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Author Psilodimitrakopoulos, S.; Orekhov, A.; Mouchliadis, L.; Jannis, D.; Maragkakis, G.M.; Kourmoulakis, G.; Gauquelin, N.; Kioseoglou, G.; Verbeeck, J.; Stratakis, E. url  doi
openurl 
  Title Optical versus electron diffraction imaging of Twist-angle in 2D transition metal dichalcogenide bilayers Type A1 Journal article
  Year 2021 Publication npj 2D Materials and Applications Abbreviated Journal  
  Volume 5 Issue 1 Pages 77  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000694849200001 Publication Date 2021-09-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2397-7132 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 4 Open Access OpenAccess  
  Notes This research has been co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call European R & T Cooperation-Grant Act of Hellenic Institutions that have successfully participated in Joint Calls for Proposals of European Networks ERA NETS (National project code: GRAPH-EYE T8 Epsilon Rho Alpha 2-00009 and European code: 26632, FLAGERA). L.M., G.Ko. and G.Ki. acknowledge funding by the Hellenic Foundation for Research and Innovation (H.F.R.I.) under the “First Call for H.F.R.I. Research Projects to support Faculty members and Researchers and the procurement of high-cost research equipment grant” (Project No: HFRI-FM17-3034). GKi, S.P. and G.M.M. acknowledge funding from a research co-financed by Greece and the European Union (European Social Fund-ESF) through the Operational Programme “Human Resources Development, Education and Lifelong Learning 2014-2020” in the context of the project “Crystal quality control of two-dimensional materials and their heterostructures via imaging of their non-linear optical properties” (MIS 5050340)“. J.V acknowledges funding from FWO G093417N ('Compressed sensing enabling low dose imaging in transmission electron microscopy') from the Flanders Research Fund, EU. J.V. and N.G. acknowledge funding from the European Union under the Horizon 2020 programme within a contract for Integrating Activities for Advanced Communities No 823717-ESTEEM3. J.V. N.G. and A.O. acknowledge funding through a GOA project ”Solarpaint" of the University of Antwerp. Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:181610 Serial 6877  
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Author Bae, J.; Cichocka, M.O.; Zhang, Y.; Bacsik, Z.; Bals, S.; Zou, X.; Willhammar, T.; Hong, S.B. pdf  url
doi  openurl
  Title Phase transformation behavior of a two-dimensional zeolite Type A1 Journal article
  Year 2019 Publication Angewandte Chemie: international edition in English Abbreviated Journal  
  Volume 58 Issue 30 Pages 10230-10235  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Understanding the molecular-level mechanisms of phase transformation in solids is of fundamental interest for functional materials such as zeolites. Two-dimensional (2D) zeolites, when used as shape-selective catalysts, can offer improved access to the catalytically active sites and a shortened diffusion length in comparison with their 3D analogues. However, few materials are known to maintain both their intralayer microporosity and structure during calcination for organic structure-directing agent (SDA) removal. Herein we report that PST-9, a new 2D zeolite which has been synthesized via the multiple inorganic cation approach and fulfills the requirements for true layered zeolites, can be transformed into the small-pore zeolite EU-12 under its crystallization conditions through the single-layer folding process, but not through the traditional dissolution/recrystallization route. We also show that zeolite crystal growth pathway can differ according to the type of organic SDAs employed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000476452700030 Publication Date 2019-05-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1433-7851; 0570-0833 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 2 Open Access OpenAccess  
  Notes We acknowledge financial support from National Creative Research Initiative Program (2012R1A3A-2048833) through the National Research Foundation of Korea, the National Research Council of Science & Technology (CRC-14-1-KRICT) grant by the Korea government (MSIP), the Swedish Research Council (2017-04321), and the Knut and Alice Wallenberg Foundation (KAW) through the project grant 3DEM-NATUR (2012.0112). T.W. acknowledges an international postdoc grant from the Swedish Research Council (2014-06948). Approved no  
  Call Number UA @ admin @ c:irua:181233 Serial 6878  
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Author Liang, Q.; Yang, D.; Xia, F.; Bai, H.; Peng, H.; Yu, R.; Yan, Y.; He, D.; Cao, S.; Van Tendeloo, G.; Li, G.; Zhang, Q.; Tang, X.; Wu, J. pdf  doi
openurl 
  Title Phase-transformation-induced giant deformation in thermoelectric Ag₂Se semiconductor Type A1 Journal article
  Year 2021 Publication Advanced Functional Materials Abbreviated Journal Adv Funct Mater  
  Volume Issue Pages 2106938  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract In most semiconducting metal chalcogenides, a large deformation is usually accompanied by a phase transformation, while the deformation mechanism remains largely unexplored. Herein, a phase-transformation-induced deformation in Ag2Se is investigated by in situ transmission electron microscopy, and a new ordered high-temperature phase (named as alpha '-Ag2Se) is identified. The Se-Se bonds are folded when the Ag+-ion vacancies are ordered and become stretched when these vacancies are disordered. Such a stretch/fold of the Se-Se bonds enables a fast and large deformation occurring during the phase transition. Meanwhile, the different Se-Se bonding states in alpha-, alpha '-, beta-Ag2Se phases lead to the formation of a large number of nanoslabs and the high concentration of dislocations at the interface, which flexibly accommodate the strain caused by the phase transformation. This study reveals the atomic mechanism of the deformation in Ag2Se inorganic semiconductors during the phase transition, which also provides inspiration for understanding the phase transition process in other functional materials.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000695142800001 Publication Date 2021-09-13  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1616-301x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 12.124 Times cited Open Access Not_Open_Access  
  Notes Approved Most recent IF: 12.124  
  Call Number UA @ admin @ c:irua:181527 Serial 6879  
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Author Zhou, X.-G.; Yang, C.-Q.; Sang, X.; Li, W.; Wang, L.; Yin, Z.-W.; Han, J.-R.; Li, Y.; Ke, X.; Hu, Z.-Y.; Cheng, Y.-B.; Van Tendeloo, G. pdf  doi
openurl 
  Title Probing the electron beam-induced structural evolution of halide perovskite thin films by scanning transmission electron microscopy Type A1 Journal article
  Year 2021 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C  
  Volume 125 Issue 19 Pages 10786-10794  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract A deep understanding of the fine structure at the atomic scale of halide perovskite materials has been limited by their sensitivity to the electron beam that is widely used for structural characterization. The sensitivity of a gamma-CsPbIBr2 perovskite thin film under electron beam irradiation is revealed by scanning transmission electron microscopy (STEM) through a universal large-range electron dose measurement, which is based on discrete single-electron events in the STEM mode. Our research indicates that the gamma-CsPbIBr2 thin film undergoes structural changes with increasing electron overall dose (e(-).A(-2)) rather than dose rate (e(-).A(-2).s(-1)), which suggests that overall dose is the key operative parameter. The electron beam-induced structural evolution of gamma-CsPbIBr2 is monitored by fine control of the electron beam dose, together with the analysis of high-resolution (S)TEM, diffraction, and energy-dispersive X-ray spectroscopy. Our results show that the gamma-CsPbIBr2 phase first forms an intermediate phase [e.g., CsPb(1-x)(IBr)((3-y))] with a superstructure of ordered vacancies in the pristine unit cell, while a fraction of Pb2+ is reduced to Pb-0. As the electron dose increases, Pb nanoparticles precipitate, while the remaining framework forms the Cs2IBr phase, accompanied by some amorphization. This work provides guidelines to minimize electron beam irradiation artifacts for atomic-resolution imaging on CsPbIBr2 thin films.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000655640900061 Publication Date 2021-05-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited Open Access Not_Open_Access  
