Records |
Author |
Neek-Amal, M.; Peeters, F.M. |
Title |
Strain-engineered graphene through a nanostructured substrate : 2 : pseudomagnetic fields |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
85 |
Issue |
19 |
Pages |
195446-195446,6 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The strain-induced pseudomagnetic field in supported graphene deposited on top of a nanostructured substrate is investigated by using atomistic simulations. A step, an elongated trench, a one-dimensional barrier, a spherical bubble, a Gaussian bump, and a Gaussian depression are considered as support structures for graphene. From the obtained optimum configurations we found very strong induced pseudomagnetic fields which can reach up to similar to 1000 T due to the strain-induced deformations in the supported graphene. Different magnetic confinements with controllable geometries are found by tuning the pattern of the substrate. The resulting induced magnetic fields for graphene on top of a step, barrier, and trench are calculated. In contrast to the step and trench the middle part of graphene on top of a barrier has zero pseudomagnetic field. This study provides a theoretical background for designing magnetic structures in graphene by nanostructuring substrates. We found that altering the radial symmetry of the deformation changes the sixfold symmetry of the induced pseudomagnetic field. |
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 |
000304394800013 |
Publication Date |
2012-05-23 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
31 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the ESF EUROCORE program EuroGRAPHENE: CONGRAN. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:98943 |
Serial |
3167 |
Permanent link to this record |
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|
|
Author |
Verberck, B.; Partoens, B.; Peeters, F.M.; Trauzettel, B. |
Title |
Strain-induced band gaps in bilayer graphene |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
85 |
Issue |
12 |
Pages |
125403-125403,10 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We present a tight-binding investigation of strained bilayer graphene within linear elasticity theory, focusing on the different environments experienced by the A and B carbon atoms of the different sublattices. We find that the inequivalence of the A and B atoms is enhanced by the application of perpendicular strain epsilon(zz), which provides a physical mechanism for opening a band gap, most effectively obtained when pulling the two graphene layers apart. In addition, perpendicular strain introduces electron-hole asymmetry and can result in linear electronic dispersion near the K point. Our findings suggest experimental means for strain-engineered band gaps in bilayer graphene. |
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 |
000301113200005 |
Publication Date |
2012-03-06 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
53 |
Open Access |
|
Notes |
; The authors would like to acknowledge O. Leenaerts, E. Mariani, K. H. Michel, and J. Schelter for useful discussions. B. V. was financially supported by the Flemish Science Foundation (FWO-Vl). This work was financially supported by the ESF program EuroGraphene under projects CONGRAN and ENTS as well as by the DFG. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:97181 |
Serial |
3168 |
Permanent link to this record |
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Author |
Scalise, E.; Houssa, M.; Pourtois, G.; Afanas'ev, V.; Stesmans, A. |
Title |
Strain-induced semiconductor to metal transition in the two-dimensional honeycomb structure of MoS2 |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Nano Research |
Abbreviated Journal |
Nano Res |
Volume |
5 |
Issue |
1 |
Pages |
43-48 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The electronic properties of two-dimensional honeycomb structures of molybdenum disulfide (MoS(2)) subjected to biaxial strain have been investigated using first-principles calculations based on density functional theory. On applying compressive or tensile bi-axial strain on bi-layer and mono-layer MoS(2), the electronic properties are predicted to change from semiconducting to metallic. These changes present very interesting possibilities for engineering the electronic properties of two-dimensional structures of MoS(2). |
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 |
000299085200006 |
Publication Date |
2011-11-10 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1998-0124;1998-0000; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.354 |
Times cited |
407 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 7.354; 2012 IF: 7.392 |
Call Number |
UA @ lucian @ c:irua:96262 |
Serial |
3169 |
Permanent link to this record |
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Author |
Gardner, G.P.; Go, Y.B.; Robinson, D.M.; Smith, P.F.; Hadermann, J.; Abakumov, A.; Greenblatt, M.; Dismukes, G.C. |
Title |
Structural requirements in lithium cobalt oxides for the catalytic oxidation of water |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
Volume |
51 |
Issue |
7 |
Pages |
1616-1619 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Weinheim |
Editor |
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Language |
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Wos |
000299946400020 |
Publication Date |
2012-01-11 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1433-7851; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
11.994 |
Times cited |
119 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 11.994; 2012 IF: 13.734 |
Call Number |
UA @ lucian @ c:irua:99173 |
Serial |
3258 |
Permanent link to this record |
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Author |
Galván Moya, J.E.; Nelissen, K.; Peeters, F.M. |
Title |
Structural transitions in vertically and horizontally coupled parabolic channels of Wigner crystals |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
18 |
Pages |
184102-184109 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Structural phase transitions in two vertically or horizontally coupled channels of strongly interacting particles are investigated. The particles are free to move in the x direction but are confined by a parabolic potential in the y direction. They interact with each other through a screened power-law potential (r(-n)e(-r/lambda)). In vertically coupled systems, the channels are stacked above each other in the direction perpendicular to the (x, y) plane, while in horizontally coupled systems both channels are aligned in the confinement direction. Using Monte Carlo (MC) simulations we obtain the ground-state configurations and the structural transitions as a function of the linear particle density and the separation between the channels. At zero temperature, the vertically coupled system exhibits a rich phase diagram with continuous and discontinuous transitions. On the other hand, the horizontally coupled system exhibits only a very limited number of phase transitions due to its symmetry. Further, we calculated the normal modes for the Wigner crystals in both cases. From MC simulations, we found that in the case of vertically coupled systems, the zigzag transition is only possible for low densities. A Ginzburg-Landau theory for the zigzag transition is presented, which predicts correctly the behavior of this transition from which we interpret the structural phase transition of the Wigner crystal through the reduction of the Brillouin zone. |
