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Author McCalla, E.; Abakumov, A.M.; Saubanere, M.; Foix, D.; Berg, E.J.; Rousse, G.; Doublet, M.-L.; Gonbeau, D.; Novak, P.; Van Tendeloo, G.; Dominko, R.; Tarascon, J.-M.
Title Visualization of O-O peroxo-like dimers in high-capacity layered oxides for Li-ion batteries Type A1 Journal article
Year 2015 Publication Science Abbreviated Journal Science
Volume 350 Issue 350 Pages 1516-1521
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Lithium-ion (Li-ion) batteries that rely on cationic redox reactions are the primary energy source for portable electronics. One pathway toward greater energy density is through the use of Li-rich layered oxides. The capacity of this class of materials (>270 milliampere hours per gram) has been shown to be nested in anionic redox reactions, which are thought to form peroxo-like species. However, the oxygen-oxygen (O-O) bonding pattern has not been observed in previous studies, nor has there been a satisfactory explanation for the irreversible changes that occur during first delithiation. By using Li2IrO3 as a model compound, we visualize the O-O dimers via transmission electron microscopy and neutron diffraction. Our findings establish the fundamental relation between the anionic redox process and the evolution of the O-O bonding in layered oxides.
Address College de France, Chimie du Solide et de l'Energie, FRE 3677, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05, France. ALISTORE-European Research Institute, FR CNRS 3104, 80039 Amiens, France. Reseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, France. Sorbonne Universites-UPMC Univ Paris 06, 4 Place Jussieu, F-75005 Paris, France. jean-marie.tarascon@college-de-france.fr
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000366591100056 Publication Date 2015-12-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0036-8075 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 37.205 Times cited 281 Open Access
Notes E.M. thanks the Fonds de Recherche du Québec–Nature et Technologies and ALISTORE–European Research Institute for funding this work, as well as the European community I3 networks for funding the neutron scattering research trip. This work was also funded by the Slovenian Research Agency research program P2-0148. This work is partially based on experiments performed at the Institut Laue Langevin. We thank J. Rodriguez-Carvajal for help with neutron scattering experiments and for fruitful discussions. We also thank M. T. Sougrati for performing the Sn-Mössbauer measurements. Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract no. DE-AC02- 06CH11357. M.S. and M.-L.D. acknowledge high-performance computational resources from GENCI-CCRT/CINES (grant cmm6691). J.-M.T. acknowledges funding from the European Research Council (ERC) (FP/2014-2020)/ERC Grant-Project670116-ARPEMA. Approved Most recent IF: 37.205; 2015 IF: 33.611
Call Number (down) c:irua:130202 Serial 4005
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Author Muguerra, H.; Pescheux, A.-C.; Meledin, A.; Van Tendeloo, G.; Soubeyroux, J.-L.
Title A La2−xGdxZr2O7layer deposited by chemical solution: a promising seed layer for the fabrication of high Jcand low cost coated conductors Type A1 Journal article
Year 2015 Publication Journal of materials chemistry C : materials for optical and electronic devices Abbreviated Journal J Mater Chem C
Volume 3 Issue 3 Pages 11766-11772
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We deposited La2-xGdxZr2O7 seed layers by a chemical solution method on a Ni-5%W substrate to study the influence of these layers on the growth process of a 60 nm-thick La2Zr2O7 layer. We measured the performances of these new buffer layers integrated in a coated conductor with a 300 nm-thick Y0.5Gd0.5Ba2Cu3O7-x layer. For the seed layers{,} we considered two different gadolinium contents (x = 0.2 and x = 0.8) and three different thicknesses for these compositions (20 nm{,} 40 nm{,} and 60 nm). The most promising buffer layer stacks are those with 20 nm of the La1.8Gd0.2Zr2O7 layer or La1.2Gd0.8Zr2O7. Indeed the La2-xGdxZr2O7/La2Zr2O7 films are highly textured{,} similar to a 100 nm-thick La2Zr2O7 layer{,} but their roughness is four times lower. Moreover they contain less and smaller pores in the seed layer than a pure La2Zr2O7 layer. The surface of La2Zr2O7 is also homogenous and crystalline with an orientation deviation from the ideal ?011? (100) direction below 10[degree]. With the 20 nm La2-xGdxZr2O7 seed layers we obtain in the coated conductors an efficiently textured transfer with no gradual degradation from the substrate throughout the superconducting layer. The highest Tc and Jc values are achieved with the La1.8Gd0.2Zr2O7 layer and are{,} respectively{,} 91 K and 1.4 MA cm-2. This trend seems to be due to an improvement of the surface quality of the Ni5%W substrate by the addition of a thin seed layer. Our results offer the potential of the La2-xGdxZr2O7 seed layers as promising alternatives for the classic Ni-5%W/LZO/CeO2/YBCO architectures.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000364826000024 Publication Date 2015-10-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2050-7526;2050-7534; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.256 Times cited 4 Open Access
Notes This work was performed within the framework of the EUROTAPES project (FP7-NMP.2011.2.2-1 Grant no. 280438), funded by the European Union. The authors also thank L. Porcar and P. Chometon for superconducting transition temperature and critical current density measurements and P. Odier for fruitful discussion. Approved Most recent IF: 5.256; 2015 IF: 4.696
Call Number (down) c:irua:130181 Serial 3968
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Author Cayado, P.; De Keukeleere, K.; Garzón, A.; Perez-Mirabet, L.; Meledin, A.; De Roo, J.; Vallés, F.; Mundet, B.; Rijckaert, H.; Pollefeyt, G.; Coll, M.; Ricart, S.; Palau, A.; Gázquez, J.; Ros, J.; Van Tendeloo, G.; Van Driessche, I.; Puig, T.; Obradors, X.
Title Epitaxial YBa2Cu3O7−xnanocomposite thin films from colloidal solutions Type A1 Journal article
Year 2015 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 28 Issue 28 Pages 124007
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A methodology of general validity to prepare epitaxial nanocomposite films based on the use of colloidal solutions containing different crystalline preformed oxide nanoparticles ( ex situ nanocomposites) is reported. The trifluoroacetate (TFA) metal–organic chemical solution deposition route is used with alcoholic solvents to grow epitaxial YBa 2 Cu 3 O 7 (YBCO) films. For this reason stabilizing oxide nanoparticles in polar solvents is a challenging goal. We have used scalable nanoparticle synthetic methodologies such as thermal and microwave-assisted solvothermal techniques to prepare CeO 2 and ZrO 2 nanoparticles. We show that stable and homogeneous colloidal solutions with these nanoparticles can be reached using benzyl alcohol, triethyleneglycol, nonanoic acid, trifluoroacetic acid or decanoic acid as protecting ligands, thereby allowing subsequent mixing with alcoholic TFA solutions. An elaborate YBCO film growth analysis of these nanocomposites allows the identification of the different relevant growth phenomena, e.g. nanoparticles pushing towards the film surface, nanoparticle reactivity, coarsening and nanoparticle accumulation at the substrate interface. Upon mitigation of these effects, YBCO nanocomposite films with high self-field critical currents ( J c ∼ 3–4 MA cm −2 at 77 K) were reached, indicating no current limitation effects associated with epitaxy perturbation, while smoothed magnetic field dependences of the critical currents at high magnetic fields and decreased effective anisotropic pinning behavior confirm the effectiveness of the novel developed approach to enhance vortex pinning. In conclusion, a novel low cost solution-derived route to high current nanocomposite superconducting films and coated conductors has been developed with very promising features.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000366288100009 Publication Date 2015-11-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 32 Open Access
Notes All authors acknowledge the EU (EU-FP7 NMP-LA-2012-280432 EUROTAPES project). ICMAB acknowledges MINECO (MAT2014-51778-C2-1-R) and Generalitat de Catalunya (2014SGR 753 and Xarmae). UGhent acknowledges the Special Research Fund (BOF), the Research Foundation Flanders (FWO) and the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT). TEM microscopy work was conducted in the Catalan Institute of Nanoscience and Nanotechnology (ICN2). The authors acknowledge the ICN2 Electron Microscopy Division for offering access to their instruments and expertise. Part of the STEM microscopy work was conducted in 'Laboratorio de Microscopias Avanzadas' at the Instituto de Nanociencia de Aragon—Universidad de Zaragoza. The authors acknowledge the LMA-INA for offering access to their instruments and expertise. JG and MC also acknowledge the Ramon y Cajal program (RYC-2012-11709 and RYC-2013-12448 respectively). Approved Most recent IF: 2.878; 2015 IF: 2.325
Call Number (down) c:irua:129593 Serial 3966
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Author Yan, Y.; Zhou, X.; Jin, H.; Li, C.-Z.; Ke, X.; Van Tendeloo, G.; Liu, K.; Yu, D.; Dressel, M.; Liao, Z.-M.
