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Author | Milovanovic, S.P.; Masir, M.R.; Peeters, F.M. | ||||
Title | Graphene hall bar with an asymmetric pn-junction | Type | A1 Journal article | ||
Year | 2013 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 113 | Issue | 19 | Pages | 193701-193708 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We investigated the magnetic field dependence of the Hall and the bend resistances in the ballistic regime for a single layer graphene Hall bar structure containing a pn-junction. When both regions are n-type the Hall resistance dominates and Hall type of plateaus are formed. These plateaus occur as a consequence of the restriction on the angle imposed by Snell's law allowing only electrons with a certain initial angles to transmit though the potential step. The size of the plateau and its position is determined by the position of the potential interface as well as the value of the applied potential. When the second region is p-type, the bend resistance dominates, which is asymmetric in field due to the presence of snake states. Changing the position of the pn-interface in the Hall bar strongly affects these states and therefore the bend resistance is also changed. Changing the applied potential, we observe that the bend resistance exhibits a peak around the charge-neutrality point (CNP), which is independent of the position of the pn-interface, while the Hall resistance shows a sign reversal when the CNP is crossed, which is in very good agreement with a recent experiment [J. R. Williams and C. M. Marcus, Phys. Rev. Lett. 107, 046602 (2011)]. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000319295200022 | Publication Date | 2013-05-16 | |
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 | 7 | Open Access | |
Notes ![]() |
This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, and the Methusalem Foundation of the Flemish government. We acknowledge fruitful discussions with M. Barbier. | Approved | Most recent IF: 2.068; 2013 IF: 2.185 | ||
Call Number | UA @ lucian @ c:irua:108999 | Serial | 1371 | ||
Permanent link to this record | |||||
Author | Milovanovic, S.P.; Masir, M.R.; Peeters, F.M. | ||||
Title | Bilayer graphene Hall bar with a pn-junction | Type | A1 Journal article | ||
Year | 2013 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 114 | Issue | 11 | Pages | 113706 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We investigate the magnetic field dependence of the Hall and the bend resistances for a ballistic Hall bar structure containing a pn-junction sculptured from a bilayer of graphene. The electric response is obtained using the billiard model, and we investigate the cases of bilayer graphene with and without a band gap. Two different conduction regimes are possible: (i) both sides of the junction have the same carrier type and (ii) one side of the junction is n-type while the other one is p-type. The first case shows Hall plateau-like features in the Hall resistance that fade away as the band gap opens. The second case exhibits a bend resistance that is asymmetric in magnetic field as a consequence of snake states along the pn-interface, where the maximum is shifted away from zero magnetic field. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000324827200031 | Publication Date | 2013-09-17 | |
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 | 3 | Open Access | |
Notes ![]() |
This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, and the Methusalem Foundation of the Flemish government. | Approved | Most recent IF: 2.068; 2013 IF: 2.185 | ||
Call Number | UA @ lucian @ c:irua:111169 | Serial | 234 | ||
Permanent link to this record | |||||
Author | Milovanović, S.P.; Moldovan, D.; Peeters, F.M. | ||||
Title | Veselago lensing in graphene with a p-n junction: Classical versus quantum effects | Type | A1 Journal article | ||
Year | 2015 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 118 | Issue | 118 | Pages | 154308 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The feasibility of Veselago lensing in graphene with a p-n junction is investigated numerically for realistic injection leads. Two different set-ups with two narrow leads are considered with absorbing or reflecting side edges. This allows us to separately determine the influence of scattering on electron focusing for the edges and the p-n interface. Both semiclassical and tight-binding simulations show a distinctive peak in the transmission probability that is attributed to the Veselago lensing effect. We investigate the robustness of this peak on the width of the injector, the position of the p-n interface, and different gate potential profiles. Furthermore, the influence of scattering by both short- and long-range impurities is considered. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000363535800022 | Publication Date | 2015-10-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-8979;1089-7550; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 19 | Open Access | |
Notes ![]() |
This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, and the Methusalem Foundation of the Flemish government. | Approved | Most recent IF: 2.068; 2015 IF: 2.183 | ||
Call Number | c:irua:129452 | Serial | 3969 | ||
Permanent link to this record | |||||
Author | Milovanović, S.P.; Masir, M.R.; Peeters, F.M. | ||||
Title | Magnetic electron focusing and tuning of the electron current with a pn-junction | Type | A1 Journal article | ||
Year | 2014 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 115 | Issue | 4 | Pages | 043719-6 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Transverse magnetic focusing properties of graphene using a ballistic four terminal structure are investigated. The electric response is obtained using the semiclassical billiard model. The transmission exhibits pronounced peaks as a consequence of skipping orbits at the edge of the structure. When we add a pn-junction between the two probes, snake states along the pn-interface appear. Injected electrons are guided by the pn-interface to one of the leads depending on the value of the applied magnetic field. Oscillations in the resistance are found depending on the amount of particles that end up in each lead. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000331210800066 | Publication Date | 2014-01-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-8979;1089-7550; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 21 | Open Access | |
Notes ![]() |
This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, and the Methusalem Foundation of the Flemish government. | Approved | Most recent IF: 2.068; 2014 IF: 2.183 | ||
Call Number | UA @ lucian @ c:irua:115801 | Serial | 1866 | ||
Permanent link to this record | |||||
Author | Milovanović, S.P.; Masir, M.R.; Peeters, F.M. | ||||
Title | Interplay between snake and quantum edge states in a graphene Hall bar with a pn-junction | Type | A1 Journal article | ||
