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Author Mortet, V.; Zhang, L.; Eckert, M.; D'Haen, J.; Soltani, A.; Moreau, M.; Troadec, D.; Neyts, E.; De Jaeger, J.C.; Verbeeck, J.; Bogaerts, A.; Van Tendeloo, G.; Haenen, K.; Wagner, P.
Title Grain size tuning of nanocrystalline chemical vapor deposited diamond by continuous electrical bias growth : experimental and theoretical study Type A1 Journal article
Year 2012 Publication Physica status solidi : A : applications and materials science Abbreviated Journal Phys Status Solidi A
Volume 209 Issue 9 Pages 1675-1682
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this work, a detailed structural and spectroscopic study of nanocrystalline diamond (NCD) thin films grown by a continuous bias assisted CVD growth technique is reported. This technique allows the tuning of grain size and phase purity in the deposited material. The crystalline properties of the films are characterized by SEM, TEM, EELS, and Raman spectroscopy. A clear improvement of the crystalline structure of the nanograined diamond film is observed for low negative bias voltages, while high bias voltages lead to thin films consisting of diamond grains of only ∼10 nm nanometer in size, showing remarkable similarities with so-called ultrananocrystalline diamond. These layers arecharacterized by an increasing amount of sp2-bonded carbon content of the matrix in which the diamond grains are embedded. Classical molecular dynamics simulations support the observed experimental data, giving insight in the underlying mechanism for the observed increase in deposition rate with bias voltage. Furthermore, a high atomic concentration of hydrogen has been determined in these films. Finally, Raman scattering analyses confirm that the Raman line observed at ∼1150 cm−1 cannot be attributed to trans-poly-acetylene, which continues to be reported in literature, reassigning it to a deformation mode of CHx bonds in NCD.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000308942100009 Publication Date 2012-09-04
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 31 Open Access
Notes M.E. and E.N. acknowledge financial support from, respectively, the Institute for Promotion of Innovation through Science and Technology in Flanders (IWT), and the Research Foundation-Flanders (FWO). J.V. gratefully acknowledges financial support from the GOA project “XANES meets ELNES” of the research fund of the University of Antwerp. Calculation support was provided by the University of Antwerp through the core facility CALCUA. G.V.T. acknowledges the ERC grant COUNTATOMS. The work was also financially supported by the joint UAUHasseltMethusalem “NANO” network, the Research Programs G.0068.07 and G.0555.10N of the Research Foundation-Flanders (FWO), the IAP-P6/42 project “Quantum Effects in Clusters and Nanowires”, and by the EU FP7 through the Integrated Infrastructure Initiative “ESMI” (No. 262348), the Marie Curie ITN “MATCON” (PITN-GA-2009-238201), and the Collaborative Project “DINAMO” (No. 245122). Approved Most recent IF: 1.775; 2012 IF: 1.469
Call Number UA @ lucian @ c:irua:101516UA @ admin @ c:irua:101516 Serial (up) 1364
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Author Afanasov, I.M.; Shornikova, O.N.; Kirilenko, D.A.; Vlasov, I.I.; Zhang, L.; Verbeeck, J.; Avdeev, V.V.; Van Tendeloo, G.
Title Graphite structural transformations during intercalation by HNO3 and exfoliation Type L1 Letter to the editor
Year 2010 Publication Carbon Abbreviated Journal Carbon
Volume 48 Issue 6 Pages 1862-1865
Keywords L1 Letter to the editor; Electron microscopy for materials research (EMAT)
Abstract Expandable graphite of two types was synthesized by (1) hydrolysis of graphite nitrate of II stage and (2) anodic polarization of graphite in 60% HNO3. Exfoliated graphite samples were produced by thermal shock of expandable graphite samples in air at 900 °C. A comparative study of microstructural distinctions of both expandable and exfoliated graphite samples was carried out using X-ray diffraction, Raman spectroscopy, electron energy loss spectroscopy and high resolution transmission electron microscopy.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000276132800021 Publication Date 2010-02-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-6223; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.337 Times cited 43 Open Access
Notes Approved Most recent IF: 6.337; 2010 IF: 4.896
Call Number UA @ lucian @ c:irua:82315UA @ admin @ c:irua:82315 Serial (up) 1379
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Author Turner, S.; Lazar, S.; Freitag, B.; Egoavil, R.; Verbeeck, J.; Put, S.; Strauven, Y.; Van Tendeloo, G.
Title High resolution mapping of surface reduction in ceria nanoparticles Type A1 Journal article
Year 2011 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 3 Issue 8 Pages 3385-3390
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Surface reduction of ceria nano octahedra with predominant {111} and {100} type surfaces is studied using a combination of aberration-corrected Transmission Electron Microscopy (TEM) and spatially resolved electron energy-loss spectroscopy (EELS) at high energy resolution and atomic spatial resolution. The valency of cerium ions at the surface of the nanoparticles is mapped using the fine structure of the Ce M4,5 edge as a fingerprint. The valency of the surface cerium ions is found to change from 4+ to 3+ owing to oxygen deficiency (vacancies) close to the surface. The thickness of this Ce3+ shell is measured using atomic-resolution Scanning Transmission Electron Microscopy (STEM)-EELS mapping over a {111} surface (the predominant facet for this ceria morphology), {111} type surface island steps and {100} terminating planes. For the {111} facets and for {111} surface islands, the reduction shell is found to extend over a single fully reduced surface plane and 12 underlying mixed valency planes. For the {100} facets the reduction shell extends over a larger area of 56 oxygen vacancy-rich planes. This finding provides a plausible explanation for the higher catalytic activity of the {100} surface facets in ceria.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000293521700057 Publication Date 2011-06-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364;2040-3372; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 127 Open Access
Notes Fwo Approved Most recent IF: 7.367; 2011 IF: 5.914
Call Number UA @ lucian @ c:irua:90361UA @ admin @ c:irua:90361 Serial (up) 1458
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Author Verbeeck, J.; Bertoni, G.; Lichte, H.
