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Author Lebedev, O.I.; Turner, S.; Liu, S.; Cool, P.; Van Tendeloo, G.
Title New nano-architectures of mesoporous silica spheres analyzed by advanced electron microscopy Type A1 Journal article
Year 2012 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 4 Issue 5 Pages 1722-1727
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Abstract (up) Using template-containing silica microspheres as a precursor, novel ordered mesoporous silica nanoparticles with a narrow pore size distribution and high crystallinity have been synthesized by various hydrothermal merging processes. Several architectures like chains, dumbbells, triangles, squares and flowers have been discovered. The linking mechanisms of these interacting silica spheres leading to the formation of ordered nano-structures are studied by HRTEM, HAADF-STEM and electron tomography and a plausible model is presented for several merging processes.
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Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000300433700051 Publication Date 2011-12-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364;2040-3372; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 5 Open Access
Notes Fwo Approved Most recent IF: 7.367; 2012 IF: 6.233
Call Number UA @ lucian @ c:irua:95038 Serial 2328
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Author Turner, S.; Lebedev, O.I.; Schroeder, F.; Fischer, R.A.; Van Tendeloo, G.
Title Direct imaging of loaded metal-organic framework materials (metal@MOF-5) Type A1 Journal article
Year 2008 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 20 Issue 17 Pages 5622-5627
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) We illustrate the potential of advanced transmission electron microscopy for the characterization of a new class of soft porous materials: metal@Zn4O(bdc)3 (metal@MOF-5; bdc = 1,4-benzenedicarboxylate). By combining several electron microscopy techniques (transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), electron diffraction (ED), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and electron tomography) and by carefully reducing the electron dose to avoid beam damage, it is possible to simultaneously characterize the MOF-5 framework material and the loaded metal nanoparticles. We also demonstrate that electron tomography can be used to accurately determine the position and distribution of the particles within the MOF-5 framework. To demonstrate the implementation of these microscopy techniques and what kind of results can be expected, measurements on gas-phase-loaded metal−organic framework materials Ru@MOF-5 and Pd@MOF-5 are presented.
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Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000258941400021 Publication Date 2008-08-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 112 Open Access
Notes Esteem 026019 Approved Most recent IF: 9.466; 2008 IF: 5.046
Call Number UA @ lucian @ c:irua:76595 Serial 714
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Author Fedina, L.; Lebedev, O.I.; Van Tendeloo, G.; van Landuyt, J.; Mironov, O.A.; Parker, E.H.C.
Title In situ HREM irradiation study of point-defect clustering in MBE-grown strained Si1-xGex/(001)Si structures Type A1 Journal article
Year 2000 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 61 Issue 15 Pages 10336-10345
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) We present a detailed analysis of the point-defect clustering in strained Si/Si(1-x)Ge(x)/(001)Si structures, including the interaction of the point defects with the strained interfaces and the sample surface during 400 kV electron irradiation at room temperature. Point-defect cluster formation is very sensitive to the type and magnitude of the strain in the Si and Si(1-x)Ge(x) layers. A small compressive strain (-0.3%) in the SiGe alloy causes an aggregation of vacancies in the form of metastable [110]-oriented chains. They are located on {113} planes and further recombine with interstitials. Tensile strain in the Si layer causes an aggregation of interstitial atoms in the forms of additional [110] rows which are inserted on {113} planes with [001]-split configurations. The chainlike configurations are characterized by a large outward lattice relaxation for interstitial rows (0.13 +/-0.01 nm) and a very small inward relaxation for vacancy chains (0.02+/-0.01 nm). A compressive strain higher than -0.5% strongly decreases point-defect generation inside the strained SiGe alloy due to the large positive value of the formation volume of a Frenkel pair. This leads to the suppression of point-defect clustering in a strained SiGe alloy so that SiGe relaxes via a diffusion of vacancies from the Si layer, giving rise to an intermixing at the Si/SiGe interface. In material with a 0.9% misfit a strongly increased flow of vacancies from the Si layer to the SiGe layer and an increased biaxial strain in SiGe bath promote the preferential aggregation of vacancies in the (001) plane, which relaxes to form intrinsic 60 degrees dislocation loops.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000086606200082 Publication Date 2002-07-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 27 Open Access
Notes Conference Name: Microsc. Semicond. Mater. Conf. Approved Most recent IF: 3.836; 2000 IF: NA
Call Number UA @ lucian @ c:irua:103456 Serial 1577
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Author Kalkert, C.; Krisponeit, J.-O.; Esseling, M.; Lebedev, O.I.; Moshnyaga, V.; Damaschke, B.; Van Tendeloo, G.; Samwer, K.
Title Resistive switching at manganite/manganite interfaces Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 99 Issue 13 Pages 132512-132512,3
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) We report bipolar resistive switching between the interfaces of manganite nanocolumns. La0.7Sr0.3MnO3 films were prepared on Al2O3 substrates, where the films grow in nanocolumns from the substrate to the surface. Conductive atomic force microscopy directly detects that the resistive switching is located at the boundaries of the grains. Furthermore, mesoscopic transport measurements reveal a tunnel magnetoresistance. In combination with the resistive switching, this leads to a total of four different resistive states.
