“Single-layer and bilayer graphene superlattices: collimation, additional Dirac points and Dirac lines”. Barbier M, Vasilopoulos P, Peeters FM, Philosophical transactions of the Royal Society : mathematical, physical and engineering sciences 368, 5499 (2010). http://doi.org/10.1098/rsta.2010.0218
Abstract: We review the energy spectrum and transport properties of several types of one-dimensional superlattices (SLs) on single-layer and bilayer graphene. In single-layer graphene, for certain SL parameters an electron beam incident on an SL is highly collimated. On the other hand, there are extra Dirac points generated for other SL parameters. Using rectangular barriers allows us to find analytical expressions for the location of new Dirac points in the spectrum and for the renormalization of the electron velocities. The influence of these extra Dirac points on the conductivity is investigated. In the limit of δ-function barriers, the transmission T through and conductance G of a finite number of barriers as well as the energy spectra of SLs are periodic functions of the dimensionless strength P of the barriers, Graphic, with vF the Fermi velocity. For a KronigPenney SL with alternating sign of the height of the barriers, the Dirac point becomes a Dirac line for P = π/2+nπ with n an integer. In bilayer graphene, with an appropriate bias applied to the barriers and wells, we show that several new types of SLs are produced and two of them are similar to type I and type II semiconductor SLs. Similar to single-layer graphene SLs, extra Dirac points are found in bilayer graphene SLs. Non-ballistic transport is also considered.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.97
Times cited: 64
DOI: 10.1098/rsta.2010.0218
|
“Tetrahedral chain order in the Sr2Fe2O5 brownmillerite”. d' Hondt H, Abakumov AM, Hadermann J, Kalyuzhnaya AS, Rozova MG, Antipov EV, Van Tendeloo G, Chemistry of materials 20, 7188 (2008). http://doi.org/10.1021/cm801723b
Abstract: The crystal structure of the Sr2Fe2O5 brownmillerite has been investigated using electron diffraction and high resolution electron microscopy. The Sr2Fe2O5 structure demonstrates two-dimensional order: the tetrahedral chains with two mirror-related configurations (L and R) are arranged within the tetrahedral layers according to the −L−R−L−R− sequence, and the layers themselves are displaced with respect to each other over 1/2[111] or 1/2[11] vectors of the brownmillerite unit cell, resulting in different ordered stacking variants. A unified superspace model is constructed for ordered stacking sequences in brownmillerites based on the average brownmillerite structure with a = 5.5298(4)Å, b = 15.5875(12)Å, c = 5.6687(4)Å, and (3 + 1)-dimensional superspace group I2/m(0βγ)0s, q = βb* + γc*, 0 ≤ β ≤ 1/2, 0 ≤ γ ≤ 1.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 64
DOI: 10.1021/cm801723b
|
“Transmission electron microscopy and Monte Carlo simulations of ordering in Au-Cu clusters produced in a laser vaporization source”. Pauwels B, Van Tendeloo G, Zhurkin E, Hou M, Verschoren G, Kuhn LT, Bouwen W, Lievens P, Physical review : B : condensed matter and materials physics 63, 165406 (2001). http://doi.org/10.1103/PhysRevB.63.165406
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 64
DOI: 10.1103/PhysRevB.63.165406
|
“Gold Nanostar-Coated Polystyrene Beads as Multifunctional Nanoprobes for SERS Bioimaging”. Serrano-Montes AB, Langer J, Henriksen-Lacey M, Jimenez de Aberasturi D, Solís DM, Taboada JM, Obelleiro F, Sentosun K, Bals S, Bekdemir A, Stellacci F, Liz-Marzán LM, The journal of physical chemistry: C : nanomaterials and interfaces 120, 20860 (2016). http://doi.org/10.1021/acs.jpcc.6b02282
Abstract: Hybrid colloidal nanocomposites comprising polystyrene beads and plasmonic gold nanostars are reported as multifunctional optical nanoprobes. Such self-assembled structures are excellent Raman enhancers for bio-applications as they feature plasmon modes in the near infrared “first biological transparency window”. In this proof of concept study, we used 4- mercaptobenzoic acid as a Raman-active molecule to optimize the density of gold nanostars on polystyrene beads, improving SERS performance and thereby allowing in vitro cell culture imaging. Interestingly, intermediate gold nanostar loadings were found to yield higher SERS response, which was confirmed by electromagnetic modeling. These engineered hybrid nanostructures notably improve the possibilities of using gold nanostars as SERS tags. Additionally, when fluorescently labeled polystyrene bead are used as colloidal carriers, the composite particles can be applied as promising tools for multimodal bioimaging.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 4.536
