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Author | Juchtmans, R.; Verbeeck, J. | ||||
Title | Orbital angular momentum in electron diffraction and its use to determine chiral crystal symmetries | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review: B: condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 92 | Issue | 92 | Pages | 134108 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | In this work we present an alternative way to look at electron diffraction in a transmission electron microscope. Instead of writing the scattering amplitude in Fourier space as a set of plane waves,we use the cylindrical Fourier transform to describe the scattering amplitude in a basis of orbital angular momentum (OAM) eigenstates. We show how working in this framework can be very convenient when investigating, e.g., rotation and screw-axis symmetries. For the latter we find selection rules on the OAM coefficients that unambiguously reveal the handedness of the screw axis. Detecting the OAM coefficients of the scattering amplitude thus offers the possibility to detect the handedness of crystals without the need for dynamical simulations, the thickness of the sample, nor the exact crystal structure. We propose an experimental setup to measure the OAM components where an image of the crystal is taken after inserting a spiral phase plate in the diffraction plane and perform multislice simulations on α quartz to demonstrate how the method indeed reveals the chirality. The experimental feasibility of the technique is discussed together with its main advantages with respect to chirality determination of screw axes. The method shows how the use of a spiral phase plate can be extended from a simple phase imaging technique to a tool to measure the local OAM decomposition of an electron wave, widening the field of interest well beyond chiral space group determination. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000362893100002 | Publication Date | 2015-10-14 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121; 1550-235x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 16 | Open Access | |
Notes | The authors acknowledge support from the FWO (As- pirant Fonds Wetenschappelijk Onderzoek–Vlaanderen), the EU under the Seventh Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483-ESTEEM2, and ERC Starting Grant No. 278510 VORTEX; esteem2jra1; ECASJO; | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | c:irua:129417 c:irua:129417UA @ admin @ c:irua:129417 | Serial | 4089 | ||
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Author | Clark, L.; Guzzinati, G.; Béché, A.; Lubk, A.; Verbeeck, J. | ||||
Title | Symmetry-constrained electron vortex propagation | Type | A1 Journal article | ||
Year | 2016 | Publication | Physical review A | Abbreviated Journal | Phys Rev A |
Volume | 93 | Issue | 93 | Pages | 063840 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Electron vortex beams hold great promise for development in transmission electron microscopy but have yet to be widely adopted. This is partly due to the complex set of interactions that occur between a beam carrying orbital angular momentum (OAM) and a sample. Herein, the system is simplified to focus on the interaction between geometrical symmetries, OAM, and topology. We present multiple simulations alongside experimental data to study the behavior of a variety of electron vortex beams after interacting with apertures of different symmetries and investigate the effect on their OAM and vortex structure, both in the far field and under free-space propagation. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000378197200006 | Publication Date | 2016-06-23 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9926 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.925 | Times cited | 7 | Open Access | |
Notes | L.C., A.B., G.G., and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510—VORTEX. J.V. and A.L. acknowledge financial support from the European Union through the 7th Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2). The Qu-Ant-EM microscope was partly funded by the Hercules fund of the Flemish Government.; esteem2jra3; ECASJO; | Approved | Most recent IF: 2.925 | ||
Call Number | c:irua:134086 c:irua:134086 | Serial | 4090 | ||
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Author | Degutis, G.; Pobedinskas, P.; Turner, S.; Lu, Y.-G.; Al Riyami, S.; Ruttens, B.; Yoshitake, T.; D'Haen, J.; Haenen, K.; Verbeeck, J.; Hardy, A.; Van Bael, M.K. | ||||
Title | CVD diamond growth from nanodiamond seeds buried under a thin chromium layer | Type | A1 Journal article | ||
Year | 2016 | Publication | Diamond and related materials | Abbreviated Journal | Diam Relat Mater |
Volume | 64 | Issue | 64 | Pages | 163-168 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | This work presents a morphological and structural analysis of CVD diamond growth on silicon from nanodiamond seeds covered by a 50 nm thick chromium layer. The role of carbon diffusion as well as chromium and carbon silicide formation is analyzed. The local diamond environment is investigated by scanning transmission electron microscopy in combination with electron energy-loss spectroscopy. The evolution of the diamond phase composition (sp3/sp2) is evaluated by micro-Raman spectroscopy. Raman and X-ray diffraction analysis are used to identify the interfacial phases formed during CVD growth. Based upon the observed morphological and structural evolution, a diamond growth model from nanodiamond seeds buried beneath a thin Cr layer is proposed. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000374608100020 | Publication Date | 2016-02-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0925-9635 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.561 | Times cited | 11 | Open Access | |
Notes | The authors acknowledge financial support provided by Research Program FWO G.056.810 and G0044.13N. A.H. and M.K.V.B are grateful to Hercules Foundation Flanders for financial support. P.P. and S.T. are Postdoctoral Fellows of the Research Foundation – Flanders (FWO). The Titan microscope used for this work was partially funded by the Hercules Foundation. | Approved | Most recent IF: 2.561 | ||
Call Number | c:irua:133624UA @ admin @ c:irua:133624 | Serial | 4091 | ||
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Author | Lottini, E.; López-Ortega, A.; Bertoni, G.; Turner, S.; Meledina, M.; Van Tendeloo, G.; de Julián Fernández, C.; Sangregorio, C. | ||||
Title | Strongly Exchange Coupled Core|Shell Nanoparticles with High Magnetic Anisotropy: A Strategy toward Rare-Earth-Free Permanent Magnets | Type | A1 Journal article | ||
Year | 2016 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
Volume | 28 | Issue | 28 | Pages | 4214-4222 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Antiferromagnetic(AFM)|ferrimagnetic(FiM) core|shell (CS) nanoparticles (NPs) of formula Co0.3Fe0.7O|Co0.6Fe2.4O4 with mean diameter from 6 to 18 nm have been synthesized through a one-pot thermal decomposition process. The CS structure has been generated by topotaxial oxidation of the core region, leading to the formation of a highly monodisperse single inverted AFM|FiM CS system with variable AFM-core diameter and constant FiM-shell thickness (~2 nm). The sharp interface, the high structural matching between both phases and the good crystallinity of the AFM material have been structurally demonstrated and are corroborated by the robust exchange-coupling between AFM and FiM phases, which gives rise to one among the largest exchange bias (HE) values ever reported for CS NPs (8.6 kOe) and to a strongly enhanced coercive field (HC). In addition, the investigation of the magnetic properties as a function of the AFM-core size (dAFM), revealed a non-monotonous trend of both HC and HE, which display a maximum value for dAFM = 5 nm (19.3 and 8.6 kOe, respectively). These properties induce a huge improvement of the capability of storing energy of the material, a result which suggests that the combination of highly anisotropic AFM|FiM materials can be an efficient strategy towards the realization of novel Rare Earth-free permanent magnets. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000378973100013 | Publication Date | 2016-05-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.466 | Times cited | 48 | Open Access | |
Notes | This work was supported by the EU-FP7 through NANOPYME Project (No. 310516) and Integrated Infrastructure Initiative ESTEEM2 (No. 312483). S.T. gratefully acknowledges the FWO Flanders for a post-doctoral scholarship.; esteem2_ta | Approved | Most recent IF: 9.466 | ||
Call Number | c:irua:134084 c:irua:134084 | Serial | 4092 | ||
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Author | Lobato, I.; Van Aert, S.; Verbeeck, J. | ||||
Title | Progress and new advances in simulating electron microscopy datasets using MULTEM | Type | A1 Journal article | ||
