | PLASMANT @ plasmant @ | Serial | 4573 | ||
| Permanent link to this record | |||||
| Author | Wang, W.; Patil, B.; Heijkers, S.; Hessel, V.; Bogaerts, A. | ||||
| Title | Nitrogen fixation by gliding arc plasma : better insight by chemical kinetics modelling | Type | A1 Journal article | ||
| Year | 2017 | Publication | Chemsuschem | Abbreviated Journal | Chemsuschem |
| Volume | 10 | Issue | 10 | Pages | 2145-2157 |
| Keywords | A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract |
The conversion of atmospheric nitrogen into valuable compounds, that is, so-called nitrogen fixation, is gaining increased interest, owing to the essential role in the nitrogen cycle of the biosphere. Plasma technology, and more specifically gliding arc plasma, has great potential in this area, but little is known about the underlying mechanisms. Therefore, we developed a detailed chemical kinetics model for a pulsed-power gliding-arc reactor operating at atmospheric pressure for nitrogen oxide synthesis. Experiments are performed to validate the model and reasonable agreement is reached between the calculated and measured NO and NO2 yields and the corresponding energy efficiency for NOx formation for different N2/O2 ratios, indicating that the model can provide a realistic picture of the plasma chemistry. Therefore, we can use the model to investigate the reaction pathways for the formation and loss of NOx. The results indicate that vibrational excitation of N2 in the gliding arc contributes significantly to activating the N2 molecules, and leads to an energy efficient way of NOx production, compared to the thermal process. Based on the underlying chemistry, the model allows us to propose solutions on how to further improve the NOx formation by gliding arc technology. Although the energy efficiency of the gliding-arc-based nitrogen fixation process at the present stage is not comparable to the world-scale HaberBosch process, we believe our study helps us to come up with more realistic scenarios of entering a cutting-edge innovation in new business cases for the decentralised production of fertilisers for agriculture, in which low-temperature plasma technology might play an important role. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Weinheim | Editor | ||
| Language | Wos | 000402122100006 | Publication Date | 2017-03-08 | |
| 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 | 42 | Open Access | OpenAccess |
| Notes | Approved | Most recent IF: 7.226 | |||
| Call Number | UA @ lucian @ c:irua:143261 | Serial | 4672 | ||
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| Author | Morozov, V.A.; Batuk, D.; Batuk, M.; Basovich, O.M.; Khaikina, E.G.; Deyneko, D.V.; Lazoryak, B.I.; Leonidov, I.I.; Abakumov, A.M.; Hadermann, J. | ||||
| Title | Luminescence Property Upgrading via the Structure and Cation Changing in AgxEu(2–x)/3WO4and AgxGd(2–x)/3–0.3Eu0.3WO4 | Type | A1 Journal article | ||
| Year | 2017 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
| Volume | 29 | Issue | 20 | Pages | 8811-8823 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The creation and ordering of A-cation vacancies and the effect of cation substitutions in the scheelite-type framework are investigated as a factor for controlling the scheelite-type structure and luminescence properties. AgxEu3+(2−x)/3□(1−2x)/3WO4 and AgxGd(2−x)/3−0.3Eu3+0.3□(1−2x)/3WO4 (x = 0.5−0) scheelite-type phases were synthesized by a solid state method, and their structures were investigated using a combination of transmission electron microscopy techniques and powder synchrotron X-ray diffraction. Transmission electron microscopy also revealed the (3 + 1)D incommensurately modulated character of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.286, 0.2) phases. The crystal structures of the scheelite-based AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286, 0.2) red phosphors have been refined from high resolution synchrotron powder X-ray diffraction data. The luminescence properties of all phases under near-ultraviolet (n-UV) light have been investigated. The excitation spectra of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286,0.2) phosphors show the strongest absorption at 395 nm, which matches well with the commercially available n-UV-emitting GaN-based LED chip. The excitation spectra of the Eu2/3□1/3WO4 and Gd0.367Eu0.30□1/3WO4 phases exhibit the highest contribution of the charge transfer band at 250 nm and thus the most efficient energy transfer mechanism between the host and the luminescent ion as compared to direct excitation. The emission spectra of all samples indicate an intense red emission due to the 5D0 → 7F2 transition of Eu3+. Concentration dependence of the 5D0 → 7F2 emission for AgxEu(2−x)/3□(1−2x)/3WO4 samples differs from the same dependence for the earlier studied NaxEu3+(2−x)/3□(1−2x)/3MoO4 (0 ≤ x ≤ 0.5) phases. The intensity of the 5D0 → 7F2 emission is reduced almost 7 times with decreasing x from 0.5 to 0, but it practically does not change in the range from x = 0.286 to x = 0.200. The emission spectra of Gd-containing samples show a completely different trend as compared to only Eu-containing samples. The Eu3+ emission under excitation of Eu3+(5L6) level (λex = 395 nm) increases more than 2.5 times with the increasing Gd3+ concentration from 0.2 (x = 0.5) to 0.3 (x = 0.2) in the AgxGd(2−x)/3−0.3Eu3+0.3□(1−2x)/3WO4, after which it remains almost constant for higher Gd3+ concentrations. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000413884900028 | Publication Date | 2017-10-24 | |
| 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 | 7 | Open Access | Not_Open_Access |
| Notes | This research was supported by FWO (project G039211N), Flanders Research Foundation. V.A.M. is grateful for financial support of the Russian Foundation for Basic Research (Grant 15-03-07741). E.G.K. and O.M.B. are grateful for financial support of the Russian Foundation for Basic Research (Grants 13-03-01020 and 16-03-00510). D.V.D. is grateful for financial support of the Russian Foundation for Basic Research (Grant 16-33-00197) and the Foundation of the President of the Russian Federation (Grant MK-7926.2016.5.). We are grateful to the ESRF for granting the beamtime. Experimental support of Andy Fitch at the ID31 beamline of ESRF is kindly acknowledged. | Approved | Most recent IF: 9.466 | ||
| Call Number | EMAT @ emat @c:irua:147241 | Serial | 4768 | ||
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| Author | Rossell, M.D.; Abakumov, A.M.; Van Tendeloo, G.; Pardo, J.A.; Santiso, J. | ||||
| Title | Structure and microstructure of epitaxial Sr4Fe6O13-\delta films on SrTiO3 | Type | A1 Journal article | ||
| Year | 2004 | Publication | Chemistry and materials | Abbreviated Journal | Chem Mater |
| Volume | 16 | Issue | Pages | 2578-2584 | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The crystal structure and the microstructure of epitaxial Sr4Fe6O13+/-delta thin films grown on a single-crystal SrTiO3 substrate by PLD have been investigated. A combination of electron diffraction and high-resolution microscopy allows us to refine the structure and to identify an incommensurate modulation in the Sr4Fe6O13+/-delta films. The incommensurate structure (q = alphaa(m)* approximate to 0.39alpha(m)*, superspace group Xmmm(alpha00)0s0) can be interpreted as an oxygen-deficient modification in the Fe2O2.5 double layers. Moreover, it is shown that the experimentally determined a component of the modulation can be used consistently to estimate the local oxygen content in the Sr4Fe6O13+/-delta films. The compound composition can therefore be described as Sr4Fe6O12+2alpha and the value alpha = 0.39 corresponds to a Sr4Fe6O12.78 composition. The misfit stress along the Sr4Fe6O13+/-delta/SrTiO3 interface is accommodated via both elastic deformation and inelastic mechanisms (misfit dislocations and 90degrees rotation twins). The present results also suggest the existence of SrFeO3 perovskite in the Sr4Fe6O13+/-delta films. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Washington, D.C. | Editor | ||
| Language | Wos | 000222252300011 | Publication Date | 2004-06-22 | |
| 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 | 26 | Open Access | |
| Notes | Approved | Most recent IF: 9.466; 2004 IF: 4.103 | |||
| Call Number | UA @ lucian @ c:irua:54770 | Serial | 3286 | ||
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| Author | Luhrs, C.C.; Molins, E.; Van Tendeloo, G.; Beltran-Porter, D.; Fuertes, A. | ||||