  Notes Approved Most recent IF: 4.536  
  Call Number UA @ admin @ c:irua:179187 Serial 6880  
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Author Samaeeaghmiyoni, V.; Cordier, P.; Demouchy, S.; Bollinger, C.; Gasc, J.; Mussi, A.; Schryvers, D.; Idrissi, H. doi  openurl
  Title Research data supporting for Stress-induced amorphization triggers deformation in the lithospheric mantle Type Dataset
  Year 2020 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords Dataset; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:180668 Serial 6881  
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Author Baral, P.; Orekhov, A.; Dohmen, R.; Coulombier, M.; Raskin, J.P.; Cordier, P.; Idrissi, H.; Pardoen, T. url  doi
openurl 
  Title Rheology of amorphous olivine thin films characterized by nanoindentation Type A1 Journal article
  Year 2021 Publication Acta Materialia Abbreviated Journal Acta Mater  
  Volume 219 Issue Pages 117257  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The rheological properties of amorphous olivine thin films deposited by pulsed laser deposition have been studied based on ambient temperature nanoindentation under constant strain-rate as well as re-laxation conditions. The amorphous olivine films exhibit a viscoelastic-viscoplastic behavior with a significant rate dependency. The strain-rate sensitivity m is equal to similar to 0 . 05 which is very high for silicates, indicating a complex out-of-equilibrium structure. The minimum apparent activation volume determined from nanoindentation experiments corresponds to Mg and Fe atomic metallic sites in the (Mg,Fe)(2)SiO4 crystalline lattice. The ambient temperature creep behavior of the amorphous olivine films differs very much from the one of single crystal olivine. This behavior directly connects to the recent demonstration of the activation of grain boundary sliding in polycrystalline olivine following grain boundary amorphization under high-stress. (C) 2021 The Authors. Published by Elsevier Ltd on behalf of Acta Materialia Inc.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000706867800004 Publication Date 2021-08-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1359-6454 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 5.301 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 5.301  
  Call Number UA @ admin @ c:irua:182592 Serial 6882  
Permanent link to this record
 

 
Author Guzzinati, G.; Béché, A.; McGrouther, D.; Verbeeck, J. doi  openurl
  Title Rotation of electron beams in the presence of localised, longitudinal magnetic fields Type Dataset
  Year 2019 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords Dataset; Electron microscopy for materials research (EMAT)  
  Abstract Electron Bessel beams have been generated by inserting an annular aperture in the illumination system of a TEM. These beams have passed through a localised magnetic field. As a result a low amount of image rotation (which is expected to be proportional to the longitudinal component of the magnetic field) is observed in the far field. A measure of this rotation should give access to the magneti field. The two datasets have been acquired in a FEI Titan3 microscope, operated at 300kV. The file focalseries.tif contains a series of images acquired varying the magnetic field through the objective lens. The file lineprofile.ser contains a series of images acquired by scanning the beam over a sample with several magnetised nanopillars. For reference, check the associated publication.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:169135 Serial 6883  
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Author Yang, M.; Orekhov, A.; Hu, Z.-Y.; Feng, M.; Jin, S.; Sha, G.; Li, K.; Samaee, V.; Song, M.; Du, Y.; Van Tendeloo, G.; Schryvers, D. pdf  url
doi  openurl
  Title Shearing and rotation of β'' and β' precipitates in an Al-Mg-Si alloy under tensile deformation : in-situ and ex-situ studies Type A1 Journal article
  Year 2021 Publication Acta Materialia Abbreviated Journal Acta Mater  
  Volume 220 Issue Pages 117310  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The interaction between dislocations and nano-precipitates during deformation directly influences hardening response of precipitation-strengthening metals such as Al-Mg-Si alloys. However, how coherent and semi-coherent nano-precipitates accommodate external deformation applied to an Al alloy remains to be elucidated. In-situ tensile experiments in a transmission electron microscope (TEM) were conducted to study the dynamic process of dislocations cutting through coherent needle-like beta '' precipitates with diameters of 3 similar to 8 nm. Comprehensive investigations using in-situ, ex-situ TEM and atom probe tomography uncovered that beta '' precipitates were firstly sheared into small fragments, and then the rotation of the fragments, via sliding along precipitate/matrix interfaces, destroyed their initially coherent interface with the Al matrix. In contrast, semi-coherent beta' precipitates with sizes similar to beta '' were more difficult to be fragmented and accumulation of dislocations at the interface increased interface misfit between beta' and the Al matrix. Consequently, beta' precipitates could basically maintain their needle-like shape after the tensile deformation. This research gains new insights into the interaction between nano-precipitates and dislocations. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000705535300005 Publication Date 2021-09-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1359-6454 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 5.301 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 5.301  
  Call Number UA @ admin @ c:irua:182528 Serial 6884  
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Author Wang, L.; Li, Y.; Yang, X.-Y.; Zhang, B.-B.; Ninane, N.; Busscher, H.J.; Hu, Z.-Y.; Delneuville, C.; Jiang, N.; Xie, H.; Van Tendeloo, G.; Hasan, T.; Su, B.-L. url  doi
openurl 
  Title Single-cell yolk-shell nanoencapsulation for long-term viability with size-dependent permeability and molecular recognition Type A1 Journal article
  Year 2021 Publication National Science Review Abbreviated Journal Natl Sci Rev  
  Volume 8 Issue 4 Pages  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Like nanomaterials, bacteria have been unknowingly used for centuries. They hold significant economic potential for fuel and medicinal compound production. Their full exploitation, however, is impeded by low biological activity and stability in industrial reactors. Though cellular encapsulation addresses these limitations, cell survival is usually compromised due to shell-to-cell contacts and low permeability. Here, we report ordered packing of silica nanocolloids with organized, uniform and tunable nanoporosities for single cyanobacterium nanoencapsulation using protamine as an electrostatic template. A space between the capsule shell and the cell is created by controlled internalization of protamine, resulting in a highly ordered porous shell-void-cell structure formation. These unique yolk-shell nano structures provide long-term cell viability with superior photosynthetic activities and resistance in harsh environments. In addition, engineering the colloidal packing allows tunable shell-pore diameter for size-dependent permeability and introduction of new functionalities for specific molecular recognition. Our strategy could significantly enhance the activity and stability of cyanobacteria for various nanobiotechnological applications.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000651827200002 Publication Date 2020-05-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2095-5138 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.843 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 8.843  
  Call Number UA @ admin @ c:irua:179085 Serial 6885  
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Author Zhao, H.; Li, C.-F.; Hu, Z.-Y.; Liu, J.; Li, Y.; Hu, J.; Van Tendeloo, G.; Chen, L.-H.; Su, B.-L. pdf  doi
openurl 
  Title Size effect of bifunctional gold in hierarchical titanium oxide-gold-cadmium sulfide with slow photon effect for unprecedented visible-light hydrogen production Type A1 Journal article