Year | 2016 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 168 | Issue | 168 | Pages | 17-27 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | A new version of the open source program MULTEM is presented here. It includes a graphical user interface, tapering truncation of the atomic potential, CPU multithreading functionality, single/double precision calculations, scanning transmission electron microscopy (STEM) simulations using experimental detector sensitivities, imaging STEM (ISTEM) simulations, energy filtered transmission electron microscopy (EFTEM) simulations, STEM electron energy loss spectroscopy (EELS) simulations along with other improvements in the algorithms. We also present a mixed channeling approach for the calculation of inelastic excitations, which allows one to considerably speed up time consuming EFTEM/STEM-EELS calculations. | ||||
Address | EMAT, University of Antwerp, Department of Physics, Groenenborgerlaan 171, B-2020 Antwerp, Belgium | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000380754100003 | Publication Date | 2016-06-11 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.843 | Times cited | 43 | Open Access | |
Notes | 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. The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0369.15N and G.0368.15N).; esteem2jra3; esteem2na3; esteem2_jra2 | Approved | Most recent IF: 2.843 | ||
Call Number | c:irua:134088 c:irua:134088UA @ admin @ c:irua:134088 | Serial | 4093 | ||
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Author | Ozkan, A.; Dufour, T.; Bogaerts, A.; Reniers, F. | ||||
Title | How do the barrier thickness and dielectric material influence the filamentary mode and CO2conversion in a flowing DBD? | Type | A1 Journal article | ||
Year | 2016 | Publication | Plasma sources science and technology | Abbreviated Journal | Plasma Sources Sci T |
Volume | 25 | Issue | 25 | Pages | 045016 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Dielectric barrier discharges (DBDs) are commonly used to generate cold plasmas at atmospheric pressure. Whatever their configuration (tubular or planar), the presence of a dielectric barrier is mandatory to prevent too much charge build up in the plasma and the formation of a thermal arc. In this article, the role of the barrier thickness (2.0, 2.4 and 2.8 mm) and of the kind of dielectric material (alumina, mullite, pyrex, quartz) is investigated on the filamentary behavior in the plasma and on the CO2 conversion in a tubular flowing DBD, by means of mass spectrometry measurements correlated with electrical characterization and IR imaging. Increasing the barrier thickness decreases the capacitance, while preserving the electrical charge. As a result, the voltage over the dielectric increases and a larger number of microdischarges is generated, which enhances the CO2 conversion. Furthermore, changing the dielectric material of the barrier, while keeping the same geometry and dimensions, also affects the CO2 conversion. The highest CO2 conversion and energy efficiency are obtained for quartz and alumina, thus not following the trend of the relative permittivity. From the electrical characterization, we clearly demonstrate that the most important parameters are the somewhat higher effective plasma voltage (yielding a somewhat higher electric field and electron energy in the plasma) for quartz, as well as the higher plasma current (and thus larger electron density) and the larger number of microdischarge filaments (mainly for alumina, but also for quartz). The latter could be correlated to the higher surface roughness for alumina and to the higher voltage over the dielectric for quartz. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000380380200030 | Publication Date | 2016-06-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0963-0252 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.302 | Times cited | 24 | Open Access | |
Notes | The authors acknowledge financial support from the IAPVII/ 12, P7/34 (Inter-university Attraction Pole) program ‘PSI-Physical Chemistry of Plasma-Surface Interactions’, financially supported by the Belgian Federal Office for Science Policy (BELSPO). A. Ozkan would like to thank the financial support given by ‘Fonds David et Alice Van Buuren’. | Approved | Most recent IF: 3.302 | ||
Call Number | c:irua:134396 | Serial | 4100 | ||
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Author | Ramachandran, D.; Egoavil, R.; Crabbe, A.; Hauffman, T.; Abakumov, A.; Verbeeck, J.; Vandendael, I.; Terryn, H.; Schryvers, D. | ||||
Title | TEM and AES investigations of the natural surface nano-oxide layer of an AISI 316L stainless steel microfibre | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of microscopy | Abbreviated Journal | J Microsc-Oxford |
Volume | 264 | Issue | 264 | Pages | 207-214 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The chemical composition, nanostructure and electronic structure of nanosized oxide scales naturally formed on the surface of AISI 316L stainless steel microfibres used for strengthening of composite materials have been characterised using a combination of scanning and transmission electron microscopy with energy-dispersive X-ray, electron energy loss and Auger spectroscopy. The analysis reveals the presence of three sublayers within the total surface oxide scale of 5.0-6.7 nm thick: an outer oxide layer rich in a mixture of FeO.Fe2 O3 , an intermediate layer rich in Cr2 O3 with a mixture of FeO.Fe2 O3 and an inner oxide layer rich in nickel. | ||||
Address | Electron Microscopy for Materials Science, University of Antwerp, Antwerp, Belgium | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000385944300009 | Publication Date | 2016-06-17 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0022-2720 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.692 | Times cited | 12 | Open Access | |
Notes | This work was supported by SIM vzw, Technologiepark 935, BE-9052 Zwijnaarde, Belgium, within the InterPoCo project of the H-INT-S horizontal program. The authors are also thankful to Stijn Van den Broeck for help in FIB sample preparation, to Hamed Heidari for useful comments and to the N.V. Bekaert S.A. company for providing the microfibres. RE acknowledges funding by the European Union Council under the 7th Framework Program (FP7) grant nr NMP3-LA-2010-246102 IFOX. | Approved | Most recent IF: 1.692 | ||
Call Number | c:irua:134087 | Serial | 4096 | ||
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Author | Nikolaev, A.V.; Lamoen, D.; Partoens, B. | ||||
Title | Extension of the basis set of linearized augmented plane wave (LAPW) method by using supplemented tight binding basis functions | Type | A1 Journal article | ||
Year | 2016 | Publication | The journal of chemical physics | Abbreviated Journal | J Chem Phys |
Volume | 145 | Issue | 145 | Pages | 014101 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | In order to increase the accuracy of the linearized augmented plane wave (LAPW) method, we present a new approach where the plane wave basis function is augmented by two different atomic radial components constructed at two different linearization energies corresponding to two different electron bands (or energy windows). We demonstrate that this case can be reduced to the standard treatment within the LAPW paradigm where the usual basis set is enriched by the basis functions of the tight binding type, which go to zero with zero derivative at the sphere boundary. We show that the task is closely related with the problem of extended core states which is currently solved by applying the LAPW method with local orbitals (LAPW+LO). In comparison with LAPW+LO, the number of supplemented basis functions in our approach is doubled, which opens up a new channel for the extension of the LAPW and LAPW+LO basis sets. The appearance of new supplemented basis functions absent in the LAPW+LO treatment is closely related with the existence of the ul-component in the canonical LAPW method. We discuss properties of additional tight binding basis functions and apply the extended basis set for computation of electron energy bands of lanthanum (face and body centered structures) and hexagonal close packed lattice of cadmium. We demonstrate that the new treatment gives lower total energies in comparison with both canonical LAPW and LAPW+LO, with the energy difference more pronounced for intermediate and poor LAPW basis sets. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000379584700003 | Publication Date | 2016-07-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-9606 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.965 | Times cited | 11 | Open Access | |
Notes | A.V.N. acknowledges useful discussions with B. Verberck, E. V. Tkalya, and A. V. Bibikov. | Approved | Most recent IF: 2.965 | ||
Call Number | c:irua:134290 | Serial | 4099 | ||
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Author | Muller-Caspary, K.; Krause, F.F.; Grieb, T.; Loffler, S.; Schowalter, M.; Béché, A.; Galioit, V.; Marquardt, D.; Zweck, J.; Schattschneider, P.; Verbeeck, J.; Rosenauer, A. | ||||
Title | Measurement of atomic electric fields and charge densities from average momentum transfers using scanning transmission electron microscopy | Type | A1 Journal article | ||
