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“Coupling of the skyrmion velocity to its breathing mode in periodically notched nanotracks”. Leliaert J, Gypens P, Milošević, MV, Van Waeyenberge B, Mulkers J, Journal of physics: D: applied physics 52, 024003 (2019). http://doi.org/10.1088/1361-6463/AAE7C1
Abstract: A thorough understanding of the skyrmion motion through nanotracks is a prerequisite to realize the full potential of spintronic applications like the skyrmion racetrack memory. One of the challenges is to place the data, i.e. skyrmions, on discrete fixed positions, e.g. below a read or write head. In the domain-wall racetrack memory, one proposed solution to this problem was patterning the nanotrack with notches. Following this approach, this paper reports on the skyrmion mobility through a nanotrack with periodic notches (constrictions) made using variations in the chiral Dzyaloshinskii-Moriya interaction. We observe that such notches induce a coupling between the mobility and the skyrmion breathing mode, which manifests itself as velocity-dependent oscillations of the skyrmion diameter and plateaus in which the velocity is independent of the driving force. Despite the fact that domain walls are far more rigid objects than skyrmions, we were able to perform an analogous study and, surprisingly, found even larger plateaus of constant velocity. For both systems it is straightforward to tune the velocity at these plateaus by changing the design of the notched nanotrack geometry, e.g. by varying the distance between the notches. Therefore, the notch-induced coupling between the excited modes and the mobility could offer a strategy to stabilize the velocity against unwanted perturbations in racetrack-like applications. In the last part of the paper we focus on the low-current mobility regimes, whose very rich dynamics at nonzero temperatures are very similar to the operating principle of recently developed probabilistic logic devices. This proves that the mobility of nanomagnetic structures through a periodically modulated track is not only interesting from a fundamental point of view, but has a future in many spintronic applications.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.588
Times cited: 10
DOI: 10.1088/1361-6463/AAE7C1
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“Non-thermal plasma-induced immunogenic cell death in cancer”. Khalili M, Daniels L, Lin A, Krebs FC, Snook AE, Bekeschus S, Bownel WB, Miller V, Journal of physics: D: applied physics 52, 423001 (2019). http://doi.org/10.1088/1361-6463/AB31C1
Abstract: Recent advances in biomedical research in cancer immunotherapy have identified the use of an oxidative stress-based approach to treat cancers, which works by inducing immunogenic cell death (ICD) in cancer cells. Since the anti-cancer effects of non-thermal plasma (NTP) are largely attributed to the reactive oxygen and nitrogen species that are delivered to and generated inside the target cancer cells, it is reasonable to postulate that NTP would be an effective modality for ICD induction. NTP treatment of tumors has been shown to destroy cancer cells rapidly and, under specific treatment regimens, this leads to systemic tumorspecific immunity. The translational benefit of NTP for treatment of cancer relies on its ability to enhance the interactions between NTP-exposed minor cells and local immune cells which initiates subsequent protective immune responses. This review discusses results from recent investigations of NTP application to induce ICD in cancer cells. With further optimization of clinical devices and treatment protocols, NTP can become an essential part of the therapeutic armament against cancer.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.588
Times cited: 6
DOI: 10.1088/1361-6463/AB31C1
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“MoSi₂N₄, single-layer : a novel two-dimensional material with outstanding mechanical, thermal, electronic and optical properties”. Bafekry A, Faraji M, Hoat DM, Shahrokhi M, Fadlallah MM, Shojaei F, Feghhi SAH, Ghergherehchi M, Gogova D, Journal Of Physics D-Applied Physics 54, 155303 (2021). http://doi.org/10.1088/1361-6463/ABDB6B
Abstract: Very recently, the 2D form of MoSi2N4 has been successfully fabricated (Hong et al 2020 Science 369 670). Motivated by these recent experimental results, we investigate the structural, mechanical, thermal, electronic and optical properties of the MoSi2N4 monolayer. The mechanical study confirms the stability of the MoSi2N4 monolayer. The Young's modulus decreases by similar to 30%, while the Poisson's ratio increases by similar to 30% compared to the corresponding values of graphene. In addition, the MoSi2N4 monolayer's work function is very similar to that of phosphorene and MoS2 monolayers. The electronic structure shows that the MoSi2N4 monolayer is an indirect semiconductor with a band gaps of 1.79 (2.35) eV using the GGA (HSE06) functional. The thermoelectric performance of the MoSi2N4 monolayer has been revealed and a figure of merit slightly larger than unity at high temperatures is calculated. The optical analysis shows that the first absorption peak for in-plane polarization is located in the visible range of the spectrum, therefore, the MoSi2N4 monolayer is a promising candidate for advanced optoelectronic nanodevices. In summary, the fascinating MoSi2N4 monoloayer is a promising 2D material for many applications due to its unique physical properties.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.588
