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Author Heshmati-Moulai, A.; Simchi, H.; Esmaeilzadeh, M.; Peeters, F.M. url  doi
openurl 
  Title Phase transition and spin-resolved transport in MoS2 nanoribbons Type A1 Journal article
  Year 2016 Publication (down) Physical review B Abbreviated Journal Phys Rev B  
  Volume 94 Issue 94 Pages 235424  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The electronic structure and transport properties of monolayer MoS2 are studied using a tight-binding approach coupled with the nonequilibrium Green's function method. A zigzag nanoribbon of MoS2 is conducting due to the intersection of the edge states with the Fermi level that is located within the bulk gap. We show that applying a transverse electric field results in the disappearance of this intersection and turns the material into a semiconductor. By increasing the electric field the band gap undergoes a two stage linear increase after which it decreases and ultimately closes. It is shown that in the presence of a uniform exchange field, this electric field tuning of the gap can be exploited to open low energy domains where only one of the spin states contributes to the electronic conductance. This introduces possibilities in designing spin filters for spintronic applications.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000394546100005 Publication Date 2016-12-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9950;2469-9969; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 7 Open Access  
  Notes ; ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:141978 Serial 4557  
Permanent link to this record
 

 
Author Cavalcante, L.S.; Chaves, A.; da Costa, D.R.; Farias, G.A.; Peeters, F.M. url  doi
openurl 
  Title All-strain based valley filter in graphene nanoribbons using snake states Type A1 Journal article
  Year 2016 Publication (down) Physical review B Abbreviated Journal Phys Rev B  
  Volume 94 Issue 7 Pages 075432  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract A pseudomagnetic field kink can be realized along a graphene nanoribbon using strain engineering. Electron transport along this kink is governed by snake states that are characterized by a single propagation direction. Those pseudomagnetic fields point towards opposite directions in the K and K' valleys, leading to valley polarized snake states. In a graphene nanoribbon with armchair edges this effect results in a valley filter that is based only on strain engineering. We discuss how to maximize this valley filtering by adjusting the parameters that define the stress distribution along the graphene ribbon.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000381889300002 Publication Date 2016-08-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 29 Open Access  
  Notes ; Discussions with R. Grassi are gratefully acknowledged. This work was supported by the Brazilian Council for Research (CNPq), under the PRONEX/FUNCAP and Science Without Borders (SWB) programs, CAPES, the Lemann Foundation, and the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:144667 Serial 4639  
Permanent link to this record
 

 
Author Fernandez, M.S.; Peeters, F.M.; Neek-Amal, M. url  doi
openurl 
  Title Electric-field-induced structural changes in water confined between two graphene layers Type A1 Journal article
  Year 2016 Publication (down) Physical review B Abbreviated Journal Phys Rev B  
  Volume 94 Issue 4 Pages 045436  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract An external electric field changes the physical properties of polar liquids due to the reorientation of their permanent dipoles. Using molecular dynamics simulations, we predict that an in-plane electric field applied parallel to the channel polarizes water molecules which are confined between two graphene layers, resulting in distinct ferroelectricity and electrical hysteresis. We found that electric fields alter the in-plane order of the hydrogen bonds: Reversing the electric field does not restore the system to the nonpolar initial state, instead a residual dipole moment remains in the system. The square-rhombic structure of 2D ice is transformed into two rhombic-rhombic structures. Our study provides insights into the ferroelectric state of water when confined in nanochannels and shows how this can be tuned by an electric field.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000381485200005 Publication Date 2016-07-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 31 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  
  Call Number UA @ lucian @ c:irua:144684 Serial 4649  
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Author Aierken, Y.; Leenaerts, O.; Peeters, F.M. url  doi
openurl 
  Title Intrinsic magnetism in penta-hexa-graphene: A first-principles study Type A1 Journal article
  Year 2016 Publication (down) Physical review B Abbreviated Journal Phys Rev B  
  Volume 94 Issue 15 Pages 155410  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Recently, several monolayer carbon allotropes have been proposed. The magnetic properties of these metal-free materials are investigated, and we explore a special type of all carbon system having an intrinsic magnetic ground state. The structure is composed of mixing pentagonal and hexagonal rings of carbon atoms, such that the unit cell consists of eleven atoms, where two C atoms each have an unpaired electron each with a local magnetic moment. The antiferromagnetic (AFM) state has a lower energy than the ferromagnetic (FM) one. However, a strain-driven transition to the FM ground state is possible. The application of strain not only lowers the energy of the FM state but it also induces an energy barrier of about 13 meV/(magnetic atom) to protect the FM state from excitation. Our findings based on first-principles calculations will motivate other works on similar metal-free magnetic monolayer materials and will have an impact on their possible applications in spintronic devices.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000385623700006 Publication Date 2016-10-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 13 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 Research Foundation-Flanders (FWO) and the Flemish Government-department EWI. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:144641 Serial 4665  
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Author Madan, I.; Kusar, P.; Baranov, V.V.; Lu-Dac, M.; Kabanov, V.V.; Mertelj, T.; Mihailovic, D. url  doi
openurl 
  Title Real-time measurement of the emergence of superconducting order in a high-temperature superconductor Type A1 Journal article
  Year 2016 Publication (down) Physical review B Abbreviated Journal Phys Rev B  
  Volume 93 Issue 22 Pages 224520  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Systems which rapidly evolve through symmetry-breaking transitions on timescales comparable to the fluctuation timescale of the single-particle excitations may behave very differently than under controlled near-ergodic conditions. A real-time investigation with high temporal resolution may reveal insights into the ordering through the transition that are not available in static experiments. We present an investigation of the system trajectory through a normal-to-superconductor transition in a prototype high-temperature superconducting cuprate in which such a situation occurs. Using a multiple pulse femtosecond spectroscopy technique we measure the system trajectory and time evolution of the single-particle excitations through the transition in La1.9Sr0.1CuO4 and compare the data to a simulation based on the time-dependent Ginzburg-Landau theory, using the laser excitation fluence as an adjustable parameter controlling the quench conditions in both experiment and theory. The comparison reveals the presence of significant superconducting fluctuations which precede the transition on short timescales. By including superconducting fluctuations as a seed for the growth of the superconducting order we can obtain a satisfactory agreement of the theory with the experiment. Remarkably, the pseudogap excitations apparently play no role in this process.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000378815800003 Publication Date 2016-07-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 5 Open Access  
