“Comparative analysis of the low-energy He+ ions scattering on Al and Al2O3 surfaces”. Fomin VM, Misko VR, Devreese JT, Brongersma HH, Nuclear Instruments &, Methods In Physics Research Section B-Beam Interactions With Materials And Atoms 145, 545 (1998). http://doi.org/10.1016/S0168-583X(98)00530-8
Keywords: A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Impact Factor: 1.109
Times cited: 9
DOI: 10.1016/S0168-583X(98)00530-8
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“Accurate evaluation of \mu-PIXE and \mu-XRF spectral data through iterative least squares fitting”. Janssens K, Vekemans B, Adams F, van Espen P, Mutsaers P, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms
T2 –, 7th International Conference on Particle Induced X-ray Emission and Its Analytical Applications, MAY 26-30, 1995, Abano Terme, Italy 109, 179 (1996). http://doi.org/10.1016/0168-583X(95)01211-7
Abstract: The integration of the nonlinear least squares X-ray spectrum evaluation progam AXIL. into a mu-PIXE and a mu-XRF setup is discussed. The use of the software when procesing data sets derived from biological and geological samples is described.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)
DOI: 10.1016/0168-583X(95)01211-7
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“Electron microscopy and Rutherford backscattering spectrometry characterisation of 6H SiC samples implanted with He+”. Frangis N, van Landuyt J, Grimaldi MG, Calcagno L, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms
T2 –, Symposium 1 on New Trends in Ion Beam Processing of Materials, at the, E-MRS 96 Spring Meeting, June 04-07, 1996, Strasbourg, France 120, 186 (1996). http://doi.org/10.1016/S0168-583X(96)00506-X
Abstract: 6H SiC single crystals were implanted al room temperature with 1 MeV He+ up to a fluence of 2 x 10(17) at./cm(2) RBS-channeling analysis with a 2 MeV He+ beam indicated the formation of extended defects or the generation of point defects at a constant concentration over a depth of about 1 mu m. Electron microscopy characterisation revealed the presence of two amorphous buried layers at depths of about 1,75 and 4.8 mu m. They an due to the implantation and to the analysing RES beam, respectively, No extended planar or linear faults were found in the region between the surface and the first amorphous layer. However, at the surface, a 50 nm thick amorphous layer was observed in which crystalline inclusions were embedded. Electron diffraction and HREM data of the inclusions were typical for diamond, These inclusions were even found in the crystalline SiC material below this layer, however at a reduced density.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 1.124
Times cited: 2
DOI: 10.1016/S0168-583X(96)00506-X
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“Ion beam synthesis of \beta-SiC at 950 degrees C and structural characterization”. Frangis N, Nejim A, Hemment PLF, Stoemenos J, van Landuyt J, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms
T2 –, Symposium J on Correlated Effects in Atomic and Cluster Ion Bombardment and Implantation/Symposium C on Pushing the Limits of Ion Beam, Processing –, Fr 112, 325 (1996). http://doi.org/10.1016/0168-583X(95)01236-2
Abstract: The structure of beta-SiC formed by carbon implantation into Si at high temperatures (850-950 degrees C) at doses ranging between 0.2 X 10(18) to 1 X 10(18) cm(-2) at 200 keV, was studied by combined cross section and high resolution transmission electron microscopy (XTEM and HRTEM). Implantation was performed on (001) and (111) Si wafers. In both cases a buried beta-SiC layer was formed having the same orientation as the Si matrix.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 1.124
Times cited: 9
DOI: 10.1016/0168-583X(95)01236-2
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“Compositional analysis of 17-18th century archaeological glass fragments, excavated in Mechelen, Belgium: comparison with data from neighboring cities in the Low Countries”. van der Linden V, Bultinck E, de Ruytter J, Schalm O, Janssens K, Devos W, Tiri W, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 239, 100 (2005). http://doi.org/10.1016/j.nimb.2005.06.219
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.109
Times cited: 15
DOI: 10.1016/j.nimb.2005.06.219
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“Ion beam synthesis of Te and Bi nanoclusters in silicon: the effect of post-implantation high frequency electromagnetic field”. Kalitzova M, Peeva A, Ignatova V, Lebedev OI, Zollo G, Vitali G, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 242, 209 (2006). http://doi.org/10.1016/j.nimb.2005.08.017
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.109
