“Exciton states and magnetooptical transitions in stacks of InGaAs/GaAs self-assembled quantum rings”. Tadić, M, Peeters FM, AIP conference proceedings 893, 851 (2007)
Abstract: Electron, hole, and exciton states in the stacks composed of three strained (InGa)As quantum rings were computed. We found considerable influence of strain on both the single particle and exciton spectra, while the oscillator strength for exciton recombination is reduced by the magnetic field.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
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“First-principles calculations of 002 structure factors for electron scattering in strained InxGa1-xAs”. Rosenauer A, Schowalter M, Glas F, Lamoen D, 107, 151 (2005)
Keywords: A1 Journal article; Electron Microscopy for Materials Science (EMAT);
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“Free-standing Si and Ge, and Ge/Si core-shell semiconductor nanowires”. Peelaers H, Partoens B, Peeters FM, Acta physica Polonica: A: general physics, solid state physics, applied physics
T2 –, WELCOME Scientific Meeting on Hybrid Nanostructures, AUG 28-31, 2011, Torun, POLAND 122, 294 (2012)
Abstract: The properties of free-standing silicon and germanium nanowires oriented along the [110] direction are studied using different first principles methods. We show the corrections due to quasi-particles to the band structures obtained using the local-density approximation. The formation energies of B and P doped nanowires are calculated, both in the absence and presence of dangling bond defects and we link these to experimental results. Furthermore, we report on the phonon properties of pure Si and Ge nanowires, as well as Ge/Si core-shell nanowires, and discuss the differences between them.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 0.469
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“From the lattice measurements of the austenite and the martensite cells to the macroscopic mechanical behavior of shape memory alloys”. Lexcellent C, Vivet A, Bouvet C, Blanc P, Satto C, Schryvers D, Journal de physique: 4 11, 317 (2001)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“HREM investigation of a Fe/GaN/Fe tunnel junction”. Nistor L, Bender H, van Landuyt J, Nemeth S, Boeve H, De Boeck J, Borghs G, Institute of physics conference series
T2 –, Royal-Microscopical-Society Conference on Microscopy of Semiconducting, Materials, MAR 25-29, 2001, Univ of Oxford, Oxford, England , 53 (2001)
Abstract: The structure of Fe/GaN/Fe ferromagnetic electrodes is studied by high resolution transmission electron microscopy. The layers grow epitaxially on the GaAs substrate with the top Fe layer 90degrees rotated compared to the bottom one. The interfaces are quite rough. There is an indication of the possible occurrence of Fe3GaAs formation on the GaAs interface.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“The influence of crystal thickness on the image tone”. van Renterghem W, Schryvers D, van Landuyt J, van Roost C, de Keyzer R, Journal of imaging science 47, 133 (2003)
Abstract: It is known that the neutral image tone of a developed photographic film becomes brownish when the thickness of the original silver halide tabular crystals is reduced. We investigate by electron microscopy to what extent the silver filament structure has changed and how it induces the shift in image tone. Therefore, two samples of AgBr {111} tabular crystals with average thicknesses of 160 nm and 90 nm respectively, are compared. It is shown that the dimensions and defect structure of the filaments are comparable, but that the 90 nm crystals result in a more widely spaced structure, which explains the shift in image tone on a qualitative level. The influence of the addition of an image toner, i.e., phenylmercaptotetrazole, on the filament structure is also investigated. An even more open filament structure of longer, but smaller filaments was observed.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 0.348
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“Influence of surface defects on the vortex transitions in mesoscopic superconductors”. Baelus BJ, Kadowaki K, Peeters FM, AIP conference proceedings 850, 745 (2006)
Abstract: Solving the nonlinear Ginzburg-Landau equations self-consistently, we investigate the influence of a triangular surface defect (i.e. pacman shaped sample) on the vortex transitions in mesoscopic superconducting disks. Depending on the size of the defect, vortices may enter/leave one by one or in pairs.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
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“Influence of twinning on the morphology of AgBr and AgCl microcrystals”. van Renterghem W, Goessens C, Schryvers D, van Landuyt J, Bollen D, de Keyzer R, van Roost C, The journal of imaging science and technology 45, 349 (2001)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.348
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“Interband optical properties of concentric type-I nanorings in a normal magnetic field”. Arsoski V, Tadić, M, Peeters FM, Acta physica Polonica: A: general physics, solid state physics, applied physics 117, 733 (2010)