Year | 2014 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 105 | Issue | 12 | Pages | 123507 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The magneto- and Hall resistance of a locally gated cross shaped graphene Hall bar is calculated. The edge of the top gate is placed diagonally across the center of the Hall cross. Four-probe resistance is calculated using the Landauer-Büttiker formalism, while the transmission coefficients are obtained using the non-equilibrium Green's function approach. The interplay between transport due to edge channels and snake states is investigated. When two edge channels are occupied, we predict oscillations in the Hall and the bend resistance as function of the magnetic field, which are a consequence of quantum interference between the occupied snake states. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000343004400090 | Publication Date | 2014-09-27 | |
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 | 18 | Open Access | |
Notes ![]() |
This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN and the Methusalem Foundation of the Flemish government. | Approved | Most recent IF: 3.411; 2014 IF: 3.302 | ||
Call Number | UA @ lucian @ c:irua:121119 | Serial | 1704 | ||
Permanent link to this record | |||||
Author | Milovanović, S.P.; Masir, M.R.; Peeters, F.M. | ||||
Title | Spectroscopy of snake states using a graphene Hall bar | Type | A1 Journal article | ||
Year | 2013 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 103 | Issue | 23 | Pages | 233502-233504 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | An approach to observe snake states in a graphene Hall bar containing a pn-junction is proposed. The magnetic field dependence of the bend resistance in a ballistic graphene Hall bar structure containing a tilted pn-junction oscillates as a function of applied magnetic field. We show that each oscillation is due to a specific snake state that moves along the pn-interface. Furthermore, depending on the value of the magnetic field and applied potential, we can control the lead in which the electrons will end up and hence control the response of the system. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000328634900090 | Publication Date | 2013-12-03 | |
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 | 15 | Open Access | |
Notes ![]() |
This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN and the Methusalem Foundation of the Flemish government. | Approved | Most recent IF: 3.411; 2013 IF: 3.515 | ||
Call Number | UA @ lucian @ c:irua:113710 | Serial | 3074 | ||
Permanent link to this record | |||||
Author | Masir, M.R.; Moldovan, D.; Peeters, F.M. | ||||
Title | Pseudo magnetic field in strained graphene : revisited | Type | A1 Journal article | ||
Year | 2013 | Publication | Solid state communications | Abbreviated Journal | Solid State Commun |
Volume | 175 | Issue | Pages | 76-82 | |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We revisit the theory of the pseudo magnetic field as induced by strain in graphene using the tight- binding approach. A systematic expansion of the hopping parameter and the deformation of the lattice vectors is presented from which we obtain an expression for the pseudo magnetic field for low energy electrons. We generalize and discuss previous results and propose a novel effective Hamiltonian. The contributions of the different terms to the pseudo field expression are investigated for a model triaxial strain profile and are compared with the full solution. Our work suggests that the previous proposed pseudo magnetic field expression is valid up to reasonably high strain (15%) and there is no K-dependent pseudo-magnetic field. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | New York, N.Y. | Editor | ||
Language | Wos | 000329538200010 | Publication Date | 2013-04-06 | |
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 | 57 | Open Access | |
Notes ![]() |
This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EURO- CORES Program EuroGRAPHENE within the project CONGRAN and the Methusalem programme of the Flemish government. | Approved | Most recent IF: 1.554; 2013 IF: 1.698 | ||
Call Number | UA @ lucian @ c:irua:114805 | Serial | 2737 | ||
Permanent link to this record | |||||
Author | Muñoz, W.A.; Covaci, L.; Peeters, F.M. | ||||
Title | Superconducting current and proximity effect in ABA and ABC multilayer graphene Josephson junctions | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 88 | Issue | 88 | Pages | 214502 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Using a numerical tight-binding approach based on the Chebyshev–Bogoliubov–de Gennes method we describe Josephson junctions made of multilayer graphene contacted by top superconducting gates. Both Bernal (ABA) and rhombohedral (ABC) stacking are considered and we find that the type of stacking has a strong effect on the proximity effect and the supercurrent flow. For both cases the pair amplitude shows a polarization between dimer and nondimer atoms, being more pronounced for rhombohedral stacking. Even though the proximity effect in nondimer sites is enhanced when compared to single-layer graphene, we find that the supercurrent is suppressed. The spatial distribution of the supercurrent shows that for Bernal stacking the current flows only in the topmost layers while for rhombohedral stacking the current flows throughout the whole structure. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000328569900004 | Publication Date | 2013-12-02 | |
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 | 4 | Open Access | |
Notes ![]() |
This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem funding of the Flemish Government | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | CMT @ cmt @ c:irua:128896 | Serial | 3962 | ||
Permanent link to this record | |||||
Author | Milovanovic, S.P.; Peeters, F.M. | ||||
Title | Characterization of the size and position of electron-hole puddles at a graphene p-n junction | Type | A1 Journal article | ||
Year | 2016 | Publication | Nanotechnology | Abbreviated Journal | Nanotechnology |
Volume | 27 | Issue | 27 | Pages | 105203 |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | The effect of an electron-hole puddle on the electrical transport when governed by snake states in a bipolar graphene structure is investigated. Using numerical simulations we show that information on the size and position of the electron-hole puddle can be obtained using the dependence of the conductance on magnetic field and electron density of the gated region. The presence of the scatterer disrupts snake state transport which alters the conduction pattern. We obtain a simple analytical formula that connects the position of the electron-hole puddle with features observed in the conductance. The size of the electron-hole puddle is estimated from the magnetic field and gate potential that maximizes the effect of the puddle on the electrical transport. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000369849200003 | Publication Date | 2016-02-11 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0957-4484 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.44 | Times cited | 3 | 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 within the project CONGRAN. We acknowledge interesting correspondence with Thiti Taychatanapat. | Approved | Most recent IF: 3.44 | ||
Call Number | c:irua:131907 | Serial | 4025 | ||
Permanent link to this record | |||||
Author | Leenaerts, O.; Partoens, B.; Peeters, F.M. | ||||
Title | Graphene: a perfect nanoballoon | Type | A1 Journal article | ||
