“An overview of wet deposition of micropollutants to the North Sea”. Struyf H, Van Grieken R, Atmospheric environment: part A : general topics 27, 2669 (1993). http://doi.org/10.1016/0960-1686(93)90036-X
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0960-1686(93)90036-X
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“NO2 verkeersmetingen in Vlaanderen door passieve bemonstering”. Potgieter-Vermaak S, Stranger M, Verlinden L, Roekens E, Van Grieken R, Die Suid-Afrikaanse tydskrif vir natuurwetenskap en tegnologie 27, 266 (2008)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Water analysis by spark-source mass-spectrometry after preconcentration on activated carbon”. Vanderborght BM, Van Grieken RE, Talanta : the international journal of pure and applied analytical chemistry 27, 417 (1980). http://doi.org/10.1016/0039-9140(80)80225-6
Abstract: For trace analyses of environmental waters, spark-source mass-spectrometry has been combined with a preconcentration procedure involving chelation of the dissolved trace elements with oxine and subsequent adsorption of the oxinates and naturally occurring organic and colloidal metal species onto activated carbon. The activated carbon is filtered off and ashed at low temperature. The residue is dissolved, an internal standard and pure graphite are added and, after drying, the electrodes are prepared. The photographically recorded mass spectrum is evaluated by a suitable computer routine. The error of the procedure is around 30%. While this preconcentration and analysis procedure is capable of measuring about 40 elements quantitatively, in practice 1025 trace elements are determined simultaneously above the 0.1-μg/l. detection limit, as is illustrated by analyses of drinking water, surface and ground water samples. Although a sophisticated technique, SSMS can be considered for regular panoramic survey analyses.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0039-9140(80)80225-6
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“Deacetylation of mannosylerythritol lipids in hydrophobic natural deep eutectic solvents”. Cassimon J, Kovács A, Neyts E, Cornet I, Billen P, European journal of organic chemistry 27, e202300934 (2023). http://doi.org/10.1002/EJOC.202300934
Abstract: Mannosylerythritol lipids (MELs) are a promising group of biosurfactants due to their high fermentation yield, selfassembly and biological activity. During fermentation by Pseudozyma aphidis, a mixture of MELs with different levels of acylation is formed, of which the fully deacetylated form is the most valuable. In order to reduce the environmental impact of deacetylation, an enzymatic process using natural deep eutectic solvents (NADES) has been developed. We tested the deacetylation of a purified MELs mixture with immobilized Candida antarctica lipase B enzyme and 2-ethylhexanol as co-substrate in 140 h reactions with different NADES. We identified hydrophobic NADES systems with similar yields and kinetics as in pure 2-ethylhexanol solvent. Our results indicate that deacetylation of MELs mixtures in NADES as a solvent is possible with yields comparable to pure co-substrate and that hydrophobic NADES without carboxylic acid compounds facilitate the reaction to the greatest extent.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Biochemical Wastewater Valorization & Engineering (BioWaVE); Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)
Impact Factor: 2.8
DOI: 10.1002/EJOC.202300934
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“Angle-resolved synchrotron photoemission and density functional theory on the iridium modified Si(111) surface”. Oncel N, Çakir D, Dil JH, Slomski B, Landolt G, Journal of physics : condensed matter 26, 285501 (2014). http://doi.org/10.1088/0953-8984/26/28/285501
Abstract: The physical and electronic properties of the Ir modified Si(1 1 1) surface have been investigated with the help of angle resolved photoemission spectroscopy and density functional theory. The surface consists of Ir-ring clusters that form a root 7 x root 7 -R19.1 degrees reconstruction. A comparison between the measured and calculated band structure of the system reveals that the dispersions of the projected bulk states and the states originating from '1x1' domains are heavily modified due to Umklapp scattering from the surface Brillouin zone. Density of states calculations show that Ir-ring clusters contribute to the states in the vicinity of the Fermi level.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 4
