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Author | Neek-Amal, M; Peeters, F.M. | ||||
Title | Partially hydrogenated and fluorinated graphene : structure, roughness, and negative thermal expansion | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 92 | Issue | 92 | Pages | 155430 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The structural properties of partially hydrogenated and fluorinated graphene with different percentages of H/F atoms are investigated using molecular dynamics simulations based on reactive force field (ReaxFF) potentials. We found that the roughness of graphene varies with the percentage (p) of H or F and in both cases is maximal around p = 50%. Similar results were obtained for partially oxidized graphene. The two-dimensional area size of partially fluorinated and hydrogenated graphene exhibits a local minimum around p = 35% coverage. The lattice thermal contraction in partially functionalized graphene is found to be one order of magnitude larger than that of fully covered graphene. We also show that the armchair structure for graphene oxide (similar to the structure of fully hydrogenated and fluorinated graphene) is unstable. Our results show that the structure of partially functionalized graphene changes nontrivially with the C : H and C : F ratio as well as with temperature. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000363294100005 | Publication Date | 2015-10-23 | |
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 | 5 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. ; | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | UA @ lucian @ c:irua:129448 | Serial | 4221 | ||
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Author | Pavlović, S.; Peeters, F.M. | ||||
Title | Electronic properties of triangular and hexagonal MoS2 quantum dots | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 91 | Issue | 91 | Pages | 155410 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Using the tight-binding approach, we calculate the electronic structure of triangular and hexagonal MoS2 quantum dots. Due to the orbital asymmetry we show that it is possible to form quantum dots with the same shape but having different electronic properties. The electronic states of triangular and hexagonal quantum dots are explored, as well as the local and total density of states and the convergence towards the bulk spectrum with dot size is investigated. Our calculations show that: (1) edge states appear in the band gap, (2) that there are a larger number of electronic states in the conduction band as compared to the valence band, and (3) the relative number of edge states decreases with increasing dot size. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000352591200005 | Publication Date | 2015-04-11 | |
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 | 44 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-VI) and the Methusalem Foundation of the Flemish government. Stefan Pavlovic is supported by JoinEU-SEE IV, Erasmus Mundus Action 2 programme. We thank J. M. Pereira for interesting discussions. ; | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | UA @ lucian @ c:irua:132516 | Serial | 4170 | ||
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Author | Chaves, A.; Low, T.; Avouris, P.; Çakir, D.; Peeters, F.M. | ||||
Title | Anisotropic exciton Stark shift in black phosphorus | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 91 | Issue | 91 | Pages | 155311 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We calculate the excitonic spectrum of few-layer black phosphorus by direct diagonalization of the effective mass Hamiltonian in the presence of an applied in-plane electric field. The strong attractive interaction between electrons and holes in this system allows one to investigate the Stark effect up to very high ionizing fields, including also the excited states. Our results show that the band anisotropy in black phosphorus becomes evident in the direction-dependent field-induced polarizability of the exciton. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000353459200005 | Publication Date | 2015-04-27 | |
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 | 88 | Open Access | |
Notes | ; Discussions with J. M. Pereira Jr. and J. S. de Souza are gratefully acknowledged. This work was supported by the Brazilian Council for Research (CNPq) through the PQ and Science Without Borders programs, the Flemish Science Foundation (FWO-Vl), the Methusalem programme of the Flemish government, and the Bilateral program (CNPq-FWO) between Flanders and Brazil. ; | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | UA @ lucian @ c:irua:132506 | Serial | 4141 | ||
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Author | Tinck, S.; Tillocher, T.; Dussart, R.; Bogaerts, A. | ||||
Title | Cryogenic etching of silicon with SF6 inductively coupled plasmas: a combined modelling and experimental study | Type | A1 Journal article | ||
Year | 2015 | Publication | Journal of physics: D: applied physics | Abbreviated Journal | J Phys D Appl Phys |
Volume | 48 | Issue | 48 | Pages | 155204 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | A hybrid Monte Carlofluid model is applied to simulate the wafer-temperature-dependent etching of silicon with SF6 inductively coupled plasmas (ICP). The bulk plasma within the ICP reactor volume as well as the surface reactions occurring at the wafer are self-consistently described. The calculated etch rates are validated by experiments. The calculations and experiments are performed at two different wafer temperatures, i.e. 300 and 173 K, resembling conventional etching and cryoetching, respectively. In the case of cryoetching, a physisorbed SFx layer (x = 06) is formed on the wafer, which is negligible at room temperature, because of fast thermal desorption, However, even in the case of cryoetching, this layer can easily be disintegrated by low-energy ions, so it does not affect the etch rates. In the investigated pressure range of 19 Pa, the etch rate is always slightly higher at cryogenic conditions, both in the experiments and in the model, and this could be explained in the model due to a local cooling of the gas above the wafer, making the gas denser and increasing the flux of reactive neutrals, like F and F2, towards the wafer. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | London | Editor | ||
Language | Wos | 000351856600009 | Publication Date | 2015-03-25 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0022-3727;1361-6463; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.588 | Times cited | 9 | Open Access | |
Notes | Approved | Most recent IF: 2.588; 2015 IF: 2.721 | |||
Call Number | c:irua:124209 | Serial | 551 | ||
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Author | Van der Paal, J.; Verlackt, C.C.; Yusupov, M.; Neyts, E.C.; Bogaerts, A. | ||||
Title | Structural modification of the skin barrier by OH radicals : a reactive molecular dynamics study for plasma medicine | Type | A1 Journal article | ||
Year | 2015 | Publication | Journal of physics: D: applied physics | Abbreviated Journal | J Phys D Appl Phys |
Volume | 48 | Issue | 48 | Pages | 155202 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | While plasma treatment of skin diseases and wound healing has been proven highly effective, the underlying mechanisms, and more generally the effect of plasma radicals on skin tissue, are not yet completely understood. In this paper, we perform ReaxFF-based reactive molecular dynamics simulations to investigate the interaction of plasma generated OH radicals with a model system composed of free fatty acids, ceramides, and cholesterol molecules. This model system is an approximation of the upper layer of the skin (stratum corneum). All interaction mechanisms observed in our simulations are initiated by H-abstraction from one of the ceramides. This reaction, in turn, often starts a cascade of other reactions, which eventually lead to the formation of aldehydes, the dissociation of ceramides or the elimination of formaldehyde, and thus eventually to the degradation of the skin barrier function. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | London | Editor | ||