  Notes ; We wish to acknowledge the useful discussion with T. W. Kibble regarding the importance of a variable quench rate in the experiment. The funding was provided by European Research Council advanced grant TRAJECTORY. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:144701 Serial 4683  
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Author Vagov, A.; Shanenko, A.A.; Milošević, M.V.; Axt, V.M.; Vinokur, V.M.; Aguiar, J.A.; Peeters, F.M. url  doi
openurl 
  Title Superconductivity between standard types: Multiband versus single-band materials Type A1 Journal article
  Year 2016 Publication (down) Physical review B Abbreviated Journal Phys Rev B  
  Volume 93 Issue 93 Pages 174503  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000375527500001 Publication Date 2016-05-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 37 Open Access  
  Notes Conselho Nacional de Desenvolvimento Científico e Tecnológico, 307552/2012-8 141911/2012-3 ; Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco, APQ-0589-1.05/08 ; U.S. Department of Energy; Approved Most recent IF: 3.836  
  Call Number CMT @ cmt @ c:irua:141732 Serial 4480  
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Author Juchtmans, R.; Verbeeck, J. url  doi
openurl 
  Title Local orbital angular momentum revealed by spiral-phase-plate imaging in transmission-electron microscopy Type A1 Journal article
  Year 2016 Publication (down) Physical Review A Abbreviated Journal Phys Rev A  
  Volume 93 Issue 93 Pages 023811  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The orbital angular momentum (OAM) of light and matter waves is a parameter that has been getting increasingly more attention over the past couple of years. Beams with a well-defined OAM, the so-called vortex beams, are applied already in, e.g., telecommunication, astrophysics, nanomanipulation, and chiral measurements in optics and electron microscopy. Also, the OAM of a wave induced by the interaction with a sample has attracted a lot of interest. In all these experiments it is crucial to measure the exact (local) OAM content of the wave, whether it is an incoming vortex beam or an exit wave after interacting with a sample. In this work we investigate the use of spiral phase plates (SPPs) as an alternative to the programmable phase plates used in optics to measure OAM. We derive analytically how these can be used to study the local OAM components of any wave function. By means of numerical simulations we illustrate how the OAM of a pure vortex beam can be measured. We also look at a sum of misaligned vortex beams and show how, by using SPPs, the position and the OAM of each individual beam can be detected. Finally, we look at the OAM induced by a magnetic dipole on a free-electron wave and show how the SPP can be used to localize the magnetic poles and measure their “magnetic charge.” Although our findings can be applied to study the OAM of any wave function, our findings are of particular interest for electron microscopy where versatile programmable phase plates do not yet exist.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000369367700006 Publication Date 2016-02-06  
  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 12 Open Access  
  Notes The authors acknowledge support from the Aspirant Fonds Wetenschappelijk Onderzoek–Vlaanderen (FPO), the EU un- der the Seventh Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483- ESTEEM2, and the ERC Starting Grant 278510 VORTEX.; esteem2jra2 ECASJO; Approved Most recent IF: 2.925  
  Call Number c:irua:131613 c:irua:131613UA @ admin @ c:irua:131613 Serial 4030  
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Author Clark, L.; Guzzinati, G.; Béché, A.; Lubk, A.; Verbeeck, J. pdf  url
doi  openurl
  Title Symmetry-constrained electron vortex propagation Type A1 Journal article
  Year 2016 Publication (down) Physical review A Abbreviated Journal Phys Rev A  
  Volume 93 Issue 93 Pages 063840  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Electron vortex beams hold great promise for development in transmission electron microscopy but have yet to be widely adopted. This is partly due to the complex set of interactions that occur between a beam carrying orbital angular momentum (OAM) and a sample. Herein, the system is simplified to focus on the interaction between geometrical symmetries, OAM, and topology. We present multiple simulations alongside experimental data to study the behavior of a variety of electron vortex beams after interacting with apertures of different symmetries and investigate the effect on their OAM and vortex structure, both in the far field and under free-space propagation.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000378197200006 Publication Date 2016-06-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9926 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.925 Times cited 7 Open Access  
  Notes L.C., A.B., G.G., and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510—VORTEX. J.V. and A.L. acknowledge financial support from the European Union through the 7th Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative (Reference No. 312483 ESTEEM2). The Qu-Ant-EM microscope was partly funded by the Hercules fund of the Flemish Government.; esteem2jra3; ECASJO; Approved Most recent IF: 2.925  
  Call Number c:irua:134086 c:irua:134086 Serial 4090  
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Author Klimin, S.N.; Tempere, J.; Verhelst, N.; Milošević, M.V. url  doi
openurl 
  Title Finite-temperature vortices in a rotating Fermi gas Type A1 Journal article
  Year 2016 Publication (down) Physical review A Abbreviated Journal Phys Rev A  
  Volume 94 Issue 94 Pages 023620  
  Keywords A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT)  
  Abstract Vortices and vortex arrays have been used as a hallmark of superfluidity in rotated, ultracold Fermi gases. These superfluids can be described in terms of an effective field theory for a macroscopic wave function representing the field of condensed pairs, analogous to the Ginzburg-Landau theory for superconductors. Here we establish how rotation modifies this effective field theory, by rederiving it starting from the action of Fermi gas in the rotating frame of reference. The rotation leads to the appearance of an effective vector potential, and the coupling strength of this vector potential to the macroscopic wave function depends on the interaction strength between the fermions, due to a renormalization of the pair effective mass in the effective field theory. The mass renormalization derived here is in agreement with results of functional renormalization-group theory. In the extreme Bose-Einstein condensate regime, the pair effective mass tends to twice the fermion mass, in agreement with the physical picture of a weakly interacting Bose gas of molecular pairs. Then we use our macroscopic-wave-function description to study vortices and the critical rotation frequencies to form them. Equilibrium vortex state diagrams are derived and they are in good agreement with available results of the Bogoliubov-de Gennes theory and with experimental data.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y. Editor  
  Language Wos 000381473100001 Publication Date 2016-08-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9934 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.925 Times cited 6 Open Access  
  Notes ; We are grateful to G. C. Strinati and H. Warringa for valuable discussions. This research was supported by the Flemish Research Foundation Projects No. G.0115.12N, No. G.0119.12N, No. G.0122.12N, and No. G.0429.15N, by the Scientific Research Network of the Flemish Research Foundation, Grant No. WO.033.09N, and by the Research Fund of the University of Antwerp. ; Approved Most recent IF: 2.925  
