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Author |
Zha, G.-Q.; Covaci, L.; Peeters, F.M.; Zhou, S.-P. |
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Title |
Majorana fermion states and fractional flux periodicity in mesoscopic d-wave superconducting loops with spin-orbit interaction |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
1 |
Pages |
014522 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We numerically investigate the spin-orbit (SO) coupling effect on the magnetic flux evolution of energy and supercurrent in mesoscopic d-wave superconducting loops by solving the spin-generalized Bogoliubov-de Gennes equations self-consistently. It is found that the energy spectrum splits when the SO interaction is involved and the Majorana zero mode can be realized in the [100] edges of square systems for an appropriate SO coupling strength. Superconducting phase transitions appear when the energy gap closes, accompanied by energy jumps between different energy parabolas in the ground state, which provides a possible mechanism to support fractional flux periodicity of supercurrent. Moreover, in the case of rectangular loops with SO coupling, the jumps of the ground-state energy gradually disappear by increasing the ratio of length to height of the sample, and a paramagnetic response with opposite direction of the screening current around zero flux value can occur in such systems. |
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Wos |
000341233800010 |
Publication Date |
2014-07-31 |
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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 |
7 |
Open Access |
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Notes |
; This work was supported by National Natural Science Foundation of China under Grants No. 61371020 and No. 61271163, by Visiting Scholar Program of Shanghai Municipal Education Commission, by Innovation Program of Shanghai Municipal Education Commission under Grant No. 13YZ006, and by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:119266 |
Serial |
1938 |
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Author |
Neek-Amal, M.; Xu, P.; Qi, D.; Thibado, P.M.; Nyakiti, L.O.; Wheeler, V.D.; Myers-Ward, R.L.; Eddy, C.R.; Gaskill, D.K.; Peeters, F.M. |
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Title |
Membrane amplitude and triaxial stress in twisted bilayer graphene deciphered using first-principles directed elasticity theory and scanning tunneling microscopy |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
6 |
Pages |
064101 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Twisted graphene layers produce a moire pattern (MP) structure with a predetermined wavelength for a given twist angle. However, predicting the membrane corrugation amplitude for any angle other than pure AB-stacked or AA-stacked graphene is impossible using first-principles density functional theory (DFT) due to the large supercell. Here, within elasticity theory, we define the MP structure as the minimum-energy configuration, thereby leaving the height amplitude as the only unknown parameter. The latter is determined from DFT calculations for AB-and AA-stacked bilayer graphene in order to eliminate all fitting parameters. Excellent agreement with scanning tunneling microscopy results across multiple substrates is reported as a function of twist angle. |
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Wos |
000339995800001 |
Publication Date |
2014-08-01 |
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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 |
12 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. M.N.-A. was supported by the EU-Marie Curie IIF postdoctoral Fellowship No. 299855. P.M.T. is thankful for the financial support of the Office of Naval Research under Grant No. N00014-10-1-0181 and the National Science Foundation under Grant No. DMR-0855358. L.O.N. acknowledges the support of the American Society for Engineering Education and Naval Research Laboratory Postdoctoral Fellow Program. Work at the US Naval Research Laboratory is supported by the Office of Naval Research. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:118774 |
Serial |
1991 |
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Permanent link to this record |
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Author |
Tongay, S.; Sahin, H.; Ko, C.; Luce, A.; Fan, W.; Liu, K.; Zhou, J.; Huang, Y.S.; Ho, C.H.; Yan, J.; Ogletree, D.F.; Aloni, S.; Ji, J.; Li, S.; Li, J.; Peeters, F.M.; Wu, J.; |
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Title |
Monolayer behaviour in bulk ReS2 due to electronic and vibrational decoupling |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
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Volume |
5 |
Issue |
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Pages |
3252 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Semiconducting transition metal dichalcogenides consist of monolayers held together by weak forces where the layers are electronically and vibrationally coupled. Isolated monolayers show changes in electronic structure and lattice vibration energies, including a transition from indirect to direct bandgap. Here we present a new member of the family, rhenium disulphide (ReS2), where such variation is absent and bulk behaves as electronically and vibrationally decoupled monolayers stacked together. From bulk to monolayers, ReS2 remains direct bandgap and its Raman spectrum shows no dependence on the number of layers. Interlayer decoupling is further demonstrated by the insensitivity of the optical absorption and Raman spectrum to interlayer distance modulated by hydrostatic pressure. Theoretical calculations attribute the decoupling to Peierls distortion of the 1T structure of ReS2, which prevents ordered stacking and minimizes the interlayer overlap of wavefunctions. Such vanishing interlayer coupling enables probing of two-dimensional-like systems without the need for monolayers. |
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Wos |
000332666700010 |
Publication Date |
2014-02-06 |
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Abbreviated Series Title |
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Edition |
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ISSN |
2041-1723; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.124 |
Times cited |
806 |
Open Access |
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Notes |
; This work was supported by the United States Department of Energy Early Career Award DE-FG02-11ER46796. The high pressure part of this work was supported by COMPRES, the Consortium for Materials Properties Research in Earth Sciences, under National Science Foundation Cooperative Agreement EAR 11-577758. The electron microscopy and nano-Auger measurements were supported by the user programme at the Molecular Foundry, which was supported by the Office of Science, Office of Basic Energy Sciences, of the United States Department of Energy under contract no. DE-AC02-05CH11231. S. A. gratefully acknowledges Dr Virginia Altoe of the Molecular Foundry for help with the TEM data acquisition and analysis. J.L. acknowledges support from the Natural Science Foundation of China for Distinguished Young Scholar (grant nos. 60925016 and 91233120). Y.-S.H. and C.-H. H. acknowledge support from the National Science Council of Taiwan under project nos. NSC 100-2112-M-011-001-MY3 and NSC 101-2221-E-011-052-MY3. H. S. was supported by the FWO Pegasus Marie Curie Long Fellowship programme. The DFT work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem programme of the Flemish government. Computational resources were partially provided by TUBITAK ULAKBIM, High Performance and Grid Computing Centre. ; |
Approved |
Most recent IF: 12.124; 2014 IF: 11.470 |
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Call Number |
UA @ lucian @ c:irua:119247 |
Serial |
2192 |
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Author |
Duarte-Neto, P.; Stosic, B.; Stosic, T.; Lessa, R.; Milošević, M.V.; Stanley, H.E. |
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Title |
Multifractal properties of a closed contour : a peek beyond the shape analysis |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
PLoS ONE |
Abbreviated Journal |
Plos One |
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Volume |
9 |
Issue |
12 |
Pages |
e115262 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
