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Batuk M (2013) New perovskite-based homologous series : AnBnO3n-2 and An+1BnO3n-1Cl. Antwerpen
Keywords: Doctoral thesis; Electron microscopy for materials research (EMAT)
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Khalilov U (2013) New perspectives on thermal and hyperthermal oxidation of Si surfaces. Antwerpen
Keywords: Doctoral thesis; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
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“NEXAFS spectromicroscopy of suspended carbon nanohorns”. Bittencourt C, Ke X, Van Tendeloo G, Tagmatarchis N, Guttmann P, Chemical physics letters 587, 85 (2013). http://doi.org/10.1016/j.cplett.2013.09.034
Abstract: We demonstrate that near-edge X-ray-absorption fine-structure spectroscopy combined with full-field transmission X-ray microscopy can be used to study the electronic structure of suspended carbon nanohorns. Based on reports of electronic structure calculations additional spectral features observed in the π region of the NEXAFS spectrum recorded on the carbon nanohorns were associated to the presence of the pentagonal rings and the folding of the graphene sheet.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.815
Times cited: 4
DOI: 10.1016/j.cplett.2013.09.034
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“Non-conventional vortex configurations in a mesoscopic flat disk”. Barba-Ortega J, Sardella E, Aguiar JA, Peeters FM, Physica: C : superconductivity 487, 47 (2013). http://doi.org/10.1016/j.physc.2013.01.021
Abstract: The influence of superficial defects on the vortex configurations of a thin superconducting disk is investigated within the time dependent Ginzburg-Landau formalism. The free energy, magnetization, vorticity, and the Cooper pair density are calculated for both metastable and stable vortex configurations and different number of defects on its surface in the presence of an external magnetic field applied perpendicular to the disk area. We show that the competition between the confinement geometry and the geometric position of the defects leads to non-conventional vortex configurations which are not compatible with the symmetry of the sample geometry. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 17
DOI: 10.1016/j.physc.2013.01.021
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“Nonvolatile resistive switching in Pt/LaAlO3/SrTiO3 heterostructures”. Wu S, Luo X, Turner S, Peng H, Lin W, Ding J, David A, Wang B, Van Tendeloo G, Wang J, Wu T;, Physical review X 3, 041027 (2013). http://doi.org/10.1103/PhysRevX.3.041027
Abstract: Resistive switching heterojunctions, which are promising for nonvolatile memory applications, usually share a capacitorlike metal-oxide-metal configuration. Here, we report on the nonvolatile resistive switching in Pt/LaAlO3/SrTiO3 heterostructures, where the conducting layer near the LaAlO3/SrTiO3 interface serves as the unconventional bottom electrode although both oxides are band insulators. Interestingly, the switching between low-resistance and high-resistance states is accompanied by reversible transitions between tunneling and Ohmic characteristics in the current transport perpendicular to the planes of the heterojunctions. We propose that the observed resistive switching is likely caused by the electric-field-induced drift of charged oxygen vacancies across the LaAlO3/SrTiO3 interface and the creation of defect-induced gap states within the ultrathin LaAlO3 layer. These metal-oxide-oxide heterojunctions with atomically smooth interfaces and defect-controlled transport provide a platform for the development of nonvolatile oxide nanoelectronics that integrate logic and memory devices.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 12.789
Times cited: 77
DOI: 10.1103/PhysRevX.3.041027
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“Novel coreshell magnetic nanoparticles for Taxol encapsulation in biodegradable and biocompatible block copolymers : preparation, characterization and release properties”. Filippousi M, Papadimitriou SA, Bikiaris DN, Pavlidou E, Angelakeris M, Zamboulis D, Tian H, Van Tendeloo G, International journal of pharmaceutics 448, 221 (2013). http://doi.org/10.1016/j.ijpharm.2013.03.025
Abstract: Theranostic polymeric nanocarriers loaded with anticancer drug Taxol and superparamagnetic iron oxide nanocrystals have been developed for possible magnetic resonance imaging (MRI) use and cancer therapy. Multifunctional nanocarriers with a coreshell structure have been prepared by coating superparamagnetic Fe3O4 nanoparticles with block copolymer of poly(ethylene glycol)-b-poly(propylene succinate) with variable molecular weights of the hydrophobic block poly(prolylene succinate). The multifunctional polymer nano-vehicles were prepared using a nanoprecipitation method. Scanning transmission electron microscopy revealed the encapsulation of magnetic nanoparticles inside the polymeric matrix. Energy dispersive X-ray spectroscopy and electron energy loss spectroscopy mapping allowed us to determine the presence of the different material ingredients in a quantitative way. The diameter of the nanoparticles is below 250 nm yielding satisfactory encapsulation efficiency. The nanoparticles exhibit a biphasic drug release pattern in vitro over 15 days depending on the molecular weight of the hydrophobic part of the polymer matrix. These new systems where anti-cancer therapeutics like Taxol and iron oxide nanoparticles (IOs) are co-encapsulated into new facile polymeric nanoparticles, could be addressed as potential multifunctional vehicles for simultaneous drug delivery and targeting imaging as well as real time monitoring of therapeutic effects.
