Home | << 1 2 3 4 5 6 7 8 9 10 11 12 13 >> |
Records | |||||
---|---|---|---|---|---|
Author | Zhang, Q.-Z.; Liu, Y.-X.; Jiang, W.; Bogaerts, A.; Wang, Y.-N. | ||||
Title | Heating mechanism in direct current superposed single-frequency and dual-frequency capacitively coupled plasmas | Type | A1 Journal article | ||
Year | 2013 | Publication | Plasma sources science and technology | Abbreviated Journal | Plasma Sources Sci T |
Volume | 22 | Issue | 2 | Pages | 025014-25018 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | In this work particle-in-cell/Monte Carlo collision simulations are performed to study the heating mechanism and plasma characteristics in direct current (dc) superposed radio-frequency (RF) capacitively coupled plasmas, operated both in single-frequency (SF) and dual-frequency (DF) regimes. An RF (60/2 MHz) source is applied on the bottom electrode to sustain the discharge, and a dc source is fixed on the top electrode. The heating mechanism appears to be very different in dc superposed SF and DF discharges. When only a single source of 60 MHz is applied, the plasma bulk region is reduced by the dc source, thus the ionization rate and hence the electron density decrease with rising dc voltage. However, when a DF source of 60 and 2 MHz is applied, the electron density can increase upon addition of a dc voltage, depending on the gap length and applied dc voltage. This is explained from the spatiotemporal ionization rates in the DF discharge. In fact, a completely different behavior is observed for the ionization rate in the two half-periods of the LF source. In the first LF half-period, the situation resembles the dc superposed SF discharge, and the reduced plasma bulk region due to the negative dc bias results in a very small effective discharge area and a low ionization rate. On the other hand, in the second half-period, the negative dc bias is to some extent counteracted by the LF voltage, and the sheath close to the dc electrode becomes particularly thin. Consequently, the amplitude of the high-frequency sheath oscillations at the top electrode is largely enhanced, while the LF sheath at the bottom electrode is in its expanding phase and can thus well confine the high-energy electrons. Therefore, the ionization rate increases considerably in this second LF half-period. Furthermore, in addition to the comparison between SF and DF discharges and the effect of gap length and dc voltage, the effect of secondary electrons is examined. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Institute of Physics | Place of Publication | Bristol | Editor | |
Language | Wos | 000317275400016 | Publication Date | 2013-03-28 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0963-0252;1361-6595; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.302 | Times cited | 9 | Open Access | |
Notes | Approved | Most recent IF: 3.302; 2013 IF: 3.056 | |||
Call Number | UA @ lucian @ c:irua:106877 | Serial | 1413 | ||
Permanent link to this record | |||||
Author | Van Duppen, B.; Peeters, F.M. | ||||
Title | Klein paradox for a pn junction in multilayer graphene | Type | A1 Journal article | ||
Year | 2013 | Publication | Europhysics letters | Abbreviated Journal | Epl-Europhys Lett |
Volume | 102 | Issue | 2 | Pages | 27001-27005 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Charge carriers in single and multilayered graphene systems behave as chiral particles due to the particular lattice symmetry of the crystal. We show that the interplay between the meta-material properties of graphene multilayers and the pseudospinorial properties of the charge carriers result in the occurrence of Klein and anti-Klein tunneling for rhombohedral stacked multilayers. We derive an algebraic formula predicting the angles at which these phenomena occur and support this with numerical calculations for systems up to four layers. We present a decomposition of an arbitrarily stacked multilayer into pseudospin doublets that have the same properties as rhombohedral systems with a lower number of layers. Copyright (C) EPLA, 2013 | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Paris | Editor | ||
Language | Wos | 000319617700017 | Publication Date | 2013-05-02 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0295-5075;1286-4854; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.957 | Times cited | 17 | Open Access | |
Notes | ; We thank S. GILLIS for valuable discussions. This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro-GRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-Vl) by an aspirant research grant to B. Van Duppen and the Methusalem Programme of the Flemish Government. ; | Approved | Most recent IF: 1.957; 2013 IF: 2.269 | ||
Call Number | UA @ lucian @ c:irua:109665 | Serial | 1763 | ||
Permanent link to this record | |||||
Author | Shanenko, A.A.; Orlova, N.V.; Vagov, A.; Milošević, M.V.; Axt, V.M.; Peeters, F.M. | ||||
Title | Nanofilms as quantum-engineered multiband superconductors : the Ginzburg-Landau theory | Type | A1 Journal article | ||
Year | 2013 | Publication | Europhysics letters | Abbreviated Journal | Epl-Europhys Lett |
Volume | 102 | Issue | 2 | Pages | 27003-27006 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Recently fabricated single-crystalline atomically flat metallic nanofilms are in fact quantum-engineered multiband superconductors. Here the multiband structure is dictated by the nanofilm thickness through the size quantization of the electron motion perpendicular to the nanofilm. This opens the unique possibility to explore superconductivity in well-controlled multi-band systems. However, a serious obstacle is the absence of a convenient and manageable theoretical tool to access new physical phenomena in such quasi-two-dimensional systems, including interplay of quantum confinement and fluctuations. Here we cover this gap and construct the appropriate multiband Ginzburg-Landau functional for nano-thin superconductors. Copyright (C) EPLA, 2013 | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Paris | Editor | ||
Language | Wos | 000319617700019 | Publication Date | 2013-05-03 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0295-5075;1286-4854; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.957 | Times cited | 8 | Open Access | |
