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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 | 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. | ||||
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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 | Yu, CP.; Vega Ibañez, F.; Béché, A.; Verbeeck, J. | ||||
Title | Quantum wavefront shaping with a 48-element programmable phase plate for electrons | Type | A1 Journal Article | ||
Year | 2023 | Publication | SciPost Physics | Abbreviated Journal | SciPost Phys. |
Volume | 15 | Issue | Pages | 223 | |
Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) | ||||
Abstract | We present a 48-element programmable phase plate for coherent electron waves produced by a combination of photolithography and focused ion beam. This brings the highly successful concept of wavefront shaping from light optics into the realm of electron optics and provides an important new degree of freedom to prepare electron quantum states. The phase plate chip is mounted on an aperture rod placed in the C2 plane of a transmission electron microscope operating in the 100-300 kV range. The phase plate's behavior is characterized by a Gerchberg-Saxton algorithm, showing a phase sensitivity of 0.075 rad/mV at 300 kV, with a phase resolution of approximately 3x10e−3π. In addition, we provide a brief overview of possible use cases and support it with both simulated and experimental results. | ||||
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Publisher | SciPost | Place of Publication | Editor | ||
Language | English | Wos | 001116838500002 | Publication Date | 2023-12-04 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2542-4653 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 5.5 | Times cited | 1 | Open Access | |
Notes | This project is the result of a long-term effort involving many differ- ent sources of funding: JV acknowledges funding from an ERC proof of concept project DLV- 789598 ADAPTEM, as well as a University IOF proof of concept project towards launching the AdaptEM spin-off and the eBEAM project, supported by the European Union’s Horizon 2020 research and innovation program FETPROACT-EIC-07-2020: emerging paradigms and com- munities. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 823717 – ESTEEM3 and via The IMPRESS project from the HORIZON EUROPE framework program for research and innovation under grant agreement n. 101094299. FV, JV, and AB acknowledge funding from G042820N ‘Explor- ing adaptive optics in transmission electron microscopy.’ CPY acknowledges funding from a TOP-BOF project from the University of Antwerp. | Approved | Most recent IF: 5.5; 2023 IF: NA | ||
Call Number | EMAT @ emat @c:irua:202037 | Serial | 8984 | ||
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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 | 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. | ||||
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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 | Grünewald, L.; Chezganov, D.; De Meyer, R.; Orekhov, A.; Van Aert, S.; Bogaerts, A.; Bals, S.; Verbeeck, J. | ||||
Title | In Situ Plasma Studies Using a Direct Current Microplasma in a Scanning Electron Microscope | Type | A1 Journal article | ||
Year | 2024 | Publication | Advanced Materials Technologies | Abbreviated Journal | Adv Materials Technologies |
Volume | Issue | Pages | |||
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Microplasmas can be used for a wide range of technological applications and to improve the understanding of fundamental physics. Scanning electron microscopy, on the other hand, provides insights into the sample morphology and chemistry of materials from the mm‐ down to the nm‐scale. Combining both would provide direct insight into plasma‐sample interactions in real‐time and at high spatial resolution. Up till now, very few attempts in this direction have been made, and significant challenges remain. This work presents a stable direct current glow discharge microplasma setup built inside a scanning electron microscope. The experimental setup is capable of real‐time in situ imaging of the sample evolution during plasma operation and it demonstrates localized sputtering and sample oxidation. Further, the experimental parameters such as varying gas mixtures, electrode polarity, and field strength are explored and experimental<italic>V</italic>–<italic>I</italic>curves under various conditions are provided. These results demonstrate the capabilities of this setup in potential investigations of plasma physics, plasma‐surface interactions, and materials science and its practical applications. The presented setup shows the potential to have several technological applications, for example, to locally modify the sample surface (e.g., local oxidation and ion implantation for nanotechnology applications) on the µm‐scale. | ||||
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Language | Wos | 001168639900001 | Publication Date | 2024-02-25 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2365-709X | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 6.8 | Times cited | Open Access | OpenAccess | |
Notes | L.G., S.B., and J.V. acknowledge support from the iBOF-21-085 PERsist research fund. D.C., S.V.A., and J.V. acknowledge funding from a TOPBOF project of the University of Antwerp (FFB 170366). R.D.M., A.B., and J.V. acknowledge funding from the Methusalem project of the University of Antwerp (FFB 15001A, FFB 15001C). A.O. and J.V. acknowledge funding from the Research Foundation Flanders (FWO, Belgium) project SBO S000121N. | Approved | Most recent IF: 6.8; 2024 IF: NA | ||
Call Number | EMAT @ emat @c:irua:204363 | Serial | 8995 | ||
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Author | Ignatova, K.; Vlasov, E.; Seddon, S.D.; Gauquelin, N.; Verbeeck, J.; Wermeille, D.; Bals, S.; Hase, T.P.A.; Arnalds, U.B. | ||||
Title | Phase coexistence induced surface roughness in V2O3/Ni magnetic heterostructures | Type | A1 Journal article | ||
Year | 2024 | Publication | APL materials | Abbreviated Journal | |
Volume | 12 | Issue | 4 | Pages | |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | We present an investigation of the microstructure changes in V2O3 as it goes through its inherent structural phase transition. Using V2O3 films with a well-defined crystal structure deposited by reactive magnetron sputtering on r-plane Al2O3 substrates, we study the phase coexistence region and its impact on the surface roughness of the films and the magnetic properties of overlying Ni magnetic layers in V2O3/Ni hybrid magnetic heterostructures. The simultaneous presence of two phases in V2O3 during its structural phase transition was identified with high resolution x-ray diffraction and led to an increase in surface roughness observed using x-ray reflectivity. The roughness reaches its maximum at the midpoint of the transition. In V2O3/Ni hybrid heterostructures, we find a concomitant increase in the coercivity of the magnetic layer correlated with the increased roughness of the V2O3 surface. The chemical homogeneity of the V2O3 is confirmed through transmission electron microscopy analysis. High-angle annular dark field imaging and electron energy loss spectroscopy reveal an atomically flat interface between Al2O3 and V2O3, as well as a sharp interface between V2O3 and Ni. | ||||
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Language | Wos | 001202661800003 | Publication Date | 2024-04-01 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2166-532X | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 6.1 | Times cited | Open Access | ||
