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Author Tian, F.; Wang, Y.; Sandhu, H.S.; Gielis, J.; Shi, P.
Title Comparison of seed morphology of two ginkgo cultivars Type A1 Journal article
Year 2020 Publication Journal Of Forestry Research Abbreviated Journal J Forestry Res
Volume 31 Issue 3 Pages 751-758
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Ginkgo biloba L. is a precious relic tree species with important economic value. Seeds, as a vital reproductive organ of plants, can be used to distinguish cultivars of the species. We chose 400 seeds from two cultivars of ginkgo (Fozhi and Maling; 200 seeds for each cultivar) as the study material and used the Gielis equation to fit the projected shape of these seeds. The coefficients of variation (CV) in root mean squared errors (RMSE) obtained from the fitted data were used to compare the level of inter-cultivar variations in seed shape. We also used the covariance analysis to compare the allometric relationships between seed weights and projected areas of these two cultivars. The Gielis equation fitted well the seed shapes of two ginkgo cultivars. The lower CV in RMSE of cultivar Fozhi than Maling indicated a less symmetrical seed shape in the latter than the former. The bootstrap percentile method showed that the seed shape differences between the two cultivars were significant. However, there was no significant difference in the exponents between the seed weights and the projected areas of these two cultivars. Overall, the significant differences in shapes between the seeds of two ginkgo cultivars were well explained by the Gielis equation; this model can be further extended to compare morphological differences in other ginkgo cultivars, and even for plant seeds or animal eggs that have similar oval shapes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000529367600005 Publication Date 2018-07-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1007-662x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3 Times cited 3 Open Access
Notes (up) ; ; Approved Most recent IF: 3; 2020 IF: 0.774
Call Number UA @ admin @ c:irua:154987 Serial 6474
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Author Kenawy, A.; Magnus, W.; Milošević, M.V.; Sorée, B.
Title Electronically tunable quantum phase slips in voltage-biased superconducting rings as a base for phase-slip flux qubits Type A1 Journal article
Year 2020 Publication Superconductor Science & Technology Abbreviated Journal Supercond Sci Tech
Volume 33 Issue 12 Pages 125002
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Quantum phase slips represent a coherent mechanism to couple flux states of a superconducting loop. Since their first direct observation, there have been substantial developments in building charge-insensitive quantum phase-slip circuits. At the heart of these devices is a weak link, often a nanowire, interrupting a superconducting loop. Owing to the very small cross-sectional area of such a nanowire, quantum phase slip rates in the gigahertz range can be achieved. Instead, here we present the use of a bias voltage across a superconducting loop to electrostatically induce a weak link, thereby amplifying the rate of quantum phase slips without physically interrupting the loop. Our simulations reveal that the bias voltage modulates the free energy barrier between subsequent flux states in a very controllable fashion, providing a route towards a phase-slip flux qubit with a broadly tunable transition frequency.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000577207000001 Publication Date 2020-09-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.6 Times cited 4 Open Access
Notes (up) ; ; Approved Most recent IF: 3.6; 2020 IF: 2.878
Call Number UA @ admin @ c:irua:172643 Serial 6503
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Author Van De Vijver, E.; Delbecque, N.; Verdoodt, A.; Seuntjens, P.
Title Estimating the urban soil information gap using exhaustive land cover data: The example of Flanders, Belgium Type A1 Journal article
Year 2020 Publication Geoderma Abbreviated Journal Geoderma
Volume 372 Issue Pages 114371
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Human activities related to urbanization and industrialization have established a vast territory of urban soil worldwide. On traditional soil maps, urban and industrial areas usually appear as blind spots as they were beyond the interest of national soil survey campaigns. Furthermore, these soil maps are likely already outdated with respect to urban soil due to rapid urban expansion in recent decades. This research aims to evaluate the use of land cover data to estimate the urban soil information gap considering the highly urbanized region of Flanders, Belgium, as a case study. The current extent and spatial distribution of anthropogenic urban soil (1) was estimated through reclassification of recently acquired (2012) exhaustive land cover data, discriminating three qualitative likelihood levels (high-intermediate-low) of anthropogenic influence by urbanization, and (2) compared with its occurrence as represented by the 'Technosols/Not Surveyed area' in the legacy soil map of Belgium, as this map unit best matches with the likelihood for anthropogenic urban soil at the time of the National Soil Survey conducted between end 1940s and mid 1970s. The proposed reclassification of the land cover map resulted in 16.3% and 16.7% of Flanders' total area that corresponds with a high and intermediate likelihood for anthropogenic urban soil, which highlights the underestimation of the anthropogenic urban soil extent as represented by the 'Technosol/Not Surveyed' unit in the legacy soil map (only 13.7%). Moreover, a more realistic spatial pattern of anthropogenic urban soil occurrence was obtained, providing an improved basis for urban soil spatial analysis studies. The produced anthropogenic urban soil likelihood map therefore presents a useful supporting tool for coordinating future soil surveys in urban environments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000535713600006 Publication Date 2020-04-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0016-7061 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.1 Times cited 2 Open Access
Notes (up) ; ; Approved Most recent IF: 6.1; 2020 IF: 4.036
Call Number UA @ admin @ c:irua:170153 Serial 6510
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Author Eliaerts, J.; Meert, N.; Dardenne, P.; Van Durme, F.; Baeten, V.; Samyn, N.; De Wael, K.
Title Evaluation of a calibration transfer between a bench top and portable Mid-InfraRed spectrometer for cocaine classification and quantification Type A1 Journal article
Year 2020 Publication Talanta Abbreviated Journal Talanta
Volume 209 Issue Pages 120481