Abstract: Two concentric two-dimensional GaAs/(Al,Ga)As nanorings in a normal magnetic field are theoretically studied. The single-band effective mass approximation is adopted for both the electron and the hole states, and the analytical solutions are given. We find that the electronic single particle states are arranged in pairs, which exhibit anticrossings and the orbital momentum transitions in the energy spectrum when magnetic field increases. Their period is essentially determined by the radius of the outer ring. The oscillator strength for interband transitions is strongly reduced close to each anticrossing. We show that an optical excitonic Aharonov-Bohm effect may occur in concentric nanorings.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 0.469
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“Intersublevel absorption in stacked n-type doped self-assembled quantum dots”. Veljkovic D, Tadić, M, Peeters FM, Materials science forum 494, 37 (2005)
Abstract: The intersublevel absorption in n-doped InAs/GaAs self-assembled quantum-dot molecules composed of three quantum dots is theoretically considered. The transition matrix elements and the transition energies are found to vary considerably with the spacer thickness. For s polarized light, decreasing the thickness of the spacer between the dots brings about crossings between the transition matrix elements, but the overall absorption is not affected by the variation of the spacer thickness. For p-polarized light and thick spacers, there are no available transitions in the single quantum dot, but a few of them emerge as a result of the electron state splitting in the stacks of coupled quantum dots, which leads to a considerable increase of the transition matrix elements, exceeding by an order of magnitude values of the matrix elements for s-polarized light.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
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“Magnetoexcitons in type-II self-assembled quantum dots and quantum-dot superlattices”. Veljkovic D, Tadić, M, Peeters FM, Recent developments in advanced materials and processes 518, 51 (2006)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
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“Measurement of the mean inner potential of ZnO nanorods by transmission electron holography”. Müller E, Kruse P, Gerthsen D, Schowalter M, Rosenauer A, Lamoen D, Kling R, Microscopy of Semiconducting Materials 107SPRINGER PROCEEDINGS IN PHYSICS, 303 (2005)
Keywords: A1 Journal article; Electron Microscopy for Materials Science (EMAT)
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“Mercator maps of orientations of a C60 molecule in single-walled nanotubes with distinct radii”. Michel KH, Verberck B, Nikolaev A, AIP conference proceedings 786, 69 (2005)
Abstract: We study the confinement of a C-60 molecule encapsulated in a cylindrical nanotube as a function of the tube radius. Drawing the Mercator maps of the potential, we find two distinct molecular orientations; for tubes with small radii, R-T less than or similar to 7 angstrom, a fivefold axis of the molecule coincides with the tube long axis, for larger radii, R-T less than or similar to 8 angstrom, a threefold axis of the molecule coincides with the tube long axis. These different orientations are caused by the relative importance of the repulsive and the attractive parts of the van der Waals potentials of the molecule with the tube wall for small and large tubes respectively. Experimental evidence is provided by the apparent splitting of A(g) modes of the C-60 molecule in resonant Raman scattering.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
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“Microstructural mechanism of development in photothermographic materials”. Potapov PL, Schryvers D, Strijckers H, van Roost C, The journal of imaging science and technology 47, 115 (2003)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.348
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“A microstructural study of the thermal stability of atomic layer deposited Al2O3 thin films”. Nistor LC, Richard O, Zhao O, Bender H, Stesmans A, Van Tendeloo G, Institute of physics conference series
T2 –, Microscopy of semiconducting materials , 397 (2003)
Abstract: The thermal stability of amorphous Al2O3 films (similar to8 and 80 nut thick) deposited by atomic layer deposition on HF-last and thin SiO2 covered (001) Si substrates is studied by transmission electron microscopy. The layers are in- and ex-situ annealed in the same temperature range.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“Modeling of magnetron and glow discharges”. Bogaerts A, Kolev I, Le vide: science, technique et applications 57, 296 (2002)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
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“Molecular dynamics simulation of temperature effects on CF(3)(+) etching of Si surface”. Jian-Ping N, Xiao-Dan L, Cheng-Li Z, You-Min Q, Ping-Ni H, Bogaerts A, Fu-Jun G, Wuli xuebao 59, 7225 (2010)
Abstract: Molecular dynamics method was employed to investigate the effects of the reaction layer formed near the surface region on CF(3)(+) etching of Si at different temperatures. The simulation results show that the coverages of F and C are sensitive to the surface temperature. With increasing temperature, the physical etching is enhanced, while the chemical etching is weakened. It is found that with increasing surface temperature, the etching rate of Si increases. As to the etching products, the yields of SiF and SiF(2) increase with temperature, whereas the yield of SiF(3) is not sensitive to the surface temperature. And the increase of the etching yield is mainly due to the increased desorption of SiF and SiF(2). The comparison shows that the reactive layer plays an important part in the subsequeat impacting, which enhances the etching rate of Si and weakens the chemical etching intensity.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 0.624