Language | Wos | 000351856600007 | Publication Date | 2015-03-25 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0022-3727;1361-6463; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.588 | Times cited | 20 | Open Access | |
Notes | Approved | Most recent IF: 2.588; 2015 IF: 2.721 | |||
Call Number | c:irua:124230 | Serial | 3242 | ||
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Author | Peymanirad, F.; Neek Amal, M.; Beheshtian, J.; Peeters, F.M. | ||||
Title | Graphene-silicene bilayer : a nanocapacitor with permanent dipole and piezoelectricity effect | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 92 | Issue | 92 | Pages | 155113 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Using density functional theory, we study the electronic properties of a graphene-silicene bilayer (GSB). A single layer of silicene binds to the graphene layer with adhesion energy of about 25 meV/atom. This adhesion energy between the two layers follows accurately the well-known -1/z(2) dispersion energy as found between two infinite parallel plates. In small flakes of GSB with hydrogenated edges, negative charge is transferred from the graphene layer to the silicene layer, producing a permanent and a switchable polar bilayer, while in an infinite GSB, the negative charge is transferred from the silicene layer to the graphene layer. The graphene-silicene bilayer is a good candidate for a nanocapacitor with piezoelectric capabilities. We found that the permanent dipole of the bilayer can be tuned by an external perpendicular electric field. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000362493400002 | Publication Date | 2015-10-09 | |
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 | 17 | Open Access | |
Notes | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | |||
Call Number | UA @ lucian @ c:irua:128762 | Serial | 4188 | ||
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Author | Milovanović, S.P.; Moldovan, D.; Peeters, F.M. | ||||
Title | Veselago lensing in graphene with a p-n junction: Classical versus quantum effects | Type | A1 Journal article | ||
Year | 2015 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 118 | Issue | 118 | Pages | 154308 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The feasibility of Veselago lensing in graphene with a p-n junction is investigated numerically for realistic injection leads. Two different set-ups with two narrow leads are considered with absorbing or reflecting side edges. This allows us to separately determine the influence of scattering on electron focusing for the edges and the p-n interface. Both semiclassical and tight-binding simulations show a distinctive peak in the transmission probability that is attributed to the Veselago lensing effect. We investigate the robustness of this peak on the width of the injector, the position of the p-n interface, and different gate potential profiles. Furthermore, the influence of scattering by both short- and long-range impurities is considered. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000363535800022 | Publication Date | 2015-10-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-8979;1089-7550; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 19 | Open Access | |
Notes | This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, and the Methusalem Foundation of the Flemish government. | Approved | Most recent IF: 2.068; 2015 IF: 2.183 | ||
Call Number | c:irua:129452 | Serial | 3969 | ||
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Author | Adami, O.-A.; Jelić, Ž.L.; Xue, C.; Abdel-Hafiez, M.; Hackens, B.; Moshchalkov, V.V.; Milošević, M.V.; Van de Vondel, J.; Silhanek, A.V. | ||||
Title | Onset, evolution, and magnetic braking of vortex lattice instabilities in nanostructured superconducting films | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review: B: condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 92 | Issue | 92 | Pages | 134506 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | In 1976, Larkin and Ovchinnikov [Zh. Eksp. Teor. Fiz. 68, 1915 (1975) [Sov. Phys.–JETP 41, 960 (1976)]] predicted that vortex matter in superconductors driven by an electrical current can undergo an abrupt dynamic transition from a flux-flow regime to a more dissipative state at sufficiently high vortex velocities. Typically, this transition manifests itself as a large voltage jump at a particular current density, so-called instability current density J∗, which is smaller than the depairing current. By tuning the effective pinning strength in Al films, using an artificial periodic pinning array of triangular holes, we show that a unique and well-defined instability current density exists if the pinning is strong, whereas a series of multiple voltage transitions appear in the relatively weaker pinning regime. This behavior is consistent with time-dependent Ginzburg-Landau simulations, where the multiple-step transition can be unambiguously attributed to the progressive development of vortex chains and subsequently phase-slip lines. In addition, we explore experimentally the magnetic braking effects, caused by a thick Cu layer deposited on top of the superconductor, on the instabilities and the vortex ratchet effect. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000362433200003 | Publication Date | 2015-10-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 21 | Open Access | |
Notes | ACKNOWLEDGMENTS: This work was partially supported by the Fonds de la Recherche Scientifique-FNRS, the Methusalem Funding of the Flemish Government, the Research Foundation-Flanders (FWO), and COST Action MP1201. The work of A.V.S. and Z.L.J. is partially supported by “Mandat d’Impulsion Scientifique” MIS F.4527.13 of the F.R.S.-FNRS. B.H. is an associate researcher of the Fonds de la Recherche Scientifique- FNRS. The authors thank J. Cuppens for the data analysis at the early stage of this work, R. Delamare for his valuable help during the fabrication of the samples, and G. Grimaldi for helpful discussions. | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | c:irua:128747 | Serial | 3981 | ||
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Author | Verreck, D.; Verhulst, A.S.; Van de Put, M.; Sorée, B.; Magnus, W.; Mocuta, A.; Collaert, N.; Thean, A.; Groeseneken, G. | ||||
Title | Full-zone spectral envelope function formalism for the optimization of line and point tunnel field-effect transistors | Type | A1 Journal article | ||
Year | 2015 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 118 | Issue | 118 | Pages | 134502 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Efficient quantum mechanical simulation of tunnel field-effect transistors (TFETs) is indispensable to allow for an optimal configuration identification. We therefore present a full-zone 15-band quantum mechanical solver based on the envelope function formalism and employing a spectral method to reduce computational complexity and handle spurious solutions. We demonstrate the versatility of the solver by simulating a 40 nm wide In0.53Ga0.47As lineTFET and comparing it to p-n-i-n configurations with various pocket and body thicknesses. We find that the lineTFET performance is not degraded compared to semi-classical simulations. Furthermore, we show that a suitably optimized p-n-i-n TFET can obtain similar performance to the lineTFET. (C) 2015 AIP Publishing LLC. | ||||
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Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000362668400025 | Publication Date | 2015-10-01 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-8979; 1089-7550 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 9 | Open Access | |