  Year 2021 Publication Journal Of Colloid And Interface Science Abbreviated Journal J Colloid Interf Sci  
  Volume 604 Issue Pages 131-139  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Gold nanoparticles (Au NPs) with surface plasmonic resonance (SPR) effect and excellent internal electron transfer ability have widely been combined with semiconductors for photocatalysis. However, the in-depth effects of Au NPs in multicomponent photocatalysts have not been completely understood. Herein, ternary titanium oxide-gold-cadmium sulfide (TiO2-Au-CdS, TAC) photocatalysts, based on hierarchical TiO2 inverse opal photonic crystal structure with different Au NPs sizes have been designed to reveal the SPR effect and internal electron transfer of Au NPs in the presence of slow photon effect. It appears that the SPR effect and internal electron transfer ability of Au NPs, depending on their sizes, play a synergistic effect on the photocatalytic enhancement. The ternary TAC-10 photocatalyst with – 10 nm Au NPs demonstrates an unprecedented hydrogen evolution rate of 47.6 mmolh-1g 1 under visible-light, demonstrating- 48% enhancement comparing to the sample without slow photon effect. In particular, a 9.83% apparent quantum yield under 450 nm monochromatic light is achieved for TAC-10. A model is proposed and finite-difference time-domain (FDTD) simulations reveal the size influence of Au NPs in ternary TAC photocatalysts. This work suggests that the rational design of bifunctional Au NPs coupling with slow photon effect could largely promote hydrogen production from visible-light driven water splitting. (c) 2021 Elsevier Inc. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000704428600004 Publication Date 2021-07-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-9797 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.233 Times cited Open Access Not_Open_Access  
  Notes Approved Most recent IF: 4.233  
  Call Number UA @ admin @ c:irua:182531 Serial 6886  
Permanent link to this record
 

 
Author Jannis, D.; Müller-Caspary, K.; Béché, A.; Oelsner, A.; Verbeeck, J. doi  openurl
  Title Spectrocopic coincidence experiment in transmission electron microscopy Type Dataset
  Year 2019 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords Dataset; Electron microscopy for materials research (EMAT)  
  Abstract This dataset contains individual EEL and EDX events where for every event (electron or X-ray), their energy and time of arrival is stored. The experiment was performed in a transmission electron microscope (Tecnai Osiris) at 200 keV. The material investigated is an Al-Mg-Si-Cu alloy. The 'full_dataset.mat' contains the full dataset and the 'subset.mat' has the first five frames of the full dataset. The attached 'EELS-EDX.ipynb' is a jupyter notebook file. This file describes the data processing in order to observe the temporal correlation between the electrons and X-rays.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:169112 Serial 6888  
Permanent link to this record
 

 
Author Bouwmeester, R.L.; de Hond, K.; Gauquelin, N.; Verbeeck, J.; Koster, G.; Brinkman, A. pdf  url
doi  openurl
  Title Stabilization of the perovskite phase in the Y-Bi-O system by using a BaBiO₃ buffer layer Type A1 Journal article
  Year 2019 Publication Physica status solidi: rapid research letters Abbreviated Journal  
  Volume 13 Issue 7 Pages 1800679  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A topological insulating phase has theoretically been predicted for the thermodynamically unstable perovskite phase of YBiO3. Here, it is shown that the crystal structure of the Y-Bi-O system can be controlled by using a BaBiO3 buffer layer. The BaBiO3 film overcomes the large lattice mismatch of 12% with the SrTiO3 substrate by forming a rocksalt structure in between the two perovskite structures. Depositing an YBiO3 film directly on a SrTiO3 substrate gives a fluorite structure. However, when the Y-Bi-O system is deposited on top of the buffer layer with the correct crystal phase and comparable lattice constant, a single oriented perovskite structure with the expected lattice constants is observed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000477671800005 Publication Date 2019-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1862-6254 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 11 Open Access  
  Notes The work at the University of Twente is financially supported by NWO through a VICI grant. N.G. and J.V. acknowledge financial support from the GOA project “Solarpaint” of the University of Antwerp. The microscope used for this experiment has been partially financed by the Hercules Fund from the Flemish Government. L. Ding is acknowledge for his help with the GPA analysis. Approved no  
  Call Number UA @ admin @ c:irua:181236 Serial 6889  
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Author Barbiellini, B.; Kuriplach, J.; Saniz, R. url  doi
openurl 
  Title Study of rechargeable batteries using advanced spectroscopic and computational techniques Type Editorial
  Year 2021 Publication Condensed Matter Abbreviated Journal  
  Volume 6 Issue 3 Pages 26  
  Keywords Editorial; Electron microscopy for materials research (EMAT)  
  Abstract Improving the efficiency and longevity of energy storage systems based on Li- and Na-ion rechargeable batteries presents a major challenge. The main problems are essentially capacity loss and limited cyclability. These effects are due to a hierarchy of factors spanning various length and time scales, interconnected in a complex manner. As a consequence, and in spite of several decades of research, a proper understanding of the ageing process has remained somewhat elusive. In recent years, however, combinations of advanced spectroscopy techniques and first-principles simulations have been applied with success to tackle this problem. In this Special Issue, we are pleased to present a selection of articles that, by precisely applying these methods, unravel key aspects of the reduction-oxidation reaction and intercalation processes. Furthermore, the approaches presented provide improvements to standard diagnostic and characterisation techniques, enabling the detection of possible Li-ion flow bottlenecks causing the degradation of capacity and cyclability.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000699368400001 Publication Date 2021-07-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2410-3896 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:181630 Serial 6890  
Permanent link to this record
 

 
Author Idrissi, H.; Samaee, V.; Lumbeeck, G.; van der Werf, T.; Pardoen, T.; Schryvers, D.; Cordier, P. doi  openurl
  Title Supporting data for “In situ Quantitative Tensile Tests on Antigorite in a Transmission Electron Microscope” Type Dataset
  Year 2019 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords Dataset; Electron microscopy for materials research (EMAT)  
  Abstract The determination of the mechanical properties of serpentinites is essential towards the understanding of the mechanics of faulting and subduction. Here, we present the first in situ tensile tests on antigorite in a transmission electron microscope. A push-to-pull deformation device is used to perform quantitative tensile tests, during which force and displacement are measured, while the microstructure is imaged with the microscope. The experiments have been performed at room temperature on beams prepared by focused ion beam. The specimens are not single crystals despite their small sizes. Orientation mapping indicated that some grains were well-oriented for plastic slip. However, no dislocation activity has been observed even though engineering tensile stress went up to 700 MPa. We show also that antigorite does not exhibit an pure elastic-brittle behaviour since, despite the presence of defects, the specimens underwent plastic deformation and did not fail within the elastic regime. Instead, we observe that strain localizes at grain boundaries. All observations concur to show that under our experimental conditions, grain boundary sliding is the dominant deformation mechanism. This study sheds a new light on the mechanical properties of antigorite and calls for further studies on the structure and properties of grain boundaries in antigorite and more generally in phyllosilicates.  
