“Atomic Layer Deposition of Pt Nanoparticles within the Cages of MIL-101: A Mild and Recyclable Hydrogenation Catalyst”. Leus K, Dendooven J, Tahir N, Ramachandran R, Meledina M, Turner S, Van Tendeloo G, Goeman J, Van der Eycken J, Detavernier C, Van Der Voort P, Nanomaterials 6, 45 (2016). http://doi.org/10.3390/nano6030045
Abstract: We present the in situ synthesis of Pt nanoparticles within MIL-101-Cr (MIL = Materials Institute Lavoisier) by means of atomic layer deposition (ALD). The obtained Pt@MIL-101 materials were characterized by means of N2 adsorption and X-ray powder diffraction (XRPD) measurements, showing that the structure of the metal organic framework was well preserved during the ALD deposition. X-ray fluorescence (XRF) and transmission electron microscopy (TEM) analysis confirmed the deposition of highly dispersed Pt nanoparticles with sizes determined by the MIL-101-Cr pore sizes and with an increased Pt loading for an increasing number of ALD cycles. The Pt@MIL-101 material was examined as catalyst in the hydrogenation of different linear and cyclic olefins at room temperature, showing full conversion for each substrate. Moreover, even under solvent free conditions, full conversion of the substrate was observed. A high concentration test has been performed showing that the Pt@MIL-101 is stable for a long reaction time without loss of activity, crystallinity and with very low Pt leaching.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 3.553
Times cited: 19
DOI: 10.3390/nano6030045
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“A MoVI grafted metal organic framework : synthesis, characterization and catalytic investigations”. Leus K, Liu Y-Y, Meledina M, Turner S, Van Tendeloo G, van der Voort P, Journal of catalysis 316, 201 (2014). http://doi.org/10.1016/j.jcat.2014.05.019
Abstract: We present the post-modification of a gallium based Metal Organic Framework, COMOC-4, with a Mo-complex. The resulting Mo@COMOC-4 was characterized by means of N2 sorption, XRPD, DRIFT, TGA, XRF, XPS and TEM analysis. The results demonstrate that even at high Mo-complex loadings on the framework, no aggregation or any Mo or Mo oxide species are formed. Moreover, the Mo@COMOC-4 was evaluated as a catalyst in the epoxidation of cyclohexene, cyclooctene and cyclododecene employing TBHP in decane as oxidant. The post-modified COMOC-4 exhibits a very high selectivity toward the epoxide (up to 100%). Regenerability and stability tests have been carried out demonstrating that the catalyst can be recycled without leaching of Mo or loss of crystallinity.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 6.844
Times cited: 36
DOI: 10.1016/j.jcat.2014.05.019
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“Inkjet printing multideposited YBCO on CGO/LMO/MgO/Y2O3/Al2O3/Hastelloy tape for 2G-coated conductors”. Roxana Vlad V, Bartolome E, Vilardell M, Calleja A, Meledin A, Obradors X, Puig T, Ricart S, Van Tendeloo G, Usoskin A, Lee S, Petrykin V, Molodyk A, IEEE transactions on applied superconductivity 28, 6601805 (2018). http://doi.org/10.1109/TASC.2018.2808403
Abstract: We present the preparation of a new architecture of coated conductor by Inkjet printing of low fluorine YBa2Cu3O7-x (YBCO) on top of SuperOx tape: CGO/LMO/IBAD-MgO/Y2O3/Al-2 O-3/Hastelloy. A five-layered multideposited, 475-nm-thick YBCO film was structurally and magnetically characterized. A good texture was achieved using this combination of buffer layers, requiring only a 30-nm-thin ion-beam-assisted deposition (IBAD)-MgO layer. The LF-YBCO CC reaches self-field critical current density values of J(c)(GB) similar to NJ 15.9 MA/cm(2) (5 K), similar to 1.23 MA/cm(2) (77 K) corresponding to an I-c (77 K) = 58.4 A/cm-width. Inkjet printing offers a flexible and cost effective method for YBCO deposition, allowing patterning of structures.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.288
Times cited: 2
DOI: 10.1109/TASC.2018.2808403
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“The quasiparticle band structure of zincblende and rocksalt ZnO”. Dixit H, Saniz R, Lamoen D, Partoens B, Journal of physics : condensed matter 22, 125505 (2010). http://doi.org/10.1088/0953-8984/22/12/125505