Notes | ; D. Verreck acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). This work was supported by imec's Industrial Affiliation Program. ; | Approved | Most recent IF: 2.068; 2015 IF: 2.183 | ||
Call Number | UA @ lucian @ c:irua:128765 | Serial | 4183 | ||
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Author | Michel, K.H.; Costamagna; Peeters, F.M. | ||||
Title | Theory of anharmonic phonons in two-dimensional crystals | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 91 | Issue | 91 | Pages | 134302 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Anharmonic effects in an atomic monolayer thin crystal with honeycomb lattice structure are investigated by analytical and numerical lattice dynamical methods. Starting from a semiempirical model for anharmonic couplings of third and fourth orders, we study the in-plane and out-of-plane (flexural) mode components of the generalized wave vector dependent Gruneisen parameters, the thermal tension and the thermal expansion coefficients as a function of temperature and crystal size. From the resonances of the displacement-displacement correlation functions, we obtain the renormalization and decay rate of in-plane and flexural phonons as a function of temperature, wave vector, and crystal size in the classical and in the quantum regime. Quantitative results are presented for graphene. There, we find that the transition temperature T-alpha from negative to positive thermal expansion is lowered with smaller system size. Renormalization of the flexural mode has the opposite effect and leads to values of T-alpha approximate to 300 K for systems of macroscopic size. Extensive numerical analysis throughout the Brillouin zone explores various decay and scattering channels. The relative importance of normal and umklapp processes is investigated. The work is complementary to crystalline membrane theory and computational studies of anharmonic effects in two-dimensional crystals. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000353031000001 | Publication Date | 2015-04-17 | |
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 | 38 | Open Access | |
Notes | ; We thank B. Verberck, D. Lamoen, and A. Dobry for useful comments. We acknowledge funding from the FWO (Belgium)-MINCyT (Argentina) collaborative research project. This work is supported by the EuroGRAPHENE project CONGRAN. ; | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | UA @ lucian @ c:irua:132512 | Serial | 4263 | ||
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Author | Juchtmans, R.; Verbeeck, J. | ||||
Title | Orbital angular momentum in electron diffraction and its use to determine chiral crystal symmetries | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review: B: condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 92 | Issue | 92 | Pages | 134108 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | In this work we present an alternative way to look at electron diffraction in a transmission electron microscope. Instead of writing the scattering amplitude in Fourier space as a set of plane waves,we use the cylindrical Fourier transform to describe the scattering amplitude in a basis of orbital angular momentum (OAM) eigenstates. We show how working in this framework can be very convenient when investigating, e.g., rotation and screw-axis symmetries. For the latter we find selection rules on the OAM coefficients that unambiguously reveal the handedness of the screw axis. Detecting the OAM coefficients of the scattering amplitude thus offers the possibility to detect the handedness of crystals without the need for dynamical simulations, the thickness of the sample, nor the exact crystal structure. We propose an experimental setup to measure the OAM components where an image of the crystal is taken after inserting a spiral phase plate in the diffraction plane and perform multislice simulations on α quartz to demonstrate how the method indeed reveals the chirality. The experimental feasibility of the technique is discussed together with its main advantages with respect to chirality determination of screw axes. The method shows how the use of a spiral phase plate can be extended from a simple phase imaging technique to a tool to measure the local OAM decomposition of an electron wave, widening the field of interest well beyond chiral space group determination. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000362893100002 | Publication Date | 2015-10-14 | |
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 | The authors acknowledge support from the FWO (As- pirant Fonds Wetenschappelijk Onderzoek–Vlaanderen), the EU under the Seventh Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483-ESTEEM2, and ERC Starting Grant No. 278510 VORTEX; esteem2jra1; ECASJO; | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | c:irua:129417 c:irua:129417UA @ admin @ c:irua:129417 | Serial | 4089 | ||
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Author | Chen, Y.; Hong-Yu, W.; Peeters, F.M.; Shanenko, A.A. | ||||
Title | Quantum-size effects and thermal response of anti-Kramer-Pesch vortex core | Type | A1 Journal article | ||
Year | 2015 | Publication | Journal of physics : condensed matter | Abbreviated Journal | J Phys-Condens Mat |
Volume | 27 | Issue | 27 | Pages | 125701 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Since the 1960's it has been well known that the basic superconductive quantities can exhibit oscillations as functions of the thickness (diameter) in superconducting nanofilms (nanowires) due to the size quantization of the electronic spectrum. However, very little is known about the effects of quantum confinement on the microscopic properties of vortices. Based on a numerical solution to the Bogoliubov-de Gennes equations, we study the quantum-size oscillations of the vortex core resulting from the sequential interchange of the Kramer-Pesch and anti-Kramer-Pesch regimes with changing nanocylinder radius. The physics behind the anti-Kramer-Pesch anomaly is displayed by utilizing a semi-analytical Anderson approximate solution. We also demonstrate that the anti-Kramer-Pesch vortex core is robust against thermal smearing and results in a distinctive two-maxima structure in the local density of states, which can be used to identify the existence of the anti-Kramer-Pesch vortex. | ||||
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Publisher | Place of Publication | London | Editor | ||
Language | Wos | 000351294700018 | Publication Date | 2015-03-09 | |
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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 | 4 | Open Access | |
Notes | ; This work was supported by the National Natural Science Foundation of China under Grant No. NSFC-11304134, the Flemish Science Foundation (FWO-Vl), and the Methusalem program. AAS acknowledges the support of the Brazilian agencies CNPq (grants 307552/2012-8 and 141911/2012-3) and FACEPE (APQ-0589-1.05/08). WHY acknowledges the support of Scientific Research Fund of Zhejiang Provincial Education Department (Y201120994). ; | Approved | Most recent IF: 2.649; 2015 IF: 2.346 | ||
Call Number | c:irua:125460 | Serial | 2787 | ||
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Author | Moors, K.; Sorée, B.; Magnus, W. | ||||
Title | Modeling surface roughness scattering in metallic nanowires | Type | A1 Journal article | ||