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract A portable Fourier Transform Mid-InfraRed (FT-MIR) spectrometer using Attenuated Total Reflectance (ATR) sampling is used for daily routine screening of seized powders. Earlier, ATR-FT-MIR combined with Support Vector Machines (SVM) algorithms resulted in a significant improvement of the screening method to a reliable and straightforward classification and quantification tool for both cocaine and levamisole. However, can this tool be transferred to new (hand-held) devices, without loss of the extensive data set? The objective of this study was to perform a calibration transfer between a newly purchased bench top (BT) spectrometer and a portable (P) spectrometer with existing calibration models. Both instruments are from the same brand and have identical characteristics and acquisition parameters (FT instrument, resolution of 4 cm(-1) and wavenumber range 4000 to 500 cm(-1)). The original SVM classification model (n = 515) and SVM quantification model (n = 378) were considered for the transfer trial. Three calibration transfer strategies were assessed: 1) adjustment of slope and bias; 2) correction of spectra from the new instrument BT to P using Piecewise Direct Standardization (PDS) and 3) building a new mixed instrument model with spectra of both instruments. For each approach, additional cocaine powders were measured (n = 682) and the results were compared with GC-MS and GC-FID. The development of a mixed instrument model was the most successful in terms of performance. The future strategy of a mixed model allows applying the models, developed in the laboratory, to portable instruments that are used on-site, and vice versa. The approach offers opportunities to exchange data within a network of forensic laboratories using other FT-MIR spectrometers.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000509632900016 Publication Date 2019-10-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0039-9140; 1873-3573 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.1 Times cited 2 Open Access
Notes (up) ; ; Approved Most recent IF: 6.1; 2020 IF: 4.162
Call Number UA @ admin @ c:irua:166475 Serial 6511
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Author Mao, J.; Milovanović, S.P.; Andelkovic, M.; Lai, X.; Cao, Y.; Watanabe, K.; Taniguchi, T.; Covaci, L.; Peeters, F.M.; Geim, A.K.; Jiang, Y.; Andrei, E.Y.
Title Evidence of flat bands and correlated states in buckled graphene superlattices Type A1 Journal article
Year 2020 Publication Nature Abbreviated Journal Nature
Volume 584 Issue 7820 Pages 215-220
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract Two-dimensional atomic crystals can radically change their properties in response to external influences, such as substrate orientation or strain, forming materials with novel electronic structure(1-5). An example is the creation of weakly dispersive, 'flat' bands in bilayer graphene for certain 'magic' angles of twist between the orientations of the two layers(6). The quenched kinetic energy in these flat bands promotes electron-electron interactions and facilitates the emergence of strongly correlated phases, such as superconductivity and correlated insulators. However, the very accurate fine-tuning required to obtain the magic angle in twisted-bilayer graphene poses challenges to fabrication and scalability. Here we present an alternative route to creating flat bands that does not involve fine-tuning. Using scanning tunnelling microscopy and spectroscopy, together with numerical simulations, we demonstrate that graphene monolayers placed on an atomically flat substrate can be forced to undergo a buckling transition(7-9), resulting in a periodically modulated pseudo-magnetic field(10-14), which in turn creates a 'post-graphene' material with flat electronic bands. When we introduce the Fermi level into these flat bands using electrostatic doping, we observe a pseudogap-like depletion in the density of states, which signals the emergence of a correlated state(15-17). This buckling of two-dimensional crystals offers a strategy for creating other superlattice systems and, in particular, for exploring interaction phenomena characteristic of flat bands. Buckled monolayer graphene superlattices are found to provide an alternative to twisted bilayer graphene for the study of flat bands and correlated states in a carbon-based material.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000559831500012 Publication Date 2020-08-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-0836 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 64.8 Times cited 75 Open Access Not_Open_Access
Notes (up) ; ; Approved Most recent IF: 64.8; 2020 IF: 40.137
Call Number UA @ admin @ c:irua:171150 Serial 6513
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Author Canossa, S.; Wuttke, S.
Title Functionalization chemistry of porous materials Type Editorial
Year 2020 Publication Advanced Functional Materials Abbreviated Journal Adv Funct Mater
Volume 30 Issue 41 Pages 2003875
Keywords Editorial; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000580514700004 Publication Date 2020-10-08
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 19 Times cited 1 Open Access OpenAccess
Notes (up) ; ; Approved Most recent IF: 19; 2020 IF: 12.124
Call Number UA @ admin @ c:irua:173614 Serial 6524
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Author Mehta, A.N.; Mo, J.; Pourtois, G.; Dabral, A.; Groven, B.; Bender, H.; Favia, P.; Caymax, M.; Vandervorst, W.
Title Grain-boundary-induced strain and distortion in epitaxial bilayer MoS₂ lattice Type A1 Journal article
Year 2020 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C
Volume 124 Issue 11 Pages 6472-6478
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Grain boundaries between 60 degrees rotated and twinned crystals constitute the dominant type of extended line defects in two-dimensional transition metal dichalcogenides (2D MX2) when grown on a single crystalline template through van der Waals epitaxy. The two most common 60 degrees grain boundaries in MX2 layers, i.e., beta- and gamma-boundaries, introduce distinct distortion and strain into the 2D lattice. They impart a localized tensile or compressive strain on the subsequent layer, respectively, due to van der Waals coupling in bilayer MX2 as determined by combining atomic resolution electron microscopy, geometric phase analysis, and density functional theory. Based on these observations, an alternate route to strain engineering through controlling intrinsic van der Waals forces in homobilayer MX2 is proposed. In contrast to the commonly used external means, this approach enables the localized application of strain to tune the electronic properties of the 2D semiconducting channel in ultra-scaled nanoelectronic applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000526396000067 Publication Date 2020-02-21
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 3.7 Times cited 2 Open Access
Notes (up) ; ; Approved Most recent IF: 3.7; 2020 IF: 4.536
Call Number UA @ admin @ c:irua:168625 Serial 6528
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Author Bafekry, A.
Title Graphene-like BC₆N single-layer: tunable electronic and magnetic properties via thickness, gating, topological defects, and adatom/molecule Type A1 Journal article
Year 2020 Publication Physica E-Low-Dimensional Systems & Nanostructures Abbreviated Journal Physica E
Volume 118 Issue Pages 113850-15
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract By using density functional theory-based first-principles calculations, we investigate the structural, electronic, optical, and transport properties of pristine single-layer BC6N. Under different external actions and functionalization. Increasing the thickness of the structure results in a decrease of the band gap. Applying a perpendicular electric field decreases the band gap and a semiconductor-to-topological insulator transition is revealed. Uniaxial and biaxial strains of +8% result in a semiconductor-to-metal transition. Nanoribbons of BC6N having zigzag edge with even (odd) values of widths, become metal (semiconductor), while the armchair edge nanoribbons exhibit robust semiconducting behavior. In addition, we systematically investigate the effect of surface adatom and molecule, substitutional impurity and defect engineering on the electronic properties of single-layer BC6N and found transitions from metal to half-metal, to ferromagnetic metal, to dilute magnetic semiconductor, and even to spin-glass semiconductor. Furthermore we found that, topological defects including vacancies and Stone–Wales type, induce magnetism in single-layer BC6N.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000515321700032 Publication Date 2019-12-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1386-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.3 Times cited 30 Open Access
