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“Electron microscopic and X-ray structural analysis of the layered crystals TaReSe4: structure, defect structure, and microstructure, including rotation twins”. Volkov VV, van Landuyt J, Amelinckx S, Pervov VS, Makhonina EV, Journal of solid state chemistry 135, 235 (1998). http://doi.org/10.1006/jssc.1997.7621
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.299
Times cited: 3
DOI: 10.1006/jssc.1997.7621
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“Electron microscopy of a family of hexagonal perovskites: one-dimensional structures related to Sr4Ni3O9”. Huvé, M, Renard C, Abraham F, Van Tendeloo G, Amelinckx S, Journal of solid state chemistry 135, 1 (1998). http://doi.org/10.1006/jssc.1997.7522
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.299
Times cited: 30
DOI: 10.1006/jssc.1997.7522
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“A generalized electrochemical aggregative growth mechanism”. Ustarroz J, Hammons JA, Altantzis T, Hubin A, Bals S, Terryn H, Journal of the American Chemical Society 135, 11550 (2013). http://doi.org/10.1021/ja402598k
Abstract: The early stages of nanocrystal nucleation and growth are still an active field of research and remain unrevealed. In this work, by the combination of aberration-corrected transmission electron microscopy (TEM) and electrochemical characterization of the electrodeposition of different metals, we provide a complete reformulation of the VolmerWeber 3D island growth mechanism, which has always been accepted to explain the early stages of metal electrodeposition and thin-film growth on low-energy substrates. We have developed a Generalized Electrochemical Aggregative Growth Mechanism which mimics the atomistic processes during the early stages of thin-film growth, by incorporating nanoclusters as building blocks. We discuss the influence of new processes such as nanocluster self-limiting growth, surface diffusion, aggregation, and coalescence on the growth mechanism and morphology of the resulting nanostructures. Self-limiting growth mechanisms hinder nanocluster growth and favor coalescence driven growth. The size of the primary nanoclusters is independent of the applied potential and deposition time. The balance between nucleation, nanocluster surface diffusion, and coalescence depends on the material and the overpotential, and influences strongly the morphology of the deposits. A small extent of coalescence leads to ultraporous dendritic structures, large surface coverage, and small particle size. Contrarily, full recrystallization leads to larger hemispherical monocrystalline islands and smaller particle density. The mechanism we propose represents a scientific breakthrough from the fundamental point of view and indicates that achieving the right balance between nucleation, self-limiting growth, cluster surface diffusion, and coalescence is essential and opens new, exciting possibilities to build up enhanced supported nanostructures using nanoclusters as building blocks.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 124
DOI: 10.1021/ja402598k
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“Preparation, structure, and electrochemistry of layered polyanionic hydroxysulfates : LiMSO4OH (M = Fe, Co, Mn) electrodes for Li-Ion batteries”. Subban CV, Ati M, Rousse G, Abakumov AM, Van Tendeloo G, Janot R, Tarascon J-M, Journal of the American Chemical Society 135, 3653 (2013). http://doi.org/10.1021/ja3125492
Abstract: The Li-ion rechargeable battery, due to its high energy density, has driven remarkable advances in portable electronics. Moving toward more sustainable electrodes could make this technology even more attractive to large-volume applications. We present here a new family of 3d-metal hydroxysulfates of general formula LiMSO4OH (M = Fe, Co, and Mn) among which (i) LiFeSO4OH reversibly releases 0.7 Li+ at an average potential of 3.6 V vs Li+/Li-0, slightly higher than the potential of currently lauded LiFePO4 (3.45 V) electrode material, and (ii) LiCoSO4OH shows a redox activity at 4.7 V vs Li+/Li-0. Besides, these compounds can be easily made at temperatures near 200 degrees C via a synthesis process that enlists a new intermediate phase of composition M-3(SO4)(2)(OH)(2) (M = Fe, Co, Mn, and Ni), related to the mineral caminite. Structurally, we found that LiFeSO4OH is a layered phase unlike the previously reported 3.2 V tavorite LiFeSO4OH. This work should provide an impetus to experimentalists for designing better electrolytes to fully tap the capacity of high-voltage Co-based hydroxysulfates, and to theorists for providing a means to predict the electrochemical redox activity of two polymorphs.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 53
DOI: 10.1021/ja3125492
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“Quantitative electron tomography : the effect of the three-dimensional point spread function”. Heidari H, van den Broek W, Bals S, Ultramicroscopy 135, 1 (2013). http://doi.org/10.1016/j.ultramic.2013.06.005
Abstract: The intensity levels in a three-dimensional (3D) reconstruction, obtained by electron tomography, can be influenced by several experimental imperfections. Such artifacts will hamper a quantitative interpretation of the results. In this paper, we will correct for artificial intensity variations by determining the 3D point spread function (PSF) of a tomographic reconstruction based on high angle annular dark field scanning transmission electron microscopy. The large tails of the PSF cause an underestimation of the intensity of smaller particles, which in turn hampers an accurate radius estimate. Here, the error introduced by the PSF is quantified and corrected a posteriori.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.843
Times cited: 6
DOI: 10.1016/j.ultramic.2013.06.005
