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Author Michel, K.H.; Verberck, B. url  doi
openurl 
  Title Theory of rigid-plane phonon modes in layered crystals Type A1 Journal article
  Year (down) 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 85 Issue 9 Pages 094303-094303,11  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The lattice dynamics of low-frequency rigid-plane modes in metallic (graphene multilayers, GML) and in insulating (hexagonal boron-nitride multilayers, BNML) layered crystals is investigated. The frequencies of shearing and compression (stretching) modes depend on the layer number N and are presented in the form of fan diagrams. The results for GML and BNML are very similar. In both cases, only the interactions (van der Waals and Coulomb) between nearest-neighbor planes are effective, while the interactions between more distant planes are screened. A comparison with recent Raman scattering results on low-frequency shear modes in GML [Tan et al., Nat. Mater., in press, doi: 10.1038/nmat3245, (2012)] is made. Relations with the low-lying rigid-plane phonon dispersions in the bulk materials are established. Master curves, which connect the fan diagram frequencies for any given N, are derived. Static and dynamic thermal correlation functions for rigid-layer shear and compression modes are calculated. The results might be of use for the interpretation of friction force experiments on multilayer crystals.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000301646000006 Publication Date 2012-03-19  
  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 38 Open Access  
  Notes ; The authors are indebted to J. Maultzsch for bringing Ref. 20 to their attention. They thank D. Lamoen, F.M. Peeters, B. Trauzettel, and C. Van Haesendonck for useful discussions. This work has been financially supported by the Research Foundation Flanders (FWO). ; Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:97787 Serial 3619  
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Author Angelomé, P.C.; Heidari Mezerji, H.; Goris, B.; Pastoriza-Santos, I.; Pérez-Juste, J.; Bals, S.; Liz-Marzán, L.M. pdf  doi
openurl 
  Title Seedless synthesis of single crystalline Au nanoparticles with unusual shapes and tunable LSPR in the near-IR Type A1 Journal article
  Year (down) 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 24 Issue 7 Pages 1393-1399  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The plasmonic properties of metal nanoparticles have acquired great importance because of their potential applications in very diverse fields. Metal nanoparticles with localized surface plasmon resonances (LSPR) in the near-infrared (NIR, 7501300 nm) are of particular interest because tissues, blood, and water display low absorption in this spectral range, thus facilitating biomedical applications. Cetyltrimethylammonium chloride (CTAC) was used to induce the seedless formation of highly anisotropic, twisted single crystalline Au nanoparticles in a single step. The LSPR of the obtained particles can be tuned from 600 nm up to 1400 nm by simply changing the reaction temperature or the reagents concentrations. The tunability of the LSPR is closely associated with significant changes in the final particle morphology, which was studied by advanced electron microscopy techniques (3D Tomography and HAADF-STEM). Kinetic experiments were carried out to establish the growth mechanism, suggesting that slow kinetics together with the complexation of the gold salt precursor to CTAC are key factors favoring the formation of these anisotropic particles.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000302487500020 Publication Date 2012-03-16  
  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 42 Open Access  
  Notes Fwo Approved Most recent IF: 9.466; 2012 IF: 8.238  
  Call Number UA @ lucian @ c:irua:97388 Serial 2959  
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Author Dachraoui, W.; Hadermann, J.; Abakumov, A.M.; Tsirlin, A.A.; Batuk, D.; Glazyrin, K.; McCammon, C.; Dubrovinsky, L.; Van Tendeloo, G. pdf  doi
openurl 
  Title Local oxygen-vacancy ordering and twinned octahedral tilting pattern in the Bi0.81Pb0.19FeO2.905 cubic perovskite Type A1 Journal article
  Year (down) 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 24 Issue 7 Pages 1378-1385  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The structure of Bi0.81Pb0.19FeO2.905 was investigated on different length scales using a combination of electron diffraction, high-resolution scanning transmission electron microscopy, synchrotron X-ray powder diffraction, and Mössbauer spectroscopy. In the 80300 K temperature range, the average crystal structure of Bi0.81Pb0.19FeO2.905 is a cubic Pm3̅m perovskite with a = 3.95368(3) Å at T = 300 K. The (Pb2+, Bi3+) cations and O2 anions are randomly displaced along the 110 cubic directions, indicating the steric activity of the lone pair on the Pb2+ and Bi3+ cations and a tilting distortion of the perovskite framework. The charge imbalance induced by the heterovalent Bi3+ → Pb2+ substitution is compensated by the formation of oxygen vacancies preserving the trivalent state of the Fe cations. On a short scale, oxygen vacancies are located in anion-deficient (FeO1.25) layers that are approximately 6 perovskite unit cells apart and transform every sixth layer of the FeO6 octahedra into a layer with a 1:1 mixture of corner-sharing FeO4 tetrahedra and FeO5 tetragonal pyramids. The anion-deficient layers act as twin planes for the octahedral tilting pattern of adjacent perovskite blocks. They effectively randomize the octahedral tilting and prevent the cooperative distortion of the perovskite framework. The disorder in the anion sublattice impedes cooperative interactions of the local dipoles induced by the off-center displacements of the Pb and Bi cations. Magnetic susceptibility measurements evidence the antiferromagnetic ordering in Bi0.81Pb0.19FeO2.905 at low temperatures.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000302487500018 Publication Date 2012-03-13  
  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 27 Open Access  
  Notes Approved Most recent IF: 9.466; 2012 IF: 8.238  
  Call Number UA @ lucian @ c:irua:97389 Serial 1829  
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Author Berdiyorov, G.R.; Hernández-Nieves, A.D.; Milošević, M.V.; Peeters, F.M.; Dominguez, D. url  doi
openurl 
  Title Flux-quantum-discretized dynamics of magnetic flux entry, exit, and annihilation in current-driven mesoscopic type-I superconductors Type A1 Journal article
  Year (down) 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 85 Issue 9 Pages 092502-092502,4  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We study nonlinear flux dynamics in a current-carrying type-I superconductor. The stray magnetic field of the current induces the intermediate state, where nucleation of flux domains is discretized to a single fluxoid at a time, while their final shape (tubular or laminar), size, and nucleation rate depend on applied current and edge conditions. The current induces opposite flux domains on opposite sides of the sample, and subsequently drives them to annihilation-which is also discretized, as a sequence of vortex-antivortex pairs. The discretization of both nucleation and annihilation leaves measurable traces in the voltage across the sample and in locally probed magnetization. The reported dynamic phenomena thus provide an unambiguous proof of a flux quantum being the smallest building block of the intermediate state in type-I superconductors.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000301183000002 Publication Date 2012-03-07  
