| Records |
Author  |
Van der Donck, M.; Peeters, F.M. |
| Title |
Rich many-body phase diagram of electrons and holes in doped monolayer transition metal dichalcogenides |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
98 |
Issue |
11 |
Pages |
115432 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We use a variational technique to study the many-body phase diagram of electrons and holes in n-doped and p-doped monolayer transition metal dichalcogenides (TMDs). We find a total of four different phases. (i) A fully spin polarized and valley polarized ferromagnetic state. (ii) A state with no global spin polarization but with spin polarization in each valley separately, i.e., spin-valley locking. (iii) A state with spin polarization in one of the valleys and little to no spin polarization in the other valley. (iv) A paramagnetic state with no valley polarization. These phases are separated by first-order phase transitions and are determined by the particle density and the dielectric constant of the substrate. We find that in the presence of a perpendicular magnetic field the four different phases persist. In the case of n-doped MoS2, a fifth phase, which is completely valley polarized but not spin polarized, appears for magnetic fields larger than 7 T and for magnetic fields larger than 23 T completely replaces the second phase. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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| Language |
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Wos |
000445507000009 |
Publication Date |
2018-09-24 |
| 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 |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
8 |
Open Access |
|
| Notes |
; This work was supported by the Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for MVDD and by the FLAG-ERA project TRANS-2D-TMD. ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ lucian @ c:irua:153622UA @ admin @ c:irua:153622 |
Serial |
5125 |
| Permanent link to this record |
| |
|
| |
| Author |
Van der Donck, M.; Peeters, F.M. |
| Title |
Interlayer excitons in transition metal dichalcogenide heterostructures |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
98 |
Issue |
11 |
Pages |
115104 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Starting from the single-particle Dirac Hamiltonian for charge carriers in monolayer transition metal dichalcogenides (TMDs), we construct a four-band Hamiltonian describing interlayer excitons consisting of an electron in one TMD layer and a hole in the other TMD layer. An expression for the electron-hole interaction potential is derived, taking into account the effect of the dielectric environment above, below, and between the two TMD layers as well as polarization effects in the transition metal layer and in the chalcogen layers of the TMD layers. We calculate the interlayer exciton binding energy and average in-plane interparticle distance for different TMD heterostructures. The effect of different dielectric environments on the exciton binding energy is investigated and a remarkable dependence on the dielectric constant of the barrier between the two layers is found, resulting from competing effects as a function of the in-plane and out-of-plane dielectric constants of the barrier. The polarization effects in the chalcogen layers, which in general reduce the exciton binding energy, can lead to an increase in binding energy in the presence of strong substrate effects by screening the substrate. The excitonic absorbance spectrum is calculated and we show that the interlayer exciton peak depends linearly on a perpendicular electric field, which agrees with recent experimental results. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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| Language |
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Wos |
000443671900004 |
Publication Date |
2018-09-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
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 Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for MVDD and by the FLAG-ERA project TRANS-2D-TMD. ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ lucian @ c:irua:153653UA @ admin @ c:irua:153653 |
Serial |
5110 |
| Permanent link to this record |
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| |
| Author |
Van der Donck, M.; Peeters, F.M. |
| Title |
Excitonic complexes in anisotropic atomically thin two-dimensional materials : black phosphorus and TiS3 |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
98 |
Issue |
23 |
Pages |
235401 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The effect of anisotropy in the energy spectrum on the binding energy and structural properties of excitons, trions, and biexcitons is investigated. To this end we employ the stochastic variational method with a correlated Gaussian basis. We present results for the binding energy of different excitonic complexes in black phosphorus (bP) and TiS3 and compare them with recent results in the literature when available, for which we find good agreement. The binding energies of excitonic complexes in bP are larger than those in TiS3. We calculate the different average interparticle distances in bP and TiS3 and show that excitonic complexes in bP are strongly anisotropic whereas in TiS3 they are almost isotropic, even though the constituent particles have an anisotropic energy spectrum. This is also confirmed by the correlation functions. |
| 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 |
000452003400009 |
Publication Date |
2018-12-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
10 |
Open Access |
|
| Notes |
; This work was supported by the Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for MVDD and by the FLAG-ERA project TRANS-2D-TMD. ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:156247 |
Serial |
5211 |
| Permanent link to this record |
| |
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| |
| Author |
Van der Donck, M.; Peeters, F.M. |
| Title |
Spectrum of exciton states in monolayer transition metal dichalcogenides : angular momentum and Landau levels |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
99 |
Issue |
11 |
Pages |
115439 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
