| Records |
| Author |
Schoelz, J.K.; Xu, P.; Meunier, V.; Kumar, P.; Neek-Amal, M.; Thibado, P.M.; Peeters, F.M. |
| Title |
Graphene ripples as a realization of a two-dimensional Ising model : a scanning tunneling microscope study |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
Physical review: B: condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
91 |
Issue |
91 |
Pages |
045413 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Ripples in pristine freestanding graphene naturally orient themselves in an array that is alternately curved-up and curved-down; maintaining an average height of zero. Using scanning tunneling microscopy (STM) to apply a local force, the graphene sheet will reversibly rise and fall in height until the height reaches 60%-70% of its maximum at which point a sudden, permanent jump occurs. We successfully model the ripples as a spin-half Ising magnetic system, where the height of the graphene plays the role of the spin. The permanent jump in height, controlled by the tunneling current, is found to be equivalent to an antiferromagnetic-to-ferromagnetic phase transition. The thermal load underneath the STM tip alters the local tension and is identified as the responsible mechanism for the phase transition. Four universal critical exponents are measured from our STM data, and the model provides insight into the statistical role of graphene's unusual negative thermal expansion coefficient. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000348762200011 |
Publication Date |
2015-01-12 |
| 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 |
21 |
Open Access |
|
| Notes |
; This work was supported in part by Office of Naval Research (USA) under Grant No. N00014-10-1-0181 and National Science Foundation (USA) under Grant No. DMR-0855358. F. M. Peeters and M. Neek-Amal were supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
| Call Number |
c:irua:123866 |
Serial  |
1377 |
| Permanent link to this record |
| |
|
| |
| Author |
Neek-Amal, M.; Peeters, F.M. |
| Title |
Graphene on hexagonal lattice substrate : stress and pseudo-magnetic field |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
104 |
Issue |
17 |
Pages |
173106 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Moire patterns in the pseudo-magnetic field and in the strain profile of graphene (GE) when put on top of a hexagonal lattice substrate are predicted from elasticity theory. The van der Waals interaction between GE and the substrate induces out-of-plane deformations in graphene which results in a strain field, and consequently in a pseudo-magnetic field. When the misorientation angle is about 0.5 degrees, a three-fold symmetric strain field is realized that results in a pseudo-magnetic field very similar to the one proposed by F. Guinea, M. I. Katsnelson, and A. K. Geim [Nature Phys. 6, 30 (2010)]. Our results show that the periodicity and length of the pseudo-magnetic field can be tuned in GE by changing the misorientation angle and substrate adhesion parameters and a considerable energy gap (23 meV) can be obtained due to out-of-plane deformation of graphene which is in the range of recent experimental measurements (20-30 meV). (C) 2014 AIP Publishing LLC. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000336142500066 |
Publication Date |
2014-05-02 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-6951;1077-3118; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.411 |
Times cited |
14 |
Open Access |
|
| 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. ; |
Approved |
Most recent IF: 3.411; 2014 IF: 3.302 |
| Call Number |
UA @ lucian @ c:irua:117724 |
Serial |
1375 |
| Permanent link to this record |
| |
|
| |
| Author |
Neek-Amal, M.; Peeters, F.M. |
| Title |
Graphene on boron-nitride : Moiré pattern in the van der Waals energy |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
104 |
Issue |
4 |
Pages |
041909-4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The spatial dependence of the van der Waals (vdW) energy between graphene and hexagonal boron-nitride (h-BN) is investigated using atomistic simulations. The van der Waals energy between graphene and h-BN shows a hexagonal superlattice structure identical to the observed Moire pattern in the local density of states, which depends on the lattice mismatch and misorientation angle between graphene and h-BN. Our results provide atomistic features of the weak van der Waals interaction between graphene and BN which are in agreement with experiment and provide an analytical expression for the size of the spatial variation of the weak van der Waals interaction. We also found that the A-B-lattice symmetry of graphene is broken along the armchair direction. (C) 2014 AIP Publishing LLC. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000331209900028 |
Publication Date |
2014-01-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-6951;1077-3118; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.411 |
Times cited |
61 |
Open Access |
|
| 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/299855. ; |
Approved |
Most recent IF: 3.411; 2014 IF: 3.302 |
| Call Number |
UA @ lucian @ c:irua:115802 |
Serial |
1374 |
| Permanent link to this record |
| |
|
| |
| Author |
Neek-Amal, M.; Peeters, F.M. |
| Title |
Graphene nanoribbons subjected to axial stress |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
8 |
Pages |
085432-085432,6 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Atomistic simulations are used to study the bending of rectangular graphene nanoribbons subjected to axial stress both for free boundary and supported boundary conditions. The shapes of the deformations of the buckled graphene nanoribbons, for small values of the stress, are sine waves where the number of nodal lines depend on the longitudinal size of the system and the applied boundary condition. The buckling strain for the supported boundary condition is found to be independent of the longitudinal size and estimated to be 0.86%. From a calculation of the free energy at finite temperature we find that the equilibrium projected two-dimensional area of the graphene nanoribbon is less than the area of a flat sheet. At the optimum length the boundary strain for the supported boundary condition is 0.48%. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000281065100007 |