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“An oxysulfate Fe2O(SO4)2 electrode for sustainable Li-based batteries”. Sun M, Rousse G, Abakumov AM, Van Tendeloo G, Sougrati M-T, Courty M, Doublet M-L, Tarascon J-M, Journal of the American Chemical Society 136, 12658 (2014). http://doi.org/10.1021/ja505268y
Abstract: High-performing Fe-based electrodes for Li-based batteries are eagerly pursued because of the abundance and environmental benignity of iron, with especially great interest in polyanionic compounds because of their flexibility in tuning the Fe3+/Fe2+ redox potential. We report herein the synthesis and structure of a new Fe-based oxysulfate phase, Fe2O(SO4)(2), made at low temperature from abundant elements, which electrochemically reacts with nearly 1.6 Li atoms at an average voltage of 3.0 V versus Li+/Li, leading to a sustained reversible capacity of similar to 125 mAh/g. The Li insertiondeinsertion process, the first ever reported in any oxysulfate, entails complex phase transformations associated with the position of iron within the FeO6 octahedra. This finding opens a new path worth exploring in the quest for new positive electrode materials.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 11
DOI: 10.1021/ja505268y
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“Creating arrays of electron vortices”. Niermann T, Verbeeck J, Lehmann M, Ultramicroscopy 136, 165 (2014). http://doi.org/10.1016/j.ultramic.2013.10.002
Abstract: We demonstrate the production of an ordered array of electron vortices making use of an electron optical setup consisting of two electrostatic biprisms. The biprism filaments are oriented nearly orthogonal with respect to each other in a transmission electron microscope. Matching the position of the filaments, we can choose to form different topological features in the electron wave. We outline the working principle of the setup and demonstrate fist experimental results. This setup partially bridges the gap between angular momentum carried by electron spin, which is intrinsic and therefore present in any position of the wave, and angular momentum carried by the vortex character of the wave, which can be extrinsic depending on the axis around which it is measured. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.843
Times cited: 9
DOI: 10.1016/j.ultramic.2013.10.002
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“Dynamic scattering theory for dark-field electron holography of 3D strain fields”. Lubk A, Javon E, Cherkashin N, Reboh S, Gatel C, Hytch M, Ultramicroscopy 136, 42 (2014). http://doi.org/10.1016/j.ultramic.2013.07.007
Abstract: Dark-held electron holography maps strain in crystal lattices into reconstructed phases over large fields of view. Here we investigate the details of the lattice strain-reconstructed phase relationship by applying dynamic scattering theory both analytically and numerically. We develop efficient analytic linear projection rules for 3D strain fields, facilitating a straight-forward calculation of reconstructed phases from 3D strained materials. They are used in the following to quantify the influence of various experimental parameters like strain magnitude, specimen thickness, excitation error and surface relaxation. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.843
Times cited: 18
DOI: 10.1016/j.ultramic.2013.07.007
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“Facile synthesis of Ba1-xKxFe2As2 superconductors via hydride route”. Zaikina JV, Batuk M, Abakumov AM, Navrotsky A, Kauziarich SM, Journal of the American Chemical Society 136, 16932 (2014). http://doi.org/10.1021/ja509907r
Abstract: We have developed a fast, easy, and scalable synthesis method for Ba1xKxFe2As2 (0 ≤ x ≤ 1) superconductors using hydrides BaH2 and KH as a source of barium and potassium metals. Synthesis from hydrides provides better mixing and easier handling of the starting materials, consequently leading to faster reactions and/or lower synthesis temperatures. The reducing atmosphere provided by the evolved hydrogen facilitates preparation of oxygen-free powders. By a combination of methods we have shown that Ba1xKxFe2As2 obtained via hydride route has the same characteristics as when it is prepared by traditional solid-state synthesis. Refinement from synchrotron powder X-ray diffraction data confirms a linear dependence of unit cell parameters upon K content as well as the tetragonal to orthorhombic transition at low temperatures for compositions with x < 0.2. Magnetic measurements revealed dome-like dependence of superconducting transition temperature Tc upon K content with a maximum of 38 K for x close to 0.4. Electron diffraction and high-resolution high-angle annular dark-field scanning transmission electron microscopy indicates an absence of Ba/K ordering, while local inhomogeneity in the Ba/K distribution takes place at a scale of several angstroms along [110] crystallographic direction.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 13
DOI: 10.1021/ja509907r
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“Is magnetic chiral dichroism feasible with electron vortices?”.Schattschneider P, Löffler S, Stöger-Pollach M, Verbeeck J, Ultramicroscopy 136, 81 (2014). http://doi.org/10.1016/j.ultramic.2013.07.012
Abstract: We discuss the feasibility of detecting magnetic transitions with focused electron vortex probes, suggested by selection rules for the magnetic quantum number. We theoretically estimate the dichroic signal strength in the L2,3 edge of ferromagnetic d metals. It is shown that under realistic conditions, the dichroic signal is undetectable for nanoparticles larger than View the MathML source. This is confirmed by a key experiment with nanometer-sized vortices.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.843
Times cited: 64
DOI: 10.1016/j.ultramic.2013.07.012
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“Core-shell-corona doxorubicin-loaded superparamagnetic Fe3O4 nanoparticles for cancer theranostics”. Semkina A, Abakumov M, Grinenko N, Abakumov A, Skorikov A, Mironova E, Davydova G, Majouga AG, Nukolova N, Kabanov A, Chekhonin V;, Colloids and surfaces: B : biointerfaces 136, 1073 (2015). http://doi.org/10.1016/j.colsurfb.2015.11.009
