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Author Liao, Z.; Huijben, M.; Zhong, Z.; Gauquelin, N.; Macke, S.; Green, R.J.; Van Aert, S.; Verbeeck, J.; Van Tendeloo, G.; Held, K.; Sawatzky, G.A.; Koster, G.; Rijnders, G.
Title Controlled lateral anisotropy in correlated manganite heterostructures by interface-engineered oxygen octahedral coupling Type A1 Journal article
Year (down) 2016 Publication Nature materials Abbreviated Journal Nat Mater
Volume 15 Issue 15 Pages 425-431
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Controlled in-plane rotation of the magnetic easy axis in manganite heterostructures by tailoring the interface oxygen network could allow the development of correlated oxide-based magnetic tunnelling junctions with non-collinear magnetization, with possible practical applications as miniaturized high-switching-speed magnetic random access memory (MRAM) devices. Here, we demonstrate how to manipulate magnetic and electronic anisotropic properties in manganite heterostructures by engineering the oxygen network on the unit-cell level. The strong oxygen octahedral coupling is found to transfer the octahedral rotation, present in the NdGaO3 (NGO) substrate, to the La2/3Sr1/3MnO3 (LSMO) film in the interface region. This causes an unexpected realignment of the magnetic easy axis along the short axis of the LSMO unit cell as well as the presence of a giant anisotropic transport in these ultrathin LSMO films. As a result we possess control of the lateral magnetic and electronic anisotropies by atomic-scale design of the oxygen octahedral rotation.
Address MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000372591700017 Publication Date 2016-03-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1476-1122 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 39.737 Times cited 273 Open Access
Notes We would like to acknowledge Dr. Evert Houwman for stimulated discussion. M.H., G.K. and G.R. acknowledge funding from DESCO program of the Dutch Foundation for Fundamental Research on Matter (FOM) with financial support from the Netherlands Organization for Scientific Research (NWO). This work was funded by the European Union Council under the 7th Framework Program (FP7) grant nr NMP3-LA-2010- 246102 IFOX. J.V. and S.V.A. acknowledges funding from FWO project G.0044.13N and G. 0368.15N. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. N.G. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. N.G., S.V.A., J.V. and G.V.T. acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative (Reference No. 312483-ESTEEM2). The Canadian work was supported by NSERC and the Max Planck-UBC Centre for Quantum Materials. Some experiments for this work were performed at the Canadian Light Source, which is funded by the Canada Foundation for Innovation, NSERC, the National Research Council of Canada, the Canadian Institutes of Health Research, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan. Z.Z. acknowledges funding from the SFB ViCoM (Austrian Science Fund project ID F4103- N13), and Calculations have been done on the Vienna Scientific Cluster (VSC).; esteem2jra2; esteem2jra3 ECASJO_; Approved Most recent IF: 39.737
Call Number c:irua:133190 c:irua:133190UA @ admin @ c:irua:133190 Serial 4041
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Author Van Duppen, B.; Tomadin, A.; Grigorenko, A.N.; Polini, M.
Title Current-induced birefringent absorption and non-reciprocal plasmons in graphene Type A1 Journal article
Year (down) 2016 Publication 2D materials Abbreviated Journal 2D Mater
Volume 3 Issue 3 Pages 015011
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We present extensive calculations of the optical and plasmonic properties of a graphene sheet carrying a dc current. By calculating analytically the density-density response function of current-carrying states at finite temperature, we demonstrate that an applied dc current modifies the Pauli blocking mechanism and that absorption acquires a birefringent character with respect to the angle between the in-plane light polarization and current flow. Employing the random phase approximation at finite temperature, we show that graphene plasmons display a degree of non-reciprocity and collimation that can be tuned with the applied current. We discuss the possibility to measure these effects.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000373936300031 Publication Date 2016-02-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.937 Times cited 5 Open Access
Notes This work was supported by the EC under the Graphene Flagship program (contract no. CNECT- ICT-604391) and MIUR through the program ‘Pro- getti Premiali 2012’ – Project ‘ABNANOTECH’. B.V. D. wishes to thank the Scuola Normale Superiore (Pisa, Italy) for the kind hospitality while this work was carried out and Research Foundation Flanders (FWO- Vl) for a PhD Fellowship. Approved Most recent IF: 6.937
Call Number c:irua:131900 c:irua:131900 Serial 4017
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Author Degutis, G.; Pobedinskas, P.; Turner, S.; Lu, Y.-G.; Al Riyami, S.; Ruttens, B.; Yoshitake, T.; D'Haen, J.; Haenen, K.; Verbeeck, J.; Hardy, A.; Van Bael, M.K.
Title CVD diamond growth from nanodiamond seeds buried under a thin chromium layer Type A1 Journal article
Year (down) 2016 Publication Diamond and related materials Abbreviated Journal Diam Relat Mater
Volume 64 Issue 64 Pages 163-168
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract This work presents a morphological and structural analysis of CVD diamond growth on silicon from nanodiamond seeds covered by a 50 nm thick chromium layer. The role of carbon diffusion as well as chromium and carbon silicide formation is analyzed. The local diamond environment is investigated by scanning transmission electron microscopy in combination with electron energy-loss spectroscopy. The evolution of the diamond phase composition (sp3/sp2) is evaluated by micro-Raman spectroscopy. Raman and X-ray diffraction analysis are used to identify the interfacial phases formed during CVD growth. Based upon the observed morphological and structural evolution, a diamond growth model from nanodiamond seeds buried beneath a thin Cr layer is proposed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000374608100020 Publication Date 2016-02-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-9635 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.561 Times cited 11 Open Access
Notes The authors acknowledge financial support provided by Research Program FWO G.056.810 and G0044.13N. A.H. and M.K.V.B are grateful to Hercules Foundation Flanders for financial support. P.P. and S.T. are Postdoctoral Fellows of the Research Foundation – Flanders (FWO). The Titan microscope used for this work was partially funded by the Hercules Foundation. Approved Most recent IF: 2.561
Call Number c:irua:133624UA @ admin @ c:irua:133624 Serial 4091
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Author Van Vlierberghe, S.