Title A holographic biprism as a perfect energy filter? Type A1 Journal article
Year 2011 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 111 Issue 7 Pages 887-893
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract It has often been stated that a holographic biprism represents a near perfect energy filter and only elastically scattered electrons can participate in the interference fringes. This is based on the assumption that the reference wave does not contain inelastically scattered electrons. In this letter we show that this is not exactly true because of the delocalised inelastic interaction of the reference wave with the sample. We experimentally and theoretically show that inelastic scattering plays a role in the fringe formation, but it is shown that this contribution is small and can usually be neglected in practice. (C) 2011 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000300461000021 Publication Date 2011-02-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 13 Open Access
Notes Fwo; Esteem 026019 Approved Most recent IF: 2.843; 2011 IF: 2.471
Call Number UA @ lucian @ c:irua:97250UA @ admin @ c:irua:97250 Serial (up) 1482
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Author Verbeeck, J.; Béché, A.; van den Broek, W.
Title A holographic method to measure the source size broadening in STEM Type A1 Journal article
Year 2012 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 120 Issue Pages 35-40
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Source size broadening is an important resolution limiting effect in modern STEM experiments. Here, we propose an alternative method to measure the source size broadening making use of a holographic biprism to create interference patterns in an empty Ronchigram. This allows us to measure the exact shape of the source size broadening with a much better sampling than previously possible. We find that the shape of the demagnified source deviates considerably from a Gaussian profile that is often assumed. We fit the profile with a linear combination of a Gaussian and a bivariate Cauchy distribution showing that even though the full width at half maximum is similar to previously reported measurements, the tails of the profile are considerable wider. This is of fundamental importance for quantitative comparison of STEM simulations with experiments as these tails make the image contrast dependent on the interatomic distance, an effect that cannot be reproduced by a single Gaussian profile of fixed width alone.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000308082600005 Publication Date 2012-06-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 29 Open Access
Notes This work was supported by funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant no. 246791 COUNTATOMS and ERC Starting Grant 278510 VORTEX. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. W. Van den Broek acknowledges funding from the Condor project, a project under the supervision of the Embedded Systems Institute (ESI) and FEI. This project is partially supported by the Dutch Ministry of Economic Affairs under the BSIK program. ECASJO_; Approved Most recent IF: 2.843; 2012 IF: 2.470
Call Number UA @ lucian @ c:irua:100466UA @ admin @ c:irua:100466 Serial (up) 1483
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Author Krause, F.F.; Ahl, J.P.; Tytko, D.; Choi, P.P.; Egoavil, R.; Schowalter, M.; Mehrtens, T.; Müller-Caspary, K.; Verbeeck, J.; Raabe, D.; Hertkorn, J.; Engl, K.; Rosenauer, A.
Title Homogeneity and composition of AlInGaN : a multiprobe nanostructure study Type A1 Journal article
Year 2015 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 156 Issue 156 Pages 29-36
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The electronic properties of quaternary AlInGaN devices significantly depend on the homogeneity of the alloy. The identification of compositional fluctuations or verification of random-alloy distribution is hence of grave importance. Here, a comprehensive multiprobe study of composition and compositional homogeneity is presented, investigating AlInGaN layers with indium concentrations ranging from 0 to 17 at% and aluminium concentrations between 0 and 39 at% employing high-angle annular dark field scanning electron microscopy (HAADF STEM), energy dispersive X-ray spectroscopy (EDX) and atom probe tomography (APT). EDX mappings reveal distributions of local concentrations which are in good agreement with random alloy atomic distributions. This was hence investigated with HAADF STEM by comparison with theoretical random alloy expectations using statistical tests. To validate the performance of these tests, HAADF STEM image simulations were carried out for the case of a random-alloy distribution of atoms and for the case of In-rich clusters with nanometer dimensions. The investigated samples, which were grown by metal-organic vapor phase epitaxy (MOVPE), were thereby found to be homogeneous on this nanometer scale. Analysis of reconstructions obtained from APT measurements yielded matching results. Though HAADF STEM only allows for the reduction of possible combinations of indium and aluminium concentrations to the proximity of isolines in the two-dimensional composition space. The observed ranges of composition are in good agreement with the EDX and APT results within the respective precisions.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000361001800006 Publication Date 2015-04-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 11 Open Access
Notes 312483 Esteem2; esteem2_ta Approved Most recent IF: 2.843; 2015 IF: 2.436
Call Number c:irua:126965 c:irua:126965UA @ admin @ c:irua:126965 Serial (up) 1485
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Author Verbeeck, J.; Tian, H.; Van Tendeloo, G.
Title How to manipulate nanoparticles with an electron beam? Type A1 Journal article
Year 2013 Publication Advanced materials Abbreviated Journal Adv Mater
Volume 25 Issue 8 Pages 1114-1117
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000315102600003 Publication Date 2012-11-26
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 75 Open Access
Notes FWO; VORTEX; Countatoms ECASJO_; Approved Most recent IF: 19.791; 2013 IF: 15.409
Call Number UA @ lucian @ c:irua:105287UA @ admin @ c:irua:105287 Serial (up) 1494
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Author Verbeeck, J.; Sc hattschneider, P.; Rosenauer, A.
