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“3D FIB/SEM study of Ni4Ti3 precipitates in Ni-Ti alloys with different thermal-mechanical histories”. Cao S, Nishida M, Somsen C, Eggeler G, Schryvers D, , 02004 (2009). http://doi.org/10.1051/esomat/200902004
Abstract: The three-dimensional size, morphology and distribution of Ni4Ti3 precipitates growing in binary Ni-rich Ni-Ti alloys have been investigated via a slice view procedure in a Dual-Beam FIB/SEM system, in order to better stress-free Ni50.8Ti49.2 alloy with all four variants of precipitates and a compressed Ni51Ti49 alloy with aligned precipitates in one family were studied. The Ni4Ti3 precipitates reach a volume fraction of 9.6% in the reconstructed region of the stress-free alloy and 4.3% in the compressed one. In both cases, the mean volume, specific surface area, sphericity and aspect ratio of the precipitates are calculated and the Pair Distribution Functions of the precipitates are obtained. It is shown that most precipitates in the stress-free sample grow larger and have a more lenticular shape, while those in the compressed sample are more cylindrical. Deviations from these ideal shapes reveal internal steps in the stress-free sample and lamellae formation in the compressed one.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
Times cited: 1
DOI: 10.1051/esomat/200902004
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“3D strain fields surrounding Ni4Ti3: direct measurement and correlation with the R-phase”. Tirry W, Schryvers D, , 02032 (2009). http://doi.org/10.1051/esomat/200902032
Abstract: Strain fields introduced by coherent Ni4Ti3 precipitates in austenitic Ni-Ti are believed to be a possible origin of why the R-phase transformation is introduced as an extra step before transforming to the B19'. The presence of this strain field was already confirmed in the past by conventional transmission electron microscopy (TEM) techniques and measured quantitatively by high resolution TEM (HRTEM). This time the geometrical phase method is applied on HRTEM micrographs to measure the full 3D strain tensor of the strain fields. Since each atomic resolution micrograph only results in a 2D measurement of the strain, observations in two different zone orientations are combined to retrieve the 3 x 3 strain tensor. In this work observations in a [1-1 1](B2) and [1 0-1](B2) zone orientation are used and this in case of precipitates with a diameter of around 50nm. In a next step the measured strain tensor is compared to the calculated eigenstrain of the R-phase in reference to the B2 matrix. This comparison shows that the introduced strain is very similar to the eigenstrain of one R-phase variant. Since for both structures, Ni4Ti3 and R-phase, four orientation variants are possible, each variant of the R-phase is thus able to accommodate the strain field of one of the Ni4Ti3 variants.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
DOI: 10.1051/esomat/200902032
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“Angular confinement and direction-dependent transmission in graphene nanostructures with magnetic barriers”. Masir MR, Vasilopoulos P, Matulis A, Peeters FM, AIP conference proceedings 1199, 363 (2009). http://doi.org/10.1063/1.3295453
Abstract: We evaluate the transmission through magnetic barriers in graphene-based nanostructures. Several particular cases are considered: a magnetic step, single and double barriers, delta -function barriers as well as barrier structures with inhomogeneous magnetic field profiles but with average magnetic field equal to zero. The transmission exhibits a strong dependence on the direction of the incident wave vector. In general the resonant structure of the transmission is significantly more pronounced for (Dirac) electrons with linear spectrum compared to that for electrons with a parabolic one.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
DOI: 10.1063/1.3295453
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“Band structure, density of states, and transmission in graphene bilayer superlattices”. Barbier M, Vasilopoulos P, Peeters FM, Pereira JM, AIP conference proceedings 1199, 547 (2009). http://doi.org/10.1063/1.3295550
Abstract: The energy spectrum and density of states of graphene bilayer superlattices (SLs) are evaluated. We take into account doping and/or gating of the layers as well as tunnel coupling between them. In addition, we evaluate the transmission through such SLs and through single or double barriers. The transmission exhibits a strong dependence on the direction of the incident wave vector.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
DOI: 10.1063/1.3295550
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“Branch current behavior at two level anti-crossings in vertical quantum dot single-particle spectra”. Payette C, Austing DG, Yu G, Gupta JA, Nair SV, Partoens B, Amaha S, Tarucha S, AIP conference proceedings 1199, 271 (2010). http://doi.org/10.1063/1.3295404
Abstract: We study single-electron-elastic-resonant-tunneling through two weakly coupled vertical quantum dots and investigate the branch current behavior at anti-crossings between two single-particle energy levels in the constituent dot spectra that are induced to approach each other by application of an out-of-dot-plane magnetic field. We observe both the familiar case of monotonic transfer of the resonant current strengths between the two branches as well as the less familiar case of concurrent enhancement and suppression (ideally complete cancellation) of the resonant current in the two branches. These two situations can be explained in terms of a simple coherent tunneling model. ©2009 American Institute of Physics
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
DOI: 10.1063/1.3295404
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“Characterization and modeling of single-particle energy levels and resonant currents in a coherent quantum dot mixer”. Austing DG, Payette C, Yu G, Gupta JA, Aers GC, Nair SV, Partoens B, Amaha S, Tarucha S, AIP conference proceedings
T2 –, 30th International Conference on the Physics of Semiconductors (ICPS-30), JUL 25-30, 2010, Seoul, SOUTH KOREA , 1 (2011). http://doi.org/10.1063/1.3666692
Abstract: We characterize and model the single-particle energy level position and resonant current strength at a three-level crossing in a coherent mixer composed of two weakly coupled vertical quantum dots. In addition to clear anticrossing behavior, an otherwise strong resonance is completely extinguished at the center of the crossing. Despite the strong variation in energy level position and resonant current strength throughout the crossing region, the resonance widths and the sum of the branch currents are found to be approximately constant.