Notes | This work was supported by the funding from the University of Iceland Research Fund, the Icelandic Research Fund Grant No. 207111. Instrumentation funding from the Icelandic Infrastructure Fund is acknowledged. This work was based on experiments per- formed at the BM28 (XMaS) beamline at the European Synchrotron Radiation Facility, Grenoble, France. XMaS is a National Research Facility funded by the UK EPSRC and managed by the Universi- ties of Liverpool and Warwick. This project has received funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 823717—ESTEEM3. | Approved | Most recent IF: 6.1; 2024 IF: 4.335 | ||
Call Number | EMAT @ emat @c:irua:205569 | Serial | 9120 | ||
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Author | Vlasov, E.; Heyvaert, W.; Ni, B.; Van Gordon, K.; Girod, R.; Verbeeck, J.; Liz-Marzán, L.M.; Bals, S. | ||||
Title | High-Throughput Morphological Chirality Quantification of Twisted and Wrinkled Gold Nanorods | Type | A1 Journal Article | ||
Year | 2024 | Publication | ACS Nano | Abbreviated Journal | ACS Nano |
Volume | Issue | Pages | |||
Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
Abstract | Chirality in gold nanostructures offers an exciting opportunity to tune their differential optical response to left- and right-handed circularly polarized light, as well as their interactions with biomolecules and living matter. However, tuning and understanding such interactions demands quantification of the structural features that are responsible for the chiral behavior. Electron tomography (ET) enables structural characterization at the single-particle level and has been used to quantify the helicity of complex chiral nanorods. However, the technique is time-consuming and consequently lacks statistical value. To address this issue, we introduce herein a high-throughput methodology that combines images acquired by secondary electron-based electron beam-induced current (SEEBIC) with quantitative image analysis. As a result, the geometric chirality of hundreds of nanoparticles can be quantified in less than 1 h. When combining the drastic gain in data collection efficiency of SEEBIC with a limited number of ET data sets, a better understanding of how the chiral structure of individual chiral nanoparticles translates into the ensemble chiroptical response can be reached. | ||||
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Language | Wos | 001227683500001 | Publication Date | 2024-04-26 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 1936-0851 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 17.1 | Times cited | Open Access | ||
Notes | The authors acknowledge financial support by the European Research Council (ERC CoG No. 815128 REALNANO to S.B.) and from MCIN/AEI/10.13039/501100011033 (Grant PID2020-117779RB-I00 to L.M.L.-M and FPI Fellowship PRE2021-097588 to K.V.G.). Funded by the European Union under Project 101131111 − DELIGHT, JV acknowledges the eBEAM project supported by the European Union’s Horizon 2020 research and innovation program FETPROACT-EIC-07- 2020: emerging paradigms and communities. | Approved | Most recent IF: 17.1; 2024 IF: 13.942 | ||
Call Number | EMAT @ emat @c:irua:206329 | Serial | 9121 | ||
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Author | Ni, S.; Houwman, E.; Gauquelin, N.; Chezganov, D.; Van Aert, S.; Verbeeck, J.; Rijnders, G.; Koster, G. | ||||
Title | Stabilizing perovskite Pb(Mg0.33Nb0.67)O3-PbTiO3 thin films by fast deposition and tensile mismatched growth template | Type | A1 Journal article | ||
Year | 2024 | Publication | ACS applied materials and interfaces | Abbreviated Journal | |
Volume | 16 | Issue | 10 | Pages | 12744-12753 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Because of its low hysteresis, high dielectric constant, and strong piezoelectric response, Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMN-PT) thin films have attracted considerable attention for the application in PiezoMEMS, field-effect transistors, and energy harvesting and storage devices. However, it remains a great challenge to fabricate phase-pure, pyrochlore-free PMN-PT thin films. In this study, we demonstrate that a high deposition rate, combined with a tensile mismatched template layer can stabilize the perovskite phase of PMN-PT films and prevent the nucleation of passive pyrochlore phases. We observed that an accelerated deposition rate promoted mixing of the B-site cation and facilitated relaxation of the compressively strained PMN-PT on the SrTiO3 (STO) substrate in the initial growth layer, which apparently suppressed the initial formation of pyrochlore phases. By employing La-doped-BaSnO3 (LBSO) as the tensile mismatched buffer layer, 750 nm thick phase-pure perovskite PMN-PT films were synthesized. The resulting PMN-PT films exhibited excellent crystalline quality close to that of the STO substrate. | ||||
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Language | Wos | 001176343700001 | Publication Date | 2024-02-29 | |
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ISSN | 1944-8244 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 9.5 | Times cited | Open Access | ||
Notes | We would like to acknowledge the Netherlands Organization for Scientific Research (NWO) for the financial support of this work. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 823717-ESTEEM3. | Approved | Most recent IF: 9.5; 2024 IF: 7.504 | ||
Call Number | UA @ admin @ c:irua:204754 | Serial | 9174 | ||
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Author | Gholam, S.; Denisov, N.; Orekhov, A.; Verbeeck, J.; Hadermann, J. | ||||
Title | An Investigation on 3D Electron Diffraction and 4-Dimensional Scanning Diffraction Tomography Using a Scanning Electron Microscope | Type | P1 Conference Proceedings | ||
Year | 2024 | Publication | Microscopy and Microanalysis | Abbreviated Journal | |
Volume | 30 | Issue | Supplement_1 | Pages | |
Keywords | P1 Conference Proceedings; Electron Microscopy for Materials Science (EMAT) ; | ||||
Abstract | During the last decade, 3D-Electron Diffraction (3D-ED) has emerged as a powerful technique for studying the structure of sub-micron particles. It is used in a variety of applications, from unit cell and space group determination to the complete solution of the structure similar to X-ray diffraction techniques. So far, this technique has been only implemented in Transmission Electron Microscopes (TEMs). Performing such an experiment in a Scanning Electron Microscope (SEM) can be challenging, mainly due to the lower acceleration voltage. This lower beam energy raises concerns about severe multiple scattering and limited transmissivity of the sample for the weakly accelerated electrons. In this work, we show the possibilities of operating similar studies in a modified SEM. For this aim, we equipped our SEM with a custom stage and holder, a direct electron detector and a custom high-angle annular dark-field detector (HAADF). A range of samples was studied in the form of lamellas and sub-micron particles, and the quality of the diffraction data was evaluated for different purposes, such as unit cell determination and space group determination. Moreover, the ability to integrate the diffraction data for structure solution and refinement has been assessed and compared to similar data acquired in a TEM. Finally, we also demonstrate the potential for combining diffraction tomography and 4-dimensional scanning transmission electron microscopy (4D-STEM) in our setup. This method opens an avenue to obtain multiple 3DED datasets out of 5D-STEM data. These 3DED datasets can be created using object tracking methods from several regions of a multi-domain particle or from multiple single crystals within the scanning region. This provides an attractive route to high-throughput and statistically relevant characterization of polycrystalline materials or powders of nanoparticles. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | Publication Date | 2024-07-24 | ||
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ISSN | 1431-9276 | ISBN | Additional Links | ||