Times cited: 64
DOI: 10.1021/acs.jpcc.6b02282
|
“Catalyst design by NH4OH treatment of USY zeolite”. Van Aelst J, Verboekend D, Philippaerts A, Nuttens N, Kurttepeli M, Gobechiya E, Haouas M, Sree SP, Denayer JFM, Martens JA, Kirschhock CEA, Taulelle F, Bals S, Baron GV, Jacobs PA, Sels BF, Advanced functional materials 25, 7130 (2015). http://doi.org/10.1002/adfm.201502772
Abstract: Hierarchical zeolites are a class of superior catalysts which couples the intrinsic zeolitic properties to enhanced accessibility and intracrystalline mass transport to and from the active sites. The design of hierarchical USY (Ultra-Stable Y) catalysts is achieved using a sustainable postsynthetic room temperature treatment with mildly alkaline NH4OH ( 0.02(M)) solutions. Starting from a commercial dealuminated USY zeolite (Si/Al = 47), a hierarchical material is obtained by selective and tuneable creation of interconnected and accessible small mesopores (2- 6 nm). In addition, the treatment immediately yields the NH4+ form without the need for additional ion exchange. After NH4OH modification, the crystal morphology is retained, whereas the microporosity and relative crystallinity are decreased. The gradual formation of dense amorphous phases throughout the crystal without significant framework atom leaching rationalizes the very high material yields (>90%). The superior catalytic performance of the developed hierarchical zeolites is demonstrated in the acid-catalyzed isomerization of alpha-pinene and the metal-catalyzed conjugation of safflower oil. Significant improvements in activity and selectivity are attained, as well as a lowered susceptibility to deactivation. The catalytic performance is intimately related to the introduced mesopores, hence enhanced mass transport capacity, and the retained intrinsic zeolitic properties.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 12.124
Times cited: 64
DOI: 10.1002/adfm.201502772
|
“Manganese‐Doping‐Induced Quantum Confinement within Host Perovskite Nanocrystals through Ruddlesden–Popper Defects”. Paul S, Bladt E, Richter AF, Döblinger M, Tong Y, Huang H, Dey A, Bals S, Debnath T, Polavarapu L, Feldmann J, Angewandte Chemie-International Edition 59, 6794 (2020). http://doi.org/10.1002/anie.201914473
Abstract: The concept of doping Mn2+ ions into II–VI semiconductor nanocrystals (NCs) was recently extended to perovskite NCs. To date, most studies on Mn2+ doped NCs focus on enhancing the emission related to the Mn2+ dopant via an energy transfer mechanism. Herein, we found that the doping of Mn2+ ions into CsPbCl3 NCs not only results in a Mn2+‐related orange emission, but also strongly influences the excitonic properties of the host NCs. We observe for the first time that Mn2+ doping leads to the formation of Ruddlesden–Popper (R.P.) defects and thus induces quantum confinement within the host NCs. We find that a slight doping with Mn2+ ions improves the size distribution of the NCs, which results in a prominent excitonic peak. However, with increasing the Mn2+ concentration, the number of R.P. planes increases leading to smaller single‐crystal domains. The thus enhanced confinement and crystal inhomogeneity cause a gradual blue shift and broadening of the excitonic transition, respectively.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 16.6
Times cited: 64
DOI: 10.1002/anie.201914473
|
“Effect of argon or helium on the CO2 conversion in a dielectric barrier discharge”. Ramakers M, Michielsen I, Aerts R, Meynen V, Bogaerts A, Plasma processes and polymers 12, 755 (2015). http://doi.org/10.1002/ppap.201400213