Keywords: P1 Proceeding; Condensed Matter Theory (CMT)
DOI: 10.1063/1.3666692
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“Classical atomic bilayers”. Peeters FM, Partoens B, Schweigert VA, Schweigert IV Plenum Press, New York, page 523 (1998).
Keywords: H1 Book chapter; Condensed Matter Theory (CMT)
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“Clinical applications of image-based airway computational fluid dynamics: assessment of inhalation medication and endobronchial devices”. de Backer JW, Vos WG, Germonpré, P, Salgado R, Parizel PM, de Backer W, Proceedings of the Society of Photo-optical Instrumentation Engineers 7262, 72621p (2009). http://doi.org/10.1117/12.811476
Abstract: Computational fluid dynamics (CFD) is a technique that is used increasingly in the biomedical field. Solving the flow equations numerically provides a convenient way to assess the efficiency of therapies and devices, ranging from cardiovascular stents and heart valves to hemodialysis workflows. Also in the respiratory field CFD has gained increasing interest, especially through the combination of three dimensional image reconstruction which results in highend patient-specific models. This paper provides an overview of clinical applications of CFD through image based modeling, resulting from recent studies performed in our center. We focused on two applications: assessment of the efficiency of inhalation medication and analysis of endobronchial valve placement. In the first application we assessed the mode of action of a novel bronchodilator in 10 treated patients and 4 controls. We assessed the local volume increase and resistance change based on the combination of imaging and CFD. We found a good correlation between the changes in volume and resistance coming from the CFD results and the clinical tests. In the second application we assessed the placement and effect of one way endobronchial valves on respiratory function in 6 patients. We found a strong patientspecific result of the therapy where in some patients the therapy resulted in complete atelectasis of the target lobe while in others the lobe remained inflated. We concluded from these applications that CFD can provide a better insight into clinically relevant therapies.
Keywords: A3 Journal article; Condensed Matter Theory (CMT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP)
DOI: 10.1117/12.811476
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Blumenau AT, Frauenheim T, Ö,berg S, Willems B, Van Tendeloo G (2004) Dislocation structures in diamond: density-functional based modelling and high resolution electron microscopy. Trans Tech Publications, s.l
Keywords: MA1 Book as author; Electron microscopy for materials research (EMAT)
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“Electric field tuning of the band gap in four layers of graphene with different stacking order”. Avetisyan AA, Partoens B, Peeters FM, Proceedings of the Society of Photo-optical Instrumentation Engineers
T2 –, Conference on Photonics and Micro and Nano-structured Materials, JUN 28-30, 2011, Yerevan, ARMENIA , 84140 (2012). http://doi.org/10.1117/12.923618
Abstract: We investigated the effect of different stacking order of the four graphene layer system on the induced band gap when positively charged top and negatively charged back gates are applied to the system. A tight-binding approach within a self-consistent Hartree approximation is used to calculate the induced charges on the different graphene layers. We show that the electric field does not open an energy gap if the multilayer graphene system contains a trilayer part with the ABA Bernal stacking.