Year | 2016 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 178 | Issue | 178 | Pages | 62-80 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | This study sheds light on the prerequisites, possibilities, limitations and interpretation of high-resolution differential phase contrast (DPC) imaging in scanning transmission electron microscopy (STEM). We draw particular attention to the well-established DPC technique based on segmented annular detectors and its relation to recent developments based on pixelated detectors. These employ the expectation value of the momentum transfer as a reliable measure of the angular deflection of the STEM beam induced by an electric field in the specimen. The influence of scattering and propagation of electrons within the specimen is initially discussed separately and then treated in terms of a two-state channeling theory. A detailed simulation study of GaN is presented as a function of specimen thickness and bonding. It is found that bonding effects are rather detectable implicitly, e.g., by characteristics of the momentum flux in areas between the atoms than by directly mapping electric fields and charge densities. For strontium titanate, experimental charge densities are compared with simulations and discussed with respect to experimental artifacts such as scan noise. Finally, we consider practical issues such as figures of merit for spatial and momentum resolution, minimum electron dose, and the mapping of larger-scale, built-in electric fields by virtue of data averaged over a crystal unit cell. We find that the latter is possible for crystals with an inversion center. Concerning the optimal detector design, this study indicates that a sampling of 5mrad per pixel is sufficient in typical applications, corresponding to approximately 10x10 available pixels. | ||||
Address | Institut fur Festkr perphysik, Universitat Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany | ||||
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Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000403862900009 | Publication Date | 2016-05-12 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.843 | Times cited | 93 | Open Access | |
Notes | K.M.-C. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG) under contract MU3660/1-1. This work was further supported by the DFG under contract RO2057/4-2 and O2057/11-1. J.V. and A.B. acknowledge funding from the European Research Council (ERC) under the 7th Framework Program (FP7), and ERC Starting Grant No. 278510-VORTEX. Experimental results are obtained on the Qu-Ant-EM microscope partly funded by the Hercules fund from the Flemish government. J.V. also acknowledges funding through a GOA project “Solarpaint” of the University of Antwerp. SL and PS acknowledge financial support by the Austrian Science Fund (FWF) under grants No. I543-N20 and J3732-N27. ECASJO_; | Approved | Most recent IF: 2.843 | ||
Call Number | c:irua:134125UA @ admin @ c:irua:134125 | Serial | 4098 | ||
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Author | Berthelot, A.; Bogaerts, A. | ||||
Title | Modeling of plasma-based CO2conversion: lumping of the vibrational levels | Type | A1 Journal article | ||
Year | 2016 | Publication | Plasma sources science and technology | Abbreviated Journal | Plasma Sources Sci T |
Volume | 25 | Issue | 25 | Pages | 045022 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Although CO2 conversion by plasma technology is gaining increasing interest, the underlying mechanisms for an energy-efficient process are still far from understood. In this work, a reduced non-equilibrium CO2 plasma chemistry set, based on level lumping of the vibrational levels, is proposed and the reliability of this level-lumping method is tested by a self-consistent zero-dimensional code. A severe reduction of the number of equations to be solved is achieved, which is crucial to be able to model non-equilibrium CO2 plasmas by 2-dimensional models. Typical conditions of pressure and power used in a microwave plasma for CO2 conversion are investigated. Several different sets, using different numbers of lumped groups, are considered. The lumped models with 1, 2 or 3 groups are able to reproduce the gas temperature, electron density and electron temperature profiles, as calculated by the full model treating all individual excited levels, in the entire pressure range investigated. Furthermore, a 3-groups model is also able to reproduce the shape of the vibrational distribution function (VDF) and gives the most reliable prediction of the CO2 conversion. A strong influence of the vibrational excitation on the plasma characteristics is observed. Finally, the limitations of the lumped-levels method are discussed. |
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Language | Wos | 000380380200036 | Publication Date | 2016-07-08 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 0963-0252 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.302 | Times cited | 33 | Open Access | |
Notes | This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 606889 and it was also carried out in the framework of the network on Physical Chemistry of Plasma-Surface Interactions—Interuniversity Attraction Poles, phase VII (PSI-IAP7) supported by the Belgian Science Policy Office (BELSPO). The computational work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UA. | Approved | Most recent IF: 3.302 | ||
Call Number | c:irua:134397 | Serial | 4101 | ||
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Author | Bal, K.M.; Neyts, E.C. | ||||
Title | Direct observation of realistic-temperature fuel combustion mechanisms in atomistic simulations | Type | A1 Journal article | ||
Year | 2016 | Publication | Chemical science | Abbreviated Journal | Chem Sci |
Volume | 7 | Issue | 7 | Pages | 5280-5286 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Atomistic simulations can in principle provide an unbiased description of all mechanisms, intermediates, and products of complex chemical processes. However, due to the severe time scale limitation of conventional simulation techniques, unrealistically high simulation temperatures are usually applied, which are a poor approximation of most practically relevant low-temperature applications. In this work, we demonstrate the direct observation at the atomic scale of the pyrolysis and oxidation of n-dodecane at temperatures as low as 700 K through the use of a novel simulation technique, collective variable-driven hyperdynamics (CVHD). A simulated timescale of up to 39 seconds is reached. Product compositions and dominant mechanisms are found to be strongly temperature-dependent, and are consistent with experiments and kinetic models. These simulations provide a first atomic-level look at the full dynamics of the complicated fuel combustion process at industrially relevant temperatures and time scales, unattainable by conventional molecular dynamics simulations. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000380893900059 | Publication Date | 2016-05-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2041-6520 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.668 | Times cited | 22 | Open Access | |
Notes | K. M. B. is funded as PhD fellow (aspirant) of the FWO-Flanders (Fund for Scientic Research-Flanders), Grant 11V8915N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), funded by the Hercules Foundation and the Flemish Government – department EWI. The authors would also like to thank S. Banerjee for assisting with the interpretation of the experimental results. | Approved | Most recent IF: 8.668 | ||
Call Number | c:irua:134577 c:irua:135670 | Serial | 4105 | ||
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Author | Liao, Z; , Green, R.J; Gauquelin, N; Macke, S.; Li, L.; Gonnissen, J; Sutarto, R.; Houwman, E.P.; Zhong, Z.; Van Aert, S.; Verbeeck, J.; Sawatzky, G.A.; Huijben, M.; Koster, G.; Rijnders, G. | ||||
Title | Long-Range Domain Structure and Symmetry Engineering by Interfacial Oxygen Octahedral Coupling at Heterostructure Interface | Type | A1 Journal article | ||
Year | 2016 | Publication | Advanced functional materials | Abbreviated Journal | Adv Funct Mater |
Volume | 26 | Issue | 26 | Pages | 6627-6634 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | In epitaxial thin film systems, the crystal structure and its symmetry deviate from the bulk counterpart due to various mechanisms such as epitaxial strain and interfacial structural coupling, which is accompanyed by a change in their properties. In perovskite materials, the crystal symmetry can be described by rotations of sixfold coordinated transition metal oxygen octahedra, which are found to be altered at interfaces. Here, it is unraveled how the local oxygen octahedral coupling at perovskite heterostructural interfaces strongly influences the domain structure and symmetry of the epitaxial films resulting in design rules to induce various structures in thin films using carefully selected combinations of substrate/buffer/film. Very interestingly it is discovered that these combinations lead to structure changes throughout the full thickness of the film. The results provide a deep insight into understanding the origin of induced structures in a perovskite heterostructure and an intelligent route to achieve unique functional properties. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000384809800010 | Publication Date | 2016-06-23 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1616-301x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 12.124 | Times cited | 23 | Open Access | |