DOI: 10.1088/0953-8984/26/28/285501
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“Controlling magnetic flux motion by arrays of zigzag-arranged magnetic bars”. Kapra AV, Misko VR, Peeters FM, Superconductor science and technology 26, 025011 (2013). http://doi.org/10.1088/0953-2048/26/2/025011
Abstract: Recent advances in manufacturing arrays of artificial pinning sites, i.e., antidots, blind holes and magnetic dots, allowed an effective control of magnetic flux in superconductors. An array of magnetic bars deposited on top of a superconducting film was shown to display different pinning regimes depending on the direction of the in-plane magnetization of the bars. Changing the sign of their magnetization results in changes in the induced magnetic pinning potentials. By numerically solving the time-dependent Ginzburg-Landau equations in a superconducting film with periodic arrays of zigzag-arranged magnetic bars, we revealed various flux dynamics regimes. In particular, we demonstrate flux pinning and flux flow, depending on the direction of the magnetization of the magnetic bars. Remarkably, the revealed different flux-motion regimes are associated with different mechanisms of vortex-antivortex dynamics. For example, we found that for an 'antiparallel' configuration of magnetic bars this dynamics involves a repeating vortex-antivortex generation and annihilation. We show that the depinning transition and the onset of flux flow can be manipulated by the magnetization of the bars and the geometry of the array. This provides an effective control of the depinning critical current that can be useful for possible fluxonics applications.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.878
Times cited: 5
DOI: 10.1088/0953-2048/26/2/025011
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“Crystal Structure and Luminescent Properties of R2-xEux(MoO4)(3) (R = Gd, Sm) Red Phosphors”. Morozov VA, Raskina MV, Lazoryak BI, Meert KW, Korthout K, Smet PF, Poelman D, Gauquelin N, Verbeeck J, Abakumov AM, Hadermann J;, Chemistry of materials 26, 7124 (2014). http://doi.org/10.1021/cm503720s
Abstract: The R-2(MoO4)(3) (R = rare earth elements) molybdates doped with Eu3+ cations are interesting red-emitting materials for display and solid-state lighting applications. The structure and luminescent properties of the R2-xEux(MoO4)(3) (R = Gd, Sm) solid solutions have been investigated as a function of chemical composition and preparation conditions. Monoclinic (alpha) and orthorhombic (beta') R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) modifications were prepared by solid-state reaction, and their structures were investigated using synchrotron powder X-ray diffraction and transmission electron microscopy. The pure orthorhombic beta'-phases could be synthesized only by quenching from high temperature to room temperature for Gd2-xEux(MoO4)(3) in the Eu3+-rich part (x > 1) and for all Sm2-xEux(MoO4)(3) solid solutions. The transformation from the alpha-phase to the beta'-phase results in a notable increase (similar to 24%) of the unit cell volume for all R2-xEux(MoO4)(3) (R = Sm, Gd) solid solutions. The luminescent properties of all R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) solid solutions were measured, and their optical properties were related to their structural properties. All R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) phosphors emit intense red light dominated by the D-5(0)-> F-7(2) transition at similar to 616 nm. However, a change in the multiplet splitting is observed when switching from the monoclinic to the orthorhombic structure, as a consequence of the change in coordination polyhedron of the luminescent ion from RO8 to RO7 for the alpha- and beta'-modification, respectively. The Gd2-xEux(MoO4)(3) solid solutions are the most efficient emitters in the range of 0 < x < 1.5, but their emission intensity is comparable to or even significantly lower than that of Sm2-xEux(MoO4)(3) for higher Eu3+ concentrations (1.5 <= x <= 1.75). Electron energy loss spectroscopy (EELS) measurements revealed the influence of the structure and element content on the number and positions of bands in the ultraviolet-visible-infrared regions of the EELS spectrum.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 24