| Title | Crystal structure of Bi6Sr8-xCa3+xO22(-0.5\leq x\leq1.7): a mixed valence bismuth oxide related to perovskite | Type | A1 Journal article | ||
| Year | 1998 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
| Volume | 10 | Issue | 7 | Pages | 1875-1881 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The crystal structure of BiSr8-xCa3+xO22 has been determined by single-crystal X-ray diffraction. This phase is the same as Bi9Sr11Ca5Oy that was previously studied by several authors as a secondary phase in the Bi-Sr-Ca-Cu-O system and coexists in thermodynamic equilibrium with the superconductors Bi2Sr2CuO6 and Bi2Sr2CaCu2O8 It crystallizes in the monoclinic space group P2(1)/c, with cell parameters a 11.037(3) Angstrom, b = 5.971(2) Angstrom, c = 19.703(7) Angstrom, beta = 101.46(3)degrees Z = 2. The structure was solved by direct methods and full-matrix least-squares refinement. It is built up by perovskite-related blocks of composition [Sr8-xBi2Ca3+xO16] that intergrow with double rows [Bi4O6] running along b. The perovskite blocks are formed by groups of five octahedra that are shifted from each other 3/2 root 2a(p) along [110](p) (a(p) being the parameter of the cubic perovskite subcell) in a zigzag configuration and are aligned with this direction parallel to the one forming an angle of 25" with the c axis. In turn, the perovskite blocks [Sr8-xBi2Ca3+xO16] are shifted from each other 1/2 of both a(p) and root 2a(p) along [100](p) and [110](p), respectively. In the double rows, two trivalent bismuth atoms are placed, forming dimeric anion complexes [Bi2O6].(6-).6- The oxygen atoms around bismuth in these dimers are placed in the vertexes of a distorted trigonal bipyramid, with one vacant position that would be occupied by the lone pairs characteristic for the electronic configuration of Bi(III). The B sites in the perovskite blocks are occupied by pentavalent bismuth atoms and calcium atoms; the remaining Sr and Ca ions occupy the A sites of the perovskite blocks with coordination numbers with oxygen ranging from 10 to 12. The mean valence for Bi is +3.67 [33.3% of Bi(V) and 66.7% of Bi(III)]. The oxygen vacancies are located in the boundaries between domains having the two possible configurations of the perovskite subcell as in the anionic superconductor Bi3BaO5.5. The oxidation of Bi6Sr8-xCa3+xO22 at 650 degrees C allows the complete filling of the oxygen vacancies to form the double perovskite (Sr2-xCax)Bi1.4Ca0.6O6 that shows 92.5% of bismuth in +5 oxidation state. The experimental high-resolution electon microscopy image and the electron diffraction pattern of powder samples along the [010]* zone axis are in good agreement with those calculated from the structural model obtained by single-crystal X-ray diffraction. The material is almost free of defects and the occurrence of planar defects is very exceptional. | ||||
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| Publisher | Place of Publication | Washington, D.C. | Editor | ||
| Language | Wos | 000075019300023 | Publication Date | 2002-07-26 | |
| 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 | 6 | Open Access | |
| Notes | Approved | Most recent IF: 9.466; 1998 IF: 3.359 | |||
| Call Number | UA @ lucian @ c:irua:104328 | Serial | 570 | ||
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| Author | Tyutyunnik, A.P.; Slobodin, B.V.; Samigullina, R.F.; Verberck, B.; Tarakina, N.V. | ||||
| Title | K2CaV2O7 : a pyrovanadate with a new layered type of structure in the A2BV2O7 family | Type | A1 Journal article | ||
| Year | 2013 | Publication | Journal of the Chemical Society : Dalton transactions | Abbreviated Journal | Dalton T |
| Volume | 42 | Issue | 4 | Pages | 1057-1064 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract |
The crystal structure of K2CaV2O7 prepared by a conventional solid-state reaction has been solved by a direct method and refined using Rietveld full profile fitting based on X-ray powder diffraction data. This compound crystallises in the triclinic space group (P (1) over bar, Z = 2) with unit cell constants a = 7.1577(1) angstrom, b = 10.5104(2) angstrom, c = 5.8187(1) angstrom, alpha = 106.3368(9)degrees, beta = 106.235(1)degrees, gamma = 71.1375(9)degrees. The structure can be described as infinite undulating CaV2O72- layers parallel to the ac plane, which consist of pairs of edge-sharing CaO6 octahedra connected to each other through V2O7 pyrogroups. The potassium atoms are positioned in two sites between the layers, with a distorted IX-fold coordination of oxygen atoms. The chemical composition obtained from the structural solution was confirmed by energy-dispersive X-ray analysis. The stability of compounds in the family of alkali metal calcium pyrovanadates is discussed based on an analysis of the correlation between anion and cation sizes and theoretical first-principles calculations. | ||||
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| Publisher | Place of Publication | London | Editor | ||
| Language | Wos | 000312659200030 | Publication Date | 2012-10-04 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1477-9226;1477-9234; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 4.029 | Times cited | 3 | Open Access | |
| Notes | ; N.V.T. acknowledges funding by the Bavarian Ministry of Sciences, Research and the Arts. B. V. was financially supported by the Flemish Science Foundation (FWO-Vlaanderen). ; | Approved | Most recent IF: 4.029; 2013 IF: 4.097 | ||
| Call Number | UA @ lucian @ c:irua:105945 | Serial | 3536 | ||
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| Author | Paria Sena, R.; Babaryk, A.A.; Khainakov, S.; Garcia-Granda, S.; Slobodyanik, N.S.; Van Tendeloo, G.; Abakumov, A.M.; Hadermann, J. | ||||
| Title | A pseudo-tetragonal tungsten bronze superstructure: a combined solution of the crystal structure of K6.4(Nb,Ta)36.3O94 with advanced transmission electron microscopy and neutron diffraction | Type | A1 Journal article | ||
| Year | 2016 | Publication | Journal of the Chemical Society : Dalton transactions | Abbreviated Journal | Dalton T |
| Volume | 45 | Issue | 45 | Pages | 973-979 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The crystal structure of the K6.4Nb28.2Ta8.1O94 pseudo-tetragonal tungsten bronze-type oxide was determined using a combination of X-ray powder diffraction, neutron diffraction and transmission electron microscopy techniques, including electron diffraction, high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), annular bright field STEM (ABF-STEM) and energy-dispersive X-ray compositional mapping (STEM-EDX). The compound crystallizes in the space group Pbam with unit cell parameters a = 37.468(9) A, b = 12.493(3) A, c = 3.95333(15) A. The structure consists of corner sharing (Nb,Ta)O6 octahedra forming trigonal, tetragonal and pentagonal tunnels. All tetragonal tunnels are occupied by K(+) ions, while 1/3 of the pentagonal tunnels are preferentially occupied by Nb(5+)/Ta(5+) and 2/3 are occupied by K(+) in a regular pattern. A fractional substitution of K(+) in the pentagonal tunnels by Nb(5+)/Ta(5+) is suggested by the analysis of the HAADF-STEM images. In contrast to similar structures, such as K2Nb8O21, also parts of the trigonal tunnels are fractionally occupied by K(+) cations. | ||||
| Address | Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp, Belgium. joke.hadermann@uantwerpen.be babaryk@univ.kiev.ua | ||||
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| Language | English | Wos | 000367614700018 | Publication Date | 2015-11-23 |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1477-9226 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 4.029 | Times cited | 6 | Open Access | |
| Notes | We thank Dr E. Suard and Dr O. Fabello for assistance in collecting the neutron diffraction data. R.P.S. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant No. 246791-COUNTATOMS. The titan microscope was partly funded by the Hercules fund from the Flemish Government. The authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483-ESTEEM2. AAB acknowledges the JSPDS ICDD Grant-in-Aid program (12-02).; esteem2jra1; esteem2jra2 | Approved | Most recent IF: 4.029 | ||
| Call Number | c:irua:130408 c:irua:130408 | Serial | 3998 | ||
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| Author | Hadermann, J.; Abakumov, A.M.; Turner, S.; Hafideddine, Z.; Khasanova, N.R.; Antipov, E.V.; Van Tendeloo, G. | ||||
| Title | Solving the structure of Li ion battery materials with precession electron diffraction : application to Li2CoPo4F | Type | A1 Journal article | ||
| Year | 2011 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