Notes | We thank B. Keimer for valuable discussions. M.H., G.K. and G.R. acknowledge funding from DESCO program of the Dutch Foundation for Fundamental Research on Matter (FOM) with financial support from the Netherlands Organization for Scientific Research (NWO). This work was funded by the European Union Council under the 7th Framework Program (FP7) grant nr NMP3-LA-2010-246102 IFOX. J.V. and S.V.A. acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0044.13N, G.0374.13N, G.0368.15N, G.0369.15N). The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. N.G. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. N.G., J.G., S.V.A., J.V. acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative (Reference No. 312483-ESTEEM2). The Canadian work was supported by NSERC and the Max Planck-UBC Centre for Quantum Materials. Some experiments for this work were performed at the Canadian Light Source, which is funded by the Canada Foundation for Innovation, NSERC, the National Research Council of Canada, the Canadian Institutes of Health Research, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan.; esteem2jra2; esteem2jra3; ECASJO_; | Approved | Most recent IF: 12.124 | ||
Call Number | EMAT @ emat @ c:irua:144663UA @ admin @ c:irua:144663 | Serial | 4106 | ||
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Author | Ozkan, A.; Dufour, T.; Silva, T.; Britun, N.; Snyders, R.; Reniers, F.; Bogaerts, A. | ||||
Title | DBD in burst mode: solution for more efficient CO2conversion? | Type | A1 Journal article | ||
Year | 2016 | Publication | Plasma sources science and technology | Abbreviated Journal | Plasma Sources Sci T |
Volume | 25 | Issue | 25 | Pages | 055005 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | CO2 conversion into value-added products has gained significant interest over the few last years, as the greenhouse gas concentrations constantly increase due to anthropogenic activities. Here we report on experiments for CO2 conversion by means of a cold atmospheric plasma using a cylindrical flowing dielectric barrier discharge (DBD) reactor. A detailed comparison of this DBD ignited in a so-called burst mode (i.e. where an AC voltage is applied during a limited amount of time) and pure AC mode is carried out to evaluate their effect on the conversion of CO2 as well as on the energy efficiency. Decreasing the duty cycle in the burst mode from 100% (i.e. corresponding to pure AC mode) to 40% leads to a rise in the conversion from 16–26% and to a rise in the energy efficiency from 15 to 23%. Based on a detailed electrical analysis, we show that the conversion correlates with the features of the microfilaments. Moreover, the root-mean-square voltage in the burst mode remains constant as a function of the process time for the duty cycles <70%, while a higher duty cycle or the usual pure AC mode leads to a clear voltage decay by more than 500 V, over approximately 90 s, before reaching a steady state regime. The higher plasma voltage in the burst mode yields a higher electric field. This causes the increasing the electron energy, and therefore their involvement in the CO2 dissociation process, which is an additional explanation for the higher CO2 conversion and energy efficiency in the burst mode. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000403945500005 | Publication Date | 2016-08-02 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1361-6595 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.302 | Times cited | 17 | Open Access | |
Notes | The authors acknowledge financial support from the IAPVII/ 12, P7/34 (Inter-university Attraction Pole) program ‘PSI-Physical Chemistry of Plasma-Surface Interactions’, financially supported by the Belgian Federal Office for Science Policy (BELSPO). A. Ozkan would also like to thank financial support given by ‘Fonds David et Alice Van Buuren’. | Approved | Most recent IF: 3.302 | ||
Call Number | c:irua:134841 | Serial | 4107 | ||
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Author | Tinck, S.; Tillocher, T.; Dussart, R.; Neyts, E.C.; Bogaerts, A. | ||||
Title | Elucidating the effects of gas flow rate on an SF6inductively coupled plasma and on the silicon etch rate, by a combined experimental and theoretical investigation | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of physics: D: applied physics | Abbreviated Journal | J Phys D Appl Phys |
Volume | 49 | Issue | 49 | Pages | 385201 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Experiments show that the etch rate of Si with SF6 inductively coupled plasma (ICP) is significantly influenced by the absolute gas flow rate in the range of 50–600 sccm, with a maximum at around 200 sccm. Therefore, we numerically investigate the effects of the gas flow rate on the bulk plasma properties and on the etch rate, to obtain more insight in the underlying reasons of this effect. A hybrid Monte Carlo—fluid model is applied to simulate an SF6 ICP. It is found that the etch rate is influenced by two simultaneous effects: (i) the residence time of the gas and (ii) the temperature profile of the plasma in the ICP volume, resulting indeed in a maximum etch rate at 200 sccm. | ||||
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Language | Wos | 000384095900011 | Publication Date | 2016-08-24 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0022-3727 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.588 | Times cited | 1 | Open Access | |
Notes | We are very grateful to Mark Kushner for providing the computational model. The Fund for Scientific Research Flanders (FWO; grant no. 0880.212.840) is acknowledged for financial support of this work. The work was carried out in part using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the University of Antwerp. | Approved | Most recent IF: 2.588 | ||
Call Number | c:irua:134867 | Serial | 4108 | ||
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Author | Ying, J.; Hu, Z.-Y.; Yang, X.-Y.; Wei, H.; Xiao, Y.-X.; Janiak, C.; Mu, S.-C.; Tian, G.; Pan, M.; Van Tendeloo, G.; Su, B.-L. | ||||
Title | High viscosity to highly dispersed PtPd bimetallic nanocrystals for enhanced catalytic activity and stability | Type | A1 Journal article | ||
Year | 2016 | Publication | Chemical communications | Abbreviated Journal | Chem Commun |
Volume | 52 | Issue | 52 | Pages | 8219-8222 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | A facile high-viscosity-solvent method is presented to synthesize PtPd bimetallic nanocrystals highly dispersed in different mesostructures (2D and 3D structures), porosities (large and small pore sizes), and compositions (silica and carbon). Further, highly catalytic activity, stability and durability of the nanometals have been proven in different catalytic reactions. | ||||
Address | State Key Laboratory Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122, Luoshi Road, Wuhan, 430070, China. xyyang@whut.edu.cn | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000378715400006 | Publication Date | 2016-05-16 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1359-7345 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.319 | Times cited | 19 | Open Access | |
Notes | This work was supported by NFSC (51472190 and 51503166), ISTCP (2015DFE52870), PCSIRT (IRT15R52) of China, and the Integrated Infrastructure Initiative of EU (312483-ESTEEM2).; esteem2jra4 | Approved | Most recent IF: 6.319 | ||
Call Number | c:irua:134660 c:irua:134660 | Serial | 4110 | ||
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Author | Bogaerts, A.; Wang, W.; Berthelot, A.; Guerra, V. | ||||
Title | Modeling plasma-based CO2conversion: crucial role of the dissociation cross section | Type | A1 Journal article | ||
Year | 2016 | Publication | Plasma sources science and technology | Abbreviated Journal | Plasma Sources Sci T |