A four-band exciton Hamiltonian is constructed starting from the single-particle Dirac Hamiltonian for charge carriers in monolayer transition metal dichalcogenides (TMDs). The angular part of the exciton wave function can be separated from the radial part, in the case of zero center of mass momentum excitons, by exploiting the eigenstates of the total exciton angular momentum operator with which the Hamiltonian commutes. We explain why this approach fails for excitons with finite center of mass momentum or in the presence of a perpendicular magnetic field and present an approximation to resolve this issue. We calculate the (binding) energy and average interparticle distance of different excited exciton states in different TMDs and compare these with results available in the literature. Remarkably, we find that the intervalley exciton ground state in the -/+ K valley has angular momentum j = +/- 1, which is due to the pseudospin of the separate particles. The exciton mass and the exciton Landau levels are calculated and we find that the degeneracy of exciton states with opposite relative angular momentum is altered by a magnetic 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 |
000462896400004 |
Publication Date |
2019-03-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
|
| Notes |
; This work was supported by the Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for MVDD and by the FLAG-ERA project TRANS-2D-TMD. ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:159406 |
Serial |
5230 |
| Permanent link to this record |
| |
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| |
| Author |
Van der Donck, M.; De Beule, C.; Partoens, B.; Peeters, F.M.; Van Duppen, B. |
| Title |
Piezoelectricity in asymmetrically strained bilayer graphene |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
| Volume |
3 |
Issue |
3 |
Pages |
035015 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We study the electronic properties of commensurate faulted bilayer graphene by diagonalizing the one-particle Hamiltonian of the bilayer system in a complete basis of Bloch states of the individual graphene layers. Our novel approach is very general and can be easily extended to any commensurate graphene-based heterostructure. Here, we consider three cases: (i) twisted bilayer graphene, (ii) bilayer graphene where triaxial stress is applied to one layer and (iii) bilayer graphene where uniaxial stress is applied to one layer. We show that the resulting superstructures can be divided into distinct classes, depending on the twist angle or the magnitude of the induced strain. The different classes are distinguished from each other by the interlayer coupling mechanism, resulting in fundamentally different low-energy physics. For the cases of triaxial and uniaxial stress, the individual graphene layers tend to decouple and we find significant charge transfer between the layers. In addition, this piezoelectric effect can be tuned by applying a perpendicular electric field. Finally, we show how our approach can be generalized to multilayer systems. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
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| Language |
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Wos |
000384072500003 |
Publication Date |
2016-08-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.937 |
Times cited |
10 |
Open Access |
|
| Notes |
; This work was supported by the Research Foundation-Flanders (FWO-Vl) through aspirant research grants to MVDD, CDB, and BVD. ; |
Approved |
Most recent IF: 6.937 |
| Call Number |
UA @ lucian @ c:irua:137203 |
Serial |
4361 |
| Permanent link to this record |
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| |
| Author |
Van der Donck, M.; Conti, S.; Perali, A.; Hamilton, A.R.; Partoens, B.; Peeters, F.M.; Neilson, D. |
| Title |
Three-dimensional electron-hole superfluidity in a superlattice close to room temperature |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
102 |
Issue |
6 |
Pages |
060503 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Although there is strong theoretical and experimental evidence for electron-hole superfluidity in separated sheets of electrons and holes at low T, extending superfluidity to high T is limited by strong two-dimensional fluctuations and Kosterlitz-Thouless effects. We show this limitation can be overcome using a superlattice of alternating electron- and hole-doped semiconductor monolayers. The superfluid transition in a three-dimensional superlattice is not topological, and for strong electron-hole pair coupling, the transition temperature T-c can be at room temperature. As a quantitative illustration, we show T-c can reach 270 K for a superfluid in a realistic superlattice of transition metal dichalcogenide monolayers. |
| 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 |
000562320700001 |
Publication Date |
2020-08-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.7 |
Times cited |
5 |
Open Access |
|
| Notes |
; This work was supported by the Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for M.V.d.D., by the FLAG-ERA project TRANS-2D-TMD, and by the Australian Government through the Australian Research Council Centre of Excellence in Future Low-Energy Electronics (Project No. CE170100039). We thank Milorad V. Milossevi ' c, Pierbiagio Pieri, and Jacques Tempere for helpful discussions. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:172064 |
Serial |
6628 |
| Permanent link to this record |
| |
|
| |
| Author |
Van der Donck, M. |
| Title |
Excitonic complexes in transition metal dichalcogenides and related materials |
Type |
Doctoral thesis |
| Year |
2019 |
Publication |
|
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
224 p. |
| Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
| Abstract |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
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Publication Date |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
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ISBN |
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Additional Links |
UA library record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:162525 |
Serial |
5412 |
| Permanent link to this record |
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| |
| Author |
van der Burgt, M.; van Esch, A.; Peeters, F.M.; van Hove, M.; Borghs, G.; Herlach, F. |