Abstract: Superparamagnetic iron oxide magnetic nanoparticles (MNPs) are successfully used as contrast agents in magnetic-resonance imaging. They can be easily functionalized for drug delivery functions, demonstrating great potential for both imaging and therapeutic applications. Here we developed new pH-responsive theranostic core-shell-corona nanoparticles consisting of superparamagentic Fe3O4 core that displays high T2 relaxivity, bovine serum albumin (BSA) shell that binds anticancer drug, doxorubicin (Dox) and poly(ethylene glycol) (PEG) corona that increases stability and biocompatibility. The nanoparticles were produced by adsorption of the BSA shell onto the Fe3O4 core followed by crosslinking of the protein layer and subsequent grafting of the PEG corona using monoamino-terminated PEG via carbodiimide chemistry. The hydrodynamic diameter, zeta-potential, composition and T2 relaxivity of the resulting nanoparticles were characterized using transmission electron microscopy, dynamic light scattering, thermogravimetric analysis and T2-relaxometry. Nanoparticles were shown to absorb Dox molecules, possibly through a combination of electrostatic and hydrophobic interactions. The loading capacity (LC) of the nanoparticles was 8 wt.%. The Dox loaded nanoparticles release the drug at a higher rate at pH 5.5 compared to pH 7.4 and display similar cytotoxicity against C6 and HEK293 cells as the free Dox. (C) 2015 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.887
Times cited: 37
DOI: 10.1016/j.colsurfb.2015.11.009
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“Using agro-environmental models to design a sustainable benchmark for the sustainable value method”. Merante P, Van Passel S, Pacini C, Agricultural Systems 136, 1 (2015). http://doi.org/10.1016/J.AGSY.2015.02.001
Abstract: Farms contribute heavily to overall sustainability. To date, various frameworks, approaches, methods and indicators have been developed to appraise how much corporations (firms, farms) contribute to sustainability. Among these, the Sustainable Value (SV) method helps to determine by which economic entity resources should be used in order to achieve the highest contributions to sustainability, by comparing company's efficiency of capital use against the efficiency of a benchmark. In this work we argue that the SV benchmark does not include certain crucial environmental concepts, such as the carrying capacity of an ecosystem or the multiple vital functions provided by ecosystem services. Thus, it is not a suitable reference for companies to evaluate their contribution to sustainability. As an alternative benchmark to standard SV applications, we propose a farm whose resource use productivity is correlated to the fulfilment of pre-determined environmental constraints: the Environmentally Sustainable Farm (ESF). To design this farm, we created an agro-environmental farm modelling framework that includes: (i) methods and approaches to assess indicators concerning specific environmental issues; (ii) an integrated ecological-economic model based on linear programming. This farm modelling framework is employed to determine both the environmental performance and the economic returns of two farming systems, conventional (CFS) and organic (OFS), which are compared using the Sustainable Value approach. Despite the fact that the OFS environmentally outperforms the CFS, none of them reaches the sustainable performances achieved by the ESF, both performing a negative Sustainable Value. The environmental constraints forced the ESF towards management choices that, although decreasing the economic performance, increase its environmental sustainability behaviour. Hence, the ESF is a viable benchmark that can be used to evaluate llllfarms' environmental sustainability. (C) 2015 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Economics; Engineering Management (ENM)
Impact Factor: 2.571
Times cited: 6
DOI: 10.1016/J.AGSY.2015.02.001
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“Increasing the cost-effectiveness of EU agri-environment policy measures through evaluation of farm and field-level environmental and economic performance”. Pacini GC, Merante P, Lazzerini G, Van Passel S, Agricultural Systems 136, 70 (2015). http://doi.org/10.1016/J.AGSY.2015.02.004
Abstract: A lot of attention in the debate on the 2014-2020 programming period of the EU CAP and rural development policy revolves around the policy's contribution to enhancing resource use efficiency, decreasing environmental impact, restoring ecosystems and how to ensure more efficient and effective agrienvironmental measures (AEMs). Nevertheless, studies that simultaneously address multiple measures with multiple environmental objectives and targets are underrepresented in the scientific literature. The objectives of the present article are (i) to present an integrated tool-kit for AEM design resulting from the combination of farm modelling with the Sustainable Value Approach (SVA), and (ii) to evaluate the potential of the tool-kit to support AEM design through an application to estimate cost-effective organic agriculture payments for the dairy sector in Mugello, northern Tuscany. Sustainability assessment of organic and conventional farming systems (OFS and CFS, respectively.) under the 2007-2013 EU CAP support schemes and a no EU support scenario show better OFS performances regarding nitrogen leaching (-52% and -47% under the current CAP and the no EU support scenarios, respectively), soil erosion (-24% and -34%), potential pesticide risks (-100%), biodiversity (+13% and +30%). Income foregone for the production of environmental benefits from organic agriculture under a no EU support scenario is equal to 210 Euro/ha. Sustainable value calculations combined with modelling results indicate soil erosion and nitrogen leaching as the environmental processes to be addressed with specific policy measures to further increase the efficiency of organic farming. A new organic agriculture support scheme designed based on such indications further increases the OFS SV and almost closes the GAP with a benchmark farm of the area, featured with ideal performances in terms of environmental and economic indicators. The payment scheme we designed with the support of the integrated tool-kit shows to be more cost-effective and efficient of current AEMs. (C) 2015 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Economics; Engineering Management (ENM)