In recent decades multifractal analysis has been successfully applied to characterize the complex temporal and spatial organization of such diverse natural phenomena as heartbeat dynamics, the dendritic shape of neurons, retinal vessels, rock fractures, and intricately shaped volcanic ash particles. The characterization of multifractal properties of closed contours has remained elusive because applying traditional methods to their quasi-one-dimensional nature yields ambiguous answers. Here we show that multifractal analysis can reveal meaningful and sometimes unexpected information about natural structures with a perimeter well-defined by a closed contour. To this end, we demonstrate how to apply multifractal detrended fluctuation analysis, originally developed for the analysis of time series, to an arbitrary shape of a given study object. In particular, we show the application of the method to fish otoliths, calcareous concretions located in fish's inner ear. Frequently referred to as the fish's “black box”, they contain a wealth of information about the fish's life history and thus have recently attracted increasing attention. As an illustrative example, we show that a multifractal approach can uncover unexpected relationships between otolith contours and size and age of fish at maturity. |
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Wos |
000347239900030 |
Publication Date |
2014-12-26 |
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Edition |
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ISSN |
1932-6203; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.806 |
Times cited |
6 |
Open Access |
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Notes |
; Funding: This work was supported by CNPq, Brazil (Projects No. 201506/2011-4, No. 303251/2010-7, and No. 306719/2012-6). MVM acknowledges support from Flemish Science Foundation (FWO-Vlaanderen) and CAPES PVE action No. BEX1392/ 11-5. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. ; |
Approved |
Most recent IF: 2.806; 2014 IF: 3.234 |
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Call Number |
UA @ lucian @ c:irua:123770 |
Serial |
2218 |
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Permanent link to this record |
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Author |
Abakumov, A.M.; Tsirlin, A.A.; Bakaimi, I.; Van Tendeloo, G.; Lappas, A. |
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Title |
Multiple twinning as a structure directing mechanism in layered rock-salt-type oxides : NaMnO2 polymorphism, redox potentials, and magnetism |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
26 |
Issue |
10 |
Pages |
3306-3315 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
New polymorphs of NaMnO2 have been observed using transmission electron microscopy and synchrotron X-ray powder diffraction. Coherent twin planes confined to the (NaMnO2) layers, parallel to the (10 (1) over bar) crystallographic planes of the monoclinic layered rock-salt-type alpha-NaMnO2 (O3) structure, form quasi-periodic modulated sequences, with the known alpha-and beta-NaMnO2 polymorphs as the two limiting cases. The energy difference between the polymorphic forms, estimated using a DFT-based structure relaxation, is on the scale of the typical thermal energies that results in a high degree of stacking disorder in these compounds. The results unveil the remarkable effect of the twin planes on both the magnetic and electrochemical properties. The polymorphism drives the magnetic ground state from a quasi-1D spin system for the geometrically frustrated alpha-polymorph through a two-leg spin ladder for the intermediate stacking sequence toward a quasi-2D magnet for the beta-polymorph. A substantial increase of the equilibrium potential for Na deintercalation upon increasing the concentration of the twin planes is calculated, providing a possibility to tune the electrochemical potential of the layered rock-salt ABO(2) cathodes by engineering the materials with a controlled concentration of twins. |
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Wos |
000336637000036 |
Publication Date |
2014-05-01 |
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Abbreviated Series Title |
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Edition |
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ISSN |
0897-4756;1520-5002; |
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 |
35 |
Open Access |
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Notes |
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Approved |
Most recent IF: 9.466; 2014 IF: 8.354 |
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Call Number |
UA @ lucian @ c:irua:117766 |
Serial |
2232 |
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Permanent link to this record |
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Author |
Esfahani, D.N.; Covaci, L.; Peeters, F.M. |
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Title |
Nonlinear response to electric field in extended Hubbard models |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
20 |
Pages |
205121 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The electric-field response of a one-dimensional ring of interacting fermions, where the interactions are described by the extended Hubbard model, is investigated. By using an accurate real-time propagation scheme based on the Chebyshev expansion of the evolution operator, we uncover various nonlinear regimes for a range of interaction parameters that allows modeling of metallic and insulating (either charge density wave or spin density wave insulators) rings. The metallic regime appears at the phase boundary between the two insulating phases and provides the opportunity to describe either weakly or strongly correlated metals. We find that the fidelity susceptibility of the ground state as a function of magnetic flux piercing the ring provides a very good measure of the short-time response. Even completely different interacting regimes behave in a similar manner at short time scales as long as the ground-state fidelity susceptibility is the same. Depending on the strength of the electric field we find various types of responses: persistent currents in the insulating phase, a dissipative regime, or damped Bloch-like oscillations with varying frequencies or even irregular in nature. Furthermore, we also consider the dimerization of the ring and describe the response of a correlated band insulator. In this case the distribution of the energy levels is more clustered and the Bloch-like oscillations become even more irregular. |
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Wos |
000345423300002 |
Publication Date |
2014-11-15 |
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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 |
3 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (Fonds Wetenschappelijk Onderzoek – FWO) and the Methusalem program of the Flemish government. One of us (L. C.) receives support as a postdoctoral fellow of the FWO. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:122204 |
Serial |
2355 |
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Author |
Ying, J.; Yang, X.-Y.; Hu, Z.-Y.; Mu, S.-C.; Janiak, C.; Geng, W.; Pan, M.; Ke, X.; Van Tendeloo, G.; Su, B.-L. |
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Title |
One particle@one cell : highly monodispersed PtPd bimetallic nanoparticles for enhanced oxygen reduction reaction |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Nano energy |
Abbreviated Journal |
Nano Energy |
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Volume |
8 |
Issue |
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Pages |
214-222 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Highly monodispersed platinum-based nanoalloys are the best-known catalysts for the oxygen reduction reaction. Although certainly promising, the durability and stability are among the main requirements for commercializing fuel cell electrocatalysts in practical applications. Herein, we synthesize highly stable, durable and catalytic active monodispersed PtPd nano-particles encapsulated in a unique one particle@one cell structure by adjusting the viscosity of solvents using mesocellular foam. PtPd nanoparticles in mesocellular carbon foam exhibit an excellent electrocatalytic activity (over 4 times mass and specific activities than the commercial Pt/C catalyst). Most importantly, this nanocatalyst shows no obvious change of structure and only a 29.5% loss in electrochemically active surface area after 5000 potential sweeps between 0.6 and 1.1 V versus reversible hydrogen electrode cycles. (C) 2014 Elsevier Ltd. All rights reserved. |
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Wos |
000340981700026 |
Publication Date |
2014-06-23 |
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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 |
2211-2855; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.343 |
Times cited |
40 |
Open Access |
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Notes |
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Approved |
Most recent IF: 12.343; 2014 IF: 10.325 |
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Call Number |
UA @ lucian @ c:irua:119255 |
Serial |
2465 |
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Permanent link to this record |
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Author |
Grujić, M.M.; Tadić, M.Z.; Peeters, F.M. |
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Title |