Title Crosslinking strategies for porous gelatin scaffolds Type A1 Journal article
Year (down) 2016 Publication Journal of materials science Abbreviated Journal
Volume 51 Issue 9 Pages 4349-4357
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract The present work reports on the application and the evaluation of a multitude of crosslinking approaches including high-energy irradiation, redox-initiating systems and conventional carbodiimide-coupling chemistry for frozen and/or freeze-dried porous gelatin scaffolds. The latter is particularly relevant for a plethora of biomedical applications such as tissue engineering supports, wound dressings, adhesive and absorbent pads for surgery, etc. Moreover, the results obtained for gelatin can be considered a proof-of-concept to be extrapolated to other polymer systems containing double bonds and/or amines and carboxylic acids to also realize scaffold crosslinking in dry or frozen state. The results showed that high-energy irradiation at -5 A degrees C enabled sufficient segmental mobility to induce chemical crosslinking after performing a cryogenic treatment of methacrylamide-modified gelatin scaffolds. Alternatively, although several redox-initiating systems were unable to chemically crosslink functionalized gelatin, the combination of ammonium persulphate and TEMED resulted in the formation of scaffolds with a reasonable gel fraction. Interestingly, carbodiimide-coupling was found suitable to crosslink freeze-dried gelatin matrices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000370342100016 Publication Date 2016-01-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2461 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:132277 Serial 7742
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Author Cabral, L.R.E.; de Aquino, B.R.C.H.T.; de Souza Silva, C.C.; Milošević, M.V.; Peeters, F.M.
Title Two-shell vortex and antivortex dynamics in a Corbino superconducting disk Type A1 Journal article
Year (down) 2016 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 93 Issue 93 Pages 014515
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We examine theoretically the dynamics of two vortex shells in pinning-free superconducting thin disks in the Corbino geometry. In the first considered case, the inner shell is composed of vortices and the outer one of antivortices, corresponding to a state induced by the stray field of an off-plane magnetic dipole placed on top of the superconductor. In the second considered case, both shells comprise vortices induced by a homogeneous external field. We derive the equation of motion for each shell within the Bardeen-Stephen model and study the dynamics analytically by assuming both shells are rigid and commensurate. In both cases, two distinct regimes for vortex shell motion are identified: For low applied currents the entire configuration rotates rigidly, while above a threshold current the shells decouple from each other and rotate at different angular velocities. Analytical expressions for the decoupling current, the recombination time in the decoupled phases, as well as the voltage-current characteristics are presented. Our analytical results are in excellent agreement with numerical molecular dynamics simulations of the full many-vortex problem.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000368481600003 Publication Date 2016-01-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121; 1550-235x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 7 Open Access
Notes ; This work was supported by the Brazilian Science Agencies CAPES, CNPq, and FACEPE under Grants No. APQ-1381-1.05/12, No. APQ 2017-1.05/12, and No. APQ-0598/1.05-08 and by EU-COST Action No. MP1201 and the Research Foundation-Flanders (FWO). ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:131541 Serial 4270
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Author Altantzis, T.; Yang, Z.; Bals, S.; Van Tendeloo, G.; Pileni, M.-P.
Title Thermal Stability of CoAu13Binary Nanoparticle Superlattices under the Electron Beam Type A1 Journal article
Year (down) 2016 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 28 Issue 28 Pages 716-719
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract One primary goal of self-assembly in nanoscale regime is to implement multifunctional binary nanoparticle superlattices into practical use. In the last decade, considerable effort has been put into the fabrication of binary nanoparticle superlattices with controllable structure and stoichiometry. However, limited effort has been made in order to improve the stability of these binary nanoparticle superlattices, which is a prerequisite for their potential application. In this work, we demonstrate that the carbon deposition from specimen contamination can play an auxiliary role during the heat treatment of binary nanoparticle superlattices. With the in-situ carbon matrix formation, the thermal stability of CoAu 13 binary nanoparticle superlattices is unambiguously enhanced.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000370112200007 Publication Date 2016-01-20
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 10 Open Access OpenAccess
Notes The research leading to these results has been supported by an Advanced Grant of the European Research Council under Grant 267129. The authors appreciate financial support by theEuropean Union under the Framework 7 program under a contract for an Integrated Infrastructure Initiative (Reference No. 262348 ESMI). S.B. acknowledges funding from ERC Starting Grant COLOURATOMS (335078).; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); Approved Most recent IF: 9.466
Call Number c:irua:131908 Serial 4040
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Author Yang, S.; Kang, J.; Yue, Q.; Coey, J.M.D.; Jiang, C.
Title Defect-modulated transistors and gas-enhanced photodetectors on ReS2 nanosheets Type A1 Journal article
Year (down) 2016 Publication Advanced Materials Interfaces Abbreviated Journal Adv Mater Interfaces
Volume 3 Issue 3 Pages 1500707
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000373149400011 Publication Date 2016-01-18
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 22 Open Access
Notes ; This work was supported by the National Natural Science Foundations of China (NSFC) under Grant No.51331001. The authors thank S. Tongay for giving them the ReS<INF>2</INF> crystals. ; Approved Most recent IF: 4.279
Call Number UA @ lucian @ c:irua:133232 Serial 4159
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Author Felgen, N.; Naydenov, B.; Turner, S.; Jelezko, F.; Reithmaier, J.P.; Popov, C.