Abstract: This paper demonstrates that the CO2 conversion in a dielectric barrier discharge rises drastically upon addition of Ar or He, and the effect is more pronounced for Ar than for He. The effective CO2 conversion, on the other hand, drops upon addition of Ar or He, which is logical due to the lower CO2 content in the gas mixture, and the same is true for the energy efficiency, because a considerable fraction of the energy is then consumed into ionization/excitation of Ar or He atoms. The higher absolute CO2 conversion upon addition of Ar or He can be explained by studying in detail the Lissajous plots and the current profiles. The breakdown voltage is lower in the CO2/Ar and CO2/He mixtures, and the discharge gap is more filled with plasma, which enhances the possibility for CO2 conversion. The rates of electron impact excitationdissociation of CO2, estimated from the electron densities and mean electron energies, are indeed higher in the CO2/Ar and (to a lower extent) in the CO2/He mixtures, compared to the pure CO2 plasma. Moreover, charge transfer between Ar+ or Ar2+ ions and CO2, followed by electron-ion dissociative recombination of the CO2+ ions, might also contribute to, or even be dominant for the CO2 dissociation. All these effects can explain the higher CO2 conversion, especially upon addition of Ar, but also upon addition of He.
Keywords: A1 Journal article; Laboratory of adsorption and catalysis (LADCA); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.846
Times cited: 63
DOI: 10.1002/ppap.201400213
|
“Electronic properties of hydrogenated silicene and germanene”. Houssa M, Scalise E, Sankaran K, Pourtois G, Afanas'ev VV, Stesmans A, Applied physics letters 98, 223107 (2011). http://doi.org/10.1063/1.3595682
Abstract: The electronic properties of hydrogenated silicene and germanene, so called silicane and germanane, respectively, are investigated using first-principles calculations based on density functional theory. Two different atomic configurations are found to be stable and energetically degenerate. Upon the adsorption of hydrogen, an energy gap opens in silicene and germanene. Their energy gaps are next computed using the HSE hybrid functional as well as the G(0)W(0) many-body perturbation method. These materials are found to be wide band-gap semiconductors, the type of gap in silicane (direct or indirect) depending on its atomic configuration. Germanane is predicted to be a direct-gap material, independent of its atomic configuration, with an average energy gap of about 3.2 eV, this material thus being potentially interesting for optoelectronic applications in the blue/violet spectral range. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3595682]
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.411
Times cited: 63
DOI: 10.1063/1.3595682
|
“First-principles simulation of oxygen diffusion in HfOx : role in the resistive switching mechanism”. Clima S, Chen YY, Degraeve R, Mees M, Sankaran K, Govoreanu B, Jurczak M, De Gendt S, Pourtois G, Applied physics letters 100, 133102 (2012). http://doi.org/10.1063/1.3697690
Abstract: Transition metal oxide-based resistor random access memory (RRAM) takes advantage of oxygen-related defects in its principle of operation. Since the change in resistivity of the material is controlled by the oxygen deficiency level, it is of major importance to quantify the kinetics of the oxygen diffusion, key factor for oxide stoichiometry. Ab initio accelerated molecular dynamics techniques are employed to investigate the oxygen diffusivity in amorphous hafnia (HfOx, x = 1.97, 1.0, 0.5). The computed kinetics is in agreement with experimental measurements. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3697690]
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.411
Times cited: 63
DOI: 10.1063/1.3697690
|
“From Bi4V2O11 to Bi4V2O10.66: the VV-VIV transformation in the Aurovillius-type framework”. Huvé, M, Vannier R-N, Nowogrocki G, Mairesse G, Van Tendeloo G, Journal of materials chemistry 6, 1339 (1996). http://doi.org/10.1039/jm9960601339
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 63
DOI: 10.1039/jm9960601339
|
“Incommensurate modulation and luminescence in the CaGd2(1-x)Eu2x(MoO4)4(1-y)(WO)4y (0\leq x\leq1, 0\leq y\leq1) red phosphors”. Morozov VA, Bertha A, Meert KW, Van Rompaey S, Batuk D, Martinez GT, Van Aert S, Smet PF, Raskina MV, Poelman D, Abakumov AM, Hadermann J;, Chemistry of materials 25, 4387 (2013). http://doi.org/10.1021/cm402729r