| Volume | 23 | Issue | 15 | Pages | 3540-3545 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The crystal structure of the Li2CoPO4F high-voltage cathode for Li ion rechargeable batteries has been completely solved from precession electron diffraction (PED) data, including the location of the Li atoms. The crystal structure consists of infinite chains of CoO4F2 octahedra sharing common edges and linked into a 3D framework by PO4 tetrahedra. The chains and phosphate anions together delimit tunnels filled with the Li atoms. This investigation demonstrates that PED can be successfully applied for obtaining structural information on a variety of Li-containing electrode materials even from single micrometer-sized crystallites. | ||||
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| Publisher | Place of Publication | Washington, D.C. | Editor | ||
| Language | Wos | 000293357100019 | Publication Date | 2011-07-11 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0897-4756;1520-5002; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 9.466 | Times cited | 46 | Open Access | |
| Notes | Fwo; Bof | Approved | Most recent IF: 9.466; 2011 IF: 7.286 | ||
| Call Number | UA @ lucian @ c:irua:90357 | Serial | 3053 | ||
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| Author | Radaelli, P.G.; Marezio, M.; Tholence, J.L.; Debrion, S.; Santoro, A.; Huang, Q.; Capponi, J.J.; Chaillout, C.; Krekels, T.; Van Tendeloo, G. | ||||
| Title | Crystal-structure of the double-hg-layer copper-oxide superconductor (Hg,Pr)2Ba2(Y,Ca)Cu2O8-\deltaas a function of doping | Type | A1 Journal article | ||
| Year | 1995 | Publication | The journal of physics and chemistry of solids | Abbreviated Journal | J Phys Chem Solids |
| Volume | 56 | Issue | 10 | Pages | 1471-1478 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The crystal structure of the newly discovered double-Hg-layer copper oxide superconductor (Hg, Pr)(2)Ba-2(Y, Ca)Cu2O8-delta was studied as a function of chemical doping using neutron and electron diffraction and high-resolution transmission electron microscopy (HREM). Rietveld refinements of the structural parameters from neutron powder diffraction data indicate that the oxygen site O3 on the mercury plane is highly defective, being both partially occupied and displaced from the high-symmetry position. The variable concentration of oxygen vacancies partially compensates for the cation doping and, together with the O3 displacement field, makes some of the Hg atoms acquire an unusual pyramidal coordination. HREM images confirm that the structure is of the '2212' type, with very few defects. In some grains, faint superstructure reflections were evidenced by electron diffraction, suggesting that both the oxygen vacancies and the O3 displacement field may order at least on a local scale. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | New York, N.Y. | Editor | ||
| Language | Wos | A1995RR95600025 | Publication Date | 2002-07-26 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0022-3697; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 1.853 | Times cited | 16 | Open Access | |
| Notes | Approved | no | |||
| Call Number | UA @ lucian @ c:irua:104423 | Serial | 574 | ||
| Permanent link to this record | |||||
| Author | Abakumov, A.M.; Hadermann, J.; Tsirlin, A.A.; Tan, H.; Verbeeck, J.; Zhang, H.; Dikarev, E.V.; Shpanchenko, R.V.; Antipov, E.V. | ||||
| Title | Original close-packed structure and magnetic properties of the Pb4Mn9O20 manganite | Type | A1 Journal article | ||
| Year | 2009 | Publication | Journal of solid state chemistry | Abbreviated Journal | J Solid State Chem |
| Volume | 182 | Issue | 8 | Pages | 2231-2238 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The crystal structure of the Pb4Mn9O20 compound (previously known as Pb0.43MnO2.18) was solved from powder X-ray diffraction, electron diffraction, and high resolution electron microscopy data (S.G. Pnma, a=13.8888(2) Å, b=11.2665(2) Å, c=9.9867(1) Å, RI=0.016, RP=0.047). The structure is based on a 6H (cch)2 close packing of pure oxygen h-type (O16) layers alternating with mixed c-type (Pb4O12) layers. The Mn atoms occupy octahedral interstices formed by the oxygen atoms of the close-packed layers. The MnO6 octahedra share edges within the layers, whereas the octahedra in neighboring layers are linked through corner sharing. The relationship with the closely related Pb3Mn7O15 structure is discussed. Magnetization measurements reveal a peculiar magnetic behavior with a phase transition at 52 K, a small net magnetization below the transition temperature, and a tendency towards spin freezing. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | London | Editor | ||
| Language | Wos | 000269066400035 | Publication Date | 2009-06-12 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0022-4596; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 2.299 | Times cited | 5 | Open Access | |
| Notes | The authors are grateful to Christoph Geibel for the help in magnetization measurements. A.Ts. acknowledges MPI CKS for hospitality and financial support during the stay. E.D. thanks the National Science Foundation (CHE-0718900) for financial support. This work was supported by the Russian Foundation of Basic Research (RFBR Grants 07-03-00664-a, 06-03-90168-a and 07-03-00890-a). The authors acknowledge financial support from the European Union under the Framework 6 program under a contract for an Integrated Infrastructure Initiative. Reference 026019 ESTEEM. | Approved | Most recent IF: 2.299; 2009 IF: 2.340 | ||
| Call Number | UA @ lucian @ c:irua:78935UA @ admin @ c:irua:78935 | Serial | 2529 | ||
| Permanent link to this record | |||||
| Author | d' Hondt, H.; Abakumov, A.M.; Hadermann, J.; Kalyuzhnaya, A.S.; Rozova, M.G.; Antipov, E.V.; Van Tendeloo, G. | ||||
| Title | Tetrahedral chain order in the Sr2Fe2O5 brownmillerite | Type | A1 Journal article | ||
| Year | 2008 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
| Volume | 20 | Issue | 22 | Pages | 7188-7194 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The crystal structure of the Sr2Fe2O5 brownmillerite has been investigated using electron diffraction and high resolution electron microscopy. The Sr2Fe2O5 structure demonstrates two-dimensional order: the tetrahedral chains with two mirror-related configurations (L and R) are arranged within the tetrahedral layers according to the −L−R−L−R− sequence, and the layers themselves are displaced with respect to each other over 1/2[111] or 1/2[11] vectors of the brownmillerite unit cell, resulting in different ordered stacking variants. A unified superspace model is constructed for ordered stacking sequences in brownmillerites based on the average brownmillerite structure with a = 5.5298(4)Å, b = 15.5875(12)Å, c = 5.6687(4)Å, and (3 + 1)-dimensional superspace group I2/m(0βγ)0s, q = βb* + γc*, 0 ≤ β ≤ 1/2, 0 ≤ γ ≤ 1. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Washington, D.C. | Editor | ||
| Language | Wos | 000261002200039 | Publication Date | 2008-10-25 | |
| 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 | 64 | Open Access | |
| Notes | Iap Vi | Approved | Most recent IF: 9.466; 2008 IF: 5.046 | ||
| Call Number | UA @ lucian @ c:irua:72945 | Serial | 3511 | ||
| Permanent link to this record | |||||
| Author | Abakumov, A.M.; King, G.; Laurinavichute, V.K.; Rozova, M.G.; Woodward, P.M.; Antipov, E.V. | ||||
| Title | The crystal structure of \alpha-K3AIF6: elpasolites and double perovskites with broken corner-sharing connectivity of the octahedral framework | Type | A1 Journal article | ||
| Year | 2009 | Publication | Inorganic chemistry | Abbreviated Journal | Inorg Chem |
| Volume | 48 | Issue | 19 | Pages | 9336-9344 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The crystal structure of α-K3AlF6 was solved and refined from a combination of powder X-ray and neutron diffraction data (a = 18.8385(3)Å, c = 33.9644(6)Å, S.G. I41/a, Z = 80, RP(X-ray) = 0.037, RP(neutron) = 0.053). The crystal structure is of the A2BB′X6 elpasolite type with the a = b ≈ ae√5, c = 4ae superstructure (ae, parameter of the elpasolite subcell) and rock-salt-type ordering of the K and Al cations over the B and B′ positions, respectively. The remarkable feature of α-K3AlF6 is a rotation of 2/5 of the AlF6 octahedra by π/4 around one of the crystal axes of the elpasolite subcell, coinciding with the 4-fold symmetry axes of the AlF6 octahedra. The rotation of the AlF6 octahedra replaces the corner-sharing between the K and Al polyhedra by edge-sharing, resulting in an increase of coordination numbers of the K cations at the B positions up to 7 and 8. Due to significant deformations of the K polyhedra, the corner-sharing connectivity of the octahedral elpasolite framework is broken and the rotations of the AlF6 octahedra do not have a cooperative character. Elpasolites and double perovskites with similar structural organization are discussed. The difference in ionic radii of the B and B′ cations as well as the tolerance factor are proposed to be the parameters governing the formation of elpasolites and double perovskites with broken corner-sharing connectivity of the octahedral framework. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Easton, Pa | Editor | ||