  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 14 Open Access  
  Notes ; This work was supported by the Belgian Science Policy (IAP), the Flemish Science Foundation (FWO-Vl), and the collaborative project FWO-MINCyT (Project No. FW/08/01). G. R. B. and A. D. H acknowledge support from FWO-Vl. A. D. H. and D. D. acknowledge support from CONICET, CNEA, and ANPCyT (Grant No. PICT07-824). ; Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:97180 Serial 1243  
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Author Verberck, B.; Partoens, B.; Peeters, F.M.; Trauzettel, B. url  doi
openurl 
  Title Strain-induced band gaps in bilayer graphene Type A1 Journal article
  Year (down) 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 85 Issue 12 Pages 125403-125403,10  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We present a tight-binding investigation of strained bilayer graphene within linear elasticity theory, focusing on the different environments experienced by the A and B carbon atoms of the different sublattices. We find that the inequivalence of the A and B atoms is enhanced by the application of perpendicular strain epsilon(zz), which provides a physical mechanism for opening a band gap, most effectively obtained when pulling the two graphene layers apart. In addition, perpendicular strain introduces electron-hole asymmetry and can result in linear electronic dispersion near the K point. Our findings suggest experimental means for strain-engineered band gaps in bilayer graphene.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000301113200005 Publication Date 2012-03-06  
  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 53 Open Access  
  Notes ; The authors would like to acknowledge O. Leenaerts, E. Mariani, K. H. Michel, and J. Schelter for useful discussions. B. V. was financially supported by the Flemish Science Foundation (FWO-Vl). This work was financially supported by the ESF program EuroGraphene under projects CONGRAN and ENTS as well as by the DFG. ; Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:97181 Serial 3168  
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Author Fang, C.M.; van Huis, M.A.; Thijsse, B.J.; Zandbergen, H.W. url  doi
openurl 
  Title Stability and crystal structures of iron carbides : a comparison between the semi-empirical modified embedded atom method and quantum-mechanical DFT calculations Type A1 Journal article
  Year (down) 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 85 Issue 5 Pages 054116-054116,7  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Iron carbides play a crucial role in steel manufacturing and processing and to a large extent determine the physical properties of steel products. The modified embedded atom method (MEAM) in combination with Lee's Fe-C potential is a good candidate for molecular dynamics simulations on larger Fe-C systems. Here, we investigate the stability and crystal structures of pure iron and binary iron carbides using MEAM and compare them with the experimental data and quantum-mechanical density functional theory calculations. The analysis shows that the Fe-C potential gives reasonable results for the relative stability of iron and iron carbides. The performance of MEAM for the prediction of the potential energy and the calculated lattice parameters at elevated temperature for pure iron phases and cementite are investigated as well. The conclusion is that Lee's MEAM Fe-C potential provides a promising basis for further molecular dynamics simulations of Fe-C alloys and steels at lower temperatures (up to 800 K).  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000300931900004 Publication Date 2012-02-29  
  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 18 Open Access  
  Notes Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:97201 Serial 3117  
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Author Krstajić, P.M.; Peeters, F.M. url  doi
openurl 
  Title Remote electron plasmon polaron in graphene Type A1 Journal article
  Year (down) 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 85 Issue 8 Pages 085436-085436,5  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The Coulomb interaction and the correlation of a remote electron with a single layer of graphene is investigated in the presence of a magnetic field applied perpendicular to the graphene layer. The remote electron polarizes the electron gas in the graphene layer, which we describe in terms of excitations of virtual plasmons in graphene. The composite quasiparticle formed by electron plus polarization is called a plasmon polaron. The ground-state energy of this quasiparticle is calculated within perturbation theory for remote electrons in different environments.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000300831900012 Publication Date 2012-02-27  
  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 4 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:97202 Serial 2869  
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Author Nayuk, R.; Zacher, D.; Schweins, R.; Wiktor, C.; Fischer, R.A.; Van Tendeloo, G.; Huber, K. pdf  doi
openurl 
  Title Modulated formation of MOF-5 nanoparticles : a SANS analysis Type A1 Journal article
  Year (down) 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 116 Issue 10 Pages 6127-6135  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract MOF-5 nanoparticles were prepared by mixing a solution of [Zn4O(C6H5COO)(6)] with a solution of benzene-1,4-dicarboxylic acid in DMF at ambient conditions. The former species mimics as a secondary building unit (SBU), and the latter acts as linker. Mixing of the two solutions induced the formation of MOF-5 nanoparticles in dilute suspension. The applied conditions were identified as suitable for a closer investigation of the particle formation process by combined light and small angle neutron scattering (SANS). Scattering analysis revealed a significant impact of the molar ratio of the two components in the reaction mixture. Excessive use of the building unit slowed down the process. A similar effect was observed upon addition of 4n-decylbenzoic acid, which is supposed to act as a modulator. The formation mechanism leads to initial intermediates, which turn into cubelike nanoparticles with a diameter of about 60-80 nm. This initial stage is followed by an extended formation period, where nucleation proceeds over hours, leading to an increasing number of nanoparticles with the same final size of 60-80 nm.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000301509600020 Publication Date 2012-02-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 24 Open Access  