Notes (up) ; ; Approved Most recent IF: 3.3; 2020 IF: 2.221
Call Number UA @ admin @ c:irua:169750 Serial 6530
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Author Li, J.; Zhu, W.; Dong, H.; Yang, Z.; Zhang, P.; Qiang, Z.
Title Impact of carrier on ammonia and organics removal from zero-discharge marine recirculating aquaculture system with sequencing batch biofilm reactor (SBBR) Type A1 Journal article
Year 2020 Publication Environmental Science And Pollution Research Abbreviated Journal Environ Sci Pollut R
Volume 27 Issue 28 Pages 34614-34623
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Marine recirculating aquaculture system (MRAS) is an effective technology that provides sustainable farming of food fish globally. However, dissolved organics material (chemical oxygen demand, COD) and especially ammonia are produced from uneaten feed and metabolic wastes of fish. To purify the MRAS water, this study adopted a sequencing biofilm batch reactor (SBBR) and comparatively investigated the performances of four different carriers on ammonia and COD removal. Results indicated that the NH4+-N removal rates were 0.045 +/- 0.05, 0.065 +/- 0.008, 0.089 +/- 0.005, and 0.093 +/- 0.003 kg/(m(3)center dot d), and the COD removal rates were 0.019 +/- 0.010, 0.213 +/- 0.010, 0.255 +/- 0.015, and 0.322 +/- 0.010 kg/(m(3)center dot d) in the SBBRs packed with porous plastic, bamboo ring, maifan stone, and ceramsite carriers, respectively. Among the four carriers, ceramsite exhibited the best performance for both NH4+-N (80%) and COD (33%) removal after the SBBR reached the steady-state operation conditions. For all carriers studied, the NH4+-N removal kinetics could be well simulated by the first-order model, and the NH4+-N and COD removal rates were logarithmically correlated with the carrier's specific surface area. Due to its high ammonia removal, stable performance and easy operation, the ceramsite-packed SBBR is feasible for MRAS water treatment.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000565020300005 Publication Date 2019-04-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0944-1344; 1614-7499 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.8 Times cited 1 Open Access
Notes (up) ; ; Approved Most recent IF: 5.8; 2020 IF: 2.741
Call Number UA @ admin @ c:irua:171932 Serial 6542
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Author Sciutto, G.; Legrand, S.; Catelli, E.; Prati, S.; Malegori, C.; Oliveri, P.; Janssens, K.; Mazzeo, R.
Title Macroscopic mid-FTIR mapping and clustering-based automated data-reduction : an advanced diagnostic tool for in situ investigations of artworks Type A1 Journal article
Year 2020 Publication Talanta Abbreviated Journal Talanta
Volume 209 Issue Pages 120575-120577
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract The present study describes a multivariate strategy that can be used for automatic on-site processing of reflection mode macro FTIR mapping (MA-rFTIR) data obtained during investigation of artworks. The chemometric strategy is based on the integration of principal component analysis (PCA) with a clustering approach in the space subtended by the three lowest-order principal components and allows to automatically identify the regions of interest (ROIs) of the area scanned and to extract the average FTIR spectra related to each ROI. Thanks to the automatic data management, in-field HSI (hyperspectral imaging)-based analyses may be performed even by staff lacking specific advanced chemometric expertise, as it is sometimes the case for conservation scientists or conservators with a scientific background. MA-rFTIR was only recently introduced in the conservation field and, in this work the technique was employed to characterize the surface of metallic artefacts. The analytical protocol was employed as part of a rapid procedure to evaluate the conservation state and the performance of cleaning methods on bronze objects. Both activities are commonly part of restoration campaigns of bronzes and require an on-site analytical procedure for efficient and effective diagnosis. The performance of the method was first evaluated on aged standard samples (bronzes with a layer of green basic copper hydroxysulphate, treated with different organic coatings) and then scrutinized in situ on areas of the 16th century Neptune fountain statue (Piazza del Nettuno, Bologna, Italy) by Gianbologna.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000509632900088 Publication Date 2019-11-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0039-9140; 1873-3573 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.1 Times cited Open Access
Notes (up) ; ; Approved Most recent IF: 6.1; 2020 IF: 4.162
Call Number UA @ admin @ c:irua:166476 Serial 6557
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Author Drukarev, E.; Mikhailov, A.; Rakhimov, K.Y.; Yusupov, H.
Title Relativistic photoeffect for s states in a central field Type A1 Journal article
Year 2020 Publication European Physical Journal D Abbreviated Journal Eur Phys J D
Volume 74 Issue 8 Pages 166-169
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We study the photoionization of the s states in the systems bound by sufficiently weak central fields V(r) for the large photon energies corresponding to the relativistic photoelectrons. We demonstrate that the energy dependence of the photoionization cross section can be obtained without solving the wave equation. We show that the shape of the energy dependence of the cross section is determined by analytical properties of the binding potential V(r). We find the cross sections for the potentials V(r) which have singularities in the origin, on the real axis and in the complex plane.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000560347800005 Publication Date 2020-08-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6060; 1434-6079 ISBN Additional Links UA library record; WoS full record
Impact Factor 1.8 Times cited Open Access
Notes (up) ; ; Approved Most recent IF: 1.8; 2020 IF: 1.288
Call Number UA @ admin @ c:irua:171172 Serial 6593
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Author Van der Donck, M.; Zarenia, M.; Peeters, F.M.
Title Reply to “Comment on `Excitons, trions, and biexcitons in transition-metal dichalcogenides: Magnetic-field dependence'” Type Editorial
Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 101 Issue 12 Pages 127402
Keywords Editorial; Condensed Matter Theory (CMT)
Abstract In the Comment, the authors state that the separation of the relative and center of mass variables in our work is not correct. Here we point out that there is a typographical error, i.e., qi instead of -e, in two of our equations which, when corrected, makes the Comment redundant. Within the ansatzes mentioned in our paper all our results are correct, in contrast to the claims of the Comment.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000519990800011 Publication Date 2020-03-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record
Impact Factor 3.7 Times cited Open Access
Notes (up) ; ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:167680 Serial 6594
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Author Blay, V.; Galian, R.E.; Muresan, L.M.; Pancratov, D.; Pinyou, P.; Zampardi, G.
Title Research frontiers in energy-related materials and applications for 2020-2030 Type A1 Journal article
Year 2020 Publication Advanced sustainable systems Abbreviated Journal
Volume 4 Issue 2 Pages 1900145
Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract This article delineates the state of the art for several materials used in the harvest, conversion, and storage of energy, and analyzes the challenges to be overcome in the decade ahead for them to reach the market and benefit society. The materials covered have had a special interest in recent years and include perovskites, materials for batteries and supercapacitors, graphene, and materials for hydrogen production and storage. Looking at the common challenges for these different systems, scientists in basic research should carefully consider commercial requirements when designing new materials. These include cost and ease of synthesis, abundance of precursors, recyclability of spent devices, toxicity, and stability. Improvements in these areas deserve more attention, as they can help bridge the gap for these technologies and facilitate the creation of partnerships between academia and industry. These improvements should be pursued in parallel with the design of novel compositions, nanostructures, and devices, which have led most interest during the past decade. Research groups are encouraged to adopt a cross-disciplinary mindset, which may allow more efficient use of existing knowledge and facilitate breakthrough innovation in both basic and applied research of energy-related materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000509006700001 Publication Date 2020-01-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2366-7486 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.1 Times cited 2 Open Access
Notes (up) ; ; Approved Most recent IF: 7.1; 2020 IF: NA
Call Number UA @ admin @ c:irua:166561 Serial 6595
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Author Liu, P.; Madsen, J.; Schiotz, J.; Wagner, J.B.; Hansen, T.W.
Title Reversible and concerted atom diffusion on supported gold nanoparticles Type A1 Journal article
Year 2020 Publication Journal Of Physics-materials Abbreviated Journal
Volume 3 Issue 2 Pages 024009
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Traditionally, direct imaging of atom diffusion is only available by scanning tunneling microscopy and field ion microscopy on geometry-constrained samples: flat surfaces for STM and needle tips for FIM. Here we show time-resolved atomic-scale HRTEM investigations of CeO2-supported Au nanoparticle surfaces to characterize the surface dynamics of atom columns on gold nanoparticles. The observed surface dynamics have been categorized into four types: layer jumping, layer gliding, re-orientation and surface reconstruction. We successfully captured atoms moving in a concerted manner with a time resolution of 0.1 s. A quantitative approach for measuring the dynamics in various gaseous surroundings at elevated temperatures is presented. An approach for measuring quantitative electron beam effects on the surface dynamics is presented by counting atom column occupation as a function of time under a range of dose rates in high vacuum.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000560432800009 Publication Date 2020-03-24
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 2 Open Access OpenAccess
Notes (up) ; ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:171320 Serial 6597
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Author Ravindra, K.; Dirtu, A.C.; Mor, S.; Wauters, E.; Van Grieken, R.
Title Source apportionment and seasonal variation in particulate PAHs levels at a coastal site in Belgium Type A1 Journal article
Year 2020 Publication Environmental Science And Pollution Research Abbreviated Journal Environ Sci Pollut R
Volume Issue Pages
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract In the present study, estimation of the atmospheric polycyclic aromatic hydrocarbons (PAHs) was done in particulate samples collected from De Haan, Belgium, during different seasons. The sampling site was situated very close to the north sea and far from the influence of local or industrial activities. The levels of PAHs depicted a distinct seasonal trend, being highest during the spring season. The observations of the study indicated a mean value of 2.6 ng m(-3) for concentration of all the 16 US EPA PAHs, thus being significantly lower when compared to results of previous studies focused on other sites. The dominating PAHs species reported were naphthalene, fluoranthene, benzo[a]anthracene, chrysene, and indeno[1,2,3c,d] pyrene. Assessment of the seasonal variation of the PAH levels was also done with respect to diagnostic ratio-based source identification, analysis of back trajectories, and principle component analysis. Burning of fossil fuels was observed to be the prominent source of atmospheric PAHs in the study area. Further, lifetime cancer risk assessment was performed to assess the detrimental health impacts on humans on being exposed to atmospheric PAHs. Particulate PAHs present in the ambient air of Belgium shows no carcinogenic health impacts. However, considering the industrial expansion in the region, efforts are required to prevent the environmental contamination of PAHs.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000516395800002 Publication Date 2020-02-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0944-1344; 1614-7499 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.8 Times cited Open Access
Notes (up) ; ; Approved Most recent IF: 5.8; 2020 IF: 2.741
Call Number UA @ admin @ c:irua:167778 Serial 6606
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Author Litzius, K.; Leliaert, J.; Bassirian, P.; Rodrigues, D.; Kromin, S.; Lemesh, I.; Zazvorka, J.; Lee, K.-J.; Mulkers, J.; Kerber, N.; Heinze, D.; Keil, N.; Reeve, R.M.; Weigand, M.; Van Waeyenberge, B.; Schuetz, G.; Everschor-Sitte, K.; Beach, G.S.D.; Klaeui, M.
Title The role of temperature and drive current in skyrmion dynamics Type A1 Journal article
Year 2020 Publication Nature Electronics Abbreviated Journal
Volume 3 Issue 1 Pages 30-36
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Magnetic skyrmions are topologically stabilized nanoscale spin structures that could be of use in the development of future spintronic devices. When a skyrmion is driven by an electric current it propagates at an angle relative to the flow of current-known as the skyrmion Hall angle (SkHA)-that is a function of the drive current. This drive dependence, as well as thermal effects due to Joule heating, could be used to tailor skyrmion trajectories, but are not well understood. Here we report a study of skyrmion dynamics as a function of temperature and drive amplitude. We find that the skyrmion velocity depends strongly on temperature, while the SkHA does not and instead evolves differently in the low- and high-drive regimes. In particular, the maximum skyrmion velocity in ferromagnetic devices is limited by a mechanism based on skyrmion surface tension and deformation (where the skyrmion transitions into a stripe). Our mechanism provides a complete description of the SkHA in ferromagnetic multilayers across the full range of drive strengths, illustrating that skyrmion trajectories can be engineered for device applications. An analysis of skyrmion dynamics at different temperatures and electric drive currents is used to develop a complete description of the skyrmion Hall angle in ferromagnetic multilayers from the creep to the flow regime and illustrates that skyrmion trajectories can be engineered for device applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000510860800012 Publication Date 2020-01-24
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 11 Open Access
Notes (up) ; ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:167863 Serial 6625
Permanent link to this record
 