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“Nanoscale morphology of a piece of ruby red Kunckel glass”. Fredrickx P, Schryvers D, Janssens K, Physics and chemistry of glasses 43, 176 (2002)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Natural mineral-marine manganese nodule as a novel catalyst for the synthesis of carbon nanotubes”. Cheng JP, Zhang XB, Ye Y, Tao XY, Liu F, Li Y, Van Tendeloo G, Journal of Wuhan University of Technology: materials science edition 21, 29 (2006)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“Novel commensurability effects in superconducting films with antidot arrays”. Berdiyorov GR, Milošević, MV, Peeters FM, Physical review letters 96, 1 (2006)
Abstract: http://dx.doi.org/doi:10.1103/PhysRevLett.96.207001
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 8.462
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“Numerical study of the size-dependent melting mechanisms of nickel nanoclusters”. Neyts EC, Bogaerts A, The journal of physical chemistry: C : nanomaterials and interfaces 113, 2771 (2009)
Abstract: Molecular dynamics simulations were used to investigate the size-dependent melting mechanism of nickel nanoclusters of various sizes. The melting process was monitored by the caloric curve, the overall cluster Lindemann index, and the atomic Lindemann index. Size-dependent melting temperatures were determined, and the correct linear dependence on inverse diameter was recovered. We found that the melting mechanism gradually changes from dynamic coexistence melting to surface melting with increasing cluster size. These findings are of importance in better understanding carbon nanotube growth by catalytic chemical vapor deposition as the phase state of the catalyst nanoparticle codetermines the growth mechanism.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.536
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“Observations of intermetallic compound formation of hot dip aluminized steel”. Kee-Hyun K, van Daele B, Van Tendeloo G, Jong-Kyu Y, Aluminium alloys: part 1-2 519-521, 1871 (2006)
Abstract: A hot dip aluminizing process to simulate the continuous galvanizing line (CGL) was carried out in three successive steps by a hot dip simulator: the pre-treatment for removing scales on the 200 x 250 mm(2) and 1mm in thickness cold rolled steel sheet, the dipping in 660 degrees C Al-Si melt for 3s and the cooling. In a pre-treatment, the steel specimen was partly coated by Au to confirm the mechanism of intermetallic compound (IMC) formation. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM) analyses were followed to observe the cross-section and the distribution of the elements. The specimen was analyzed in the boundary of the dipped-undipped part to see the formation mechanism of the aluminized steel. An intermetallic compound (IMC) is rapidly developed and grown in the steel-liquid interface. It has been usually reported that the IMC was formed by the dissolution of iron in the steel substrate toward the melt and the diffusion of aluminum in an opposite direction. The specimen is covered with aluminum-10 wt.% silicon, forms the IMC in the part that was not Au coated. However, IMC is not formed in the Au-coated part. The interface of the dipped-undipped is also analyzed by EDX. At the interface of the steel-IMC, it is clearly shown that the IMC is only formed in the dipped part and exists in the steel substrate as well, and contributes by iron, aluminum and silicon. The result clearly shows that only aluminum diffuses into the steel substrate without the dissolution of iron and forms the IMC between the steel substrate and the melt. Au coating and the short dipping time prevent the iron from dissolving into the aluminum melt. By TEM combined with focused ion beam (FIB) sample preparation, the IMC is confirmed as Fe2SiAl8, a hexagonal structure with space group P6(3)/mmc.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“One-dimensional modelling of a capacitively coupled rf plasma in silane/helium, including small concentrations of O2 and N2”. de Bleecker K, Herrebout D, Bogaerts A, Gijbels R, Descamps P, Journal of physics: D: applied physics 36, 1826 (2003)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.588
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“The optical excitonic Aharonov-Bohm effect in a few nanometer wide type-I nanorings”. Tadić, M, Arsoski V, Čukarić, N, Peeters FM, Acta physica Polonica: A: general physics, solid state physics, applied physics 117, 974 (2010)
Abstract: The optical excitonic Aharonov-Bohm effect in type-1 three-dimensional (In, Ga)As/GaAs nanorings in theoretically explored. The single-particle states of the electron and the hole are extracted from the effective mass theory in the presence of inhomogeneous strain, and an exact numerical diagonalization approach is used to compute the exciton states and the oscillator strength fx for exciton recombination. We studied both the large lithographically-defined and small self-assembled rings. Only in smaller self-assembled nanorings we found optical excitonic AharonovBohm effect. Those oscillations are established by anticrossings between the optically active exciton states with zero orbital momentum. In lithographically defined rings, whose average radius is 33 nm, fx shows no oscillations, whereas in the smaller self-assembled nanoring with average radius of 11.5 nm oscillations in fx for the ground exciton state are found as function of the magnetic field that is superposed on a linear dependence. These oscillations are smeared out at finite temperature, thus photoluminescence intensity exhibits step-like variation with magnetic field even at temperature as small as 4.2 K.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 0.469