Title Incorporation and study of SiV centers in diamond nanopillars Type A1 Journal article
Year (down) 2016 Publication Diamond and related materials Abbreviated Journal Diam Relat Mater
Volume 64 Issue 64 Pages 64-69
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We report on the incorporation of SiV centers during hot filament chemical vapor deposition of diamond on top of diamond nanopillars with diameters down to 100 nm. The nanopillars themselves were prepared from nano crystalline diamond films by applying electron beam lithography and inductively coupled plasma reactive ion etching. The optical investigations revealed the presence of ensembles of SiV color centers incorporated during the overgrowth step. (C) 2016 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000374608100009 Publication Date 2016-01-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-9635 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.561 Times cited 14 Open Access
Notes Approved Most recent IF: 2.561
Call Number UA @ lucian @ c:irua:133623 Serial 4193
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Author van den Broek, B.; Houssa, M.; Iordanidou, K.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A.
Title Functional silicene and stanene nanoribbons compared to graphene: electronic structure and transport Type A1 Journal article
Year (down) 2016 Publication 2D materials Abbreviated Journal 2D Mater
Volume 3 Issue 1 Pages 015001
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Since the advent of graphene, other 2D materials have garnered interest; notably the single element materials silicene, germanene, and stanene. Weinvestigate the ballistic current-voltage (I-V) characteristics of armchair silicene and stanene armchair nanoribbons (AXNRs with X = Si, Sn) using a combination of density functional theory and non-equilibrium Green's functions. The impact of out-of-plane electric field and in-plane uniaxial strain on the ribbon geometries, electronic structure, and (I-V)s are considered and contrasted with graphene. Since silicene and stanene are sp(2)/sp(3) buckled layers, the electronic structure can be tuned by an electric field that breaks the sublattice symmetry, an effect absent in graphene. This decreases the current by similar to 50% for Sn, since it has the largest buckling. Uniaxial straining of the ballistic channel affects the AXNR electronic structure in multiple ways: it changes the bandgap and associated effective carrier mass, and creates a local buckling distortion at the lead-channel interface which induces a interface dipole. Due to the increasing sp(3) hybridization character with increasing element mass, large reconstructions rectify the strained systems, an effect absent in sp(2) bonded graphene. This results in a smaller strain effect on the current: a decrease of 20% for Sn at 15% tensile strain compared to a similar to 75% decrease for C.
Address
Corporate Author Thesis
Publisher IOP Publishing Place of Publication Bristol Editor
Language Wos 000373936300021 Publication Date 2016-01-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.937 Times cited 19 Open Access
Notes Approved Most recent IF: 6.937
Call Number UA @ lucian @ c:irua:144746 Serial 4658
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Author Tahir, M.; Vasilopoulos, P.; Peeters, F.M.
Title Quantum magnetotransport properties of a MoS2 monolayer Type A1 Journal article
Year (down) 2016 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 93 Issue 93 Pages 035406
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study transport properties of a MoS2 monolayer in the presence of a perpendicular magnetic field B. We derive and discuss its band structure and take into account spin and valley Zeeman effects. Compared to a conventional two-dimensional electron gas, these effects lead to new quantum Hall plateaus and new peaks in the longitudinal resistivity as functions of the magnetic field. The field B leads to a significant enhancement of the spin splitting in the conduction band, to a beating of the Shubnikov-de Haas (SdH) oscillations in the low-field regime, and to their splitting in the high-field regime. The Zeeman fields suppress significantly the beating of the SdH oscillations in the low-field regime and strongly enhance their splitting at high fields. The spin and valley polarizations show a similar beating pattern at low fields and are clearly separated at high fields in which they attain a value higher than 90%.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000367663500003 Publication Date 2016-01-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121; 1550-235x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 42 Open Access
Notes ; This work was supported by the Canadian NSERC Grant No. OGP0121756 (M.T., P.V.) and by the Flemish Science Foundation (FWO-Vl) (F.M.P.). ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:131093 Serial 4233
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Author Heyne, M.H.; Chiappe, D.; Meersschaut, J.; Nuytten, T.; Conard, T.; Bender, H.; Huyghebaert, C.; Radu, I.P.; Caymax, M.; de Marneffe, J.F.; Neyts, E.C.; De Gendt, S.;
Title Multilayer MoS2 growth by metal and metal oxide sulfurization Type A1 Journal article
Year (down) 2016 Publication Journal of materials chemistry C : materials for optical and electronic devices Abbreviated Journal J Mater Chem C
Volume 4 Issue 4 Pages 1295-1304
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We investigated the deposition of MoS2 multilayers on large area substrates. The pre-deposition of metal or metal oxide with subsequent sulfurization is a promising technique to achieve layered films. We distinguish a different reaction behavior in metal oxide and metallic films and investigate the effect of the temperature, the H2S/H-2 gas mixture composition, and the role of the underlying substrate on the material quality. The results of the experiments suggest a MoS2 growth mechanism consisting of two subsequent process steps. At first, the reaction of the sulfur precursor with the metal or metal oxide occurs, requiring higher temperatures in the case of metallic film compared to metal oxide. At this stage, the basal planes assemble towards the diffusion direction of the reaction educts and products. After the sulfurization reaction, the material recrystallizes and the basal planes rearrange parallel to the substrate to minimize the surface energy. Therefore, substrates with low roughness show basal plane assembly parallel to the substrate. These results indicate that the substrate character has a significant impact on the assembly of low dimensional MoS2 films.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000370723300020 Publication Date 2016-01-05
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 Open Access
Notes Approved Most recent IF: 5.256
Call Number UA @ lucian @ c:irua:132327 Serial 4211
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Author Fedotov, S.S.; Khasanova, N.R.; Samarin, A.S.; Drozhzhin, O.A.; Batuk, D.; Karakulina, O.M.; Hadermann, J.; Abakumov, A.M.; Antipov, E.V.