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 |
000310683600002 |
Publication Date |
2012-11-05 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:105150 |
Serial |
3271 |
Permanent link to this record |
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Author |
Napolsky, P.S.; Drozhzhin, O.A.; Istomin, S.Y.; Kazakov, S.M.; Antipov, E.V.; Galeeva, A.V.; Gippius, A.A.; Svensson, G.; Abakumov, A.M.; Van Tendeloo, G. |
Title |
Structure and high-temperature properties of the (Sr,Ca,Y)(Co,Mn)O3-y perovskites – perspective cathode materials for IT-SOFC |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
192 |
Issue |
|
Pages |
186-194 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Oxygen deficient perovskites Sr0.75Y0.25Co1-xMnxO3-y, x=0.5 and 0.75, were prepared by using the citrate route at 1373-1573 K for 48 h. The cubic Pm-3m perovskite structure for x=0.5 was confirmed by electron diffraction study and refined using neutron powder diffraction (NPD) data. For x=0.75, the superstructure corresponding to a=root 2 x a(per), b=2 x a(per), c=root 2 x a(per) (a(0)b(-)b(-) tilt system, space group Imma) was revealed by electron diffraction. The solid solution Sr0.75-xCaxY0.25Co0.25Mn0.75O3-y, 0.1 <= x <= 0.6 and compound Ca0.75Y0.25Mn0.85Co0.15O2.92 were prepared in air at 1573 K for 48 h. The crystal structure of Ca0.75Y0.25Mn0.85Co0.15O2.92 was refined using NPD data (S.G. Pnma, a=5.36595(4), b=7.5091(6), c=5.2992(4) angstrom, R-p=0.057, R-wp=0.056, chi(2)=4.26). High-temperature thermal expansion properties of the prepared compounds were studied in air using both dilatometry and high-temperature X-ray powder diffraction data (HTXRPD). They expanding non-linearly at 298-1073 K due to the loss of oxygen at high temperatures. Calculated average thermal expansion coefficients (TECs) for Sr0.75Y0.25Co1-xMnxO3-y, x=0.5, 0.75 and Ca0.75Y0.25Mn0.85Co0.15O2.92(1) are 15.5, 15.1, and 13.8 ppm K-1, respectively. Anisotropy of the thermal expansion along different unit cell axes was observed for Sr0.15Ca0.6Y0.25Co0.25Mn0.75O3-y, and Ca0.75Y0.25Mn0.85Co0.15O2.92. Conductivity of Sr0.75Y0.25Co1-xMnxO3-y, x=0.5 and 0.75 increases with the temperature reaching 110 S/cm for x=0.5 and 44 S/cm for x=0.75 at 1173 K. Samples of Sr0.75-xCaxY0.25Co0.25Mn0.75O3-y, 0.1 <= y <= 0.6 were found to be n-type conductors at room temperature with the similar temperature dependence of the conductivity and demonstrated the increase of the sigma value from similar to 1 to similar to 50 S/cm as the temperature increases from 300 to 1173 K. Their conductivity is described in terms of the small polaron charge transport with the activation energy (E-p) increasing from 340 to 430 meV with an increase of the calcium content from x=0 to x=0.6. (C) 2012 Elsevier Inc. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000307028300030 |
Publication Date |
2012-03-31 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0022-4596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.299; 2012 IF: 2.040 |
Call Number |
UA @ lucian @ c:irua:101119 |
Serial |
3279 |
Permanent link to this record |
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Author |
Dixon, E.; Hadermann, J.; Hayward, M.A. |
Title |
Structures and magnetism of La1-xSrxMnO3-(0.5+x)/2 (0.67\leq x\leq1) phases |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
24 |
Issue |
8 |
Pages |
1486-1495 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Topotactic reduction of La1-xSrxMnO3 (0.67 <= x <= 1) phases with sodium hydride yields a series of isoelectronic materials of composition La1-xSrxMnO3-(0.5+x)/2. Lanthanum rich members of the series (0.67 <= x <= 0.83) adopt anion deficient perovskite structures with a 6-layer -OTOOT'O- stacking sequence of sheets of octahedra/square-based pyramids (O) and sheets of tetrahedra (T). The strontium rich members of the series (0.83 <= x <= 1) incorporate “step defects” into this 6-layer structure in which the OTOOT'O stacking sequence is converted into either OOTOOT' or TOOT'OO at a defect plane which runs perpendicular to the [201] lattice plane. The step defects appear to provide a mechanism to relieve lattice strain and accommodate additional anion deficiency in phases with x > 0.83. Magnetization and neutron diffraction data indicate La1-xSrxMnO3-(0.5+x)/2 phases adopt antiferromagnetically ordered states at low-temperature in which the ordered arrangement of magnetic spins is incommensurate with the crystallographic lattice. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000303092300011 |
Publication Date |
2012-03-28 |
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 |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
13 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 9.466; 2012 IF: 8.238 |
Call Number |
UA @ lucian @ c:irua:98253 |
Serial |
3318 |
Permanent link to this record |
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Author |
Schattschneider, P.; Stöger-Pollach, M.; Löffler, S.; Steiger-Thirsfeld, A.; Hell, J.; Verbeeck, J. |
Title |
Sub-nanometer free electrons with topological charge |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
115 |
Issue |
|
Pages |
21-25 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The holographic mask technique is used to create freely moving electrons with quantized angular momentum. With electron optical elements they can be focused to vortices with diameters below the nanometer range. The understanding of these vortex beams is important for many applications. Here, we produce electron vortex beams and compare them to a theory of electrons with topological charge. The experimental results show excellent agreement with simulations. As an immediate application, fundamental experimental parameters like spherical aberration and partial coherence are determined. (C) 2012 Elsevier B.V. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000302962400004 |
Publication Date |
2012-01-30 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
24 |
Open Access |
|
Notes |
vortex ECASJO_; |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
Call Number |
UA @ lucian @ c:irua:98279 |
Serial |
3344 |
Permanent link to this record |
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Author |
Zarenia, M.; Leenaerts, O.; Partoens, B.; Peeters, F.M. |