DOI: 10.1021/cm503720s
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“The deviation from parallel shear flow as an indicator of linear eddy-viscosity model inaccuracy”. Gorlé, C, Larsson J, Emory M, Iaccarino G, Physics of fluids 26, 051702 (2014). http://doi.org/10.1063/1.4876577
Abstract: A marker function designed to indicate in which regions of a generic flow field the results from linear eddy-viscosity turbulence models are plausibly inaccurate is introduced. The marker is defined to identify regions that deviate from parallel shear flow. For two different flow fields it is shown that these regions largely coincide with regions where the prediction of the Reynolds stress divergence is inaccurate. The marker therefore offers a guideline for interpreting results obtained from Reynolds-averaged Navier-Stokes simulations and provides a basis for the further development of turbulence model-form uncertainty quantification methods. (C) 2014 AIP Publishing LLC.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.232
Times cited: 19
DOI: 10.1063/1.4876577
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“Electron microscopy and diffraction study of the composition dependency of the 3R microtwinned martensite in Ni-Al”. Schryvers D, de Saegher B, van Landuyt J, Materials research bulletin 26, 57 (1991)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.288
Times cited: 11
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“Electronic and optical properties of core-shell nanowires in a magnetic field”. Ravi Kishore VV, Partoens B, Peeters FM, Journal of physics : condensed matter 26, 095501 (2014). http://doi.org/10.1088/0953-8984/26/9/095501
Abstract: The electronic and optical properties of zincblende nanowires are investigated in the presence of a uniform magnetic field directed along the [001] growth direction within the k . p method. We focus our numerical study on core-shell nanowires consisting of the III-V materials GaAs, AlxGa1-xAs and AlyGa1-y/0.51In0.49P. Nanowires with electrons confined in the core exhibit a Fock-Darwin-like spectrum, whereas nanowires with electrons confined in the shell show Aharonov-Bohm oscillations. Thus, by properly choosing the core and the shell materials of the nanowire, the optical properties in a magnetic field can be tuned in very different ways.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 10
DOI: 10.1088/0953-8984/26/9/095501
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“Enhanced self-assembly of metal oxides and metal-organic frameworks from precursors with magnetohydrodynamically induced long-lived collective spin states”. Breynaert E, Emmerich J, Mustafa D, Bajpe SR, Altantzis T, Van Havenbergh K, Taulelle F, Bals S, Van Tendeloo G, Kirschhock CEA, Martens JA;, Advanced materials 26, 5173 (2014). http://doi.org/10.1002/adma.201400835
Abstract: Magneto-hydrodynamic generation of long-lived collective spin states and their impact on crystal morphology is demonstrated for three different, technologically relevant materials: COK-16 metal organic framework, manganese oxide nanotubes, and vanadium oxide nano-scrolls.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 19.791
Times cited: 7
DOI: 10.1002/adma.201400835
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“Exact broken-symmetry states and Hartree-Fock solutions for quantum dots at high magnetic fields”. Szafran B, Peeters FM, Bednarek S, Adamowski J, Physica. E: Low-dimensional systems and nanostructures
T2 –, 3rd International Conference on Quantum Dots (QD 2004), MAY 10-13, 2004, Max Bell Bldg Banff Ctr, Banff, Canada 26, 252 (2005). http://doi.org/10.1016/j.physe.2004.08.059
Abstract: Wigner molecules formed at high magnetic fields in circular and elliptic quantum dots are studied by exact diagonalization (ED) and unrestricted Hartree-Fock (UHF) methods with multicenter basis of displaced lowest Landau level wave functions. The broken symmetry states with semi-classical charge density constructed from superpositions of the ED solutions are compared to the UHF results. UHF overlooks the dependence of the few-electron wave functions on the actual relative positions of electrons localized in different charge puddles and partially compensates for this neglect by an exaggerated separation of charge islands which are more strongly localized than in the exact broken-symmetry states. (C) 2004 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 2.221
