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“Dry reforming of methane in a nanosecond repetitively pulsed discharge: chemical kinetics modeling”. Zhang L, Heijkers S, Wang W, Martini LM, Tosi P, Yang D, Fang Z, Bogaerts A, Plasma Sources Science &, Technology 31, 055014 (2022). http://doi.org/10.1088/1361-6595/ac6bbc
Abstract: Nanosecond pulsed discharge plasma shows a high degree of non-equilibrium, and exhibits relatively high conversions in the dry reforming of methane. To further improve the application, a good insight of the underlying mechanisms is desired. We developed a chemical kinetics model to explore the underlying plasma chemistry in nanosecond pulsed discharge. We compared the calculated conversions and product selectivities with experimental results, and found reasonable agreement in a wide range of specific energy input. Hence, the chemical kinetics model is able to provide insight in the underlying plasma chemistry. The modeling results predict that the most important dissociation reaction of CO<sub>2</sub>and CH<sub>4</sub>is electron impact dissociation. C<sub>2</sub>H<sub>2</sub>is the most abundant hydrocarbon product, and it is mainly formed upon reaction of two CH<sub>2</sub>radicals. Furthermore, the vibrational excitation levels of CO<sub>2</sub>contribute for 85% to the total dissociation of CO<sub>2</sub>.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.8
DOI: 10.1088/1361-6595/ac6bbc
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“Foundations of plasma catalysis for environmental applications”. Bogaerts A, Neyts EC, Guaitella O, Murphy AB, Plasma Sources Science &, Technology (2022). http://doi.org/10.1088/1361-6595/ac5f8e
Abstract: Plasma catalysis is gaining increasing interest for various applications, but the underlying mechanisms are still far from understood. Hence, more fundamental research is needed to understand these mechanisms. This can be obtained by both modelling and experiments. This foundations paper describes the fundamental insights in plasma catalysis, as well as efforts to gain more insights by modelling and experiments. Furthermore, it discusses the state-of-the-art of the major plasma catalysis applications, as well as successes and challenges of technology transfer of these applications.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.8
DOI: 10.1088/1361-6595/ac5f8e
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“Coupling the COST reference plasma jet to a microfluidic device: a computational study”. Bissonnette-Dulude J, Heirman P, Coulombe S, Bogaerts A, Gervais T, Reuter S, Plasma Sources Science and Technology 33, 015001 (2024). http://doi.org/10.1088/1361-6595/ad1421
Abstract: The use of microfluidic devices in the field of plasma-liquid interaction can unlock unique possibilities to investigate the effects of plasma-generated reactive species for environmental and biomedical applications. So far, very little simulation work has been performed on microfluidic devices in contact with a plasma source. We report on the modelling and computational simulation of physical and chemical processes taking place in a novel plasma-microfluidic platform. The main production and transport pathways of reactive species both in plasma and liquid are modelled by a novel modelling approach that combines 0D chemical kinetics and 2D transport mechanisms. This combined approach, applicable to systems where the transport of chemical species occurs in unidirectional flows at high Péclet numbers, decreases calculation times considerably compared to regular 2D simulations. It takes advantage of the low computational time of the 0D reaction models while providing spatial information through multiple plug-flow simulations to yield a quasi-2D model. The gas and liquid flow profiles are simulated entirely in 2D, together with the chemical reactions and transport of key chemical species. The model correctly predicts increased transport of hydrogen peroxide into the liquid when the microfluidic opening is placed inside the plasma effluent region, as opposed to inside the plasma region itself. Furthermore, the modelled hydrogen peroxide production and transport in the microfluidic liquid differs by less than 50% compared with experimental results. To explain this discrepancy, the limits of the 0D–2D combined approach are discussed.