Notes | ; This work was supported by the “Odysseus” Program of the Flemish Government and the Flemish Science Foundation (FWO-Vl). ; | Approved | Most recent IF: 1.957; 2013 IF: 2.269 | ||
Call Number | UA @ lucian @ c:irua:109859 | Serial | 2257 | ||
Permanent link to this record | |||||
Author | Lu, Y.-G.; Turner, S.; Verbeeck, J.; Janssens, S.D.; Haenen, K.; Van Tendeloo, G. | ||||
Title | Local bond length variations in boron-doped nanocrystalline diamond measured by spatially resolved electron energy-loss spectroscopy | Type | A1 Journal article | ||
Year | 2013 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 103 | Issue | 3 | Pages | 032105-5 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Variations in local bond length and coordination in boron-doped nanocrystalline diamond (NCD) films have been studied through changes in the fine structure of boron and carbon K-edges in electron energy-loss spectra, acquired in a scanning transmission electron microscope. The presence of high concentrations of B in pristine diamond regions and enrichment of B at defects in single NCD grains is demonstrated. Local bond length variations are evidenced through an energy shift of the carbon 1s → σ* edge at B-rich defective regions within single diamond grains, indicating an expansion of the diamond bond length at sites with local high B content. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000322146300049 | Publication Date | 2013-07-17 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-6951; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.411 | Times cited | 15 | Open Access | |
Notes | Iap P6/42; Fwo G056810n; 262348 Esmi; 246791 Countatoms; 278510 Vortex; Fwo ECASJO_; | Approved | Most recent IF: 3.411; 2013 IF: 3.515 | ||
Call Number | UA @ lucian @ c:irua:109210UA @ admin @ c:irua:109210 | Serial | 1824 | ||
Permanent link to this record | |||||
Author | Lubk, A.; Clark, L.; Guzzinati, G.; Verbeeck, J. | ||||
Title | Topological analysis of paraxially scattered electron vortex beams | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : A : atomic, molecular and optical physics | Abbreviated Journal | Phys Rev A |
Volume | 87 | Issue | 3 | Pages | 033834-33838 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | We investigate topological aspects of subnanometer electron vortex beams upon elastic propagation through atomic scattering potentials. Two main aspects can be distinguished: (i) significantly reduced delocalization compared to a similar nonvortex beam if the beam centers on an atomic column and (ii) site symmetry dependent splitting of higher-order vortex beams. Furthermore, the results provide insight into the complex vortex line fabric within the elastically scattered wave containing characteristic vortex loops predominantly attached to atomic columns and characteristic twists of vortex lines around atomic columns. DOI: 10.1103/PhysRevA.87.033834 | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | American Physical Society | Place of Publication | New York, N.Y | Editor | |
Language | Wos | 000316790600011 | Publication Date | 2013-03-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1050-2947;1094-1622; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.925 | Times cited | 26 | Open Access | |
Notes | Countatoms; Vortex; Esteem2; esteem2jra3 ECASJO; | Approved | Most recent IF: 2.925; 2013 IF: 2.991 | ||
Call Number | UA @ lucian @ c:irua:108496 | Serial | 3673 | ||
Permanent link to this record | |||||
Author | Maignan, A.; Singh, K.; Simon, C.; Lebedev, O.I.; Martin, C.; Tan, H.; Verbeeck, J.; Van Tendeloo, G. | ||||
Title | Magnetic and magnetodielectric properties of erbium iron garnet ceramic | Type | A1 Journal article | ||
Year | 2013 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 113 | Issue | 3 | Pages | 033905-5 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | An Er3Fe5O12 ceramic has been sintered in oxygen atmosphere at 1400 °C for dielectric measurements. Its structural quality at room temperature has been checked by combining transmission electron microscopy and X-ray diffraction. It crystallizes in the cubic space group Ia3d with a = 12.3488(1). The dielectric permittivity ([variantgreekepsilon]′) and losses (tan δ) measurements as a function of temperature reveal the existence of two anomalies, a broad one between 110 K and 80 K, attributed to the Er3+ spin reorientation, and a second sharper feature at about 45 K associated to the appearance of irreversibility on the magnetic susceptibility curves. In contrast to the lack of magnetic field impact on [variantgreekepsilon]′ for the former anomaly, a complex magnetic field effect has been evidenced below 45 K. The isothermal [variantgreekepsilon]′(H) curves show the existence of positive magnetodielectric effect, reaching a maximum of 0.14% at 3 T and 10 K. Its magnitude decreases as H is further increased. Interestingly, for the lowest H values, a linear regime in the [variantgreekepsilon]′(H) curve is observed. From this experimental study, it is concluded that the [variantgreekepsilon]′ anomaly, starting above the compensation temperature Tc (75 K) and driven by the internal magnetic field, is not sensitive to an applied external magnetic field. Thus, below 45 K, it is the magnetic structure which is responsible for the coupling between spin and charge in this iron garnet. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000313670600042 | Publication Date | 2013-01-16 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-8979; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 15 | Open Access | |
Notes | Vortex; Countatoms ECASJO_; | Approved | Most recent IF: 2.068; 2013 IF: 2.185 | ||
Call Number | UA @ lucian @ c:irua:106182UA @ admin @ c:irua:106182 | Serial | 1861 | ||
Permanent link to this record | |||||
Author | Li, D.Y.; Zeng, Y.J.; Pereira, L.M.C.; Batuk, D.; Hadermann, J.; Zhang, Y.Z.; Ye, Z.Z.; Temst, K.; Vantomme, A.; Van Bael, M.J.; Van Haesendonck, C.; | ||||
Title | Anisotropic magnetism and spin-dependent transport in Co nanoparticle embedded ZnO thin films | Type | A1 Journal article | ||
