“On the phase-like nature of the 7M structure in Ni-Al”. Schryvers D, Tanner LE, Ecomaterials , 849 (1994). http://doi.org/10.1016/B978-1-4832-8381-4.50198-0
Abstract: The existence of the (52) stacking of the 7M martensite structure in Ni-Al is discussed in view of different experimental observations relating this structure to the premartensitic anomalies. It is concluded that the extreme fineness of the twinning is inherited from the wavelength of the premartensitic anomalies, while, given this dimension, the actual stacking tries to comply with stress free habit plane conditions by choosing the specific (52) stacking.
Keywords: A3 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
DOI: 10.1016/B978-1-4832-8381-4.50198-0
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“On the relationship between morphology, composition and structure of Al-Cu-Fe crystals and quasicrystals”. Balzuweit K, Meekes H, Van Tendeloo G, de Boer JL, Philosophical magazine: B: physics of condensed matter: electronic, optical and magnetic properties 67, 513 (1993). http://doi.org/10.1080/13642819308207689
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 10
DOI: 10.1080/13642819308207689
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“On the relationship between the twin internal structure and the work-hardening rate of TWIP steels”. Idrissi H, Renard K, Schryvers D, Jacques PJ, Scripta materialia 63, 961 (2010). http://doi.org/10.1016/j.scriptamat.2010.07.016
Abstract: FeMnC and FeMnSiAl TWIP steels deformed under the same conditions exhibit different work-hardening rates. The present study investigates the microstructure of plastically deformed FeMnC and FeMnSiAl samples, particularly the internal structure of the mechanically generated twins and their topology at the grain scale. Twins in the FeMnC steel are finer and full of sessile dislocations, rendering this material distinctly stronger with an improved work-hardening rate.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.747
Times cited: 145
DOI: 10.1016/j.scriptamat.2010.07.016
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“On the role of microstructural defects on precipitation, damage, and healing behavior in a novel Al-0.5Mg2Si alloy”. Kashiwar A, Arseenko M, Simar A, Idrissi H, Materials &, design 239, 112765 (2024). http://doi.org/10.1016/J.MATDES.2024.112765
Abstract: A recently developed healable Al-Mg2Si designed by the programmed damage and repair (PDR) strategy is studied considering the role microstructural defects play on precipitation, damage, and healing. The alloy incorporates sacrificial Mg2Si particles that precipitate after friction stir processing (FSP). They act as damage localization sites and are healable based on the solid-state diffusion of Al-matrix. A combination of different transmission electron microscopy (TEM) imaging techniques enabled the visualization and quantification of various crystallographic defects and the spatial distribution of Mg2Si precipitates. Intragrain nucleation is found to be the dominant mechanism for precipitation during FSP whereas grain boundaries and subgrain boundaries mainly lead to coarsening of the precipitates. The statistical and spatial analyses of the damaged particles have shown particle fracture as the dominant damage mechanism which is strongly dependent on the size and aspect ratio of the particles whereas the damage was not found to depend on the location of the precipitates within the matrix. The damaged particles are associated with dislocations accumulated around them. The interplay of these dislocations is directly visualized during healing based on in situ TEM heating which revealed recovery in the matrix as an operative mechanism during the diffusion healing of the PDR alloy.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 8.4
DOI: 10.1016/J.MATDES.2024.112765
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“On the stress state dependence of the twinning rate and work hardening in twinning-induced plasticity steels”. Renard K, Idrissi H, Schryvers D, Jacques PJ, Scripta materialia 66, 966 (2012). http://doi.org/10.1016/j.scriptamat.2012.01.063