Title AVPO4F (A = Li, K): A 4 V Cathode Material for High-Power Rechargeable Batteries Type A1 Journal article
Year (down) 2016 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 28 Issue 28 Pages 411-415
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A novel potassium-based fluoride-phosphate, KVPO4F, with a KTiOPO4 (KTP) type structure is synthesized and characterized. About 85% of potassium has been electrochemically extracted on oxidation producing a cathode material with attractive performance for Li-ion batteries. The material operates at the electrode potential near 4V vs Li/Li+ exhibiting a sloping voltage profile, extremely low polarization, small volume change of about 2% and excellent rate capability, maintaining more than 75% of the initial capacity at 40C discharge rate without significant fading.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000368949900002 Publication Date 2016-01-04
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 46 Open Access
Notes The authors kindly thank Dr. S. N. Putilin for XRD measurements, Dr. O. A. Shlyakhtin for the assistance in cryochemical synthesis, Ph.D. students A. A. Sadovnikov and E. A. Karpukhina for SEM imaging and FTIR spectra respectively. The work was partly supported by Russian Science Foundation (grant 16-19-00190), Skoltech Center for Electrochemical Energy Storage and Moscow State University Devel-opment Program up to 2020. J. Hadermann, O.M. Karakulina and A.M. Abakumov acknowledge support from FWO under grant G040116N. Approved Most recent IF: 9.466
Call Number c:irua:131583 Serial 4001
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Author Poelma, R.H.; Fan, X.; Hu, Z.-Y.; Van Tendeloo, G.; van Zeijl, H.W.; Zhang, G.Q.
Title Effects of Nanostructure and Coating on the Mechanics of Carbon Nanotube Arrays Type A1 Journal article
Year (down) 2016 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
Volume 26 Issue 26 Pages 1233-1242
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Nanoscale materials are one of the few engineering materials that can be grown from the bottom up in a controlled manner. Here, the effects of nanostructure and nanoscale conformal coating on the mechanical behavior of vertically aligned carbon nanotube (CNT) arrays through experiments and simulation are systematically investigated. A modeling approach is developed and used to quantify the compressive strength and modulus of the CNT array under large deformation. The model accounts for the porous

nanostructure, which contains multiple CNTs with random waviness, van der Waals interactions, fracture strain, contacts, and frictional forces. CNT array micropillars are grown and their porous nanostructure is controlled by the infi ltration and deposition of thin conformal coatings using chemical vapor deposition. Flat-punch nanoindentation experiments reveal signifi cant changes in material properties as a function of coating thickness. The simulations explain the experimental results and show the novel failure transition regime that changes from collective CNT buckling toward structural collapse due to fracture. The compressive strength and the elastic

modulus increase exponentially as a function of the coating thickness and demonstrate a unique dependency on the CNT waviness. More interestingly, a design rule is identifi ed that predicts the optimum coating thickness for porous materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000371078100010 Publication Date 2016-01-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301X ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 17 Open Access
Notes The research leading to the TEM/HAADF-STEM results received funding from the EC Framework 7 Program ESTEEM2 (Reference 312483). We wish to acknowledge the support of the Else Kooi Laboratory for their assistance during the clean room processing.; esteem2_ta Approved Most recent IF: 12.124
Call Number c:irua:130060 c:irua:130060 Serial 3996
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Author Neubert, S.; Mitoraj, D.; Shevlin, S.A.; Pulisova, P.; Heimann, M.; Du, Y.; Goh, G.K.L.; Pacia, M.; Kruczała, K.; Turner, S.; Macyk, W.; Guo, Z.X.; Hocking, R.K.; Beranek, R.;
Title Highly efficient rutile TiO2 photocatalysts with single Cu(II) and Fe(III) surface catalytic sites Type A1 Journal article
Year (down) 2016 Publication Journal of materials chemistry A : materials for energy and sustainability Abbreviated Journal J Mater Chem A
Volume 4 Issue 4 Pages 3127-3138
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
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.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000371077300040 Publication Date 2015-12-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2050-7488; 2050-7496 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.867 Times cited 44 Open Access
Notes Approved Most recent IF: 8.867
Call Number UA @ lucian @ c:irua:132322 Serial 4191
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Author Khalilov, U.; Yusupov, M.; Bogaerts, A.; Neyts, E.C.
Title Selective Plasma Oxidation of Ultrasmall Si Nanowires Type A1 Journal article
Year (down) 2016 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 120 Issue 120 Pages 472-477
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Device performance of Si|SiOx core-shell based nanowires critically depends on the exact control over the oxide thickness. Low-temperature plasma oxidation is a highly promising alternative to thermal oxidation allowing for improved control over the oxidation process, in particular for ultrasmall Si nanowires. We here elucidate the room temperature plasma oxidation mechanisms of ultrasmall Si nanowires using hybrid molecular dynamics / force-bias Monte Carlo simulations. We demonstrate how the oxidation and concurrent water formation mechanisms are a function of the oxidizing plasma species and we demonstrate how the resulting core-shell oxide thickness can be controlled through these species. A new mechanism of water formation is discussed in detail. The results provide a detailed atomic level explanation of the oxidation process of highly curved Si surfaces. These results point out a route toward plasma-based formation of ultrathin core-shell Si|SiOx nanowires at room temperature.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000368562200057 Publication Date 2015-12-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 3 Open Access
Notes U.K. and M.Y. gratefully acknowledge financial support from the Research Foundation – Flanders (FWO), Grants 12M1315N and 1200216N. This work was carried out in part using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UA. We thank Prof. A. C. T. van Duin for sharing the ReaxFF code. Approved Most recent IF: 4.536
Call Number c:irua:130677 Serial 4002
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Author Berdiyorov, G.R.; El-Mellouhi, F.; Madjet, M.E.; Alharbi, F.H.; Peeters, F.M.; Kais, S.