Year | 2013 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 114 | Issue | 3 | Pages | 033909-6 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Oriented Co nanoparticles were obtained by Co ion implantation in crystalline ZnO thin films grown by pulsed laser deposition. Transmission electron microscopy revealed the presence of elliptically shaped Co precipitates with nanometer size, which are embedded in the ZnO thin films, resulting in anisotropic magnetic behavior. The low-temperature resistance of the Co-implanted ZnO thin films follows the Efros-Shklovskii type variable-range-hopping. Large negative magnetoresistance (MR) exceeding 10% is observed in a magnetic field of 1 T at 2.5K and the negative MR survives up to 250K (0.3%). The negative MR reveals hysteresis as well as anisotropy that correlate well with the magnetic properties, clearly demonstrating the presence of spin-dependent transport. (C) 2013 AIP Publishing LLC. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000322202700071 | Publication Date | 2013-07-17 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-8979; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 10 | Open Access | |
Notes | Approved | Most recent IF: 2.068; 2013 IF: 2.185 | |||
Call Number | UA @ lucian @ c:irua:110765 | Serial | 126 | ||
Permanent link to this record | |||||
Author | Esfahani, D.N.; Covaci, L.; Peeters, F.M. | ||||
Title | Field effect on surface states in a doped Mott-insulator thin film | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 3 | Pages | 035131-35136 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Surface effects of a doped thin film made of a strongly correlated material are investigated both in the absence and presence of a perpendicular electric field. We use an inhomogeneous Gutzwiller approximation for a single-band Hubbard model in order to describe correlation effects. For low doping, the bulk value of the quasiparticle weight is recovered exponentially deep into the slab, but with increasing doping, additional Friedel oscillations appear near the surface. We show that the inverse correlation length has a power-law dependence on the doping level. In the presence of an electrical field, considerable changes in the quasiparticle weight can be realized throughout the system. We observe a large difference (as large as five orders of magnitude) in the quasiparticle weight near the opposite sides of the slab. This effect can be significant in switching devices that use the surface states for transport. DOI: 10.1103/PhysRevB.87.035131 | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000313941000001 | Publication Date | 2013-01-29 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 4 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-VI). ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:110086 | Serial | 1190 | ||
Permanent link to this record | |||||
Author | Turner, S.; Lebedev, O.I.; Verbeeck, J.; Gehrke, K.; Moshnyaga, V.; Van Tendeloo, G. | ||||
Title | Structural phase transition and spontaneous interface reconstruction in La2/3Ca1/3MnO3/BaTiO3 superlattices | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 3 | Pages | 035418-8 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | (La2/3Ca1/3MnO3)n/(BaTiO3)m (LCMOn/BTOm) superlattices on MgO and SrTiO3 substrates with different layer thicknesses (n = 10, 38, 40 and m = 5, 18, 20) have been grown by metal organic aerosol deposition (MAD) and have been fully characterized down to the atomic scale to study the interface characteristics. Scanning transmission electron microscopy combined with spatially resolved electron energy-loss spectroscopy provides clear evidence for the existence of atomically sharp interfaces in MAD grown films, which exhibit epitaxial growth conditions, a uniform normal strain, and a fully oxidized state. Below a critical layer thickness the LCMO structure is found to change from the bulk Pnma symmetry to a pseudocubic R3̅ c symmetry. An atomically flat interface reconstruction consisting of a single Ca-rich atomic layer is observed on the compressively strained BTO on LCMO interface, which is thought to partially neutralize the total charge from the alternating polar atomic layers in LCMO as well as relieving strain at the interface. No interface reconstruction is observed at the tensile strained LCMO on BTO interface. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000313940400008 | Publication Date | 2013-01-23 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 12 | Open Access | |
Notes | FWO; Hercules; Countatoms | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:106180 | Serial | 3245 | ||
Permanent link to this record | |||||
Author | Zarenia, M.; Pereira, J.M., Jr.; Peeters, F.M.; Farias, G.A. | ||||
Title | Snake states in graphene quantum dots in the presence of a p-n junction | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 3 | Pages | 035426 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We investigate the magnetic interface states of graphene quantum dots that contain p-n junctions. Within a tight-binding approach, we consider rectangular quantum dots in the presence of a perpendicular magnetic field containing p-n as well as p-n-p and n-p-n junctions. The results show the interplay between the edge states associated with the zigzag terminations of the sample and the snake states that arise at the p-n junction due to the overlap between electron and hole states at the potential interface. Remarkable localized states are found at the crossing of the p-n junction with the zigzag edge having a dumb-bell-shaped electron distribution. The results are presented as a function of the junction parameters and the applied magnetic flux. DOI: 10.1103/PhysRevB.87.035426 | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000313941000003 | Publication Date | 2013-01-29 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 16 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-VI), the European Science Foundation (ESF) under the EUROCORES program EuroGRAPHENE (project CONGRAN), the Brazilian agency CNPq (Pronex), and the bilateral projects between Flanders and Brazil and the collaboration project FWO-CNPq. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:110087 | Serial | 3048 | ||
Permanent link to this record | |||||
Author | Leenaerts, O.; Sahin, H.; Partoens, B.; Peeters, F.M. | ||||