Impact Factor: 2.571
Times cited: 12
DOI: 10.1016/J.AGSY.2015.02.004
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Oliveira MC, Yusupov M, Cordeiro RM, Bogaerts A (2021) Unraveling the permeation of reactive species across nitrated membranes by computer simulations. 104768
Abstract: Reactive oxygen and nitrogen species (RONS) are involved in many biochemical processes, including nitrooxidative stress that causes cancer cell death, observed in cancer therapies such as photodynamic therapy and cold atmospheric plasma. However, their mechanisms of action and selectivity still remain elusive due to the complexity of biological cells. For example, it is not well known how RONS generated by cancer therapies permeate the cell membrane to cause nitro-oxidative damage. There are many studies dedicated to the permeation of RONS across native and oxidized membranes, but not across nitrated membranes, another lipid product also generated during nitro-oxidative stress. Herein, we performed molecular dynamics (MD) simulations to calculate the free energy barrier of RONS permeation across nitrated membranes. Our results show that hydrophilic RONS, such as hydroperoxyl radical (HO2) and peroxynitrous acid (ONOOH), have relatively low barriers compared to hydrogen peroxide (H2O2) and hydroxyl radical (HO), and are more prone to permeate the membrane than for the native or peroxidized membranes, and similar to aldehyde-oxidized membranes. Hydrophobic RONS like molecular oxygen (O2), nitrogen dioxide (NO2) and nitric oxide (NO) even have insignificant barriers for permeation. Compared to native and peroxidized membranes, nitrated membranes are more permeable, suggesting that we must not only consider oxidized membranes during nitro-oxidative stress, but also nitrated membranes, and their role in cancer therapies.
Keywords: A1 Journal Article;Reactive oxygen and nitrogen species; Nitro-oxidative stress; Molecular dynamics simulations; Nitrated membranes; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 1.836
DOI: 10.1016/j.compbiomed.2021.104768
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“Evaluation of multi-element analysis of blood serum by energy-dispersive x-ray spectrometry”. Robberecht H, Van Grieken R, Shani J, Barak S, Analytica chimica acta 136, 285 (1982). http://doi.org/10.1016/S0003-2670(01)95388-7
Abstract: Conventional energy-dispersive x-ray fluorescence is applied in the analysis of blood serum to give the concentrations of 710 elements simultaneously with minimal manipulation of the samples. Simple spotting onto a Mylar carrier of 250 μl of serum, doped with two internal standards, was chosen as the sample preparation step. Some 200 serum samples, analyzed in replicate (n = 26), were used to evaluate this procedure. The detection limits are 4 μg ml-1 for K and Ca, 0.50.2 μg ml-1 for Fe, Cu, Pb and Zn, and less than 0.1 μg ml-1 for Se, Rb and Sr. Well above these limits, the standard deviation is around 10%. Comparison with the results of other measurements on the same samples indicates an accuracy of that order. The simplicity and high throughput, and the possibility of automating the x.r.f. measurements, make the proposed procedure suitable for screening large numbers of sera.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S0003-2670(01)95388-7
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“Dispersion in the wake of a rectangular building : validation of two Reynolds-averaged Navier-Stokes modelling approaches”. Gorlé, C, van Beeck J, Rambaud P, Boundary-layer meteorology 137, 115 (2010). http://doi.org/10.1007/s10546-010-9521-0
Abstract: When modelling the turbulent dispersion of a passive tracer using Reynolds-averaged Navier-Stokes (RANS) simulations, two different approaches can be used. The first consists of solving a transport equation for a scalar, where the governing parameters are the mean velocity field and the turbulent diffusion coefficient, given by the ratio of the turbulent viscosity and the turbulent Schmidt number Sc (t) . The second approach uses a Lagrangian particle tracking algorithm, where the governing parameters are the mean velocity and the fluctuating velocity field, which is determined from the turbulence kinetic energy and the Lagrangian time T (L) . A comparison between the two approaches and wind-tunnel data for the dispersion in the wake of a rectangular building immersed in a neutral atmospheric boundary layer (ABL) is presented. Particular attention was paid to the influence of turbulence model parameters on the flow and concentration field. In addition, an approach to estimate Sc (t) and T (L) based on the calculated flow field is proposed. The results show that applying modified turbulence model constants to enable correct modelling of the ABL improves the prediction for the velocity and concentration fields when the modification is restricted to the region for which it was derived. The difference between simulated and measured concentrations is smaller than 25% or the uncertainty of the data on 76% of the points when solving the transport equation for a scalar with the proposed formulation for Sc (t) , and on 69% of the points when using the Lagrangian particle tracking with the proposed formulation for T (L) .