Volume | 25 | Issue | 25 | Pages | 055016 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Plasma-based CO2 conversion is gaining increasing interest worldwide. A large research effort is devoted to improving the energy efficiency. For this purpose, it is very important to understand the underlying mechanisms of the CO2 conversion. The latter can be obtained by computer modeling, describing in detail the behavior of the various plasma species and all relevant chemical processes. However, the accuracy of the modeling results critically depends on the accuracy of the assumed input data, like cross sections. This is especially true for the cross section of electron impact dissociation, as the latter process is believed to proceed through electron impact excitation, but it is not clear from the literature which excitation channels effectively lead to dissociation. Therefore, the present paper discusses the effect of different electron impact dissociation cross sections reported in the literature on the calculated CO2 conversion, for a dielectric barrier discharge (DBD) and a microwave (MW) plasma. Comparison is made to experimental data for the DBD case, to elucidate which cross section might be the most realistic. This comparison reveals that the cross sections proposed by Itikawa and by Polak and Slovetsky both seem to underestimate the CO2 conversion. The cross sections recommended by Phelps with thresholds of 7 eV and 10.5 eV yield a CO2 conversion only slightly lower than the experimental data, but the sum of both cross sections overestimates the values, indicating that these cross sections represent dissociation, but most probably also include other (pure excitation) channels. Our calculations indicate that the choice of the electron impact dissociation cross section is crucial for the DBD, where this process is the dominant mechanism for CO2 conversion. In the MW plasma, it is only significant at pressures up to 100 mbar, while it is of minor importance for higher pressures, when dissociation proceeds mainly through collisions of CO2 with heavy particles. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000384030600001 | Publication Date | 2016-08-31 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1361-6595 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.302 | Times cited | 57 | Open Access | |
Notes | The authors would like to thank R Snoeckx and S Heijkers for the interesting discussions. This research was supported by the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 606889, the European Marie Skłodowska-Curie Individual Fellowship project ‘GlidArc’ within Horizon2020, the FWO project (grant G.0383.16N), and the Network on Physical Chemistry of Plasma-Surface Interactions—Interuniversity Attraction Poles, phase VII (PSI-IAP7), supported by the Belgian Science Policy Office (BELSPO). The computational work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UA. VG was partially supported by the Portuguese FCT— Fundação para a Ci | Approved | Most recent IF: 3.302 | ||
Call Number | c:irua:135070 | Serial | 4111 | ||
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Author | Bercx, M.; Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. | ||||
Title | First-principles analysis of the spectroscopic limited maximum efficiency of photovoltaic absorber layers for CuAu-like chalcogenides and silicon | Type | A1 Journal article | ||
Year | 2016 | Publication | Physical chemistry, chemical physics | Abbreviated Journal | Phys Chem Chem Phys |
Volume | 18 | Issue | 18 | Pages | 20542-20549 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | Chalcopyrite semiconductors are of considerable interest for application as absorber layers in thin-film photovoltaic cells. When growing films of these compounds, however, they are often found to contain CuAu-like domains, a metastable phase of chalcopyrite. It has been reported that for CuInS2, the presence of the CuAu-like phase improves the short circuit current of the chalcopyrite-based photovoltaic cell. We investigate the thermodynamic stability of both phases for a selected list of I-III-VI2 materials using a first-principles density functional theory approach. For the CuIn-VI2 compounds, the difference in formation energy between the chalcopyrite and CuAu-like phase is found to be close to 2 meV per atom, indicating a high likelihood of the presence of CuAu-like domains. Next, we calculate the spectroscopic limited maximum efficiency (SLME) of the CuAu-like phase and compare the results with those of the corresponding chalcopyrite phase. We identify several candidates with a high efficiency, such as CuAu-like CuInS2, for which we obtain an SLME of 29% at a thickness of 500 nm. We observe that the SLME can have values above the Shockley-Queisser (SQ) limit, and show that this can occur because the SQ limit assumes the absorptivity to be a step function, thus overestimating the radiative recombination in the detailed balance approach. This means that it is possible to find higher theoretical efficiencies within this framework simply by calculating the J-V characteristic with an absorption spectrum. Finally, we expand our SLME analysis to indirect band gap absorbers by studying silicon, and find that the SLME quickly overestimates the reverse saturation current of indirect band gap materials, drastically lowering their calculated efficiency. | ||||
Address | EMAT & CMT groups, Department of Physics, University of Antwerp, Campus Groenenborger, Groenenborgerlaan 171, 2020 Antwerp, Belgium. marnik.bercx@uantwerpen.be | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000381428600058 | Publication Date | 2016-07-08 |
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ISSN | 1463-9076 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.123 | Times cited | 34 | Open Access | |
Notes | We acknowledge financial support of FWO-Vlaanderen through projects G.0150.13N and G.0216.14N and ERA-NET RUS Plus/FWO, Grant G0D6515N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO FWOVlaanderen. | Approved | Most recent IF: 4.123 | ||
Call Number | c:irua:135091 | Serial | 4112 | ||
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Author | Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. | ||||
Title | First-principles study of the optoelectronic properties and photovoltaic absorber layer efficiency of Cu-based chalcogenides | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 120 | Issue | 120 | Pages | 085707 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | Cu-based chalcogenides are promising materials for thin-film solar cells with more than 20% measured cell efficiency. Using first-principles calculations based on density functional theory, the optoelectronic properties of a group of Cu-based chalcogenides Cu2-II-IV-VI4 is studied. They are then screened with the aim of identifying potential absorber materials for photovoltaic applications. The spectroscopic limited maximum efficiency (SLME) introduced by Yu and Zunger [Phys. Rev. Lett. 108, 068701 (2012)] is used as a metric for the screening. After constructing the currentvoltage curve, the SLME is calculated from the maximum power output. The role of the nature of the band gap, direct or indirect, and also of the absorptivity of the studied materials on the maximum theoretical power conversion efficiency is studied. Our results show that Cu2II-GeSe4 with II¼ Cd and Hg, and Cu2-II-SnS4 with II ¼ Cd, Hg, and Zn have a higher theoretical efficiency compared with the materials currently used as absorber layer. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000383913400074 | Publication Date | 2016-08-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
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ISSN | 0021-8979 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 29 | Open Access | |
Notes | We acknowledge the financial support from the FWO-Vlaanderen through project G.0150.13N and a GOA fund from the University of Antwerp. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), bothfunded by the FWO-Vlaanderen and the Flemish Government–department EWI. | Approved | Most recent IF: 2.068 | ||
Call Number | c:irua:135089 | Serial | 4113 | ||
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Author | Pant, A.; Torun, E.; Chen, B.; Bhat, S.; Fan, X.; Wu, K.; Wright, D.P.; Peeters, F.M.; Soignard, E.; Sahin, H.; Tongay, S. | ||||
Title | Strong dichroic emission in the pseudo one dimensional material ZrS3 | Type | A1 Journal article | ||
Year | 2016 | Publication | Nanoscale | Abbreviated Journal | Nanoscale |
Volume | 8 | Issue | 8 | Pages | 16259-16265 |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | Zirconium trisulphide (ZrS3), a member of the layered transition metal trichalcogenides (TMTCs) family, has been studied by angle-resolved photoluminescence spectroscopy (ARPLS). The synthesized ZrS3 layers possess a pseudo one-dimensional nature where each layer consists of ZrS3 chains extending along the b-lattice direction. Our results show that the optical properties of few-layered ZrS3 are highly anisotropic as evidenced by large PL intensity variation with the polarization direction. Light is efficiently absorbed when the E-field is polarized along the chain (b-axis), but the field is greatly attenuated and absorption is reduced when it is polarized vertical to the 1D-like chains as the wavelength of the exciting light is much longer than the width of each 1D chain. The observed PL variation with polarization is similar to that of conventional 1D materials, i.e., nanowires, and nanotubes, except for the fact that here the 1D chains interact with each other giving rise to a unique linear dichroism response that falls between the 2D (planar) and 1D (chain) limit. These results not only mark the very first demonstration of PL polarization anisotropy in 2D systems, but also provide novel insight into how the interaction between adjacent 1D-like chains and the 2D nature of each layer influences the overall optical anisotropy of pseudo-1D materials. Results are anticipated to have an impact on optical technologies such as polarized detectors, near-field imaging, communication systems, and bio-applications relying on the generation and detection of polarized light. | ||||
