Records |
Author |
Samaee, V.; Dupraz, M.; Pardoen, T.; VAn Swygenhoven, H.; Schryvers, D.; Idrissi, H. |
Title |
Deciphering the interactions between single arm dislocation sources and coherent twin boundary in nickel bi-crystal |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat Commun |
Volume |
12 |
Issue |
1 |
Pages |
962 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The introduction of a well-controlled population of coherent twin boundaries (CTBs) is an attractive route to improve the strength ductility product in face centered cubic (FCC) metals. However, the elementary mechanisms controlling the interaction between single arm dislocation sources (SASs), often present in nanotwinned FCC metals, and CTB are still not well understood. Here, quantitative in-situ transmission electron microscopy (TEM) observations of these mechanisms under tensile loading are performed on submicron Ni bi-crystal. We report that the absorption of curved screw dislocations at the CTB leads to the formation of constriction nodes connecting pairs of twinning dislocations at the CTB plane in agreement with large scale 3D atomistic simulations. The coordinated motion of the twinning dislocation pairs due to the presence of the nodes leads to a unique CTB sliding mechanism, which plays an important role in initiating the fracture process at a CTB ledge. TEM observations of the interactions between non-screw dislocations and the CTB highlight the importance of the synergy between the repulsive force of the CTB and the back stress from SASs when the interactions occur in small volumes. Interactions of dislocations with coherent twin boundaries contribute to strength and ductility in metals, but investigating the interaction mechanisms is challenging. Here the authors unravel these mechanisms through quantitative in-situ transmission electron microscopy observations in nickel bi-crystal samples under tensile loading. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000620142700024 |
Publication Date |
2021-02-11 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 12.124 |
Call Number |
UA @ admin @ c:irua:176680 |
Serial |
6722 |
Permanent link to this record |
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Author |
Wang, H.S.; Chen, L.; Elibol, K.; He, L.; Wang, H.; Chen, C.; Jiang, C.; Li, C.; Wu, T.; Cong, C.X.; Pennycook, T.J.; Argentero, G.; Zhang, D.; Watanabe, K.; Taniguchi, T.; Wei, W.; Yuan, Q.; Meyer, J.C.; Xie, X. |
Title |
Towards chirality control of graphene nanoribbons embedded in hexagonal boron nitride |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Nature Materials |
Abbreviated Journal |
Nat Mater |
Volume |
|
Issue |
|
Pages |
1-10 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Oriented trenches are created in h-BN using different catalysts, and used as templates to grow seamlessly integrated armchair and zigzag graphene nanoribbons with chirality-dependent electrical and magnetic conductance properties. The integrated in-plane growth of graphene nanoribbons (GNRs) and hexagonal boron nitride (h-BN) could provide a promising route to achieve integrated circuitry of atomic thickness. However, fabrication of edge-specific GNRs in the lattice of h-BN still remains a significant challenge. Here we developed a two-step growth method and successfully achieved sub-5-nm-wide zigzag and armchair GNRs embedded in h-BN. Further transport measurements reveal that the sub-7-nm-wide zigzag GNRs exhibit openings of the bandgap inversely proportional to their width, while narrow armchair GNRs exhibit some fluctuation in the bandgap-width relationship. An obvious conductance peak is observed in the transfer curves of 8- to 10-nm-wide zigzag GNRs, while it is absent in most armchair GNRs. Zigzag GNRs exhibit a small magnetic conductance, while armchair GNRs have much higher magnetic conductance values. This integrated lateral growth of edge-specific GNRs in h-BN provides a promising route to achieve intricate nanoscale circuits. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000571692500001 |
Publication Date |
2020-09-21 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1476-1122; 1476-4660 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
41.2 |
Times cited |
3 |
Open Access |
Not_Open_Access |
Notes |
; H.W. and X.X. thank J.H. Edgar (Kansas State University, USA) for supplying the partial h-BN crystals. H. S. Wang, L. Chen and H. Wang thank M. Liu, X. Qiu and J. Pan from NCNT of China, F. Liou, H. Tsai, M. Crommie from UCB, USA, J. Xue and P. Yu from ShanghaiTech University and S. Wang from SJTU for nc-AFM measurement. H. S. Wang, L. Chen and H. Wang thank B. Sun and S. Li from Hunan University for the fusion of the STEM image and the electron energy loss spectroscopy mapping images. Funding: The work was partially supported by the National Key R&D program (Grant No. 2017YFF0206106), the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB30000000), the National Science Foundation of China (Grant No. 51772317, 51302096, 61774040, 91964102), the Science and Technology Commission of Shanghai Municipality (Grant No. 16ZR1442700, 16ZR1402500 18511110700), Shanghai Rising-Star Program (A type) (Grant No.18QA1404800), the Hubei Provincial Natural Science Foundation of China (Grant No. ZRMS2017000370), China Postdoctoral Science Foundation (Grant No. 2017M621563, 2018T110415), and the Fundamental Research Funds of Wuhan City (No. 2016060101010075). C.L. acknowledges support from the European Union's Horizon 2020 research and innovation programme under the Marie Skodowska-Curie grants No. 656378 – Interfacial Reactions. T.J.P. acknowledges funding from European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie grant agreement no. 655760-DIGIPHASE. K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by the MEXT, Japan and the CREST (JPMJCR15F3), JST. C.X.C. acknowledges financial support from the National Young 1000 Talent Plan of China and the National Key R&D Program of China (No. 2018YFA0703700). L.H. acknowledges financial support from the programme of China Scholarships Council (No. 201706160037). ; |
Approved |
Most recent IF: 41.2; 2020 IF: 39.737 |
Call Number |
UA @ admin @ c:irua:171944 |
Serial |
6633 |
Permanent link to this record |
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Author |
Wang, D.; Dasgupta, T.; van der Wee, E.B.; Zanaga, D.; Altantzis, T.; Wu, Y.; Coli, G.M.; Murray, C.B.; Bals, S.; Dijkstra, M.; van Blaaderen, A. |
Title |
Binary icosahedral clusters of hard spheres in spherical confinement |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Nature Physics |
Abbreviated Journal |
Nat Phys |
Volume |
|
Issue |
|
Pages |
1-9 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) |
Abstract |
The influence of geometry on the local and global packing of particles is important to many fundamental and applied research themes, such as the structure and stability of liquids, crystals and glasses. Here we show by experiments and simulations that a binary mixture of hard-sphere-like nanoparticles crystallizing into a MgZn(2)Laves phase in bulk spontaneously forms icosahedral clusters in slowly drying droplets. Using advanced electron tomography, we are able to obtain the real-space coordinates of all the spheres in the icosahedral clusters of up to about 10,000 particles. The local structure of 70-80% of the particles became similar to that of the MgCu(2)Laves phase. These observations are important for photonic applications. In addition, we observed in simulations that the icosahedral clusters nucleated away from the spherical boundary, which is distinctly different from that of the single species clusters. Our findings open the way for particle-level studies of nucleation and growth of icosahedral clusters, and of binary crystallization. The authors investigate out-of-equilibrium crystallization of a binary mixture of sphere-like nanoparticles in small droplets. They observe the spontaneous formation of an icosahedral structure with stable MgCu(2)phases, which are promising for photonic applications. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000564497300002 |
Publication Date |
2020-08-31 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
1745-2473; 1745-2481 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
19.6 |
Times cited |
38 |
Open Access |
OpenAccess |
Notes |
; D.W., E.B.v.d.W. and A.v.B. acknowledge partial financial support from the European Research Council under the European Union's Seventh Framework Programme (FP-2007-2013)/ERC Advanced Grant Agreement 291667 HierarSACol. T.D. and M. D. acknowledge financial support from the Industrial Partnership Programme, 'Computational Sciences for Energy Research' (grant number 13CSER025), of the Netherlands Organization for Scientific Research (NWO), which was co-financed by Shell Global Solutions International BV G.M.C. was also financially supported by NWO. S.B. acknowledges financial support from ERC Consolidator Grant Number 815128 REALNANO. T.A. acknowledges a post-doctoral grant from the Research Foundation Flanders (FWO, Belgium). C.B.M. and Y.W. acknowledge support for materials synthesis from the Office of Naval Research Multidisciplinary University Research Initiative Award ONR N00014-18-1-2497. G. A. Blab is gratefully acknowledged for 3D printing numerous truncated tetrahedra, which increased our understanding of the connection between the binary icosahedral cluster and Laves phase structures. N. Tasios is sincerely thanked for providing the code for the diffraction pattern calculation. M. Hermes is sincerely thanked for providing interactive views of the structures in this work. We thank G. van Tendeloo, M. Engel, J. Wang, S. Dussi, L. Filion, E. Boattini, S. Paliwal, N. Tasios, B. van der Meer, I. Lobato, J. Wu and L. Laurens for fruitful discussions. We acknowledge the EM Square centre at Utrecht University for the access to the microscopes. ; sygma |