Impact Factor | 2.8 | Times cited | Open Access | ||
Notes | The authors acknowledge the financial support of the Research Foundation Flanders (FWO, Belgium) project SBO S000121N. The authors are also grateful to Amsterdam Scientific Instruments. | Approved | Most recent IF: 2.8; 2024 IF: 1.891 | ||
Call Number | EMAT @ emat @ | Serial | 9269 | ||
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Author | Schrenker, N.J.; Braeckevelt, T.; De Backer, A.; Livakas, N.; Yu, C.-P.; Friedrich, T.; Roeffaers, M.B.J.; Hofkens, J.; Verbeeck, J.; Manna, L.; Van Speybroeck, V.; Van Aert, S.; Bals, S. | ||||
Title | Investigation of the Octahedral Network Structure in Formamidinium Lead Bromide Nanocrystals by Low-Dose Scanning Transmission Electron Microscopy | Type | A1 Journal Article | ||
Year | 2024 | Publication | Nano Letters | Abbreviated Journal | Nano Lett. |
Volume | 24 | Issue | 35 | Pages | 10936-10942 |
Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
Abstract | Metal halide perovskites (MHP) are highly promising semiconductors. In this study, we focus on FAPbBr3 nanocrystals, which are of great interest for green light-emitting diodes. Structural parameters significantly impact the properties of MHPs and are linked to phase instability, which hampers long-term applications. Clearly, there is a need for local and precise characterization techniques at the atomic scale, such as transmission electron microscopy. Because of the high electron beam sensitivity of MHPs, these investigations are extremely challenging. Here, we applied a low-dose method based on four-dimensional scanning transmission electron microscopy. We quantified the observed elongation of the projections of the Br atomic columns, suggesting an alternation in the position of the Br atoms perpendicular to the Pb–Br–Pb bonds. Together with molecular dynamics simulations, these results remarkably reveal local distortions in an on-average cubic structure. Additionally, this study provides an approach to prospectively investigating the fundamental degradation mechanisms of MHPs. | ||||
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Language | Wos | Publication Date | 2024-09-04 | ||
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Series Volume | Series Issue | Edition | |||
ISSN | 1530-6984 | ISBN | Additional Links | ||
Impact Factor | 10.8 | Times cited | Open Access | ||
Notes | The authors acknowledge financial support from the Research Foundation-Flanders (FWO) through project fundings (G0A7723N) and a postdoctoral fellowship to N.J.S. (FWO Grants 1238622N and V413524N). The authors acknowledge financial support from iBOF-21-085 PERSIST. S.B. and S.V.A. acknowledge financial support from the European Commission by ERC Consolidator Grant 815128 (REALNANO) and Grant 770887 (PICOMETRICS). L.M. acknowledges financial support from the European Commission by ERC Advanced Grant 101095974 (NEHA). V.V.S. furthermore acknowledges the Research Fund of Ghent University (BOF) for its financial support. The computational resources and services used in this work were provided by VSC (Flemish Supercomputer Center), funded by the Research Foundation-Flanders (FWO), and the Flemish Government. | Approved | Most recent IF: 10.8; 2024 IF: 12.712 | ||
Call Number | EMAT @ emat @ | Serial | 9273 | ||
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Author | Tan, H.; Turner, S.; Yucelen, E.; Verbeeck, J.; Van Tendeloo, G. | ||||
Title | 2D atomic mapping of oxidation states in transition metal oxides by scanning transmission electron microscopy and electron energy-loss spectroscopy : reply | Type | Editorial | ||
Year | 2012 | Publication | Physical review letters | Abbreviated Journal | Phys Rev Lett |
Volume | 108 | Issue | 25 | Pages | 259702 |
Keywords | Editorial; Electron microscopy for materials research (EMAT) | ||||
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Language | Wos | 000305568700038 | Publication Date | 2012-06-19 | |
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ISSN | 0031-9007 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 8.462 | Times cited | Open Access | ||
Notes | Approved | Most recent IF: 8.462; 2012 IF: 7.943 | |||
Call Number | UA @ admin @ c:irua:100293 | Serial | 5370 | ||
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Author | Turner, S.; Shenderova, O.; da Pieve, F.; Lu, Y.-G.; Yücelen, E.; Verbeeck, J.; Lamoen, D.; Van Tendeloo, G. | ||||
Title | Aberration-corrected microscopy and spectroscopy analysis of pristine, nitrogen containing detonation nanodiamond | Type | A1 Journal article | ||
Year | 2013 | Publication | Physica status solidi : A : applications and materials science | Abbreviated Journal | Phys Status Solidi A |
Volume | 210 | Issue | 10 | Pages | 1976-1984 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Aberration-corrected transmission electron microscopy, electron energy-loss spectroscopy, and density functional theory (DFT) calculations are used to solve several key questions about the surface structure, the particle morphology, and the distribution and nature of nitrogen impurities in detonation nanodiamond (DND) cleaned by a recently developed ozone treatment. All microscopy and spectroscopy measurements are performed at a lowered acceleration voltage (80/120kV), allowing prolonged and detailed experiments to be carried out while minimizing the risk of knock-on damage or surface graphitization of the nanodiamond. High-resolution TEM (HRTEM) demonstrates the stability of even the smallest nanodiamonds under electron illumination at low voltage and is used to image the surface structure of pristine DND. High resolution electron energy-loss spectroscopy (EELS) measurements on the fine structure of the carbon K-edge of nanodiamond demonstrate that the typical * pre-peak in fact consists of three sub-peaks that arise from the presence of, amongst others, minimal fullerene-like reconstructions at the nanoparticle surfaces and deviations from perfect sp(3) coordination at defects in the nanodiamonds. Spatially resolved EELS experiments evidence the presence of nitrogen within the core of DND particles. The nitrogen is present throughout the whole diamond core, and can be enriched at defect regions. By comparing the fine structure of the experimental nitrogen K-edge with calculated energy-loss near-edge structure (ELNES) spectra from DFT, the embedded nitrogen is most likely related to small amounts of single substitutional and/or A-center nitrogen, combined with larger nitrogen clusters. | ||||
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Language | Wos | 000329299700025 | Publication Date | 2013-10-18 | |
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ISSN | 1862-6300; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.775 | Times cited | 37 | Open Access | |
Notes | 262348 ESMI; 246791 COUNTATOMS; FWO; Hercules; GOA XANES meets ELNES | Approved | Most recent IF: 1.775; 2013 IF: 1.525 | ||
Call Number | UA @ lucian @ c:irua:110821UA @ admin @ c:irua:110821 | Serial | 41 | ||
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Author | Morozov, V.A.; Raskina, M.V.; Lazoryak, B.I.; Meert, K.W.; Korthout, K.; Smet, P.F.; Poelman, D.; Gauquelin, N.; Verbeeck, J.; Abakumov, A.M.; Hadermann, J.; | ||||
Title | Crystal Structure and Luminescent Properties of R2-xEux(MoO4)(3) (R = Gd, Sm) Red Phosphors | Type | A1 Journal article | ||
Year | 2014 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
