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“Topochemical nitridation with anion vacancy -assisted N3-/O2- exchange”. Mikita R, Aharen T, Yamamoto T, Takeiri F, Ya T, Yoshimune W, Fujita K, Yoshida S, Tanaka K, Batuk D, Abakumov AM, Brown CM, Kobayashi Y, Kageyama H;, Journal of the American Chemical Society 138, 3211 (2016). http://doi.org/10.1021/jacs.6b00088
Abstract: We present how the introduction of anion vacancies in oxyhydrides enables a route to access new oxynitrides, by conducting ammonolysis of perovskite oxyhydride EuTiO3-xHx (x similar to 0.18). At 400 degrees C, similar to our studies on BaTiO3-xHx, hydride lability enables a low temperature direct ammonolysis of EUTi3.82+O-2.82/H-0.18, leading to the N3-/H--exchanged product EuTi4+O2.82No0.12 square 0.06 center dot When the ammonolysis temperature was increased up to 800 degrees C, we observed a further nitridation involving N3-/O2- exchange, yielding a fully oxidized Eu3+Ti4+O2N with the GdFeO3-type distortion (Pnma) as a metastable phase, instead of pyrochlore structure. Interestingly, the same reactions using the oxide EuTiO3 proceeded through a 1:1 exchange of N3- with O-2 only above 600 degrees C and resulted in incomplete nitridation to EuTi02.25N0.75, indicating that anion vacancies created during the initial nitridation process of EuTiO2.82H0.18 play a crucial role in promoting anion (N3-/O2-) exchange at high temperatures. Hence, by using (hydride-induced) anion-deficient precursors, we should be able to expand the accessible anion composition of perovskite oxynitrides.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 28
DOI: 10.1021/jacs.6b00088
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“Structural study of the new complex oxides Ba5-ySryR2-xAl2Zr1+xO13+x/2 (R=Gd-Lu, Y, Sc)”. Shpanchenko RV, Abakumov AM, Antipov EV, Nistor L, Van Tendeloo G, Amelinckx S, Journal of solid state chemistry 118, 180 (1995). http://doi.org/10.1006/jssc.1995.1329
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.133
Times cited: 8
DOI: 10.1006/jssc.1995.1329
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“Conversion of platelets into dislocation loops and voidite formation in type IaB diamonds”. Evans T, Kiflawi I, Luyten W, Van Tendeloo G, Woods GS, Proceedings of the Royal Society of London: series A: mathematical and physical sciences 449, 295 (1995). http://doi.org/10.1098/rspa.1995.0045
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.192
Times cited: 32
DOI: 10.1098/rspa.1995.0045
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“Crystal chemistry of mercury based layered cuprates and oxycarbonates”. Raveau B, Hervieu M, Michel C, Martin C, Maignan A, Van Tendeloo G Narosa, New Delhi, page 132 (1995).
Keywords: H3 Book chapter; Electron microscopy for materials research (EMAT)
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“Structural aspect of YBa2Cu3O7-x films on Sis with complex barrier layers”. Vasiliev AL, Van Tendeloo G, Amelinckx S, Boikov Y, Olsson E, Ivanov Z, Physica: C : superconductivity 244, 373 (1995). http://doi.org/10.1016/0921-4534(95)00080-1
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.942
Times cited: 28
DOI: 10.1016/0921-4534(95)00080-1
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“Synthesis and characterization of mercury based “1222&rdquo, cuprates (Hg1-xMx)(Sr,Ba)2Pr2Cu2O9-\delta (M = Pr, Pb, Bi, Tl)”. Hervieu M, Van Tendeloo G, Michel C, Martin C, Maignan A, Raveau B, Journal of solid state chemistry 115, 525 (1995). http://doi.org/10.1006/jssc.1995.1169
Abstract: Five new layered cuprates, with a 1222-type structure, have been synthesized according to the formula (Hg(1-x)M(x))(Sr,Ba)(2) Pr2Cu2O9-delta with M = Pr, Pb, Pi, and Tl. They crystallize in a tetragonal cell with a approximate to a(p) and c approximate to 29.5 Angstrom; their structure consists in a triple intergrowth of oxygen-deficient perovskite, rock-salt-and fluorite-type layers. They are characterized by a mixed [Hg(1-x)M(x)O(1-delta)] layer in the rock-sail-type slice. The ED and HREM studies show that Tl, Bi, and Pb are statistically distributed in the mixed [Hg(1-x)M(x)O(1-delta)] layer, contrary to Pr which involves an ordering phenomenon along a. Different stacking defects are observed and discussed as well as the cleavage mode of the crystals. (C) 1995 Academic Press, Inc.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.133