Approved |
Most recent IF: 19.6; 2020 IF: 22.806 |
Call Number |
UA @ admin @ c:irua:172044 |
Serial |
6460 |
Permanent link to this record |
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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 |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000559831500012 |
Publication Date |
2020-08-12 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0028-0836 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
64.8 |
Times cited |
109 |
Open Access |
Not_Open_Access |
Notes |
; ; |
Approved |
Most recent IF: 64.8; 2020 IF: 40.137 |
Call Number |
UA @ admin @ c:irua:171150 |
Serial |
6513 |
Permanent link to this record |
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Author |
Choisez, L.; Ding, L.; Marteleur, M.; Idrissi, H.; Pardoen, T.; Jacques, P.J. |
Title |
High temperature rise dominated cracking mechanisms in ultra-ductile and tough titanium alloy |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat Commun |
Volume |
11 |
Issue |
1 |
Pages |
2110 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Extensive use of titanium alloys is partly hindered by a lack of ductility, strain hardening, and fracture toughness. Recently, several beta -metastable titanium alloys were designed to simultaneously activate both transformation-induced plasticity and twinning-induced plasticity effects, resulting in significant improvements to their strain hardening capacity and resistance to plastic localization. Here, we report an ultra-large fracture resistance in a Ti-12Mo alloy (wt.%), that results from a high resistance to damage nucleation, with an unexpected fracture phenomenology under quasi-static loading. Necking develops at a large uniform true strain of 0.3 while fracture initiates at a true fracture strain of 1.0 by intense through-thickness shear within a thin localized shear band. Transmission electron microscopy reveals that dynamic recrystallization occurs in this band, while local partial melting is observed on the fracture surface. Shear band temperatures of 1250-2450 degrees C are estimated by the fusible coating method. The reported high ductility combined to the unconventional fracture process opens alternative avenues toward Ti alloys toughening. Specific titanium alloys combine transformation-induced plasticity and twinning-induced plasticity for improved work hardening. Here, the authors show that these alloys also have an ultra-large fracture resistance and an unexpected fracture mechanism via dynamic recrystallization and local melting in a deformation band. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000558816700010 |
Publication Date |
2020-04-30 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
16.6 |
Times cited |
1 |
Open Access |
OpenAccess |
Notes |
; The Fonds National de Recherche Scientifique FNRS is gratefully acknowledged for the grant no. T.0127.19, the research grant of L.C. and the research mandate of H.I. The authors are thankful to J. Adrien and E. Maire for their help with the X-ray tomography analysis, to J.D. Embury for the fruitful discussions and to F. Prima for provisioning the material. ; |
Approved |
Most recent IF: 16.6; 2020 IF: 12.124 |
Call Number |
UA @ admin @ c:irua:171318 |
Serial |
6536 |
Permanent link to this record |
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Author |
Bourgeois, L.; Zhang, Y.; Zhang, Z.; Chen, Y.; Medhekar, N., V |
Title |
Transforming solid-state precipitates via excess vacancies |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat Commun |
Volume |
11 |
Issue |
1 |
Pages |
1248 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Many phase transformations associated with solid-state precipitation look structurally simple, yet, inexplicably, take place with great difficulty. A classic case of difficult phase transformations is the nucleation of strengthening precipitates in high-strength lightweight aluminium alloys. Here, using a combination of atomic-scale imaging, simulations and classical nucleation theory calculations, we investigate the nucleation of the strengthening phase theta' onto a template structure in the aluminium-copper alloy system. We show that this transformation can be promoted in samples exhibiting at least one nanoscale dimension, with extremely high nucleation rates for the strengthening phase as well as for an unexpected phase. This template-directed solid-state nucleation pathway is enabled by the large influx of surface vacancies that results from heating a nanoscale solid. Template-directed nucleation is replicated in a bulk alloy as well as under electron irradiation, implying that this difficult transformation can be facilitated under the general condition of sustained excess vacancy concentrations. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000549162600025 |
Publication Date |
2020-03-06 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
16.6 |
Times cited |
5 |
Open Access |
OpenAccess |
Notes |
; The authors are indebted to Matthew Weyland for his expert advice on aberrationcorrected scanning transmission electron microscopy. L.B. would like to acknowledge initial discussions with B.C. Muddle and J.F. Nie many years ago regarding the possible thermodynamic role of vacancies in solid-state precipitation. The authors acknowledge funding from the Australian Research Council (LE0454166, LE110100223), the Victorian State Government and Monash University for instrumentation, and use of the facilities within the Monash Centre for Electron Microscopy. The authors thank Flame Burgmann, Dougal McCulloch and Edwin Mayes for access to and assistance at the Microscopy and Microanalysis Facility at RMIT University. L.B. and N.M. acknowledge the financial support of the Australian Research Council (DP150100558). Authors also gratefully acknowledge the computational support from MonARCH, MASSIVE and the National Computing Infrastructure and Pawsey Supercomputing Centre. ZZ and YZ are thankful to Monash University for a Monash Graduate Scholarship, a Monash International Postgraduate Research Scholarship. Z.Z. is grateful for a Monash Centre for Electron Microscopy Postgraduate Scholarship. The authors are grateful to Anita Hill for advice. ; |
Approved |
Most recent IF: 16.6; 2020 IF: 12.124 |
Call Number |
UA @ admin @ c:irua:170797 |
Serial |
6635 |
Permanent link to this record |
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Author |
Haug, C.; Ruebeling, F.; Kashiwar, A.; Gumbsch, P.; Kübel, C.; Greiner, C. |
Title |
Early deformation mechanisms in the shear affected region underneath a copper sliding contact |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat Commun |
Volume |
11 |
Issue |
1 |
Pages |
839-8 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Dislocation mediated plastic deformation decisively influences the friction coefficient and the microstructural changes at many metal sliding interfaces during tribological loading. This work explores the initiation of a tribologically induced microstructure in the vicinity of a copper twin boundary. Two distinct horizontal dislocation traces lines (DTL) are observed in their interaction with the twin boundary beneath the sliding interface. DTL formation seems unaffected by the presence of the twin boundary but the twin boundary acts as an indicator of the occurring deformation mechanisms. Three concurrent elementary processes can be identified: simple shear of the subsurface area in sliding direction, localized shear at the primary DTL and crystal rotation in the layers above and between the DTLs around axes parallel to the transverse direction. Crystal orientation analysis demonstrates a strong compatibility of these proposed processes. Quantitatively separating these different deformation mechanisms is crucial for future predictive modeling of tribological contacts. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
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Publication Date |
2020-02-11 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2041-1723 |
ISBN |
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Additional Links |
UA library record |
Impact Factor |
16.6 |
Times cited |
|
Open Access |
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Notes |
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Approved |
Most recent IF: 16.6; 2020 IF: 12.124 |
Call Number |
UA @ admin @ c:irua:183619 |
Serial |
6863 |
Permanent link to this record |
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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. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000510860800012 |
Publication Date |
2020-01-24 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
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ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