Title Image simulation of high resolution energy filtered TEM images Type A1 Journal article
Year 2009 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 109 Issue 4 Pages 350-360
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Inelastic image simulation software is presented, implementing the double channeling approximation which takes into account the combination of multiple elastic and single inelastic scattering in a crystal. The approach is described with a density matrix formalism. Two applications in high resolution energy filtered (EFTEM) transmission electron microscopy (TEM) images are presented: thickness-defocus maps for SrTiO3 and exit plane intensities for an (LaAlO3)3(SrTiO3)3 multilayer system. Both systems show a severe breakdown in direct interpretability which becomes worse for higher acceleration voltages, thicker samples and lower excitation edge energies. Since this effect already occurs in the exit plane intensity, it is a fundamental limit and image simulations in EFTEM are indispensable just as they are indispensable for elastic high resolution TEM images.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000265345400009 Publication Date 2009-01-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 36 Open Access
Notes Fwo; Esteem 026019 Approved Most recent IF: 2.843; 2009 IF: 2.067
Call Number UA @ lucian @ c:irua:77272UA @ admin @ c:irua:77272 Serial (up) 1552
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Author Potapov, P.L.; Verbeeck, J.; Schattschneider, P.; Lichte, H.; van Dyck, D.
Title Inelastic electron holography as a variant of the Feynman thought experiment Type A1 Journal article
Year 2007 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 107 Issue 8 Pages 559-567
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract Using a combination of electron holography and energy filtering, interference fringes produced after inelastic interaction of electrons with hydrogen molecules are examined. Surprisingly, the coherence of inelastic scattering increases when moving from the surface of a hydrogen-containing bubble to the vacuum. This phenomenon can be understood in terms of the Feynman two-slit thought experiment with a variable ambiguity of the which-way registration. (C) 2006 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000246937000001 Publication Date 2006-12-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 13 Open Access
Notes Fwo G.0147.06 Approved Most recent IF: 2.843; 2007 IF: 1.996
Call Number UA @ lucian @ c:irua:103588UA @ admin @ c:irua:103588 Serial (up) 1605
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Author Van Boxem, R.; Partoens, B.; Verbeeck, J.
Title Inelastic electron-vortex-beam scattering Type A1 Journal article
Year 2015 Publication Physical review : A : atomic, molecular and optical physics Abbreviated Journal Phys Rev A
Volume 91 Issue 91 Pages 032703
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract Recent theoretical and experimental developments in the field of electron-vortex-beam physics have raised questions about what exactly this novelty in the field of electron microscopy (and other fields, such as particle physics) really provides. An important part of the answer to these questions lies in scattering theory. The present investigation explores various aspects of inelastic quantum scattering theory for cylindrically symmetric beams with orbital angular momentum. The model system of Coulomb scattering on a hydrogen atom provides the setting to address various open questions: How is momentum transferred? Do vortex beams selectively excite atoms, and how can one employ vortex beams to detect magnetic transitions? The analytical approach presented here provides answers to these questions. OAM transfer is possible, but not through selective excitation; rather, by pre- and postselection one can filter out the relevant contributions to a specific signal.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000351035000004 Publication Date 2015-03-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1050-2947;1094-1622; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.925 Times cited 31 Open Access
Notes Fwo; 312483 Esteem2; 278510 Vortex; esteem2jra3 ECASJO; Approved Most recent IF: 2.925; 2015 IF: 2.808
Call Number c:irua:123925 c:irua:123925UA @ admin @ c:irua:123925 Serial (up) 1607
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Author Dobrynin, A.N.; Ievlev, D.N.; Hendrich, C.; Temst, K.; Lievens, P.; Hörmann, U.; Verbeeck, J.; Van Tendeloo, G.; Vantomme, A.
Title Influence of finite size effects on exchange anisotropy in oxidized Co nanocluster assembled films Type A1 Journal article
Year 2006 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 73 Issue 24 Pages 245416,1-8
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We compare the magnetic properties of Co cluster assembled films with different degrees of oxidation. Clusters with grain size (2.3 +/- 0.7) nm are produced in a laser vaporization cluster source and soft-landed in ultrahigh vacuum conditions, forming highly porous nanogranular films. After exposure to air for different periods of time, the Co clusters oxidize and the sample may be considered as a thin antiferromagnetic Co oxide matrix containing ferromagnetic Co clusters. Magnetization measurements were performed in a temperature range from 300 down to 5 K, at applied magnetic fields up to 30 kOe. The exchange bias value at 5 K for the strongly oxidized sample is 4.8 kOe against the value of 0.75 kOe for the less oxidized sample. The mean values of the thicknesses of the Co oxide layers are estimated to be 0.6 and 0.3 nm for the more and less oxidized sample, respectively. We propose a method of measuring the exchange bias inducing temperature, i.e., the temperature at which exchange anisotropy is established. We determined the mean inducing temperatures for both samples, which are 55 and 25 K, respectively, for the more and less oxidized samples. Both temperatures are well below the bulk CoO Neel temperature of 292 K. A low value of the inducing temperature of the Co oxide layer is a consequence of its subnanometer thickness, while a large exchange bias value is a consequence of different dimensionality of Co clusters and Co oxide matrix.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000238696900114 Publication Date 2006-06-16
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 17 Open Access
Notes Fwo; Gao; Iap; Hprn-Ct Approved Most recent IF: 3.836; 2006 IF: 3.107
Call Number UA @ lucian @ c:irua:59709UA @ admin @ c:irua:59709 Serial (up) 1622
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Author Burriel, M.; Casa-Cabanas, M.; Zapata, J.; Tan, H.; Verbeeck, J.; Solis, C.; Roqueta, J.; Skinner, S.J.; Kilner, J.A.; Van Tendeloo, G.; Santiso, J.