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.573
Times cited: 16
DOI: 10.1007/s10546-010-9521-0
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“Quantitative composition determination at the atomic level using model-based high-angle annular dark field scanning transmission electron microscopy”. Martinez GT, Rosenauer A, de Backer A, Verbeeck J, Van Aert S, Ultramicroscopy 137, 12 (2014). http://doi.org/10.1016/j.ultramic.2013.11.001
Abstract: High angle annular dark field scanning transmission electron microscopy (HAADF STEM) images provide sample information which is sensitive to the chemical composition. The image intensities indeed scale with the mean atomic number Z. To some extent, chemically different atomic column types can therefore be visually distinguished. However, in order to quantify the atomic column composition with high accuracy and precision, model-based methods are necessary. Therefore, an empirical incoherent parametric imaging model can be used of which the unknown parameters are determined using statistical parameter estimation theory (Van Aert et al., 2009, [1]). In this paper, it will be shown how this method can be combined with frozen lattice multislice simulations in order to evolve from a relative toward an absolute quantification of the composition of single atomic columns with mixed atom types. Furthermore, the validity of the model assumptions are explored and discussed.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.843
Times cited: 74
DOI: 10.1016/j.ultramic.2013.11.001
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“Study and modeling of the Solid Electrolyte Interphase behavior on nano-silicon anodes by Electrochemical Impedance Spectroscopy”. Radvanyi E, Van Havenbergh K, Porcher W, Jouanneau S, Bridel J-S, Put S, Franger S, Electrochimica acta 137, 751 (2014). http://doi.org/10.1016/j.electacta.2014.06.069
Abstract: The instability of the Solid Electrolyte Interphase (SEI) at the surface of nano-silicon electrodes has been recognized as one of the key issues to explain the rapid capacity fading of theses electrodes. In this paper, two distinct Si-based systems are studied by using Electrochemical Impedance Spectroscopy (EIS). First, several EIS spectra are recorded along the second electrochemical cycle. Although the active material, the electrode formulation, and the experimental conditions are different for the two systems, the same phenomena are observed in both cases: (i) the SEI deposit around 50 kHz, (ii) the charge transfer (CT) with a characteristic frequency varying from 300 to 1 500 Hz, and (iii) an inductive loop at ∼1 Hz which appears only when the potential of the electrode is below 0.35 V vs Li. As the latter has never been reported for Si-based electrodes, the second step of the work consists in understanding this phenomenon. Thanks to the results obtained in a set of several complementary experiments, we finally attribute the inductive loop to the constant formation/deposition of SEI products, in competition with the CT process. In addition, we propose a mechanism for this specific phenomenon and the equivalent circuit to fit the recorded EIS spectra.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.798
Times cited: 36
DOI: 10.1016/j.electacta.2014.06.069
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“Understanding the roles of anionic redox and oxygen release during electrochemical cycling of lithium-rich layered Li4FeSbO6”. McCalla E, Sougrati MT, Rousse G, Berg EJ, Abakumov A, Recham N, Ramesha K, Sathiya M, Dominko R, Van Tendeloo G, Novák P, Tarascon JM;, Journal of the American Chemical Society 137, 4804 (2015). http://doi.org/10.1021/jacs.5b01424
Abstract: Li-rich oxides continue to be of immense interest as potential next generation Li-ion battery positive electrodes, and yet the role of oxygen during cycling is still poorly understood. Here, the complex electrochemical behavior of Li4FeSbO6 materials is studied thoroughly with a variety of methods. Herein, we show that oxygen release occurs at a distinct voltage plateau from the peroxo/superoxo formation making this material ideal for revealing new aspects of oxygen redox processes in Li-rich oxides. Moreover, we directly demonstrate the limited reversibility of the oxygenated species (O-2(n-); n = 1, 2, 3) for the first time. We also find that during charge to 4.2 V iron is oxidized from +3 to an unusual +4 state with the concomitant formation of oxygenated species. Upon further charge to 5.0 V, an oxygen release process associated with the reduction of iron +4 to +3 is present, indicative of the reductive coupling mechanism between oxygen and metals previously reported. Thus, in full state of charge, lithium removal is fully compensated by oxygen only, as the iron and antimony are both very close to their pristine states. Besides, this charging step results in complex phase transformations that are ultimately destructive to the crystallinity of the material. Such findings again demonstrate the vital importance of fully understanding the behavior of oxygen in such systems. The consequences of these new aspects of the electrochemical behavior of lithium-rich oxides are discussed in detail.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 86
DOI: 10.1021/jacs.5b01424
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“Mechanisms of elementary hydrogen ion-surface interactions during multilayer graphene etching at high surface temperature as a function of flux”. Aussems DUB, Bal KM, Morgan TW, van de Sanden MCM, Neyts EC, Carbon 137, 527 (2018). http://doi.org/10.1016/j.carbon.2018.05.051
