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Author Zhang, Z.; Lobato, I.; De Backer, A.; Van Aert, S.; Nellist, P.
Title Fast generation of calculated ADF-EDX scattering cross-sections under channelling conditions Type A1 Journal article
Year 2023 Publication Ultramicroscopy Abbreviated Journal
Volume (up) 246 Issue Pages 113671
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Advanced materials often consist of multiple elements which are arranged in a complicated structure. Quantitative scanning transmission electron microscopy is useful to determine the composition and thickness of nanostructures at the atomic scale. However, significant difficulties remain to quantify mixed columns by comparing the resulting atomic resolution images and spectroscopy data with multislice simulations where dynamic scattering needs to be taken into account. The combination of the computationally intensive nature of these simulations and the enormous amount of possible mixed column configurations for a given composition indeed severely hamper the quantification process. To overcome these challenges, we here report the development of an incoherent non-linear method for the fast prediction of ADF-EDX scattering cross-sections of mixed columns under channelling conditions. We first explain the origin of the ADF and EDX incoherence from scattering physics suggesting a linear dependence between those two signals in the case of a high-angle ADF detector. Taking EDX as a perfect incoherent reference mode, we quantitatively examine the ADF longitudinal incoherence under different microscope conditions using multislice simulations. Based on incoherent imaging, the atomic lensing model previously developed for ADF is now expanded to EDX, which yields ADF-EDX scattering cross-section predictions in good agreement with multislice simulations for mixed columns in a core–shell nanoparticle and a high entropy alloy. The fast and accurate prediction of ADF-EDX scattering cross-sections opens up new opportunities to explore the wide range of ordering possibilities of heterogeneous materials with multiple elements.
Address
Corporate Author Zezhong Zhang Thesis
Publisher Place of Publication Editor
Language Wos 000995063900001 Publication Date 2022-12-28
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 2.2 Times cited Open Access OpenAccess
Notes European Research Council 770887 PICOMETRICS; Fonds Wetenschappelijk Onderzoek No.G.0502.18N; Horizon 2020, 770887 ; Horizon 2020 Framework Programme; European Research Council, 823717 ESTEEM3 ; esteem3reported; esteem3JRa Approved Most recent IF: 2.2; 2023 IF: 2.843
Call Number EMAT @ emat @c:irua:195890 Serial 7251
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Author Krekels, T.; Kaesche, S.; Van Tendeloo, G.
Title 2√2 ap x 2√ ap phase in superconducting ceramics Type A1 Journal article
Year 1995 Publication Physica: C : superconductivity Abbreviated Journal Physica C
Volume (up) 248 Issue 3/4 Pages 317-327
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract By means of electron diffraction the 2 root 2 a(p) x 2 root 2 a(p) phase, well-known in YBa2Cu3O7-delta was observed in two other perovskite-based materials (Y0.75Ce0.25)(2)(Sr0.85Y0.15)(2)AlCU2O9 and Bi1.8Pb0.4Sr2Ca2Cu3O10+x. Highly correlated ordering is observed in the ab-plane, the correlation along the c-direction being weak. The plane group of the superstructure symmetry elements was determined on the basis of observed reflection conditions in diffraction patterns. Our results unambiguously rule out oxygen ordering as a possible origin of the superstructure. Experimental evidence points out that the superstructure is associated with the CuO2 layers, that are the only structural elements common to the three compounds studied. A model is proposed where the CuO2 sheet is displacively modulated. Experimental evidence suggests a correlation between adjacent CuO2 sheets. Comparison of simulated and experimental [001] zone diffraction patterns strongly supports our model.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos A1995RJ45000012 Publication Date 2003-04-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-4534; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.942 Times cited 13 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:13317 c:irua:13317 Serial 8
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Author Jacobs, K.; van Daele, B.; Leys, M.; Moerman, I.; Van Tendeloo, G.
Title Effect of growth interrupt and growth rate on MOVPE-grown InGaN/GaN MQW structures Type A1 Journal article
Year 2003 Publication Journal of crystal growth Abbreviated Journal J Cryst Growth
Volume (up) 248 Issue Pages 498-502
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000180446900091 Publication Date 2002-12-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-0248; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.751 Times cited 14 Open Access
Notes was dubbel; dubbel eruit gehaald Approved Most recent IF: 1.751; 2003 IF: 1.414
Call Number UA @ lucian @ c:irua:54785 Serial 810
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Author Lamoen, D.; Parrinello, M.
Title Geometry and electronic structure of porphyrines and porphyrazines Type A1 Journal article
Year 1996 Publication Chemical Physics Letters Abbreviated Journal Chem Phys Lett
Volume (up) 248 Issue Pages 309
Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos A1996TR41900002 Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0009-2614 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.897 Times cited 46 Open Access
Notes Approved CHEMISTRY, PHYSICAL 88/144 Q3 # PHYSICS, ATOMIC, MOLECULAR & CHEMICAL 19/35 Q3 #
Call Number UA @ lucian @ c:irua:15821 Serial 1329
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Author Hunter, E.C.; Battle, P.D.; Sena, R.P.; Hadermann, J.
Title Ferrimagnetism as a consequence of cation ordering in the perovskite LaSr2Cr2SbO9 Type A1 Journal article
Year 2017 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume (up) 248 Issue Pages 96-103
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A polycrystalline sample of LaSr2Cr2SbO9 has been synthesised using a standard ceramic method and characterized by x-ray and neutron diffraction, magnetometry and electron microscopy. The perovskite-related compound crystallises in the triclinic space group I1 with unit cell parameters of a=5.5344(6) angstrom, b=5.5562(5) angstrom, c=7.8292(7) angstrom, a=89.986(12)degrees, beta=90.350(5)degrees and gamma=89.926(9)degrees at room temperature. The two crystallographically-distinct, six-coordinate cation sites are occupied by Cr3+ and Sb5+ in ratios of 0.868(2):0.132(2) and 0.462(2):0.538(2). Ac and de magnetometry revealed that LaSr2Cr2SbO9 is ferrimagnetic below 150 K with a magnetisation of similar to 1.25 mu(B) per formula unit in 50 kOe at 5 K. Neutron diffraction showed that the cations on the two sites order in a G-type arrangement with a mean Cr3+ moment of 2.17(1) mu(B) at 5 K, consistent with a magnetisation of 1.32 mu(B) per formula unit.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000396386300012 Publication Date 2017-01-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 14 Open Access Not_Open_Access
Notes ; Experiments at the ISIS Pulsed Neutron and Muon Source were supported by the STFC. We are grateful to I. da Silva for the assistance provided at ISIS and to the EPSRC for financial support under Grant EP/M018954/1. We also thank Diamond Light Source Ltd (EE13284) for the award of beamtime. ; Approved Most recent IF: 2.299
Call Number UA @ lucian @ c:irua:142413 Serial 4657
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Author Fomin, V.M.; Misko, V.R.; Devreese, J.T.; Moshchalkov, V.V.
Title Phase boundaries of superconducting mesoscopic square loops Type A1 Journal article
Year 1998 Publication Abbreviated Journal