Abstract: Scheelite related compounds (A',A '') [(B',B '')O-4], with B', B '' = W and/or Mo are promising new light-emitting materials for photonic applications, including phosphor converted LEDs (light-emitting diodes). In this paper, the creation and ordering of A-cation vacancies and the effect of cation substitutions in the scheelite-type framework are investigated as a factor for controlling the scheelite-type structure and luminescent properties. CaGd2(1-x)Eu2x(MoO4)(4(1-y))(WO4)(4y) (0 <= x <= 1, 0 <= y <= 1) solid solutions with scheelite-type structure were synthesized by a solid state method, and their structures were investigated using a combination of transmission electron microscopy techniques and powder X-ray diffraction. Within this series all complex molybdenum oxides have (3 + 2)D incommensurately modulated structures with superspace group I4(1)/a(alpha,beta,0)00(-beta,alpha,0)00, while the structures of all tungstates are (3 + 1)D incommensurately modulated with superspace group I2/b(alpha beta 0)00. In both cases the modulation arises because of cation-vacancy ordering at the A site. The prominent structural motif is formed by columns of A-site vacancies running along the c-axis. These vacant columns occur in rows of two or three aligned along the [110] direction of the scheelite subcell. The replacement of the smaller Gd3+ by the larger Eu3+ at the A-sublattice does not affect the nature of the incommensurate modulation, but an increasing replacement of Mo6+ by W6+ switches the modulation from (3 + 2)D to (3 + 1)D regime. Thus, these solid solutions can be considered as a model system where the incommensurate modulation can be monitored as a function of cation nature while the number of cation vacancies at the A sites remain constant upon the isovalent cation replacement. All compounds' luminescent properties were measured, and the optical properties were related to the structural properties of the materials. CaGd2(1-x)(MoO4)(4(1-y))(WO4)(4y) phosphors emit intense red light dominated by the D-5(0)-F-7(2) transition at 612 nm, along with other transitions from the D-5(1) and D-5(0) excited states. The intensity of the 5D0-7F2 transition reaches a maximum at x = 0.5 for y = 0 and 1.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 63
DOI: 10.1021/cm402729r
|
“Optical Aharonov-Bohm effect in stacked type-II quantum dots”. Kuskovsky IL, MacDonald W, Govorov AO, Mourokh L, Wei X, Tamargo MC, Tadić, M, Peeters FM, Physical review : B : condensed matter and materials physics 76, 035342 (2007). http://doi.org/10.1103/PhysRevB.76.035342
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 63
DOI: 10.1103/PhysRevB.76.035342
|
“Realization of artificial ice systems for magnetic vortices in a superconducting MoGe thin film with patterned nanostructures”. Latimer ML, Berdiyorov GR, Xiao ZL, Peeters FM, Kwok WK, Physical review letters 111, 067001 (2013). http://doi.org/10.1103/PhysRevLett.111.067001
Abstract: We report an anomalous matching effect in MoGe thin films containing pairs of circular holes arranged in such a way that four of those pairs meet at each vertex point of a square lattice. A remarkably pronounced fractional matching was observed in the magnetic field dependences of both the resistance and the critical current. At the half matching field the critical current can be even higher than that at zero field. This has never been observed before for vortices in superconductors with pinning arrays. Numerical simulations within the nonlinear Ginzburg-Landau theory reveal a square vortex ice configuration in the ground state at the half matching field and demonstrate similar characteristic features in the field dependence of the critical current, confirming the experimental realization of an artificial ice system for vortices for the first time.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 8.462
Times cited: 63
DOI: 10.1103/PhysRevLett.111.067001
|
“Nanoribbons: From fundamentals to state-of-the-art applications”. Yagmurcukardes M, Peeters FM, Senger RT, Sahin H, Applied physics reviews 3, 041302 (2016). http://doi.org/10.1063/1.4966963