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  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:169107 Serial 6891  
Permanent link to this record
 

 
Author Penders, A.; Konstantinovic, M.J.; Van Renterghem, W.; Bosch, R.W.; Schryvers, D. url  doi
openurl 
  Title TEM investigation of SCC crack tips in high Si stainless steel tapered specimens Type A1 Journal article
  Year 2021 Publication Corrosion Engineering Science And Technology Abbreviated Journal Corros Eng Sci Techn  
  Volume Issue Pages  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The stress corrosion cracking (SCC) mechanism is investigated in high Si duplex stainless steel in a simulated PWR environment based on TEM analysis of FIB-extracted SCC crack tips. The microstructural investigation in the near vicinity of SCC crack tips illustrates a strain-rate dependence in SCC mechanisms. Detailed analysis of the crack tip morphology, that includes crack tip oxidation and surrounding deformation field, indicates the existence of an interplay between corrosion- and deformation-driven failure as a function of the strain rate. Slow strain-rate crack tips exhibit a narrow cleavage failure which can be linked to the film-induced failure mechanism, while rounded shaped crack tips for faster strain rates could be related to the strain-induced failure. As a result, two nominal strain-rate-dependent failure regimes dominated either by corrosion or deformation-driven cracking mechanisms can be distinguished.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000695956400001 Publication Date 2021-09-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1478-422x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 0.879 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 0.879  
  Call Number UA @ admin @ c:irua:181533 Serial 6892  
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Author Mallick, S.; Khalsa, G.; Kaaret, J.Z.; Zhang, W.; Batuk, M.; Gibbs, A.S.; Hadermann, J.; Halasyamani, P.S.; Benedek, N.A.; Hayward, M.A. url  doi
openurl 
  Title The influence of the 6s² configuration of Bi³+ on the structures of A ' BiNb₂O₇ (A ' = Rb, Na, Li) layered perovskite oxides Type A1 Journal article
  Year 2021 Publication Journal of the Chemical Society : Dalton transactions Abbreviated Journal  
  Volume 50 Issue 42 Pages 15359-15369  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Solid state compounds which exhibit non-centrosymmetric crystal structures are of great interest due to the physical properties they can exhibit. The 'hybrid improper' mechanism – in which two non-polar distortion modes couple to, and stabilize, a further polar distortion mode, yielding an acentric crystal structure – offers opportunities to prepare a range of novel non-centrosymmetric solids, but examples of compounds exhibiting acentric crystal structures stabilized by this mechanism are still relatively rare. Here we describe a series of bismuth-containing layered perovskite oxide phases, RbBiNb2O7, LiBiNb2O7 and NaBiNb2O7, which have structural frameworks compatible with hybrid-improper ferroelectricity, but also contain Bi3+ cations which are often observed to stabilize acentric crystal structures due to their 6s(2) electronic configurations. Neutron powder diffraction analysis reveals that RbBiNb2O7 and LiBiNb2O7 adopt polar crystal structures (space groups I2cm and B2cm respectively), compatible with stabilization by a trilinear coupling of non-polar and polar modes. The Bi3+ cations present are observed to enhance the magnitude of the polar distortions of these phases, but are not the primary driver for the acentric structure, as evidenced by the observation that replacing the Bi3+ cations with Nd3+ cations does not change the structural symmetry of the compounds. In contrast the non-centrosymmetric, but non-polar structure of NaBiNb2O7 (space group P2(1)2(1)2(1)) differs significantly from the centrosymmetric structure of NaNdNb2O7, which is attributed to a second-order Jahn-Teller distortion associated with the presence of the Bi3+ cations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000706651100001 Publication Date 2021-10-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1477-9234 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:182584 Serial 6893  
Permanent link to this record
 

 
Author Lezaack, M.B.; Hannard, F.; Zhao, L.; Orekhov, A.; Adrien, J.; Miettinen, A.; Idrissi, H.; Simar, A. pdf  doi
openurl 
  Title Towards ductilization of high strength 7XXX aluminium alloys via microstructural modifications obtained by friction stir processing and heat treatments Type A1 Journal article
  Year 2021 Publication Materialia Abbreviated Journal  
  Volume 20 Issue Pages 101248  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract High strength 7XXX aluminium series reach exceptional strength, higher than all other industrial aluminium alloys. However, they suffer from a lack of ductility compared to softer series. This work presents a procedure to improve the ductility of 7475 Al alloy in high strength condition, reaching a true fracture strain of 70% at full 500 MPa T6 yield strength. Using friction stir processing (FSP) and post-FSP heat treatments, 100% of industrial rolled material T6 yield stress is maintained but a 180% increase in fracture strain is measured for the processed material. This ductility improvement is studied by in-situ synchrotron X-ray tomography and is explained by the reduction of intermetallic particles size and the homogenization of their spatial distribution. Furthermore, the microstructure after FSP shows equiaxed refined grains which favour crack deviation as opposed to large cracks parallel to the elongated coarse grains in rolled plate. These results are paving the way to better formability and crashworthiness of 7XXX alloys.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000718127100006 Publication Date 2021-10-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2589-1529 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:184145 Serial 6894  
Permanent link to this record
 

 
Author Lavor, I.R.; da Costa, D.R.; Covaci, L.; Milošević, M.V.; Peeters, F.M.; Chaves, A. url  doi
openurl 
  Title Zitterbewegung of moiré excitons in twisted MoS₂/WSe₂ heterobilayers Type A1 Journal article
  Year 2021 Publication Physical review letters Abbreviated Journal  