Abstract: We present the quasiparticle band structure of ZnO in its zincblende (ZB) and rocksalt (RS) phases at the Γ point, calculated within the GW approximation. The effect of the pd hybridization on the quasiparticle corrections to the band gap is discussed. We compare three systems, ZB-ZnO which shows strong pd hybridization and has a direct band gap, RS-ZnO which is also hybridized but includes inversion symmetry and therefore has an indirect band gap, and ZB-ZnS which shows a weaker hybridization due to a change of the chemical species from oxygen to sulfur. The quasiparticle corrections are calculated with different numbers of valence electrons in the Zn pseudopotential. We find that the Zn20 + pseudopotential is essential for the adequate treatment of the exchange interaction in the self-energy. The calculated GW band gaps are 2.47 eV and 4.27 eV respectively, for the ZB and RS phases. The ZB-ZnO band gap is underestimated compared to the experimental value of 3.27 by ~ 0.8 eV. The RS-ZnO band gap compares well with the experimental value of 4.5 eV. The underestimation for ZB-ZnO is correlated with the strong pd hybridization. The GW band gap for ZnS is 3.57 eV, compared to the experimental value of 3.8 eV.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 53
DOI: 10.1088/0953-8984/22/12/125505
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“Ab initio study of shallow acceptors in bixbyite V2O3”. Sarmadian N, Saniz R, Partoens B, Lamoen D, Journal of applied physics 117, 015703 (2015). http://doi.org/10.1063/1.4905316
Abstract: We present the results of our study on p-type dopability of bixbyite V2O3 using the Heyd, Scuseria, and Ernzerhof hybrid functional (HSE06) within the density functional theory (DFT) formalism. We study vanadium and oxygen vacancies as intrinsic defects and substitutional Mg, Sc, and Y as extrinsic defects. We find that Mg substituting V acts as a shallow acceptor, and that oxygen vacancies are electrically neutral. Hence, we predict Mg-doped V2O3 to be a p-type conductor. Our results also show that vanadium vacancies are relatively shallow, with a binding energy of 0.14 eV, so that they might also lead to p-type conductivity.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Impact Factor: 2.068
Times cited: 3
DOI: 10.1063/1.4905316
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“Tight-binding studio : a technical software package to find the parameters of tight-binding Hamiltonian”. Nakhaee M, Ketabi SA, Peeters FM, Computer Physics Communications 254, 107379 (2020). http://doi.org/10.1016/J.CPC.2020.107379
Abstract: We present the Tight-Binding Studio (TB Studio) software package that calculates the different parameters of a tight-binding Hamiltonian from a set of Bloch energy bands obtained from first principle theories such as density functional theory, Hartree-Fock calculations or semi-empirical band-structure theory. This will be helpful for scientists who are interested in studying electronic and optical properties of structures using Green's function theory within the tight-binding approximation. TB Studio is a cross-platform application written in C++ with a graphical user interface design that is user-friendly and easy to work with. This software is powered by Linear Algebra Package C interface library for solving the eigenvalue problems and the standard high performance OpenGL graphic library for real time plotting. TB Studio and its examples together with the tutorials are available for download from tight-binding.com. Program summary Program Title: Tight-Binding Studio Program Files doi:http://dx.doi.org/10.17632/j6x5mwzm2d.1 Licensing provisions: LGPL Programming language: C++ External routines: BLAS, LAPACK, LAPACKE, wxWidgets, OpenGL, MathGL Nature of problem: Obtaining Tight-Binding Hamiltonian from a set of Bloch energy bands obtained from first-principles calculations. Solution method: Starting from the simplified LCAO method, a tight-binding model in the two-center approximation is constructed. The Slater and Koster (SK) approach is used to calculate the parameters of the TB Hamiltonian. By using non-linear fitting approaches the optimal values of the SK parameters are obtained such that the TB energy eigenvalues are as close as possible to those from first-principles calculations. We obtain the expression for the Hamiltonian and the overlap matrix elements between the different orbitals of the different atoms in an orthogonal or non-orthogonal basis set. (C) 2020 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 6.3
Times cited: 27
DOI: 10.1016/J.CPC.2020.107379
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“CFD modeling of transient adsorption/desorption behavior in a gas phase photocatalytic fiber reactor”. Verbruggen SW, Keulemans M, van Walsem J, Tytgat T, Lenaerts S, Denys S, Chemical engineering journal 292, 42 (2016). http://doi.org/10.1016/J.CEJ.2016.02.014
Abstract: We present the use of computational fluid dynamics (CFD) for accurately determining the adsorption parameters of acetaldehyde on photocatalytic fiber filter material, integrated in a continuous flow system. Unlike the traditional analytical analysis based on Langmuir adsorption, not only steady-state situations but also transient phenomena can be accounted for. Air displacement effects in the reactor and gas detection cell are investigated and inherently made part of the model. Incorporation of a surface aldol condensation reaction in the CFD analysis further improves the accuracy of the model which enables to extract precise, intrinsic adsorption parameters for situations in which analytical analysis would otherwise fail.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 6.216