  Call Number UA @ lucian @ c:irua:135686 Serial 4304  
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Author Juchtmans, R.; Guzzinati, G.; Verbeeck, J. url  doi
openurl 
  Title Extension of Friedel's law to vortex-beam diffraction Type A1 Journal article
  Year 2016 Publication (down) Physical Review A Abbreviated Journal Phys Rev A  
  Volume 94 Issue 94 Pages 033858  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Friedel's law states that the modulus of the Fourier transform of real functions is centrosymmetric, while the phase is antisymmetric. As a consequence of this, elastic scattering of plane-wave photons or electrons within the first-order Born-approximation, as well as Fraunhofer diffraction on any aperture, is bound to result in centrosymmetric diffraction patterns. Friedel's law, however, does not apply for vortex beams, and centrosymmetry in general is not present in their diffraction patterns. In this work we extend Friedel's law for vortex beams by showing that the diffraction patterns of vortex beams with opposite topological charge, scattered on the same two-dimensional potential, always are centrosymmetric to one another, regardless of the symmetry of the scattering object. We verify our statement by means of numerical simulations and experimental data. Our research provides deeper understanding in vortex-beam diffraction and can be used to design new experiments to measure the topological charge of vortex beams with diffraction gratings or to study general vortex-beam diffraction.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000384374500010 Publication Date 2016-09-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9926 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.925 Times cited 13 Open Access  
  Notes The authors acknowledge support from the FWO (Aspirant Fonds Wetenschappelijk Onderzoek – Vlaanderen) and 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.; ECASJO_; Approved Most recent IF: 2.925  
  Call Number EMAT @ emat @ c:irua:137200UA @ admin @ c:irua:137200 Serial 4314  
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Author Juchtmans, R.; Clark, L.; Lubk, A.; Verbeeck, J. url  doi
openurl 
  Title Spiral phase plate contrast in optical and electron microscopy Type A1 Journal article
  Year 2016 Publication (down) Physical review A Abbreviated Journal Phys Rev A  
  Volume 94 Issue 94 Pages 023838  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The use of phase plates in the back focal plane of a microscope is a well-established technique in optical microscopy to increase the contrast of weakly interacting samples and is gaining interest in electron microscopy as well. In this paper we study the spiral phase plate (SPP), also called helical, vortex, or two-dimensional Hilbert phase plate, which adds an angularly dependent phase of the form exp(iℓϕk) to the exit wave in Fourier space. In the limit of large collection angles, we analytically calculate that the average of a pair of l=+-1

SPP filtered images is directly proportional to the gradient squared of the exit wave, explaining the edge contrast previously seen in optical SPP work. We discuss the difference between a clockwise-anticlockwise pair of SPP filtered images and derive conditions under which the modulus of the wave's gradient can be seen directly from one SPP filtered image. This work provides the theoretical background to interpret images obtained with a SPP, thereby opening new perspectives for new experiments to study, for example, magnetic materials in an electron microscope.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000381882800011 Publication Date 2016-08-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9926 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.925 Times cited 10 Open Access  
  Notes The authors acknowledge support from the FWO (Aspirant Fonds Wetenschappelijk Onderzoek – Vlaanderen) and 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.; ECASJO_ Approved Most recent IF: 2.925  
  Call Number EMAT @ emat @ c:irua:140086 Serial 4418  
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Author Orlova, N.V.; Kuopanportti, P.; Milošević, M.V. url  doi
openurl 
  Title Skyrmionic vortex lattices in coherently coupled three-component Bose-Einstein condensates Type A1 Journal article
  Year 2016 Publication (down) Physical Review A Abbreviated Journal Phys Rev A  
  Volume 94 Issue 2 Pages 023617  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We show numerically that a harmonically trapped and coherently Rabi-coupled three-component Bose-Einstein condensate can host unconventional vortex lattices in its rotating ground state. The discovered lattices incorporate square and zig-zag patterns, vortex dimers and chains, and doubly quantized vortices, and they can be quantitatively classified in terms of a skyrmionic topological index, which takes into account the multicomponent nature of the system. The exotic ground-state lattices arise due to the intricate interplay of the repulsive density-density interactions and the Rabi couplings as well as the ubiquitous phase frustration between the components. In the frustrated state, domain walls in the relative phases can persist between some components even at strong Rabi coupling, while vanishing between others. Consequently, in this limit the three-component condensate effectively approaches a two-component condensate with only density-density interactions. At intermediate Rabi coupling strengths, however, we face unique vortex physics that occurs neither in the two-component counterpart nor in the purely density-density-coupled three-component system.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000381303800006 Publication Date 2016-08-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9926;2469-9934; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.925 Times cited 16 Open Access  
  Notes ; This work was supported by the Research Foundation Flanders (FWO). P. K. acknowledges financial support from the Emil Aaltonen Foundation, the Finnish Cultural Foundation, the Magnus Ehrnrooth Foundation, and the Technology Industries of Finland Centennial Foundation. The authors thank R. P. Anderson, E. Babaev, I. O. Cherednikov, V. R. Misko, T. P. Simula, and J. Tempere for useful comments and discussions. ; Approved Most recent IF: 2.925  
  Call Number UA @ lucian @ c:irua:144673 Serial 4688  
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Author Mulkers, J.; Milošević, M.V.; Van Waeyenberge, B. url  doi
openurl 
  Title Cycloidal versus skyrmionic states in mesoscopic chiral magnets Type A1 Journal article
  Year 2016 Publication (down) Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 93 Issue 93 Pages 214405  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract When subjected to the interfacially induced Dzyaloshinskii-Moriya interaction, the ground state in thin ferromagnetic films with high perpendicular anisotropy is cycloidal. The period of this cycloidal state depends on the strength of the Dzyaloshinskii-Moriya interaction. In this work, we have studied the effect of confinement on the magnetic ground state and excited states, and we determined the phase diagram of thin strips and thin square platelets by means of micromagnetic calculations. We show that multiple cycloidal states with different periods can be stable in laterally confined films, where the period of the cycloids does not depend solely on the Dzyaloshinskii-Moriya interaction strength but also on the dimensions of the film. The more complex states comprising skyrmions are also found to be stable, though with higher energy.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000377298600006 Publication Date 2016-06-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 28 Open Access  
  Notes ; ; Approved Most recent IF: 3.836  
  Call Number c:irua:133919 Serial 4081  
Permanent link to this record
 

 
Author Bakalov, P.; Esfahani, D.N.; Covaci, L.; Peeters, F.M.; Tempere, J.; Locquet, J.-P. url  doi