Times cited: 1
DOI: 10.1016/j.nimb.2005.08.017
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“Molecular dynamics simulation of the impact behaviour of various hydrocarbon species on DLC”. Neyts E, Bogaerts A, Gijbels R, Benedikt J, van de Sanden MCM, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 228, 315 (2005). http://doi.org/10.1016/j.nimb.2004.10.063
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.109
Times cited: 19
DOI: 10.1016/j.nimb.2004.10.063
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“Molecular information in static SIMS for the speciation of inorganic compounds”. van Ham R, Adriaens A, van Vaeck L, Gijbels R, Adams F, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 161/163, 245 (2000). http://doi.org/10.1016/S0168-583X(99)00750-8
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.109
Times cited: 19
DOI: 10.1016/S0168-583X(99)00750-8
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“Nanohardness and structure of nitrogen implanted SixAly coatings post-implanted with oxygen”. Jacobs M, Bodart F, Terwagne G, Schryvers D, Poulet A, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 147, 231 (1999). http://doi.org/10.1016/S0168-583X(98)00535-7
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.109
Times cited: 3
DOI: 10.1016/S0168-583X(98)00535-7
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“Confocal μ-XRF depth analysis of paint layers”. Šmit Ž, Janssens K, Proost K, Langus I, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 219, 35 (2004). http://doi.org/10.1016/J.NIMB.2004.01.024
Abstract: Focused narrow-band beam of the synchrotron radiation was used for in-depth analysis of historic and modern paint layers. The fluorescent radiation induced by 21 keV impact radiation was detected by a Si(Li) detector equipped with a polycapillary X-ray lens in con-focal geometry. Scanning of the sample was performed by a motorized xyz stage. Space resolution of 30 ìm was achieved. The procedure of evaluation of concentrations was based on the independent parameter method and included absorption of radiation in the outer layers and secondary fluorescence enhancement induced by hard X-rays of the same and neighboring layers.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.109
Times cited: 69
DOI: 10.1016/J.NIMB.2004.01.024
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“Determination of localized Fe2+/Fe3+ ratios in inks of historic documents by means of \mu-XANES”. Proost K, Janssens K, Wagner B, Bulska E, Schreiner M, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 213, 723 (2004). http://doi.org/10.1016/S0168-583X(03)01693-8
Abstract: An important part of the European cultural heritage is composed of hand-written documents. Many of these documents were drawn up with iron-gall ink. This type of ink present a serious conservation problem, as it slowly oxidizes ('burns') the paper it is written on, thereby gradually disintegrating the historic document. Acid hydrolysis of the cellulose and/or the oxidation of organic compounds promoted by radical intermediates that are formed due to the presence of Fe2+ ions are considered to be the cause of the disintegration. mu-XANES measurements were performed with a lateral resolution of 30-50 mum in order to determine the local Fe2+/Fe3+ ratio in 19th C. documents from the Austrian National Archives and fragments of 16th C documents from the Polish National Library. In the 19th C documents, no significant amount of Fe2+ was detected. On the other hand, in the 16th C fragments, significant amounts of Fe2+ and appreciable differences in distribution of Fe2+ and Fe3+ within individual letters/ink stains were observed. (C) 2003 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.109
DOI: 10.1016/S0168-583X(03)01693-8
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“Micro-distribution of heavy elements in highly inhomogeneous particles generated from μ-beam XRF/XRD analysis”. Rindby A, Engström P, Janssens K, Osán J, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 124, 591 (1997)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.109
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“Trace element fingerprinting of façon-de-Venise glass”. Šmit Ž, Bulska E, Janssens K, Bulska E, Wagner B, Kos M, Lazar I, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 239, 94 (2005). http://doi.org/10.1016/J.NIMB.2005.06.182
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.109
Times cited: 27
DOI: 10.1016/J.NIMB.2005.06.182