Abstract: The influence of the stress state on the twinning rate and work hardening is studied in the case of an FeMnC TWIP steel strained in uniaxial tension, simple shear and rolling. The resulting stressstrain responses exhibit marked differences. The twinning rate, number of activated twinning systems in each grain, twin thickness and transmission of twins across grain boundaries are dependent on the imposed stress state during straining. Relationships between twin features and macroscopic work hardening rate are established.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 3.747
Times cited: 41
DOI: 10.1016/j.scriptamat.2012.01.063
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“On the superconducting phase boundary for a mesoscopic square loop”. Fomin VM, Misko VR, Devreese JT, Moshchalkov VV, Solid State Communications 101, 303 (1997)
Keywords: A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Impact Factor: 1.554
Times cited: 39
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Kirschhock CEA, Liang D, Aerts A, Aerts CA, Kremer SPB, Jacobs PA, Van Tendeloo G, Martens JA (2004) On the TEM and AFM evidence of zeosil nanoslabs present during the synthesis of silicalite-1 : reply. Weinheim, 4562–4564
Keywords: L1 Letter to the editor; Electron microscopy for materials research (EMAT)
Impact Factor: 11.994
DOI: 10.1002/anie.200460541
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“On the use of TEM in the characterization of nanocomposites”. Monticelli O, Musina Z, Russo S, Bals S, Materials letters 61, 3446 (2007). http://doi.org/10.1016/j.matlet.2006.11.086
Abstract: Both an organically modified commercial clay of montmorillonite type (MMT) and its nanocomposites, based either on polyamide 6 (PA6) or an epoxy resin, as matrix polymer, have been characterized by transmission electron microscopy (TEM). Sample micrographs, taken at increasing exposure times (t(e)), have shown the gradual disappearance of clay layers, because of an amorphisation of the MMT crystalline structures caused by prolonged sample exposure to electron beam. Indeed, the above phenomenon, which is mostly evident in the case of intercalated nanocomposites, makes the detection of the layered silicate dispersion in the polymer matrix rather difficult and compels to perform TEM measurements using very short exposure times. Moreover, the microscopy accelerating voltage has turned out to affect sample stability; namely, when decreasing the above parameter, the disappearance of clay structure occurs at lower exposure times. (C) 2006 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.572
Times cited: 28
DOI: 10.1016/j.matlet.2006.11.086
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“On-chip very low strain rate rheology of amorphous olivine films”. Coulombier M, Baral P, Orekhov A, Dohmen R, Raskin JP, Pardoen T, Cordier P, Idrissi H, Acta materialia 266, 119693 (2024). http://doi.org/10.1016/J.ACTAMAT.2024.119693
Abstract: Recent observations made by the authors revealed the activation of stress induced amorphization and sliding at grain boundary in olivine [1], a mechanism which is expected to play a pivotal role in the viscosity drop at the lithosphere-asthenosphere boundary and the brittle -ductile transition in the lithospheric mantle. However, there is a lack of information in the literature regarding the intrinsic mechanical properties and the elementary deformation mechanisms of this material, especially at time scales relevant for geodynamics. In the present work, amorphous olivine films were obtained by pulsed laser deposition (PLD). The mechanical response including the rate dependent behavior are investigated using a tension -on -chip (TOC) method developed at UCLouvain allowing to perform creep/relaxation tests on thin films at extremely low strain rates. In the present work, strain rate down to 10-12 s- 1 was reached which is unique. High strain rate sensitivity of 0.054 is observed together with the activation of relaxation at the very early stage of deformation. Furthermore, digital image correlation (DIC), used for the first time on films deformed by TOC, reveals local strain heterogeneities. The relationship between such heterogeneities, the high strain rate sensitivity and the effect of the electron beam in the scanning electron microscope is discussed and compared to the literature.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 9.4
DOI: 10.1016/J.ACTAMAT.2024.119693