Volume (up) 249/251 Issue Pages 476-479
Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000074919400101 Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record;
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:21905 Serial 2577
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Author Blank, D.H.A.; Rijnders, A.J.H.M.; Verhoeven, M.A.J.; Bergs, R.M.H.; Rogalla, H.; Verbist, K.; Lebedev, O.; Van Tendeloo, G.
Title Characterisation of multilayer ramp-type REBa2Cu3O7-\delta structures by scanning probe microscopy and high-resolution electron microscopy Type A1 Journal article
Year 1997 Publication Journal of alloys and compounds T2 – Symposium on High Temperature Superconductor Thin Films, Growth, Mechanisms, Interfaces, Multilayers, at the 1996 Spring Meeting of the European-Materials-Society, June 04-07, 1996, Strasbourg, France Abbreviated Journal J Alloy Compd
Volume (up) 251 Issue 1-2 Pages 206-208
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract We studied the morphology of ramps in REBa2CU3O7 (REBCO) epitaxial films on SrTiO3 substrates, fabricated by RF magnetron sputter deposition and pulsed laser deposition (PLD), by scanning probe microscopy (SPM) and high resolution electron microscopy (HREM). The ramps were fabricated by Ar ion beam etching using masks of standard photoresist and TIN. AFM-studies on ramps in sputter deposited films show a strong dependence, i.e. formation of facets and ridges, on the angle of incidence of the ion beam with respect to the substrate surface as well as the rotation angle with respect to the crystal axes of the substrate. Ramps in pulsed laser deposited films did not show this dependence, Furthermore, we studied the effect of an anneal step prior to the deposition of barrier layers (i.e. PrBa2CU3O7, SrTiO3, CeO2) on the ramp. First results show a recrystallization of the ramp surface, resulting in terraces and a non-homogeneous growth of the barrier material on top of it. The thickness variations, for thin layers of barrier material, con even become much larger than expected from the amount of deposited material and are dependent on the deposition and anneal conditions. HREM studies show a well defined interface between barrier layer and electrodes. The angle of the ramp depends on the etch rate of the mask and REBCO, and on the angle of incidence of the ion beam. TiN has a much lower etch rate compared to photoresist, resulting in an angle of the ramp comparable to the angle of incidence, resulting in a low etching rate on the ramp. These results will lead to improved electrical characteristics of ramp-type junctions.
Address
Corporate Author Thesis
Publisher Elsevier Science Place of Publication Lausanne Editor
Language Wos A1997XM34000046 Publication Date 2002-07-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-8388; ISBN Additional Links UA library record; WoS full record
Impact Factor 3.133 Times cited Open Access
Notes Approved Most recent IF: 3.133; 1997 IF: 1.035
Call Number UA @ lucian @ c:irua:95868 Serial 310
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Author Lu, J.; Martinez, G.T.; Van Aert, S.; Schryvers, D.
Title Lattice deformations in quasi-dynamic strain glass visualised and quantified by aberration corrected electron microscopy Type A1 Journal article
Year 2014 Publication Physica status solidi: B: basic research Abbreviated Journal Phys Status Solidi B
Volume (up) 251 Issue 10 Pages 2034-2040
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Advanced transmission electron microscopy and statistical parameter estimated quantification procedures were applied to study the room temperature quasi-dynamical strain glass state in NiTi alloys. Nanosized strain pockets are visualised and the displacements of the atom columns are quantified. A comparison is made with conventional high-resolution transmission electron microscopy images of point defect induced strains in NiAl alloys.
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos 000344360000009 Publication Date 2014-03-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-1972; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.674 Times cited 2 Open Access
Notes Fwo Approved Most recent IF: 1.674; 2014 IF: 1.489
Call Number UA @ lucian @ c:irua:120471 Serial 1801
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Author Idrissi, H.; Amin-Ahmadi, B.; Wang, B.; Schryvers, D.
Title Review on TEM analysis of growth twins in nanocrystalline palladium thin films : toward better understanding of twin-related mechanisms in high stacking fault energy metals Type A1 Journal article
Year 2014 Publication Physica status solidi: B: basic research Abbreviated Journal Phys Status Solidi B
Volume (up) 251 Issue 6 Pages 1111-1124
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Various modes of transmission electron microscopy including aberration corrected imaging were used in order to unravel the fundamental mechanisms controlling the formation of growth twins and the evolution of twin boundaries under mechanical and hydrogen loading modes in nanocrystalline (nc) palladium thin films. The latter were produced by electron-beam evaporation and sputter deposition and subjected to uniaxial tensile deformation as well as hydriding/dehydriding cycles. The results show that the twins form by dissociation of grain boundaries. The coherency of Σ3{111} coherent twin boundaries considerably decreases with deformation due to dislocation/twin boundary interactions while Σ3{112} incoherent twin boundaries dissociate under hydrogen cycling into two-phase boundaries bounding a new and unstable 9R phase. The effect of these elementary mechanisms on the macroscopic behavior of the palladium films is discussed and compared to recent experimental and simulation works in the literature. The results provide insightful information to guide the production of well-controlled population of growth twins in high stacking fault energy nc metallic thin films. The results also indicate directions for further enhancement of the mechanical properties of palladium films as needed for instance in palladium-based membranes in hydrogen applications.
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos 000337608600001 Publication Date 2014-02-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-1972; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.674 Times cited 7 Open Access
Notes Iap P7/21; Fwo G012012n Approved Most recent IF: 1.674; 2014 IF: 1.489
Call Number UA @ lucian @ c:irua:114580 Serial 2905
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Author Ben Hafsia, A.; Hendrickx, M.; Batuk, M.; Khitouni, M.; Hadermann, J.; Greneche, J.-M.; Rammeh, N.
Title Crystal structure study of manganese and titanium substituted BaLaFe2O6-δ Type A1 Journal article
Year 2017 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume (up) 251 Issue 251 Pages 186-193
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Barium lanthanum ferrite and four Mn/Ti substituted materials were synthesized by the sol-gel method. The crystal structure of the materials was studied by a combination of X-ray powder diffraction, electron diffraction, scanning transmission electron microscopy and 57Fe Mössbauer spectrometry. BaLaFe2O6-δ has a cubic perovskite structure and Ba0.7La1.3FeMnO6-δ is distorted perovskite with the R-3c symmetry, both from electron diffraction and X-ray powder diffraction. However, according to transmission electron microscopy, the crystals of BaLaFeTiO6-δ, BaLaFeTi0.5Mn0.5O6-δ, and BaLaFe0.5Ti0.5MnO6-δ consist of nanodomains with different symmetries (Pm3m next to R-3c due to octahedral tilts), whereas the bulk X-ray powder diffraction patterns for these compounds correspond to the simple cubic structure. 57Fe Mössbauer spectrometry confirms that all materials contain high spin state Fe3+ ions which are strongly influenced by the chemical disorder