Title Effect of halide-mixing on the electronic transport properties of organometallic perovskites Type A1 Journal article
Year (down) 2016 Publication Solar energy materials and solar cells T2 – 2nd International Renewable and Sustainable Energy Conference (IRSEC), OCT 17-19, 2014, Ouarzazate, MOROCCO Abbreviated Journal Sol Energ Mat Sol C
Volume 148 Issue 148 Pages 2-10
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Using density-functional theory in combination with the nonequilibrium Green's function formalism, we study the effect of iodide/chloride and iodide/bromide mixing on the electronic transport in lead based organometallic perovskite CH3NH3PbI3, which is known to be an effective tool to tune the electronic and optical properties of such materials. We found that depending on the level and position of the halide mixing, the electronic transport can be increased by more than a factor of 4 for a given voltage biasing. The largest current is observed for small concentration of bromide substitutions located at the equatorial sites. However, full halide substitution has a negative effect on the transport properties of this material: the current drops by an order of magnitude for both CH3NH3PbCl3 and CH3NH3PbBr3 samples. (C) 2015 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Elsevier science bv Place of Publication Amsterdam Editor
Language Wos 000371944500002 Publication Date 2015-12-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0927-0248 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.784 Times cited 23 Open Access
Notes ; ; Approved Most recent IF: 4.784
Call Number UA @ lucian @ c:irua:133150 Serial 4165
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Author Ji, G.; Tan, Z.; Lu, Y.; Schryvers, D.; Li, Z.; Zhang, D.
Title Heterogeneous interfacial chemical nature and bonds in a W-coated diamond/Al composite Type A1 Journal article
Year (down) 2016 Publication Materials characterization Abbreviated Journal Mater Charact
Volume 112 Issue 112 Pages 129-133
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Heterogeneous Al/Al4C3/Al2O3/diamond{111}, Al/nanolayered Al4C3/diamond{111} and Al12W particle/Al4C3/Al2O3/diamond{111} multi-interfaces have been developed at the nanoscale in a W-coated diamond/Al composite produced by vacuum hot pressing. The formation of nanoscale Al4C3 crystals is strongly associated with local O enrichment and can be further promoted by Al12W interfacial particles. The latter effectively contributes to enhance interfacial chemical bonding reducing interfacial thermal resistance and, in turn, enhancing thermal conductivity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000370109200015 Publication Date 2015-12-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.714 Times cited 7 Open Access
Notes This work is financially supported by the FWO project of Belgium (No. U2 FA 070100/3506), the travel funding BQR (No. R8DIV AUE) provided by Université Lille 1, the National Natural Science Foundation of China (Grant No. 51401123) and the China Postdoctoral Science Foundation (Grant No. 2014 M561469) for Dr. Z.Q. Tan. Dr. W.G. Grünewald (LeicaMicrosystems, Germany) is also thanked for the assistance of surface preparation. Approved Most recent IF: 2.714
Call Number c:irua:129976 Serial 3987
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Author Berdiyorov, G.R.; Madjet, M.E.; El-Mellouhi, F.; Peeters, F.M.
Title Effect of crystal structure on the electronic transport properties of the organometallic perovskite CH3NH3PbI3 Type A1 Journal article
Year (down) 2016 Publication Solar energy materials and solar cells T2 – 2nd International Renewable and Sustainable Energy Conference (IRSEC), OCT 17-19, 2014, Ouarzazate, MOROCCO Abbreviated Journal Sol Energ Mat Sol C
Volume 148 Issue 148 Pages 60-66
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Using density-functional theory in combination with the nonequilibrium Green's function formalism, we study the effect of the crystal lattice structure of organometallic perovskite CH3NH3PbI3 on its electronic transport properties. Both dispersive interactions and spin-orbit coupling are taken into account in describing structural and electronic properties of the system. We consider two different phases of the material, namely the orthorhombic and cubic lattice structures, which are energetically stable at low (< 160 K) and high (> 330 K) temperatures, respectively. The sizable geometrical differences between the two structures in term of lattice parameters, PbI6 octahedral tilts, rotation and deformations, have considerable impact on the transport properties of the material. For example, at zero bias and for all considered electron energies, the cubic phase has a larger transmission than the orthorhombic one, although both show similar electronic densities of states. Depending on the applied voltage, the current in the cubic system can be several orders of magnitude larger as compared to the one obtained for the orthorhombic sample. We attribute this enhancement in the transmission to the presence of extended states in the cubic phase due to the symmetrically shaped and ordered PbI6 octaherdra. (C) 2015 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Elsevier science bv Place of Publication Amsterdam Editor
Language Wos 000371944500011 Publication Date 2015-11-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0927-0248 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.784 Times cited 16 Open Access
Notes ; ; Approved Most recent IF: 4.784
Call Number UA @ lucian @ c:irua:133151 Serial 4163
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Author Zhang, F.; Inokoshi, M.; Batuk, M.; Hadermann, J.; Naert, I.; Van Meerbeek, B.; Vleugels, J.
Title Strength, toughness and aging stability of highly-translucent Y-TZP ceramics for dental restorations Type A1 Journal article
Year (down) 2016 Publication Dental materials Abbreviated Journal Dent Mater
Volume 32 Issue 12 Pages E327-E337
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Objective. The aim was to evaluate the optical properties, mechanical properties and aging stability of yttria-stabilized zirconia with different compositions, highlighting the influence of the alumina addition, Y2O3 content and La2O3 doping on the translucency. Methods. Five different Y-TZP zirconia powders (3 commercially available and 2 experimentally modified) were sintered under the same conditions and characterized by X-ray diffraction with Rietveld analysis and scanning electron microscopy (SEM). Translucency (n = 6/group) was measured with a color meter, allowing to calculate the translucency parameter (TP) and the contrast ratio (CR). Mechanical properties were appraised with four-point bending strength (n = 10), single edge V-notched beam (SEVNB) fracture toughness (n = 8) and Vickers hardness (n = 10). The aging stability was evaluated by measuring the tetragonal to monoclinic transformation (n = 3) after accelerated hydrothermal aging in steam at 134 degrees C, and the transformation curves were fitted by the Mehl-Avrami-Johnson (MAJ) equation. Data were analyzed by one-way ANOVA, followed by Tukey's HSD test (alpha = 0.05). Results. Lowering the alumina content below 0.25 wt.% avoided the formation of alumina particles and therefore increased the translucency of 3Y-TZP ceramics, but the hydrothermal aging stability was reduced. A higher yttria content (5 mol%) introduced about 50% cubic zirconia phase and gave rise to the most translucent and aging-resistant Y-TZP ceramics, but the fracture toughness and strength were considerably sacrificed. 0.2 mol% La2O3 doping of 3Y-TZP tailored the grain boundary chemistry and significantly improved the aging resistance and translucency. Although the translucency improvement by La2O3 doping was less effective than for introducing a substantial amount of cubic zirconia, this strategy was able to maintain the mechanical properties of typical 3Y-TZP ceramics. Significance. Three different approaches were compared to improve the translucency of 3YTZP ceramics. (C) 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Copenhagen Editor
Language Wos 000389516400003 Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0109-5641 ISBN Additional Links UA library record; WoS full record
Impact Factor 4.07 Times cited 47 Open Access
Notes Approved Most recent IF: 4.07
Call Number UA @ lucian @ c:irua:140246 Serial 4447
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Author Liao, Z.L.; Green, R.J.; Gauquelin, N.; Gonnissen, J.; Van Aert, S.; Verbeeck, J.; et al.