| Title |
High field transport in high carrier density GaAs/Ga0.8In0.2As/Ga0.75Al0.25As heterostructures |
Type |
A1 Journal article |
| Year |
1993 |
Publication |
Physica: B : condensed matter |
Abbreviated Journal |
Physica B |
| Volume |
184 |
Issue |
|
Pages |
211-215 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| 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 |
Amsterdam |
Editor |
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| Language |
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Wos |
A1993KU62100042 |
Publication Date |
2002-10-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4526; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.319 |
Times cited |
4 |
Open Access |
|
| Notes |
|
Approved |
|
| Call Number |
UA @ lucian @ c:irua:5792 |
Serial |
1432 |
| Permanent link to this record |
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| |
| Author |
van der Burgt, M.; Thoen, P.; Herlach, F.; Peeters, F.M.; Harris, J.J.; Foxon, C.T. |
| Title |
The quantized Hall effect in pulsed magnetic fields |
Type |
A1 Journal article |
| Year |
1992 |
Publication |
Physica: B |
Abbreviated Journal |
Physica B |
| Volume |
177 |
Issue |
|
Pages |
409-413 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
A1992HP25000086 |
Publication Date |
2002-10-17 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
|
Edition |
|
| ISSN |
0921-4526; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.319 |
Times cited |
14 |
Open Access |
|
| Notes |
|
Approved |
MATERIALS SCIENCE, MULTIDISCIPLINARY 96/271 Q2 # |
| Call Number |
UA @ lucian @ c:irua:3026 |
Serial |
2770 |
| Permanent link to this record |
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| |
| Author |
van der Burgt, M.; Peeters, F.M.; Singleton, J.; Nicholas, R.J.; Herlach, F.; Harris, J.J.; Foxon, C.T. |
| Title |
Measuring quantum Hall resistors in pulsed magnetic fields |
Type |
P3 Proceeding |
| Year |
1995 |
Publication |
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Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
750-753 |
| Keywords |
P3 Proceeding; Condensed Matter Theory (CMT) |
| Abstract |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
World Scientific |
Place of Publication |
Singapore |
Editor |
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| Language |
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Wos |
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Publication Date |
0000-00-00 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
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ISBN |
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Additional Links |
UA library record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ lucian @ c:irua:12207 |
Serial |
1968 |
| Permanent link to this record |
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| |
| Author |
van der Burgt, M.; Karavolas, V.C.; Peeters, F.M.; Singleton, J.; Nicholas, R.J.; Herlach, F.; Harris, J.J.; van Hove, M.; Borghs, G. |
| Title |
High field magnetotransport in a Ga0.8In0.2As quantum well with a parallel δ-layer |
Type |
P3 Proceeding |
| Year |
1995 |
Publication |
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Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
588-591 |
| Keywords |
P3 Proceeding; Condensed Matter Theory (CMT) |
| Abstract |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
World Scientific |
Place of Publication |
Singapore |
Editor |
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| Language |
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Wos |
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Publication Date |
0000-00-00 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
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ISBN |
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Additional Links |
UA library record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
PHYSICS, APPLIED 28/145 Q1 # |
| Call Number |
UA @ lucian @ c:irua:12206 |
Serial |
1431 |
| Permanent link to this record |
| |
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| |
| Author |
van der Burgt, M.; Karavolas, V.C.; Peeters, F.M.; Singleton, J.; Nicholas, R.J.; Herlach, F.; Harris, J.J.; van Hove, M.; Borghs, G. |
| Title |
Magnetotransport in a pseudomorhic GaAs/Ga0.8In0.2As/Ga0.75Al0.25As heterostructure with a Si δ-doping layer |
Type |
A1 Journal article |
| Year |
1995 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
52 |
Issue |
|
Pages |
12218-12231 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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| Language |
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Wos |
A1995TB96600102 |
Publication Date |
0000-00-00 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121; 0163-1829 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.736 |
Times cited |
35 |
Open Access |
|
| Notes |
|
Approved |
|
| Call Number |
UA @ lucian @ c:irua:12192 |
Serial |
1932 |
| Permanent link to this record |
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| |
| Author |
van der Burgt, M.; Karavolas, V.C.; Peeters, F.M.; Singleton, J.; Nicholas, R.J.; Herlach, F.; Harris, J.J.; Van Hove, M.; Borghs, G. |
| Title |
Magnetotransport in a pseudomorphic GaAs/Ga0.8In0.2As/Ga0.75Al0.25As heterostructure with a Si \delta-doping layer |
Type |
A1 Journal article |
| Year |
1995 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
52 |
Issue |
16 |
Pages |
12218-12231 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Magnetotransport properties of a pseudomorphic GsAs/Ga0.8In0.2As/Ga0.75Al0.25As heterostructure are investigated in pulsed magnetic fields up to 50 T and at temperatures of T = 1.4 and 4.2 K. The structure studied consists of a Si delta layer parallel to a Ga0.8In0.2As quantum well (QW). The dark electron density of the structure is n(c) = 1.67 x 10(16) m(-2). By illumination the density can be increased up to a factor of 4; this way the second subband in the Ga0.08In0.2As QW can become populated as well as the Si delta layer. The presence of electrons in the delta layer results in drastic changes in the transport data, especially at magnetic fields beyond 30 T. The phenomena observed are interpreted as (i) magnetic freeze-out of carriers in the delta layer when a low density of electrons is present in the delta layer, and (ii) quantization of the electron motion in the two-dimensional electron gases in both the Ga0.8In0.2As QW and the Si delta layer in the case of high densities. These conclusions are corroborated by the numerical results of our theoretical model. We obtain satisfactory agreement between model and experiment. |
