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Author |
Lottini, E.; López-Ortega, A.; Bertoni, G.; Turner, S.; Meledina, M.; Van Tendeloo, G.; de Julián Fernández, C.; Sangregorio, C. |
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Title |
Strongly Exchange Coupled Core|Shell Nanoparticles with High Magnetic Anisotropy: A Strategy toward Rare-Earth-Free Permanent Magnets |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
28 |
Issue |
28 |
Pages |
4214-4222 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Antiferromagnetic(AFM)|ferrimagnetic(FiM) core|shell (CS) nanoparticles (NPs) of formula Co0.3Fe0.7O|Co0.6Fe2.4O4 with mean diameter from 6 to 18 nm have been synthesized through a one-pot thermal decomposition process. The CS structure has been generated by topotaxial oxidation of the core region, leading to the formation of a highly monodisperse single inverted AFM|FiM CS system with variable AFM-core diameter and constant FiM-shell thickness (~2 nm). The sharp interface, the high structural matching between both phases and the good crystallinity of the AFM material have been structurally demonstrated and are corroborated by the robust exchange-coupling between AFM and FiM phases, which gives rise to one among the largest exchange bias (HE) values ever reported for CS NPs (8.6 kOe) and to a strongly enhanced coercive field (HC). In addition, the investigation of the magnetic properties as a function of the AFM-core size (dAFM), revealed a non-monotonous trend of both HC and HE, which display a maximum value for dAFM = 5 nm (19.3 and 8.6 kOe, respectively). These properties induce a huge improvement of the capability of storing energy of the material, a result which suggests that the combination of highly anisotropic AFM|FiM materials can be an efficient strategy towards the realization of novel Rare Earth-free permanent magnets. |
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Wos |
000378973100013 |
Publication Date |
2016-05-20 |
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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 |
0897-4756 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
48 |
Open Access |
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Notes |
This work was supported by the EU-FP7 through NANOPYME Project (No. 310516) and Integrated Infrastructure Initiative ESTEEM2 (No. 312483). S.T. gratefully acknowledges the FWO Flanders for a post-doctoral scholarship.; esteem2_ta |
Approved |
Most recent IF: 9.466 |
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Call Number  |
c:irua:134084 c:irua:134084 |
Serial |
4092 |
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Author |
Béché, A.; Juchtmans, R.; Verbeeck, J. |
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Title |
Efficient creation of electron vortex beams for high resolution STEM imaging |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
178 |
Issue |
178 |
Pages |
12-19 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The recent discovery of electron vortex beams carrying quantised angular momentum in the TEM has led to an active field of research, exploring a variety of potential applications including the possibility of mapping magnetic states at the atomic scale. A prerequisite for this is the availability of atomic sized electron vortex beams at high beam current and mode purity. In this paper we present recent progress showing that by making use of the Aharonov-Bohm effect near the tip of a long single domain ferromagnetic Nickel needle, a very efficient aperture for the production of electron vortex beams can be realised. The aperture transmits more than 99% of all electrons and provides a vortex mode purity of up to 92%. Placing this aperture in the condenser plane of a state of the art Cs corrected microscope allows us to demonstrate atomic resolution HAADF STEM images with spatial resolution better than 1 Angstrom, in agreement with theoretical expectations and only slightly inferior to the performance of a non-vortex probe on the same instrument. |
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Address |
EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000403862900003 |
Publication Date |
2016-05-10 |
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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 |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
30 |
Open Access |
OpenAccess |
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Notes |
A.B. and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX. J.V. acknowledges funding from FWO project G.0044.13N ('Charge ordering').; ECASJO_; |
Approved |
Most recent IF: 2.843 |
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Call Number |
c:irua:134085 c:irua:134085UA @ admin @ c:irua:134085 |
Serial |
4094 |
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Author |
Clark, L.; Guzzinati, G.; Béché, A.; Lubk, A.; Verbeeck, J. |
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Title |
Symmetry-constrained electron vortex propagation |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Physical review A |
Abbreviated Journal |
Phys Rev A |
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Volume |
93 |
Issue |
93 |
Pages |
063840 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Electron vortex beams hold great promise for development in transmission electron microscopy but have yet to be widely adopted. This is partly due to the complex set of interactions that occur between a beam carrying orbital angular momentum (OAM) and a sample. Herein, the system is simplified to focus on the interaction between geometrical symmetries, OAM, and topology. We present multiple simulations alongside experimental data to study the behavior of a variety of electron vortex beams after interacting with apertures of different symmetries and investigate the effect on their OAM and vortex structure, both in the far field and under free-space propagation. |
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Place of Publication |
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Wos |
000378197200006 |
Publication Date |
2016-06-23 |
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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 |
2469-9926 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.925 |
Times cited |
7 |
Open Access |
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Notes |
L.C., A.B., G.G., and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510—VORTEX. J.V. and A.L. acknowledge financial support from the European Union through the 7th Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2). The Qu-Ant-EM microscope was partly funded by the Hercules fund of the Flemish Government.; esteem2jra3; ECASJO; |
Approved |
Most recent IF: 2.925 |
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Call Number |
c:irua:134086 c:irua:134086 |
Serial |
4090 |
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Author |
Lobato, I.; Van Aert, S.; Verbeeck, J. |
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Title |
Progress and new advances in simulating electron microscopy datasets using MULTEM |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
168 |
Issue |
168 |
Pages |
17-27 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A new version of the open source program MULTEM is presented here. It includes a graphical user interface, tapering truncation of the atomic potential, CPU multithreading functionality, single/double precision calculations, scanning transmission electron microscopy (STEM) simulations using experimental detector sensitivities, imaging STEM (ISTEM) simulations, energy filtered transmission electron microscopy (EFTEM) simulations, STEM electron energy loss spectroscopy (EELS) simulations along with other improvements in the algorithms. We also present a mixed channeling approach for the calculation of inelastic excitations, which allows one to considerably speed up time consuming EFTEM/STEM-EELS calculations. |
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Address |
EMAT, University of Antwerp, Department of Physics, Groenenborgerlaan 171, B-2020 Antwerp, Belgium |
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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 |
English |
Wos |
000380754100003 |
Publication Date |
2016-06-11 |
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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 |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
43 |
Open Access |
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Notes |
The authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483- ESTEEM2. The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0369.15N and G.0368.15N).; esteem2jra3; esteem2na3; esteem2_jra2 |
Approved |
Most recent IF: 2.843 |
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Call Number |
c:irua:134088 c:irua:134088UA @ admin @ c:irua:134088 |
Serial |
4093 |
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Author |