Volume | 26 | Issue | 24 | Pages | 7124-7136 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The R-2(MoO4)(3) (R = rare earth elements) molybdates doped with Eu3+ cations are interesting red-emitting materials for display and solid-state lighting applications. The structure and luminescent properties of the R2-xEux(MoO4)(3) (R = Gd, Sm) solid solutions have been investigated as a function of chemical composition and preparation conditions. Monoclinic (alpha) and orthorhombic (beta') R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) modifications were prepared by solid-state reaction, and their structures were investigated using synchrotron powder X-ray diffraction and transmission electron microscopy. The pure orthorhombic beta'-phases could be synthesized only by quenching from high temperature to room temperature for Gd2-xEux(MoO4)(3) in the Eu3+-rich part (x > 1) and for all Sm2-xEux(MoO4)(3) solid solutions. The transformation from the alpha-phase to the beta'-phase results in a notable increase (similar to 24%) of the unit cell volume for all R2-xEux(MoO4)(3) (R = Sm, Gd) solid solutions. The luminescent properties of all R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) solid solutions were measured, and their optical properties were related to their structural properties. All R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) phosphors emit intense red light dominated by the D-5(0)-> F-7(2) transition at similar to 616 nm. However, a change in the multiplet splitting is observed when switching from the monoclinic to the orthorhombic structure, as a consequence of the change in coordination polyhedron of the luminescent ion from RO8 to RO7 for the alpha- and beta'-modification, respectively. The Gd2-xEux(MoO4)(3) solid solutions are the most efficient emitters in the range of 0 < x < 1.5, but their emission intensity is comparable to or even significantly lower than that of Sm2-xEux(MoO4)(3) for higher Eu3+ concentrations (1.5 <= x <= 1.75). Electron energy loss spectroscopy (EELS) measurements revealed the influence of the structure and element content on the number and positions of bands in the ultraviolet-visible-infrared regions of the EELS spectrum. | ||||
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Language | Wos | 000347139700027 | Publication Date | 2014-11-27 | |
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ISSN | 0897-4756;1520-5002; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.466 | Times cited | 24 | Open Access | |
Notes | Fwo G039211n; G004413n; 278510 Vortex ECASJO_; | Approved | Most recent IF: 9.466; 2014 IF: 8.354 | ||
Call Number | UA @ lucian @ c:irua:122829UA @ admin @ c:irua:122829 | Serial | 558 | ||
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Author | Verbeeck, J.; Bals, S.; Lamoen, D.; Luysberg, M.; Huijben, M.; Rijnders, G.; Brinkman, A.; Hilgenkamp, H.; Blank, D.H.A.; Van Tendeloo, G. | ||||
Title | Electronic reconstruction at n-type SrTiO3/LaAlO3 interfaces | Type | A1 Journal article | ||
Year | 2010 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 81 | Issue | 8 | Pages | 085113,1-085113,6 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Electron-energy-loss spectroscopy (EELS) is used to investigate single layers of LaAlO3 grown on SrTiO3 having an n-type interface as well as multilayers of LaAlO3 and SrTiO3 in which both n- and p-type interfaces occur. Only minor changes in Ti valence at the n-type interface are observed. This finding seems to contradict earlier experiments for other SrTiO3/LaAlO3 systems where large deviations in Ti valency were assumed to be responsible for the conductivity of these interfaces. Ab initio calculations have been carried out in order to interpret our EELS results. Using the concept of Bader charges, it is demonstrated that the so-called polar discontinuity is mainly resolved by lattice distortions and to a far lesser extent by changes in valency for both single layer and multilayer geometries. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000275053300040 | Publication Date | 2010-02-18 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 25 | Open Access | |
Notes | Esteem 026019; Fwo | Approved | Most recent IF: 3.836; 2010 IF: 3.774 | ||
Call Number | UA @ lucian @ c:irua:81768UA @ admin @ c:irua:81768 | Serial | 1005 | ||
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Author | Morozov, V.A.; Lazoryak, B.I.; Shmurak, S.Z.; Kiselev, A.P.; Lebedev, O.I.; Gauquelin, N.; Verbeeck, J.; Hadermann, J.; Van Tendeloo, G. | ||||
Title | Influence of the structure on the properties of NaxEuy(MoO4)z red phosphors | Type | A1 Journal article | ||
Year | 2014 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
Volume | 26 | Issue | 10 | Pages | 3238-3248 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Scheelite related compounds (A',A '')(n)[(B',B '')O-4](m) with B', B '' = W and/or Mo are promising new materials for red phosphors in pc-WLEDs (phosphor-converted white-light-emitting-diode) and solid-state lasers. Cation substitution in CaMoO4 of Ca2+ by the combination of Na+ and Eu3+, with the creation of A cation vacancies, has been investigated as a factor for controlling the scheelite-type structure and the luminescent properties. Na5Eu(MoO4)(4) and NaxEu(2-x)/33+square(2-x)/3MoO4 (0.138 <= x <= 0.5) phases with a scheelite-type structure were synthesized by the solid state method; their structural characteristics were investigated using transmission electron microscopy. Contrary to powder synchrotron X-ray diffraction before, the study by electron diffraction and high resolution transmission electron microscopy in this paper revealed that Na0.286Eu0.571MoO4 has a (3 + 2)D incommensurately modulated structure and that (3 + 2)D incommensurately modulated domains are present in Na0.200Eu0.600MoO4. It also confirmed the (3 + 1)D incommensurately modulated character of Na(0.138)Eu(0.621)Mo04. The luminescent properties of all phases under near-ultraviolet (n-UV) light have been investigated. The excitation spectra of these phosphors show the strongest absorption at about 395 nm, which matches well with the commercially available n-UV-emitting GaN-based LED chip. The emission spectra indicate an intense red emission due to the D-5(0) -> F-7(2) transition of Eu3+, with local minima in the intensity at Na0.286Eu0.571MoO4 and Na0.200Eu0.600MoO4 for similar to 613 nm and similar to 616 nm bands. The phosphor Na5Eu(MoO4)(4) shows the brightest red light emission among the phosphors in the Na2MoO4-Eu2/3MoO4 system and the maximum luminescence intensity of Na5Eu(MoO4)(4) (lambda(ex) = 395 nm) in the D-5(0) -> F-7(2) transition region is close to that of the commercially used red phosphor YVO4:Eu3+ (lambda(ex) = 326 nm). Electron energy loss spectroscopy measurements revealed the influence of the structure and Na/Eu cation distribution on the number and positions of bands in the UV-optical-infrared regions of the EELS spectrum. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000336637000028 | Publication Date | 2014-05-01 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756;1520-5002; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.466 | Times cited | 53 | Open Access | |
Notes | Fwo G039211n; Fwo G004413n; 278510 Vortex ECASJO_; | Approved | Most recent IF: 9.466; 2014 IF: 8.354 | ||
Call Number | UA @ lucian @ c:irua:117765UA @ admin @ c:irua:117765 | Serial | 1652 | ||
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Author | Li, Y.; Tan, H.; Lebedev, O.; Verbeeck, J.; Biermans, E.; Van Tendeloo, G.; Su, B.-L. | ||||
Title | Insight into the growth of multiple branched MnOOH nanorods | Type | A1 Journal article | ||
Year | 2010 | Publication | Crystal growth & design | Abbreviated Journal | Cryst Growth Des |