Abstract: Atomically thin nanoribbons (NRs) have been at the forefront of materials science and nanoelectronics in recent years. State-of-the-art research on nanoscale materials has revealed that electronic, magnetic, phononic, and optical properties may differ dramatically when their one-dimensional forms are synthesized. The present article aims to review the recent advances in synthesis techniques and theoretical studies on NRs. The structure of the review is organized as follows: After a brief introduction to low dimensional materials, we review different experimental techniques for the synthesis of graphene nanoribbons (GNRs) with their advantages and disadvantages. In addition, theoretical investigations on width and edge-shape-dependent electronic and magnetic properties, functionalization effects, and quantum transport properties of GNRs are reviewed. We then devote time to the NRs of the transition metal dichalcogenides (TMDs) family. First, various synthesis techniques, E-field-tunable electronic and magnetic properties, and edge-dependent thermoelectric performance of NRs of MoS2 and WS2 are discussed. Then, strongly anisotropic properties, growth-dependent morphology, and the weakly width-dependent bandgap of ReS2 NRs are summarized. Next we discuss TMDs having a T-phase morphology such as TiSe2 and stable single layer NRs of mono-chalcogenides. Strong edge-type dependence on characteristics of GaS NRs, width-dependent Seebeck coefficient of SnSe NRs, and experimental analysis on the stability of ZnSe NRs are reviewed. We then focus on the most recently emerging NRs belonging to the class of transition metal trichalcogenides which provide ultra-high electron mobility and highly anisotropic quasi-1D properties. In addition, width-, edge-shape-, and functionalization-dependent electronic and mechanical properties of blackphosphorus, a monoatomic anisotropic material, and studies on NRs of group IV elements (silicene, germanene, and stanene) are reviewed. Observation of substrate-independent quantum well states, edge and width dependent properties, the topological phase of silicene NRs are reviewed. In addition, H-2 concentration-dependent transport properties and anisotropic dielectric function of GeNRs and electric field and strain sensitive I-V characteristics of SnNRs are reviewed. We review both experimental and theoretical studies on the NRs of group III-V compounds. While defect and N-termination dependent conductance are highlighted for boron nitride NRs, aluminum nitride NRs are of importance due to their dangling bond, electric field, and strain dependent electronic and magnetic properties. Finally, superlattice structure of NRs of GaN/AlN, Si/Ge, G/BN, and MoS2/WS2 is reviewed. Published by AIP Publishing.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 13.667
Times cited: 63
DOI: 10.1063/1.4966963
|
“A 94K Hg-based superconductor with a “1212&rdquo, structure HG0.5Bi0.5Sr2Ca1-xRxCu2O6+\delta (R=ND,Y,Pr)”. Pelloquin D, Hervieu M, Michel C, Van Tendeloo G, Maignan A, Raveau B, Physica: C : superconductivity 216, 257 (1993)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.942
Times cited: 62
|
“Ab initio study of the structure, infrared spectra and heat of formation of C4”. Martin JML, François JP, Gijbels R, The journal of chemical physics 94, 3753 (1991)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.952
Times cited: 62
|
“Crystallographic shear structures as a route to anion-deficient perovskites”. Abakumov AM, Hadermann J, Bals S, Nikolaev IV, Antipov EV, Van Tendeloo G, Angewandte Chemie: international edition in English 45, 6697 (2006). http://doi.org/10.1002/anie.200602480
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 11.994
Times cited: 62
DOI: 10.1002/anie.200602480
|
“Influence of vacancy defects on the thermal stability of silicene: a reactive molecular dynamics study”. Berdiyorov GR, Peeters FM, RSC advances 4, 1133 (2014). http://doi.org/10.1039/c3ra43487g
Abstract: The effect of vacancy defects on the structural properties and the thermal stability of free standing silicene – a buckled structure of hexagonally arranged silicon atoms – is studied using reactive molecular dynamics simulations. Pristine silicene is found to be stable up to 1500 K, above which the system transits to a three-dimensional amorphous configuration. Vacancy defects result in local structural changes in the system and considerably reduce the thermal stability of silicene: depending on the size of the vacancy defect, the critical temperature decreases by more than 30%. However, the system is still found to be stable well above room temperature within our simulation time of 500 ps. We found that the, stability of silicene can be increased by saturating the dangling bonds at the defect edges by foreign atoms (e.g., hydrogen).