Keywords: A1 Journal Article; non-thermal plasma, microfluidic, plasma-liquid interactions, modelling; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 3.8
DOI: 10.1088/1361-6595/ad1421
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“Insights into the limitations to vibrational excitation of CO2: validation of a kinetic model with pulsed glow discharge experiments”. Biondo O, Fromentin C, Silva T, Guerra V, van Rooij G, Bogaerts A, Plasma Sources Science &, Technology 31, 074003 (2022). http://doi.org/10.1088/1361-6595/ac8019
Abstract: Vibrational excitation represents an efficient channel to drive the dissociation of CO<sub>2</sub>in a non-thermal plasma. Its viability is investigated in low-pressure pulsed discharges, with the intention of selectively exciting the asymmetric stretching mode, leading to stepwise excitation up to the dissociation limit of the molecule. Gas heating is crucial for the attainability of this process, since the efficiency of vibration–translation (V–T) relaxation strongly depends on temperature, creating a feedback mechanism that can ultimately thermalize the discharge. Indeed, recent experiments demonstrated that the timeframe of V–T non-equilibrium is limited to a few milliseconds at ca. 6 mbar, and shrinks to the<italic>μ</italic>s-scale at 100 mbar. With the aim of backtracking the origin of gas heating in pure CO<sub>2</sub>plasma, we perform a kinetic study to describe the energy transfers under typical non-thermal plasma conditions. The validation of our kinetic scheme with pulsed glow discharge experiments enables to depict the gas heating dynamics. In particular, we pinpoint the role of vibration–vibration–translation relaxation in redistributing the energy from asymmetric to symmetric levels of CO<sub>2</sub>, and the importance of collisional quenching of CO<sub>2</sub>electronic states in triggering the heating feedback mechanism in the sub-millisecond scale. This latter finding represents a novelty for the modelling of low-pressure pulsed discharges and we suggest that more attention should be paid to it in future studies. Additionally, O atoms convert vibrational energy into heat, speeding up the feedback loop. The efficiency of these heating pathways, even at relatively low gas temperature and pressure, underpins the lifetime of V–T non-equilibrium and suggests a redefinition of the optimal conditions to exploit the ‘ladder-climbing’ mechanism in CO<sub>2</sub>discharges.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.8
DOI: 10.1088/1361-6595/ac8019
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“Ammonia decomposition in a dielectric barrier discharge plasma: Insights from experiments and kinetic modeling”. Andersen Ja, van 't Veer K, Christensen Jm, Østberg M, Bogaerts A, Jensen Ad, Chemical engineering science 271, 118550 (2023). http://doi.org/10.1016/j.ces.2023.118550
Abstract: Utilizing ammonia as a storage medium for hydrogen is currently receiving increased attention. A possible method to retrieve the hydrogen is by plasma-catalytic decomposition. In this work, we combined an experimental study, using a dielectric barrier discharge plasma reactor, with a plasma kinetic model, to get insights into the decomposition mechanism. The experimental results revealed a similar effect on the ammonia conversion when changing the flow rate and power, where increasing the specific energy input (higher power or lower flow rate) gave an increased conversion. A conversion as high as 82 % was achieved at a specific energy input of 18 kJ/Nl. Furthermore, when changing the discharge volume from 31 to 10 cm3, a change in the plasma distribution factor from 0.2 to 0.1 was needed in the model to best describe the conversions of the experiments. This means that a smaller plasma volume caused a higher transfer of energy through micro-discharges (non-uniform plasma), which was found to promote the decomposition of ammonia. These results indicate that it is the collisions between NH3 and the high-energy electrons that initiate the decomposition. Moreover, the rate of ammonia destruction was found by the model to be in the order of 1022 molecules/(cm3 s) during the micro-discharges, which is 5 to 6 orders of magnitude higher than in the afterglows. A considerable re-formation of ammonia was found to take place in the afterglows, limiting the overall conversion. In addition, the model revealed that implementation of packing material in the plasma introduced high concentrations of surface-bound hydrogen atoms, which introduced an additional ammonia re-formation pathway through an Eley-Rideal reaction with gas phase NH2. Furthermore, a more uniform plasma is predicted in the presence of MgAl2O4, which leads to a lower average electron energy during micro-discharges and a lower conversion (37 %) at a comparable residence time for the plasma alone (51 %).