resulting from various cationic environments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000402581200024 Publication Date 2017-04-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited Open Access Not_Open_Access
Notes This study has been supported by the Tunisian Ministry of Higher Education and Scientific Research and by the University of Antwerp BOF Grant 33024 funding scheme. Approved Most recent IF: 2.299
Call Number EMAT @ emat @ c:irua:143988 Serial 4582
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Author Chin, C.-M.; Sena, R.P.; Hunter, E.C.; Hadermann, J.; Battle, P.D.
Title Interplay of structural chemistry and magnetism in perovskites : a study of CaLn2Ni2WO9: Ln=La, Pr, Nd Type A1 Journal article
Year 2017 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume (up) 251 Issue Pages 224-232
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Polycrystalline samples of CaLn(2)Ni(2)WO(9) (Ln=La, Pr, Nd) have been synthesized and characterised by a combination of X-ray and neutron diffraction, electron microscopy and magnetometry. Each composition adopts a perovskite-like structure with a similar to 5.50, b similar to 5.56, c similar to 7.78 angstrom beta similar to 90.1 degrees in space group P2(1)/n. Of the two crystallographically distinct six-coordinate sites, one is occupied entirely (Ln=Pr) or predominantly (Ln=La, Nd) by Ni2+ and the other by Ni2+ and W6+ in a ratio of approximately 1:2. None of the compounds shows long-range magnetic order at 5 K. The magnetometry data show that the magnetic moments of the Ni2+ cations form a spin glass below 30 K in each case. The Pr3+ moments in CaPr2Ni2WO9 also freeze but the Nd3+ moments in CaNd2Ni2WO9 do not. This behaviour is contrasted with that observed in other (A,A')B2B'O-9 perovskites.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000402581200030 Publication Date 2017-04-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 5 Open Access OpenAccess
Notes ; We thank EPSRC for funding through grant EP/M0189541. CMC thanks the Croucher Foundation and Oxford University for a graduate scholarship. We are grateful to Ivan da Silva who provided experimental assistance at ISIS and to Maria Batuk for help with the STEM-EDX analysis. ; Approved Most recent IF: 2.299
Call Number UA @ lucian @ c:irua:144179 Serial 4664
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Author Lobato, I.; De Backer, A.; Van Aert, S.
Title Real-time simulations of ADF STEM probe position-integrated scattering cross-sections for single element fcc crystals in zone axis orientation using a densely connected neural network Type A1 Journal article
Year 2023 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume (up) 251 Issue Pages 113769
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Quantification of annular dark field (ADF) scanning transmission electron microscopy (STEM) images in terms