Times cited: 12
DOI: 10.1016/J.CEJ.2016.02.014
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“Unusual dimensionality effects and surface charge density in 2D Mg(OH)2”. Suslu A, Wu K, Sahin H, Chen B, Yang S, Cai H, Aoki T, Horzum S, Kang J, Peeters FM, Tongay S;, Scientific reports 6, 20525 (2016). http://doi.org/10.1038/srep20525
Abstract: We present two-dimensional Mg(OH)(2) sheets and their vertical heterojunctions with CVD-MoS2 for the first time as flexible 2D insulators with anomalous lattice vibration and chemical and physical properties. New hydrothermal crystal growth technique enabled isolation of environmentally stable monolayer Mg(OH)(2) sheets. Raman spectroscopy and vibrational calculations reveal that the lattice vibrations of Mg(OH)(2) have fundamentally different signature peaks and dimensionality effects compared to other 2D material systems known to date. Sub-wavelength electron energy-loss spectroscopy measurements and theoretical calculations show that Mg(OH)(2) is a 6 eV direct-gap insulator in 2D, and its optical band gap displays strong band renormalization effects from monolayer to bulk, marking the first experimental confirmation of confinement effects in 2D insulators. Interestingly, 2D-Mg(OH)(2) sheets possess rather strong surface polarization (charge) effects which is in contrast to electrically neutral h-BN materials. Using 2D-Mg(OH)(2) sheets together with CVD-MoS2 in the vertical stacking shows that a strong change transfer occurs from n-doped CVD-MoS2 sheets to Mg(OH)(2), naturally depleting the semiconductor, pushing towards intrinsic doping limit and enhancing overall optical performance of 2D semiconductors. Results not only establish unusual confinement effects in 2D-Mg(OH)(2), but also offer novel 2D-insulating material with unique physical, vibrational, and chemical properties for potential applications in flexible optoelectronics.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 4.259
Times cited: 39
DOI: 10.1038/srep20525
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“Efficient numerical approach to inhomogeneous superconductivity: the Chebyshev-Bogoliubov-de Gennes method”. Covaci L, Peeters FM, Berciu M, Physical review letters 105, 167006 (2010). http://doi.org/10.1103/PhysRevLett.105.167006
Abstract: We propose a highly efficient numerical method to describe inhomogeneous superconductivity by using the kernel polynomial method in order to calculate the Greens functions of a superconductor. Broken translational invariance of any type (impurities, surfaces, or magnetic fields) can be easily incorporated. We show that limitations due to system size can be easily circumvented and therefore this method opens the way for the study of scenarios and/or geometries that were unaccessible before. The proposed method is highly efficient and amenable to large scale parallel computation. Although we only use it in the context of superconductivity, it is applicable to other inhomogeneous mean-field theories.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 8.462
Times cited: 80
DOI: 10.1103/PhysRevLett.105.167006
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“On the ferromagnetic exchange in Mn-doped III-V semiconductors”. Ivanov VA, Krstajic PM, Peeters FM, Fleurov V, Kikoin K, Physica: B : condensed matter
T2 –, 23rd International Conference on Low Temperature Physics (LT23), AUG 20-27, 2002, HIROSHIMA, JAPAN 329, 1282 (2003). http://doi.org/10.1016/S0921-4526(02)02240-8
Abstract: We propose a microscopic model for double exchange in GaAs:Mn, GaP:Mn which is based on the interaction between the transition metal impurities and the heavy holes of host semiconductor. The kinematic exchange is derived and the Curie temperature is calculated which agrees with recent experiments. (C) 2003 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.386
Times cited: 5
DOI: 10.1016/S0921-4526(02)02240-8
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“Measuring Dynamic Structural Changes of Nanoparticles at the Atomic Scale Using Scanning Transmission Electron Microscopy”. De wael A, De Backer A, Jones L, Varambhia A, Nellist PD, Van Aert S, Physical Review Letters 124, 106105 (2020). http://doi.org/10.1103/PhysRevLett.124.106105