Abstract: In order to optimize the plasma-synthesis and modification process of carbon nanomaterials for applications such as nanoelectronics and energy storage, a deeper understanding of fundamental hydrogengraphite/graphene interactions is required. Atomistic simulations by Molecular Dynamics have proven to be indispensable to illuminate these phenomena. However, severe time-scale limitations restrict them to very fast processes such as reflection, while slow thermal processes such as surface diffusion and molecular desorption are commonly inaccessible. In this work, we could however reach these thermal processes for the first time at time-scales and surface temperatures (1000 K) similar to high-flux plasma exposure experiments during the simulation of multilayer graphene etching by 5 eV H ions. This was achieved by applying the Collective Variable-Driven Hyperdynamics biasing technique, which extended the inter-impact time over a range of six orders of magnitude, down to a more realistic ion-flux of 1023m2s1. The results show that this not only causes a strong shift from predominant ion-to thermally induced interactions, but also significantly affects the hydrogen uptake and surface evolution. This study thus elucidates H ion-graphite/graphene interaction mechanisms and stresses the importance of including long time-scales in atomistic simulations at high surface temperatures to understand the dynamics of the ion-surface system.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 6.337
Times cited: 4
DOI: 10.1016/j.carbon.2018.05.051
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“Reducing winter peaks in electricity consumption: A choice experiment to structure demand response programs”. Srivastava A, Van Passel S, Kessels R, Valkering P, Laes E, Energy Policy 137, 111183 (2020). http://doi.org/10.1016/j.enpol.2019.111183
Abstract: Winter peaks in Belgian electricity demand are significantly higher than the summer peaks, creating a greater potential for imbalances between demand and supply. This potential is exacerbated because of the risk of outages in its ageing nuclear power plants, which are being phased out in the medium term. This paper conducts a choice experiment to investigate the acceptability of a load control-based demand response program in the winter months. It surveys 186 respondents on their willingness to accept limits on the use of home appliances in return for a compensation. Results indicate that respondents are most affected by the days of the week that their appliance usage would be curtailed, and by the compensation they would receive. The willingness to enroll in a program increases with age, environmental consciousness, home ownership, and lower privacy concerns. The analysis predicts that 95% of the sample surveyed could enroll in a daily load control program for a compen- sation of €41 per household per year. Thus while an initial rollout among older and more pro-environment homeowners could be successful, a wider implementation would require an explanation of its environmental and financial benefits to the population, and a greater consideration of their data privacy concerns.
Keywords: A1 Journal Article; Engineering Management (ENM) ;
Impact Factor: 9
DOI: 10.1016/j.enpol.2019.111183
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“Deeper insights into the photoluminescence properties and (photo)chemical reactivity of cadmium red (CdS1-xSex) paints in renowned twentieth century paintings by state-of-the-art investigations at multiple length scales”. Monico L, Rosi F, Vivani R, Cartechini L, Janssens K, Gauquelin N, Chezganov D, Verbeeck J, Cotte M, D'Acapito F, Barni L, Grazia C, Buemi LP, Andral J-L, Miliani C, Romani A, The European Physical Journal Plus 137, 311 (2022). http://doi.org/10.1140/EPJP/S13360-022-02447-7
Abstract: Cadmium red is the name used for denoting a class of twentieth century artists' pigments described by the general formula CdS1-xSex. For their vibrant hues and excellent covering power, a number of renowned modern and contemporary painters, including Jackson Pollock, often used cadmium reds. As direct band gap semiconductors, CdS1-xSex compounds undergo direct radiative recombination (with emissions from the green to orange region) and radiative deactivation from intragap trapping states due to crystal defects, which give rise to two peculiar red-NIR emissions, known as deep level emissions (DLEs). The positions of the DLEs mainly depend on the Se content of CdS1-xSex; thus, photoluminescence and diffuse reflectance vis-NIR spectroscopy have been profitably used for the non-invasive identification of different cadmium red varieties in artworks over the last decade. Systematic knowledge is however currently lacking on what are the parameters related to intrinsic crystal defects of CdS1-xSex and environmental factors influencing the spectral properties of DLEs as well as on the overall (photo)chemical reactivity of cadmium reds in paint matrixes. Here, we present the application of a novel multi-length scale and multi-method approach to deepen insights into the photoluminescence properties and (photo)chemical reactivity of cadmium reds in oil paintings by combining both well established and new non-invasive/non-destructive analytical techniques, including macro-scale vis-NIR and vibrational spectroscopies and micro-/nano-scale advanced electron microscopy mapping and X-ray methods employing synchrotron radiation and conventional sources. Macro-scale vis-NIR spectroscopy data obtained from the in situ non-invasive analysis of nine masterpieces by Gerardo Dottori, Jackson Pollock and Nicolas de Stael allowed classifying the CdS1-xSex-paints in three groups, according to the relative intensity of the two DLE bands. These outcomes, combined with results from micro-/nano-scale electron microscopy mapping and X-ray analysis of a set of CdS1-xSex powders and artificially aged paint mock-ups, indicated that the relative intensity of DLEs is not affected by the morphology, microstructure and local atomic environment of the pigment particles but it is influenced by the presence of moisture. Furthermore, the extensive study of artificially aged oil paint mock-ups permitted us to provide first evidence of the tendency of cadmium reds toward photo-degradation and to establish that the conversion of CdS1-xSex to CdSO4 and/or oxalates is triggered by the oil binding medium and moisture level and depends on the Se content. Based on these findings, we could interpret the localized presence of CdSO4 and cadmium oxalate as alteration products of the original cadmium red paints in two paintings by Pollock.