Volume | 10 | Issue | 7 | Pages | 2969-2976 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Multiple branched manganese oxide hydroxide (MnOOH) nanorods prepared by a hydrothermal process were extensively studied by transmission electron microscopy (TEM). A model of the branch formation is proposed together with a study of the interface structure. The sword-like tip plays a crucial role for the nanorods to form different shapes. Importantly, the branching occurs at an angle of around either 57 degrees or 123 degrees. Specifically, a (111) twin plane can only be formed at the interface with a 123 degrees angle. The interfaces formed with a 57 degrees angle usually contain edge dislocations. Electron energy loss spectroscopy (EELS) demonstrates that the whole crystal has a uniform chemical composition. Interestingly, an epitaxial growth of Mn3O4 at the radial surface was also observed under electron beam irradiation; this is because of the rough purification of the products. The proposed mechanism is expected to shed light on the branched/dendrite nanostructure growth and to provide opportunities for further novel nanomaterial structure growth and design. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000279422700027 | Publication Date | 2010-06-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1528-7483;1528-7505; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.055 | Times cited | 41 | Open Access | |
Notes | Fwo; Esteem 026019 | Approved | Most recent IF: 4.055; 2010 IF: 4.390 | ||
Call Number | UA @ lucian @ c:irua:83886UA @ admin @ c:irua:83886 | Serial | 1672 | ||
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Author | Gehrke, K.; Moshnyaga, V.; Samwer, K.; Lebedev, O.I.; Verbeeck, J.; Kirilenko, D.; Van Tendeloo, G. | ||||
Title | Interface controlled electronic variations in correlated heterostructures | Type | A1 Journal article | ||
Year | 2010 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 82 | Issue | 11 | Pages | 113101,1-113101,4 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | An interface modification of (LaCa)MnO3-BaTiO3 superlattices was found to massively influence magnetic and magnetotransport properties. Moreover it determines the crystal structure of the manganite layers, changing it from orthorhombic (Pnma) for the conventional superlattice (cSL), to rhombohedral (R3̅ c) for the modified one (mSL). While the cSL shows extremely nonlinear ac transport, the mSL is an electrically homogeneous material. The observations go beyond an oversimplified picture of dead interface layers and evidence the importance of electronic correlations at perovskite interfaces. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000281643200001 | Publication Date | 2010-09-07 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 9 | Open Access | |
Notes | This work was supported by DFG via SFB 602, TPA2. | Approved | Most recent IF: 3.836; 2010 IF: 3.774 | ||
Call Number | UA @ lucian @ c:irua:84249UA @ admin @ c:irua:84249 | Serial | 1691 | ||
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Author | Béché, A.; Van Boxem, R.; Van Tendeloo, G.; Verbeeck, J. | ||||
Title | Magnetic monopole field exposed by electrons | Type | A1 Journal article | ||
Year | 2014 | Publication | Nature physics | Abbreviated Journal | Nat Phys |
Volume | 10 | Issue | 1 | Pages | 26-29 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The experimental search for magnetic monopole particles(1-3) has, so far, been in vain. Nevertheless, these elusive particles of magnetic charge have fuelled a rich field of theoretical study(4-10). Here, we created an approximation of a magnetic monopole in free space at the end of a long, nanoscopically thin magnetic needle(11). We experimentally demonstrate that the interaction of this approximate magnetic monopole field with a beam of electrons produces an electron vortex state, as theoretically predicted for a true magnetic monopole(3,11-18). This fundamental quantum mechanical scattering experiment is independent of the speed of the electrons and has consequences for all situations where electrons meet such monopole magnetic fields, as, for example, in solids. The set-up not only shows an attractive way to produce electron vortex states but also provides a unique insight into monopole fields and shows that electron vortices might well occur in unexplored solid-state physics situations. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000328940100012 | Publication Date | 2013-11-29 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1745-2473;1745-2481; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 22.806 | Times cited | 131 | Open Access | |
Notes | Vortex; Countatoms; Fwo ECASJO_; | Approved | Most recent IF: 22.806; 2014 IF: 20.147 | ||
Call Number | UA @ lucian @ c:irua:113740UA @ admin @ c:irua:113740 | Serial | 1885 | ||
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Author | Boullay, P.; David, A.; Sheets, W.C.; Lüders, U.; Prellier, W.; Tan, H.; Verbeeck, J.; Van Tendeloo, G.; Gatel, C.; Vincze, G.; Radi, Z. | ||||
Title | Microstructure and interface studies of LaVO3/SrVO3 superlattices | Type | A1 Journal article | ||
Year | 2011 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 83 | Issue | 12 | Pages | 125403-125403,6 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The structure and interface characteristics of (LaVO3)6m(SrVO3)m superlattices deposited on a (100)-SrTiO3 substrate were studied using transmission electron microscopy (TEM). Cross-section TEM studies revealed that both LaVO3 (LVO) and SrVO3 (SVO) layers are good single-crystal quality and epitaxially grown with respect to the substrate. It is evidenced that LVO layers are made of two orientational variants of a distorted perovskite compatible with bulk LaVO3, while SVO layers suffers from a tetragonal distortion due to the substrate-induced stain. Electron energy loss spectroscopy investigations indicate changes in the fine structure of the V L23 edge, related to a valence change between the LaVO3 and the SrVO3 layers. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000288160300006 | Publication Date | 2011-03-09 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 26 | Open Access | |
Notes | Fwo; Esteem 026019 | Approved | Most recent IF: 3.836; 2011 IF: 3.691 | ||
Call Number | UA @ lucian @ c:irua:88648UA @ admin @ c:irua:88648 | Serial | 2054 | ||
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Author | Verbeeck, J.; Bertoni, G. | ||||
Title | Model-based quantification of EELS: is standardless quantification possible? | Type | A1 Journal article | ||
Year | 2008 | Publication | Microchimica acta | Abbreviated Journal | Microchim Acta |
Volume | 161 | Issue | 3/4 | Pages | 439-443 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Electron energy loss spectroscopy (EELS) is an ideal tool to obtain chemical information from nanoscale volumes. Quantification of the experimental spectra however has prevented for a long time access to the available information in a reliable and reproducible way. We present recent advances in model-based quantification of EELS spectra and show that we obtain the best possible precision for a given dataset, as well as remarkably good accuracies when applied to three different materials. The results are shown to be far superior over conventional quantification techniques and could hold a promise for standardless quantification of EELS spectra. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000256175600024 | Publication Date | 2008-02-22 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 0026-3672;1436-5073; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.58 | Times cited | 5 | Open Access | |
Notes | Esteem 026019; Fwo; G.0425.05; Iap V; Goa 2005 | Approved | Most recent IF: 4.58; 2008 IF: 1.910 | ||
Call Number | UA @ lucian @ c:irua:69292UA @ admin @ c:irua:69292 | Serial | 2100 | ||
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Author | Jorissen, K.; Rehr, J.J.; Verbeeck, J. | ||||
Title | Multiple scattering calculations of relativistic electron energy loss spectra | Type | A1 Journal article | ||
