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Author Martin, É.; Gossuin, Y.; Bals, S.; Kavak, S.; Vuong, Q.L.
Title Monte Carlo simulations of the magnetic behaviour of iron oxide nanoparticle ensembles: taking size dispersion, particle anisotropy, and dipolar interactions into account Type A1 Journal article
Year 2022 Publication European physical journal : B : condensed matter and complex systems Abbreviated Journal Eur Phys J B
Volume 95 Issue 12 Pages 201
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In this work, the magnetic properties of superparamagnetic iron oxide nanoparticles (SPIONs) submitted to an external magnetic field are studied using a Metropolis algorithm. The influence on the M(B) curves of the size distribution of the nanoparticles, of uniaxial anisotropy, and of dipolar interaction between the cores are examined, as well as the influence of drying the samples under a zero or non-zero magnetic field. It is shown that the anisotropy impacts the shape of the magnetization curves, which then deviate from a pure Langevin behaviour, whereas the dipolar interaction has no influence on the curves at 300 K for small particles (with a radius of 3 nm). The fitting of the magnetization curves of particles with magnetic anisotropy to a Langevin model (including a size distribution of the particles) can then lead to erroneous values of the distribution parameters. The simulation results are qualitatively compared to experimental results obtained for iron oxide nanoparticles (with a 3.21 nm median radius).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000901937400001 Publication Date 2022-12-21
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 1434-6028 ISBN Additional Links UA library record; WoS full record
Impact Factor 1.6 Times cited Open Access OpenAccess
Notes The authors would like to thank Sophie Laurent from the University of Mons for the access to the Dynamic Light Scattering equipment. Computational resources have been provided by the Consortium des Equipements de Calcul Intensif (C ´ ECI), funded by the ´ Fonds de la Recherche Scientifique de Belgique (F.R.S.- FNRS) under Grant No. 2.5020.11 and by the Walloon Region. Approved Most recent IF: 1.6
Call Number EMAT @ emat @c:irua:192706 Serial 7232
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Author Duden, E.I.; Savaci, U.; Turan, S.; Sevik, C.; Demiroglu, I.
Title Intercalation of argon in honeycomb structures towards promising strategy for rechargeable Li-ion batteries Type A1 Journal article
Year 2023 Publication Journal of physics : condensed matter Abbreviated Journal
Volume 35 Issue 8 Pages 085301-85311
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract High-performance rechargeable batteries are becoming very important for high-end technologies with their ever increasing application areas. Hence, improving the performance of such batteries has become the main bottleneck to transferring high-end technologies to end users. In this study, we propose an argon intercalation strategy to enhance battery performance via engineering the interlayer spacing of honeycomb structures such as graphite, a common electrode material in lithium-ion batteries (LIBs). Herein, we systematically investigated the LIB performance of graphite and hexagonal boron nitride (h-BN) when argon atoms were sent into between their layers by using first-principles density-functional-theory calculations. Our results showed enhanced lithium binding for graphite and h-BN structures when argon atoms were intercalated. The increased interlayer space doubles the gravimetric lithium capacity for graphite, while the volumetric capacity also increased by around 20% even though the volume was also increased. The ab initio molecular dynamics simulations indicate the thermal stability of such graphite structures against any structural transformation and Li release. The nudged-elastic-band calculations showed that the migration energy barriers were drastically lowered, which promises fast charging capability for batteries containing graphite electrodes. Although a similar level of battery promise was not achieved for h-BN material, its enhanced battery capabilities by argon intercalation also support that the argon intercalation strategy can be a viable route to enhance such honeycomb battery electrodes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000899825400001 Publication Date 2022-12-05
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record
Impact Factor 2.7 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 2.7; 2023 IF: 2.649
Call Number UA @ admin @ c:irua:193399 Serial 7313
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Author Souza, J.C.B.; Vizarim, N.P.; Reichhardt, C.J.O.; Reichhardt, C.; Venegas, P.A.