Times cited: 2
DOI: 10.1016/j.physe.2004.08.059
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“The extracellular matrix protein 1: its molecular interaction and implication in tumor progression”. Sercu S, Zhang L, Merregaert J, Cancer investigation 26, 375 (2008). http://doi.org/10.1080/07357900701788148
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.007
Times cited: 41
DOI: 10.1080/07357900701788148
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“Factors Influencing the Conductivity of Aqueous Sol(ution)-Gel-Processed Al-Doped ZnO Films”. Damm H, Adriaensens P, De Dobbelaere C, Capon B, Elen K, Drijkoningen J, Conings B, Manca JV, D’Haen J, Detavernier C, Magusin PCMM, Hadermann J, Hardy A, Van Bael MK;, Chemistry of materials 26, 5839 (2014). http://doi.org/10.1021/cm501820a
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 24
DOI: 10.1021/cm501820a
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“Global and local superconductivity in boron-doped granular diamond”. Zhang G, Turner S, Ekimov EA, Vanacken J, Timmermans M, Samuely T, Sidorov VA, Stishov SM, Lu Y, Deloof B, Goderis B, Van Tendeloo G, Van de Vondel J, Moshchalkov VV;, Advanced materials 26, 2034 (2014). http://doi.org/10.1002/adma.201304667
Abstract: Strong granularity-correlated and intragrain modulations of the superconducting order parameter are demonstrated in heavily boron-doped diamond situated not yet in the vicinity of the metal-insulator transition. These modulations at the superconducting state (SC) and at the global normal state (NS) above the resistive superconducting transition, reveal that local Cooper pairing sets in prior to the global phase coherence.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 19.791
Times cited: 34
DOI: 10.1002/adma.201304667
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“A hard oxide semiconductor with a direct and narrow bandgap and switchable pn electrical conduction”. Ovsyannikov SV, Karkin AE, Morozova NV, Shchennikov VV, Bykova E, Abakumov AM, Tsirlin AA, Glazyrin KV, Dubrovinsky L, Advanced materials 26, 8185 (2014). http://doi.org/10.1002/adma.201403304
Abstract: An oxide semiconductor (perovskite-type Mn2O3) is reported which has a narrow and direct bandgap of 0.45 eV and a high Vickers hardness of 15 GPa. All the known materials with similar electronic band structures (e.g., InSb, PbTe, PbSe, PbS, and InAs) play crucial roles in the semiconductor industry. The perovskite-type Mn2O3 described is much stronger than the above semiconductors and may find useful applications in different semiconductor devices, e.g., in IR detectors.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 19.791
Times cited: 27
DOI: 10.1002/adma.201403304
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“In-phase motion of Josephson vortices in stacked SNS Josephson junctions : effect of ordered pinning”. Berdiyorov GR, Savel'ev SE, Kusmartsev FV, Peeters FM, Superconductor science and technology 26, 125010 (2013). http://doi.org/10.1088/0953-2048/26/12/125010
Abstract: The dynamics of Josephson vortices (fluxons) in artificial stacks of superconducting-normal-superconducting Josephson junctions is investigated using the anisotropic time-dependent Ginzburg-Landau theory in the presence of a square/rectangular array of pinning centers (holes). For small values of the applied drive, fluxons in different junctions move out of phase, forming a periodic triangular lattice. A rectangular lattice of moving fluxons is observed at larger currents, which is in agreement with previous theoretical predictions (Koshelev and Aranson 2000 Phys. Rev. Lett. 85 3938). This 'superradiant' flux-flow state is found to be stable in a wide region of applied current. The stability range of this ordered state is considerably larger than the one obtained for the pinning-free sample. Clear commensurability features are observed in the current-voltage characteristics of the system with pronounced peaks in the critical current at (fractional) matching fields. The effect of density and strength of the pinning centers on the stability of the rectangular fluxon lattice is discussed. Predicted synchronized motion of fluxons in the presence of ordered pinning can be detected experimentally using the rf response of the system, where enhancement of the Shapiro-like steps is expected due to the synchronization.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.878