Year | 2010 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 81 | Issue | 15 | Pages | 155108,1-155108,6 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | A generalization of the real-space Greens-function approach is presented for ab initio calculations of relativistic electron energy loss spectra (EELS) which are particularly important in anisotropic materials. The approach incorporates relativistic effects in terms of the transition tensor within the dipole-selection rule. In particular, the method accounts for relativistic corrections to the magic angle in orientation resolved EELS experiments. The approach is validated by a study of the graphite C K edge, for which we present an accurate magic angle measurement consistent with the predicted value. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000277210500038 | Publication Date | 2010-04-13 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 24 | Open Access | |
Notes | Fwo; Esteem 026019 | Approved | Most recent IF: 3.836; 2010 IF: 3.774 | ||
Call Number | UA @ lucian @ c:irua:82805UA @ admin @ c:irua:82805 | Serial | 2230 | ||
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Author | Schattschneider, P.; Verbeeck, J.; Mauchamp, V.; Jaouen, M.; Hamon, A.-L. | ||||
Title | Real-space simulations of spin-polarized electronic transitions in iron | Type | A1 Journal article | ||
Year | 2010 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 82 | Issue | 14 | Pages | 144418-144418,11 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | After the advent of energy-loss magnetic chiral dichroism (EMCD) in 2006, rapid progress in theoretical understanding and in experimental performance was achieved, recently demonstrating a spatial resolution of better than 2 nm. Similar to the x-ray magnetic circular dichroism technique, EMCD is used to study atom specific magnetic moments. The latest generation of electron microscopes opens the road to the mapping of spin moments on the atomic scale with this method. Here the theoretical background to reach this challenging aim is elaborated. Numerical simulations of the L3 transition in an Fe specimen, based on a combination of the density-matrix approach for inelastic electron scattering with the propagation of the probe electron in the lattice potential indicate the feasibility of single spin mapping in the electron microscope. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000282678900006 | Publication Date | 2010-10-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 11 | Open Access | |
Notes | P.S. acknowledges the support of the Austrian Science Fund, Project No. I543-N20. | Approved | Most recent IF: 3.836; 2010 IF: 3.774 | ||
Call Number | UA @ lucian @ c:irua:85029UA @ admin @ c:irua:85029 | Serial | 2832 | ||
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Author | Turner, S.; Lebedev, O.I.; Verbeeck, J.; Gehrke, K.; Moshnyaga, V.; Van Tendeloo, G. | ||||
Title | Structural phase transition and spontaneous interface reconstruction in La2/3Ca1/3MnO3/BaTiO3 superlattices | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 3 | Pages | 035418-8 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | (La2/3Ca1/3MnO3)n/(BaTiO3)m (LCMOn/BTOm) superlattices on MgO and SrTiO3 substrates with different layer thicknesses (n = 10, 38, 40 and m = 5, 18, 20) have been grown by metal organic aerosol deposition (MAD) and have been fully characterized down to the atomic scale to study the interface characteristics. Scanning transmission electron microscopy combined with spatially resolved electron energy-loss spectroscopy provides clear evidence for the existence of atomically sharp interfaces in MAD grown films, which exhibit epitaxial growth conditions, a uniform normal strain, and a fully oxidized state. Below a critical layer thickness the LCMO structure is found to change from the bulk Pnma symmetry to a pseudocubic R3̅ c symmetry. An atomically flat interface reconstruction consisting of a single Ca-rich atomic layer is observed on the compressively strained BTO on LCMO interface, which is thought to partially neutralize the total charge from the alternating polar atomic layers in LCMO as well as relieving strain at the interface. No interface reconstruction is observed at the tensile strained LCMO on BTO interface. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000313940400008 | Publication Date | 2013-01-23 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 12 | Open Access | |
Notes | FWO; Hercules; Countatoms | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:106180 | Serial | 3245 | ||
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Author | Lebedev, O.I.; Verbeeck, J.; Van Tendeloo, G.; Hayashi, N.; Terashima, T.; Takano, M. | ||||
Title | Structure and microstructure of epitaxial SrnFenO3n-1 films | Type | A1 Journal article | ||
Year | 2004 | Publication | Philosophical magazine | Abbreviated Journal | Philos Mag |
Volume | 84 | Issue | 36 | Pages | 3825-3841 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Thin films of SrFeO3-x (0 less than or equal to x less than or equal to 0.5) (SFO) grown on a (LaAlO3)(0.3) (SrAl0.5Ta0.5O3)(0.7) (LSAT) substrate by Pulsed laser deposition have been structurally investigated by electron diffraction and high resolution transmission electron microscopy for different post-deposition oxygen treatments. During the deposition and post-growth oxidation, the oxygen-reduced SFO films accept extra oxygen along the tetrahedral layers to minimize the elastic strain energy. The oxidation process stops at a concentration SFO2.875 and/or SFO2.75 because a zero misfit with the LSAT substrate is reached. A possible growth mechanism and phase transition mechanism are suggested. The non-oxidized films exhibit twin boundaries having a local perovskite-type structure with a nominal composition close to SFO3. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000225854700001 | Publication Date | 2005-01-28 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 1478-6435;1478-6443; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.505 | Times cited | 4 | Open Access | |
Notes | reprint | Approved | Most recent IF: 1.505; 2004 IF: 1.167 | ||
Call Number | UA @ lucian @ c:irua:54755 | Serial | 3287 | ||
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Author | Morozov, V.A.; Arakcheeva, A.V.; Pattison, P.; Meert, K.W.; Smet, P.F.; Poelman, D.; Gauquelin, N.; Verbeeck, J.; Abakumov, A.M.; Hadermann, J. | ||||
Title | KEu(MoO4)2 : polymorphism, structures, and luminescent properties | Type | A1 Journal article | ||
Year | 2015 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
Volume | 27 | Issue | 27 | Pages | 5519-5530 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | In this paper, with the example of two different polymorphs of KEu(MoO4)2, the influence of the ordering of the A-cations on the luminescent properties in scheelite related compounds (A′,A″)n[(B′,B″)O4]m is investigated. The polymorphs were synthesized using a solid state method. The study confirmed the existence of only two polymorphic forms at annealing temperature range 9231203 K and ambient pressure: a low temperature anorthic α-phase and a monoclinic high temperature β-phase with an incommensurately modulated structure. The structures of both polymorphs were solved using transmission electron microscopy and refined from synchrotron powder X-ray diffraction data. The monoclinic β-KEu(MoO4)2 has a (3+1)-dimensional incommensurately modulated structure (superspace group I2/b(αβ0)00, a = 5.52645(4) Å, b = 5.28277(4) Å, c = 11.73797(8) Å, γ = 91.2189(4)o, q = 0.56821(2)a*0.12388(3)b*), whereas the anorthic α-phase is (3+1)-dimensional commensurately modulated (superspace group I1̅(αβγ)0, a = 5.58727(22) Å, b = 5.29188(18)Å, c = 11.7120(4) Å, α = 90.485(3)o, β = 88.074(3)o, γ = 91.0270(23)o, q = 1/2a* + 1/2c*). In both cases the modulation arises due to Eu/K cation ordering at the A site: the formation of a 2-dimensional Eu3+ network is characteristic for the α-phase, while a 3-dimensional Eu3+-framework is observed for the β-phase structure. The luminescent properties of KEu(MoO4)2 samples prepared under different annealing conditions were measured, and the relation between their optical properties and their structures is discussed. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000360323700011 | Publication Date | 2015-07-29 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756;1520-5002; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.466 | Times cited | 26 | Open Access | |