  Volume 127 Issue 10 Pages 106801  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract The moire pattern observed in stacked noncommensurate crystal lattices, such as heterobilayers of transition metal dichalcogenides, produces a periodic modulation of their band gap. Excitons subjected to this potential landscape exhibit a band structure that gives rise to a quasiparticle dubbed the moire exciton. In the case of MoS2/WSe2 heterobilayers, the moire trapping potential has honeycomb symmetry and, consequently, the moire exciton band structure is the same as that of a Dirac-Weyl fermion, whose mass can be further tuned down to zero with a perpendicularly applied field. Here we show that, analogously to other Dirac-like particles, the moire exciton exhibits a trembling motion, also known as Zitterbewegung, whose long timescales are compatible with current experimental techniques for exciton dynamics. This promotes the study of the dynamics of moire excitons in van der Waals heterostructures as an advantageous solid-state platform to probe Zitterbewegung, broadly tunable by gating and interlayer twist angle.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000692200800020 Publication Date 2021-08-31  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1079-7114 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 4 Open Access OpenAccess  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:181599 Serial 6896  
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Author Meng, X.; Chen, S.; Peng, H.; Bai, H.; Zhang, S.; Su, X.; Tan, G.; Van Tendeloo, G.; Sun, Z.; Zhang, Q.; Tang, X.; Wu, J. pdf  doi
openurl 
  Title Ferroelectric engineering : enhanced thermoelectric performance by local structural heterogeneity Type A1 Journal article
  Year 2022 Publication Science China : materials Abbreviated Journal Sci China Mater  
  Volume Issue Pages  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Although traditional ferroelectric materials are usually dielectric and nonconductive, GeTe is a typical ferroelectric semiconductor, possessing both ferroelectric and semiconducting properties. GeTe is also a widely studied thermoelectric material, whose performance has been optimized by doping with various elements. However, the impact of the ferroelectric domains on the thermoelectric properties remains unclear due to the difficulty to directly observe the ferroelectric domains and their evolutions under actual working conditions where the material is exposed to high temperatures and electric currents. Herein, based on in-situ investigations of the ferroelectric domains and domain walls in both pure and Sb-doped GeTe crystals, we have been able to analyze the dynamic evolution of the ferroelectric domains and domain walls, exposed to an electric field and temperature. Local structural heterogeneities and nano-sized ferroelectric domains are generated due to the interplay of the Sb3+ dopant and the Ge-vacancies, leading to the increased number of charged domain walls and a much improved thermoelectric performance. This work reveals the fundamental mechanism of ferroelectric thermoelectrics and provides insights into the decoupling of previously interdependent properties such as thermo-power and electrical conductivity.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000749973500001 Publication Date 2022-02-02  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2095-8226; 2199-4501 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.1 Times cited Open Access Not_Open_Access  
  Notes Approved Most recent IF: 8.1  
  Call Number UA @ admin @ c:irua:186429 Serial 6959  
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Author Lu, W.; Cui, W.; Zhao, W.; Lin, W.; Liu, C.; Van Tendeloo, G.; Sang, X.; Zhao, W.; Zhang, Q. pdf  doi
openurl 
  Title In situ atomistic insight into magnetic metal diffusion across Bi0.5Sb1.5Te3 quintuple layers Type A1 Journal article
  Year 2022 Publication Advanced Materials Interfaces Abbreviated Journal Adv Mater Interfaces  
  Volume Issue Pages 2102161  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Diffusion and occupancy of magnetic atoms in van der Waals (VDW) layered materials have significant impact on applications such as energy storage, thermoelectrics, catalysis, and topological phenomena. However, due to the weak VDW bonding, most research focus on in-plane diffusion within the VDW gap, while out-of-plane diffusion has rarely been reported. Here, to investigate out-of-plane diffusion in VDW-layered Bi2Te3-based alloys, a Ni/Bi0.5Sb1.5Te3 heterointerface is synthesized by depositing magnetic Ni metal on a mechanically exfoliated Bi0.5Sb1.5Te3 (0001) substrate. Diffusion of Ni atoms across the Bi0.5Sb1.5Te3 quintuple layers is directly observed at elevated temperatures using spherical-aberration-corrected scanning transmission electron microscopy (STEM). Density functional theory calculations demonstrate that the diffusion energy barrier of Ni atoms is only 0.31-0.45 eV when they diffuse through Te-3(Bi, Sb)(3) octahedron chains. Atomic-resolution in situ STEM reveals that the distortion of the Te-3(Bi, Sb)(3) octahedron, induced by the Ni occupancy, drives the formation of coherent NiM (M = Bi, Sb, Te) at the heterointerfaces. This work can lead to new strategies to design novel thermoelectric and topological materials by introducing magnetic dopants to VDW-layered materials.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000751742300001 Publication Date 2022-02-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2196-7350 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 5.4 Times cited Open Access Not_Open_Access  
  Notes Approved Most recent IF: 5.4  
  Call Number UA @ admin @ c:irua:186421 Serial 6960  
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Author Sun, C.; Liao, X.; Peng, H.; Zhang, C.; Van Tendeloo, G.; Zhao, Y.; Wu, J. url  doi
openurl 
  Title Interfacial gliding-driven lattice oxygen release in layered cathodes Type A1 Journal article
  Year 2022 Publication Cell reports physical science Abbreviated Journal  