Title Surface-Facet-Dependent Phonon Deformation Potential in Individual Strained Topological Insulator Bi2Se3 Nanoribbons Type A1 Journal article
Year 2015 Publication ACS nano Abbreviated Journal Acs Nano
Volume 9 Issue 9 Pages 10244-10251
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Strain is an important method to tune the properties of topological insulators. For example, compressive strain can induce superconductivity in Bi2Se3 bulk material. Topological insulator nanostructures are the superior candidates to utilize the unique surface states due to the large surface to volume ratio. Therefore, it is highly desirable to monitor the local strain effects in individual topological insulator nanostructures. Here, we report the systematical micro-Raman spectra of single strained Bi2Se3 nanoribbons with different thicknesses and different surface facets, where four optical modes are resolved in both Stokes and anti-Stokes Raman spectral lines. A striking anisotropy of the strain dependence is observed in the phonon frequency of strained Bi2Se3 nanoribbons grown along the ⟨112̅0⟩ direction. The frequencies of the in-plane Eg2 and out-of-plane A1g1 modes exhibit a nearly linear blue-shift against bending strain when the nanoribbon is bent along the ⟨112̅0⟩ direction with the curved {0001} surface. In this case, the phonon deformation potential of the Eg2 phonon for 100 nm-thick Bi2Se3 nanoribbon is up to 0.94 cm–1/%, which is twice of that in Bi2Se3 bulk material (0.52 cm–1/%). Our results may be valuable for the strain modulation of individual topological insulator nanostructures.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000363915300079 Publication Date 2015-09-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851;1936-086X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.942 Times cited 14 Open Access
Notes Y.Y. would like to thank Xuewen Fu for helpful discussions. This work was supported by MOST (Nos. 2013CB934600, 2013CB932602) and NSFC (Nos. 11274014, 11234001). Approved Most recent IF: 13.942; 2015 IF: 12.881
Call Number (down) c:irua:129216 Serial 3963
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Author Cabana, L.; Gonzalez-Campo, A.; Ke, X.; Van Tendeloo, G.; Nunez, R.; Tobias, G.
Title Efficient Chemical Modification of Carbon Nanotubes with Metallacarboranes Type A1 Journal article
Year 2015 Publication Chemistry: a European journal Abbreviated Journal Chem-Eur J
Volume 21 Issue 21 Pages 16792-16795
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract As-produced single-walled carbon nanotubes (SWCNTs) tend to aggregate in bundles due to pi-pi interactions. Several approaches are nowadays available to debundle, at least partially, the nanotubes through surface modification by both covalent and noncovalent approaches. Herein, we explore different strategies to afford an efficient covalent functionalization of SWCNTs with cobaltabisdicarbollide anions. Aberration-corrected HRTEM analysis reveals the presence of metallacarboranes along the walls of the SWCNTs. This new family of materials presents an outstanding water dispersibility that facilitates its processability for potential applications.
Address Institut de Ciencia de Materials de Barcelona (ICMAB-CSIC), Campus Universitari de la UAB. 08193, Bellaterra (Spain). gerard.tobias@icmab.es
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000366501600011 Publication Date 2015-10-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0947-6539; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.317 Times cited 5 Open Access
Notes The research leading to these results received financial support from MINECO (MAT2014-53500-R; CTQ2013-44670-R), Generalitat de Catalunya (2014/SGR/149), and from the European Commission under the FP7 ITN Marie-Curie Network programme RADDEL (grant agreement 290023), the Integrated Infrastructure Initiative No. 262348 European Soft Matter Infrastructure (ESMI) and the European Research Council, ERC Grant No 246791-COUNTATOMS. A.G.C. thanks the CSIC for the JAE-DOC grant. Approved Most recent IF: 5.317; 2015 IF: 5.731
Call Number (down) c:irua:129215 Serial 3964
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Author Barreca, D.; Carraro, G.; Gasparotto, A.; Maccato, C.; Warwick, M.E.A.; Kaunisto, K.; Sada, C.; Turner, S.; Gönüllü, Y.; Ruoko, T.-P.; Borgese, L.; Bontempi, E.; Van Tendeloo, G.; Lemmetyinen, H.; Mathur, S.
Title Fe2O3-TiO2Nano-heterostructure Photoanodes for Highly Efficient Solar Water Oxidation Type A1 Journal article
Year 2015 Publication Advanced Materials Interfaces Abbreviated Journal Adv Mater Interfaces
Volume 2 Issue 2 Pages 1500313
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Harnessing solar energy for the production of clean hydrogen by photo­electrochemical water splitting represents a very attractive, but challenging approach for sustainable energy generation. In this regard, the fabrication of Fe2O3–TiO2 photoanodes is reported, showing attractive performances [≈2.0 mA cm−2 at 1.23 V vs. the reversible hydrogen electrode in 1 M NaOH] under simulated one-sun illumination. This goal, corresponding to a tenfold photoactivity enhancement with respect to bare Fe2O3, is achieved by atomic layer deposition of TiO2 over hematite (α-Fe2O3) nanostructures fabricated by plasma enhanced-chemical vapor deposition and final annealing at 650 °C. The adopted approach enables an intimate Fe2O3–TiO2 coupling, resulting in an electronic interplay at the Fe2O3/TiO2 interface. The reasons for the photocurrent enhancement determined by TiO2 overlayers with increasing thickness are unraveled by a detailed chemico-physical investigation, as well as by the study of photo­generated charge carrier dynamics. Transient absorption spectroscopy shows that the increased photoelectrochemical response of heterostructured photoanodes compared to bare hematite is due to an enhanced separation of photogenerated charge carriers and more favorable hole dynamics for water oxidation. The stable responses obtained even in simulated seawater provides a feasible route in view of the eventual large-scale generation of renewable energy.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000368914700011 Publication Date 2015-09-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2196-7350; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.279 Times cited 56 Open Access
Notes The authors kindly acknowledge the fi nancial support under the FP7 project “SOLAROGENIX” (NMP4-SL-2012-310333), as well as Padova University ex-60% 2012–2014 projects, Grant No. CPDR132937/13 (SOLLEONE), and Regione Lombardia-INSTM ATLANTE projects. S.T. acknowledges the FWO Flanders for a postdoctoral scholarship. Approved Most recent IF: 4.279; 2015 IF: NA
Call Number (down) c:irua:129201 Serial 3957
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Author Erbe, M.; Hänisch, J.; Hühne, R.; Freudenberg, T.; Kirchner, A.; Molina-Luna, L.; Damm, C.; Van Tendeloo, G.; Kaskel, S.; Schultz, L.; Holzapfel, B.