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“One particle@one cell : highly monodispersed PtPd bimetallic nanoparticles for enhanced oxygen reduction reaction”. Ying J, Yang X-Y, Hu Z-Y, Mu S-C, Janiak C, Geng W, Pan M, Ke X, Van Tendeloo G, Su B-L, Nano energy 8, 214 (2014). http://doi.org/10.1016/j.nanoen.2014.06.010
Abstract: Highly monodispersed platinum-based nanoalloys are the best-known catalysts for the oxygen reduction reaction. Although certainly promising, the durability and stability are among the main requirements for commercializing fuel cell electrocatalysts in practical applications. Herein, we synthesize highly stable, durable and catalytic active monodispersed PtPd nano-particles encapsulated in a unique one particle@one cell structure by adjusting the viscosity of solvents using mesocellular foam. PtPd nanoparticles in mesocellular carbon foam exhibit an excellent electrocatalytic activity (over 4 times mass and specific activities than the commercial Pt/C catalyst). Most importantly, this nanocatalyst shows no obvious change of structure and only a 29.5% loss in electrochemically active surface area after 5000 potential sweeps between 0.6 and 1.1 V versus reversible hydrogen electrode cycles. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 12.343
Times cited: 40
DOI: 10.1016/j.nanoen.2014.06.010
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“One step toward a new generation of C-MOS compatible oxide p-n junctions: Structure of the LSMO/ZnO interface elucidated by an experimental and theoretical synergic work”. Pullini D, Sgroi M, Mahmoud A, Gauquelin N, Maschio L, Lorenzo-Ferrari AM, Groenen R, Damen C, Rijnders G, van den Bos KHW, Van Aert S, Verbeeck J, ACS applied materials and interfaces 9, 20974 (2017). http://doi.org/10.1021/acsami.7b04089
Abstract: Heterostructures formed by La0.7Sr0.3MnO3/ZnO (LSMO/ZnO) interfaces exhibit extremely interesting electronic properties making them promising candidates for novel oxide p–n junctions, with multifunctional features. In this work, the structure of the interface is studied through a combined experimental/theoretical approach. Heterostructures were grown epitaxially and homogeneously on 4″ silicon wafers, characterized by advanced electron microscopy imaging and spectroscopy and simulated by ab initio density functional theory calculations. The simulation results suggest that the most stable interface configuration is composed of the (001) face of LSMO, with the LaO planes exposed, in contact with the (112̅0) face of ZnO. The ab initio predictions agree well with experimental high-angle annular dark field scanning transmission electron microscopy images and confirm the validity of the suggested structural model. Electron energy loss spectroscopy confirms the atomic sharpness of the interface. From statistical parameter estimation theory, it has been found that the distances between the interfacial planes are displaced from the respective ones of the bulk material. This can be ascribed to the strain induced by the mismatch between the lattices of the two materials employed
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.504
Times cited: 4
DOI: 10.1021/acsami.7b04089
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“One-pot synthesis of carbon-coated nanostructured iron oxide on few-layer graphene for lithium-ion batteries”. Sun Z, Madej E, Wiktor, Sinev I, Fischer RA, Van Tendeloo G, Muhler M, Schuhmann W, Ventosa E, Chemistry: a European journal 21, 16154 (2015). http://doi.org/10.1002/chem.201501935
Abstract: Nanostructure engineering has been demonstrated to improve the electrochemical performance of iron oxide based electrodes in Li-ion batteries (LIBs). However, the synthesis of advanced functional materials often requires multiple steps. Herein, we present a facile one-pot synthesis of carbon-coated nanostructured iron oxide on few-layer graphene through high-pressure pyrolysis of ferrocene in the presence of pristine graphene. The ferrocene precursor supplies both iron and carbon to form the carbon-coated iron oxide, while the graphene acts as a high-surface-area anchor to achieve small metal oxide nanoparticles. When evaluated as a negative-electrode material for LIBs, our composite showed improved electrochemical performance compared to commercial iron oxide nanopowders, especially at fast charge/discharge rates.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.317