Orbital magnetic moments in insulating Dirac systems : impact on magnetotransport in graphene van der Waals heterostructures |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
20 |
Pages |
205408 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
In honeycomb Dirac systems with broken inversion symmetry, orbital magnetic moments coupled to the valley degree of freedom arise due to the topology of the band structure, leading to valley-selective optical dichroism. On the other hand, in Dirac systems with prominent spin-orbit coupling, similar orbital magnetic moments emerge as well. These moments are coupled to spin, but otherwise have the same functional form as the moments stemming from spatial inversion breaking. After reviewing the basic properties of these moments, which are relevant for a whole set of newly discovered materials, such as silicene and germanene, we study the particular impact that these moments have on graphene nanoengineered barriers with artificially enhanced spin-orbit coupling. We examine transmission properties of such barriers in the presence of a magnetic field. The orbital moments are found to manifest in transport characteristics through spin-dependent transmission and conductance, making them directly accessible in experiments. Moreover, the Zeeman-type effects appear without explicitly incorporating the Zeeman term in the models, i.e., by using minimal coupling and Peierls substitution in continuum and the tight-binding methods, respectively. We find that a quasiclassical view is able to explain all the observed phenomena. |
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Wos |
000344915800009 |
Publication Date |
2014-11-10 |
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Series Editor |
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Abbreviated Series Title |
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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 |
5 |
Open Access |
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Notes |
; This work was supported by the Ministry of Education, Science and Technological Development (Serbia), and the Fonds Wetenschappelijk Onderzoek (Belgium). ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:122141 |
Serial |
2497 |
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Permanent link to this record |
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Author |
Berdiyorov, G.R.; Milošević, M.V.; Savel'ev, S.; Kusmartsev, F.; Peeters, F.M. |
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Title |
Parametric amplification of vortex-antivortex pair generation in a Josephson junction |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
13 |
Pages |
134505 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using advanced three-dimensional simulations, we show that an Abrikosov vortex, trapped inside a cavity perpendicular to an artificial Josephson junction, can serve as a very efficient source for generation of Josephson vortex-antivortex pairs in the presence of the applied electric current. In such a case, the nucleation rate of the pairs can be tuned in a broad range by an out-of-plane ac magnetic field in a broad range of frequencies. This parametrically amplified vortex-antivortex nucleation can be considered as a macroscopic analog of the dynamic Casimir effect, where fluxon pairs mimic the photons and the ac magnetic field plays the role of the oscillating mirrors. The emerging vortex pairs in our system can be detected by the pronounced features in the measured voltage characteristics, or through the emitted electromagnetic radiation, and exhibit resonant dynamics with respect to the frequency of the applied magnetic field. Reported tunability of the Josephson oscillations can be useful for developing high-frequency emission devices. |
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Wos |
000344025100003 |
Publication Date |
2014-10-06 |
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Abbreviated Series Title |
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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 |
22 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-VI) and the Leverhulme Trust. G.R.B. acknowledges support from a EU-Marie Curie individual grant (Grant No. 253057) ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:121176 |
Serial |
2553 |
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Permanent link to this record |
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Author |
Croitoru, M.D.; Buzdin, A.I. |
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Title |
Peculiarities of the orbital effect in the Fulde-Ferrell-Larkin-Ovchinnikov state in quasi-one-dimensional superconductors |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
89 |
Issue |
22 |
Pages |
224506 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using the quasiclassical formalism, we determine the low-temperature phase diagram of a quasi-one-dimensional superconductor, taking into account the interchain Josephson coupling and the paramagnetic spin splitting. We show that the anisotropy of the onset of superconductivity changes in the FFLO state as compared with the conventional superconducting phase. It can result in anomalous peaks in the field-direction dependence of the upper critical field when the magnetic field length equals to the FFLO period. This regime is characterized by the lock-in effect of the FFLO modulation wave vector, which is governed by the magnetic length. Furthermore, in the FFLO phase, the anisotropy of the upper critical field is inverted at T-1(**) = 0.5T(c0), where the orbital anisotropy disappears. We suggest that an experimental study of the anisotropy of the upper critical field can provide very reach information about the parameters of the FFLO phase in quasi-1D samples. |
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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 |
000336975000005 |
Publication Date |
2014-06-09 |
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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 |
|
Open Access |
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|
Notes |
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Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:117749 |
Serial |
2569 |
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Permanent link to this record |
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Author |
Gou, H.; Tsirlin, A.A.; Bykova, E.; Abakumov, A.M.; Van Tendeloo, G.; Richter, A.; Ovsyannikov, S.V.; Kurnosov, A.V.; Trots, D.M.; Konôpková, Z.; Liermann, H.P.; Dubrovinsky, L.; Dubrovinskaia, N.; |
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Title |
Peierls distortion, magnetism, and high hardness of manganese tetraboride |
Type |
A1 Journal article |
|
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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|
Volume |
89 |
Issue |
6 |
Pages |
064108-64109 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
We report crystal structure, electronic structure, and magnetism of manganese tetraboride, MnB4, synthesized under high-pressure, high-temperature conditions. In contrast to superconducting FeB4 and metallic CrB4, which are both orthorhombic, MnB4 features a monoclinic crystal structure. Its lower symmetry originates from a Peierls distortion of the Mn chains. This distortion nearly opens the gap at the Fermi level, but despite the strong dimerization and the proximity of MnB4 to the insulating state, we find indications for a sizable paramagnetic effective moment of about 1.7 mu(B)/f.u., ferromagnetic spin correlations, and, even more surprisingly, a prominent electronic contribution to the specific heat. However, no magnetic order has been observed in standard thermodynamic measurements down to 2 K. Altogether, this renders MnB4 a structurally simple but microscopically enigmatic material; we argue that its properties may be influenced by electronic correlations. |
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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 |
000332405000002 |
Publication Date |
2014-02-24 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
|
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
3.836 |
Times cited |
39 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:115819 |
Serial |
2571 |
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Permanent link to this record |
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Author |
Zhao, C.X.; Xu, W.; Dong, H.M.; Peeters, F.M. |
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Title |
Plasmon and coupled plasmon-phonon modes in graphene in the presence of a driving electric field |
Type |
A1 Journal article |
|
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
89 |
Issue |
19 |
Pages |