Keywords: A1 Journal article; Pharmacology. Therapy; Electron microscopy for materials research (EMAT)
Impact Factor: 3.649
Times cited: 29
DOI: 10.1016/j.ijpharm.2013.03.025
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“Novel functional imaging of changes in small airways of patients treated with extrafine beclomethasone/formoterol”. Vos W, de Backer J, Poli G, De Volder A, Ghys L, Van Holsbeke C, Vinchurkar S, De Backer L, de Backer W, Respiration 86, 393 (2013). http://doi.org/10.1159/000347120
Abstract: Background: Inhaled formulations using extrafine particles of long-acting beta(2)-agonists and corticosteroids were developed to optimize asthma treatment. Findings that these combinations reach and treat smaller airways more effectively are predominantly based on general non-specific outcomes with little information on regional characteristics. Objectives: This study aims to assess long-term effects of extrafine beclomethasone/formoterol on small airways of asthmatic patients using novel functional imaging methods. Methods: Twenty-four stable asthma patients were subdivided into three groups (steroid naive, n = 7; partially controlled, n = 6; well controlled, n = 11). Current treatment was switched to a fixed combination of extrafine beclomethasone/formoterol (Foster (R); Chiesi Pharmaceuticals, Parma, Italy). Patients underwent lung function evaluation and thorax high-resolution computerized tomography (HRCT) scan. Local airway resistance was obtained from computational fluid dynamics (CFD). Results: After 6 months, the entire population showed improvement in pre-bronchodilation imaging parameters, including small airway volume (p = 0.0007), resistance (p = 0.011), and asthma control score (p = 0.016). Changes in small airway volume correlated with changes in asthma control score (p = 0.004). Forced expiratory volume in 1 s (p = 0.044) and exhaled nitric oxide (p = 0.040) also improved. Functional imaging provided more detail and clinical relevance compared to lung function tests, especially in the well-controlled group where only functional imaging parameters showed significant improvement, while the correlation with asthma control score remained. Conclusions: Extrafine beclomethasone/formoterol results in a significant reduction of small airway obstruction, detectable by functional imaging (HRCT/CFD). Changes in imaging parameters correlated significantly with clinically relevant improvements. This indicates that functional imaging is a useful tool for sensitive assessment of changes in the respiratory system after asthma treatment. Copyright (C) 2013 S. Karger AG, Basel
Keywords: A1 Journal article; Biophysics and Biomedical Physics; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP)
Impact Factor: 2.772
Times cited: 30
DOI: 10.1159/000347120
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“Numerical investigation of SiO2 coating deposition in wafer processing reactors with SiCl4/O2/Ar inductively coupled plasmas”. Tinck S, De Schepper P, Bogaerts A, Plasma processes and polymers 10, 714 (2013). http://doi.org/10.1002/ppap.201300005
Abstract: Simulations and experiments are performed to obtain a better insight in the plasma enhanced chemical vapor deposition process of SiO2 by SiCl4/O2/Ar plasmas for introducing a SiO2-like coating in wafer processing reactors. Reaction sets describing the plasma and surface chemistry of the SiCl4/O2/Ar mixture are presented. Typical calculation results include the bulk plasma characteristics, i.e., electrical properties, species densities, and information on important production and loss processes, as well as the chemical composition of the deposited coating, and the thickness uniformity of the film on all reactor surfaces. The film deposition characteristics, and the trends for varying discharge conditions, are explained based on the plasma behavior, as calculated by the model.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.846
Times cited: 3
DOI: 10.1002/ppap.201300005
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“On the low-temperature growth mechanism of single walled carbon nanotubes in plasma enhanced chemical vapor deposition”. Shariat M, Shokri B, Neyts EC, Chemical physics letters 590, 131 (2013). http://doi.org/10.1016/j.cplett.2013.10.061
Abstract: Despite significant progress in single walled carbon nanotube (SWCNT) production by plasma enhanced chemical vapor deposition (PECVD), the growth mechanism in this method is not clearly understood. We employ reactive molecular dynamics simulations to investigate how plasma-based deposition allows growth at low temperature. We first investigate the SWCNT growth mechanism at low and high temperatures under conditions similar to thermal CVD and PECVD. We then show how ion bombardment during the nucleation stage increases the carbon solubility in the catalyst at low temperature. Finally, we demonstrate how moderate energy ions sputter amorphous carbon allowing for SWCNT growth at 500 K. (C) 2013 Elsevier B. V. All rights reserved.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.815