Publication Date |
2010-08-20 |
| 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 |
92 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:84583 |
Serial |
1373 |
| Permanent link to this record |
| |
|
| |
| Author |
Neek-Amal, M.; Covaci, L.; Shakouri, K.; Peeters, F.M. |
| Title |
Electronic structure of a hexagonal graphene flake subjected to triaxial stress |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
88 |
Issue |
11 |
Pages |
115428 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The electronic properties of a triaxially strained hexagonal graphene flake with either armchair or zigzag edges are investigated using molecular dynamics simulations and tight-binding calculations. We found that (i) the pseudomagnetic field in strained graphene flakes is not uniform neither in the center nor at the edge of zigzag terminated flakes, (ii) the pseudomagnetic field is almost zero in the center of armchair terminated flakes but increases dramatically near the edges, (iii) the pseudomagnetic field increases linearly with strain, for strains lower than 15% but increases nonlinearly beyond it, (iv) the local density of states in the center of the zigzag hexagon exhibits pseudo-Landau levels with broken sublattice symmetry in the zeroth pseudo-Landau level, and in addition there is a shift in the Dirac cone due to strain induced scalar potentials, and (v) there is size effect in pseudomagnetic field. This study provides a realistic model of the electronic properties of inhomogeneously strained graphene where the relaxation of the atomic positions is correctly included together with strain induced modifications of the hopping terms up to next-nearest neighbors. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000324690400008 |
Publication Date |
2013-09-24 |
| 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 |
46 |
Open Access |
|
| Notes |
; This work was supported by the EU-Marie Curie IIF postdoctoral Fellowship/ 299855 (for M.N.-A.), the ESF EuroGRAPHENE project CONGRAN, the Flemish Science Foundation (FWO-Vl) and the Methusalem Funding of the Flemish government. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
| Call Number |
UA @ lucian @ c:irua:111168 |
Serial |
1011 |
| Permanent link to this record |
| |
|
| |
| Author |
Singh, S.K.; Neek-Amal, M.; Peeters, F.M. |
| Title |
Electronic properties of graphene nano-flakes : energy gap, permanent dipole, termination effect, and Raman spectroscopy |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
The journal of chemical physics |
Abbreviated Journal |
J Chem Phys |
| Volume |
140 |
Issue |
7 |
Pages |
074304-74309 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The electronic properties of graphene nano-flakes (GNFs) with different edge passivation are investigated by using density functional theory. Passivation with F and H atoms is considered: C-Nc X-Nx (X = F or H). We studied GNFs with 10 < N-c < 56 and limit ourselves to the lowest energy configurations. We found that: (i) the energy difference Delta between the highest occupied molecular orbital and the lowest unoccupied molecular orbital decreases with N-c, (ii) topological defects (pentagon and heptagon) break the symmetry of the GNFs and enhance the electric polarization, (iii) the mutual interaction of bilayer GNFs can be understood by dipole-dipole interaction which were found sensitive to the relative orientation of the GNFs, (iv) the permanent dipoles depend on the edge terminated atom, while the energy gap is independent of it, and (v) the presence of heptagon and pentagon defects in the GNFs results in the largest difference between the energy of the spin-up and spin-down electrons which is larger for the H-passivated GNFs as compared to F-passivated GNFs. Our study shows clearly the effect of geometry, size, termination, and bilayer on the electronic properties of small GNFs. This study reveals important features of graphene nano-flakes which can be detected using Raman spectroscopy. (C) 2014 AIP Publishing LLC. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000332039900020 |
Publication Date |
2014-02-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0021-9606;1089-7690; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.965 |
Times cited |
30 |
Open Access |
|
| Notes |
; This work was supported by the EU-Marie Curie IIF postdoctoral 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. ; |
Approved |
Most recent IF: 2.965; 2014 IF: 2.952 |
| Call Number |
UA @ lucian @ c:irua:115857 |
Serial |
1002 |
| Permanent link to this record |
| |
|
| |
| Author |
Neek-Amal, M.; Peeters, F.M. |
| Title |
Effect of grain boundary on the buckling of graphene nanoribbons |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
100 |
Issue |
10 |
Pages |
101905-101905,4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The buckling of graphene nano-ribbons containing a grain boundary is studied using atomistic simulations where free and supported boundary conditions are invoked. We consider the buckling transition of two kinds of grain boundaries with special symmetry. When graphene contains a large angle grain boundary with theta = 21.8 degrees, the buckling strains are larger than those of perfect graphene when the ribbons with free (supported) boundary condition are subjected to compressive tension parallel (perpendicular) to the grain boundary. This is opposite for the results of theta = 32.2 degrees. The shape of the deformations of the buckled graphene nanoribbons depends on the boundary conditions, the presence of the particular used grain boundaries, and the direction of applied in-plane compressive tension. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3692573] |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000301655500021 |
Publication Date |
2012-03-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.411 |
Times cited |