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Antwerp X-ray Imaging and Spectroscopy (AXIS)
Impact Factor: 3.4
Times cited: 3
DOI: 10.1140/EPJP/S13360-022-02447-7
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“Rhodotorula kratochvilovae outperforms Cutaneotrichosporon oleaginosum in the valorisation of lignocellulosic wastewater to microbial oil”. Broos W, Wittner N, Dries J, Vlaeminck SE, Gunde-Cimerman N, Cornet I, Process biochemistry (1991) 137, 229 (2024). http://doi.org/10.1016/J.PROCBIO.2024.01.009
Abstract: Rhodotorula kratochvilovae has shown to be a promising species for microbial oil production from lignin-derived compounds. Yet, information on R. kratochvilovae’s detoxification and microbial oil production is scarce. This study investigated the growth and microbial oil production on the phenolic-containing effluent from poplar steam explosion and its detoxification with five R. kratochvilovae strains (EXF11626, EXF9590, EXF7516, EXF3697, EXF3471) and compared them with Cutaneotrichosporon oleaginosum. The R. kratochvilovae strains reached a maximum growth rate up to four times higher than C. oleaginosum. Furthermore, all R. kratochvilovae strains generally degraded phenolics more rapidly and to a larger extent than C. oleaginosum. However, the diluted substrate limited the lipid production by all strains as the maximum lipid content and titre were 10.5% CDW and 0.40 g/L, respectively. Therefore, future work should focus on increasing lipid production by using advanced fermentation strategies and stimulating the enzyme excretion by the yeasts for complex substrate breakdown.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL); Biochemical Wastewater Valorization & Engineering (BioWaVE)
Impact Factor: 4.4
DOI: 10.1016/J.PROCBIO.2024.01.009
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“Observation of temperature induced phase transitions in TiO superconducting thin film via infrared measurement”. Zhou S, Zhang C, Xu W, Zhang J, Xiao Y, Ding L, Wen H, Cheng X, Hu C, Li H, Li X, Peeters FM, Infrared physics and technology 137, 105160 (2024). http://doi.org/10.1016/J.INFRARED.2024.105160
Abstract: In contrast to conventional polycrystalline titanium oxide (TiO), it was found recently that the superconducting transition temperature Tc can be significantly enhanced from about 2 K to 7.4 K in cubic TiO thin films grown epitaxially on alpha-Al2O3 substrates. This kind of TiO film is also expected to have distinctive optoelectronic properties, which are still not very clear up to now. Herein, by using infrared (IR) reflection measurement we investigate the temperature-dependent optoelectronic response of a cubic TiO thin film, in which temperature induced phase transitions are observed. The semiconductor-, metallic- and semiconductor-like electronic phases of this superconducting film are found in the temperature regimes from 10 to 110 K, 110 to 220 K and above 220 K, respectively. The results obtained optically are consistent with those measured by transport experiment. Furthermore, based on an improved reflection model developed here, we extract the complex optical conductivity of the cubic TiO thin film. We are able to approximately determine the characteristic parameters (e.g., effective electron mass, carrier density, scattering time, etc.) for different electronic phases by fitting the optical conductivity with the modified Lorentz formula. These results not only deepen our understanding of the fundamental physics for cubic TiO thin films but also may find applications in optoelectronic devices based on superconductors.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.3
DOI: 10.1016/J.INFRARED.2024.105160
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“High-resolution electron microscopy and electron tomography: resolution versus precision”. Van Aert S, den Dekker AJ, van Dyck D, van den Bos A, Journal of structural biology 138, 21 (2002). http://doi.org/10.1016/S1047-8477(02)00016-3
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Impact Factor: 2.767
Times cited: 33
DOI: 10.1016/S1047-8477(02)00016-3
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“Synthesis and structural study of Pb2Re2O7-x pyrochlores”. Abakumov AM, Shpanchenko RV, Antipov EV, Kopnin EM, Capponi JJ, Marezio M, Lebedev OI, Van Tendeloo G, Amelinckx S, Journal of solid state chemistry 138, 220 (1998). http://doi.org/10.1006/jssc.1998.7778
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.299
Times cited: 5
DOI: 10.1006/jssc.1998.7778
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“Supracrystalline Colloidal Eggs: Epitaxial Growth and Freestanding Three-Dimensional Supracrystals in Nanoscaled Colloidosomes”. Yang Z, Altantzis T, Zanaga D, Bals S, Van Tendeloo G, Pileni M-P, Journal of the American Chemical Society 138, 3493 (2016). http://doi.org/10.1021/jacs.5b13235