Times cited: 14
DOI: 10.1016/j.cplett.2013.10.061
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“Optoelectronic properties of ABC-stacked trilayer graphene”. Xiao YM, Xu W, Zhang YY, Peeters FM, Physica status solidi: B: basic research 250, 86 (2013). http://doi.org/10.1002/pssb.201248169
Abstract: We present a theoretical study on the optoelectronic properties of ABC-stacked trilayer graphene (TLG). The optical conductance and light transmittance are evaluated through using the energy-balance equation derived from the Boltzmann equation for an air/graphene/dielectric-wafer system in the presence of linearly polarized radiation field. The results obtained from two band structure models are examined and compared. For short wavelength radiation, the universal optical conductance sigma(0) = 3e(2)/(4h) can be obtained. Importantly, there exists an optical absorption window in the radiation wavelength range 10-200 mu m, which is induced by different transition energies required for inter- and intra-band optical absorption channels. As a result, we find that the position and width of this window depend sensitively on temperature and carrier density of the system, especially the lower frequency edge. There is a small characteristic absorption peak at about 82 mu m where the largest interband transition states exist in the ABC-stacked TLG model, in contrast to the relatively smooth curves in a simplified model. These theoretical results indicate that TLG has some interesting and important physical properties which can be utilized to realize infrared or THz optoelectronic devices.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.674
Times cited: 6
DOI: 10.1002/pssb.201248169
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“Ordered and disordered packing of coronene molecules in carbon nanotubes”. Verberck B, Okazaki T, Tarakina NV, Physical chemistry, chemical physics 15, 18108 (2013). http://doi.org/10.1039/c3cp52797b
Abstract: Monte Carlo simulations of coronene molecules in single-walled carbon nanotubes (SWCNTs) and dicoronylene molecules in SWCNTs are performed. Depending on the diameter D of the encapsulating SWCNT, regimes favoring the formation of ordered, one-dimensional (1D) stacks of tilted molecules (D <= 1.7 nm for coronene@SWCNT, 1.5 nm <= D <= 1.7 nm for dicoronylene@SWCNT) and regimes with disordered molecular arrangements and increased translational mobilities enabling the thermally induced polymerization of neighboring molecules resulting in the formation of graphene nanoribbons (GNRs) are observed. The results show that the diameter of the encapsulating nanotube is a crucial parameter for the controlled synthesis of either highly ordered 1D structures or GNR precursors.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 4.123
Times cited: 9
DOI: 10.1039/c3cp52797b
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“Origin of magnetism and quasiparticles properties in Cr-doped TiO2”. da Pieve F, Di Matteo S, Rangel T, Giantomassi M, Lamoen D, Rignanese G-M, Gonze X, Physical review letters 110, 136402 (2013). http://doi.org/10.1103/PhysRevLett.110.136402
Abstract: Combining the local spin density approximation (LSDA)+U and an analysis of superexchange interactions beyond density functional theory, we describe the magnetic ground state of Cr-doped TiO2, an intensively studied and debated dilute magnetic oxide. In parallel, we correct our LSDA+U (+ superexchange) ground state through GW corrections (GW@LSDA+U) that reproduce the position of the impurity states and the band gaps in satisfying agreement with experiments. Because of the different topological coordinations of Cr-Cr bonds in the ground states of rutile and anatase, superexchange interactions induce either ferromagnetic or antiferromagnetic couplings of Cr ions. In Cr-doped anatase, this interaction leads to a new mechanism which stabilizes a (nonrobust) ferromagnetic ground state, in keeping with experimental evidence, without the need to invoke F-center exchange. The interplay between structural defects and vacancies in contributing to the superexchange is also unveiled.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 8.462
Times cited: 15
DOI: 10.1103/PhysRevLett.110.136402