 
Author Bafekry, A.; Akgenc, B.; Shayesteh, S.F.; Mortazavi, B.
Title Tunable electronic and magnetic properties of graphene/carbon-nitride van der Waals heterostructures Type A1 Journal article
Year 2020 Publication Applied Surface Science Abbreviated Journal Appl Surf Sci
Volume 505 Issue Pages 144450-144459
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In this paper, we explore the electronic properties of C3N, C3N4 and C4N3 and graphene (Gr) van der Waals heterostructures by conducing extensive first-principles calculations. The acquired results show that these heterostructures can show diverse electronic properties, such as the metal (Gr on C3N), semiconductor with narrow band gap (Gr on C3N4) and ferromagnetic-metal (Gr on C4N3). We furthermore explored the effect of vacancies, atom substitution, topological, antisite and Stone-Wales defects on the structural and electronic properties of considered heterostructures. Our results show that the vacancy defects introduce localized states near the Fermi level and create a local magnetic moment. The Gr/C3N heterostructures with the single and double vacancy defects exhibit a ferromagnetic-metal, while Stone-Wales defects show an indirect semiconductor with the band gap of 0.2 eV. The effects of adsorption and insertion of O, C, Be, Cr, Fe and Co atoms on the electronic properties of Gr/C3N have been also elaborately studied. Our results highlight that the electronic and magnetic properties of garphene/carbon-nitride lateral heterostructures can be effectively modified by point defects and impurities.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000510846500052 Publication Date 2019-11-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited 26 Open Access
Notes (up) ; ; Approved Most recent IF: 6.7; 2020 IF: 3.387
Call Number UA @ admin @ c:irua:167732 Serial 6638
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Author Bafekry, A.; Neek-Amal, M.
Title Tuning the electronic properties of graphene-graphitic carbon nitride heterostructures and heterojunctions by using an electric field Type A1 Journal article
Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 101 Issue 8 Pages 085417-10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Integration of graphene-based two-dimensional materials is essential for nanoelectronics applications. Using density-functional theory, we systematically investigate the electronic properties of vertically stacked graphene-graphitic carbon nitrides (GE/GCN). We also studied the covalently lateral stitched graphene-graphitic carbon nitrides (GE-GCN heterojunctions). The effects of perpendicular electric field on the electronic properties of six different heterostructures, i.e., (i) one layer of GE on top of a layer of CnNm with (n, m) = (3,1), (3,4), and (4,3) and (ii) three heterostructures CnNm/Cn'Nm', where (n, m) not equal (n', m') are elucidated. The most important calculated features are (i) the systems GE/C3N4, C3N/C3N4, GE-C3N, GE-C4N3, and C3N-C3N4 exhibit semiconducting characteristics having small band gaps of Delta(0)=20, 250, 100, 100, 80 meV, respectively while (ii) the systems GE/C4N3, C3N/C4N3, and C3N-C4N3 show ferromagnetic-metallic properties. In particular, we found that, in semiconducting heterostructures, the band gap increases nontrivially with increasing the absolute value of the applied perpendicular electric field. This work is useful for designing heterojunctions and heterostructures made of graphene and other two-dimensional materials such as those proposed in recent experiments [X. Liu and M. C. Hersam Sci. Adv. 5, 6444 (2019)].
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000515659700007 Publication Date 2020-02-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited 24 Open Access
Notes (up) ; ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:167760 Serial 6640
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Author Bafekry, A.; Neek-Amal, M.; Peeters, F.M.
Title Two-dimensional graphitic carbon nitrides: strain-tunable ferromagnetic ordering Type A1 Journal article
Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 101 Issue 16 Pages 165407-165408
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using first-principle calculations, we systematically study strain tuning of the electronic properties of two- dimensional graphitic carbon nitride nanosheets with empirical formula CnNm. We found the following: (i) the ferromagnetic ordered state in the metal-free systems (n, m) = (4,3), (10,9), and (14,12) remains stable in the presence of strain of about 6%. However, the system (9,7) loses its ferromagnetic ordering when increasing strain. This is due to the presence of topological defects in the (9,7) system, which eliminates the asymmetry between spin up and spin down of the p(z) orbitals when strain is applied. (ii) By applying uniaxial strain, a band gap opens in systems which are initially gapless. (iii) In semiconducting systems which have an initial gap of about 1 eV, the band gap is closed with applying uniaxial strain.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000523630200012 Publication Date 2020-04-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited 22 Open Access
Notes (up) ; ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:168560 Serial 6643
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Author Obeid, M.M.; Bafekry, A.; Rehman, S.U.; Nguyen, C., V.
Title A type-II GaSe/HfS₂ van der Waals heterostructure as promising photocatalyst with high carrier mobility Type A1 Journal article
Year 2020 Publication Applied Surface Science Abbreviated Journal Appl Surf Sci
Volume 534 Issue Pages 147607
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In this paper, the electronic, optical, and photocatalytic properties of GaSe/HfS2 heterostructure are studied via first-principles calculations. The stability of the vertically stacked heterobilayers is validated by the binding energy, phonon spectrum, and ab initio molecular dynamics simulation. The results reveal that the most stable GaSe/HfS2 heterobilayer retains a type-II alignment with an indirect bandgap 1.40 eV. As well, the results also show strong optical absorption intensity in the studied heterostructure (1.8 x 10(5) cm(-1)). The calculated hole mobility is 1376 cm(2) V-1 s(-1), while electron mobility reaches 911 cm(2) V-1 s(-1) along the armchair and zigzag directions. By applying an external electric field, the bandgap and band offset of the designed heterostructure can be effectively modified. Remarkably, a stronger external electric field can create nearly free electron states in the vicinity of the bottom of the conduction band, which induces indirect-to-direct bandgap transition as well as a semiconductor-to-metal transition. In contrast, the electronic properties of GaSe/HfS2 heterostructure are predicted to be insensitive to biaxial strain. The current work reveals that GaSe/HfS2 heterostructure is a promising candidate as a novel photocatalytic material for hydrogen generation in the visible range.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000582367700045 Publication Date 2020-08-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited 4 Open Access
Notes (up) ; ; Approved Most recent IF: 6.7; 2020 IF: 3.387
Call Number UA @ admin @ c:irua:174301 Serial 6682
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Author Jalali, H.; Khoeini, F.; Peeters, F.M.; Neek-Amal, M.
Title Hydration effects and negative dielectric constant of nano-confined water between cation intercalated MXenes Type A1 Journal article
Year 2021 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 13 Issue 2 Pages 922-929
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Using electrochemical methods a profound enhancement of the capacitance of electric double layer capacitor electrodes was reported when water molecules are strongly confined into the two-dimensional slits of titanium carbide MXene nanosheets [A. Sugahara et al., Nat. Commun., 2019, 10, 850]. We study the effects of hydration on the dielectric properties of nanoconfined water and supercapacitance properties of the cation intercalated MXene. A model for the electric double layer capacitor is constructed where water molecules are strongly confined in two-dimensional slits of MXene. We report an abnormal dielectric constant and polarization of nano-confined water between MXene layers. We found that by decreasing the ionic radius of the intercalated cations and in a critical hydration shell radius the capacitance of the system increases significantly (similar or equal to 200 F g(-1)) which can be interpreted as a negative permittivity. This study builds a bridge between the fundamental understanding of the dielectric properties of nanoconfined water and the capability of using MXene films for supercapacitor technology, and in doing so provides a solid theoretical support for recent experiments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000610368100035 Publication Date 2020-12-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 3 Open Access Not_Open_Access
Notes (up) ; ; Approved Most recent IF: 7.367
Call Number UA @ admin @ c:irua:176141 Serial 6690
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Author Annys, A.; Jannis, D.; Verbeeck, J.; Annys, A.; Jannis, D.; Verbeeck, J.
Title Deep learning for automated materials characterisation in core-loss electron energy loss spectroscopy Type A1 Journal article
Year 2023 Publication Scientific reports Abbreviated Journal
Volume 13 Issue 1 Pages 13724
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Electron energy loss spectroscopy (EELS) is a well established technique in electron microscopy that yields information on the elemental content of a sample in a very direct manner. One of the persisting limitations of EELS is the requirement for manual identification of core-loss edges and their corresponding elements. This can be especially bothersome in spectrum imaging, where a large amount of spectra are recorded when spatially scanning over a sample area. This paper introduces a synthetic dataset with 736,000 labeled EELS spectra, computed from available generalized oscillator strength tables, that represents 107 K, L, M or N core-loss edges and 80 chemical elements. Generic lifetime broadened peaks are used to mimic the fine structure due to band structure effects present in experimental core-loss edges. The proposed dataset is used to train and evaluate a series of neural network architectures, being a multilayer perceptron, a convolutional neural network, a U-Net, a residual neural network, a vision transformer and a compact convolutional transformer. An ensemble of neural networks is used to further increase performance. The ensemble network is used to demonstrate fully automated elemental mapping in a spectrum image, both by directly mapping the predicted elemental content and by using the predicted content as input for a physical model-based mapping.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001052937600046 Publication Date 2023-08-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2045-2322 ISBN Additional Links UA library record; WoS full record
Impact Factor 4.6 Times cited Open Access OpenAccess
Notes (up) A.A. would like to acknowledge the resources and services used in this work provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation – Flanders (FWO) and the Flemish Government. J.V. acknowledges the IMPRESS project. The IMPRESS project has received funding from the HORIZON EUROPE framework program for research and innovation under grant agreement n. 101094299. Approved Most recent IF: 4.6; 2023 IF: 4.259
Call Number UA @ admin @ c:irua:198647 Serial 8846
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Author Walters, A.A.; Santacana-Font, G.; Li, J.; Routabi, N.; Qin, Y.; Claes, N.; Bals, S.; Tzu-Wen Wang, J.; Al-Jamal, K.T.
Title Nanoparticle-MediatedIn SituMolecular Reprogramming of Immune Checkpoint Interactions for Cancer Immunotherapy Type A1 Journal article
Year 2021 Publication Acs Nano Abbreviated Journal Acs Nano
Volume 15 Issue 11 Pages 17549-17564
Keywords A1 Journal article; Pharmacology. Therapy; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Immune checkpoint blockade involves targeting immune