| Language | Wos | 000270091000039 | Publication Date | 2009-09-03 | |
| 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 | 20 | Open Access | |
| Notes | Approved | Most recent IF: 4.857; 2009 IF: 4.657 | |||
| Call Number | UA @ lucian @ c:irua:79733 | Serial | 568 | ||
| Permanent link to this record | |||||
| Author | Alekseeva, A.M.; Abakumov, A.M.; Leither-Jasper, A.; Schnelle, W.; Prots, Y.; Van Tendeloo, G.; Antipov, E.V.; Grin, Y. | ||||
| Title | Spatial separation of covalent, ionic, and metallic interactions in Mg11Rh18B8 and Mg3Rh5B3 | Type | A1 Journal article | ||
| Year | 2013 | Publication | Chemistry: a European journal | Abbreviated Journal | Chem-Eur J |
| Volume | 19 | Issue | 52 | Pages | 17860-17870 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The crystal structures of Mg11Rh18B8 and Mg3Rh5B3 have been investigated by using single-crystal X-ray diffraction. Mg11Rh18B8: space group P4/mbm; a=17.9949(7), c=2.9271(1)angstrom; Z=2. Mg3Rh5B3: space group Pmma; a=8.450(2), b=2.8644(6), c=11.602(2)angstrom; Z=2. Both crystal structures are characterized by trigonal prismatic coordination of the boron atoms by rhodium atoms. The [BRh6] trigonal prisms form arrangements with different connectivity patterns. Analysis of the chemical bonding by means of the electron-localizability/electron-density approach reveals covalent BRh interactions in these arrangements and the formation of BRh polyanions. The magnesium atoms that are located inside the polyanions interact ionically with their environment, whereas, in the structure parts, which are mainly formed by Mg and Rh atoms, multicenter (metallic) interactions are observed. Diamagnetic behavior and metallic electron transport of the Mg11Rh18B8 and Mg3Rh5B3 phases are in agreement with the bonding picture and the band structure. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Weinheim | Editor | ||
| Language | Wos | 000328531000028 | Publication Date | 2013-12-02 | |
| 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 | 5 | Open Access | |
| Notes | Approved | Most recent IF: 5.317; 2013 IF: 5.696 | |||
| Call Number | UA @ lucian @ c:irua:113697 | Serial | 3064 | ||
| Permanent link to this record | |||||
| Author | King, G.; Abakumov, A.M.; Hadermann, J.; Alekseeva, A.M.; Rozova, M.G.; Perkisas, T.; Woodward, P.M.; Van Tendeloo, G.; Antipov, E.V. | ||||
| Title | Crystal structure and phase transitions in Sr3WO6 | Type | A1 Journal article | ||
| Year | 2010 | Publication | Inorganic chemistry | Abbreviated Journal | Inorg Chem |
| Volume | 49 | Issue | 13 | Pages | 6058-6065 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The crystal structures of the beta and gamma polymorphs of Sr3WO6 and the gamma <->beta phase transition have been investigated using electron diffraction, synchrotron X-ray powder diffraction, and neutron powder diffraction. The gamma-Sr3WO6 polymorph is stable above T-c approximate to 470 K and adopts a monoclinically distorted double perovskite A(2)BB'O-6= Sr2SrWO6 structure (space group Cc, a = 10.2363(1)angstrom, b= 17.9007(1)angstrom, c= 11.9717(1)angstrom, beta=125.585(1)degrees at T= 1373 K, Z=12, corresponding to a = a(p)+1/2b(p) – 1/2c(p), b =3/2b(p) + 3/2c(p), c =-b(p) + c(p), a(p),b(p), c(p), lattice vectors of the parent Fm (3) over barm double perovskite structure). Upon cooling it undergoes a continuous phase transition into the triclinically distorted beta-Sr3WO6 phase (space group Cl, a = 10.09497(3)angstrom, b = 17.64748(5)angstrom, c = 11.81400(3)angstrom, alpha = 89.5470(2)degrees, beta= 125.4529(2)degrees, gamma =90.2889(2)degrees at T= 300 K). Both crystal structures of Sr3WO6 belong to a family of double perovskites with broken corner sharing connectivity of the octahedral framework. A remarkable feature of the gamma-Sr3WO6 structure is a non-cooperative rotation of the WO6 octahedra. One third of the WO6 octahedra are rotated by 45 about either the bp or the cp axis of the parent double perovskite structure. As a result, the WO6 octahedra do not share corners but instead share edges with the coordination polyhedra of the Sr cations at the B positions increasing their coordination number from 6 to 7 or 8. The crystal structure of the beta-phase is very close to the structure of the gamma-phase; decreasing symmetry upon the gamma ->beta transformation occurs because of unequal octahedral rotation angles about the bp and cp axes and increasing distortions of the WO6 octahedra. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Easton, Pa | Editor | ||
| Language | Wos | 000279211500036 | Publication Date | 2010-06-09 | |
| 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; 2010 IF: 4.326 | |||
| Call Number | UA @ lucian @ c:irua:83877 | Serial | 562 | ||
| Permanent link to this record | |||||
| Author | King, G.; Abakumov, A.M.; Woodward, P.M.; Llobet, A.; Tsirlin, A.A.; Batuk, D.; Antipov, E.V. | ||||
| Title | The high-temperature polymorphs of K3AlF6 | Type | A1 Journal article | ||
| Year | 2011 | Publication | Inorganic chemistry | Abbreviated Journal | Inorg Chem |
| Volume | 50 | Issue | 16 | Pages | 7792-7801 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The crystal structures of the three high-temperature polymorphs of K3AlF6 have been solved from neutron powder diffraction, synchrotron X-ray powder diffraction, and electron diffraction data. The β-phase (stable between 132 and 153 °C) and γ-phase (stable between 153 to 306 °C) can be described as unusually complex superstructures of the double-perovskite structure (K2KAlF6) which result from noncooperative tilting of the AlF6 octahedra. The β-phase is tetragonal, space group I4/m, with lattice parameters of a = 13.3862(5) Å and c = 8.5617(3) Å (at 143 °C) and Z = 10. In this phase, one-fifth of the AlF6 octahedra are rotated about the c-axis by 45° while the other four-fifths remain untilted. The large 45° rotations result in edge sharing between these AlF6 octahedra and the neighboring K-centered polyhedra, resulting in pentagonal bipyramidal coordination for four-fifths of the K+ ions that reside on the B-sites of the perovskite structure. The remaining one-fifth of the K+ ions on the B-sites retain octahedral coordination. The γ-phase is orthorhombic, space group Fddd, with lattice parameters of a = 36.1276(4) Å, b = 17.1133(2) Å, and c = 12.0562(1) Å (at 225 °C) and Z = 48. In the γ-phase, one-sixth of the AlF6 octahedra are randomly rotated about one of two directions by 45° while the other five-sixths remain essentially untilted. These rotations result in two-thirds of the K+ ions on the B-site obtaining 7-fold coordination while the other one-third remain in octahedral coordination. The δ-phase adopts the ideal cubic double-perovskite structure, space group Fmm, with a = 8.5943(1) Å at 400 °C. However, pair distribution function analysis shows that locally the δ-phase is quite different from its long-range average crystal structure. The AlF6 octahedra undergo large-amplitude rotations which are accompanied by off-center displacements of the K+ ions that occupy the 12-coordinate A-sites. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Easton, Pa | Editor | ||
| Language | Wos | 000293493100052 | Publication Date | 2011-07-11 | |
| 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 | 19 | Open Access | |
| Notes | Approved | Most recent IF: 4.857; 2011 IF: 4.601 | |||
| Call Number | UA @ lucian @ c:irua:91131 | Serial | 1468 | ||
| Permanent link to this record | |||||
| Author | Gélard, J.; Jehanathan, N.; Roussel, H.; Gariglio, S.; Lebedev, O.I.; Van Tendeloo, G.; Dubourdieu, C. | ||||
| Title | Off-stoichiometry effects on the crystalline and defect structure of hexagonal manganite REMnO3 films (RE = Y, Er, Dy) | Type | A1 Journal article | ||
| Year | 2011 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