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“Characterization of impact materials around Barringer meteor crater by micro-PIXE nd micro-SRXRF techniques”. Uzonyi I, Szöör G, Rozsa P, Vekemans B, Vincze L, Adams F, Drakopoulos M, Somogyi A, Kiss ÁZ, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 219/220, 555 (2004). http://doi.org/10.1016/J.NIMB.2004.01.119
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.NIMB.2004.01.119
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“Monte Carlo simulation of X-ray spectra from low energy electrons using optical data”. Roet D, van Espen P, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 268, 2794 (2010). http://doi.org/10.1016/J.NIMB.2010.07.004
Abstract: An approach using optical data to simulate both the bremsstrahlung continuum and characteristic K and L X-ray lines generated by low energy electrons (cfr. electron microscopy) in solids is discussed in this paper. The necessary analytical expressions together with the data to calculate the relevant cross sections for elastic and inelastic interactions at these energies along with variance reduction techniques are given. The results of the Monte Carlo simulation are compared to experimental data measured with a JEOL 6300 electron microscope.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.NIMB.2010.07.004
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“Precise gamma ray measurement of the radial distribution of a cracking catalyst at diluted concentrations in a glass riser”. Dantas CC, Dos Santos VA, Melo ACBA, Van Grieken R, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 251, 201 (2006). http://doi.org/10.1016/J.NIMB.2006.05.009
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.NIMB.2006.05.009
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“Study of dpa distributions in electron irradiated YBCO slabs through MCCM algorithm”. Piñera I, Cruz CM, van Espen P, Abreu Y, Leyva A, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 274, 191 (2012). http://doi.org/10.1016/J.NIMB.2011.11.021
Abstract: The Monte Carlo assisted Classical Method (MCCM) consists on a calculation procedure for determining the displacements per atom (dpa) distribution in solid materials. This algorithm allows studying the gamma and electron irradiation damage in different materials. It is based on the electrons elastic scattering classic theories and the use of Monte Carlo simulation for the physical processes involved. The present study deals with the Monte Carlo simulation of electron irradiation effects on YBa2Cu3O7-x (YBCO) slabs using the MCNPX code system. Displacements per atom distributions are obtained through the MCCM for electron irradiation up to 10 MeV. In-depth dpa profiles for electrons and positrons are obtained and analysed. Also, dpa contributions from each atomic specie in the material are calculated. It was found that the dpa distribution is more homogeneous in the material volume when increasing energy of incident electrons. Also, the dpa produced by positrons has no relevance when irradiating with electrons, in contrast with previous similar gamma irradiation studies. All the results are presented and discussed in this contribution. (C) 2011 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.NIMB.2011.11.021
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“Total electron yield (TEY) detection mode Cr K-edge XANES spectroscopy as a direct method to probe the composition of the surface of darkened chrome yellow (PbCr1-xSxO4) and potassium chromate paints”. Monico L, d'Acapito F, Cotte M, Janssens K, Romani A, Ricci G, Miliani C, Cartechini L, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 539, 141 (2023). http://doi.org/10.1016/J.NIMB.2023.03.040
Abstract: The darkening of chromate-pigments, including chrome yellows (PbCr1-xSxO4), is a surface phenomenon affecting late 19th-early 20th c. paintings, such as those by Van Gogh. Exploring analytical strategies that contribute to a deep understanding of darkening is therefore significant for the long-term conservation of unique masterpieces. Here, we examined the capabilities of Cr K-edge XANES spectroscopy collected at the same time in X-ray fluorescence yield (XFY) and total electron yield (TEY) detection modes to selectively study the surface composition of darkened oil paint mock-ups composed of chrome yellow (PbCr0.2S0.8O4) or potassium chromate. By discussing advantages and drawbacks in using XFY/TEY modes in relation to XFY & mu;-XANES analysis from sectioned samples, we aim at assessing if TEY-XANES spectroscopy: (i) is a selective surface method to determine the abundance of different Cr-species from paint fragments; (ii) can contribute to optimize the analytical strategy by limiting time consuming sample preparation procedures; (iii) can decrease the probability of radiation damage.