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.108
Times cited: 62
DOI: 10.1039/c3ra43487g
|
“A new “1201&rdquo, mercury cuprate: the 27K-superconductor HG0.5Bi0.5Sr2-xLaxCuO5-\delta”. Pelloquin D, Michel C, Van Tendeloo G, Maignan A, Hervieu M, Raveau B, Physica: C : superconductivity 214, 87 (1993)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.942
Times cited: 62
|
“Platinumcarbon nanotube interaction”. Bittencourt C, Hecq M, Felten A, Pireaux JJ, Ghijsen J, Felicissimo MP, Rudolf P, Drube W, Ke X, Van Tendeloo G, Chemical physics letters 462, 260 (2008). http://doi.org/10.1016/j.cplett.2008.07.082
Abstract: The interaction between evaporated Pt and pristine or oxygen-plasma-treated multiwall carbon nanotubes (CNTs) is investigated. Pt is found to nucleate at defect sites, whether initially present or introduced by oxygen plasma treatment. The plasma treatment induces a uniform dispersion of Pt nanoparticles at the CNT surface. The absence of additional features in the C 1s core level spectrum indicates that no mixed PtC phase is formed. The formation of COPt bonds at the cluster-CNT interface is suggested to reduce the electronic interaction between Pt nanoparticles and the CNT surface.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.815
Times cited: 62
DOI: 10.1016/j.cplett.2008.07.082
|
“Strain-engineered graphene through a nanostructured substrate : 1 : deformations”. Neek-Amal M, Peeters FM, Physical review : B : condensed matter and materials physics 85, 195445 (2012). http://doi.org/10.1103/PhysRevB.85.195445
Abstract: Using atomistic simulations we investigate the morphological properties of graphene deposited on top of a nanostructured substrate. Sinusoidally corrugated surfaces, steps, elongated trenches, one-dimensional and cubic barriers, spherical bubbles, Gaussian bumps, and Gaussian depressions are considered as support structures for graphene. The graphene-substrate interaction is governed by van der Waals forces and the profile of the graphene layer is determined by minimizing the energy using molecular dynamics simulations. Based on the obtained optimum configurations, we found that (i) for graphene placed over sinusoidally corrugated substrates with corrugation wavelengths longer than 2 nm, the graphene sheet follows the substrate pattern while for supported graphene it is always suspended across the peaks of the substrate, (ii) the conformation of graphene to the substrate topography is enhanced when increasing the energy parameter in the van der Waals model, (iii) the adhesion of graphene into the trenches depends on the width of the trench and on the graphene's orientation, i. e., in contrast to a small-width (3 nm) nanoribbon with armchair edges, the one with zigzag edges follows the substrate profile, (iv) atomic-scale graphene follows a Gaussian bump substrate but not the substrate with a Gaussian depression, and (v) the adhesion energy due to van der Waals interaction varies in the range [0.1-0.4] J/m(2).
