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“Direct observation of laser-induced crystallization of a-C : H films”. Nistor LC, van Landuyt J, Ralchenko VG, Kononenko TV, Obraztsova ED, Strelnitsky VE, Applied physics A : materials science &, processing 58, 137 (1994). http://doi.org/10.1007/BF00332170
Abstract: The post-growth modification of diamond-like amorphous hydrogenated carbon a-C:H films by laser treatment has been studied by transmission electron microscopy and Raman spectroscopy. a-C:H films grown on Si substrates by benzene decomposition in a rf glow discharge were irradiated with 15 ns pulses of a KrF-excimer laser with fluences in the ran e of E = 50-700 mJ/cm(2). At fluences below 100 mJ/cm(2) an increase in the number of graphitic clusters and in their ordering was evidenced from Raman spectra, while the film structure remained amorphous according to electron microscopy and electron diffraction observations. At higher fluences the appearance of diamond particles of 2-7 nm size, embedded into the lower crystallized graphitic matrix, was observed and simultaneously a progressive growth of graphite nanocrystals with dimensions from 2 nm to 4 nm was deduced from Raman measurements. The maximum thickness of the crystallized surface layer (approximate to 400 nm) and the degree of laser annealing are limited by the film ablation which starts at E > 250 mJ/cm(2). The laser-treated areas lose their chemical inertness. In particular, chemical etching in chromium acid becomes possible, which may be used for patterning the highly inert carbon films.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 73
DOI: 10.1007/BF00332170
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“Electron-diffraction evidence for ordering of interstitial silver ions in silver bromide microcrystals”. Goessens C, Schryvers D, van Dyck D, van Landuyt J, de Keyzer R, Physica status solidi: A 143, 277 (1994). http://doi.org/10.1002/pssa.2211430211
Abstract: The occurrence and origin of diffuse intensity contours in electron micrographs of AgBr crystals are investigated. The observations are interpreted in terms of a model, which attributes diffuse scattering to the presence of predominant atom or vacancy clusters of a particular polyhedral type. It is shown that irrespective of the crystal morphology, interstitial Ag ions order in AgBr material in clusters of finite size along 001 type planes. A different geometry of the diffuse intensity locus observed for triangular and hexagonal tabular grains is explained in terms of the different twin plane morphology of these grains.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Times cited: 7
DOI: 10.1002/pssa.2211430211
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“Structural aspects of Bi2-xPbxSr3.5Cu2(CO3)O8-\delta for 0\leq x\leq0.75 : an electron-microscopy study”. Zhang XF, Van Tendeloo G, Amelinckx S, Pelloquin D, Michel C, Hervieu M, Raveau B, Journal of solid state chemistry 113, 327 (1994). http://doi.org/10.1006/jssc.1994.1378
Abstract: The structure and defect structure of Bi2-xPbxSr3.5Cu2 (CO3)O8-delta compounds with 0 less-than-or-equal-to x less-than-or-equal-to 0.75 are carefully investigated by electron diffraction and high-resolution electron microscopy. All compounds have an orthorhombic structure with a almost-equal-to b almost-equal-to 5.4 angstrom and c almost-equal-to 39.5 angstrom. The length of the b-axis decreases monotonically with increasing x. The space group for the basic structure is Abm2. The structure can be considered as an intergrowth of Bi2Sr2CuO6 lamellae with Sr2CuO2 (CO3) lamellae along the c-axis. CO3 groups behave as bridges connecting the CuO6 octahedra. In the x = 0 compound the carbon atoms are shifted away from their symmetry positions; the orientational ordering of the CO3 groups (or the carbon shift) in successive CO planes alternates along +b and -b. Typical Bi-type and Pb-type modulations are found along the b-axis up to a Pb content x = 0.5. Electron beam irradiation destroys the ordering of the CO3 groups and alters the modulated structure. (C) 1994 Academic press, inc.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.133
Times cited: 8
DOI: 10.1006/jssc.1994.1378