openurl 
  Title Electric-field-driven Mott metal-insulator transition in correlated thin films : an inhomogeneous dynamical mean-field theory approach Type A1 Journal article
  Year 2016 Publication (down) Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 93 Issue 93 Pages 165112  
  Keywords A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT)  
  Abstract Simulations are carried out based on the dynamical mean-field theory (DMFT) in order to investigate the properties of correlated thin films for various values of the chemical potential, temperature, interaction strength, and applied transverse electric field. Application of a sufficiently strong field to a thin film at half filling leads to the appearance of conducting regions near the surfaces of the film, whereas in doped slabs the application of a field leads to a conductivity enhancement on one side of the film and a gradual transition to the insulating state on the opposite side. In addition to the inhomogeneous DMFT, a local density approximation (LDA) is considered in which the particle density n, quasiparticle residue Z, and spectral weight at the Fermi level A(ω=0) of each layer are approximated by a homogeneous bulk environment. A systematic comparison between the two approaches reveals that the less expensive LDA results are in good agreement with the DMFT approach, except close to the metal-to-insulator transition points and in the layers immediately at the film surfaces. LDA values for n are overall more reliable than those for Z and A(ω=0). The hysteretic behavior (memory effect) characteristic of the bulk doping driven Mott transition persists in the slab.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000373572700002 Publication Date 2016-04-09  
  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 5 Open Access  
  Notes ; This work was partially funded by the Flemish Fund for Scientific Research (FWO Belgium) under FWO Grant No. G.0520.10 and the joint FWF (Austria)-FWO Grant No. GOG6616N, and by the SITOGA FP7 project. Most of the calculations were performed on KU Leuven's ThinKing HPC cluster provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government-department EWI. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:132872 Serial 4167  
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Author Tahir, M.; Vasilopoulos, P.; Peeters, F.M. url  doi
openurl 
  Title Quantum magnetotransport properties of a MoS2 monolayer Type A1 Journal article
  Year 2016 Publication (down) Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 93 Issue 93 Pages 035406  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We study transport properties of a MoS2 monolayer in the presence of a perpendicular magnetic field B. We derive and discuss its band structure and take into account spin and valley Zeeman effects. Compared to a conventional two-dimensional electron gas, these effects lead to new quantum Hall plateaus and new peaks in the longitudinal resistivity as functions of the magnetic field. The field B leads to a significant enhancement of the spin splitting in the conduction band, to a beating of the Shubnikov-de Haas (SdH) oscillations in the low-field regime, and to their splitting in the high-field regime. The Zeeman fields suppress significantly the beating of the SdH oscillations in the low-field regime and strongly enhance their splitting at high fields. The spin and valley polarizations show a similar beating pattern at low fields and are clearly separated at high fields in which they attain a value higher than 90%.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000367663500003 Publication Date 2016-01-05  
  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 42 Open Access  
  Notes ; This work was supported by the Canadian NSERC Grant No. OGP0121756 (M.T., P.V.) and by the Flemish Science Foundation (FWO-Vl) (F.M.P.). ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:131093 Serial 4233  
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Author Cabral, L.R.E.; de Aquino, B.R.C.H.T.; de Souza Silva, C.C.; Milošević, M.V.; Peeters, F.M. url  doi
openurl 
  Title Two-shell vortex and antivortex dynamics in a Corbino superconducting disk Type A1 Journal article
  Year 2016 Publication (down) Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 93 Issue 93 Pages 014515  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We examine theoretically the dynamics of two vortex shells in pinning-free superconducting thin disks in the Corbino geometry. In the first considered case, the inner shell is composed of vortices and the outer one of antivortices, corresponding to a state induced by the stray field of an off-plane magnetic dipole placed on top of the superconductor. In the second considered case, both shells comprise vortices induced by a homogeneous external field. We derive the equation of motion for each shell within the Bardeen-Stephen model and study the dynamics analytically by assuming both shells are rigid and commensurate. In both cases, two distinct regimes for vortex shell motion are identified: For low applied currents the entire configuration rotates rigidly, while above a threshold current the shells decouple from each other and rotate at different angular velocities. Analytical expressions for the decoupling current, the recombination time in the decoupled phases, as well as the voltage-current characteristics are presented. Our analytical results are in excellent agreement with numerical molecular dynamics simulations of the full many-vortex problem.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000368481600003 Publication Date 2016-01-25  
  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 7 Open Access  
  Notes ; This work was supported by the Brazilian Science Agencies CAPES, CNPq, and FACEPE under Grants No. APQ-1381-1.05/12, No. APQ 2017-1.05/12, and No. APQ-0598/1.05-08 and by EU-COST Action No. MP1201 and the Research Foundation-Flanders (FWO). ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:131541 Serial 4270  
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Author Filez, M.; Redekop, E.A.; Galvita, V.V.; Poelman, H.; Meledina, M.; Turner, S.; Van Tendeloo, G.; Bell, A.T.; Marin, G.B. pdf  url
doi  openurl
  Title The role of hydrogen during Pt-Ga nanocatalyst formation Type A1 Journal article
  Year 2016 Publication (down) Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 18 Issue 18 Pages 3234-3243  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Hydrogen plays an essential role during the in situ assembly of tailored catalytic materials, and serves as key ingredient in multifarious chemical reactions promoted by these catalysts. Despite intensive debate for several decades, the existence and nature of hydrogen-involved mechanisms – such as hydrogen-spillover, surface migration – have not been unambiguously proven and elucidated up to date. Here, Pt-Ga alloy formation is used as a probe reaction to study the behavior and atomic transport of H and Ga, starting from Pt nanoparticles on hydrotalcite-derived Mg(Ga)(Al)Ox supports. In situ XANES spectroscopy, time-resolved TAP kinetic experiments, HAADF-STEM imaging and EDX mapping are combined to probe Pt, Ga and H in a series of H2 reduction experiments up to 650 degrees C. Mg(Ga)(Al)Ox by itself dissociates hydrogen, but these dissociated hydrogen species do not induce significant reduction of Ga3+ cations in the support. Only in the presence of Pt, partial reduction of Ga3+ into Gadelta+ is observed, suggesting that different reaction mechanisms dominate for Pt- and Mg(Ga)(Al)Ox-dissociated hydrogen species. This partial reduction of Ga3+ is made possible by Pt-dissociated H species which spillover onto non-reducible Mg(Al)Ox or partially reducible Mg(Ga)(Al)Ox and undergo long-range transport over the support surface. Moderately mobile Gadelta+Ox migrates towards Pt clusters, where Gadelta+ is only fully reduced to Ga0 on condition of immediate stabilization inside Pt-Ga alloyed nanoparticles.  