| Volume | 23 | Issue | 5 | Pages | 1232-1238 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The crystalline and defect structure of epitaxial hexagonal RExMnyO3 (RE = Er, Dy) films with varying cationic composition was investigated by X-ray diffraction and transmission electron microscopy. The films are composed of a strained layer at the interface with the substrate and of a relaxed layer on top of it. The critical thickness is of 10 to 25 nm. For Mn-rich films (or RE deficient), an off-stoichiometric composition maintaining the hexagonal LuMnO3-type structure is stabilized over a large range of the RE/Mn ratio (0.72−1.00), with no Mn-rich secondary phases observed. A linear dependence of the out-of-plane lattice parameter with RE/Mn is observed in this range. Out-of-phase boundary (OPB) extended defects are observed in all films and exhibit a local change in stoichiometry. Such a large solubility limit in the RE deficient region points toward the formation of vacancies on the RE site (RExMnO3−δ, with 0.72 ≤ x < 1), a phenomenon that is encountered in perovskite manganites such as LaxMnO3−δ (x < 1) and that may strongly impact the physical properties of hexagonal manganites. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Washington, D.C. | Editor | ||
| Language | Wos | 000287767200022 | Publication Date | 2011-02-03 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0897-4756;1520-5002; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 9.466 | Times cited | 17 | Open Access | |
| Notes | Approved | Most recent IF: 9.466; 2011 IF: 7.286 | |||
| Call Number | UA @ lucian @ c:irua:88649 | Serial | 2430 | ||
| Permanent link to this record | |||||
| Author | Efimov, K.; Xu, Q.; Feldhoff, A. | ||||
| Title | Transmission electron microscopy study of BA0.5Sr0.5CO0.8Fe0.2O3-\delta Perovskite decomposition at intermediate temperatures | Type | A1 Journal article | ||
| Year | 2010 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
| Volume | 22 | Issue | 21 | Pages | 5866-5875 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The cubic perovskite Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-delta) (denoted BSCF) is the state-of-the-art ceramic membrane material used for oxygen separation technologies above 1150 K. BSCF is a mixed oxygen-ion and electron conductor (MIEC) and exhibits one of the highest oxygen permeabilities reported so far for dense oxides. Additionally, it has excellent phase stability above 1150 K. In the intermediate temperature range (750-1100 K), however, BSCF suffers from a slow decomposition of the cubic perovskite into variants with hexagonal stacking that are barriers to oxygen transport. To elucidate details of the decomposition process, both sintered BSCF ceramic and powder were annealed for 180-240 h in ambient air at temperatures below 1123 K and analyzed by different transmission electron microscopy techniques. Aside from hexagonal perovskite Ba(0.5)Sr(0.5)CoO(3-delta) , the formation of lamellar noncubic phases was observed in the quenched samples. The structure of the lamellae with the previously unknown composition Ba(1-x)Sr(x)Co(2-y)Fe(y)O(5-delta) was found to be related to the 15R hexagonal perovskite polytype. The valence and spin-state transition of cobalt leading to a considerable diminution of its ionic radius can be considered a reason for BSCF's inherent phase instability at intermediate temperatures. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Washington, D.C. | Editor | ||
| Language | Wos | 000283623700010 | Publication Date | 2010-10-13 | |
| 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 | 117 | Open Access | |
| Notes | Esteem 026019 | Approved | Most recent IF: 9.466; 2010 IF: 6.400 | ||
| Call Number | UA @ lucian @ c:irua:95546 | Serial | 3720 | ||
| Permanent link to this record | |||||
| Author | Vervloessem, E.; Gromov, M.; De Geyter, N.; Bogaerts, A.; Gorbanev, Y.; Nikiforov, A. | ||||
| Title | NH3and HNOxFormation and Loss in Nitrogen Fixation from Air with Water Vapor by Nonequilibrium Plasma | Type | A1 Journal article | ||
| Year | 2023 | Publication | ACS Sustainable Chemistry and Engineering | Abbreviated Journal | |
| Volume | 11 | Issue | 10 | Pages | 4289-4298 |
| Keywords | A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract |
The current global energy crisis indicated that increasing our insight into nonfossil fuel nitrogen fixation pathways for synthetic fertilizer production is more crucial than ever. Nonequilibrium plasma is a good candidate because it can use N2 or air as a N source and water directly as a H source, instead of H2 or fossil fuel (CH4). In this work, we investigate NH3 gas phase formation pathways from humid N2 and especially humid air up to 2.4 mol % H2O (100% relative humidity at 20 °C) by optical emission spectroscopy and Fouriertransform infrared spectroscopy. We demonstrate that the nitrogen fixation capacity is increased when water vapor is added, as this enables HNO2 and NH3 production in both N2 and air. However, we identified a significant loss mechanism for NH3 and HNO2 that occurs in systems where these species are synthesized simultaneously; i.e., downstream from the plasma, HNO2 reacts with NH3 to form NH4NO2, which rapidly decomposes into N2 and H2O. We also discuss approaches to prevent this loss mechanism, as it reduces the effective nitrogen fixation when not properly addressed and therefore should be considered in future works aimed at optimizing plasma-based N2 fixation. In-line removal of HNO2 or direct solvation in liquid are two proposed strategies to suppress this loss mechanism. Indeed, using liquid H2O is beneficial for accumulation of the N2 fixation products. Finally, in humid air, we also produce NH4NO3, from the reaction of HNO3 with NH3, which is of direct interest for fertilizer application. |
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000953337700001 | Publication Date | 2023-03-13 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2168-0485 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 8.4 | Times cited | Open Access | OpenAccess | |
| Notes | This research is supported by the Excellence of Science FWOFNRS project (NITROPLASM, FWO grant ID GoF9618n, EOS ID 30505023), the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant No. 810182 − SCOPE ERC Synergy project), and the Fund for Scientific Research (FWO) Flanders Bioeconomy project (grant No. G0G2322N), funded by the European Union-NextGenerationEU. | Approved | Most recent IF: 8.4; 2023 IF: 5.951 | ||
| Call Number | PLASMANT @ plasmant @c:irua:195878 | Serial | 7254 | ||
| Permanent link to this record | |||||
| Author | Cuypers, B.; Vermeylen, S.; Hammerschmid, D.; Trashin, S.; Rahemi, V.; Konijnenberg, A.; De Schutter, A.; Cheng, C.-H.C.; Giordano, D.; Verde, C.; De Wael, K.; Sobott, F.; Dewilde, S.; Van Doorslaer, S. | ||||
| Title | Antarctic fish versus human cytoglobins : the same but yet so different | Type | A1 Journal article | ||
| Year | 2017 | Publication | Journal of inorganic biochemistry | Abbreviated Journal | J Inorg Biochem |
| Volume | 173 | Issue | Pages | 66-78 | |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract |
The cytoglobins of the Antarctic fish Chaenocephalus aceratus and Dissostichus mawsoni have many features in common with human cytoglobin. These cytoglobins are heme proteins in which the ferric and ferrous forms have a characteristic hexacoordination of the heme iron, i.e. axial ligation of two endogenous histidine residues, as confirmed by electron paramagnetic resonance, resonance Raman and optical absorption spectroscopy. The combined spectroscopic analysis revealed only small variations in the heme-pocket structure, in line with the small variations observed for the redox potential. Nevertheless, some striking differences were also discovered. Resonance Raman spectroscopy showed that the stabilization of an exogenous heme ligand, such as CO, occurs differently in human cytoglobin in comparison with Antarctic fish cytoglobins. Furthermore, while it has been extensively reported that human cytoglobin is essentially monomeric and can form an intramolecular disulfide bridge that can influence the ligand binding kinetics, 3D modeling of the Antarctic fish cytoglobins indicates that the cysteine residues are too far apart to form such an intramolecular bridge. Moreover, gel filtration and mass spectrometry reveal the occurrence of non-covalent multimers (up to pentamers) in the Antarctic fish cytoglobins that are formed at low concentrations. Stabilization of these oligomers by disulfide-bridge formation is possible, but not essential. If intermolecular disulfide bridges are formed, they influence the heme-pocket structure, as is shown by EPR measurements. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000405159600007 | Publication Date | 2017-04-28 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0162-0134 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.348 | Times cited | 7 | Open Access | |