Times cited: 8
DOI: 10.1002/chem.201501935
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“One-pot synthesis of catalytically stable and active nanoreactors: encapsulation of size-controlled nanoparticles within a hierarchically macroporous core@ordered mesoporous shell system”. Yang X-Y, Li Y, Van Tendeloo G, Xiao F-S, Su B-L, Advanced materials 21, 1368 (2009). http://doi.org/10.1002/adma.200802914
Abstract: Size-controlled, catalytically active nanoparticles are successfully encapsulated in a one-pot synthesis to form novel hierarchical macroporous core@mesoporous shell structures, where macroporous cores are connected by uniform and ordered mesoporous channels. Most importantly, the encapsulated nanoparticles can be used as nanoreactors, with high activities and excellent long-term recycling stability.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 19.791
Times cited: 61
DOI: 10.1002/adma.200802914
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“One-pot synthesis of Pt catalysts based on layered double hydroxides: an application in propane dehydrogenation”. Filez M, Redekop EA, Poelman H, Galvita VV, Meledina M, Turner S, Van Tendeloo G, Detavernier C, Marin GB, Catalysis science &, technology 6, 1863 (2016). http://doi.org/10.1039/C5CY01274K
Abstract: Simple methods for producing noble metal catalysts with well-defined active sites and improved performance are highly desired in the chemical industry. However, the development of such methods still presents a formidable synthetic challenge. Here, we demonstrate a one-pot synthesis route for the controlled production of bimetallic Pt–In catalysts based on the single-step formation of Mg,Al,Pt,In-containing layered double hydroxides (LDHs). Besides their simple synthesis, these Pt–In catalysts exhibit superior propane dehydrogenation activity compared to their multi-step synthesized analogs. The presented material serves as a showcase for the one-pot synthesis of a broader class of LDH-derived mono- and multimetallic Pt catalysts. The compositional flexibility provided by LDH materials can pave the way towards highperforming Pt-based catalysts with tunable physicochemical properties.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.773
Times cited: 12
DOI: 10.1039/C5CY01274K
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“One-Step Microheterogeneous Formation of Rutile@Anatase Core–Shell Nanostructured Microspheres Discovered by Precise Phase Mapping”. Tarasov A, Hu Z-Y, Meledina M, Trusov G, Goodilin E, Van Tendeloo G, Dobrovolsky Y, The journal of physical chemistry: C : nanomaterials and interfaces 121, 4443 (2017). http://doi.org/10.1021/acs.jpcc.6b12991
Abstract: Nanostructured core−shell microspheres with a rough rutile core and a thin anatase shell are synthesized via a one-step heterogeneous templated hydrolysis process of TiCl4 vapor on the aerosol water−air interface. The rutile-in-anatase core−shell structure has been evidenced by different electron microscopy techniques, including electron energy-loss spectroscopy and 3D electron tomography. A new mechanism for the formation of a crystalline rutile core inside the anatase shell is proposed based on a statistical evaluation of a large number of electron microscopy data. We found that the control over the TiCl4 vapor pressure, the ratio between TiCl4 and H2O aerosol, and the reaction conditions plays a crucial role in the formation of the core−shell morphology and increases the yield of nanostructured microspheres.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 4.536
Times cited: 4
DOI: 10.1021/acs.jpcc.6b12991
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“One-step synthesis of a suspended ultrathin graphene oxide film: Application in transmission electron microscopy”. Kirilenko DA, Dideykin AT, Aleksenskiy AE, Sitnikova AA, Konnikov SG, Vul' AY, Micron 68, 23 (2015). http://doi.org/10.1016/j.micron.2014.08.006