Times cited: 5
DOI: 10.1006/jssc.1995.1169
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“Fullerenen: een nieuwe vorm van koolstof”. Van Tendeloo G, Echo 3: essays voor chemie-onderwijs , 79 (1995)
Keywords: A3 Journal article; Electron microscopy for materials research (EMAT)
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“A structure model and growth mechanism for multishell carbon nanotubes”. Amelinckx S, Bernaerts D, Zhang XB, Van Tendeloo G, van Landuyt J, Science 267, 1334 (1995). http://doi.org/10.1126/science.267.5202.1334
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 33.611
Times cited: 169
DOI: 10.1126/science.267.5202.1334
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“Ordering principles and defect structure of “1201”, “1212”, and “1222&rdquo, type (Hg,Pr)-Sr-(Sr,Ca,Pr)-Cu-O superconductors”. Van Tendeloo G, Hervieu M, Zhang XF, Raveau B, Journal of solid state chemistry 114, 369 (1995). http://doi.org/10.1006/jssc.1995.1057
Abstract: The new families of superconducting compounds ''1201'' (Hg0.4Pr0.6Sr2CuO4+delta), ''1212'' (Hg0.4Pr0.6Sr2(Ca1-x-ySrxPry) Cu2O6+delta), and ''1222'' (Hg0.4Pr0.6Sr2(Pr1.7Sr0.3)(2)Cu2O8+delta) all show ordering between praseodymium and mercury in the (Hg,Pr)O-delta plane, reducing the symmetry from tetragonal to orthorhombic or even to monoclinic. In the 1201 compound the ordered superstructure can be described as O-I (a(I) approximate to 2a(p), b(I), approximate to a(p), c(I) approximate to c(1201)). In the 1212 compound two distinct superstructures are identified, O-I (a(I) approximate to 2a(p), b(II) approximate to a(p), c(I) approximate to c(1212)) and O-II (a(II) approximate to 2a(p), b(II) approximate to a(p), c(II) approximate to 2c(1212)). In some compounds, such as Hg0.4Pr0.6Sr2(Ca0.4Sr0.4Pr0.2) Cu2O6+delta, the Hg-Pr ordering is only present in microdomains, but due to an ordering between Sr layers and Ca layers, the c-axis doubles and one obtains a tetragonal superstructure T-III (a(III) approximate to a(p), c(III) approximate to 2c(1212)). In the 1222 compound, ordering in the (Pr,Hg)O-delta plane is very defective; a large number of translation defects actually reduce the symmetry to triclinic. (C) 1995 Academic Press, Inc.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.133
Times cited: 11
DOI: 10.1006/jssc.1995.1057
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“Structural investigations of recently discovered high Tc superconductors”. Van Tendeloo G, Krekels T, Amelinckx S, Babu TGN, Greaves C, Hervieu M, Michel C, Raveau B, Microscopy research and technique 30, 102 (1995). http://doi.org/10.1002/jemt.1070300203
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.154
Times cited: 4
DOI: 10.1002/jemt.1070300203
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“Suppression of superconductivity in Hg-1223 and Hg-1234 by partial replacement of Hg by carbon”. Kopnin EM, Antipov EV, Capponi JJ, Bordet P, Chaillout C, de Brion S, Marezio M, Bobylev AP, Van Tendeloo G, Physica: C : superconductivity 243, 222 (1995). http://doi.org/10.1016/0921-4534(95)00010-0
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.942
Times cited: 22
DOI: 10.1016/0921-4534(95)00010-0
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“Structural aspects of AuCu I or AuCu II and a cuboidal black configuration of f.c.c. disordered phase in AuCu-Pt and AuCu-Ag pseudobinary alloys”. Udoh K-I, El- Araby AM, Tanaka Y, Hisatsune K, Yasuda K, Van Tendeloo G, van Landuyt J, Materials science and engineering: part A: structural materials: properties, microstructure and processing 203, 154 (1995). http://doi.org/10.1016/0921-5093(95)09850-X
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.567
Times cited: 15
DOI: 10.1016/0921-5093(95)09850-X
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“Point defect reactions in silicon studies in situ by high flux electron irradiation in high voltage transmission electron microscope”. Vanhellemont J, Romano-Rodriguez A, Fedina L, van Landuyt J, Aseev A, Materials science and technology 11, 1194 (1995)
Keywords: A3 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 7
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Van Boxem R (2015) Electron vortex beams : an in-depth theoretical study. Antwerpen