11 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:167863 |
Serial |
6625 |
Permanent link to this record |
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Author |
Quan, L.N.; Ma, D.; Zhao, Y.; Voznyy, O.; Yuan, H.; Bladt, E.; Pan, J.; de Arquer, F.P.G.; Sabatini, R.; Piontkowski, Z.; Emwas, A.-H.; Todorovic, P.; Quintero-Bermudez, R.; Walters, G.; Fan, J.Z.; Liu, M.; Tan, H.; Saidaminov, M., I; Gao, L.; Li, Y.; Anjum, D.H.; Wei, N.; Tang, J.; McCamant, D.W.; Roeffaers, M.B.J.; Bals, S.; Hofkens, J.; Bakr, O.M.; Lu, Z.-H.; Sargent, E.H. |
Title |
Edge stabilization in reduced-dimensional perovskites |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat Commun |
Volume |
11 |
Issue |
1 |
Pages |
170 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Reduced-dimensional perovskites are attractive light-emitting materials due to their efficient luminescence, color purity, tunable bandgap, and structural diversity. A major limitation in perovskite light-emitting diodes is their limited operational stability. Here we demonstrate that rapid photodegradation arises from edge-initiated photooxidation, wherein oxidative attack is powered by photogenerated and electrically-injected carriers that diffuse to the nanoplatelet edges and produce superoxide. We report an edge-stabilization strategy wherein phosphine oxides passivate unsaturated lead sites during perovskite crystallization. With this approach, we synthesize reduced-dimensional perovskites that exhibit 97 +/- 3% photoluminescence quantum yields and stabilities that exceed 300 h upon continuous illumination in an air ambient. We achieve green-emitting devices with a peak external quantum efficiency (EQE) of 14% at 1000 cd m(-2); their maximum luminance is 4.5 x 10(4) cd m(-2) (corresponding to an EQE of 5%); and, at 4000 cd m(-2), they achieve an operational half-lifetime of 3.5 h. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000551458200001 |
Publication Date |
2020-01-10 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
16.6 |
Times cited |
147 |
Open Access |
OpenAccess |
Notes |
; This publication is based in part on work supported by an award (KUS-11-009-21) from the King Abdullah University of Science and Technology (KAUST), by the Ontario Research Fund Research Excellence Program, by the Ontario Research Fund (ORF), by the Natural Sciences and Engineering Research Council (NSERC) of Canada, and by the US Department of Navy, Office of Naval Research (Grant Award No. N00014-17-12524). H.Y. acknowledges the Research Foundation-Flanders (FWO Vlaanderen) for a postdoctoral fellowship. E.B. gratefully acknowledges financial support by the Research Foundation-Flanders (FWO Vlaanderen). S.B. acknowledges financial support from European Research Council (ERC Starting Grant #815128-REALNANO). M.B.J.R. and J.H. acknowledge the Research Foundation-Flanders (FWO, Grants G.0962.13, G.0B39.15, AKUL/11/14 and G0H6316N), KU Leuven Research Fund (C14/15/053) and the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013)/ ERC Grant Agreement No. [307523], ERC-Stg LIGHT to M.B.J.R. DFT calculations were performed on the IBM BlueGene Q supercomputer with support from the Southern Ontario Smart Computing Innovation Platform (SOSCIP). M.I.S. acknowledges the Banting Postdoctoral Fellowship program from the Natural Sciences and Engineering Research Council of Canada (NSERC). H.T. acknowledges the Netherlands Organisation for Scientific Research (NWO) for a Rubicon grant (680-50-1511). ; sygma |
Approved |
Most recent IF: 16.6; 2020 IF: 12.124 |
Call Number |
UA @ admin @ c:irua:171327 |
Serial |
6496 |
Permanent link to this record |
|
|
|
Author |
Du, K.; Zhang, M.; Dai, C.; Zhou, Z.N.; Xie, Y.W.; Ren, Z.H.; Tian, H.; Chen, L.Q.; Van Tendeloo, G.; Zhang, Z. |
Title |
Manipulating topological transformations of polar structures through real-time observation of the dynamic polarization evolution |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
10 |
Issue |
10 |
Pages |
4864 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Topological structures based on controllable ferroelectric or ferromagnetic domain configurations offer the opportunity to develop microelectronic devices such as high-density memories. Despite the increasing experimental and theoretical insights into various domain structures (such as polar spirals, polar wave, polar vortex) over the past decade, manipulating the topological transformations of polar structures and comprehensively understanding its underlying mechanism remains lacking. By conducting an in-situ non-contact bias technique, here we systematically investigate the real-time topological transformations of polar structures in PbTiO3/SrTiO3 multilayers at an atomic level. The procedure of vortex pair splitting and the transformation from polar vortex to polar wave and out-of-plane polarization are observed step by step. Furthermore, the redistribution of charge in various topological structures has been demonstrated under an external bias. This provides new insights for the symbiosis of polar and charge and offers an opportunity for a new generation of microelectronic devices. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
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Language |
|
Wos |
000492835100002 |
Publication Date |
2019-10-25 |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 12.124 |
Call Number |
UA @ admin @ c:irua:164681 |
Serial |
6307 |
Permanent link to this record |
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|
Author |
Chaves, A.; Neilson, D. |
Title |
Exotic state seen at high temperatures |
Type |
Editorial |
Year |
2019 |
Publication |
Nature |
Abbreviated Journal |
Nature |
Volume |
574 |
Issue |
7776 |
Pages |
39-40 |
Keywords |
Editorial; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
The phenomenon of Bose-Einstein condensation is typically limited to extremely low temperatures. The effect has now been spotted at much higher temperatures for particles called excitons in atomically thin semiconductors. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000488832500022 |
Publication Date |
2019-10-02 |
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 |
40.137 |
Times cited |
2 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 40.137 |
Call Number |
UA @ admin @ c:irua:163739 |
Serial |
5413 |
Permanent link to this record |
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|
|
Author |
Meysman, F.J.R.; Cornelissen, R.; Trashin, S.; Bonne, R.; Hidalgo-Martinez, S.; van der Veen, J.; Blom, C.J.; Karman, C.; Hou, J.-L.; Eachambadi, R.T.; Geelhoed, J.S.; De Wael, K.; Beaumont, H.J.E.; Cleuren, B.; Valcke, R.; van der Zant, H.S.J.; Boschker, H.T.S.; Manca, J.V. |
Title |
A highly conductive fibre network enables centimetre-scale electron transport in multicellular cable bacteria |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
10 |
Issue |
10 |
Pages |
4120 |
Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Biological electron transport is classically thought to occur over nanometre distances, yet recent studies suggest that electrical currents can run along centimetre-long cable bacteria. The phenomenon remains elusive, however, as currents have not been directly measured, nor have the conductive structures been identified. Here we demonstrate that cable bacteria conduct electrons over centimetre distances via highly conductive fibres embedded in the cell envelope. Direct electrode measurements reveal nanoampere currents in intact filaments up to 10.1 mm long (>2000 adjacent cells). A network of parallel periplasmic fibres displays a high conductivity (up to 79 S cm(-1)), explaining currents measured through intact filaments. Conductance rapidly declines upon exposure to air, but remains stable under vacuum, demonstrating that charge transfer is electronic rather than ionic. Our finding of a biological structure that efficiently guides electrical currents over long distances greatly expands the paradigm of biological charge transport and could enable new bio-electronic applications. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
|
Language |
|
Wos |
000485216900006 |
Publication Date |
2019-09-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
10 |
Open Access |
|
Notes |
; This research was financially supported by the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013) through ERC Grant 306933 (F.J.R.M.), the Research Foundation Flanders (FWO project grant G031416N), and the Netherlands Organisation for Scientific Research (VICI grant 016.VICI.170.072 to F.J.R.M.). H.J.E.B., C.J.B. and H.S.J.Z. were supported by the Netherlands Organisation for Scientific Research (NWO/OCW), as part of the Frontiers of Nanoscience program. R.B. is supported by an 'aspirant' grant from Research Foundation Flanders (FWO). We thank Laurine Burdorf (UAntwerpen) for help with Thiothrix cultivation, Marlies Nijemeisland (Faculty of Aerospace, TU Delft) for assistance with Raman microscopy, and Jan D'Haen (UHasselt) and Renaat Dasseville (UGent) for help with EM imaging. ; |
Approved |
Most recent IF: 12.124 |
Call Number |
UA @ admin @ c:irua:162795 |
Serial |
5451 |
Permanent link to this record |
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|
Author |