Year | 2008 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 93 | Issue | 19 | Pages | 193107,1-193107,3 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We have performed a first-principles density functional theory investigation of the penetration of helium atoms through a graphene monolayer with defects. The relaxation of the graphene layer caused by the incoming helium atoms does not have a strong influence on the height of the energy barriers for penetration. For defective graphene layers, the penetration barriers decrease exponentially with the size of the defects but they are still sufficiently high that very large defects are needed to make the graphene sheet permeable for small atoms and molecules. This makes graphene a very promising material for the construction of nanocages and nanomembranes. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000260944100090 | Publication Date | 2008-11-12 | |
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 | 295 | Open Access | |
Notes ![]() |
This work was supported by the Flemish Science Foundation (FWO-Vl), the NOI-BOF of the University of Antwerp, and the Belgian Science Policy (IAP). | Approved | Most recent IF: 3.411; 2008 IF: 3.726 | ||
Call Number | UA @ lucian @ c:irua:73196 | Serial | 1368 | ||
Permanent link to this record | |||||
Author | Leenaerts, O.; Partoens, B.; Peeters, F.M. | ||||
Title | Adsorption of H2O, NH3, CO, NO2, and NO on graphene: a first-principles study | Type | A1 Journal article | ||
Year | 2008 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 77 | Issue | Pages | 125416,1-6 | |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Motivated by the recent realization of graphene sensors to detect individual gas molecules, we investigate the adsorption of H2O, NH3, CO, NO2, and NO on a graphene substrate using first-principles calculations. The optimal adsorption position and orientation of these molecules on the graphene surface is determined and the adsorption energies are calculated. Molecular doping, i.e., charge transfer between the molecules and the graphene surface, is discussed in light of the density of states and the molecular orbitals of the adsorbates. The efficiency of doping of the different molecules is determined and the influence of their magnetic moment is discussed. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000254543000133 | Publication Date | 2008-03-18 | |
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 | 1392 | Open Access | |
Notes ![]() |
This work was supported by the Flemish Science Foundation FWO-Vl, by the NOI-BOF of the University of Antwerp, and by the Belgian Science Policy IAP. | Approved | Most recent IF: 3.836; 2008 IF: 3.322 | ||
Call Number | UA @ lucian @ c:irua:69634 | Serial | 67 | ||
Permanent link to this record | |||||
Author | Leenaerts, O.; Partoens, B.; Peeters, F.M. | ||||
Title | Paramagnetic adsorbates on graphene: a charge transfer analysis | Type | A1 Journal article | ||
Year | 2008 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 92 | Issue | 24 | Pages | 243125,1-3 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We introduce a modified version of the Hirshfeld charge analysis method and demonstrate its accurateness by calculating the charge transfer between the paramagnetic molecule NO2 and graphene. The charge transfer between paramagnetic molecules and a graphene layer as calculated with ab initio methods can crucially depend on the size of the supercell used in the calculation. This has important consequences for adsorption studies involving paramagnetic molecules such as NO2 physisorbed on graphene or on carbon nanotubes. © 2008 American Institute of Physics. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000256934900099 | Publication Date | 2008-06-24 | |
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 | 79 | Open Access | |
Notes ![]() |
This work was supported by the Flemish Science Foundation (FWO-Vl), the NOI-BOF of the University of Antwerp, and the Belgian Science Policy (IAP). Discussions with C. Van Alsenoy are gratefully acknowledged. | Approved | Most recent IF: 3.411; 2008 IF: 3.726 | ||
Call Number | UA @ lucian @ c:irua:69619 | Serial | 2552 | ||
Permanent link to this record | |||||
Author | Aierken, Y.; Çakır, D.; Sevik, C.; Peeters, F.M. | ||||
Title | Thermal properties of black and blue phosphorenes from a first-principles quasiharmonic approach | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 92 | Issue | 92 | Pages | 081408 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Different allotropes of phosphorene are possible of which black and blue phosphorus are the most stable. While blue phosphorus has isotropic properties, black phosphorus is strongly anisotropic in its electronic and optical properties due to its anisotropic crystal structure. In this work, we systematically investigated the lattice thermal properties of black and blue phosphorene by using first-principles calculations based on the quasiharmonic approximation approach. Similar to the optoelectronic and electronic properties, we predict that black phosphorene has highly anisotropic thermal properties, in contrast to the blue phase. The linear thermal expansion coefficients along the zigzag and armchair direction differ up to 20% in black phosphorene. The armchair direction of black phosphorene is more expandable as compared to the zigzag direction and the biaxial expansion of blue phosphorene under finite temperature. Our comparative analysis reveals that the inclusion of finite-temperature effects makes the blue phase thermodynamically more stable over the black phase above 135 K. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000359860700005 | Publication Date | 2015-08-19 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 124 | Open Access | |
Notes ![]() |
This work was supported by the Flemish Science Founda- tion (FWO-Vl) and the Methusalem foundation of the Flem- ish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Comput- ing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. C.S. acknowledges the support from Anadolu University (BAP-1407F335), and Turkish Academy of Sciences (TUBA-GEBIP). | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | c:irua:127754 | Serial | 4034 | ||
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Author | Pulinthanathu Sree, S.; Dendooven, J.; Geerts, L.; Ramachandran, R.K.; Javon, E.; Ceyssens, F.; Breynaert, E.; Kirschhock, C.E.A.; Puers, R.; Altantzis, T.; Van Tendeloo, G.; Bals, S.; Detavernier, C.; Martens, J.A. | ||||
Title | 3D porous nanostructured platinum prepared using atomic layer deposition | Type | A1 Journal article | ||
Year | 2017 | Publication | Journal of materials chemistry A : materials for energy and sustainability | Abbreviated Journal | J Mater Chem A |
Volume | 5 | Issue | 5 | Pages | 19007-19016 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | A robust and easy to handle 3D porous platinum structure was created via replicating the 3D channel system of an ordered mesoporous silica material using atomic layer deposition (ALD) over micrometer distances. After ALD of Pt in the silica material, the host template was digested using hydrogen fluoride (HF). A fully connected ordered Pt nanostructure was obtained with morphology and sizes corresponding to that of the pores of the host matrix, as revealed with high-resolution scanning transmission electron microscopy and electron tomography. The Pt nanostructure consisted of hexagonal Pt rods originating from the straight mesopores (11 nm) of the host structure and linking features resulting from Pt replication of the interconnecting mesopore segments (2–4 nm) present in the silica host structure. Electron tomography of partial replicas, made by incomplete infilling of Zeotile-4 material with Pt, provided insight in the connectivity and formation mechanism of the Pt nanostructure by ALD. The Pt replica was evaluated for its potential use as electrocatalyst for the hydrogen evolution reaction, one of the half-reactions of water electrolysis, and as microelectrode for biomedical sensing. The Pt replica showed high activity for the hydrogen evolution reaction and electrochemical characterization revealed a large impedance improvement in comparison with reference Pt electrodes. |