18 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 3.411; 2012 IF: 3.794 |
| Call Number |
UA @ lucian @ c:irua:97794 |
Serial |
809 |
| Permanent link to this record |
| |
|
| |
| Author |
Seyed-Talebi, S.M.; Beheshtian, J.; Neek-Amal, M. |
| Title |
Doping effect on the adsorption of NH3 molecule onto graphene quantum dot : from the physisorption to the chemisorption |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
| Volume |
114 |
Issue |
12 |
Pages |
124307-7 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The adsorption of ammonia molecule onto a graphene hexagonal flake, aluminum (Al) and boron (B) doped graphene flakes (graphene quantum dots, GQDs) are investigated using density functional theory. We found that NH3 molecule is absorbed to the hollow site through the physisorption mechanism without altering the electronic properties of GQD. However, the adsorption energy of NH3 molecule onto the Al- and B-doped GQDs increases with respect GQD resulting chemisorption. The adsorption of NH3 onto the Al-doped and B-doped GQDs makes graphene locally buckled, i.e., B-doped and Al-doped GQDs are not planar. The adsorption mechanism onto a GQD is different than that of graphene. This study reveals important features of the edge passivation and doping effects of the adsorption mechanism of external molecules onto the graphene quantum dots. (C) 2013 AIP Publishing LLC. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000325391100057 |
Publication Date |
2013-09-26 |
| 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 |
10 |
Open Access |
|
| Notes |
; This work was supported by the EU-Marie Curie IIF Fellowship/299855 for M.-N.A. ; |
Approved |
Most recent IF: 2.068; 2013 IF: 2.185 |
| Call Number |
UA @ lucian @ c:irua:112201 |
Serial |
750 |
| Permanent link to this record |
| |
|
| |
| Author |
Neek-Amal, M.; Peeters, F.M. |
| Title |
Defected graphene nanoribbons under axial compression |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
97 |
Issue |
15 |
Pages |
153118,1-153118,3 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The buckling of defected rectangular graphene nanoribbons when subjected to axial stress with supported boundary conditions is investigated using atomistic simulations. The buckling strain and mechanical stiffness of monolayer graphene decrease with the percentage of randomly distributed vacancies. The elasticity to plasticity transition in the stress-strain curve, at low percentage of vacancies, are found to be almost equal to the buckling strain thresholds and they decrease with increasing percentage of vacancies. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000283216900069 |
Publication Date |
2010-10-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.411 |
Times cited |
43 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (WO-Vl) and the Belgian Science Policy (IAP) ; |
Approved |
Most recent IF: 3.411; 2010 IF: 3.841 |
| Call Number |
UA @ lucian @ c:irua:85789 |
Serial |
624 |
| Permanent link to this record |
| |
|
| |
| Author |
Neek-Amal, M.; Peeters, F.M. |
| Title |
Buckled circular monolayer graphene : a graphene nano-bowl |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
23 |
Issue |
4 |
Pages |
045002-045002,8 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We investigate the stability of circular monolayer graphene subjected to a radial load using non-equilibrium molecular dynamics simulations. When monolayer graphene is radially stressed, after some small circular strain (~0.4%) it buckles and bends into a new bowl-like shape. Young's modulus is calculated from the linear relation between stress and strain before the buckling threshold, which is in agreement with experimental results. The prediction of elasticity theory for the buckling threshold of a radially stressed plate is presented and its results are compared to the one of our atomistic simulation. The Jarzynski equality is used to estimate the difference between the free energy of the non-compressed states and the buckled states. From a calculation of the free energy we obtain the optimum radius for which the system feels the minimum boundary stress. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000286142800003 |
Publication Date |
2010-12-16 |
| 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 |
27 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 2.649; 2011 IF: 2.546 |
| Call Number |
UA @ lucian @ c:irua:88043 |
Serial |
259 |
| Permanent link to this record |
| |
|
| |
| Author |
Neek-Amal, M.; Beheshtian, J.; Sadeghi, A.; Michel, K.H.; Peeters, F.M. |
| Title |
Boron nitride mono layer : a strain-tunable nanosensor |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
| Volume |
117 |
Issue |
25 |
Pages |
13261-13267 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
The influence of triaxial in-plane strain on the electronic properties of a hexagonal boron-nitride sheet is investigated using density functional theory. Different from graphene, the triaxial strain localizes the molecular orbitals of the boron-nitride flake in its center depending on the direction of the applied strain. The proposed technique for localizing the molecular orbitals that are close to the Fermi level in the center of boron nitride flakes can be used to actualize engineered nanosensors, for instance, to selectively detect gas molecules. We show that the central part of the strained flake adsorbs polar molecules more strongly as compared with an unstrained sheet. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000321236400041 |
Publication Date |
2013-06-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.536 |
Times cited |
38 |
Open Access |
|
| Notes |
; This work was supported by the EU-Marie Curie IIF postdoc Fellowship/299855 (for M.N.-A.), the ESF EuroGRAPHENE project CONGRAN, the Flemish Science Foundation (FWO-VI), and the Methusalem Funding of the Flemish government. AS. would like to thank the Universiteit Antwerpen for its hospitality. ; |
Approved |
Most recent IF: 4.536; 2013 IF: 4.835 |
| Call Number |
UA @ lucian @ c:irua:109829 |
Serial |
249 |
| Permanent link to this record |