Notes | 278510 Vortex; Fwo G039211n; G004413n ECASJO_; | Approved | Most recent IF: 9.466; 2015 IF: 8.354 | ||
Call Number | c:irua:127244 | Serial | 3537 | ||
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Author | Sankaran, K.J.; Hoang, D.Q.; Srinivasu, K.; Korneychuk, S.; Turner, S.; Drijkoningen, S.; Pobedinskas, P.; Verbeeck, J.; Leou, K.C.; Lin, I.N.; Haenen, K. | ||||
Title | Type | A1 Journal article | |||
Year | 2016 | Publication | Physica status solidi : A : applications and materials science | Abbreviated Journal | Phys Status Solidi A |
Volume | 213 | Issue | 10 | Pages | 2654-2661 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Utilization of Au and nanocrystalline diamond ( NCD) as interlayers noticeably modifies the microstructure and field electron emission ( FEE) properties of hexagonal boron nitride nanowalls ( hBNNWs) grown on Si substrates. The FEE properties of hBNNWs on Au could be turned on at a low turn-on field of 14.3V mu m(-1), attaining FEE current density of 2.58mAcm(-2) and life-time stability of 105 min. Transmission electron microscopy reveals that the Au-interlayer nucleates the hBN directly, preventing the formation of amorphous boron nitride ( aBN) in the interface, resulting in enhanced FEE properties. But Au forms as droplets on the Si substrate forming again aBN at the interface. Conversely, hBNNWs on NCD shows superior in life-time stability of 287 min although it possesses inferior FEE properties in terms of larger turn-on field and lower FEE current density as compared to that of hBNNWs-Au. The uniform and continuous NCD film on Si also circumvents the formation of aBN phases and allows hBN to grow directly on NCD. Incorporation of carbon in hBNNWs from the NCD-interlayer improves the conductivity of hBNNWs, which assists in transporting the electrons efficiently from NCD to hBNNWs that results in better field emission of electrons with high life-time stability. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim | ||||
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Language | Wos | 000388321500017 | Publication Date | 2016-09-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1862-6300 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.775 | Times cited | 5 | Open Access | |
Notes | The authors like to thank the financial support of the Research Foundation Flanders (FWO) via Research Projects G.0456.12 and G.0044.13N, the Methusalem “NANO” network. K. J. Sankaran, P. Pobedinskas, and S. Turner are FWO Postdoctoral Fellows of the Research Foundations Flanders (FWO). | Approved | Most recent IF: 1.775 | ||
Call Number | UA @ lucian @ c:irua:144644UA @ admin @ c:irua:144644 | Serial | 4655 | ||
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Author | Sankaran, K.J.; Duc Quang Hoang; Korneychuk, S.; Kunuku, S.; Thomas, J.P.; Pobedinskas, P.; Drijkoningen, S.; Van Bael, M.K.; D'Haen, J.; Verbeeck, J.; Leou, K.-C.; Leung, K.T.; Lin, I.-N.; Haenen, K. | ||||
Title | Hierarchical hexagonal boron nitride nanowall-diamond nanorod heterostructures with enhanced optoelectronic performance | Type | A1 Journal article | ||
Year | 2016 | Publication | RSC advances | Abbreviated Journal | Rsc Adv |
Volume | 6 | Issue | 93 | Pages | 90338-90346 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | A superior field electron emission (FEE) source made from a hierarchical heterostructure, where two-dimensional hexagonal boron nitride (hBN) nanowalls were coated on one-dimensional diamond nanorods (DNRs), is fabricated using a simple and scalable method. FEE characteristics of hBN-DNR display a low turn-on field of 6.0 V mu m(-1), a high field enhancement factor of 5870 and a high life-time stability of 435 min. Such an enhancement in the FEE properties of hBN-DNR derives from the distinctive material combination, i.e., high aspect ratio of the heterostructure, good electron transport from the DNR to the hBN nanowalls and efficient field emission of electrons from the hBN nanowalls. The prospective application of these heterostructures is further evidenced by enhanced microplasma devices using hBN-DNR as a cathode, in which the threshold voltage was lowered to 350 V, affirming the role of hBN-DNR in the improvement of electron emission. | ||||
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Language | Wos | 000385451800044 | Publication Date | 2016-09-12 | |
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ISSN | 2046-2069 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.108 | Times cited | 8 | Open Access | |
Notes | The authors like to thank the financial support of the Research Foundation Flanders (FWO) via Research Projects G.0456.12 and G.0044.13N, the Methusalem “NANO” network. KJ Sankaran, and P Pobedinskas are Postdoctoral Fellows of the Research Foundation-Flanders (FWO). | Approved | Most recent IF: 3.108 | ||
Call Number | UA @ lucian @ c:irua:144757UA @ admin @ c:irua:144757 | Serial | 4662 | ||
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Author | Drijkoningen, S.; Pobedinskas, P.; Korneychuk, S.; Momot, A.; Balasubramaniam, Y.; Van Bael, M.K.; Turner, S.; Verbeeck, J.; Nesladekt, M.; Haenen, K. | ||||
Title | On the Origin of Diamond Plates Deposited at Low Temperature | Type | A1 Journal article | ||
Year | 2017 | Publication | Crystal growth & design | Abbreviated Journal | Cryst Growth Des |
Volume | 17 | Issue | 8 | Pages | 4306-4314 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The crucial requirement for diamond growth at low temperatures, enabling a wide range of new applications, is a high plasma density at a low gas pressure, which leads to a low thermal load onto sensitive substrate materials. While these conditions are not within reach for resonance cavity plasma systems, linear antenna microwave delivery systems allow the deposition of high quality diamond films at temperatures around 400 degrees C and at pressures below 1 mbar. In this work the codeposition of high quality plates and octahedral diamond grains in nanocrystalline films is reported. In contrast to previous reports claiming the need for high temperatures (T >= 850 degrees C), low temperatures (320 degrees C <= T <= 410 degrees C) were sufficient to deposit diamond plate structures. Cross-sectional high resolution transmission electron microscopy studies show that these plates are faulty cubic diamond terminated by large {111} surface facets with very little sp(2) bonded carbon in the grain boundaries. Raman and electron energy loss spectroscopy studies confirm a high diamond quality, above 93% sp(3) carbon content. Three potential mechanisms, that can account for the initial development of the observed plates rich with stacking faults, and are based on the presence of impurities, are proposed. | ||||
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Language | Wos | 000407089600031 | Publication Date | 2017-06-30 | |
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ISSN | 1528-7483 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.055 | Times cited | 23 | Open Access | Not_Open_Access |
Notes | ; The Research Foundation – Flanders (FWO) is gratefully acknowledged for financial support in the form of the Postdoctoral Fellowships of P.P. and S.T., contract G.0044.13N “Charge ordering” (S.K., J.V.), the Methusalem “Nano” network, and the Hercules-linear antenna and Raman equipment. ; | Approved | Most recent IF: 4.055 | ||
Call Number | UA @ lucian @ c:irua:145735UA @ admin @ c:irua:145735 | Serial | 4746 | ||