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000411232100010 | Publication Date | 2017-06-28 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2050-7488 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.867 | Times cited | 9 | Open Access | OpenAccess |
Notes ![]() |
This work was supported by the Flemish government through long-term structural funding (Methusalem) to JAM and FWO for a research project (G0A5417N). JD, TA and FC acknowledge Flemish FWO for a post-doctoral fellowship. S. B. acknowledges funding from ERC Starting Grant COLOURATOMS (335078). (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); saraecas; ECAS_Sara; | Approved | Most recent IF: 8.867 | ||
Call Number | EMAT @ emat @ c:irua:144624 c:irua:144624 c:irua:144624UA @ admin @ c:irua:144624 | Serial | 4634 | ||
Permanent link to this record | |||||
Author | Wolf, D.; Rodriguez, L.A.; Béché, A.; Javon, E.; Serrano, L.; Magen, C.; Gatel, C.; Lubk, A.; Lichte, H.; Bals, S.; Van Tendeloo, G.; Fernández-Pacheco, A.; De Teresa, J.M.; Snoeck, E. | ||||
Title | 3D Magnetic Induction Maps of Nanoscale Materials Revealed by Electron Holographic Tomography | Type | A1 Journal article | ||
Year | 2015 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
Volume | 27 | Issue | 27 | Pages | 6771-6778 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The investigation of three-dimensional (3D) ferromagnetic nanoscale materials constitutes one of the key research areas of the current magnetism roadmap, and carries great potential to impact areas such as data storage, sensing and biomagnetism. The properties of such nanostructures are closely connected with their 3D magnetic nanostructure, making their determination highly valuable. Up to now, quantitative 3D maps providing both the internal magnetic and electric configuration of the same specimen with high spatial resolution are missing. Here, we demonstrate the quantitative 3D reconstruction of the dominant axial component of the magnetic induction and electrostatic potential within a cobalt nanowire (NW) of 100 nm in diameter with spatial resolution below 10 nanometers by applying electron holographic tomography. The tomogram was obtained using a dedicated TEM sample holder for acquisition, in combination with advanced alignment and tomographic reconstruction routines. The powerful approach presented here is widely applicable to a broad range of 3D magnetic nanostructures and may trigger the progress of novel spintronic non-planar nanodevices. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000362920700037 | Publication Date | 2015-09-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756;1520-5002; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.466 | Times cited | 50 | Open Access | OpenAccess |
Notes ![]() |
This work was supported by the European Union under the Seventh Framework Program under a contract for an Inte-grated Infrastructure Initiative Reference 312483-ESTEEM2. S.B. and A.B. gratefully acknowledge funding by ERC Starting grants number 335078 COLOURATOMS and number 278510 VORTEX. AF-P acknowledges an EPSRC Early Career fellowship and support from the Winton Foundation. E.S., C.G. and L.A. R. acknowledge the French ANR program for support though the project EMMA.; esteem2jra4; ECASJO;; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); | Approved | Most recent IF: 9.466; 2015 IF: 8.354 | ||
Call Number | c:irua:129180 c:irua:129180 c:irua:129180 | Serial | 3950 | ||
Permanent link to this record | |||||
Author | Moldovan, D.; Peeters, F.M. | ||||
Title | Strain engineering of the electronic properties of bilayer graphene quantum dots: Strain engineering of the electronic properties of bilayer graphene quantum dots | Type | A1 Journal article | ||
Year | 2015 | Publication | Physica status solidi: rapid research letters | Abbreviated Journal | Phys Status Solidi-R |
Volume | 10 | Issue | 10 | Pages | 39-45 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We study the effect of mechanical deformations on the elec- tronic properties of hexagonal flakes of bilayer graphene. The behavior of electrons induced by triaxial strain can be de- scribed by an effective pseudo-magnetic field which is homo- geneous in the center of the flake. We find that in-plane strain, applied to both layers equally, can break the layer symmetry leading to different behavior in the top and bottom layers of graphene. At low energy, just one of the layers feels the pseudo-magnetic field: the zero-energy pseudo-Landau level is missing in the second layer, thus creating a gap be- tween the lowest non-zero levels. While the layer asymmetry is most significant at zero energy, interaction with the edges of the flake extends the effect to higher pseudo-Landau lev- els. The behavior of the top and bottom layers may be re- versed by rotating the triaxial strain by 60°. |
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000368814500005 | Publication Date | 2015-08-18 | |
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 ![]() |
This work was supported by the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-Vl) and the Methusalem Funding of the Flemish Government. | Approved | Most recent IF: 3.032; 2015 IF: 2.142 | ||
Call Number | c:irua:129592 | Serial | 3970 | ||
Permanent link to this record | |||||
Author | Moldovan, D.; Masir, M.R.; Covaci, L.; Peeters, F.M. | ||||
Title | Resonant valley filtering of massive Dirac electrons | Type | A1 Journal article | ||
Year | 2012 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 86 | Issue | 11 | Pages | 115431 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Electrons in graphene, in addition to their spin, have two pseudospin degrees of freedom: sublattice and valley pseudospin. Valleytronics uses the valley degree of freedom as a carrier of information similarly to the way spintronics uses electron spin. We show how a double-barrier structure consisting of electric and vector potentials can be used to filter massive Dirac electrons based on their valley index. We study the resonant transmission through a finite number of barriers and we obtain the energy spectrum of a superlattice consisting of electric and vector potentials. When a mass term is included, the energy bands and energy gaps at the K and K′ points are different and they can be tuned by changing the potential. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000309173300004 | Publication Date | 2012-09-21 | |
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 | 55 | Open Access | |
Notes ![]() |
This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro- GRAPHENE within the 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:101835 | Serial | 2896 | ||
Permanent link to this record | |||||