  Notes Approved Most recent IF: 4.536; 2012 IF: 4.814  
  Call Number UA @ lucian @ c:irua:97789 Serial 2163  
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Author Nasr Esfahani, D.; Covaci, L.; Peeters, F.M. url  doi
openurl 
  Title Electric-field-induced shift of the Mott metal-insulator transition in thin films Type A1 Journal article
  Year (down) 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 85 Issue 8 Pages 085110-085110,8  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The ground-state properties of a paramagnetic Mott insulator at half-filling are investigated in the presence of an external electric field using the inhomogeneous Gutzwiller approximation for a single-band Hubbard model in a slab geometry. We find that the metal-insulator transition is shifted toward higher Hubbard repulsions by applying an electric field perpendicular to the slab. The main reason is the accumulation of charges near the surface. The spatial distribution of site-dependent quasiparticle weight shows that it is maximal in a few layers beneath the surface, while the central sites where the field is screened have a very low quasiparticle weight. Our results show that above a critical-field value, states near the surface will be metallic, while the bulk quasiparticle weight is extremely suppressed but never vanishing, even for large Hubbard repulsions above the bulk zero-field critical value. Below the critical-field value, our results hint toward an insulating state in which the electric field is totally screened and the slab is again at half-filling.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000300240100002 Publication Date 2012-02-14  
  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 3 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vlaanderen) and the Belgian Science Policy (IAP). ; Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:97208 Serial 884  
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Author Ribbens, S.; Beyers, E.; Schellens, K.; Mertens, M.; Ke, X.; Bals, S.; Van Tendeloo, G.; Meynen, V.; Cool, P. pdf  doi
openurl 
  Title Systematic evaluation of thermal and mechanical stability of different commercial and synthetic photocatalysts in relation to their photocatalytic activity Type A1 Journal article
  Year (down) 2012 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat  
  Volume 156 Issue Pages 62-72  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)  
  Abstract The effect of thermal treatment and mechanical stress on the structural and photocatalytic properties of eight different (synthetic and commercial) photocatalysts has been thoroughly investigated. Different mesoporous Ti-based materials were prepared via surfactant based synthesis routes (e.g. Pluronic 123, CTMABr = Cetyltrimethylammonium bromide) or via template-free synthesis routes (e.g. trititanate nanotubes). Also, the stabilizing effect of the NaOH/NH4OH post-treatment on the templated mesoporous materials and their photocatalytic activity was investigated. Furthermore, the thermal and mechanical properties of commercially available titanium dioxides such as P25 Evonik® and Millenium PC500® were studied. The various photocatalysts were analyzed with N2-sorption, X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) to obtain information concerning the specific surface area, pore volume, crystal structure, morphology, phase transitions, etc. In general, results show that the NaOH post-treatment leads to an increased control of the crystallization process during calcination resulting in a higher thermal stability, but at the same time diminishes the photocatalytic activity. Mesoporous materials in which pre-synthesized nanoparticles are used as titania source have the best mechanical stability whereas the mechanical stability of the nanotubes is the most limited. At increased temperatures and pressures, the tested commercial titanium dioxides lose their superior photocatalytic activity caused by a decreased accessibility of the active sites. The observed changes in adsorption capacities and photocatalytic activities cannot be assigned to one single phenomenon. In this respect, it shows the need to define a general/standard method to compare different photocatalysts. Furthermore, it is shown that the photocatalytic properties do not necessarily deteriorate under thermal stress, but can be improved due to crystallization, even though the initial material is (partially) destroyed. It is shown that the usefulness of a specific type of photocatalyst strongly depends on the application and the temperature/pressure to which it needs to resist.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000303625200010 Publication Date 2012-02-08  
  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 8 Open Access  
  Notes Fwo Approved Most recent IF: 3.615; 2012 IF: 3.365  
  Call Number UA @ lucian @ c:irua:96910 Serial 3466  
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Author Bourgeois, J.; Hervieu, M.; Poienar, M.; Abakumov, A.M.; Elkaïm, E.; Sougrati, M.T.; Porcher, F.; Damay, F.; Rouquette, J.; Van Tendeloo, G.; Maignan, A.; Haines, J.; Martin, C.; url  doi
openurl 
  Title Evidence of oxygen-dependent modulation in LuFe2O4 Type A1 Journal article
  Year (down) 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 85 Issue 6 Pages 064102-064120,10  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A polycrystalline sample of LuFe2O4 has been investigated by means of powder synchrotron x-ray and neutron diffraction and transmission electron microscopy (TEM), along with Mössbauer spectroscopy and transport and magnetic properties. A monoclinic distortion is unambiguously evidenced, and the crystal structure is refined in the monoclinic C2/m space group [aM = 5.9563(1) Å, bM = 3.4372(1) Å, cM = 8.6431(1) Å, β = 103.24(1)°]. Along with the previously reported modulations distinctive of the charge-ordering (CO) of the iron species, a new type of incommensurate order is observed, characterized by a vector q⃗1 = α1a⃗M* + γ1c⃗M* (with α1 ≅ 0.55, γ1 ≅ 0.13). In situ heating TEM observations from 300 to 773 K confirm that the satellites associated with q⃗1 vanish completely, only at a temperature significantly higher than the CO temperature. This incommensurate modulation has a displacive character and corresponds primarily to a transverse displacive modulation wave of the Lu cations position, as revealed by the high resolution, high angle annular dark field scanning TEM images and in agreement with synchrotron data refinements. Analyses of vacuum-annealed samples converge toward the hypothesis of a new ordering mechanism, associated with a tiny oxygen deviation from the O4 stoichiometry.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000299896900003 Publication Date 2012-02-06  
  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 24 Open Access  
  Notes Hercules Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:95042 Serial 1095  
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Author Tikhomirov, V.K.; Rodríguez, V.D.; Méndez-Ramos, J.; del- Castillo, J.; Kirilenko, D.; Van Tendeloo, G.; Moshchalkov, V.V. pdf  doi
openurl 