DOI: 10.1088/1361-6463/ABDB6B
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Bal KM, Neyts EC (2021) Quantifying the impact of vibrational nonequilibrium in plasma catalysis: insights from a molecular dynamics model of dissociative chemisorption. 394004
Abstract: The rate, selectivity and efficiency of plasma-based conversion processes is strongly affected by nonequilibrium phenomena. High concentrations of vibrationally excited molecules are such a plasma-induced effect. It is frequently assumed that vibrationally excited molecules are important in plasma catalysis because their presence lowers the apparent activation energy of dissociative chemisorption reactions and thus increases the conversion rate. A detailed atomic-level understanding of vibrationally stimulated catalytic reactions in the context of plasma catalysis is however lacking. Here, we couple a recently developed statistical model of a plasma-induced vibrational nonequilibrium to molecular dynamics simulations, enhanced sampling methods, and machine learning techniques. We quantify the impact of a vibrational nonequilibrium on the dissociative chemisorption barrier of H2 and CH4 on nickel catalysts over a wide range of vibrational temperatures. We investigate the effect of surface structure and compare the role of different vibrational modes of methane in the dissociation process. For low vibrational temperatures, very high vibrational efficacies are found, and energy in bend vibrations appears to dominate the dissociation of methane. The relative impact of vibrational nonequilibrium is much higher on terrace sites than on surface steps. We then show how our simulations can help to interpret recent experimental results, and suggest new paths to a better understanding of plasma catalysis.
Keywords: A1 Journal Article;plasma catalysis; vibrational nonequilibrium; dissociative chemisorption; free energy barriers; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 2.588
DOI: 10.1088/1361-6463/ac113a
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“Prediction of two-dimensional bismuth-based chalcogenides Bi₂X₃(X = S, Se, Te) monolayers with orthorhombic structure : a first-principles study”. Bafekry A, Faraji M, Fadlallah MM, Jappor HR, Hieu NN, Ghergherehchi M, Feghhi SAH, Gogova D, Journal Of Physics D-Applied Physics 54, 395103 (2021). http://doi.org/10.1088/1361-6463/AC118C
Abstract: First-principles calculation is a very powerful tool for discovery and design of novel two-dimensional materials with unique properties needed for the next generation technology. Motivated by the successful preparation of Bi2S3 nanosheets with orthorhombic structure in the last year, herein we gain a deep theoretical insight into the crystal structure, stability, electronic and optical properties of Bi2X3 (X = S, Se, Te) monolayers of orthorhombic phase employing the first-principles calculations. The Molecular dynamics study, phonon spectra, criteria for elastic stability, and cohesive energy results confirm the desired stability of the Bi2X3 monolayers. From S, to Se and Te, the work function value as well as stability of the systems decrease due to the decline in electronegativity. Mechanical properties study reveals that Bi2X3 monolayers have brittle nature. The electronic bandgap values of Bi2S3, Bi2Se3 and Bi2Te3 monolayers are predicted by the HSE06 functional to be 2.05, 1.20 and 1.16 eV, respectively. By assessing the optical properties, it has been found that Bi2X3 monolayers can absorb ultraviolet light. The high in-plane optical anisotropy offers an additional degree of freedom in the design of optical devices. The properties revealed in our survey will stimulate and inspire the search for new approaches of orthorhombic Bi2X3 (X = S, Se, Te) monolayers synthesis and properties manipulation for fabrication of novel nanoelectronic and optoelectronic devices.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.588
DOI: 10.1088/1361-6463/AC118C
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“Crystallographic aspects related to advanced tribological multilayers of Cr/CrN and Ti/TiN types produced by pulsed laser deposition (PLD)”. Major L, Morgiel J, Major B, Lackner JM, Waldhauser W, Ebner R, Nistor L, Van Tendeloo G, Surface and coatings technology 200, 6190 (2006). http://doi.org/10.1016/j.surfcoat.2005.11.021
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.589
Times cited: 32
DOI: 10.1016/j.surfcoat.2005.11.021
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“Macroscale computer simulations to investigate the chemical vapor deposition of thin metal-oxide films”. Neyts E, Bogaerts A, de Meyer M, van Gils S, Surface and coatings technology 201, 8838 (2007). http://doi.org/10.1016/j.surfcoat.2007.04.102
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.589
Times cited: 5
DOI: 10.1016/j.surfcoat.2007.04.102