Asapu, R.; Claes, N.; Bals, S.; Denys, S.; Detavernier, C.; Lenaerts, S.; Verbruggen, S.W. |
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Title |
Silver-polymer core-shell nanoparticles for ultrastable plasmon-enhanced photocatalysis |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Applied catalysis : B : environmental |
Abbreviated Journal |
Appl Catal B-Environ |
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Volume |
200 |
Issue |
200 |
Pages |
31-38 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Affordable silver-polymer core-shell nanoparticles are prepared using the layer-by-layer (LbL) technique. The metallic silver core is encapsulated with an ultra-thin protective shell that prevents oxidation and clustering without compromising the plasmonic properties. The core-shell nanoparticles retain their plasmonic near field enhancement effect, as studied from finite element numerical simulations. Control over the shell thickness up to the sub-nanometer level is there for key. The particles are used to prepare a plasmonic Ag-TiO2 photocatalyst of which the gas phase photocatalytic activity is monitored over a period of four months. The described system outperforms pristine TiO2 and retains its plasmonic enhancement in contrast to TiO2 modified with bare silver nanoparticles. With this an important step is made toward the development of long-term stable plasmonic (photocatalytic) applications. |
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Corporate Author |
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Wos |
000384775600004 |
Publication Date |
2016-06-28 |
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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 |
0926-3373 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.446 |
Times cited |
45 |
Open Access |
OpenAccess |
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Notes |
CD, SL and SWV acknowledge the Research Foundation − Flanders (FWO) for financial support. CD further acknowledges BOF-UGent (GOA 01G01513) and the Hercules Foundation (AUGE/09/014). SB acknowledges the European Research Council for the ERC Starting Grant #335078-COLOURATOM.; ECAS_Sara; (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); |
Approved |
Most recent IF: 9.446 |
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Call Number |
c:irua:134384 c:irua:134384UA @ admin @ c:irua:134384 |
Serial |
4104 |
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Author |
Altantzis, T.; Coutino-Gonzalez, E.; Baekelant, W.; Martinez, G.T.; Abakumov, A.M.; Van Tendeloo, G.; Roeffaers, M.B.J.; Bals, S.; Hofkens, J. |
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Title |
Direct Observation of Luminescent Silver Clusters Confined in Faujasite Zeolites |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
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Volume |
10 |
Issue |
10 |
Pages |
7604-7611 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
One of the ultimate goals in the study of metal clusters is the correlation between the atomic-scale organization and their physicochemical properties. However, direct observation of the atomic organization of such minuscule metal clusters is heavily hindered by radiation damage imposed by the different characterization techniques. We present direct evidence of the structural arrangement, at an atomic level, of luminescent silver species stabilized in faujasite (FAU) zeolites using aberration-corrected scanning transmission electron microscopy. Two different silver clusters were identified in Ag-FAU zeolites, a trinuclear silver species associated with green emission and a tetranuclear silver species related to yellow emission. By combining direct imaging with complementary information obtained from X-ray powder diffraction and Rietveld analysis, we were able to elucidate the main differences at an atomic scale between luminescent (heat-treated) and nonluminescent (cation-exchanged) Ag-FAU zeolites. It is expected that such insights will trigger the directed synthesis of functional metal nanocluster-zeolite composites with tailored luminescent properties. |
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Address |
RIES, Hokkaido University , N20W10, Kita-Ward Sapporo 001-0020, Japan |
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Corporate Author |
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Place of Publication |
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Language |
English |
Wos |
000381959100043 |
Publication Date |
2016-07-08 |
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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 |
1936-0851 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.942 |
Times cited |
57 |
Open Access |
OpenAccess |
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Notes |
The authors gratefully acknowledge financial support from the Belgian Federal government (Belspo through the IAP-VI/27 and IAP-VII/05 programs), the European Union’s Seventh Framework Programme (FP7/2007-2013 under grant agreement no. 310651 SACS and no. 312483-ESTEEM2), the Flemish government in the form of long-term structural funding “Methusalem” grant METH/15/04 CASAS2, the Hercules foundation (HER/11/14), the “Strategisch Initiatief Materialen” SoPPoM program, and the Fund for Scientific Research Flanders (FWO) grants G.0349.12 and G.0B39.15. S.B. acknowledges funding from ERC Starting Grant COLOURATOMS (335078). The authors thank Prof. S. Van Aert for helpful discussions, Dr. T. De Baerdemaeker for XRD measurements, Mr. B. Dieu for the preparation of graphical material, and UOP Antwerp for the kind donation of zeolite samples.; esteem2jra4; ECASSara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); |
Approved |
Most recent IF: 13.942 |
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Call Number |
c:irua:134576 c:irua:134576 |
Serial |
4102 |
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Author |
Sankaran, K.J.; Hoang, D.Q.; Kunuku, S.; Korneychuk, S.; Turner, S.; Pobedinskas, P.; Drijkoningen, S.; Van Bael, M.K.; D' Haen, J.; Verbeeck, J.; Leou, K.-C.; Lin, I.-N.; Haenen, K. |
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Title |
Enhanced optoelectronic performances of vertically aligned hexagonal boron nitride nanowalls-nanocrystalline diamond heterostructures |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
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Volume |
6 |
Issue |
6 |
Pages |
29444 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Field electron emission (FEE) properties of vertically aligned hexagonal boron nitride nanowalls (hBNNWs) grown on Si have been markedly enhanced through the use of nitrogen doped nanocrystalline diamond (nNCD) films as an interlayer. The FEE properties of hBNNWs-nNCD heterostructures show a low turn-on field of 15.2 V/mum, a high FEE current density of 1.48 mA/cm(2) and life-time up to a period of 248 min. These values are far superior to those for hBNNWs grown on Si substrates without the nNCD interlayer, which have a turn-on field of 46.6 V/mum with 0.21 mA/cm(2) FEE current density and life-time of 27 min. Cross-sectional TEM investigation reveals that the utilization of the diamond interlayer circumvented the formation of amorphous boron nitride prior to the growth of hexagonal boron nitride. Moreover, incorporation of carbon in hBNNWs improves the conductivity of hBNNWs. Such a unique combination of materials results in efficient electron transport crossing nNCD-to-hBNNWs interface and inside the hBNNWs that results in enhanced field emission of electrons. The prospective application of these materials is manifested by plasma illumination measurements with lower threshold voltage (370 V) and longer life-time, authorizing the role of hBNNWs-nNCD heterostructures in the enhancement of electron emission. |
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Address |
IMOMEC, IMEC vzw, 3590 Diepenbeek, Belgium |
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Corporate Author |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000379391000001 |
Publication Date |
2016-07-12 |
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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 |
2045-2322 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.259 |
Times cited |
15 |
Open Access |
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Notes |
The authors like to thank the financial support of the Research Foundation Flanders (FWO) via Research Project G.0456.12, G0044.13N and the Methusalem “NANO” network. Kamatchi Jothiramalingam Sankaran, Stuart Turner, and Paulius Pobedinskas are Postdoctoral Fellows of the Research Foundations Flanders (FWO). |
Approved |
Most recent IF: 4.259 |
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Call Number |
c:irua:134643 c:irua:134643UA @ admin @ c:irua:134643 |
Serial |
4119 |
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Author |
