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“Extended defects formation in Si crystals by clustering of intrinsic point defects studied by in-situ electron irradiation in an HREM”. Fedina L, Gutakovskii A, Aseev A, van Landuyt J, Vanhellemont J, Physica status solidi: A: applied research
T2 –, International Conference on Extended Defects in Semiconductors (EDS 98), Sept. 06-11, 1998, Jaszowiec, Poland 171, 147 (1999). http://doi.org/10.1002/(SICI)1521-396X(199901)171:1<147::AID-PSSA147>3.0.CO;2-U
Abstract: In situ irradiation experiments in a high resolution electron microscope JEOL-4000EX at room temperature resulted in discovery of the isolated and combined clustering of vacancies and self-interstitial atoms on {111}- and {113}-habit planes both leading to an extended defect formation in Si crystals. The type of the defect is strongly affected by the type of supersaturation of point defects depending on the crystal thickness during electron irradiation. Because of the existence of energy barriers against recombination of interstitials with the extended aggregates of vacancies, a large family of intermediate defect configurations (IDCs) is formed on {113}- and {111}-habit planes at a low temperature under interstitial supersaturation in addition to the well-known {133}-defects of interstitial type. The formation of metastable IDCs inside vacancy aggregates prevents a way of recombination of defects in extended shape.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 40
DOI: 10.1002/(SICI)1521-396X(199901)171:1<147::AID-PSSA147>3.0.CO;2-U
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“Structural aspects of CVD idamond wafers grown at different hydrogen flow rates”. Nistor L, van Landuyt J, Ralchenko V, Physica status solidi: A: applied research 171, 5 (1999). http://doi.org/10.1002/(SICI)1521-396X(199907)174:1<5::AID-PSSA5>3.3.CO;2-3
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 15
DOI: 10.1002/(SICI)1521-396X(199907)174:1<5::AID-PSSA5>3.3.CO;2-3
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“TEM study on precipitation behavior in Cu-Co alloys”. Takeda M, Suzuki N, Shinohara G, Endo T, van Landuyt J, Physica status solidi: A: applied research 168, 27 (1998). http://doi.org/10.1002/(SICI)1521-396X(199807)168:1<27::AID-PSSA27>3.0.CO;2-S
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 18
DOI: 10.1002/(SICI)1521-396X(199807)168:1<27::AID-PSSA27>3.0.CO;2-S
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“Evolution of crystallographic phases in (Sr1-xCax)TiO3 with composition (x)”. Ranjan R, Pandey D, Schuddinck W, Richard O, De Meulenaere P, van Landuyt J, Van Tendeloo G, Journal of solid state chemistry 162, 20 (2001). http://doi.org/10.1006/jssc.2001.9336
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.299
Times cited: 45
DOI: 10.1006/jssc.2001.9336
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“Electron microscopic and X-ray structural analysis of the layered crystals TaReSe4: structure, defect structure, and microstructure, including rotation twins”. Volkov VV, van Landuyt J, Amelinckx S, Pervov VS, Makhonina EV, Journal of solid state chemistry 135, 235 (1998). http://doi.org/10.1006/jssc.1997.7621
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.299
Times cited: 3
DOI: 10.1006/jssc.1997.7621
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“Metal and composite nanocluster precipitate formation in silicon dioxide implanted with Sb+ ions”. Ignatova VA, Lebedev OI, Watjen U, van Vaeck L, van Landuyt J, Gijbels R, Adams F, Journal of applied physics 92, 4336 (2002). http://doi.org/10.1063/1.1508425
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.068
Times cited: 5
DOI: 10.1063/1.1508425
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“Structural studies on new ternary oxides Ba8Ta4Ti3O24 and Ba10Ta7.04Ti1.2O30”. Shpanchenko RV, Nistor L, Van Tendeloo G, van Landuyt J, Amelinckx S, Journal of solid state chemistry 114, 560 (1995). http://doi.org/10.1006/jssc.1995.1086