regulatory molecules with antibodies. Preclinically, complex multiantibody

regimes of both inhibitory and stimulatory targets are a promising

candidate for the next generation of immunotherapy. However, in this

setting, the antibody platform may be limited due to excessive toxicity

caused by off target effects as a result of systemic administration. RNA

can be used as an alternate to antibodies as it can both downregulate

immunosuppressive checkpoints (siRNA) or induce expression of

immunostimulatory checkpoints (mRNA). In this study, we demonstrate

that the combination of both siRNA and mRNA in a single

formulation can simultaneously knockdown and induce expression of

immune checkpoint targets, thereby reprogramming the tumor

microenvironment from immunosuppressive to immunostimulatory

phenotype. To achieve this, RNA constructs were synthesized and

formulated into stable nucleic acid lipid nanoparticles (SNALPs); the SNALPs produced were 140−150 nm in size with >80%

loading efficiency. SNALPs could transfect macrophages and B16F10 cells in vitro resulting in 75% knockdown of inhibitory

checkpoint (PDL1) expression and simultaneously express high levels of stimulatory checkpoint (OX40L) with minimal

toxicity. Intratumoral treatment with the proposed formulation resulted in statistically reduced tumor growth, a greater

density of CD4+ and CD8+ infiltrates in the tumor, and immune activation within tumor-draining lymph nodes. These data

suggest that a single RNA-based formulation can successfully reprogram multiple immune checkpoint interactions on a

cellular level. Such a candidate may be able to replace future immune checkpoint therapeutic regimes composed of both