Abstract: The concept of template-confined chemical reactions allows the synthesis of complex molecules that would hardly be producible through conventional method. This idea was developed to produce high quality nanocrystals more than 20 years ago. However, template-mediated assembly of colloidal nanocrystals is still at an elementary level, not only because of the limited templates suitable for colloidal assemblies, but also because of the poor control over the assembly of nanocrystals within a confined space. Here, we report the design of a new system called “supracrystalline colloidal eggs” formed by controlled assembly of nanocrystals into complex colloidal supracrystals through superlattice-matched epitaxial overgrowth along the existing colloidosomes. Then, with this concept, we extend the supracrystalline growth to lattice-mismatched binary nanocrystal superlattices, in order to reach anisotropic superlattice growths, yielding freestanding binary nanocrystal supracrystals that could not be produced previously.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 57
DOI: 10.1021/jacs.5b13235
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“Topochemical nitridation with anion vacancy -assisted N3-/O2- exchange”. Mikita R, Aharen T, Yamamoto T, Takeiri F, Ya T, Yoshimune W, Fujita K, Yoshida S, Tanaka K, Batuk D, Abakumov AM, Brown CM, Kobayashi Y, Kageyama H;, Journal of the American Chemical Society 138, 3211 (2016). http://doi.org/10.1021/jacs.6b00088
Abstract: We present how the introduction of anion vacancies in oxyhydrides enables a route to access new oxynitrides, by conducting ammonolysis of perovskite oxyhydride EuTiO3-xHx (x similar to 0.18). At 400 degrees C, similar to our studies on BaTiO3-xHx, hydride lability enables a low temperature direct ammonolysis of EUTi3.82+O-2.82/H-0.18, leading to the N3-/H--exchanged product EuTi4+O2.82No0.12 square 0.06 center dot When the ammonolysis temperature was increased up to 800 degrees C, we observed a further nitridation involving N3-/O2- exchange, yielding a fully oxidized Eu3+Ti4+O2N with the GdFeO3-type distortion (Pnma) as a metastable phase, instead of pyrochlore structure. Interestingly, the same reactions using the oxide EuTiO3 proceeded through a 1:1 exchange of N3- with O-2 only above 600 degrees C and resulted in incomplete nitridation to EuTi02.25N0.75, indicating that anion vacancies created during the initial nitridation process of EuTiO2.82H0.18 play a crucial role in promoting anion (N3-/O2-) exchange at high temperatures. Hence, by using (hydride-induced) anion-deficient precursors, we should be able to expand the accessible anion composition of perovskite oxynitrides.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 28
DOI: 10.1021/jacs.6b00088
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“Atomic Structure of Wurtzite CdSe (Core)/CdS (Giant Shell) Nanobullets Related to Epitaxy and Growth”. Bladt E, van Dijk-Moes RJA, Peters J, Montanarella F, de Mello Donega C, Vanmaekelbergh D, Bals S, Journal of the American Chemical Society 138, 14288 (2016). http://doi.org/10.1021/jacs.6b06443
Abstract: Hetero-nanocrystals consisting of a CdSe core and a giant CdS shell have shown remarkable optical properties which are promising for applications in opto-electrical devices. Since these properties sensitively depend on the size and shape, a morphological characterization is of high interest. Here, we present a High Angle Annular Dark Field Scanning Transmission Electron Microscopy (HAADF-STEM) study of CdSe (core) / CdS (giant shell) hetero-nanocrystals. Electron tomography reveals that the nanocrystals have a bullet shape, either ending in a tip or a small dip, and that the CdSe core is positioned closer to the tip (or dip) than to the hexagonal base. Based on a high resolution HAADF-STEM study, we were able to determine all the surface facets. We present a heuristic model for the different growth stages of the CdS crystal around the CdSe core.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 28
DOI: 10.1021/jacs.6b06443
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“Galvanic Replacement Coupled to Seeded Growth as a Route for Shape-Controlled Synthesis of Plasmonic Nanorattles”. Polavarapu L, Zanaga D, Altantzis T, Rodal-Cedeira S, Pastoriza-Santos I, Pérez-Juste J, Bals S, Liz-Marzán LM, Journal of the American Chemical Society 138, 11453 (2016). http://doi.org/10.1021/jacs.6b06706
Abstract: Shape-controlled synthesis of metal nanoparticles (NPs) requires mechanistic understanding toward the development of modern nanoscience and nanotechnology. We demonstrate here an unconventional shape transformation of Au@Ag core−shell NPs (nanorods and nanocubes) into octahedral nanorattles via roomtemperature galvanic replacement coupled with seeded growth. The corresponding morphological and chemical transformations were investigated in three dimensions, using state-of-the-art X-ray energy-dispersive spectroscopy (XEDS) tomography. The addition of a reducing agent (ascorbic acid) plays a key role in this unconventional mechanistic path, in which galvanic replacement is found to dominate initially when the shell is made of Ag, while seeded growth suppresses transmetalation when a composition of Au:Ag (∼60:40) is reached in the shell, as revealed by quantitative XEDS tomography. This work not only opens new avenues toward the shape control of hollow NPs beyond the morphology of sacrificial templates, but also expands our understanding of chemical transformations in nanoscale galvanic replacement reactions. The XEDS electron tomography study presented here can be generally applied to investigate a wide range of nanoscale morphological and chemical transformations.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 75
DOI: 10.1021/jacs.6b06706
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