195447 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We present a theoretical study of the plasmon and coupled plasmon-phonon modes induced by intraband electron-electron interaction in graphene in the presence of driving dc electric field. We find that the electric field dependence of these collective excitation modes in graphene differs significantly from that in a conventional two-dimensional electron gas with a parabolic energy spectrum. This is due mainly to the fact that graphene has a linear energy spectrum and the Fermi velocity of electrons in graphene is much larger than the drift velocity of electrons. The obtained results demonstrate that the plasmon and coupled plasmon-phonon modes in graphene can be tuned by applying not only the gate voltage but also the source-to-drain field. The manipulation of plasmon and coupled plasmon-phonon modes by source-to-drain voltage can let graphene be more conveniently applied as an advanced plasmonic material. |
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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 |
000336841000007 |
Publication Date |
2014-05-29 |
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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 |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
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Notes |
; This work was supported by the Ministry of Science and Technology of China (Grant No. 2011YQ130018), the Department of Science and Technology of Yunnan Province, the Chinese Academy of Sciences, and by the National Natural Science Foundation of China (Grant No. 11247002). ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:117764 |
Serial |
2642 |
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Permanent link to this record |
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Author |
El-Gogary, R.I.; Rubio, N.; Wang, J.T.W.; Al-Jamal, W.T.; Bourgognon, M.; Kafa, H.; Naeem, M.; Klippstein, R.; Abbate, V.; Leroux, F.; Bals, S.; Van Tendeloo, G.; Kamel, A.O.; Awad, G.A.S.; Mortada, N.D.; Al-Jamal, K.T.; |
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Title |
Polyethylene glycol conjugated polymeric nanocapsules for targeted delivery of quercetin to folate-expressing cancer cells in vitro and in vivo |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
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Volume |
8 |
Issue |
2 |
Pages |
1384-1401 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
In this work we describe the formulation and characterization of chemically modified polymeric nanocapsules incorporating the anticancer drug, quercetin, for the passive and active targeting to tumors. Folic acid was conjugated to poly(lactide-co-glycolide) (PLGA) polymer to facilitate active targeting to cancer cells. Two different methods for the conjugation of PLGA to folic acid were employed utilizing polyethylene glycol (PEG) as a spacer. Characterization of the conjugates was performed using FTIR and H-1 NMR studies. The PEG and folk acid content was independent of the conjugation methodology employed. PEGylation has shown to reduce the size of the nanocapsule; moreover, zeta-potential was shown to be polymer-type dependent. Comparative studies on the cytotoxicity and cellular uptake of the different formulations by He La cells, in the presence and absence of excess folic acid, were carried out using MTT assay and Confocal Laser Scanning Microscopy, respectively. Both results confirmed the selective uptake and cytotoxicity of the folic acid targeted nanocapsules to the folate enriched cancer cells in a folate-dependent manner. Finally, the passive tumor accumulation and the active targeting of the nanocapsules to folate-expressing cells were confirmed upon intravenous administration in He La or IGROV-1 tumor-bearing mice. The developed nanocapsules provide a system for targeted delivery of a range of hydrophobic anticancer drugs in vivo. |
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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 |
000332059200032 |
Publication Date |
2014-01-07 |
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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;1936-086X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.942 |
Times cited |
144 |
Open Access |
Not_Open_Access |
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Notes |
290023 Raddel; 262348 Esmi; Iap-Pai |
Approved |
Most recent IF: 13.942; 2014 IF: 12.881 |
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Call Number |
UA @ lucian @ c:irua:115862 |
Serial |
2670 |
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Permanent link to this record |
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Author |
Carraro, G.; Gasparotto, A.; Maccato, C.; Bontempi, E.; Lebedev, O.I.; Sada, C.; Turner, S.; Van Tendeloo, G.; Barreca, D. |
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Title |
Rational synthesis of F-doped iron oxides on Al2O3(0001) single crystals |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
RSC advances |
Abbreviated Journal |
Rsc Adv |
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Volume |
4 |
Issue |
94 |
Pages |
52140-52146 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A plasma enhanced-chemical vapor deposition (PE-CVD) route to Fe2O3-based materials on Al2O3(0001) single crystals at moderate growth temperatures (200-400 degrees C) is reported. The use of the fluorinated Fe(hfa)(2)TMEDA (hfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate; TMEDA = N,N,N',N'-tetramethylethylenediamine) molecular precursor in Ar/O-2 plasmas enabled an in situ F-doping of iron oxide matrices, with a fluorine content tunable as a function of the adopted preparative conditions. Variations of the thermal energy supply enabled control of the system phase composition, resulting in gamma-Fe2O3 at 200 degrees C and alpha-Fe2O3 nanostructures at higher deposition temperatures. Notably, at 400 degrees C the formation of highly oriented alpha-Fe2O3 nanocolumns characterized by an epitaxial relation with the Al2O3(0001) substrate was observed. Beside fluorine content, phase composition and nano-organization, even the system optical properties and, in particular, energy gap values, could be tailored by proper modifications of processing parameters. |
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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 |
000344389000041 |
Publication Date |
2014-10-02 |
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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 |
2046-2069; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.108 |
Times cited |
4 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.108; 2014 IF: 3.840 |
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Call Number |
UA @ lucian @ c:irua:121239 |
Serial |
2813 |
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Permanent link to this record |
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Author |
Carraro, G.; Gasparotto, A.; Maccato, C.; Bontempi, E.; Lebedev, O.I.; Sada, C.; Turner, S.; Van Tendeloo, G.; Barreca, D. |
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Title |
Rational synthesis of F-doped iron oxides on Al2O3(0001) single crystals |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Rsc Advances |
Abbreviated Journal |
Rsc Adv |
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Volume |
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Issue |
94 |
Pages |
52140-52146 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A plasma enhanced-chemical vapor deposition (PE-CVD) route to Fe2O3-based materials on Al2O3(0001) single crystals at moderate growth temperatures (200400 °C) is reported. The use of the fluorinated Fe(hfa)2TMEDA (hfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate; TMEDA = N,N,N′,N′-tetramethylethylenediamine) molecular precursor in Ar/O2 plasmas enabled an in situ F-doping of iron oxide matrices, with a fluorine content tunable as a function of the adopted preparative conditions. Variations of the thermal energy supply enabled control of the system phase composition, resulting in γ-Fe2O3 at 200 °C and α-Fe2O3 nanostructures at higher deposition temperatures. Notably, at 400 °C the formation of highly oriented α-Fe2O3 nanocolumns characterized by an epitaxial relation with the Al2O3(0001) substrate was observed. Beside fluorine content, phase composition and nano-organization, even the system optical properties and, in particular, energy gap values, could be tailored by proper modifications of processing parameters. |
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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 |
000344389000041 |
Publication Date |
2014-10-02 |
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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 |
2046-2069; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.108 |
Times cited |
4 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.108; 2014 IF: 3.840 |
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Call Number |
UA @ lucian @ c:irua:119529 |
Serial |
2814 |
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Permanent link to this record |
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Author |