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“Modeling of gas discharge plasmas: What can we learn from it?”.Bogaerts A, de Bleecker K, Kolev I, Madani M, Surface and coatings technology 200, 62 (2005). http://doi.org/10.1016/j.surfcoat.2005.02.057
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.589
Times cited: 11
DOI: 10.1016/j.surfcoat.2005.02.057
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“Oscillating sliding wear of mono- and multilayer ceramic coatings in air”. Huq MZ, Celis JP, Meneve J, Stals L, Schryvers D, Surface and coatings technology 113, 242 (1999). http://doi.org/10.1016/S0257-8972(99)00009-2
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.589
Times cited: 10
DOI: 10.1016/S0257-8972(99)00009-2
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“Oxidation barrier of Cu and Fe powder by Atomic Layer Deposition”. Cremers V, Rampelberg G, Barhoum A, Walters P, Claes N, Oliveira TM de, Assche GV, Bals S, Dendooven J, Detavernier C, Surface and coatings technology 349, 1032 (2018). http://doi.org/10.1016/j.surfcoat.2018.06.048
Abstract: Atomic layer deposition (ALD) is a vapor based technique which allows to deposit uniform, conformal films with a thickness control at the atomic scale. In this research, Al 2 O 3 coatings were deposited on micrometer-sized Fe and Cu powder (particles) using the thermal trimethylaluminum (TMA)/ water (H 2 O) process in a rotary pump-type ALD reactor. Rotation of the powder during deposition was required to obtain a pinhole-free ALD coating. The protective nature of the coating was evaluated by quantifying its effectiveness in protecting the metal particles during oxidative annealing treatments. The Al 2 O 3 coated powders were annealed in ambient air while in-situ thermogravimetric analysis (TGA) and in-situ x-ray diffraction (XRD) data were acquired. The thermal stability of a series of Cu and Fe powder with different Al 2 O 3 thicknesses were determined with TGA. In both samples a clear shift in oxidation temperature is visible. For Cu and Fe powder coated with 25 nm Al 2 O 3 , we observed an increase of the oxidation temperature with 300-400°C. For the Cu powder a thin film of only 8 nm is required to obtain an initial increase in oxidation temperature of 200°C. In contrast, for Fe powder a thicker coating of 25 nm is required. In both cases, the oxidation temperature increases with increasing thickness of the Al 2 O 3 coating. These results illustrate that the Al 2 O 3 thin film, deposited by the thermal ALD process (TMA/H 2 O) can be an efficient and pinhole-free barrier layer for micrometer-sized powder particles, provided that the powder is properly agitated during the process to ensure sufficient vapour-solid interaction.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.589
Times cited: 10
DOI: 10.1016/j.surfcoat.2018.06.048
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“Characterisation of a high-power impulse magnetron sputtered C/Mo/W wear resistant coating by transmission electron microscopy”. Sharp J, Mueller IC, Mandal P, Abbas A, Nord M, Doye A, Ehiasarian A, Hovsepian P, MacLaren I, Rainforth WM, Surface and coatings technology 377, 124853 (2019). http://doi.org/10.1016/J.SURFCOAT.2019.08.007
Abstract: Thin films of C/Mo/W deposited using combined UBM/HIPIMS sputtering show 2-8 nm clusters of material richer in Mo and W than the matrix (found by EDS microanalysis), with structures that resemble graphitic onions with the metal atoms arranged regularly within them. EELS microanalysis showed the clusters to be rich in W and Mo. As the time averaged power used in the pulsed HIPIMS magnetron was increased, the clusters became more defined, larger, and arranged into layers with amorphous matrix between them. Films deposited with average HIPIMS powers of 4 kW and 6 kW also showed a periodic modulation of the cluster density within the finer layers giving secondary, wider stripes in TEM. By analysing the ratio between the finer and coarser layers, it was found that this meta-layering is related to the substrate rotation in the deposition chamber but in a non-straightforward way. Reasons for this are proposed. The detailed structure of the clusters remains unknown and is the subject of further work. Fluctuation electron microscopy results indicated the presence of crystal planes with the graphite interlayer spacing, crystal planes in hexagonal WC perpendicular to the basal plane, and some plane spacings found in Mo2C. Other peaks in the FEM results suggested symmetry-related starting points for future determination of the structure of the clusters.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.589
Times cited: 1
DOI: 10.1016/J.SURFCOAT.2019.08.007
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“Preparation, structural and optical characterization of nanocrystalline ZnO doped with luminescent Ag-nanoclusters”. Kuznetsov AS, Lu Y-G, Turner S, Shestakov MV, Tikhomirov VK, Kirilenko D, Verbeeck J, Baranov AN, Moshchalkov VV, Optical materials express 2, 723 (2012). http://doi.org/10.1364/OME.2.000723