Title Engineering properties by long range symmetry propagation initiated at perovskite heterostructure interface Type A1 Journal article
Year (down) 2016 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
Volume Issue Pages 1-25
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In epitaxial thin film systems, the crystal structure and its symmetry deviate from the bulk counterpart due to various mechanisms such as epitaxial strain and interfacial structural coupling, which induce an accompanying change in their properties. In perovskite materials, the crystal symmetry can be described by rotations of 6-fold coordinated transition metal oxygen octahedra, which are found to be altered at interfaces. Here, we unravel how the local oxygen octahedral coupling (OOC) at perovskite heterostructural interfaces initiates a different symmetry in epitaxial films and provide design rules to induce various symmetries in thin films by careful selecting appropriate combinations of substrate/buffer/film. Very interestingly we discovered that these combinations lead to symmetry changes throughout the full thickness of the film. Our results provide a deep insight into understanding the origin of induced crystal symmetry in a perovskite heterostructure and an intelligent route to achieve unique functional properties.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301x ISBN Additional Links UA library record
Impact Factor 12.124 Times cited Open Access
Notes Approved Most recent IF: 12.124
Call Number UA @ lucian @ c:irua:134842 Serial 4176
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Author Yan, L.; Tan, Z.; Ji, G.; Li, Z.; Fan, G.; Schryvers, D.; Shan, A.; Zhang, D.
Title A quantitative method to characterize the Al4C3-formed interfacial reaction: the case study of MWCNT/Al composites Type A1 Journal article
Year (down) 2015 Publication Materials characterization Abbreviated Journal Mater Charact
Volume 112 Issue 112 Pages 213-218
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The Al4C3-formed interfacial reaction plays an important role in tuning the mechanical and thermal properties of carbon/aluminum (C/Al) composites reinforced with carbonaceous materials such as multi-wall carbon nanotube (MWCNT) and graphene nanosheet. In terms of the hydrolysis nature of Al4C3, an electrochemical dissolution method was developed to quantitatively characterize the extent of C/Al interfacial reaction, which involves dissolving the composite samples in alkaline solution first, then collecting and measuring the CH4 gas released by Al4C3 hydrolysis with a gas chromatograph. Through a case study with powder metallurgy fabricated 2.0 wt.% MWCNT/Al composites, the detectability limit of the proposed method is 0.4 wt.% Al4C3, corresponding to 5 % extent of interfacial reaction with a measurement error of ±3 %. And then, with the already known MWCNT/Al reaction extent vs different sintering temperature and time, the reaction kinetics with an activation energy of 281 kJ mol-1 was successfully derived. Therefore, this rapid, sensitive, accurate method supplies an useful tool to optimize the processing and properties of all kinds of C/Al composites via interface design/control.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000370109200026 Publication Date 2015-12-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.714 Times cited 24 Open Access
Notes The authors would like to acknowledge the financial support of the National Basic Research Program of China (973 Program, No. 2012CB619600), the National High-Tech R&D Program (863 Program, No. 2012AA030611), the National Natural Science Foundation (Nos. 51071100, 51131004, 51401123, 51511130038) and the research grant (Nos. 14DZ2261200, 15JC1402100, 14520710100) from Shanghai government. Dr. Z.Q. Tan would also like to thank the project funded by the China Postdoctoral Science Foundation (No. 2014M561469). The research leading to these results has partially received funding from the European Union Seventh Framework Program under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative – I3).; esteem2_jra2 Approved Most recent IF: 2.714; 2015 IF: 1.845
Call Number c:irua:130066 c:irua:130066 Serial 3997
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Author Sobrino Fernandez, M.M.; Neek-Amal, M.; Peeters, F.M.
Title AA-stacked bilayer square ice between graphene layers Type A1 Journal article
Year (down) 2015 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 92 Issue 92 Pages 245428
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Water confined between two graphene layers with a separation of a few A forms a layered two-dimensional ice structure. Using large scale molecular dynamics simulations with the adoptable ReaxFF interatomic potential we found that flat monolayer ice with a rhombic-square structure nucleates between the graphene layers which is nonpolar and nonferroelectric. We provide different energetic considerations and H-bonding results that explain the interlayer and intralayer properties of two-dimensional ice. The controversial AA stacking found experimentally [Algara-Siller et al., Nature (London) 519, 443 (2015)] is consistent with our minimum-energy crystal structure of bilayer ice. Furthermore, we predict that an odd number of layers of ice has the same lattice structure as monolayer ice, while an even number of ice layers exhibits the square ice AA stacking of bilayer ice.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000366731800004 Publication Date 2015-12-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121; 1550-235x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 40 Open Access
Notes ; This work was supported by the ESF-Eurographene project CONGRAN, and the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 3.836; 2015 IF: 3.736
Call Number c:irua:130203 Serial 4127
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Author Dell'Anna, L.; Perali, A.; Covaci, L.; Neilson, D.