Abstract: We propose a new method to measure atomic scale dynamics of nanoparticles from experimental high-resolution annular dark field scanning transmission electron microscopy images. By using the so-called hidden Markov model, which explicitly models the possibility of structural changes, the number of atoms in each atomic column can be quantified over time. This newly proposed method outperforms the current atom-counting procedure and enables the determination of the probabilities and cross sections for surface diffusion. This method is therefore of great importance for revealing and quantifying the atomic structure when it evolves over time via adatom dynamics, surface diffusion, beam effects, or during in situ experiments.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 8.6
DOI: 10.1103/PhysRevLett.124.106105
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“Electrostatically confined quantum rings in bilayer graphene”. Zarenia M, Pereira JM, Peeters FM, Farias GA, Nano letters 9, 4088 (2009). http://doi.org/10.1021/nl902302m
Abstract: We propose a new system where electron and hole states are electrostatically confined into a quantum ring in bilayer graphene. These structures can be created by tuning the gap of the graphene bilayer using nanostructured gates or by position-dependent doping. The energy levels have a magnetic field (B0) dependence that is strikingly distinct from that of usual semiconductor quantum rings. In particular, the eigenvalues are not invariant under a B0 ¨ −B0 transformation and, for a fixed total angular momentum index m, their field dependence is not parabolic, but displays two minima separated by a saddle point. The spectra also display several anticrossings, which arise due to the overlap of gate-confined and magnetically confined states.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 12.712
Times cited: 42
DOI: 10.1021/nl902302m
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“Novel power-to-syngas concept for plasma catalytic reforming coupled with water electrolysis”. Li K, Liu J-L, Li X-S, Lian H-Y, Zhu X, Bogaerts A, Zhu A-M, Chemical engineering journal 353, 297 (2018). http://doi.org/10.1016/j.cej.2018.07.111
Abstract: We propose a novel Power to Synthesis Gas (P2SG) approach, composed of two high-efficiency and renewable electricity-driven units, i.e., plasma catalytic reforming (PCR) and water electrolysis (WE), to produce high quality syngas from CH4, CO2 and H2O. As WE technology is already commercial, we mainly focus on the PCR unit, consisting of gliding arc plasma and Ni-based catalyst, for oxidative dry reforming of methane. An energy efficiency of 78.9% and energy cost of 1.0 kWh/Nm3 at a CH4 conversion of 99% and a CO2 conversion of 79% are obtained. Considering an energy efficiency of 80% for WE, the P2SG system yields an overall energy efficiency of 79.3% and energy cost of 1.8 kWh/Nm3. High-quality syngas is produced without the need for posttreatment units, featuring the ideal stoichiometric number of 2, with concentration of 94.6 vol%, and a desired CO2 fraction of 1.9 vol% for methanol synthesis. The PCR unit has the advantage of fast response to adapting to fluctuation of renewable electricity, avoiding local hot spots in the catalyst bed and coking, in contrast to conventional catalytic processes. Moreover, pure O2 from the WE unit is directly utilized by the PCR unit for oxidative dry reforming of methane, and thus, no air separation unit, like in conventional processes, is required. This work demonstrates the viability of the P2SG approach for large-scale energy storage of renewable electricity via electricity-to-fuel conversion.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 6.216
Times cited: 7
DOI: 10.1016/j.cej.2018.07.111
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“Plasma chemical looping : unlocking high-efficiency CO₂, conversion to clean CO at mild temperatures”. Long Y, Wang X, Zhang H, Wang K, Ong W-L, Bogaerts A, Li K, Lu C, Li X, Yan J, Tu X, Zhang H, JACS Au (2024). http://doi.org/10.1021/JACSAU.4C00153
Abstract: We propose a plasma chemical looping CO2 splitting (PCLCS) approach that enables highly efficient CO2 conversion into O-2-free CO at mild temperatures. PCLCS achieves an impressive 84% CO2 conversion and a 1.3 mmol g(-1) CO yield, with no O-2 detected. Crucially, this strategy significantly lowers the temperature required for conventional chemical looping processes from 650 to 1000 degrees C to only 320 degrees C, demonstrating a robust synergy between plasma and the Ce0.7Zr0.3O2 oxygen carrier (OC). Systematic experiments and density functional theory (DFT) calculations unveil the pivotal role of plasma in activating and partially decomposing CO2, yielding a mixture of CO, O-2/O, and electronically/vibrationally excited CO2*. Notably, these excited CO2* species then efficiently decompose over the oxygen vacancies of the OCs, with a substantially reduced activation barrier (0.86 eV) compared to ground-state CO2 (1.63 eV), contributing to the synergy. This work offers a promising and energy-efficient pathway for producing O-2-free CO from inert CO2 through the tailored interplay of plasma and OCs.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