Keywords: A1 Journal article; Engineering sciences. Technology; Antwerp X-ray Imaging and Spectroscopy (AXIS)
Impact Factor: 1.3
DOI: 10.1016/J.NIMB.2023.03.040
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“Atomic structure of alloys close to phase transitions”. Van Tendeloo G, Schryvers D, Nucleation and growth processes in materials 580, 283 (2000)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“Computed electronic and optical properties of SnO2 under compressive stress”. Miglio A, Saniz R, Waroquiers D, Stankovski M, Giantomassi M, Hautier G, Rignanese G-M, Gonze X, Optical materials 38, 161 (2014). http://doi.org/10.1016/j.optmat.2014.10.017
Abstract: We consider the effects of three different types of applied compressive stress on the structural, electronic and optical properties of rutile SnO2. We use standard density functional theory (OFT) to determine the structural parameters. The effective masses and the electronic band gap, as well as their stress derivatives, are computed within both DFT and many-body perturbation theory (MBPT). The stress derivatives for the SnO2 direct band gap are determined to be 62, 38 and 25 meV/GPa within MBPT for applied hydrostatic, biaxial and uniaxial stress, respectively. Compared to DFT, this is a clear improvement with respect to available experimental data. We also estimate the exciton binding energies and their stress coefficients and compute the absorption spectrum by solving the Bethe-Salpeter equation. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.238
Times cited: 6
DOI: 10.1016/j.optmat.2014.10.017
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“Effect of heat-treatment on luminescence and structure of Ag nanoclusters doped oxyfluoride glasses and implication for fiber drawing”. Kuznetsov AS, Cuong NT, Tikhomirov VK, Jivanescu M, Stesmans A, Chibotaru LF, Velázquez JJ, Rodríguez VD, Kirilenko D, Van Tendeloo G, Moshchalkov VV, Optical materials 34, 616 (2012). http://doi.org/10.1016/j.optmat.2011.09.007
Abstract: The effect of heat treatment on the structure and luminescence of Ag nanoclusters doped oxyfluoride glasses was studied and the implication for drawing the corresponding fibers doped with luminescent Ag nanoclusters has been proposed. The heat treatment results, first, in condensation of the Ag nanoclusters into larger Ag nanoparticles and loss of Ag luminescence, and further heat treatment results in precipitation of a luminescent-loss nano- and microcrystalline Ag phases onto the surface of the glass. Thus, the oxyfluoride fiber doped with luminescent Ag nanoclusters was pulled from the viscous glass melt and its attenuation loss was 0.19 dB/cm in the red part of the spectrum; i.e. near to the maximum of Ag nanoclusters luminescence band. The nucleation centers for the Ag nanoclusters in oxyfluoride glasses have been suggested to be the fluorine vacancies and their nanoclusters.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.238
Times cited: 25
DOI: 10.1016/j.optmat.2011.09.007
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“Structural characterization of Er-doped Li2O-Al2O3-SiO2 glass ceramics”. Krsmanovic R, Bals S, Bertoni G, Van Tendeloo G, Optical materials 30, 1183 (2008). http://doi.org/10.1016/j.optmat.2007.05.045
Abstract: Particularly favourable properties of glass ceramics are developed on the basis of two key advantages of these materials: the variation of chemical composition and of microstructure. Therefore, detailed structural and chemical information are necessary to get insight in novel glass ceramic materials. We present here two examples of Er-doped Li2O-Al2O3-SiO2, with different quantities of ZrO2, both obtained with sol-gel synthesis. Different transmission electron microscopy techniques: conventional TEM, HRTEM, and EELS are used and the results are compared with those previously obtained with XRD and Rietveld analysis. We also demonstrate the 3D reconstruction, obtained from HAADF-STEM imaging, to determine the morphology of nanosize precipitates in these composites. (c) 2007 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.238
Times cited: 12
DOI: 10.1016/j.optmat.2007.05.045
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“Preparation, structural and optical characterization of nanocrystalline ZnO doped with luminescent Ag-nanoclusters”. Kuznetsov AS, Lu Y-G, Turner S, Shestakov MV, Tikhomirov VK, Kirilenko D, Verbeeck J, Baranov AN, Moshchalkov VV, Optical materials express 2, 723 (2012). http://doi.org/10.1364/OME.2.000723