| 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 |
A1995TB96600102 |
Publication Date |
2002-07-27 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.736 |
Times cited |
43 |
Open Access |
|
| Notes |
|
Approved |
PHYSICS, APPLIED 28/145 Q1 # |
| Call Number |
UA @ lucian @ c:irua:99708 |
Serial |
1933 |
| Permanent link to this record |
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| |
| Author |
van der Burgt, J.S.; Geuchies, J.J.; van der Meer, B.; Vanrompay, H.; Zanaga, D.; Zhang, Y.; Albrecht, W.; Petukhov, A.V.; Filion, L.; Bals, S.; Swart, I.; Vanmaekelbergh, D. |
| Title |
Cuboidal supraparticles self-assembled from cubic CsPbBr3 perovskite nanocrystals |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
| Volume |
122 |
Issue |
122 |
Pages |
15706-15712 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Colloidal CsPbBr3 nanocrystals (NCs) have emerged as promising candidates for various opto-electronic applications, such as light-emitting diodes, photodetectors, and solar cells. Here, we report on the self-assembly of cubic NCs from an organic suspension into ordered cuboidal supraparticles (SPs) and their structural and optical properties. Upon increasing the NC concentration or by addition of a nonsolvent, the formation of the SPs occurs homogeneously in the suspension, as monitored by in situ X-ray scattering measurements. The three-dimensional structure of the SPs was resolved through high-angle annular dark-field scanning transmission electron microscopy and electron tomography. The NCs are atomically aligned but not connected. We characterize NC vacancies on superlattice positions both in the bulk and on the surface of the SPs. The occurrence of localized atomic-type NC vacancies-instead of delocalized ones-indicates that NC-NC attractions are important in the assembly, as we verify with Monte Carlo simulations. Even when assembled in SPs, the NCs show bright emission, with a red shift of about 30 meV compared to NCs in suspension. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000439003600071 |
Publication Date |
2018-06-14 |
| 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 |
60 |
Open Access |
OpenAccess |
| Notes |
; The authors thank Dr. Rajeev Dattani and Jacques Gorini from the ID02 beamline of the ESRF for their excellent assistance during the X-ray scattering experiments. We also thank Carlo van Overbeek, P. Tim Prins, and Federico Montanarella for their support during the synchrotron experiments. The authors gratefully acknowledge Prof. Dr. Alfons van Blaaderen for fruitful discussions. D.V. acknowledges funding from NWO-CW TOPPUNT “Superficial superstructures.” J.J.G. acknowledges the joint Debye and ESRF graduate programs for the financial support. H.V. gratefully acknowledges the financial support by the Flemish Fund for Scientific Research (FWO grant 1S32617NN). S.B. acknowledges the financial support from the European Research Council (ERC Starting grant # 335078-COLOURATOMS). Y.Z. acknowledges the financial support from the European Union's Horizon 2020 research and innovation program, under the Marie Sklodowska-Curie grant agreement #665501 through a FWO [PEGASUS]2 Marie Sklodowska-Curie fellowship (12U4917N). W.A. acknowledges the financial support from the European Research Council under the European Unions Seventh Framework Program (FP-2007-2013)/ERC Advanced grant agreement 291667 HierarSACol. ; ecas_Sara |
Approved |
Most recent IF: 4.536 |
| Call Number |
UA @ lucian @ c:irua:153161UA @ admin @ c:irua:153161 |
Serial |
5087 |
| Permanent link to this record |
| |
|
| |
| Author |
Van den Hoek, J.; Daems, N.; Arnouts, S.; Hoekx, S.; Bals, S.; Breugelmans, T. |
| Title |
Improving stability of CO₂ electroreduction by incorporating Ag NPs in N-doped ordered mesoporous carbon structures |
Type |
A1 Journal article |
| Year |
2024 |
Publication |
ACS applied materials and interfaces |
Abbreviated Journal |
|
| Volume |
16 |
Issue |
6 |
Pages |
6931-6947 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) |
| Abstract |
The electroreduction of carbon dioxide (eCO2RR) to CO using Ag nanoparticles as an electrocatalyst is promising as an industrial carbon capture and utilization (CCU) technique to mitigate CO2 emissions. Nevertheless, the long-term stability of these Ag nanoparticles has been insufficient despite initial high Faradaic efficiencies and/or partial current densities. To improve the stability, we evaluated an up-scalable and easily tunable synthesis route to deposit low-weight percentages of Ag nanoparticles (NPs) on and into the framework of a nitrogen-doped ordered mesoporous carbon (NOMC) structure. By exploiting this so-called nanoparticle confinement strategy, the nanoparticle mobility under operation is strongly reduced. As a result, particle detachment and agglomeration, two of the most pronounced electrocatalytic degradation mechanisms, are (partially) blocked and catalyst durability is improved. Several synthesis parameters, such as the anchoring agent, the weight percentage of Ag NPs, and the type of carbonaceous support material, were modified in a controlled manner to evaluate their respective impact on the overall electrochemical performance, with a strong emphasis on operational stability. The resulting powders were evaluated through electrochemical and physicochemical characterization methods, including X-ray diffraction (XRD), N2-physisorption, Inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (SEM), SEM-energy-dispersive X-ray spectroscopy (SEM-EDS), high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), STEM-EDS, electron tomography, and X-ray photoelectron spectroscopy (XPS). The optimized Ag/soft-NOMC catalysts showed both a promising selectivity (∼80%) and stability compared with commercial Ag NPs while decreasing the loading of the transition metal by more than 50%. The stability of both the 5 and 10 wt % Ag/soft-NOMC catalysts showed considerable improvements by anchoring the Ag NPs on and into a NOMC framework, resulting in a 267% improvement in CO selectivity after 72 h (despite initial losses) compared to commercial Ag NPs. These results demonstrate the promising strategy of anchoring Ag NPs to improve the CO selectivity during prolonged experiments due to the reduced mobility of the Ag NPs and thus enhanced stability. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