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.7
DOI: 10.1016/j.ces.2023.118550
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“Current State of Cold Atmospheric Plasma and Cancer‐Immunity Cycle: Therapeutic Relevance and Overcoming Clinical Limitations Using Hydrogels”. Živanić, M, Espona‐Noguera A, Lin A, Canal C, Advanced Science , 2205803 (2023). http://doi.org/10.1002/advs.202205803
Abstract: Cold atmospheric plasma (CAP) is a partially ionized gas that gains attention
as a well-tolerated cancer treatment that can enhance anti-tumor immune
responses, which are important for durable therapeutic effects. This review
offers a comprehensive and critical summary on the current understanding of
mechanisms in which CAP can assist anti-tumor immunity: induction of
immunogenic cell death, oxidative post-translational modifications of the
tumor and its microenvironment, epigenetic regulation of aberrant gene
expression, and enhancement of immune cell functions. This should provide
a rationale for the effective and meaningful clinical implementation of CAP. As
discussed here, despite its potential, CAP faces different clinical limitations
associated with the current CAP treatment modalities: direct exposure of
cancerous cells to plasma, and indirect treatment through injection of
plasma-treated liquids in the tumor. To this end, a novel modality is proposed:
plasma-treated hydrogels (PTHs) that can not only help overcome some of the
clinical limitations but also offer a convenient platform for combining CAP
with existing drugs to improve therapeutic responses and contribute to the
clinical translation of CAP. Finally, by integrating expertise in biomaterials and
plasma medicine, practical considerations and prospective for the
development of PTHs are offered.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 15.1
DOI: 10.1002/advs.202205803
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“The 2021 release of the Quantemol database (QDB) of plasma chemistries and reactions”. Tennyson J, Mohr S, Hanicinec M, Dzarasova A, Smith C, Waddington S, Liu B, Alves LL, Bartschat K, Bogaerts A, Engelmann SU, Gans T, Gibson AR, Hamaguchi S, Hamilton KR, Hill C, O’Connell D, Rauf S, van ’t Veer K, Zatsarinny O, Plasma Sources Science &, Technology 31, 095020 (2022). http://doi.org/10.1088/1361-6595/ac907e
Abstract: The Quantemol database (QDB) provides cross sections and rates of processes important for plasma models; heavy particle collisions (chemical reactions) and electron collision processes are considered. The current version of QDB has data on 28 917 processes between 2485 distinct species plus data for surface processes. These data are available via a web interface or can be delivered directly to plasma models using an application program interface; data are available in formats suitable for direct input into a variety of popular plasma modeling codes including HPEM, COMSOL, ChemKIN, CFD-ACE+, and VisGlow. QDB provides ready assembled plasma chemistries plus the ability to build bespoke chemistries. The database also provides a Boltzmann solver for electron dynamics and a zero-dimensional model. Thesedevelopments, use cases involving O<sub>2</sub>, Ar/NF<sub>3</sub>, Ar/NF<sub>3</sub>/O<sub>2</sub>, and He/H<sub>2</sub>O/O<sub>2</sub>chemistries, and plans for the future are presented.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.8
DOI: 10.1088/1361-6595/ac907e
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“Simulation of glow and arc discharges in nitrogen: effects of the cathode emission mechanisms”. Tsonev I, Boothroyd J, Kolev S, Bogaerts A, PLASMA SOURCES SCIENCE &, TECHNOLOGY 32, 054002 (2023). http://doi.org/10.1088/1361-6595/acc96c
Abstract: Experimental evidence in the literature has shown that low-current direct current nitrogen discharges can exist in both glow and arc regimes at atmospheric pressure. However, modelling investigations of the positive column that include the influence of the cathode phenomena are scarce. In this work we developed a 2D axisymmetric model of a plasma discharge in flowing nitrogen gas, studying the influence of the two cathode emission mechanisms—thermionic field emission and secondary electron emission—on the cathode region and the positive column. We show for an inlet gas flow velocity of 1 m s<sup>−1</sup>in the current range of 80–160 mA, that the electron emission mechanism from the cathode greatly affects the size and temperature of the cathode region, but does not significantly influence the discharge column at atmospheric pressure. We also demonstrate that in the discharge column the electron density balance is local and the electron production and destruction is dominated by volume processes. With increasing flow velocity, the discharge contraction is enhanced due to the increased convective heat loss. The cross sectional area of the conductive region is strongly dependent on the gas velocity and heat conductivity of the gas.
Keywords: A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 3.8
DOI: 10.1088/1361-6595/acc96c
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“Germanium vacancy centre formation in CVD nanocrystalline diamond using a solid dopant source”. Mary Joy R, Pobedinskas P, Bourgeois E, Chakraborty T, Görlitz J, Herrmann D, Noël C, Heupel J, Jannis D, Gauquelin N, D'Haen J, Verbeeck J, Popov C, Houssiau L, Becher C, Nesládek M, Haenen K, Science talks 5, 100157 (2023). http://doi.org/10.1016/j.sctalk.2023.100157
Keywords: A3 Journal article; Electron microscopy for materials research (EMAT)
DOI: 10.1016/j.sctalk.2023.100157
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“Does non-thermal plasma modify biopolymers in solution? A chemical and mechanistic study for alginate”. Tampieri F, Espona-Noguera A, Labay C, Ginebra M-P, Yusupov M, Bogaerts A, Canal C, Biomaterials Science (2023). http://doi.org/10.1039/D3BM00212H
Abstract: In the last decades, non-thermal plasma has been extensively investigated as a relevant tool for various biomedical applications, ranging from tissue decontamination to regeneration and from skin treatment to tumor therapies. This high versatility is due to the different kinds and amount of reactive oxygen and nitrogen species that can be generated during a plasma treatment and put in contact with the biological target. Some recent studies report that solutions of biopolymers with the ability to generate hydrogels, when treated with plasma, can enhance the generation of reactive species and influence their stability, resulting thus in the ideal media for indirect treatments of biological targets. The direct effects of the plasma treatment on the structure of biopolymers in water solution, as well as the chemical mechanisms responsible for the enhanced generation of RONS, are not yet fully understood. In this study, we aim at filling this gap by investigating, on the one hand, the nature and extent of the modifications induced by plasma treatment in alginate solutions, and, on the other hand, at using this information to explain the mechanisms responsible for the enhanced generation of reactive species as a consequence of the treatment. The approach we use is twofold: (i) investigating the effects of plasma treatment on alginate solutions, by size exclusion chromatography, rheology and scanning electron microscopy and (ii) study of a molecular model (glucuronate) sharing its chemical structure, by chromatography coupled with mass spectrometry and by molecular dynamics simulations. Our results point out the active role of the biopolymer chemistry during direct plasma treatment. Short-lived reactive species, such as OH radicals and O atoms, can modify the polymer structure, affecting its functional groups and causing partial fragmentation. Some of these chemical modifications, like the generation of organic peroxide, are likely responsible for the secondary generation of long-lived reactive species such as hydrogen peroxide and nitrite ions. This is relevant in view of using biocompatible hydrogels as vehicles for storage and delivery reactive species for targeted therapies.
