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Author Pramanik, G.; Kvakova, K.; Thottappali, M.A.; Rais, D.; Pfleger, J.; Greben, M.; El-Zoka, A.; Bals, S.; Dracinsky, M.; Valenta, J.; Cigler, P.
Title Inverse heavy-atom effect in near infrared photoluminescent gold nanoclusters Type A1 Journal article
Year 2021 Publication Nanoscale Abbreviated Journal (up) Nanoscale
Volume 12 Issue 23 Pages 10462-10467
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Fluorophores functionalized with heavy elements show enhanced intersystem crossing due to increased spin-orbit coupling, which in turn shortens the fluorescence decay lifetime (tau(PL)). This phenomenon is known as the heavy-atom effect (HAE). Here, we report the observation of increased tau(PL) upon functionalisation of near-infrared photoluminescent gold nanoclusters with iodine. The heavy atom-mediated increase in tau(PL) is in striking contrast with the HAE and referred to as inverse HAE. Femtosecond and nanosecond transient absorption spectroscopy revealed overcompensation of a slight decrease in lifetime of the transition associated with the Au core (ps) by a large increase in the long-lived triplet state lifetime associated with the Au shell, which contributed to the observed inverse HAE. This unique observation of inverse HAE in gold nanoclusters provides the means to enhance the triplet excited state lifetime.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000657052500001 Publication Date 2021-06-30
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 1 Open Access OpenAccess
Notes The authors acknowledge support from GACR project no. 18-12533S. G. P. acknowledges support from EUSMI project no. E180200060; J. P. from the Ministry of Education, Youth and Sports of the Czech Republic – Program INTER-EXCELLENCE (LTAUSA19066). Approved Most recent IF: 7.367
Call Number UA @ admin @ c:irua:179052 Serial 6843
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Author Pramanik, G.; Kvakova, K.; Thottappali, M.A.; Rais, D.; Pfleger, J.; Greben, M.; El-Zoka, A.; Bals, S.; Dracinsky, M.; Valenta, J.; Cigler, P.
Title Inverse heavy-atom effect in near infrared photoluminescent gold nanoclusters Type A1 Journal Article
Year 2021 Publication Nanoscale Abbreviated Journal (up) Nanoscale
Volume 13 Issue 23 Pages 10462-10467
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract Fluorophores functionalized with heavy elements show enhanced intersystem crossing due to increased spin–orbit coupling, which in turn shortens the fluorescence decay lifetime (<italic>τ</italic><sup>PL</sup>). This phenomenon is known as the heavy-atom effect (HAE). Here, we report the observation of increased<italic>τ</italic><sup>PL</sup>upon functionalisation of near-infrared photoluminescent gold nanoclusters with iodine. The heavy atom-mediated increase in<italic>τ</italic><sup>PL</sup>is in striking contrast with the HAE and referred to as inverse HAE. Femtosecond and nanosecond transient absorption spectroscopy revealed overcompensation of a slight decrease in lifetime of the transition associated with the Au core (ps) by a large increase in the long-lived triplet state lifetime associated with the Au shell, which contributed to the observed inverse HAE. This unique observation of inverse HAE in gold nanoclusters provides the means to enhance the triplet excited state lifetime.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2021-05-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364 ISBN Additional Links
Impact Factor 7.367 Times cited 7 Open Access OpenAccess
Notes The authors acknowledge support from GACR project Nr.18- 12533S. G. P. acknowledges support from EUSMI project No. E180200060; J.P. from the Ministry of Education, Youth and Sports of the Czech Republic – Program INTER-EXCELLENCE (LTAUSA19066). Approved Most recent IF: 7.367
Call Number EMAT @ emat @ Serial 6950
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Author Yagmurcukardes, M.; Sozen, Y.; Baskurt, M.; Peeters, F.M.; Sahin, H.
Title Interface-dependent phononic and optical properties of GeO/MoSO heterostructures Type A1 Journal article
Year 2021 Publication Nanoscale Abbreviated Journal (up) Nanoscale
Volume Issue Pages
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract The interface-dependent electronic, vibrational, piezoelectric, and optical properties of van der Waals heterobilayers, formed by buckled GeO (b-GeO) and Janus MoSO structures, are investigated by means of first-principles calculations. The electronic band dispersions show that O/Ge and S/O interface formations result in a type-II band alignment with direct and indirect band gaps, respectively. In contrast, O/O and S/Ge interfaces give rise to the formation of a type-I band alignment with an indirect band gap. By considering the Bethe-Salpeter equation (BSE) on top of G(0)W(0) approximation, it is shown that different interfaces can be distinguished from each other by means of the optical absorption spectra as a consequence of the band alignments. Additionally, the low- and high-frequency regimes of the Raman spectra are also different for each interface type. The alignment of the individual dipoles, which is interface-dependent, either weakens or strengthens the net dipole of the heterobilayers and results in tunable piezoelectric coefficients. The results indicate that the possible heterobilayers of b-GeO/MoSO asymmetric structures possess various electronic, optical, and piezoelectric properties arising from the different interface formations and can be distinguished by means of various spectroscopic techniques.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000738899600001 Publication Date 2021-12-09
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 5 Open Access Not_Open_Access
Notes Approved Most recent IF: 7.367
Call Number UA @ admin @ c:irua:184722 Serial 6998
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Author Fatermans, J.; Romolini, G.; Altantzis, T.; Hofkens, J.; Roeffaers, M.B.J.; Bals, S.; Van Aert, S.