Author | Udayabhaskararao, T.; Altantzis, T.; Houben, L.; Coronado-Puchau, M.; Langer, J.; Popovitz-Biro, R.; Liz-Marzán, L.M.; Vuković, L.; Král, P.; Bals, S.; Klajn, R. | ||||
Title | Tunable porous nanoallotropes prepared by post-assembly etching of binary nanoparticle superlattices | Type | A1 Journal article | ||
Year | 2017 | Publication | Science | Abbreviated Journal | Science |
Volume | 358 | Issue | 358 | Pages | 514-518 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Self-assembly of inorganic nanoparticles has been used to prepare hundreds of different colloidal crystals, but almost invariably with the restriction that the particles must be densely packed. Here,we show that non–close-packed nanoparticle arrays can be fabricated through the selective removal of one of two components comprising binary nanoparticle superlattices. First, a variety of binary nanoparticle superlattices were prepared at the liquid-air interface, including several arrangements that were previously unknown. Molecular dynamics simulations revealed the particular role of the liquid in templating the formation of superlattices not achievable through self-assembly in bulk solution. Second, upon stabilization, all of these binary superlattices could be transformed into distinct “nanoallotropes”—nanoporous materials having the same chemical composition but differing in their nanoscale architectures. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000413757500043 | Publication Date | 2017-10-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0036-8075 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 37.205 | Times cited | 113 | Open Access | OpenAccess |
Notes ![]() |
This work was supported by the European Research Council (grants 336080 CONFINEDCHEM to R.K. and 335078 COLOURATOM to S.B.), the Rothschild Caesarea Foundation (R.K.), the NSF (Division of Materials Research, grant 1506886) (P.K.), the European Commission (grant EUSMI 731019 to L.M.L.-M. and S.B.), and the startup funding from the University of Texas at El Paso (L.V.). L.M.L.-M. acknowledges funding from the Spanish Ministerio de Economía y Competitividad (grant MAT2013- 46101-R). T.A. acknowledges funding from the Research Foundation Flanders (FWO, Belgium) through a postdoctoral grant. The computer support was provided by the Texas Advanced Computing Center. All data are reported in the main text and supplementary materials. ECAS_Sara (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); | Approved | Most recent IF: 37.205 | ||
Call Number | EMAT @ emat @c:irua:147242UA @ admin @ c:irua:147242 | Serial | 4770 | ||
Permanent link to this record | |||||
Author | Altantzis, T.; Wang, D.; Kadu, A.; van Blaaderen, A.; Bals, S. | ||||
Title | Optimized 3D Reconstruction of Large, Compact Assemblies of Metallic Nanoparticles | Type | A1 Journal article | ||
Year | 2021 | Publication | Journal Of Physical Chemistry C | Abbreviated Journal | J Phys Chem C |
Volume | 125 | Issue | 47 | Pages | 26240-26246 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | 3D characterization of assemblies of nanoparticles is of great importance to determine their structure-property connection. Such investigations become increasingly more challenging when the assemblies become larger and more compact. In this paper, we propose an optimized approach for electron tomography to minimize artefacts related to beam broadening in High Angle Annular Dark-Field Scanning Transmission Electron Microscopy mode. These artefacts are typically present at one side of the reconstructed 3D data set for thick nanoparticle assemblies. To overcome this problem, we propose a procedure in which two tomographic tilt series of the same sample are acquired. After acquiring the first series, the sample is flipped over 180o, and a second tilt series is acquired. By merging the two reconstructions, blurring in the reconstructed volume is minimized. Next, this approach is combined with an advanced three-dimensional reconstruction algorithm yielding quantitative structural information. Here, the approach is applied to a thick and compact assembly of spherical Au nanoparticles, but the methodology can we used to investigate a broad range of samples. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000752810100031 | Publication Date | 2021-12-02 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1932-7447 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.536 | Times cited | 4 | Open Access | OpenAccess |
Notes ![]() |
This work was supported by the European Research Council (grant No. 815128−REALNANO to S.B.). T.A. acknowledges the University of Antwerp Research fund (BOF). D.W. and A.v.B. acknowledge partial financial support from the European Research Council under the European Union’s Seventh Framework Program (FP-2007-2013)/ERC Advanced Grant Agreement 291667 HierarSACol. D.W. acknowledges an Individual Fellowship funded by the Marie Sklodowska-Curie Actions (MSCA) in Horizon 2020 program (grant 894254 SuprAtom).; sygmaSB | Approved | Most recent IF: 4.536 | ||
Call Number | EMAT @ emat @c:irua:185224 | Serial | 6904 | ||
Permanent link to this record | |||||
Author | Arslan Irmak, E.; Liu, P.; Bals, S.; Van Aert, S. | ||||
Title | 3D Atomic Structure of Supported Metallic Nanoparticles Estimated from 2D ADF STEM Images: A Combination of Atom – Counting and a Local Minima Search Algorithm | Type | A1 Journal article | ||
Year | 2021 | Publication | Small methods | Abbreviated Journal | Small Methods |
Volume | Issue | Pages | 2101150 | ||
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Determining the three-dimensional (3D) atomic structure of nanoparticles (NPs) is critical to understand their structure-dependent properties. It is hereby important to perform such analyses under conditions relevant for the envisioned application. Here, we investigate the 3D structure of supported Au NPs at high temperature, which is of importance to understand their behavior during catalytic reactions. To overcome limitations related to conventional high-resolution electron tomography at high temperature, 3D characterization of NPs with atomic resolution has been performed by applying atom-counting using atomic resolution annular darkfield scanning transmission electron microscopy (ADF STEM) images followed by structural relaxation. However, at high temperatures, thermal displacements, which affect the ADF STEM intensities, should be taken into account. Moreover, it is very likely that the structure of a NP investigated at elevated temperature deviates from a ground state configuration, which is difficult to determine using purely computational energy minimization approaches. In this paper, we therefore propose an optimized approach using an iterative local minima search algorithm followed by molecular dynamics (MD) structural relaxation of candidate structures associated with each local minimum. In this manner, it becomes possible to investigate the 3D atomic structure of supported NPs, which may deviate from their ground state configuration. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000716511600001 | Publication Date | 2021-11-10 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2366-9608 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | 12 | Open Access | OpenAccess | |
Notes ![]() |
This work was supported by the European Research Council (Grant 815128 REALNANO to SB, Grant 770887 PICOMETRICS to SVA, Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project funding (G.0267.18N, G.0502.18N, G.0346.21N).; sygmaSB; esteem3jra; esteem3reported | Approved | Most recent IF: NA | ||