Title | First-principles investigation of B- and N-doped fluorographene | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 88 | Issue | 3 | Pages | 035434-35435 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The effect of substitutional doping of fluorographene with boron and nitrogen atoms on its electronic and magnetic properties is investigated using first-principles calculations. It is found that boron dopants can be readily incorporated in the fluorographene crystal where they act as shallow acceptors and cause hole doping, but no changes in the magnetic properties are observed. Nitrogen dopants act as deep donors and give rise to a magnetic moment, but the resulting system becomes chemically unstable. These results are opposite to what was found for substitutional doping of graphane, i.e., hydrogenated graphene, in which case B substituents induce magnetism and N dopants do not. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000322083700002 | Publication Date | 2013-07-22 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 16 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program of the Flemish government. H.S. is supported by a FWO Pegasus-long Marie Curie Fellowship. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center VSC. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:109807 | Serial | 1210 | ||
Permanent link to this record | |||||
Author | Moldovan, D.; Masir, M.R.; Peeters, F.M. | ||||
Title | Electronic states in a graphene flake strained by a Gaussian bump | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 88 | Issue | 3 | Pages | 035446-35447 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The effect of strain in graphene is usually modeled by a pseudomagnetic vector potential which is, however, derived in the limit of small strain. In realistic cases deviations are expected in view of graphene's very high strain tolerance, which can be up to 25%. Here we investigate the pseudomagnetic field generated by a Gaussian bump and we show that it exhibits significant differences with numerical tight-binding results. Furthermore, we calculate the electronic states in the strained region for a hexagon shaped flake with armchair edges. We find that the sixfold symmetry of the wave functions inside the Gaussian bump is directly related to the different effects of strain along the fundamental directions of graphene: zigzag and armchair. Low energy electrons are strongly confined in the armchair directions and are localized on the carbon atoms of a single sublattice. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000322587500003 | Publication Date | 2013-07-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 50 | Open Access | |
Notes | ; This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro-GRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-Vl), and the Methusalem Funding of the Flemish Government. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:109800 | Serial | 1007 | ||
Permanent link to this record | |||||
Author | Dixit, H.; Lamoen, D.; Partoens, B. | ||||
Title | Quasiparticle band structure of rocksalt-CdO determined using maximally localized Wannier functions | Type | A1 Journal article | ||
Year | 2013 | Publication | Journal of physics : condensed matter | Abbreviated Journal | J Phys-Condens Mat |
Volume | 25 | Issue | 3 | Pages | 035501-35505 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | CdO in the rocksalt structure is an indirect band gap semiconductor. Thus, in order to determine its band gap one needs to calculate the complete band structure. However, in practice, the exact evaluation of the quasiparticle band structure for the large number of k-points which constitute the different symmetry lines in the Brillouin zone can be an extremely demanding task compared to the standard density functional theory (DFT) calculation. In this paper we report the full quasiparticle band structure of CdO using a plane-wave pseudopotential approach. In order to reduce the computational effort and time, we make use of maximally localized Wannier functions (MLWFs). The MLWFs offer a highly accurate method for interpolation of the DFT or GW band structure from a coarse k-point mesh in the irreducible Brillouin zone, resulting in a much reduced computational effort. The present paper discusses the technical details of the scheme along with the results obtained for the quasiparticle band gap and the electron effective mass. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | London | Editor | ||
Language | Wos | 000313100500010 | Publication Date | 2012-12-12 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0953-8984;1361-648X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.649 | Times cited | 7 | Open Access | |
Notes | Fwo | Approved | Most recent IF: 2.649; 2013 IF: 2.223 | ||
Call Number | UA @ lucian @ c:irua:105296 | Serial | 2801 | ||
Permanent link to this record | |||||
Author | Van Boxem, R.; Verbeeck, J.; Partoens, B. | ||||
Title | Spin effects in electron vortex states | Type | A1 Journal article | ||
Year | 2013 | Publication | Europhysics letters | Abbreviated Journal | Epl-Europhys Lett |
Volume | 102 | Issue | 4 | Pages | 40010-40016 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | The recent experimental realization of electron vortex beams opens up a wide research domain previously unexplored. The present paper explores the relativistic properties of these electron vortex beams, and quantifies deviations from the scalar wave theory. It is common in electron optics to use the Schrodinger equation neglecting spin. The present paper investigates the role of spin and the total angular momentum J(z) and how it pertains to the vortex states. As an application, we also investigate if it is possible to use holographic reconstruction to create novel total angular momentum eigenstates in a transmission electron microscope. It is demonstrated that relativistic spin coupling effects disappear in the paraxial limit, and spin effects in holographically created electron vortex beams can only be exploited by using specialized magnetic apertures. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Paris | Editor | ||
Language | Wos | 000321118600011 | Publication Date | 2013-06-11 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0295-5075;1286-4854; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.957 | Times cited | 11 | Open Access | |