Title Influence of the microstructure on the high-temperature transport properties of GdBaCo2O5.5+\delta epitaxial films Type A1 Journal article
Year 2010 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 22 Issue 19 Pages 5512-5520
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Epitaxial thin films of GdBaCo2O5.5+δ (GBCO) grown by pulsed laser deposition have been studied as a function of deposition conditions. The variation in film structure, domain orientation, and microstructure upon deviations in the cation composition have been correlated with the charge transport properties of the films. The epitaxial GBCO films mainly consist of single- and double-perovskite regions that are oriented in different directions depending on the deposition temperature. Additionally, cobalt depletion induces the formation of a high density of stacking defects in the films, consisting of supplementary GdO planes along the c-axis of the material. The presence of such defects progressively reduces the electrical conductivity. The films closer to the stoichiometric composition have shown p-type electronic conductivity at high pO2 with values as high as 800 S/cm at 330 °C in 1 atm O2, and with a pO2 power dependence with an exponent as low as 1/25, consistent with the behavior reported for bulk GBCO. These values place GBCO thin films as a very promising material to be applied as cathodes in intermediate temperature solid oxide fuel cells.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000282471000013 Publication Date 2010-09-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 17 Open Access
Notes Fwo; Esteem 026019 Approved Most recent IF: 9.466; 2010 IF: 6.400
Call Number UA @ lucian @ c:irua:85412UA @ admin @ c:irua:85412 Serial (up) 1648
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Author Morozov, V.A.; Lazoryak, B.I.; Shmurak, S.Z.; Kiselev, A.P.; Lebedev, O.I.; Gauquelin, N.; Verbeeck, J.; Hadermann, J.; Van Tendeloo, G.
Title Influence of the structure on the properties of NaxEuy(MoO4)z red phosphors Type A1 Journal article
Year 2014 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 26 Issue 10 Pages 3238-3248
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Scheelite related compounds (A',A '')(n)[(B',B '')O-4](m) with B', B '' = W and/or Mo are promising new materials for red phosphors in pc-WLEDs (phosphor-converted white-light-emitting-diode) and solid-state lasers. Cation substitution in CaMoO4 of Ca2+ by the combination of Na+ and Eu3+, with the creation of A cation vacancies, has been investigated as a factor for controlling the scheelite-type structure and the luminescent properties. Na5Eu(MoO4)(4) and NaxEu(2-x)/33+square(2-x)/3MoO4 (0.138 <= x <= 0.5) phases with a scheelite-type structure were synthesized by the solid state method; their structural characteristics were investigated using transmission electron microscopy. Contrary to powder synchrotron X-ray diffraction before, the study by electron diffraction and high resolution transmission electron microscopy in this paper revealed that Na0.286Eu0.571MoO4 has a (3 + 2)D incommensurately modulated structure and that (3 + 2)D incommensurately modulated domains are present in Na0.200Eu0.600MoO4. It also confirmed the (3 + 1)D incommensurately modulated character of Na(0.138)Eu(0.621)Mo04. The luminescent properties of all phases under near-ultraviolet (n-UV) light have been investigated. The excitation spectra of these phosphors show the strongest absorption at about 395 nm, which matches well with the commercially available n-UV-emitting GaN-based LED chip. The emission spectra indicate an intense red emission due to the D-5(0) -> F-7(2) transition of Eu3+, with local minima in the intensity at Na0.286Eu0.571MoO4 and Na0.200Eu0.600MoO4 for similar to 613 nm and similar to 616 nm bands. The phosphor Na5Eu(MoO4)(4) shows the brightest red light emission among the phosphors in the Na2MoO4-Eu2/3MoO4 system and the maximum luminescence intensity of Na5Eu(MoO4)(4) (lambda(ex) = 395 nm) in the D-5(0) -> F-7(2) transition region is close to that of the commercially used red phosphor YVO4:Eu3+ (lambda(ex) = 326 nm). Electron energy loss spectroscopy measurements revealed the influence of the structure and Na/Eu cation distribution on the number and positions of bands in the UV-optical-infrared regions of the EELS spectrum.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000336637000028 Publication Date 2014-05-01
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 53 Open Access
Notes Fwo G039211n; Fwo G004413n; 278510 Vortex ECASJO_; Approved Most recent IF: 9.466; 2014 IF: 8.354
Call Number UA @ lucian @ c:irua:117765UA @ admin @ c:irua:117765 Serial (up) 1652
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Author Li, Y.; Tan, H.; Lebedev, O.; Verbeeck, J.; Biermans, E.; Van Tendeloo, G.; Su, B.-L.
Title Insight into the growth of multiple branched MnOOH nanorods Type A1 Journal article
Year 2010 Publication Crystal growth & design Abbreviated Journal Cryst Growth Des
Volume 10 Issue 7 Pages 2969-2976
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Multiple branched manganese oxide hydroxide (MnOOH) nanorods prepared by a hydrothermal process were extensively studied by transmission electron microscopy (TEM). A model of the branch formation is proposed together with a study of the interface structure. The sword-like tip plays a crucial role for the nanorods to form different shapes. Importantly, the branching occurs at an angle of around either 57 degrees or 123 degrees. Specifically, a (111) twin plane can only be formed at the interface with a 123 degrees angle. The interfaces formed with a 57 degrees angle usually contain edge dislocations. Electron energy loss spectroscopy (EELS) demonstrates that the whole crystal has a uniform chemical composition. Interestingly, an epitaxial growth of Mn3O4 at the radial surface was also observed under electron beam irradiation; this is because of the rough purification of the products. The proposed mechanism is expected to shed light on the branched/dendrite nanostructure growth and to provide opportunities for further novel nanomaterial structure growth and design.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000279422700027 Publication Date 2010-06-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1528-7483;1528-7505; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.055 Times cited 41 Open Access
Notes Fwo; Esteem 026019 Approved Most recent IF: 4.055; 2010 IF: 4.390
Call Number UA @ lucian @ c:irua:83886UA @ admin @ c:irua:83886 Serial (up) 1672
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Author Gehrke, K.; Moshnyaga, V.; Samwer, K.; Lebedev, O.I.; Verbeeck, J.; Kirilenko, D.; Van Tendeloo, G.