Times cited: 5
DOI: 10.1088/0953-2048/26/12/125010
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“Influence of strain on the Stark effect in InP/GaInP quantum discs”. Leoni P, Partoens B, Peeters FM, Physica. E: Low-dimensional systems and nanostructures 26, 312 (2005). http://doi.org/10.1016/j.physe.2004.08.069
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.221
Times cited: 1
DOI: 10.1016/j.physe.2004.08.069
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“Influence of the structure on the properties of NaxEuy(MoO4)z red phosphors”. Morozov VA, Lazoryak BI, Shmurak SZ, Kiselev AP, Lebedev OI, Gauquelin N, Verbeeck J, Hadermann J, Van Tendeloo G, Chemistry of materials 26, 3238 (2014). http://doi.org/10.1021/cm500966g
Abstract: Scheelite related compounds (A',A '')(n)[(B',B '')O-4](m) with B', B '' = W and/or Mo are promising new materials for red phosphors in pc-WLEDs (phosphor-converted white-light-emitting-diode) and solid-state lasers. Cation substitution in CaMoO4 of Ca2+ by the combination of Na+ and Eu3+, with the creation of A cation vacancies, has been investigated as a factor for controlling the scheelite-type structure and the luminescent properties. Na5Eu(MoO4)(4) and NaxEu(2-x)/33+square(2-x)/3MoO4 (0.138 <= x <= 0.5) phases with a scheelite-type structure were synthesized by the solid state method; their structural characteristics were investigated using transmission electron microscopy. Contrary to powder synchrotron X-ray diffraction before, the study by electron diffraction and high resolution transmission electron microscopy in this paper revealed that Na0.286Eu0.571MoO4 has a (3 + 2)D incommensurately modulated structure and that (3 + 2)D incommensurately modulated domains are present in Na0.200Eu0.600MoO4. It also confirmed the (3 + 1)D incommensurately modulated character of Na(0.138)Eu(0.621)Mo04. The luminescent properties of all phases under near-ultraviolet (n-UV) light have been investigated. The excitation spectra of these phosphors show the strongest absorption at about 395 nm, which matches well with the commercially available n-UV-emitting GaN-based LED chip. The emission spectra indicate an intense red emission due to the D-5(0) -> F-7(2) transition of Eu3+, with local minima in the intensity at Na0.286Eu0.571MoO4 and Na0.200Eu0.600MoO4 for similar to 613 nm and similar to 616 nm bands. The phosphor Na5Eu(MoO4)(4) shows the brightest red light emission among the phosphors in the Na2MoO4-Eu2/3MoO4 system and the maximum luminescence intensity of Na5Eu(MoO4)(4) (lambda(ex) = 395 nm) in the D-5(0) -> F-7(2) transition region is close to that of the commercially used red phosphor YVO4:Eu3+ (lambda(ex) = 326 nm). Electron energy loss spectroscopy measurements revealed the influence of the structure and Na/Eu cation distribution on the number and positions of bands in the UV-optical-infrared regions of the EELS spectrum.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 53
DOI: 10.1021/cm500966g
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“Interface-induced modulation of charge and polarization in thin film Fe3O4”. Tian H, Verbeeck J, Brück S, Paul M, Kufer D, Sing M, Claessen R, Van Tendeloo G, Advanced materials 26, 461 (2014). http://doi.org/10.1002/adma.201303329
Abstract: Charge and polarization modulations in Fe3O4 are controlled by taking advantage of interfacial strain effects. The feasibility of oxidation state control by strain modification is demonstrated and it is shown that this approach offers a stable configuration at room temperature. Direct evidence of how a local strain field changes the atomic coordination and introduces atomic displacements leading to polarization of Fe ions is presented.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 19.791
Times cited: 15
DOI: 10.1002/adma.201303329
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“Interlayer structure in YBCO-coated conductors prepared by chemical solution deposition”. Molina L, Egoavil R, Turner S, Thersleff T, Verbeeck J, Holzapfel B, Eibl O, Van Tendeloo G, Superconductor science and technology 26, 075016 (2013). http://doi.org/10.1088/0953-2048/26/7/075016