  Title Optimizing Er/Yb ratio and content in Er-Yb co-doped glass-ceramics for enhancement of the up- and down-conversion luminescence Type A1 Journal article
  Year (down) 2012 Publication Solar energy materials and solar cells Abbreviated Journal Sol Energ Mat Sol C  
  Volume 100 Issue Pages 209-215  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Er3+Yb3+ co-doped transparent glass-ceramics with varying Er/Yb content and ratio have been prepared. High quantum yields for up- and down-conversion luminescence by energy transfer from Yb3+ to Er3+ and from Er3+ to Yb3+, respectively, have been detected and optimized with respect to the Er/Yb content and ratio, and proposed in particular for up- and down-conversion of solar spectrum for enhancement of the efficiency of solar cells. The rise and decay kinetics for the population of the excited levels of Er3+ and Yb3+ have been studied and fit. Based on these experimental data, the mechanisms for the energy transfers have been suggested with emphasis on the optimized Er/Yb content and ratio for enhancement of the efficiency of the Er3+↔Yb3+ energy transfers.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000303034700030 Publication Date 2012-02-04  
  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 66 Open Access  
  Notes Fwo Approved Most recent IF: 4.784; 2012 IF: 4.630  
  Call Number UA @ lucian @ c:irua:97392 Serial 2493  
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Author Lu, Y.-G.; Verbeeck, J.; Turner, S.; Hardy, A.; Janssens, S.D.; De Dobbelaere, C.; Wagner, P.; Van Bael, M.K.; Van Tendeloo, G. pdf  doi
openurl 
  Title Analytical TEM study of CVD diamond growth on TiO2 sol-gel layers Type A1 Journal article
  Year (down) 2012 Publication Diamond and related materials Abbreviated Journal Diam Relat Mater  
  Volume 23 Issue Pages 93-99  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The early growth stages of chemical vapor deposition (CVD) diamond on a solgel TiO2 film with buried ultra dispersed diamond seeds (UDD) have been studied. In order to investigate the diamond growth mechanism and understand the role of the TiO2 layer in the growth process, high resolution transmission electron microscopy (HRTEM), energy-filtered TEM and electron energy loss spectroscopy (EELS) techniques were applied to cross sectional diamond film samples. We find evidence for the formation of TiC crystallites inside the TiO2 layer at different diamond growth stages. However, there is no evidence that diamond nucleation starts from these crystallites. Carbon diffusion into the TiO2 layer and the chemical bonding state of carbon (sp2/sp3) were both extensively investigated. We provide evidence that carbon diffuses through the TiO2 layer and that the diamond seeds partially convert to amorphous carbon during growth. This carbon diffusion and diamond to amorphous carbon conversion make the seed areas below the TiO2 layer grow and bend the TiO2 layer upwards to form the nucleation center of the diamond film. In some of the protuberances a core of diamond seed remains, covered by amorphous carbon. It is however unlikely that the remaining seeds are still active during the growth process.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000302887600017 Publication Date 2012-01-26  
  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 16 Open Access  
  Notes Iap; Esteem 026019; Fwo Approved Most recent IF: 2.561; 2012 IF: 1.709  
  Call Number UA @ lucian @ c:irua:95037UA @ admin @ c:irua:95037 Serial 111  
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Author Latimer, M.L.; Berdiyorov, G.R.; Xiao, Z.L.; Kwok, W.K.; Peeters, F.M. url  doi
openurl 
  Title Vortex interaction enhanced saturation number and caging effect in a superconducting film with a honeycomb array of nanoscale holes Type A1 Journal article
  Year (down) 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 85 Issue 1 Pages 012505-012505,4  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The electrical transport properties of a MoGe thin film with a honeycomb array of nanoscale holes are investigated. The critical current of the system shows nonmatching anomalies as a function of applied magnetic field, enabling us to distinguish between multiquanta vortices trapped in the holes and interstitial vortices located between the holes. The number of vortices trapped in each hole is found to be larger than the saturation number predicted for an isolated hole and shows a nonlinear field dependence, leading to the caging effect as predicted from the Ginzburg-Landau (GL) theory. Our experimental results are supplemented by numerical simulations based on the GL theory.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000299867200001 Publication Date 2012-01-26  
  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 41 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP) (theory) and by the US Department of Energy (DOE) Grant No. DE-FG02-06ER46334 (experiment). G. R. B. acknowledges an individual grant from FWO-Vl. W. K. K. acknowledges support from DOE BES under Contract No. DE-AC02-06CH11357, which also funds Argonne's Center for Nanoscale Materials (CNM), where the focused-ion-beam milling was performed. M.L.L was a recipient of the NIU/ANL Distinguished Graduate Fellowship. ; Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:96224 Serial 3866  
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Author Djotyan, A.P.; Avetisyan, A.A.; Hao, Y.L.; Peeters, F.M. doi  openurl
  Title Shallow donor near a semiconductor surface in the presence of locally spherical scanning tunneling microscope tip Type P1 Proceeding
  Year (down) 2012 Publication Proceedings of the Society of Photo-optical Instrumentation Engineers T2 – Conference on Photonics and Micro and Nano-structured Materials, JUN 28-30, 2011, Yerevan, ARMENIA Abbreviated Journal  
  Volume Issue Pages 84140-84148  
  Keywords P1 Proceeding; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract We developed a variational approach to investigate the ground state energy and the extend of the wavefunction of a neutral donor located near a semiconductor surface in the presence of scanning tunneling microscope (STM) metallic tip. We apply the effective mass approximation and use a variational wavefunction that takes into account the influence of all image charges that arise due to the presence of a metallic tip. The behavior of the ground state energy when the tip approaches the semiconductor surface is investigated.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000303856600020 Publication Date 2012-01-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 8414 Series Issue Edition  
  ISSN ISBN Additional Links UA library record; WoS full record  
  Impact Factor Times cited Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), and the Belgian Science Policy. One of us (AAA) was supported by a fellowship from the Belgian Federal Science Policy Office (Belspo). ; Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:113047 Serial 2987  
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Author Avetisyan, A.A.; Partoens, B.; Peeters, F.M. doi  openurl