Title |
Substrate-induced chiral states in graphene |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
8 |
Pages |
085451 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Unidirectional chiral states are predicted in single layer graphene which originate from the breaking of the sublattice symmetry due to an asymmetric mass potential. The latter can be created experimentally using boron-nitride (BN) substrates with a line defect (B-B or N-N) that changes the induced mass potential in graphene. Solving the Dirac-Weyl equation, the obtained energy spectrum is compared with the one calculated using ab initio density functional calculations. We found that these one-dimensional chiral states are very robust and they can even exist in the presence of a small gap between the mass regions. In the latter case additional bound states are found that are topologically different from those chiral states. |
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 |
000308005600015 |
Publication Date |
2012-08-28 |
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 |
Impact Factor |
3.836 |
Times cited |
41 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), and the European Science Foundation (ESF) under the EUROCORES Program: EuroGRAPHENE (project CONGRAN). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:101100 |
Serial |
3347 |
Permanent link to this record |
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Author |
Chen, Y.; Shanenko, A.A.; Perali, A.; Peeters, F.M. |
Title |
Superconducting nanofilms : molecule-like pairing induced by quantum confinement |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
24 |
Issue |
18 |
Pages |
185701-185701,8 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Quantum confinement of the perpendicular motion of electrons in single-crystalline metallic superconducting nanofilms splits the conduction band into a series of single-electron subbands. A distinctive feature of such a nanoscale multi-band superconductor is that the energetic position of each subband can vary significantly with changing nanofilm thickness, substrate material, protective cover and other details of the fabrication process. It can occur that the bottom of one of the available subbands is situated in the vicinity of the Fermi level. We demonstrate that the character of the superconducting pairing in such a subband changes dramatically and exhibits a clear molecule-like trend, which is very similar to the well-known crossover from the Bardeen-Cooper-Schrieffer regime to Bose-Einstein condensation (BCS-BEC) observed in trapped ultracold fermions. For Pb nanofilms with thicknesses of 4 and 5 monolayers (MLs) this will lead to a spectacular scenario: up to half of all the Cooper pairs nearly collapse, shrinking in the lateral size (parallel to the nanofilm) down to a few nanometers. As a result, the superconducting condensate will be a coherent mixture of almost molecule-like fermionic pairs with ordinary, extended Cooper pairs. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000303500900018 |
Publication Date |
2012-04-05 |
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 |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
26 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). AAS thanks A Bianconi, M D Croitoru and A V Vagov for useful discussions. AAS acknowledges the hospitality and fruitful interactions with G C Strinati, P Pieri and D Neilson during his visit to the University of Camerino, supported by the School of Advanced Studies of the University of Camerino. ; |
Approved |
Most recent IF: 2.649; 2012 IF: 2.355 |
Call Number |
UA @ lucian @ c:irua:98223 |
Serial |
3357 |
Permanent link to this record |
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Author |
Chen, Y.; Shanenko, A.A.; Peeters, F.M. |
Title |
Superconducting transition temperature of Pb nanofilms : impact of thickness-dependent oscillations of the phonon-mediated electron-electron coupling |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
85 |
Issue |
22 |
Pages |
224517-224517,6 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
To date, several experimental groups reported measurements of the thickness dependence of T-c of atomically uniform single-crystalline Pb nanofilms. The reported amplitude of the T-c oscillations varies significantly from one experiment to another. Here we propose that the reason for this unresolved issue is an interplay of the quantum-size variations in the single-electron density of states with thickness-dependent oscillations in the phonon-mediated electron-electron coupling. Such oscillations in the coupling depend on the substrate material, the quality of the interface, the protection cover, and other details of the fabrication process, changing from one experiment to another. This explains why the available data do not exhibit one-voice consistency about the amplitude of the T-c oscillations. Our analyses are based on a numerical solution of the Bogoliubov-de Gennes equations for a superconducting slab. |
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 |
000305251300006 |
Publication Date |
2012-06-14 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
24 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:99076 |
Serial |
3368 |
Permanent link to this record |
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Author |
Charkin, D.O.; Urmanov, A.V.; Kazakov, S.M.; Batuk, D.; Abakumov, A.M.; Knöner, S.; Gati, E.; Wolf, B.; Lang, M.; Shevelkov, A.V.; Van Tendeloo, G.; Antipov, E.V.; |
Title |
Synthesis, crystal structure, transport, and magnetic properties of novel ternary copper phosphides, A2Cu6P5(A = Sr, Eu) and EuCu4P3 |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
Volume |
51 |
Issue |
16 |
Pages |
8948-8955 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Three new ternary copper phosphides, Sr2Cu6P5, Eu2Cu6P5, and EuCu4P3, have been synthesized from the elements in evacuated silica capsules. Eu2Cu6P5 and Sr2Cu6P5 adopt the Ca2Cu6P5-type structure, while EuCu4P3 is isostructural to BaMg4Si3 and still remains the only representative of this structure type among the ternary Cu pnictides. All three materials show metallic conductivity in the temperature range 2 K <= T <= 290 K, with no indication for superconductivity. For Eu2Cu6P5 and EuCu4P3, long-range magnetic order was observed, governed by 4f local moments on the Eu atoms with predominant ferromagnetic interactions. While Eu2Cu6P5 shows a single ferromagnetic transition at T-C = 34 K, the magnetic behavior of EuCu4P3 is more complex, giving rise to three consecutive magnetic phase transitions at 70, 43, and 18 K. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
|
Language |
|
Wos |
000307606200042 |
Publication Date |
2012-07-31 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.857 |
Times cited |
13 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.857; 2012 IF: 4.593 |