Abstract: Nanocrystalline ZnO doped with Ag-nanoclusters has been synthesized by a salt solid state reaction. Three overlapping broad emission bands due to the Ag nanoclusters have been detected at about 570, 750 and 900 nm. These emission bands are excited by an energy transfer from the exciton state of the ZnO host when pumped in the wavelength range from 250 to 400 nm. The 900 nm emission band shows characteristic orbital splitting into three components pointing out that the anisotropic crystalline wurtzite host of ZnO is responsible for this feature. Heat-treatment and temperature dependence studies confirm the origin of these emission bands. An energy level diagram for the emission process and a model for Ag nanoclusters sites are suggested. The emission of nanocrystalline ZnO doped with Ag nanoclusters may be applied for white light generation, displays driven by UV light, down-convertors for solar cells and luminescent lamps.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.591
DOI: 10.1364/OME.2.000723
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“Composition and crystal structure of resorbable calcium phosphate thin films”. Tuck L, Sayer M, Mackenzie M, Hadermann J, Dunfield D, Pietak A, Reid JW, Stratilatov AD, Journal of materials science 41, 4273 (2006). http://doi.org/10.1007/s10853-005-5532-5
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.599
Times cited: 2
DOI: 10.1007/s10853-005-5532-5
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“Hydrothermal processing of barium strontium titanate sol-gel composite thin films”. Zelonka K, Sayer M, Freundorfer AP, Hadermann J, Journal of materials science 41, 3885 (2006). http://doi.org/10.1007/s10853-005-5525-4
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.599
Times cited: 10
DOI: 10.1007/s10853-005-5525-4
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“Mesoporous TiO2 from poly(N,N-dimethylacrylamide)-b-polystyrene block copolymers for long-term acetaldehyde photodegradation”. Billet J, Vandewalle S, Meire M, Blommaerts N, Lommens P, Verbruggen SW, De Buysser K, Du Prez F, Van Driesche I, Journal of materials science 55, 1933 (2019). http://doi.org/10.1007/S10853-019-04024-3
Abstract: Although already some mesoporous (2–50 nm) sol–gel TiO2 synthesis strategies exist, no pore size control beyond the 12 nm range is possible without using specialized organic structure-directing agents synthetized via controlled anionic/radical polymerizations. Here, we present the use of reversible addition–fragmentation chain transfer (RAFT) polymerization as a straightforward and industrial applicable alternative to the existing controlled polymerization methods for structure-directing agent synthesis. Poly(N,N-dimethylacrylamide)-block-polystyrene (PDMA-b-PS) block copolymer, synthesized via RAFT, was chosen as structure-directing agent for the formation of the mesoporous TiO2. Crack-free thin layers TiO2 with tunable pores from 8 to 45 nm could be acquired. For the first time, in a detailed and systematic approach, the influence of the block size and dispersity of the block copolymer is experimentally screened for their influence on the final meso-TiO2 layers. As expected, the mesoporous TiO2 pore sizes showed a clear correlation to the polystyrene block size and the dispersity of the PDMA-b-PS block copolymer. Surprisingly, the dispersity of the polymer was shown not to be affecting the standard deviation of the pores. As a consequence, RAFT could be seen as a viable alternative to the aforementioned controlled polymerization reactions for the synthesis of structure-directing agents enabling the formation of mesoporous pore size-controlled TiO2. To examine the photocatalytic activity of the mesoporous TiO2 thin layers, the degradation of acetaldehyde, a known indoor pollutant, was studied. Even after 3 years of aging, the TiO2 thin layer retained most of its activity.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 2.599
Times cited: 2
DOI: 10.1007/S10853-019-04024-3
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“Microwave-assisted synthesis of mesoporous titania with increased crystallinity, specific surface area, and photocatalytic activity”. Meire M, Verbruggen SW, Lenaerts S, Lommens P, Van Der Voort P, Van Driessche I, Journal of materials science 51, 9822 (2016). http://doi.org/10.1007/S10853-016-0215-Y
Abstract: Mesoporous titanium dioxide is a material finding its use in a wide range of applications. For many of these, it is important to achieve a high degree of crystallinity in the material. It is generally accepted that the use of the soft templating approach to synthesize mesoporous titania, results in a compromise between crystallinity and specific surface area due to thermal instability of the used templates. In this paper, we explore how the use of microwave irradiation can influence the crystallinity, specific surface area, and the electronic properties of mesoporous titania. Therefore, we combined microwave radiation with an evaporation-induced self-assembly (EISA) synthesis. We show that additional microwave treatment at carefully chosen synthesis steps can enhance the crystallinity with 20 % without causing significant loss of surface area (>360 m2/g). Surface photovoltage measurements were used to investigate the electronic properties. The photocatalytic activity of the samples was evaluated in aqueous media by following the degradation of an industrial dye, methylene blue, and the herbicide isoproturon under UV irradiation and in gaseous media looking at the degradation of acetaldehyde, a common indoor pollutant under UVA irradiation. In all cases, the microwave treatment results in more active materials.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 2.599