Call Number | EMAT @ emat @c:irua:183289 | Serial | 6820 | ||
Permanent link to this record | |||||
Author | Liu, P.; Arslan Irmak, E.; De Backer, A.; De wael, A.; Lobato, I.; Béché, A.; Van Aert, S.; Bals, S. | ||||
Title | Three-dimensional atomic structure of supported Au nanoparticles at high temperature | Type | A1 Journal article | ||
Year | 2021 | Publication | Nanoscale | Abbreviated Journal | Nanoscale |
Volume | 13 | Issue | Pages | ||
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Au nanoparticles (NPs) deposited on CeO2 are extensively used as thermal catalysts since the morphology of the NPs is expected to be stable at elevated temperatures. Although it is well known that the activity of Au NPs depends on their size and surface structure, their three-dimensional (3D) structure at the atomic scale has not been completely characterized as a function of temperature. In this paper, we overcome the limitations of conventional electron tomography by combining atom counting applied to aberration-corrected scanning transmission electron microscopy images and molecular dynamics relaxation. In this manner, we are able to perform an atomic resolution 3D investigation of supported Au NPs. Our results enable us to characterize the 3D equilibrium structure of single NPs as a function of temperature. Moreover, the dynamic 3D structural evolution of the NPs at high temperatures, including surface layer jumping and crystalline transformations, has been studied. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000612999200029 | Publication Date | 2020-12-29 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2040-3364 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 7.367 | Times cited | 13 | Open Access | OpenAccess |
Notes ![]() |
This work was supported by the European Research Council (Grant 815128 REALNANO to SB, Grant 770887 PICOMETRICS to SVA, Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through grants to A. D. w. and A. D. B. and project funding G.0267.18N.; sygma; esteem3JRA; esteem3reported | Approved | Most recent IF: 7.367 | ||
Call Number | EMAT @ emat @c:irua:174858 | Serial | 6665 | ||
Permanent link to this record | |||||
Author | Hugenschmidt, M.; Jannis, D.; Kadu, A.A.; Grünewald, L.; De Marchi, S.; Perez-Juste, J.; Verbeeck, J.; Van Aert, S.; Bals, S. | ||||
Title | Low-dose 4D-STEM tomography for beam-sensitive nanocomposites | Type | A1 Journal article | ||
Year | 2023 | Publication | ACS materials letters | Abbreviated Journal | |
Volume | 6 | Issue | 1 | Pages | 165-173 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Electron tomography is essential for investigating the three-dimensional (3D) structure of nanomaterials. However, many of these materials, such as metal-organic frameworks (MOFs), are extremely sensitive to electron radiation, making it difficult to acquire a series of projection images for electron tomography without inducing electron-beam damage. Another significant challenge is the high contrast in high-angle annular dark field scanning transmission electron microscopy that can be expected for nanocomposites composed of a metal nanoparticle and an MOF. This strong contrast leads to so-called metal artifacts in the 3D reconstruction. To overcome these limitations, we here present low-dose electron tomography based on four-dimensional scanning transmission electron microscopy (4D-STEM) data sets, collected using an ultrafast and highly sensitive direct electron detector. As a proof of concept, we demonstrate the applicability of the method for an Au nanostar embedded in a ZIF-8 MOF, which is of great interest for applications in various fields, including drug delivery. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 001141178500001 | Publication Date | 2023-12-11 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2639-4979 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | Times cited | Open Access | Not_Open_Access | ||
Notes ![]() |
This work was supported by the European Research Council (Grant 815128 REALNANO to S.B., Grant 770887 PICOMETRICS to S.V.A.). J.P.-J. and S.M. acknowledge financial support from the MCIN/AEI/10.13039/501100011033 (Grants No. PID2019-108954RB-I00) and EU Horizon 2020 research and innovation program under grant agreement no. 883390 (SERSing). J.V., S.B., S.V.A., and L.G. acknowledge funding from the Flemish government (iBOF-21-085 PERsist). | Approved | Most recent IF: NA | ||
Call Number | UA @ admin @ c:irua:202771 | Serial | 9053 | ||
Permanent link to this record | |||||
Author | De Backer, A.; Zhang, Z.; van den Bos, K.H.W.; Bladt, E.; Sánchez‐Iglesias, A.; Liz‐Marzán, L.M.; Nellist, P.D.; Bals, S.; Van Aert, S. | ||||
Title | Element Specific Atom Counting at the Atomic Scale by Combining High Angle Annular Dark Field Scanning Transmission Electron Microscopy and Energy Dispersive X‐ray Spectroscopy | Type | A1 Journal article | ||
Year | 2022 | Publication | Small methods | Abbreviated Journal | Small Methods |
Volume | Issue | Pages | 2200875 | ||
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | A new methodology is presented to count the number of atoms in multimetallic nanocrystals by combining energy dispersive X-ray spectroscopy (EDX) and high angle annular dark field scanning transmission electron microscopy (HAADF STEM). For this purpose, the existence of a linear relationship between the incoherent HAADF STEM and EDX images is exploited. Next to the number of atoms for each element in the atomic columns, the method also allows quantification of the error in the obtained number of atoms, which is of importance given the noisy nature of the acquired EDX signals. Using experimental images of an Au@Ag core–shell nanorod, it is demonstrated that 3D structural information can be extracted at the atomic scale. Furthermore, simulated data of an Au@Pt core–shell nanorod show the prospect to characterize heterogeneous nanostructures with adjacent atomic numbers. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000862072700001 | Publication Date | 2022-09-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2366-9608 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 12.4 | Times cited | 5 | Open Access | OpenAccess |
Notes ![]() |
This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S.V.A., Grant 815128 REALNANO to S.B., and Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0267.18N, G.0502.18N, G.0346.21N) and a postdoctoral grant to A.D.B.; esteem3reported; esteem3JRA | Approved | Most recent IF: 12.4 | ||
Call Number | EMAT @ emat @c:irua:191570 | Serial | 7109 | ||
Permanent link to this record | |||||
Author | Lobato, I.; Friedrich, T.; Van Aert, S. | ||||
Title | Deep convolutional neural networks to restore single-shot electron microscopy images | Type | A1 Journal article | ||
Year | 2024 | Publication | N P J Computational Materials | Abbreviated Journal | npj Comput Mater |