Title Using magnetic stripes to stabilize superfluidity in electron-hole double monolayer graphene Type A1 Journal article
Year (down) 2015 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 92 Issue 92 Pages 220502
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Experiments have confirmed that double monolayer graphene does not generate finite-temperature electron-hole superfluidity, because of very strong screening of the pairing attraction. The linear dispersing energy bands in monolayer graphene block any attempt to reduce the strength of the screening. We propose a hybrid device with two sheets of monolayer graphene in a modulated periodic perpendicular magnetic field. The field preserves the isotropic Dirac cones of the original monolayers but reduces the slope of the cones, making the monolayer Fermi velocity v(F) smaller. We demonstrate that with current experimental techniques, the reduction in vF can weaken the screening sufficiently to allow electron-hole superfluidity at measurable temperatures.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000366500100004 Publication Date 2015-12-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 7 Open Access
Notes ; We thank M. Zarenia for useful discussions. L.D. acknowledges financial support from MIUR: FIRB 2012, Grant No. RBFR12NLNA_002, and PRIN, Grant No. 2010LLKJBX. A.P. and D.N. acknowledge financial support from University of Camerino FAR project CESEMN. L.C. acknowledges financial support from Flemish Science Foundation (FWO). ; Approved Most recent IF: 3.836; 2015 IF: 3.736
Call Number c:irua:130211 Serial 4069
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Author Missault, N.; Vasilopoulos, P.; Vargiamidis, V.; Peeters, F.M.; Van Duppen, B.
Title Spin- and valley-dependent transport through arrays of ferromagnetic silicene junctions Type A1 Journal article
Year (down) 2015 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 92 Issue 92 Pages 195423
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study ballistic transport of Dirac fermions in silicene through arrays of barriers, of width d, in the presence of an exchange field M and a tunable potential of height U or depth-U. The spin-and valley-resolved conductances as functions of U or M, exhibit resonances away from the Dirac point (DP) and close to it a pronounced dip that becomes a gap when a critical electric field E-z is applied. This gap widens by increasing the number of barriers and can be used to realize electric field-controlled switching of the current. The spin p(s) and valley p(v) polarizations of the current near the DP increase with Ez or M and can reach 100% for certain of their values. These field ranges widen significantly by increasing the number of barriers. Also, ps and pv oscillate nearly periodically with the separation between barriers or wells and can be inverted by reversing M.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000364998100006 Publication Date 2015-11-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121; 1550-235x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 54 Open Access
Notes ; This work was supported by the Canadian NSERC Grant No. OGP0121756 (P.V.) and by the Flemish Science Foundation (FWO-Vl) with a Ph.D. research grant (B.V.D.). ; Approved Most recent IF: 3.836; 2015 IF: 3.736
Call Number UA @ lucian @ c:irua:130264 Serial 4247
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Author Kang, J.; Horzum, S.; Peeters, F.M.
Title Heterostructures of graphene and nitrogenated holey graphene: Moire pattern and Dirac ring Type A1 Journal article
Year (down) 2015 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 92 Issue 92 Pages 195419
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Nitrogenated holey graphene (NHG) is a recently synthesized two-dimensional material. In this paper the structural and electronic properties of heterostructures of graphene and NHG are investigated using first-principles and tight-binding calculations. Due to the lattice mismatch between NHG and graphene, the formation of a moire pattern is preferred in the graphene/NHG heterostructure, instead of a lattice-coherent structure. In moire-patterned graphene/NHG, the band gap opening at the K point is negligible, and the linear band dispersion of graphene survives. Applying an electric field modifies the coupling strength between the two atomic layers. The Fermi velocity upsilon(F) is reduced as compared to the one of pristine graphene, and its magnitude depends on the twist angle theta between graphene and NHG: For theta = 0 degrees, upsilon(F) is 30% of that of graphene, and it increases rapidly to a value of 80% with increasing theta. The heterostructure exhibits electron-hole asymmetry in upsilon(F), which is large for small theta. In NHG encapsulated between two graphene layers, a “Dirac ring” appears around the K point. Its presence is robust with respect to the relative stacking of the two graphene layers. These findings can be useful for future applications of graphene/NHG heterostructures.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000364998000006 Publication Date 2015-11-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121; 1550-235x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 33 Open Access
Notes Approved Most recent IF: 3.836; 2015 IF: 3.736
Call Number UA @ lucian @ c:irua:130266 Serial 4189
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Author Brito, B.G.A.; Candido, L.; Hai, G.-Q.; Peeters, F.M.
Title Quantum effects in a free-standing graphene lattice : path-integral against classical Monte Carlo simulations Type A1 Journal article
Year (down) 2015 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 92 Issue 92 Pages 195416
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In order to study quantum effects in a two-dimensional crystal lattice of a free-standing monolayer graphene, we have performed both path-integral Monte Carlo (PIMC) and classical Monte Carlo (MC) simulations for temperatures up to 2000 K. The REBO potential is used for the interatomic interaction. The total energy, interatomic distance, root-mean-square displacement of the atom vibrations, and the free energy of the graphene layer are calculated. The obtained lattice vibrational energy per atom from the classical MC simulation is very close to the energy of a three-dimensional harmonic oscillator 3k(B)T. The PIMC simulation shows that quantum effects due to zero-point vibrations are significant for temperatures T < 1000 K. The quantum contribution to the lattice vibrational energy becomes larger than that of the classical lattice for T < 400 K. The lattice expansion due to the zero-point motion causes an increase of 0.53% in the lattice parameter. A minimum in the lattice parameter appears at T similar or equal to 500 K. Quantum effects on the atomic vibration amplitude of the graphene lattice and its free energy are investigated.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000368095400004 Publication Date 2015-11-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121; 1550-235x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 22 Open Access
Notes ; This research was supported by the Brazilian agencies FAPESP, FAPEG, and CNPq, the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. ; Approved Most recent IF: 3.836; 2015 IF: 3.736
Call Number UA @ lucian @ c:irua:131144 Serial 4232
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Author Yao, X.; Cao, S.; Zhang, X.P.; Schryvers, D.