of composition or thickness often relies on probe-position integrated scattering cross sections (PPISCS). In

order to compare experimental PPISCS with theoretically predicted ones, expensive simulations are needed for

a given specimen, zone axis orientation, and a variety of microscope settings. The computation time of such

simulations can be in the order of hours using a single GPU card. ADF STEM simulations can be efficiently

parallelized using multiple GPUs, as the calculation of each pixel is independent of other pixels. However, most

research groups do not have the necessary hardware, and, in the best-case scenario, the simulation time will

only be reduced proportionally to the number of GPUs used. In this manuscript, we use a learning approach and

present a densely connected neural network that is able to perform real-time ADF STEM PPISCS predictions as

a function of atomic column thickness for most common face-centered cubic (fcc) crystals (i.e., Al, Cu, Pd, Ag,

Pt, Au and Pb) along [100] and [111] zone axis orientations, root-mean-square displacements, and microscope

parameters. The proposed architecture is parameter efficient and yields accurate predictions for the PPISCS

values for a wide range of input parameters that are commonly used for aberration-corrected transmission

electron microscopes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001011617200001 Publication Date 2023-06-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record
Impact Factor 2.2 Times cited Open Access OpenAccess
Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G034621N and G0A7723N) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF), Belgium. Approved Most recent IF: 2.2; 2023 IF: 2.843
Call Number EMAT @ emat @c:irua:197275 Serial 8812
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Author Ardashnikova, E.I.; Lubarsky, S.V.; Denisenko, D.I.; Shpanchenko, R.V.; Antipov, E.V.; Van Tendeloo, G.
Title A new way of synthesis and characterization of superconducting oxyfluoride Sr2Cu(O,F)4+\delta Type A1 Journal article
Year 1995 Publication Physica: C : superconductivity Abbreviated Journal Physica C
Volume (up) 253 Issue 3/4 Pages 259-265
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Superconducting Cu mixed oxyfluoride, Sr,Cu(O, F)(4+delta), was Obtained via fluorination of Sr2CuO3 by XeF2 in the 100-250 degrees C temperature range in a closed Ni container. The prepared samples exhibited a lower T-c in comparison with earlier reported values. Different samples in the Sr-Cu-O-F system were prepared by a solid-state reaction at 220-400 degrees C, but no formation of the oxyfluoride was detected even with an addition of xenon difluoride. These data allow one to draw conclusions on the metastability of the oxyfluoride under the conditions used, Electron microscopy and X-ray powder diffraction studies revealed large amounts of badly crystallized SrF2; this could be a reason for the small superconducting volume fraction as well as for the inhomogeneous distribution of the anions.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos A1995TE08400007 Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-4534 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.942 Times cited 29 Open Access
Notes Approved PHYSICS, APPLIED 28/145 Q1 #
Call Number UA @ lucian @ c:irua:13322 Serial 2337
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Author Tang, Y.; Sena, R.P.; Aydeev, M.; Battle, P.D.; Cadogan, J.M.; Hadermann, J.; Hunter, E.C.
Title Magnetic properties of the 6H perovskite Ba3Fe2TeO9 Type A1 Journal article
Year 2017 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume (up) 253 Issue Pages 347-354
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A polycrystalline sample of Ba3Fe2TeO9 having the 6H perovskite structure has been prepared in a solid-state reaction and studied by a combination of electron microscopy, Mossbauer spectroscopy, magnetometry, X-ray diffraction and neutron diffraction. Partial ordering of Fe3+ and Te6+ cations occurs over the six-coordinate sites; the corner-sharing octahedra are predominantly occupied by the former and the face-sharing octahedra by a 1:1 mixture of the two. On cooling through the temperature range 18 < T/K < 295 an increasing number of spins join an antiferromagnetic backbone running through the structure while the remainder show complex relaxation effects. At 3 K an antiferromagnetic phase and a spin glass coexist.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000406572600047 Publication Date 2017-06-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 6 Open Access OpenAccess
Notes ; We thank EPSRC for financial support through grant EP/M018954/1. ; Approved Most recent IF: 2.299
Call Number UA @ lucian @ c:irua:145692 Serial 4743
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Author Zeng, C.Y.; Cao, S.; Li, Y.Y.; Zhao, Z.X.; Yao, X.Y.; Ma, X.; Zhang, X.P.
Title A hidden single-stage martensitic transformation from B2 parent phase to B19 ' martensite phase in an aged Ni51Ti49 alloy Type A1 Journal article
Year 2019 Publication Materials letters Abbreviated Journal Mater Lett
Volume (up) 253 Issue 253 Pages 99-101
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The aged Ni-rich NiTi shape memory alloys (SMAs) exhibit the multi-stage martensitic transformation (MMT), which has important influences on functional properties and practical applications of the NiTi SMAs. A hidden single-stage martensitic transformation from B2 parent phase to B19' martensite phase is found in an aged Ni51Ti49 alloy, which happens concurrently with a commonly observed two-stage martensitic transformation B2-R-B19' (R: martensite phase) and actually composes one stage of a multi-stage martensitic transformation (MMT) together with the two-stage one. B2-B19' martensitic transformation occurs in the NiTi matrix containing Ni4Ti3 precipitates with relatively large inter-particle space, while B2-R-B19' transformation takes place in the NiTi matrix with Ni4Ti3 precipitates having relatively small inter-particle space. (C) 2019 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000482629500025 Publication Date 2019-06-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0167-577x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.572 Times cited Open Access
Notes ; This work was supported by the Natural Science Foundation of Guangdong Province under Grant Nos. 2018B0303110012 and 2017A030313323, and the National Natural Science Foundation of China under Grant Nos. 51401081 and 51571092. ; Approved Most recent IF: 2.572
Call Number UA @ admin @ c:irua:162764 Serial 5381
Permanent link to this record
 