Li, D.Y.; Zeng, Y.J.; Batuk, D.; Pereira, L.M.C.; Ye, Z.Z.; Fleischmann, C.; Menghini, M.; Nikitenko, S.; Hadermann, J.; Temst, K.; Vantomme, A.; Van Bael, M.J.; Locquet, J.P.; Van Haesendonck, C.; |
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Title |
Relaxor ferroelectricity and magnetoelectric coupling in ZnOCo nanocomposite thin films : beyond multiferroic composites |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
ACS applied materials and interfaces |
Abbreviated Journal |
Acs Appl Mater Inter |
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Volume |
6 |
Issue |
7 |
Pages |
4737-4742 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
ZnOCo nanocomposite thin films are synthesized by combination of pulsed laser deposition of ZnO and Co ion implantation. Both superparamagnetism and relaxor ferroelectricity as well as magnetoelectric coupling in the nanocomposites have been demonstrated. The unexpected relaxor ferroelectricity is believed to be the result of the local lattice distortion induced by the incorporation of the Co nanoparticles. Magnetoelectric coupling can be attributed to the interaction between the electric dipole moments and the magnetic moments, which are both induced by the incorporation of Co. The introduced ZnOCo nanocomposite thin films are different from conventional strain-mediated multiferroic composites. |
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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 |
000334572800018 |
Publication Date |
2014-03-05 |
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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 |
1944-8244;1944-8252; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.504 |
Times cited |
21 |
Open Access |
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Notes |
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Approved |
Most recent IF: 7.504; 2014 IF: 6.723 |
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Call Number |
UA @ lucian @ c:irua:117063 |
Serial |
2864 |
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Permanent link to this record |
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Author |
Berdiyorov, G.R.; Milošević, M.V.; Peeters, F.M. |
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Title |
Reply to “Comment on 'Vortices induced in a superconducting loop by asymmetric kinetic inductance and their detection in transport measurements' ” |
Type |
Editorial |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
5 |
Pages |
056502 |
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Keywords |
Editorial; Condensed Matter Theory (CMT) |
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Abstract |
Our calculations, within known limitations of Ginzburg-Landau theory, are fully correct and valid for transport phenomena in asymmetric mesoscopic superconductors, deep in the superconducting state. We deemed the experiments of Burlakov et al. [JETP Lett. 86, 517 (2007)] relevant and important to mention in the general context of our paper since the observed shifts in the oscillations of different quantities are qualitatively similar, even though those measurements are performed close to the superconducting-normal state transition in the so-called Little-Parks regime. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Language |
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Wos |
000341266400006 |
Publication Date |
2014-08-28 |
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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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
1 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:119256 |
Serial |
2876 |
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Permanent link to this record |
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Author |
Scuracchio, P.; Costamagna; Peeters, F.M.; Dobry, A. |
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Title |
Role of atomic vacancies and boundary conditions on ballistic thermal transport in graphene nanoribbons |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
3 |
Pages |
035429 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Quantum thermal transport in armchair and zigzag graphene nanoribbons is investigated in the presence of single atomic vacancies and subject to different boundary conditions. We start with a full comparison of the phonon polarizations and energy dispersions as given by a fifth-nearest-neighbor force-constant model (5NNFCM) and by elasticity theory of continuum membranes (ETCM). For free-edge ribbons, we discuss the behavior of an additional acoustic edge-localized flexural mode, known as fourth acoustic branch (4ZA), which has a small gap when it is obtained by the 5NNFCM. Then, we show that ribbons with supported edges have a sample-size dependent energy gap in the phonon spectrum which is particularly large for in-plane modes. Irrespective to the calculation method and the boundary condition, the dependence of the energy gap for the low-energy optical phonon modes against the ribbon width W is found to be proportional to 1/W for in-plane, and 1/W-2 for out-of-plane phonon modes. Using the 5NNFCM, the ballistic thermal conductance and its contributions from every single phonon mode are then obtained by the nonequilibrium Green's function technique. We found that, while edge and central localized single atomic vacancies do not affect the low-energy transmission function of in-plane phonon modes, they reduce considerably the contributions of the flexural modes. On the other hand, in-plane modes contributions are strongly dependent on the boundary conditions and at low temperatures can be highly reduced in supported-edge samples. These findings could open a route to engineer graphene based devices where it is possible to discriminate the relative contribution of polarized phonons and to tune the thermal transport on the nanoscale. |
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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 |
000339443800009 |
Publication Date |
2014-07-21 |
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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;1550-235X; |
ISBN |
|
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 |
; Discussions with S. D. Dalosto and K. H. Michel are gratefully acknowledged. This work was partially supported by PIP 11220090100392 of CONICET (Argentina) and the Flemish Science Foundation (FWO-VI). We acknowledge funding from the FWO (Belgium)-MINCyT (Argentina) collaborative research project. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:118698 |
Serial |
2911 |
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Permanent link to this record |
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Author |
Xu, P.; Dong, L.; Neek-Amal, M.; Ackerman, M.L.; Yu, J.; Barber, S.D.; Schoelz, J.K.; Qi, D.; Xu, F.; Thibado, P.M.; Peeters, F.M.; |
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Title |
Self-organized platinum nanoparticles on freestanding graphene |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
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Volume |
8 |
Issue |
3 |
Pages |
2697-2703 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Freestanding graphene membranes were successfully functionalized with platinum nanoparticles (Pt NPs). High-resolution transmission electron microscopy revealed a homogeneous distribution of single-crystal Pt NPs that tend to exhibit a preferred orientation. Unexpectedly, the NPs were also found to be partially exposed to the vacuum with the top Pt surface raised above the graphene substrate, as deduced from atomic-scale scanning tunneling microscopy images and detailed molecular dynamics simulations. Local strain accumulation during the growth process is thought to be the origin of the NP self-organization. These findings are expected to shape future approaches in developing Pt NP catalysts for fuel cells as well as NP-functionalized graphene-based high-performance electronics. |
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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 |
000333539400085 |
Publication Date |
2014-02-05 |
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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;1936-086X; |
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 |
38 |
Open Access |
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Notes |
; M.N.A. acknowledges financial support by the EU-Marie Curie IIF postdoc Fellowship/299855. F.M.P. acknowledges financial support by the ESF-EuroGRAPHENE project CONGRAN, the Flemish Science Foundation (FWO-VI), and the Methusalem Foundation of the Flemish Government. L.D. acknowledges financial support by the Taishan Overseas Scholar program (tshw20091005), the International Science & Technology Cooperation Program of China (2014DFA60150), the National Natural Science Foundation of China (51172113), the Shandong Natural Science Foundation (JQ201118), the Qingdao Municipal Science and Technology Commission (12-1-4-136-hz), and the National Science Foundation (DMR-0821159). P.M.T. is thankful for the financial support of the Office of Naval Research under Grant No. N00014-10-1-0181 and the National Science Foundation under Grant No. DMR-0855358. ; |