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“Oxidation and degradation of native wheat starch by acidic bromate in water at room temperature”. Komulainen S, Verlackt C, Pursiainen J, Lajunen M, Carbohydrate Polymers 93, 73 (2013). http://doi.org/10.1016/j.carbpol.2012.06.001
Abstract: Native wheat starch was oxidized by benign acidic bromate in water at room temperature. HPLC-ELSD study indicated that starch degraded in the course of oxidation but it still had a polymeric structure characterized by H-1, C-13, HSQC and HMBC NMR measurements. Products were generally water-soluble fragments but the use of a short reaction time and dilute reaction mixture yielded water-insoluble products. Titration of the products showed, that the increase of the starch content and reaction time increased the content of carbonyl and carboxyl groups in the range of 0.5-2.5% and 1.7-17.2%, respectively, in the product fragments. A mechanism for the oxidation reaction was proposed. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Impact Factor: 4.811
Times cited: 32
DOI: 10.1016/j.carbpol.2012.06.001
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“Perovskite transparent conducting oxides : an ab initio study”. Dabaghmanesh S, Saniz R, Amini MN, Lamoen D, Partoens B, Journal of physics : condensed matter 25, 415503 (2013). http://doi.org/10.1088/0953-8984/25/41/415503
Abstract: We present an ab initio study of the electronic structure and of the formation energies of various point defects in BaSnO3 and SrGeO3. We show that La and Y impurities substituting Ba or Sr are shallow donors with a preferred 1 + charge state. These defects have a low formation energy within all the suitable equilibrium growth conditions considered. Oxygen vacancies behave as shallow donors as well, preferring the 2 + charge state. Their formation energies, however, are higher in most growth conditions, indicating a limited contribution to conductivity. The calculated electron effective mass in BaSnO3, with a value of 0.21 me, and the very high mobility reported recently in La-doped BaSnO3 single-crystals, suggest that remarkably low scattering rates can be achieved in the latter. In the case of SrGeO3, our results point to carrier density and mobility values in the low range for typical polycrystalline TCOs, in line with experiment.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.649
Times cited: 17
DOI: 10.1088/0953-8984/25/41/415503
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“Phonon-assisted Zener tunneling in a p-n diode silicon nanowire”. Carrillo-Nunez H, Magnus W, Vandenberghe WG, Sorée B, Peeters FM, Solid state electronics 79, 196 (2013). http://doi.org/10.1016/j.sse.2012.09.004
Abstract: The Zener tunneling current flowing through a biased, abrupt p-n junction embedded in a cylindrical silicon nanowire is calculated. As the band gap becomes indirect for sufficiently thick wires, Zener tunneling and its related transitions between the valence and conduction bands are mediated by short-wavelength phonons interacting with mobile electrons. Therefore, not only the high electric field governing the electrons in the space-charge region but also the transverse acoustic (TA) and transverse optical (TO) phonons have to be incorporated in the expression for the tunneling current. The latter is also affected by carrier confinement in the radial direction and therefore we have solved the Schrodinger and Poisson equations self-consistently within the effective mass approximation for both conduction and valence band electrons. We predict that the tunneling current exhibits a pronounced dependence on the wire radius, particularly in the high-bias regime. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.58
Times cited: 2
DOI: 10.1016/j.sse.2012.09.004
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“Phonon softening and direct to indirect band gap crossover in strained single-layer MoSe2”. Horzum S, Sahin H, Cahangirov S, Cudazzo P, Rubio A, Serin T, Peeters FM, Physical review : B : condensed matter and materials physics 87, 125415 (2013). http://doi.org/10.1103/PhysRevB.87.125415
Abstract: Motivated by recent experimental observations of Tongay et al. [Nano Lett. 12, 5576 (2012)] we show how the electronic properties and Raman characteristics of single layer MoSe2 are affected by elastic biaxial strain. We found that with increasing strain: (1) the E' and E '' Raman peaks (E-2g and E-1g in bulk) exhibit significant redshifts (up to similar to 30 cm(-1)), (2) the position of the A'(1) peak remains at similar to 180 cm(-1) (A(1g) in bulk) and does not change considerably with further strain, (3) the dispersion of low energy flexural phonons crosses over from quadratic to linear, and (4) the electronic band structure undergoes a direct to indirect band gap crossover under similar to 3% biaxial tensile strain. Thus the application of strain appears to be a promising approach for a rapid and reversible tuning of the electronic, vibrational, and optical properties of single layer MoSe2 and similar MX2 dichalcogenides. DOI:10.1103/PhysRevB.87.125415