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“Structural considerations and high-resolution electron-microscopy observations on LanTin-\deltaO3n(n\geq4\delta)”. Van Tendeloo G, Amelinckx S, Darriet B, Bontchev R, Darriet J, Weill F, Journal of solid state chemistry 108, 314 (1994). http://doi.org/10.1006/jssc.1994.1048
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.133
Times cited: 29
DOI: 10.1006/jssc.1994.1048
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“The texture of catalytically grown coil-shaped carbon nanotubes”. Zhang XB, Zhang XF, Bernaerts D, Van Tendeloo G, Amelinckx S, van Landuyt J, Ivanov V, Nagy JB, Lambin P, Lucas AA, Europhysics letters 27, 141 (1994). http://doi.org/10.1209/0295-5075/27/2/011
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.095
Times cited: 168
DOI: 10.1209/0295-5075/27/2/011
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“The anharmonic-force field of thioformaldehyde, h2cs, by ab-initio methods”. Martin JML, Francois, Gijbels R, Journal of molecular spectroscopy 168, 363 (1994). http://doi.org/10.1006/jmsp.1994.1285
Abstract: The quartic force field of thioformaldehyde has been calculated ab initio using large basis sets and augmented coupled cluster methods. Calculated fundamentals are in excellent agreement with experiment, as is the most important Coriolis coupling constant. Computed values for the anharmonicity, rovibrational coupling, and centrifugal distortion constants of the four isotopomers (H2CS)-S-32, (H2CS)-S-34, (HDCS)-S-32, and (D2CS)-S-32 have been reported. Predictions have been made for all vibrational transitions from the ground state to excited states with at most two quanta for these isotopomers, both using second-order perturbation theory corrected for Darling-Dennison resonance and using vibrational SCF-CI calculations. For (D2CS)-S-32, perturbation theory performs quite well; for the other isotopomers, performance is poorer for states involving excitation of the out-of-plane bend and, for the (H2CS)-S-32 and (H2CS)-S-34 isotopomers, also for the antisymmetric bend that is in severe Coriolis resonance with it. A possible explanation has been suggested. (C) 1994 Academic Press, Inc.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.482
Times cited: 18
DOI: 10.1006/jmsp.1994.1285
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“Effects of air pollution on historic buildings and monuments (1986-1990): scientific basis for conservation: analytical study of the weathering of building stones under field-exposure conditions”. Van Grieken R, Vleugels G, Sweevers E, Dewolfs R, European cultural heritage newsletter on research 8, 2 (1994)
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Shallow donor impurities in GaAs/AlxGa1-xAs superlattices in a magnetic-field”. Shi JM, Peeters FM, Devreese JT, Physical review : B : condensed matter and materials physics 50, 15182 (1994). http://doi.org/10.1103/PhysRevB.50.15182
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 3.736
Times cited: 71
DOI: 10.1103/PhysRevB.50.15182
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“Dynamics of a finite classical two-dimensional system”. Schweigert VA, Peeters FM, Superlattices and microstructures 16, 243 (1994). http://doi.org/10.1016/S0749-6036(09)80007-4
Abstract: The spectral properties of a classical two-dimensional (2D) cluster of charged particles which are confined by a quadratic potential are calculated. Using the method of Newton optimization we obtain the ground state and the metastable states. For a given configuration the eigenvectors and eigenfrequencies for the normal modes are obtained using the Householder diagonalization technique for the dynamical matrix whose elements are the second derivative of the potential energy. For small clusters the lowest excitation corresponds to an intershell rotation. Magic numbers are associated to clusters which are most stable against intershell rotation. For large clusters the lowest excitation is a vortex/anti-vortex pair.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.097
Times cited: 4
DOI: 10.1016/S0749-6036(09)80007-4
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“Atomic structure and defect structure of the superconducting HgBa2Can-1CunO2n+2+\delta homologous series”. Van Tendeloo G, Chaillout C, Capponi JJ, Marezio M, Antipov EV, Physica: C : superconductivity 223, 219 (1994). http://doi.org/10.1016/0921-4534(94)91264-5