Keywords: Doctoral thesis; Electron microscopy for materials research (EMAT)
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“A transmission electron microscopy study of tweed-like structures in Al62Cu17.5CO17.5Si3 decagonal quasicrystals”. Zhang Z, Geng W, van Landuyt J, Van Tendeloo G, Philosophical magazine: A: physics of condensed matter: defects and mechanical properties 71, 1177 (1995)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 7
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“Structural aspects of carbon nanotubes”. Bernaerts D, Amelinckx S, Zhang XB, Van Tendeloo G, van Landuyt J, , 551 (1995)
Keywords: P3 Proceeding; Electron microscopy for materials research (EMAT)
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“The morphology, structure and texture of carbon nanotubes: an electron microscopy study”. Amelinckx S, Bernaerts D, Van Tendeloo G, van Landuyt J, Lucas AA, Mathot M, Lambin P, , 515 (1995)
Keywords: P3 Proceeding; Electron microscopy for materials research (EMAT)
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“In-situ HVEM study of dislocation generation in patterned stress fields at silicon surfaces”. Vanhellemont J, Claeys C, van Landuyt J, Physica status solidi: A: applied research 150, 497 (1995). http://doi.org/10.1002/pssa.2211500144
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 6
DOI: 10.1002/pssa.2211500144
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“Modification of the multislice method for calculating coherent STEM images”. Chen JH, van Dyck D, op de Beeck M, Broeckx J, van Landuyt J, Physica status solidi: A: applied research 150, 13 (1995). http://doi.org/10.1002/pssa.2211500103
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Times cited: 5
DOI: 10.1002/pssa.2211500103
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“Electron microscopy study of coiled carbon tubules”. Bernaerts D, Zhang XB, Zhang XF, Amelinckx S, Van Tendeloo G, van Landuyt J, Ivanov V, Nagy JB, Philosophical magazine: A: physics of condensed matter: defects and mechanical properties 71, 605 (1995). http://doi.org/10.1080/01418619508244470
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 72
DOI: 10.1080/01418619508244470
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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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“Gallium colloid formation during ion implantation of glass”. Hole DE, Townsend PD, Barton JD, Nistor LC, van Landuyt J, Journal of non-crystalline solids 180, 266 (1995). http://doi.org/10.1016/0022-3093(94)00477-3
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.766
Times cited: 34
DOI: 10.1016/0022-3093(94)00477-3
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“Solution-derived YBa2Cu3O7-\delta (YBCO) superconducting films with BaZrO3 (BZO) nanodots based on reverse micelle stabilized nanoparticles”. Bretos I, Schneller T, Falter M, Baecker M, Hollmann E, Woerdenweber R, Molina-Luna L, Van Tendeloo G, Eibl O, Journal of materials chemistry C : materials for optical and electronic devices 3, 3971 (2015). http://doi.org/10.1039/c4tc02543a
Abstract: Superconducting YBa2Cu3O7-delta (YBCO) films with artificial BaZrO3 (BZO) nanodots were prepared using a chemical solution deposition method involving hybrid solutions composed of trifluoroacetate-based YBCO precursors and reverse micelle stabilized BZO nanoparticle dispersions. Microemulsion-mediated synthesis was used to obtain nano-sized (similar to 12 nm) and mono-dispersed BZO nanoparticles that preserve their features once introduced into the YBCO solution, as revealed by dynamic light scattering. Phase pure, epitaxial YBCO films with randomly oriented BZO nanodots distributed over their whole microstructure were grown from the hybrid solutions on (100) LaAlO3 substrates. The morphology of the YBCO-BZO nanocomposite films was strongly influenced by the amount of nanoparticles incorporated into the system, with contents ranging from 5 to 40 mol%. Scanning electron microscopy showed a high density of isolated second-phase defects consisting of BZO nanodots in the nanocomposite film with 10 mol% of BZO. Furthermore, a direct observation and quantitative analysis of lattice defects in the form of interfacial edge dislocations directly induced by the BZO nanodots was evidenced by transmission electron microscopy. The superconducting properties (77 K) of the YBCO films improved considerably by the presence of such nanodots, which seem to enhance the morphology of the sample and therefore the intergranular critical properties. The incorporation of preformed second-phase defects (here, BZO) during the growth of the superconducting phase is the main innovation of this novel approach for the all-solution based low-cost fabrication of long-length coated conductors.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.256