Title Atomic-scale detection of individual lead clusters confined in Linde Type A zeolites Type A1 Journal article
Year 2022 Publication Nanoscale Abbreviated Journal (up) Nanoscale
Volume Issue Pages
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract Structural analysis of metal clusters confined in nanoporous materials is typically performed by X-ray-driven techniques. Although X-ray analysis has proved its strength in the characterization of metal clusters, it provides averaged structural information. Therefore, we here present an alternative workflow for bringing the characterization of confined metal clusters towards the local scale. This workflow is based on the combination of aberration-corrected transmission electron microscopy (TEM), TEM image simulations, and powder X-ray diffraction (XRD) with advanced statistical techniques. In this manner, we were able to characterize the clustering of Pb atoms in Linde Type A (LTA) zeolites with Pb loadings as low as 5 wt%. Moreover, individual Pb clusters could be directly detected. The proposed methodology thus enables a local-scale characterization of confined metal clusters in zeolites. This is important for further elucidation of the connection between the structure and the physicochemical properties of such systems.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000809619900001 Publication Date 0000-00-00
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 6.7 Times cited 2 Open Access OpenAccess
Notes The authors acknowledge the Research Foundation Flanders through project fundings (FWO, G026718N, G050218N, ZW15_09-G0H6316N, and W002221N) and through a PhD scholarship to G.R. (grant 11C6920N), as well as iBOF-21-085 PERSIST. T.A. and S.V.A. acknowledge funding from the University of Antwerp Research fund (BOF). J.H. acknowledges the Flemish government through long-term structural funding Methusalem (CASAS2, Meth/15/04) and the MPI as MPI fellow. M.R. acknowledges funding by the KU Leuven Research Fund (C14/19/079). S.B. and S.V.A. acknowledge funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program (ERC Consolidator Grants No. 815128−REALNANO and No. 770887−PICOMETRICS). The authors thank Dr. D. Chernyshov for the collection of XRD measurements. Approved Most recent IF: 6.7
Call Number EMAT @ emat @c:irua:189061 Serial 7076
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Author Wang, Y.; Sztranyovszky, Z.; Zilli, A.; Albrecht, W.; Bals, S.; Borri, P.; Langbein, W.
Title Quantitatively linking morphology and optical response of individual silver nanohedra Type A1 Journal article
Year 2022 Publication Nanoscale Abbreviated Journal (up) Nanoscale
Volume 14 Issue 30 Pages 11028-11037
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The optical response of metal nanoparticles is governed by plasmonic resonances, which are dictated by the particle morphology. A thorough understanding of the link between morphology and optical response requires quantitatively measuring optical and structural properties of the same particle. Here we present such a study, correlating electron tomography and optical micro-spectroscopy. The optical measurements determine the scattering and absorption cross-section spectra in absolute units, and electron tomography determines the 3D morphology. Numerical simulations of the spectra for the individual particle geometry, and the specific optical set-up used, allow for a quantitative comparison including the cross-section magnitude. Silver nanoparticles produced by photochemically driven colloidal synthesis, including decahedra, tetrahedra and bi-tetrahedra are investigated. A mismatch of measured and simulated spectra is found in some cases when assuming pure silver particles, which is explained by the presence of a few atomic layers of tarnish on the surface, not evident in electron tomography. The presented method tightens the link between particle morphology and optical response, supporting the predictive design of plasmonic nanomaterials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000828704000001 Publication Date 2022-07-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364; 2040-3372 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited 1 Open Access OpenAccess
Notes Z.S. acknowledges the UK Engineering and Physical Sciences Research Council (EPSRC) for his Ph.D. studentship award (grant EP/R513003/1). Y.W. acknowledges Iwan Moreels (University of Ghent) for training in nanoparticle synthesis. Y.W. acknowledges the Biotechnology and Biological Sciences Research Council (BBSRC) for his Ph.D. studentship award (grant BB/L015889/1). This work was supported by the UK EPSRC (grants EP/I005072/1 and EP/M028313/1), and by the European Commission (EUSMI E191000350). W.A. acknowledges an Individual Fellowship from the Marie Skodowska-Curie actions (MSCA) under the EU's Horizon 2020 program (Grant 797153, SOPMEN). We thank Lukas Payne and Iestyn Pope for contributions to the development of the hardware and software used for the optical measurements. Approved Most recent IF: 6.7
Call Number UA @ admin @ c:irua:189578 Serial 7092
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Author Bekaert, J.; Sevik, C.; Milošević, M.V.