001158812100001 |
Publication Date |
2023-12-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1944-8244 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
9.5 |
Times cited |
|
Open Access |
Not_Open_Access: Available from 21.06.2024 |
| Notes |
|
Approved |
Most recent IF: 9.5; 2024 IF: 7.504 |
| Call Number |
UA @ admin @ c:irua:202309 |
Serial |
9045 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Heuvel, W.; Tikhomirov, V.K.; Kirilenko, D.; Schildermans, N.; Chibotaru, L.F.; Vanacken, J.; Gredin, P.; Mortier, M.; Van Tendeloo, G.; Moshchalkov, V.V. |
| Title |
Ultralow blocking temperature and breakdown of the giant spin model in Er3+-doped nanoparticles |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
9 |
Pages |
094421-094421,8 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The magnetization of luminescent Er3+-doped PbF2 nanoparticles (formula Er0.3Pb0.7F2.3) has been studied. Despite the high concentration of the doping Er3+ ions and relatively large size (8 nm) of these nanoparticles we have found no deviation between field-cooled and zero-field-cooled magnetization curves down to T=0.35 K, which points out an ultralow blocking temperature for the reversal of magnetization. We also have found strongly deviating magnetization curves M(H/T) for different temperatures T. These results altogether show that the investigated nanoparticles are not superparamagnetic, but rather each Er3+ ion in these nanoparticles is found in a paramagnetic state down to very low temperatures, which implies the breakdown of the Néel-Brown giant spin model in the case of these nanoparticles. Calculations of magnetization within a paramagnetic model of noninteracting Er3+ ions completely support this conclusion. Due to the ultralow blocking temperature, these nanoparticles have a potential for magnetic field-induced nanoscale refrigeration with an option of their optical localization and temperature control. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000281773300005 |
Publication Date |
2010-09-13 |
| 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 |
11 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:85423 |
Serial |
3796 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Broek, W.; Verbeeck, J.; Schryvers, D.; de Backer, S.; Scheunders, P. |
| Title |
Tomographic spectroscopic imaging; an experimental proof of concept |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
109 |
Issue |
4 |
Pages |
296-303 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
Recording the electron energy loss spectroscopy data cube with a series of energy filtered images is a dose inefficient process because the energy slit blocks most of the electrons. When recording the data cube by scanning an electron probe over the sample, perfect dose efficiency is attained; but due to the low current in nanoprobes, this often is slower, with a smaller field of view. In W. Van den Broek et al. [Ultramicroscopy, 106 (2006) 269], we proposed a new method to record the data cube, which is more dose efficient than an energy filtered series. It produces a set of projections of the data cube and then tomographically reconstructs it. In this article, we demonstrate these projections in practice, we present a simple geometrical model that allows for quantification of the projection angles and we present the first successful experimental reconstruction, all on a standard post-column instrument. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000265345400003 |
Publication Date |
2008-12-10 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
1 |
Open Access |
|
| Notes |
Esteem 026019 |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
| Call Number |
UA @ lucian @ c:irua:77271 |
Serial |
3671 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Broek, W.; Verbeeck, J.; de Backer, S.; Scheunders, P.; Schryvers, D. |
| Title |
Acquisition of the EELS data cube by tomographic reconstruction |
Type |
A1 Journal article |
| Year |
2006 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
106 |
Issue |
4/5 |
Pages |
269-276 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
Energy filtered TEM, EFTEM, provides three-dimensional data, two spatial and one spectral dimension. We propose to acquire these data by measuring a series of images with a defocused energy filter. It will be shown that each image is a projection of the data on the detector and that reconstruction of the data out of a sufficient number of such projections using a tomographic reconstruction algorithm is possible. This technique uses only a fraction of the electron dose an energy filtered series (EFS) needs for the same spectral and spatial resolution and the same mean signal-to-noise ratio. (c) 2005 Elsevier B.V. All rights reserved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000236042300003 |
Publication Date |
2005-11-30 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
6 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.843; 2006 IF: 1.706 |
| Call Number |
UA @ lucian @ c:irua:56910UA @ admin @ c:irua:56910 |
Serial |
55 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Broek, W.; Van Aert, S.; van Dyck, D. |
| Title |
Fully automated measurement of the modulation transfer function of charge-coupled devices above the Nyquist frequency |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Microscopy and microanalysis |
Abbreviated Journal |
Microsc Microanal |
| Volume |
18 |
Issue |
2 |
Pages |
336-342 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
The charge-coupled devices used in electron microscopy are coated with a scintillating crystal that gives rise to a severe modulation transfer function (MTF). Exact knowledge of the MTF is imperative for a good correspondence between image simulation and experiment. We present a practical method to measure the MTF above the Nyquist frequency from the beam blocker's shadow image. The image processing has been fully automated and the program is made public. The method is successfully tested on three cameras with various beam blocker shapes. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Cambridge, Mass. |