Times cited: 19
DOI: 10.1039/c4tc02543a
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“Structural, electrochemical and magnetic properties of a novel KFeSO4F polymorph”. Lander L, Rousse G, Abakumov AM, Sougrati M, Van Tendeloo G, Tarascon J-M, Journal of materials chemistry A : materials for energy and sustainability 3, 19754 (2015). http://doi.org/10.1039/c5ta05548b
Abstract: In the quest for sustainable and low-cost positive electrode materials for Li-ion batteries, we discovered, as reported herein, a new low temperature polymorph of KFeSO4F. Contrary to the high temperature phase crystallizing in a KTiOPO4-like structure, this new phase adopts a complex layer-like structure built on FeO4F2 octahedra and SO4 tetrahedra, with potassium cations located in between the layers, as solved using neutron and synchrotron diffraction experiments coupled with electron diffraction. The detailed analysis of the structure reveals an alternation of edge-and corner-shared FeO4F2 octahedra leading to a large monoclinic cell of 1771.774(7) angstrom(3). The potassium atoms are mobile within the structure as deduced by ionic conductivity measurements and confirmed by the bond valence energy landscape approach thus enabling a partial electrochemical removal of K+ and uptake of Li+ at an average potential of 3.7 V vs. Li+/Li-0. Finally, neutron diffraction experiments coupled with SQUID measurements reveal a long range antiferromagnetic ordering of the Fe2+ magnetic moments below 22 K with a possible magnetoelectric behavior.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 8.867
Times cited: 11
DOI: 10.1039/c5ta05548b
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“The incorporation of nanoparticles into conventional glass-ionomer dental restorative cements”. Gjorgievska E, Van Tendeloo G, Nicholson JW, Coleman NJ, Slipper IJ, Booth S, Microscopy and microanalysis 21, 392 (2015). http://doi.org/10.1017/S1431927615000057
Abstract: Conventional glass-ionomer cements (GICs) are popular restorative materials, but their use is limited by their relatively low mechanical strength. This paper reports an attempt to improve these materials by incorporation of 10 wt% of three different types of nanoparticles, aluminum oxide, zirconium oxide, and titanium dioxide, into two commercial GICs (ChemFil((R)) Rock and EQUIA (TM) Fil). The results indicate that the nanoparticles readily dispersed into the cement matrix by hand mixing and reduced the porosity of set cements by filling the empty spaces between the glass particles. Both cements showed no significant difference in compressive strength with added alumina, and ChemFil((R)) Rock also showed no significant difference with zirconia. By contrast, ChemFil((R)) Rock showed significantly higher compressive strength with added titania, and EQUIA (TM) Fil showed significantly higher compressive strength with both zirconia and titania. Fewer air voids were observed in all nanoparticle-containing cements and this, in turn, reduced the development of cracks within the matrix of the cements. These changes in microstructure provide a likely reason for the observed increases in compressive strength, and overall the addition of nanoparticles appears to be a promising strategy for improving the physical properties of GICs.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.891
Times cited: 15
DOI: 10.1017/S1431927615000057
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“Hollow Zn/Co Zeolitic Imidazolate Framework (ZIF) and Yolk-Shell Metal@Zn/Co ZIF nanostructures”. Roesler C, Aijaz A, Turner S, Filippousi M, Shahabi A, Xia W, Van Tendeloo G, Muhler M, Fischer RA, Chemistry: a European journal 22, 3304 (2016). http://doi.org/10.1002/chem.201503619