| Notes | ; The authors acknowledge the support of the University of Antwerp GOA-BOF funding (28312), FWO funding (G.0687.13) and the Hercules foundation for funding of the Synapt G2 instrument. This study was carried out in the framework of the SCAR program “Antarctic Thresholds – Ecosystem Resilience and Adaptation” (AnT-ERA). It was financially supported by the Italian National Program for Antarctic Research (PNRA). Research of A. De Schutter is funded by a PhD grant of the Agency for Innovation by Science and Technology (121339) (IWT, Belgium). C-H C. Cheng acknowledges funding support from US National Science Foundation Polar Programs (ANT-1142158). ; | Approved | Most recent IF: 3.348 | ||
| Call Number | UA @ admin @ c:irua:144826 | Serial | 5474 | ||
| Permanent link to this record | |||||
| Author | Monico, L.; Janssens, K.; Vanmeert, F.; Cotte, M.; Brunetti, B.G.; van der Snickt, G.; Leeuwestein, M.; Plisson, J.S.; Menu, M.; Miliani, C. | ||||
| Title | Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods : part 5 : effects of nonoriginal surface coatings into the nature and distribution of chromium and sulfur species in chrome yellow paints | Type | A1 Journal article | ||
| Year | 2014 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
| Volume | 86 | Issue | 21 | Pages | 10804-10811 |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract |
The darkening of lead chromate yellow pigments, caused by a reduction of the chromate ions to Cr(III) compounds, is known to affect the appearance of several paintings by Vincent van Gogh. In previous papers of this series, we demonstrated that the darkening is activated by light and depends on the chemical composition and crystalline structure of the pigments. In this work, the results of Part 2 are extended and complemented with a new study aimed at deepening the knowledge of the nature and distribution of Cr and S species at the interface between the chrome yellow paint and the nonoriginal coating layer. For this purpose, three microsamples from two varnished paintings by Van Gogh and a waxed low relief by Gauguin (all originally uncoated) have been examined. Because nonoriginal coatings are often present in artwork by Van Gogh and contemporaries, the understanding of whether or not their application has influenced the morphological and/or physicochemical properties of the chrome yellow paint underneath is relevant in view of the conservation of these masterpieces. In all the samples studied, microscopic X-ray fluorescence (mu-XRF) and X-ray absorption near edge structure (mu-XANES) investigations showed that Cr(III)-based alteration products are present in the form of grains inside the coating (generally enriched of S species) and also homogeneously widespread at the paint surface. The distribution of Cr(III) species may be explained by the mechanical friction caused by the coating application by brush that picked up and redistributed the superficial Cr compounds, likely already present in the reduced state as result of the photodegradation process. The analysis of the XANES profiles allowed us to obtain new insights into the nature of the Cr(III) alteration products, that were identified as sulfate-, oxide-, organo-metal-, and chloride-based compounds. Building upon the knowledge acquired through the examination of original paint samples and from the investigation of aged model paints in the last Part 4 paper, in this study we aim to characterize a possible relation between the chemical composition of the coating and the chrome yellow degradation pathways by studying photochemically aged model samples covered with a dammar varnish contaminated with sulfide and sulfate salts. Cr speciation results did not show any evidence of the active role of the varnish and added S species on the reduction process of chrome yellows. | ||||
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| Language | Wos | 000344510200043 | Publication Date | 2014-10-10 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 6.32 | Times cited | 25 | Open Access | |
| Notes | ; This research was supported by the Italian projects PRIN (SICH) and PON (ITACHA). The text also presents results from Interuniversity Attraction Poles Programme Belgian Science Policy (S2-ART project S4DA), GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. ESRF is acknowledged for the grants received (experiments EC-799 and EC-1051). L.M. acknowledges the CNR for the financial support received in the framework of the Short Term Mobility Programme 2013. Thanks are expressed to Ella Hendriks (Van Gogh Museum, Amsterdam) and Muriel Geldof (Cultural Heritage Agency of The Netherlands) for selecting and sharing the information on the cross-section taken from Bank of the Seine. All the staff of the Van Gogh Museum, the Kroller-Muller Museum, and the Musee d'Orsay are acknowledged for the agreeable cooperation. ; | Approved | Most recent IF: 6.32; 2014 IF: 5.636 | ||
| Call Number | UA @ admin @ c:irua:122100 | Serial | 5570 | ||
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| Author | Monico, L.; van der Snickt, G.; Janssens, K.; de Nolf, W.; Miliani, C.; Dik, J.; Radepont, M.; Hendriks, E.; Geldof, M.; Cotte, M. | ||||
| Title | Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods : 2 : original paint layer samples | Type | A1 Journal article | ||
| Year | 2011 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
| Volume | 83 | Issue | 4 | Pages | 1224-1231 |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract |
The darkening of the original yellow areas painted with the chrome yellow pigment (PbCrO4, PbCrO4·xPbSO4, or PbCrO4·xPbO) is a phenomenon widely observed on several paintings by Vincent van Gogh, such as the famous different versions of Sunflowers. During our previous investigations on artificially aged model samples of lead chromate, we established for the first time that darkening of chrome yellow is caused by reduction of PbCrO4 to Cr2O3·2H2O (viridian green), likely accompanied by the presence of another Cr(III) compound, such as either Cr2(SO4)3·H2O or (CH3CO2)7Cr3(OH)2 [chromium(III) acetate hydroxide]. In the second part of this work, in order to demonstrate that this reduction phenomenon effectively takes place in real paintings, we study original paint samples from two paintings of V. van Gogh. As with the model samples, in view of the thin superficial alteration layers that are present, high lateral resolution spectroscopic methods that make use of synchrotron radiation (SR), such as microscopic X-ray absorption near edge (μ-XANES) and X-ray fluorescence spectrometry (μ-XRF) were employed. Additionally, μ-Raman and mid-FTIR analyses were carried out to completely characterize the samples. On both paint microsamples, the local presence of reduced Cr was demonstrated by means of μ-XANES point measurements. The presence of Cr(III) was revealed in specific areas, in some cases correlated to the presence of Ba(sulfate) and/or to that of aluminum silicate compounds. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000287176900012 | Publication Date | 2011-02-14 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 6.32 | Times cited | 84 | Open Access | |
| Notes | ; This research was funded by grants from ESRF (experiment EC-504) and by HASYLAB (experiments 11-20080130 EC and 11-20070157 EC) and was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) project nos. G.0103.04, G.0689.06, and G.0704.08. The staff of the Van Gogh Museum, Amsterdam, is acknowledged for their agreeable cooperation and for the authorization to publish the images of the paintings in this article. L.M. was financially supported by the Erasmus Placement in the framework of Lifelong Learning Programme (A.Y. 2009-2010). The EU Community's FP7 Research Infrastructures program under the CHARISMA Project (Grant Agreement 228330) is also acknowledged. ; | Approved | Most recent IF: 6.32; 2011 IF: 5.856 | ||
| Call Number | UA @ admin @ c:irua:88795 | Serial | 5571 | ||
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| Author | Batuk, D.; Batuk, M.; Tsirlin, A.A.; Hadermann, J.; Abakumov, A.M. | ||||
| Title | Trapping of Oxygen Vacancies at Crystallographic Shear Planes in Acceptor-Doped Pb-Based Ferroelectrics | Type | A1 Journal article | ||