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Language | Wos | 000384531600018 | Publication Date | 2016-08-09 | |
Series Editor | Series Title | Abbreviated Series Title | |||
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ISSN | 2040-3364 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 7.367 | Times cited | 54 | Open Access | |
Notes | ; S. Tongay gratefully acknowledges support from NSF DMR-1552220. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). HS is supported by a FWO postdoctoral fellowship. ; | Approved | Most recent IF: 7.367 | ||
Call Number | UA @ lucian @ c:irua:144656 | Serial | 4116 | ||
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Author | De Keukeleere, K.; Cayado, P.; Meledin, A.; Vallès, F.; De Roo, J.; Rijckaert, H.; Pollefeyt, G.; Bruneel, E.; Palau, A.; Coll, M.; Ricart, S.; Van Tendeloo, G.; Puig, T.; Obradors, X.; Van Driessche, I. | ||||
Title | Superconducting YBa2Cu3O7-δNanocomposites Using Preformed ZrO2Nanocrystals: Growth Mechanisms and Vortex Pinning Properties | Type | A1 Journal article | ||
Year | 2016 | Publication | Advanced Electronic Materials | Abbreviated Journal | |
Volume | 2 | Issue | 2 | Pages | 1600161 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Although high temperature superconductors are promising for power applications, the production of low-cost coated conductors with high current densities—at high magnetic fields—remains challenging. A superior superconducting YBa2Cu3O7–δ nanocomposite is fabricated via chemical solution deposition (CSD) using preformed nanocrystals (NCs). Preformed, colloidally stable ZrO2 NCs are added to the trifluoroacetic acid based precursor solution and the NCs' stability is confirmed up to 50 mol% for at least 2.5 months. These NCs tend to disrupt the epitaxial growth of YBa2Cu3O7–δ, unless a thin seed layer is applied. A 10 mol% ZrO2 NC addition proved to be optimal, yielding a critical current density JC of 5 MA cm−2 at 77 K in self-field. Importantly, this new approach results in a smaller magnetic field decay of JC(H//c) for the nanocomposite compared to a pristine film. Furthermore, microstructural analysis of the YBa2Cu3O7–δ nanocomposite films reveals that different strain generation mechanisms may occur compared to the spontaneous segregation approach. Yet, the generated nanostrain in the YBa2Cu3O7–δ nanocomposite results in an improvement of the superconducting properties similar to the spontaneous segregation approach. This new approach, using preformed NCs in CSD coatings, can be of great potential for high magnetic field applications. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000386624100003 | Publication Date | 2016-09-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2199160X | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | 26 | Open Access | ||
Notes | This work was financially supported by a BOF research fund of Ghent University (BOF11/DOC/286), FWO Flanders (F08512), and Eurotapes, a collaborative project funded by the European Community’s Seven Framework Program (EU-FP7 NMP-LA-2012-280432). We also acknowledge MINECO and FEDER funds for MAT2014-51778-C2-1-R and the Center of Excellence award Severo Ochoa SEV-2015-0496, and SGR753 from the Generalitat of Catalunya. MC acknowledges RyC contract 2013-12448 | Approved | Most recent IF: NA | ||
Call Number | EMAT @ emat @ c:irua:135171 | Serial | 4118 | ||
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Author | Sankaran, K.J.; Hoang, D.Q.; Kunuku, S.; Korneychuk, S.; Turner, S.; Pobedinskas, P.; Drijkoningen, S.; Van Bael, M.K.; D' Haen, J.; Verbeeck, J.; Leou, K.-C.; Lin, I.-N.; Haenen, K. | ||||
Title | Enhanced optoelectronic performances of vertically aligned hexagonal boron nitride nanowalls-nanocrystalline diamond heterostructures | Type | A1 Journal article | ||
Year | 2016 | Publication | Scientific reports | Abbreviated Journal | Sci Rep-Uk |
Volume | 6 | Issue | 6 | Pages | 29444 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Field electron emission (FEE) properties of vertically aligned hexagonal boron nitride nanowalls (hBNNWs) grown on Si have been markedly enhanced through the use of nitrogen doped nanocrystalline diamond (nNCD) films as an interlayer. The FEE properties of hBNNWs-nNCD heterostructures show a low turn-on field of 15.2 V/mum, a high FEE current density of 1.48 mA/cm(2) and life-time up to a period of 248 min. These values are far superior to those for hBNNWs grown on Si substrates without the nNCD interlayer, which have a turn-on field of 46.6 V/mum with 0.21 mA/cm(2) FEE current density and life-time of 27 min. Cross-sectional TEM investigation reveals that the utilization of the diamond interlayer circumvented the formation of amorphous boron nitride prior to the growth of hexagonal boron nitride. Moreover, incorporation of carbon in hBNNWs improves the conductivity of hBNNWs. Such a unique combination of materials results in efficient electron transport crossing nNCD-to-hBNNWs interface and inside the hBNNWs that results in enhanced field emission of electrons. The prospective application of these materials is manifested by plasma illumination measurements with lower threshold voltage (370 V) and longer life-time, authorizing the role of hBNNWs-nNCD heterostructures in the enhancement of electron emission. | ||||
Address | IMOMEC, IMEC vzw, 3590 Diepenbeek, Belgium | ||||
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Language | English | Wos | 000379391000001 | Publication Date | 2016-07-12 |
Series Editor | Series Title | Abbreviated Series Title | |||
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ISSN | 2045-2322 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.259 | Times cited | 15 | Open Access | |
Notes | The authors like to thank the financial support of the Research Foundation Flanders (FWO) via Research Project G.0456.12, G0044.13N and the Methusalem “NANO” network. Kamatchi Jothiramalingam Sankaran, Stuart Turner, and Paulius Pobedinskas are Postdoctoral Fellows of the Research Foundations Flanders (FWO). | Approved | Most recent IF: 4.259 | ||
Call Number | c:irua:134643 c:irua:134643UA @ admin @ c:irua:134643 | Serial | 4119 | ||
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Author | Ekimov, E.A.; Kudryavtsev, O.S.; Turner, S.; Korneychuk, S.; Sirotinkin, V.P.; Dolenko, T.A.; Vervald, A.M.; Vlasov, I.I. | ||||
Title | The effect of molecular structure of organic compound on the direct high-pressure synthesis of boron-doped nanodiamond: Effect of organic compound on synthesis of boron-doped nanodiamond | Type | A1 Journal article | ||
Year | 2016 | Publication | Physica status solidi : A : applications and materials science | Abbreviated Journal | Phys Status Solidi A |
Volume | 213 | Issue | 213 | Pages | 2582-2589 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Evolution of crystalline phases with temperature has been studied in materials produced by high-pressure high-temperature treatment of 9-borabicyclo[3.3.1]nonane dimer (9BBN), triphenylborane and trimesitylborane. The boron-doped diamond nanoparticles with a size below 10 nm were obtained at 8–9 GPa and temperatures 970–1250 °C from 9BBN only. Bridged structure and the presence of boron atom in the carbon cycle of 9BBN were revealed to be a key point for the direct synthesis of doped diamond nanocrystals. The diffusional transformation of the disordered carbon phase is suggested to be the main mechanism of the nanodiamond formation from 9BBN in the temperature range of 970–1400 °C. Aqueous suspensions of primary boron-doped diamond nanocrystals were prepared upon removal of non-diamond phases that opens wide opportunities for application of this new nanomaterial in electronics and biotechnologies. | ||||
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Language | Wos | 000388321500006 | Publication Date | 2016-07-04 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 1862-6300 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.775 | Times cited | 8 | Open Access | |
Notes | Approved | Most recent IF: 1.775 | |||
Call Number | EMAT @ emat @ c:irua:135175 | Serial | 4120 | ||
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Author | Turner, S.; Idrissi, H.; Sartori, A.F.; Korneychuck, S.; Lu, Y.-G.; Verbeeck, J.; Schreck, M.; Van Tendeloo, G. | ||||
Title | Direct imaging of boron segregation at dislocations in B:diamond heteroepitaxial films | Type | A1 Journal article | ||
Year | 2016 | Publication | Nanoscale | Abbreviated Journal | Nanoscale |