Ying, J.; Hu, Z.-Y.; Yang, X.-Y.; Wei, H.; Xiao, Y.-X.; Janiak, C.; Mu, S.-C.; Tian, G.; Pan, M.; Van Tendeloo, G.; Su, B.-L. |
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Title |
High viscosity to highly dispersed PtPd bimetallic nanocrystals for enhanced catalytic activity and stability |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Chemical communications |
Abbreviated Journal |
Chem Commun |
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Volume |
52 |
Issue |
52 |
Pages |
8219-8222 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A facile high-viscosity-solvent method is presented to synthesize PtPd bimetallic nanocrystals highly dispersed in different mesostructures (2D and 3D structures), porosities (large and small pore sizes), and compositions (silica and carbon). Further, highly catalytic activity, stability and durability of the nanometals have been proven in different catalytic reactions. |
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Address |
State Key Laboratory Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122, Luoshi Road, Wuhan, 430070, China. xyyang@whut.edu.cn |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000378715400006 |
Publication Date |
2016-05-16 |
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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 |
1359-7345 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.319 |
Times cited |
19 |
Open Access |
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Notes |
This work was supported by NFSC (51472190 and 51503166), ISTCP (2015DFE52870), PCSIRT (IRT15R52) of China, and the Integrated Infrastructure Initiative of EU (312483-ESTEEM2).; esteem2jra4 |
Approved |
Most recent IF: 6.319 |
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Call Number |
c:irua:134660 c:irua:134660 |
Serial |
4110 |
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Author |
Kinnear, C.; Rodriguez-Lorenzo, L.; Clift, M.J.D.; Goris, B.; Bals, S.; Rothen, B.; Fink, A.S. |
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Title |
Decoupling the shape parameter to assess gold nanorod uptake by mammalian cells |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
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Volume |
8 |
Issue |
8 |
Pages |
16416-16426 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The impact of nanoparticles (NPs) upon biological systems can be fundamentally associated with their physicochemical parameters. A further often-stated tenet is the importance of NP shape on rates of endocytosis. However, given the convoluted parameters concerning the NP-cell interaction, it is experimentally challenging to attribute any findings to shape alone. Herein we demonstrate that shape, below a certain limit, which is specific to nanomedicine, is not important for the endocytosis of spherocylinders by either epithelial or macrophage cells in vitro. Through a systematic approach, we reshaped a single batch of gold nanorods into different aspect ratios resulting in near-spheres and studied their cytotoxicity, (pro-)inflammatory status, and endocytosis/exocytosis. It was found that on a length scale of ~10-90 nm and at aspect ratios less than 5, NP shape has little impact upon their entry into either macrophages or epithelial cells. Conversely, nanorods with an aspect ratio above 5 were preferentially endocytosed by epithelial cells, whereas there was a lack of shape dependent uptake following exposure to macrophages in vitro. These findings have implications both in the understanding of nanoparticle reshaping mechanisms, as well as in the future rational design of nanomaterials for biomedical 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 |
000384531600036 |
Publication Date |
2016-08-08 |
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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 |
2040-3364 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.367 |
Times cited |
23 |
Open Access |
OpenAccess |
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Notes |
The authors would like to thank C. Endes for her help and technical assistance with all cell culture experiments. The work was supported by the Adolphe Merkle Foundation, the Swiss National Science Foundation (PP00P2123373), the Swiss National Science Foundation through the National Centre of Competence in Research Bio-Inspired Materials, the Flemish Fund for Scientific Research (FWO Vlaanderen) through a postdoctoral research grant, and the European Research Council (ERC Starting Grant #335078-COLOURATOMS). The authors also appreciate financial support from the European Union under the Seventh Framework Program (Integrated Infrastructure Initiative N. 262348 European Soft Matter Infrastructure, ESMI).; ECASSara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 7.367 |
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Call Number |
c:irua:135087 c:irua:135087 |
Serial |
4109 |
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Author |
Hill, E.H.; Claes, N.; Bals, S.; Liz-Marzán, L.M. |
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| |
Title |
Layered Silicate Clays as Templates for Anisotropic Gold Nanoparticle Growth |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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| |
Volume |
28 |
Issue |
28 |
Pages |
5131-5139 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Clay minerals are abundant natural materials arising in the presence of water and are composed of small particles of different sizes and shapes. The interlamellar space between layered silicate clays can also be used to host a variety of different organic and inorganic guest molecules or particles. Recent studies of clay−metal hybrids formed by impregnation of nanoparticles into the interlayer spaces of the clays have not demonstrated the ability for templated growth following the shape of the particles. Following this line of interest, a method for the synthesis of gold nanoparticles on the synthetic layered silicate clay laponite was developed. This approach can be used to make metal−clay nanoparticles with a variety of morphologies while retaining the molecular adsorption properties of the clay. The surface enhanced Raman scattering enhancement of these particles was also found to be greater than that obtained from other metal nanoparticles of a similar morphology, likely due to increased dye adsorption by the presence of the clay. The hybrid particles presented herein will contribute to further study of plasmonic
sensing, catalysis, dye aggregation, and novel composite 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 |
000380576700031 |
Publication Date |
2016-07-02 |
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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 |
0897-4756 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
9.466 |
Times cited |
13 |
Open Access |
OpenAccess |
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| |
Notes |
This work has been supported by the European Research Council (ERC Advanced Grant No. 267867, PLASMAQUO). E.H.H. thanks the Spanish Ministry of Economy and Competitiveness for providing a Juan de la Cierva Fellowship (FJCI-2014-22598). N.C. and S.B. acknowledge financial support from European Research Council (ERC Starting Grant #335078-COLOURATOM). We gratefully acknowledge A. B. Serrano-Montes for providing the seed-mediated Au nanostars.; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); |
Approved |
Most recent IF: 9.466 |
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| |
Call Number |
c:irua:135178 c:irua:135178 |
Serial |
4117 |
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| Permanent link to this record |
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Author |
Goris, B.; Meledina, M.; Turner, S.; Zhong, Z.; Batenburg, K.J.; Bals, S. |
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| |
Title |
Three dimensional mapping of Fe dopants in ceria nanocrystals using direct spectroscopic electron tomography |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
| |
Volume |
171 |
Issue |
171 |
Pages |
55-62 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Electron tomography is a powerful technique for the 3D characterization of the morphology of nanostructures. Nevertheless, resolving the chemical composition of complex nanostructures in 3D remains challenging and the number of studies in which electron energy loss spectroscopy (EELS) is combined with tomography is limited. During the last decade, dedicated reconstruction algorithms have been developed for HAADF-STEM tomography using prior knowledge about the investigated sample. Here, we will use the prior knowledge that the experimental spectrum of each reconstructed voxel is a linear combination of a well-known set of references spectra in a so-called direct spectroscopic tomography technique. Based on a simulation experiment, it is shown that this technique provides superior results in comparison to conventional reconstruction methods for spectroscopic data, especially for spectrum images containing a relatively low signal to noise ratio. Next, this technique is used to investigate the spatial distribution of Fe dopants in Fe:Ceria nanoparticles in 3D. It is shown that the presence of the Fe2+ dopants is correlated with a reduction of the Ce atoms from Ce4+ towards Ce3+. In addition, it is demonstrated that most of the Fe dopants are located near the voids inside the nanoparticle. |