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Author | Li, L.; Liao, Z.; Gauquelin, N.; Minh Duc Nguyen; Hueting, R.J.E.; Gravesteijn, D.J.; Lobato, I.; Houwman, E.P.; Lazar, S.; Verbeeck, J.; Koster, G.; Rijnders, G. | ||||
Title | Epitaxial stress-free growth of high crystallinity ferroelectric PbZr0.52Ti0.48O3 on GaN/AlGaN/Si(111) substrate | Type | A1 Journal article | ||
Year | 2018 | Publication | Advanced Materials Interfaces | Abbreviated Journal | Adv Mater Interfaces |
Volume | 5 | Issue | 2 | Pages | 1700921 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('Due to its physical properties gallium-nitride (GaN) is gaining a lot of attention as an emerging semiconductor material in the field of high-power and high-frequency electronics applications. Therefore, the improvement in the performance and/or perhaps even extension in functionality of GaN based devices would be highly desirable. The integration of ferroelectric materials such as lead-zirconate-titanate (PbZrxTi1-xO3) with GaN has a strong potential to offer such an improvement. However, the large lattice mismatch between PZT and GaN makes the epitaxial growth of Pb(Zr1-xTix)O-3 on GaN a formidable challenge. This work discusses a novel strain relaxation mechanism observed when MgO is used as a buffer layer, with thicknesses down to a single unit cell, inducing epitaxial growth of high crystallinity Pb(Zr0.52Ti0.48)O-3 (PZT) thin films. The epitaxial PZT films exhibit good ferroelectric properties, showing great promise for future GaN device applications.')); | ||||
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Language | Wos | 000423173800005 | Publication Date | 2017-11-27 | |
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ISSN | 2196-7350 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.279 | Times cited | 15 | Open Access | Not_Open_Access |
Notes | ; L.L., Z.L.L., and N.G. contributed equally to this work. L.L. acknowledges financial support from Nano Next NL (Grant no. 7B 04). The authors acknowledge NXP for providing the GaN/AlGaN/Si (111) wafer. N.G. acknowledges funding from the Geconcentreerde Onderzoekacties (GOA) project “Solarpaint” of the University of Antwerp and J.V. acknowledges funding from the Research Foundation Flanders (FWO, Belgium) project 42/FA070100/6088 “nieuwe eigenschappen in complexe Oxides.” N.G. acknowledges the EUROTAPES project (FP7-NMP.2011.2.2-1 Grant no. 280432) which partly funded this study. ; | Approved | Most recent IF: 4.279 | ||
Call Number | UA @ lucian @ c:irua:148427UA @ admin @ c:irua:148427 | Serial | 4872 | ||
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Author | Becker, M.; Guzzinati, G.; Béché, A.; Verbeeck, J.; Batelaan, H. | ||||
Title | Asymmetry and non-dispersivity in the Aharonov-Bohm effect | Type | A1 Journal article | ||
Year | 2019 | Publication | Nature communications | Abbreviated Journal | Nat Commun |
Volume | 10 | Issue | 10 | Pages | 1700 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Decades ago, Aharonov and Bohm showed that electrons are affected by electromagnetic potentials in the absence of forces due to fields. Zeilinger's theorem describes this absence of classical force in quantum terms as the “dispersionless” nature of the Aharonov-Bohm effect. Shelankov predicted the presence of a quantum “force” for the same Aharonov-Bohm physical system as elucidated by Berry. Here, we report an experiment designed to test Shelankov's prediction and we provide a theoretical analysis that is intended to elucidate the relation between Shelankov's prediction and Zeilinger's theorem. The experiment consists of the Aharonov-Bohm physical system; free electrons pass a magnetized nanorod and far-field electron diffraction is observed. The diffraction pattern is asymmetric confirming one of Shelankov's predictions and giving indirect experimental evidence for the presence of a quantum “force”. Our theoretical analysis shows that Zeilinger's theorem and Shelankov's result are both special cases of one theorem. | ||||
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Language | Wos | 000464338100011 | Publication Date | 2019-04-12 | |
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ISSN | 2041-1723 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 12.124 | Times cited | 12 | Open Access | OpenAccess |
Notes | ; H.B. would like to thank Michael Berry for bringing the presence of a quantum “force” to our attention. A.B., G.G. and J.V. acknowledge support from the European Research Council under the 7th Framework Program (FP7) ERC Starting Grant 278510 VORTEX. G.G. acknowledges support from the Fonds Wetenschappelijk Onderzoek -Vlaanderen (FWO). M.B. and H.B. acknowledge support by the U.S. National Science Foundation under Grant No. 1602755. ; | Approved | Most recent IF: 12.124 | ||
Call Number | UA @ admin @ c:irua:159341 | Serial | 5241 | ||
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Author | Müller-Caspary, K.; Krause, F.F.; Winkler, F.; Béché, A.; Verbeeck, J.; Van Aert, S.; Rosenauer, A. | ||||
Title | Comparison of first moment STEM with conventional differential phase contrast and the dependence on electron dose | Type | A1 Journal article | ||
Year | 2019 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 203 | Issue | 203 | Pages | 95-104 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | This study addresses the comparison of scanning transmission electron microscopy (STEM) measurements of momentum transfers using the first moment approach and the established method that uses segmented annular detectors. Using an ultrafast pixelated detector to acquire four-dimensional, momentum-resolved STEM signals, both the first moment calculation and the calculation of the differential phase contrast (DPC) signals are done for the same experimental data. In particular, we investigate the ability to correct the segment-based signal to yield a suitable approximation of the first moment for cases beyond the weak phase object approximation. It is found that the measurement of momentum transfers using segmented detectors can approach the first moment measurement as close as 0.13 h/nm in terms of a root mean square (rms) difference in 10 nm thick SrTiO3 for a detector with 16 segments. This amounts to 35% of the rms of the momentum transfers. In addition, we present a statistical analysis of the precision of first moment STEM as a function of dose. For typical experimental settings with recent hardware such as a Medipix3 Merlin camera attached to a probe-corrected STEM, we find that the precision of the measurement of momentum transfers stagnates above certain doses. This means that other instabilities such as specimen drift or scan noise have to be taken into account seriously for measurements that target, e.g., the detection of bonding effects in the charge density. | ||||
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Language | Wos | 000465021000013 | Publication Date | 2018-12-30 | |
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ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.843 | Times cited | 25 | Open Access | OpenAccess |
Notes | ; The direct electron detector (Medipix3 Merlin) was funded by the Hercules fund from the Flemish Government. K. Muller-Caspary acknowledges funding from the Initiative and Network Fund of the Helmholtz Association within the framework of the Helmholtz Young Investigator Group moreSTEM (VH-NG-1317) at Forschungszentrum Julich, Germany. F. F. Krause acknowledges funding from the Central Research Development Fund of the University of Bremen, Germany. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 770887). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) and the Research Fund of the University of Antwerp. ; | Approved | Most recent IF: 2.843 | ||
Call Number | UA @ admin @ c:irua:160213 | Serial | 5242 | ||
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