Year | 2015 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 118 | Issue | 118 | Pages | 124307 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Ando's model provides a rigorous quantum-mechanical framework for electron-surface roughness scattering, based on the detailed roughness structure. We apply this method to metallic nanowires and improve the model introducing surface roughness distribution functions on a finite domain with analytical expressions for the average surface roughness matrix elements. This approach is valid for any roughness size and extends beyond the commonly used Prange-Nee approximation. The resistivity scaling is obtained from the self-consistent relaxation time solution of the Boltzmann transport equation and is compared to Prange-Nee's approach and other known methods. The results show that a substantial drop in resistivity can be obtained for certain diameters by achieving a large momentum gap between Fermi level states with positive and negative momentum in the transport direction. (C) 2015 AIP Publishing LLC. | ||||
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Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000362565800032 | Publication Date | 2015-09-24 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-8979; 1089-7550 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 11 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 2.068; 2015 IF: 2.183 | ||
Call Number | UA @ lucian @ c:irua:129425 | Serial | 4207 | ||
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Author | Cayado, P.; De Keukeleere, K.; Garzón, A.; Perez-Mirabet, L.; Meledin, A.; De Roo, J.; Vallés, F.; Mundet, B.; Rijckaert, H.; Pollefeyt, G.; Coll, M.; Ricart, S.; Palau, A.; Gázquez, J.; Ros, J.; Van Tendeloo, G.; Van Driessche, I.; Puig, T.; Obradors, X. | ||||
Title | Epitaxial YBa2Cu3O7−xnanocomposite thin films from colloidal solutions | Type | A1 Journal article | ||
Year | 2015 | Publication | Superconductor science and technology | Abbreviated Journal | Supercond Sci Tech |
Volume | 28 | Issue | 28 | Pages | 124007 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | A methodology of general validity to prepare epitaxial nanocomposite films based on the use of colloidal solutions containing different crystalline preformed oxide nanoparticles ( ex situ nanocomposites) is reported. The trifluoroacetate (TFA) metal–organic chemical solution deposition route is used with alcoholic solvents to grow epitaxial YBa 2 Cu 3 O 7 (YBCO) films. For this reason stabilizing oxide nanoparticles in polar solvents is a challenging goal. We have used scalable nanoparticle synthetic methodologies such as thermal and microwave-assisted solvothermal techniques to prepare CeO 2 and ZrO 2 nanoparticles. We show that stable and homogeneous colloidal solutions with these nanoparticles can be reached using benzyl alcohol, triethyleneglycol, nonanoic acid, trifluoroacetic acid or decanoic acid as protecting ligands, thereby allowing subsequent mixing with alcoholic TFA solutions. An elaborate YBCO film growth analysis of these nanocomposites allows the identification of the different relevant growth phenomena, e.g. nanoparticles pushing towards the film surface, nanoparticle reactivity, coarsening and nanoparticle accumulation at the substrate interface. Upon mitigation of these effects, YBCO nanocomposite films with high self-field critical currents ( J c ∼ 3–4 MA cm −2 at 77 K) were reached, indicating no current limitation effects associated with epitaxy perturbation, while smoothed magnetic field dependences of the critical currents at high magnetic fields and decreased effective anisotropic pinning behavior confirm the effectiveness of the novel developed approach to enhance vortex pinning. In conclusion, a novel low cost solution-derived route to high current nanocomposite superconducting films and coated conductors has been developed with very promising features. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000366288100009 | Publication Date | 2015-11-16 | |
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 | 32 | Open Access | |
Notes | All authors acknowledge the EU (EU-FP7 NMP-LA-2012-280432 EUROTAPES project). ICMAB acknowledges MINECO (MAT2014-51778-C2-1-R) and Generalitat de Catalunya (2014SGR 753 and Xarmae). UGhent acknowledges the Special Research Fund (BOF), the Research Foundation Flanders (FWO) and the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT). TEM microscopy work was conducted in the Catalan Institute of Nanoscience and Nanotechnology (ICN2). The authors acknowledge the ICN2 Electron Microscopy Division for offering access to their instruments and expertise. Part of the STEM microscopy work was conducted in 'Laboratorio de Microscopias Avanzadas' at the Instituto de Nanociencia de Aragon—Universidad de Zaragoza. The authors acknowledge the LMA-INA for offering access to their instruments and expertise. JG and MC also acknowledge the Ramon y Cajal program (RYC-2012-11709 and RYC-2013-12448 respectively). | Approved | Most recent IF: 2.878; 2015 IF: 2.325 | ||
Call Number | c:irua:129593 | Serial | 3966 | ||
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Author | Garcia, J.H.; Covaci, L.; Rappoport, T.G. | ||||
Title | Real-space calculation of the conductivity tensor for disordered topological matter | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review letters | Abbreviated Journal | Phys Rev Lett |
Volume | 114 | Issue | 114 | Pages | 116602 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We describe an efficient numerical approach to calculate the longitudinal and transverse Kubo conductivities of large systems using Bastin's formulation. We expand the Green's functions in terms of Chebyshev polynomials and compute the conductivity tensor for any temperature and chemical potential in a single step. To illustrate the power and generality of the approach, we calculate the conductivity tensor for the quantum Hall effect in disordered graphene and analyze the effect of the disorder in a Chern insulator in Haldane's model on a honeycomb lattice. | ||||
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Publisher | Place of Publication | New York, N.Y. | Editor | ||
Language | Wos | 000351430600010 | Publication Date | 2015-03-20 | |
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 | 69 | Open Access | |
Notes | ; We acknowledge A. R. Hernandez, A. Ferreira, and E. Mucciolo for discussions. T. G. R and J. H. G acknowledge the Brazilian agencies CNPq, FAPERJ, and INCT de Nanoestruturas de Carbono for financial support. L. C. acknowledges the Flemish Science Foundation (FWO-Vlaanderen) for financial support. ; | Approved | Most recent IF: 8.462; 2015 IF: 7.512 | ||
Call Number | c:irua:125467 | Serial | 2827 | ||
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Author | da Costa, D.R.; Zarenia, M.; Chaves, A.; Farias, G.A.; Peeters, F.M. | ||||
Title | Energy levels of bilayer graphene quantum dots | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 92 | Issue | 92 | Pages | 115437 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Within a tight binding approach we investigate the energy levels of hexagonal and triangular bilayer graphene (BLG) quantum dots (QDs) with zigzag and armchair edges. We study AA- and AB-(Bernal) stacked BLG QDs and obtain the energy levels in both the absence and the presence of a perpendicular electric field (i.e., biased BLG QDs). Our results show that the size dependence of the energy levels is different from that of monolayer graphene QDs. The energy spectrum of AB-stacked BLG QDs with zigzag edges exhibits edge states which spread out into the opened energy gap in the presence of a perpendicular electric field. We found that the behavior of these edges states is different for the hexagonal and triangular geometries. In the case of AA-stacked BLG QDs, the electron and hole energy levels cross each other in both cases of armchair and zigzag edges as the dot size or the applied bias increases. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000361663700003 | Publication Date | 2015-09-24 | |
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 | 21 | Open Access | |
Notes | ; This work was financially supported by CNPq, under contract NanoBioEstruturas 555183/2005-0, PRONEX/FUNCAP, CAPES Foundation under the process number BEX 7178/13-1, the Flemish Science Foundation (FWO-Vl), the Bilateral programme between CNPq and FWO-Vl, and the Brazilian Program Science Without Borders (CsF). ; | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | UA @ lucian @ c:irua:128726 | Serial | 4173 | ||