Mogg, L.; Hao, G.-P.; Zhang, S.; Bacaksiz, C.; Zou, Y.; Haigh, S.J.; Peeters, F.M.; Geim, A.K.; Lozada-Hidalgo, M. |
Title |
Atomically thin micas as proton-conducting membranes |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Nature nanotechnology |
Abbreviated Journal |
Nat Nanotechnol |
Volume |
14 |
Issue |
10 |
Pages |
962-+ |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Monolayers of graphene and hexagonal boron nitride (hBN) are highly permeable to thermal protons1,2. For thicker two-dimensional (2D) materials, proton conductivity diminishes exponentially, so that, for example, monolayer MoS2 that is just three atoms thick is completely impermeable to protons1. This seemed to suggest that only one-atom-thick crystals could be used as proton-conducting membranes. Here, we show that few-layer micas that are rather thick on the atomic scale become excellent proton conductors if native cations are ion-exchanged for protons. Their areal conductivity exceeds that of graphene and hBN by one to two orders of magnitude. Importantly, ion-exchanged 2D micas exhibit this high conductivity inside the infamous gap for proton-conducting materials3, which extends from ∼100 °C to 500 °C. Areal conductivity of proton-exchanged monolayer micas can reach above 100 S cm−2 at 500 °C, well above the current requirements for the industry roadmap4. We attribute the fast proton permeation to ~5-Å-wide tubular channels that perforate micas’ crystal structure, which, after ion exchange, contain only hydroxyl groups inside. Our work indicates that there could be other 2D crystals5 with similar nanometre-scale channels, which could help close the materials gap in proton-conducting applications. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
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Editor |
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Language |
|
Wos |
000488977100016 |
Publication Date |
2019-09-02 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1748-3387; 1748-3395 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
38.986 |
Times cited |
44 |
Open Access |
|
Notes |
; The work was supported by the Lloyd's Register Foundation, the Engineering and Physical Sciences Research Council (EPSRC)-EP/N010345/1, EP/M010619/1 and EP/ P009050/1, the European Research Council, the Graphene Flagship and the Royal Society. M.L.-H. acknowledges a Leverhulme Early Career Fellowship, G.-P.H. acknowledges a Marie Curie International Incoming Fellowship, and L.M. acknowledges the EPSRC NOWNano programme for funding. Y.Z. acknowledges the assistance of Eric Prestat in TEM specimen preparation. Computational resources were provided by the TUBITAK ULAKBIM High Performance and Grid Computing Center (TR-Grid e-Infrastructure). ; |
Approved |
Most recent IF: 38.986 |
Call Number |
UA @ admin @ c:irua:163589 |
Serial |
5407 |
Permanent link to this record |
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|
|
Author |
He, L.; Wang, H.; Chen, L.; Wang, X.; Xie, H.; Jiang, C.; Li, C.; Elibol, K.; Meyer, J.; Watanabe, K.; Taniguchi, T.; Wu, Z.; Wang, W.; Ni, Z.; Miao, X.; Zhang, C.; Zhang, D.; Wang, H.; Xie, X. |
Title |
Isolating hydrogen in hexagonal boron nitride bubbles by a plasma treatment |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
10 |
Issue |
1 |
Pages |
2815 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Atomically thin hexagonal boron nitride (h-BN) is often regarded as an elastic film that is impermeable to gases. The high stabilities in thermal and chemical properties allow h-BN to serve as a gas barrier under extreme conditions. Here, we demonstrate the isolation of hydrogen in bubbles of h-BN via plasma treatment. Detailed characterizations reveal that the substrates do not show chemical change after treatment. The bubbles are found to withstand thermal treatment in air, even at 800°C. Scanning transmission electron microscopy investigation shows that the h-BN multilayer has a unique aligned porous stacking nature, which is essential for the character of being transparent to atomic hydrogen but impermeable to hydrogen molecules. In addition, we successfully demonstrated the extraction of hydrogen gases from gaseous compounds or mixtures containing hydrogen element. The successful production of hydrogen bubbles on h-BN flakes has potential for further application in nano/ micro-electromechanical systems and hydrogen storage. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000473002500004 |
Publication Date |
2019-06-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
8 |
Open Access |
Not_Open_Access |
Notes |
The work was partially supported by the National Key R&D program (Grant No. 2017YFF0206106), the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB30000000), the National Science Foundation of China (Grant Nos. 51772317, 51302096), the Science and Technology Commission of Shanghai Municipality (Grant No. 16ZR1442700), the Hubei Provincial Natural Science Foundation of China (Grant No. ZRMS2017000370), and the Fundamental Research Funds of Wuhan City (No. 2016060101010075). K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by the MEXT, Japan and JSPS KAKENHI Grant Numbers JP15K21722. C.L. acknowledges support from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grants No. 656378—Interfacial Reactions. L.H. acknowledges financial support from the program of China Scholarships Council (No. 201706160037). H.W. and D.Z. thank Y. Gu, Y. Ma, X. Chen (Shanghai Institute of Technical Physics, Chinese Academy of Sciences) for FTIR spectra measurement. L.C. and L.H. thank Q. Liu and Z. Liu (Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences) for measurement in XPS spectra and mass spectra. |
Approved |
Most recent IF: 12.124 |
Call Number |
EMAT @ emat @c:irua:160714 |
Serial |
5191 |
Permanent link to this record |
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|
Author |
Becker, M.; Guzzinati, G.; Béché, A.; Verbeeck, J.; Batelaan, H. |
Title |
Asymmetry and non-dispersivity in the Aharonov-Bohm effect |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
10 |
Issue |
10 |
Pages |
1700 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Decades ago, Aharonov and Bohm showed that electrons are affected by electromagnetic potentials in the absence of forces due to fields. Zeilinger's theorem describes this absence of classical force in quantum terms as the “dispersionless” nature of the Aharonov-Bohm effect. Shelankov predicted the presence of a quantum “force” for the same Aharonov-Bohm physical system as elucidated by Berry. Here, we report an experiment designed to test Shelankov's prediction and we provide a theoretical analysis that is intended to elucidate the relation between Shelankov's prediction and Zeilinger's theorem. The experiment consists of the Aharonov-Bohm physical system; free electrons pass a magnetized nanorod and far-field electron diffraction is observed. The diffraction pattern is asymmetric confirming one of Shelankov's predictions and giving indirect experimental evidence for the presence of a quantum “force”. Our theoretical analysis shows that Zeilinger's theorem and Shelankov's result are both special cases of one theorem. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
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Editor |
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Language |
|
Wos |
000464338100011 |
Publication Date |
2019-04-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
12 |
Open Access |
OpenAccess |
Notes |
; H.B. would like to thank Michael Berry for bringing the presence of a quantum “force” to our attention. A.B., G.G. and J.V. acknowledge support from the European Research Council under the 7th Framework Program (FP7) ERC Starting Grant 278510 VORTEX. G.G. acknowledges support from the Fonds Wetenschappelijk Onderzoek -Vlaanderen (FWO). M.B. and H.B. acknowledge support by the U.S. National Science Foundation under Grant No. 1602755. ; |
Approved |
Most recent IF: 12.124 |
Call Number |
UA @ admin @ c:irua:159341 |
Serial |
5241 |
Permanent link to this record |
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|
Author |
Krehl, J.; Guzzinati, G.; Schultz, J.; Potapov, P.; Pohl, D.; Martin, J.; Verbeeck, J.; Fery, A.; Büchner, B.; Lubk, A. |
Title |
Spectral field mapping in plasmonic nanostructures with nanometer resolution |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
9 |
Issue |
1 |
Pages |
4207 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Plasmonic nanostructures and -devices are rapidly transforming light manipulation technology by allowing to modify and enhance optical fields on sub-wavelength scales. Advances in this field rely heavily on the development of new characterization methods for the fundamental nanoscale interactions. However, the direct and quantitative mapping of transient electric and magnetic fields characterizing the plasmonic coupling has been proven elusive to date. Here we demonstrate how to directly measure the inelastic momentum transfer of surface plasmon modes via the energy-loss filtered deflection of a focused electron beam in a transmission electron microscope. By scanning the beam over the sample we obtain a spatially and spectrally resolved deflection map and we further show how this deflection is related quantitatively to the spectral component of the induced electric and magnetic fields pertaining to the mode. In some regards this technique is an extension to the established differential phase contrast into the dynamic regime. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