Approved |
Most recent IF: 13.942; 2014 IF: 12.881 |
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Call Number |
UA @ lucian @ c:irua:116881 |
Serial |
2978 |
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Permanent link to this record |
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Author |
Shakouri, K.; Vasilopoulos, P.; Vargiamidis, V.; Peeters, F.M. |
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Title |
Spin- and valley-dependent magnetotransport in periodically modulated silicene |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
12 |
Pages |
125444 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The low-energy physics of silicene is described by Dirac fermions with a strong spin-orbit interaction and its band structure can be controlled by an external perpendicular electric field E-z. We investigate the commensurability oscillations in silicene modulated by a weak periodic potential V = V-0 cos(2 pi y/a(0)) with a(0) as its period, in the presence of a perpendicular magnetic field B and of a weak sinusoidal electric field E-z = E-0 cos(2 pi y/b(0)), where b(0) is its period. We show that the spin and valley degeneracy of the Landau levels is lifted, due to the modulation, and that the interplay between the strong spin-orbit interaction and the potential and electric field modulations can result in spin- and valley-resolved magnetotransport. At very weak magnetic fields the commensurability oscillations induced by a weak potential modulation can exhibit a beating pattern depending on the strength of the homogenous electric field Ez but this is not the case when only Ez is modulated. The Hall conductivity plateaus acquire a step structure, due to spin and valley intra-Landau-level transitions, that is absent in unmodulated silicene. The results are critically contrasted with those for graphene and the two-dimensional electron gas. |
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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 |
000342497700008 |
Publication Date |
2014-09-25 |
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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 |
|
|
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
3.836 |
Times cited |
31 |
Open Access |
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|
Notes |
; Our work was supported by the Flemish Science Foundation (FWO-VI), the Methusalem Foundation of the Flemish Government, and by the Canadian NSERC Grant No. OGP0121756. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:119946 |
Serial |
3079 |
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Permanent link to this record |
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Author |
Van Duppen, B.; Vasilopoulos, P.; Peeters, F.M. |
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Title |
Spin and valley polarization of plasmons in silicene due to external fields |
Type |
A1 Journal article |
|
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
3 |
Pages |
035142 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The electronic properties of the two-dimensional material silicene are strongly influenced by the application of a perpendicular electric field E-z and of an exchange field M due to adatoms positioned on the surface or a ferromagnetic substrate. Within the random phase approximation, we investigate how electron-electron interactions are affected by these fields and present analytical and numerical results for the dispersion of plasmons, their lifetime, and their oscillator strength. We find that the combination of the fields E-z and M brings a spin and valley texture to the particle-hole excitation spectrum and allows the formation of spin-and valley-polarized plasmons. When the Fermi level lies in the gap of one spin in one valley, the intraband region of the corresponding spectrum disappears. For zero E-z and finite M the spin symmetry is broken and spin polarization is possible. The lifetime and oscillator strength of the plasmons are shown to depend strongly on the number of spin and valley type electrons that form the electron-hole pairs. |
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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 |
000339974700001 |
Publication Date |
2014-07-30 |
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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 |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
49 |
Open Access |
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Notes |
; This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro-GRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-Vl) by an aspirant grant to B.V.D., the Methusalem Foundation of the Flemish Government, and by the Canadian NSERC Grant No. OGP0121756. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:118776 |
Serial |
3080 |
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Permanent link to this record |
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Author |
Berdiyorov, G.R.; Neek-Amal, M.; Peeters, F.M.; van Duin, A.C.T. |
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Title |
Stabilized silicene within bilayer graphene : a proposal based on molecular dynamics and density-functional tight-binding calculations |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
89 |
Issue |
2 |
Pages |
024107-6 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Freestanding silicene is predicted to display comparable electronic properties as graphene. However, the yet synthesized silicenelike structures have been only realized on different substrates which turned out to exhibit versatile crystallographic structures that are very different from the theoretically predicted buckled phase of freestanding silicene. This calls for a different approach where silicene is stabilized using very weakly interacting surfaces. We propose here a route by using graphene bilayer as a scaffold. The confinement between the flat graphene layers results in a planar clustering of Si atoms with small buckling, which is energetically unfavorable in vacuum. Buckled hexagonal arrangement of Si atoms similar to freestanding silicene is observed for large clusters, which, in contrast to Si atoms on metallic surfaces, is only very weakly van der Waals coupled to the graphene layers. These clusters are found to be stable well above room temperature. Our findings, which are supported by density-functional tight-binding calculations, show that intercalating bilayer graphene with Si is a favorable route to realize silicene. |
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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 |
000332226200002 |
Publication Date |
2014-01-24 |
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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 |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
43 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. M.N.-A. was supported by the EU-Marie Curie IIF postdoc Fellowship/299855. One of us (F. M. P.) acknowledges discussions with Professor Hongjun Gao. G. R. B acknowledges the support of the King Fahd University of Petroleum and Minerals, Saudi Arabia, under the TPRG131-CS-15 DSR project. A.C.T.vD acknowledges funding from AFOSR Grants No. FA9550-10-1-0563 and No. FA9550-11-1-0158. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:115829 |
Serial |
3140 |
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Permanent link to this record |
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Author |
Toledano-Luque, M.; Matagne, P.; Sibaja-Hernandez, A.; Chiarella, T.; Ragnarsson, L.-A.; Sorée, B.; Cho, M.; Mocuta, A.; Thean, A. |
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Title |
Superior reliability of junctionless pFinFETs by reduced oxide electric field |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
IEEE electron device letters |
Abbreviated Journal |
Ieee Electr Device L |
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Volume |
35 |
Issue |
12 |
Pages |
1179-1181 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Superior reliability of junctionless (JL) compared with inversion-mode field-effect transistors (FETs) is experimentally demonstrated on bulk FinFET wafers. The reduced negative bias temperature instability (NBTI) of JL pFETs outperforms the previously reported best NBTI reliability data obtained with Si channel devices and guarantees 10-year lifetime at typical operating voltages and high temperature. This behavior is understood through the reduced oxide electric field and lessened interaction between charge carriers and oxide traps during device operation. These findings encourage the investigation of JL devices with alternative channels as a promising alternative for 7-nm technology nodes meeting reliability targets. |