Title Interface controlled electronic variations in correlated heterostructures Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue 11 Pages 113101,1-113101,4
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract An interface modification of (LaCa)MnO3-BaTiO3 superlattices was found to massively influence magnetic and magnetotransport properties. Moreover it determines the crystal structure of the manganite layers, changing it from orthorhombic (Pnma) for the conventional superlattice (cSL), to rhombohedral (R3̅ c) for the modified one (mSL). While the cSL shows extremely nonlinear ac transport, the mSL is an electrically homogeneous material. The observations go beyond an oversimplified picture of dead interface layers and evidence the importance of electronic correlations at perovskite interfaces.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000281643200001 Publication Date 2010-09-07
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 9 Open Access
Notes This work was supported by DFG via SFB 602, TPA2. Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:84249UA @ admin @ c:irua:84249 Serial (up) 1691
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Author Shapoval, O.; Huehn, S.; Verbeeck, J.; Jungbauer, M.; Belenchuk, A.; Moshnyaga, V.
Title Interface-controlled magnetism and transport of ultrathin manganite films Type A1 Journal article
Year 2013 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 113 Issue 17 Pages 17c711-3
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We report ferromagnetic, T-C = 240 K, and metallic, T-MI = 250 K, behaviors of a three unit cell thick interface engineered lanthanum manganite film, grown by metalorganic aerosol deposition technique on SrTiO3(100) substrates. Atomically resolved electron microscopy and chemical analysis show that ultrathin manganite films start to grow with La-O layer on a strongly Mn/Ti-intermixed interface, engineered by an additional deposition of 2 u.c. of Sr-Mn-O. Such interface engineering results in a hole-doped manganite layer and stabilizes ferromagnetism and metallic conductivity down to the thickness of d = 3 u.c. The films with d = 8 u.c. demonstrate a bulk-like transport behavior with T-MI similar to T-C = 310 – 330 K. (C) 2013 American Institute of Physics.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000319292800195 Publication Date 2013-03-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 7 Open Access
Notes Ifox; Countatoms; Vortex; Esteem2; esteem2jra3 ECASJO; Approved Most recent IF: 2.068; 2013 IF: 2.185
Call Number UA @ lucian @ c:irua:109009UA @ admin @ c:irua:109009 Serial (up) 1692
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Author Tian, H.; Verbeeck, J.; Brück, S.; Paul, M.; Kufer, D.; Sing, M.; Claessen, R.; Van Tendeloo, G.
Title Interface-induced modulation of charge and polarization in thin film Fe3O4 Type A1 Journal article
Year 2014 Publication Advanced materials Abbreviated Journal Adv Mater
Volume 26 Issue 3 Pages 461-465
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Charge and polarization modulations in Fe3O4 are controlled by taking advantage of interfacial strain effects. The feasibility of oxidation state control by strain modification is demonstrated and it is shown that this approach offers a stable configuration at room temperature. Direct evidence of how a local strain field changes the atomic coordination and introduces atomic displacements leading to polarization of Fe ions is presented.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000334289300011 Publication Date 2013-10-25
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 15 Open Access
Notes Vortex; FWO; Countatoms; Hercules ECASJO_; Approved Most recent IF: 19.791; 2014 IF: 17.493
Call Number UA @ lucian @ c:irua:112419UA @ admin @ c:irua:112419 Serial (up) 1694
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Author Molina, L.; Egoavil, R.; Turner, S.; Thersleff, T.; Verbeeck, J.; Holzapfel, B.; Eibl, O.; Van Tendeloo, G.
Title Interlayer structure in YBCO-coated conductors prepared by chemical solution deposition Type A1 Journal article
Year 2013 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 26 Issue 7 Pages 075016-75018
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The functionality of YBa2Cu3O7−δ (YBCO)-coated conductor technology depends on the reliability and microstructural properties of a given tape or wire architecture. Particularly, the interface to the metal tape is of interest since it determines the adhesion, mechanical stability of the film and thermal contact of the film to the substrate. A trifluoroacetate (TFA)metal organic deposition (MOD) prepared YBCO film deposited on a chemical solution-derived buffer layer architecture based on CeO2/La2Zr2O7 and grown on a flexible Ni5 at.%W substrate with a {100}⟨001⟩ biaxial texture was investigated. The YBCO film had a thickness was 440 nm and a jc of 1.02 MA cm−2 was determined at 77 K and zero external field. We present a sub-nanoscale analysis of a fully processed solution-derived YBCO-coated conductor by aberration-corrected scanning transmission electron microscopy (STEM) combined with electron energy-loss spectroscopy (EELS). For the first time, structural and chemical analysis of the valence has been carried out on the sub-nm scale. Intermixing of Ni, La, Ce, O and Ba takes place at these interfaces and gives rise to nanometer-sized interlayers which are a by-product of the sequential annealing process. Two distinct interfacial regions were analyzed in detail: (i) the YBCO/CeO2/La2Zr2O7 region (10 nm interlayer) and (ii) the La2Zr2O7/Ni5 at.%W substrate interface region (20 nm NiO). This is of particular significance for the functionality of these YBCO-coated conductor architectures grown by chemical solution deposition.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000319973800024 Publication Date 2013-05-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 11 Open Access
Notes vortex; Countatoms; Fwo; Esteem2; esteem2jra2; esteem2jra3 ECASJO_; Approved Most recent IF: 2.878; 2013 IF: 2.796
Call Number UA @ lucian @ c:irua:108704UA @ admin @ c:irua:108704 Serial (up) 1698
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Author Verbeeck, J.