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 171
DOI: 10.1103/PhysRevB.87.125415
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“Photoconductivity of nanocrystalline SnO2 sensitized with colloidal CdSe quantum dots”. Vasiliev RB, Babynina AV, Maslova OA, Rumyantseva MN, Ryabova LI, Dobrovolsky AA, Drozdov KA, Khokhlov DR, Abakumov AM, Gaskov AM, Journal of materials chemistry C : materials for optical and electronic devices 1, 1005 (2013). http://doi.org/10.1039/c2tc00236a
Abstract: A highly reproducible photoresponse is observed in nanocrystalline SnO2 thick films sensitized with CdSe quantum dots. The effect of the SnO2 matrix microstructure on the photoconductivity kinetics and photoresponse amplitude is demonstrated. The photoresponse of the sensitized SnO2 thick films reaches more than two orders of magnitude under illumination with the wavelength of the excitonic transition of the quantum dots. Long-term photoconductivity kinetics and photoresponse dependence on illumination intensity reveal power-law behavior inherent to the disordered nature of SnO2. The photoconductivity of the samples rises with the coarsening of the granular structure of the SnO2 matrix. At the saturation region, the photoresponse amplitude remains stable under 10(4) pulses of illumination switching, demonstrating a remarkably high stability.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.256
Times cited: 13
DOI: 10.1039/c2tc00236a
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“Piezoelectric surface acoustical phonon limited mobility of electrons in graphene on a GaAs substrate”. Zhang SH, Xu W, Badalyan SM, Peeters FM, Physical review : B : condensed matter and materials physics 87, 075443 (2013). http://doi.org/10.1103/PhysRevB.87.075443
Abstract: We study the mobility of Dirac fermions in monolayer graphene on a GaAs substrate, limited by the combined action of the extrinsic potential of piezoelectric surface acoustical phonons of GaAs (PA) and of the intrinsic deformation potential of acoustical phonons in graphene (DA). In the high-temperature (T) regime, the momentum relaxation rate exhibits the same linear dependence on T but different dependencies on the carrier density n, corresponding to the mobility mu proportional to 1 root n and 1/n, respectively for the PA and DA scattering mechanisms. In the low-T Bloch-Gruneisen regime, the mobility shows the same square-root density dependence mu proportional to root n, but different temperature dependencies mu proportional to T-3 and T-4, respectively for PA and DA phonon scattering. DOI: 10.1103/PhysRevB.87.075443
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 25
DOI: 10.1103/PhysRevB.87.075443
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“Plasma-based dry reforming : a computational study ranging from the nanoseconds to seconds time scale”. Snoeckx R, Aerts R, Tu X, Bogaerts A, The journal of physical chemistry: C : nanomaterials and interfaces 117, 4957 (2013). http://doi.org/10.1021/jp311912b
Abstract: We present a computational study for the conversion of CH4 and CO2 into value-added chemicals, i.e., the so-called dry reforming of methane, in a dielectric barrier discharge reactor. A zero-dimensional chemical kinetics model is applied to study the plasma chemistry in a 1:1 CH4/CO2 mixture. The calculations are first performed for one microdischarge pulse and its afterglow, to study in detail the chemical pathways of the conversion. Subsequently, long time-scale simulations are carried out, corresponding to real residence times in the plasma, assuming a large number of consecutive microdischarge pulses, to mimic the conditions of the filamentary discharge regime in a dielectric barrier discharge (DBD) reactor. The conversion of CH4 and CO2 as well as the selectivity of the formed products and the energy cost and energy efficiency of the process are calculated and compared to experiments for a range of different powers and gas flows, and reasonable agreement is reached.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.536
Times cited: 118
DOI: 10.1021/jp311912b
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“Plasma enhanced growth of single walled carbon nanotubes at low temperature : a reactive molecular dynamics simulation”. Shariat M, Hosseini SI, Shokri B, Neyts EC, Carbon 65, 269 (2013). http://doi.org/10.1016/j.carbon.2013.08.025