|
Wos |
000447074200005 |
Publication Date |
2018-10-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
15 |
Open Access |
OpenAccess |
Notes |
G.G. acknowledges support from a postdoctoral fellowship grant from the Fonds Wetenschappelijk Onderzoke-Vlaanderen (FWO). A.L. and J.K. have received funding from the European Research Council (ERC) under the Horizon 2020 research and innovation program of the European Union (grant agreement no. 715620). |
Approved |
Most recent IF: 12.124 |
Call Number |
EMAT @ emat @c:irua:154355 |
Serial |
5058 |
Permanent link to this record |
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|
|
Author |
Zhou, Y.; Che, F.; Liu, M.; Zou, C.; Liang, Z.; De Luna, P.; Yuan, H.; Li, J.; Wang, Z.; Xie, H.; Li, H.; Chen, P.; Bladt, E.; Quintero-Bermudez, R.; Sham, T.-K.; Bals, S.; Hofkens, J.; Sinton, D.; Chen, G.; Sargent, E.H. |
Title |
Dopant-induced electron localization drives CO2 reduction to C2 hydrocarbons |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Nature chemistry |
Abbreviated Journal |
Nat Chem |
Volume |
10 |
Issue |
10 |
Pages |
974-980 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The electrochemical reduction of CO2 to multi-carbon products has attracted much attention because it provides an avenue to the synthesis of value-added carbon-based fuels and feedstocks using renewable electricity. Unfortunately, the efficiency of CO2 conversion to C-2 products remains below that necessary for its implementation at scale. Modifying the local electronic structure of copper with positive valence sites has been predicted to boost conversion to C-2 products. Here, we use boron to tune the ratio of Cu delta+ to Cu-0 active sites and improve both stability and C-2-product generation. Simulations show that the ability to tune the average oxidation state of copper enables control over CO adsorption and dimerization, and makes it possible to implement a preference for the electrosynthesis of C-2 products. We report experimentally a C-2 Faradaic efficiency of 79 +/- 2% on boron-doped copper catalysts and further show that boron doping leads to catalysts that are stable for in excess of similar to 40 hours while electrochemically reducing CO2 to multi-carbon hydrocarbons. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
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Language |
|
Wos |
000442395200013 |
Publication Date |
2018-07-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1755-4330; 1755-4349 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
25.87 |
Times cited |
700 |
Open Access |
OpenAccess |
Notes |
; This work was supported financially by funding from TOTAL S.A., the Ontario Research Fund: Research Excellence Program, the Natural Sciences and Engineering Research Council of Canada, the CIFAR Bio-Inspired Solar Energy programme, a University of Toronto Connaught grant, the Ministry of Science, Natural Science Foundation of China (21471040, 21271055 and 21501035), the Innovation-Driven Plan in Central South University project (2017CX003), a project from State Key Laboratory of Powder Metallurgy in Central South University, the Thousand Youth Talents Plan of China and Hundred Youth Talents Program of Hunan and the China Scholarship Council programme. This work benefited from the soft X-ray microcharacterization beamline at CLS, sector 20BM at the APS and the Ontario Centre for the Characterisation of Advanced Materials at the University of Toronto. H.Y. acknowledges financial support from the Research Foundation-Flanders (FWO postdoctoral fellowship). C.Z. acknowledges support from the International Academic Exchange Fund for Joint PhD Students from Tianjin University. P.D.L. acknowledges financial support from the Natural Sciences and Engineering Research Council in the form of the Canada Graduate Scholarship-Doctoral award. S.B. and E.B. acknowledge financial support from the European Research Council (ERC Starting Grant # 335078-COLOURATOMS). The authors thank B. Zhang, N. Wang, C. T. Dinh, T. Zhuang, J. Li and Y. Zhao for fruitful discussions, as well as Y. Hu and Q. Xiao from CLS, and Z. Finfrock and M. Ward from APS for their help during the course of study. Computations were performed on the SOSCIP Consortium's Blue Gene/Q computing platform. SOSCIP is funded by the Federal Economic Development Agency of Southern Ontario, the Province of Ontario, IBM Canada, Ontario Centres of Excellence, Mitacs and 15 Ontario academic member institutions. ; ecas_sara |
Approved |
Most recent IF: 25.87 |
Call Number |
UA @ lucian @ c:irua:153693UA @ admin @ c:irua:153693 |
Serial |
5091 |
Permanent link to this record |
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|
|
Author |
Zhou, K.-G.; Vasu, K.S.; Cherian, C.T.; Neek-Amal, M.; Zhang, J.C.; Ghorbanfekr-Kalashami, H.; Huang, K.; Marshall, O.P.; Kravets, V.G.; Abraham, J.; Su, Y.; Grigorenko, A.N.; Pratt, A.; Geim, A.K.; Peeters, F.M.; Novoselov, K.S.; Nair, R.R. |
Title |
Electrically controlled water permeation through graphene oxide membranes |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Nature |
Abbreviated Journal |
Nature |
Volume |
559 |
Issue |
7713 |
Pages |
236-+ |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Controlled transport of water molecules through membranes and capillaries is important in areas as diverse as water purification and healthcare technologies(1-7). Previous attempts to control water permeation through membranes (mainly polymeric ones) have concentrated on modulating the structure of the membrane and the physicochemical properties of its surface by varying the pH, temperature or ionic strength(3,8). Electrical control over water transport is an attractive alternative; however, theory and simulations(9-14) have often yielded conflicting results, from freezing of water molecules to melting of ice(14-16) under an applied electric field. Here we report electrically controlled water permeation through micrometre-thick graphene oxide membranes(17-21). Such membranes have previously been shown to exhibit ultrafast permeation of water(17,22) and molecular sieving properties(18,21), with the potential for industrial-scale production. To achieve electrical control over water permeation, we create conductive filaments in the graphene oxide membranes via controllable electrical breakdown. The electric field that concentrates around these current-carrying filaments ionizes water molecules inside graphene capillaries within the graphene oxide membranes, which impedes water transport. We thus demonstrate precise control of water permeation, from ultrafast permeation to complete blocking. Our work opens up an avenue for developing smart membrane technologies for artificial biological systems, tissue engineering and filtration. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000438240900052 |
Publication Date |
2018-07-05 |
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 |
40.137 |
Times cited |
216 |
Open Access |
|
Notes |
; This work was supported by the Royal Society, Engineering and Physical Sciences Research Council, UK (EP/K016946/1, EP/N013670/1 and EP/P00119X/1), British Council (award reference number 279336045), European Research Council (contract 679689) and Lloyd's Register Foundation. We thank J. Waters for assisting with X-ray measurements and G. Yu for electrical measurements. ; |
Approved |
Most recent IF: 40.137 |
Call Number |
UA @ lucian @ c:irua:152420UA @ admin @ c:irua:152420 |
Serial |
5096 |
Permanent link to this record |
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|
|
Author |
Hu, S.; Gopinadhan, K.; Rakowski, A.; Neek-Amal, M.; Heine, T.; Grigorieva, I.V.; Haigh, S.J.; Peeters, F.M.; Geim, A.K.; Lozada-Hidalgo, M. |
Title |
Transport of hydrogen isotopes through interlayer spacing in van der Waals crystals |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Nature nanotechnology |
Abbreviated Journal |
Nat Nanotechnol |
Volume |
13 |
Issue |
6 |
Pages |
468-+ |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Atoms start behaving as waves rather than classical particles if confined in spaces commensurate with their de Broglie wavelength. At room temperature this length is only about one angstrom even for the lightest atom, hydrogen. This restricts quantum-confinement phenomena for atomic species to the realm of very low temperatures(1-5). Here, we show that van der Waals gaps between atomic planes of layered crystals provide angstrom-size channels that make quantum confinement of protons apparent even at room temperature. Our transport measurements show that thermal protons experience a notably higher barrier than deuterons when entering van der Waals gaps in hexagonal boron nitride and molybdenum disulfide. This is attributed to the difference in the de Broglie wavelengths of the isotopes. Once inside the crystals, transport of both isotopes can be described by classical diffusion, albeit with unexpectedly fast rates comparable to that of protons in water. The demonstrated angstrom-size channels can be exploited for further studies of atomistic quantum confinement and, if the technology can be scaled up, for sieving hydrogen isotopes. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000434715700015 |