Keywords: P1 Proceeding; Engineering sciences. Technology; Condensed Matter Theory (CMT)
DOI: 10.1117/12.923618
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“Few-particle states in coupled electron-hole quantum dots”. Anisimovas E, Peeters FM, Functions II , 330 (2003). http://doi.org/10.1142/9789812705129_0029
Abstract: We apply the exact diagonalization technique to calculate the ground and excited states of a bipolar artificial molecule composed of two vertically coupled quantum dots containing different types of carriers electrons and holes in equilibrium. In this system, the magnetic field tunes the relative role of intra-dot Coulomb interaction while the inter-dot separation sets the strength of inter-dot correlations. We find an intricate pattern of the switching of the ground-state angular momentum with increasing magnetic field and a rearrangement of approximate single-particle levels as a function of the inter-dot coupling strength.
Keywords: P1 Proceeding; Condensed Matter Theory (CMT)
DOI: 10.1142/9789812705129_0029
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“Investigation of Ag, Ag2S and Ag(Br,I) small particles by HREM and AEM”. Oleshko V, Schryvers D, Gijbels R, Jacob W s.l., page 293 (1998).
Keywords: H3 Book chapter; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
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“Landau-level dispersion and the quantum Hall plateaus in bilayer graphene”. Zarenia M, Vasilopoulos P, Pourtolami N, Peeters FM, AIP conference proceedings 1566, 275 (2013). http://doi.org/10.1063/1.4848392
Abstract: We study the quantum Hall effect (QHE) in bilayer graphene using the Kubo-Greenwood formula. At zero temperature the Hall conductivity sigma(yx) is given by sigma(yx) – 4(N + 1)e(2)/h with N the index of the highest occupied Landau level (LL). Including the dispersion of the LLs and their width, due to e. g. scattering by impurities, produces the plateau of the n = 0 LL in agreement with experimental results on doped samples and similar theoretical results on single-layer graphene plateaus widen with impurity concentration. Further, the evaluated resistivity rho(xx) exhibits a strong, oscillatory dependence on the electron concentration. Explicit results are obtained for delta-function impurities.
Keywords: P1 Proceeding; Condensed Matter Theory (CMT)
DOI: 10.1063/1.4848392
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“Large bipolarons and high-Tc materials”. Devreese JT, Verbist G, Peeters FM Cambridge University Press, Cambridge, page 385 (1995).
Keywords: H3 Book chapter; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
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Goorden L, Van Tendeloo G, Lenaerts S, Deblonde M, et al. (2009) Nanotechnologie: gewikt en gewogen. NanoSoc
Keywords: Minutes and reports; Engineering sciences. Technology; Engineering Management (ENM); Sustainable Energy, Air and Water Technology (DuEL); Electron microscopy for materials research (EMAT)
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Goorden L, Van Tendeloo G, Lenaerts S, Deblonde M, van Oudheusden M, et al. (2009) Nanotechnologie op de agenda. NanoSoc
Keywords: Minutes and reports; Engineering sciences. Technology; Engineering Management (ENM); Society and Environment; Sustainable Energy, Air and Water Technology (DuEL); Electron microscopy for materials research (EMAT)
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“A new method to calculate leakage current and its applications for sub-45nm MOSFETs”. Lujan GS, Magnus W, Soree B, Pourghaderi MA, Veloso A, van Dal MJH, Lauwers A, Kubicek S, De Gendt S, Heyns M, De Meyer K, Solid-State Device Research (ESSDERC), European Conference
T2 – ESSDERC 2005 : proceedings of 35th European Solid-State Device Research Conference, September 12-16, 2005, Grenoble, France. Ieee, S.l., page 489 (2005).
Abstract: This paper proposes a new quantum mechanical model for the calculation of leakage currents. The model incorporates both variational calculus and the transfer matrix method to compute the subband energies and the life times of the inversion layer states. The use of variational calculus simplifies the subband energy calculation due to the analytical firm of the wave functions, which offers an attractive perspective towards the calculation of the electron mobility in the channel. The model can be extended to high-k dielectrics with several layers. Good agreement between experimental data and simulation results is obtained for metal gate capacitors.
Keywords: H1 Book chapter; Condensed Matter Theory (CMT)
DOI: 10.1109/ESSDER.2005.1546691
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“Observation of paramagnetic supercurrent in mesoscopic superconducting rings and disks using multiple-small-tunnel-junction method”. Kanda A, Baelus BJ, Peeters FM, Kadowaki K, Ootuka Y, , 204 (2005). http://doi.org/10.1142/9789812701619_0032
Abstract: Responses of mesoscopic superconducting rings and disks to perpendicular magnetic fields are studied by using the multiple-small-tunnel-junction method, in which transport properties of several small tunnel junctions attached to the sample are measured simultaneously. This allows us for a direct experimental observation of the paramagnetic supercurrent, which is closely related to the paramagnetic Meissner effect. The results are compared with numerical results based on the nonlinear Ginzburg-Landau theory.