Abstract: Low-temperature growth of carbon nanotubes (CNTs) has been claimed to provide a route towards chiral-selective growth, enabling a host of applications. In this contribution, we employ reactive molecular dynamics simulations to demonstrate how plasma-based deposition allows such low-temperature growth. We first show how ion bombardment during the growth affects the carbon dissolution and precipitation process. We then continue to demonstrate how a narrow ion energy window allows CNT growth at 500 K. Finally, we also show how CNTs in contrast cannot be grown in thermal CVD at this low temperature, but only at high temperature, in agreement with experimental data. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 6.337
Times cited: 21
DOI: 10.1016/j.carbon.2013.08.025
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“Plasma-induced destruction of bacterial cell wall components : a reactive molecular dynamics simulation”. Yusupov M, Bogaerts A, Huygh S, Snoeckx R, van Duin ACT, Neyts EC, The journal of physical chemistry: C : nanomaterials and interfaces 117, 5993 (2013). http://doi.org/10.1021/jp3128516
Abstract: Nonthermal atmospheric pressure plasmas are gaining increasing attention for biomedical applications. However, very little fundamental information on the interaction mechanisms between the plasma species and biological cells is currently available. We investigate the interaction of important plasma species, such as OH, H2O2, O, O3, as well as O2 and H2O, with bacterial peptidoglycan by means of reactive molecular dynamics simulations, aiming for a better understanding of plasma disinfection. Our results show that OH, O, O3, and H2O2 can break structurally important bonds of peptidoglycan (i.e., CO, CN, or CC bonds), which consequently leads to the destruction of the bacterial cell wall. The mechanisms behind these breakups are, however, dependent on the impinging plasma species, and this also determines the effectiveness of the cell wall destruction.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.536
Times cited: 59
DOI: 10.1021/jp3128516
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“Plasma nanoscience : from nano-solids in plasmas to nano-plasmas in solids”. Ostrikov K, Neyts EC, Meyyappan M, Advances in physics 62, 113 (2013). http://doi.org/10.1080/00018732.2013.808047
Abstract: The unique plasma-specific features and physical phenomena in the organization of nanoscale soild-state systems in a broad range of elemental composition, structure, and dimensionality are critically reviewed. These effects lead to the possibility to localize and control energy and matter at nanoscales and to produce self-organized nano-solids with highly unusual and superior properties. A unifying conceptual framework based on the control of production, transport, and self-organization of precursor species is introduced and a variety of plasma-specific non-equilibrium and kinetics-driven phenomena across the many temporal and spatial scales is explained. When the plasma is localized to micrometer and nanometer dimensions, new emergent phenomena arise. The examples range from semiconducting quantum dots and nanowires, chirality control of single-walled carbon nanotubes, ultra-fine manipulation of graphenes, nano-diamond, and organic matter to nano-plasma effects and nano-plasmas of different states of matter.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 21.818
Times cited: 380
DOI: 10.1080/00018732.2013.808047
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“Plasmonic excitations in Coulomb-coupled N-layer graphene structures”. Zhu J-J, Badalyan SM, Peeters FM, Physical review : B : condensed matter and materials physics 87, 085401 (2013). http://doi.org/10.1103/PhysRevB.87.085401
Abstract: We study Dirac plasmons and their damping in spatially separated N-layer graphene structures at finite doping and temperatures. The plasmon spectrum consists of one optical excitation with square-root dispersion and N – 1 acoustical excitations with linear dispersion, which are undamped at zero temperature and finite doping within a triangular energy region outside the electron-hole continuum. In the long-wavelength limit the energy and weight of the optical plasmon modes increase, respectively, as the square root and linearly with N in agreement with recent experimental findings. The energy and weight of the upper-lying acoustical branches also increase with N. This increase is strongest for the uppermost acoustical mode, and we find that its energy can exceed at some value of momentum the plasmon energy in an individual graphene sheet. Meanwhile, the energy of the low-lying acoustical branches decreases weakly with N as compared with the single acoustical mode in double-layer graphene structures. Our numerical calculations provide a detailed understanding of the overall behavior of the wave-vector dependence of the optical and acoustical multilayer plasmon modes and show how their dispersion and damping are modified as a function of temperature, interlayer spacing, and inlayer carrier density in (un)balanced graphene multilayer structures. DOI: 10.1103/PhysRevB.87.085401