Times cited: 8
DOI: 10.1007/S10853-016-0215-Y
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“Evidence of early medieval soda ash glass in the archaeological site of San Genesio (Tuscany)”. Cagno S, Favaretto L, Mendera M, Izmer A, Vanhaecke F, Janssens K, Journal of archaeological science 39, 1540 (2012). http://doi.org/10.1016/J.JAS.2011.12.031
Abstract: The early medieval period marks an important turning point in the history of glassmaking, since it comprises the transition period between the mineral-based silica-soda-lime glass of the Roman tradition and the plant ash-based glass. With the aim of expanding the knowledge on the glass recipes and technologies of this period, 37 glass samples were analyzed, originating from the archaeological excavations of San Genesio (Tuscany) and dated from the fourth to the eleventh century. The major and minor element concentrations were measured with SEM-EDX, while the trace elements were quantified with LA-ICP-MS. The results were compared with published compositions of glass samples of similar age in order to highlight differences and similarities. The results offer a very interesting view on the glass circulation in the religious/residential/manufacturing center of San Genesio in the early medieval period. Most of the glass has a typical late-Roman composition, but some glass fragments are identified as soda ash glass. These are among the earliest medieval ash-fluxed glasses ever found in the Italian peninsula. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Philosophy; History; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.602
Times cited: 24
DOI: 10.1016/J.JAS.2011.12.031
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“Raw materials for medieval to post-medieval Tuscan glassmaking : new insight from LA-ICP-MS analyses”. Cagno S, Mendera M, Jeffries T, Janssens K, Journal of archaeological science 37, 3030 (2010). http://doi.org/10.1016/J.JAS.2010.06.030
Abstract: LA-ICP-MS analyses were performed on a set of Tuscan (post) medieval archaeological glass finds dated to the 1316th century in order to quantitatively determine the trace element contents. The results are used for defining and distinguishing several compositional groups. The trace element data are consistent with the distinctions obtained by considering the major element data determined via quantitative SEM-EDX, but allow to obtain new insights into the nature and quality of the silica sources employed and the presumed method of ash purification.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.602
Times cited: 38
DOI: 10.1016/J.JAS.2010.06.030
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“Study of medieval glass fragments from Savona (Italy) and their relation with the glass produced in Altare”. Cagno S, Badano MB, Mathis F, Strivay D, Janssens K, Journal of archaeological science 39, 2191 (2012). http://doi.org/10.1016/J.JAS.2012.03.013
Abstract: Altare was in the medieval and post-medieval period an important glassmaking center in the Liguria region in Northern Italy. The first historical evidence of glassmaking in Altare is dated to the twelfth century. In spite of that, due to the continuity of glassmaking up to the present time and the contemporaneous intensive urbanization of the territory, no medieval glass from Altare or its immediate vicinity has been analyzed up to now. In this work, glass from archaeological excavations in the center of Savona, city with close ties with the glassmaking center, was studied. Glass fragments, dated from the tenth to the sixteenth century were selected from the collections of the Archaeological Museum in Savona and non-destructively analyzed with quantitative PIXE-PIGE. The resulting compositions, compared with known glass productions of the same time and evaluated on the basis of historical documents, offer an interesting panorama on the variety of glass circulation in Liguria. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.602
Times cited: 21
DOI: 10.1016/J.JAS.2012.03.013
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“How do plasma-generated OH radicals react with biofilm components? Insights from atomic scale simulations”. Khosravian N, Bogaerts A, Huygh S, Yusupov M, Neyts EC, Biointerphases 10, 029501 (2015). http://doi.org/10.1116/1.4904339
Abstract: The application of nonthermal atmospheric pressure plasma is emerging as an alternative and efficient technique for the inactivation of bacterial biofilms. In this study, reactive molecular dynamics simulations were used to examine the reaction mechanisms of hydroxyl radicals, as key reactive oxygen plasma species in biological systems, with several organic molecules (i.e., alkane, alcohol, carboxylic acid, and amine), as prototypical components of biomolecules in the biofilm. Our results demonstrate that organic molecules containing hydroxyl and carboxyl groups may act as trapping agents for the OH radicals. Moreover, the impact of OH radicals on N-acetyl-glucosamine, as constituent component of staphylococcus epidermidis biofilms, was investigated. The results show how impacts of OH radicals lead to hydrogen abstraction and subsequent molecular damage. This study thus provides new data on the reaction mechanisms of plasma species, and particularly the OH radicals, with fundamental components of bacterial biofilms.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.603