Title Magnus induced diode effect for skyrmions in channels with periodic potentials Type A1 Journal article
Year 2023 Publication Journal of physics : condensed matter Abbreviated Journal
Volume 35 Issue 1 Pages 015804-15810
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using a particle based model, we investigate the skyrmion dynamical behavior in a channel where the upper wall contains divots of one depth and the lower wall contains divots of a different depth. Under an applied driving force, skyrmions in the channels move with a finite skyrmion Hall angle that deflects them toward the upper wall for -x direction driving and the lower wall for +x direction driving. When the upper divots have zero height, the skyrmions are deflected against the flat upper wall for -x direction driving and the skyrmion velocity depends linearly on the drive. For +x direction driving, the skyrmions are pushed against the lower divots and become trapped, giving reduced velocities and a nonlinear velocity-force response. When there are shallow divots on the upper wall and deep divots on the lower wall, skyrmions get trapped for both driving directions; however, due to the divot depth difference, skyrmions move more easily under -x direction driving, and become strongly trapped for +x direction driving. The preferred -x direction motion produces what we call a Magnus diode effect since it vanishes in the limit of zero Magnus force, unlike the diode effects observed for asymmetric sawtooth potentials. We show that the transport curves can exhibit a series of jumps or dips, negative differential conductivity, and reentrant pinning due to collective trapping events. We also discuss how our results relate to recent continuum modeling on a similar skyrmion diode system.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000880827900001 Publication Date 2022-10-22
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.7 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 2.7; 2023 IF: 2.649
Call Number UA @ admin @ c:irua:192031 Serial 7320
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Author Kocabas, T.; Cakir, D.; Sevik, C.
Title First-principles discovery of stable two-dimensional materials with high-level piezoelectric response Type A1 Journal article
Year 2021 Publication Journal Of Physics-Condensed Matter Abbreviated Journal J Phys-Condens Mat
Volume 33 Issue 11 Pages 115705
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The rational design of two-dimensional (2D) piezoelectric materials has recently garnered great interest due to their increasing use in technological applications, including sensor technology, actuating devices, energy harvesting, and medical applications. Several materials possessing high piezoelectric response have been reported so far, but a high-throughput first-principles approach to estimate the piezoelectric potential of layered materials has not been performed yet. In this study, we systematically investigated the piezoelectric (e(11), d(11)) and elastic (C-11 and C-12) properties of 128 thermodynamically stable 2D semiconductor materials by employing first-principle methods. Our high-throughput approach demonstrates that the materials containing Group-V elements produce significantly high piezoelectric strain constants, d(11) > 40 pm V-1, and 49 of the materials considered have the e(11) coefficient higher than MoS2 insomuch as BrSSb has one of the largest d(11) with a value of 373.0 pm V-1. Moreover, we established a simple empirical model in order to estimate the d(11) coefficients by utilizing the relative ionic motion in the unit cell and the polarizability of the individual elements in the compounds.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000605852800001 Publication Date 2020-12-15
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 2.649
Call Number UA @ admin @ c:irua:193761 Serial 7971
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Author Silva, F.C.O.; Menezes, R.M.; Cabral, L.R.E.; de Souza Silva, C.C.
Title Formation and stability of conformal spirals in confined 2D crystals Type A1 Journal article
Year 2020 Publication Journal Of Physics-Condensed Matter Abbreviated Journal J Phys-Condens Mat
Volume 32 Issue 50 Pages 505401
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate the ground-state and dynamical properties of nonuniform two-dimensional (2D) clusters of long-range interacting particles. We demonstrate that, when the confining external potential is designed to produce an approximate 1/ r 2 density profile, the particles crystallize into highly ordered structures featuring spiral crystalline lines. Despite the strong inhomogeneity of the observed configurations, most of them are characterized by small density of topological defects, typical of conformal crystals, and the net topological charge induced by the simply-connected geometry of the system is concentrated near the cluster center. These crystals are shown to be robust with respect to thermal fluctuations up to a certain threshold temperature, above which the net charge is progressively redistributed from the center to the rest of the system and the topological order is lost. The crystals are also resilient to the shear stress produced by a small nonuniform azimuthal force field, rotating as a rigid body (RB). For larger forces, topological defects proliferate and the RB rotation gives place to plastic flow.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2020-08-19
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record
Impact Factor 2.7 Times cited Open Access
Notes Approved Most recent IF: 2.7; 2020 IF: 2.649
Call Number UA @ admin @ c:irua:191093 Serial 7978
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Author Abreu, Y.; Cruz, C.M.; Pinera, I.; Leyva, A.; Cabal, A.E.; van Espen, P.; Van Remortel, N.