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 59
DOI: 10.1103/PhysRevB.87.085401
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“Platinum and palladium on carbon nanotubes : experimental and theoretical studies”. Adjizian JJ, De Marco P, Suarez-Martinez I, El Mel AA, Snyders R, Gengler RYN, Rudolf P, Ke X, Van Tendeloo G, Bittencourt C, Ewels CP;, Chemical physics letters 571, 44 (2013). http://doi.org/10.1016/j.cplett.2013.03.079
Abstract: Pristine and oxygen plasma functionalised carbon nanotubes (CNTs) were studied after the evaporation of Pt and Pd atoms. High resolution transmission electron microscopy shows the formation of metal nanoparticles at the CNT surface. Oxygen functional groups grafted by the plasma functionalization act as nucleation sites for metal nanoparticles. Analysis of the C1s core level spectra reveals that there is no covalent bonding between the Pt or Pd atoms and the CNT surface. Unlike other transition metals such as titanium and copper, neither Pd nor Pt show strong oxygen interaction or surface oxygen scavenging behaviour.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.815
Times cited: 23
DOI: 10.1016/j.cplett.2013.03.079
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“Polar and magnetic layered A-site and rock salt B-site-ordered NaLnFeWO6 (Ln = La, Nd) perovskites”. Retuerto M, Li MR, Ignatov A, Croft M, Ramanujachary KV, Chi S, Hodges JP, Dachraoui W, Hadermann J, Tran TT, Halasyamani PS, Grams CP, Hemberger J, Greenblatt M;, Inorganic chemistry 52, 12482 (2013). http://doi.org/10.1021/ic401491y
Abstract: We have expanded the double perovskite family of materials with the unusual combination of layered order in the A sublattice and rock salt order over the B sublattice to compounds NaLaFeWO6 and NaNdFeWO6. The materials have been synthesized and studied by powder X-ray diffraction, neutron diffraction, electron diffraction, magnetic measurements, X-ray absorption spectroscopy, dielectric measurements, and second harmonic generation. At room temperature, the crystal structures of both compounds can be defined in the noncentrosymmetric monoclinic P2(1) space group resulting from the combination of ordering both in the A and B sublattices, the distortion of the cell due to tilting of the octahedra, and the displacement of certain cations. The magnetic studies show that both compounds are ordered antiferromagnetically below T-N approximate to 25 K for NaLaFeWO6 and at similar to 21 K for NaNdFeWO6. The magnetic structure of NaNdFeWO6 has been solved with a propagation vector k = (1/2 0 1/2) as an antiferromagnetic arrangement of Fe and Nd moments. Although the samples are potential multiferroics, the dielectric measurements do not show a ferroelectric response.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.857
Times cited: 17
DOI: 10.1021/ic401491y
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“Polar and magnetic Mn2FeMO6 (M=Nb, Ta) with LiNbO3-type structure : high-pressure synthesis”. Li MR, Walker D, Retuerto M, Sarkar T, Hadermann J, Stephens PW, Croft M, Ignatov A, Grams CP, Hemberger J, Nowik I, Halasyamani PS, Tran TT, Mukherjee S, Dasgupta TS, Greenblatt M;, Angewandte Chemie: international edition in English 52, 8406 (2013). http://doi.org/10.1002/anie.201302775
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 11.994
Times cited: 53
DOI: 10.1002/anie.201302775
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“Polyhedral iron oxide coreshell nanoparticles in a biodegradable polymeric matrix : preparation, characterization and application in magnetic particle hyperthermia and drug delivery”. Filippousi M, Altantzis T, Stefanou G, Betsiou M, Bikiaris DN, Angelakeris M, Pavlidou E, Zamboulis D, Van Tendeloo G, RSC advances 3, 24367 (2013). http://doi.org/10.1039/c3ra43747g