Title BaHfO3artificial pinning centres in TFA-MOD-derived YBCO and GdBCO thin films Type A1 Journal article
Year 2015 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 28 Issue 28 Pages 114002
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Chemical solution deposition (CSD) is a promising way to realize REBa2Cu3O7−x (REBCO;RE = rare earth (here Y, Gd))-coated conductors with high performance in applied magnetic fields. However, the preparation process contains numerous parameters which need to be tuned to achieve high-quality films. Therefore, we investigated the growth of REBCO thin films containing nanometre-scale BaHfO3 (BHO) particles as pinning centres for magnetic flux lines, with emphasis on the influence of crystallization temperature and substrate on the microstructure and superconductivity. Conductivity, microscopy and x-ray investigations show an enhanced performance of BHO nano-composites in comparison to pristine REBCO. Further, those measurements reveal the superiority of GdBCO to YBCO—e.g. by inductive critical current densities, Jc, at self-field and 77 K. YBCO is outperformed by more than 1 MA cm−2 with Jc values of up to 5.0 MA cm−2 for 265 nm thick layers of GdBCO(BHO) on lanthanum aluminate. Transport in-field Jc measurements demonstrate high pinning force maxima of around 4 GN m−3 for YBCO(BHO) and GdBCO(BHO). However, the irreversibility fields are appreciably higher for GdBCO. The critical temperature was not significantly reduced upon BHO addition to both YBCO and GdBCO, indicating a low tendency for Hf diffusion into the REBCO matrix. Angular-dependent Jc measurements show a reduction of the anisotropy in the same order of magnitude for both REBCO compounds. Theoretical models suggest that more than one sort of pinning centre is active in all CSD films.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000366193000003 Publication Date 2015-09-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 36 Open Access
Notes Experimental work was mainly done at IFW Dresden. We thank Juliane Scheiter and Dr Jens Ingolf Mönch of IFW Dresden for technical assistance. The research leading to these results received funding from EUROTAPES, a collaborative project funded by the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement no. NMP-LA-2012-280 432. L Molina-Luna and G Van Tendeloo acknowledge funding from the European Research Council (ERC grant nr. 24 691-COUNTATOMS). Approved Most recent IF: 2.878; 2015 IF: 2.325
Call Number (down) c:irua:129200 Serial 3941
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Author Pollefeyt, G.; Meledin, A.; Pop, C.; Ricart, S.; Hühne, R.; Van Tendeloo, G.; Van Driessche, I.
Title Chemical stability of YBiO3 buffer layers for implementation in YBa2Cu3O7-δ coated conductors Type A1 Journal article
Year 2015 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 100 Issue 100 Pages 224-231
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract In this work, the chemical and microstructural stability of YBiO3 buffer layers during the growth of YBa2Cu3O7-δ (YBCO) was studied. The superconducting YBCO films were deposited via both Pulsed Laser Deposition as well as Chemical Solution Deposition. Although excellent superconducting properties are obtained in both cases, self-field critical current densities of 3.6 and 1.2 MA/cm2 respectively, chemical instability of the YBiO3 buffer layer is observed. An elaborate transmission electron microscopy study showed that in the case of vacuum deposited YBCO, the YBiO3 becomes unstable and Bi2O3 sublimates out of the architecture. Due to this structural instability, an intermediate Y2O3 layer is obtained which maintains it microstructural orientation relation with the substrate and acts as growth template for YBCO. For chemical solution deposited YBCO, reaction of YBCO with the YBiO3 buffer layer is observed, leading to large grains of YBa2BiO6 which are pushed towards the surface of the films and strongly reduce the superconducting properties. Upon using high growth temperatures for the superconducting layer, these secondary phases decompose, which subsequently leads to Bi2O3 sublimation and a textured YBCO film which directly nucleated onto the LaAlO3 single crystal substrate. Hence, this electron microscopy study indicates that bismuth-based buffer layers systems are not suitable for implementation in coated conductors.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000362616400023 Publication Date 2015-08-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6454; ISBN Additional Links UA library record; WoS full record
Impact Factor 5.301 Times cited Open Access
Notes One of the authors (G.P.) would like to thank the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT) for funding. Part of this work was performed within the framework of the EuroTapes project (FP7-NMP.2011.2.2-1 Grant No. 280438), funded by the European Union. Approved Most recent IF: 5.301; 2015 IF: 4.465
Call Number (down) c:irua:128757 Serial 3953
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Author Kerkhofs, S.; Willhammar, T.; Van Den Noortgate, H.; Kirschhock, C.E.A.; Breynaert, E.; Van Tendeloo, G.; Bals, S.; Martens, J.A.
Title Self-Assembly of Pluronic F127—Silica Spherical Core–Shell Nanoparticles in Cubic Close-Packed Structures Type A1 Journal article
Year 2015 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 27 Issue 27 Pages 5161-5169
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A new ordered mesoporous silica material (COK-19) with cubic symmetry is synthesized by silicate polycondensation in a citric acid/citrate buffered micellar solution of Pluronic F127 triblock copolymer near neutral pH. SAXS, nitrogen adsorption, TEM, and electron tomography reveal the final material has a cubic close packed symmetry (Fm3̅m) with isolated spherical mesopores interconnected through micropores. Heating of the synthesis medium from room temperature to 70 °C results in a mesopore size increase from 7.0 to 11.2 nm. Stepwise addition of the silicate source allows isolation of a sequence of intermediates that upon characterization with small-angle X-ray scattering uncovers the formation process via formation and aggregation of individual silica-covered Pluronic micelles.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000359499100003 Publication Date 2015-07-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 39 Open Access OpenAccess
Notes J.A.M. acknowledges the Flemish government for long-term structural funding (Methusalem, METH/08/04). The Belgian government is acknowledged for financing the interuniversity poles of attraction (IAP-PAI, P7/05 FS2). G.V.T., S.B. and T.W. acknowledge financial support from European Research Council (ERC Starting Grant no. 335078-COLOURATOMS). E.B. acknowledges financial support the Flemish FWO for a postdoctoral fellowship (1265013N). The authors gratefully thank Kristof Houthoofd for performing the NMR experiments.; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); Approved Most recent IF: 9.466; 2015 IF: 8.354
Call Number (down) c:irua:127758 Serial 3977
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Author Van Tendeloo, L.; Wangermez, W.; Kurttepeli, M.; de Blochouse, B.; Bals, S.; Van Tendeloo, G.; Martens, J.A.; Maes, A.; Kirschhock, C.E.A.; Breynaert, E.
Title Chabazite : stable cation-exchanger in hyper alkaline concrete pore water Type A1 Journal article
Year 2015 Publication Environmental science and technology Abbreviated Journal Environ Sci Technol
Volume 49 Issue 49 Pages 2358-2365
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract To avoid impact on the environment, facilities for permanent disposal of hazardous waste adopt multibarrier design schemes. As the primary barrier very often consists of cement-based materials, two distinct aspects are essential for the selection of suitable complementary barriers: (1) selective sorption of the contaminants in the repository and (2) long-term chemical stability in hyperalkaline concrete-derived media. A multidisciplinary approach combining experimental strategies from environmental chemistry and materials science is therefore essential to provide a reliable assessment of potential candidate materials. Chabazite is typically synthesized in 1 M KOH solutions but also crystallizes in simulated young cement pore water, a pH 13 aqueous solution mainly containing K+ and Na+ cations. Its formation and stability in this medium was evaluated as a function of temperature (60 and 85 °C) over a timeframe of more than 2 years and was also asessed from a mechanistic point of view. Chabazite demonstrates excellent cation-exchange properties in simulated young cement pore water. Comparison of its Cs+ cation exchange properties at pH 8 and pH 13 unexpectedly demonstrated an increase of the KD with increasing pH. The combined results identify chabazite as a valid candidate for inclusion in engineered barriers for concrete-based waste disposal.