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Author | Leenaerts, O.; Schoeters, B.; Partoens, B. | ||||
Title | Stable kagome lattices from group IV elements | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 91 | Issue | 91 | Pages | 115202 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | A thorough investigation of three-dimensional kagome lattices of group IV elements is performed with first-principles calculations. The investigated kagome lattices of silicon and germanium are found to be of similar stability as the recently proposed carbon kagome lattice. Carbon and silicon kagome lattices are both direct-gap semiconductors but they have qualitatively different electronic band structures. While direct optical transitions between the valence and conduction bands are allowed in the carbon case, no such transitions can be observed for silicon. The kagome lattice of germanium exhibits semimetallic behavior but can be transformed into a semiconductor after compression. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000351900700003 | Publication Date | 2015-03-10 | |
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 | ; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vl). The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Hercules Foundation and the Flemish Government – department EWI. ; | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | c:irua:125516 | Serial | 3144 | ||
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Author | Molina-Luna, L.; Duerrschnabel, M.; Turner, S.; Erbe, M.; Martinez, G.T.; Van Aert, S.; Holzapfel, B.; Van Tendeloo, G. | ||||
Title | Atomic and electronic structures of BaHfO3-doped TFA-MOD-derived YBa2Cu3O7−δthin films | Type | A1 Journal article | ||
Year | 2015 | Publication | Superconductor science and technology | Abbreviated Journal | Supercond Sci Tech |
Volume | 28 | Issue | 28 | Pages | 115009 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Tailoring the properties of oxide-based nanocomposites is of great importance for a wide range of materials relevant for energy technology. YBa2Cu3O7−δ (YBCO) superconducting thin films containing nanosized BaHfO3 (BHO) particles yield a significant improvement of the magnetic flux pinning properties and a reduced anisotropy of the critical current density. These films were prepared by chemical solution deposition (CSD) on (100) SrTiO3 (STO) substrates yielding critical current densities up to 3.6 MA cm−2 at 77 K and self-field. Transport in-field J c measurements demonstrated a high pinning force maximum of around 6 GN/m3 for a sample annealed at T = 760 °C that has a doping of 12 mol% of BHO. This sample was investigated by scanning transmission electron microscopy (STEM) in combination with electron energy-loss spectroscopy (EELS) yielding strain and spectral maps. Spherical BHO nanoparticles of 15 nm in size were found in the matrix, whereas the particles at the interface were flat. A 2 nm diffusion layer containing Ti was found at the YBCO (BHO)/STO interface. Local lattice deformation mapping at the atomic scale revealed crystal defects induced by the presence of both sorts of BHO nanoparticles, which can act as pinning centers for magnetic flux lines. Two types of local lattice defects were identified and imaged: (i) misfit edge dislocations and (ii) Ba-Cu-Cu-Ba stacking faults (Y-248 intergrowths). The local electronic structure and charge transfer were probed by high energy resolution monochromated electron energy-loss spectroscopy. This technique made it possible to distinguish superconducting from non-superconducting areas in nanocomposite samples with atomic resolution in real space, allowing the identification of local pinning sites on the order of the coherence length of YBCO (~1.5 nm) and the determination of 0.25 nm dislocation cores. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000366193000018 | Publication Date | 2015-09-25 | |
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 | 4 | Open Access | |
Notes | The authors thank financial support from the European Union under the Framework 6 program as a contract for an Integrated Infrastructure Initiative (References No. 026019 ESTEEM) and by the EUFP6 Research Project “NanoEngineered Superconductors for Power Applications” NESPA no. MRTN-CT-2006-035619. This work was supported by funding from the European Research Council under the Seventh Framework Programme (FP7). L.M.L, S.T. and G.V.T acknowledge ERC grant N°246791 – COUNTATOMS and funding under a contract for an Integrated Infrastructure Initiative, Reference No. 312483- ESTEEM2, as well as the EC project EUROTAPES. G.T.M. and S.V.A acknowledge financial support from the Fund for Scientific Research-Flanders (Reference G.0064.10N and G.0393.11N). M.D. acknowledges financial support from the LOEWE research cluster RESPONSE (Hessen, Germany). M.E. has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement n° NMP-LA-2012-280432.; esteem2jra2; esteem2jra3 | Approved | Most recent IF: 2.878; 2015 IF: 2.325 | ||
Call Number | c:irua:129199 c:irua:129199 | Serial | 3942 | ||
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Author | Erbe, M.; Hänisch, J.; Hühne, R.; Freudenberg, T.; Kirchner, A.; Molina-Luna, L.; Damm, C.; Van Tendeloo, G.; Kaskel, S.; Schultz, L.; Holzapfel, B. | ||||
Title | BaHfO3artificial pinning centres in TFA-MOD-derived YBCO and GdBCO thin films | Type | A1 Journal article | ||
Year | 2015 | Publication | Superconductor science and technology | Abbreviated Journal | Supercond Sci Tech |
Volume | 28 | Issue | 28 | Pages | 114002 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Chemical solution deposition (CSD) is a promising way to realize REBa2Cu3O7−x (REBCO;RE = rare earth (here Y, Gd))-coated conductors with high performance in applied magnetic fields. However, the preparation process contains numerous parameters which need to be tuned to achieve high-quality films. Therefore, we investigated the growth of REBCO thin films containing nanometre-scale BaHfO3 (BHO) particles as pinning centres for magnetic flux lines, with emphasis on the influence of crystallization temperature and substrate on the microstructure and superconductivity. Conductivity, microscopy and x-ray investigations show an enhanced performance of BHO nano-composites in comparison to pristine REBCO. Further, those measurements reveal the superiority of GdBCO to YBCO—e.g. by inductive critical current densities, Jc, at self-field and 77 K. YBCO is outperformed by more than 1 MA cm−2 with Jc values of up to 5.0 MA cm−2 for 265 nm thick layers of GdBCO(BHO) on lanthanum aluminate. Transport in-field Jc measurements demonstrate high pinning force maxima of around 4 GN m−3 for YBCO(BHO) and GdBCO(BHO). However, the irreversibility fields are appreciably higher for GdBCO. The critical temperature was not significantly reduced upon BHO addition to both YBCO and GdBCO, indicating a low tendency for Hf diffusion into the REBCO matrix. Angular-dependent Jc measurements show a reduction of the anisotropy in the same order of magnitude for both REBCO compounds. Theoretical models suggest that more than one sort of pinning centre is active in all CSD films. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000366193000003 | Publication Date | 2015-09-25 | |
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 | 36 | Open Access | |
Notes | Experimental work was mainly done at IFW Dresden. We thank Juliane Scheiter and Dr Jens Ingolf Mönch of IFW Dresden for technical assistance. The research leading to these results received funding from EUROTAPES, a collaborative project funded by the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement no. NMP-LA-2012-280 432. L Molina-Luna and G Van Tendeloo acknowledge funding from the European Research Council (ERC grant nr. 24 691-COUNTATOMS). | Approved | Most recent IF: 2.878; 2015 IF: 2.325 | ||