Keywords: P1 Proceeding; Condensed Matter Theory (CMT)
DOI: 10.1142/9789812701619_0032
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“Phonon band structures of Si nanowires”. Peelaers H, Partoens B, Peeters FM, AIP conference proceedings 1199, 323 (2009). http://doi.org/10.1063/1.3295432
Abstract: We present full ab initio calculations of the phonon band structure of thin Si nanowires oriented along the [110] direction. Using these phonon dispersion relations we investigate the structural stability of these wires. We found that all studied wires were stable also when doped with either B or P, if the unit cell was taken sufficiently large along the wire axis. The evolution of the phonon dispersion relations and of the sound velocities with respect to the wire diameters is discussed. Softening is observed for acoustic modes and hardening for optical phonon modes with increasing wire diameters.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
DOI: 10.1063/1.3295432
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“Pinning of the martensitic microstructures by dislocations in Cu74.08Al23.13Be2.79”. Idrissi H, Schryvers D, Salje EKH, Zhang H, Carpenter MA, Moya X, , 02029 (2009). http://doi.org/10.1051/esomat/200902029
Abstract: A single crystal of Cu74.08Al23.13Be2.79 undergoes a martensitic phase transition at 246K and 232K under heating and cooling, respectively. Surprisingly, the martensite phase is elastically much harder than the austenite phase showing that interfaces between various crystallographic variants are strongly pinned and can not be moved by external stress while the phase boundary between the austenite and martensite regions in the sample remains mobile. This unusual behavior was revealed by Dynamical Mechanical Analysis and Resonant Ultrasound Spectroscopy. Transmission Electron Microscopy shows that the pinning is generated by dislocations, which are inherited from the austenite phase. Such dislocations can hinder the movement of stacking faults in the 18R martensite structure or twin boundaries between martensite variants.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
Times cited: 2
DOI: 10.1051/esomat/200902029
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“Real time path integrals in studies of quantum dots dynamics: non-monotonous decay rate and reappearance of rabi rotations”. Vagov A, Croitoru MD, Axt VM, Kuhn T, Peeters F, Path Integrals : New Trends and Perspectives, Proceedings , 57 (2008). http://doi.org/10.1142/9789812837271_0007
Abstract: The dynamics of strongly confined laser driven semiconductor quantum dots coupled to phonons is studied theoretically by calculating the time evolution of the reduced density matrix using the path integral method. We explore the cases of long pulses, strong dot-phonon and dot-laser coupling and high temperatures, which up to now have been inaccessible. We find that the decay rate of the Rabi oscillations is a non-monotonic function of the laser field leading to the decay and reappearance of the Rabi oscillations in the field dependence of the dot exciton population.
Keywords: P1 Proceeding; Condensed Matter Theory (CMT)
DOI: 10.1142/9789812837271_0007
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“Reliability of copper dual damascene influenced by pre-clean”. Tokei Z, Lanckmans F, van den Bosch G, Van Hove M, Maex K, Bender H, Hens S, van Landuyt J, Analysis Of Integrated Circuits , 118 (2002). http://doi.org/10.1109/IPFA.2002.1025629
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
Times cited: 5
DOI: 10.1109/IPFA.2002.1025629
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“Semiconductor”. Peeters FM McGraw-Hill, New York, page 350 (1997).
Keywords: H3 Book chapter; Condensed Matter Theory (CMT)
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“Shallow donor near a semiconductor surface in the presence of locally spherical scanning tunneling microscope tip”. Djotyan AP, Avetisyan AA, Hao YL, Peeters FM, Proceedings of the Society of Photo-optical Instrumentation Engineers
T2 –, Conference on Photonics and Micro and Nano-structured Materials, JUN 28-30, 2011, Yerevan, ARMENIA , 84140 (2012). http://doi.org/10.1117/12.923562
Abstract: We developed a variational approach to investigate the ground state energy and the extend of the wavefunction of a neutral donor located near a semiconductor surface in the presence of scanning tunneling microscope (STM) metallic tip. We apply the effective mass approximation and use a variational wavefunction that takes into account the influence of all image charges that arise due to the presence of a metallic tip. The behavior of the ground state energy when the tip approaches the semiconductor surface is investigated.