Address
Corporate Author Thesis
Publisher Place of Publication Easton, Pa Editor
Language Wos 000349806400047 Publication Date 2015-01-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0013-936X;1520-5851; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.198 Times cited 13 Open Access OpenAccess
Notes This work was supported by long-term structural funding by the Flemish Government (Methusalem) and by ONDRAF/ NIRAS, the Belgian Agency for Radioactive Waste and Fissile Materials, as part of the program on surface disposal of Belgian Category A waste. The Belgian government is acknowledged for financing the interuniversity poles of attraction (IAP-PAI). G.V.T. and S.B. acknowledge financial support from European Research Council (ERC Advanced Grant no. 24691-COUNTATOMS, ERC Starting Grant no. 335078-COLOURATOMS).; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); Approved Most recent IF: 6.198; 2015 IF: 5.330
Call Number (down) c:irua:127695 Serial 307
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Author Chen, J.J.; Wang, Q.; Meng, J.; Ke, X.; Van Tendeloo, G.; Bie, Y.Q.; Liu, J.; Liu, K.; Liao, Z.M.; Sun, D.; Yu, D.;
Title Photovoltaic effect and evidence of carrier multiplication in graphene vertical homojunctions with asymmetrical metal contacts Type A1 Journal article
Year 2015 Publication ACS nano Abbreviated Journal Acs Nano
Volume 9 Issue 9 Pages 8851-8858
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Graphene exhibits exciting potentials for high-speed wideband photodetection and high quantum efficiency solar energy harvest because of its broad spectral absorption, fast photoelectric response, and potential carrier multiplication. Although photocurrent can be generated near a metalgraphene interface in lateral devices, the photoactive area is usually limited to a tiny one-dimensional line-like interface region. Here, we report photoelectric devices based on vertical graphene two-dimensional homojunction, which is fabricated via vertically stacking four graphene monolayers with asymmetric metal contacts. The devices show excellent photovoltaic output with excitation wavelength ranging from visible light to mid-infrared. The wavelength dependence of the internal quantum efficiency gives direct evidence of the carrier multiplication effect in graphene. The simple fabrication process, easy scale-up, large photoresponsive active area, and broadband response of the vertical graphene device are very promising for practical applications in optoelectronics and photovoltaics.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000361935800023 Publication Date 2015-08-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851;1936-086X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.942 Times cited 11 Open Access
Notes 246791 Countatoms Approved Most recent IF: 13.942; 2015 IF: 12.881
Call Number (down) c:irua:127689 Serial 2615
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Author Paolella, A.; Bertoni, G.; Hovington, P.; Feng, Z.; Flacau, R.; Prato, M.; Colombo, M.; Marras, S.; Manna, L.; Turner, S.; Van Tendeloo, G.; Guerfi, A.; Demopoulos, G.P.; Zaghib, K.;
Title Cation exchange mediated elimination of the Fe-antisites in the hydrothermal synthesis of LiFePO4 Type A1 Journal article
Year 2015 Publication Nano energy Abbreviated Journal Nano Energy
Volume 16 Issue 16 Pages 256-267
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract In this work we elucidate the elimination of mechanism Fe-antisite defects in lithium iron phosphate (LiFePO4) during the hydrothermal synthesis. Compelling evidence of this effect is provided by combining Neutron Powder Diffraction (NPD), High Resolution (Scanning) Transmission Electron Microscopy (HR-(S)TEM), Electron Energy Loss Spectroscopy (EELS), X-Ray Photoelectron Spectroscopy (XPS) and calculations. We found: i) the first intermediate vivianite inevitably creates Fe-antisite defects in LiFePO4; ii) the removal of these antisite defects by cation exchange is assisted by a nanometer-thick amorphous layer, rich in Li, that enwraps the LiFePO4 crystals.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000364579300027 Publication Date 2015-06-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2211-2855; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.343 Times cited 27 Open Access
Notes The authorswanttoacknowledgeVincentGariepy,Cathe- rine Gagnon,JulieTrottier,DanielClement,Dr.CyrilFaure of IREQ,Dr.GaiaTomaselloofInstitutfürTheoretische PhysikFreieUniversitätBerlinandProf.MichelArmandof CICenergigune forhelpfuldiscussionsandtechnical supports. Approved Most recent IF: 12.343; 2015 IF: 10.325
Call Number (down) c:irua:127688 Serial 296
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Author Liu, J.; Hu, Z.-Y.; Peng, Y.; Huang, H.-W.; Li, Y.; Wu, M.; Ke, X.-X.; Van Tendeloo, G.; Su, B.-L.
Title 2D ZnO mesoporous single-crystal nanosheets with exposed {0001} polar facets for the depollution of cationic dye molecules by highly selective adsorption and photocatalytic decomposition Type A1 Journal article
Year 2016 Publication Applied catalysis : B : environmental Abbreviated Journal Appl Catal B-Environ
Volume 181 Issue 181 Pages 138-145
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Two dimensional (2D) ZnO nanosheets are ideal system for dimensionally confined transport phenomenon investigation owing to specific surface atomic configuration. Therefore, 2D ZnO porous nanosheets with single-crystal nature and {0001} polar facets, likely display some specific physicochemical properties. In this work, for the first time, 2D ZnO mesoporous single-crystal nanosheets (ZnO-MSN) with {0001} polar facets have been designed and prepared via an intriguing colloidal templating approach through controlling the infiltration speed for the suspension of EG-capped ZnO nanoparticles and polymer colloids. The EG-capped ZnO nanoparticles are very helpful for single-crystal nanosheet formation, while the polymer colloids play dual roles on the mesoporosity generation and {0001} polar facets formation within the mesopores. Such special 2D structure not only accelerates the hole-electron separation and the electron transportation owing to the single-crystal nature, but also enhances the selective adsorption of organic molecules owing to the porous structure and the exposed {0001} polar facets with more O-termination (000-1) surfaces: the 2D ZnO-MSN shows highly selective adsorption and significantly higher photodegradation for positively charged rhodamine B than those for negatively charged methyl orange and neutral phenol, comparing with ZnO nanoparticles (ZnO-NP) and ZnO commercial nanoparticles (ZnO-CNP) with high surface areas. This work may shed some light on better understanding the synthesis of 2D porous single-crystal nanosheet with exposed polar surfaces and photocatalytic mechanism of nanostructured semiconductors in a mixed organic molecules system.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000364256000015 Publication Date 2015-08-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0926-3373; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.446 Times cited 60 Open Access
Notes 246791 Countatoms Approved Most recent IF: 9.446
Call Number (down) c:irua:127638 c:irua:127638 c:irua:127638 Serial 10
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Author Papageorgiou, D.G.; Filippousi, M.; Pavlidou, E.; Chrissafis, K.; Van Tendeloo, G.; Bikiaris, D.
Title Effect of clay modification on structureproperty relationships and thermal degradation kinetics of \beta-polypropylene/clay composite materials Type A1 Journal article
Year 2015 Publication Journal of thermal analysis and calorimetry Abbreviated Journal J Therm Anal Calorim
Volume 122 Issue 122 Pages 393-406
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The influence of neat and organically modified montmorillonite on the structureproperty relationships of a β-nucleated polypropylene matrix has been thoroughly investigated. High-angle annular dark field scanning transmission electron microscopy revealed that the organic modification of clay facilitated the dispersion of the clay, while X-ray diffractograms showed the α-nucleating effect of the clays on the β-nucleated matrix. The results from tensile tests showed that the organic modification of MMT affected profoundly only the tensile strength at yield and at break. The effect of the organic modification of the clay on the thermal stability of the composites was finally evaluated by thermogravimetric analysis, where the samples filled with oMMT decomposed faster than the ones filled with neat MMT, due to the decomposition of the organic salts that were initially used for the modification of MMT. A kinetics study of the thermal degradation of the composites was also performed, in order to export additional conclusions on the activation energy of the samples.