Abstract: Nanocrystalline ZnO doped with Ag-nanoclusters has been synthesized by a salt solid state reaction. Three overlapping broad emission bands due to the Ag nanoclusters have been detected at about 570, 750 and 900 nm. These emission bands are excited by an energy transfer from the exciton state of the ZnO host when pumped in the wavelength range from 250 to 400 nm. The 900 nm emission band shows characteristic orbital splitting into three components pointing out that the anisotropic crystalline wurtzite host of ZnO is responsible for this feature. Heat-treatment and temperature dependence studies confirm the origin of these emission bands. An energy level diagram for the emission process and a model for Ag nanoclusters sites are suggested. The emission of nanocrystalline ZnO doped with Ag nanoclusters may be applied for white light generation, displays driven by UV light, down-convertors for solar cells and luminescent lamps.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.591
DOI: 10.1364/OME.2.000723
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“Nanoscale mapping by electron energy-loss spectroscopy reveals evolution of organic solar cell contact selectivity”. Guerrero A, Pfannmöller M, Kovalenko A, Ripolles TS, Heidari H, Bals S, Kaufmann L-D, Bisquert J, Garcia-Belmonte G, Organic electronics: physics, materials, applications 16, 227 (2015). http://doi.org/10.1016/j.orgel.2014.11.007
Abstract: Organic photovoltaic (OPV) devices are on the verge of commercialization being long-term stability a key challenge. Morphology evolution during lifetime has been suggested to be one of the main pathways accounting for performance degradation. There is however a lack of certainty on how specifically the morphology evolution relates to individual electrical parameters on operating devices. In this work a case study is created based on a thermodynamically unstable organic active layer which is monitored over a period of one year under non-accelerated degradation conditions. The morphology evolution is revealed by compositional analysis of ultrathin cross-sections using nanoscale imaging in scanning transmission electron microscopy (STEM) coupled with electron energy-loss spectroscopy (EELS). Additionally, devices are electrically monitored in real-time using the non-destructive electrical techniques capacitance-voltage (C-V) and Impedance Spectroscopy (IS). By comparison of imaging and electrical techniques the relationship between nanoscale morphology and individual electrical parameters of device operation can be conclusively discerned. It is ultimately observed how the change in the cathode contact properties occurring after the migration of fullerene molecules explains the improvement in the overall device performance. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.399
Times cited: 24
DOI: 10.1016/j.orgel.2014.11.007
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“Aberration-corrected microscopy and spectroscopy analysis of pristine, nitrogen containing detonation nanodiamond”. Turner S, Shenderova O, da Pieve F, Lu Y-G, Yücelen E, Verbeeck J, Lamoen D, Van Tendeloo G, Physica status solidi : A : applications and materials science 210, 1976 (2013). http://doi.org/10.1002/pssa.201300315
Abstract: Aberration-corrected transmission electron microscopy, electron energy-loss spectroscopy, and density functional theory (DFT) calculations are used to solve several key questions about the surface structure, the particle morphology, and the distribution and nature of nitrogen impurities in detonation nanodiamond (DND) cleaned by a recently developed ozone treatment. All microscopy and spectroscopy measurements are performed at a lowered acceleration voltage (80/120kV), allowing prolonged and detailed experiments to be carried out while minimizing the risk of knock-on damage or surface graphitization of the nanodiamond. High-resolution TEM (HRTEM) demonstrates the stability of even the smallest nanodiamonds under electron illumination at low voltage and is used to image the surface structure of pristine DND. High resolution electron energy-loss spectroscopy (EELS) measurements on the fine structure of the carbon K-edge of nanodiamond demonstrate that the typical * pre-peak in fact consists of three sub-peaks that arise from the presence of, amongst others, minimal fullerene-like reconstructions at the nanoparticle surfaces and deviations from perfect sp(3) coordination at defects in the nanodiamonds. Spatially resolved EELS experiments evidence the presence of nitrogen within the core of DND particles. The nitrogen is present throughout the whole diamond core, and can be enriched at defect regions. By comparing the fine structure of the experimental nitrogen K-edge with calculated energy-loss near-edge structure (ELNES) spectra from DFT, the embedded nitrogen is most likely related to small amounts of single substitutional and/or A-center nitrogen, combined with larger nitrogen clusters.