  Volume 3 Issue 1 Pages  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The oxygen release of layered cathodes causes many battery failures, but the underlying mechanism in an actual working cathode is still elusive as it involves secondary agglomerates that introduce complicated boundary structures. Here, we report a general structure instability on the mismatch boundaries driven by interfacial gliding-it introduces a shear stress causing a distortion of the metal-oxygen octahedra framework that reduces its kinetic stability. The migration of cations and diffusion of oxygen vacancies continue to degrade the whole particle from the boundary to the interior, followed by the formation of nano-sized cracks on the fast-degrading interfaces. This work reveals a robust chemical and mechanical interplay on the oxygen release inherent to the intergranular boundaries of layered cathodes. It also suggests that radially patterned columnar grains with low-angle planar boundaries would be an efficient approach to mitigate the boundary oxygen release.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000745659500012 Publication Date 2021-12-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:186420 Serial 6961  
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Author Missen, O.P.; Mills, S.J.; Canossa, S.; Hadermann, J.; Nenert, G.; Weil, M.; Libowitzky, E.; Housley, R.M.; Artner, W.; Kampf, A.R.; Rumsey, M.S.; Spratt, J.; Momma, K.; Dunstan, M.A. url  doi
openurl 
  Title Polytypism in mcalpineite : a study of natural and synthetic Cu₃TeO₆ Type A1 Journal article
  Year 2022 Publication Acta Crystallographica. Section B: Structural Science, Crystal Engineering and Materials (Online) Abbreviated Journal Acta Crystallogr B  
  Volume 78 Issue 1 Pages  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Synthetic and naturally occurring forms of tricopper orthotellurate, (Cu3TeO6)-Te-II-O-IV (the mineral mcalpineite) have been investigated by 3D electron diffraction (3D ED), X-ray powder diffraction (XRPD), Raman and infrared (IR) spectroscopic measurements. As a result of the diffraction analyses, (Cu3TeO6)-Te-II-O-IV is shown to occur in two polytypes. The higher-symmetric (Cu3TeO6)-Te-II-O-IV-1C polytype is cubic, space group 1a (3) over bar, with a = 9.537 (1) angstrom and V = 867.4 (3) angstrom(3) as reported in previous studies. The 1C polytype is a well characterized structure consisting of alternating layers of (CuO6)-O-II octahedra and both (CuO6)-O-II and (TeO6)-O-VI octahedra in a patchwork arrangement. The structure of the lower-symmetric orthorhombic (Cu3TeO6)-Te-II-O-IV-2O polytype was determined for the first time in this study by 3D ED and verified by Rietveld refinement. The 2O polytype crystallizes in space group Pcca, with a = 9.745 (3) angstrom, b = 9.749 (2) angstrom, c = 9.771 (2) angstrom and V = 928.3 (4) angstrom(3) . High-precision XRPD data were also collected on (Cu3TeO6)-Te-II-O-IV-2O to verify the lower-symmetric structure by performing a Rietveld refinement. The resultant structure is identical to that determined by 3D ED, with unit-cell parameters a = 9.56157 (19) angstrom, b = 9.55853 (11) angstrom, c = 9.62891 (15) angstrom and V = 880.03 (2) angstrom(3) . The lower symmetry of the 2O polytype is a consequence of a different cation ordering arrangement, which involves the movement of every second (CuO6)-O-II and (TeO6)-O-VI octahedral layer by (1/4, 1/4, 0), leading to an offset of (TeO6)-O-VI and (CuO6)-O-II octahedra in every second layer giving an ABAB* stacking arrangement. Syntheses of (Cu3TeO6)-Te-II-O-IV showed that low-temperature (473 K) hydrothermal conditions generally produce the 2O polytype. XRPD measurements in combination with Raman spectroscopic analysis showed that most natural mcalpineite is the orthorhombic 2O polytype. Both XRPD and Raman spectroscopy measurements may be used to differentiate between the two polytypes of (Cu3TeO6)-Te-II-O-IV. In Raman spectroscopy, (Cu3TeO6)-Te-II-O-IV-1C has a single strong band around 730 cm(-1), whereas (Cu3TeO6)-Te-II-O-IV-2O shows a broad double maximum with bands centred around 692 and 742 cm(-1).  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000752899700003 Publication Date 2022-01-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2052-5206 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.9 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 1.9  
  Call Number UA @ admin @ c:irua:186529 Serial 6962  
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Author Charalampopoulou, E.; Lambrinou, K.; Van der Donck, T.; Paladino, B.; Di Fonzo, F.; Azina, C.; Eklund, P.; Mraz, S.; Schneider, J.M.; Schryvers, D.; Delville, R. pdf  url
doi  openurl
  Title Early stages of dissolution corrosion in 316L and DIN 1.4970 austenitic stainless steels with and without anticorrosion coatings in static liquid lead-bismuth eutectic (LBE) at 500 degrees C Type A1 Journal article
  Year 2021 Publication Materials Characterization Abbreviated Journal Mater Charact  
  Volume 178 Issue Pages 111234  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract This work addresses the early stages (<= 1000 h) of the dissolution corrosion behavior of 316L and DIN 1.4970 austenitic stainless steels in contact with oxygen-poor (C-O < 10(-8) mass%), static liquid lead-bismuth eutectic (LBE) at 500 degrees C for 600-1000 h. The objective of this study was to determine the relative early-stage resistance of the uncoated steels to dissolution corrosion and to assess the protectiveness of select candidate coatings (Cr2AlC, Al2O3, V2AlxCy). The simultaneous exposure of steels with intended differences in microstructure and thermomechanical state showed the effects of steel grain size, density of annealing/deformation twins, and secondary precipitates on the steel dissolution corrosion behavior. The findings of this study provide recommendations on steel manufacturing with the aim of using the steels to construct Gen-IV lead-cooled fast reactors.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000752582700001 Publication Date 2021-06-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.714 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 2.714  
  Call Number UA @ admin @ c:irua:186509 Serial 7061  
Permanent link to this record
 

 
Author Arslan Irmak, E. url  openurl
  Title Modelling three-dimensional nanoparticle transformations based on quantitative transmission electron microscopy Type Doctoral thesis
  Year 2022 Publication Abbreviated Journal  
  Volume Issue Pages 169 p.  