Title Interpretation of “Energy-filtered electron-diffracted beam holography” by R.A. Herring Type A1 Journal article
Year 2006 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 106 Issue 6 Pages 461-465
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A straightforward application of the theoretical framework presented by Verbeeck et al. [Ultramicroscopy 102 (2005) 239] is presented to explain the energy-filtered electron-diffracted beam holography experiments published by Herring [Ultramicroscopy 104 (2005) 261]. It is shown that the theory is in agreement with all experimental findings, which leads to the interpretation that the experiments are mainly measuring the angular coherence of the source image rather than exposing details on the coherence properties of inelastic scattering. A change in experimental parameters is proposed, which could result in interesting information about the coherence in all inelastic scattering process. (c) 2006 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000237491600002 Publication Date 2006-01-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 8 Open Access
Notes Fwo Approved Most recent IF: 2.843; 2006 IF: 1.706
Call Number UA @ lucian @ c:irua:58283UA @ admin @ c:irua:58283 Serial (up) 1710
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Author Conings, B.; Drijkoningen, J.; Gauquelin, N.; Babayigit, A.; D'Haen, J.; D'Olieslaeger, L.; Ethirajan, A.; Verbeeck, J.; Manca, J.; Mosconi, E.; Angelis, F.D.; Boyen, H.G.;
Title Intrinsic thermal instability of methylammonium lead trihalide perovskite Type A1 Journal article
Year 2015 Publication Laser physics review Abbreviated Journal Adv Energy Mater
Volume 5 Issue 5 Pages 1500477
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Organolead halide perovskites currently are the new front-runners as light absorbers in hybrid solar cells, as they combine efficiencies passing already 20% with deposition temperatures below 100 °C and cheap solution-based fabrication routes. Long-term stability remains a major obstacle for application on an industrial scale. Here, it is demonstrated that significant decomposition effects already occur during annealing of a methylammonium lead triiode perovskite at 85 °C even in inert atmosphere thus violating international standards. The observed behavior supports the view of currently used perovskite materials as soft matter systems with low formation energies, thus representing a major bottleneck for their application, especially in countries with high average temperatures. This result can trigger a broader search for new perovskite families with improved thermal stability.
Address
Corporate Author Thesis
Publisher Place of Publication S.l. Editor
Language Wos 000359374900005 Publication Date 2015-06-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1614-6832; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 16.721 Times cited 1691 Open Access
Notes FWO G004413N; GOA Solarpaint Approved Most recent IF: 16.721; 2015 IF: 16.146
Call Number c:irua:127298UA @ admin @ c:irua:127298 Serial (up) 1719
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Author Schattschneider, P.; Löffler, S.; Stöger-Pollach, M.; Verbeeck, J.
Title Is magnetic chiral dichroism feasible with electron vortices? Type A1 Journal article
Year 2014 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 136 Issue Pages 81-85
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We discuss the feasibility of detecting magnetic transitions with focused electron vortex probes, suggested by selection rules for the magnetic quantum number. We theoretically estimate the dichroic signal strength in the L2,3 edge of ferromagnetic d metals. It is shown that under realistic conditions, the dichroic signal is undetectable for nanoparticles larger than View the MathML source. This is confirmed by a key experiment with nanometer-sized vortices.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000327884700011 Publication Date 2013-07-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 64 Open Access
Notes Countatoms; Vortex; Esteem2; esteem2jra3 ECASJO; Approved Most recent IF: 2.843; 2014 IF: 2.436
Call Number UA @ lucian @ c:irua:110952UA @ admin @ c:irua:110952 Serial (up) 1750
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Author Van Rompaey, S.; Dachraoui, W.; Turner, S.; Podyacheva, O.Y.; Tan, H.; Verbeeck, J.; Abakumov, A.; Hadermann, J.
Title Layered oxygen vacancy ordering in Nb-doped SrCo1-xFexO3-\delta perovskite Type A1 Journal article
Year 2013 Publication Zeitschrift für Kristallographie Abbreviated Journal Z Krist-Cryst Mater
Volume 228 Issue 1 Pages 28-34
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The crystal structure of SrCo0.7Fe0.2Nb0.1O2.72 was determined using a combination of precession electron diffraction (PED), high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and spatially resolved electron energy loss spectroscopy (STEM-EELS). The structure has a tetragonal P4/mmm symmetry with cell parameters a = b = a(p), c = 2a(p) (a(p) being the cell parameter of the perovskite parent structure). Octahedral BO2 layers alternate with the anion-deficient BO1.4 layers, the different B cations are randomly distributed over both layers. The specific feature of the SrCo0.7Fe0.2NB0.1O2.72 microstructure is a presence of extensive nanoscale twinning resulting in domains with alignment of the tetragonal c-axis along all three cubic direction of the perovskite subcell.
Address
Corporate Author Thesis
Publisher Place of Publication München Editor
Language Wos 000315475900004 Publication Date 2013-01-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2194-4946; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.179 Times cited 9 Open Access
Notes Fwo; Countatoms Approved Most recent IF: 3.179; 2013 IF: NA
Call Number UA @ lucian @ c:irua:107698UA @ admin @ c:irua:107698 Serial (up) 1808
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Author Lu, Y.-G.; Turner, S.; Verbeeck, J.; Janssens, S.D.; Haenen, K.; Van Tendeloo, G.
Title Local bond length variations in boron-doped nanocrystalline diamond measured by spatially resolved electron energy-loss spectroscopy Type A1 Journal article
Year 2013 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 103 Issue 3 Pages 032105-5
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Variations in local bond length and coordination in boron-doped nanocrystalline diamond (NCD) films have been studied through changes in the fine structure of boron and carbon K-edges in electron energy-loss spectra, acquired in a scanning transmission electron microscope. The presence of high concentrations of B in pristine diamond regions and enrichment of B at defects in single NCD grains is demonstrated. Local bond length variations are evidenced through an energy shift of the carbon 1s → σ* edge at B-rich defective regions within single diamond grains, indicating an expansion of the diamond bond length at sites with local high B content.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000322146300049 Publication Date 2013-07-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 15 Open Access
Notes Iap P6/42; Fwo G056810n; 262348 Esmi; 246791 Countatoms; 278510 Vortex; Fwo ECASJO_; Approved Most recent IF: 3.411; 2013 IF: 3.515
Call Number UA @ lucian @ c:irua:109210UA @ admin @ c:irua:109210 Serial (up) 1824
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Author Turner, S.; Lu, Y.-G.; Janssens, S.D.; da Pieve, F.; Lamoen, D.; Verbeeck, J.; Haenen, K.; Wagner, P.; Van Tendeloo, G.