Editor |
|
| Language |
|
Wos |
000302084700011 |
Publication Date |
2012-02-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1431-9276;1435-8115; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.891 |
Times cited |
15 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 1.891; 2012 IF: 2.495 |
| Call Number |
UA @ lucian @ c:irua:96557 |
Serial |
1297 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Broek, W.; Van Aert, S.; van Dyck, D. |
| Title |
A model based atomic resolution tomographic algorithm |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
109 |
Issue |
12 |
Pages |
1485-1490 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
Tomography with high angular annular dark field scanning transmission electron microscopy at atomic resolution can be greatly improved if one is able to take advantage of prior knowledge. In this paper we present a reconstruction technique that explicitly takes into account the microscope parameters and the atomic nature of the projected object. This results in a more accurate estimate of the atomic positions and in a good resistance to noise. The reconstruction is a maximum likelihood estimator of the object. Moreover, the limits to the precision have been explored, allowing for a prediction of the amount of expected noise in the reconstruction for a certain experimental setup. We believe that the proposed reconstruction technique can be generalized to other tomographic experiments. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000271840200010 |
Publication Date |
2009-08-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
17 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
| Call Number |
UA @ lucian @ c:irua:78588 |
Serial |
2097 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Broek, W.; Van Aert, S.; van Dyck, D. |
| Title |
A model based reconstruction technique for depth sectioning with scanning transmission electron microscopy |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
110 |
Issue |
5 |
Pages |
548-554 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
Depth sectioning in high angular annular dark field scanning transmission electron microscopy is considered a candidate for three-dimensional characterization on the atomic scale. However at present the depth resolution is still far from the atomic level, due to strong limitations in the opening angle of the beam. In this paper we introduce a new, parameter based tomographic reconstruction algorithm that allows to make maximal use of the prior knowledge about the constituent atom types and the microscope settings, so as to retrieve the atomic positions and push the resolution to the atomic level in all three dimensions. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000279065700022 |
Publication Date |
2009-09-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
16 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2010 IF: 2.063 |
| Call Number |
UA @ lucian @ c:irua:83690 |
Serial |
2104 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Broek, W.; Van Aert, S.; Goos, P.; van Dyck, D. |
| Title |
Throughput maximization of particle radius measurements by balancing size and current of the electron probe |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
111 |
Issue |
7 |
Pages |
940-947 |
| Keywords |
A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
In thispaperweinvestigatewhichprobesizemaximizesthethroughputwhenmeasuringtheradiusof nanoparticlesinhighangleannulardarkfieldscanningtransmissionelectronmicroscopy(HAADFSTEM). The sizeandthecorrespondingcurrentoftheelectronprobedeterminetheprecisionoftheestimateofa particlesradius.Maximizingthroughputmeansthatamaximumnumberofparticlesshouldbeimaged withinagiventimeframe,sothataprespecifiedprecisionisattained.WeshowthatBayesianstatistical experimentaldesignisaveryusefulapproachtodeterminetheoptimalprobesizeusingacertainamount of priorknowledgeaboutthesample.Thedependenceoftheoptimalprobesizeonthedetectorgeometry and thediameter,variabilityandatomicnumberoftheparticlesisinvestigated.Anexpressionforthe optimalprobesizeintheabsenceofanykindofpriorknowledgeaboutthespecimenisderivedaswell. |
| Address |
|
| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000300461000026 |
Publication Date |
2010-11-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
7 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.843; 2011 IF: 2.471 |
| Call Number |
UA @ lucian @ c:irua:89657 |
Serial |
3659 |
| Permanent link to this record |
| |
|
| |
| Author |
Van den Broek, W.; Rosenauer, A.; Van Aert, S.; Sijbers, J.; van Dyck, D. |
| Title |
A memory efficient method for fully three-dimensional object reconstruction with HAADF STEM |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
141 |
Issue |
|
Pages |
22-31 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
The conventional approach to object reconstruction through electron tomography is to reduce the three-dimensional problem to a series of independent two-dimensional slice-by-slice reconstructions. However, at atomic resolution the image of a single atom extends over many such slices and incorporating this image as prior knowledge in tomography or depth sectioning therefore requires a fully three-dimensional treatment. Unfortunately, the size of the three-dimensional projection operator scales highly unfavorably with object size and readily exceeds the available computer memory. In this paper, it is shown that for incoherent image formation the memory requirement can be reduced to the fundamental lower limit of the object size, both for tomography and depth sectioning. Furthermore, it is shown through multislice calculations that high angle annular dark field scanning transmission electron microscopy can be sufficiently incoherent for the reconstruction of single element nanocrystals, but that dynamical diffraction effects can cause classification problems if more than one element is present. (C) 2014 Elsevier B.V. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000335766600004 |
Publication Date |
2014-03-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
6 |
Open Access |
|
| Notes |