Abstract: Ultrathin graphene films find their use as advantageous support for nano- and biomaterials investigations. Thin film causes a very slight deterioration to measured signals, thus providing more details of the object's structure at nanoscale. The ultimate thinness of graphene works in the best way for this purpose. However, obtaining suspended thin film of a large-area, which is convenient for applications, is often a relatively complicated and time-consuming task. Here we present a one-step 1-min technique for synthesis of an extremely thin (about 1-2 nm) continuous film suspended over cells of a conventional copper grid (50-400 mu m mesh). This technique enables us to acquire a large-area film which is water-resistant, stable in organic solvents and can act as a support when studying nanoparticles or biomaterials. Moreover, the very mechanism of the film formation can be interesting from the point of view of other applications of ultrathin graphene oxide papers. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.98
Times cited: 13
DOI: 10.1016/j.micron.2014.08.006
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“One-step synthesis of shelled PbS nanoparticles in a layered double hydroxide matrix”. Lukashin AV, Eliseev AA, Zhuravleva NG, Vertegel AA, Tretyakov YD, Lebedev OI, Van Tendeloo G, Mendeleev communications , 174 (2004). http://doi.org/10.1070/MC2004v014n04ABEH001973
Abstract: The one-step preparation of capped PbS nanoparticles in an inorganic matrix via UV-induced decomposition of lead thiosulfate complexes intercalated into a hydrotalcite-type layered double hydroxide is reported.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.741
Times cited: 9
DOI: 10.1070/MC2004v014n04ABEH001973
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Nord M, Verbeeck J (2019) Open Source Development Tools for Robust and Reproducible Electron Microscopy Data Analysis. 138–139
Keywords: P3; Electron Microscopy for Materials Science (EMAT) ;
Impact Factor: 1.891
DOI: 10.1017/S1431927619001429
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“Optical and photoelectrical properties of nanocrystalline indium oxide with small grains”. Forsh EA, Abakumov AM, Zaytsev VB, Konstantinova EA, Forsh PA, Rumyantseva MN, Gaskov AM, Kashkarov PK, Thin solid films : an international journal on the science and technology of thin and thick films 595, 25 (2015). http://doi.org/10.1016/j.tsf.2015.10.053
Abstract: Optical properties, spectral dependence of photoconductivity and photoconductivity decay in nanocrystalline indium oxide In2O3 are studied. A number of nanostructured In2O3 samples with various nanocrystals size are prepared by sol-gel method and characterized using various techniques. The mean nanocrystals size varies from 7 to 8 nm to 39-41 nm depending on the preparation conditions. Structural characterization of the In2O3 samples is performed by means of transmission electron microscopy and X-ray powder diffraction. The combined analysis of ultraviolet-visible absorption spectroscopy and diffuse reflectance spectroscopy shows that nanostructuring leads to the change in optical band gap: optical band gap of the In2O3 samples (with an average nanocrystal size from 7 to 41 nm) is equal to 2.8 eV. We find out the correlation between spectral dependence of photoconductivity and optical properties of nanocrystalline In2O3: sharp increase in photoconductivity was observed to begin at 2.8 eV that is equal to the optical bandgap in the In2O3 samples, and reached its maximum at 3.2-3.3 eV. The combined analysis of the slow photoconductivity decay in air, vacuum and argon, that was accurately fitted by a stretched-exponential function, and electron paramagnetic resonance (EPR) measurements shows that the kinetics of photoconductivity decay is strongly depended on the presence of oxygen molecules in the ambient of In2O3 nanocrystals. There is the quantitative correlation between EPR and photoconductivity data. Based on the obtained data we propose the model clearing up the phenomenon of permanent photoconductivity decay in nanocrystalline In2O3. (C) 2015 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.879
Times cited: 18
DOI: 10.1016/j.tsf.2015.10.053
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“Optical encoding of luminescent carbon nanodots in confined spaces”. Bartholomeeusen E, De Cremer G, Kennes K, Hammond C, Hermans I, Lu J-B, Schryvers D, Jacobs PA, Roeffaers MBJ, Hofkens J, Sels BF, Coutino-Gonzalez E, Chemical Communications 57, 11952 (2021). http://doi.org/10.1039/D1CC04777A