Call Number | c:irua:129200 | Serial | 3941 | ||
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Author | Homm, P.; Dillemans, L.; Menghini, M.; Van Bilzen, B.; Bakalov, P.; Su, C.Y.; Lieten, R.; Houssa, M.; Nasr Esfahani, D.; Covaci, L.; Peeters, F.M.; Seo, J.W.; Locquet, J.P.; | ||||
Title | Collapse of the low temperature insulating state in Cr-doped V2O3 thin films | Type | A1 Journal article | ||
Year | 2015 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 107 | Issue | 107 | Pages | 111904 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We have grown epitaxial Cr-doped V2O3 thin films with Cr concentrations between 0% and 20% on (0001)-Al2O3 by oxygen-assisted molecular beam epitaxy. For the highly doped samples (>3%), a regular and monotonous increase of the resistance with decreasing temperature is measured. Strikingly, in the low doping samples (between 1% and 3%), a collapse of the insulating state is observed with a reduction of the low temperature resistivity by up to 5 orders of magnitude. A vacuum annealing at high temperature of the films recovers the low temperature insulating state for doping levels below 3% and increases the room temperature resistivity towards the values of Cr-doped V2O3 single crystals. It is well-know that oxygen excess stabilizes a metallic state in V2O3 single crystals. Hence, we propose that Cr doping promotes oxygen excess in our films during deposition, leading to the collapse of the low temperature insulating state at low Cr concentrations. These results suggest that slightly Cr-doped V2O3 films can be interesting candidates for field effect devices. (C) 2015 AIP Publishing LLC. | ||||
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Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000361639200020 | Publication Date | 2015-09-19 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-6951; 1077-3118 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.411 | Times cited | 14 | Open Access | |
Notes | ; The authors acknowledge financial support from the FWO Project No. G052010N10 as well as the EU-FP7 SITOGA Project. P.H. acknowledges support from Becas Chile-CONICYT. ; | Approved | Most recent IF: 3.411; 2015 IF: 3.302 | ||
Call Number | UA @ lucian @ c:irua:128728 | Serial | 4149 | ||
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Author | Torun, E.; Sahin, H.; Bacaksiz, C.; Senger, R.T.; Peeters, F.M. | ||||
Title | Tuning the magnetic anisotropy in single-layer crystal structures | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 92 | Issue | 92 | Pages | 104407 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The effect of an applied electric field and the effect of charging are investigated on themagnetic anisotropy (MA) of various stable two-dimensional (2D) crystals such as graphene, FeCl2, graphone, fluorographene, and MoTe2 using first-principles calculations. We found that themagnetocrystalline anisotropy energy of Co-on-graphene and Os-doped-MoTe2 systems change linearly with electric field, opening the possibility of electric field tuningMAof these compounds. In addition, charging can rotate the easy-axis direction ofCo-on-graphene andOs-doped-MoTe2 systems from the out-of-plane (in-plane) to in-plane (out-of-plane) direction. The tunable MA of the studied materials is crucial for nanoscale electronic technologies such as data storage and spintronics devices. Our results show that controlling the MA of the mentioned 2D crystal structures can be realized in various ways, and this can lead to the emergence of a wide range of potential applications where the tuning and switching of magnetic functionalities are important. | ||||
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Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000360961400004 | Publication Date | 2015-09-11 | |
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 | 37 | 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. C.B. and R.T.S. acknowledge support from TUBITAK Project No. 111T318. ; | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | UA @ lucian @ c:irua:127838 | Serial | 4269 | ||
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Author | Schoeters, B.; Leenaerts, O.; Pourtois, G.; Partoens, B. | ||||
Title | Ab-initio study of the segregation and electronic properties of neutral and charged B and P dopants in Si and Si/SiO2 nanowires | Type | A1 Journal article | ||
Year | 2015 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 118 | Issue | 118 | Pages | 104306 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | We perform first-principles calculations to investigate the preferred positions of B and P dopants, both neutral and in their preferred charge state, in Si and Si/SiO2 core-shell nanowires (NWs). In order to understand the observed trends in the formation energy, we isolate the different effects that determine these formation energies. By making the distinction between the unrelaxed and the relaxed formation energy, we separate the impact of the relaxation from that of the chemical environment. The unrelaxed formation energies are determined by three effects: (i) the effect of strain caused by size mismatch between the dopant and the host atoms, (ii) the local position of the band edges, and (iii) a screening effect. In the case of the SiNW (Si/SiO2 NW), these effects result in an increase of the formation energy away from the center (interface). The effect of relaxation depends on the relative size mismatch between the dopant and host atoms. A large size mismatch causes substantial relaxation that reduces the formation energy considerably, with the relaxation being more pronounced towards the edge of the wires. These effects explain the surface segregation of the B dopants in a SiNW, since the atomic relaxation induces a continuous drop of the formation energy towards the edge. However, for the P dopants, the formation energy starts to rise when moving from the center but drops to a minimum just next to the surface, indicating a different type of behavior. It also explains that the preferential location for B dopants in Si/SiO2 core-shell NWs is inside the oxide shell just next to the interface, whereas the P dopants prefer the positions next to the interface inside the Si core, which is in agreement with recent experiments. These preferred locations have an important impact on the electronic properties of these core-shell NWs. Our simulations indicate the possibility of hole gas formation when B segregates into the oxide shell. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000361636900031 | Publication Date | 2015-09-09 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-8979 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 3 | Open Access | |
Notes | This work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish government and the Universiteit Antwerpen. | Approved | Most recent IF: 2.068; 2015 IF: 2.183 | ||
Call Number | c:irua:128729 | Serial | 4056 | ||
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Author | Yagmurcukardes, M.; Sahin, H.; Kang, J.; Torun, E.; Peeters, F.M.; Senger, R.T. | ||||
Title | Pentagonal monolayer crystals of carbon, boron nitride, and silver azide | Type | A1 Journal article | ||