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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 |
000389106200007 |
Publication Date |
2016-09-06 |
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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 |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.843 |
Times cited |
13 |
Open Access |
OpenAccess |
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Notes |
The work was supported by the Research Foundation Flanders (FWO Vlaanderen) by project funding (G038116N, 3G004613) and by a post-doctoral research grants to B.G. S.B. acknowledges funding from the European Research Council (Starting Grant no. COLOURATOMS 335078). K.J.B. acknowledges funding from The Netherlands Organization for Scientific Research (NWO) (program 639.072.005.). We would like to thank Dr. Hilde Poelman, Dr. Vladimir Galvita and Prof. Dr. Guy B. Marin for the synthesis of the investigated sample.; ECAS_Sara; (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); |
Approved |
Most recent IF: 2.843 |
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| |
Call Number |
c:irua:135185 c:irua:135185 |
Serial |
4123 |
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| Permanent link to this record |
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Author |
Gonnissen, J.; Batuk, D.; Nataf, G.F.; Jones, L.; Abakumov, A.M.; Van Aert, S.; Schryvers, D.; Salje, E.K.H. |
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| |
Title |
Direct Observation of Ferroelectric Domain Walls in LiNbO3: Wall-Meanders, Kinks, and Local Electric Charges |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Advanced functional materials |
Abbreviated Journal |
Adv Funct Mater |
|
| |
Volume |
26 |
Issue |
26 |
Pages |
7599-7604 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Direct observations of the ferroelectric domain boundaries in LiNbO3 are performed using high-resolution high-angle annular dark field scanning transmission electron microscopy imaging, revealing a very narrow width of the domain wall between the 180° domains. The domain walls demonstrate local side-way meandering, which results in inclinations even when the overall wall orientation follows the ferroelectric polarization. These local meanders contain kinks with “head-to-head” and “tail-to-tail” dipolar configurations and are therefore locally charged. The charged meanders are confined to a few cation layers along the polarization direction and are separated by longer stretches of straight domain walls. |
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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 |
000388166700006 |
Publication Date |
2016-09-16 |
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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 |
1616-301X |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
12.124 |
Times cited |
23 |
Open Access |
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Notes |
J.G. acknowledges the support from the Research Foundation Flanders (FWO, Belgium) through various project fundings (G.0368.15N, G.0369.15N, and G.0374.13N), as well as the financial support from the European Union Seventh Framework Program (FP7/2007–2013) under Grant agreement no. 312483 (ESTEEM2). The authors thank J. Hadermann for useful suggestions on the interpretation of the HAADFSTEM images. E.K.H.S. thanks the EPSRC (EP/K009702/1) and the Leverhulme Trust (EM-2016-004) for support. G.F.N. thanks the National Research Fund, Luxembourg (FNR/P12/4853155/Kreisel) for support.; esteem2_jra2 |
Approved |
Most recent IF: 12.124 |
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| |
Call Number |
c:irua:135336 c:irua:135336 |
Serial |
4129 |
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| Permanent link to this record |
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Author |
Gonnissen, J.; De Backer, A.; den Dekker, A.J.; Sijbers, J.; Van Aert, S. |
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Title |
Detecting and locating light atoms from high-resolution STEM images: The quest for a single optimal design |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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| |
Volume |
170 |
Issue |
170 |
Pages |
128-138 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
In the present paper, the optimal detector design is investigated for both detecting and locating light atoms from high resolution scanning transmission electron microscopy (HR STEM) images. The principles of detection theory are used to quantify the probability of error for the detection of light atoms from HR STEM images. To determine the optimal experiment design for locating light atoms, use is made of the so-called Cramer-Rao Lower Bound (CRLB). It is investigated if a single optimal design can be found for both the detection and location problem of light atoms. Furthermore, the incoming electron dose is optimised for both research goals and it is shown that picometre range precision is feasible for the estimation of the atom positions when using an appropriate incoming electron dose under the optimal detector settings to detect light atoms. |
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Address |
Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium. Electronic address: sandra.vanaert@uantwerpen.be |
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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 |
English |
Wos |
000386925500014 |
Publication Date |
2016-07-26 |
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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 |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
6 |
Open Access |
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Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0368.15, G.0369.15 and G.0374.13) and a postdoctoral research grant to A. De Backer. The research leading to these results has also received funding from the European Union Seventh Framework Programme [FP7/2007-2013] under Grant agreement no. 312483 (ESTEEM2). The authors would also like to thank A. Rosenauer for providing access to the STEMsim software and Gerardo T. Martinez for fruitful discussions.; esteem2_jra2 |
Approved |
Most recent IF: 2.843 |
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Call Number |
c:irua:135337 c:irua:135337 |
Serial |
4128 |
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| Permanent link to this record |
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Author |
Tong, J.; Fu, Y.; Domaretskiy, D.; Della Pia, F.; Dagar, P.; Powell, L.; Bahamon, D.; Huang, S.; Xin, B.; Costa Filho, R.N.; Vega, L.F.; Grigorieva, I.V.; Peeters, F.M.; Michaelides, A.; Lozada-Hidalgo, M. |
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Title |
Control of proton transport and hydrogenation in double-gated graphene |
Type |
A1 Journal Article |
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Year |
2024 |
Publication |
Nature |
Abbreviated Journal |
Nature |
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| |
Volume |
630 |
Issue |
8017 |
Pages |
619-624 |
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Keywords |
A1 Journal Article; Condensed Matter Theory (CMT) ; |
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Abstract |
The basal plane of graphene can function as a selective barrier that is permeable to protons but impermeable to all ions and gases, stimulating its use in applications such as membranes, catalysis and isotope separation. Protons can chemically adsorb on graphene and hydrogenate it, inducing a conductor–insulator transition that has been explored intensively in graphene electronic devices. However, both processes face energy barriersand various strategies have been proposed to accelerate proton transport, for example by introducing vacancies, incorporating catalytic metalsor chemically functionalizing the lattice. But these techniques can compromise other properties, such as ion selectivity or mechanical stability. Here we show that independent control of the electric field,<italic>E</italic>, at around 1 V nm<sup>−1</sup>, and charge-carrier density,<italic>n</italic>, at around 1 × 10<sup>14</sup> cm<sup>−2</sup>, in double-gated graphene allows the decoupling of proton transport from lattice hydrogenation and can thereby accelerate proton transport such that it approaches the limiting electrolyte current for our devices. Proton transport and hydrogenation can be driven selectively with precision and robustness, enabling proton-based logic and memory graphene devices that have on–off ratios spanning orders of magnitude. Our results show that field effects can accelerate and decouple electrochemical processes in double-gated 2D crystals and demonstrate the possibility of mapping such processes as a function of<italic>E</italic>and<italic>n</italic>, which is a new technique for the study of 2D electrode–electrolyte interfaces. |