Times cited: 10
DOI: 10.1116/1.4904339
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“Identification of the biologically active liquid chemistry induced by a nonthermal atmospheric pressure plasma jet”. Wende K, Williams P, Dalluge J, Van Gaens W, Aboubakr H, Bischof J, von Woedtke T, Goyal SM, Weltmann KD, Bogaerts A, Masur K, Bruggeman PJ;, Biointerphases 10, 029518 (2015). http://doi.org/10.1116/1.4919710
Abstract: The mechanism of interaction of cold nonequilibrium plasma jets with mammalian cells in physiologic liquid is reported. The major biological active species produced by an argon RF plasma jet responsible for cell viability reduction are analyzed by experimental results obtained through physical, biological, and chemical diagnostics. This is complemented with chemical kinetics modeling of the plasma source to assess the dominant reactive gas phase species. Different plasma chemistries are obtained by changing the feed gas composition of the cold argon based RF plasma jet from argon, humidified argon (0.27%), to argon/oxygen (1%) and argon/air (1%) at constant power. A minimal consensus physiologic liquid was used, providing isotonic and isohydric conditions and nutrients but is devoid of scavengers or serum constituents. While argon and humidified argon plasma led to the creation of hydrogen peroxide dominated action on the mammalian cells, argonoxygen and argonair plasma created a very different biological action and was characterized by trace amounts of hydrogen peroxide only. In particular, for the argonoxygen (1%), the authors observed a strong negative effect on mammalian cell proliferation and metabolism. This effect was distance dependent and showed a half life time of 30 min in a scavenger free physiologic buffer. Neither catalase and mannitol nor superoxide dismutase could rescue the cell proliferation rate. The strong distance dependency of the effect as well as the low water solubility rules out a major role for ozone and singlet oxygen but suggests a dominant role of atomic oxygen. Experimental results suggest that O reacts with chloride, yielding Cl2 − or ClO−. These chlorine species have a limited lifetime under physiologic conditions and therefore show a strong time dependent biological activity. The outcomes are compared with an argon MHz plasma jet (kinpen) to assess the differences between these (at least seemingly) similar plasma sources.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.603
Times cited: 137
DOI: 10.1116/1.4919710
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“Modeling of the plasma chemistry and plasmasurface interactions in reactive plasmas”. Bogaerts A, De Bie C, Eckert M, Georgieva V, Martens T, Neyts E, Tinck S, Pure and applied chemistry 82, 1283 (2010). http://doi.org/10.1351/PAC-CON-09-09-20
Abstract: In this paper, an overview is given of modeling activities going on in our research group, for describing the plasma chemistry and plasmasurface interactions in reactive plasmas. The plasma chemistry is calculated by a fluid approach or by hybrid Monte Carlo (MC)fluid modeling. An example of both is illustrated in the first part of the paper. The example of fluid modeling is given for a dielectric barrier discharge (DBD) in CH4/O2, to describe the partial oxidation of CH4 into value-added chemicals. The example of hybrid MCfluid modeling concerns an inductively coupled plasma (ICP) etch reactor in Ar/Cl2/O2, including also the description of the etch process. The second part of the paper deals with the treatment of plasmasurface interactions on the atomic level, with molecular dynamics (MD) simulations or a combination of MD and MC simulations.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.626
Times cited: 13
DOI: 10.1351/PAC-CON-09-09-20
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“Recent advances in analysis of trace elements in environmental samples by X-ray based techniques (IUPAC Technical Report)”. Terzano R, Denecke MA, Falkenberg G, Miller B, Paterson D, Janssens K, Pure and applied chemistry 91, 1029 (2019). http://doi.org/10.1515/PAC-2018-0605