 
Author Denisov, N.; Jannis, D.; Orekhov, A.; Müller-Caspary, K.; Verbeeck, J.
Title Characterization of a Timepix detector for use in SEM acceleration voltage range Type A1 Journal article
Year 2023 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume (up) 253 Issue Pages 113777
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Hybrid pixel direct electron detectors are gaining popularity in electron microscopy due to their excellent properties. Some commercial cameras based on this technology are relatively affordable which makes them attractive tools for experimentation especially in combination with an SEM setup. To support this, a detector characterization (Modulation Transfer Function, Detective Quantum Efficiency) of an Advacam Minipix and Advacam Advapix detector in the 15–30 keV range was made. In the current work we present images of Point Spread Function, plots of MTF/DQE curves and values of DQE(0) for these detectors. At low beam currents, the silicon detector layer behaviour should be dominant, which could make these findings transferable to any other available detector based on either Medipix2, Timepix or Timepix3 provided the same detector layer is used.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001026912700001 Publication Date 2023-06-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record
Impact Factor 2.2 Times cited Open Access OpenAccess
Notes The authors acknowledge the financial support of the Research Foundation Flanders (FWO, Belgium) project SBO S000121N. The authors are grateful to Dr. Lobato for productive discussion of methods. Approved Most recent IF: 2.2; 2023 IF: 2.843
Call Number EMAT @ emat @c:irua:198258 Serial 8815
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Author Lin, K.; Pescarmona, P.P.; Vandepitte, H.; Liang, D.; Van Tendeloo, G.; Jacobs, P.A.
Title Synthesis and catalytic activity of Ti-MCM-41 nanoparticles with highly active titanium sites Type A1 Journal article
Year 2008 Publication Journal of catalysis Abbreviated Journal J Catal
Volume (up) 254 Issue 1 Pages 64-70
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Ti-MCM-41 nanoparticles 80-160 nm in diameter (Ti-MCM-41 NP) were successfully prepared by a dilute solution route in sodium hydroxide medium at ambient temperature. Ti-MCM-41 NP were characterized by X-ray diffraction, nitrogen adsorption/desorption isotherms, SEM, TEM. FT-IR, and UV-vis spectroscopy. The characterization results showed the existence of highly ordered hexagonal mesoporous structure and tetrahedral Ti species in Ti-MCM-41 NP. In the epoxidation of cyclohexene with aqueous H2O2, Ti-MCM-41 NP displayed higher conversion and initial reaction rate than a Ti-MCM-41 sample with normal particle size (Ti-MCM-41 LP). Diffusion of the reactants was accelerated and the accessibility to the catalytic Ti species was enhanced in the shorter channels in Ti-MCM-41 NP samples. Ti-MCM-41 NP showed much higher selectivity for cyclohexene oxide compared with Ti-MCM-41 LP, suggesting reduced hydrolysis of cyclohexene oxide with water in the former case. The increased selectivity for cyclohexene oxide can be attributed to the lower concentration of residual surface silanols in Ti-MCM-41 NP and the shorter residence time of epoxide in the shorter mesoporous channels. Ti-MCM-41 NP also appears to be a suitable catalyst in the epoxidation of a bulky substrate, like cholesterol, with tert-butyl hydroperoxide. (c) 2007 Elsevier Inc. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication San Diego, Calif. Editor
Language Wos 000253646100006 Publication Date 2008-01-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-9517; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.844 Times cited 52 Open Access
Notes Approved Most recent IF: 6.844; 2008 IF: 5.167
Call Number UA @ lucian @ c:irua:103092 Serial 3409
Permanent link to this record
 