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Corporate Author |
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Place of Publication |
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Wos |
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Publication Date |
2024-06-20 |
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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 |
0028-0836 |
ISBN |
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Additional Links |
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| |
Impact Factor |
64.8 |
Times cited |
|
Open Access |
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| |
Notes |
This work was supported by UKRI (EP/X017745: M.L.-H; EP/X035891: A.M.), the Directed Research Projects Program of the Research and Innovation Center for Graphene and 2D Materials at Khalifa University (RIC2D-D001: M.L.-H., L.F.V. and D.B.), The Royal Society (URF\R1\201515: M.L.-H.) and the European Research Council (101071937: A.M.). Part of this work was supported by the Flemish Science Foundation (FWO-Vl, G099219N). A.M. acknowledges access to the UK national high-performance computing service (ARCHER2). |
Approved |
Most recent IF: 64.8; 2024 IF: 40.137 |
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Call Number |
CMT @ cmt @ |
Serial |
9247 |
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Author |
Krstajić, P.M.; Van Duppen, B.; Peeters, F.M. |
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Title |
Plasmons and their interaction with electrons in trilayer graphene |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
88 |
Issue |
19 |
Pages |
195423 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The interaction between electrons and plasmons in trilayer graphene is investigated within the Overhauser approach resulting in the “plasmaron” quasiparticle. This interaction is cast into a field theoretical problem, and its effect on the energy spectrum is calculated using improved Wigner-Brillouin perturbation theory. The plasmaron spectrum is shifted with respect to the bare electron spectrum by ΔE(k)∼150−200meV for ABC stacked trilayer graphene and for ABA trilayer graphene by ΔE(k)∼30−150 meV[ ΔE(k) ∼1 −5meV] for the hyperbolic (linear) part of the spectrum. The shift in general increases with the electron concentration and electron momentum. The dispersion of plasmarons is more pronounced in ABC stacked than in ABA stacked trilayer graphene, because of the different energy band structure and their different plasmon dispersion. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
000327239200003 |
Publication Date |
2013-11-21 |
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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 |
1098-0121 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
10 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), by the ESF-EuroGRAPHENE project CON-GRAN, and by the Serbian Ministry of Education and Science, within the Project No. TR 32008. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
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Call Number |
CMT @ cmt @ c:irua:112702 |
Serial |
4489 |
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| Permanent link to this record |
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Author |
Muñoz, W.A.; Covaci, L.; Peeters, F.M. |
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Title |
Superconducting current and proximity effect in ABA and ABC multilayer graphene Josephson junctions |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
88 |
Issue |
88 |
Pages |
214502 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using a numerical tight-binding approach based on the Chebyshev–Bogoliubov–de Gennes method we describe Josephson junctions made of multilayer graphene contacted by top superconducting gates. Both Bernal (ABA) and rhombohedral (ABC) stacking are considered and we find that the type of stacking has a strong effect on the proximity effect and the supercurrent flow. For both cases the pair amplitude shows a polarization between dimer and nondimer atoms, being more pronounced for rhombohedral stacking. Even though the proximity effect in nondimer sites is enhanced when compared to single-layer graphene, we find that the supercurrent is suppressed. The spatial distribution of the supercurrent shows that for Bernal stacking the current flows only in the topmost layers while for rhombohedral stacking the current flows throughout the whole structure. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
000328569900004 |
Publication Date |
2013-12-02 |
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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 |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
4 |
Open Access |
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Notes |
This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem funding of the Flemish Government |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
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Call Number |
CMT @ cmt @ c:irua:128896 |
Serial |
3962 |
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Author |
Bekaert, J.; Vercauteren, S.; Aperis, A.; Komendová, L.; Prozorov, R.; Partoens, B.; Milošević, M.V. |
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Title |
Anisotropic type-I superconductivity and anomalous superfluid density in OsB2 |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
94 |
Issue |
94 |
Pages |
144506 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We present a microscopic study of superconductivity in OsB2 , and discuss the origin and characteristic length
scales of the superconducting state. From first-principles we show that OsB2 is characterized by three different
Fermi sheets, and we prove that this fermiology complies with recent quantum-oscillation experiments. Using the
found microscopic properties, and experimental data from the literature, we employ Ginzburg-Landau relations
to reveal that OsB2 is a distinctly type-I superconductor with a very low Ginzburg-Landau parameter κ—a rare
property among compound materials. We show that the found coherence length and penetration depth corroborate
the measured thermodynamic critical field. Moreover, our calculation of the superconducting gap structure using
anisotropic Eliashberg theory and ab initio calculated electron-phonon interaction as input reveals a single but
anisotropic gap. The calculated gap spectrum is shown to give an excellent account for the unconventional
behavior of the superfluid density of OsB2 measured in experiments as a function of temperature. This reveals
that gap anisotropy can explain such behavior, observed in several compounds, which was previously attributed
solely to a two-gap nature of superconductivity. |
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Place of Publication |
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Language |
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Wos |
000385622500009 |
Publication Date |
2016-10-12 |
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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 |
2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
19 |
Open Access |
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Notes |
Fonds Wetenschappelijk Onderzoek; European Cooperation in Science and Technology, MP1201 ; Vetenskapsrådet; |
Approved |
Most recent IF: 3.836 |
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Call Number |
CMT @ cmt @ c:irua:139020 |
Serial |
4338 |
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Author |
Callewaert, V.; Saniz, R.; Barbiellini, B.; Partoens, B. |
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Title |
Surface states and positron annihilation spectroscopy: results and prospects from a first-principles approach |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
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Volume |
791 |
Issue |
791 |
Pages |
012036 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The trapping of positrons at the surface of a material can be exploited to study quite selectively the surface properties of the latter by means of positron annihilation spectroscopy techniques. To support these, it is desirable to be able to theoretically predict the existence of such positronic surface states and to describe their annihilation characteristics with core or valence surface electrons in a reliable way. Here, we build on the well-developed first-principles techniques for the study of positrons in bulk solids as well as on previous models for surfaces, and investigate two schemes that can improve the theoretical description of the interaction of positrons with surfaces. One is based on supplementing the local-density correlation potential with the corrugated image potential at the surface, and the other is based on the weighted-density approximation to correlation. We discuss our results for topological insulators, graphene layers, and quantum dots, with emphasis on the information that can be directly related to experiment. We also discuss some open theoretical problems that should be addressed by future research. |