Abstract: The ternary oxides Ba8Ta4Ti3O24 and Ba10Ta7.04Ti1.2O30 were synthesized and their crystal structures and defects were studied by means of X-ray powder diffraction, electron diffraction, and high resolution electron microscopy. The crystal structure of Ba8Ta4Ti3O24 is based on the 8H (cchc)(2) close-packed stacking (a 10.0314 Angstrom, c = 18.869 Angstrom, SG P6(3)/mcm, Z = 3) and that of Ba10Ta7.04Ti1.2O30 and on the 10H (cchcc)(2) close-packed stacking (a = 5.7981 Angstrom, c = 23.755 Angstrom, SG P6(3)/mmc, Z = 1) of BaO3 layers. The structural refinements gave the following values for the R factors for Ba8Ta4Ti3O24 (Ba10Ta7.04Ti1.2O30) R(I) = 0.041 (0.039), R(P) = 0.108 (0.118), and R(wP) = 0.094 (0.099). The main feature of both structures is the presence of two types of face-sharing octahedra (FSO) with different occupancies by Ta atoms, Ti atoms, and vacancies, which results in the formation of a superstructure. It was shown that in the Ba8Ta4Ti3O24 structure these pairs of FSO occur in an ordered fashion and in the Ba10Ta7.04Ti1.2O30 structure in a disordered fashion. The existence of the wide range of solid solutions was shown to be also a consequence of the presence of one of the two types of face-sharing octahedra. (C) 1995 Academic Press, Inc,
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.133
Times cited: 23
DOI: 10.1006/jssc.1995.1086
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“Chemical and structural analysis of etching residue layers in semiconductor devices with energy filtering transmission electron microscopy”. Hens S, van Landuyt J, Bender H, Boullart W, Vanhaelemeersch S, Materials science in semiconductor processing 4, 109 (2001). http://doi.org/10.1016/S1369-8001(00)00147-5
Abstract: The use of an energy-filtering held emission gun transmission electron microscope (CM30 FEG Ultratwin) allows, apart from imaging morphologies down to nanometer scale, the fast acquisition of high-resolution element distributions. Electrons that have lost energy corresponding to characteristic inner-shell loss edges are used to form the element maps. The production of Ultra Large-Scale Integration (ULSI) devices with dimensions below 0.25 mum requires among others the formation of a multilayer metallization scheme by means of repeatedly applying the deposition and etching of dielectrics and metals. In this work the evolution of the surface chemical species on etched Al lines in a post-etch cleaning process has been investigated by energy filtering transmission electron microscopy, with the aim to understand the role of each process step on the removal of the etching residues. (C) 2001 Elsevier Science Ltd. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 2.359
DOI: 10.1016/S1369-8001(00)00147-5
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“The influence of the h-BN morphology and structure on the c-BN growth”. Nistor L, Teodorescu V, Ghica C, van Landuyt J, Dinca G, Georgeoni P, Diamond and related materials
T2 –, 11th European Conference on Diamond, Diamond-like Materials, Carbon, Nanotubes, Nitrides and Silicon Carbide (Diamond 2000), SEP 03-08, 2000, OPORTO, PORTUGAL 10, 1352 (2001). http://doi.org/10.1016/S0925-9635(00)00377-0
Abstract: The morphology and structure of hexagonal graphitic BN (h-BN) powders with graphitization indices GI <5, used as precursors for the synthesis of cubic BN (c-BN) crystals, has been investigated by transmission electron microscopy in diffraction contrast and high resolution. We show that besides the GI, which is a general parameter for controlling the structural quality of h-EN ponders, some other microstructural features strongly influence the synthesis of c-BN. In our opinion, the high reactivity of some h-BN powders results from the presence of some nucleation centers for c-BN, observed at the edges of the h-BN particles. They are formed by a rearrangement of the graphitic (0002) planes by bending back, joining in pairs and forming locally nanoarches (half nanotubes). In these particular places, the nature of bonding locally turns towards sp(3), as in the case of c-BN, (C) 2001 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.561
Times cited: 17
DOI: 10.1016/S0925-9635(00)00377-0
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“The use of convergent beam electron diffraction for stress measurements in shallow trench isolation structures”. Stuer C, van Landuyt J, Bender H, Rooyackers R, Badenes G, Materials science in semiconductor processing 4, 117 (2001). http://doi.org/10.1016/S1369-8001(00)00110-4