Abstract: Metal-organic frameworks (MOFs) feature a great possibility for a broad spectrum of applications. Hollow MOF structures with tunable porosity and multifunctionality at the nanoscale with beneficial properties are desired as hosts for catalytically active species. Herein, we demonstrate the formation of well-defined hollow Zn/Co-based zeolitic imidazolate frameworks (ZIFs) by use of epitaxial growth of Zn-MOF (ZIF-8) on preformed Co-MOF (ZIF-67) nanocrystals that involve in situ self-sacrifice/excavation of the Co-MOF. Moreover, any type of metal nanoparticles can be accommodated in Zn/Co-ZIF shells to generate yolk-shell metal@ZIF structures. Transmission electron microscopy and tomography studies revealed the inclusion of these nanoparticles within hollow Zn/Co-ZIF with dominance of the Zn-MOF as shell. Our findings lead to a generalization of such hollow systems that are working effectively to other types of ZIFs.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.317
Times cited: 43
DOI: 10.1002/chem.201503619
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“Process variability in Cu2ZnSnSe4 solar cell devices: Electrical and structural investigations”. Brammertz G, Buffiere M, Verbist C, Bekaert J, Batuk M, Hadermann J, et al, The conference record of the IEEE Photovoltaic Specialists Conference
T2 –, IEEE 42nd Photovoltaic Specialist Conference (PVSC), JUN 14-19, 2015, New Orleans, LA (2015)
Abstract: We have fabricated 9.7% efficient Cu2ZnSnSe4/CdS/ZnO solar cells by H2Se selenization of sequentially sputtered metal layers. Despite the good efficiency obtained, process control appears to be difficult. In the present contribution we compare the electrical and physical properties of two devices with nominal same fabrication procedure, but 1% and 9.7% power conversion efficiency respectively. We identify the problem of the lower performing device to be the segregation of ZnSe phases at the backside of the sample. This ZnSe seems to be the reason for the strong bias dependent photocurrent observed in the lower performing devices, as it adds a potential barrier for carrier collection. The reason for the different behavior of the two nominally same devices is not fully understood, but speculated to be related to sputtering variability.
Keywords: P1 Proceeding; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
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“Highly efficient rutile TiO2 photocatalysts with single Cu(II) and Fe(III) surface catalytic sites”. Neubert S, Mitoraj D, Shevlin SA, Pulisova P, Heimann M, Du Y, Goh GKL, Pacia M, Kruczała K, Turner S, Macyk W, Guo ZX, Hocking RK, Beranek R;, Journal of materials chemistry A : materials for energy and sustainability 4, 3127 (2016). http://doi.org/10.1039/c5ta07036h
Abstract: Highly active photocatalysts were obtained by impregnation of nanocrystalline rutile TiO2 powders with small amounts of Cu(II) and Fe(III) ions, resulting in the enhancement of initial rates of photocatalytic degradation of 4-chlorophenol in water by factors of 7 and 4, compared to pristine rutile, respectively. Detailed structural analysis by EPR and X-ray absorption spectroscopy (EXAFS) revealed that Cu(II) and Fe(III) are present as single species on the rutile surface. The mechanism of the photoactivity enhancement was elucidated by a combination of DFT calculations and detailed experimental mechanistic studies including photoluminescence measurements, photocatalytic experiments using scavengers, OH radical detection, and photopotential transient measurements. The results demonstrate that the single Cu(II) and Fe(III) ions act as effective cocatalytic sites, enhancing the charge separation, catalyzing “dark” redox reactions at the interface, thus improving the normally very low quantum yields of UV light-activated TiO2 photocatalysts. The exact mechanism of the photoactivity enhancement differs depending on the nature of the cocatalyst. Cu(II)-decorated samples exhibit fast transfer of photogenerated electrons to Cu(II/I) sites, followed by enhanced catalysis of dioxygen reduction, resulting in improved charge separation and higher photocatalytic degradation rates. At Fe(III)-modified rutile the rate of dioxygen reduction is not improved and