Abstract: The functionality of YBa2Cu3O7−δ (YBCO)-coated conductor technology depends on the reliability and microstructural properties of a given tape or wire architecture. Particularly, the interface to the metal tape is of interest since it determines the adhesion, mechanical stability of the film and thermal contact of the film to the substrate. A trifluoroacetate (TFA)metal organic deposition (MOD) prepared YBCO film deposited on a chemical solution-derived buffer layer architecture based on CeO2/La2Zr2O7 and grown on a flexible Ni5 at.%W substrate with a {100}⟨001⟩ biaxial texture was investigated. The YBCO film had a thickness was 440 nm and a jc of 1.02 MA cm−2 was determined at 77 K and zero external field. We present a sub-nanoscale analysis of a fully processed solution-derived YBCO-coated conductor by aberration-corrected scanning transmission electron microscopy (STEM) combined with electron energy-loss spectroscopy (EELS). For the first time, structural and chemical analysis of the valence has been carried out on the sub-nm scale. Intermixing of Ni, La, Ce, O and Ba takes place at these interfaces and gives rise to nanometer-sized interlayers which are a by-product of the sequential annealing process. Two distinct interfacial regions were analyzed in detail: (i) the YBCO/CeO2/La2Zr2O7 region (10 nm interlayer) and (ii) the La2Zr2O7/Ni5 at.%W substrate interface region (20 nm NiO). This is of particular significance for the functionality of these YBCO-coated conductor architectures grown by chemical solution deposition.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.878
Times cited: 11
DOI: 10.1088/0953-2048/26/7/075016
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“Multiband k\cdot p calculation of exciton diamagnetic shift in InP/InGaP self-assembled quantum dots”. Tadić, M, Mlinar V, Peeters FM, Physica. E: Low-dimensional systems and nanostructures
T2 –, 3rd International Conference on Quantum Dots (QD 2004), MAY 10-13, 2004, Max Bell Bldg Banff Ctr, Banff, Canada 26, 212 (2005). http://doi.org/10.1016/j.physe.2004.08.101
Abstract: Exciton states in self-assembled InP/In0.49Ga0.51P quantum dots subject to magnetic fields up to 50T are calculated. Strain and band mixing are explicitly taken into account in the single-particle models of the electronic structure, while an exact diagonalization approach is adopted to compute the exciton states. Reasonably good agreement with magneto-photoluminescence measurements on InP self-assembled quantum dots is found. As a result of the polarization and angular momentum sensitive selection rules, the exciton ground state is dark. For in-plane polarized light, the magnetic field barely affects the exciton spatial localization, and consequently the exciton oscillator strength for recombination increases only slightly with increasing field. For z polarized light, a sharp increase of the oscillator strength beyond 30 T is found which is attributed to the enhanced s character of the relevant portion of the exciton wave function. (C) 2004 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 2.221
Times cited: 4
DOI: 10.1016/j.physe.2004.08.101
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“Multiple twinning as a structure directing mechanism in layered rock-salt-type oxides : NaMnO2 polymorphism, redox potentials, and magnetism”. Abakumov AM, Tsirlin AA, Bakaimi I, Van Tendeloo G, Lappas A, Chemistry of materials 26, 3306 (2014). http://doi.org/10.1021/cm5011696
Abstract: New polymorphs of NaMnO2 have been observed using transmission electron microscopy and synchrotron X-ray powder diffraction. Coherent twin planes confined to the (NaMnO2) layers, parallel to the (10 (1) over bar) crystallographic planes of the monoclinic layered rock-salt-type alpha-NaMnO2 (O3) structure, form quasi-periodic modulated sequences, with the known alpha-and beta-NaMnO2 polymorphs as the two limiting cases. The energy difference between the polymorphic forms, estimated using a DFT-based structure relaxation, is on the scale of the typical thermal energies that results in a high degree of stacking disorder in these compounds. The results unveil the remarkable effect of the twin planes on both the magnetic and electrochemical properties. The polymorphism drives the magnetic ground state from a quasi-1D spin system for the geometrically frustrated alpha-polymorph through a two-leg spin ladder for the intermediate stacking sequence toward a quasi-2D magnet for the beta-polymorph. A substantial increase of the equilibrium potential for Na deintercalation upon increasing the concentration of the twin planes is calculated, providing a possibility to tune the electrochemical potential of the layered rock-salt ABO(2) cathodes by engineering the materials with a controlled concentration of twins.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 35