Abstract: Shallow trench isolation (STI) is a promising technology for the isolation structures of the new generation of ULSI devices with dimensions below 0.18 mum. The various processing steps cause stress fields in STI structures, which can lead to defect formation in the silicon substrate. In their turn, stress fields affect the electrical parameters and the reliability of devices. Convergent beam electron diffraction (CBED) is used in this study to examine the influence of a wet and a dry pre-gate oxidation on the stress distribution around STI structures. The measurements are performed on STI structures with different width and spacing. CBED analysis is compared with bright-field TEM images. Defects are observed in high-strain areas of small isolated structures. (C) 2001 Elsevier Science Ltd. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 2.359
Times cited: 6
DOI: 10.1016/S1369-8001(00)00110-4
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“Chemical and structural characterization of oxygen precipitates in silicon by infrared spectroscopy and TEM”. de Gryse O, Clauws P, Lebedev O, van Landuyt J, Vanhellemont J, Claeys C, Simoen E, Physica: B : condensed matter
T2 –, 21st International Conference on Defects in Semiconductors, JUL 16-20, 2001, GIESSEN, GERMANY 308, 294 (2001). http://doi.org/10.1016/S0921-4526(01)00801-8
Abstract: Infrared absorption spectra of polyhedral and platelet oxygen precipitates are analyzed using a modified Day-Thorpe approach (J. Phys.: Condens. Matter 11 (1999) 2551). The aspect ratio has been determined by TEM measurements. The reduced spectral function and the stoichiometry are extracted from the absorption spectra and the concentration of precipitated interstitial oxygen. One set of spectra reveal a Frohlich frequency around 1100 cm(-1) and another around 1110-1120 cm(-1). It is shown that the shift in the Frohlich frequency is not due to a different stoichiometry, but due to the detailed structure in the reduced spectral function. The oxygen precipitates consist of SiO. with gammaapproximate to1.1-1.2+/-0.1. (C) 2001 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.386
Times cited: 3
DOI: 10.1016/S0921-4526(01)00801-8
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“A 2a2a3c superstructure in hexagonal Ni1-xS : a study by means of electron-diffraction and HRTEM”. Lioutas CB, Manolikas C, Van Tendeloo G, van Landuyt J, Journal of crystal growth 126, 457 (1993). http://doi.org/10.1016/0022-0248(93)90051-W
Abstract: The high temperature phase of Ni1-xS has the NiAs-type structure. The coexistence of two superstructures, ''3a3a3c'' and ''2a2a3c'' with the basic phase is confirmed by means of electron diffraction. The 2a2a3c superstructure is studied by means of electron diffraction and high resolution electron microscopy. A structure model is proposed based on the periodic insertion of stacking faults in the NiAs-type basic structure and the ordering of vacancies in alternate metal-atom layers. Microtwinning in very narrow slabs is found to be a main feature of the 2a2a3c regions and two defect models are discussed.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.698
Times cited: 4
DOI: 10.1016/0022-0248(93)90051-W
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“Carbon nano-tubes: their formation process and observation by electron microscopy”. Zhang XF, Zhang XB, Van Tendeloo G, Amelinckx S, op de Beeck M, van Landuyt J, Journal of crystal growth 130, 368 (1993). http://doi.org/10.1016/0022-0248(93)90522-X
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.698
Times cited: 190
DOI: 10.1016/0022-0248(93)90522-X
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“Conical, helically woud, graphite whiskers: a limliting member of the “fullerenes”?”.Amelinckx S, Luyten W, Krekels T, Van Tendeloo G, van Landuyt J, Journal of crystal growth 121, 543 (1992). http://doi.org/10.1016/0022-0248(92)90561-V
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.698
Times cited: 43
DOI: 10.1016/0022-0248(92)90561-V
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“Round-robin investigation of silicon-oxide on silicon reference materials for ellipsometry”. Vanhellemont J, Maes HE, Schaekers M, Armigliato A, Cerva H, Cullis A, de Sande J, Dinges H, Hallais J, Nayar V, Pickering C, Stehlé, JL, Van Landuyt J, Walker C, Werner H, Salieri P;, Applied surface science
T2 –, SYMP ON DIAGNOSTIC TECHNIQUES FOR SEMICONDUCTOR MATERIALS ANALYSIS AND, FABRICATION PROCESS CONTROL, AT THE 1992 SPRING CONF OF THE EUROPEAN, MATERIALS RESEARCH SOC, JUN 02-05, 1992, STRASBOURG, FRANCE 63, 45 (1993). http://doi.org/10.1016/0169-4332(93)90062-G