Title Hyperfine electric parameters calculation in Si samples implanted with 57Mn\rightarrow57Fe Type A1 Journal article
Year 2014 Publication Physica: B : condensed matter Abbreviated Journal
Volume 445 Issue Pages 1-4
Keywords A1 Journal article; Particle Physics Group; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Nowadays the electronic structure calculations allow the study of complex systems determining the hyperfine parameters measured at a probe atom, including the presence of crystalline defects. The hyperfine electric parameters have been measured by Mossbauer spectroscopy in silicon materials implanted with Mn-57 ->,Fe-57 ions, observing four main contributions to the spectra. Nevertheless, some ambiguities still remain in the Fe-57 Mossbauer spectra interpretation in this case, regarding the damage configurations and its evolution with annealing. In the present work several implantation environments are evaluated and the Fe-57 hyperfine parameters are calculated. The observed correlation among the studied local environments and the experimental observations is presented, and a tentative microscopic description of the behavior and thermal evolution of the characteristic defects local environments of the probe atoms concerning the location of vacancies and interstitial Si in the neighborhood of Fe-57 ions in substitutional and interstitial sites is proposed. (C) 2014 Elsevier B.V. All rights reserved
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000336478700001 Publication Date 2014-03-22
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0921-4526; 1873-2135 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:117697 Serial 8046
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Author Bulut, P.; Beceren, B.; Yildirim, S.; Sevik, C.; Gurel, T.
Title Promising room temperature thermoelectric conversion efficiency of zinc-blende AgI from first principles Type A1 Journal article
Year 2021 Publication Journal Of Physics-Condensed Matter Abbreviated Journal J Phys-Condens Mat
Volume 33 Issue 1 Pages 015501
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The theoretical investigation on structural, vibrational, and electronic properties of zinc-blende (ZB) AgI were carried out employing first principles density functional theory calculations. Thermoelectric properties then were predicted through semi-classical Boltzmann transport equations within the constant relaxation time approximation. Equilibrium lattice parameter, bulk modulus, elastic constants, and vibrational properties were calculated by using generalized gradient approximation. Calculated properties are in good agreement with available experimental values. Electronic and thermoelectric properties were investigated both with and without considering spin-orbit coupling (SOC) effect which is found to have a strong influence on p-type Seebeck coefficient as well as the power factor of the ZB-AgI. By inclusion of SOC, a reduction of the band-gap and p-type Seebeck coefficients as well as the power factor was found which is the indication of that spin-orbit interaction cannot be ignored for p-type thermoelectric properties of the ZB-AgI. By using deformation potential theory for electronic relaxation time and experimentally predicted lattice thermal conductivity, we obtained aZTvalue 1.69 (0.89) at 400 K for n-type (p-type) carrier concentration of 1.5 x 10(18)(4.6 x10(19)) cm(-3)that makes ZB-AgI as a promising room temperature thermoelectric material.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000577217600001 Publication Date 2020-09-14
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record
Impact Factor 2.649 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 2.649
Call Number UA @ admin @ c:irua:193762 Serial 8425
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Author Menezes, R.M.; Sardella, E.; Cabral, L.R.E.; de Souza Silva, C.C.
Title Self-assembled vortex crystals induced by inhomogeneous magnetic textures Type A1 Journal article
Year 2019 Publication Journal of physics : condensed matter Abbreviated Journal
Volume 31 Issue 17 Pages 175402
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate the self-assembly of vortices in a type-II superconducting disk subjected to highly nonuniform confining potentials produced by inhomogeneous magnetic textures. Using a series of numerical experiments performed within the Ginzburg–Landau theory, we show that vortices can arrange spontaneously in highly nonuniform, defect-free crystals, reminiscent of conformal lattices, even though the strict conditions for the conformal crystal are not fulfilled. These results contradict continuum-limit theory, which predicts that the order of a nonuniform crystal is unavoidably frustrated by the presence of topological defects. By testing different cooling routes of the superconductor, we observed several different self-assembled configurations, each of which corresponding to one in a set of allowed conformal transformations, which depends on the magnetic and thermal histories of the system.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2019-01-30
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:191094 Serial 8511
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Author da Costa, D.R.; Chaves, A.; Farias, G.A.; Peeters, F.M.