stimulatory- and inhibitory-receptor-targeting antibodies.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000747115200039 Publication Date 2021-11-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.942 Times cited 11 Open Access OpenAccess
Notes (up) A.A.W. is the grateful recipient of a Maplethorpe Fellowship. K.A.J. acknowledges funding from the British Council (Newton Fund, 337313), Wellcome Trust (WT103913), and the Cancer Research UK King’s Health Partners Centre at King’s College London. Financial support is acknowledged from the European Commission under the Horizon 2020 Programme, by means of Grant Agreement No. 731019 (EUSMI). Images were drawn on BioRender.com. Approved Most recent IF: 13.942
Call Number EMAT @ emat @c:irua:183950 Serial 6829
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Author Béché, A.; Goris, B.; Freitag, B.; Verbeeck, J.
Title Development of a fast electromagnetic beam blanker for compressed sensing in scanning transmission electron microscopy Type A1 Journal article
Year 2016 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 108 Issue 108 Pages 093103
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The concept of compressed sensing was recently proposed to significantly reduce the electron dose in scanning transmission electron microscopy (STEM) while still maintaining the main features in the image. Here, an experimental setup based on an electromagnetic beam blanker placed in the condenser plane of a STEM is proposed. The beam blanker deflects the beam with a random pattern, while the scanning coils are moving the beam in the usual scan pattern. Experimental images at both the medium scale and high resolution are acquired and reconstructed based on a discrete cosine algorithm. The obtained results confirm that compressed sensing is highly attractive to limit beam damage in experimental STEM even though some remaining artifacts need to be resolved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000375329200043 Publication Date 2016-03-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 40 Open Access
Notes (up) A.B and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX and under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2), from the GOA project SOLARPAINT and the POC project I13/009 from the University of Antwerp. B.G. acknowledges the Research Foundation Flanders (FWO Vlaanderen) for a postdoctoral research grant. The QuAnTem microscope was partially funded by the Hercules Foundation. We thank Zhaoliang Liao from the Mesa+ laboratory at the University of Twente for the perovskite test sample.; esteem2jra3 ECASJO; Approved Most recent IF: 3.411
Call Number c:irua:131895 c:irua:131895UA @ admin @ c:irua:131895 Serial 4023
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Author Béché, A.; Winkler, R.; Plank, H.; Hofer, F.; Verbeeck, J.
Title Focused electron beam induced deposition as a tool to create electron vortices Type A1 Journal article
Year 2015 Publication Micron Abbreviated Journal Micron
Volume 80 Issue 80 Pages 34-38
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Focused electron beam induced deposition (FEBID) is a microscopic technique that allows geometrically controlled material deposition with very high spatial resolution. This technique was used to create a spiral aperture capable of generating electron vortex beams in a transmission electron microscope (TEM). The vortex was then fully characterized using different TEM techniques, estimating the average orbital angular momentum to be approximately 0.8variant Planck's over 2pi per electron with almost 60% of the beam ending up in the l=1 state.
Address EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000366770100006 Publication Date 2015-09-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0968-4328; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.98 Times cited 21 Open Access
Notes (up) A.B and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX. J.V., R.W., H.P. and F.H. acknowledge financial support from the European Union under the 7th Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2). R.W and H.P also acknowledge financial support by the COST action CELINA (Nr. CM1301) and the EUROSTARS project TRIPLE-S (Nr. E!8213). The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government.; esteem2jra3 ECASJO; Approved Most recent IF: 1.98; 2015 IF: 1.988
Call Number c:irua:129203 c:irua:129203UA @ admin @ c:irua:129203 Serial 3946
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Author Béché, A.; Juchtmans, R.; Verbeeck, J.
Title Efficient creation of electron vortex beams for high resolution STEM imaging Type A1 Journal article
Year 2017 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 178 Issue 178 Pages 12-19
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The recent discovery of electron vortex beams carrying quantised angular momentum in the TEM has led to an active field of research, exploring a variety of potential applications including the possibility of mapping magnetic states at the atomic scale. A prerequisite for this is the availability of atomic sized electron vortex beams at high beam current and mode purity. In this paper we present recent progress showing that by making use of the Aharonov-Bohm effect near the tip of a long single domain ferromagnetic Nickel needle, a very efficient aperture for the production of electron vortex beams can be realised. The aperture transmits more than 99% of all electrons and provides a vortex mode purity of up to 92%. Placing this aperture in the condenser plane of a state of the art Cs corrected microscope allows us to demonstrate atomic resolution HAADF STEM images with spatial resolution better than 1 Angstrom, in agreement with theoretical expectations and only slightly inferior to the performance of a non-vortex probe on the same instrument.
Address EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000403862900003 Publication Date 2016-05-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 30 Open Access OpenAccess
Notes (up) A.B. and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX. J.V. acknowledges funding from FWO project G.0044.13N ('Charge ordering').; ECASJO_; Approved Most recent IF: 2.843
Call Number c:irua:134085 c:irua:134085UA @ admin @ c:irua:134085 Serial 4094
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Author Prabhakara, V.; Jannis, D.; Guzzinati, G.; Béché, A.; Bender, H.; Verbeeck, J.
Title HAADF-STEM block-scanning strategy for local measurement of strain at the nanoscale Type A1 Journal article
Year 2020 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 219 Issue Pages 113099
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Lattice strain measurement of nanoscale semiconductor devices is crucial for the semiconductor industry as strain substantially improves the electrical performance of transistors. High resolution scanning transmission electron microscopy (HR-STEM) imaging is an excellent tool that provides spatial resolution at the atomic scale and strain information by applying Geometric Phase Analysis or image fitting procedures. However, HR-STEM images regularly suffer from scanning distortions and sample drift during image acquisition. In this paper, we propose a new scanning strategy that drastically reduces artefacts due to drift and scanning distortion, along with extending the field of view. It consists of the acquisition of a series of independent small subimages containing an atomic resolution image of the local lattice. All subimages are then analysed individually for strain by fitting a nonlinear model to the lattice images. The method allows flexible tuning of spatial resolution and the field of view within the limits of the dynamic range of the scan engine while maintaining atomic resolution sampling within the subimages. The obtained experimental strain maps are quantitatively benchmarked against the Bessel diffraction technique. We demonstrate that the proposed scanning strategy approaches the performance of the diffraction technique while having the advantage that it does not require specialized diffraction cameras.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000594768500006 Publication Date 2020-09-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.2 Times cited 4 Open Access OpenAccess
Notes (up) A.B. D.J. and J.V. acknowledge funding through FWO project G093417N ('Compressed sensing enabling low dose imaging in transmission electron microscopy') from the Flanders Research Fund. J.V acknowledges funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3. The Qu-Ant-EM microscope and the direct electron detector used in the diffraction experiments was partly funded by the Hercules fund from the Flemish Government. This project has received funding from the GOA project “Solarpaint” of the University of Antwerp. GG acknowledges support from a postdoctoral fellowship grant from the Fonds Wetenschappelijk Onderzoek – Vlaanderen (FWO). Special thanks to Dr. Thomas Nuytten, Prof. Dr. Wilfried Vandervorst, Dr. Paola Favia, Dr. Olivier Richard from IMEC, Leuven and Prof. Dr. Sara Bals from EMAT, Antwerp for their continuous support and collaboration with the project and to the IMEC processing group for the device fabrication. Approved Most recent IF: 2.2; 2020 IF: 2.843