Abstract: The main results and conclusions are presented of a round robin study of silicon oxide on silicon reference samples for ellipsometry. The oxide films with nominal thicknesses of 10, 50 and 120 nm are grown by thermal oxidation. The oxide film thicknesses have been determined by single wavelength ellipsometry (SWE), by spectroscopic ellipsometry (SE) and by cross-sectional conventional and high-resolution transmission electron microscopy (TEM and HREM) in different laboratories. The main conclusions are that special precautions have to be taken in order to use TEM as a reliable thickness measurement technique; that single wavelength ellipsometry can be used with great accuracy and reproducibility for the 50 and 120 nm film thicknesses but that it shows some inherent problems for the 10 nm films; and that spectroscopic ellipsometry showed for all film thicknesses an accuracy and reproducibility which is clearly superior to that of SWE.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.711
Times cited: 13
DOI: 10.1016/0169-4332(93)90062-G
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“SO4-chain formation and ordering in [YSrCa]Sr2Cu2.78(SO4)0.22O7-\delta”. Krekels T, Milat O, Van Tendeloo G, van Landuyt J, Amelinckx S, Slater PR, Greaves C, Physica: C : superconductivity 210, 439 (1993). http://doi.org/10.1016/0921-4534(93)90988-3
Abstract: YBCO-based materials containing SO4-tetrahedra centered on the Cu(1)-sites of the CuO-chain plane have been examined by means of electron diffraction and high resolution electron microscopy. An incommensurate modulation is observed and attributed to the ordering of b-oriented SO4-rich chains in the Cu(1)-S-O-layer, described in terms of an SO4-concentration wave.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.942
Times cited: 18
DOI: 10.1016/0921-4534(93)90988-3
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“Electron diffraction effects of conical, helically wound, graphite whiskers”. Luyten W, Krekels T, Amelinckx S, Van Tendeloo G, van Dyck D, van Landuyt J, Ultramicroscopy 49, 123 (1993). http://doi.org/10.1016/0304-3991(93)90219-N
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Impact Factor: 2.436
Times cited: 14
DOI: 10.1016/0304-3991(93)90219-N
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“In situ HREM study of electron irradiation effects in AgCl microcrystals”. Goessens C, Schryvers D, van Landuyt J, de Keyzer R, Ultramicroscopy 40, 151 (1992). http://doi.org/10.1016/0304-3991(92)90056-P
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.436
Times cited: 10
DOI: 10.1016/0304-3991(92)90056-P
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“Inelastic scattering of high-energy electrons in a crystal in thermal equilibrium with the environment: 1: theoretical framework”. Fanidis C, van Dyck D, van Landuyt J, Ultramicroscopy 41, 55 (1992). http://doi.org/10.1016/0304-3991(92)90094-Z
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Impact Factor: 2.436
Times cited: 17
DOI: 10.1016/0304-3991(92)90094-Z
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“The reciprocal space of carbon tubes: a detailed interpretation of the electron diffraction effects”. Zhang XB, Zhang XF, Amelinckx S, Van Tendeloo G, van Landuyt J, Ultramicroscopy 54, 237 (1994). http://doi.org/10.1016/0304-3991(94)90123-6
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.436
Times cited: 59
DOI: 10.1016/0304-3991(94)90123-6
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“A simple preparation method for air-sensitive specimens for transmission electron microscopy demonstrated by Rb6C60”. Zhang XF, Zhang XB, Bernaerts D, Van Tendeloo G, Amelinckx S, van Landuyt J, Werner H, Ultramicroscopy 55, 25 (1994). http://doi.org/10.1016/0304-3991(94)90077-9
Abstract: In this paper a particularly simple but efficient method is presented by which samples of alkali-doped C-60 materials or other air-sensitive materials can be prepared and transferred into a transmission electron microscope for direct observations and investigations. Flexible, transparent glove bags are used which are filled to a slight overpressure with dry nitrogen. Under this protective atmosphere, the air-sensitive sample is mounted in the specimen holder and inserted in the vacuum of the electron microscope. Rb6C60 which is prepared and transferred into the microscope in this way has been investigated by transmission electron microscopy (TEM). The results confirm the bcc structure and especially the location of the rubidium atoms.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.436
Times cited: 2
DOI: 10.1016/0304-3991(94)90077-9