Abstract: The perfect as well as the defect structure of several members of the superconducting family HgBa2Can-1CunO2n+2+delta have been studied in detail by electron diffraction and high-resolution electron microscopy Identification of the cation configuration is possible, even in the defect regions, with the help of computer simulations. The fine structure of several defects is analyzed in detail, the most common defect being the intergrowth of slabs corresponding to different n values in the title formula. In general, however, the crystals are of a high perfection, particularly for the lower n members. The occurrence of double (HgO)delta layers is seen occasionally, indicating the possible existence of a material with a double mercury layer. Some of these defects are possibly related to recently discovered anomalies at 250 K in these compounds.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.942
Times cited: 30
DOI: 10.1016/0921-4534(94)91264-5
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“The domain configuration of the Au11In3 phase”. Kifune K, Yamamoto K, Maruyama S, Van Tendeloo G, Philosophical magazine letters 69, 211 (1994). http://doi.org/10.1080/09500839408241594
Abstract: The crystal structure of Au11In3 thin film alloys have been analysed by means of electron diffraction and high-resolution electron microscopy. The electron diffraction pattern and the high-resolution electron microscopy revealed that this structure was incommensurate and had a domain structure consisting of three kinds of structural unit. The approximant structural model, which is based on a h.c.p. stacking of the layers, is hexagonal with lattice parameters a = 7.612 nm and c = 0-478 nm.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.087
Times cited: 2
DOI: 10.1080/09500839408241594
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“The study of carbon nanotubules produced by catalytic method”. Ivanov V, Nagy JB, Lambin P, Lucas A, Zhang XB, Zhang XF, Bernaerts D, Van Tendeloo G, Amelinckx S, van Landuyt J, Chemical physics letters 223, 329 (1994). http://doi.org/10.1016/0009-2614(94)00467-6
Abstract: Catalytic methods for the production of carbon nanotubules have been developed based on the decomposition of acetylene on well-dispersed metal particles strongly adsorbed on a support. Cobalt on silica was found to be the best catalyst-support combination for the production of graphitic tubules. The method for the catalyst preparation and the reaction conditions were optimized. Straight and coiled carbon tubules were obtained with inner and outer diameter of 3-7 and 15-20 nm, respectively, and up to 30 mum in length. These nanotubules were not coated by amorphous carbon. Traces of amorphous carbon could be removed by hydrogen. High resolution electron microscopy images and electron diffraction patterns of the straight nanotubules were similar to those obtained by the arc-discharge method. Coiled nanotubules were revealed by TEM to be regular polygonized helices where the bends are caused by pairs of pentagon-heptagon carbon rings among the hexagonal network.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.897
Times cited: 405
DOI: 10.1016/0009-2614(94)00467-6
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“Non-linear mapping of microbeam proton-induced X-ray emission data for source identification of North Sea aerosols”. Treiger B, Injuk J, Bondarenko I, van Espen P, Van Grieken R, Breitenbach L, Wätjen U, Spectrochimica acta: part B : atomic spectroscopy 49, 345 (1994). http://doi.org/10.1016/0584-8547(94)80029-4
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)
DOI: 10.1016/0584-8547(94)80029-4
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“Accurate ab initio quartic force fields and thermochemistry of FNO and CINO”. Martin JML, François JP, Gijbels R, The journal of physical chemistry 98, 11394 (1994). http://doi.org/10.1021/j100095a022