Title Enhancing superconductivity in MXenes through hydrogenation Type A1 Journal article
Year 2022 Publication Nanoscale Abbreviated Journal (up) Nanoscale
Volume 14 Issue 27 Pages 9918-9924
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Two-dimensional transition metal carbides and nitrides (MXenes) are an emerging class of atomically-thin superconductors, whose characteristics are highly prone to tailoring by surface functionalization. Here we explore the use of hydrogen adatoms to enhance phonon-mediated superconductivity in MXenes, based on first-principles calculations combined with Eliashberg theory. We first demonstrate the stability of three different structural models of hydrogenated Mo- and W-based MXenes. Particularly high critical temperatures of over 30 K are obtained for hydrogenated Mo2N and W2N. Several mechanisms responsible for the enhanced electron-phonon coupling are uncovered, namely (i) hydrogen-induced changes in the phonon spectrum of the host MXene, (ii) emerging hydrogen-based phonon modes, and (iii) charge transfer from hydrogen to the MXene layer, boosting the density of states at the Fermi level. Finally, we demonstrate that hydrogen adatoms are moreover able to induce superconductivity in MXenes that are not superconducting in pristine form, such as Nb2C.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000820350600001 Publication Date 2022-06-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364; 2040-3372 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited 2 Open Access OpenAccess
Notes Approved Most recent IF: 6.7
Call Number UA @ admin @ c:irua:189580 Serial 7155
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Author Faraji, F.; Neek-Amal, M.; Neyts, E.C.; Peeters, F.M.
Title Indentation of graphene nano-bubbles Type A1 Journal article
Year 2022 Publication Nanoscale Abbreviated Journal (up) Nanoscale
Volume 14 Issue 15 Pages 5876-5883
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Molecular dynamics simulations are used to investigate the effect of an AFM tip when indenting graphene nano bubbles filled by a noble gas (i.e. He, Ne and Ar) up to the breaking point. The failure points resemble those of viral shells as described by the Foppl-von Karman (FvK) dimensionless number defined in the context of elasticity theory of thin shells. At room temperature, He gas inside the bubbles is found to be in the liquid state while Ne and Ar atoms are in the solid state although the pressure inside the nano bubble is below the melting pressure of the bulk. The trapped gases are under higher hydrostatic pressure at low temperatures than at room temperature.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000776763000001 Publication Date 2022-03-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364; 2040-3372 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited 2 Open Access OpenAccess
Notes Approved Most recent IF: 6.7
Call Number UA @ admin @ c:irua:187924 Serial 7171
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Author Frolov, A.S.; Callaert, C.; Batuk, M.; Hadermann, J.; Volykhov, A.A.; Sirotina, A.P.; Amati, M.; Gregoratti, L.; Yashina, L.V.
Title Nanoscale phase separation in the oxide layer at GeTe (111) surfaces Type A1 Journal article
Year 2022 Publication Nanoscale Abbreviated Journal (up) Nanoscale
Volume 14 Issue 35 Pages 12918-12927
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract As a semiconductor ferroelectric, GeTe has become a focus of renewed attention due to the recent discovery of giant Rashba splitting. It already has a wide range of applications, from thermoelectricity to data storage. Its stability in ambient air, as well as the structure and properties of an oxide layer, define the processing media for device production and operation. Here, we studied a reaction between the GeTe (111) surface and molecular oxygen for crystals having solely inversion domains. We evaluated the reaction kinetics both ex situ and in situ using NAP XPS. The structure of the oxide layer is extensively discussed, where, according to HAADF-STEM and STEM-EDX, nanoscale phase separation of GeO2 and Te is observed, which is unusual for semiconductors. We believe that such behaviour is closely related to the ferroelectric properties and the domain structure of GeTe.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000847743300001 Publication Date 2022-08-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364; 2040-3372 ISBN Additional Links UA library record; WoS full record
Impact Factor 6.7 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 6.7
Call Number UA @ admin @ c:irua:190665 Serial 7181
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Author Abedi, S.; Sisakht, E.T.; Hashemifar, S.J.; Cherati, N.G.; Sarsari, I.A.; Peeters, F.M.