DOI: 10.1021/cm5011696
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“Nanoscale ordering in oxygen deficient quintuple perovskite Sm2-\epsilonBa3+\epsilonFe5O15-\delta : implication for magnetism and oxygen stoichiometry”. Volkova NE, Lebedev OI, Gavrilova LY, Turner S, Gauquelin N, Seikh MM, Caignaert V, Cherepanov VA, Raveau B, Van Tendeloo G, Chemistry of materials 26, 6303 (2014). http://doi.org/10.1021/cm503276p
Abstract: The investigation of the system SmBaFe-O in air has allowed an oxygen deficient perovskite Sm2-epsilon Ba3+epsilon Fe5O15-delta (delta = 0.75, epsilon = 0.125) to be synthesized. In contrast to the XRPD pattern which gives a cubic symmetry (a(p) = 3.934 angstrom), the combined HREM/EELS study shows that this phase is nanoscale ordered with a quintuple tetragonal cell, a(p) X a(p) X 5(ap). The nanodomains exhibit a unique stacking sequence of the A-site cationic layers along the crystallographic c-axis, namely SmBaBa/SmBa/SmBaSm, and are chemically twinned in the three crystallographic directions. The nanoscale ordering of this perovskite explains its peculiar magnetic properties on the basis of antiferromagnetic interactions with spin blockade at the boundary between the nanodomains. The variation of electrical conductivity and oxygen content of this oxide versus temperature suggest potential SOFC applications. They may be related to the particular distribution of oxygen vacancies in the lattice and to the 3d(5)(L) under bar configuration of iron.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 16
DOI: 10.1021/cm503276p
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“Nickel/carbon composite materials based on expanded graphite”. Afanasov IM, Lebedev OI, Kolozhvary BA, Smirnov AV, Van Tendeloo G, New carbon materials 26, 335 (2011). http://doi.org/10.1016/S1872-5805(11)60085-1
Abstract: Monolithic nickel/carbon (Ni/C) composites were prepared from coal tar pitch-impregnated compressed expanded graphite pre-decorated with NiO particles (EGNiO) by pyrolysis at 550 °C and subsequent steam activation at 800 °C. The microstructural arrangement of the Ni-comprising nanoparticles in the composites was investigated using transmission electron microscopy. The specific surface area and porosity of the composites were analyzed by nitrogen adsorption. The catalytic activity of the composites was compared with the material obtained by the conventional H2 treatment of EGNiO using hydrocracking of 2,2,3-trimethylpentane as a model reaction.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 7
DOI: 10.1016/S1872-5805(11)60085-1
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“Oscillating spin-orbit interaction as a source of spin-polarized wavepackets in two-terminal nanoscale devices”. Szaszko-Bogar V, Foeldi P, Peeters FM, Journal of physics : condensed matter 26, 135302 (2014). http://doi.org/10.1088/953-8984/26/13/135302
Abstract: Ballistic transport through nanoscale devices with time-dependent Rashba-type spin- orbit interaction (SOI) can lead to spin-polarized wavepackets that appear even for completely unpolarized input. The SOI that oscillates in a finite domain generates density and spin polarization fluctuations that leave the region as propagating waves. In particular, spin polarization has space and time dependence even in regions without SOI. Our results are based on an analytical solution of the time-dependent Schrodinger equation. The relevant Floquet quasi-energies that are obtained appear in the energy spectrum of both the transmitted and the reflected waves.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.649
DOI: 10.1088/953-8984/26/13/135302