Address
Corporate Author Thesis
Publisher Place of Publication S.l. Editor
Language Wos 000361431200042 Publication Date 2015-04-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1388-6150;1588-2926; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.953 Times cited 7 Open Access
Notes 262348 Esmi Approved Most recent IF: 1.953; 2015 IF: 2.042
Call Number (down) c:irua:127492 Serial 805
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Author Barreca, D.; Carraro, G.; Warwick, M.E.A.; Kaunisto, K.; Gasparotto, A.; Gombac, V.; Sada, C.; Turner, S.; Van Tendeloo, G.; Maccato, C.; Fornasiero, P.;
Title Fe2O3-TiO2 nanosystems by a hybrid PE-CVD/ALD approach : controllable synthesis, growth mechanism, and photocatalytic properties Type A1 Journal article
Year 2015 Publication CrystEngComm Abbreviated Journal Crystengcomm
Volume 17 Issue 17 Pages 6219-6226
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Supported Fe2O3–TiO2 nanocomposites are fabricated by an original vapor phase synthetic strategy, consisting of the initial growth of Fe2O3 nanosystems on fluorine-doped tin oxide substrates by plasma enhanced-chemical vapor deposition, followed by atomic layer deposition of TiO2 overlayers with variable thickness, and final thermal treatment in air. A thorough characterization of the target systems is carried out by X-ray diffraction, atomic force microscopy, field emission-scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. High purity nanomaterials characterized by the co-presence of Fe2O3 (hematite) and TiO2 (anatase), with an intimate Fe2O3–TiO2 contact, are successfully obtained. In addition, photocatalytic tests demonstrate that, whereas both single-phase oxides do not show appreciable activity, the composite systems are able to degrade methyl orange aqueous solutions under simulated solar light, and even visible light, with an efficiency directly dependent on TiO2 overlayer thickness. This finding opens attractive perspectives for eventual applications in wastewater treatment.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000358915300018 Publication Date 2015-07-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1466-8033; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.474 Times cited 25 Open Access
Notes The research leading to these results has received funding from the FP7 project “SOLAROGENIX” IJNMP4-SL-2012- 310333), as well as from Padova University ex-60% 2012–2015 projects, grant no. CPDR132937/13 (SOLLEONE), and Regione Lombardia-INSTM ATLANTE projects. S. T. acknowledges the FWO Flanders for a post-doctoral scholarship. Thanks are also due to Prof. S. Mathur and Dr. Y. Gönüllü (Department of Chemistry, Cologne University, Germany) for their precious help and assistance in ALD depositions, and to Prof. E. Bontempi (Chemistry for Technologies Laboratory, Brescia University, Italy) for XRD analyses. Approved Most recent IF: 3.474; 2015 IF: 4.034
Call Number (down) c:irua:127237 Serial 3531
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Author Filippousi, M.; Siafaka, P.I.; Amanatiadou, E.P.; Nanaki, S.G.; Nerantzaki, M.; Bikiaris, D.N.; Vizirianakis, I.S.; Van Tendeloo, G.
Title Modified chitosan coated mesoporous strontium hydroxyapatite nanorods as drug carriers Type A1 Journal article
Year 2015 Publication Journal of materials chemistry B : materials for biology and medicine Abbreviated Journal J Mater Chem B
Volume 3 Issue 3 Pages 5991-6000
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Mesoporous strontium hydroxyapatite (SrHAp) nanorods (NRs) have been successfully synthesized using a simple and efficient chemical route, i.e. the hydrothermal method. Structural and morphological characterization of the as-synthesized SrHAp NRs have been performed by transmission electron microscopy (TEM) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM). TEM and HAADF-STEM measurements of the NRs reveal the coexistence of longer and shorter particles with the length ranging from 50 nm to 400 nm and a diameter of about 20-40 nm. Electron tomography measurements of the NRs allow us to better visualize the mesopores and their facets. Two model drugs, hydrophobic risperidone and hydrophilic pramipexole, were loaded into the SrHAp NRs. These nanorods were coated using a modified chitosan (CS) with poly(2-hydroxyethyl methacrylate) (PHEMA), in order to encapsulate the drug-loaded SrHAp nanoparticles and reduce the cytotoxicity of the loaded materials. The drug release from neat and encapsulated SrHAp NRs mainly depends on the drug hydrophilicity. Importantly, although neat SrHAp nanorods exhibit some cytotoxicity against Caco-2 cells, the Cs-g-PHEMA-SrHAp drug-loaded nanorods show an acceptable cytocompatibility.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000358065100009 Publication Date 2015-06-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2050-750X;2050-7518; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.543 Times cited 24 Open Access
Notes Approved Most recent IF: 4.543; 2015 IF: 4.726
Call Number (down) c:irua:127131 Serial 2161
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Author Nerantzaki, M.; Filippousi, M.; Van Tendeloo, G.; Terzopoulou, Z.; Bikiaris, D.; Goudouri, O.M.; Detsch, R.; Grueenewald, A.; Boccaccini, A.R.
Title Novel poly(butylene succinate) nanocomposites containing strontium hydroxyapatite nanorods with enhanced osteoconductivity for tissue engineering applications Type A1 Journal article
Year 2015 Publication Express polymer letters Abbreviated Journal Express Polym Lett
Volume 9 Issue 9 Pages 773-789
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Three series of poly(butylene succinate) (PBSu) nanocomposites containing 0.5, 1 and 2.5 wt% strontium hydroxyapatite [Sr-5(PO4)(3)OH] nanorods (SrHAp nrds) were prepared by in situ polymerisation. The structural effects of Sr-5(PO4)(3)OH nanorods, for the different concentrations, inside the polymeric matrix (PBSu), were studied through high angle annular dark field scanning transmission electron microscopy (HAADF-STEM). HAADF-STEM measurements revealed that the SrHAp nanorods at low concentrations are dispersed inside the polymeric PBSu matrix while in 1 wt% some aggregates are formed. These aggregations affect the mechanical properties giving an enhancement for the concentration of 0.5 wt% SrHAp nrds in tensile strength, while a reduction is recorded for higher loadings of the nanofiller. Studies on enzymatic hydrolysis revealed that all nanocomposites present higher hydrolysis rates than neat PBSu, indicating that nanorods accelerate the hydrolysis degradation process. In vitro bioactivity tests prove that SrHAp nrds promote the formation of hydroxyapatite on the PBSu surface. All nanocomposites were tested also in relevant cell culture using osteoblast-like cells (MG-63) to demonstrate their biocompatibility showing SrHAp nanorods support cell attachment.
Address
Corporate Author Thesis
Publisher Budapest University of Technology and Economics Department of Polymer Engineering Place of Publication Budapest, Hungary Editor
Language Wos 000357287800004 Publication Date 2015-06-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1788-618X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.983 Times cited 21 Open Access
Notes 262348 Esmi Approved Most recent IF: 2.983; 2015 IF: 2.761
Call Number (down) c:irua:127009 Serial 2382
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Author Ke, X.; Bittencourt, C.; Van Tendeloo, G.