Publication Date |
2018-04-04 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
1748-3387; 1748-3395 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
38.986 |
Times cited |
32 |
Open Access |
|
Notes |
; The authors acknowledge support from the Lloyd's Register Foundation, EPSRC – EP/N010345/1, the European Research Council ARTIMATTER project – ERC-2012-ADG and from Graphene Flagship. M.L.-H. acknowledges a Leverhulme Early Career Fellowship. ; |
Approved |
Most recent IF: 38.986 |
Call Number |
UA @ lucian @ c:irua:152014UA @ admin @ c:irua:152014 |
Serial |
5046 |
Permanent link to this record |
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Author |
Perez, A.J.; Jacquet, Q.; Batuk, D.; Iadecola, A.; Saubanere, M.; Rousse, G.; Larcher, D.; Vezin, H.; Doublet, M.-L.; Tarascon, J.-M. |
Title |
Approaching the limits of cationic and anionic electrochemical activity with the Li-rich layered rocksalt Li3IrO4 |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature energy |
Abbreviated Journal |
Nat Energy |
Volume |
2 |
Issue |
12 |
Pages |
954-962 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The Li-rich rocksalt oxides Li2MO3 (M = 3d/4d/5d transition metal) are promising positive-electrode materials for Li-ion batteries, displaying capacities exceeding 300 mAh g(-1) thanks to the participation of the oxygen non-bonding O(2p) orbitals in the redox process. Understanding the oxygen redox limitations and the role of the O/M ratio is therefore crucial for the rational design of materials with improved electrochemical performances. Here we push oxygen redox to its limits with the discovery of a Li3IrO4 compound (O/M = 4) that can reversibly take up and release 3.5 electrons per Ir and possesses the highest capacity ever reported for any positive insertion electrode. By quantitatively monitoring the oxidation process, we demonstrate the material's instability against O-2 release on removal of all Li. Our results show that the O/M parameter delineates the boundary between the material's maximum capacity and its stability, hence providing valuable insights for further development of high-capacity materials. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000430218300001 |
Publication Date |
2017-12-06 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
2058-7546 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
55 |
Open Access |
Not_Open_Access |
Notes |
; We thank P. Pearce for providing the beta-Li<INF>2</INF>IrO<INF>3</INF> and L. Lemarquis for helping in the DEMS experiment. We are particularly grateful to S. Belin, V. Briois and L. Stievano for helpful discussions on XAS analysis and synchrotron SOLEIL (France) for providing beamtime at the ROCK beamline (financed by the French National Research Agency (ANR) as part of the 'Investissements d'Avenir' programme, reference: ANR-10-EQPX-45). A.J.P and A. I. acknowledge the GdR C(RS) 2 for the workshop organized on a chemometric approach for XAS data analysis. V. Nassif is acknowledged for her help during neutron diffraction experiments performed at Institut Laue Langevin on D1B. Use of the 11-BM mail service of the APS at Argonne National Laboratory was supported by the US Department of Energy under contract No. DE-AC02-06CH11357 and is gratefully acknowledged. This work has been performed with the support of the European Research Council (ERC) (FP/2014)/ERC Grant- Project 670116 ARPEMA. ; |
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:150926 |
Serial |
4962 |
Permanent link to this record |
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Author |
Li, J.; Pereira, P.J.; Yuan, J.; Lv, Y.-Y.; Jiang, M.-P.; Lu, D.; Lin, Z.-Q.; Liu, Y.-J.; Wang, J.-F.; Li, L.; Ke, X.; Van Tendeloo, G.; Li, M.-Y.; Feng, H.-L.; Hatano, T.; Wang, H.-B.; Wu, P.-H.; Yamaura, K.; Takayama-Muromachi, E.; Vanacken, J.; Chibotaru, L.F.; Moshchalkov, V.V. |
Title |
Nematic superconducting state in iron pnictide superconductors |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
8 |
Issue |
1 |
Pages |
1880 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Nematic order often breaks the tetragonal symmetry of iron-based superconductors. It arises from regular structural transition or electronic instability in the normal phase. Here, we report the observation of a nematic superconducting state, by measuring the angular dependence of the in-plane and out-of-plane magnetoresistivity of Ba 0.5 K 0.5 Fe 2 As 2 single crystals. We find large twofold oscillations in the vicinity of the superconducting transition, when the direction of applied magnetic field is rotated within the basal plane. To avoid the influences from sample geometry or current flow direction, the sample was designed as Corbino-shape for in-plane and mesa-shape for out-of-plane measurements. Theoretical analysis shows that the nematic superconductivity arises from the weak mixture of the quasi-degenerate s-wave and d-wave components of the superconducting condensate, most probably induced by a weak anisotropy of stresses inherent to single crystals. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000416933400002 |
Publication Date |
2017-11-27 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
8 |
Open Access |
OpenAccess |
Notes |
The authors J.L., P.J.P., and J.Y. contributed equally to this work. J.L. and J.Y. designed the experiments. J.L., H.-L.F., K.Y., and E.T.-M. grew the single crystals. J.L., J.Y., Y.-Y.L., M.-P.J., D.L., M.-Y.L., T.H., H.-B.W., P.-H.W., K.Y., E.T.-M., J.V., and V.V.M. fabricated the devices and measured transport properties. J.L., Y.-Y.L., Z.-Q.L., Y.-J.L., J.-F.W., and L.L. studied on the pulsed high field measurements. X.K. and G.V.T. measured the low temperature TEM. All authors discussed the data. J.L., P.J.P., and L.F.C. proposed the model and simulated the results. J.L., P.J.P., K.Y., E.T.-M., and L.F.C. analyzed the data and prepared the manuscript. |
Approved |
Most recent IF: 12.124 |
Call Number |
EMAT @ emat @c:irua:147348 |
Serial |
4772 |
Permanent link to this record |
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Author |
Dendooven, J.; Ramachandran, R.K.; Solano, E.; Kurttepeli, M.; Geerts, L.; Heremans, G.; Ronge, J.; Minjauw, M.M.; Dobbelaere, T.; Devloo-Casier, K.; Martens, J.A.; Vantomme, A.; Bals, S.; Portale, G.; Coati, A.; Detavernier, C. |
Title |
Independent tuning of size and coverage of supported Pt nanoparticles using atomic layer deposition |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
8 |
Issue |
8 |
Pages |
1074 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Synthetic methods that allow for the controlled design of well-defined Pt nanoparticles are highly desirable for fundamental catalysis research. In this work, we propose a strategy that allows precise and independent control of the Pt particle size and coverage. Our approach exploits the versatility of the atomic layer deposition (ALD) technique by combining two ALD processes for Pt using different reactants. The particle areal density is controlled by tailoring the number of ALD cycles using trimethyl(methylcyclopentadienyl) platinum and oxygen, while subsequent growth using the same Pt precursor in combination with nitrogen plasma allows for tuning of the particle size at the atomic level. The excellent control over the particle morphology is clearly demonstrated by means of in situ and ex situ X-ray fluorescence and grazing incidence small angle X-ray scattering experiments, providing information about the Pt loading, average particle dimensions, and mean center-to-center particle distance. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000413353500023 |
Publication Date |
2017-10-16 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
88 |
Open Access |
OpenAccess |
Notes |
; This research was funded by the Research Foundation-Flanders (FWO), the Special Research Fund BOF of Ghent University (GOA 01G01513) and the Flemish Government (Medium-scale research infrastructure funding-Hercules funding). J. D., T. D. and M. M. M. acknowledge the FWO for a research fellowship. S. B. acknowledges the European Research Council, ERC grant no. 335078-Colouratom. For the GISAXS and XRF measurements at SOLEIL, the authors received funding from the European Community's Trans National Access Program CALIPSO. We are also grateful to the SOLEIL and ESRF staff for smoothly running the facilities. The authors thank G. Verellen for his help with drawing the 3D sketches. ; ecas_Sara |
Approved |
Most recent IF: 12.124 |
Call Number |
UA @ lucian @ c:irua:146668UA @ admin @ c:irua:146668 |
Serial |
4786 |
Permanent link to this record |
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Author |
Jiang, Y.; Mao, J.; Moldovan, D.; Masir, M.R.; Li, G.; Watanabe, K.; Taniguchi, T.; Peeters, F.M.; Andrei, E.Y. |
Title |
Tuning a circular p-n junction in graphene from quantum confinement to optical guiding |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature nanotechnology |
Abbreviated Journal |
Nat Nanotechnol |
Volume |
12 |
Issue |
11 |
Pages |
1045-+ |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