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.775
Times cited: 37
DOI: 10.1002/pssa.201300315
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“Grain size tuning of nanocrystalline chemical vapor deposited diamond by continuous electrical bias growth : experimental and theoretical study”. Mortet V, Zhang L, Eckert M, D'Haen J, Soltani A, Moreau M, Troadec D, Neyts E, De Jaeger JC, Verbeeck J, Bogaerts A, Van Tendeloo G, Haenen K, Wagner P, Physica status solidi : A : applications and materials science 209, 1675 (2012). http://doi.org/10.1002/pssa.201200581
Abstract: In this work, a detailed structural and spectroscopic study of nanocrystalline diamond (NCD) thin films grown by a continuous bias assisted CVD growth technique is reported. This technique allows the tuning of grain size and phase purity in the deposited material. The crystalline properties of the films are characterized by SEM, TEM, EELS, and Raman spectroscopy. A clear improvement of the crystalline structure of the nanograined diamond film is observed for low negative bias voltages, while high bias voltages lead to thin films consisting of diamond grains of only ∼10 nm nanometer in size, showing remarkable similarities with so-called ultrananocrystalline diamond. These layers arecharacterized by an increasing amount of sp2-bonded carbon content of the matrix in which the diamond grains are embedded. Classical molecular dynamics simulations support the observed experimental data, giving insight in the underlying mechanism for the observed increase in deposition rate with bias voltage. Furthermore, a high atomic concentration of hydrogen has been determined in these films. Finally, Raman scattering analyses confirm that the Raman line observed at ∼1150 cm−1 cannot be attributed to trans-poly-acetylene, which continues to be reported in literature, reassigning it to a deformation mode of CHx bonds in NCD.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.775
Times cited: 31
DOI: 10.1002/pssa.201200581
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“Morphological TEM studies and magnetoresistance analysis of sputtered Al-substituted ZnO films : the role of oxygen”. Van Gompel M, Atalay AY, Gaulke A, Van Bael MK, D'Haen J, Turner S, Van Tendeloo G, Vanacken J, Moshchalkov VV, Wagner P, Physica status solidi : A : applications and materials science 212, 1191 (2015). http://doi.org/10.1002/pssa.201431888
Abstract: In this article, we report on the synthesis of thin, epitaxial films of the transparent conductive oxide Al:ZnO on (0001)-oriented synthetic sapphire substrates by DC sputtering from targets with a nominal 1 at.% Al substitution. The deposition was carried out at an unusually low substrate temperature of only 250 °C in argonoxygen mixtures as well as in pure argon. The impact of the processgas composition on the morphology was analysed by transmission electron microscopy, revealing epitaxial growth in all the cases with a minor impact of the process parameters on the resulting grain sizes. The transport properties resistivity, Hall effect and magnetoresistance were studied in the range from 10 to 300 K in DC and pulsed magnetic fields up to 45 T. While the carrier density and mobility are widely temperature independent, we identified a low fieldlow temperature regime in which the magnetoresistance shows an anomalous, negative behaviour. At higher fields and temperatures, the magnetoresistance exhibits a more conventional, positive curvature with increasing field strength. As a possible explanation, we propose carrier scattering at localised magnetic trace impurities and magnetic correlations.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.775
DOI: 10.1002/pssa.201431888