Abstract: Polyhedral magnetic iron oxide nanocrystals with multiple facets have been embedded in biocompatible and biodegradable polymeric matrices in order to study their structural, magnetic features and alternating-current (AC) magnetic heating efficiency. The encapsulation of iron oxide nanoparticles into a polymer matrix was confirmed by transmission electron microscopy and further corroborated by high angle annular dark field scanning transmission electron microscopy (HAADF-STEM). HAADF-STEM tomography proved that the iron oxide nanocrystals consist of well-defined polyhedral structures with multiple facets. The magnetic features were found to be in good agreement with the structural and morphological features and are maintained even after encapsulation. Furthermore, the magnetic nanoparticles inside these matrices may be considered as good candidates for biomedical applications in hyperthermia treatments because of their high heating capacity exhibited under an alternating magnetic field. The anticancer Taxol drug was encapsulated in these nanoparticles and its physical state and release rate at 37 and 42 °C was studied.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.108
Times cited: 19
DOI: 10.1039/c3ra43747g
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“Preparation, structure, and electrochemistry of layered polyanionic hydroxysulfates : LiMSO4OH (M = Fe, Co, Mn) electrodes for Li-Ion batteries”. Subban CV, Ati M, Rousse G, Abakumov AM, Van Tendeloo G, Janot R, Tarascon J-M, Journal of the American Chemical Society 135, 3653 (2013). http://doi.org/10.1021/ja3125492
Abstract: The Li-ion rechargeable battery, due to its high energy density, has driven remarkable advances in portable electronics. Moving toward more sustainable electrodes could make this technology even more attractive to large-volume applications. We present here a new family of 3d-metal hydroxysulfates of general formula LiMSO4OH (M = Fe, Co, and Mn) among which (i) LiFeSO4OH reversibly releases 0.7 Li+ at an average potential of 3.6 V vs Li+/Li-0, slightly higher than the potential of currently lauded LiFePO4 (3.45 V) electrode material, and (ii) LiCoSO4OH shows a redox activity at 4.7 V vs Li+/Li-0. Besides, these compounds can be easily made at temperatures near 200 degrees C via a synthesis process that enlists a new intermediate phase of composition M-3(SO4)(2)(OH)(2) (M = Fe, Co, Mn, and Ni), related to the mineral caminite. Structurally, we found that LiFeSO4OH is a layered phase unlike the previously reported 3.2 V tavorite LiFeSO4OH. This work should provide an impetus to experimentalists for designing better electrolytes to fully tap the capacity of high-voltage Co-based hydroxysulfates, and to theorists for providing a means to predict the electrochemical redox activity of two polymorphs.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 53
DOI: 10.1021/ja3125492
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“Probing the dynamic response of antivortex, interstitial and trapped vortex lattices on magnetic periodic pinning potentials”. Gomez A, Gonzalez EM, Gilbert DA, Milošević, MV, Liu K, Vicent JL, Superconductor science and technology 26, 085018 (2013). http://doi.org/10.1088/0953-2048/26/8/085018
Abstract: The dynamics of the pinned vortex, antivortex and interstitial vortex have been studied in superconducting/magnetic hybrids consisting of arrays of Co/Pd multilayer nanodots embedded in Nb films. The magnetic nanodots show out-of-plane magnetization at the remanent state. This magnetic state allows for superconducting vortex lattices of different types in an applied homogeneous magnetic field. We experimentally and theoretically show three such lattices: (i) a lattice containing only antivortices; (ii) a vortex lattice entirely pinned on the dots; and (iii) a vortex lattice with pinned and interstitial vortices. Between the flux creep (low vortex velocity) and the free flux flow (high vortex velocity) regimes the interaction between the magnetic array and the vortex lattice governs the vortex dynamics, which in turn enables distinguishing experimentally the type of vortex lattice which governs the dissipation. We show that the vortex lattice with interstitial vortices has the highest onset velocity where the lattice becomes ordered, whereas the pinned vortex lattice has the smallest onset velocity. Further, for this system, we directly estimate that the external force needed to depin vortices is 60% larger than the one needed to depin antivortices; therefore we are able to decouple the antivortex-vortex motion.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.878
Times cited: 7
DOI: 10.1088/0953-2048/26/8/085018
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“Pseudo magnetic field in strained graphene : revisited”. Masir MR, Moldovan D, Peeters FM, Solid state communications 175, 76 (2013). http://doi.org/10.1016/j.ssc.2013.04.001
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.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.554
Times cited: 57
DOI: 10.1016/j.ssc.2013.04.001
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