“Influence of strain, specimen orientation and background estimation on composition evaluation of InAs/GaAs by TEM”. Rossi EHM, Van Tendeloo G, Rosenauer A, Philosophical magazine 87, 4461 (2007). http://doi.org/10.1080/14786430701551905
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.505
Times cited: 1
DOI: 10.1080/14786430701551905
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“First-principles calculations of the mean inner Coulomb potential for sphalerite type II.VI semiconductors”. Schowalter M, Lamoen D, Kruse P, Gerthsen D, Rosenauer A, Applied Physics Letters 85, 4938 (2004). http://doi.org/10.1063/1.1823598
Keywords: A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Impact Factor: 3.411
Times cited: 16
DOI: 10.1063/1.1823598
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“Ab initio computation of the mean inner Coulomb potential of technological important semiconductors”. Schowalter M, Rosenauer A, Lamoen D, Kruse P, Gerthsen D, 1007, 233 (2005)
Keywords: A1 Journal article; Electron Microscopy for Materials Science (EMAT);
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“Ab initio computation of the mean inner Coulomb potential of wurtzite-type semiconductors and gold”. Schowalter M, Rosenauer A, Lamoen D, Kruse P, Gerthsen D, Applied Physics Letters 88, Artn 232108 (2006). http://doi.org/10.1063/1.2210453
Keywords: A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Impact Factor: 3.411
Times cited: 8
DOI: 10.1063/1.2210453
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“Calculation of Debye-Waller temperature factors for GaAs”. Schowalter M, Rosenauer A, Titantah JT, Lamoen D, Springer proceedings in physics 120, 195 (2008)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“Computation and parametrization of the temperature dependence of Debye-Waller factors for group IV, III-V and II-VI semiconductors”. Schowalter M, Rosenauer A, Titantah JT, Lamoen D, Acta crystallographica: section A: foundations of crystallography 65, 5 (2009). http://doi.org/10.1107/S0108767308031437
Abstract: We calculated the temperature dependence of the Debye-Waller factors for a variety of group IV, III-V and II-VI semiconductors from 0.1 to 1000 K. The approach used to fit the temperature dependence is described and resulting fit parameters are tabulated for each material. The Debye-Waller factors are deduced from generalized phonon densities of states which were derived from first principles using the WIEN2k and the ABINIT codes.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.725
Times cited: 51
DOI: 10.1107/S0108767308031437
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“Temperature-dependent Debye-Waller factors for semiconductors with the wurtzite-type structure”. Schowalter M, Rosenauer A, Titantah JT, Lamoen D, Acta crystallographica: section A: foundations of crystallography 65, 227 (2009). http://doi.org/10.1107/S0108767309004966
Abstract: We computed Debye-Waller factors in the temperature range from 0.1 to 1000 K for AlN, GaN, InN, ZnO and CdO with the wurtzite-type structure. The Debye-Waller factors were derived from phonon densities of states obtained from Hellmann-Feynman forces computed within the density-functional-theory formalism. The temperature dependences of the Debye-Waller factors were fitted and fit parameters are given.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.725
Times cited: 23
DOI: 10.1107/S0108767309004966
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“Ab initio based atomic scattering amplitudes and {002} electron structure factors of InxGa1-xAs/GaAs quantum wells”. Titantah JT, Lamoen D, Schowalter M, Rosenauer A, Journal of physics : conference series 209, 012040 (2010). http://doi.org/10.1088/1742-6596/209/1/012040
Abstract: The atomic scattering amplitudes of the various atoms of the systems Ga1−xInxAs, GaAs1−xNx and InAs1−xNx are calculated using the density functional theory (DFT) approach. The scattering amplitudes of N, Ga, As and In in the model systems are compared with the frequently used Doyle and Turner values. Deviation from the latter values is found for small scattering vectors (s<0.3Å−1) and for these scattering vectors dependence on the orientation of the scattering vector and the chemical environment is reported. We suggest a parametrization of these modified scattering amplitudes (MASAs) for small scattering vectors (s<1.0Å−1). The MASAs are exploited within zero pressure classical Metropolis Monte Carlo (MC), finite temperature calculations to investigate the effect of quantum well size on the electron {002} structure factor (SF) of Ga1−xInxAs quantum wells.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
DOI: 10.1088/1742-6596/209/1/012040
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“Bond length variation in Ga1-xInxAs crystals from the Tersoff potential”. Titantah JT, Lamoen D, Schowalter M, Rosenauer A, Journal of applied physics 101, 123508 (2007). http://doi.org/10.1063/1.2748338
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.068
Times cited: 19
DOI: 10.1063/1.2748338
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“Density-functional theory calculations of the electron energy-loss near-edge structure of Li-intercalated graphite”. Titantah JT, Lamoen D, Schowalter M, Rosenauer A, Carbon 47, 2501 (2009). http://doi.org/10.1016/j.carbon.2009.05.002