Call Number EMAT @ emat @c:irua:172485 Serial 6404
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Author Canossa, S.; Ferrari, E.; Sippel, P.; Fischer, J.K.H.; Pfattner, R.; Frison, R.; Masino, M.; Mas-Torrent, M.; Lunkenheimer, P.; Rovira, C.; Girlando, A.
Title Tetramethylbenzidine-TetrafluoroTCNQ (TMB-TCNQF(4)) : a narrow-gap semiconducting salt with room-temperature relaxor ferroelectric behavior Type A1 Journal article
Year 2021 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C
Volume 125 Issue 46 Pages 25816-25824
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract We present an extension and revision of the spectroscopic and structural data of the mixed-stack charge-transfer (CT) crystal 3,3 ',5,5 '-tetramethylbenzidine-tetrafluorotetracyano-quinodimethane (TMB-TCNQF4), associated with new electric and dielectric measurements. Refinement of synchrotron structural data at low temperature has led to revise the previously reported C2/m structure. The revised structure is P2(1)/m, with two dimerized stacks per unit cell, and is consistent with the low temperature vibrational data. However, polarized Raman data in the low-frequency region also indicate that by increasing temperature above 200 K, the structure presents an increasing degree of disorder, mainly along the stack axis. X-ray diffraction data at room temperature have confirmed that the correct structure is P2(1)/ m -no phase transitions -but did not allow substantiating the presence of disorder. On the other hand, dielectric measurements have evidenced a typical relaxor ferroelectric behavior already at room temperature, with a peak in the real part of dielectric constant epsilon'(T,v) around 200 K and 0.1 Hz. The relaxor behavior is explained in terms of the presence of spin solitons separating domains of opposite polarity that yield to ferroelectric nanodomains. TMB-TCNQF(4) is confirmed to be a narrow-gap band semiconductor (Ea similar to 0.3 eV) with a room-temperature conductivity of similar to 10(-4) Omega(-1) cm(-1).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000731170500008 Publication Date 0000-00-00
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 (up) A.G. thanks Prof. Pascale Foury-Leylekian for very helpful discussions about the crystallographic issues. R.F. thanks Prof. Anthony Linden for his help in the X-ray diffraction data collection. J.K.H.F. and P.L. acknowledge funding from the Deutsche Forschungsgemeinschaft (DFG) via the Transregional Collaborative Research Center TRR80 (Augsburg, Munich). R.P. and M.M.-T. acknowledge support from the Marie Curie Cofund, Beatriu de Pinós Fellowships (Grant nos. AGAUR 2017 BP 00064). This work was also supported by the Spanish Ministry project GENESIS PID2019-111682RBI00, the “Severo Ochoa” Programme for Centers of Excellence in R&D (FUNFUTURE, CEX2019-000917-S), and the Generalitat de Catalunya (2017-SGR-918). The Elettra Synchrotron (CNR Trieste) is acknowledged for granting the beamtime at the single-crystal diffraction beamline XRD1 (Proposal ID 20185483). In Parma, the work has benefited from the equipment and support of the COMP-HUB Initiative, funded by the “Departments of Excellence” program of the Approved Most recent IF: 4.536
Call Number UA @ admin @ c:irua:184866 Serial 7066
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Author Kirkwood, N.; De Backer, A.; Altantzis, T.; Winckelmans, N.; Longo, A.; Antolinez, F.V.; Rabouw, F.T.; De Trizio, L.; Geuchies, J.J.; Mulder, J.T.; Renaud, N.; Bals, S.; Manna, L.; Houtepen, A.J.
Title Locating and controlling the Zn content in In(Zn)P quantum dots Type A1 Journal article
Year 2019 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 32 Issue 32 Pages 557-565
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Zinc is routinely employed in the synthesis of InP quantum dots (QDs) to improve the photoluminescence efficiency and carrier mobility of the resulting In(Zn)P alloy nanostructures. The exact location of Zn in the final structures and the mechanism by which it enhances the optoelectronic properties of the QDs is debated. We use synchrotron X-ray absorbance spectroscopy to show that the majority of Zn in In(Zn)P QDs is located at their surface as Zn-carboxylates. However, a small amount of Zn is present inside the bulk of the QDs with the consequent contraction of their lattice, as confirmed by combining high resolution high-angle annular dark-field imaging scanning transmission electron microscopy (HAADF-STEM) with statistical parameter estimation theory. We further demonstrate that the Zn content and its incorporation into the QDs can be tuned by the ligation of commonly employed Zn carboxylate precursors: the use of highly reactive Zn-acetate leads to the formation of undesired Zn3P2 and the final nanostructures being characterized by broad optical features, whereas Zn-carboxylates with longer carbon chains lead to InP crystals with much lower zinc content and narrow optical features. These results can explain the differences between structural and optical properties of In(Zn)P samples reported across the literature, and provide a rational method to tune the amount of Zn in InP nanocrystals and to drive the incorporation of Zn either as surface Zn-carboxylate, as a substitutional dopant inside the InP crystal lattice, or even predominantly as Zn3P2.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000507721600056 Publication Date 2019-12-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 39 Open Access OpenAccess
Notes (up) A.J.H. acknowledges support from the European Research Council Horizon 2020 ERC Grant Agreement No. 678004 (Doping on Demand). This research is supported by the Dutch Technology Foundation TTW, which is part of The Netherlands Organization for Scientific Research (NWO), and which is partly funded by Ministry of Economic Affairs. SB acknowledges funding from the European Research Council (grant 815128 REALNANO). The authors gratefully acknowledge funding from the Research Foundation Flanders (FWO, Belgium) through project funding G.0381.16N and a postdoctoral grant to A.D.B. AJH, LM and JM acknowledge support from the H2020 Collaborative Project TEQ (Grant No. 766900).; sygma Approved Most recent IF: 9.466
Call Number EMAT @ emat @c:irua:165234 Serial 5438
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Author Turner, S.; Verbeeck, J.; Ramezanipour, F.; Greedan, J.E.; Van Tendeloo, G.; Botton, G.A.
Title Atomic resolution coordination mapping in Ca2FeCoO5 brownmillerite by spatially resolved electron energy-loss spectroscopy Type A1 Journal article
Year 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 24 Issue 10 Pages 1904-1909
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Using a combination of high-angle annular dark field scanning transmission electron microscopy and atomically resolved electron energy-loss spectroscopy at high energy resolution in an aberration-corrected electron microscope, we demonstrate the capability of coordination mapping in complex oxides. Brownmillerite compound Ca2FeCoO5, consisting of repetitive octahedral and tetrahedral coordination layers with Fe and Co in a fixed 3+ valency, is selected to demonstrate the principle of atomic resolution coordination mapping. Analysis of the Co-L2,3 and the Fe-L2,3 edges shows small variations in the fine structure that can be specifically attributed to Co/Fe in tetrahedral or in octahedral coordination. Using internal reference spectra, we show that the coordination of the Fe and Co atoms in the compound can be mapped at atomic resolution.
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Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000304237500024 Publication Date 2012-04-25
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 33 Open Access
Notes (up) A.M. Abakumov is thanked for fruitful discussions. S.T. gratefully acknowledges the Fund for Scientific Research Flanders (FWO). J.E.G. and GAB. acknowledge the support of the NSERC of Canada through Discovery Grants. The Canadian Centre for Electron Microscopy is a National Facility supported by NSERC and McMaster University and was funded by the Canada Foundation for Innovation and the Ontario Government. Part of this work was supported by funding from the European Research Council under the FP7, ERC Grant N 246791 COUNTATOMS and ERC Starting Grant N 278510 VORTEX. The EMAT microscope is partially funded by the Hercules fund of the Flemish Government. ECASJO_; Approved Most recent IF: 9.466; 2012 IF: 8.238
Call Number UA @ lucian @ c:irua:98379UA @ admin @ c:irua:98379 Serial 175
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