the photocatalytic enhancement is attributed to higher production of highly oxidizing hydroxyl radicals produced by alternative oxygen reduction pathways opened by the presence of catalytic Fe(III/II) sites. Importantly, it was demonstrated that excessive heat treatment (at 450 degrees C) of photocatalysts leads to loss of activity due to migration of Cu(II) and Fe(III) ions from TiO2 surface to the bulk, accompanied by formation of oxygen vacancies. The demonstrated variety of mechanisms of photoactivity enhancement at single site catalyst-modified photocatalysts holds promise for developing further tailored photocatalysts for various applications.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 8.867
Times cited: 44
DOI: 10.1039/c5ta07036h
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“Self-assembly of gas-phase synthesized magnesium nanoparticles on room temperature substrates”. Venturi F, Calizzi M, Bals S, Perkisas T, Pasquini L, Materials research express 2, 015007 (2015). http://doi.org/10.1088/2053-1591/2/1/015007
Abstract: Magnesium nanoparticles (NPs) with initial size in the 10-50 nmrange were synthesized by inert gas condensation under helium flow and deposited on room temperature substrates. The morphology and crystal structure of the NPs ensemble were investigated as a function of the deposition time by complementary electron microscopy techniques, including high resolution imaging and chemical mapping. With increasing amount of material, strong coarsening phenomena were observed at room temperature: small NPs disappeared while large faceted NPs developed, leading to a 5-fold increase of the average NPs size within a few minutes. The extent of coarsening and the final morphology depended also on the nature of the substrate. Furthermore, large single-crystal NPs were seen to arise from the self-organization of primary NPs units, providing a mechanism for crystal growth. The dynamics of the self-assembly process involves the basic steps of NPs sticking, diffusion on substrate, coordinated rotation and attachment/coalescence. Key features are the surface energy anisotropy, reflected by the faceted shape of the NPs, and the low melting point of the material. The observed phenomena have strong implications in relation to the synthesis and stability of nanostructures based on Mg or other elements with similar features.
Keywords: A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT)
Impact Factor: 1.068
Times cited: 14
DOI: 10.1088/2053-1591/2/1/015007
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“Texturing of hydrothermally synthesized BaTiO3 in a strong magnetic field by slip casting”. Özen M, Mertens M, Snijkers F, Van Tendeloo G, Cool P, Ceramics international 42, 5382 (2016). http://doi.org/10.1016/j.ceramint.2015.12.073
Abstract: Barium titanate powder was processed by slip casting in a rotating strong magnetic field of 9.4 T. The orientation factor of the sintered compact was analyzed by the X-ray diffraction technique and the microstructure (grain-size) was analyzed by scanning electron microscope. The hydrothermally prepared barium titanate was used as matrix material and the molten-salt synthesized barium titanate, with a larger particle-size, was used as template for the templated grain-growth process. Addition of large template particles was observed to increase the orientation factor of the sintered cast (5 vol% loading). Template particles acted as starting grains for the abnormal grain-growth process and the average grain-size was increased after sintering. Increasing the solid loading (15 vol%) resulted in a similar orientation factor with a decrease of the average grain size by more than half. However, addition of templates to the 15 vol% cast had a negative effect on the orientation factor. The impingement of growing particles was stated as the primary cause of particle misorientation resulting in a low orientation factor after sintering. Different heating conditions were tested and it was determined that a slow heating rate gave the highest orientation factor, the smallest average grain-size and the highest relative density. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Impact Factor: 2.986
Times cited: 11
DOI: 10.1016/j.ceramint.2015.12.073
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