Abstract: Stable emissive carbon nanodots were generated in zeolite crystals using near infrared photon irradiation gradually converting the occluded organic template, originally used to synthesize the zeolite crystals, into discrete luminescent species consisting of nano-sized carbogenic fluorophores, as ascertained using Raman microscopy, and steady-state and time-resolved spectroscopic techniques. Photoactivation in a confocal laser fluorescence microscope allows 3D resolved writing of luminescent carbon nanodot patterns inside zeolites providing a cost-effective and non-toxic alternative to previously reported metal-based nanoclusters confined in zeolites, and opens up opportunities in bio-labelling and sensing applications.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 6.319
DOI: 10.1039/D1CC04777A
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“Optical enhancement of a printed organic tandem solar cell using diffractive nanostructures”. Mayer JA, Offermans T, Chrapa M, Pfannmöller M, Bals S, Ferrini R, Nisato G, Optics express 26, A240 (2018). http://doi.org/10.1364/OE.26.00A240
Abstract: Solution processable organic tandem solar cells offer a promising approach to achieve cost-effective, lightweight and flexible photovoltaics. In order to further enhance the efficiency of optimized organic tandem cells, diffractive light-management nanostructures were designed for an optimal redistribution of the light as function of both wavelength and propagation angles in both sub-cells. As the fabrication of these optical structures is compatible with roll-to-roll production techniques such as hot-embossing or UV NIL imprinting, they present an optimal cost-effective solution for printed photovoltaics. Tandem cells with power conversion efficiencies of 8-10% were fabricated in the ambient atmosphere by doctor blade coating, selected to approximate the conditions during roll-to-roll manufacturing. Application of the light management structure onto an 8.7% efficient encapsulated tandem cell boosted the conversion efficiency of the cell to 9.5%. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.307
Times cited: 9
DOI: 10.1364/OE.26.00A240
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“Optical spectroscopy of oxygen precipitates in heavily doped p-type silicon”. Simoen E, Loo R, Claeys C, de Gryse O, Clauws P, van Landuyt J, Lebedev O, Journal of physics : condensed matter
T2 –, Conference on Extended Defects in Semiconductors (EDS 2002), JUN 01-06, 2002, BOLOGNA, ITALY 14, 13185 (2002). http://doi.org/10.1088/0953-8984/14/48/367
Abstract: Results are presented on the photoluminescence (PL) characterization of heavily doped p(+) Czochralski silicon, which has been subjected to a two-step, oxygen precipitation heat treatment. It will be shown that the presence of oxygen precipitates gives rise to the D1, D2 and D5 lines, where the energy of the D1 line shifts to lower values for a stronger degree of precipitation. The occurrence of these PL features is also a function of the boron concentration in the p(+) material. The PL results are compared with Fourier transform infrared absorption data and with transmission electron microscope, results. From this, it is concluded that PL has a good potential for use in the assessment of oxygen precipitation in heavily doped silicon.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.649
Times cited: 3
DOI: 10.1088/0953-8984/14/48/367
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“Optical versus electron diffraction imaging of Twist-angle in 2D transition metal dichalcogenide bilayers”. Psilodimitrakopoulos S, Orekhov A, Mouchliadis L, Jannis D, Maragkakis GM, Kourmoulakis G, Gauquelin N, Kioseoglou G, Verbeeck J, Stratakis E, npj 2D Materials and Applications 5, 77 (2021). http://doi.org/10.1038/S41699-021-00258-5
Abstract: Atomically thin two-dimensional (2D) materials can be vertically stacked with van der Waals bonds, which enable interlayer coupling. In the particular case of transition metal dichalcogenide (TMD) bilayers, the relative direction between the two monolayers, coined as twist-angle, modifies the crystal symmetry and creates a superlattice with exciting properties. Here, we demonstrate an all-optical method for pixel-by-pixel mapping of the twist-angle with a resolution of 0.55(degrees), via polarization-resolved second harmonic generation (P-SHG) microscopy and we compare it with four-dimensional scanning transmission electron microscopy (4D STEM). It is found that the twist-angle imaging of WS2 bilayers, using the P-SHG technique is in excellent agreement with that obtained using electron diffraction. The main advantages of the optical approach are that the characterization is performed on the same substrate that the device is created on and that it is three orders of magnitude faster than the 4D STEM. We envisage that the optical P-SHG imaging could become the gold standard for the quality examination of TMD superlattice-based devices.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Times cited: 4