Abstract: Trace elements analysis is a fundamental challenge in environmental sciences. Scientists measure trace elements in environmental media in order to assess the quality and safety of ecosystems and to quantify the burden of anthropogenic pollution. Among the available analytical techniques, X-ray based methods are particularly powerful, as they can quantify trace elements in situ. Chemical extraction is not required, as is the case for many other analytical techniques. In the last few years, the potential for X-ray techniques to be applied in the environmental sciences has dramatically increased due to developments in laboratory instruments and synchrotron radiation facilities with improved sensitivity and spatial resolution. In this report, we summarize the principles of the X-ray based analytical techniques most frequently employed to study trace elements in environmental samples. We report on the most recent developments in laboratory and synchrotron techniques, as well as advances in instrumentation, with a special attention on X-ray sources, detectors, and optics. Lastly, we inform readers on recent applications of X-ray based analysis to different environmental matrices, such as soil, sediments, waters, wastes, living organisms, geological samples, and atmospheric particulate, and we report examples of sample preparation.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.626
Times cited: 3
DOI: 10.1515/PAC-2018-0605
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“Enhanced biomedical heat-triggered carriers via nanomagnetism tuning in ferrite-based nanoparticles”. Angelakeris M, Li ZA, Hilgendorff M, Simeonidis K, Sakellari D, Filippousi M, Tian H, Van Tendeloo G, Spasova M, Acet M, Farle M, Journal of magnetism and magnetic materials 381, 179 (2015). http://doi.org/10.1016/j.jmmm.2014.12.069
Abstract: Biomedical nanomagnetic carriers are getting a higher impact in therapy and diagnosis schemes while their constraints and prerequisites are more and more successfully confronted. Such particles should possess a well-defined size with minimum agglomeration and they should be synthesized in a facile and reproducible high-yield way together with a controllable response to an applied static or dynamic field tailored for the specific application. Here, we attempt to enhance the heating efficiency in magnetic particle hyperthermia treatment through the proper adjustment of the core-shell morphology in ferrite particles, by controlling exchange and dipolar magnetic interactions at the nanoscale. Thus, core-shell nanoparticles with mutual coupling of magnetically hard (CoFe2O4) and soft (MnFe2O4) components are synthesized with facile synthetic controls resulting in uniform size and shell thickness as evidenced by high resolution transmission electron microscopy imaging, excellent crystallinity and size monodispersity. Such a magnetic coupling enables the fine tuning of magnetic anisotropy and magnetic interactions without sparing the good structural, chemical and colloidal stability. Consequently, the magnetic heating efficiency of CoFe2O4. and MnFe2O4 core-shell nanoparticles is distinctively different horn that of their counterparts, even though all these nanocrystals were synthesized under similar conditions. For better understanding of the AC magnetic hyperthermia response and its correlation with magnetic-origin features we study the effect of the volume ratio of magnetic hard and soft phases in the bimagnetic core-shell nanocrystals. Eventually, such particles may be considered as novel heating carriers that under further biomedical functionalization may become adaptable multifunctional heat-triggered nanoplatforms. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.63
Times cited: 20
DOI: 10.1016/j.jmmm.2014.12.069
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“Exciton trapping in a hybrid ferromagnetic/semiconductor magnetic antidot”. Freire JAK, Matulis A, Peeters FM, Freire VN, Farias GA, Journal of magnetism and magnetic materials 226/230, 2038 (2001). http://doi.org/10.1016/S0304-8853(00)01081-7
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.63
Times cited: 2
DOI: 10.1016/S0304-8853(00)01081-7
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“Ferromagnetism in stacked bilayers of Pd/C60”. Ghosh S, Tongay S, Hebard AF, Sahin H, Peeters FM, Journal of magnetism and magnetic materials 349, 128 (2014). http://doi.org/10.1016/j.jmmm.2013.07.024
Abstract: We provide experimental evidence for the existence of ferromagnetism in bilayers of Pd/C-60 which is supported by theoretical calculations based on density functional theory (DFT). The observed ferromagnetism is surprising as C-60 and Pd films are both non-ferromagnetic in the non-interacting limit. Magnetization (M) versus applied field (H) data acquired at different temperatures (T) show magnetic hysteresis with typical coercive fields (H-c) on the order of 50 Oe. From the temperature-dependent magnetization M(T) we extract a Curie temperature (T-c >= 550 K) using Bloch-like power law extrapolations to high temperatures. Using DFT calculations we investigated all plausible scenarios for the interaction between the C-60 molecules and the Pd slabs, Pd single atoms and Pd clusters. DFT shows that while the C-60 molecules are nonmagnetic, Pd films have a degenerate ground state that subject to a weak perturbation, can become ferromagnetic. Calculations also show that the interaction of C-60 molecules with excess Pd atoms and with sharp edges of a Pd slab is the most likely configuration that render the system ferromagnetic Interestingly, the calculated charge transfer (0.016 e per surface Pd atom, 0.064 e per Pd for intimate contact region) between C-60 and Pd does not appear to play an important role. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.63
Times cited: 8
DOI: 10.1016/j.jmmm.2013.07.024