DOI: 10.1021/JACSAU.4C00153
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“Scheme for the generation of entangled atomic state in cavity QED”. Duan ZL, Chen ZY, Zhang JT, Feng XL, Xu ZZ, European physical journal : D : atomic, molecular and optical physics 30, 275 (2004). http://doi.org/10.1140/epjd/e2004-00086-2
Abstract: We propose a scheme to generate the entangled state of two Lambda-type three-level atoms trapped in a cavity. The atoms are initially prepared in their excited state and the cavity in vacuum state. Each atom has two possibilities to deexcite to one of the ground states. If two different polarized photons are detected subsequently, it is sure that both atoms are in different ground states. But which atom is in which ground state cannot be determined, the atoms are thus prepared in a superposition of two ground states, i.e., an entangled state. In comparison with the proposal of Hong and Lee [Phys. Rev. Lett. 89, 237901 (2002)], the requirement of a single polarized photon source can be avoided in our scheme.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.288
Times cited: 4
DOI: 10.1140/epjd/e2004-00086-2
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“Quantum diffusion: A simple, exactly solvable model”. Magnus W, Nelissen K, Physica: A : theoretical and statistical physics 417, 96 (2015). http://doi.org/10.1016/j.physa.2014.09.041
Abstract: We propose a simple quantum mechanical model describing the time dependent diffusion current between two fermion reservoirs that were initially disconnected and characterized by different densities or chemical potentials. The exact, analytical solution of the model yields the transient behavior of the coupled fermion systems evolving to a final steady state, whereas the long-time behavior is determined by a power law rather than by exponential decay. Similar results are obtained for the entropy production which is proportional to the diffusion current. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.243
DOI: 10.1016/j.physa.2014.09.041
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“Sorting the modes contributing to guidance in strain-induced graphene waveguides”. Villegas CEP, Tavares MRS, Hai G-Q, Peeters FM, New journal of physics 15, 023015 (2013). http://doi.org/10.1088/1367-2630/15/2/023015
Abstract: We propose a simple way of probing the number of modes contributing to the channeling in graphene waveguides which are formed by a gauge potential produced by mechanical strain. The energy mode structure for both homogeneous and non-homogeneous strain regimes is carefully studied using the continuum description of the Dirac equation. We found that high strain values privilege negative (instead of positive) group velocities throughout the guidance, sorting the types of modes flowing through it. We also show how the effect of a substrate-induced gap competes against the strain.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.786
Times cited: 7
DOI: 10.1088/1367-2630/15/2/023015
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“Tight-binding model investigation of the biaxial strain induced topological phase transition in GeCH3”. Rezaei M, Sisakht ET, Fazileh F, Aslani Z, Peeters FM, Physical review B 96, 085441 (2017). http://doi.org/10.1103/PHYSREVB.96.085441
Abstract: We propose a tight-binding (TB) model, that includes spin-orbit coupling (SOC), to describe the electronic properties of methyl-substituted germanane (GeCH3). This model gives an electronic spectrum in agreement with first principle results close to the Fermi level. Using the Z(2) formalism, we show that a topological phase transition from a normal insulator (NI) to a quantum spin Hall (QSH) phase occurs at 11.6% biaxial tensile strain. The sensitivity of the electronic properties of this system on strain, in particular its transition to the topological insulating phase, makes it very attractive for applications in strain sensors and other microelectronic applications.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 10
DOI: 10.1103/PHYSREVB.96.085441
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“Tunable skewed edges in puckered structures”. Grujić, MM, Ezawa M, Tadic MZ, Peeters FM, Physical review B 93, 245413 (2016). http://doi.org/10.1103/PhysRevB.93.245413