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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 |
000400610500036 |
Publication Date |
2017-02-22 |
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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 |
1742-6588 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
|
Times cited |
1 |
Open Access |
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Notes |
We acknowledge financial support from FWO-Vlaanderen (projects G.0150.13 and G.0224.14N). This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), 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: NA |
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Call Number |
CMT @ cmt @ c:irua:140847 |
Serial |
4425 |
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Author |
Eijt, S.W.H.; Shi, W.; Mannheim, A.; Butterling, M.; Schut, H.; Egger, W.; Dickmann, M.; Hugenschmidt, C.; Shakeri, B.; Meulenberg, R.W.; Callewaert, V.; Saniz, R.; Partoens, B.; Barbiellini, B.; Bansil, A.; Melskens, J.; Zeman, M.; Smets, A.H.M.; Kulbak, M.; Hodes, G.; Cahen, D.; Brück, E. |
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| |
Title |
New insights into the nanostructure of innovative thin film solar cells gained by positron annihilation spectroscopy |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
|
| |
Volume |
791 |
Issue |
791 |
Pages |
012021 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Recent studies showed that positron annihilation methods can provide key insights into the nanostructure and electronic structure of thin film solar cells. In this study, positron annihilation lifetime spectroscopy (PALS) is applied to investigate CdSe quantum dot (QD) light absorbing layers, providing evidence of positron trapping at the surfaces of the QDs. This enables one to monitor their surface composition and electronic structure. Further, 2D-Angular Correlation of Annihilation Radiation (2D-ACAR) is used to investigate the nanostructure of divacancies in photovoltaic-high-quality a-Si:H films. The collected momentum distributions were converted by Fourier transformation to the direct space representation of the electron-positron autocorrelation function. The evolution of the size of the divacancies as a function of hydrogen dilution during deposition of a-Si:H thin films was examined. Finally, we present a first positron Doppler Broadening of Annihilation Radiation (DBAR) study of the emerging class of highly efficient thin film solar cells based on perovskites. |
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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 |
000400610500021 |
Publication Date |
2017-02-22 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1742-6588 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
|
Times cited |
1 |
Open Access |
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| |
Notes |
The work at Delft University of Technology was supported by the China Scholarship Council (CSC) grant of W.S., by ADEM, A green Deal in Energy Materials of the Ministry of Economic Affairs of The Netherlands (www.adem- innovationlab.nl), and the STW Vidi grant of A.S., Grant No. 10782. The PALS study is based upon experiments performed at the PLEPS instrument of the NEPOMUC facility at the Heinz Maier-Leibnitz Zentrum (MLZ), Garching, Germany, and was supported by the European Commission under the 7 th Framework Programme, Key Action: Strengthening the European Research Area, Research Infrastructures, Contract No. 226507, NMI3. The work at University of Maine was supported by the National Science Foundation under Grant No. DMR-1206940. Research at the University of Antwerp was supported by FWO grants G022414N and G015013. 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. The work at the Weizmann Institute was supported by the Sidney E. Frank Foundation through the Israel Science Foundation, by the Israel Ministry of Science, and the Israel National Nano-Initiative. D.C. holds the Sylvia and Rowland Schaefer Chair in Energy Research. |
Approved |
Most recent IF: NA |
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| |
Call Number |
CMT @ cmt @ c:irua:140850 |
Serial |
4426 |
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| Permanent link to this record |
| |
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| |
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Author |
Vagov, A.; Shanenko, A.A.; Milošević, M.V.; Axt, V.M.; Vinokur, V.M.; Aguiar, J.A.; Peeters, F.M. |
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| |
Title |
Superconductivity between standard types: Multiband versus single-band materials |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
93 |
Issue |
93 |
Pages |
174503 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
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| |
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 |
000375527500001 |
Publication Date |
2016-05-06 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
37 |
Open Access |
|
|
| |
Notes |
Conselho Nacional de Desenvolvimento Científico e Tecnológico, 307552/2012-8 141911/2012-3 ; Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco, APQ-0589-1.05/08 ; U.S. Department of Energy; |
Approved |
Most recent IF: 3.836 |
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| |
Call Number |
CMT @ cmt @ c:irua:141732 |
Serial |
4480 |
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| Permanent link to this record |
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| |
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Author |
Mulkers, J.; Van Waeyenberge, B.; Milošević, M.V. |
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| |
Title |
Effects of spatially engineered Dzyaloshinskii-Moriya interaction in ferromagnetic films |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
95 |
Issue |
95 |
Pages |
144401 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
The Dzyaloshinskii-Moriya interaction (DMI) is a chiral interaction that favors formation of domain walls. Recent experiments and ab initio calculations show that there are multiple ways to modify the strength of the interfacially induced DMI in thin ferromagnetic films with perpendicular magnetic anisotropy. In this paper we reveal theoretically the effects of spatially varied DMI on the magnetic state in thin films. In such heterochiral 2D structures we report several emergent phenomena, ranging from the equilibrium spin canting at the interface between regions with different DMI, over particularly strong confinement of domain walls and skyrmions within high-DMI tracks, to advanced applications such as domain tailoring nearly at will, design of magnonic waveguides, and much improved skyrmion racetrack memory. |
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| |
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 |
000399382100003 |
Publication Date |
2017-04-03 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
60 |
Open Access |
|
|
| |
Notes |
Fonds Wetenschappelijk Onderzoek, G098917N ; |
Approved |
Most recent IF: 3.836 |
|
| |
Call Number |
CMT @ cmt @ c:irua:141917 |
Serial |
4534 |
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| Permanent link to this record |
| |
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| |
|
Author |
Han, F.W.; Xu, W.; Li, L.L.; Zhang, C.; Dong, H.M.; Peeters, F.M. |
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| |
Title |
Electronic and transport properties of n-type monolayer black phosphorus at low temperatures |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
95 |
Issue |
95 |
Pages |
115436 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
We present a detailed theoretical study of the electronic and transport properties of monolayer black phosphorus (BP). This study is motivated by recent experimental activities in investigating n-type few-layer BP systems. The electron density of states, the screening length, and the low-temperature electron mobility are calculated for monolayer BP (MLBP). In particular, the electron transport mobilities along the armchair and zigzag directions are examined on the basis of the momentum-balance equation derived from a semiclassical Boltzmann equation. The anisotropic electron mobilities in MLBP along different directions are demonstrated where the electron-impurity scattering is considered. Furthermore, we compare the results obtained from two electronic band structures of MLBP and find that the simplified model can describe quite rightly the electronic and transport properties of MLBP. This study is relevant to the application of few-layer BP based electronic systems as advanced electronic devices. |