Call Number |
UA @ lucian @ c:irua:102217 |
Serial |
3453 |
Permanent link to this record |
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Author |
Ribbens, S.; Beyers, E.; Schellens, K.; Mertens, M.; Ke, X.; Bals, S.; Van Tendeloo, G.; Meynen, V.; Cool, P. |
Title |
Systematic evaluation of thermal and mechanical stability of different commercial and synthetic photocatalysts in relation to their photocatalytic activity |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Microporous and mesoporous materials: zeolites, clays, carbons and related materials |
Abbreviated Journal |
Micropor Mesopor Mat |
Volume |
156 |
Issue |
|
Pages |
62-72 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA) |
Abstract |
The effect of thermal treatment and mechanical stress on the structural and photocatalytic properties of eight different (synthetic and commercial) photocatalysts has been thoroughly investigated. Different mesoporous Ti-based materials were prepared via surfactant based synthesis routes (e.g. Pluronic 123, CTMABr = Cetyltrimethylammonium bromide) or via template-free synthesis routes (e.g. trititanate nanotubes). Also, the stabilizing effect of the NaOH/NH4OH post-treatment on the templated mesoporous materials and their photocatalytic activity was investigated. Furthermore, the thermal and mechanical properties of commercially available titanium dioxides such as P25 Evonik® and Millenium PC500® were studied. The various photocatalysts were analyzed with N2-sorption, X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) to obtain information concerning the specific surface area, pore volume, crystal structure, morphology, phase transitions, etc. In general, results show that the NaOH post-treatment leads to an increased control of the crystallization process during calcination resulting in a higher thermal stability, but at the same time diminishes the photocatalytic activity. Mesoporous materials in which pre-synthesized nanoparticles are used as titania source have the best mechanical stability whereas the mechanical stability of the nanotubes is the most limited. At increased temperatures and pressures, the tested commercial titanium dioxides lose their superior photocatalytic activity caused by a decreased accessibility of the active sites. The observed changes in adsorption capacities and photocatalytic activities cannot be assigned to one single phenomenon. In this respect, it shows the need to define a general/standard method to compare different photocatalysts. Furthermore, it is shown that the photocatalytic properties do not necessarily deteriorate under thermal stress, but can be improved due to crystallization, even though the initial material is (partially) destroyed. It is shown that the usefulness of a specific type of photocatalyst strongly depends on the application and the temperature/pressure to which it needs to resist. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
|
Wos |
000303625200010 |
Publication Date |
2012-02-08 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1387-1811; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.615 |
Times cited |
8 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 3.615; 2012 IF: 3.365 |
Call Number |
UA @ lucian @ c:irua:96910 |
Serial |
3466 |
Permanent link to this record |
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Author |
Pachoud, E.; Bréard, Y.; Martin, C.; Maignan, A.; Abakumov, A.M.; Suard, E.; Smith, R.I.; Suchomel, M.R. |
Title |
Bi0.75Sr0.25FeO3-\delta : revealing order/disorder phenomena by combining diffraction techniques |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Solid state communications |
Abbreviated Journal |
Solid State Commun |
Volume |
152 |
Issue |
5 |
Pages |
331-336 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The local and long range structure of polycrystalline samples of Bi0.75Sr0.25FeO3-delta has been probed by neutron and synchrotron X-ray diffraction coupled with transmission electron microscopy. It is found that the long range structure on average can be described by the cubic space group Pm-3m (a(p) congruent to 3.951 angstrom). However, the refinements revealed large atomic displacements for the (Bi, Sr) cations and the oxygen atoms from their ideal positions. The electron microscopy study indicates the existence of local phenomena like local ordering of oxygen vacancies, which are segregated at the randomly spaced parallel (FeO2-delta) planes, or the existence of region of different symmetry, probably R3c. At room temperature, the compound exhibits G-type antiferromagnetism (T-N congruent to 650 K) with a magnetic moment of congruent to 3.7 mu(B). (C) 2012 Elsevier Ltd. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000301329200001 |
Publication Date |
2011-12-19 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0038-1098; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.554 |
Times cited |
6 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.554; 2012 IF: 1.534 |
Call Number |
UA @ lucian @ c:irua:97820 |
Serial |
3516 |
Permanent link to this record |
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Author |
Tsirlin, A.A.; Abakumov, A.M.; Ritter, C.; Rosner, H. |
Title |
(CuCl)LaTa2O\text{7} and quantum phase transition in the (CuX)LaM2O7 family (X=Cl, Br; M=Nb, Ta) |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
6 |
Pages |
064440-12 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We apply neutron diffraction, high-resolution synchrotron x-ray diffraction, magnetization measurements, electronic structure calculations, and quantum Monte-Carlo simulations to unravel the structure and magnetism of (CuCl)LaTa2O7. Despite the pseudo-tetragonal crystallographic unit cell, this compound features an orthorhombic superstructure, similar to the Nb-containing (CuX)LaNb2O7 with X = Cl and Br. The spin lattice entails dimers formed by the antiferromagnetic fourth-neighbor coupling J(4), as well as a large number of nonequivalent interdimer couplings quantified by an effective exchange parameter J(eff). In (CuCl)LaTa2O7, the interdimer couplings are sufficiently strong to induce the long-range magnetic order with the Neel temperature T-N similar or equal to 7 K and the ordered magnetic moment of 0.53 mu(B), as measured with neutron diffraction. This magnetic behavior can be accounted for by J(eff)/J(4) similar or equal to 1.6 and J(4) similar or equal to 16 K. We further propose a general magnetic phase diagram for the (CuCl)LaNb2O7-type compounds, and explain the transition from the gapped spin-singlet (dimer) ground state in (CuCl)LaNb2O7 to the long-range antiferromagnetic order in (CuCl)LaTa2O7 and (CuBr)LaNb2O7 by an increase in the magnitude of the interdimer couplings J(eff)/J(4), with the (CuCl)LaM2O7 (M = Nb, Ta) compounds lying on different sides of the quantum critical point that separates the singlet and long-range-ordered magnetic ground states. |