Title Possibilities and limitations of advanced transmission electron microscopy for carbon-based nanomaterials Type A1 Journal article
Year 2015 Publication Beilstein journal of nanotechnology Abbreviated Journal Beilstein J Nanotech
Volume 6 Issue 6 Pages 1541-1557
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract A major revolution for electron microscopy in the past decade is the introduction of aberration correction, which enables one to increase both the spatial resolution and the energy resolution to the optical limit. Aberration correction has contributed significantly to the imaging at low operating voltages. This is crucial for carbon-based nanomaterials which are sensitive to electron irradiation. The research of carbon nanomaterials and nanohybrids, in particular the fundamental understanding of defects and interfaces, can now be carried out in unprecedented detail by aberration-corrected transmission electron microscopy (AC-TEM). This review discusses new possibilities and limits of AC-TEM at low voltage, including the structural imaging at atomic resolution, in three dimensions and spectroscopic investigation of chemistry and bonding. In situ TEM of carbon-based nanomaterials is discussed and illustrated through recent reports with particular emphasis on the underlying physics of interactions between electrons and carbon atoms.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000357977300001 Publication Date 2015-07-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2190-4286; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.127 Times cited 10 Open Access
Notes 246791 Countatoms Approved Most recent IF: 3.127; 2015 IF: 2.670
Call Number (down) c:irua:126857 Serial 2682
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Author Van Gompel, M.; Atalay, A.Y.; Gaulke, A.; Van Bael, M.K.; D'Haen, J.; Turner, S.; Van Tendeloo, G.; Vanacken, J.; Moshchalkov, V.V.; Wagner, P.
Title Morphological TEM studies and magnetoresistance analysis of sputtered Al-substituted ZnO films : the role of oxygen Type A1 Journal article
Year 2015 Publication Physica status solidi : A : applications and materials science Abbreviated Journal Phys Status Solidi A
Volume 212 Issue 212 Pages 1191-1201
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In this article, we report on the synthesis of thin, epitaxial films of the transparent conductive oxide Al:ZnO on (0001)-oriented synthetic sapphire substrates by DC sputtering from targets with a nominal 1 at.% Al substitution. The deposition was carried out at an unusually low substrate temperature of only 250 °C in argonoxygen mixtures as well as in pure argon. The impact of the processgas composition on the morphology was analysed by transmission electron microscopy, revealing epitaxial growth in all the cases with a minor impact of the process parameters on the resulting grain sizes. The transport properties resistivity, Hall effect and magnetoresistance were studied in the range from 10 to 300 K in DC and pulsed magnetic fields up to 45 T. While the carrier density and mobility are widely temperature independent, we identified a low fieldlow temperature regime in which the magnetoresistance shows an anomalous, negative behaviour. At higher fields and temperatures, the magnetoresistance exhibits a more conventional, positive curvature with increasing field strength. As a possible explanation, we propose carrier scattering at localised magnetic trace impurities and magnetic correlations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000356706500003 Publication Date 2015-04-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1862-6300; ISBN Additional Links UA library record; WoS full record
Impact Factor 1.775 Times cited Open Access
Notes Methusalem project NANO; FWO; 246791 COUNTATOMS Approved Most recent IF: 1.775; 2015 IF: 1.616
Call Number (down) c:irua:126732 Serial 2204
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Author Li, J.; Ji, M.; Schwarz, T.; Ke, X.; Van Tendeloo, G.; Yuan, J.; Pereira, P.J.; Huang, Y.; Zhang, G.; Feng, H.L.; Yuan, Y.H.; Hatano, T.; Kleiner, R.; Koelle, D.; Chibotaru, L.F.; Yamaura, K.; Wang, H.B.; Wu, P.H.; Takayama-Muromachi, E.; Vanacken, J.; Moshchalkov, V.V.;
Title Local destruction of superconductivity by non-magnetic impurities in mesoscopic iron-based superconductors Type A1 Journal article
Year 2015 Publication Nature communications Abbreviated Journal Nat Commun
Volume 6 Issue 6 Pages 7614
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The determination of the pairing symmetry is one of the most crucial issues for the iron-based superconductors, for which various scenarios are discussed controversially. Non-magnetic impurity substitution is one of the most promising approaches to address the issue, because the pair-breaking mechanism from the non-magnetic impurities should be different for various models. Previous substitution experiments demonstrated that the non-magnetic zinc can suppress the superconductivity of various iron-based superconductors. Here we demonstrate the local destruction of superconductivity by non-magnetic zinc impurities in Ba0.5K0.5Fe2As2 by exploring phase-slip phenomena in a mesoscopic structure with 119 × 102 nm2 cross-section. The impurities suppress superconductivity in a three-dimensional Swiss cheese-like pattern with in-plane and out-of-plane characteristic lengths slightly below ~1.34 nm. This causes the superconducting order parameter to vary along abundant narrow channels with effective cross-section of a few square nanometres. The local destruction of superconductivity can be related to Cooper pair breaking by non-magnetic impurities.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000358857000007 Publication Date 2015-07-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 12 Open Access
Notes 246791 Countatoms Approved Most recent IF: 12.124; 2015 IF: 11.470
Call Number (down) c:irua:126677 Serial 1827
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Author Van Havenbergh, K.; Turner, S.; Driesen, K.; Bridel, J.-S.; Van Tendeloo, G.
Title Solidelectrolyte interphase evolution of carbon-coated silicon nanoparticles for lithium-ion batteries monitored by transmission electron microscopy and impedance spectroscopy Type A1 Journal article
Year 2015 Publication Energy technology Abbreviated Journal Energy Technol-Ger
Volume 3 Issue 3 Pages 699-708
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The main drawbacks of silicon as the most promising anode material for lithium-ion batteries (theoretical capacity=3572 mAh g−1) are lithiation-induced volume changes and the continuous formation of a solidelectrolyte interphase (SEI) upon cycling. A recent strategy is to focus on the influence of coatings and composite materials. To this end, the evolution of the SEI, as well as an applied carbon coating, on nanosilicon electrodes during the first electrochemical cycles is monitored. Two specific techniques are combined: Transmission Electron Microscopy (TEM) is used to study the surface evolution of the nanoparticles on a very local scale, whereas electrochemical impedance spectroscopy (EIS) provides information on the electrode level. A TEMEELS fingerprint signal of carbonate structures from the SEI is discovered, which can be used to differentiate between the SEI and a graphitic carbon matrix. Furthermore, the shielding effect of the carbon coating and the thickness evolution of the SEI are described.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000357869100003 Publication Date 2015-06-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2194-4288; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.789 Times cited Open Access
Notes IWT Flanders Approved Most recent IF: 2.789; 2015 IF: 2.824
Call Number (down) c:irua:126676 Serial 3051
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Author McCalla, E.; Prakash, A.S.; Berg, E.; Saubanere, M.; Abakumov, A.M.; Foix, D.; Klobes, B.; Sougrati, M.T.; Rousse, G.; Lepoivre, F.; Mariyappan, S.; Doublet, M.L.; Gonbeau, D.; Novak, P.; Van Tendeloo, G.; Hermann, R.P.; Tarascon, J.M.;
Title Reversible Li-intercalation through oxygen reactivity in Li-rich Li-Fe-Te oxide materials Type A1 Journal article
Year 2015 Publication Journal of the electrochemical society Abbreviated Journal J Electrochem Soc
Volume 162 Issue 162 Pages A1341-A1351
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Lithium-rich oxides are a promising class of positive electrode materials for next generation lithium-ion batteries, and oxygen plays a prominent role during electrochemical cycling either by forming peroxo-like species and/or by irreversibly forming oxygen gas during first charge. Here, we present Li-Fe-Te-O materials which show a tremendous amount of oxygen gas release. This oxygen release accounts for nearly all the capacity during the first charge and results in vacancies as seen by transmission electron microscopy. There is no oxidation of either metal during charge but significant changes in their environments. These changes are particularly extreme for tellurium. XRD and neutron powder diffraction both show limited Changes during cycling and no appreciable change in lattice parameters. A density functional theory study of this material is performed and demonstrates that the holes created on some of the oxygen atoms upon oxidation are partially stabilized through the formation of shorter O-O bonds, i.e. (O-2)(n-) species which on further delithiation show a spontaneous O-2 de-coordination from the cationic network and migration to the now empty lithium layer. The rate limiting step during charge is undoubtedly the diffusion of oxygen either out along the lithium layer or via columns of oxygen atoms. (C) 2015 The Electrochemical Society. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000355643700030 Publication Date 2015-04-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0013-4651;1945-7111; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.259 Times cited 23 Open Access
Notes Approved Most recent IF: 3.259; 2015 IF: 3.266
Call Number (down) c:irua:126445 Serial 2903
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Author Vidick, D.; Ke, X.; Devillers, M.; Poleunis, C.; Delcorte, A.; Moggi, P.; Van Tendeloo, G.; Hermans, S.