ResearchFoundationFlanders(FWO;G.0393.11; G.0064.10;andG.0374.13); European Union Seventh Frame- workProgramme [FP7/2007-2013]under Grant agreement no. 312483 (ESTEEM2).; esteem2jra2; esteem2jra4 |
Approved |
Most recent IF: 2.843; 2014 IF: 2.436 |
| Call Number |
UA @ lucian @ c:irua:117650 |
Serial |
1992 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Broek, W.; Rosenauer, A.; Goris, B.; Martinez, G.T.; Bals, S.; Van Aert, S.; van Dyck, D. |
| Title |
Correction of non-linear thickness effects in HAADF STEM electron tomography |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
116 |
Issue |
|
Pages |
8-12 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
In materials science, high angle annular dark field scanning transmission electron microscopy is often used for tomography at the nanometer scale. In this work, it is shown that a thickness dependent, non-linear damping of the recorded intensities occurs. This results in an underestimated intensity in the interior of reconstructions of homogeneous particles, which is known as the cupping artifact. In this paper, this non-linear effect is demonstrated in experimental images taken under common conditions and is reproduced with a numerical simulation. Furthermore, an analytical derivation shows that these non-linearities can be inverted if the imaging is done quantitatively, thus preventing cupping in the reconstruction. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000304473700002 |
Publication Date |
2012-03-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
67 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
| Call Number |
UA @ lucian @ c:irua:96558 |
Serial |
518 |
| Permanent link to this record |
| |
|
| |
| Author |
Van den Broek, W.; Reed, B.W.; Béché, A.; Velazco, A.; Verbeeck, J.; Koch, C.T. |
| Title |
Various compressed sensing setups evaluated against Shannon sampling under constraint of constant illumination |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
IEEE transactions on computational imaging |
Abbreviated Journal |
|
| Volume |
5 |
Issue |
3 |
Pages |
502-514 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Under the constraint of constant illumination, an information criterion is formulated for the Fisher information that compressed sensing measurements in optical and transmission electron microscopy contain about the underlying parameters. Since this approach requires prior knowledge of the signal's support in the sparse basis, we develop a heuristic quantity, the detective quantum efficiency (DQE), that tracks this information criterion well without this knowledge. In this paper, it is shown that for the investigated choice of sensing matrices, and in the absence of read-out noise, i.e., with only Poisson noise present, compressed sensing does not raise the amount of Fisher information in the recordings above that of Shannon sampling. Furthermore, enabled by the DQE's analytical tractability, the experimental designs are optimized by finding out the optimal fraction of on pixels as a function of dose and read-out noise. Finally, we introduce a regularization and demonstrate, through simulations and experiment, that it yields reconstructions attaining minimum mean squared error at experimental settings predicted by the DQE as optimal. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000480352600013 |
Publication Date |
2019-01-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2333-9403 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.546 |
Times cited |
7 |
Open Access |
|
| Notes |
; This work was supported by the Hercules fund from the Flemish Government (Qu-Ant-EM microscope used for the experimental data). The work of W. Van den Broek was supported by the DFG under Grant BR 5095/2-1 (Compressed sensing in ptychography and transmission electron microscopy). The work of A. Beche, A. Velazco, and J. Verbeeck was supported by the FWO under Grant G093417N (Compressed sensing enabling low dose imaging in transmission electron microscopy). The work of Christoph T. Koch was supported by the DFG under Grant CRC 951. The associate editor coordinating the review of this manuscript and approving it for publication was Dr. Chrysanthe Preza. ; |
Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:161792 |
Serial |
5368 |
| Permanent link to this record |
| |
|
| |
| Author |
Van den Broek, W.; Jannis, D.; Verbeeck, J. |
| Title |
Convexity constraints on linear background models for electron energy-loss spectra |
Type |
A1 Journal Article |
| Year |
2023 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
254 |
Issue |
|
Pages |
113830 |
| Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
| Abstract |
In this paper convexity constraints are derived for a background model of electron energy loss spectra (EELS) that is linear in the fitting parameters. The model outperforms a power-law both on experimental and simulated backgrounds, especially for wide energy ranges, and thus improves elemental quantification results. Owing to the model’s linearity, the constraints can be imposed through fitting by quadratic programming. This has important advantages over conventional nonlinear power-law fitting such as high speed and a guaranteed unique solution without need for initial parameters. As such, the need for user input is significantly reduced, which is essential for unsupervised treatment of large datasets. This is demonstrated on a demanding spectrum image of a semiconductor device sample with a high number of elements over a wide energy range. |
| Address |
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| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
|
Publication Date |
2023-08-15 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record |
| Impact Factor |
2.2 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
ECSEL, 875999 ; Horizon 2020; Horizon 2020 Framework Programme; Electronic Components and Systems for European Leadership; |
Approved |
Most recent IF: 2.2; 2023 IF: 2.843 |
| Call Number |
EMAT @ emat @c:irua:200588 |
Serial |
8961 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Broek, M.; Peeters, F.M. |
| Title |
Confined states in two-dimensional flat elliptic quantum dots and elliptic quantum wires |
Type |
A1 Journal article |
| Year |
2001 |
Publication |
Physica. E: Low-dimensional systems and nanostructures |
Abbreviated Journal |
Physica E |
| Volume |