Keywords: P1 Proceeding; Engineering sciences. Technology; Condensed Matter Theory (CMT)
DOI: 10.1117/12.923562
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“Space charge limited electron emission from a Cu surface under ultrashort pulsed laser irradiation”. Wendelen W, Autrique D, Bogaerts A, AIP conference proceedings 1278, 407 (2010). http://doi.org/10.1063/1.3507129
Abstract: In this theoretical study, the electron emission from a copper surface under ultrashort pulsed laser irradiation is investigated using a one dimensional particle in cell model. Thermionic emission as well as multi-photon photoelectron emission were taken into account. The emitted electrons create a negative space charge above the target, consequently the generated electric field reduces the electron emission by several orders of magnitude. The simulations indicate that the space charge effect should be considered when investigating electron emission related phenomena in materials under ultrashort pulsed laser irradiation of metals.the word abstract, but do replace the rest of this text. ©2010 American Institute of Physics
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
DOI: 10.1063/1.3507129
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“Stability of vortex-antivortex “molecules&rdquo, in mesoscopic superconducting triangles”. Misko VR, Fomin VM, Devreese JT, Moshchalkov VV, 3rd International Symposium on Mesoscopic Superconductivity and, Spintronics, MAR 01-04, 2004, Atsug, 191 (2005). http://doi.org/10.1142/9789812701619_0030
Abstract: We have revealed thermodynamically stable vortex-antivortex configurations in mesoscopic type I superconducting equilateral triangles. The revealed effect is explained by two factors: (i) vortex confinement in mesoscopic triangles and (ii) appearance of the vortex-antivortex repulsion in mesoscopic type I superconductor triangles in the vicinity of the dual point. The stability of the obtained solutions is examined as a function of material and external parameters – the Ginzburg-Landau parameter K and temperature – as well as a function of a distortion of the sample's shape. The vortex-antivortex. “molecule” turns out to be stable in a wide range of the parameters that makes it possible its experimental visualization.
Keywords: A1 Journal article; Electron Microscopy for Materials Science (EMAT);
DOI: 10.1142/9789812701619_0030
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“Statistical estimation of oxygen atomic positions eith sub Ångstrom precision from exit wave reconstruction”. Bals S, Van Aert S, Van Tendeloo G, van Dyck D, Avila-Brande D, Microscopy and microanalysis 11, 556 (2005)
Keywords: A3 Journal article; Electron microscopy for materials research (EMAT); Vision lab
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“Structural description of high Tc cuprate superconductors”. Milat O, Van Tendeloo G, Amelinckx S, Spie 2697, 95 (1996). http://doi.org/10.1117/12.250232
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
DOI: 10.1117/12.250232
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“Superconducting nanowires: quantum-confinement effect on the critical magnetic field and supercurrent”. Croitoru MD, Shanenko AA, Peeters FM, , 327 (2010). http://doi.org/10.1142/9789814289153_0025
Abstract: We study the effect, of electron confinement on the superconducting-to-normal phase transition driven by a magnetic field and/or on the current-carrying state of the superconducting condensate in nanowires. Our investigation is based on a self-consistent. numerical solution of the Bogoliubov-de Gennes equations. We show that, in a parallel magnetic field and/or in the presence of supercurrent the transition from superconducting to normal phase occurs as a cascade of discontinuous jumps in the superconducting order parameter for diameters D < 10 divided by 15 nm at T = 0. The critical magnetic held exhibits quantum-size oscillations with pronounced resonant enhancements.
Keywords: P1 Proceeding; Condensed Matter Theory (CMT)
DOI: 10.1142/9789814289153_0025
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“TEM study of the mechanism of Ni ion release from Nitinol wires with original oxides”. Tian H, Schryvers D, Shabalovskaya S, van Humbeeck J, , 05027 (2009). http://doi.org/10.1051/esomat/200905027
Abstract: The surface of commercial Nitinol wires with original oxides and a thickness in the 30-190 nm range was investigated by different state of art TEM techniques. The oxide surface layer was identified as a combination of TiO and TiO2 depending on the processing of the wire. Between the core of the wires and the oxidized surface, an interfacial Ni3Ti nanolayer was observed while Ni nanoparticles are found inside the original oxide. The particle sizes, their distribution in the surface and the Ti-O stoichiometry were deduced from the analysis of the obtained data. Molecular dynamics calculations performed for evaluation of the stability of Ni particles relative to the atomic state revealed that a pure Ni particle has a lower energy than free Ni atoms inside the TiO2 lattice. The obtained results are discussed with respect to surface stability and Ni release in the human body.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
Times cited: 1
DOI: 10.1051/esomat/200905027
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