<script type='text/javascript'>document.write(unpmarked('The photon-like propagation of the Dirac electrons in graphene, together with its record-high electronic mobility(1-3), can lead to applications based on ultrafast electronic response and low dissipation(4-6). However, the chiral nature of the charge carriers that is responsible for the high mobility also makes it difficult to control their motion and prevents electronic switching. Here, we show how to manipulate the charge carriers by using a circular p-n junction whose size can be continuously tuned from the nanometre to the micrometre scale(7,8). The junction size is controlled with a dual-gate device consisting of a planar back gate and a point-like top gate made by decorating a scanning tunnelling microscope tip with a gold nanowire. The nanometre-scale junction is defined by a deep potential well created by the tip-induced charge. It traps the Dirac electrons in quantum-confined states, which are the graphene equivalent of the atomic collapse states (ACSs) predicted to occur at supercritically charged nuclei(9-13). As the junction size increases, the transition to the optical regime is signalled by the emergence of whispering-gallery modes(14-16), similar to those observed at the perimeter of acoustic or optical resonators, and by the appearance of a Fabry-Perot interference pattern(17-20) for junctions close to a boundary.')); |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000414531800011 |
Publication Date |
2017-09-15 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1748-3387; 1748-3395 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
38.986 |
Times cited |
65 |
Open Access |
|
Notes |
; The authors acknowledge funding provided by DOE-FG02-99ER45742 (STM/STS) and NSF DMR 1708158 (fabrication). Theoretical work was supported by ESF-EUROCORES-EuroGRAPHENE, FWO VI and the Methusalem program of the Flemish government. ; |
Approved |
Most recent IF: 38.986 |
Call Number |
UA @ lucian @ c:irua:147406 |
Serial |
4902 |
Permanent link to this record |
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Author |
Trashin, S.; Rahemi, V.; Ramji, K.; Neven, L.; Gorun, S.M.; De Wael, K. |
Title |
Singlet oxygen-based electrosensing by molecular photosensitizers |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
8 |
Issue |
|
Pages |
16108 |
Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Enzyme-based electrochemical biosensors are an inspiration for the development of (bio)analytical techniques. However, the instability and reproducibility of the reactivity of enzymes, combined with the need for chemical reagents for sensing remain challenges for the construction of useful devices. Here we present a sensing strategy inspired by the advantages of enzymes and photoelectrochemical sensing, namely the integration of aerobic photocatalysis and electrochemical analysis. The photosensitizer, a bioinspired perfluorinated Zn phthalocyanine, generates singlet-oxygen from air under visible light illumination and oxidizes analytes, yielding electrochemically-detectable products while resisting the oxidizing species it produces. Compared with enzymatic detection methods, the proposed strategy uses air instead of internally added reactive reagents, features intrinsic baseline correction via on/off light switching and shows C-F bonds-type enhanced stability. It also affords selectivity imparted by the catalytic process and nano-level detection, such as 20 nM amoxicillin in μl sample volumes. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000405466200002 |
Publication Date |
2017-07-14 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
26 |
Open Access |
|
Notes |
; Evonik is thanked for providing samples of silicon and titanium oxides. Support from the National Science Foundation (SMG) for a portion of this work is gratefully acknowledged. FWO and UAntwerpen (BOF) are acknowledged for financial support. ; |
Approved |
Most recent IF: 12.124 |
Call Number |
UA @ admin @ c:irua:144538 |
Serial |
5833 |
Permanent link to this record |
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Author |
Embon, L.; Anahory, Y.; Jelić, Z.L.; Lachman, E.O.; Myasoedov, Y.; Huber, M.E.; Mikitik, G.P.; Silhanek, A.V.; Milošević, M.V.; Gurevich, A.; Zeldov, E. |
Title |
Imaging of super-fast dynamics and flow instabilities of superconducting vortices |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
8 |
Issue |
|
Pages |
85 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Quantized magnetic vortices driven by electric current determine key electromagnetic properties of superconductors. While the dynamic behavior of slow vortices has been thoroughly investigated, the physics of ultrafast vortices under strong currents remains largely unexplored. Here, we use a nanoscale scanning superconducting quantum interference device to image vortices penetrating into a superconducting Pb film at rates of tens of GHz and moving with velocities of up to tens of km/s, which are not only much larger than the speed of sound but also exceed the pair-breaking speed limit of superconducting condensate. These experiments reveal formation of mesoscopic vortex channels which undergo cascades of bifurcations as the current and magnetic field increase. Our numerical simulations predict metamorphosis of fast Abrikosov vortices into mixed Abrikosov-Josephson vortices at even higher velocities. This work offers an insight into the fundamental physics of dynamic vortex states of superconductors at high current densities, crucial for many applications. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000405900400002 |
Publication Date |
2017-07-13 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
124 |
Open Access |
|
Notes |
; We would like to thank M.L. Rappaport for fruitful discussions and technical support. This work was supported by the US-Israel Binational Science Foundation (BSF) grant No. 2014155 and the Israel Science Foundation grant No. 132/14. A.G. was also supported by the United States Department of Energy under Grant No. DE-SC0010081. M.V.M. acknowledges support from Research Foundation-Flanders (FWO). The work of Z.L.J. and A.V.S. was partially supported by “Mandat d'Impulsion Scientifique” MIS F.4527.13 of the F.R.S.-FNRS. This work benefited from the support of COST action MP-1201. ; |
Approved |
Most recent IF: 12.124 |
Call Number |
UA @ lucian @ c:irua:144832 |
Serial |
4720 |
Permanent link to this record |
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Author |
Chirayath, V.A.; Callewaert, V.; Fairchild, A.J.; Chrysler, M.D.; Gladen, R.W.; Mcdonald, A.D.; Imam, S.K.; Shastry, K.; Koymen, A.R.; Saniz, R.; Barbiellini, B.; Rajeshwar, K.; Partoens, B.; Weiss, A.H. |
Title |
Auger electron emission initiated by the creation of valence-band holes in graphene by positron annihilation |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
8 |
Issue |
8 |
Pages |
16116 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Auger processes involving the filling of holes in the valence band are thought to make important contributions to the low-energy photoelectron and secondary electron spectrum from many solids. However, measurements of the energy spectrum and the efficiency with which electrons are emitted in this process remain elusive due to a large unrelated background resulting from primary beam-induced secondary electrons. Here, we report the direct measurement of the energy spectra of electrons emitted from single layer graphene as a result of the decay of deep holes in the valence band. These measurements were made possible by eliminating competing backgrounds by employing low-energy positrons (<1.25 eV) to create valence-band holes by annihilation. Our experimental results, supported by theoretical calculations, indicate that between 80 and 100% of the deep valence-band holes in graphene are filled via an Auger transition. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000405398200001 |
Publication Date |
2017-07-13 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
20 |
Open Access |
|
Notes |
The experiments in this work were supported by the grant NSF DMR 1508719. A.H.W and A.R.K. gratefully acknowledge support for the building of advanced positron beam through the grant NSF DMR MRI 1338130. V.C. and R.S. were supported by the FWO-Vlaanderen through Project No. G. 0224.14N. The computational resources and services used in this work were in part provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government (EWI Department). The work at Northeastern University was supported by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences grant number DE-FG02-07ER46352 (core research), and benefited from Northeastern University’s Advanced Scientific Computation Center (ASCC), the NERSC supercomputing center through DOE grant number DE-AC02-05CH11231, and support (applications to layered materials) from the DOE EFRC: Center for the Computational Design of Functional Layered Materials (CCDM) under DE-SC0012575. |
Approved |
Most recent IF: 12.124 |
Call Number |
CMT @ cmt @ c:irua:144625 |
Serial |
4627 |
Permanent link to this record |
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Author |
Ghorbanfekr-Kalashami, H.; Vasu, K.S.; Nair, R.R.; Peeters, F.M.; Neek-Amal, M. |
Title |
Dependence of the shape of graphene nanobubbles on trapped substance |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
8 |
Issue |
8 |
Pages |