Keywords: A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 6.6
DOI: 10.1039/D3BM00212H
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“Nitrogen Oxidation in a Multi-Pin Plasma System in the Presence and Absence of a Plasma/Liquid Interface”. Adhami Sayad Mahaleh M, Narimisa M, Nikiforov A, Gromov M, Gorbanev Y, Bitar R, Morent R, De Geyter N, Applied Sciences 13, 7619 (2023). http://doi.org/10.3390/app13137619
Abstract: The recent energy crisis revealed that there is a strong need to replace hydrocarbon-fueled industrial nitrogen fixation processes by alternative, more sustainable methods. In light of this, plasma-based nitrogen fixation remains one of the most promising options, considering both theoretical and experimental aspects. Lately, plasma interacting with water has received considerable attention in nitrogen fixation applications as it can trigger a unique gas- and liquid-phase chemistry. Within this context, a critical exploration of plasma-assisted nitrogen fixation with or without water presence is of great interest with an emphasis on energy costs, particularly in plasma reactors which have potential for large-scale industrial application. In this work, the presence of water in a multi-pin plasma system on nitrogen oxidation is experimentally investigated by comparing two pulsed negative DC voltage plasmas in metal–metal and metal–liquid electrode configurations. The plasma setups are designed to create similar plasma properties, including plasma power and discharge regime in both configurations. The system energy cost is calculated, considering nitrogen-containing species generated in gas and liquid phases as measured by a gas analyzer, nitrate sensor, and a colorimetry method. The energy cost profile as a function of specific energy input showed a strong dependency on the plasma operational frequency and the gas flow rate, as a result of different plasma operation regimes and initiated reverse processes. More importantly, the presence of the plasma/liquid interface increased the energy cost up to 14 ± 8%. Overall, the results showed that the presence of water in the reaction zone has a negative impact on the nitrogen fixation process.
Keywords: A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 2.7
DOI: 10.3390/app13137619
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“Assessing neutral transport mechanisms in aspect ratio dependent etching by means of experiments and multiscale plasma modeling”. Vanraes P, Parayil Venugopalan S, Besemer M, Bogaerts A, Plasma Sources Science and Technology 32, 064004 (2023). http://doi.org/10.1088/1361-6595/acdc4f
Abstract: Since the onset of pattern transfer technologies for chip manufacturing, various strategies have been developed to circumvent or overcome aspect ratio dependent etching (ARDE). These methods have, however, their own limitations in terms of etch non-idealities, throughput or costs. Moreover, they have mainly been optimized for individual in-device features and die-scale patterns, while occasionally ending up with poor patterning of metrology marks, affecting the alignment and overlay in lithography. Obtaining a better understanding of the underlying mechanisms of ARDE and how to mitigate them therefore remains a relevant challenge to date, for both marks and advanced nodes. In this work, we accordingly assessed the neutral transport mechanisms in ARDE by means of experiments and multiscale modeling for SiO<sub>2</sub>etching with CHF<sub>3</sub>/Ar and CF<sub>4</sub>/Ar plasmas. The experiments revealed a local maximum in the etch rate for an aspect ratio around unity, i.e. the simultaneous occurrence of regular and inverse reactive ion etching lag for a given etch condition. We were able to reproduce this ARDE trend in the simulations without taking into account charging effects and the polymer layer thickness, suggesting shadowing and diffuse reflection of neutrals as the primary underlying mechanisms. Subsequently, we explored four methods with the simulations to regulate ARDE, by varying the incident plasma species fluxes, the amount of polymer deposition, the ion energy and angular distribution and the initial hardmask sidewall angle, for which the latter was found to be promising in particular. Although our study focusses on feature dimensions characteristic to metrology marks and back-end-of-the-line integration, the obtained insights have a broader relevance, e.g. to the patterning of advanced nodes. Additionally, this work supports the insight that physisorption may be more important in plasma etching at room temperature than originally thought, in line with other recent studies, a topic on which we recommend further research.