Notes | 312483 Esteem2; N246791 Countatoms; 278510 Vortex; esteem2jra1; esteem2jra3 ECASJO_; | Approved | Most recent IF: 1.957; 2013 IF: 2.269 | ||
Call Number | UA @ lucian @ c:irua:109852 | Serial | 3087 | ||
Permanent link to this record | |||||
Author | Wu, S.; Luo, X.; Turner, S.; Peng, H.; Lin, W.; Ding, J.; David, A.; Wang, B.; Van Tendeloo, G.; Wang, J.; Wu, T.; | ||||
Title | Nonvolatile resistive switching in Pt/LaAlO3/SrTiO3 heterostructures | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review X | Abbreviated Journal | Phys Rev X |
Volume | 3 | Issue | 4 | Pages | 041027-14 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
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. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | College Park, Md | Editor | ||
Language | Wos | 000328862400001 | Publication Date | 2013-12-17 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2160-3308; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 12.789 | Times cited | 77 | Open Access | |
Notes | FWO;FP7;IFOX; Countatoms; Hercules | Approved | Most recent IF: 12.789; 2013 IF: 8.463 | ||
Call Number | UA @ lucian @ c:irua:112524 | Serial | 2365 | ||
Permanent link to this record | |||||
Author | Sahin, H.; Sivek, J.; Li, S.; Partoens, B.; Peeters, F.M. | ||||
Title | Stone-Wales defects in silicene : formation, stability, and reactivity of defect sites | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 88 | Issue | 4 | Pages | 045434-45436 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | During the synthesis of ultrathin materials with hexagonal lattice structure Stone-Wales (SW) type of defects are quite likely to be formed and the existence of such topological defects in the graphenelike structures results in dramatic changes of their electronic and mechanical properties. Here we investigate the formation and reactivity of such SW defects in silicene. We report the energy barrier for the formation of SW defects in freestanding (similar to 2.4 eV) and Ag(111)-supported (similar to 2.8 eV) silicene and found it to be significantly lower than in graphene (similar to 9.2 eV). Moreover, the buckled nature of silicene provides a large energy barrier for the healing of the SW defect and therefore defective silicene is stable even at high temperatures. Silicene with SW defects is semiconducting with a direct band gap of 0.02 eV and this value depends on the concentration of defects. Furthermore, nitrogen substitution in SW-defected silicene shows that the defect lattice sites are the least preferable substitution locations for the N atoms. Our findings show the easy formation of SW defects in silicene and also provide a guideline for band gap engineering in silicene-based materials through such defects. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000322113300007 | Publication Date | 2013-07-23 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 93 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. H.S. is supported by a FWO Pegasus Marie Curie Fellowship. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:109805 | Serial | 3162 | ||
Permanent link to this record | |||||
Author | Couet, S.; Peelaers, H.; Trekels, M.; Houben, K.; Petermann, C.; Hu, M.Y.; Zhao, J.Y.; Bi, W.; Alp, E.E.; Menéndez, E.; Partoens, B.; Peeters, F.M.; Van Bael, M.J.; Vantomme, A.; Temst, K.; | ||||
Title | Interplay between lattice dynamics and superconductivity in Nb3Sn thin films | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 88 | Issue | 4 | Pages | 045437-7 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We investigate the link between superconductivity and atomic vibrations in Nb3Sn films with a thickness ranging from 10 to 50 nm. The challenge of measuring the phonon density of states (PDOS) of these films has been tackled by employing the technique of nuclear inelastic scattering by Sn-119 isotopes to reveal the Sn-partial phonon density of states. With the support of ab initio calculations, we evaluate the effect of reduced film thickness on the PDOS. This approach allows us to estimate the changes in superconducting critical temperature T-c induced by phonon confinement, which turned out to be limited to a few tenths of K. The presented method is successful for the Nb3Sn system and paves the way for more systematic studies of the role of phonon confinement in Sn-containing superconductors. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000322529900004 | Publication Date | 2013-07-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 5 | Open Access | |
Notes | ; The authors would like to cordially thank Dr. Rudolf Ruffer from the nuclear resonant scattering group of the ESRF for the support and gratefully acknowledge the ESRF for providing beamtime for the preliminary phonon study. S. C., K. H., and E. M. thank the Flemish Science Foundation (FWO-Vl) for their personal fellowship. This work was supported by FWO-Vl, the Methusalem program of the Flemish government, and the Concerted Research Action program (GOA/09/ 006) and (GOA/14/007). Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:109801 | Serial | 1702 | ||
Permanent link to this record | |||||
Author | H. Zhang, N. Gauquelin, G.A. Botton and J.Y.T. Wei | ||||
Title | Attenuation of superconductivity in manganite/cuprate heterostructures by epitaxially induced CuO intergrowths | Type | A1 Journal Article | ||
Year | 2013 | Publication | Applied Physics Letters | Abbreviated Journal | |
Volume | 103 | Issue | Pages | 052606 | |
Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
Abstract | We examine the effect of CuO intergrowths on the superconductivity in epitaxial La 2/3 Ca 1/3 MnO 3 / YBa 2 Cu 3 O 7−δ La2/3Ca1/3MnO3/YBa2Cu3O7−δ (LCMO/YBCO) thin-film heterostructures. Scanning transmission electron microscopy on bilayer LCMO/YBCO thin films revealed double CuO-chain intergrowths which form regions with the 247 lattice structure in the YBCO layer. These nanoscale 247 regions do not appear in x-ray diffraction, but can physically account for the reduced critical temperature (Tc) of bilayer thin films relative to unilayer films with the same YBCO thickness, at least down to ∼25 nm. We attribute the CuO intergrowths to the bilayer heteroepitaxial mismatch and the Tc reduction to the generally lower Tc seen in bulk 247 samples. These epitaxially-induced CuO intergrowths provide a microstructural mechanism for the attenuation of superconductivity in LCMO/YBCO heterostructures. |
