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“Hydrogen-induced high-temperature superconductivity in two-dimensional materials : the example of hydrogenated monolayer MgB2”. Bekaert J, Petrov M, Aperis A, Oppeneer PM, Milošević, MV, Physical review letters 123, 077001 (2019). http://doi.org/10.1103/PHYSREVLETT.123.077001
Abstract: Hydrogen-based compounds under ultrahigh pressure, such as the polyhydrides H3S and LaH10, superconduct through the conventional electron-phonon coupling mechanism to attain the record critical temperatures known to date. Here we exploit the intrinsic advantages of hydrogen to strongly enhance phonon-mediated superconductivity in a completely different system, namely, a two-dimensional material with hydrogen adatoms. We find that van Hove singularities in the electronic structure, originating from atomiclike hydrogen states, lead to a strong increase of the electronic density of states at the Fermi level, and thus of the electron-phonon coupling. Additionally, the emergence of high-frequency hydrogen-related phonon modes in this system boosts the electron-phonon coupling further. As a concrete example, we demonstrate the effect of hydrogen adatoms on the superconducting properties of monolayer MgB2, by solving the fully anisotropic Eliashberg equations, in conjunction with a first-principles description of the electronic and vibrational states, and their coupling. We show that hydrogenation leads to a high critical temperature of 67 K, which can be boosted to over 100 K by biaxial tensile strain.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 8.462
Times cited: 42
DOI: 10.1103/PHYSREVLETT.123.077001
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“Nanocrystalline ZnO(Ga) : paramagnetic centers, surface acidity and gas sensor properties”. Vorobyeva N, Rumyantseva M, Filatova D, Konstantinova E, Grishina D, Abakumov A, Turner S, Gaskov A, Sensors and actuators : B : chemical 182, 555 (2013). http://doi.org/10.1016/j.snb.2013.03.068
Abstract: Nanocrystalline ZnO and ZnO(Ga) samples with different gallium content were prepared by wet-chemical method. Introduction of gallium leads to the increase of amount of weak acid sites such as surface hydroxyl groups. Gas sensing properties toward 0.22 ppm H2S and NO2 were studied at 100450 °C by DC conductance measurements. The optimal temperature for gas sensing experiments was determined. Sensor signal toward H2S decreases with increase of Ga concentration. The dependence of ZnO(Ga) sensor signal to NO2 on the gallium content has non-monotonous character, which correlates with the change of conductivity of the samples in air and concentration of paramagnetic donor states.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.401
Times cited: 42
DOI: 10.1016/j.snb.2013.03.068
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“Structure and microstructure of nanoscale mesoporous silica spheres”. Lebedev OI, Van Tendeloo G, Collart O, Cool P, Vansant EF, Solid state sciences 6, 489 (2004). http://doi.org/10.1016/j.solidstatesciences.2004.01.013
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Impact Factor: 1.811
Times cited: 42
DOI: 10.1016/j.solidstatesciences.2004.01.013
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“Calculation of crater profiles on a flat cathode in a direct current glow discharge, and comparison with experiment”. Bogaerts A, Gijbels R, Spectrochimica acta: part B : atomic spectroscopy 52, 765 (1997)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.241
Times cited: 42
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“Spatial monitoring of organohalogen compounds in surface water and sediments of a rural-urban river basin in Tanzania”. Hellar-Kihampa H, De Wael K, Lugwisha E, Govindan M, Covaci A, Van Grieken R, The science of the total environment 447, 186 (2013). http://doi.org/10.1016/J.SCITOTENV.2012.12.083
Abstract: The presence of persistent organic pollutants in Tanzanian environment is not well monitored despite the existing pollution potential from a number of sources. In this study, we investigated for the first time, the concentration profiles of different organohalogen compounds such as organochlorine pesticide residues (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in environmental samples (water and sediments) from the Pangani river basin (PRB). The PRB is one of the largest drainage basins in Tanzania, with its watershed exposed to multiple input sources of trace organic contaminants. Surface water and sediments were sampled from 12 representative stations of diverse characteristics and land-use practices, in three distinct seasons, and extracted by liquidliquid and Soxhlet extraction methods, respectively. Water samples were analyzed by GC-ECD for OCPs only, while sediment samples were analyzed for OCPs, PCBs and PBDEs by GC/MS. Seven compounds, dominated by HCH isomers (5104460 pg/L) and DDT analogs (1601460 pg/L),were detected in the water samples. These concentrations are far below the WHO guidelines for drinking water quality. A total of 42 compounds (8 OCPs, 28 PCB congeners and 6 PBDE congeners) were detected in the sediment samples. Their respective total concentration ranges were 24510,230; 35711,000 and 382175 pg/g dry weight. The spatial distribution patterns and Hierarchical Cluster Analysis reflected the impact of historical agricultural usage in sugarcane plantations (OCPs), and urbanization (PCBs and PBDEs). Risk assessment using sediment quality guidelines indicated no ecotoxicological risks. The results we have found provide preliminary data on levels of the organic contaminants in Pangani river basin as a new insight on the environmental quality of the area.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre
Impact Factor: 4.9
Times cited: 42
DOI: 10.1016/J.SCITOTENV.2012.12.083
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“The properties of SIRT, TVM, and DART for 3D imaging of tubular domains in nanocomposite thin-films and sections”. Chen D, Goris B, Bleichrodt F, Heidari Mezerji H, Bals S, Batenburg KJ, de With G, Friedrich H, Ultramicroscopy 147, 137 (2014). http://doi.org/10.1016/j.ultramic.2014.08.005
Abstract: In electron tomography, the fidelity of the 3D reconstruction strongly depends on the employed reconstruction algorithm. In this paper, the properties of SIRT, TVM and DART reconstructions are studied with respect to having only a limited number of electrons available for imaging and applying different angular sampling schemes. A well-defined realistic model is generated, which consists of tubular domains within a matrix having slab-geometry. Subsequently, the electron tomography workflow is simulated from calculated tilt-series over experimental effects to reconstruction. In comparison with the model, the fidelity of each reconstruction method is evaluated qualitatively and quantitatively based on global and local edge profiles and resolvable distance between particles. Results show that the performance of all reconstruction methods declines with the total electron dose. Overall, SIRT algorithm is the most stable method and insensitive to changes in angular sampling. TVM algorithm yields significantly sharper edges in the reconstruction, but the edge positions are strongly influenced by the tilt scheme and the tubular objects become thinned. The DART algorithm markedly suppresses the elongation artifacts along the beam direction and moreover segments the reconstruction which can be considered a significant advantage for quantification. Finally, no advantage of TVM and DART to deal better with fewer projections was observed.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.843
Times cited: 42
DOI: 10.1016/j.ultramic.2014.08.005
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