Volume | 10 | Issue | 1 | Pages | 10 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Advanced electron microscopy techniques, including scanning electron microscopes (SEM), scanning transmission electron microscopes (STEM), and transmission electron microscopes (TEM), have revolutionized imaging capabilities. However, achieving high-quality experimental images remains a challenge due to various distortions stemming from the instrumentation and external factors. These distortions, introduced at different stages of imaging, hinder the extraction of reliable quantitative insights. In this paper, we will discuss the main sources of distortion in TEM and S(T)EM images, develop models to describe them, and propose a method to correct these distortions using a convolutional neural network. We validate the effectiveness of our method on a range of simulated and experimental images, demonstrating its ability to significantly enhance the signal-to-noise ratio. This improvement leads to a more reliable extraction of quantitative structural information from the images. In summary, our findings offer a robust framework to enhance the quality of electron microscopy images, which in turn supports progress in structural analysis and quantification in materials science and biology. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 001138183000001 | Publication Date | 2024-01-09 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2057-3960 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | Times cited | Open Access | OpenAccess | ||
Notes ![]() |
This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S.V.A.). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G034621N, G0A7723N and EOS 40007495). S.V.A. acknowledges funding from the University of Antwerp Research Fund (BOF). The authors thank Lukas Grünewald for data acquisition and support for Fig. 7. | Approved | Most recent IF: NA | ||
Call Number | EMAT @ emat @c:irua:202714 | Serial | 8994 | ||
Permanent link to this record | |||||
Author | De Backer, A.; Van Aert, S.; Faes, C.; Arslan Irmak, E.; Nellist, P.D.; Jones, L. | ||||
Title | Experimental reconstructions of 3D atomic structures from electron microscopy images using a Bayesian genetic algorithm | Type | A1 Journal article | ||
Year | 2022 | Publication | N P J Computational Materials | Abbreviated Journal | npj Comput Mater |
Volume | 8 | Issue | 1 | Pages | 216 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | We introduce a Bayesian genetic algorithm for reconstructing atomic models of monotype crystalline nanoparticles from a single projection using Z-contrast imaging. The number of atoms in a projected atomic column obtained from annular dark field scanning transmission electron microscopy images serves as an input for the initial three-dimensional model. The algorithm minimizes the energy of the structure while utilizing a priori information about the finite precision of the atom-counting results and neighbor-mass relations. The results show promising prospects for obtaining reliable reconstructions of beam-sensitive nanoparticles during dynamical processes from images acquired with sufficiently low incident electron doses. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000866500900001 | Publication Date | 2022-10-12 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2057-3960 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | Open Access | OpenAccess | ||
Notes ![]() |
This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S.V.A. and Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0267.18N, G.0502.18N, G.0346.21N) and a postdoctoral grant to A.D.B. L.J. acknowledges Science Foundation Ireland (SFI – grant number URF/RI/191637), the Royal Society, and the AMBER Centre. The authors acknowledge Aakash Varambhia for his assistance and expertise with the experimental recording and use of characterization facilities within the David Cockayne Centre for Electron Microscopy, Department of Materials, University of Oxford, and in particular the EPSRC (EP/K040375/1 South of England Analytical Electron Microscope).; esteem3reported; esteem3JRA | Approved | Most recent IF: NA | ||
Call Number | EMAT @ emat @c:irua:191398 | Serial | 7114 | ||
Permanent link to this record | |||||
Author | De Backer, A.; Bals, S.; Van Aert, S. | ||||
Title | A decade of atom-counting in STEM: From the first results toward reliable 3D atomic models from a single projection | Type | A1 Journal article | ||
Year | 2023 | Publication | Ultramicroscopy | Abbreviated Journal | |
Volume | Issue | Pages | 113702 | ||
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Quantitative structure determination is needed in order to study and understand nanomaterials at the atomic scale. Materials characterisation resulting in precise structural information is a crucial point to understand the structure–property relation of materials. Counting the number of atoms and retrieving the 3D atomic structure of nanoparticles plays an important role here. In this paper, an overview will be given of the atom-counting methodology and its applications over the past decade. The procedure to count the number of atoms will be discussed in detail and it will be shown how the performance of the method can be further improved. Furthermore, advances toward mixed element nanostructures, 3D atomic modelling based on the atom-counting results, and quantifying the nanoparticle dynamics will be highlighted. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000953765800001 | Publication Date | 2023-02-10 | |
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 | 2.2 | Times cited | 3 | Open Access | OpenAccess |
Notes ![]() |
This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert, Grant 815128 REALNANO to S. Bals, and Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0267.18N, G.0502.18N, G.0346.21N, and EOS 30489208) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF) . The authors also thank the colleagues who have contributed to this work over the years, including T. Altantzis, E. Arslan Irmak, K.J. Batenburg, E. Bladt, A. De wael, R. Erni, C. Faes, B. Goris, L. Jones, L.M. Liz-Marzán, I. Lobato, G.T. Martinez, P.D. Nellist, M.D. Rosell, A. Rosenauer, K.H.W. van den Bos, A. Varambhia, and Z. Zhang.; esteem3reported; esteem3JRA | Approved | Most recent IF: 2.2; 2023 IF: 2.843 | ||
Call Number | EMAT @ emat @c:irua:195896 | Serial | 7236 | ||
Permanent link to this record | |||||
Author | Şentürk, DG.; Yu, CP.; De Backer, A.; Van Aert, S. | ||||
Title | Atom counting from a combination of two ADF STEM images | Type | A1 Journal article | ||
Year | 2024 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 255 | Issue | Pages | 113859 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | To understand the structure–property relationship of nanostructures, reliably quantifying parameters, such as the number of atoms along the projection direction, is important. Advanced statistical methodologies have made it possible to count the number of atoms for monotype crystalline nanoparticles from a single ADF STEM image. Recent developments enable one to simultaneously acquire multiple ADF STEM images. Here, we present an extended statistics-based method for atom counting from a combination of multiple statistically independent ADF STEM images reconstructed from non-overlapping annular detector collection regions which improves the accuracy and allows one to retrieve precise atom-counts, especially for images acquired with low electron doses and multiple element structures. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 001089064200001 | Publication Date | 2023-09-23 | |
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 | 2.2 | Times cited | Open Access | OpenAccess | |
Notes ![]() |