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“Polaron effects on cyclotron mass due to interface and slab phonons in GaAs/AlGaAs quantum wells”. Hai G-Q, Studart N, Peeters FM, Brazilian journal of physics 26, 219 (1996)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 0.81
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“Probing the dynamic response of antivortex, interstitial and trapped vortex lattices on magnetic periodic pinning potentials”. Gomez A, Gonzalez EM, Gilbert DA, Milošević, MV, Liu K, Vicent JL, Superconductor science and technology 26, 085018 (2013). http://doi.org/10.1088/0953-2048/26/8/085018
Abstract: The dynamics of the pinned vortex, antivortex and interstitial vortex have been studied in superconducting/magnetic hybrids consisting of arrays of Co/Pd multilayer nanodots embedded in Nb films. The magnetic nanodots show out-of-plane magnetization at the remanent state. This magnetic state allows for superconducting vortex lattices of different types in an applied homogeneous magnetic field. We experimentally and theoretically show three such lattices: (i) a lattice containing only antivortices; (ii) a vortex lattice entirely pinned on the dots; and (iii) a vortex lattice with pinned and interstitial vortices. Between the flux creep (low vortex velocity) and the free flux flow (high vortex velocity) regimes the interaction between the magnetic array and the vortex lattice governs the vortex dynamics, which in turn enables distinguishing experimentally the type of vortex lattice which governs the dissipation. We show that the vortex lattice with interstitial vortices has the highest onset velocity where the lattice becomes ordered, whereas the pinned vortex lattice has the smallest onset velocity. Further, for this system, we directly estimate that the external force needed to depin vortices is 60% larger than the one needed to depin antivortices; therefore we are able to decouple the antivortex-vortex motion.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.878
Times cited: 7
DOI: 10.1088/0953-2048/26/8/085018
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“Reply to Comment on “Frustrated octahedral tilting distortion in the incommensurately modulated Li3xNd2/3-xTiO3 perovskites””. Abakumov AM, Erni R, Tsirlin AA, Chemistry of materials 26, 1288 (2014). http://doi.org/10.1021/cm500005d
Keywords: Editorial; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 1
DOI: 10.1021/cm500005d
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“The role of nanocluster aggregation, coalescence, and recrystallization in the electrochemical deposition of platinum nanostructures”. Ustarroz J, Altantzis T, Hammons JA, Hubin A, Bals S, Terryn H, Chemistry of materials 26, 2396 (2014). http://doi.org/10.1021/cm403178b
Abstract: By using an optimized characterization approach that combines aberration-corrected transmission electron microscopy, electron tomography, and in situ ultrasmall angle X-ray scattering (USAXS), we show that the early stages of Pt electrochemical growth on carbon substrates may be affected by the aggregation, self-alignment, and partial coalescence of nanoclusters of d ≈ 2 nm. The morphology of the resulting nanostructures depends on the degree of coalescence and recrystallization of nanocluster aggregates, which in turn depends on the electrodeposition potential. At low overpotentials, a self-limiting growth mechanism may block the epitaxial growth of primary nanoclusters and results in loose dendritic aggregates. At more negative potentials, the extent of nanocluster coalescence and recrystallization is larger and further growth by atomic incorporation may be allowed. On one hand, this suggests a revision of the VolmerWeber island growth mechanism. Whereas this theory has traditionally assumed direct attachment as the only growth mechanism, it is suggested that nanocluster self-limiting growth, aggregation, and coalescence should also be taken into account during the early stages of nanoscale electrodeposition. On the other hand, depending on the deposition potential, ultrahigh porosities can be achieved, turning electrodeposition in an ideal process for highly active electrocatalyst production without the need of using high surface area carbon supports.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 55
DOI: 10.1021/cm403178b
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