  Title Electric field tuning of the band gap in four layers of graphene with different stacking order Type P1 Proceeding
  Year (down) 2012 Publication Proceedings of the Society of Photo-optical Instrumentation Engineers T2 – Conference on Photonics and Micro and Nano-structured Materials, JUN 28-30, 2011, Yerevan, ARMENIA Abbreviated Journal  
  Volume Issue Pages 84140-84148  
  Keywords P1 Proceeding; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract We investigated the effect of different stacking order of the four graphene layer system on the induced band gap when positively charged top and negatively charged back gates are applied to the system. A tight-binding approach within a self-consistent Hartree approximation is used to calculate the induced charges on the different graphene layers. We show that the electric field does not open an energy gap if the multilayer graphene system contains a trilayer part with the ABA Bernal stacking.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000303856600012 Publication Date 2012-01-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 8414 Series Issue Edition  
  ISSN ISBN Additional Links UA library record; WoS full record  
  Impact Factor Times cited Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), and the BelgianScience Policy (IAP). One of us (A.A.A.) was supported by a fellowship from the Belgian Federal Science Policy Office (BELSPO). ; Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:113046 Serial 886  
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Author Vagov, A.V.; Shanenko, A.A.; Milošević, M.V.; Axt, V.M.; Peeters, F.M. url  doi
openurl 
  Title Extended Ginzburg-Landau formalism : systematic expansion in small deviation from the critical temperature Type A1 Journal article
  Year (down) 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 85 Issue 1 Pages 014502-014502,17  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Based on the Gor'kov formalism for a clean s-wave superconductor, we develop an extended version of the single-band Ginzburg-Landau (GL) theory by means of a systematic expansion in the deviation from the critical temperature T(c), i.e., tau = 1 – T/T(c). We calculate different contributions to the order parameter and the magnetic field: the leading contributions (proportional to tau(1/2) in the order parameter and. t in the magnetic field) are controlled by the standard GL theory, while the next-to-leading terms (proportional to tau(3/2) in the gap and proportional to tau(2) in the magnetic field) constitute the extended GL (EGL) approach. We derive the free-energy functional for the extended formalism and the corresponding expression for the current density. To illustrate the usefulness of our formalism, we calculate, in a semianalytical form, the temperature-dependent correction to the GL parameter at which the surface energy becomes zero, and analytically, the temperature dependence of the thermodynamic critical field. We demonstrate that the EGL formalism is not just a mathematical extension to the theory: variations of both the gap and the thermodynamic critical field with temperature calculated within the EGL theory are found in very good agreement with the full BCS results down to low temperatures, which dramatically improves the applicability of the formalism compared to its standard predecessor.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000298985100002 Publication Date 2012-01-10  
  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 36 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP). A. V. V. is grateful to V. Zalipaev for important comments. A. A. S. thanks W. Pogosov for helpful notes. Discussions with E. H. Brandt and A. Perali are appreciated. ; Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:96232 Serial 1155  
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Author Hardy, A.; Van Elshocht, S.; De Dobbelaere, C.; Hadermann, J.; Pourtois, G.; De Gendt, S.; Afanas'ev, V.V.; Van Bael, M.K. pdf  doi
openurl 
  Title Properties and thermal stability of solution processed ultrathin, high-k bismuth titanate (Bi2Ti2O7) films Type A1 Journal article
  Year (down) 2012 Publication Materials research bulletin Abbreviated Journal Mater Res Bull  
  Volume 47 Issue 3 Pages 511-517  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Ultrathin bismuth titanate films (Bi2Ti2O7, 5-25 nm) are deposited onto SiO2/Si substrates by aqueous chemical solution deposition and their evolution during annealing is studied. The films crystallize into a preferentially oriented, pure pyrochlore phase between 500 and 700 degrees C, depending on the film thickness and the total thermal budget. Crystallization causes a strong increase of surface roughness compared to amorphous films. An increase of the interfacial layer thickness is observed after anneal at 600 degrees C, together with intermixing of bismuth with the substrate as shown by TEM-EDX. The band gap was determined to be similar to 3 eV from photoconductivity measurements and high dielectric constants between 30 and 130 were determined from capacitance voltage measurements, depending on the processing conditions. (C) 2012 Elsevier Ltd. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000301994100001 Publication Date 2012-01-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0025-5408; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.446 Times cited Open Access  
  Notes Approved Most recent IF: 2.446; 2012 IF: 1.913  
  Call Number UA @ lucian @ c:irua:97797 Serial 2727  
Permanent link to this record
 

 
Author Vodolazov, D.Y.; Peeters, F.M. url  doi
openurl 
  Title Enhancement of the retrapping current of superconducting microbridges of finite length Type A1 Journal article
  Year (down) 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 85 Issue 2 Pages 024508-024508,6  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We theoretically find that the resistance of a superconducting microbridge or nanowire decreases while the retrapping current I(r) for the transition to the superconducting state increases when one suppresses the magnitude of the order parameter vertical bar Delta vertical bar in the attached superconducting leads. This effect is a consequence of the increased energy interval for diffusion of the “hot” nonequilibrium quasiparticles (induced by the oscillations of vertical bar Delta vertical bar in the center of the microbridge) to the leads. The effect is absent in short microbridges (with length less than the coherence length) and it is relatively weak in long microbridges (with length larger than the inelastic relaxation length of the nonequilibrium distribution function). A nonmonotonous dependence of I(r) on the length of the microbridge is predicted. Our results are important for the explanation of the enhancement of the critical current and the appearance of negative magnetoresistance observed in many recent experiments on superconducting microbridges or nanowires.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000298863400005 Publication Date 2012-01-06  