15844 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Van der Waals (vdW) interaction between two-dimensional crystals (2D) can trap substances in high pressurized (of order 1 GPa) on nanobubbles. Increasing the adhesion between the 2D crystals further enhances the pressure and can lead to a phase transition of the trapped material. We found that the shape of the nanobubble can depend critically on the properties of the trapped substance. In the absence of any residual strain in the top 2D crystal, flat nanobubbles can be formed by trapped long hydrocarbons (that is, hexadecane). For large nanobubbles with radius 130 nm, our atomic force microscopy measurements show nanobubbles filled with hydrocarbons (water) have a cylindrical symmetry (asymmetric) shape which is in good agreement with our molecular dynamics simulations. This study provides insights into the effects of the specific material and the vdW pressure on the microscopic details of graphene bubbles. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000403417500001 |
Publication Date |
2017-06-16 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
44 |
Open Access |
|
Notes |
We acknowledge fruitful discussion with Irina Grigorieva and Andre K. Geim. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program, the Royal Society and the Engineering and Physical Sciences Research Council, UK (EP/K016946/1). M.N.-A. was supported by Iran National Science Foundation (INSF). |
Approved |
Most recent IF: 12.124 |
Call Number |
CMT @ cmt @ c:irua:144189 |
Serial |
4580 |
Permanent link to this record |
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Author |
Guzzinati, G.; Béché, A.; Lourenço-Martins, H.; Martin, J.; Kociak, M.; Verbeeck, J. |
Title |
Probing the symmetry of the potential of localized surface plasmon resonances with phase-shaped electron beams |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
8 |
Issue |
8 |
Pages |
14999 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Plasmonics, the science and technology of the interaction of light with metallic objects, is fundamentally changing the way we can detect, generate and manipulate light. Although the field is progressing swiftly, thanks to the availability of nanoscale manufacturing and analysis methods, fundamental properties such as the plasmonic excitations’ symmetries cannot be accessed directly, leading to a partial, sometimes incorrect, understanding of their properties. Here we overcome this limitation by deliberately shaping the wave function of an electron beam to match a plasmonic excitations’ symmetry in a modified transmission electron microscope. We show experimentally and theoretically that this offers selective detection of specific plasmon modes within metallic nanoparticles, while excluding modes with other symmetries. This method resembles the widespread use of polarized light for the selective excitation of plasmon modes with the advantage of locally probing the response of individual plasmonic objects and a far wider range of symmetry selection criteria. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000399084300001 |
Publication Date |
2017-04-12 |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
84 |
Open Access |
OpenAccess |
Notes |
; We thank F.J. Garcia de Abajo and D.M. Ugarte for interesting and fruitful discussion. This work was supported by funding from the European Research Council under the 7th Framework Program (FP7) ERC Starting Grant 278510 VORTEX. Financial support from the European Union under the Framework 7 program under a contract for an Integrated Infrastructure Initiative (Reference number 312483 ESTEEM2) is also gratefully acknowledged. Aluminum nanostructures were fabricated using the Nanomat nanofabrication facility. ; |
Approved |
Most recent IF: 12.124 |
Call Number |
EMAT @ emat @ c:irua:142205UA @ admin @ c:irua:142205 |
Serial |
4548 |
Permanent link to this record |
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Author |
Willhammar, T.; Sentosun, K.; Mourdikoudis, S.; Goris, B.; Kurttepeli, M.; Bercx, M.; Lamoen, D.; Partoens, B.; Pastoriza-Santos, I.; Pérez-Juste, J.; Liz-Marzán, L.M.; Bals, S.; Van Tendeloo, G. |
Title |
Structure and vacancy distribution in copper telluride nanoparticles influence plasmonic activity in the near-infrared |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
8 |
Issue |
8 |
Pages |
14925 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
Abstract |
Copper chalcogenides find applications in different domains including photonics, photothermal therapy and photovoltaics. CuTe nanocrystals have been proposed as an alternative to noble metal particles for plasmonics. Although it is known that deviations from stoichiometry are a prerequisite for plasmonic activity in the near-infrared, an accurate description of the material and its (optical) properties is hindered by an insufficient understanding of the atomic structure and the influence of defects, especially for materials in their nanocrystalline form. We demonstrate that the structure of Cu1.5±xTe nanocrystals canbe determined using electron diffraction tomography. Real-space high-resolution electron tomography directly reveals the three-dimensional distribution of vacancies in the structure. Through first-principles density functional theory, we furthermore demonstrate that the influence of these vacancies on the optical properties of the nanocrystals is determined. Since our methodology is applicable to a variety of crystalline nanostructured materials, it is expected to provide unique insights concerning structure–property correlations. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000397799700001 |
Publication Date |
2017-03-30 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
37 |
Open Access |
OpenAccess |
Notes |
The work was financially supported by the European Research Council through an ERC Starting Grant (#335078-COLOURATOMS). T.W. acknowledges the Swedish Research Council for an international postdoc grant. We acknowledge financial support of FWO-Vlaanderen through project G.0216.14N, G.0369.15N and a postdoctoral research grant to B.G. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO-Vlaanderen and the Flemish Government–Department EWI. The work was further supported by the Spanish MINECO (MAT2013-45168-R). S.M. thanks the Action ooSupporting Postdoctoral Researchers44 of the Operational Program ‘Education and Lifelong Learning’ (Action’s Beneficiary: General Secretariat for Research and Technology of Greece), which was co-financed by the European Social Fund (ESF) and the Greek State. (ROMEO:green; preprint:; postprint:can ; pdfversion:can); ECAS_Sara |
Approved |
Most recent IF: 12.124 |
Call Number |
EMAT @ emat @ c:irua:142203UA @ admin @ c:irua:142203 |
Serial |
4538 |
Permanent link to this record |
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Author |
Lepot, K.; Addad, A.; Knoll, A.H.; Wang, J.; Troadec, D.; Béché, A.; Javaux, E.J. |
Title |
Iron minerals within specific microfossil morphospecies of the 1.88 Ga Gunflint Formation |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
8 |
Issue |
8 |
Pages |
14890 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Problematic microfossils dominate the palaeontological record between the Great Oxidation Event 2.4 billion years ago (Ga) and the last Palaeoproterozoic iron formations, deposited 500–600 million years later. These fossils are often associated with iron-rich sedimentary rocks, but their affinities, metabolism, and, hence, their contributions to Earth surface oxidation and Fe deposition remain unknown. Here we show that specific microfossil populations of the 1.88 Ga Gunflint Iron Formation contain Fe-silicate and Fe-carbonate nanocrystal concentrations in cell interiors. Fe minerals are absent in/on all organically preserved cell walls. These features are consistent with in vivo intracellular Fe biomineralization, with subsequent in situ recrystallization, but contrast with known patterns of post-mortem Fe mineralization. The Gunflint populations that display relatively large cells (thick-walled spheres, filament-forming rods) and intra-microfossil Fe minerals are consistent with oxygenic photosynthesizers but not with other Fe-mineralizing microorganisms studied so far. Fe biomineralization may have protected oxygenic photosynthesizers against Fe2+ toxicity during the Palaeoproterozoic. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000397129900001 |
Publication Date |
2017-03-23 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
20 |
Open Access |
OpenAccess |
Notes |
We thank J.-P. Cullus (thin sections), G. Spronck and C. Henrist (TEM), M. Cabié and C. Dominici (FIB), S. Bernard and C. Karunakaran (STXM), F. Bourdelle and G. Ji (EELS), P. Recourt (SEM). This study was co-funded by FRFC Grant no. 2.4558.09F (E.J.J.), CNRS-INSU (K.L.), FNRS (K.L.), ERC StG ELiTE Grant no. 308074 (E.J.J.), BELSPO IAP PLANET TOPERS (E.J.J.), NASA Astrobiology Institute (A.H.K.), Conseil Régional du Nord-Pas de Calais+European Regional Development Fund+CNRS-INSU (TEM in Lille), FP7-ESMI no. 262348 (TEM at EMAT Antwerp) and ANR-15-CE31-0003-01 (M6fossils, K.L.). We thank Noah Planavsky and two anonymous reviewers for thorough reviews that helped improve the paper. |
Approved |
Most recent IF: 12.124 |
Call Number |
EMAT @ emat @ c:irua:141919 |
Serial |
4536 |
Permanent link to this record |