Abstract: We have studied the structural and electronic properties of lithium-intercalated graphite (LIG) for various Li content. Atomic relaxation shows that Li above the center of the carbon hexagon in a AAAA stacked graphite is the only stable Li configuration in stage 1 intercalated graphite. Lithium and Carbon 1s energy-loss near-edge structure (ELNES) calculations are performed on the Li-intercalated graphite using the core-excited density-functional theory formulation. Several features of the Li 1s ELNES are correlated with reported experimental features. The ELNES spectra of Li is found to be electron beam orientation sensitive and this property is used to assign the origin of the various Li 1s ELNES features. Information about core-hole screening by the valence electrons and charge transfer in the LIG systems is obtained from the C 1s ELNES and valence charge density difference calculations, respectively.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 6.337
Times cited: 12
DOI: 10.1016/j.carbon.2009.05.002
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“Effect of temperature on the 002 electron structure factor and its consequence for the quantification of ternary and quaternary III-V crystals”. Titantah JT, Lamoen D, Schowalter M, Rosenauer A, Springer proceedings in physics 120, 189 (2008)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“Modified atomic scattering amplitudes and size effects on the 002 and 220 electron structure factors of multiple Ga1-xInxAs/GaAs quantum wells”. Titantah JT, Lamoen D, Schowalter M, Rosenauer A, Journal of applied physics 105, 084310 (2009). http://doi.org/10.1063/1.3115407
Abstract: The modified atomic scattering amplitudes (MASAs) of mixed Ga<sub>1-x</sub>In<sub>x</sub>As, GaAs<sub>1-x</sub>N<sub>x</sub>, and InAs<sub>1-x</sub>N<sub>x</sub> are calculated using the density functional theory approach and the results are compared with those of the binary counterparts. The MASAs of N, Ga, As, and In for various scattering vectors in various chemical environments and in the zinc-blende structure are compared with the frequently used Doyle and Turner values. Deviation from the Doyle and Turner results is found for small scattering vectors (s<0.3 Å<sup>-1</sup>) and for these scattering vectors the MASAs are found to be sensitive to the orientation of the scattering vector and on the chemical environment. The chemical environment sensitive MASAs are used within zero pressure classical Metropolis Monte Carlo, finite temperature calculations to investigate the effect of well size on the electron 002 and 220 structure factors (SFs). The implications of the use of the 002 (200) spot for the quantification of nanostructured Ga<sub>1-x</sub>In<sub>x</sub>As systems are examined while the 220 SF across the well is evaluated and is found to be very sensitive to the in-plane static displacements.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.068
DOI: 10.1063/1.3115407
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“Size effects and strain state of Ga1-xInxAs/GaAs multiple quantum wells: Monte Carlo study”. Titantah JT, Lamoen D, Schowalter M, Rosenauer A, Physical review : B : condensed matter and materials physics 78, 165326 (2008). http://doi.org/10.1103/PhysRevB.78.165326
Abstract: The effect of the size of the GaAs barrier and the Ga1−xInxAs well on the structural properties of a Ga1−xInxAs/GaAs multiple quantum well structure is investigated using the Metropolis Monte Carlo approach based on a well-parametrized Tersoff potential. It is found that within the well the Ga-As and In-As bond lengths undergo contractions whose magnitude increases with increasing In content in sharp contrast with bond-length variations in the bulk Ga1−xInxAs systems. For fixed barrier size and In content, the contraction of the bonds is also found to increase with increasing size of the well. Using the local atomic structure of the heterostructures, a more local analysis of the strain state of the systems is given and comparison with the prediction of macroscopic continuum elasticity theory shows deviations from the latter.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 5
DOI: 10.1103/PhysRevB.78.165326
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“Temperature effect on the 002 structure factor of ternary Ga1-xInxAs crystals”. Titantah JT, Lamoen D, Schowalter M, Rosenauer A, Physical review : B : condensed matter and materials physics 76, 073303 (2007). http://doi.org/10.1103/PhysRevB.76.073303
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 3
DOI: 10.1103/PhysRevB.76.073303
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“Procedure to count atoms with trustworthy single-atom sensitivity”. Van Aert S, de Backer A, Martinez GT, Goris B, Bals S, Van Tendeloo G, Rosenauer A, Physical review : B : condensed matter and materials physics 87, 064107 (2013). http://doi.org/10.1103/PhysRevB.87.064107
Abstract: We report a method to reliably count the number of atoms from high-angle annular dark field scanning transmission electron microscopy images. A model-based analysis of the experimental images is used to measure scattering cross sections at the atomic level. The high sensitivity of these measurements in combination with a thorough statistical analysis enables us to count atoms with single-atom sensitivity. The validity of the results is confirmed by means of detailed image simulations. We will show that the method can be applied to nanocrystals of arbitrary shape, size, and atom type without the need for a priori knowledge about the atomic structure.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 106