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“Optimization of the amount of catalyst and reaction time in single wall nanotube production”. Horvath ZE, Biro LP, Van Tendeloo G, Tondeur C, Bister G, Pierard N, Fonseca A, Nagy JB, Diffusion and defect data : solid state data : part B : solid state phenomena 94, 271 (2003)
Abstract: The influence of the amount of catalyst and the reaction time on the quantity and quality of catalytically grown single wall carbon nanotubes (SWNT) was investigated. The aim was to optimize some of the SWNT growth parameters using TEM and HRTEM. The thickness of catalyst layer influences the synthesis of the nanotube because the gas composition can differ between top and bottom. Microscopic investigation of the grown SWNT samples showed that the thicker the catalyst layer the lower relative nanotube content, so the deeper parts of the catalyst layer are less effective: The optimum time for the reaction was found to be 10 minutes. This may be understood assuming that nanotube growth needs an initial incubation time while the activity of the catalyst decreases steadily until the nariotube growth stops.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“Orientational charge density waves and the metal-insulator transition in polymerized KC60”. Verberck B, Nikolaev AV, Michel KH, AIP conference proceedings 723, 339 (2004)
Abstract: Polymerized KC60 undergoes a structural phase transition accompanied by a metal-insulator transition around 50 K. To explain the structural aspect, a mechanism involving small orientational deviations of the valence electron density on every C-60 monomer orientational charge density waves (OCDWs) – has already been proposed earlier. In the present work, we address the metal-insulator transition using the OCDW concept. We are inspired by the analogy between a polymer chain exhibiting an OCDW and a linear atomic chain undergoing a static lattice deformation doubling the unit cell: such a deformation implies a band gap at the zone boundary, yielding an insulating state (Peierls instability). Within our view, a similar mechanism occurs in polymerized KC60; the OCDW plays the role of the lattice deformation. We present tight-binding band structure calculations and conclude that the metal-insulator transition can indeed be explained using OCDWs, but that the threedimensionality of the crystal plays an unexpected key role.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
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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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“Periodic microtwinning as a possible mechanism for the accommodation of the epitaxial film-substrate mismatch in the La1-xSrxMnO3/SrTiO3 system”. Lebedev OI, Van Tendeloo G, Amelinckx S, Razavi F, Habermeier H-U, Philosophical magazine: A: physics of condensed matter: defects and mechanical properties 81, 797 (2001)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“Positron annihilation study of nanocrystalline Ni3Al : simulations and measurements”. Kuriplach J, van Petegem S, Hou M, Van Tendeloo G, Schryvers D, et al, Materials science forum
T2 –, 12th International Conference on Positron Annihilation (ICPA-12), AUG 06-12, 2000, UNIV BUNDERSWEHR MUNCHEN, NEUBIBERG, GERMANY 363-3, 94 (2001)
Abstract: A positron lifetime experiment is performed on samples produced by the compaction of nanocrystalline Ni3Al powder synthesized by the inert-gas condensation technique. In the lifetime spectrum we observe two components corresponding to defects. Computer (virtual) samples of n-Ni3Al are obtained using molecular dynamics combined with the Metropolis Monte Carlo technique. Positron lifetime calculations are then performed on selected regions of simulated samples. For this purpose, a new computational technique based on a generalization of the atomic superposition method for non-periodic systems was developed. Lifetimes calculated in this way are compared to experiment.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“Present state of the composition evaluation of ternary semiconductor nanostructures by lattice fringe analysis”. Rosenauer A, Gerthsen D, Van Aert S, van Dyck D, den Dekker AJ, Institute of physics conference series , 19 (2003)
Abstract: Semiconductor heterostructures are used for the fabrication of optoelectronic devices. Performance of such devices is governed by their chemical morphology. The composition distribution of quantum wells and dots is influenced by kinetic growth processes which are not understood completely at present. To obtain more information about these effects, methods for composition determination with a spatial resolution at a near atomic scale are necessary. In this paper we focus on the present state of the composition evaluation by the lattice fringe analysis (CELFA) technique and explain the basic ideas, optimum imaging conditions, precision and accuracy.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
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