Year | 2015 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 118 | Issue | 118 | Pages | 104303 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | In this study, we present a theoretical investigation of structural, electronic, and mechanical properties of pentagonal monolayers of carbon (p-graphene), boron nitride (p-B2N4 and p-B4N2), and silver azide (p-AgN3) by performing state-of-the-art first principles calculations. Our total energy calculations suggest feasible formation of monolayer crystal structures composed entirely of pentagons. In addition, electronic band dispersion calculations indicate that while p-graphene and p-AgN3 are semiconductors with indirect bandgaps, p-BN structures display metallic behavior. We also investigate the mechanical properties (in-plane stiffness and the Poisson's ratio) of four different pentagonal structures under uniaxial strain. p-graphene is found to have the highest stiffness value and the corresponding Poisson's ratio is found to be negative. Similarly, p-B2N4 and p-B4N2 have negative Poisson's ratio values. On the other hand, the p-AgN3 has a large and positive Poisson's ratio. In dynamical stability tests based on calculated phonon spectra of these pentagonal monolayers, we find that only p-graphene and p-B2N4 are stable, but p-AgN3 and p-B4N2 are vulnerable against vibrational excitations. | ||||
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Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000361636900028 | Publication Date | 2015-09-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-8979; 1089-7550 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 79 | 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). H.S. was supported by a FWO Pegasus Long Marie Curie Fellowship. H.S. and R.T.S. acknowledge the support from TUBITAK through Project No. 114F397. ; | Approved | Most recent IF: 2.068; 2015 IF: 2.183 | ||
Call Number | UA @ lucian @ c:irua:128415 | Serial | 4223 | ||
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Author | Aierken, Y.; Leenaerts, O.; Peeters, F.M. | ||||
Title | Defect-induced faceted blue phosphorene nanotubes | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 92 | Issue | 92 | Pages | 104104 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The properties of a new class of phosphorene nanotubes (PNT) are investigated by performing first-principles calculations. We demonstrate that it is advantageous to use blue phosphorene in order to make small nanotubes and propose a way to create low-energy PNTs by the inclusion of defect lines. Five different types of defect lines are investigated and incorporated in various combinations. The resulting defect-induced faceted PNTs have negligible bending stresses which leads to a reduction in the formation energy with respect to round PNTs. Our armchair faceted PNTs have similar formation energies than the recently proposed multiphase faceted PNTs, but they have a larger variety of possible structures. Our zigzag faceted PNTs have lower formation energies than round tubes and multiphase faceted nanotubes. The electronic properties of the defect-induced faceted PNTs are determined by the defect lines which control the band gap and the shape of the electronic states at the band edges. These band gaps increase with the radius of the nanotubes and converge to those of isolated defect lines. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000361037200006 | Publication Date | 2015-09-12 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 24 | Open Access | |
Notes | This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vl). The computational resources and ser- vices used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Hercules Foundation and the Flemish Government, department EWI. | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | c:irua:127837 | Serial | 4033 | ||
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Author | Verlackt, C.C.W.; Neyts, E.C.; Jacob, T.; Fantauzzi, D.; Golkaram, M.; Shin, Y.-K.; van Duin, A.C.T.; Bogaerts, A. | ||||
Title | Atomic-scale insight into the interactions between hydroxyl radicals and DNA in solution using the ReaxFF reactive force field | Type | A1 Journal article | ||
Year | 2015 | Publication | New journal of physics | Abbreviated Journal | New J Phys |
Volume | 17 | Issue | 17 | Pages | 103005 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Cold atmospheric pressure plasmas have proven to provide an alternative treatment of cancer by targeting tumorous cells while leaving their healthy counterparts unharmed. However, the underlying mechanisms of the plasma–cell interactions are not yet fully understood. Reactive oxygen species, and in particular hydroxyl radicals (OH), are known to play a crucial role in plasma driven apoptosis of malignant cells. In this paper we investigate the interaction of OH radicals, as well as H2O2 molecules and HO2 radicals, with DNA by means of reactive molecular dynamics simulations using the ReaxFF force field. Our results provide atomic-scale insight into the dynamics of oxidative stress on DNA caused by the OH radicals, while H2O2 molecules appear not reactive within the considered timescale. Among the observed processes are the formation of 8-OH-adduct radicals, forming the first stages towards the formation of 8-oxoGua and 8-oxoAde, H-abstraction reactions of the amines, and the partial opening of loose DNA ends in aqueous solution. |
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000367328100001 | Publication Date | 2015-10-02 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1367-2630; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.786 | Times cited | 18 | Open Access | |
Notes | CCWV,ECN and AB acknowledge the contribution of J Van Beeck who is investigating the interaction between H2O2 andDNAusingrMDsimulations. Furthermore, they acknowledge financial support from the Fund for Scientific Research—Flanders (project number G012413N). The calculations were performed using the Turing HPCinfrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the Universiteit Antwerpen. TJ and DF gratefully acknowledge support from the European Research Council through the ERC-Starting GrantTHEOFUN(Grant Agreement No. 259608). | Approved | Most recent IF: 3.786; 2015 IF: 3.558 | ||
Call Number | c:irua:129178 | Serial | 3955 | ||
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Author | Zha, G.-Q.; Covaci, L.; Peeters, F.M.; Zhou, S.-P. | ||||
Title | Majorana zero-energy modes and spin current evolution in mesoscopic superconducting loop systems with spin-orbit interaction | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 92 | Issue | 92 | Pages | 094516 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The Majorana zero modes and persistent spin current in mesoscopic d-wave-superconducting loops with spin-orbit (SO) interaction are investigated by numerically solving the spin-generalized Bogoliubov-de Gennes equations self-consistently. For some appropriate strength of the SO coupling, Majorana zero-energy states and sharp jumps of the spin-polarized currents can be observed when the highest energy levels cross the Fermi energy in the spectrum, leading to spin currents with opposite chirality flowing near the inner and outer edges of the sample. When the threaded magnetic flux turns on, four flux-dependent patterns of the persistent spin current with step-like features show up, accompanied by Majorana edge modes at flux values where the energy gap closes. Moreover, the Majorana zero mode is highly influenced by the direction of the Zeeman field. A finite in-plane field can lead to the gap opening since the inversion symmetry is broken. Remarkably, multiple Majorana zero-energy states occur in the presence of an out-of-plane field h(z), and the number of steps in the spin current evolution can be effectively tuned by the field strength due to the shift of Majorana zero modes. Finally, when the loop sample contains surface indentation defects, zero-energy modes can always show up in the presence of an appropriate h(z). Interestingly, multiple Majorana states may be present in the system with a corner defect even if h(z) = 0. | ||||
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Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000362081000002 | Publication Date | 2015-09-30 | |
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 | 11 | Open Access | |