11 |
Issue |
|
Pages |
345-355 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
North-Holland |
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000173201200007 |
Publication Date |
2002-07-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1386-9477; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.221 |
Times cited |
54 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.221; 2001 IF: 1.009 |
| Call Number |
UA @ lucian @ c:irua:37307 |
Serial |
486 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Broek, B.; Houssa, M.; Scalise, E.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A. |
| Title |
First-principles electronic functionalization of silicene and germanene by adatom chemisorption |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Applied surface science |
Abbreviated Journal |
Appl Surf Sci |
| Volume |
291 |
Issue |
|
Pages |
104-108 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
This study presents first-principles results on the electronic functionalization of silicene and germanene monolayers by means of chemisorption of adatom species H, Li, F, Sc, Ti, V. Three general adatom-monolayer configurations are considered, each having its distinct effect on the electronic structure, yielding metallic or semiconducting dispersions depending on the adatom species and configuration. The induced bandgap is a (in)direct F gap ranging from 0.2 to 2.3 eV for both silicene and germanene. In general the alternating configuration was found to be the most energetically stable. The boatlike and chairlike conformers are degenerate with the former having anisotropic effective carrier masses. The top configuration leads to the planar monolayer and predominately to a gapped dispersion. The hollow configuration with V adatoms retains the Dirac cone, but with strong orbital planar hybridization at the Fermi level. We also observe a planar surface state the Fermi level for the latter systems. (C) 2013 Elsevier B.V. All rights reserved. |
| Address |
|
| Corporate Author |
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Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000329327700023 |
Publication Date |
2013-09-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0169-4332; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.387 |
Times cited |
32 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.387; 2014 IF: 2.711 |
| Call Number |
UA @ lucian @ c:irua:113766 |
Serial |
1208 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Broek, B.; Houssa, M.; Scalise, E.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A. |
| Title |
Two-dimensional hexagonal tin : ab initio geometry, stability, electronic structure and functionalization |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
| Volume |
1 |
Issue |
|
Pages |
021004 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
We study the structural, mechanical and electronic properties of the two-dimensional (2D) allotrope of tin: tinene/stanene using first-principles calculation within density functional theory, implemented in a set of computer codes. Continuing the trend of the group-IV 2D materials graphene, silicene and germanene; tinene is predicted to have a honeycomb lattice with lattice parameter of a(0) = 4.62 angstrom and a buckling of d(0) = 0.92 angstrom. The electronic dispersion shows a Dirac cone with zero gap at the Fermi energy and a Fermi velocity of v(F) = 0.97 x 10(6) m s(-1); including spin-orbit coupling yields a bandgap of 0.10 eV. The monolayer is thermally stable up to 700 K, as indicated by first-principles molecular dynamics, and has a phonon dispersion without imaginary frequencies. We explore applied electric field and applied strain as functionalization mechanisms. Combining these two mechanisms allows for an induced bandgap up to 0.21 eV, whilst retaining the linear dispersion, albeit with degraded electronic transport parameters. |
| Address |
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| Corporate Author |
|
Thesis |
|
| Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000353650400004 |
Publication Date |
2014-08-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.937 |
Times cited |
58 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 6.937; 2014 IF: NA |
| Call Number |
UA @ lucian @ c:irua:134432 |
Serial |
4530 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Broek, B.; Houssa, M.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A. |
| Title |
Current-voltage characteristics of armchair Sn nanoribbons |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Physica status solidi: rapid research letters |
Abbreviated Journal |
Phys Status Solidi-R |
| Volume |
8 |
Issue |
11 |
Pages |
931-934 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
Two-dimensional group-IV lattices silicene and germanene are known to share many of graphene's remarkable mechanical and electronic properties. Due to the out-of-plane buckling of the former materials, there are more means of electronic funtionalization, e.g. by applying uniaxial strain or an out-of-plane electric field. We consider monolayer hexagonal Sn (stanene) as an ideal candidate to feasibly implement and exploit graphene physics for nanoelectronic applications: with increased out-of-plane buckling and sizable spin-orbit coupling it lends itself to improved Dirac cone engineering. We investigate the ballistic charge transport regime of armchair Sn nanoribbons, classified according to the ribbon width W = {3m – 1, 3m, 3m + 1} with integer m. We study transport through (non-magnetic) armchair ribbons using a combination of density functional theory and non-equilibrium Green's functions. Sn ribbons have earlier current onsets and carry currents 20% larger than C/Si/Ge-nanoribbons as the contact resistance of these ribbons is found to be comparable. ((c) 2014 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim) |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Berlin |
Editor |
|
| Language |
|
Wos |
000345274300009 |
Publication Date |
2014-09-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1862-6254; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.032 |
Times cited |
9 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.032; 2014 IF: 2.142 |
| Call Number |
UA @ lucian @ c:irua:122148 |
Serial |
594 |
| Permanent link to this record |