  Address Laboratory for Chemical Technology (LCT), Ghent University, Technologiepark 914, B-9052 Ghent, Belgium. hilde.poelman@ugent.be  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Wos 000369506000106 Publication Date 2016-01-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.123 Times cited 10 Open Access  
  Notes This work was supported by the Fund for Scientific Research Flanders (FWO: G.0209.11), the ‘Long Term Structural Methusalem Funding by the Flemish Government’, the IAP 7/05 Interuniversity Attraction Poles Programme – Belgian State – Belgian Science Policy, and the Fund for Scientific Research Flanders (FWO-Vlaanderen) in supplying financing of beam time at the DUBBLE beam line of the ESRF and travel costs and a postdoctoral fellowship for S.T. The authors acknowledge the assistance from D. Banerjee (XAS campaign 26-01-979) at DUBBLE. E. A. Redekop acknowledges the Marie Curie International Incoming Fellowship granted by the European Commission (Grant Agreement No. 301703). The authors also express their gratitude to V. Bliznuk for acquisition of the TEM images. Approved Most recent IF: 4.123  
  Call Number c:irua:132315 Serial 4000  
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Author Bercx, M.; Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. pdf  url
doi  openurl
  Title First-principles analysis of the spectroscopic limited maximum efficiency of photovoltaic absorber layers for CuAu-like chalcogenides and silicon Type A1 Journal article
  Year 2016 Publication (down) Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 18 Issue 18 Pages 20542-20549  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract Chalcopyrite semiconductors are of considerable interest for application as absorber layers in thin-film photovoltaic cells. When growing films of these compounds, however, they are often found to contain CuAu-like domains, a metastable phase of chalcopyrite. It has been reported that for CuInS2, the presence of the CuAu-like phase improves the short circuit current of the chalcopyrite-based photovoltaic cell. We investigate the thermodynamic stability of both phases for a selected list of I-III-VI2 materials using a first-principles density functional theory approach. For the CuIn-VI2 compounds, the difference in formation energy between the chalcopyrite and CuAu-like phase is found to be close to 2 meV per atom, indicating a high likelihood of the presence of CuAu-like domains. Next, we calculate the spectroscopic limited maximum efficiency (SLME) of the CuAu-like phase and compare the results with those of the corresponding chalcopyrite phase. We identify several candidates with a high efficiency, such as CuAu-like CuInS2, for which we obtain an SLME of 29% at a thickness of 500 nm. We observe that the SLME can have values above the Shockley-Queisser (SQ) limit, and show that this can occur because the SQ limit assumes the absorptivity to be a step function, thus overestimating the radiative recombination in the detailed balance approach. This means that it is possible to find higher theoretical efficiencies within this framework simply by calculating the J-V characteristic with an absorption spectrum. Finally, we expand our SLME analysis to indirect band gap absorbers by studying silicon, and find that the SLME quickly overestimates the reverse saturation current of indirect band gap materials, drastically lowering their calculated efficiency.  