  Keywords Doctoral thesis; Electron microscopy for materials research (EMAT)  
  Abstract Nanomaterials are materials that have at least one dimension in the nanometer length scale, which corresponds to a billionth of a meter. When three dimensions are confined to the nanometer scale, these materials are referred to as nanoparticles. These materials are of great interest since they exhibit unique physical and chemical properties that cannot be observed for bulk systems. Due to their unique and often superior properties, nanomaterials have become central in the field of electronics, catalysis, and medicine. Moreover, they are expected to be one of the most promising systems to tackle many challenges that our society is facing, such as reducing the emission of greenhouse gases and finding effective treatments for cancer. The unique properties of nanomaterials are linked to their size, shape, structure, and composition. If one is able to measure the positions of the atoms, their chemical nature, and the bonding between them, it becomes possible to predict the physicochemical properties of nanomaterials. In this manner, the development of novel nanostructures can be triggered. However, the morphology and structure of nanomaterials are highly sensitive to the conditions for relevant applications, such as elevated temperatures or intense light illumination. Furthermore, any small change in the local structure at higher temperatures or pressures may significantly modify their performance. Hence, three-dimensional (3D) characterization of nanomaterials under application-relevant conditions is important in designing them with desired functional properties for specific applications. Among different structural characterization approaches, transmission electron microscopy (TEM) is one of the most efficient and versatile tools to investigate the structure and composition of nanomaterials since it can provide atomically resolved images, which are sensitive to the local 3D structure of the investigated sample. However, TEM only provides two-dimensional (2D) images of the 3D nanoparticle, which may lead to an incomplete understanding of their structure-property relationship. The most known and powerful technique for the 3D characterization of nanomaterials is electron tomography, where the images of a nanostructured material taken from different directions are mathematically combined to retrieve its 3D structure. Although these experiments are already state-of-the-art, 3D characterization by TEM is typically performed under ultra-high vacuum conditions and at room temperature. Such conditions are unfortunately not sufficient to understand transformations during synthesis or applications of nanomaterials. This limitation can be overcome by in situ TEM where external stimuli, such as heat, gas, and liquids, can be controllably introduced inside the TEM using specialized holders. However, there are some technical limitations to successful perform 3D in situ electron tomography experiments. For example, the long acquisition time required to collect a tilt series limits this technique when one wants to observe 3D dynamic changes with atomic resolution. A solution for this problem is the estimation of the 3D structure of nanomaterials from 2D projection images acquired along a single viewing direction. For this purpose, annular dark field scanning TEM (ADF STEM) imaging mode provides a valuable tool for quantitative structural investigation of nanomaterials from single 2D images due to its thickness and mass sensitivity. For quantitative analysis, an ADF STEM image is considered as a 2D array of pixels where relative variation of pixel intensity values is proportional to the total number of atoms and the atomic number of the elements in the sample. By applying advanced statistical approaches to these images, structural information, such as the number or types of atoms, can be retrieved with high accuracy and precision. The outcome can then be used to build a 3D starting model for energy minimization by atomistic simulations, for example, molecular dynamics simulations or the Monte Carlo method. However, this methodology needs to be further evaluated for in situ experiments. This thesis is devoted to presenting robust approaches to accurately define the 3D atomic structure of nanoparticles under application-relevant conditions and understand the mechanism behind the atomic-scale dynamics in nanoparticles in response to environmental stimuli.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:188295 Serial 7063  
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Author Idrissi, H.; Carrez, P.; Cordier, P. url  doi
openurl 
  Title On amorphization as a deformation mechanism under high stresses Type A1 Journal article
  Year 2022 Publication Current opinion in solid state and materials science Abbreviated Journal Curr Opin Solid St M  
  Volume 26 Issue 1 Pages 100976-17  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract In this paper we review the work related to amorphization under mechanical stress. Beyond pressure, we highlight the role of deviatoric or shear stresses. We show that the most recent works make amorphization appear as a deformation mechanism in its own right, in particular under extreme conditions (shocks, deformations under high stresses, high strain-rates).  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000779433300002 Publication Date 2022-01-13  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1359-0286 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 11 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 11  
  Call Number UA @ admin @ c:irua:188014 Serial 7064  
Permanent link to this record
 

 
Author Sun, C.; Street, M.; Zhang, C.; Van Tendeloo, G.; Zhao, W.; Zhang, Q. pdf  url
doi  openurl
  Title Boron structure evolution in magnetic Cr₂O₃ thin films Type A1 Journal article
  Year 2022 Publication Materials Today Physics Abbreviated Journal  
  Volume 27 Issue Pages 100753-100757  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract B substituting O in antiferromagnetic Cr2O3 is known to increase the Ne ' el temperature, whereas the actual B dopant site and the corresponding functionality remains unclear due to the complicated local structure. Herein, A combination of electron energy loss spectroscopy and first-principles calculations were used to unveil B local structures in B doped Cr2O3 thin films. B was found to form either magnetic active BCr4 tetrahedra or various inactive BO3 triangles in the Cr2O3 lattice, with a* and z* bonds exhibiting unique spectral features. Identification of BO3 triangles was achieved by changing the electron momentum transfer to manipulate the differential cross section for the 1s-z* and 1s-a* transitions. Modeling the experimental spectra as a linear combination of simulated B K edges reproduces the experimental z* / a* ratios for 15-42% of the B occupying the active BCr4 structure. This result is further supported by first-principles based thermodynamic calculations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000827323200003 Publication Date 2022-06-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2542-5293 ISBN Additional Links UA library record; WoS full record  
  Impact Factor 11.5 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 11.5  
  Call Number UA @ admin @ c:irua:189660 Serial 7078  
Permanent link to this record
 

 
Author Savina, A.A.; Saiutina, V.V.; Morozov, A.V.; Boev, A.O.; Aksyonov, D.A.; Dejoie, C.; Batuk, M.; Bals, S.; Hadermann, J.; Abakumov, A.M. pdf  doi
openurl 
  Title Chemistry, local molybdenum clustering, and electrochemistry in the Li2+xMo1-xO3 solid solutions Type A1 Journal article
  Year 2022 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 61 Issue 14 Pages 5637-5652  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A broad range of cationic nonstoichiometry has been demonstratedfor the Li-rich layered rock-salt-type oxide Li2MoO3, which has generally been considered as a phase with a well-defined chemical composition. Li2+xMo1-xO3(-0.037 <= x <= 0.124) solid solutions were synthesized via hydrogen reduction ofLi2MoO4in the temperature range of 650-1100 degrees C, withxdecreasing with theincrease of the reduction temperature. The solid solutions adopt a monoclinicallydistorted O3-type layered average structure and demonstrate a robust localordering of the Li cations and Mo3triangular clusters within the mixed Li/Mocationic layers. The local structure was scrutinized in detail by electron diffractionand aberration-corrected scanning transmission electron microcopy (STEM),resulting in an ordering model comprising a uniform distribution of the Mo3clusters compatible with local electroneutrality and chemical composition. The geometry of the triangular clusters with their oxygenenvironment (Mo3O13groups) has been directly visualized using differential phase contrast STEM imaging. The established localstructure was used as input for density functional theory (DFT)-based calculations; they support the proposed atomic arrangementand provide a plausible explanation for the staircase galvanostatic charge profiles upon electrochemical Li+extraction fromLi2+xMo1-xO3in Li cells. According to DFT, all electrochemical capacity in Li2+xMo1-xO3solely originates from the cationic Moredox process, which proceeds via oxidation of the Mo3triangular clusters into bent Mo3chains where the electronic capacity of the clusters depends on the initial chemical composition and Mo oxidation state defining the width of the first charge low-voltageplateau. Further oxidation at the high-voltage plateau proceeds through decomposition of the Mo3chains into Mo2dimers and further into individual Mo6+cations  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000789034200023 Publication Date 2022-04-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0020-1669 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.6 Times cited 3 Open Access Not_Open_Access  