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“Study on the giant positive magnetoresistance and Hall effect in ultrathin graphite flakes”. Vansweevelt R, Mortet V, D' Haen J, Ruttens bart, van Haesendonck C, Partoens B, Peeters FM, Wagner P, Physica status solidi : A : applications and materials science 208, 1252 (2011). http://doi.org/10.1002/pssa.201001206
Abstract: In this paper, we report on the electronic transport properties of mesoscopic, ultrathin graphite flakes with a thickness corresponding to a stack of 150 graphene layers. The graphite flakes show an unexpectedly strong positive magnetoresistance (PMR) already at room temperature, which scales in good approximation with the square of the magnetic field. Furthermore, we show that the resistivity is unaffected by magnetic fields oriented in plane with the graphene layers. Hall effect measurements indicate that the charge carriers are p-type and their concentration increases with increasing temperature while the mobility is decreasing. The Hall voltage is non-linear in higher magnetic fields. Possible origins of the observed effects are discussed. Ball and stick model of the two topmost carbon layers of the hexagonal graphite structure.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.775
Times cited: 8
DOI: 10.1002/pssa.201001206
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“The effect of molecular structure of organic compound on the direct high-pressure synthesis of boron-doped nanodiamond: Effect of organic compound on synthesis of boron-doped nanodiamond”. Ekimov EA, Kudryavtsev OS, Turner S, Korneychuk S, Sirotinkin VP, Dolenko TA, Vervald AM, Vlasov II, Physica status solidi : A : applications and materials science 213, 2582 (2016). http://doi.org/10.1002/pssa.201600181
Abstract: Evolution of crystalline phases with temperature has been studied in materials produced by high-pressure high-temperature treatment of 9-borabicyclo[3.3.1]nonane dimer (9BBN), triphenylborane and trimesitylborane. The boron-doped diamond nanoparticles with a size below 10 nm were obtained at 8–9 GPa and temperatures 970–1250 °C from 9BBN only. Bridged structure and the presence of boron atom in the carbon cycle of 9BBN were revealed to be a key point for the direct synthesis of doped diamond nanocrystals. The diffusional transformation of the disordered carbon phase is suggested to be the main mechanism of the nanodiamond formation from 9BBN in the temperature range of 970–1400 °C. Aqueous suspensions of primary boron-doped diamond nanocrystals were prepared upon removal of non-diamond phases that opens wide opportunities for application of this new nanomaterial in electronics and biotechnologies.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.775
Times cited: 8
DOI: 10.1002/pssa.201600181
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Sankaran KJ, Hoang DQ, Srinivasu K, Korneychuk S, Turner S, Drijkoningen S, Pobedinskas P, Verbeeck J, Leou KC, Lin IN, Haenen K, Physica status solidi : A : applications and materials science 213, 2654 (2016). http://doi.org/10.1002/PSSA.201600233
Abstract: Utilization of Au and nanocrystalline diamond ( NCD) as interlayers noticeably modifies the microstructure and field electron emission ( FEE) properties of hexagonal boron nitride nanowalls ( hBNNWs) grown on Si substrates. The FEE properties of hBNNWs on Au could be turned on at a low turn-on field of 14.3V mu m(-1), attaining FEE current density of 2.58mAcm(-2) and life-time stability of 105 min. Transmission electron microscopy reveals that the Au-interlayer nucleates the hBN directly, preventing the formation of amorphous boron nitride ( aBN) in the interface, resulting in enhanced FEE properties. But Au forms as droplets on the Si substrate forming again aBN at the interface. Conversely, hBNNWs on NCD shows superior in life-time stability of 287 min although it possesses inferior FEE properties in terms of larger turn-on field and lower FEE current density as compared to that of hBNNWs-Au. The uniform and continuous NCD film on Si also circumvents the formation of aBN phases and allows hBN to grow directly on NCD. Incorporation of carbon in hBNNWs from the NCD-interlayer improves the conductivity of hBNNWs, which assists in transporting the electrons efficiently from NCD to hBNNWs that results in better field emission of electrons with high life-time stability. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.775
Times cited: 5
DOI: 10.1002/PSSA.201600233
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