Notes | ; This work was supported by National Natural Science Foundation of China under Grants No. 61371020, No. 61271163, and No. 61571277, by the Visiting Scholar Program of Shanghai Municipal Education Commission, and by the Flemish Science Foundation (FWO-Vl). ; | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | UA @ lucian @ c:irua:132467 | Serial | 4203 | ||
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Author | Shestakov, M.V.; Meledina, M.; Turner, S.; Baekelant, W.; Verellen, N.; Chen, X.; Hofkens, J.; Van Tendeloo, G.; Moshchalkov, V.V. | ||||
Title | Luminescence of fixed site Ag nanoclusters in a simple oxyfluoride glass host and plasmon absorption of amorphous Ag nanoparticles in a complex oxyfluoride glass host | Type | P1 Proceeding | ||
Year | 2015 | Publication | Proceedings of the Society of Photo-optical Instrumentation Engineers T2 – 8th International Conference on Photonics, Devices, and System VI, AUG 27-29, 2014, Prague, CZECH REPUBLIC | Abbreviated Journal | |
Volume | Issue | Pages | Unsp 94501n | ||
Keywords | P1 Proceeding; Electron microscopy for materials research (EMAT) | ||||
Abstract | Ag nanocluster-doped glasses have been prepared by a conventional melt-quenching method. The effect of melt temperature and dwell time on the formation of Ag nanoclusters and Ag nanoparticles in simple host oxyfluoride glasses has been studied. The increase of melt temperature and dwell time results in the dissolution of Ag nanoparticles and substantial red-shift of absorption and photoluminescence spectra of the prepared glasses. The quantum yield of the glasses is similar to 5% and does not depend on melt temperature and dwell time. The prepared glasses may be used as red phosphors or down-conversion layers for solar-cells. | ||||
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Publisher | Spie-int soc optical engineering | Place of Publication | Bellingham | Editor | |
Language | Wos | 000349404500057 | Publication Date | 2015-01-06 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | 9450 | Series Issue | Edition | ||
ISSN | 978-1-62841-566-7 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | Times cited | Open Access | |||
Notes | Approved | Most recent IF: NA | |||
Call Number | UA @ lucian @ c:irua:144783 | Serial | 4668 | ||
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Author | Juchtmans, R.; Béché, A.; Abakumov, A.; Batuk, M.; Verbeeck, J. | ||||
Title | Using electron vortex beams to determine chirality of crystals in transmission electron microscopy | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 91 | Issue | 91 | Pages | 094112 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | We investigate electron vortex beams elastically scattered on chiral crystals. After deriving a general expression for the scattering amplitude of a vortex electron, we study its diffraction on point scatterers arranged on a helix. We derive a relation between the handedness of the helix and the topological charge of the electron vortex on one hand and the symmetry of the higher-order Laue zones in the diffraction pattern on the other for kinematically and dynamically scattered electrons. We then extend this to atoms arranged on a helix as found in crystals which belong to chiral space groups and propose a method to determine the handedness of such crystals by looking at the symmetry of the diffraction pattern. In contrast to alternative methods, our technique does not require multiple scattering, which makes it possible to also investigate extremely thin samples in which multiple scattering is suppressed. In order to verify the model, elastic scattering simulations are performed, and an experimental demonstration on Mn2Sb2O7 is given in which we find the sample to belong to the right-handed variant of its enantiomorphic pair. This demonstrates the usefulness of electron vortex beams to reveal the chirality of crystals in a transmission electron microscope and provides the required theoretical basis for further developments in this field. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000352017000002 | Publication Date | 2015-03-27 | |
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 | 54 | Open Access | |
Notes | Fwo; 312483 Esteem2; 278510 Vortex; esteem2jra1; esteem2jra2 ECASJO_; | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | c:irua:125512 c:irua:125512 | Serial | 3825 | ||
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Author | Hoek, M.; Coneri, F.; Poccia, N.; Renshaw Wang, X.; Ke, X.; Van Tendeloo, G.; Hilgenkamp, H. | ||||
Title | Strain accommodation through facet matching in La1.85Sr0.15CuO4/Nd1.85Ce0.15CuO4 ramp-edge junctions | Type | A1 Journal article | ||
Year | 2015 | Publication | APL materials | Abbreviated Journal | Apl Mater |
Volume | 3 | Issue | 3 | Pages | 086101 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Scanning nano-focused X-ray diffraction and high-angle annular dark-field scanning transmission electron microscopy are used to investigate the crystal structure of ramp-edge junctions between superconducting electron-doped Nd1.85Ce0.15CuO4 and superconducting hole-doped La1.85Sr0.15CuO4 thin films, the latter being the top layer. On the ramp, a new growth mode of La1.85Sr0.15CuO4 with a 3.3° tilt of the c-axis is found. We explain the tilt by developing a strain accommodation model that relies on facet matching, dictated by the ramp angle, indicating that a coherent domain boundary is formed at the interface. The possible implications of this growth mode for the creation of artificial domains in morphotropic materials are discussed. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000360656800009 | Publication Date | 2015-08-03 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2166-532X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.335 | Times cited | 4 | Open Access | |
Notes | 312483 Esteem2; 246791 Countatoms; esteem2_jra2 | Approved | Most recent IF: 4.335; 2015 IF: NA | ||
Call Number | c:irua:127690 c:irua:127690 | Serial | 3163 | ||
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Author | Bacaksiz, C.; Sahin, H.; Ozaydin, H.D.; Horzum, S.; Senger, R.T.; Peeters, F.M. | ||||
Title | Hexagonal A1N : dimensional-crossover-driven band-gap transition | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 91 | Issue | 91 | Pages | 085430 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Motivated by a recent experiment that reported the successful synthesis of hexagonal (h) AlN [Tsipas et al., Appl. Phys. Lett. 103, 251605 (2013)], we investigate structural, electronic, and vibrational properties of bulk, bilayer, and monolayer structures of h-AlN by using first-principles calculations. We show that the hexagonal phase of the bulk h-AlN is a stable direct-band-gap semiconductor. The calculated phonon spectrum displays a rigid-layer shear mode at 274 cm(-1) and an E-g mode at 703 cm(-1), which are observable by Raman measurements. In addition, single-layer h-AlN is an indirect-band-gap semiconductor with a nonmagnetic ground state. For the bilayer structure, AA'-type stacking is found to be the most favorable one, and interlayer interaction is strong. While N-layered h-AlN is an indirect-band-gap semiconductor for N = 1 – 9, we predict that thicker structures (N >= 10) have a direct band gap at the Gamma point. The number-of-layer-dependent band-gap transitions in h-AlN is interesting in that it is significantly different from the indirect-to-direct crossover obtained in the transition-metal dichalcogenides. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000350319200020 | Publication Date | 2015-02-27 | |
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 | 99 | 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). C.B. and R.T.S. acknowledge the support from TUBITAK Project No 114F397. H.S. is supported by a FWO Pegasus Long Marie Curie Fellowship. ; | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | c:irua:125416 | Serial | 1421 | ||
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