Title Heterometal nanoparticles from Ru-based molecular clusters covalently anchored onto functionalized carbon nanotubes and nanofibers Type A1 Journal article
Year 2015 Publication Beilstein journal of nanotechnology Abbreviated Journal Beilstein J Nanotech
Volume 6 Issue 6 Pages 1287-1297
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Heterometal clusters containing Ru and Au, Co and/or Pt are anchored onto carbon nanotubes and nanofibers functionalized with chelating phosphine groups. The cluster anchoring yield is related to the amount of phosphine groups available on the nanocarbon surface. The ligands of the anchored molecular species are then removed by gentle thermal treatment in order to form nanoparticles. In the case of Au-containing clusters, removal of gold atoms from the clusters and agglomeration leads to a bimodal distribution of nanoparticles at the nanocarbon surface. In the case of Ru-Pt species, anchoring occurs without reorganization through a ligand exchange mechanism. After thermal treatment, ultrasmall (1-3 nm) bimetal Ru-Pt nanoparticles are formed on the surface of the nanocarbons. Characterization by high resolution transmission electron microscopy (HRTEM) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) confirms their bimetal nature on the nanoscale. The obtained bimetal nanoparticles supported on nanocarbon were tested as catalysts in ammonia synthesis and are shown to be active at low temperature and atmospheric pressure with very low Ru loading.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000355908400001 Publication Date 2015-06-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2190-4286; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.127 Times cited 7 Open Access
Notes 246791 Countatoms; 262348 Esmi Approved Most recent IF: 3.127; 2015 IF: 2.670
Call Number (down) c:irua:126431 Serial 1420
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Author Schutyser, W.; Van den Bosch, S.; Dijkmans, J.; Turner, S.; Meledina, M.; Van Tendeloo, G.; Debecker, D.P.; Sels, B.F.
Title Selective nickel-catalyzed conversion of model and lignin-derived phenolic compounds to cyclohexanone-based polymer building blocks Type A1 Journal article
Year 2015 Publication Chemsuschem Abbreviated Journal Chemsuschem
Volume 8 Issue 8 Pages 1805-1818
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Valorization of lignin is essential for the economics of future lignocellulosic biorefineries. Lignin is converted into novel polymer building blocks through four steps: catalytic hydroprocessing of softwood to form 4-alkylguaiacols, their conversion into 4-alkylcyclohexanols, followed by dehydrogenation to form cyclohexanones, and Baeyer-Villiger oxidation to give caprolactones. The formation of alkylated cyclohexanols is one of the most difficult steps in the series. A liquid-phase process in the presence of nickel on CeO2 or ZrO2 catalysts is demonstrated herein to give the highest cyclohexanol yields. The catalytic reaction with 4-alkylguaiacols follows two parallel pathways with comparable rates: 1) ring hydrogenation with the formation of the corresponding alkylated 2-methoxycyclohexanol, and 2) demethoxylation to form 4-alkylphenol. Although subsequent phenol to cyclohexanol conversion is fast, the rate is limited for the removal of the methoxy group from 2-methoxycyclohexanol. Overall, this last reaction is the rate-limiting step and requires a sufficient temperature (> 250 degrees C) to overcome the energy barrier. Substrate reactivity (with respect to the type of alkyl chain) and details of the catalyst properties (nickel loading and nickel particle size) on the reaction rates are reported in detail for the Ni/CeO2 catalyst. The best Ni/CeO2 catalyst reaches 4-alkylcyclohexanol yields over 80 %, is even able to convert real softwood-derived guaiacol mixtures and can be reused in subsequent experiments. A proof of principle of the projected cascade conversion of lignocellulose feedstock entirely into caprolactone is demonstrated by using Cu/ZrO2 for the dehydrogenation step to produce the resultant cyclohexanones (approximate to 80%) and tin-containing beta zeolite to form 4-alkyl-e-caprolactones in high yields, according to a Baeyer-Villiger-type oxidation with H2O2.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000355220300020 Publication Date 2015-04-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1864-5631; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.226 Times cited 71 Open Access
Notes Fwo Approved Most recent IF: 7.226; 2015 IF: 7.657
Call Number (down) c:irua:126406 Serial 2967
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Author Sun, M.; Rousse, G.; Abakumov, A.M.; Saubanere, M.; Doublet, M.-L.; Rodriguez-Carvajal, J.; Van Tendeloo, G.; Tarascon, J.-M.
Title Li2Cu2O(SO4)2: a possible electrode for sustainable Li-based batteries showing a 4.7 V redox activity vs Li+/Li0 Type A1 Journal article
Year 2015 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 27 Issue 27 Pages 3077-3087
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Li-ion batteries rely on the use of insertion positive electrodes with performances scaling with the redox potential of the 31) metals accompanying Liuptake/removal. Although not commonly studied, the Cu2+/Cu3+ redox potential has been predicted from theoretical calculations to possibly offer a high operating voltage redox couple. We herein report the synthesis and crystal structure of a hitherto-unknown oxysulfate phase, Li2Cu2O(SO4)(2), which contains infinite edgesharing CuO4 chains and presents attractive electrochemical redox activity with respect to Li+/Li, namely amphoteric characteristics. Li2Cu2O(SO4)(2) shows redox activity at 4.7 V vs Li+/Li corresponding to the oxidation of Cu2+ to Cu3+ enlisting ligand holes and associated with the reversible uptake-removal of 0.3 Li. Upon reduction, this compound reversibly uptakes similar to 2 Li at an average potential of about 2.5 V vs Li+/Li, associated with the Cu2+/Cu+ redox couple. The mechanism of the reactivity upon reduction is discussed in detail, with particular attention to the occasional appearance of an oscillation wave in the discharge profile. Our work demonstrates that Cu-based compounds can indeed be fertile scientific ground in the search for new high-energy-density electrodes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000353865800043 Publication Date 2015-03-25
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 20 Open Access
Notes Approved Most recent IF: 9.466; 2015 IF: 8.354
Call Number (down) c:irua:126061 Serial 3541
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Author Warwick, M.E.A.; Kaunisto, K.; Barreca, D.; Carraro, G.; Gasparotto, A.; Maccato, C.; Bontempi, E.; Sada, C.; Ruoko, T.P.; Turner, S.; Van Tendeloo, G.;
Title Vapor phase processing of \alpha-Fe2O3 photoelectrodes for water splitting : an insight into the structure/property interplay Type A1 Journal article
Year 2015 Publication ACS applied materials and interfaces Abbreviated Journal Acs Appl Mater Inter
Volume 7 Issue 7 Pages 8667-8676
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Harvesting radiant energy to trigger water photoelectrolysis and produce clean hydrogen is receiving increasing attention in the search of alternative energy resources. In this regard, hematite (alpha-Fe2O3) nanostructures with controlled nano-organization have been fabricated and investigated for use as anodes in photoelectrochemical (PEC) cells. The target systems have been grown on conductive substrates by plasma enhanced-chemical vapor deposition (PE-CVD) and subjected to eventual ex situ annealing in air to further tailor their structure and properties. A detailed multitechnique approach has enabled to elucidate between system characteristics and the generated photocurrent. The present alpha-Fe2O3 systems are characterized by a high purity and hierarchical morphologies consisting of nanopyramids/organized dendrites, offering a high contact area with the electrolyte. PEC data reveal a dramatic response enhancement upon thermal treatment, related to a more efficient electron transfer. The reasons underlying such a phenomenon are elucidated and discussed by transient absorption spectroscopy (TAS) studies of photogenerated charge carrier kinetics, investigated on different time scales for the first time on PE-CVD Fe2O3 nanostructures.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000353931300037 Publication Date 2015-04-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1944-8244;1944-8252; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.504 Times cited 51 Open Access