Title Prediction of novel two-dimensional Dirac nodal line semimetals in Al₂B₂ and AlB₄ monolayers Type A1 Journal article
Year 2022 Publication Nanoscale Abbreviated Journal (up) Nanoscale
Volume 14 Issue 31 Pages 11270-11283
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Topological semimetal phases in two-dimensional (2D) materials have gained widespread interest due to their potential applications in novel nanoscale devices. Despite the growing number of studies on 2D topological nodal lines (NLs), candidates with significant topological features that combine nontrivial topological semimetal phase with superconductivity are still rare. Herein, we predict Al2B2 and AlB4 monolayers as new 2D nonmagnetic Dirac nodal line semimetals with several novel features. Our extensive electronic structure calculations combined with analytical studies reveal that, in addition to multiple Dirac points, these 2D configurations host various highly dispersed NLs around the Fermi level, all of which are semimetal states protected by time-reversal and in-plane mirror symmetries. The most intriguing NL in Al2B2 encloses the K point and crosses the Fermi level, showing a considerable dispersion and thus providing a fresh playground to explore exotic properties in dispersive Dirac nodal lines. More strikingly, for the AlB4 monolayer, we provide the first evidence for a set of 2D nonmagnetic open type-II NLs coexisting with superconductivity at a rather high transition temperature. The coexistence of superconductivity and nontrivial band topology in AlB4 not only makes it a promising material to exhibit novel topological superconducting phases, but also a rather large energy dispersion of type-II nodal lines in this configuration may offer a platform for the realization of novel topological features in the 2D limit.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000831003900001 Publication Date 2022-06-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364; 2040-3372 ISBN Additional Links UA library record; WoS full record
Impact Factor 6.7 Times cited 5 Open Access Not_Open_Access
Notes Approved Most recent IF: 6.7
Call Number UA @ admin @ c:irua:189505 Serial 7196
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Author Khalilov, U.; Vets, C.; Neyts, E.C.
Title Molecular evidence for feedstock-dependent nucleation mechanisms of CNTs Type A1 Journal article
Year 2019 Publication Nanoscale Horizons Abbreviated Journal (up) Nanoscale Horiz.
Volume 4 Issue 3 Pages 674-682
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Atomic scale simulations have been shown to be a powerful tool for elucidating the growth mechanisms of carbon nanotubes. The growth picture is however not entirely clear yet due to the gap between current simulations and real experiments. We here simulate for the first time the nucleation and subsequent growth of single-wall carbon nanotubes (SWNTs) from oxygen-containing hydrocarbon feedstocks using the hybrid Molecular Dynamics/Monte Carlo technique. The underlying nucleation mechanisms of Ni-catalysed SWNT growth are discussed in detail. Specifically, we find that as a function of the feedstock, different carbon fractions may emerge as the main growth species, due to a competition between the feedstock decomposition, its rehydroxylation and its contribution to etching of the growing SWNT. This study provides a further understanding of the feedstock effects in SWNT growth in comparison with available experimental evidence as well as with<italic>ab initio</italic>and other simulation data, thereby reducing the simulation–experiment gap.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000471816500011 Publication Date 2019-01-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2055-6756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 1 Open Access Not_Open_Access: Available from 03.01.2020
Notes Fonds Wetenschappelijk Onderzoek, 12M1318N 1S22516N ; The authors gratefully acknowledge financial support from the Research Foundation Flanders (FWO), Belgium (Grant numbers 12M1318N and 1S22516N). The work was carried out in part using the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Centre VSC, funded by FWO and the Flemish Government (Department EWI). We thank Prof. A. C. T. van Duin for sharing the reax-code and forcefield parameters. Approved Most recent IF: NA
Call Number PLASMANT @ plasmant @UA @ admin @ c:irua:159658 Serial 5169
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Author Zarenia, M.; Pereira, J.M.; Peeters, F.M.; Farias, G. de A.
Title Topological confinement in an antisymmetric potential in bilayer graphene in the presence of a magnetic field Type A1 Journal article
Year 2011 Publication Nanoscale research letters Abbreviated Journal (up) Nanoscale Res Lett
Volume 6 Issue Pages 452,1-452,10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate the effect of an external magnetic field on the carrier states that are localized at a potential kink and a kink-antikink in bilayer graphene. These chiral states are localized at the interface between two potential regions with opposite signs.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000293299800001 Publication Date 2011-07-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1556-276X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.833 Times cited 4 Open Access
Notes ; This work was supported by the Brazilian agency CNPq (Pronex), the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the bilateral projects between Flanders and Brazil and FWO-CNPq. ; Approved Most recent IF: 2.833; 2011 IF: NA
Call Number UA @ lucian @ c:irua:91745 Serial 3674
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