  Address EMAT & CMT groups, Department of Physics, University of Antwerp, Campus Groenenborger, Groenenborgerlaan 171, 2020 Antwerp, Belgium. marnik.bercx@uantwerpen.be  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Wos 000381428600058 Publication Date 2016-07-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.123 Times cited 34 Open Access  
  Notes We acknowledge financial support of FWO-Vlaanderen through projects G.0150.13N and G.0216.14N and ERA-NET RUS Plus/FWO, Grant G0D6515N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO FWOVlaanderen. Approved Most recent IF: 4.123  
  Call Number c:irua:135091 Serial 4112  
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Author Aierken, Y.; Leenaerts, O.; Peeters, F.M. pdf  url
doi  openurl
  Title A first-principles study of stable few-layer penta-silicene Type A1 Journal article
  Year 2016 Publication (down) Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 18 Issue 18 Pages 18486-18492  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Recently penta-graphene was proposed as a stable two-dimensional carbon allotrope consisting of a single layer of interconnected carbon pentagons [Zhang et al., PNAS, 2015, 112, 2372]. Its silicon counterpart, penta-silicene, however, is not stable. In this work, we show that multilayers of penta-silicene form stable materials with semiconducting or metallic properties, depending on the stacking mode. We demonstrate their dynamic stability through their phonon spectrum and using molecular dynamics. A particular type of bilayer penta-silicene is found to have lower energy than all of the known hexagonal silicene bilayers and forms therefore the most stable bilayer silicon material predicted so far. The electronic and mechanical properties of these new silicon allotropes are studied in detail and their behavior under strain is investigated. We demonstrate that strain can be used to tune its band gap.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000379486200077 Publication Date 2016-06-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.123 Times cited 42 Open Access  
  Notes ; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vl). The computational resources 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: 4.123  
  Call Number UA @ lucian @ c:irua:134942 Serial 4132  
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Author Calizzi, M.; Venturi, F.; Ponthieu, M.; Cuevas, F.; Morandi, V.; Perkisas, T.; Bals, S.; Pasquini, L. pdf  doi
openurl 
  Title Gas-phase synthesis of Mg-Ti nanoparticles for solid-state hydrogen storage Type A1 Journal article
  Year 2016 Publication (down) Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 18 Issue 18 Pages 141-148  
  Keywords A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT)  
  Abstract Mg-Ti nanostructured samples with different Ti contents were prepared via compaction of nanoparticles grown by inert gas condensation with independent Mg and Ti vapour sources. The growth set-up offered the option to perform in situ hydrogen absorption before compaction. Structural and morphological characterisation was carried out by X-ray diffraction, energy dispersive spectroscopy and electron microscopy. The formation of an extended metastable solid solution of Ti in hcp Mg was detected up to 15 at% Ti in the as-grown nanoparticles, while after in situ hydrogen absorption, phase separation between MgH2 and TiH2 was observed. At a Ti content of 22 at%, a metastable Mg-Ti-H fcc phase was observed after in situ hydrogen absorption. The co-evaporation of Mg and Ti inhibited nanoparticle coalescence and crystallite growth in comparison with the evaporation of Mg only. In situ hydrogen absorption was beneficial to subsequent hydrogen behaviour, studied by high pressure differential scanning calorimetry and isothermal kinetics. A transformed fraction of 90% was reached within 100 s at 300 degrees C during both hydrogen absorption and desorption. The enthalpy of hydride formation was not observed to differ from bulk MgH2.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000368755500014 Publication Date 2015-11-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.123 Times cited 31 Open Access Not_Open_Access  
  Notes ; Part of this work was supported by the COST Action MP1103 “Nanostructured materials for solid-state hydrogen storage”. ; Approved Most recent IF: 4.123  
  Call Number UA @ lucian @ c:irua:131589 Serial 4184  
Permanent link to this record
 

 
Author Yagmurcukardes, M.; Horzum, S.; Torun, E.; Peeters, F.M.; Senger, R.T. url  doi
openurl 
  Title Nitrogenated, phosphorated and arsenicated monolayer holey graphenes Type A1 Journal article
  Year 2016 Publication (down) Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 18 Issue 18 Pages 3144-3150  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Motivated by a recent experiment that reported the synthesis of a new 2D material nitrogenated holey graphene (C2N) [Mahmood et al., Nat. Commun., 2015, 6, 6486], the electronic, magnetic, and mechanical properties of nitrogenated (C2N), phosphorated (C2P) and arsenicated (C2As) monolayer holey graphene structures are investigated using first-principles calculations. Our total energy calculations indicate that, similar to the C2N monolayer, the formation of the other two holey structures are also energetically feasible. Calculated cohesive energies for each monolayer show a decreasing trend going from the C2N to C2As structure. Remarkably, all the holey monolayers considered are direct band gap semiconductors. Regarding the mechanical properties (in-plane stiffness and Poisson ratio), we find that C2N has the highest in-plane stiffness and the largest Poisson ratio among the three monolayers. In addition, our calculations reveal that for the C2N, C2P and C2As monolayers, creation of N and P defects changes the semiconducting behavior to a metallic ground state while the inclusion of double H impurities in all holey structures results in magnetic ground states. As an alternative to the experimentally synthesized C2N, C2P and C2As are mechanically stable and flexible semiconductors which are important for potential applications in optoelectronics.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000369506000095 Publication Date 2015-12-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.123 Times cited 36 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). ; Approved Most recent IF: 4.123  
  Call Number UA @ lucian @ c:irua:132313 Serial 4214  
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Author Ali, S.; Myasnichenko, V.S.; Neyts, E.C. pdf  url
doi  openurl
  Title Size-dependent strain and surface energies of gold nanoclusters Type A1 Journal article
  Year 2016 Publication (down) Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 18 Issue 18 Pages 792-800  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Gold nanocluster properties exhibit unique size-dependence. In this contribution, we employ reactive molecular dynamics simulations to calculate the size- and temperature-dependent surface energies, strain energies and atomic displacements for icosahedral, cuboctahedral, truncated octahedral and decahedral Au-nanoclusters. The calculations demonstrate that the surface energy decreases with increasing cluster size at 0 K but increases with size at higher temperatures. The calculated melting curves as a function of cluster size demonstrate the Gibbs-Thomson effect. Atomic displacements and strain are found to strongly depend on the cluster size and both are found to increase with increasing cluster size. These results are of importance for understanding the size-and temperature-dependent surface processes on gold nanoclusters.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000369480600017 Publication Date 2015-11-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.123 Times cited 37 Open Access  
  Notes Approved Most recent IF: 4.123  
  Call Number UA @ lucian @ c:irua:131626 Serial 4243  