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Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000295618000052 Publication Date 2011-09-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 10 Open Access
Notes Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number UA @ lucian @ c:irua:91884 Serial 2881
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Author Barreca, D.; Carraro, G.; Gasparotto, A.; Maccato, C.; Lebedev, O.I.; Parfenova, A.; Turner, S.; Tondello, E.; Van Tendeloo, G.
Title Tailored vapor-phase growth of CuxO-TiO2(x=1,2) nanomaterials decorated with Au particles Type A1 Journal article
Year 2011 Publication Langmuir: the ACS journal of surfaces and colloids Abbreviated Journal Langmuir
Volume 27 Issue 10 Pages 6409-6417
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) We report on the fabrication of CuxOTiO2 (x = 1, 2) nanomaterials by an unprecedented vapor-phase approach. The adopted strategy involves the growth of porous CuxO matrices by means of chemical vapor deposition (CVD), followed by the controlled dispersion of TiO2 nanoparticles. The syntheses are performed on Si(100) substrates at temperatures of 400550 °C under wet oxygen atmospheres, adopting Cu(hfa)2·TMEDA (hfa =1,1,1,5,5,5-hexafluoro-2,4-pentanedionate; TMEDA = N,N,N′,N′-tetramethylethylenediamine) and Ti(O-iPr)2(dpm)2 (O-iPr = isopropoxy; dpm = 2,2,6,6-tetramethyl-3,5-heptanedionate) as copper and titanium precursors, respectively. Subsequently, finely dispersed gold nanoparticles are introduced in the as-prepared systems via radio frequency (RF)-sputtering under mild conditions. The synthesis process results in the formation of systems with chemical composition and nano-organization strongly dependent on the nature of the initial CuxO matrix and on the deposited TiO2 amount. The decoration with low-size gold clusters paves the way to the engineering of hierarchically organized nanomaterials.
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Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000290292900082 Publication Date 2011-04-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0743-7463;1520-5827; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.833 Times cited 36 Open Access
Notes Fwo Approved Most recent IF: 3.833; 2011 IF: 4.186
Call Number UA @ lucian @ c:irua:88940 Serial 3467
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Author Philippaerts, A.; Paulussen, S.; Breesch, A.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Sels, B.; Jacobs, P.
Title Unprecedented shape selectivity in hydrogenation of triacylglycerol molecules with Pt/ZSM-5 zeolite Type A1 Journal article
Year 2011 Publication Angewandte Chemie: international edition in English Abbreviated Journal Angew Chem Int Edit
Volume 50 Issue 17 Pages 3947-3949
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Well tuned: ZSM-5 with platinum nanoparticles preferably hydrogenates trans fatty acids over cis isomers in model triacylglycerols for geometric reasons. The central fatty acid chain reacts faster, pointing to pore mouth adsorption in a tuning fork conformation (see picture). This conformation induces stepwise hydrogenation, resulting in fast removal of the unstable central triene, while formation of saturated chains is limited.
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Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000289514100025 Publication Date 2011-03-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1433-7851; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 11.994 Times cited 31 Open Access
Notes Approved Most recent IF: 11.994; 2011 IF: 13.455
Call Number UA @ lucian @ c:irua:88381 Serial 3814
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Author Vernimmen, J.; Meynen, V.; Herregods, S.J.F.; Mertens, M.; Lebedev, O.I.; Van Tendeloo, G.; Cool, P.
Title New insights in the formation of combined zeolitic/mesoporous materials by using a one-pot templating synthesis Type A1 Journal article
Year 2011 Publication European journal of inorganic chemistry Abbreviated Journal Eur J Inorg Chem
Volume Issue 27 Pages 4234-4240
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Abstract (up) Zeolitic growth is often absent or occurs in separate phases when synthetic strategies based on the combination of zeolite templates and mesopore templating agents are applied. In this work, zeolitic growth and mesopore formation have been investigated at different temperatures by applying a one-pot templating approach, based on a TS-1 zeolite synthesis whereby part of the microtemplate (tetrapropylammonium hydroxide, TPAOH) is replaced by a mesotemplate (hexadecyltrimethylammonium bromide, CTMABr). Moreover, the synthesis duration and the molar ratio of the microtemplate/mesotemplate have also been studied. The different syntheses clearly show the inherent competitive mechanism between zeolitic growth and mesopore formation. These insights have led to the conclusion that by following a one-pot templating strategy with standard, nonexotic commercial templates, i.e. CTMABr and TPAOH, it is not possible to develop a true hierarchical mesoporous zeolite, meaning a mesoporous siliceous material with highly crystalline zeolitic walls. The resultant materials are instead combined zeolitic/mesoporous composite structures with, however, highly tuneable and controllable porosity characteristics.
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Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000296143500014 Publication Date 2011-08-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-1948; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.444 Times cited 7 Open Access
Notes Fwo Approved Most recent IF: 2.444; 2011 IF: 3.049
Call Number UA @ lucian @ c:irua:91574 Serial 2315
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