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Author Moshnyaga, V.; Damaschke, B.; Shapoval, O.; Belenchuk, A.; Faupel, J.; Lebedev, O.I.; Verbeeck, J.; Van Tendeloo, G.; Mücksch, M.; Tsurkan, V.; Tidecks, R.; Samwer, K.
Title Structural phase transition at the percolation threshold in epitaxial (La0.7Ca0.3MnO3)1-x:(MgO)x nanocomposite films Type A1 Journal article
Year 2003 Publication Nature materials Abbreviated Journal Nat Mater
Volume 2 Issue 4 Pages 247-252
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract 'Colossal magnetoresistance' in perovskite manganites such as La0.7Ca0.3MnO3 (LCMO), is caused by the interplay of ferro-paramagnetic, metal-insulator and structural phase transitions. Moreover, different electronic phases can coexist on a very fine scale resulting in percolative electron transport. Here we report on (LCMO)(1-x):(MgO)(x) (0 < x less than or equal to 0.8) epitaxial nano-composite films in which the structure and magnetotransport properties of the manganite nanoclusters can be tuned by the tensile stress originating from the MgO second phase. With increasing x, the lattice of LCMO was found to expand, yielding a bulk tensile strain. The largest colossal magnetoresistance of 10(5)% was observed at the percolation threshold in the conductivity at x(c) approximate to 0.3, which is coupled to a structural phase transition from orthorhombic (0 < x less than or equal to 0.1) to rhombohedral R (3) over barc structure (0.33 less than or equal to x less than or equal to 0.8). An increase of the Curie temperature for the R (3) over barc phase was observed. These results may provide a general method for controlling the magnetotransport properties of manganite-based composite films by appropriate choice of the second phase.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000182052700022 Publication Date 2003-03-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1476-1122;1476-4660; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 39.737 Times cited (up) 177 Open Access
Notes Approved Most recent IF: 39.737; 2003 IF: 10.778
Call Number UA @ lucian @ c:irua:54855 Serial 3247
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Author Neira, I.S.; Kolen'ko, Y.V.; Lebedev, O.I.; Van Tendeloo, G.; Gupta, H.S.; Guitián, F.; Yoshimura, M.
Title An effective morphology control of hydroxyapatite crystals via hydrothermal synthesis Type A1 Journal article
Year 2009 Publication Crystal growth & design Abbreviated Journal Cryst Growth Des
Volume 9 Issue 1 Pages 466-474
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A facile urea-assisted hydrothermal synthesis and systematic characterization of hydroxyapatite (HA) with calcium nitrate tetrahydrate and diammonium hydrogen phosphate as precursors are reported. The advantage of the proposed technique over previously reported synthetic approaches is the simple but precise control of the HA crystals morphology, which is achieved by employing an intensive, stepwise, and slow thermal decomposition of urea as well as varying initial concentrations of starting reagents. Whereas the plate-, hexagonal prism- and needle-like HA particles preferentially growth along the c-axis, the smaller and fine-plate-like HA crystals demonstrate crystal growth along the (102) and (211) directions, uncommon for HA. Furthermore, it was established that the hydrothermally derived powdered products are phase-pure HA containing CO32− anions in the crystal lattice, that is, AB-type carbonated hydroxyapatite. Transmission electron microscopy (TEM) and electron diffraction (ED) of selected samples reveal that the as-prepared HA crystals are single-crystalline and exhibit a nearly defect-free microstructure. The hardness and elastic modulus of the hexagonal prism-like HA crystals have been investigated on a nanoscale using the nanoindentation technique; the observed trends are discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000262332700073 Publication Date 2008-11-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1528-7483;1528-7505; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.055 Times cited (up) 183 Open Access
Notes Esteem 026019 Approved Most recent IF: 4.055; 2009 IF: 4.162
Call Number UA @ lucian @ c:irua:75740 Serial 853
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Author Lebedev, O.I.; Millange, F.; Serre, C.; Van Tendeloo, G.; Férey, G.
Title First direct imaging of giant pores of the metal-organic framework MIL-101 Type A1 Journal article
Year 2005 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 17 Issue 26 Pages 6525-6527
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000234187300007 Publication Date 2005-12-20
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 (up) 191 Open Access
Notes Approved Most recent IF: 9.466; 2005 IF: 4.818
Call Number UA @ lucian @ c:irua:56404 Serial 1197
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Author Esken, D.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Fischer, R.A.