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Author Aierken, Y.; Çakir, D.; Peeters, F.M. pdf  doi
openurl 
  Title Strain enhancement of acoustic phonon limited mobility in monolayer TiS3 Type A1 Journal article
  Year 2016 Publication (down) Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 18 Issue 18 Pages 14434-14441  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Strain engineering is an effective way to tune the intrinsic properties of a material. Here, we show by using first-principles calculations that both uniaxial and biaxial tensile strain applied to monolayer TiS3 are able to significantly modify its intrinsic mobility. From the elastic modulus and the phonon dispersion relation we determine the tensile strain range where structure dynamical stability of the monolayer is guaranteed. Within this region, we find more than one order of enhancement of the acoustic phonon limited mobility at 300 K (100 K), i.e. from 1.71 x 10(4) (5.13 x 10(4)) cm(2) V-1 s(-1) to 5.53 x 10(6) (1.66 x 10(6)) cm(2) V-1 s(-1). The degree of anisotropy in both mobility and effective mass can be tuned by using tensile strain. Furthermore, we can either increase or decrease the band gap of TiS3 monolayer by applying strain along different crystal directions. This property allows us to use TiS3 not only in electronic but also in optical applications.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000378102700036 Publication Date 2016-05-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.123 Times cited 24 Open Access  
  Notes ; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-V1). Computational resources were provided by HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation and the Flemish Government-department EWI. ; Approved Most recent IF: 4.123  
  Call Number UA @ lucian @ c:irua:134628 Serial 4250  
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Author Dabaghmanesh, S.; Neyts, E.C.; Partoens, B. pdf  doi
openurl 
  Title van der Waals density functionals applied to corundum-type sesquioxides : bulk properties and adsorption of CH3 and C6H6 on (0001) surfaces Type A1 Journal article
  Year 2016 Publication (down) Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 18 Issue 18 Pages 23139-23146  
  Keywords A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract van der Waals (vdW) forces play an important role in the adsorption of molecules on the surface of solids. However, the choice of the most suitable vdW functional for different systems is an essential problem which must be addressed for different systems. The lack of a systematic study on the performance of the vdW functionals in the bulk and adsorption properties of metal-oxides motivated us to examine different vdW approaches and compute the bulk and molecular adsorption properties of alpha-Cr2O3, alpha-Fe2O3, and alpha-Al2O3. For the bulk properties, we compared our results for the heat of formation, cohesive energy, lattice parameters and bond distances between the different vdW functionals and available experimental data. Next we studied the adsorption of benzene and CH3 molecules on top of different oxide surfaces. We employed different approximations to exchange and correlation within DFT, namely, the Perdew-Burke-Ernzerhof (PBE) GGA, (PBE)+U, and vdW density functionals [ DFT(vdW-DF/DF2/optPBE/optB86b/optB88)+U] as well as DFT-D2/D3(+U) methods of Grimme for the bulk calculations and optB86b-vdW(+U) and DFT-D2(+U) for the adsorption energy calculations. Our results highlight the importance of vdW interactions not only in the adsorption of molecules, but importantly also for the bulk properties. Although the vdW contribution in the adsorption of CH3 (as a chemisorption interaction) is less important compared to the adsorption of benzene (as a physisorption interaction), this contribution is not negligible. Also adsorption of benzene on ferryl/chromyl terminated surfaces shows an important chemisorption contribution in which the vdW interactions become less significant.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000382109300040 Publication Date 2016-07-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.123 Times cited 6 Open Access  
  Notes ; This work was supported by the Strategic Initiative Materials in Flanders (SIM). The computational resources and services used in this work were provided by the Vlaams Supercomputer Centrum (VSC) and the HPC infrastructure of the University of Antwerp. ; Approved Most recent IF: 4.123  
  Call Number UA @ lucian @ c:irua:135701 Serial 4311  
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Author Berdiyorov, G.R.; Bahlouli, H.; Peeters, F.M. pdf  url
doi  openurl
  Title Effect of substitutional impurities on the electronic transport properties of graphene Type A1 Journal article
  Year 2016 Publication (down) Physica. E: Low-dimensional systems and nanostructures Abbreviated Journal Physica E  
  Volume 84 Issue 84 Pages 22-26  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract Density-functional theory in combination with the nonequilibrium Green's function formalism is used to study the effect of substitutional doping on the electronic transport properties of hydrogen passivated zig-zag graphene nanoribbon devices. B, N and Si atoms are used to substitute carbon atoms located at the center or at the edge of the sample. We found that Si -doping results in better electronic transport as compared to the other substitutions. The transmission spectrum also depends on the location of the substitutional dopants: for single atom doping the largest transmission is obtained for edge substitutions, whereas substitutions in the middle of the sample give larger transmission for double carbon substitutions. The obtained results are explained in terms of electron localization in the system due to the presence of impurities. (C) 2016 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher North-Holland Place of Publication Amsterdam Editor  
  Language Wos 000382489600004 Publication Date 2016-05-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1386-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.221 Times cited 17 Open Access  
  Notes ; H.B. and F.M.P. acknowledge the support from King Fahd University of Petroleum and Minerals, Saudi Arabia, under research group project RG1329-1 and RG1329-2. G.R.B. acknowledges fruitful discussions with Dr. M.E. Madjet from Qatar Environment and Energy Research Institute. ; Approved Most recent IF: 2.221  
  Call Number UA @ lucian @ c:irua:135699 Serial 4301  
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Author Hawrylak, P.; Peeters, F.; Ensslin, K. pdf  doi
openurl 
  Title Carbononics : integrating electronics, photonics and spintronics with graphene quantum dots Preface Type Editorial
  Year 2016 Publication (down) Physica status solidi: rapid research letters Abbreviated Journal Phys Status Solidi-R  
  Volume 10 Issue 10 Pages 11-12  
  Keywords Editorial; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Wiley-v c h verlag gmbh Place of Publication Weinheim Editor  
  Language Wos 000368814500002 Publication Date 2016-01-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1862-6254 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.032 Times cited 7 Open Access  
  Notes ; ; Approved Most recent IF: 3.032  
  Call Number UA @ lucian @ c:irua:131600 Serial 4146  
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Author Michel, K.H.; Neek-Amal, M.; Peeters, F.M. pdf  doi
openurl 
  Title Static flexural modes and piezoelectricity in 2D and layered crystals Type A1 Journal article
  Year 2016 Publication (down) Physica status solidi: B: basic research Abbreviated Journal Phys Status Solidi B  