Volume | 8 | Issue | 8 | Pages | 2212-2218 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | A thin film of heavily B-doped diamond has been grown epitaxially by microwave plasma chemical vapor deposition on an undoped diamond layer, on top of a Ir/YSZ/Si(001) substrate stack, to study the boron segregation and boron environment at the dislocations present in the film. The density and nature of the dislocations were investigated by conventional and weak-beam dark-field transmission electron microscopy techniques, revealing the presence of two types of dislocations: edge and mixed-type 45 degrees dislocations. The presence and distribution of B in the sample was studied using annular dark-field scanning transmission electron microscopy and spatially resolved electron energy-loss spectroscopy. Using these techniques, a segregation of B at the dislocations in the film is evidenced, which is shown to be intermittent along the dislocation. A single edge-type dislocation was selected to study the distribution of the boron surrounding the dislocation core. By imaging this defect at atomic resolution, the boron is revealed to segregate towards the tensile strain field surrounding the edge-type dislocations. An investigation of the fine structure of the B-K edge at the dislocation core shows that the boron is partially substitutionally incorporated into the diamond lattice and partially present in a lower coordination (sp(2)-like hybridization). | ||||
Address | EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium. stuart.turner@uantwerpen.be | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000368860900053 | Publication Date | 2015-12-21 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2040-3364 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 7.367 | Times cited | 15 | Open Access | |
Notes | S. T. acknowledges the fund for scien tific research Flanders (FWO) for a post-doctoral scholarship and under contract number G.0044.13N | Approved | Most recent IF: 7.367 | ||
Call Number | c:irua:131597UA @ admin @ c:irua:131597 | Serial | 4121 | ||
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Author | Babynina, A.; Fedoruk, M.; Kuhler, P.; Meledin, A.; Doblinger, M.; Lohmueller, T. | ||||
Title | Bending Gold Nanorods with Light | Type | A1 Journal article | ||
Year | 2016 | Publication | Nano letters | Abbreviated Journal | Nano Lett |
Volume | 16 | Issue | 16 | Pages | 6485-6490 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | V-shaped gold nanoantennas are the functional components of plasmonic metasurfaces, which are capable of manipulating light in unprecedented ways. Designing a metasurface requires the custom arrangement of individual antennas with controlled shape and orientation. Here, we show how highly crystalline gold nanorods in solution can be bend, one-by one, into a V-shaped geometry and printed to the surface of a solid support through a combination of plasmonic heating and optical force. Significantly, we demonstrate that both the bending angle and the orientation of each rod-antenna can be adjusted independent from each other by tuning the laser intensity and polarization. This approach is applicable for the patterning of V-shaped plasmonic antennas on almost any substrate, which holds great potential for the fabrication of ultrathin optical components and devices. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000385469800072 | Publication Date | 2016-09-06 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1530-6984 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 12.712 | Times cited | 24 | Open Access | |
Notes | PMID:27598653 We would also like to thank Prof. Jochen Feldmann and Bernhard Bohn for fruitful discussions. | Approved | Most recent IF: 12.712 | ||
Call Number | c:irua:135172 | Serial | 4122 | ||
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Author | Kirilenko, D.A.; Brunkov, P.N. | ||||
Title | Measuring the height-to-height correlation function of corrugation in suspended graphene | Type | A1 Journal article | ||
Year | 2016 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 165 | Issue | 165 | Pages | 1-7 |
Keywords | A1 Journal article; Electron Microscopy for Materials Science (EMAT); | ||||
Abstract | Nanocorrugation of 2D crystals is an important phenomenon since it affects their electronic and mechanical properties. The corrugation may have various sources; one of them is flexural phonons that, in particular, are responsible for the thermal conductivity of graphene. A study of corrugation of just the suspended graphene can reveal much of valuable information on the physics of this complicated phenomenon. At the same time, the suspended crystal nanorelief can hardly be measured directly because of high flexibility of the 2D crystal. Moreover, the relief portion related to rapid out-of-plane oscillations (flexural phonons) is also inaccessible by such measurements. Here we present a technique for measuring the Fourier components of the height-height correlation function H(q) of suspended graphene which includes the effect of flexural phonons. The technique is based on the analysis of electron diffraction patterns. The H(q) is measured in the range of wavevectors q approximately 0.4-4.5nm(-1). At the upper limit of this range H(q) does follow the T/kappaq(4) law. So, we measured the value of suspended graphene bending rigidity kappa=1.2+/-0.4eV at ambient temperature T approximately 300K. At intermediate wave vectors, H(q) follows a slightly weaker exponent than theoretically predicted q(-3.15) but is closer to the results of the molecular dynamics simulation. At low wave vectors, the dependence becomes even weaker, which may be a sign of influence of charge carriers on the dynamics of undulations longer than 10nm. The technique presented can be used for studying physics of flexural phonons in other 2D materials. | ||||
Address | Ioffe Institute, Politekhnicheskaya ul. 26, 194021 St-Petersburg, Russia; ITMO University, Kronverksky pr. 49, 197101 St. Petersburg, Russia | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000375946200001 | Publication Date | 2016-03-28 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0304-3991 | ISBN | Additional Links | ||
Impact Factor | 2.843 | Times cited | 3 | Open Access | |
Notes | D.K. thanks the RFBR (Grant no. 16-32-60165) for the partial support of this research. The work was carried out in part at the Joint Research Center “Material Science and Characterization in Advanced Technologies” (St-Petersburg, Russia) under the financial support from the Ministry of Education and Science of the Russian Federation (Agreement 14.621.21.0007, 04.12.2014, id RFMEFI62114X0007, the use of the Jeol JEM-2100F microscope) and at EMAT, Universiteit Antwerpen (Antwerpen, Belgium), (the use of the FEI Tecnai G2 microscope). | Approved | Most recent IF: 2.843 | ||
Call Number | EMAT @ emat @ | Serial | 4124 | ||
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Author | Sobrino Fernandez, M.M.; Neek-Amal, M.; Peeters, F.M. | ||||
Title | AA-stacked bilayer square ice between graphene layers | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 92 | Issue | 92 | Pages | 245428 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Water confined between two graphene layers with a separation of a few A forms a layered two-dimensional ice structure. Using large scale molecular dynamics simulations with the adoptable ReaxFF interatomic potential we found that flat monolayer ice with a rhombic-square structure nucleates between the graphene layers which is nonpolar and nonferroelectric. We provide different energetic considerations and H-bonding results that explain the interlayer and intralayer properties of two-dimensional ice. The controversial AA stacking found experimentally [Algara-Siller et al., Nature (London) 519, 443 (2015)] is consistent with our minimum-energy crystal structure of bilayer ice. Furthermore, we predict that an odd number of layers of ice has the same lattice structure as monolayer ice, while an even number of ice layers exhibits the square ice AA stacking of bilayer ice. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000366731800004 | Publication Date | 2015-12-17 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121; 1550-235x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 40 | Open Access | |
Notes | ; This work was supported by the ESF-Eurographene project CONGRAN, and the Flemish Science Foundation (FWO-Vl). ; | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | c:irua:130203 | Serial | 4127 | ||
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Author | Gonnissen, J.; De Backer, A.; den Dekker, A.J.; Sijbers, J.; Van Aert, S. | ||||
Title | Detecting and locating light atoms from high-resolution STEM images: The quest for a single optimal design | Type | A1 Journal article | ||
Year | 2016 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 170 | Issue | 170 | Pages | 128-138 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab | ||||
Abstract | In the present paper, the optimal detector design is investigated for both detecting and locating light atoms from high resolution scanning transmission electron microscopy (HR STEM) images. The principles of detection theory are used to quantify the probability of error for the detection of light atoms from HR STEM images. To determine the optimal experiment design for locating light atoms, use is made of the so-called Cramer-Rao Lower Bound (CRLB). It is investigated if a single optimal design can be found for both the detection and location problem of light atoms. Furthermore, the incoming electron dose is optimised for both research goals and it is shown that picometre range precision is feasible for the estimation of the atom positions when using an appropriate incoming electron dose under the optimal detector settings to detect light atoms. | ||||