Keywords: A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 3.8
DOI: 10.1088/1361-6595/acdc4f
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“NH3 decomposition for H2 production by thermal and plasma catalysis using bimetallic catalysts”. Meng S, Li S, Sun S, Bogaerts A, Liu Y, Yi Y, Chemical Engineering Science 283, 119449 (2024). http://doi.org/10.1016/j.ces.2023.119449
Abstract: Plasma catalysis has emerged as a promising approach for driving thermodynamically unfavorable chemical
reactions. Nevertheless, comprehending the mechanisms involved remains a challenge, leading to uncertainty
about whether the optimal catalyst in plasma catalysis aligns with that in thermal catalysis. In this research, we
explore this question by studying monometallic catalysts (Fe, Co, Ni and Mo) and bimetallic catalysts (Fe-Co, Mo-
Co, Fe-Ni and Mo-Ni) in both thermal catalytic and plasma catalytic NH3 decomposition. Our findings reveal that
the Fe-Co bimetallic catalyst exhibits the highest activity in thermal catalysis, the Fe-Ni bimetallic catalyst
outperforms others in plasma catalysis, indicating a discrepancy between the optimal catalysts for the two
catalytic modes in NH3 decomposition. Comprehensive catalyst characterization, kinetic analysis, temperature
program surface reaction experiments and plasma diagnosis are employed to discuss the key factors influencing
NH3 decomposition performance.
Keywords: A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 4.7
DOI: 10.1016/j.ces.2023.119449
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“Heterogeneous Pt-catalyzed transfer dehydrogenation of long-chain alkanes with ethylene”. de la Croix T, Claes N, Eyley S, Thielemans W, Bals S, De Vos D, Catalysis Science &, Technology (2023). http://doi.org/10.1039/D3CY00370A
Abstract: The dehydrogenation of long-chain alkanes to olefins and alkylaromatics is a challenging endothermic reaction, typically requiring harsh conditions which can lead to low selectivity and coking. More favorable thermodynamics can be achieved by using a hydrogen acceptor, such as ethylene. In this work, the potential of heterogeneous platinum catalysts for the transfer dehydrogenation of long-chain alkanes is investigated, using ethylene as a convenient hydrogen acceptor. Pt/C and Pt–Sn/C catalysts were prepared<italic>via</italic>a simple polyol method and characterized with CO pulse chemisorption, HAADF-STEM, and EDX measurements. Conversion of ethylene was monitored<italic>via</italic>gas-phase FTIR, and distribution of liquid products was analyzed<italic>via</italic>GC-FID, GC-MS, and 1H-NMR. Compared to unpromoted Pt/C, Sn-promoted catalysts show lower initial reaction rates, but better resistance to catalyst deactivation, while increasing selectivity towards alkylaromatics. Both reaction products and ethylene were found to inhibit the reaction significantly. At 250 °C for 22 h, TON up to 28 and 86 mol per mol Pt were obtained for Pt/C and PtSn<sub>2</sub>/C, respectively, with olefin selectivities of 94% and 53%. The remaining products were mainly unbranched alkylaromatics. These findings show the potential of simple heterogeneous catalysts in alkane transfer dehydrogenation, for the preparation of valuable olefins and alkylaromatics, or as an essential step in various tandem reactions.