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“The evolution of HVEM application in antwerp”. van Landuyt J, Ultramicroscopy
T2 –, 2nd Osaka International Symp.on High-Voltage Electron Microscopy : New Directions and Future Aspects of High Voltage Electron Microscopy, November 8-10, 1990, Osaka University, Osaka, Japan 39, 287 (1991). http://doi.org/10.1016/0304-3991(91)90208-N
Abstract: The evolution of the use of the 1250 keV high-voltage electron microscope in Antwerp is sketched by illustrating a non-exhaustive set of examples in various fields. One of the main present fields of application gets some more attention, i.e. the defect studies as produced by processing steps in microelectronic devices: (i) strain-induced dislocations at the edges of various device isolation interlayers, (ii) morphologies resulting from high-energy ion implantation creating buried layers for silicon on insulator (SOI) and other implantation technologies.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.436
DOI: 10.1016/0304-3991(91)90208-N
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“Defects in high-dose oxygen implanted silicon : a TEM study”. Deveirman A, van Landuyt J, Vanhellemont J, Maes HE, Yallup K, Vacuum: the international journal and abstracting service for vacuum science and technology
T2 –, 1ST SIOMX WORKSHOP ( SEPARATION BY IMPLANTATION OF OXYGEN ) ( SWI-88 ), NOV 07-08, 1988, UNIV SURREY, GUILDFORD, ENGLAND 42, 367 (1991). http://doi.org/10.1016/0042-207X(91)90055-N
Abstract: Results are discussed of a transmission electron microscopy study of high-dose oxygen implanted silicon. In addition to the general high temperature (> 1200-degrees-C) annealing treatments also annealings at 'low' temperatures (1000-1100-degrees-C) were performed in order to slow down the precipitate and defect reactions. The observed dissolution of the oxide precipitates during prolonged high temperature annealing is explained by critical radius considerations. Threading dislocations are the remaining lattice defects in the silicon overlayer and cannot be removed by further annealing. Low temperature annealing results in the formation and subsequent unfaulting of extrinsic stacking fault loops below the buried oxide layer.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.858
Times cited: 4
DOI: 10.1016/0042-207X(91)90055-N
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“Microstructure and spectroscopy studies on cubic boron nitride synthesized under high-pressure conditions”. Nistor LC, Nistor SV, Dinca G, Georgeoni P, van Landuyt J, Manfredotti C, Vittone E, Journal of physics : condensed matter 14, 10983 (2002). http://doi.org/10.1088/0953-8984/14/44/414
Abstract: High-resolution electron microscopy (HREM) studies of the microstructure and specific defects in hexagonal boron nitride (h-BN) precursors and cubic boron nitride (c-BN) crystals made under high-pressure high-temperature conditions revealed the presence of half-nanotubes at the edges of the h-BN particles. Their sp(3) bonding tendency could strongly influence the nucleation rates of c-BN. The atomic resolution at extended dislocations was insufficient to allow us to determine the stacking fault energy in the c-BN crystals. Its mean value of 191 +/- 15 mJ m(-2) is of the same order of magnitude as that of diamond. High-frequency (94 GHz) electron paramagnetic resonance studies on c-BN single crystals have produced new data on the D1 centres associated with the boron species. Ion-beam-induced luminescence measurements have indicated that c-BN is a very interesting luminescent material, which is characterized by four luminescence bands and exhibits a better resistance to ionizing radiation than CVD diamond.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.649
Times cited: 7
DOI: 10.1088/0953-8984/14/44/414
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“Optical spectroscopy of oxygen precipitates in heavily doped p-type silicon”. Simoen E, Loo R, Claeys C, de Gryse O, Clauws P, van Landuyt J, Lebedev O, Journal of physics : condensed matter
T2 –, Conference on Extended Defects in Semiconductors (EDS 2002), JUN 01-06, 2002, BOLOGNA, ITALY 14, 13185 (2002). http://doi.org/10.1088/0953-8984/14/48/367