  Notes The authors acknowledge Russian Science Foundation (grant 20-43-01012) and Research Foundation Flanders (FWO Vlaanderen, project number G0F1320N) for financial support. The authors are grateful to AICF of Skoltech for providing access to electron microscopy equipment. The authors are grateful to Prof. G. Van Tendeloo for discussing the results. Approved Most recent IF: 4.6  
  Call Number UA @ admin @ c:irua:188631 Serial 7079  
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Author Quintelier, M.; Perkisas, T.; Poppe, R.; Batuk, M.; Hendrickx, M.; Hadermann, J. url  doi
openurl 
  Title Determination of spinel content in cycled Li1.2Ni0.13Mn0.54Co0.13O2 using three-dimensional electron diffraction and precession electron diffraction Type A1 Journal article
  Year 2021 Publication Symmetry-Basel Abbreviated Journal Symmetry-Basel  
  Volume 13 Issue 11 Pages 1989-17  
  Keywords A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM); Electron microscopy for materials research (EMAT)  
  Abstract Among lithium battery cathode materials, Li1.2Ni0.13Mn0.54Co0.13O2 (LR-NMC) has a high theoretical capacity, but suffers from voltage and capacity fade during cycling. This is partially ascribed to transition metal cation migration, which involves the local transformation of the honeycomb layered structure to spinel-like nano-domains. Determination of the honeycomb layered/spinel phase ratio from powder X-ray diffraction data is hindered by the nanoscale of the functional material and the domains, diverse types of twinning, stacking faults, and the possible presence of the rock salt phase. Determining the phase ratio from transmission electron microscopy imaging can only be done for thin regions near the surfaces of the crystals, and the intense beam that is needed for imaging induces the same transformation to spinel as cycling does. In this article, it is demonstrated that the low electron dose sufficient for electron diffraction allows the collection of data without inducing a phase transformation. Using calculated electron diffraction patterns, we demonstrate that it is possible to determine the volume ratio of the different phases in the particles using a pair-wise comparison of the intensities of the reflections. Using this method, the volume ratio of spinel structure to honeycomb layered structure is determined for a submicron sized crystal from experimental three-dimensional electron diffraction (3D ED) and precession electron diffraction (PED) data. Both twinning and the possible presence of the rock salt phase are taken into account. After 150 charge-discharge cycles, 4% of the volume in LR-NMC particles was transformed irreversibly from the honeycomb layered structure to the spinel structure. The proposed method would be applicable to other multi-phase materials as well.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000815310500001 Publication Date 2021-10-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2073-8994 ISBN Additional Links UA library record; WoS full record  
  Impact Factor 1.457 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 1.457  
  Call Number UA @ admin @ c:irua:189468 Serial 7080  
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Author Poulain, R.; Lumbeeck, G.; Hunka, J.; Proost, J.; Savolainen, H.; Idrissi, H.; Schryvers, D.; Gauquelin, N.; Klein, A. pdf  doi
openurl 
  Title Electronic and chemical properties of nickel oxide thin films and the intrinsic defects compensation mechanism Type A1 Journal article
  Year 2022 Publication ACS applied electronic materials Abbreviated Journal  
  Volume 4 Issue 6 Pages 2718-2728  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Although largely studied, contradictory results on nickel oxide (NiO) properties can be found in the literature. We herein propose a comprehensive study that aims at leveling contradictions related to NiO materials with a focus on its conductivity, surface properties, and the intrinsic charge defects compensation mechanism with regards to the conditions preparation. The experiments were performed by in situ photo-electron spectroscopy, electron energy loss spectroscopy, and optical as well as electrical measurements on polycrystalline NiO thin films prepared under various preparation conditions by reactive sputtering. The results show that surface and bulk properties were strongly related to the deposition temperature with in particular the observation of Fermi level pinning, high work function, and unstable oxygen-rich grain boundaries for the thin films produced at room temperature but not at high temperature (>200 degrees C). Finally, this study provides substantial information about surface and bulk NiO properties enabling to unveil the origin of the high electrical conductivity of room temperature NiO thin films and also for supporting a general electronic charge compensation mechanism of intrinsic defects according to the deposition temperature.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000819431200001 Publication Date 2022-06-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2637-6113 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:189555 Serial 7081  
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Author Vishwakarma, M.; Batra, Y.; Hadermann, J.; Singh, A.; Ghosh, A.; Mehta, B.R. pdf  doi
openurl 
  Title Exploring the role of graphene oxide as a co-catalyst in the CZTS photocathodes for improved photoelectrochemical properties Type A1 Journal article
  Year 2022 Publication ACS applied energy materials Abbreviated Journal  
  Volume 5 Issue 6 Pages 7538-7549  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The hydrogen evolution properties of CZTS heterostructure photocathodes are reported with graphene oxide (GO) as a co-catalyst layer coated by a drop-cast method and an Al2O3 protection layer fabricated using atomic layer deposition. In the CZTS absorber, a minor deviation from stoichiometry across the cross section of the thin film results in nanoscale growth of spurious phases, but the kesterite phase remains the dominant phase. We have investigated the band alignment parameters such as the band gap, work function, and Fermi level position that are crucial for making kesterite-based heterostructure devices. The photocurrent density in the photocathode CZTS/CdS/ZnO is found to be improved to -4.71 mAmiddotcm(-2) at -0.40 V-RHE, which is 3 times that of the pure CZTS. This enhanced photoresponse can be attributed to faster carrier separation at p-n junction regions driven by upward band bending at CZTS grain boundaries and the ZnO layer. GO as a co-catalyst over the heterostructure photocathode significantly improves the photocurrent density to -6.14 mAmiddotcm(-2) at -0.40 V-RHE by effective charge migration in the CZTS/CdS/ZnO/GO configuration, but the onset potential shifts only after application of the Al2O3 protection layer. Significant photocurrents of -29 mAmiddotcm(-2) at -0.40 V-RHE and -8 mAmiddotcm(-2) at 0 V-RHE are observed, with an onset potential of 0.7 V-RHE in CZTS/CdS/ZnO/GO/Al2O3. The heterostructure configuration and the GO co-catalyst reduce the charge-transfer resistance, while the Al2O3 top layer provides a stable photocurrent for a prolonged time (similar to 16 h). The GO co-catalyst increases the flat band potential from 0.26 to 0.46 V-RHE in CZTS/CdS/ZnO/GO, which supports the bias-induced band bending at the electrolyte-electrode interface.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication (up) Editor  
  Language Wos 000820418400001 Publication Date 2022-05-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2574-0962 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.4 Times cited Open Access Not_Open_Access  
  Notes Approved Most recent IF: 6.4  
  Call Number UA @ admin @ c:irua:189666 Serial 7082  
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