Address | Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium. Electronic address: sandra.vanaert@uantwerpen.be | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000386925500014 | Publication Date | 2016-07-26 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.843 | Times cited | 6 | Open Access | |
Notes | The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0368.15, G.0369.15 and G.0374.13) and a postdoctoral research grant to A. De Backer. The research leading to these results has also received funding from the European Union Seventh Framework Programme [FP7/2007-2013] under Grant agreement no. 312483 (ESTEEM2). The authors would also like to thank A. Rosenauer for providing access to the STEMsim software and Gerardo T. Martinez for fruitful discussions.; esteem2_jra2 | Approved | Most recent IF: 2.843 | ||
Call Number | c:irua:135337 c:irua:135337 | Serial | 4128 | ||
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Author | Gonnissen, J.; Batuk, D.; Nataf, G.F.; Jones, L.; Abakumov, A.M.; Van Aert, S.; Schryvers, D.; Salje, E.K.H. | ||||
Title | Direct Observation of Ferroelectric Domain Walls in LiNbO3: Wall-Meanders, Kinks, and Local Electric Charges | Type | A1 Journal article | ||
Year | 2016 | Publication | Advanced functional materials | Abbreviated Journal | Adv Funct Mater |
Volume | 26 | Issue | 26 | Pages | 7599-7604 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Direct observations of the ferroelectric domain boundaries in LiNbO3 are performed using high-resolution high-angle annular dark field scanning transmission electron microscopy imaging, revealing a very narrow width of the domain wall between the 180° domains. The domain walls demonstrate local side-way meandering, which results in inclinations even when the overall wall orientation follows the ferroelectric polarization. These local meanders contain kinks with “head-to-head” and “tail-to-tail” dipolar configurations and are therefore locally charged. The charged meanders are confined to a few cation layers along the polarization direction and are separated by longer stretches of straight domain walls. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000388166700006 | Publication Date | 2016-09-16 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1616-301X | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 12.124 | Times cited | 23 | Open Access | |
Notes | J.G. acknowledges the support from the Research Foundation Flanders (FWO, Belgium) through various project fundings (G.0368.15N, G.0369.15N, and G.0374.13N), as well as the financial support from the European Union Seventh Framework Program (FP7/2007–2013) under Grant agreement no. 312483 (ESTEEM2). The authors thank J. Hadermann for useful suggestions on the interpretation of the HAADFSTEM images. E.K.H.S. thanks the EPSRC (EP/K009702/1) and the Leverhulme Trust (EM-2016-004) for support. G.F.N. thanks the National Research Fund, Luxembourg (FNR/P12/4853155/Kreisel) for support.; esteem2_jra2 | Approved | Most recent IF: 12.124 | ||
Call Number | c:irua:135336 c:irua:135336 | Serial | 4129 | ||
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Author | Spadaro, M.C.; Luches, P.; Bertoni, G.; Grillo, V.; Turner, S.; Van Tendeloo, G.; Valeri, S.; D'Addato, S. | ||||
Title | Influence of defect distribution on the reducibility of CeO2-x nanoparticles | Type | A1 Journal article | ||
Year | 2016 | Publication | Nanotechnology | Abbreviated Journal | Nanotechnology |
Volume | 27 | Issue | 27 | Pages | 425705 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Ceria nanoparticles (NPs) are fundamental in heterogeneous catalysis because of their ability to store or release oxygen depending on the ambient conditions. Their oxygen storage capacity is strictly related to the exposed planes, crystallinity, density and distribution of defects. In this work a study of ceria NPs produced with a ligand-free, physical synthesis method is presented. The NP films were grown by a magnetron sputtering based gas aggregation source and studied by high resolution- and scanning-transmission electron microscopy and x-ray photoelectron spectroscopy. In particular, the influence of the oxidation procedure on the NP reducibility has been investigated. The different reducibility has been correlated to the exposed planes, crystallinity and density and distribution of structural defects. The results obtained in this work represent a basis to obtain cerium oxide NP with desired oxygen transport properties. | ||||
Address | Dipartimento FIM, Universita di Modena e Reggio Emilia, via G. Campi 213/a, I-41125 Modena, Italy. CNR-NANO, via G. Campi 213/a, I-41125 Modena, Italy | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000385483900004 | Publication Date | 2016-09-15 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0957-4484 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.44 | Times cited | 11 | Open Access | |
Notes | The authors gratefully acknowledge financial support by the Italian MIUR under grant FIRB RBAP115AYN (Oxides at the nanoscale: multifunctionality and applications). The activity is performed within the COST Action CM1104 'Reducible oxide chemistry, structure and functions'. The research leading to these results has received funding also from the European Union Seventh Framework Programme under Grant Agreement 312483—ESTEEM2 (Integrated Infrastructure Initiative–I3).; esteem2_ta | Approved | Most recent IF: 3.44 | ||
Call Number | EMAT @ emat @ c:irua:135424 | Serial | 4130 | ||
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Author | Wang, W.; Bogaerts, A. | ||||
Title | Effective ionisation coefficients and critical breakdown electric field of CO2at elevated temperature: effect of excited states and ion kinetics | Type | A1 Journal article | ||
Year | 2016 | Publication | Plasma sources science and technology | Abbreviated Journal | Plasma Sources Sci T |
Volume | 25 | Issue | 25 | Pages | 055025 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Electrical breakdown by the application of an electric field occurs more easily in hot gases than in cold gases because of the extra electron-species interactions that occur as a result of dissociation, ionization and excitation at higher temperature. This paper discusses some overlooked physics and clarifies inaccuracies in the evaluation of the effective ionization coefficients and the critical reduced breakdown electric field of CO2 at elevated temperature, considering the influence of excited states and ion kinetics. The critical reduced breakdown electric field is obtained by balancing electron generation and loss mechanisms using the electron energy distribution function (EEDF) derived from the Boltzmann transport equation under the two-term approximation. The equilibrium compositions of the hot gas mixtures are determined based on Gibbs free energy minimization considering the ground states as well as vibrationally and electronically excited states as independent species, which follow a Boltzmann distribution with a fixed excitation temperature. The interaction cross sections between electrons and the excited species, not reported previously, are properly taken into account. Furthermore, the ion kinetics, including electron–ion recombination, associative electron detachment, charge transfer and ion conversion into stable negative ion clusters, are also considered. Our results indicate that the excited species lead to a greater population of high-energy electrons at higher gas temperature and this affects the Townsend rate coefficients (i.e. of electron impact ionization and attachment), but the critical reduced breakdown electric field strength of CO2 is only affected when also properly accounting for the ion kinetics. Indeed, the latter greatly influences the effective ionization coefficients and hence the critical reduced breakdown electric field at temperatures above 1500 K. The rapid increase of the dissociative electron attachment cross-section of molecular oxygen with rising vibrational quantum number leads to a larger electron loss rate and this enhances the critical reduced breakdown electric field strength in the temperature range where the concentration of molecular oxygen is relatively high. The results obtained in this work show reasonable agreement with experimental results from literature, and are important for the evaluation of the dielectric strength of CO2 in a highly reactive environment at elevated temperature. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000385494000006 | Publication Date | 2016-09-22 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1361-6595 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.302 | Times cited | 3 | Open Access | |
Notes | Skłodowska-Curie Individual Fellowship ‘GlidArc’ within Horizon2020 (Grant No.657304) and the FWO project (grant G.0383.16N). The computational work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UA. | Approved | Most recent IF: 3.302 | ||
Call Number | PLASMANT @ plasmant @ c:irua:135515 | Serial | 4281 | ||
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