Title Local boron environment in B-doped nanocrystalline diamond films Type A1 Journal article
Year 2012 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 4 Issue 19 Pages 5960-5964
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Thin films of heavily B-doped nanocrystalline diamond (B:NCD) have been investigated by a combination of high resolution annular dark field scanning transmission electron microscopy and spatially resolved electron energy-loss spectroscopy performed on a state-of-the-art aberration corrected instrument to determine the B concentration, distribution and the local B environment. Concentrations of [similar]1 to 3 at.% of boron are found to be embedded within individual grains. Even though most NCD grains are surrounded by a thin amorphous shell, elemental mapping of the B and C signal shows no preferential embedding of B in these amorphous shells or in grain boundaries between the NCD grains, in contrast with earlier work on more macroscopic superconducting polycrystalline B-doped diamond films. Detailed inspection of the fine structure of the boron K-edge and comparison with density functional theory calculated fine structure energy-loss near-edge structure signatures confirms that the B atoms present in the diamond grains are substitutional atoms embedded tetrahedrally into the diamond lattice.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000308705900026 Publication Date 2012-08-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364;2040-3372; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 39 Open Access
Notes FWO G056810N; GOA XANES meets ELNES; 246791 COUNTATOMS; Hercules; 262348 ESMI; Methusalem Nano Approved Most recent IF: 7.367; 2012 IF: 6.233
Call Number UA @ lucian @ c:irua:101227UA @ admin @ c:irua:101227 Serial (up) 1825
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Author Brück, S.; Paul, M.; Tian, H.; Müller, A.; Kufer, D.; Praetorius, C.; Fauth, K.; Audehm, P.; Goering, E.; Verbeeck, J.; Van Tendeloo, G.; Sing, M.; Claessen, R.;
Title Magnetic and electronic properties of the interface between half metallic Fe3O4 and semiconducting ZnO Type A1 Journal article
Year 2012 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 100 Issue 8 Pages 081603-081603,4
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We have investigated the magnetic depth profile of an epitaxial Fe3O4 thin film grown directly on a semiconducting ZnO substrate by soft x-ray resonant magnetic reflectometry (XRMR) and electron energy loss spectroscopy (EELS). Consistent chemical profiles at the interface between ZnO and Fe3O4 are found from both methods. Valence selective EELS and XRMR reveal independently that the first monolayer of Fe at the interface between ZnO and Fe3O4 contains only Fe3+ ions. Besides this narrow 2.5 Å interface layer, Fe3O4 shows magnetic bulk properties throughout the whole film making highly efficient spin injection in this system feasible.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000300711200014 Publication Date 2012-02-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 12 Open Access
Notes The authors thank E. Pellegrin for helpful comments and S. Macke for help with the software REMAGX. S.B. acknowledges financial support by the HZB, Berlin, and the Australian Government via Grant No. RM08550. H.T. acknowledges funding from GOA project “XANES meets ELNES,” J.V. and G.V.T. acknowledge funding from the European Research Council under Grant No. 46791-COUN-TATOMS. The authors acknowledge financial support by the DFG through Forschergruppe FOR 1162. Approved Most recent IF: 3.411; 2012 IF: 3.794
Call Number UA @ lucian @ c:irua:95041UA @ admin @ c:irua:95041 Serial (up) 1860
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Author Maignan, A.; Singh, K.; Simon, C.; Lebedev, O.I.; Martin, C.; Tan, H.; Verbeeck, J.; Van Tendeloo, G.
Title Magnetic and magnetodielectric properties of erbium iron garnet ceramic Type A1 Journal article
Year 2013 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 113 Issue 3 Pages 033905-5
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract An Er3Fe5O12 ceramic has been sintered in oxygen atmosphere at 1400 °C for dielectric measurements. Its structural quality at room temperature has been checked by combining transmission electron microscopy and X-ray diffraction. It crystallizes in the cubic space group Ia3d with a = 12.3488(1). The dielectric permittivity ([variantgreekepsilon]′) and losses (tan δ) measurements as a function of temperature reveal the existence of two anomalies, a broad one between 110 K and 80 K, attributed to the Er3+ spin reorientation, and a second sharper feature at about 45 K associated to the appearance of irreversibility on the magnetic susceptibility curves. In contrast to the lack of magnetic field impact on [variantgreekepsilon]′ for the former anomaly, a complex magnetic field effect has been evidenced below 45 K. The isothermal [variantgreekepsilon]′(H) curves show the existence of positive magnetodielectric effect, reaching a maximum of 0.14% at 3 T and 10 K. Its magnitude decreases as H is further increased. Interestingly, for the lowest H values, a linear regime in the [variantgreekepsilon]′(H) curve is observed. From this experimental study, it is concluded that the [variantgreekepsilon]′ anomaly, starting above the compensation temperature Tc (75 K) and driven by the internal magnetic field, is not sensitive to an applied external magnetic field. Thus, below 45 K, it is the magnetic structure which is responsible for the coupling between spin and charge in this iron garnet.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000313670600042 Publication Date 2013-01-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 15 Open Access
Notes Vortex; Countatoms ECASJO_; Approved Most recent IF: 2.068; 2013 IF: 2.185
Call Number UA @ lucian @ c:irua:106182UA @ admin @ c:irua:106182 Serial (up) 1861
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Author Béché, A.; Van Boxem, R.; Van Tendeloo, G.; Verbeeck, J.