Keywords: A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Impact Factor: 5
DOI: 10.1039/D3CY00370A
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“Bloch and localized electrons in semiconductor superlattices”. Helm M, Hilber W, Fromherz T, Peeters FM, Alavi K, Pathak RN, Semiconductor science and technology 9, 1989 (1994). http://doi.org/10.1088/0268-1242/9/11S/022
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.19
Times cited: 1
DOI: 10.1088/0268-1242/9/11S/022
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“Compositional characterization of nickel silicides by HAADF-STEM imaging”. Verleysen E, Bender H, Richard O, Schryvers D, Vandervorst W, Journal of materials science 46, 2001 (2011). http://doi.org/10.1007/s10853-010-5191-z
Abstract: A methodology for the quantitative compositional characterization of nickel silicides by high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) imaging is presented. HAADF-STEM images of a set of nickel silicide reference samples Ni3Si, Ni31Si12, Ni2Si, NiSi and NiSi2 are taken at identical experimental conditions. The correlation between sample thickness and HAADF-STEM intensity is discussed. In order to quantify the relationship between the experimental Z-contrast intensities and the composition of the analysed layers, the ratio of the HAADF-STEM intensity to the sample thickness or to the intensity of the silicon substrate is determined for each nickel silicide reference sample. Diffraction contrast is still detected on the HAADF-STEM images, even though the detector is set at the largest possible detection angle. The influence on the quantification results of intensity fluctuations caused by diffraction contrast and channelling is examined. The methodology is applied to FUSI gate devices and to horizontal TFET devices with different nickel silicides formed on source, gate and drain. It is shown that, if the elements which are present are known, this methodology allows a fast quantitative 2-dimensional compositional analysis.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.599
Times cited: 1
DOI: 10.1007/s10853-010-5191-z
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“Critical assessment of the process of growth of a YBa2Cu3O7-\delta layer on Y2BaCuO5”. Jacques P, Verbist K, Lapin J, Ryelandt L, Van Tendeloo G, Delannay F, Superconductor science and technology 9, 176 (1996). http://doi.org/10.1088/0953-2048/9/3/008
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.325
Times cited: 1
DOI: 10.1088/0953-2048/9/3/008
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“Disappearance of magnetophonon resonance at high magnetic fields in GaAs-GaAlAs heterojunctions”. Leadley DR, Nicholas RJ, Singleton J, Xu W, Peeters FM, Devreese JT, van Bockstal L, Herlach F, Perenboom JAAJ, Harris JJ, Foxon CT, Surface science : a journal devoted to the physics and chemistry of interfaces 305, 327 (1994). http://doi.org/10.1016/0039-6028(94)90910-5
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 1.925
Times cited: 1
DOI: 10.1016/0039-6028(94)90910-5
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“EM characterization of precipitates in as-cast and annealed Ni45.5Ti45.5Nb9 shape memory alloys”. Shi H, Frenzel J, Schryvers D, Materials science forum 738/739, 113 (2013). http://doi.org/10.4028/www.scientific.net/MSF.738-739.113
Abstract: Nb-rich precipitates in the matrix of as-cast and annealed Ni45.5Ti45.5Nb9 alloys are investigated by scanning and scanning transmission electron microscopy, including slice-and-view and geometric phase analysis (GPA). The Nb-rich bcc nano-precipitates in the as-cast alloy have a 10% lattice parameter difference with the B2 matrix and reveal compensating interface dislocations. The 3D reconstruction of the configuration of small Nb-rich precipitates in the annealed alloy reveals a wall-like distribution of precipitates, which may increase the thermal hysteresis of the material.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
Times cited: 1
DOI: 10.4028/www.scientific.net/MSF.738-739.113
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“Formation of Mn304/C core-shell nanowires and a new MN-O phase by electron beam irradiation”. Du GH, Van Tendeloo G, Applied physics A : materials science &, processing 91, 393 (2008). http://doi.org/10.1007/s00339-008-4430-5
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.455
Times cited: 1
DOI: 10.1007/s00339-008-4430-5
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“Magneto-oscillations of the gate current in a laterally modulated two-dimensional electron gas”. Blom FAP, Peeters FM, van de Zanden K, van Hove M, Surface science : a journal devoted to the physics and chemistry of interfaces 361/362, 851 (1996). http://doi.org/10.1016/0039-6028(96)00549-3
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.925
Times cited: 1
DOI: 10.1016/0039-6028(96)00549-3
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“New method to determine the parity of the number of twin planes in tabular silver halide microcrystals from top views”. Goessens C, Schryvers D, van Landuyt J, de Keyzer R, The journal of imaging science and technology 41, 301 (1997)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.348
Times cited: 1
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“A scanning electron microscopy study on hollow silica microspheres: defects and influences of the synthesis composition”. Liu S, Wei M, Sui X, Cheng X, Cool P, Van Tendeloo G, Journal of sol-gel science and technology 49, 373 (2009). http://doi.org/10.1007/s10971-008-1875-0
Abstract: Defects on hollow silica spheres synthesized in a tetraethylorthosilicate-octylamine-HCl-H2O system were recorded by scanning microscope. Based on the results, influences of synthesis composition on the formation of these defects are discussed. It is evidenced that products prepared with different octylamine-to-tetraethylorthosilicate ratios may have surface depressions, cracks and non-hollow microspheres. However, by changing water and acid additions, these defects could be reduced or eliminated. Generally, samples synthesized with a large octylamine addition commonly exhibit surface depressions. A small octylamine or a large water addition benefits the formation of solid silica microspheres among the product. Acid, although is not indispensable for the formation of hollow spheres, helps to eliminate or reduce depressions on the hollow shells. It is explained that the added acid gives rise to a relative localized fast hydrolysis versus condensation, facilitating an easy mobility of hydrolyzed silica species, and consequently the shell surface is smoothened.