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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 |
000399140700012 |
Publication Date |
2017-03-27 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
12 |
Open Access |
|
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| |
Notes |
National Natural Science Foundation of China, 11574319 11304316 11304317 11604380 ; Ministry of Science and Technology of the People's Republic of China, 2011YQ130018 ; Chinese Academy of Sciences; |
Approved |
Most recent IF: 3.836 |
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| |
Call Number |
CMT @ cmt @ c:irua:142431 |
Serial |
4564 |
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| 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. |
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| |
Title |
Dependence of the shape of graphene nanobubbles on trapped substance |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
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| |
Volume |
8 |
Issue |
8 |
Pages |
15844 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
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. |
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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 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
12.124 |
Times cited |
44 |
Open Access |
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| |
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 |
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| |
Call Number |
CMT @ cmt @ c:irua:144189 |
Serial |
4580 |
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| Permanent link to this record |
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| |
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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. |
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| |
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 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
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. |
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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 |
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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 |
|
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| |
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
12.124 |
Times cited |
20 |
Open Access |
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| |
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 |
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| |
Call Number |
CMT @ cmt @ c:irua:144625 |
Serial |
4627 |
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| Permanent link to this record |
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Author |
Stosic, D.; Mulkers, J.; Van Waeyenberge, B.; Ludermir, T.B.; Milošević, M.V. |
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Title |
Paths to collapse for isolated skyrmions in few-monolayer ferromagnetic films |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
95 |
Issue |
21 |
Pages |
214418 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Magnetic skyrmions are topological spin configurations in materials with chiral Dzyaloshinskii-Moriya interaction (DMI), that are potentially useful for storing or processing information. To date, DMI has been found in few bulk materials, but can also be induced in atomically thin magnetic films in contact with surfaces with large spin-orbit interactions. Recent experiments have reported that isolated magnetic skyrmions can be stabilized even near room temperature in few-atom-thick magnetic layers sandwiched between materials that provide asymmetric spin-orbit coupling. Here we present the minimum-energy path analysis of three distinct mechanisms for the skyrmion collapse, based on ab initio input and the performed atomic-spin simulations. We focus on the stability of a skyrmion in three atomic layers of Co, either epitaxial on the Pt(111) surface or within a hybrid multilayer where DMI nontrivially varies per monolayer due to competition between different symmetry breaking from two sides of the Co film. In laterally finite systems, their constrained geometry causes poor thermal stability of the skyrmion toward collapse at the boundary, which we show to be resolved by designing the high-DMI structure within an extended film with lower or no DMI. |
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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 |
000404015500001 |
Publication Date |
2017-06-23 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
48 |
Open Access |
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| |
Notes |
This work was supported by the Research Foundation, Flanders (FWO-Vlaanderen) and Brazilian agency CNPq (Grants No. 442668/2014-7 and No. 140840/2016-8). |
Approved |
Most recent IF: 3.836 |
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| |
Call Number |
CMT @ cmt @c:irua:144865 |
Serial |
4704 |
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| Permanent link to this record |
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Author |
Hafiz, H.; Suzuki, K.; Barbiellini, B.; Orikasa, Y.; Callewaert, V.; Kaprzyk, S.; Itou, M.; Yamamoto, K.; Yamada, R.; Uchimoto, Y.; Sakurai, Y.; Sakurai, H.; Bansil, A. |
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Title |
Visualizing redox orbitals and their potentials in advanced lithium-ion battery materials using high-resolution x-ray Compton scattering |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Science Advances |
Abbreviated Journal |
Sci. Adv. |
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| |
Volume |
3 |
Issue |
8 |
Pages |
e1700971 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Reduction-oxidation (redox) reactions are the key processes that underlie the batteries powering smartphones, laptops, and electric cars. A redox process involves transfer of electrons between two species. For example, in a lithium-ion battery, current is generated when conduction electrons from the lithium anode are transferred to the redox orbitals of the cathode material. The ability to visualize or image the redox orbitals and how these orbitals evolve under lithiation and delithiation processes is thus of great fundamental and practical interest for understanding the workings of battery materials. We show that inelastic scattering spectroscopy using high-energy x-ray photons (Compton scattering) can yield faithful momentum space images of the redox orbitals by considering lithium iron phosphate (LiFePO4 or LFP) as an exemplar cathode battery material. Our analysis reveals a new link between voltage and the localization of transition metal 3d orbitals and provides insight into the puzzling mechanism of potential shift and how it is connected to the modification of the bond between the transition metal and oxygen atoms. Our study thus opens a novel spectroscopic pathway for improving the performance of battery materials. |
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Corporate Author |
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Place of Publication |
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Editor |
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Language |
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Wos |
000411589900055 |
Publication Date |
2017-08-24 |
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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 |
|
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| |
ISSN |
2375-2548 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
|
Times cited |
9 |
Open Access |
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| |
Notes |
The work at Northeastern University was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (grant no. DE-FG02-07ER46352) and benefited from the Northeastern University’s Advanced Scientific Computation Center and the National Energy Research Scientific Computing Center supercomputing center through DOE grant no. DEAC02-05CH11231. The work at Gunma University, Japan Synchrotron Radiation Research Institute (JASRI), and Kyoto University was supported by the Japan Science and Technology Agency. K.S. was supported by Grant-in-Aid for Young Scientists (B) from MEXT KAKENHI under grant nos. 24750065 and 15K17873. The Compton scattering experiments were performed with the approval of JASRI (proposal no. 2014A1289). V.C. was supported by the FWO-Vlaanderen through project no. G. 1161 0224.14N. |
Approved |
Most recent IF: NA |
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| |
Call Number |
CMT @ cmt @c:irua:145034 |
Serial |
4637 |
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| Permanent link to this record |