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 |
000308127600006 |
Publication Date |
2012-08-29 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:101886 |
Serial |
3526 |
Permanent link to this record |
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Author |
Morozov, V.; Arakcheeva, A.; Redkin, B.; Sinitsyn, V.; Khasanov, S.; Kudrenko, E.; Raskina, M.; Lebedev, O.; Van Tendeloo, G. |
Title |
Na2/7Gd4/7MoO4 : a modulated scheelite-type structure and conductivity properties |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
Volume |
51 |
Issue |
9 |
Pages |
5313-5324 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Scheelite-type compounds with the general formula (A1,A2)n[(B1,B2)O4]m (2/3 ≤ n/m ≤ 3/2) are the subject of large interest owing to their stability, relatively simple preparation, and optical properties. The creation of cation vacancies (□) in the scheelite-type framework and the ordering of A cations and vacancies can be a new factor in controlling the scheelite-type structure and properties. For a long time, cation-deficient Nd3+:M2/7Gd4/7□1/7MoO4 (M = Li, Na) compounds were considered as potential lasers with diode pumping. They have a defect scheelite-type 3D structure (space group I41/a) with a random distribution of Li+(Na+), Gd3+, and vacancies in the crystal. A Na2/7Gd4/7MoO4 single crystal with scheelite-type structure has been grown by the Czochralski method. Transmission electron microscopy revealed that Na2/7Gd4/7MoO4 has a (3 + 2)D incommensurately modulated structure. The (3 + 2)D incommensurately modulated scheelite-type cation-deficient structure of Na2/7Gd4/7MoO4 [super space group I4̅ (αβ0,βα0)00] has been solved from single-crystal diffraction data. The solution of the (3 + 2)D incommensurately modulated structure revealed the partially disordered distribution of vacancies and Na and Gd cations. High-temperature conductivity measurements performed along the [100] and [001] orientation of the single crystal revealed that the conductivity of Na2/7Gd4/7MoO4 at T = 973 K equals σ = 1.13 × 105 Ω1 cm1. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000303952900055 |
Publication Date |
2012-04-19 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.857 |
Times cited |
37 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.857; 2012 IF: 4.593 |
Call Number |
UA @ lucian @ c:irua:98385 |
Serial |
3547 |
Permanent link to this record |
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Author |
Chernov, S.V.; Dobrovolsky, Y.A.; Istomin, S.Y.; Antipov, E.V.; Grins, J.; Svensson, G.; Tarakina, N.V.; Abakumov, A.M.; Van Tendeloo, G.; Eriksson, S.G.; Rahman, S.M.H.; |
Title |
_Sr{2}GaScO5, Sr10Ga6Sc4O25, and SrGa0.75Sc0.25O2.5 : a play in the octahedra to tetrahedra ratio in oxygen-deficient perovskites |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
Volume |
51 |
Issue |
2 |
Pages |
1094-1103 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Three different perovskite-related phases were isolated in the SrGa(1-x)Sc(x)O(2.5) system: Sr(2)GaScO(5), Sr(10)Ga(6)Sc(4)O(25), and SrGa(0.75)Sc(0.25)O(2.5), Sr(2)GaScO(5) (x = 0.5) crystallizes in a brownrnillerite-type structure [space group (S.G.) Icmm, a = 5.91048(5) angstrom, b = 15.1594(1) angstrom, and c = 5.70926(4) angstrom] with complete ordering of Sc(3+) and Ga(3+) over octahedral and tetrahedral positions, respectively. The crystal structure of Sr(10)Ga(6)Sc(4)O(25) (x = 0.4) was determined by the Monte Carlo method and refined using a combination of X-ray, neutron, and electron diffraction data [S.G. I4(1)/a, a = 17.517(1) angstrom, c = 32.830(3) angstrom]. It represents a novel type of ordering of the B cations and oxygen vacancies in perovskites. The crystal structure of Sr(10)Ga(6)Sc(4)O(25) can be described as a stacking of eight perovskite layers along the c axis ...[-(Sc/Ga)O(1.6)-SrO(0.8)-(Sc/Ga)O(1.8)-SrO(0.8)-](2 center dot center dot center dot) Similar to Sr(2)GaScO(5), this structure features a complete ordering of the Sc(3+) and Ga(3+) cations over octahedral and tetrahedral positions, respectively, within each layer. A specific feature of the crystal structure of Sr(10)Ga(6)Sc(4)O(25) is that one-third of the tetrahedra have one vertex not connected with other Sc/Ga cations. Further partial replacement of Sc(3+) by Ga(3+) leads to the formation of the cubic perovskite phase SrGa(0.75)Sc(0.25)O(2.5) (x = 0.25) with a = 3.9817(4) angstrom. This compound incorporates water molecules in the structure forming SrGa(0.75)Sc(0.25)O(2.5)center dot xH(2)O hydrate, which exhibits a proton conductivity of similar to 2.0 x 10(-6) S/cm at 673 K. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000299028800042 |
Publication Date |
2011-12-22 |
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 |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.857 |
Times cited |
14 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.857; 2012 IF: 4.593 |
Call Number |
UA @ lucian @ c:irua:96229 |
Serial |
3559 |
Permanent link to this record |
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Author |
Wang, B.; Idrissi, H.; Shi, H.; Colla, M.S.; Michotte, S.; Raskin, J.P.; Pardoen, T.; Schryvers, D. |
Title |
Texture-dependent twin formation in nanocrystalline thin Pd films |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Scripta materialia |
Abbreviated Journal |
Scripta Mater |
Volume |
66 |
Issue |
11 |
Pages |
866-871 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Nanocrystalline Pd films were produced by electron-beam evaporation and sputter deposition. The electron-beam-evaporated films reveal randomly oriented nanograins with a relatively high density of growth twins, unexpected in view of the high stacking fault energy of Pd. In contrast, sputter-deposited films show a clear 〈1 1 1〉 crystallographic textured nanostructure without twins. These results provide insightful information to guide the generation of microstructures with enhanced strength/ductility balance in high stacking fault energy nanocrystalline metallic thin films. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000303621900007 |
Publication Date |
2012-01-31 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1359-6462; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.747 |
Times cited |
19 |
Open Access |
|
Notes |
Iap; Fwo |
Approved |
Most recent IF: 3.747; 2012 IF: 2.821 |
Call Number |
UA @ lucian @ c:irua:96955 |
Serial |
3566 |
Permanent link to this record |
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Author |
Croitoru, M.D.; Vagov, A.; Shanenko, A.A.; Axt, V.M. |
Title |
The Cooper problem in nanoscale : enhancement of the coupling due to confinement |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
Volume |
25 |
Issue |
12 |
Pages |
124001-124005 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