Abstract: The quartic force fields of FNO and CINO have been computed at the CCSD(T)/cc-pVTZ level. Using an ''augmented'' basis set dramatically improves results for FNO but has no significant effect for CINO. The best computed force field for FNO yields harmonic frequencies and fundamentals in excellent agreement with experiment. Overall, the force fields proposed in the present work are probably the most reliable ones ever published for these molecules. Total atomization energies have been computed using basis sets of spdfg quality: our best estimates are Sigma D-0 = 208.5 +/- 1 and 185.4 +/- 1 kcal/mol for FN0 and CINO, respectively. The computed value for FNO suggests a problem with the established experimental heat of formation. Thermodynamic tables in JANAF style at 100-2000 K are presented for both FNO and CINO.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Times cited: 21
DOI: 10.1021/j100095a022
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“A transmission electron-microscopy study of crystalline surface domains on al-co decagonal quasi-crystals and the \tau2-Al13CO4 approximant”. Zhang Z, Ma LN, Liao XZ, van Landuyt J, Philosophical magazine letters 70, 303 (1994). http://doi.org/10.1080/09500839408240991
Abstract: Twin-domains of a b.c.c. crystalline phase with a = 0.29 nm have been found in a surface layer on surfaces of Al-Co decagonal quasicrystals and the coexisting tau(2)-Al13Co4 crystalline approximant. These surface layer domains are introduced during the preparation of electron microscopy thin films by ion milling.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.087
Times cited: 4
DOI: 10.1080/09500839408240991
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“Ab initio study of the spectroscopy, kinetics, and thermochemistry of the C2N and CN2 molecules”. Martin JML, Taylor PR, François JP, Gijbels R, Chemical physics letters 226, 475 (1994). http://doi.org/10.1016/0009-2614(94)00758-6
Abstract: Several structures and electronic states of the C2N and CN2 molecules have been studied using complete active space SCF (CASSCF), multireference configuration interaction (MRCI), and coupled cluster (CCSD(T)) methods. Both molecules are very stable. Our best computed total atomization energies SIGMAD(e) are 288.6 +/- 2 kcal/mol for CN2, and 294.1 +/- 2 kcal/mol for C2N. The CNC and CCN structures for C2N are nearly isoenergetic. CNN(3PI) lies about 30 kcal/mol above NCN(3PI(g)), but has a high barrier towards interconversion and is therefore observed experimentally. Computed harmonic frequencies for CNN are sensitive to the correlation treatment: they are reproduced well using multireference methods as well as the CCSD(T) method. High spin contamination has a detrimental effect on computed harmonic frequencies at the CCSD(T) level.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.897
Times cited: 46
DOI: 10.1016/0009-2614(94)00758-6
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“Stabilization of mercury-based superconductors by foreign cations”. Raveau B, Michel C, Hervieu M, Van Tendeloo G, Maignan A, Annales de chimie (1914)
T2 –, 4th North-African Materials Science Symposium (JMSM 94), NOV 23-24, 1994, CASABLANCA, MOROCCO 19, 487 (1994)
Abstract: The recently discovered superconducting mercury-based cuprates HgBa2Can-1CunO2n+2+delta have proved difficult to synthesize as single phases and are sensitive to environment (CO2, moisture). The present paper gives an overview of new series mercury based superconductors, whose stabilisation is based on the fact that a foreign cation with a higher valency than Hg(II) must be introduced in the mercury layers, in order to fill up partially the oxygen vacancies of these layers. By this method, several new series of superconductors involving strontium instead of barium with critical temperatures ranging from 27 K to 95 K have been isolated : Hg0.5Bi0.5Sr2-xLaxCuO4+delta, Hg(0.5)Bi(0.5)Sr(2)Ca(1-x)R(x)Cu(2)O(6+delta) (R Y, Nd, Pr), Pb0.7Hg0.3Sr2-xLaxCuO4+delta, Pb(0.7)Hg(0.3)Sr(2)Ca(1-x)R(x)Cu(2)O(6+delta) (R = Y, Nd) Hg(1-x)Pr(x)Sr(2)A(1-x')Pr(x') Cu2O6+delta (A = Sr, Ca), Pb0.7Hg0.3Sr2Cu2CO3O7 and Hg1-xCrxSr2CuO4+delta. The behaviour of the praseodymium cuprates that exhibit a rather sharp transition and reach a Tc of 85 K is especially discussed. A method to synthesize new ''Ba-Hg'' superconducting cuprates with the 1212 structure at normal pressure with a Tc up to 110 K is also presented.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 2
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