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Author |
Callewaert, V.; Saniz, R.; Barbiellini, B.; Bansil, A.; Partoens, B. |
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Title |
Application of the weighted-density approximation to the accurate description of electron-positron correlation effects in materials |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
96 |
Issue |
8 |
Pages |
085135 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
We discuss positron-annihilation lifetimes for a set of illustrative bulk materials within the framework of the weighted-density approximation (WDA). The WDA can correctly describe electron-positron correlations in strongly inhomogeneous systems, such as surfaces, where the applicability of (semi-)local approximations is limited. We analyze the WDA in detail and show that the electrons which cannot screen external charges efficiently, such as the core electrons, cannot be treated accurately via the pair correlation of the homogeneous electron gas. We discuss how this problem can be addressed by reducing the screening in the homogeneous electron gas by adding terms depending on the gradient of the electron density. Further improvements are obtained when core electrons are treated within the LDA and the valence electron using the WDA. Finally, we discuss a semiempirical WDA-based approach in which a sum rule is imposed to reproduce the experimental lifetimes. |
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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 |
000408342600003 |
Publication Date |
2017-08-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
|
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| |
Notes |
Fonds Wetenschappelijk Onderzoek, G. 0224.14N ; U.S. Department of Energy, DE-FG02-07ER46352 DE-AC02-05CH11231 DE-SC0012575 ; |
Approved |
Most recent IF: 3.836 |
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| |
Call Number |
CMT @ cmt @c:irua:145703 |
Serial |
4703 |
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| Permanent link to this record |
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Author |
Leliaert, J.; Mulkers, J.; De Clercq, J.; Coene, A.; Dvornik, M.; Van Waeyenberge, B. |
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Title |
Adaptively time stepping the stochastic Landau-Lifshitz-Gilbert equation at nonzero temperature: Implementation and validation in MuMax3 |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
AIP advances |
Abbreviated Journal |
Aip Adv |
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| |
Volume |
7 |
Issue |
12 |
Pages |
125010 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Thermal fluctuations play an increasingly important role in micromagnetic research relevant for various biomedical and other technological applications. Until now, it was deemed necessary to use a time stepping algorithm with a fixed time step in order to perform micromagnetic simulations at nonzero temperatures. However, Berkov and Gorn have shown in [D. Berkov and N. Gorn, J. Phys.: Condens. Matter,14, L281, 2002] that the drift term which generally appears when solving stochastic differential equations can only influence the length of the magnetization. This quantity is however fixed in the case of the stochastic Landau-Lifshitz-Gilbert equation. In this paper, we exploit this fact to straightforwardly extend existing high order solvers with an adaptive time stepping algorithm. We implemented the presented methods in the freely available GPU-accelerated micromagnetic software package MuMax3 and used it to extensively validate the presented methods. Next to the advantage of having control over the error tolerance, we report a twenty fold speedup without a loss of accuracy, when using the presented methods as compared to the hereto best practice of using Heun’s solver with a small fixed time step. |
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Wos |
000418492500010 |
Publication Date |
2017-12-11 |
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ISSN |
2158-3226 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.568 |
Times cited |
13 |
Open Access |
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Notes |
This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vlaanderen) through Project No. G098917N and a postdoctoral fellowship (A.C.). J. L. is supported by the Ghent University Special Research Fund (BOF postdoctoral fellowship). We gratefully acknowl- edge the support of NVIDIA Corporation with the donation of the Titan Xp GPU used for this research. |
Approved |
Most recent IF: 1.568 |
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Call Number |
CMT @ cmt @c:irua:147860 |
Serial |
4799 |
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Author |
Mulkers, J.; Van Waeyenberge, B.; Milošević, M.V. |
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Title |
Tunable Snell's law for spin waves in heterochiral magnetic films |
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A1 Journal article |
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Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
97 |
Issue |
10 |
Pages |
104422 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Thin ferromagnetic films with an interfacially induced DMI exhibit nontrivial asymmetric dispersion relations that lead to unique and useful magnonic properties. Here we derive an analytical expression for the magnon propagation angle within the micromagnetic framework and show how the dispersion relation can be approximated with a comprehensible geometrical interpretation in the k space of the propagation of spin waves. We further explore the refraction of spin waves at DMI interfaces in heterochiral magnetic films, after deriving a generalized Snell's law tunable by an in-plane magnetic field, that yields analytical expressions for critical incident angles. The found asymmetric Brewster angles at interfaces of regions with different DMI strengths, adjustable by magnetic field, support the conclusion that heterochiral ferromagnetic structures are an ideal platform for versatile spin-wave guides. |
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000428238600006 |
Publication Date |
2018-03-26 |
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ISSN |
2469-9950 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
20 |
Open Access |
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Notes |
This work was supported by the Research Foundation- Flanders (FWO-Vlaanderen) through Project No. G098917N. |
Approved |
Most recent IF: 3.836 |
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Call Number |
CMT @ cmt @c:irua:150118UA @ admin @ c:irua:150118 |
Serial |
4915 |
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Author |
Cavalcante, L.S.R.; Chaves, A.; Van Duppen, B.; Peeters, F.M.; Reichman, D.R. |
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Title |
Electrostatics of electron-hole interactions in van der Waals heterostructures |
Type |
A1 Journal article |
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2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
97 |
Issue |
12 |
Pages |
125427 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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The role of dielectric screening of electron-hole interaction in van der Waals heterostructures is theoretically investigated. A comparison between models available in the literature for describing these interactions is made and the limitations of these approaches are discussed. A simple numerical solution of Poisson's equation for a stack of dielectric slabs based on a transfer matrix method is developed, enabling the calculation of the electron-hole interaction potential at very low computational cost and with reasonable accuracy. Using different potential models, direct and indirect exciton binding energies in these systems are calculated within Wannier-Mott theory, and a comparison of theoretical results with recent experiments on excitons in two-dimensional materials is discussed. |
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Wos |
000427983700007 |
Publication Date |
2018-03-21 |
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ISSN |
2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
22 |
Open Access |
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Notes |
Discussions with A. Chernikov and A. Raja are gratefully acknowledged. This work has been financially supported by CNPq, through the PRONEX/FUNCAP, PQ, and Science Without Borders programs, and the FWO-CNPq bilateral program between Brazil and Flanders. B.V.D. acknowledges support from the Flemish Science Foundation (FWO-Vl) through a postdoctoral fellowship. D.R.R. was supported by NSF CHE-1464802. |
Approved |
Most recent IF: 3.836 |
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Call Number |
CMT @ cmt @c:irua:150835UA @ admin @ c:irua:150835 |
Serial |
4953 |
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