Keywords: A1 Journal article; Laboratory of adsorption and catalysis (LADCA); Electron microscopy for materials research (EMAT)
Impact Factor: 1.575
Times cited: 1
DOI: 10.1007/s10971-008-1875-0
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“The superstructure and superconductivity of Ru1222 based RuSr2Gd2-x-yYyCexCu2O10-\delta compounds”. Tan H, Lebedev OI, McLaughlin AC, Van Tendeloo G, Superconductor science and technology 23, 115013 (2010). http://doi.org/10.1088/0953-2048/23/11/115013
Abstract: For the first time, the local structure and physical properties of Ru1222 based compounds (RuSr(2)Gd(1.4)Ce(0.6)Cu(2)O(10-delta) and RuSr(2)Gd(1.8-x)Y(0.2)CexCu(2)O(10) (x = 0.90-0.55)) have been investigated and analyzed together on the very same compounds. The Ru1222 superstructure was confirmed by TEM at a local scale and was suggested to have an orthorhombic symmetry with space group Aba2 and lattice parameters a(s) similar or equal to root 2a, b(s) similar or equal to root 2a and c(s) = c. This new Ru1222 superstructure distortion from tetragonal symmetry is proposed to have a positive correlation with the superconductivity variation of these compounds. The more the distortion towards orthorhombic symmetry, the higher the critical superconducting temperature these compounds can achieve. The T(c)(0) of RuSr(2)Gd(1.8-x)Y(0.2)Ce(x)Cu(2)O(10-delta) (x = 0.85-0.55) increases monotonically from 4 to 16 K when x decreases from 0.85 to 0.70, then RuSr(2)Gd(2)Cu(2)O(8) defects emerge and the T(c) decreases with decreasing x. Ru1212 defects are observed to intergrow epitaxially with the Ru1222 structure as lamellas along the c-axis in RuSr(2)Gd(1.4)Ce(0.6)Cu(2)O(10-delta). Although Ru1212 is a superconductor, the intergrowth severely restrains its superconductivity.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.878
Times cited: 1
DOI: 10.1088/0953-2048/23/11/115013
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“Symmetry-adapted rotator functions for molecules in cylindrical confinement”. Verberck B, International journal of molecular sciences 12, 317 (2011). http://doi.org/10.3390/ijms12010317
Abstract: We present a general description of the formalism of symmetry-adapted rotator functions (SARFs) for molecules in cylindrical confinement. Molecules are considered as clusters of interaction centers (ICs), can have any symmetry, and can display different types of ICs. Cylindrical confinement can be realized by encapsulation in a carbon nanotube (CNT). The potential energy of a molecule surrounded by a CNT can be calculated by evaluating a limited number of terms of an expansion into SARFs, which offers a significant reduction of the computation time. Optimal molecular orientations can be deduced from the resulting potential energy landscape. Examples, including the case of a molecule with cubic symmetry inside a CNT, are discussed.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.226
Times cited: 1
DOI: 10.3390/ijms12010317
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“TEM study of B2 + L12 decomposition in a nanoscale Ni-rich Ni-Al film”. Schryvers D, Yandouzi M, Toth L, Thin solid films : an international journal on the science and technology of thin and thick films 326, 126 (1998). http://doi.org/10.1016/S0040-6090(98)00545-8
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.879
Times cited: 1
DOI: 10.1016/S0040-6090(98)00545-8
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“XPS and TOFSIMS studies of shallow Si/Si1-xGex/Si layers”. Conard T, de Witte H, Loo R, Verheyen P, Vandervorst W, Caymax M, Gijbels R, Thin solid films : an international journal on the science and technology of thin and thick films 343/344, 583 (1999). http://doi.org/10.1016/S0040-6090(99)00122-4
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.879
Times cited: 1
DOI: 10.1016/S0040-6090(99)00122-4
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“Synthesis and structural characterization of a novel Sillén &ndash, Aurivillius bismuth oxyhalide, PbBi3VO7.5Cl, and its derivatives”. Charkin DO, Plokhikh IV, Kazakov SM, Kalmykov SN, Akinfiev VS, Gorbachev AV, Batuk M, Abakumov AM, Teterin YA, Maslakov KI, Teterin AY, Ivanov KE, Solid state sciences 75, 27 (2018). http://doi.org/10.1016/j.solidstatesciences.2017.11.006