Title Valley filtering in graphene due to substrate-induced mass potential Type A1 Journal article
Year 2017 Publication Journal of physics : condensed matter Abbreviated Journal
Volume 29 Issue 21 Pages 215502
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The interaction of monolayer graphene with specific substrates may break its sublattice symmetry and results in unidirectional chiral states with opposite group velocities in the different Dirac cones (Zarenia et al 2012 Phys. Rev. B 86 085451). Taking advantage of this feature, we propose a valley filter based on a transversal mass kink for low energy electrons in graphene, which is obtained by assuming a defect region in the substrate that provides a change in the sign of the substrate-induced mass and thus creates a non-biased channel, perpendicular to the kink, for electron motion. By solving the time-dependent Schrodinger equation for the tight-binding Hamiltonian, we investigate the time evolution of a Gaussian wave packet propagating through such a system and obtain the transport properties of this graphene-based substrate-induced quantum point contact. Our results demonstrate that efficient valley filtering can be obtained, provided: (i) the electron energy is sufficiently low, i.e. with electrons belonging mostly to the lowest sub-band of the channel, and (ii) the channel length (width) is sufficiently long (narrow). Moreover, even though the transmission probabilities for each valley are significantly affected by impurities and defects in the channel region, the valley polarization in this system is shown to be robust against their presence.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000400092700002 Publication Date 2017-04-24
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 15 Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:152636 Serial 8730
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Author Leenaerts, O.; Partoens, B.; Peeters, F.M.; Volodin, A.; van Haesendonck, C.
Title The work function of few-layer graphene Type A1 Journal article
Year 2017 Publication Journal of physics : condensed matter Abbreviated Journal
Volume 29 Issue 3 Pages 035003
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A theoretical and experimental study of the work function of few-layer graphene is reported. The influence of the number of layers on the work function is investigated in the presence of a substrate, a molecular dipole layer, and combinations of the two. The work function of few-layer graphene is almost independent of the number of layers with only a difference between monolayer and multilayer graphene of about 60 meV. In the presence of a charge-donating substrate the charge distribution is found to decay exponentially away from the substrate and this is directly reflected in the work function of few-layer graphene. A dipole layer changes the work function only when placed in between the substrate and few-layer graphene through a change of the charge transfer between the two.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000425250600002 Publication Date 2016-11-16
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 61 Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:164938 Serial 8760
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Author Bekaert, J.; Bringmans, L.; Milošević, M.V.
Title Ginzburg-Landau surface energy of multiband superconductors : derivation and application to selected systems Type A1 Journal article
Year 2023 Publication Journal of physics : condensed matter Abbreviated Journal
Volume 35 Issue 32 Pages 325602-325610
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We determine the energy of an interface between a multiband superconducting and a normal half-space, in presence of an applied magnetic field, based on a multiband Ginzburg-Landau (GL) approach. We obtain that the multiband surface energy is fully determined by the critical temperature, electronic densities of states, and superconducting gap functions associated with the different band condensates. This furthermore yields an expression for the thermodynamic critical magnetic field, in presence of an arbitrary number of contributing bands. Subsequently, we investigate the sign of the surface energy as a function of material parameters, through numerical solution of the GL equations. Here, we consider two distinct cases: (i) standard multiband superconductors with attractive interactions, and (ii) a three-band superconductor with a chiral ground state with phase frustration, arising from repulsive interband interactions. Furthermore, we apply this approach to several prime examples of multiband superconductors, such as metallic hydrogen and MgB2, based on microscopic parameters obtained from first-principles calculations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000986281900001 Publication Date 2023-05-03
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record
Impact Factor 2.7 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 2.7; 2023 IF: 2.649
Call Number UA @ admin @ c:irua:196664 Serial 8875
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Author Wang, S.; Tian, H.; Sun, M.
Title Valley-polarized and enhanced transmission in graphene with a smooth strain profile Type A1 Journal article
Year 2023 Publication Journal of physics : condensed matter Abbreviated Journal
Volume 35 Issue 30 Pages 304002-304013
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We explore the influence of strain on the valley-polarized transmission of graphene by employing the wave-function matching and the non-equilibrium Green's function technique. When the transmission is along the armchair direction, we show that the valley polarization and transmission can be improved by increasing the width of the strained region and increasing (decreasing) the extensional strain in the armchair (zigzag) direction. It is noted that the shear strain does not affect transmission and valley polarization. Furthermore, when we consider the smooth strain barrier, the valley-polarized transmission can be enhanced by increasing the smoothness of the strain barrier. We hope that our finding can shed new light on constructing graphene-based valleytronic and quantum computing devices by solely employing strain.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000977124700001 Publication Date 2023-04-11
Series Editor Series Title Abbreviated Series Title (up)
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.7 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 2.7; 2023 IF: 2.649
Call Number UA @ admin @ c:irua:196718 Serial 8953
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