  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 Russian Foundation for Basic Research, Russian Agency of Education, under the Federal Target Programme “Scientific and Educational Personnel of Innovative Russia in 2009-2013” and the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:96235 Serial 1065  
Permanent link to this record
 

 
Author Rønnow, T.F.; Pedersen, T.G.; Partoens, B. url  doi
openurl 
  Title Biexciton binding energy in fractional dimensional semiconductors Type A1 Journal article
  Year (down) 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 85 Issue 4 Pages 045412-045412,7  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Biexcitons in fractional dimensional spaces are studied using variational quantum Monte Carlo. We investigate the biexciton binding energy as a function of the electron-hole mass fraction sigma as well as study the dimensional dependence of biexcitons for sigma = 0 and sigma = 1. As our first application of this model we treat the H(2) molecule in two and three dimensions. Next we investigate biexcitons in carbon nanotubes within the fractional dimensional model. To this end we find a relation between the nanotube radius and the effective dimension. The results of both applications are compared with results obtained using different models and we find a reasonable agreement. Within the fractional dimensional model we find that the biexciton binding energy in carbon nanotubes accurately scales as E(B)(r,epsilon) = 1280 meV angstrom/(r epsilon), as a function of radius r and the dielectric screening epsilon.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000298922200008 Publication Date 2012-01-06  
  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 21 Open Access  
  Notes ; ; Approved Most recent IF: 3.836; 2012 IF: 3.767  
  Call Number UA @ lucian @ c:irua:96234 Serial 231  
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Author de Oliveira, E.L.; Albuquerque, E.L.; de Sousa, J.S.; Farias, G.A.; Peeters, F.M. doi  openurl
  Title Configuration-interaction excitonic absorption in small Si/Ge and Ge/Si core/shell nanocrystals Type A1 Journal article
  Year (down) 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 116 Issue 7 Pages 4399-4407  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract The excitonic properties of Si(core)/Ge(shell) and Ge(core)/Si(shell) nanocrystals (NC's) with diameters of similar to 1.9 nm are investigated using a combination density functional ab initio method to obtain the single particle wave functions and a configuration interaction method to compute the exciton fine structure and absorption coefficient. These core/shell structures exhibit type II confinement, which is more pronounced for the Si/Ge NC as a consequence of strain. The absorption coefficients of these NC's exhibit a single dominant peak, which has a much larger oscillator strength than the multipeaks found for pure Si and Ge NC's. The exciton lifetime in Si, Ge, and Ge/Si shows a small i:emperature dependence in the range 10-300 K, whereas in Si/Ge, the exciton lifetime decreases more than an order of magnitude in the same temperature range.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000301156500007 Publication Date 2012-01-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 44 Open Access  
  Notes ; The authors acknowledge financial support from CNPq and the bilateral program between Flanders and Brazil and the Belgian Science Foundation (IAP). ; Approved Most recent IF: 4.536; 2012 IF: 4.814  
  Call Number UA @ lucian @ c:irua:113045 Serial 482  
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Author Van Aert, S.; Turner, S.; Delville, R.; Schryvers, D.; Van Tendeloo, G.; Salje, E.K.H. pdf  doi
openurl 
  Title Direct observation of ferrielectricity at ferroelastic domain boundaries in CaTiO3 by electron microscopy Type A1 Journal article
  Year (down) 2012 Publication Advanced materials Abbreviated Journal Adv Mater  
  Volume 24 Issue 4 Pages 523-527  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract High-resolution aberration-corrected transmission electron microscopy aided by statistical parameter estimation theory is used to quantify localized displacements at a (110) twin boundary in orthorhombic CaTiO3. The displacements are 36 pm for the Ti atoms and confined to a thin layer. This is the first direct observation of the generation of ferroelectricity by interfaces inside this material which opens the door for domain boundary engineering.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Weinheim Editor  
  Language Wos 000299156400011 Publication Date 2011-12-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0935-9648; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 19.791 Times cited 150 Open Access  
  Notes Fwo Approved Most recent IF: 19.791; 2012 IF: 14.829  
  Call Number UA @ lucian @ c:irua:94110 Serial 717  
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Author Ustarroz, J.; Ke, X.; Hubin, A.; Bals, S.; Terryn, H. pdf  doi
openurl 
  Title New insights into the early stages of nanoparticle electrodeposition Type A1 Journal article
  Year (down) 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 116 Issue 3 Pages 2322-2329  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Electrodeposition is an increasingly important method to synthesize supported nanoparticles, yet the early stages of electrochemical nanoparticle formation are not perfectly understood. In this paper, the early stages of silver nanoparticle electrodeposition on carbon substrates have been studied by aberration-corrected TEM, using carbon-coated TEM grids as electrochemical electrodes. In this manner we have access to as-deposited nanoparticle size distribution and structural characterization at the atomic scale combined with electrochemical measurements, which represents a breakthrough in a full understanding of the nanoparticle electrodeposition mechanisms. Whereas classical models, based upon characterization at the nanoscale, assume that electrochemical growth is only driven by direct attachment, the results reported hereafter indicate that early nanoparticle growth is mostly driven by nanocluster surface movement and aggregation. Hence, we conclude that electrochemical nulceation and growth models should be revised and that an electrochemical aggregative growth mechanism should be considered in the early stages of nanoparticle electrodeposition.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000299584400037 Publication Date 2011-12-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 104 Open Access  
  Notes Fwo Approved Most recent IF: 4.536; 2012 IF: 4.814  
  Call Number UA @ lucian @ c:irua:96225 Serial 2316  
Permanent link to this record
 

 
Author Coghe, F.; Tirry, W.; Rabet, L.; Schryvers, D.; Van Houtte, P. pdf  doi
openurl 
  Title Importance of twinning in static and dynamic compression of a Ti-6Al-4V titanium alloy with an equiaxed microstructure Type A1 Journal article
  Year (down) 2012 Publication Materials science and engineering: part A: structural materials: properties, microstructure and processing Abbreviated Journal Mat Sci Eng A-Struct  