Title Magnetic monopole field exposed by electrons Type A1 Journal article
Year 2014 Publication Nature physics Abbreviated Journal Nat Phys
Volume 10 Issue 1 Pages 26-29
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The experimental search for magnetic monopole particles(1-3) has, so far, been in vain. Nevertheless, these elusive particles of magnetic charge have fuelled a rich field of theoretical study(4-10). Here, we created an approximation of a magnetic monopole in free space at the end of a long, nanoscopically thin magnetic needle(11). We experimentally demonstrate that the interaction of this approximate magnetic monopole field with a beam of electrons produces an electron vortex state, as theoretically predicted for a true magnetic monopole(3,11-18). This fundamental quantum mechanical scattering experiment is independent of the speed of the electrons and has consequences for all situations where electrons meet such monopole magnetic fields, as, for example, in solids. The set-up not only shows an attractive way to produce electron vortex states but also provides a unique insight into monopole fields and shows that electron vortices might well occur in unexplored solid-state physics situations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000328940100012 Publication Date 2013-11-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1745-2473;1745-2481; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 22.806 Times cited 131 Open Access
Notes Vortex; Countatoms; Fwo ECASJO_; Approved Most recent IF: 22.806; 2014 IF: 20.147
Call Number UA @ lucian @ c:irua:113740UA @ admin @ c:irua:113740 Serial (up) 1885
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Author Tan, H.; Egoavil, R.; Béché, A.; Martinez, G.T.; Van Aert, S.; Verbeeck, J.; Van Tendeloo, G.; Rotella, H.; Boullay, P.; Pautrat, A.; Prellier, W.
Title Mapping electronic reconstruction at the metal-insulator interface in LaVO3/SrVO3 heterostructures Type A1 Journal article
Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 88 Issue 15 Pages 155123-155126
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A (LaVO3)6/(SrVO3)(3) superlattice is studied with a combination of sub-A resolved scanning transmission electron microscopy and monochromated electron energy-loss spectroscopy. The V oxidation state is mapped with atomic spatial resolution enabling us to investigate electronic reconstruction at the LaVO3/SrVO3 interfaces. Surprisingly, asymmetric charge distribution is found at adjacent chemically symmetric interfaces. The local structure is proposed and simulated with a double channeling calculation which agrees qualitatively with our experiment. We demonstrate that local strain asymmetry is the likely cause of the electronic asymmetry of the interfaces. The electronic reconstruction at the interfaces extends much further than the chemical composition, varying from 0.5 to 1.2 nm. This distance corresponds to the length of charge transfer previously found in the (LaVO3)./(SrVO3). metal/insulating and the (LaAlO3)./(SrTiO3). insulating/insulating interfaces.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000326087100003 Publication Date 2013-10-21
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 15 Open Access
Notes Hercules; 246791 COUNTATOMS; 278510 VORTEX; 246102 IFOX; 312483 ESTEEM2; FWO; GOA XANES meets ELNES; esteem2jra3 ECASJO; Approved Most recent IF: 3.836; 2013 IF: 3.664
Call Number UA @ lucian @ c:irua:112733UA @ admin @ c:irua:112733 Serial (up) 1944
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Author Schattschneider, P.; Schaffer, B.; Ennen, I.; Verbeeck, J.
Title Mapping spin-polarized transitions with atomic resolution Type A1 Journal article
Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 85 Issue 13 Pages 134422-134422,8
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The coupling of angstrom-sized electron probes with spin-polarized electronic transitions shows that the inelastically scattered probe electron is in a mixed state containing electron vortices with nonzero orbital angular momentum. These electrons create an asymmetric intensity distribution in energy filtered diffraction patterns, giving access to maps of the magnetic moments with atomic resolution. A feasibility experiment shows evidence of the predicted effect. Potential applications are column-by-column maps of magnetic ordering, and the creation of angstrom-sized free electrons with orbital angular momentum by inelastic scattering in a thin ferromagnetic foil.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000302608100004 Publication Date 2012-04-11
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 The authors thank A. Bleloch, S. Loffler, and P. Nellist for fruitful discussions and suggestions. P.S. acknowledges financial support from the Austrian Science Fund, Project No. I543-N20. The support of the EPSRC for the SuperSTEM facility is gratefully acknowledged. J.V. acknowledges support from the European Research Council under the 7th Framework Program (FP7), ERC Grant No. 246791-COUNTATOMS and ERC Starting Grant No. 278510-VORTEX. ECASJO_; Approved Most recent IF: 3.836; 2012 IF: 3.767
Call Number UA @ lucian @ c:irua:97390UA @ admin @ c:irua:97390 Serial (up) 1945
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Author Guzzinati, G.; Clark, L.; Béché, A.; Verbeeck, J.
Title Measuring the orbital angular momentum of electron beams Type A1 Journal article
Year 2014 Publication Physical review : A : atomic, molecular and optical physics Abbreviated Journal Phys Rev A
Volume 89 Issue Pages 025803
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The recent demonstration of electron vortex beams has opened up the new possibility of studying orbital angular momentum (OAM) in the interaction between electron beams and matter. To this aim, methods to analyze the OAM of an electron beam are fundamentally important and a necessary next step. We demonstrate the measurement of electron beam OAM through a variety of techniques. The use of forked holographic masks, diffraction from geometric apertures, and diffraction from a knife edge and the application of an astigmatic lens are all experimentally demonstrated. The viability and limitations of each are discussed with supporting numerical simulations.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000332224100014 Publication Date 2014-02-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1050-2947;1094-1622; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.925 Times cited 42 Open Access
Notes Vortex; FP7; Countatoms; ESTEEM2; esteem2jra3 ECASJO; Approved Most recent IF: 2.925; 2014 IF: 2.808
Call Number UA @ lucian @ c:irua:114577UA @ admin @ c:irua:114577 Serial (up) 1972
Permanent link to this record