||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000322723000063 | Publication Date | 2013-08-02 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | ISBN | Additional Links | |||
Impact Factor | Times cited | 12 | Open Access | ||
Notes | Approved | Most recent IF: NA | |||
Call Number | EMAT @ emat @ | Serial | 4546 | ||
Permanent link to this record | |||||
Author | Ding, J.F.; Lebedev, O.I.; Turner, S.; Tian, Y.F.; Hu, W.J.; Seo, J.W.; Panagopoulos, C.; Prellier, W.; Van Tendeloo, G.; Wu, T. | ||||
Title | Interfacial spin glass state and exchange bias in manganite bilayers with competing magnetic orders | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 5 | Pages | 054428-7 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The magnetic properties of manganite bilayers composed of G-type antiferromagnetic (AFM) SrMnO3 and double-exchange ferromagnetic (FM) La0.7Sr0.3MnO3 are studied. A spin-glass state is observed as a result of competing magnetic orders and spin frustration at the La0.7Sr0.3MnO3/SrMnO3 interface. The dependence of the irreversible temperature on the cooling magnetic field follows the Almeida-Thouless line. Although an ideal G-type AFM SrMnO3 is featured with a compensated spin configuration, the bilayers exhibit exchange bias below the spin glass freezing temperature, which is much lower than the Néel temperature of SMO, indicating that the exchange bias is strongly correlated with the spin glass state. The results indicate that the spin frustration that originates from the competition between the AFM super-exchange and the FM double-exchange interactions can induce a strong magnetic anisotropy at the La0.7Sr0.3MnO3/SrMnO3 interface. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000315271200002 | Publication Date | 2013-02-22 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 98 | Open Access | |
Notes | FWO; COUNTATOMS; Hercules | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:107349 | Serial | 1696 | ||
Permanent link to this record | |||||
Author | Dixit, H.; Tandon, N.; Cottenier, S.; Saniz, R.; Lamoen, D.; Partoens, B. | ||||
Title | Erratum : First-principles study of possible shallow donors in ZnAl2O4 spinel [Phys. Rev. B 87, 174101 (2013)] | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 88 | Issue | 5 | Pages | 059905-2 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | |||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000323572600009 | Publication Date | 2013-08-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 1 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:110015 | Serial | 1080 | ||
Permanent link to this record | |||||
Author | Van Aert, S.; de Backer, A.; Martinez, G.T.; Goris, B.; Bals, S.; Van Tendeloo, G.; Rosenauer, A. | ||||
Title | Procedure to count atoms with trustworthy single-atom sensitivity | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 6 | Pages | 064107-6 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | We report a method to reliably count the number of atoms from high-angle annular dark field scanning transmission electron microscopy images. A model-based analysis of the experimental images is used to measure scattering cross sections at the atomic level. The high sensitivity of these measurements in combination with a thorough statistical analysis enables us to count atoms with single-atom sensitivity. The validity of the results is confirmed by means of detailed image simulations. We will show that the method can be applied to nanocrystals of arbitrary shape, size, and atom type without the need for a priori knowledge about the atomic structure. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000315144700006 | Publication Date | 2013-02-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 106 | Open Access | |
Notes | FWO; 262348 ESMI; 312483 ESTEEM2;246791 COUNTATOMS; Hercules 3; esteem2_jra2 | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:105674 | Serial | 2718 | ||
Permanent link to this record | |||||
Author | Saniz, R.; Partoens, B.; Peeters, F.M. | ||||
Title | Confinement effects on electron and phonon degrees of freedom in nanofilm superconductors : a Green function approach | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 6 | Pages | 064510-64513 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The Green function approach to the Bardeen-Cooper-Schrieffer theory of superconductivity is used to study nanofilms. We go beyond previous models and include effects of confinement on the strength of the electron-phonon coupling as well as on the electronic spectrum and on the phonon modes. Within our approach, we find that in ultrathin films, confinement effects on the electronic screening become very important. Indeed, contrary to what has been advanced in recent years, the sudden increases of the density of states when new bands start to be occupied as the film thickness increases, tend to suppress the critical temperature rather than to enhance it. On the other hand, the increase of the number of phonon modes with increasing number of monolayers in the film leads to an increase in the critical temperature. As a consequence, the superconducting critical parameters in such nanofilms are determined by these two competing effects. Furthermore, in sufficiently thin films, the condensate consists of well-defined subcondensates associated with the occupied bands, each with a distinct coherence length. The subcondensates can interfere constructively or destructively giving rise to an interference pattern in the Cooper pair probability density. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000315374100009 | Publication Date | 2013-02-25 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 6 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl). R.S. thanks M. R. Norman, B. Soree, and L. Komendova for useful comments. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:107072 | Serial | 487 | ||
Permanent link to this record | |||||
Author | Clark, L.; Béché, A.; Guzzinati, G.; Lubk, A.; Mazilu, M.; Van Boxem, R.; Verbeeck, J. | ||||
Title | Exploiting lens aberrations to create electron-vortex beams | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review letters | Abbreviated Journal | Phys Rev Lett |