Abstract: We propose a type of edges arising due to the anisotropy inherent in the puckered structure of a honeycomb system such as in phosphorene. Skewed-zigzag and skewed-armchair nanoribbons are semiconducting and metallic, respectively, in contrast to their normal edge counterparts. Their band structures are tunable, and a metal-insulator transition is induced by an electric field. We predict a field-effect transistor based on the edge states in skewed-armchair nanoribbons, where the edge state is gapped by applying arbitrary small electric field E-z. A topological argument is presented, revealing the condition for the emergence of such edge states.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 29
DOI: 10.1103/PhysRevB.93.245413
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“A weak compatibility condition for precipitation with application to the microstructure of PbTe-Sb2Te3 thermoelectrics”. Chen X, Cao S, Ikeda T, Srivastava V, Snyder GJ, Schryvers D, James RD, Acta materialia 59, 6124 (2011). http://doi.org/10.1016/j.actamat.2011.06.025
Abstract: We propose a weak condition of compatibility between phases applicable to cases exhibiting full or partial coherence and Widmanstätten microstructure. The condition is applied to the study of Sb2Te3 precipitates in a PbTe matrix in a thermoelectric alloy. The weak condition of compatibility predicts elongated precipitates lying on a cone determined by a transformation stretch tensor. Comparison of this cone with the long directions of precipitates determined by a slice-and-view method of scanning electron microscopy combined with focused ion beam sectioning shows good agreement between theory and experiment. A further study of the morphology of precipitates by the Eshelby method suggests that interfacial energy also plays a role and gives an approximate value of interfacial energy per unit area of 250 dyn cm−1.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 5.301
Times cited: 8
DOI: 10.1016/j.actamat.2011.06.025
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“Bound states and lifetime of an electron on a bulk helium surface”. Degani MH, Farias GA, Peeters FM, Physical review : B : condensed matter and materials physics 72, 125408 (2005). http://doi.org/10.1103/PhysRevB.72.125408
Abstract: We propose an effective potential for an excess electron near the helium liquid-vapor interface that takes into account the diffuseness of the liquid-vapor interface and the classical image potential. The splitting of the first two excited states of the excess electron bound to the helium liquid-vapor interface as a function of an external constant electric field applied perpendicular to the interface is in excellent agreement with recent experiments. The effect of a parallel magnetic field on the energy levels are calculated. Single-electron tunneling of the electron out of its surface state is studied as a function of the electric field applied to the system. We found that the tunneling time has a linear dependence on the electric field.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 11
DOI: 10.1103/PhysRevB.72.125408
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“An efficient way of including thermal diffuse scattering in simulation of scanning transmission electron microscopic images”. Croitoru MD, van Dyck D, Van Aert S, Bals S, Verbeeck J, Ultramicroscopy 106, 933 (2006). http://doi.org/10.1016/j.ultramic.2006.04.006
Abstract: We propose an improved image simulation procedure for atomic-resolution annular dark-field scanning transmission electron microscopy (STEM) based on the multislice formulation, which takes thermal diffuse scattering fully into account. The improvement with regard to the classical frozen phonon approach is realized by separating the lattice configuration statistics from the dynamical scattering so as to avoid repetitive calculations. As an example, the influence of phonon scattering on the image contrast is calculated and investigated. STEM image simulation of crystals can be applied with reasonable computing times to problems involving a large number of atoms and thick or large supercells.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Vision lab
Impact Factor: 2.843
Times cited: 18
DOI: 10.1016/j.ultramic.2006.04.006
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“Tuning the polarized quantum phonon transmission in graphene nanoribbons”. Scuracchio P, Dobry A, Costamagna S, Peeters FM, Nanotechnology 26, 305401 (2015). http://doi.org/10.1088/0957-4484/26/30/305401