In 1956 Cooper demonstrated (1956 Phys. Rev. 104 1189) that, no matter how weak the attraction is, two electrons in three-dimensional (3D) space just above the Fermi sea could be bound. In this work we investigate the influence of confinement on the binding energy of a Cooper pair. We show that confinement-induced modification of the Fermi sea results in a significant increase of the binding energy, when the bottom of an energy subband is very close to the Fermi surface. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000311418100004 |
Publication Date |
2012-11-08 |
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 |
0953-2048;1361-6668; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.878 |
Times cited |
9 |
Open Access |
|
Notes |
; MDC acknowledges support by the European Community under the Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR). ; |
Approved |
Most recent IF: 2.878; 2012 IF: 2.758 |
Call Number |
UA @ lucian @ c:irua:105121 |
Serial |
3573 |
Permanent link to this record |
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Author |
Ao, Z.M.; Hernández-Nieves, A.D.; Peeters, F.M.; Li, S. |
Title |
The electric field as a novel switch for uptake/release of hydrogen for storage in nitrogen doped graphene |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
Volume |
14 |
Issue |
4 |
Pages |
1463-1467 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Nitrogen-doped graphene was recently synthesized and was reported to be a catalyst for hydrogen dissociative adsorption under a perpendicular applied electric field (F). In this work, the diffusion of H atoms on N-doped graphene, in the presence and absence of an applied perpendicular electric field, is studied using density functional theory. We demonstrate that the applied field can significantly facilitate the binding of hydrogen molecules on N-doped graphene through dissociative adsorption and diffusion on the surface. By removing the applied field the absorbed H atoms can be released efficiently. Our theoretical calculation indicates that N-doped graphene is a promising hydrogen storage material with reversible hydrogen adsorption/desorption where the applied electric field can act as a switch for the uptake/release processes. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
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Language |
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Wos |
000298754500018 |
Publication Date |
2011-11-21 |
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 |
1463-9076;1463-9084; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.123 |
Times cited |
67 |
Open Access |
|
Notes |
; Financial support of the Vice-Chancellor's Postdoctoral Research Fellowship Program (SIR50/PS19184) and the ECR grant (SIR30/PS24201) from the University of New South Wales are acknowledged. This work is also supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 4.123; 2012 IF: 3.829 |
Call Number |
UA @ lucian @ c:irua:96266 |
Serial |
3578 |
Permanent link to this record |
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Author |
Komendová, L.; Shanenko, A.A.; Milošević, M.V.; Peeters, F.M. |
Title |
The healing lengths in two-band superconductors in extended Ginzburg-Landau theory |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
Volume |
479 |
Issue |
|
Pages |
126-129 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We study the vortex profiles in two-gap superconductors using the extended Ginzburg-Landau theory. The results shed more light on the disparity between the effective length scales in two bands. We compare the behavior expected from the standard Ginzburg-Landau theory with this new approach, and find good qualitative agreement in the case of LiFeAs. (C) 2011 Elsevier B.V. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000308580600029 |
Publication Date |
2012-01-04 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0921-4534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.404 |
Times cited |
1 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the ESF-INSTANS network. ; |
Approved |
Most recent IF: 1.404; 2012 IF: 0.718 |
Call Number |
UA @ lucian @ c:irua:101871 |
Serial |
3585 |
Permanent link to this record |
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Author |
Costamagna, S.; Neek-Amal, M.; Los, J.H.; Peeters, F.M. |
Title |
Thermal rippling behavior of graphane |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
4 |
Pages |
041408-4 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Thermal fluctuations of single layer hydrogenated graphene (graphane) are investigated using large scale atomistic simulations. By analyzing the mean square value of the height fluctuations < h(2)> and the height-height correlation function H(q) for different system sizes and temperatures, we show that hydrogenated graphene is an unrippled system in contrast to graphene. The height fluctuations are bounded, which is confirmed by a H(q) tending to a constant in the long wavelength limit instead of showing the characteristic scaling law q(4-eta)(eta similar or equal to 0.85) predicted by membrane theory. This unexpected behavior persists up to temperatures of at least 900 K and is a consequence of the fact that in graphane the thermal energy can be accommodated by in-plane bending modes, i.e., modes involving C-C-C bond angles in the buckled carbon layer, instead of leading to significant out-of-plane fluctuations that occur in graphene. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
|
Wos |
000306649200002 |
Publication Date |
2012-07-23 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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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 |
Impact Factor |
3.836 |
Times cited |
46 |
Open Access |
|
Notes |
; We thank A. Fasolino, A. Dobry, and K. H. Michel for their useful comments. S.C. is supported by the Belgian Science Foundation (BELSPO). This work is supported by the ESF-EuroGRAPHENE project CONGRAN and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:100840 |
Serial |
3630 |
Permanent link to this record |
|
|
|
Author |
Goris, B.; van Huis, M.A.; Bals, S.; Zandbergen, H.W.; Manna, L.; Van Tendeloo, G. |
Title |
Thermally induced structural and morphological changes of CdSe/CdS octapods |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Small |
Abbreviated Journal |
Small |
Volume |
8 |
Issue |
6 |
Pages |