Volume | 111 | Issue | 6 | Pages | 064801-64805 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | A model for a new electron-vortex beam production method is proposed and experimentally demonstrated. The technique calls on the controlled manipulation of the degrees of freedom of the lens aberrations to achieve a helical phase front. These degrees of freedom are accessible by using the corrector lenses of a transmission electron microscope. The vortex beam is produced through a particular alignment of these lenses into a specifically designed astigmatic state and applying an annular aperture in the condenser plane. Experimental results are found to be in good agreement with simulations. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | New York, N.Y. | Editor | ||
Language | Wos | 000322921200009 | Publication Date | 2013-08-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0031-9007;1079-7114; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.462 | Times cited | 66 | Open Access | |
Notes | Vortex; Esteem2; Countatoms; FWO; Esteem2jra3 ECASJO; | Approved | Most recent IF: 8.462; 2013 IF: 7.728 | ||
Call Number | UA @ lucian @ c:irua:109340UA @ admin @ c:irua:109340 | Serial | 1148 | ||
Permanent link to this record | |||||
Author | Neyts, E.C.; Ostrikov, K.; Han, Z.J.; Kumar, S.; van Duin, A.C.T.; Bogaerts, A. | ||||
Title | Defect healing and enhanced nucleation of carbon nanotubes by low-energy ion bombardment | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review letters | Abbreviated Journal | Phys Rev Lett |
Volume | 110 | Issue | 6 | Pages | 065501-65505 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Structural defects inevitably appear during the nucleation event that determines the structure and properties of single-walled carbon nanotubes. By combining ion bombardment experiments with atomistic simulations we reveal that ion bombardment in a suitable energy range allows these defects to be healed resulting in an enhanced nucleation of the carbon nanotube cap. The enhanced growth of the nanotube cap is explained by a nonthermal ion-induced graphene network restructuring mechanism. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | New York, N.Y. | Editor | ||
Language | Wos | 000314687300022 | Publication Date | 2013-02-07 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0031-9007;1079-7114; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.462 | Times cited | 50 | Open Access | |
Notes | Approved | Most recent IF: 8.462; 2013 IF: 7.728 | |||
Call Number | UA @ lucian @ c:irua:105306 | Serial | 616 | ||
Permanent link to this record | |||||
Author | Latimer, M.L.; Berdiyorov, G.R.; Xiao, Z.L.; Peeters, F.M.; Kwok, W.K. | ||||
Title | Realization of artificial ice systems for magnetic vortices in a superconducting MoGe thin film with patterned nanostructures | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review letters | Abbreviated Journal | Phys Rev Lett |
Volume | 111 | Issue | 6 | Pages | 067001-67005 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
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. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | New York, N.Y. | Editor | ||
Language | Wos | 000322799200013 | Publication Date | 2013-08-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0031-9007;1079-7114; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.462 | Times cited | 63 | Open Access | |
Notes | ; This work was supported by the US Department of Energy DOE BES under Contract No. DE-AC02-06CH11357 (transport measurements), the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government (numerical simulations). G. R. B. acknowledges an individual grant from FWO-Vl. The nanopatterning and morphological analysis were performed at Argonne's Center for Nanoscale Materials (CNM) which is funded by DOE BES under Contract No. DE-AC02-06CH11357. We are grateful to Dr. Charles Reichhardt in Los Alamos National Laboratory for stimulating discussions and critical comments. Z. L. X. acknowledges DOE BES Grant No. DE-FG02-06ER46334 (sample fabrication and imaging). M. L. L. was a recipient of the NIU/ANL Distinguished Graduate Fellowship grant. ; | Approved | Most recent IF: 8.462; 2013 IF: 7.728 | ||
Call Number | UA @ lucian @ c:irua:110750 | Serial | 2836 | ||
Permanent link to this record | |||||
Author | Amin-Ahmadi, B.; Idrissi, H.; Delmelle, R.; Pardoen, T.; Proost, J.; Schryvers, D. | ||||
Title | High resolution transmission electron microscopy characterization of fcc -> 9R transformation in nanocrystalline palladium films due to hydriding | Type | A1 Journal article | ||
Year | 2013 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 102 | Issue | 7 | Pages | 071911-71914 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Sputtered nanocrystalline palladium thin films with nanoscale growth twins have been subjected to hydriding cycles. The evolution of the twin boundaries has been investigated using high resolution transmission electron microscopy. Surprisingly, the Sigma 3{112} incoherent twin boundaries dissociate after hydriding into two phase boundaries bounding a 9R phase. This phase which corresponds to single stacking faults located every three {111} planes in the fcc Pd structure was not expected because of the high stacking fault energy of Pd. This observation is connected to the influence of the Hydrogen on the stacking fault energy of palladium and the high compressive stresses building up during hydriding. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4793512] | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000315596700023 | Publication Date | 2013-02-26 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-6951; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.411 | Times cited | 14 | Open Access | |
Notes | Iap | Approved | Most recent IF: 3.411; 2013 IF: 3.515 | ||
Call Number | UA @ lucian @ c:irua:108303 | Serial | 1462 | ||
Permanent link to this record | |||||
Author | Shestakov, M.V.; Meledina, M.; Turner, S.; Tikhomirov, V.K.; Verellen, N.; Rodríguez, V.D.; Velázquez, J.J.; Van Tendeloo, G.; Moshchalkov, V.V. | ||||
Title | The size and structure of Ag particles responsible for surface plasmon effects and luminescence in Ag homogeneously doped bulk glass | Type | A1 Journal article | ||