DOI: 10.1038/S41699-021-00258-5
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“Optimal aperture sizes and positions for EMCD experiments”. Verbeeck J, Hébert, Rubino S, Novák P, Rusz J, Houdellier F, Gatel C, Schattschneider P, Ultramicroscopy 108, 865 (2008). http://doi.org/10.1016/j.ultramic.2008.02.007
Abstract: The signal-to-noise ratio (SNR) in energy-loss magnetic chiral dichroism (EMCD)the equivalent of X-ray magnetic circular dichroism (XMCD) in the electron microscopeis optimized with respect to the detector shape, size and position. We show that an important increase in SNR over previous experiments can be obtained when taking much larger detector sizes. We determine the ideal shape of the detector but also show that round apertures are a good compromise if placed in their optimal position. We develop the theory for a simple analytical description of the EMCD experiment and then apply it to dynamical multibeam Bloch wave calculations and to an experimental data set. In all cases it is shown that a significant and welcome improvement of the SNR is possible.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.843
Times cited: 27
DOI: 10.1016/j.ultramic.2008.02.007
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“Optimal experiment design for element specific atom counting using multiple annular dark field scanning transmission electron microscopy detectors”. Sentürk DG, De Backer A, Friedrich T, Van Aert S, Ultramicroscopy 242, 113626 (2022). http://doi.org/10.1016/j.ultramic.2022.113626
Abstract: This paper investigates the possible benefits for counting atoms of different chemical nature when analysing multiple 2D scanning transmission electron microscopy (STEM) images resulting from independent annular dark field (ADF) detector regimes. To reach this goal, the principles of statistical detection theory are used to quantify the probability of error when determining the number of atoms in atomic columns consisting of multiple types of elements. In order to apply this theory, atom-counting is formulated as a statistical hypothesis test, where each hypothesis corresponds to a specific number of atoms of each atom type in an atomic column. The probability of error, which is limited by the unavoidable presence of electron counting noise, can then be computed from scattering-cross sections extracted from multiple ADF STEM images. Minimisation of the probability of error as a function of the inner and outer angles of a specified number of independent ADF collection regimes results in optimal experimental designs. Based on simulations of spherical Au@Ag and Au@Pt core–shell nanoparticles, we investigate how the combination of two non-overlapping detector regimes helps to improve the probability of error when unscrambling two types of atoms. In particular, the combination of a narrow low angle ADF detector with a detector formed by the remaining annular collection regime is found to be optimal. The benefit is more significant if the atomic number Z difference becomes larger. In
addition, we show the benefit of subdividing the detector regime into three collection areas for heterogeneous nanostructures based on a structure consisting of three types of elements, e.g., a mixture of Au, Ag and Al atoms. Finally, these results are compared with the probability of error resulting when one would ultimately use a pixelated 4D STEM detector and how this could help to further reduce the incident electron dose.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.2
DOI: 10.1016/j.ultramic.2022.113626
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“Optimal experiment design for nanoparticle atom counting from ADF STEM images”. de Backer A, Fatermans J, den Dekker AJ, Van Aert S Advances in imaging and electron physics
T2 – Advances in imaging and electron physics. page 145 (2021).