| Year | 2015 | Publication | Angewandte Chemie: international edition in English | Abbreviated Journal | Angew Chem Int Edit |
| Volume | 54 | Issue | 54 | Pages | 14787-14790 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The defect chemistry of the ferroelectric material PbTiO3 after doping with Fe(III) acceptor ions is reported. Using advanced transmission electron microscopy and powder X-ray and neutron diffraction, we demonstrate that even at concentrations as low as circa 1.7% (material composition approximately ABO2.95), the oxygen vacancies are trapped into extended planar defects, specifically crystallographic shear planes. We investigate the evolution of these defects upon doping and unravel their detailed atomic structure using the formalism of superspace crystallography, thus unveiling their role in nonstoichiometry in the Pb-based perovskites. | ||||
| Address | Chemistry Department, Moscow State University, 119991, Moscow (Russia). artem.abakumov@uantwerpen.be | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | English | Wos | 000367723400031 | Publication Date | 2015-10-21 |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1433-7851 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 11.994 | Times cited | 3 | Open Access | |
| Notes | A.M.A. is grateful to the Russian Science Foundation (grant 14-13-00680). AT was funded by the Mobilitas grant MTT77 of the ESF and by the Federal Ministry for Education and Research through the Sofja Kovalevskaya Award of Alexander von Humboldt Foundation. | Approved | Most recent IF: 11.994; 2015 IF: 11.261 | ||
| Call Number | c:irua:131104 | Serial | 4080 | ||
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| Author | Perreault, P.; Kummamuru, N.B.; Gonzalez Quiroga, A.; Lenaerts, S. | ||||
| Title | CO2 capture initiatives : are governments, society, industry and the financial sector ready? | Type | A1 Journal article | ||
| Year | 2022 | Publication | Current Opinion in Chemical Engineering | Abbreviated Journal | Curr Opin Chem Eng |
| Volume | 38 | Issue | Pages | 100874 | |
| Keywords | A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) | ||||
| Abstract |
The deployment of CCUS plants does not match the enormous requirements to meet the CO2 emission reductions fixed during the Paris agreement, and we must ask ourselves what is refraining the technology deployment, especially in light of the recent high CO2 prices. Owing to the higher costs than their fossil counterparts, Carbon Capture & Utilization represents a long-term solution. In addition to a gigantic scale-up effort even for the most mature Carbon Capture & Storage (CCS) technologies, various factors are responsible for the slow roll-out of CCS projects. Luckily, the financial sector and governments are playing their role. Support from the public is however key, and an open communication is required to convert social tolerance into social acceptance. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000885329800001 | Publication Date | 2022-10-28 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2211-3398 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 6.6 | Times cited | Open Access | OpenAccess | |
| Notes | Approved | Most recent IF: 6.6 | |||
| Call Number | UA @ admin @ c:irua:191272 | Serial | 7137 | ||
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| Author | Heyne, M.H.; de Marneffe, J.-F.; Nuytten, T.; Meersschaut, J.; Conard, T.; Caymax, M.; Radu, I.; Delabie, A.; Neyts, E.C.; De Gendt, S. | ||||
| Title | The conversion mechanism of amorphous silicon to stoichiometric WS2 | Type | A1 Journal article | ||
| Year | 2018 | Publication | Journal of materials chemistry C : materials for optical and electronic devices | Abbreviated Journal | J Mater Chem C |
| Volume | 6 | Issue | 15 | Pages | 4122-4130 |
| Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract |
The deposition of ultra-thin tungsten films and their related 2D chalcogen compounds on large area dielectric substrates by gas phase reactions is challenging. The lack of nucleation sites complicates the adsorption of W-related precursors and subsequent sulfurization usually requires high temperatures. We propose here a technique in which a thin solid amorphous silicon film is used as reductant for the gas phase precursor WF6 leading to the conversion to metallic W. The selectivity of the W conversion towards the underlying dielectric surfaces is demonstrated. The role of the Si surface preparation, the conversion temperature, and Si thickness on the formation process is investigated. Further, the in situ conversion of the metallic tungsten into thin stoichiometric WS2 is achieved by a cyclic approach based on WF6 and H2S pulses at the moderate temperature of 450 1C, which is much lower than usual oxide sulfurization processes. | ||||
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| Language | Wos | 000430538000036 | Publication Date | 2018-03-20 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2050-7526 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 5.256 | Times cited | 4 | Open Access | OpenAccess |
| Notes | This work was supported throughout a strategic fundamental research grant for M. H. by the agency Flanders innovation & entrepreneurship (VLAIO). | Approved | Most recent IF: 5.256 | ||
| Call Number | PLASMANT @ plasmant @c:irua:150968 | Serial | 4921 | ||
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| Author | Pauwels, D.; Geboes, B.; Hereijgers, J.; Choukroun, D.; De Wael, K.; Breugelmans, T. | ||||
| Title | The application of an electrochemical microflow reactor for the electrosynthetic aldol reaction of acetone to diacetone alcohol | Type | A1 Journal article | ||
| Year | 2017 | Publication | Chemical engineering research and design | Abbreviated Journal | Chem Eng Res Des |
| Volume | 128 | Issue | Pages | 205-213 | |
| Keywords | A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP); Applied Electrochemistry & Catalysis (ELCAT) | ||||
| Abstract |
The design and application of an electrochemical micro-flow reactor for the aldol reaction of acetone to diacetone alcohol (DAA) is reported. The modular reactor could be readily disassembled and reassembled to change the electrodes, incorporate a membrane and remove possible obstructions. The productivity and efficiency was quantified. Using a platinum deposit as electrocatalyst or an inert glassy carbon electrode as working electrode, the maximum obtainable equilibrium concentration of ±15 m% was reached after a single pass up to a flow rate of 8 ml min−1, yielding 0.57 g min−1 DAA (3.46 mmol cm−3 min−1) at an efficiency of 0.33 g C−1 on platinum and 0.50 g min−1 (3.04 mmol cm−3 min−1) at 1.20 g C−1 on glassy carbon. Note that no optimisation studies have been made in the present paper. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000424736500018 | Publication Date | 2017-10-20 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0263-8762 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 2.538 | Times cited | 2 | Open Access | |
| Notes | ; The authors would like to thank Bert De Mot for assisting with the measurements. Jonas Hereijgers greatly acknowledges the Research Foundation – Flanders (FWO) for support through a Post-Doctoral grant (12Q8817N). ; | Approved | Most recent IF: 2.538 | ||
| Call Number | UA @ admin @ c:irua:146943 | Serial | 5871 | ||
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| Author | Bigiani, L.; Andreu, T.; Maccato, C.; Fois, E.; Gasparotto, A.; Sada, C.; Tabacchi, G.; Krishnan, D.; Verbeeck, J.; Ramon Morante, J.; Barreca, D. | ||||
| Title | Engineering Au/MnO₂ hierarchical nanoarchitectures for ethanol electrochemical valorization | Type | A1 Journal article | ||
| Year | 2020 | Publication | Journal Of Materials Chemistry A | Abbreviated Journal | J Mater Chem A |
| Volume | 8 | Issue | 33 | Pages | 16902-16907 |
| Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The design of eco-friendly electrocatalysts for ethanol valorization is an open challenge towards sustainable hydrogen production. Herein we present an original fabrication route to effective electrocatalysts for the ethanol oxidation reaction (EOR). In particular, hierarchical MnO(2)nanostructures are grown on high-area nickel foam scaffolds by a plasma-assisted strategy and functionalized with low amounts of optimally dispersed Au nanoparticles. This strategy leads to catalysts with a unique morphology, designed to enhance reactant-surface contacts and maximize active site utilization. The developed nanoarchitectures show superior performances for ethanol oxidation in alkaline media. We reveal that Au decoration boosts MnO(2)catalytic activity by inducing pre-dissociation and pre-oxidation of the adsorbed ethanol molecules. This evidence validates our strategy as an effective route for the development of green electrocatalysts for efficient electrical-to-chemical energy conversion. | ||||