  Volume 537 Issue Pages 1-10  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Whereas deformation twinning is known to be an important deformation mechanism for hexagonal materials like magnesium and pure titanium, so far almost no literature exists on the twinning behaviour of the Ti-6Al-4V alloy. In this work it was shown that the activation of twinning as a deformation mechanism could have a pronounced effect on the mechanical behaviour of the Ti-6Al-4V alloy. This effect is even more pronounced under dynamic loading conditions. Transmission electron microscopy showed that only the {1 0 1 2}{1 0 1 1} tensile twin system was activated under certain loading conditions. Light-optical microscopy and electron backscatter diffraction data were afterwards used to experimentally determine the twin fractions. The importance of twinning for the texture evolution was also studied. It was shown that even small twin fractions can lead to distinct texture features, especially due to the discrete reorientation of the c-axes. The experimental results were compared to simulated results that were obtained with a viscoplastic self-consistent crystal plasticity code, after experimental validation that twinning can be reliably modelled as a unidirectional slip system. Although good agreement was obtained for the experimental and simulated stress-strain curves, the simulated results concerning twinning correlated well only on a qualitative basis as the simulated twin fractions were systematically higher than the experimental fractions. This seems to strengthen the hypothesis made by other research groups that complete grains might reorient by twinning. (C) 2011 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lausanne Editor  
  Language Wos 000301473300001 Publication Date 2011-12-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0921-5093; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.094 Times cited 35 Open Access  
  Notes Approved Most recent IF: 3.094; 2012 IF: 2.108  
  Call Number UA @ lucian @ c:irua:97818 Serial 1565  
Permanent link to this record
 

 
Author Bouvier, S.; Benmhenni, N.; Tirry, W.; Gregory, F.; Nixon, M.E.; Cazacu, O.; Rabet, L. pdf  doi
openurl 
  Title Hardening in relation with microstructure evolution of high purity \alpha-titanium deformed under monotonic and cyclic simple shear loadings at room temperature Type A1 Journal article
  Year (down) 2012 Publication Materials science and engineering: part A: structural materials: properties, microstructure and processing Abbreviated Journal Mat Sci Eng A-Struct  
  Volume 535 Issue Pages 12-21  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The aim of this paper is to gain understanding of the quasi-static, large strain deformation behavior at room-temperature of high-purity alpha-Ti with an initial split-basal texture. Simple shear tests were conducted along different directions in order to quantify the material's anisotropy and hardening evolution for different strain paths such as monotonic, Bauschinger, and cyclic loadings. The stress-strain curves indicate that the material displays strong anisotropy in the flow behavior. In order to capture the link between microstructure evolution (occurrence of twinning, grain size evolution, etc.) and the macroscopic response, a thoroughly detailed multi-scale characterization using scanning electron microscope (SEM) observations and electron backscattered diffraction (EBSD) analysis was also conducted. Specifically, EBSD analyses indicate that the twin activity and grain fragmentation are responsible for the observed difference between the macroscopic hardening rates corresponding to different directions and loading paths. (C) 2011 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lausanne Editor  
  Language Wos 000301402400003 Publication Date 2011-12-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0921-5093; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.094 Times cited 22 Open Access  
  Notes Approved Most recent IF: 3.094; 2012 IF: 2.108  
  Call Number UA @ lucian @ c:irua:97824 Serial 1410  
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Author Piñera, I.; Cruz, C.M.; van Espen, P.; Abreu, Y.; Leyva, A. pdf  doi
openurl 
  Title Study of dpa distributions in electron irradiated YBCO slabs through MCCM algorithm Type A1 Journal article
  Year (down) 2012 Publication Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms Abbreviated Journal  
  Volume 274 Issue Pages 191-194  
  Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The Monte Carlo assisted Classical Method (MCCM) consists on a calculation procedure for determining the displacements per atom (dpa) distribution in solid materials. This algorithm allows studying the gamma and electron irradiation damage in different materials. It is based on the electrons elastic scattering classic theories and the use of Monte Carlo simulation for the physical processes involved. The present study deals with the Monte Carlo simulation of electron irradiation effects on YBa2Cu3O7-x (YBCO) slabs using the MCNPX code system. Displacements per atom distributions are obtained through the MCCM for electron irradiation up to 10 MeV. In-depth dpa profiles for electrons and positrons are obtained and analysed. Also, dpa contributions from each atomic specie in the material are calculated. It was found that the dpa distribution is more homogeneous in the material volume when increasing energy of incident electrons. Also, the dpa produced by positrons has no relevance when irradiating with electrons, in contrast with previous similar gamma irradiation studies. All the results are presented and discussed in this contribution. (C) 2011 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000301611900031 Publication Date 2011-12-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-583x 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:97819 Serial 8595  
Permanent link to this record
 

 
Author Bertrand, L.; Robinet, L.; Thoury, M.; Janssens, K.; Cohen, S.X.; Schöder, S. pdf  doi
openurl 
  Title Cultural heritage and archaeology materials studied by synchrotron spectroscopy and imaging Type A1 Journal article
  Year (down) 2012 Publication Applied physics A : materials science & processing Abbreviated Journal Appl Phys A-Mater  