937-942 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Branched nanostructures are of great interest because of their promising optical and electronic properties. For successful and reliable integration in applications such as photovoltaic devices, the thermal stability of the nanostructures is of major importance. Here the different domains (CdSe cores, CdS pods) of the heterogeneous octapods are shown to have different thermal stabilities, and heating is shown to induce specific shape changes. The octapods are heated from room temperature to 700 °C, and investigated using (analytical and tomographic) transmission electron microscopy (TEM). At low annealing temperatures, pure Cd segregates in droplets at the outside of the octapods, indicating non-stochiometric composition of the octapods. Furthermore, the tips of the pods lose their faceting and become rounded. Further heating to temperatures just below the sublimation temperature induces growth of the zinc blende core at the expense of the wurtzite pods. At higher temperatures, (500700 °C), sublimation of the octapods is observed in real time in the TEM. Three-dimensional tomographic reconstructions reveal that the four pods pointing into the vacuum have a lower thermal stability than the four pods that are in contact with the support. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000301718800021 |
Publication Date |
2012-01-31 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1613-6810; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.643 |
Times cited |
20 |
Open Access |
|
Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 8.643; 2012 IF: 7.823 |
Call Number |
UA @ lucian @ c:irua:95040 |
Serial |
3633 |
Permanent link to this record |
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|
|
Author |
Lajevardipour, A.; Neek-Amal, M.; Peeters, F.M. |
Title |
Thermomechanical properties of graphene : valence force field model approach |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
24 |
Issue |
17 |
Pages |
175303-175303,8 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Using the valence force field model of Perebeinos and Tersoff (2009 Phys. Rev. B 79 241409(R)), different energy modes of suspended graphene subjected to tensile or compressive strain are studied. By carrying out Monte Carlo simulations it is found that: (i) only for small strains (vertical bar epsilon vertical bar (sic) 0.02) is the total energy symmetrical in the strain, while it behaves completely differently beyond this threshold; (ii) the important energy contributions in stretching experiments are stretching, angle bending, an out-of-plane term, and a term that provides repulsion against pi-pi misalignment; (iii) in compressing experiments the two latter terms increase rapidly, and beyond the buckling transition stretching and bending energies are found to be constant; (iv) from stretching-compressing simulations we calculated the Young's modulus at room temperature 350 +/- 3.15 N m(-1), which is in good agreement with experimental results (340 +/- 50 N m(-1)) and with ab initio results (322-353) N m(-1); (v) molar heat capacity is estimated to be 24.64 J mol(-1) K-1 which is comparable with the Dulong-Petit value, i. e. 24.94 J mol(-1) K-1, and is almost independent of the strain; (vi) nonlinear scaling properties are obtained from height-height correlations at finite temperature; (vii) the used valence force field model results in a temperature independent bending modulus for graphene, and (viii) the Gruneisen parameter is estimated to be 0.64. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000303499700012 |
Publication Date |
2012-04-05 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
29 |
Open Access |
|
Notes |
; We acknowledge helpful comments by V Perebeinos, S Costamagna, A Fasolino and J H Los. This work was supported by the Flemish science foundation (FWO-Vl) and the Belgium Science Policy (IAP). ; |
Approved |
Most recent IF: 2.649; 2012 IF: 2.355 |
Call Number |
UA @ lucian @ c:irua:99123 |
Serial |
3639 |
Permanent link to this record |
|
|
|
Author |
Muñoz, W.A.; Covaci, L.; Peeters, F.M. |
Title |
Tight-binding study of bilayer graphene Josephson junctions |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
18 |
Pages |
184505-184507 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Using highly efficient simulations of the tight-binding Bogoliubov-de-Gennes model, we solved self-consistently for the pair correlation and the Josephson current in a superconducting-bilayer graphene-superconducting Josephson junction. Different doping levels for the non-superconducting link are considered in the short- and long-junction regimes. Self-consistent results for the pair correlation and superconducting current resemble those reported previously for single-layer graphene except at the Dirac point, where remarkable differences in the proximity effect are found, as well as a suppression of the superconducting current in the long-junction regime. Inversion symmetry is broken by considering a potential difference between the layers and we found that the supercurrent can be switched if the junction length is larger than the Fermi length. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000310840400005 |
Publication Date |
2012-11-07 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-VI). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:105149 |
Serial |
3661 |
Permanent link to this record |
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|
|
Author |
de Sousa, J.S.; Covaci, L.; Peeters, F.M.; Farias, G.A. |
Title |
Time-dependent investigation of charge injection in a quantum dot containing one electron |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
Volume |
112 |
Issue |
9 |
Pages |
093705-93709 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The interaction of an injected electron towards a quantum dot (QD) containing a single confined electron is investigated using a flexible time-dependent quantum mechanics formalism, which allows both electrons to move and undergo quantum transitions. Different scenarios combining quantum dot dimensions, dielectric constant, injected wave packet energy, and width were explored, and our main results are: (i) due to the large characteristic transitions times between the confined state in the quantum dot and the delocalized state in the continuum, it is relatively difficult to ionize the occupied QD by Coulomb interaction solely and (ii) the charging state of the quantum dot can be sensed by direct injection of charges. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4759292] |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000311968400052 |
Publication Date |
2012-11-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-8979; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.068 |
Times cited |
1 |
Open Access |
|
Notes |
; This work was financially supported by the Brazilian National Research Council (CNPq), under Contract No. NanoBioEstruturas 555183/2005-0, Fundao Cearense de Apoio ao Desenvolvimento Cientfico e Tecnolgico (Funcap), CAPES, Pronex/CNPq/ Funcap, the Bilateral program between Flanders and Brazil, and the Flemish Science Foundation (FWO). ; |
Approved |
Most recent IF: 2.068; 2012 IF: 2.210 |
Call Number |
UA @ lucian @ c:irua:106014 |
Serial |
3664 |
Permanent link to this record |
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|