 
Author Hofer, C.; Pennycook, T.J.
Title Reliable phase quantification in focused probe electron ptychography of thin materials Type A1 Journal Article
Year 2023 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume (up) 254 Issue Pages 113829
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract Electron ptychography provides highly sensitive, dose efficient phase images which can be corrected for aberrations after the data has been acquired. This is crucial when very precise quantification is required, such as with sensitivity to charge transfer due to bonding. Drift can now be essentially eliminated as a major impediment to focused probe ptychography, which benefits from the availability of easily interpretable simultaneous Z-contrast imaging. However challenges have remained when quantifying the ptychographic phases of atomic sites. The phase response of a single atom has a negative halo which can cause atoms to reduce in phase when brought closer together. When unaccounted for, as in integrating methods of quantification, this effect can completely obscure the effects of charge transfer. Here we provide a new method of quantification that overcomes this challenge, at least for 2D materials, and is robust to experimental parameters such as noise, sample tilt.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001071608700001 Publication Date 2023-08-18
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 2.2 Times cited Open Access
Notes FWO, G013122N ; Horizon 2020 Framework Programme; Horizon 2020; European Research Council, 802123-HDEM ; European Research Council; Approved Most recent IF: 2.2; 2023 IF: 2.843
Call Number EMAT @ emat @c:irua:200272 Serial 8987
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Author Van den Broek, W.; Jannis, D.; Verbeeck, J.
Title Convexity constraints on linear background models for electron energy-loss spectra Type A1 Journal Article
Year 2023 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume (up) 254 Issue Pages 113830
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract In this paper convexity constraints are derived for a background model of electron energy loss spectra (EELS) that is linear in the fitting parameters. The model outperforms a power-law both on experimental and simulated backgrounds, especially for wide energy ranges, and thus improves elemental quantification results. Owing to the model’s linearity, the constraints can be imposed through fitting by quadratic programming. This has important advantages over conventional nonlinear power-law fitting such as high speed and a guaranteed unique solution without need for initial parameters. As such, the need for user input is significantly reduced, which is essential for unsupervised treatment of large datasets. This is demonstrated on a demanding spectrum image of a semiconductor device sample with a high number of elements over a wide energy range.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2023-08-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record
Impact Factor 2.2 Times cited Open Access Not_Open_Access
Notes ECSEL, 875999 ; Horizon 2020; Horizon 2020 Framework Programme; Electronic Components and Systems for European Leadership; Approved Most recent IF: 2.2; 2023 IF: 2.843
Call Number EMAT @ emat @c:irua:200588 Serial 8961
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Author Şentürk, DG.; Yu, CP.; De Backer, A.; Van Aert, S.
Title Atom counting from a combination of two ADF STEM images Type A1 Journal article
Year 2024 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume (up) 255 Issue Pages 113859
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract To understand the structure–property relationship of nanostructures, reliably quantifying parameters, such as the number of atoms along the projection direction, is important. Advanced statistical methodologies have made it possible to count the number of atoms for monotype crystalline nanoparticles from a single ADF STEM image. Recent developments enable one to simultaneously acquire multiple ADF STEM images. Here, we present an extended statistics-based method for atom counting from a combination of multiple statistically independent ADF STEM images reconstructed from non-overlapping annular detector collection regions which improves the accuracy and allows one to retrieve precise atom-counts, especially for images acquired with low electron doses and multiple element structures.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001089064200001 Publication Date 2023-09-23
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 2.2 Times cited Open Access OpenAccess
Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G034621N, G0A7723N, and EOS 40007495) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF). Approved Most recent IF: 2.2; 2024 IF: 2.843
Call Number EMAT @ emat @c:irua:201008 Serial 8964
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Author Gao, C.; Hofer, C.; Pennycook, T.J.
Title On central focusing for contrast optimization in direct electron ptychography of thick samples Type A1 Journal article
Year 2024 Publication Ultramicroscopy Abbreviated Journal
Volume (up) 256 Issue Pages 113879-7
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Ptychography provides high dose efficiency images that can reveal light elements next to heavy atoms. However, despite ptychography having an otherwise single signed contrast transfer function, contrast reversals can occur when the projected potential becomes strong for both direct and iterative inversion ptychography methods. It has recently been shown that these reversals can often be counteracted in direct ptychography methods by adapting the focus. Here we provide an explanation of why the best contrast is often found with the probe focused to the middle of the sample. The phase contribution due to defocus at each sample slice above and below the central plane in this configuration effectively cancels out, which can prevent contrast reversals when dynamical scattering effects are not overly strong. In addition we show that the convergence angle can be an important consideration for removal of contrast reversals in relatively thin samples.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001112166400001 Publication Date 2023-11-03
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 2.2 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 2.2; 2024 IF: 2.843
Call Number UA @ admin @ c:irua:202029 Serial 9066
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Author Chin, C.-M.; Battle, P.D.; Blundell, S.J.; Hunter, E.; Lang, F.; Hendrickx, M.; Sena, R.P.; Hadermann, J.
Title Comparative study of the magnetic properties of La3Ni2B'O9 for B' = Nb, Ta or Sb Type A1 Journal article
Year 2018 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume (up) 258 Issue 258 Pages 825-834
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Polycrystalline samples of La3Ni2NbO9 and La3Ni2TaO9 have been characterised by X-ray and neutron diffraction, electron microscopy, magnetometry and muon spin relaxation (mu SR); the latter technique was also applied to La3Ni2SbO9. On the length scale of a neutron diffraction experiment, the six-coordinate sites of the monoclinic perovskite structure are occupied in a 1:1 ordered manner by Ni and a random 1/3Ni/2/3B' mixture. Electron microscopy demonstrated that this 1:1 ordering is maintained over microscopic distances, although diffuse scattering indicative of short-range ordering on the mixed site was observed. No magnetic Bragg scattering was observed in neutron diffraction patterns collected from La3Ni2B'O-9 (B' = Nb or Ta) at 5 K although in each case mu SR identified the presence of static spins below 30 K. Magnetometry showed that La3Ni2NbO9 behaves as a spin glass below 29 K but significant short-range interactions are present in La3Ni2NbO9 below 85 K. The contrasting properties of these compounds are discussed in terms of their microstructure.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000423650400107 Publication Date 2017-12-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 6 Open Access Not_Open_Access
Notes ; We thank EPSRC for funding through Grants EP/M0189541 and EP/N023803. CMC thanks the Croucher Foundation and Oxford University for a graduate scholarship. We are grateful E. Suard for experimental assistance at ILL. ; Approved Most recent IF: 2.299
Call Number UA @ lucian @ c:irua:149284 Serial 4928
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Author Istomin, S.Y.; Morozov, A.V.; Abdullayev, M.M.; Batuk, M.; Hadermann, J.; Kazakov, S.M.; Sobolev, A.V.; Presniakov, I.A.; Antipov, E.V.
Title High-temperature properties of (La,Ca)(Fe,Mg,Mo)O3-\delta perovskites as prospective electrode materials for symmetrical SOFC Type A1 Journal article
Year 2018 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume (up) 258 Issue 258 Pages 1-10
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract La1-yCayFe0.5+x(Mg,Mo)(0.5-x)O3-delta oxides with the orthorhombic GdFeO3-type perovskite structure have been synthesized at 1573 K. Transmission electron microscopy study for selected samples shows the coexistence of domains of perovskite phases with ordered and disordered B-cations. Mossbauer spectroscopy studies performed at 300 K and 573 K show that while compositions with low Ca-content (La0.55Ca0.45Fe0.5Mg0.2625Mo0.2375O3-delta and La0.5Ca0.5Fe0.6Mg0.175Mo0.225O3-delta) are nearly oxygen stoichiometric, La0.2Ca0.8Fe0.5Mg0.2625Mo0.2375O3-delta is oxygen deficient with delta approximate to 0.15. Oxides are stable in reducing atmosphere (Ar/H-2, 8%) at 1173 K for 12 h. No additional phases have been observed at XRPD patterns of all studied perovskites and Ce1-xGdxO2-x/2 electrolyte mixtures treated at 1173-1373K, while Fe-rich compositions (x >= 0.1) react with Zr1-xYxO2-x/2 electrolyte above 1273 K. Dilatometry studies reveal that all samples show rather low thermal expansion coefficients (TECs) in air of 11.4-12.7 ppm K-1. In reducing atmosphere their TECs were found to increase up to 12.1-15.4 ppm K-1 due to chemical expansion effect. High-temperature electrical conductivity measurements in air and Ar/H-2 atmosphere show that the highest conductivity is observed for Fe- and Ca-rich compositions. Moderate values of electrical conductivity and TEC together with stability towards chemical interaction with typical SOFC electrolytes make novel Fe-containing perovskites promising electrode materials for symmetrical solid oxide fuel cell.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000423650400001 Publication Date 2017-10-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 5 Open Access Not_Open_Access
Notes ; This work was financially supported by Russian Science Foundation (project number 16-13-10327). ; Approved Most recent IF: 2.299
Call Number UA @ lucian @ c:irua:149283 Serial 4936
Permanent link to this record
 