  Volume 106 Issue 2 Pages 377-396  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The use of synchrotron radiation techniques to study cultural heritage and archaeological materials has undergone a steep increase over the past 10-15 years. The range of materials studied is very broad and encompasses painting materials, stone, glass, ceramics, metals, cellulosic and wooden materials, and a cluster of organic-based materials, in phase with the diversity observed at archaeological sites, museums, historical buildings, etc. Main areas of investigation are: (1) the study of the alteration and corrosion processes, for which the unique non-destructive speciation capabilities of X-ray absorption have proved very beneficial, (2) the understanding of the technologies and identification of the raw materials used to produce archaeological artefacts and art objects and, to a lesser extent, (3) the investigation of current or novel stabilisation, conservation and restoration practices. In terms of the synchrotron methods used, the main focus so far has been on X-ray techniques, primarily X-ray fluorescence, absorption and diffraction, and Fourier-transform infrared spectroscopy. We review here the use of these techniques from recent works published in the field demonstrating the breadth of applications and future potential offered by third generation synchrotron techniques. New developments in imaging and advanced spectroscopy, included in the UV/visible and IR ranges, could even broaden the variety of materials studied, in particular by fostering more studies on organic and complex organic-inorganic mixtures, while new support activities at synchrotron facilities might facilitate transfer of knowledge between synchrotron specialists and users from archaeology and cultural heritage sciences.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000299749000009 Publication Date 2011-11-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0947-8396 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.455 Times cited 55 Open Access  
  Notes ; The authors acknowledge the critical reading by B. Berrie (National Gallery of Art, Washington DC, USA). We thank J. Mass (Conservation Department, Winterthur Museum and Country Estate, Winterthur, DE, USA), H. Roemich (Institute of Fine Arts, New York University, USA), J. Hiller (Non-Crystalline Diffraction Beamline, Diamond Light Source, Didcot, UK) and J.-P. Echard (Laboratoire de recherche et de restauration, Musee de la musique, Paris, France) for their comments on the presentation of their work in the manuscript. The IPANEMA platform is jointly developed by CNRS, MNHN, the French Ministry of Culture and Communication and SOLEIL, and benefits from a CPER grant (MESR, Region Ile-de-France). Support by the Access to Research Infrastructures activity in the 7th Framework Programme of the EU (CHARISMA Grant Agreement n. 228330) and the NWO Science4Arts programme are acknowledged. ; Approved Most recent IF: 1.455; 2012 IF: 1.545  
  Call Number UA @ admin @ c:irua:99166 Serial 5561  
Permanent link to this record
 

 
Author Casavola, M.; van Huis, M.A.; Bals, S.; Lambert, K.; Hens, Z.; Vanmaekelbergh, D. pdf  doi
openurl 
  Title Anisotropic cation exchange in PbSe/CdSe core/shell nanocrystals of different geometry Type A1 Journal article
  Year (down) 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 24 Issue 2 Pages 294-302  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We present a study of Cd2+-for-Pb2+ exchange in PbSe nanocrystals (NCs) with cube, star, and rod shapes. Prolonged temperature-activated cation exchange results in PbSe/CdSe heterostructured nanocrystals (HNCs) that preserve their specific overall shape, whereas the PbSe core is strongly faceted with dominance of {111} facets. Hence, cation exchange proceeds while the Se anion lattice is preserved, and well-defined {111}/{111} PbSe/CdSe interfaces develop. Interestingly, by quenching the reaction at different stages of the cation exchange new structures have been isolated, such as coreshell nanorods, CdSe rods that contain one or two separated PbSe dots and fully zinc blende CdSe nanorods. The crystallographically anisotropic cation exchange has been characterized by a combined HRTEM/HAADF-STEM study of heterointerface evolution over reaction time and temperature. Strikingly, Pb and Cd are only intermixed at the PbSe/CdSe interface. We propose a plausible model for the cation exchange based on a layer-by-layer replacement of Pb2+ by Cd2+ enabled by a vacancy-assisted cation migration mechanism.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000299367500008 Publication Date 2011-11-17  
  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 136 Open Access  
  Notes Esteem 026019 Approved Most recent IF: 9.466; 2012 IF: 8.238  
  Call Number UA @ lucian @ c:irua:94211 Serial 124  
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Author Jalabert, D.; Pelloux-Gervais, D.; Béché, A.; Hartmann, J.M.; Gergaud, P.; Rouvière, J.L.; Canut, B. doi  openurl
  Title Depth strain profile with sub-nm resolution in a thin silicon film using medium energy ion scattering Type A1 Journal article
  Year (down) 2012 Publication Physica Status Solidi A-Applications And Materials Science Abbreviated Journal Phys Status Solidi A  
  Volume 209 Issue 2 Pages 265-267  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The depth strain profile in silicon from the Si (001) substrate to the surface of a 2 nm thick Si/12 nm thick SiGe/bulk Si heterostructure has been determined by medium energy ion scattering (MEIS). It shows with sub-nanometer resolution and high strain sensitivity that the thin Si cap presents residual compressive strain caused by Ge diffusion coming from the fully strained SiGe layer underneath. The strain state of the SiGe buffer have been checked by X-ray diffraction (XRD) and nano-beam electron diffraction (NBED) measurements.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000303382700005 Publication Date 2011-11-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1862-6300; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.775 Times cited 3 Open Access  
  Notes Approved Most recent IF: 1.775; 2012 IF: 1.469  
  Call Number UA @ lucian @ c:irua:136430 Serial 4497  
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Author Kuznetsov, A.S.; Cuong, N.T.; Tikhomirov, V.K.; Jivanescu, M.; Stesmans, A.; Chibotaru, L.F.; Velázquez, J.J.; Rodríguez, V.D.; Kirilenko, D.; Van Tendeloo, G.; Moshchalkov, V.V. pdf  doi
openurl 
  Title Effect of heat-treatment on luminescence and structure of Ag nanoclusters doped oxyfluoride glasses and implication for fiber drawing Type A1 Journal article
  Year (down) 2012 Publication Optical materials Abbreviated Journal Opt Mater  
  Volume 34 Issue 4 Pages 616-621  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The effect of heat treatment on the structure and luminescence of Ag nanoclusters doped oxyfluoride glasses was studied and the implication for drawing the corresponding fibers doped with luminescent Ag nanoclusters has been proposed. The heat treatment results, first, in condensation of the Ag nanoclusters into larger Ag nanoparticles and loss of Ag luminescence, and further heat treatment results in precipitation of a luminescent-loss nano- and microcrystalline Ag phases onto the surface of the glass. Thus, the oxyfluoride fiber doped with luminescent Ag nanoclusters was pulled from the viscous glass melt and its attenuation loss was 0.19 dB/cm in the red part of the spectrum; i.e. near to the maximum of Ag nanoclusters luminescence band. The nucleation centers for the Ag nanoclusters in oxyfluoride glasses have been suggested to be the fluorine vacancies and their nanoclusters.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000300124500006 Publication Date 2011-10-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0925-3467; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.238 Times cited 25 Open Access  
  Notes Methusalem Approved Most recent IF: 2.238; 2012 IF: 1.918  
  Call Number UA @ lucian @ c:irua:93632 Serial 811  
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