DOI: 10.1103/PhysRevB.87.064107
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“Locating light and heavy atomic column positions with picometer precision using ISTEM”. van den Bos KHW, Krause FF, Béché, A, Verbeeck J, Rosenauer A, Van Aert S, Ultramicroscopy 172, 75 (2016). http://doi.org/10.1016/j.ultramic.2016.10.003
Abstract: Recently, imaging scanning transmission electron microscopy (ISTEM) has been proposed as a promising new technique combining the advantages of conventional TEM (CTEM) and STEM [1]. The ability to visualize light and heavy elements together makes it a particularly interesting new, spatially incoherent imaging mode. Here, we evaluate this technique in term of precision with which atomic column locations can be measured. By using statistical parameter estimation theory, we will show that these locations can be accurately measured with a precision in the picometer range. Furthermore, a quantitative comparison is made with HAADF STEM imaging to investigate the advantages of ISTEM.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.843
Times cited: 8
DOI: 10.1016/j.ultramic.2016.10.003
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“Correction of non-linear thickness effects in HAADF STEM electron tomography”. van den Broek W, Rosenauer A, Goris B, Martinez GT, Bals S, Van Aert S, van Dyck D, Ultramicroscopy 116, 8 (2012). http://doi.org/10.1016/j.ultramic.2012.03.005
Abstract: In materials science, high angle annular dark field scanning transmission electron microscopy is often used for tomography at the nanometer scale. In this work, it is shown that a thickness dependent, non-linear damping of the recorded intensities occurs. This results in an underestimated intensity in the interior of reconstructions of homogeneous particles, which is known as the cupping artifact. In this paper, this non-linear effect is demonstrated in experimental images taken under common conditions and is reproduced with a numerical simulation. Furthermore, an analytical derivation shows that these non-linearities can be inverted if the imaging is done quantitatively, thus preventing cupping in the reconstruction.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Impact Factor: 2.843
Times cited: 67
DOI: 10.1016/j.ultramic.2012.03.005
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“A memory efficient method for fully three-dimensional object reconstruction with HAADF STEM”. Van den Broek W, Rosenauer A, Van Aert S, Sijbers J, van Dyck D, Ultramicroscopy 141, 22 (2014). http://doi.org/10.1016/j.ultramic.2014.03.008
Abstract: The conventional approach to object reconstruction through electron tomography is to reduce the three-dimensional problem to a series of independent two-dimensional slice-by-slice reconstructions. However, at atomic resolution the image of a single atom extends over many such slices and incorporating this image as prior knowledge in tomography or depth sectioning therefore requires a fully three-dimensional treatment. Unfortunately, the size of the three-dimensional projection operator scales highly unfavorably with object size and readily exceeds the available computer memory. In this paper, it is shown that for incoherent image formation the memory requirement can be reduced to the fundamental lower limit of the object size, both for tomography and depth sectioning. Furthermore, it is shown through multislice calculations that high angle annular dark field scanning transmission electron microscopy can be sufficiently incoherent for the reconstruction of single element nanocrystals, but that dynamical diffraction effects can cause classification problems if more than one element is present. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Impact Factor: 2.843
Times cited: 6
DOI: 10.1016/j.ultramic.2014.03.008
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“Image simulation of high resolution energy filtered TEM images”. Verbeeck J, Sc hattschneider P, Rosenauer A, Ultramicroscopy 109, 350 (2009). http://doi.org/10.1016/j.ultramic.2009.01.003
Abstract: Inelastic image simulation software is presented, implementing the double channeling approximation which takes into account the combination of multiple elastic and single inelastic scattering in a crystal. The approach is described with a density matrix formalism. Two applications in high resolution energy filtered (EFTEM) transmission electron microscopy (TEM) images are presented: thickness-defocus maps for SrTiO3 and exit plane intensities for an (LaAlO3)3(SrTiO3)3 multilayer system. Both systems show a severe breakdown in direct interpretability which becomes worse for higher acceleration voltages, thicker samples and lower excitation edge energies. Since this effect already occurs in the exit plane intensity, it is a fundamental limit and image simulations in EFTEM are indispensable just as they are indispensable for elastic high resolution TEM images.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.843
Times cited: 36
DOI: 10.1016/j.ultramic.2009.01.003
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“Computational aspects in quantitative EELS”. Verbeeck J, Van Aert S, Zhang L, Haiyan T, Schattschneider P, Rosenauer A, Microscopy and microanalysis 16, 240 (2010). http://doi.org/10.1017/S143192761005511X
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.891
DOI: 10.1017/S143192761005511X
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