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“Mechanisms of double magnetic exchange in dilute magnetic semiconductors”. Fleurov V, Kikoin K, Ivanov VA, Krstajic PM, Peeters FM, Journal of magnetism and magnetic materials
T2 –, International Conference on Magnetism (ICM 2003), JUL 27-AUG 01, 2003, Rome, ITALY 272, 1967 (2004). http://doi.org/10.1016/j.jmmm.2003.12.1067
Abstract: A microscopic Hamiltonian for interacting manganese impurities in dilute magnetic semiconductors (DMS) is derived. It is shown that in p-type III-V DMS, the indirect exchange between Mn impurities has similarities with the Zener mechanism in transition metal oxides. Here the mobile and localized holes near the top of the valence band play the role of unoccupied p-orbitals which induce ferromagnetism. T-C estimated from the proposed kinematic exchange agrees with experiments on (Ga,Mn)As. The model is also applicable to the p-doped (Ga,Mn)P system. The magnetic ordering in n-type (Ga,Mn)N is due to exchange between the electrons localized on the levels lying deep in the forbidden energy gap. This mechanism is even closer to the original Zener mechanism. (C) 2003 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.63
Times cited: 12
DOI: 10.1016/j.jmmm.2003.12.1067
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“On the nature of ferromagnetism in dilute magnetic semiconductors : GaAs:Mn and GaP:Mn”. Ivanov VA, Krstajic PM, Peeters FM, Fleurov V, Kikoin K, Journal of magnetism and magnetic materials
T2 –, 2nd Moscow International Symposium on Magnetism (MISM 2001), JUN 20-24, 2001, MOSCOW STATE UNIV, MOSCOW, RUSSIA 258, 237 (2003). http://doi.org/10.1016/S0304-8853(02)01023-5
Abstract: On the basis of a simplified Hamiltonian for transition metal impurities in diluted magnetic semiconductors (DMS), the nature of ferromagnetism in p-type III-V DMS are investigated. Ferromagnetism is governed by the Anderson-Hubbard parameter for 3d electrons of Mn2+ and their strong hybridization with the hole carriers in the semiconducting medium. The origin of ferromagnetism in these materials has similarity with the Zener mechanism. From the energetically preferable parallel orientation of Mn spins the Curie temperature is calculated for GaAs:Mn. (C) 2002 Published by Elsevier Science B.V.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.63
Times cited: 10
DOI: 10.1016/S0304-8853(02)01023-5
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“Relation between structure, charge ordering and magnetotransport properties in Nd0.5Ca0.5Mn1-xCrxO3 manganites”. Schuddinck W, Van Tendeloo G, Barnabé, A, Hervieu M, Raveau B, Journal of magnetism and magnetic materials
T2 –, Symposium G Material Physics Issues and Applications of Magnetic Oxides, at the E-MRS Spring Meeting, JUN 01-04, 1999, Strasbourg, France 211, 105 (2000). http://doi.org/10.1016/S0304-8853(99)00720-9
Abstract: The relationships between incommensurability, charge ordering and magnetotransport properties in Nd0.5Ca0.5Mn1-xCrxO3 manganites have been studied by electron diffraction and lattice imaging versus temperature with 0.02 less than or equal to x less than or equal to 0.07. All compositions show an incommensurate superstructure over the whole temperature domain, despite the fact that they are ferromagnetic and conductive below 140 K, The q-vector (1/2 – delta)a* decreases with increasing temperature for all compositions x. For a given temperature q also decreases with x. Lattice images obtained at low temperature give a clear view of the characteristics of the incommensurate structure. They also provide a better understanding of the charge ordering process. The low-temperature form of the Cr-doped manganites is not a perfectly doubled cell [[2a(p)root 2 x 2a(p) x a(p)root 2]], but defects inducing a tripled cell occur pseudo-periodically. (C) 2000 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.63
Times cited: 16
DOI: 10.1016/S0304-8853(99)00720-9
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“Buckled circular monolayer graphene : a graphene nano-bowl”. Neek-Amal M, Peeters FM, Journal of physics : condensed matter 23, 045002 (2011). http://doi.org/10.1088/0953-8984/23/4/045002
Abstract: We investigate the stability of circular monolayer graphene subjected to a radial load using non-equilibrium molecular dynamics simulations. When monolayer graphene is radially stressed, after some small circular strain (~0.4%) it buckles and bends into a new bowl-like shape. Young's modulus is calculated from the linear relation between stress and strain before the buckling threshold, which is in agreement with experimental results. The prediction of elasticity theory for the buckling threshold of a radially stressed plate is presented and its results are compared to the one of our atomistic simulation. The Jarzynski equality is used to estimate the difference between the free energy of the non-compressed states and the buckled states. From a calculation of the free energy we obtain the optimum radius for which the system feels the minimum boundary stress.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 27
DOI: 10.1088/0953-8984/23/4/045002
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