Author |
Bittencourt, C.; Krüger, P.; Lagos, M.J.; Ke, X.; Van Tendeloo, G.; Ewels, C.; Umek, P.; Guttmann, P. |
Title |
Towards atomic resolution in sodium titanate nanotubes using near-edge X-ray-absorption fine-structure spectromicroscopy combined with multichannel multiple-scattering calculations |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Beilstein journal of nanotechnology |
Abbreviated Journal |
Beilstein J Nanotech |
Volume |
3 |
Issue |
|
Pages |
789-797 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Recent advances in near-edge X-ray-absorption fine-structure spectroscopy coupled with transmission X-ray microscopy (NEXAFS-TXM) allow large-area mapping investigations of individual nano-objects with spectral resolution up to E/Delta E = 104 and spatial resolution approaching 10 nm. While the state-of-the-art spatial resolution of X-ray microscopy is limited by nanostructuring process constrains of the objective zone plate, we show here that it is possible to overcome this through close coupling with high-level theoretical modelling. Taking the example of isolated bundles of hydrothermally prepared sodium titanate nanotubes ((Na,H)TiNTs) we are able to unravel the complex nanoscale structure from the NEXAFS-TXM data using multichannel multiple-scattering calculations, to the extent of being able to associate specific spectral features in the O K-edge and Ti L-edge with oxygen atoms in distinct sites within the lattice. These can even be distinguished from the contribution of different hydroxyl groups to the electronic structure of the (Na,H)TiNTs. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000311482400001 |
Publication Date |
2012-11-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2190-4286; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.127 |
Times cited |
13 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.127; 2012 IF: 2.374 |
Call Number |
UA @ lucian @ c:irua:105140 |
Serial |
3684 |
Permanent link to this record |
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Author |
Lucena, D.; Tkachenko, D.V.; Nelissen, K.; Misko, V.R.; Ferreira, W.P.; Farias, G.A.; Peeters, F.M. |
Title |
Transition from single-file to two-dimensional diffusion of interacting particles in a quasi-one-dimensional channel |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Physical review : E : statistical, nonlinear, and soft matter physics |
Abbreviated Journal |
Phys Rev E |
Volume |
85 |
Issue |
3:1 |
Pages |
031147-031147,12 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Diffusive properties of a monodisperse system of interacting particles confined to a quasi-one-dimensional channel are studied using molecular dynamics simulations. We calculate numerically the mean-squared displacement (MSD) and investigate the influence of the width of the channel (or the strength of the confinement potential) on diffusion in finite-size channels of different shapes (i.e., straight and circular). The transition from single-file diffusion to the two-dimensional diffusion regime is investigated. This transition [ regarding the calculation of the scaling exponent (alpha) of the MSD <Delta x(2)(t)> proportional to t(alpha)] as a function of the width of the channel is shown to change depending on the channel's confinement profile. In particular, the transition can be either smooth (i.e., for a parabolic confinement potential) or rather sharp (i.e., for a hard-wall potential), as distinct from infinite channels where this transition is abrupt. This result can be explained by qualitatively different distributions of the particle density for the different confinement potentials. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
American Institute of Physics |
Place of Publication |
Woodbury (NY) |
Editor |
|
Language |
|
Wos |
000302117900003 |
Publication Date |
2012-03-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1539-3755;1550-2376; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.366 |
Times cited |
38 |
Open Access |
|
Notes |
; This work was supported by CNPq, FUNCAP (Pronex grant), the “Odysseus” program of the Flemish Government, the Flemish Science Foundation (FWO-Vl), the bilateral program between Flanders and Brazil, and the collaborative program CNPq-FWO-Vl. ; |
Approved |
Most recent IF: 2.366; 2012 IF: 2.313 |
Call Number |
UA @ lucian @ c:irua:97784 |
Serial |
3699 |
Permanent link to this record |
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|
|
Author |
Barbier, M. |
Title |
Transport properties of nanostructures and superlattices on single-layer and bilayer graphene |
Type |
Doctoral thesis |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
|
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
|
Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Antwerpen |
Editor |
|
Language |
|
Wos |
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Publication Date |
0000-00-00 |
Series Editor |
|
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 |
|
ISBN |
|
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:100632 |
Serial |
3728 |
Permanent link to this record |
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|
Author |
Wang, H.; Cuppens, J.; Biermans, E.; Bals, S.; Fernandez-Ballester, L.; Kvashnina, K.O.; Bras, W.; van Bael, M.J.; Temst, K.; Vantomme, A. |
Title |
Tuning of the size and the lattice parameter of ion-beam synthesized Pb nanoparticles embedded in Si |
Type |
A1 Journal article |
Year ![sorted by Year field, ascending order (up)](img/sort_asc.gif) |
2012 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
Volume |
45 |
Issue |
3 |
Pages |
035301-035301,7 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The size and lattice constant evolution of Pb nanoparticles (NPs) synthesized by high fluence implantation in crystalline Si have been studied with a variety of experimental techniques. Results obtained from small-angle x-ray scattering showed that the Pb NPs grow with increasing implantation fluence and annealing duration. The theory of NP growth kinetics can be applied to qualitatively explain the size evolution of the Pb NPs during the implantation and annealing processes. Moreover, the lattice constant of the Pb NPs was evaluated by conventional x-ray diffraction. The lattice dilatation was observed to decrease with increasing size of the Pb NPs. Such lattice constant tuning can be attributed to the pseudomorphism caused by the lattice mismatch between the Pb NPs and the Si matrix. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000299308400008 |
Publication Date |
2011-12-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-3727;1361-6463; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.588 |
Times cited |
5 |
Open Access |
|
Notes |
Fwo; Iap |
Approved |
Most recent IF: 2.588; 2012 IF: 2.528 |
Call Number |
UA @ lucian @ c:irua:94208 |
Serial |
3754 |
Permanent link to this record |