Title Au@ZIFs: stabilization and encapsulation of cavity-size matching gold clusters inside functionalized Zeolite Imidazolate Frameworks, ZIFs Type A1 Journal article
Year 2010 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 22 Issue 23 Pages 6393-6401
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The selective formation and stabilization of very small, naked metal particles inside the cavities of metal organic frameworks (MOFs) and the simultaneous realization of an even distribution of the particles throughout the crystalline MOF host matrix over a wide range of metal loading are challenging goals. MOFs reveal high specific surface areas, tunable pore sizes, and organic linkers, which are able to interact with guests. The chemically very robust zeolite imidazolate frameworks (ZIFs) are a subclass of MOFs. We chose the microporous sodalite-like ZIF-8 (Zn(MelM)(2); IM = imidazolate) and ZIF-90 (Zn(ICA)(2); ICA = imidazolate-2-carboxyaldehyde) as host matrices to influence the dispersion of imbedded gold nanoparticles (Au NPs). The metal loading was achieved via gas phase infiltration of [Au(CO)Cl] followed by a thermal hydrogenation step to form the Au NPs. Low-dose high-resolution transmission electron microscopy ((HR)TEM) and electron tomography reveal a homogeneous distribution of Au NPs throughout the ZIF matrix. The functional groups of ZIF-90 direct the anchoring of intermediate Au species and stabilize drastically smaller and quite monodisperse Au NPs in contrast to the parent not functionalized ZIF-8. The particles can be very small, match the cavity size and approach defined molecular clusters of magic numbers, i.e., Au(55), independently from the level of loading. Post-synthetic oxidation of the aldehyde groups to yield alkyl esters by the adjacent, catalytically active metal NPs is presented as a new concept of encapsulating nanoparticles inside MOFs and allows multiple steps of metal loadings without decomposition of the MOF.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000284975100025 Publication Date 2010-11-12
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 (up) 194 Open Access
Notes Esteem 026019 Approved Most recent IF: 9.466; 2010 IF: 6.400
Call Number UA @ lucian @ c:irua:95530 Serial 208
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Author Kolen'ko, Y.V.; Kovnir, K.A.; Gavrilov, A.I.; Garshev, A.V.; Frantti, J.; Lebedev, O.I.; Churagulov, B.R.; Van Tendeloo, G.; Yoshimura, M.
Title Hydrothermal synthesis and characterization of nanorods of various titanates and titanium dioxide Type A1 Journal article
Year 2006 Publication The journal of physical chemistry : B : condensed matter, materials, surfaces, interfaces and biophysical Abbreviated Journal J Phys Chem B
Volume 110 Issue 9 Pages 4030-4038
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000235944500033 Publication Date 2006-03-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1520-6106;1520-5207; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.177 Times cited (up) 234 Open Access
Notes Approved Most recent IF: 3.177; 2006 IF: 4.115
Call Number UA @ lucian @ c:irua:56988 Serial 1540
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Author Schröder, F.; Esken, D.; Cokoja, M.; van den Berg, M.W.E.; Lebedev, O.I.; Van Tendeloo, G.; Walaszek, B.; Buntkowsky, G.; Limbach, H.H.; Chaudret, B.; Fischer, R.A.;
Title Ruthenium nanoparticles inside porous (Zn40(bdC)(3)) by hydrogenolysis of adsorbed (Ru(cod)(cot)): a solid-state reference system for surfactant-stabilized ruthenium colloids Type A1 Journal article
Year 2008 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
Volume 130 Issue 19 Pages 6119-6130
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000255620200018 Publication Date 2008-04-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.858 Times cited (up) 272 Open Access
Notes Esteem 026019 Approved Most recent IF: 13.858; 2008 IF: 8.091
Call Number UA @ lucian @ c:irua:68851 Serial 2934
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Author Godefroo, S.; Hayne, M.; Jivanescu, M.; Stesmans, A.; Zacharias, M.; Lebedev, O.I.; Van Tendeloo, G.; Moshchalkov, V.V.
Title Classification and control of the origin of photoluminescence from Si nanocrystals Type A1 Journal article
Year 2008 Publication Nature nanotechnology Abbreviated Journal Nat Nanotechnol
Volume 3 Issue 3 Pages 174-178
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Silicon dominates the electronics industry, but its poor optical properties mean that III-V compound semiconductors are preferred for photonics applications. Photoluminescence at visible wavelengths was observed from porous Si at room temperature in 1990, but the origin of these photons (do they arise from highly localized defect states or quantum confinement effects?) has been the subject of intense debate ever since. Attention has subsequently shifted from porous Si to Si nanocrystals, but the same fundamental question about the origin of the photoluminescence has remained. Here we show, based on measurements in high magnetic fields, that defects are the dominant source of light from Si nanocrystals. Moreover, we show that it is possible to control the origin of the photoluminescence in a single sample: passivation with hydrogen removes the defects, resulting in photoluminescence from quantum-confined states, but subsequent ultraviolet illumination reintroduces the defects, making them the origin of the light again.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000254743600017 Publication Date 2008-03-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1748-3387;1748-3395; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 38.986 Times cited (up) 426 Open Access
Notes Fwo Approved Most recent IF: 38.986; 2008 IF: 20.571
Call Number UA @ lucian @ c:irua:102630 Serial 373
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