Abstract: We propose systems that allow a tuning of the phonon transmission function T(omega) in graphene nanoribbons by using C-13 isotope barriers, antidot structures, and distinct boundary conditions. Phonon modes are obtained by an interatomic fifth-nearest neighbor force-constant model (5NNFCM) and T(omega) is calculated using the non-equilibrium Green's function formalism. We show that by imposing partial fixed boundary conditions it is possible to restrict contributions of the in-plane phonon modes to T(omega) at low energy. On the contrary, the transmission functions of out-of-plane phonon modes can be diminished by proper antidot or isotope arrangements. In particular, we show that a periodic array of them leads to sharp dips in the transmission function at certain frequencies omega(nu) which can be pre-defined as desired by controlling their relative distance and size. With this, we demonstrated that by adequate engineering it is possible to govern the magnitude of the ballistic transmission functions T(omega) in graphene nanoribbons. We discuss the implications of these results in the design of controlled thermal transport at the nanoscale as well as in the enhancement of thermo-electric features of graphene-based materials.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 3.44
Times cited: 5
DOI: 10.1088/0957-4484/26/30/305401
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“Low-strain Si/O superlattices with tunable electronic properties : ab initio calculations”. Nishio K, Lu AKA, Pourtois G, Physical review : B : condensed matter and materials physics 91, 165303 (2015). http://doi.org/10.1103/PhysRevB.91.165303
Abstract: We propose that low-strain Si/O superlattices can be constructed by connecting reconstructed Si{001} surfaces by Si-O-Si bridges. Ab initio calculations show that our models are energetically more favorable than all the models proposed so far. The part of our Si/O superlattice model is experimentally accessible just by oxidizing a Si( 001) substrate. To complete our Si/O superlattice model, we propose a three-step method. We also explore the potential of our Si/O superlattice models for new materials used in future Si electronics. We find that the location of the channel where the carriers travel can be controlled between the interfaces and the Si layers by the insertion of O atoms into the Si-Si dimers. By revealing the origins of the interface electron and hole states, we find that similar interface states should be easily achieved for Si slabs and Si substrates. Interestingly, the interface electrons and holes have small effective masses in the direction parallel to the channel and large effective masses in the direction normal to the channel, which makes the Si/O superlattices attractive to be used for channel materials. We also find that the valley splitting of Si is enhanced by the formation of the Si/O/Si interfaces, which is ideal for developing Si-based qubits. Our findings open new perspectives to design and control the electronic properties of Si.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.836
Times cited: 6
DOI: 10.1103/PhysRevB.91.165303
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“Plasmonic ‘rainbow&rsquo, photocatalyst with broadband solar light response for environmental applications”. Verbruggen SW, Keulemans M, Goris B, Blommaerts N, Bals S, Martens JA, Lenaerts S, Applied catalysis : B : environmental 188, 147 (2016). http://doi.org/10.1016/j.apcatb.2016.02.002
Abstract: We propose the concept of a ‘rainbow’ photocatalyst that consists of TiO2 modified with gold-silver alloy nanoparticles of various sizes and compositions, resulting in a broad plasmon absorption band that covers the entire UV–vis range of the solar spectrum. It is demonstrated that this plasmonic ‘rainbow’ photocatalyst is 16% more effective than TiO2 P25 under both simulated and real solar light for pollutant degradation at the solid-gas interface. With this we provide a promising strategy to maximize the spectral response for solar to chemical energy conversion.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 9.446
Times cited: 47
DOI: 10.1016/j.apcatb.2016.02.002
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“Enhancement of electron-hole superfluidity in double few-layer graphene”. Zarenia M, Perali A, Neilson D, Peeters FM, Scientific reports 4, 7319 (2014). http://doi.org/10.1038/srep07319
Abstract: We propose two coupled electron-hole sheets of few-layer graphene as a new nanostructure to observe superfluidity at enhanced densities and enhanced transition temperatures. For ABC stacked few-layer graphene we show that the strongly correlated electron-hole pairing regime is readily accessible experimentally using current technologies. We find for double trilayer and quadlayer graphene sheets spatially separated by a nano-thick hexagonal boron-nitride insulating barrier, that the transition temperature for electron-hole superfluidity can approach temperatures of 40 K.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 4.259
Times cited: 38
DOI: 10.1038/srep07319
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“Comparative analysis of tight-binding models for transition metal dichalcogenides”. Jorissen B, Covaci L, Partoens B, SciPost physics core 7, 004 (2024). http://doi.org/10.21468/SCIPOSTPHYSCORE.7.1.004