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| Language | Wos | 000562931300008 | Publication Date | 2020-07-21 | |
| 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 | 11.9 | Times cited | 16 | Open Access | OpenAccess |
| Notes | ; This work was financially supported by Padova University DOR 2016-2019 and P-DiSC #03BIRD2018-UNIPD OXYGENA projects, as well as by the INSTM Consortium (INSTMPD004 – NETTUNO), AMGA Foundation Mn4Energy project and Insubria University FAR2018. J. V. and D. K. acknowledge funding from the Flemish Government (Hercules), GOA project “Solarpaint” (Antwerp University) and European Union's H2020 programme under grant agreement no. 823717 ESTEEM3. The authors are grateful to Dr Gianluca Corr for skillful technical support. ; esteem3TA; esteem3reported | Approved | Most recent IF: 11.9; 2020 IF: 8.867 | ||
| Call Number | UA @ admin @ c:irua:171989 | Serial | 6506 | ||
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| Author | Naik, P.V.; Wee, L.H.; Meledina, M.; Turner, S.; Li, Y.; Van Tendeloo, G.; Martens, J.A.; Vankelecom, I.F.J. | ||||
| Title | PDMS membranes containing ZIF-coated mesoporous silica spheres for efficient ethanol recovery via pervaporation | Type | A1 Journal article | ||
| Year | 2016 | Publication | Journal of materials chemistry A : materials for energy and sustainability | Abbreviated Journal | J Mater Chem A |
| Volume | 4 | Issue | 4 | Pages | 12790-12798 |
| Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The design of functional micro- and mesostructured composite materials is significantly important for separation processes. Mesoporous silica is an attractive material for fast diffusion, while microporous zeolitic imidazolate frameworks (ZIFs) are beneficial for selective adsorption and diffusion. In this work, ZIF-71 and ZIF-8 nanocrystals were grown on the surface of mesoporous silica spheres (MSS) via the seeding and regrowth approach in order to obtain monodispersed MSS-ZIF-71 and MSS-ZIF-8 spheres with a particle size of 2-3 mm. These MSS-ZIF spheres were uniformly dispersed into a polydimethylsiloxane (PDMS) matrix to prepare mixed matrix membranes (MMMs). These MMMs were evaluated for the separation of ethanol from water via pervaporation. The pervaporation results reveal that the MSS-ZIF filled MMMs substantially improve the ethanol recovery in both aspects viz. flux and separation factor. These MMMs outperforms the unfilled PDMS membranes and the conventional carbon and zeolite filled MMMs. As expected, the mesoporous silica core allows very fast flow of the permeating compound, while the hydrophobic ZIF coating enhances the ethanol selectivity through its specific pore structure, hydrophobicity and surface chemistry. It can be seen that ZIF-8 mainly has a positive impact on the selectivity, while ZIF-71 enhances fluxes more significantly. | ||||
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| Publisher | Place of Publication | Cambridge | Editor | ||
| Language | Wos | 000382015100012 | Publication Date | 2016-07-12 | |
| 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 | 26 | Open Access | |
| Notes | Approved | Most recent IF: 8.867 | |||
| Call Number | UA @ lucian @ c:irua:137188 | Serial | 4395 | ||
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| Author | Brienza, F.; Van Aelst, K.; Devred, F.; Magnin, D.; Tschulkow, M.; Nimmegeers, P.; Van Passel, S.; Sels, B.F.; Gerin, P.; Debecker, D.P.; Cybulska, I. | ||||
| Title | Unleashing lignin potential through the dithionite-assisted organosolv fractionation of lignocellulosic biomass | Type | A1 Journal article | ||
| Year | 2022 | Publication | Chemical Engineering Journal | Abbreviated Journal | Chem Eng J |
| Volume | 450 | Issue | 3 | Pages | 138179-14 |
| Keywords | A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM); Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS) | ||||
| Abstract |
The development of biomass pretreatment approaches that, next to (hemi)cellulose valorization, aim at the conversion of lignin to chemicals is essential for the long-term success of a biorefinery. Herein, we discuss a dithionite-assisted organosolv fractionation (DAOF) of lignocellulose in n-butanol and water to produce cellulosic pulp and mono-/oligo-aromatics. The study frames the technicalities of this biorefinery process and relates them to the features of the obtained product streams. We comprehensively identify and quantify all products of interest: solid pulp (acid hydrolysis-HPLC, ATR-FTIR, XRD, SEM, enzymatic hydrolysis-HPLC), lignin derivatives (GPC, GC-MS/FID, 1H-13C HSQC NMR, ICP-AES), and carbohydrate derivatives (HPLC). These results were used for inspecting the economic feasibility of DAOF. In the best process configuration, a high yield of monophenolics was reached (~20%, based on acid insoluble lignin in birch sawdust). Various other lignocellulosic feedstocks were also explored, showing that DAOF is particularly effective on hardwood and herbaceous biomass. Overall, this study demonstrates that DAOF is a viable fractionation method for the sustainable upgrading of lignocellulosic biomass. | ||||
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| Language | Wos | 000888204900005 | Publication Date | 2022-07-20 | |
| 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 | 15.1 | Times cited | Open Access | OpenAccess | |
| Notes | Approved | Most recent IF: 15.1 | |||
| Call Number | UA @ admin @ c:irua:189322 | Serial | 7373 | ||
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| Author | Bigiani, L.; Gasparotto, A.; Maccato, C.; Sada, C.; Verbeeck, J.; Andreu, T.; Morante, J.R.; Barreca, D. | ||||
| Title | Dual improvement of beta-MnO₂ oxygen evolution electrocatalysts via combined substrate control and surface engineering | Type | A1 Journal article | ||
| Year | 2020 | Publication | Chemcatchem | Abbreviated Journal | Chemcatchem |
| Volume | Issue | Pages | 1-10 | ||
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
The development of catalysts with high intrinsic activity towards the oxygen evolution reaction (OER) plays a critical role in sustainable energy conversion and storage. Herein, we report on the development of efficient (photo)electrocatalysts based on functionalized MnO(2)systems. Specifically,beta-MnO(2)nanostructures grown by plasma enhanced-chemical vapor deposition on fluorine-doped tin oxide (FTO) or Ni foams were decorated with Co(3)O(4)or Fe(2)O(3)nanoparticles by radio frequency sputtering. Upon functionalization, FTO-supported materials yielded a performance increase with respect to bare MnO2, with current densities at 1.65 Vvs. the reversible hydrogen electrode (RHE) up to 3.0 and 3.5 mA/cm(2)in the dark and under simulated sunlight, respectively. On the other hand, the use of highly porous and conductive Ni foam substrates enabled to maximize cooperative interfacial effects between catalyst components. The best performing Fe2O3/MnO(2)system provided a current density of 17.9 mA/cm(2)at 1.65 Vvs. RHE, an overpotential as low as 390 mV, and a Tafel slope of 69 mV/decade under dark conditions, comparing favorably with IrO(2)and RuO(2)benchmarks. Overall, the control of beta-MnO2/substrate interactions and the simultaneous surface property engineering pave the way to an efficient energy generation from abundant natural resources. | ||||
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| Language | Wos | 000571229000001 | Publication Date | 2020-09-18 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1867-3880; 1867-3899 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 4.5 | Times cited | 5 | Open Access | Not_Open_Access |
| Notes | ; This work has been financially supported by Padova University DOR 2017-2019, P-DiSC #03BIRD2016-UNIPD and #03BIRD2018-UNIPD projects. A.G. acknowledges AMGA Foundation and INSTM Consortium. J.V. gratefully acknowledges funding from the GOA project “Solarpaint” of the University of Antwerp and the European Union's Horizon 2020 research and innovation programme under grant agreement No 823717-ESTEEM3. ; esteem3TA; esteem3reported | Approved | Most recent IF: 4.5; 2020 IF: 4.803 | ||
| Call Number | UA @ admin @ c:irua:171949 | Serial | 6493 | ||
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