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 62
DOI: 10.1103/PhysRevB.85.195445
|
“Unusual ultra-low-frequency fluctuations in freestanding graphene”. Xu P, Neek-Amal M, Barber SD, Schoelz JK, Ackerman ML, Thibado PM, Sadeghi A, Peeters FM, Nature communications 5, 3720 (2014). http://doi.org/10.1038/ncomms4720
Abstract: Intrinsic ripples in freestanding graphene have been exceedingly difficult to study. Individual ripple geometry was recently imaged using scanning tunnelling microscopy, but these measurements are limited to static configurations. Thermally-activated flexural phonon modes should generate dynamic changes in curvature. Here we show how to track the vertical movement of a one-square-angstrom region of freestanding graphene using scanning tunnelling microscopy, thereby allowing measurement of the out-of-plane time trajectory and fluctuations over long time periods. We also present a model from elasticity theory to explain the very-low-frequency oscillations. Unexpectedly, we sometimes detect a sudden colossal jump, which we interpret as due to mirror buckling. This innovative technique provides a much needed atomic-scale probe for the time-dependent behaviours of intrinsic ripples. The discovery of this novel progenitor represents a fundamental advance in the use of scanning tunnelling microscopy, which together with the application of a thermal load provides a low-frequency nano-resonator.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 12.124
Times cited: 62
DOI: 10.1038/ncomms4720
|
“VEGF-targeted magnetic nanoparticles for MRI visualization of brain tumor”. Abakumov MA, Nukolova NV, Sokolsky-Papkov M, Shein SA, Sandalova TO, Vishwasrao HM, Grinenko NF, Gubsky IL, Abakumov AM, Kabanov AV, Chekhonin VP;, Nanomedicine: nanotechnology, biology and medicine 11, 825 (2015). http://doi.org/10.1016/j.nano.2014.12.011
Abstract: This work is focused on synthesis and characterization of targeted magnetic nanoparticles as magnetic resonance imaging (MRI) agents for in vivo visualization of gliomas. Ferric oxide (Fe3O4) cores were synthesized by thermal decomposition and coated with bovine serum albumin (BSA) to form nanoparticles with D-eff of 53 +/- 9 nm. The BSA was further cross-linked to improve colloidal stability. Monoclonal antibodies against vascular endothelial growth factor (mAbVEGF) were covalently conjugated to BSA through a polyethyleneglycol linker. Here we demonstrate that 1) BSA coated nanoparticles are stable and non-toxic to different cells at concentration up to 2.5 mg/mL; 2) conjugation of monoclonal antibodies to nanoparticles promotes their binding to VEGF-positive glioma C6 cells in vitro; 3) targeted nanoparticles are effective in MRI visualization of the intracranial glioma. Thus, mAbVEGF-targeted BSA-coated magnetic nanoparticles are promising MRI contrast agents for glioma visualization. (C) 2015 Elsevier Inc. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 5.72
Times cited: 62
DOI: 10.1016/j.nano.2014.12.011
|
“Anisotropic electronic, mechanical, and optical properties of monolayer WTe2”. Torun E, Sahin H, Cahangirov S, Rubio A, Peeters FM, Journal of applied physics 119, 074307 (2016). http://doi.org/10.1063/1.4942162
Abstract: Using first-principles calculations, we investigate the electronic, mechanical, and optical properties of monolayer WTe2. Atomic structure and ground state properties of monolayer WTe2 (T-d phase) are anisotropic which are in contrast to similar monolayer crystals of transition metal dichalcogenides, such as MoS2, WS2, MoSe2, WSe2, and MoTe2, which crystallize in the H-phase. We find that the Poisson ratio and the in-plane stiffness is direction dependent due to the symmetry breaking induced by the dimerization of the W atoms along one of the lattice directions of the compound. Since the semimetallic behavior of the T-d phase originates from this W-W interaction (along the a crystallographic direction), tensile strain along the dimer direction leads to a semimetal to semiconductor transition after 1% strain. By solving the Bethe-Salpeter equation on top of single shot G(0)W(0) calculations, we predict that the absorption spectrum of T-d-WTe2 monolayer is strongly direction dependent and tunable by tensile strain. (C) 2016 AIP Publishing LLC.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.068
Times cited: 62
DOI: 10.1063/1.4942162
|
“Condition for the occurrence of phase slip centers in superconducting nanowires under applied current or voltage”. Michotte S, Mátéfi-Tempfli S, Piraux L, Vodolazov DY, Peeters FM, Physical review : B : condensed matter and materials physics 69, 094512 (2004). http://doi.org/10.1103/PhysRevB.69.094512
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 61