 
Author Şentürk, D.G.; De Backer, A.; Van Aert, S.
Title Element specific atom counting for heterogeneous nanostructures: Combining multiple ADF STEM images for simultaneous thickness and composition determination Type A1 Journal Article
Year 2024 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume (up) 259 Issue Pages 113941
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract In this paper, a methodology is presented to count the number of atoms in heterogeneous nanoparticles based on the combination of multiple annular dark field scanning transmission electron microscopy (ADF STEM) images. The different non-overlapping annular detector collection regions are selected based on the principles of optimal statistical experiment design for the atom-counting problem. To count the number of atoms, the total intensities of scattered electrons for each atomic column, the so-called scattering cross-sections, are simultaneously compared with simulated library values for the different detector regions by minimising the squared differences. The performance of the method is evaluated for simulated Ni@Pt and Au@Ag core-shell nanoparticles. Our approach turns out to be a dose efficient alternative for the investigation of beam-sensitive heterogeneous materials as compared to the combination of ADF STEM and energy dispersive X-ray spectroscopy.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2024-02-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record
Impact Factor 2.2 Times cited Open Access OpenAccess
Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0346.21N, GOA7723N, and EOS 40007495) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF). Approved Most recent IF: 2.2; 2024 IF: 2.843
Call Number EMAT @ emat @c:irua:204353 Serial 8996
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Author Hodges, J.P.; Slater, P.R.; Edwards, P.P.; Greaves, C.; Slaski, M.; Van Tendeloo, G.; Amelinckx, S.
Title Observation of superconductivity (Tc = 50K) in a new tetragonal alkaline-earth cuprate Sr0.8Ba1.2CuO3+\delta synthesised at ambient pressure Type A1 Journal article
Year 1996 Publication Physica: C : superconductivity Abbreviated Journal Physica C
Volume (up) 260 Issue Pages 249-256
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos A1996UJ48400011 Publication Date 2003-05-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-4534; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.942 Times cited 7 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:16872 Serial 2421
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Author Delamare, M.P.; Hervieu, M.; Wang, J.; Provost, J.; Monot, I.; Verbist, K.; Van Tendeloo, G.
Title Combination of CeO2 and PtO2 doping for the strong enhancement of Jc under magnetic field in melt-textured superconductor YBaCuO Type A1 Journal article
Year 1996 Publication Physica: C : superconductivity Abbreviated Journal Physica C
Volume (up) 262 Issue 3/4 Pages 220-226
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A combination of CeO2 and PtO2 doping has been studied in melt-processed YBa2Cu3O7-x. This study was carried out using an optimized well established MTG process. The cerium-platinum doped samples exhibit a high fishtail effect with a J(c) of 4.3 x 10(4) A/cm(2) under an applied field of 1 T. Microstructural and nanostructural studies have been performed. The 211 and BaCeO3 inclusions are a few micrometers wide and the formation of a metastable nanocrystalline phase (Y4Ba4)Cu-8-x(Ce,Pt)(x)O-20+delta related to the perovskite is detected. The 123 grains show no specific extended defect generated by the doping process. The relationship between structure and properties are discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos A1996UV45000011 Publication Date 2003-05-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-4534; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.942 Times cited 27 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:15467 Serial 397
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Author Pardo, J.A.; Santiso, J.; Solis, C.; Garcia, G.; Figueras, A.; Rossell, M.D.; Van Tendeloo, G.
Title Epitaxial Sr4Fe6O13\pm\delta films obtained by pulsed laser deposition Type A1 Journal article
Year 2004 Publication Journal of crystal growth Abbreviated Journal J Cryst Growth
Volume (up) 262 Issue Pages 334-340
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000189098700052 Publication Date 2003-11-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-0248; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.751 Times cited 8 Open Access
Notes Iap V-1 Approved Most recent IF: 1.751; 2004 IF: 1.707
Call Number UA @ lucian @ c:irua:54786 Serial 1074
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Author Lin, K.; Pescarmona, P.P.; Houthoofd, K.; Liang, D.; Van Tendeloo, G.; Jacobs, P.A.
Title Direct room-temperature synthesis of methyl-functionalized Ti-MCM-41 nanoparticles and their catalytic performance in epoxidation Type A1 Journal article
Year 2009 Publication Journal of catalysis Abbreviated Journal J Catal
Volume (up) 263 Issue 1 Pages 75-82