Notes 246791 Countatoms; Fwo Approved Most recent IF: 7.504; 2015 IF: 6.723
Call Number (down) c:irua:126059 Serial 3836
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Author McCalla, E.; Sougrati, M.T.; Rousse, G.; Berg, E.J.; Abakumov, A.; Recham, N.; Ramesha, K.; Sathiya, M.; Dominko, R.; Van Tendeloo, G.; Novák, P.; Tarascon, J.M.;
Title Understanding the roles of anionic redox and oxygen release during electrochemical cycling of lithium-rich layered Li4FeSbO6 Type A1 Journal article
Year 2015 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
Volume 137 Issue 137 Pages 4804-4814
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Li-rich oxides continue to be of immense interest as potential next generation Li-ion battery positive electrodes, and yet the role of oxygen during cycling is still poorly understood. Here, the complex electrochemical behavior of Li4FeSbO6 materials is studied thoroughly with a variety of methods. Herein, we show that oxygen release occurs at a distinct voltage plateau from the peroxo/superoxo formation making this material ideal for revealing new aspects of oxygen redox processes in Li-rich oxides. Moreover, we directly demonstrate the limited reversibility of the oxygenated species (O-2(n-); n = 1, 2, 3) for the first time. We also find that during charge to 4.2 V iron is oxidized from +3 to an unusual +4 state with the concomitant formation of oxygenated species. Upon further charge to 5.0 V, an oxygen release process associated with the reduction of iron +4 to +3 is present, indicative of the reductive coupling mechanism between oxygen and metals previously reported. Thus, in full state of charge, lithium removal is fully compensated by oxygen only, as the iron and antimony are both very close to their pristine states. Besides, this charging step results in complex phase transformations that are ultimately destructive to the crystallinity of the material. Such findings again demonstrate the vital importance of fully understanding the behavior of oxygen in such systems. The consequences of these new aspects of the electrochemical behavior of lithium-rich oxides are discussed in detail.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000353177100036 Publication Date 2015-03-26
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 86 Open Access
Notes Approved Most recent IF: 13.858; 2015 IF: 12.113
Call Number (down) c:irua:126019 Serial 3805
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Author Filippousi, M.; Turner, S.; Katsikini, M.; Pinakidou, F.; Zamboulis, D.; Pavlidou, E.; Van Tendeloo, G.
Title Direct observation and structural characterization of natural and metal ion-exchanged HEU-type zeolites Type A1 Journal article
Year 2015 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat
Volume 210 Issue 210 Pages 185-193
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The atomic structure of natural HEU-type zeolite and two ion-exchanged variants of the zeolite, Ag+ (Ag-HEU) and Zn2+ (Zn-HEU) ion exchanged HEU-type zeolites, are investigated using advanced transmission electron microscopy techniques in combination with X-ray powder diffraction and X-ray absorption fine structure measurements. In both ion-exchanged materials, loading of the natural HEU zeolite is confirmed. Using low-voltage, aberration-corrected transmission electron microscopy at low-dose conditions, the local crystal structure of natural HEU-type zeolite is determined and the interaction of the ion-exchanged natural zeolites with the Ag+ and Zn2+ ions is studied. In the case of Ag-HEU, the presence of Ag+ ions and clusters at extra-framework sites as well as Ag nanoparticles has been confirmed. The Ag nanoparticles are preferentially positioned at the zeolite surface. For Zn-HEU, no large Zn(O) nanopartides are present, instead, the HEU channels are evidenced to be decorated by small Zn(O) clusters. (c) 2015 Elsevier Inc. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000353733300024 Publication Date 2015-02-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1387-1811; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.615 Times cited 5 Open Access
Notes 246791 Countatoms; Iap-Pai; Fwo Approved Most recent IF: 3.615; 2015 IF: 3.453
Call Number (down) c:irua:126006 Serial 715
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Author Lu, Y.-G.; Turner, S.; Ekimov, E.A.; Verbeeck, J.; Van Tendeloo, G.
Title Boron-rich inclusions and boron distribution in HPHT polycrystalline superconducting diamond Type A1 Journal article
Year 2015 Publication Carbon Abbreviated Journal Carbon
Volume 86 Issue 86 Pages 156-162
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Polycrystalline boron-doped superconducting diamond, synthesized at high pressure and high temperature (HPHT) via a reaction of a single piece of crystalline boron with monolithic graphite, has been investigated by analytical transmission electron microscopy. The local boron distribution and boron environment have been studied by a combination of (scanning) transmission electron microscopy ((S)TEM) and spatially resolved electron energy-loss spectroscopy (EELS). High resolution TEM imaging and EELS elemental mapping have established, for the first time, the presence of largely crystalline diamond-diamond grain boundaries within the material and have evidenced the presence of substitutional boron dopants within individual diamond grains. Confirmation of the presence of substitutional B dopants has been obtained through comparison of acquired boron K-edge EELS fine structures with known references. This confirmation is important to understand the origin of superconductivity in polycrystalline B-doped diamond. In addition to the substitutional boron doping, boron-rich inclusions and triple-points, both amorphous and crystalline, with chemical compositions close to boron carbide B4C, are evidenced. (C) 2015 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000352922700019 Publication Date 2015-01-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-6223; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.337 Times cited 20 Open Access
Notes FWO; 246791 COUNTATOMS; 278510 VORTEX; Hercules ECASJO_; Approved Most recent IF: 6.337; 2015 IF: 6.196
Call Number (down) c:irua:125994UA @ admin @ c:irua:125994 Serial 250
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Author Javon, E.; Gaceur, M.; Dachraoui, W.; Margeat, O.; Ackermann, J.; Ilenia Saba, M.; Delugas, P.; Mattoni, A.; Bals, S.; Van Tendeloo, G.
Title Competing forces in the self-assembly of coupled ZnO nanopyramids Type A1 Journal article
Year 2015 Publication ACS nano Abbreviated Journal Acs Nano
Volume 9 Issue 9 Pages 3685-3694
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Self-assembly (SA) of nanostructures has recently gained increasing interest. A clear understanding of the process is not straightforward since SA of nanoparticles is a complex multiscale phenomenon including different driving forces. Here, we study the SA between aluminum doped ZnO nanopyramids into couples by combining inorganic chemistry and advanced electron microscopy techniques with atomistic simulations. Our results show that the SA of the coupled nanopyramids is controlled first by morphology, as coupling only occurs in the case of pyramids with well-developed facets of the basal planes. The combination of electron microscopy and atomistic modeling reveals that the coupling is further driven by strong ligandligand interaction between the bases of the pyramids as dominant force, while screening effects due to Al doping or solvent as well as corecore interaction are only minor contributions. Our combined approach provides a deeper understanding of the complex interplay between the interactions at work in the coupled SA of ZnO nanopyramids.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000353867000030 Publication Date 2015-03-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851;1936-086X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.942 Times cited 21 Open Access OpenAccess
Notes Esmi; 335078 Colouratom; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); Approved Most recent IF: 13.942; 2015 IF: 12.881
Call Number (down) c:irua:125978 Serial 434
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