Abstract: Results are presented on the photoluminescence (PL) characterization of heavily doped p(+) Czochralski silicon, which has been subjected to a two-step, oxygen precipitation heat treatment. It will be shown that the presence of oxygen precipitates gives rise to the D1, D2 and D5 lines, where the energy of the D1 line shifts to lower values for a stronger degree of precipitation. The occurrence of these PL features is also a function of the boron concentration in the p(+) material. The PL results are compared with Fourier transform infrared absorption data and with transmission electron microscope, results. From this, it is concluded that PL has a good potential for use in the assessment of oxygen precipitation in heavily doped silicon.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.649
Times cited: 3
DOI: 10.1088/0953-8984/14/48/367
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“Observation of Sb203 nanocrystals in SiO2 after Sb ion implantation”. Ignatova VA, Lebedev OI, Wätjen U, van Vaeck L, van Landuyt J, Gijbels R, Adams F, Microchimica acta 139, 77 (2002). http://doi.org/10.1007/s006040200043
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.58
Times cited: 3
DOI: 10.1007/s006040200043
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“Electron microscopy of carbon nanotubes and related structures”. Bernaerts D, Amelinckx S, Van Tendeloo G, van Landuyt J, The journal of physics and chemistry of solids 58, 1807 (1997). http://doi.org/10.1016/S0022-3697(98)80003-6
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.059
Times cited: 12
DOI: 10.1016/S0022-3697(98)80003-6
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“A counterion-catalyzed (S0H+)(X-I+) pathway toward heat- and steam-stable mesostructured silica assembled from amines in acidic conditions”. Cassiers K, van der Voort P, Linssen T, Vansant EF, Lebedev O, van Landuyt J, The journal of physical chemistry : B : condensed matter, materials, surfaces, interfaces and biophysical 107, 3690 (2003). http://doi.org/10.1021/jp026696v
Abstract: An alternative pathway to assemble mesoporous molecular sieve silicas is developed using nonionic alkylamines and N,N-dimethylalkylamines (SO) as structure-directing agents in acidic conditions. The synthesized mesostructures possess wormhole-like frameworks with pore sizes and pore volumes in the range of 20-90 Angstrom and 0.5-1.3 cm(3)/g, respectively. The formation of the mesophase is controlled by a counterion-mediated mechanism of the type (S(0)H(+))(X(-)I(+)), where S(0)H(+) are protonated water molecules that are hydrogen bonded to the lone electron pairs on the amine surfactant headgroups (S(0)H(+)), X(-) is the counteranion originating from the acid, and I(+) are the positively charged (protonated) silicate species. We found that the stronger the ion X(-) is bonded to S(0)H(+), the more it catalyzes the silica condensation into (S(0)H(+))(X(-)I(+)). Br(-) is shown to be a strong binding anion and therefore a fast silica polymerization promoter compared to Cl(-) resulting in the formation of a higher quality mesophase for the Br(-) syntheses. We also showed that the polymerization rate of the silica, dictated by the counterion, controls the morphology of the mesostructures from nonuniform agglomerated blocks in the case of Br(-) syntheses to spherical particles for the Cl(-) syntheses. Next to many benefits such as low temperature, short synthesis time, and the use of inexpensive, nontoxic, and easily extractable amine templates, the developed materials have a remarkable higher thermal and hydrothermal stability compared to hexagonal mesoporous silica, which is also prepared with nonionic amines but formed through the S(0)I(0) mechanism.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Impact Factor: 3.177
Times cited: 9
DOI: 10.1021/jp026696v
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“Electron microscopy characterisation of erbium silicide-thin films grown on a Si(111) substrate”. Frangis N, Van Tendeloo G, van Landuyt J, Muret P, Nguyen TTA, Applied surface science 102, 163 (1996). http://doi.org/10.1016/0169-4332(96)00040-2
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.711
Times cited: 9
DOI: 10.1016/0169-4332(96)00040-2
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“High crystalline quality erbium silicide films on (100) silicon grown in high vacuum”. Kaltsas G, Travlos A, Nassiopoulos AG, Frangis N, van Landuyt J, Applied surface science 102, 151 (1996). http://doi.org/10.1016/0169-4332(96)00036-0
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.711
Times cited: 14
DOI: 10.1016/0169-4332(96)00036-0
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