Abstract: We provide a comprehensive analysis of the prominent tight-binding (TB) models for transition metal dichalcogenides (TMDs) available in the literature. We inspect the construction of these TB models, discuss their parameterization used and conduct a thorough comparison of their effectiveness in capturing important electronic properties. Based on these insights, we propose a novel TB model for TMDs designed for enhanced computational efficiency. Utilizing MoS2 as a representative case, we explain why specific models offer a more accurate description. Our primary aim is to assist researchers in choosing the most appropriate TB model for their calculations on TMDs.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
DOI: 10.21468/SCIPOSTPHYSCORE.7.1.004
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“Ferromagnetism in stacked bilayers of Pd/C60”. Ghosh S, Tongay S, Hebard AF, Sahin H, Peeters FM, Journal of magnetism and magnetic materials 349, 128 (2014). http://doi.org/10.1016/j.jmmm.2013.07.024
Abstract: We provide experimental evidence for the existence of ferromagnetism in bilayers of Pd/C-60 which is supported by theoretical calculations based on density functional theory (DFT). The observed ferromagnetism is surprising as C-60 and Pd films are both non-ferromagnetic in the non-interacting limit. Magnetization (M) versus applied field (H) data acquired at different temperatures (T) show magnetic hysteresis with typical coercive fields (H-c) on the order of 50 Oe. From the temperature-dependent magnetization M(T) we extract a Curie temperature (T-c >= 550 K) using Bloch-like power law extrapolations to high temperatures. Using DFT calculations we investigated all plausible scenarios for the interaction between the C-60 molecules and the Pd slabs, Pd single atoms and Pd clusters. DFT shows that while the C-60 molecules are nonmagnetic, Pd films have a degenerate ground state that subject to a weak perturbation, can become ferromagnetic. Calculations also show that the interaction of C-60 molecules with excess Pd atoms and with sharp edges of a Pd slab is the most likely configuration that render the system ferromagnetic Interestingly, the calculated charge transfer (0.016 e per surface Pd atom, 0.064 e per Pd for intimate contact region) between C-60 and Pd does not appear to play an important role. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.63
Times cited: 8
DOI: 10.1016/j.jmmm.2013.07.024
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“Probing confined vortices with a superconducting nanobridge”. Foltyn M, Norowski K, Wyszynski MJ, De Arruda AS, Milošević, MV, Zgirski M, Physical review applied 19, 044073 (2023). http://doi.org/10.1103/PHYSREVAPPLIED.19.044073
Abstract: We realize a superconducting nanodevice in which vortex traps in the form of an aluminum square are integrated with a Dayem nanobridge. We perform field cooling of the traps arriving to different vortex configurations, dependent on the applied magnetic field, to demonstrate that the switching current of the bridge is highly sensitive to the presence and location of vortices in the trap. Our measurements exhibit unprecedented precision and ability to detect the first and successive vortex entries into all fabricated traps, from few hundred nm to 2 mu m in size. The experimental results are corroborated by Ginzburg-Landau simulations, which reveal the subtle yet crucial changes in the density of the superconducting condensate in the vicinity of the bridge with every additional vortex entry and relocation inside the trap. An ease of integration and simplicity make our design a convenient platform for studying dynamics of vortices in strongly confining geometries, involving a promise to manipulate vortex states electronically with simultaneous in situ control and monitoring.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 4.6
DOI: 10.1103/PHYSREVAPPLIED.19.044073
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“Direct evidence of spontaneous quantum dot formation in a thick InGaN epilayer”. Nistor L, Bender H, Vantomme A, Wu MF, van Landuyt J, O'Donnell KP, Martin R, Jacobs K, Moerman I, Applied physics letters 77, 507 (2000). http://doi.org/10.1063/1.127026
Abstract: We report a direct observation of quantum dots formed spontaneously in a thick InGaN epilayer by high resolution transmission electron microscopy. Investigation of a (280 nm thick) In0.22Ga0.78N single layer, emitting in the blue/green spectral region, reveals quantum dots with estimated sizes in the range of 1.5-3 nm. Such sizes are in very good agreement with calculations based on the luminescence spectra of this specimen. (C) 2000 American Institute of Physics. [S0003-6951(00)00930-X].
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 44
DOI: 10.1063/1.127026
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