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Methyl-functionalized Ti-MCM-41 nanoparticles with a size of 80 to 160 nm (Me-Ti-MCM-41 NP) were directly prepared via a dilute solution route by the co-condensation of tetraethoxysilane and methylalkoxysilanes in sodium hydroxide medium at room temperature. The characterization results showed the existence of ordered hexagonal mesoporous structure and tetrahedral Ti species in the nanoparticles. In the epoxidation of cyclohexene with tert-butyl hydroperoxide and aqueous H2O2, Me-Ti-MCM-41 NP samples displayed higher turnover frequencies (TOFs) for cyclohexene and initial reaction rates compared to Ti-MCM-41 and methyl-functionalized Ti-MCM-41 with normal particle size and to non-functionalized Ti-MCM-41 nanoparticles. Simultaneously, a higher selectivity for cyclohexene epoxide was observed in the case of aqueous H2O2, suggesting that the hydrolysis of cyclohexene epoxide with water is reduced on Me-Ti-MCM-41 NP samples. The improved catalytic behavior of Me-Ti-MCM-41 NP is discussed both in terms of the nanosize and methylation of the surface of the catalyst particles. The regeneration of Me-Ti-MCM-41 NP with tert-butyl hydroperoxide solution was evaluated via washing and calcination approaches.
Address
Corporate Author Thesis
Publisher Place of Publication San Diego, Calif. Editor
Language Wos 000265000800008 Publication Date 2009-02-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-9517; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.844 Times cited 89 Open Access
Notes Iwt; Iap; Goa Approved Most recent IF: 6.844; 2009 IF: 5.288
Call Number UA @ lucian @ c:irua:76395 Serial 720
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Author Mary Joy, R.; Pobedinskas, P.; Baule, N.; Bai, S.; Jannis, D.; Gauquelin, N.; Pinault-Thaury, M.-A.; Jomard, F.; Sankaran, K.J.; Rouzbahani, R.; Lloret, F.; Desta, D.; D’Haen, J.; Verbeeck, J.; Becker, M.F.; Haenen, K.
Title The effect of microstructure and film composition on the mechanical properties of linear antenna CVD diamond thin films Type A1 Journal article
Year 2024 Publication Acta materialia Abbreviated Journal Acta Materialia
Volume (up) 264 Issue Pages 119548
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract This study reports the impact of film microstructure and composition on the Young’s modulus and residual stress in nanocrystalline diamond (NCD) thin films ( thick) grown on silicon substrates using a linear antenna microwave plasma-enhanced chemical vapor deposition (CVD) system. Combining laser acoustic wave spectroscopy to determine the elastic properties with simple wafer curvature measurements, a straightforward method to determine the intrinsic stress in NCD films is presented. Two deposition parameters are varied: (1) the substrate temperature from 400 °C to 900 °C, and (2) the [P]/[C] ratio from 0 ppm to 8090 ppm in the H2/CH4/CO2/PH3 diamond CVD plasma. The introduction of PH3 induces a transition in the morphology of the diamond film, shifting from NCD with larger grains to ultra-NCD with a smaller grain size, concurrently resulting in a decrease in Young’s modulus. Results show that the highest Young’s modulus of (113050) GPa for the undoped NCD deposited at 800 °C is comparable to single crystal diamond, indicating that NCD with excellent mechanical properties is achievable with our process for thin diamond films. Based on the film stress results, we propose the origins of tensile intrinsic stress in the diamond films. In NCD, the tensile intrinsic stress is attributed to larger grain size, while in ultra-NCD films the tensile intrinsic stress is due to grain boundaries and impurities.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001126632800001 Publication Date 2023-11-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6454 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.4 Times cited Open Access Not_Open_Access
Notes This work was financially supported by the Special Research Fund (BOF) via Methusalem NANO network, the Research Foundation – Flanders (FWO) via Project G0D4920N, and the CORNET project nr 263-EN “ULTRAHARD: Ultrahard optical diamond coatings” (2020–2021). Approved Most recent IF: 9.4; 2024 IF: 5.301
Call Number EMAT @ emat @c:irua:202169 Serial 8989
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Author Lu, J.; Bartholomeeusen, E.; Sels, B.F.; Schryvers, D.
Title Internal architecture of coffin-shaped ZSM-5 zeolite crystals with hourglass contrast unravelled by focused ion beam-assisted transmission electron microscopy: INTERNAL ARCHITECTURE OF COFFIN-SHAPED Type A1 Journal article
Year 2017 Publication Journal of microscopy Abbreviated Journal J Microsc-Oxford
Volume (up) 265 Issue 265 Pages 27-33
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Optical microscopy, focused ion beam and transmission electron microscopy are combined to study the internal architecture in a coffin-shaped ZSM-5 crystal showing an hourglass contrast in optical microscopy. Based on parallel lamellas from different positions in the crystal, the orientation relationships between the intergrowth components of the crystal are studied and the internal architecture and growth mechanism are illustrated. The crystal is found to contain two pyramid-like components aside from a central component. Both pyramid-like components are rotated by 90 degrees along the common c-axis and with respect to the central component while the interfaces between the components show local zig-zag feature, the latter indicating variations in relative growth velocity of the two components. The pyramid-like intergrowth components are larger and come closer to one another in the middle of the crystal than at the edges, but they do not connect. A model of multisite nucleation and growth of 90 degrees intergrowth components is proposed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000392487400004 Publication Date 2016-08-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2720 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.692 Times cited 4 Open Access OpenAccess
Notes Fonds Wetenschappelijk Onderzoek, G.0603.10N ; Approved Most recent IF: 1.692
Call Number EMAT @ emat @ c:irua:141015 Serial 4437
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