  Volume 253 Issue 253 Pages 2311-2315  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Piezo- and flexoelectricity are manifestations of electromechanical coupling in solids with potential applications in nanoscale materials. Naumov etal. [Phys. Rev. Lett. 102, 217601 (2009)] have shown by first principles calculations that a monolayer BN sheet becomes macroscopically polarized in-plane when in a corrugated state. Here, we investigate the interplay of layer corrugation and in-plane polarization by atomistic lattice dynamics. We treat the coupling between static flexural modes and in-plane atomic ion displacements as an anharmonic effect, similar to the membrane effect that is at the origin of negative thermal expansion in layered crystals. We have derived analytical expressions for the corrugation-induced static in-plane strains and the optical displacements with the resulting polarization response functions. Beyond h-BN, the theory applies to transition metal dichalcogenides and dioxides. Numerical calculations show that the effects are considerably stronger for 2D h-BN than for 2H-MoS2.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Berlin Editor  
  Language Wos 000390339000002 Publication Date 2016-10-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-1972 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.674 Times cited 5 Open Access  
  Notes ; The authors acknowledge useful discussions with L. Wirtz, A. Molina-Sanchez, and C. Sevik. This work was supported by the ESF-Eurographene project CONGRAN, and the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 1.674  
  Call Number UA @ lucian @ c:irua:140309 Serial 4462  
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Author Ekimov, E.A.; Kudryavtsev, O.S.; Turner, S.; Korneychuk, S.; Sirotinkin, V.P.; Dolenko, T.A.; Vervald, A.M.; Vlasov, I.I. pdf  doi
openurl 
  Title The effect of molecular structure of organic compound on the direct high-pressure synthesis of boron-doped nanodiamond: Effect of organic compound on synthesis of boron-doped nanodiamond Type A1 Journal article
  Year 2016 Publication (down) Physica status solidi : A : applications and materials science Abbreviated Journal Phys Status Solidi A  
  Volume 213 Issue 213 Pages 2582-2589  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Evolution of crystalline phases with temperature has been studied in materials produced by high-pressure high-temperature treatment of 9-borabicyclo[3.3.1]nonane dimer (9BBN), triphenylborane and trimesitylborane. The boron-doped diamond nanoparticles with a size below 10 nm were obtained at 8–9 GPa and temperatures 970–1250 °C from 9BBN only. Bridged structure and the presence of boron atom in the carbon cycle of 9BBN were revealed to be a key point for the direct synthesis of doped diamond nanocrystals. The diffusional transformation of the disordered carbon phase is suggested to be the main mechanism of the nanodiamond formation from 9BBN in the temperature range of 970–1400 °C. Aqueous suspensions of primary boron-doped diamond nanocrystals were prepared upon removal of non-diamond phases that opens wide opportunities for application of this new nanomaterial in electronics and biotechnologies.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000388321500006 Publication Date 2016-07-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1862-6300 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.775 Times cited 8 Open Access  
  Notes Approved Most recent IF: 1.775  
  Call Number EMAT @ emat @ c:irua:135175 Serial 4120  
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Author Sankaran, K.J.; Hoang, D.Q.; Srinivasu, K.; Korneychuk, S.; Turner, S.; Drijkoningen, S.; Pobedinskas, P.; Verbeeck, J.; Leou, K.C.; Lin, I.N.; Haenen, K. pdf  doi
openurl 
  Title Type A1 Journal article
  Year 2016 Publication (down) Physica status solidi : A : applications and materials science Abbreviated Journal Phys Status Solidi A  
  Volume 213 Issue 10 Pages 2654-2661  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Utilization of Au and nanocrystalline diamond ( NCD) as interlayers noticeably modifies the microstructure and field electron emission ( FEE) properties of hexagonal boron nitride nanowalls ( hBNNWs) grown on Si substrates. The FEE properties of hBNNWs on Au could be turned on at a low turn-on field of 14.3V mu m(-1), attaining FEE current density of 2.58mAcm(-2) and life-time stability of 105 min. Transmission electron microscopy reveals that the Au-interlayer nucleates the hBN directly, preventing the formation of amorphous boron nitride ( aBN) in the interface, resulting in enhanced FEE properties. But Au forms as droplets on the Si substrate forming again aBN at the interface. Conversely, hBNNWs on NCD shows superior in life-time stability of 287 min although it possesses inferior FEE properties in terms of larger turn-on field and lower FEE current density as compared to that of hBNNWs-Au. The uniform and continuous NCD film on Si also circumvents the formation of aBN phases and allows hBN to grow directly on NCD. Incorporation of carbon in hBNNWs from the NCD-interlayer improves the conductivity of hBNNWs, which assists in transporting the electrons efficiently from NCD to hBNNWs that results in better field emission of electrons with high life-time stability. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000388321500017 Publication Date 2016-09-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1862-6300 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.775 Times cited 5 Open Access  
  Notes The authors like to thank the financial support of the Research Foundation Flanders (FWO) via Research Projects G.0456.12 and G.0044.13N, the Methusalem “NANO” network. K. J. Sankaran, P. Pobedinskas, and S. Turner are FWO Postdoctoral Fellows of the Research Foundations Flanders (FWO). Approved Most recent IF: 1.775  
  Call Number UA @ lucian @ c:irua:144644UA @ admin @ c:irua:144644 Serial 4655  
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Author Horzum, S.; Torun, E.; Serin, T.; Peeters, F.M. pdf  doi
openurl 
  Title Structural, electronic and optical properties of Cu-doped ZnO : experimental and theoretical investigation Type A1 Journal article
  Year 2016 Publication (down) Philosophical magazine Abbreviated Journal Philos Mag  
  Volume 96 Issue 96 Pages 1743-1756  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract Experiments are supplemented with ab initio density functional theory (DFT) calculations in order to investigate how the structural, electronic and optical properties of zinc oxide (ZnO) thin films are modified upon Cu doping. Changes in characteristic properties of doped thin films, that are deposited on a glass substrate by sol-gel dip coating technique, are monitored using X-ray diffraction (XRD) and UV measurements. Our ab initio calculations show that the electronic structure of ZnO can be well described by DFT+U/G(0)W(0) method and we find that Cu atom substitutional doping in ZnO is the most favourable case. Our XRD measurements reveal that the crystallite size of the films decrease with increasing Cu doping. Moreover, we determine the optical constants such as refractive index, extinction coefficient, optical dielectric function and optical energy band gap values of the films by means of UV-Vis transmittance spectra. The optical band gap of ZnO the thin film linearly decreases from 3.25 to 3.20 eV at 5% doping. In addition, our calculations reveal that the electronic defect states that stem from Cu atoms are not optically active and the optical band gap is determined by the ZnO band edges. Experimentally observed structural and optical results are in good agreement with our theoretical results.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000376076500002 Publication Date 2016-05-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1478-6435 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.505 Times cited 29 Open Access  
  Notes ; Theoretical part of 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. Experimental part of this work was supported by Ankara University BAP under Project Number [14B0443001]. ; Approved Most recent IF: 1.505  
  Call Number UA @ lucian @ c:irua:134161 Serial 4254  
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