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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 |
000345575400006 |
Publication Date |
2014-10-21 |
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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 |
0741-3106;1558-0563; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.048 |
Times cited |
13 |
Open Access |
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Notes |
; This work was supported by the imec's Core Partner Program. The review of this letter was arranged by Editor J. Schmitz. ; |
Approved |
Most recent IF: 3.048; 2014 IF: 2.754 |
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Call Number |
UA @ lucian @ c:irua:122192 |
Serial |
3378 |
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Permanent link to this record |
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Author |
Mordvinova, N.; Emelin, P.; Vinokurov, A.; Dorofeev, S.; Abakumov, A.; Kuznetsova, T. |
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Title |
Surface processes during purification of InP quantum dots |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Beilstein journal of nanotechnology |
Abbreviated Journal |
Beilstein J Nanotech |
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Volume |
5 |
Issue |
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Pages |
1220-1225 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Recently, a new simple and fast method for the synthesis of InP quantum dots by using phosphine as phosphorous precursor and myristic acid as surface stabilizer was reported. Purification after synthesis is necessary to obtain samples with good optical properties. Two methods of purification were compared and the surface processes which occur during purification were studied. Traditional precipitation with acetone is accompanied by a small increase in photoluminescence. It occurs that during the purification the hydrolysis of the indium precursor takes place, which leads to a better surface passivation. The electrophoretic purification technique does not increase luminescence efficiency but yields very pure quantum dots in only a few minutes. Additionally, the formation of In(OH)(3) during the low temperature synthesis was explained. Purification of quantum dots is a very significant part of post-synthetical treatment that determines the properties of the material. But this subject is not sufficiently discussed in the literature. The paper is devoted to the processes that occur at the surface of quantum dots during purification. A new method of purification, electrophoresis, is investigated and described in particular. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Language |
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Wos |
000339912400002 |
Publication Date |
2014-08-06 |
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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 |
2190-4286; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.127 |
Times cited |
5 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.127; 2014 IF: 2.670 |
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Call Number |
UA @ lucian @ c:irua:118748 |
Serial |
3397 |
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Permanent link to this record |
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Author |
Vodolazov, D.Y.; Peeters, F.M. |
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Title |
Temporary cooling of quasiparticles and delay in voltage response of superconducting bridges after abruptly switching on the supercritical current |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
9 |
Pages |
094504 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We revisit the problem of the dynamic response of a superconducting bridge after abruptly switching on the supercritical current. In contrast to previous theoretical works we take into account spatial gradients and use both the local temperature approach and the kinetic equation for the distribution function of quasiparticles. We find that the temperature dependence of the finite delay time t(d) in the voltage response is model dependent and relatively large t(d) is connected with temporary cooling of quasiparticles during decay of superconducting order parameter vertical bar Delta vertical bar in time. It turns out that the presence of even small inhomogeneities in the bridge or finite length of the homogenous bridge favors a local suppression of vertical bar Delta vertical bar during the dynamic response. It results in a decrease of the delay time, in comparison with the spatially uniform model, due to the diffusion of nonequilibrium quasiparticles from the region with locally suppressed vertical bar Delta vertical bar. In the case when the current density is maximal near the edge of a not very wide bridge the delay time is mainly connected with the time needed for the nucleation (entrance) of the first vortex and t(d) could be tuned by a weak external magnetic field. We also find that a short alternating current pulse (sinusoidlike) with zero time average may result in a nonzero time- averaged voltage response where its sign depends on the phase of the ac current. |
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Place of Publication |
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Language |
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Wos |
000342103600002 |
Publication Date |
2014-09-10 |
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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 |
2 |
Open Access |
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Notes |
; This work was partially supported by the Russian Foundation for Basic Research (Project No. 12-02-00509), by the Ministry of Education and Science of the Russian Federation (the agreement of August 27, 2013, No. 02.B.49.21.0003, between The Ministry of Education and Science of the Russian Federation and Lobachevsky State University of Nizhni Novgorod) and by the European Science Foundation (ESF) within the framework of the activity entitled “Exploring the Physics of Small Devices (EPSD)” (Project No. 4327). ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:119908 |
Serial |
3504 |
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Permanent link to this record |
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Author |
Neek-Amal, M.; Xu, P.; Schoelz, J.K.; Ackerman, M.L.; Barber, S.D.; Thibado, P.M.; Sadeghi, A.; Peeters, F.M. |
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Title |
Thermal mirror buckling in freestanding graphene locally controlled by scanning tunnelling microscopy |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
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Volume |
5 |
Issue |
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Pages |
4962 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Knowledge of and control over the curvature of ripples in freestanding graphene are desirable for fabricating and designing flexible electronic devices, and recent progress in these pursuits has been achieved using several advanced techniques such as scanning tunnelling microscopy. The electrostatic forces induced through a bias voltage (or gate voltage) were used to manipulate the interaction of freestanding graphene with a tip (substrate). Such forces can cause large movements and sudden changes in curvature through mirror buckling. Here we explore an alternative mechanism, thermal load, to control the curvature of graphene. We demonstrate thermal mirror buckling of graphene by scanning tunnelling microscopy and large-scale molecular dynamic simulations. The negative thermal expansion coefficient of graphene is an essential ingredient in explaining the observed effects. This new control mechanism represents a fundamental advance in understanding the influence of temperature gradients on the dynamics of freestanding graphene and future applications with electro-thermal-mechanical nanodevices. |
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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 |
000342984800018 |
Publication Date |
2014-09-17 |
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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 |
2041-1723; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.124 |
Times cited |
36 |
Open Access |
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Notes |
; Financial support for this study was provided, in part, by the Office of Naval Research under grant N00014-10-1-0181, the National Science Foundation under grant DMR-0855358, the EU-Marie Curie IIF postdoc Fellowship/299855 (for M. N.-A.), the ESF-EuroGRAPHENE project CONGRAN, the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. M.N.-A. has also been supported partially by BOF project of University of Antwerp number 28033. ; |
Approved |
Most recent IF: 12.124; 2014 IF: 11.470 |
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Call Number |