Year | 2013 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 114 | Issue | 7 | Pages | 073102-73105 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | As-prepared and heat-treated oxyfluoride glasses, co-doped with Ag nanoclusters/nanoparticles, are prepared at 0.15 at. % Ag concentration. The as-prepared glass shows an absorption band in the UV/violet attributed to the presence of amorphous Ag nanoclusters with an average size of 1.1 nm. The luminescence spectra of the untreated glass can also be ascribed to these Ag nanoclusters. Upon heat-treatment, the clusters coalesce into Ag nanoparticles with an average size of 2.3 nm, and the glasses show an extra surface plasmon absorption band in the visible. These particles, however, cease to emit due to ascribing plasmonic properties of bulk silver. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000323510900003 | Publication Date | 2013-08-16 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-8979; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 19 | Open Access | |
Notes | Fwo | Approved | Most recent IF: 2.068; 2013 IF: 2.185 | ||
Call Number | UA @ lucian @ c:irua:109455 | Serial | 3031 | ||
Permanent link to this record | |||||
Author | Molina, L.; Egoavil, R.; Turner, S.; Thersleff, T.; Verbeeck, J.; Holzapfel, B.; Eibl, O.; Van Tendeloo, G. | ||||
Title | Interlayer structure in YBCO-coated conductors prepared by chemical solution deposition | Type | A1 Journal article | ||
Year | 2013 | Publication | Superconductor science and technology | Abbreviated Journal | Supercond Sci Tech |
Volume | 26 | Issue | 7 | Pages | 075016-75018 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The functionality of YBa2Cu3O7−δ (YBCO)-coated conductor technology depends on the reliability and microstructural properties of a given tape or wire architecture. Particularly, the interface to the metal tape is of interest since it determines the adhesion, mechanical stability of the film and thermal contact of the film to the substrate. A trifluoroacetate (TFA)metal organic deposition (MOD) prepared YBCO film deposited on a chemical solution-derived buffer layer architecture based on CeO2/La2Zr2O7 and grown on a flexible Ni5 at.%W substrate with a {100}⟨001⟩ biaxial texture was investigated. The YBCO film had a thickness was 440 nm and a jc of 1.02 MA cm−2 was determined at 77 K and zero external field. We present a sub-nanoscale analysis of a fully processed solution-derived YBCO-coated conductor by aberration-corrected scanning transmission electron microscopy (STEM) combined with electron energy-loss spectroscopy (EELS). For the first time, structural and chemical analysis of the valence has been carried out on the sub-nm scale. Intermixing of Ni, La, Ce, O and Ba takes place at these interfaces and gives rise to nanometer-sized interlayers which are a by-product of the sequential annealing process. Two distinct interfacial regions were analyzed in detail: (i) the YBCO/CeO2/La2Zr2O7 region (10 nm interlayer) and (ii) the La2Zr2O7/Ni5 at.%W substrate interface region (20 nm NiO). This is of particular significance for the functionality of these YBCO-coated conductor architectures grown by chemical solution deposition. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Bristol | Editor | ||
Language | Wos | 000319973800024 | Publication Date | 2013-05-28 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0953-2048;1361-6668; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.878 | Times cited | 11 | Open Access | |
Notes | vortex; Countatoms; Fwo; Esteem2; esteem2jra2; esteem2jra3 ECASJO_; | Approved | Most recent IF: 2.878; 2013 IF: 2.796 | ||
Call Number | UA @ lucian @ c:irua:108704UA @ admin @ c:irua:108704 | Serial | 1698 | ||
Permanent link to this record | |||||
Author | Li, B.; Djotyan, A.P.; Hao, Y.L.; Avetisyan, A.A.; Peeters, F.M. | ||||
Title | Effect of a perpendicular magnetic field on the shallow donor states near a semiconductor-metal interface | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 7 | Pages | 075313-75319 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We investigate the influence of an external perpendicular magnetic field on the lowest-energy states of an electron bound to a donor which is located near a semiconductor-metal interface. The problem is treated within the effective mass approach and the lowest-energy states are obtained through (1) the “numerically exact” finite element method, and (2) a variational approach using a trial wave function where all image charges that emerge due to the presence of the metallic gate are taken into account. The trial wave functions are constructed such that they reduce to an exponential behavior for sufficiently small magnetic fields and become Gaussian for intermediate and large magnetic fields. The average electron-donor distance can be controlled by the external magnetic field. We find that the size of the 2p(z) state depends strongly on the magnetic field when the donor is close to the interface, showing a nonmonotonic behavior, in contrast with the ground and the other excited states. DOI: 10.1103/PhysRevB.87.075313 | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000314874800017 | Publication Date | 2013-02-13 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 1 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl). ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:107664 | Serial | 793 | ||
Permanent link to this record | |||||
Author | Zhang, S.H.; Xu, W.; Badalyan, S.M.; Peeters, F.M. | ||||
Title | Piezoelectric surface acoustical phonon limited mobility of electrons in graphene on a GaAs substrate | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 7 | Pages | 075443-75445 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
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 | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000315375200008 | Publication Date | 2013-02-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 25 | Open Access | |
Notes | ; This work was supported by the ESF-Eurocores program EuroGRAPHENE (CONGRAN project) and the Flemish Science Foundation (FWO-VI). ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:107655 | Serial | 2622 | ||
Permanent link to this record |