Abstract: A new Sillen – Aurivillius family of layered bismuth oxyhalides has been designed and successfully constructed on the basis of PbBiO2X(X = halogen) synthetic perites and g-form of Bi2VO5.5 solid elec- trolyte. This demonstrates, for the first time, the ability of the latter to serve as a building block in construction of mixed-layer structures. The parent compound PbBi3VO7.5-dCl (d = 0.05) has been investigated by powder XRD, TEM, XPS methods and magnetic susceptibility measurements. An unexpected but important condition for the formation of the mixed-layer structure is partial (ca. 5%) reduction of VV into VIV which probably suppresses competitive formation of apatite-like Pb – Bi vanadates. This reduction also stabilizes the g polymorphic form of Bi2VO5.5 not only in the intergrowth structure, but in Bi2V1-xMxO5.5-y (M – Nb, Sb) solid solutions.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.811
Times cited: 1
DOI: 10.1016/j.solidstatesciences.2017.11.006
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“The role of healed N-vacancy defective BC2N sheet and nanotube by NO molecule in oxidation of NO and CO gas molecules”. Nematollahi P, Esrafili MD, Neyts EC, Surface science : a journal devoted to the physics and chemistry of interfaces 672-673, 39 (2018). http://doi.org/10.1016/J.SUSC.2018.03.002
Abstract: In this study, the healing of N-vacancy boron carbonitride nanosheet (NV-BC2NNS) and nanotube (NV-BC2NNT) by NO molecule is studied by means of density functional theory calculations. Two different N-vacancies are considered in each of these structures in which the vacancy site is surrounded by either three B-atoms (NB) or by two B- and one C-atom (NBC). By means of the healed BC2NNS and BC2NNT as a support, the removal of two toxic gas molecules (NO and CO) are applicable. It should be noted that the obtained energy barriers of both healing and oxidizing processes are significantly lower than those of graphene, carbon nanotubes or boron nitride nanostructures. Also, at the end of the oxidation process, the pure BC2NNS or BC2NNT is obtained without any additional defects. Therefore, by using this method, we can considerably purify the defective BC2NNS/BC2NNT. Moreover, according to the thermochemistry calculations we can further confirm that the healing process of the NV-BC2NNS and NV-BC2NNT by NO are feasible at room temperature. So, we can claim that this study could be very helpful in both purifying the defective BC2NNS/BC2NNT while in the same effort removing toxic NO and CO gases.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.062
Times cited: 1
DOI: 10.1016/J.SUSC.2018.03.002
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“Influence of 4H-SiC substrate miscut on the epitaxy and microstructure of AlGaN/GaN heterostructures”. Gkanatsiou A, Lioutas CB, Frangis N, Polychroniadis EK, Prystawko P, Leszczynski M, Altantzis T, Van Tendeloo G, Materials science in semiconductor processing 91, 159 (2019). http://doi.org/10.1016/j.mssp.2018.11.008
Abstract: AlGaN/GaN heterostructures were grown on “on-axis” and 2° off (0001) 4H-SiC substrates by metalorganic vapor phase epitaxy (MOVPE). Structural characterization was performed by transmission electron microscopy. The dislocation density, being greater in the on-axis case, is gradually reduced in the GaN layer and is forming
dislocation loops in the lower region. Steps aligned along [11̅00] in the off-axis case give rise to simultaneous defect formation. In the on-axis case, an almost zero density of steps is observed, with the main origin of defects probably being the orientation mismatch at the grain boundaries between the small not fully coalesced AlN grains. V-shaped formations are observed in the AlN nucleation layer, but are more frequent in the off-axis case, probably enhanced by the presence of steps. These V-shaped formations are completely overgrown by the GaN layer, during the subsequent deposition, presenting AlGaN areas in the walls of the defect, indicating an interdiffusion between the layers. Finally, at the AlGaN/GaN heterostructure surface in the on-axis case, V-shapes are observed, with the AlN spacer and AlGaN (21% Al) thickness on relaxed GaN exceeding the critical thickness for relaxation. On the other hand, no relaxation in the form of V-shape creation is observed in the off-axis case, probably due to the smaller AlGaN thickness (less than 21% Al). The AlN spacer layer, grown in between the heterostructure, presents a uniform thickness and clear interfaces.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.359
Times cited: 1
DOI: 10.1016/j.mssp.2018.11.008
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