Title Microstructural Characterization and Transformation Behavior of Porous Ni50.8Ti49.2 Type P1 Proceeding
Year (down) 2015 Publication Materials Today: Proceedings Abbreviated Journal
Volume 2 Issue 2 Pages S833-S836
Keywords P1 Proceeding; Electron microscopy for materials research (EMAT)
Abstract Porous Ni50.8Ti49.2 bulk material was prepared by powder metallurgy sintering. Solid solution and aging treatments were applied to improve the phase homogeneity and phase transformation behavior. Scanning and transmission electron microscopy, aided by energy dispersive X-ray analysis, were used to study the microstructure and chemical phase content of the alloys. In-situ cooling was carried out to observe the phase transformation behavior. As-received material contains dispersed Ni2Ti4O particles while Ni4Ti3 precipitates appear after aging. Close to pore edges, the latter have a preferential orientation due to the induced stress fields in the matrix.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000371032100081 Publication Date 2015-11-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2214-7853 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes The author gratefully acknowledges the Chinese Scholarship Council (CSC) for providing a scholarship and the Key Project of the Natural Science Foundation of Guangdong Province under grant No. S2013020012805. Approved Most recent IF: NA
Call Number c:irua:129980 Serial 3989
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Author Van Aelst, J.; Verboekend, D.; Philippaerts, A.; Nuttens, N.; Kurttepeli, M.; Gobechiya, E.; Haouas, M.; Sree, S.P.; Denayer, J.F.M.; Martens, J.A.; Kirschhock, C.E.A.; Taulelle, F.; Bals, S.; Baron, G.V.; Jacobs, P.A.; Sels, B.F.
Title Catalyst design by NH4OH treatment of USY zeolite Type A1 Journal article
Year (down) 2015 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
Volume 25 Issue 25 Pages 7130-7144
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Hierarchical zeolites are a class of superior catalysts which couples the intrinsic zeolitic properties to enhanced accessibility and intracrystalline mass transport to and from the active sites. The design of hierarchical USY (Ultra-Stable Y) catalysts is achieved using a sustainable postsynthetic room temperature treatment with mildly alkaline NH4OH ( 0.02(M)) solutions. Starting from a commercial dealuminated USY zeolite (Si/Al = 47), a hierarchical material is obtained by selective and tuneable creation of interconnected and accessible small mesopores (2- 6 nm). In addition, the treatment immediately yields the NH4+ form without the need for additional ion exchange. After NH4OH modification, the crystal morphology is retained, whereas the microporosity and relative crystallinity are decreased. The gradual formation of dense amorphous phases throughout the crystal without significant framework atom leaching rationalizes the very high material yields (>90%). The superior catalytic performance of the developed hierarchical zeolites is demonstrated in the acid-catalyzed isomerization of alpha-pinene and the metal-catalyzed conjugation of safflower oil. Significant improvements in activity and selectivity are attained, as well as a lowered susceptibility to deactivation. The catalytic performance is intimately related to the introduced mesopores, hence enhanced mass transport capacity, and the retained intrinsic zeolitic properties.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000366503700003 Publication Date 2015-10-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 64 Open Access OpenAccess
Notes ; The authors thank Dr. M. Thommes and Dr. K. Cychosz for numerous and helpful discussions on the correct evaluation of the Ar isotherms. I. Cuppens is acknowledged for ICP-AES analyses. Research was funded through a PhD grant to J.V.A. of the Agency for Innovation by Science and Technology in Flanders (IWT). D.V. and A.P. acknowledge F.W.O.-Vlaanderen (Research Foundation Flanders) for a postdoctoral fellowship. N.N. thanks the KU Leuven for financial support (FLOF). E.G., C.K., and J.M. acknowledge the long-term structural funding by the Flemish Government (Methusalem). S.B. acknowledges the European Research Council for funding under the European Union's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement No. 335078-COLOURATOMS. The authors are grateful for financial support by the Belgian government through Interuniversity Attraction Poles (IAP-PAI). They also thank Oleon NV for supplying safflower oil. ; ecas_Sara Approved Most recent IF: 12.124; 2015 IF: 11.805
Call Number UA @ lucian @ c:irua:130214 Serial 4147
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Author Neek-Amal, M; Peeters, F.M.
Title Partially hydrogenated and fluorinated graphene : structure, roughness, and negative thermal expansion Type A1 Journal article
Year (down) 2015 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 92 Issue 92 Pages 155430
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The structural properties of partially hydrogenated and fluorinated graphene with different percentages of H/F atoms are investigated using molecular dynamics simulations based on reactive force field (ReaxFF) potentials. We found that the roughness of graphene varies with the percentage (p) of H or F and in both cases is maximal around p = 50%. Similar results were obtained for partially oxidized graphene. The two-dimensional area size of partially fluorinated and hydrogenated graphene exhibits a local minimum around p = 35% coverage. The lattice thermal contraction in partially functionalized graphene is found to be one order of magnitude larger than that of fully covered graphene. We also show that the armchair structure for graphene oxide (similar to the structure of fully hydrogenated and fluorinated graphene) is unstable. Our results show that the structure of partially functionalized graphene changes nontrivially with the C : H and C : F ratio as well as with temperature.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000363294100005 Publication Date 2015-10-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121; 1550-235x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 5 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. ; Approved Most recent IF: 3.836; 2015 IF: 3.736
Call Number UA @ lucian @ c:irua:129448 Serial 4221
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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 (down) 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.
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Language Wos 000364826000024 Publication Date 2015-10-21
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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 c:irua:130181 Serial 3968
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