DOI: 10.1103/PhysRevB.69.094512
|
“ELNES study of carbon K-edge spectra of plasma deposited carbon films”. Hamon A-L, Verbeeck J, Schryvers D, Benedikt J, van den Sanden RMCM, Journal of materials chemistry 14, 2030 (2004). http://doi.org/10.1039/b406468m
Abstract: Electron energy loss spectroscopy was used to investigate the bonding of plasma deposited carbon films. The experimental conditions include the use of a specific collection angle for which the shape of the spectra is free of the orientation dependency usually encountered in graphite due to its anisotropic structure. The first quantification process of the energy loss near-edge structure was performed by a standard fit of the collected spectrum, corrected for background and multiple scattering, with three Gaussian functions followed by a comparison with the graphite spectrum obtained under equivalent experimental conditions. In a second approach a fitting model directly incorporating the background subtraction and multiple scattering removal was applied. The final numerical results are interpreted in view of the deposition conditions of the films and the actual fitting procedure with the related choice of parameters.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 6.626
Times cited: 61
DOI: 10.1039/b406468m
|
“Fabrication, interface characterization and modeling of oriented graphite flakes/Si/Al composites for thermal management applications”. Zhou C, Ji G, Chen Z, Wang M, Addad A, Schryvers D, Wang H, Materials and design 63, 719 (2014). http://doi.org/10.1016/j.matdes.2014.07.009
Abstract: Highly thermally conductive graphite flakes (Gf)/Si/Al composites have been fabricated using Gf, Si powder and an AlSi7Mg0.3 alloy by an optimized pressure infiltration process for thermal management applications. In the composites, the layers of Gf were spaced apart by Si particles and oriented perpendicular to the pressing direction, which offered the opportunity to tailor the thermal conductivity (TC) and coefficient of thermal expansion (CTE) of the composites. Microstructural characterization revealed that the formation of a clean and tightly-adhered interface at the nanoscale between the side surface of the Gf and Al matrix, devoid of a detrimental Al4C3 phase and a reacted amorphous AlSiOC layer, contributed to excellent thermal performance along the alignment direction. With increasing volume fraction of Gf from 13.7 to 71.1 vol.%, the longitudinal (i.e. parallel to the graphite layers) TC of the composites increased from 179 to 526 W/m K, while the longitudinal CTE decreased from 12.1 to 7.3 ppm/K (matching the values of electronic components). Furthermore, the modified layers-in-parallel model better fitted the longitudinal TC data than the layers-in-parallel model and confirmed that the clean and tightly-adhered interface is favorable for the enhanced longitudinal TC.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 61
DOI: 10.1016/j.matdes.2014.07.009
|
“Graphene on boron-nitride : Moiré, pattern in the van der Waals energy”. Neek-Amal M, Peeters FM, Applied physics letters 104, 041909 (2014). http://doi.org/10.1063/1.4863661
Abstract: The spatial dependence of the van der Waals (vdW) energy between graphene and hexagonal boron-nitride (h-BN) is investigated using atomistic simulations. The van der Waals energy between graphene and h-BN shows a hexagonal superlattice structure identical to the observed Moire pattern in the local density of states, which depends on the lattice mismatch and misorientation angle between graphene and h-BN. Our results provide atomistic features of the weak van der Waals interaction between graphene and BN which are in agreement with experiment and provide an analytical expression for the size of the spatial variation of the weak van der Waals interaction. We also found that the A-B-lattice symmetry of graphene is broken along the armchair direction. (C) 2014 AIP Publishing LLC.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 61
DOI: 10.1063/1.4863661
|
“Infrared absorption in superlattices: a probe of the miniband dispersion and the structure of the impurity band”. Helm M, Hilber W, Fromherz T, Peeters FM, Alavi K, Pathak R, Physical review : B : condensed matter and materials physics 48, 1601 (1993). http://doi.org/10.1103/PhysRevB.48.1601
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.736
Times cited: 61
DOI: 10.1103/PhysRevB.48.1601
|
“Vortex styructure of thin mesoscopic disks with enhanced superconductivity”. Yampolskii SV, Peeters FM, Physical review : B : condensed matter and materials physics 62, 9663 (2000). http://doi.org/10.1103/PhysRevB.62.9663
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 61
DOI: 10.1103/PhysRevB.62.9663
|