UA @ lucian @ c:irua:121121 |
Serial |
3628 |
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Permanent link to this record |
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Author |
de Sena, S.H.R.; Pereira, J.M.; Peeters, F.M.; Farias, G.A. |
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Title |
Topological confinement in trilayer graphene |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
89 |
Issue |
3 |
Pages |
035420-35425 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We calculate the spectrum of states that are localized at the interface between two regions of opposite bias in trilayer graphene (TLG). These potential profiles, also known as potential kinks, have been predicted to support two different branches of localized states for the case of bilayer graphene, and show similarities to the surface states of topological insulators. On the other hand, we found that ABC stacked TLG exhibits three different unidimensional branches of states in each valley that are confined to the kink interface. They have the property E(k(y)) = -E(-k(y)) when belonging to the same valley and E-K(k(y)) = -E-K' (-k(y)). A kink-antikink potential profile opens a gap in the spectrum of these one-dimensional states. |
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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 |
000332220800005 |
Publication Date |
2014-01-21 |
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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;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 Brazilian Council for Research (CNPq-PRONEX), the Flemish Science Foundation (FWO-Vl), and the Bilateral project between CNPq and FWO-Vl and the Brazilian program Science Without Borders (CsF). ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:115830 |
Serial |
3676 |
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Permanent link to this record |
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Author |
Çakir, D.; Sahin, H.; Peeters, F.M. |
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Title |
Tuning of the electronic and optical properties of single-layer black phosphorus by strain |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
20 |
Pages |
205421 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using first principles calculations we showed that the electronic and optical properties of single-layer black phosphorus (BP) depend strongly on the applied strain. Due to the strong anisotropic atomic structure of BP, its electronic conductivity and optical response are sensitive to the magnitude and the orientation of the applied strain. We found that the inclusion of many body effects is essential for the correct description of the electronic properties of monolayer BP; for example, while the electronic gap of strainless BP is found to be 0.90 eV by using semilocal functionals, it becomes 2.31 eV when many-body effects are taken into account within the G(0)W(0) scheme. Applied tensile strain was shown to significantly enhance electron transport along zigzag direction of BP. Furthermore, biaxial strain is able to tune the optical band gap of monolayer BP from 0.38 eV (at -8% strain) to 2.07 eV (at 5.5%). The exciton binding energy is also sensitive to the magnitude of the applied strain. It is found to be 0.40 eV for compressive biaxial strain of -8%, and it becomes 0.83 eV for tensile strain of 4%. Our calculations demonstrate that the optical response of BP can be significantly tuned using strain engineering which appears as a promising way to design novel photovoltaic devices that capture a broad range of solar spectrum. |
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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 |
000345642000015 |
Publication Date |
2014-11-17 |
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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 |
219 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. H.S. is supported by a FWO Pegasus Marie Curie-long Fellowship. D.C. is supported by a FWO Pegasus-short Marie Curie Fellowship. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:122203 |
Serial |
3752 |
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Permanent link to this record |
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Author |
Xu, P.; Neek-Amal, M.; Barber, S.D.; Schoelz, J.K.; Ackerman, M.L.; Thibado, P.M.; Sadeghi, A.; Peeters, F.M. |
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Title |
Unusual ultra-low-frequency fluctuations in freestanding graphene |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
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Volume |
5 |
Issue |
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Pages |
3720 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Intrinsic ripples in freestanding graphene have been exceedingly difficult to study. Individual ripple geometry was recently imaged using scanning tunnelling microscopy, but these measurements are limited to static configurations. Thermally-activated flexural phonon modes should generate dynamic changes in curvature. Here we show how to track the vertical movement of a one-square-angstrom region of freestanding graphene using scanning tunnelling microscopy, thereby allowing measurement of the out-of-plane time trajectory and fluctuations over long time periods. We also present a model from elasticity theory to explain the very-low-frequency oscillations. Unexpectedly, we sometimes detect a sudden colossal jump, which we interpret as due to mirror buckling. This innovative technique provides a much needed atomic-scale probe for the time-dependent behaviours of intrinsic ripples. The discovery of this novel progenitor represents a fundamental advance in the use of scanning tunnelling microscopy, which together with the application of a thermal load provides a low-frequency nano-resonator. |
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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 |
000335223200007 |
Publication Date |
2014-04-28 |
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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 |
2041-1723; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.124 |
Times cited |
62 |
Open Access |
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Notes |
; This work was financially supported, in part, by the Office of Naval Research under grant N00014-10-1-0181, the National Science Foundation under grant DMR-0855358, the EU-Marie Curie IIF postdoc Fellowship/299855 (for M.N.-A.), the ESF-Euro-GRAPHENE project CONGRAN, the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. ; |
Approved |
Most recent IF: 12.124; 2014 IF: 11.470 |
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Call Number |
UA @ lucian @ c:irua:117201 |
Serial |
3819 |
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Author |
Chen, Y.; Shanenko, A.A.; Peeters, F.M. |
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Title |
Vortex anomaly in low-dimensional fermionic condensates : quantum confinement breaks chirality |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
89 |
Issue |
5 |
Pages |
054513-54515 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Chiral fermions are responsible for low-temperature properties of vortices in fermionic condensates, both superconducting (charged) and superfluid (neutral). One of the most striking consequences of this fact is that the core of a single-quantum vortex collapses at low temperatures, T -> 0 (i.e., the Kramer-Pesch effect for superconductors), due to the presence of chiral quasiparticles in the vortex-core region. We show that the situation changes drastically for fermionic condensates confined in quasi-one-dimensional and quasi-two-dimensional geometries. Here quantum confinement breaks the chirality of in-core fermions. As a result, instead of the ultimate shrinking, the core of a single-quantum vortex extends at low temperatures, and the condensate profile surprisingly mimics the multiquantum vortex behavior. Our findings are relevant for nanoscale superconductors, such as recent metallic nanoislands on silicon, and also for ultracold superfluid Fermi gases in cigar-shaped and pancake-shaped atomic traps. |
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Wos |
000332396800005 |
Publication Date |
2014-02-19 |
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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 |
5 |
Open Access |
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Notes |
; This work was supported by the “Odysseus” Program of the Flemish Government, the Flemish Science Foundation (FWO-Vl), the Methusalem Program, and the National Science Foundation of China under Grant No. NSFC-11304134. A. A. S. acknowledges the support of Brazilian agencies CNPq and FACEPE (Grant No. APQ-0589-1.05/08). ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:115822 |
Serial |
3850 |
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Permanent link to this record |