Abstract: In this chapter, the principles of detection theory are used to quantify the probability of error for atom counting from high-resolution scanning transmission electron microscopy (HRSTEM) images. Binary and multiple hypothesis testing have been investigated in order to determine the limits to the precision with which the number of atoms in a projected atomic column can be estimated. The probability of error has been calculated when using STEM images, scattering cross-sections or peak intensities as a criterion to count atoms. Based on this analysis, we conclude that scattering cross-sections perform almost equally well as images and perform better than peak intensities. Furthermore, the optimal STEM detector design can be derived for atom counting using the expression of the probability of error. We show that for very thin objects the low-angle annular dark-field (LAADF) regime is optimal and that for thicker objects the optimal inner detector angle increases.
Keywords: H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab
DOI: 10.1016/BS.AIEP.2021.01.005
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“Optimal experimental design for nano-particle atom-counting from high-resolution STEM images”. de Backer A, De wael A, Gonnissen J, Van Aert S, Ultramicroscopy 151, 46 (2015). http://doi.org/10.1016/j.ultramic.2014.10.015
Abstract: In the present paper, the principles of detection theory are used to quantify the probability of error for atom-counting from high resolution scanning transmission electron microscopy (HR STEM) images. Binary and multiple hypothesis testing have been investigated in order to determine the limits to the precision with which the number of atoms in a projected atomic column can be estimated. The probability of error has been calculated when using STEM images, scattering cross-sections or peak intensities as a criterion to count atoms. Based on this analysis, we conclude that scattering cross-sections perform almost equally well as images and perform better than peak intensities. Furthermore, the optimal STEM detector design can be derived for atom-counting using the expression for the probability of error. We show that for very thin objects LAADF is optimal and that for thicker objects the optimal inner detector angle increases.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.843
Times cited: 24
DOI: 10.1016/j.ultramic.2014.10.015
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“Optimal experimental design for the detection of light atoms from high-resolution scanning transmission electron microscopy images”. Gonnissen J, de Backer A, den Dekker AJ, Martinez GT, Rosenauer A, Sijbers J, Van Aert S, Applied physics letters 105, 063116 (2014). http://doi.org/10.1063/1.4892884
Abstract: We report an innovative method to explore the optimal experimental settings to detect light atoms from scanning transmission electron microscopy (STEM) images. Since light elements play a key role in many technologically important materials, such as lithium-battery devices or hydrogen storage applications, much effort has been made to optimize the STEM technique in order to detect light elements. Therefore, classical performance criteria, such as contrast or signal-to-noise ratio, are often discussed hereby aiming at improvements of the direct visual interpretability. However, when images are interpreted quantitatively, one needs an alternative criterion, which we derive based on statistical detection theory. Using realistic simulations of technologically important materials, we demonstrate the benefits of the proposed method and compare the results with existing approaches.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Impact Factor: 3.411
Times cited: 12
DOI: 10.1063/1.4892884
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“Optimal experimental design of STEM measurement of atom column positions”. Van Aert S, den Dekker AJ, van Dyck D, van den Bos A, Ultramicroscopy 90, 273 (2002). http://doi.org/10.1016/S0304-3991(01)00152-8
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Impact Factor: 2.843
Times cited: 35
DOI: 10.1016/S0304-3991(01)00152-8
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“Optimal sample preparation to characterize corrosion in historical photographs with analytical TEM”. Grieten E, Caen J, Schryvers D, Microscopy and microanalysis 20, 1585 (2014). http://doi.org/10.1017/S1431927614012860
Abstract: An alternative focused ion beam preparation method is used for sampling historical photographs containing metallic nanoparticles in a polymer matrix. We use the preparation steps of classical ultra-microtomy with an alternative final sectioning with a focused ion beam. Transmission electron microscopy techniques show that the lamella has a uniform thickness, which is an important factor for analytical transmission electron microscopy. Furthermore, the method maintains the spatial distribution of nanoparticles in the soft matrix. The results are compared with traditional preparation techniques such as ultra-microtomy and classical focused ion beam milling.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Antwerp Cultural Heritage Sciences (ARCHES)
Impact Factor: 1.891
DOI: 10.1017/S1431927614012860
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