This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G034621N, G0A7723N, and EOS 40007495) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF). | Approved | Most recent IF: 2.2; 2024 IF: 2.843 | ||
Call Number | EMAT @ emat @c:irua:201008 | Serial | 8964 | ||
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Author | Lobato, I.; De Backer, A.; Van Aert, S. | ||||
Title | Real-time simulations of ADF STEM probe position-integrated scattering cross-sections for single element fcc crystals in zone axis orientation using a densely connected neural network | Type | A1 Journal article | ||
Year | 2023 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 251 | Issue | Pages | 113769 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Quantification of annular dark field (ADF) scanning transmission electron microscopy (STEM) images in terms of composition or thickness often relies on probe-position integrated scattering cross sections (PPISCS). In order to compare experimental PPISCS with theoretically predicted ones, expensive simulations are needed for a given specimen, zone axis orientation, and a variety of microscope settings. The computation time of such simulations can be in the order of hours using a single GPU card. ADF STEM simulations can be efficiently parallelized using multiple GPUs, as the calculation of each pixel is independent of other pixels. However, most research groups do not have the necessary hardware, and, in the best-case scenario, the simulation time will only be reduced proportionally to the number of GPUs used. In this manuscript, we use a learning approach and present a densely connected neural network that is able to perform real-time ADF STEM PPISCS predictions as a function of atomic column thickness for most common face-centered cubic (fcc) crystals (i.e., Al, Cu, Pd, Ag, Pt, Au and Pb) along [100] and [111] zone axis orientations, root-mean-square displacements, and microscope parameters. The proposed architecture is parameter efficient and yields accurate predictions for the PPISCS values for a wide range of input parameters that are commonly used for aberration-corrected transmission electron microscopes. |
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 001011617200001 | Publication Date | 2023-06-01 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 2.2 | Times cited | Open Access | OpenAccess | |
Notes ![]() |
This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G034621N and G0A7723N) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF), Belgium. | Approved | Most recent IF: 2.2; 2023 IF: 2.843 | ||
Call Number | EMAT @ emat @c:irua:197275 | Serial | 8812 | ||
Permanent link to this record | |||||
Author | Şentürk, D.G.; De Backer, A.; Van Aert, S. | ||||
Title | Element specific atom counting for heterogeneous nanostructures: Combining multiple ADF STEM images for simultaneous thickness and composition determination | Type | A1 Journal Article | ||
Year | 2024 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 259 | Issue | Pages | 113941 | |
Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
Abstract | In this paper, a methodology is presented to count the number of atoms in heterogeneous nanoparticles based on the combination of multiple annular dark field scanning transmission electron microscopy (ADF STEM) images. The different non-overlapping annular detector collection regions are selected based on the principles of optimal statistical experiment design for the atom-counting problem. To count the number of atoms, the total intensities of scattered electrons for each atomic column, the so-called scattering cross-sections, are simultaneously compared with simulated library values for the different detector regions by minimising the squared differences. The performance of the method is evaluated for simulated Ni@Pt and Au@Ag core-shell nanoparticles. Our approach turns out to be a dose efficient alternative for the investigation of beam-sensitive heterogeneous materials as compared to the combination of ADF STEM and energy dispersive X-ray spectroscopy. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | Publication Date | 2024-02-19 | ||
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 | OpenAccess | |
Notes ![]() |
This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0346.21N, GOA7723N, and EOS 40007495) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF). | Approved | Most recent IF: 2.2; 2024 IF: 2.843 | ||
Call Number | EMAT @ emat @c:irua:204353 | Serial | 8996 | ||
Permanent link to this record | |||||
Author | Sentürk, D.G.; De Backer, A.; Friedrich, T.; Van Aert, S. | ||||
Title | Optimal experiment design for element specific atom counting using multiple annular dark field scanning transmission electron microscopy detectors | Type | A1 Journal article | ||
Year | 2022 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 242 | Issue | Pages | 113626 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | This paper investigates the possible benefits for counting atoms of different chemical nature when analysing multiple 2D scanning transmission electron microscopy (STEM) images resulting from independent annular dark field (ADF) detector regimes. To reach this goal, the principles of statistical detection theory are used to quantify the probability of error when determining the number of atoms in atomic columns consisting of multiple types of elements. In order to apply this theory, atom-counting is formulated as a statistical hypothesis test, where each hypothesis corresponds to a specific number of atoms of each atom type in an atomic column. The probability of error, which is limited by the unavoidable presence of electron counting noise, can then be computed from scattering-cross sections extracted from multiple ADF STEM images. Minimisation of the probability of error as a function of the inner and outer angles of a specified number of independent ADF collection regimes results in optimal experimental designs. Based on simulations of spherical Au@Ag and Au@Pt core–shell nanoparticles, we investigate how the combination of two non-overlapping detector regimes helps to improve the probability of error when unscrambling two types of atoms. In particular, the combination of a narrow low angle ADF detector with a detector formed by the remaining annular collection regime is found to be optimal. The benefit is more significant if the atomic number Z difference becomes larger. In addition, we show the benefit of subdividing the detector regime into three collection areas for heterogeneous nanostructures based on a structure consisting of three types of elements, e.g., a mixture of Au, Ag and Al atoms. Finally, these results are compared with the probability of error resulting when one would ultimately use a pixelated 4D STEM detector and how this could help to further reduce the incident electron dose. |
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000873778100001 | Publication Date | 0000-00-00 | |
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 | 2.2 | Times cited | Open Access | OpenAccess | |
Notes ![]() |
This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert and Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0346.21N and EOS 30489208) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF).; esteem3reported; esteem3jra | Approved | Most recent IF: 2.2 | ||
Call Number | EMAT @ emat @c:irua:190925 | Serial | 7118 | ||
Permanent link to this record |